Sample records for residual antibiotics responsible
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Antibiotic Residues - A Global Health Hazard
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Nisha A.R.
Full Text Available Use of Antibiotic that might result in deposition of residues in meat, milk and eggs must not be permitted in food intended for human consumption. If use of antibiotics is necessary as in prevention and treatment of animal diseases, a withholding period must be observed until the residues are negligible or no longer detected. The use of antibiotics to bring about improved performance in growth and feed efficiency, to synchronize or control of reproductive cycle and breeding performance also often lead to harmful residual effects. Concern over antibiotic residues in food of animal origin occurs in two times; one which produces potential threat to direct toxicity in human, second is whether the low levels of antibiotic exposure would result in alteration of microflora, cause disease and the possible development of resistant strains which cause failure of antibiotic therapy in clinical situations. A withdrawal period is established to safeguard human from exposure of antibiotic added food. The withdrawal time is the time required for the residue of toxicological concern to reach safe concentration as defined by tolerance. It is the interval from the time an animal is removed from medication until permitted time of slaughter. Heavy responsibility is placed on the veterinarian and livestock producer to observe the period for a withdrawal of a drug prior to slaughter to assure that illegal concentration of drug residue in meat, milk and egg do not occur. Use of food additives may improve feed efficiency 17% in beef cattle, 10% in lambs, 15% in poultry and 15% in swine. But their indiscriminate use will produce toxicity in consumers. WHO and FAO establish tolerances for a drug, pesticide or other chemical in the relevant tissues of food producing animals. The tolerance is the tissue concentration below, which a marker residue for the drug or chemical must fall in the target tissue before that animal edible tissues are considered safe for human
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Detection of residues antibiotics in food using a microbiological method
International Nuclear Information System (INIS)
Ben Ali, Ahmed
2007-01-01
Antibiotics are effective therapeutic agents because of their property of selective bacterial toxicity which helps controlling infections. Animals, just like humans, can be treated with antibiotics. This use of antibiotics can lead to the development of resistance. Resistant strains may cause severe infections in humans and animals. In addition, antibiotic residues might represent a problem for human health. Our objective is to develop a microbiological method for the detection of antibiotic residues in poultry(muscle, liver,...). For this purpose, antibiotic sensitive bacteria and selective agar media were used. An inhibition growth zone surrounds each of the food samples containing antibiotic residues after a prescribed incubation time. (Author). 23 refs
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Antibiotic residues in milk from small dairy farms in rural Peru.
Redding, L E; Cubas-Delgado, F; Sammel, M D; Smith, G; Galligan, D T; Levy, M Z; Hennessy, S
2014-01-01
The use of antibiotics in livestock can pose a public health threat, especially if antibiotic residues remain in the food product. Understanding how often and why farmers sell products with antibiotic residues is critical to improving the quality of these products. To understand how often milk with antibiotic residues is sold on small farms in a major dairy-producing region of Peru and identify factors associated with selling milk with antibiotic residues, we tested milk samples for antibiotic residues from every provider on three routes of commercial milk companies and from bulk tanks of farmers currently treating cows with antibiotics. We also asked farmers if they sold milk from treated cows and examined factors associated with the tendency to do so. The prevalence of milk contamination with antibiotic residues on commercial routes was low (0-4.2%); however, 33/36 farmers treating their animals with antibiotics sold milk that tested positive for antibiotic residues. The self-reported sale of milk from treated cows had a sensitivity, specificity, and positive and negative predictive values of 75.8%, 100%, 100% and 27.2%, respectively (with testing of milk for residues as the gold standard). Finally, 69/156 randomly selected farmers reported selling milk from treated cows, and farmers' knowledge of antibiotics and the milk purchaser were significantly associated with a farmer's tendency to report doing so. Educating farmers on the risks associated with antibiotics and enforcement of penalties for selling contaminated milk by milk companies are needed to improve milk quality.
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The importance of antibiotic residues presence detection in milk
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Dubravka Samaržija
2002-01-01
Full Text Available Antibiotic residues are the most present inhibitory substances in milkhaving undesirable effect on human health, technological characteristics and the quality of milk and dairy products. In order to protect consumer's health and to ensure high quality milk production, European Union (EU regulation 2377/90 sets a maximum permitted levels for antibiotic residues in milk. Although the presence of antibiotic residues in milk can be due to animal diseases treatment, and in the case of milking animals, they are mostly present after mastitis treatment. The aim of this work is to stress the importance of the continuous control on antibiotic residues presence in milk, due to the role that milk and dairy products have in human nutrition. In this paper, different groups of antibiotics, mechanisms of theirs action, mistakes occurring in dairy products manufacture as well as the methods for theirs detection are described.
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Determination of Antibiotic Residues in Milk by Microbial Inhibitory Tests
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Juščáková D.
2017-09-01
Full Text Available Undesirable substances enter the organism of animals mostly via feed, water or veterinary medicines and their residues pass subsequently into the products of animal origin. In dairy cows, sheep and goats these residues are eliminated particularly in milk. Milk intended for human consumption must comply with safety criteria also with respect to residues of antibiotics. The aim of this study was to determine the presence or absence of antibiotic residues in the milk using the tests Milchtest and Premi®Test. While the Milchtest was developed for the determination of antibiotic residues in cow, sheep and goat milk, the Premi®Test is intended for the determination of antibiotic residues in meat juice, liver, kidneys, fish, eggs and in the urine of animals treated with antibiotics. As examined matrices, we used 45 samples of raw cow’s milk collected at 3 agricultural farms and 10 samples of milk offered to consumers at grocery stores. When using the Milchtest, 8 samples tested positive and 10 provided dubious results while testing with the Premi®Test showed that only 6 samples were positive for antibiotics. Comparison of the results confirmed a higher detection sensitivity of Milchtest reflected in higher numbers of positive samples and the detection of dubious results in samples of raw cow’s milk. However, it should be noted that even the Premi®Test, although not intended preferably for the determination of antibiotics in milk, can be used, if needed, for the preliminary screening of antibiotic residues in such a matrix.
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Monitoring Antibiotic Residues and Corresponding Antibiotic Resistance Genes in an Agroecosystem
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Yasser M. Awad
2015-01-01
Full Text Available Antibiotic resistance genes (ARGs have been commonly reported due to the overuse worldwide of antibiotics. Antibiotic overuse disturbs the environment and threatens public human health. The objective of this study was to measure the residual concentrations of veterinary antibiotics in the tetracycline group (TCs, including tetracycline (TC and chlortetracycline (CTC, as well as those in the sulfonamide group (SAs, including sulfamethazine (SMT, sulfamethoxazole (SMX, and sulfathiazole (STZ. We also isolated the corresponding ARGs in the agroecosystem. Four sediment samples and two rice paddy soil samples were collected from sites near a swine composting facility along the Naerincheon River in Hongcheon, Korea. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS was employed with a solid-phase extraction method to measure the concentration of each antibiotic. ARGs were identified by the qualitative polymerase chain-reaction using synthetic primers. SAs and their corresponding ARGs were highly detected in sediment samples whereas TCs were not detected except for sediments sample #1. ARGs for TCs and SAs were detected in rice paddy soils, while ARGs for TCs were only found in sediment #2 and #4. Continuous monitoring of antibiotic residue and its comprehensive impact on the environment is needed to ensure environmental health.
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Screening of antibiotics residues and development a new kit
International Nuclear Information System (INIS)
Elkhaoui, Faycel
2009-01-01
The first part of the work was to detect antibiotic residues in animal nutriment: chicken, fish, eggs and milk, by methods of screening: First Test and Delvotest. The second part covered the development of a new kit for the detection of antibiotics residues for honey and competitor kit First Test and saving time and money.
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Receptor-based screening assays for the detection of antibiotics residues - A review.
Ahmed, Saeed; Ning, Jianan; Cheng, Guyue; Ahmad, Ijaz; Li, Jun; Mingyue, Liu; Qu, Wei; Iqbal, Mujahid; Shabbir, M A B; Yuan, Zonghui
2017-05-01
Consumer and regulatory agencies have a high concern to antibiotic residues in food producing animals, so appropriate screening assays of fast, sensitive, low cost, and easy sample preparation for the identification of these residues are essential for the food-safety insurance. Great efforts in the development of a high-throughput antibiotic screening assay have been made in recent years. Concerning the screening of antibiotic residue, this review elaborate an overview on the availability, advancement and applicability of antibiotic receptor based screening assays for the safety assessment of antibiotics usage (i.e. radio receptor assay, enzyme labeling assays, colloidal gold receptor assay, enzyme colorimetry assay and biosensor assay). This manuscript also tries to shed a light on the selection, preparation and future perspective of receptor protein for antibiotic residue detection. These assays have been introduced for the screening of numerous food samples. Receptor based screening technology for antibiotic detection has high accuracy. It has been concluded that at the same time, it can detect a class of drugs for certain receptor, and realize the multi-residue detection. These assays offer fast, easy and precise detection of antibiotics. Copyright © 2017 Elsevier B.V. All rights reserved.
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Antibiotics threaten wildlife: circulating quinolone residues and disease in Avian scavengers.
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Jesús A Lemus
Full Text Available Antibiotic residues that may be present in carcasses of medicated livestock could pass to and greatly reduce scavenger wildlife populations. We surveyed residues of the quinolones enrofloxacin and its metabolite ciprofloxacin and other antibiotics (amoxicillin and oxytetracycline in nestling griffon Gyps fulvus, cinereous Aegypius monachus and Egyptian Neophron percnopterus vultures in central Spain. We found high concentrations of antibiotics in the plasma of many nestling cinereous (57% and Egyptian (40% vultures. Enrofloxacin and ciprofloxacin were also found in liver samples of all dead cinereous vultures. This is the first report of antibiotic residues in wildlife. We also provide evidence of a direct association between antibiotic residues, primarily quinolones, and severe disease due to bacterial and fungal pathogens. Our results indicate that, by damaging the liver and kidney and through the acquisition and proliferation of pathogens associated with the depletion of lymphoid organs, continuous exposure to antibiotics could increase mortality rates, at least in cinereous vultures. If antibiotics ingested with livestock carrion are clearly implicated in the decline of the vultures in central Spain then it should be considered a primary concern for conservation of their populations.
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Residual volume in vials of antibiotics used in pediatrics.
Chaves, Caroline Magna Pessoa; Bezerra, Carolina Martins; Lima, Francisca Elisângela Teixeira; Cardoso, Maria Vera Lúcia Moreira Leitão; Fonseca, Said Gonçalves da Cruz; Silva, Viviane Martins da
2017-06-12
Quantifying residual volume contained in vials of antibiotics used in pediatrics. This is an experiment involving samples from vials of antibiotics used in a pediatric hospital. Residual volume was identified by calculating the difference in weight measurement before and after the vials were washed. Evaluation of the residual volume difference in the vials was determined by the Wilcoxon non-parametric test for a sample and established at a significance level of 5%. 105 samples of antibiotics were selected. The correct use of the antibiotics oxacillin (88.57%) and ceftriaxone (94.28%) predominated with low residual values. The same did not occur for procaine benzylpenicillin + potassium benzylpenicillin, since a greater residual volume was discarded in 74.28% of the vials. We highlight the need for improvements in managing antibiotics in the institution under study, so that the excess volume of the antibiotics in the vials is used within the acceptable stable time. It is also necessary that the disposal of the residual volume be adequately disposed, since it presents a risk to public health and the environment. Quantificar o volume residual contido em frascos-ampola de antibióticos utilizados na pediatria. Trata-se de um experimento com amostras de frascos-ampola de antibióticos utilizados em hospital pediátrico. O volume residual foi identificado calculando-se a diferença da aferição do peso antes e após a lavagem do frasco-ampola. A avaliação da diferença dos volumes residuais nos frascos-ampola foi determinada pelo teste não paramétrico de Wilcoxon para uma amostra e estabelecido o nível de significância de 5%. Foram selecionadas 105 amostras de antibióticos. Predominou o correto aproveitamento dos antibióticos oxacilina (88,57%) e ceftriaxona (94,28%), com baixos valores residuais. O mesmo não ocorreu com a benzilpenicilina procaína + potássica, pois em 74,28% dos frascos houve descarte de volume residual superior. Destaca-se a necessidade de
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Detection of antibiotic residues in food by Charm II test
International Nuclear Information System (INIS)
Addali, Mohamed
2014-01-01
Antibiotics are used in food to: -therapy and prophylaxis, -increase the productivity of the food producing animals. The presence of antimicrobial residues: -constitutes a potential human health hazard. has significant impact on international food trade. has implications on technological process in dairy industry. Detection of antibiotic residues is of great interest. It helps protect humans against the effects of such residues, the more it can support the participation of our country in international trade. Charm II test is one of the methods of detection of antimicrobial residues. The tests utilize microbial or antibody receptor assay technology. The sample is incubated with a binding agent (microbial cells with specific receptor sites or with specific antibodies attached) and a tracer (the radio-labeled version of the antibiotic to be detected). The amount of tracer on the binding agent is measured using a scintillation counter and is compared to a pre-determined cut-off or control point. If contaminating antibiotic is present, it will prevent the binding of the tracer by occupying the receptors on the binding agent. The less labeled tracer detected, the more contaminating antibiotic there is present in the sample. This work, carried out at the Radiochemical Laboratory of the National Centre of Nuclear Science and Technology, has two parts: 1/ The first is reserved to a literature review provides an overview on antibiotics and the charm II method. 2/ The second is devoted to the experimental study and presentation of results.
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MICROBIOLOGICAL EVALUATION OF ANTIBIOTIC RESIDUES IN MEAT, MILK AND EGGS
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Abdul Jabbar
2013-04-01
Full Text Available Microbiological tests are widely used to detect antibiotic residues in the meat, milk and eggs for better care of the quality and health safety. In the present study microbiological inhibition test i.e. Swab Test on Animal Food (STAF was developed indigenously for screening of animal foods for presence of antibiotic residues. In this test local isolated culture of Bacillus subtilis was used as a test microorganism due to its high sensitivity to detect a wide range of antibiotics commonly used in animal disorders. The concentration of spore suspension of Bacillus subtilis JS2004 used in the formation of STAF plate was optimized at 2x107 spores/ ml. At this concentration, inhibition zone around Neomycin control disc was 10-16 mm. Nutrient agar was used as a medium in spore suspension and 0.4% dextrose was added as a constituent of medium. Zones of inhibition around swab samples and Neomycin control disc were observed and the diameter was measured. All swab samples showing a minimum of 2 mm wide inhibition zone around them were considered as positive for presence of antibiotic residues. The swab samples showing no zone of inhibition or a zone measuring less than 2 mm were considered as negative. Results of application of STAF test was on animal food samples revealed the high incidence of antibiotic residues.
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van Wagenberg, Coen P A; Backus, Gé B C; van der Vorst, Jack G A J; Urlings, Bert A P
2012-11-01
The EU prescribes that food business operators must use food chain information to assist in food safety control. This study analyses usefulness of food chain information about antibiotic usage covering the 60-day period prior to delivery of pigs to slaughter in the control of antibiotic residues in pork. A dataset with 479 test results for antibiotic residues in tissue samples of finishing pigs delivered to a Dutch slaughter company was linked to information provided by pig producers about antibiotic usage in these finishing pigs. Results show that twice as many producers reported using antibiotics in the group of 82 producers with antibiotic residues (11.0%) compared to the group without antibiotic residues (5.5%) (p=0.0686). For 89% of consignments with a finishing pig with antibiotic residues, the producer reported 'did not use antibiotics'. Food chain information about antibiotic usage provided by Dutch pig producers was no guarantee for absence of antibiotic residues in delivered finishing pigs. Copyright © 2012 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Rezgui, Adel
2009-01-01
The first part of the work was to detect antibiotic residues in animal nutriment: chicken, fish, eggs and milk, by methods of screening. The second part covered the development of a new kit for the detection of antibiotic residues. (Author)
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Determination of veterinary antibiotic residues in foods of animal origin by liquid chromatography
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Pedro Enrique La Rosa Zambrano
2018-05-01
Full Text Available TITLE: Determination of veterinary antibiotic residues in foods of animal origin by liquid chromatography Introduction: The presence of certain infectious agents makes necessary the use of antibiotics to ensure the welfare of animals destined for human consumption; however, the withdrawal time must be considered and respected since there is the possibility of finding residues above the permitted levels, which could constitute a risk to public health. Objective: Present a collection of information based on how is performed the detection and quantification of antibiotic residues in various products of animal origin using chromatography methods. Method: Review of databases in Elsevier, SciELO, Springer, Hindawi, FAO, EFSA, Senasa and Sanipes, using keywords such as “liquid chromatography”, “mass spectrometry”, “antibiotic residues” and “products of animal origin” in Spanish and English. Results: They were selected 71 references among articles, book chapters, norms and regulations published between 2000 and 2017, which it is emphasized that chromatographic methodologies for antibiotic residues monitoring must be sensitive, reproducible, reliable and identify volumes in mg/kg; likewise, they must follow the requirements of international standards for the maximum residue limits detecction. Conclusions: Liquid chromatography coupled to a mass spectrometer is the most used technique to allow the separation of complex matrices based on the molecular weight of the compound (antibiotic or its fragments; however, It is complex, expensive and requires highly trained personnel.
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Douglas Ruben Call
2013-07-01
Full Text Available When we consider factors that contribute to the emergence, amplification, and persistence of antibiotic resistant bacteria, the conventional assumption is that antibiotic use is the primary driver in these processes and that selection occurs primarily in the patient or animal. Evidence suggests that this may not always be the case. Experimental trials show that parenteral administration of a third-generation cephalosporin (ceftiofur in cattle has limited or short-term effects on the prevalence of ceftiofur-resistant bacteria in the gastrointestinal tract. While this response may be sufficient to explain a pattern of widespread resistance to cephalosporins, approximately two-thirds of ceftiofur metabolites are excreted in the urine raising the possibility that environmental selection plays an important additive role in the amplification and maintenance of antibiotic resistant E. coli on farms. Consequently, we present a rationale for an environmental selection hypothesis whereby excreted antibiotic residues such as ceftiofur are a significant contributor to the proliferation of antibiotic resistant bacteria in food animal systems. We also present a mathematical model of our hypothesized system as a guide for designing experiments to test this hypothesis. If supported for antibiotics such as ceftiofur, then there may be new approaches to combat the proliferation of antibiotic resistance beyond the prudent use mantra.
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Assays of residual antibiotics after treatment of γ-ray and UV irradiation
International Nuclear Information System (INIS)
Shin, Ji Hye; Nam, Ji Hyun; Lee, Dong Hun; Yu, Seung Ho; Lee, Myun Joo
2010-01-01
The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and γ-ray irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after γ-ray and UV irradiation. Most samples were degraded by γ-ray irradiation (1 ∼ 2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with γ-ray and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of γ-ray irradiated cephradine measured by AMS test were 2 times higher than of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that γ-ray irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation
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Masumeh Abasi
2016-05-01
Full Text Available Antibiotic residues in food stuff and their transmission to the consumers have some consequences such as bacterial resistance, allergic reactions, intoxication, carcinogenic effects and disturbing of intestine natural flora. Among microbiologic methods, four plate test (FPT is used to detect antibiotic residues in food stuff, which performs in four culture media with different pH values and test bacteria. The aim of this study was investigation of antibiotic residues in edible tissues of slaughtered broilers in Maragheh abattoir using FPT method. For this reason, 40 slaughtered broilers carcasses in Maragheh abattoir (from 10 different poultry farms were sampled. The sampling was conducted randomly from breast and leg muscles, gizzard as well as liver of each carcass. According to results of current study, 60% of liver samples, 55% of leg samples, 52.5% of breast samples and 52.5% of gizzard samples contained antibiotic residues. Moreover, the amount of antibiotic residues among different samples did not show statistical significance (p>0.05. The highest occurrence of antibiotic residue was found in two flocks (100% and the lowest occurrence was recorded for another two flocks (0%. According to the health hazard of antibiotic residues in foods, continuous monitoring is recommended for edible tissues of broilers.
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The residues and environmental risks of multiple veterinary antibiotics in animal faeces.
Li, Yan-Xia; Zhang, Xue-Lian; Li, Wei; Lu, Xiao-Fei; Liu, Bei; Wang, Jing
2013-03-01
To understand the residues and ecological risks of veterinary antibiotics (VAs) in animal faeces from concentrated animal feeding operations in northeastern China, 14 VAs were identified by high performance liquid chromatography, and the preliminary risks of six antibiotics were assessed using the hazard quotient (HQ). The investigated VAs occurred in 7.41 to 57.41 % of the 54 samples, and the levels ranged from 0.08 to 56.81 mg kg(-1). Tetracyclines were predominant with a maximum level of 56.81 mg kg(-1) mostly detected in pig faeces. Sulfonamides were common and detected with the highest concentration of 7.11 mg kg(-1). Fluoroquinolones were more widely detected in chicken faeces rather than in pig or cow faeces, which contained the dominant antibiotic enrofloxacin. In comparison, the residue of tylosin was less frequently found. The risk evaluations of the six antibiotics revealed that tetracyclines, especially oxytetracycline, displayed the greatest ecological risk because of its high HQ value of 15.75. The results of this study imply that multiple kinds of VAs were jointly used in animal feeding processes in the study area. These medicine residues in animal faeces may potentially bring ecological risks if the animal manure is not treated effectively.
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Fathollah Aalipour
2013-01-01
Full Text Available Aims: In this study, the prevalence of antibiotic residues in pasteurized and sterilized commercial milk available in Shahre-kourd, Iran, was investigated. In addition, the influence of seasonal temperature changes on the prevalence of contamination was studied. Materials and Methods: Commercial milk samples of 187, including 154 pasteurized and 33 sterilized, milk samples were collected from the market between early January 2012 and late July of the same year. The presence of antibiotic residues was detected using the microbiological detection test kit, Eclipse 100, as a semi-quantitative method. Results: The results showed that 37 of the samples (19.8% have contained antibiotic residues above the European Union Maximum Residues Limits (EU-MRLs, of which 28 samples (14.97% were found to be contaminated but at the concentrations below the EU-MRLs. There was no significant difference between the contamination rate of pasteurized and Ultra High Temperature (UHT-sterilized samples. Similarly, variation of weather temperature with seasons had no effect on the contamination prevalence of milk samples ( P > 0.05. Conclusion: Based on the result of this study, antibiotics residues were present in the majority of milk samples. Neither the season nor the type of thermal processing of the commercial milks had noticeable impact on the prevalence level of the milk samples. However, an increasing trend of prevalence level for antibiotic residues was observed with increasing the temperature through the warm season.
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Isaac Olufemi Olatoye
2016-09-01
Full Text Available Background and Aim: There are global public health and economic concerns on chemical residues in food of animal origin. The use of antibiotics in dairy cattle for the treatment of diseases such as mastitis has contributed to the presence of residues in dairy products. Penicillin residues as low as 1 ppb can lead to allergic reactions and shift of resistance patterns in microbial population as well as interfere with the processing of several dairy products. Antibiotic monitoring is an essential quality control measure in safe milk production. This study was aimed at determining antibiotic residue contamination and the level of penicillin in dairy products from Fulani cattle herds in Oyo State. Materials and Methods: The presence of antibiotic residues in 328 samples of fresh milk, 180 local cheese (wara, and 90 fermented milk (nono from Southwest, Nigeria were determined using Premi® test kit (R-Biopharm AG, Germany followed by high-performance liquid chromatography analysis of penicillin-G residue. Results: Antibiotic residues were obtained in 40.8%, 24.4% and 62.3% fresh milk, wara and nono, respectively. Penicillin-G residue was also detected in 41.1% fresh milk, 40.2% nono and 24.4% wara at mean concentrations of 15.22±0.61, 8.24±0.50 and 7.6±0.60 μg/L with 39.3%, 36.7% and 21.1%, respectively, containing penicillin residue above recommended Codex maximum residue limit (MRL of 5 μg/L in dairy. There was no significant difference between the mean penicillin residues in all the dairy products in this study. Conclusion: The results are of food safety concern since the bulk of the samples and substantial quantities of dairy products in Oyo state contained violative levels of antibiotic residues including penicillin residues in concentrations above the MRL. This could be due to indiscriminate and unregulated administration of antibiotics to dairy cattle. Regulatory control of antibiotic use, rapid screening of milk and dairy farmers
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The effectiveness of sewage treatment processes to remove faecal pathogens and antibiotic residues
Hendricks, Rahzia; Pool, Edmund John
2012-01-01
Pathogens and antibiotics enter the aquatic environment via sewage effluents and may pose a health risk to wild life and humans. The aim of this study was to determine the levels of faecal bacteria, and selected antibiotic residues in raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and membrane technologies were incorporated in the treatment processes. Coliforms and Escherichia coli (E. coli) were used as bioindicators for faecal bacteria. A chromogenic test was used to screen for coliforms and E. coli. Fluoroquinolones and sulfamethoxazole are commonly used antibiotics and were selected to monitor the efficiency of sewage treatment processes for antibiotic removal. Enzyme Linked Immunosorbent Assays (ELISAs) were used to quantitate antibiotic residues in raw and treated sewage. Raw intake water at all treatment plants contained total coliforms and E. coli. High removal of E. coli by treatment processes was evident for treatment plant 2 and 3 only. Fluoroquinolones and sulfamethoxazole were detected in raw wastewater from all sewage treatment plants. Treatment processes at plant 1 did not reduce the fluoroquinolone concentration in treated sewage effluents. Treatment processes at plant 2 and 3 reduced the fluoroquinolone concentration by 21% and 31%, respectively. Treatment processes at plant 1 did not reduce the sulfamethoxazole concentration in treated sewage effluents. Treatment processes at plant 2 and 3 reduced sulfamethoxazole by 34% and 56%, respectively. This study showed that bacteria and antibiotic residues are still discharged into the environment. Further research needs to be undertaken to improve sewage treatment technologies, thereby producing a better quality treated sewage effluent. PMID:22242882
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Zhang, Haibo; Zhou, Yang; Huang, Yujuan; Wu, Longhua; Liu, Xinghua; Luo, Yongming
2016-06-01
The protected vegetable farming is a style of high frequent rotation farming which requires a huge amount of fertilizers to maintain soil fertility. A total of 125 surface soils covering from east to west of China were sampled for the analysis of 17 antibiotics in order to identify antibiotics contamination caused by long-term manures application. The results indicate that the agricultural land has accumulated a statistically significantly higher antibiotics concentration than conventional open croplands. The maximum oxytetracycline concentration was 8400 μg kg(-1), the highest level that has ever been reported for oxytetracycline in soils. The residual concentration is decided by both plant duration and manure type. Short-term (antibiotics residue in the soils on the whole. Principal component analysis suggests that the various combinations of antibiotic compounds in the soil may be used to trace the manure source. The antibiotics in soil may threaten water quality through contamination by diffusion. Ciprofloxacin and sulfachinoxalin are calculated to be a higher migration risk to surface waters, hence their environmental fate requires further study. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Antibiotic Residues in Milk from Three Popular Kenyan Milk Vending Machines.
Kosgey, Amos; Shitandi, Anakalo; Marion, Jason W
2018-05-01
Milk vending machines (MVMs) are growing in popularity in Kenya and worldwide. Milk vending machines dispense varying quantities of locally sourced, pasteurized milk. The Kenya Dairy Board has a regulatory framework, but surveillance is weak because of several factors. Milk vending machines' milk is not routinely screened for antibiotics, thereby increasing potential for antibiotic misuse. To investigate, a total of 80 milk samples from four commercial providers ( N = 25), street vendors ( N = 21), and three MVMs ( N = 34) were collected and screened in Eldoret, Kenya. Antibiotic residue surveillance occurred during December 2016 and January 2017 using Idexx SNAP ® tests for tetracyclines, sulfamethazine, beta-lactams, and gentamicin. Overall, 24% of MVM samples and 24% of street vendor samples were presumably positive for at least one antibiotic. No commercial samples were positive. Research into cost-effective screening methods and increased monitoring by food safety agencies are needed to uphold hazard analysis and critical control point for improving antibiotic stewardship throughout the Kenyan private dairy industry.
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Addo, K K; Mensah, G I; Aning, K G; Nartey, N; Nipah, G K; Bonsu, C; Akyeh, M L; Smits, H L
2011-02-01
To investigate the microbiological quality and the presence of antibiotic residues in raw cow milk and in some indigenous milk products produced and marketed by the informal sector in the coastal savannah zone of Ghana. Milk samples were aseptically collected from 224 kraals and samples of 26 indigenous milk products were purchased from processors and retailers. Total plate counts, total coliform counts and the presence of Escherichia coli and E. coli O157:H7 were determined in all 250 samples. Milk samples were also tested for antibiotic residues. Total plate counts exceeded 10⁵ CFU/ml in 45.2% of the samples while coliforms exceeded 10³ CFU/ml in 66.0% and E. coli was detected in 11.2%. E. coli was present in raw cow milk but not in the indigenous products and all E. coli isolates were negative for E. coli O157:H7. Antibiotic residues were detected in 3.1% of the raw cow milk samples. Bulk milk contains unacceptable levels of hygiene indicators and antibiotic residues and is a potential source of milk-borne infections. The detection of E. coli and antibiotic residues raises public health concerns about the safety of fresh unpasteurized cow milk in the coastal savannah zone of Ghana and calls for improved farm hygiene, the need for milk pasteurization and the sensible use of antibiotics in the milk industry. © 2010 Blackwell Publishing Ltd.
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Microbial System for Identification of Antibiotic Residues in Milk
Nagel, Orlando Guillermo; Molina Pons, Mª Pilar; Althaus, Rafael Lisandro
2011-01-01
[EN] The aim of this study was to evaluate the ResScreen (R) microbiological system for the identification of antibiotic residues in milk. This microbiological system consists of two methods, the BT (betalactams and tetracyclines) and BS (betalactams and sulfamides) bioassays, containing spores of G. stearothermophilus subsp. calidolactis, culture media and indicators (acid-base and redox). The detection limits of 29 antimicrobial agents were calculated using a logistic regression model. ...
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Xi, Xiuping; Wang, Min; Chen, Yongshan; Yu, Shen; Hong, Youwei; Ma, Jun; Wu, Qian; Lin, Qiaoyin; Xu, Xiangrong
2015-06-15
Residual antibiotics from aquacultural farming may alter microbial community structure in aquatic environments in ways that may adversely or positively impact microbially-mediated ecological functions. This study investigated 26 ponds (26 composited samples) used to produce fish, razor clam and shrimp (farming and drying) and 2 channels (10 samples) in a saltwater aquacultural farm in southern China to characterize microbial community structure (represented by phospholipid fatty acids) in surface sediments (0-10 cm) with long-term exposure to residual antibiotics. 11 out of 14 widely-used antibiotics were quantifiable at μg kg(-1) levels in sediments but their concentrations did not statistically differ among ponds and channels, except norfloxacin in drying shrimp ponds and thiamphenicol in razor clam ponds. Concentrations of protozoan PLFAs were significantly increased in sediments from razor clam ponds while other microbial groups were similar among ponds and channels. Both canonical-correlation and stepwise-multiple-regression analyses on microbial community and residual antibiotics suggested that roxithromycin residuals were significantly related to shifts in microbial community structure in sediments. This study provided field evidence that multiple residual antibiotics at low environmental levels from aquacultural farming do not produce fundamental shifts in microbial community structure. Copyright © 2015 Elsevier B.V. All rights reserved.
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Pro biotic as Alternative to Antibiotic for Broiler Chicken fed Food Industrial Residual Oil
International Nuclear Information System (INIS)
EL-Faramawy, A.A.; El-Maghraby, A.F.; El-Danasoury, M.M.; Hussien, H.A.; Hegazy, E.S.
2016-01-01
This study aimed to evaluate the effect of pro biotic (some lactic acid bacteria) with different levels of food industrial residual oil in broiler commercial diets on growth performance, meat yield, internal organs, economical efficiency and performance index. One hundred and eighty one day old Cobb chicks (45 ± 0.4 g) were equally and randomly divided into 6 groups namely; the antibiotic with fresh oil (FO), the antibiotic with mixed oil (MO) [FO+RO ( 1:1 w/w)], the antibiotic with food industrial residual oil (RO), the pro biotic with FO, the pro biotic with MO and the pro biotic with RO. Virginiamycin, Phibro, USA (15 ppm), was the antibiotic, while a mixture of lactic acid bacteria is chosen as pro biotic. Both were added to the water. During the experiment which lasted for 42 days, the body weight, the feed intake and the mortality rate were recorded at 2, 4 and 6 weeks of age then the body weight gain, feed conversion ratio, economical efficiency and performance index were calculated. The results revealed that the average body weight, body weight gain and feed consumption significantly (P 0.05) while liver increased significantly (P<0.05) in pro biotic FO and gizzard in all pro biotic group and antibiotic MO. The highest performance index was observed in groups of birds treated with pro biotic with MO followed by birds treated with pro biotic FO without significant difference. It could be concluded that supplementation of pro biotic in broiler diet containing different levels of RO was economically more beneficial than antibiotic
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Diwan, Vishal; Purohit, Manju; Chandran, Salesh; Parashar, Vivek; Shah, Harshada; Mahadik, Vijay K; Stålsby Lundborg, Cecilia; Tamhankar, Ashok J
2017-05-29
Antibiotic resistance (ABR) is one of the major health emergencies for global society. Little is known about the ABR of environmental bacteria and therefore it is important to understand ABR reservoirs in the environment and their potential impact on health. Quantitative and qualitative data will be collected during a 3-year follow-up study of a river associated with religious mass-bathing in Central India. Surface-water and sediment samples will be collected from seven locations at regular intervals for 3 years during religious mass-bathing and in absence of it to monitor water-quality, antibiotic residues, resistant bacteria, antibiotic resistance genes and metals. Approval has been obtained from the Ethics Committee of R.D. Gardi Medical College, Ujjain, India (No. 2013/07/17-311). The results will address the issue of antibiotic residues and antibiotic resistance with a focus on a river environment in India within a typical socio-behavioural context of religious mass-bathing. It will enhance our understanding about the relationship between antibiotic residue levels, water-quality, heavy metals and antibiotic resistance patterns in Escherichia coli isolated from river-water and sediment, and seasonal differences that are associated with religious mass-bathing. We will also document, identify and clarify the genetic differences/similarities relating to phenotypic antibiotic resistance in bacteria in rivers during religious mass-bathing or during periods when there is no mass-bathing.
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Gaudin, Valérie; Rault, Annie; Hedou, Celine; Soumet, Christophe; Verdon, Eric
2017-09-01
Efficient screening methods are needed to control antibiotic residues in eggs. A microbiological kit (Explorer® 2.0 test (Zeu Inmunotech, Spain)) and an immunobiosensor kit (Microarray II (AM® II) on Evidence Investigator™ system (Randox, UK)) have been evaluated and validated for screening of antibiotic residues in eggs, according to the European decision EC/2002/657 and to the European guideline for the validation of screening methods. The e-reader™ system, a new automatic incubator/reading system, was coupled to the Explorer 2.0 test. The AM II kit can detect residues of six different families of antibiotics in different matrices including eggs. For both tests, a different liquid/liquid extraction of eggs had to be developed. Specificities of the Explorer 2.0 and AM II kit were equal to 8% and 0% respectively. The detection capabilities were determined for 19 antibiotics, with representatives from different families, for Explorer 2.0 and 12 antibiotics for the AM II kit. For the nine antibiotics having a maximum residue limit (MRL) in eggs, the detection capabilities CCβ of Explorer 2.0 were below the MRL for four antibiotics, equal to the MRL for two antibiotics and between 1 and 1.5 MRLs for the three remaining antibiotics (tetracyclines). For the antibiotics from other families, the detection capabilities were low for beta-lactams and sulfonamides and satisfactory for dihydrostreptomycin (DHS) and fluoroquinolones, which are usually difficult to detect with microbiological tests. The CCβ values of the AM II kit were much lower than the respective MRLs for three detected antibiotics (tetracycline, oxytetracycline, tylosin). Concerning the nine other antibiotics, the detection capabilities determined were low. The highest CCβ was obtained for streptomycin (100 µg kg -1 ).
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Directory of Open Access Journals (Sweden)
Young-Sik Choe
2016-12-01
Full Text Available Abstract As a novel strategy to remove β-lactam antibiotic residues from fish tissues, utilization of β-lactamase, enzyme that normally degrades β-lactam structure-containing drugs, was explored. The enzyme (TEM-52 selectively degraded β-lactam antibiotics but was completely inactive against tetracycline-, quinolone-, macrolide-, or aminoglycoside-structured antibacterials. After simultaneous administration of the enzyme with cefazolin (a β-lactam antibiotic to the carp, significantly lowered tissue cefazolin levels were observed. It was confirmed that the enzyme successfully reached the general circulation after intraperitoneal administration, as the carp serum obtained after enzyme injection could also degrade cefazolin ex vivo. These results suggest that antibiotics-degrading enzymes can be good candidates for antibiotic residue depuration.
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Directory of Open Access Journals (Sweden)
Vishal Diwan
2017-05-01
Full Text Available Background: Antibiotic resistance (ABR is one of the major health emergencies for global society. Little is known about the ABR of environmental bacteria and therefore it is important to understand ABR reservoirs in the environment and their potential impact on health. Method/Design: Quantitative and qualitative data will be collected during a 3-year follow-up study of a river associated with religious mass-bathing in Central India. Surface-water and sediment samples will be collected from seven locations at regular intervals for 3 years during religious mass-bathing and in absence of it to monitor water-quality, antibiotic residues, resistant bacteria, antibiotic resistance genes and metals. Approval has been obtained from the Ethics Committee of R.D. Gardi Medical College, Ujjain, India (No. 2013/07/17-311. Results: The results will address the issue of antibiotic residues and antibiotic resistance with a focus on a river environment in India within a typical socio-behavioural context of religious mass-bathing. It will enhance our understanding about the relationship between antibiotic residue levels, water-quality, heavy metals and antibiotic resistance patterns in Escherichia coli isolated from river-water and sediment, and seasonal differences that are associated with religious mass-bathing. We will also document, identify and clarify the genetic differences/similarities relating to phenotypic antibiotic resistance in bacteria in rivers during religious mass-bathing or during periods when there is no mass-bathing.
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Use of antibiotics in food animals has generated concern as the presence of these residues in food may contribute to increased microbial resistance in humans. Fluoroquinolone antibiotics are thus now no longer allowed by the U.S. Food and Drug Administration for use in poultry and monitoring of the...
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Directory of Open Access Journals (Sweden)
Grzegorz Siedlewicz
2016-07-01
Full Text Available The main objective of this study was to adapt analytical procedures for determining antibiotic residues in solid and aquatic samples to marine sediments and to investigate the occurrence of 9 sulfonamides, trimethoprim and 2 quinolones in southern Baltic Sea sediments. The analytical procedure was applied to sediment samples characterized as sand and silty sand. The validation results showed that a sensitive and efficient method applying tandem solid-phase extraction (SPE and liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS was obtained. Analytes were determined in the lower ng g−1 range with good accuracy and precision. The proposed analytical procedure was applied to the analysis of 13 sediment samples collected from the Baltic Sea along the Polish coast. Concentrations of antibiotic residues in environmental samples were calculated based on external matrix-matched calibration. Residues of nine out of twelve of the above antibiotics were detected in sediment samples in a concentrations of up to 419.2 ng g−1 d.w. (dry weight. Sulfamethoxazole and sulfachloropyridazine were the most frequently detected compounds (58% of the analyzed samples. The occurrence frequency of trimethoprim was 42% and it was always detected simultaneously with sulfamethoxazole. Preliminary studies on the spatial distribution of the analyzed antibiotics indicate a high level of antibiotics occurring in the Pomeranian Bay and close to the mouths of Polish rivers. The study is the first one to demonstrate the occurrence of antibiotic residues in sediments of the Polish coastal area. The obtained results suggest that sediment can be an important secondary source of antibiotic residues in the marine environment.
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Czech Academy of Sciences Publication Activity Database
Čvančarová, Monika; Moeder, M.; Filipová, Alena; Cajthaml, Tomáš
2015-01-01
Roč. 136, OCT 2015 (2015), s. 311-320 ISSN 0045-6535 R&D Projects: GA TA ČR TE01020218; GA ČR GA13-28283S Institutional support: RVO:61388971 Keywords : Fluoroquinolone antibiotics * White rot fungi * Residual antibacterial activity Subject RIV: EE - Microbiology, Virology Impact factor: 3.698, year: 2015
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Chen, Jinfeng; Xu, Huilian; Sun, Yingbo; Huang, Lili; Zhang, Peixia; Zou, Chunping; Yu, Bo; Zhu, Genfa; Zhao, Chaoyi
2016-02-01
Pollution caused by residual antibiotics is a worldwide environmental issue. Antibiotic residues often occur in aquatic ecosystems, posing threats to the health of aquatic organisms. The effects of antibiotic residues on the growth of crop plants and on human health are reasonably well known. However, less is known about antibiotic effects on wetland plants. Therefore, we studied the response and tolerance of ten clonal wetland plants grown in soil spiked with sulfadiazine at 10 mg kg(-1) (an environmentally relevant concentration) and 100 mg kg(-1). At 10 mg kg(-1), ramet number was the least affected trait, while root number was the most affected among plant species. Plant shoot and total biomass were reduced in all species except in Cyperus malaccensis var. brevifolius and Panicum repens. Chlorophyll content was reduced in Alocasia macrorrhiza, Saururus chinensis, and Commelina diffusa. In general, Panicum paludosum and C. malaccensis var. brevifolius showed the least reduction of growth parameters, whereas growth of both A. macrorrhiza and S. chinensis was severely reduced. At 100 mg kg(-1), negative responses occurred in all species. Comprehensive tolerance analysis revealed that P. paludosum and C. malaccensis var. brevifolius were the species most resistant to sulfadiazine. These species are potential candidates for sulfadiazine polluted wetland restoration. A. macrorrhiza and S. chinensis were the most susceptible species and they should be protected from sulfadiazine pollution. Relative plant shoot biomass and height were the most useful indicators for evaluating plant tolerance to sulfadiazine. Plant tolerance to sulfadiazine was associated with the differences of plants in height and shoot biomass. Copyright © 2015 Elsevier B.V. All rights reserved.
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Moghadam, Mortez Mohammadzadeh; Amiri, Mostafa; Riabi, Hamed Ramezani Awal; Riabi, Hamid Ramezani Awal
2016-12-01
The presence of antibiotic residues in milk and other products livestock is a health problem which can endanger public health. Antibiotics are used widely in animal husbandry to treat diseases related to bacterial infections. Antimicrobial drugs have been in use for decades in industry. They are commonly used in livestock facilities to treat mastitis. This study aimed to investigate antibiotic residues in pasteurized milk distributed in schools, in milk collection centers, and in milk production factories in Gonabad city. This cross-sectional study was conducted on 251 samples of commercial pasteurized milk packet distributed in schools (code A), raw milk collection centers in Gonabad city (code B), and pasteurized milk production factories (code C) in Gonabad city. The Copan test kit of Denmark Christian Hansen Company was used to monitor antibiotic residues in milk. The data were analysed employing Chi-square test and one-way analysis of variance (ANOVA) to determine significant differences using SPSS software version 20. The significant level was considered at pmilk samples were collected out of which 143 (57%) were code A, 84 (33.5%) code B and 24 (9.6%) code C. Total number of 189 samples (75.2%) were negative and 62 (24.8%) were positive. From the three types of milk samples, 41 samples (28.7%) of the code A, 18 samples (21.4%) of the code B and 3 samples (12.5%) of the code C were positive. In general, from the milk samples most contaminated with antibiotics, 17 samples were positive in January and regarding code A, 13 samples were positive in the same month. There was not a significant difference among the three types of milk (p>0.05). The highest number of milk samples (n=7) contaminated with antibiotics were related to code B (38.5%). Most positive cases were related to code A in winter. Also, there was no significant difference among the three types of contaminated milk regarding the year and month (p=0.164 and p=0.917, respectively). Pasteurized milk
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Rossi, Rosanna; Saluti, Giorgio; Moretti, Simone; Diamanti, Irene; Giusepponi, Danilo; Galarini, Roberta
2018-02-01
Milk is an important and beneficial food from a nutritional point of view, being an indispensable source of high quality proteins. Furthermore, it is a raw material for many dairy products, such as yoghurt, cheese, cream etc. Before reaching consumers, milk goes through production, processing and circulation. Each step involves potentially unsafe factors, such as chemical contamination that can affect milk quality. Antibiotics are widely used in veterinary medicine for dry cow therapy and mastitis treatment in lactating cows, which can cause the presence of antimicrobial residues in milk. In order to ensure consumers' safety, milk is analyzed to make sure that the fixed Maximum Residue Limits (MRLs) for antibiotics are not exceeded. Multiclass methods can monitor more drug classes through a single analysis, so they are faster, less time-consuming and cheaper than traditional methods (single-class); this aspect is particularly important for milk, which is a highly perishable food. Nevertheless, multiclass methods for veterinary drug residues in foodstuffs are real analytical challenges. This article reviews the major multiclass methods published for the determination of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry, with a special focus on sample preparation approaches.
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Estimation of selected residual antibiotics in muscle, kidney, liver, and egg of layer chicken
International Nuclear Information System (INIS)
Amjad, H.; Iqbal, J.; Naeem, M.
2006-01-01
The present studies were conducted for the estimation of quinolone residues in our local poultry products. The poultry products included muscle, kidney, liver and egg (yolk and white). The quinolones included in this study were, oxolonic acid, flumequine, enrofloxacin, and ciprofloxacin. An assessment of the variation of each analyte (quinolones antibiotic residues) in these products was made. A comparison was made among the analyte (quinolones) concentrations in different tissues/organs and their internationally permissible safer maximum residue limits (MRLS'). Infra Red spectra were used to detect the presence and identification of different quinolones. HPLC with ODS Column and U.V. detector was used for the quantification. (author)
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Pengov, A; Kirbis, A
2009-04-01
Very few drugs on the market are approved for use in lactating ewes. Veterinarians in the European Union are allowed to prescribe drugs in an off-label manner but are then obligated to assure that residues do not enter the food chain. In case of mastitis treatment in dairy ewes antibiotic preparations designed and authorized for the bovine mammary gland are usually used. Due to inter-species differences, available bovine data cannot be accurately extrapolated for use in the dairy ewe. The objective of the study was therefore to determine appropriate withdrawal periods for ewe's milk following mastitis treatment with two commercial lactating cow products. For the detection of all components standard agar plate diffusion techniques were used. Regardless of the therapy regime and the product used, residues of antibiotics in milk were detected up to 192h after the last infusion. These results indicate that the required withholding periods for ewe's milk are considerably longer than recommended on the label for bovine milk.
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Dahshan, Hesham; Abd-Elall, Amr Mohamed Mohamed; Megahed, Ayman Mohamed; Abd-El-Kader, Mahdy A; Nabawy, Ehab Elsayed
2015-02-01
In Egypt, poultry production constitutes one of the main sources of pollution with veterinary antibiotics (VAs) into the environment. About 80 % of meat production in Egypt is of poultry origin, and the potential environmental risks associated with the use of VAs in these farms have not yet been properly evaluated. Thus, the main purpose of this research was to evaluate the prevalence of antibiotic-resistant enteric key bacteria and the incidence of residual antibiotics in poultry farm environmental samples and to determine whether fertilizing soils with poultry litter from farms potentially brings ecological risks. From December 2011 to September 2012, a total of 225 litter, bird dropping, and water samples were collected from 75 randomly selected boiler poultry farms. A high prevalence of Escherichia coli (n = 179; 79.5 %) in contrast to the low prevalence of Salmonella spp. (n = 7; 3.1 %) was detected. Amongst E. coli isolates, serotypes O142:K86, O125:K70, O91:K, and O119:K69 were the most common. Meanwhile, Salmonella enterica serotypes emek and enteritidis were recovered. The antibiograms using the disc diffusion method revealed significantly more common resistant and multi-resistant isolates in broiler poultry farms. Residues of tetracycline and ciprofloxacin were detected at 2.125 and 1.401 mg kg(-1) mean levels, respectively, in environmental samples contaminated with E. coli-resistant strains by HPLC. The risk evaluations highlighted that tetracycline residues in poultry litter significantly display environmental risks with a hazard quotient value above 1 (1.64). Our study implies that ineffective implementation of veterinary laws which guide and guard against incorrect VA usage may potentially bring health and environmental risks.
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Fejzic, Nihad; Begagic, Muris; Šerić-Haračić, Sabina; Smajlovic, Muhamed
2014-08-27
Beta lactam antibiotics are widely used in therapy of cattle, particularly for the treatment of mastitis. Over 95% of residue testing in dairies in Bosnia and Herzegovina is for Beta lactams. The aim of this paper is to compare the efficacy of three most common screening tests for Beta lactam residues in cow's milk in our country. The tests used in the study are SNAP β Lactam test (Idexx), Rosa Charm β Lactam test and Inhibition MRL test. Study samples included: standardized concentrations of penicillin solution (0, 2, 3, 4, 5 and 6 ppb). In addition we tested milk samples from three equal size study groups (not receiving any antibiotic therapy, treated with Beta lactams for mastitis and treated with Beta lactams for diseases other than mastitis). Sensitivity and specificity were determined for each test, using standard penicillin concentrations with threshold value set at concentration of 4 ppb (Maximum residue level - MLR). Additionally we determined proportions of presumably false negative and false positive results for each test using results of filed samples testing. Agreement of test results for each test pair was assessed through Kappa coefficients interpreted by Landis-Koch scale. Detection level of all tests was shown to be well below MRL. This alongside with effects of natural inhibitors in milk contributed to finding of positive results in untreated and treated animals after the withholding period. Screening tests for beta lactam residues are important tools for ensuring that milk for human consumption is free from antibiotics residues.
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Directory of Open Access Journals (Sweden)
Nihad Fejzic
2014-08-01
Full Text Available Beta lactam antibiotics are widely used in therapy of cattle, particularly for the treatment of mastitis. Over 95% of residue testing in dairies in Bosnia and Herzegovina is for Beta lactams. The aim of this paper is to compare the efficacy of three most common screening tests for Beta lactam residues in cow’s milk in our country. The tests used in the study are SNAP β Lactam test (Idexx, Rosa Charm β Lactam test and Inhibition MRL test. Study samples included: standardized concentrations of penicillin solution (0, 2, 3, 4, 5 and 6 ppb. In addition we tested milk samples from three equal size study groups (not receiving any antibiotic therapy, treated with Beta lactams for mastitis and treated with Beta lactams for diseases other than mastitis. Sensitivity and specificity were determined for each test, using standard penicillin concentrations with threshold value set at concentration of 4 ppb (Maximum residue level – MLR. Additionally we determined proportions of presumably false negative and false positive results for each test using results of filed samples testing. Agreement of test results for each test pair was assessed through Kappa coefficients interpreted by Landis-Koch scale. Detection level of all tests was shown to be well below MRL. This alongside with effects of natural inhibitors in milk contributed to finding of positive results in untreated and treated animals after the withholding period. Screening tests for beta lactam residues are important tools for ensuring that milk for human consumption is free from antibiotics residues.
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Li, Xiaohua; Liu, Chong; Chen, Yongxing; Huang, Hongkun; Ren, Tianzhi
2018-04-01
A survey was conducted in regions of North China to better understand the effect of antibiotic residue pollution from swine feedlots to nearby groundwater environment. A total of nine experimental sites located in the regions of Beijing, Hebei, and Tianjin were selected to analyze the presence of residues of 11 most commonly used antibiotics, including tetracyclines (TCs), fluoroquinolones (FQNs), sulfonamides (SAs), macrolides, and fenicols, by using liquid chromatography spectrometry. The three most common antibiotics were TCs, FQNs, and SAs, with mean concentrations of 416.4, 228.8, and 442.4 μg L -1 in wastewater samples; 19.9, 11.8, and 0.3 μg L -1 in groundwater samples from swine feedlots; and 29.7, 14.0, and 0 μg L -1 in groundwater samples from villages. Ordination analysis revealed that the composition and distribution of antibiotics and antibiotic resistance genes (AGRs) were similar in groundwater samples from swine feedlots and villages. FQNs and TCs occurred along the path from wastewater to groundwater at high concentrations and showed correlations with ARGs, with a strong correlation between FQN resistance gene (qnrA) copy number. FQN concentration was also found (P swine feedlots through wastewater could disseminate into surrounding groundwater environments together with ARG occurrence (i.e., qnrA, sulI, sulII, tetG, tetM, and tetO). Overall, this study suggests that the spread of veterinary antibiotics from swine feedlots to groundwater environments should be highly attended and controlled by restricting excess antibiotic usage or improving the technology of manure management.
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Residues of selected antibiotics in the South Moravian Rivers, Czech Republic.
Jarova, Katerina; Vavrova, Milada; Koleckarova, Alice
2015-01-01
The aim of this study was to assess the contamination level of aquatic ecosystems of the Oslava and the Jihlava Rivers, and of the Nove Mlyny Water Reservoir, situated in the South Moravian Region (Czech Republic), by residues of selected veterinary pharmaceuticals. We isolated and determined 10 sulfonamide antibiotics in samples of surface water and bottom sediments using optimized analytical methods. A representative number of sampling sites in the entire basin of selected waters were chosen. Samples were collected particularly near the larger cities in order to assess their possible impact to the aquatic ecosystems. Extraction, pre-concentration and purification of samples were performed using optimized methods of solid phase extraction and pressurized solvent extraction. Final identification and quantification were carried out by high-performance liquid chromatography coupled with diode array detector. The concentration of sulfonamides in water samples were all under the limit of detection. Regarding sediment samples, sulfadimidine was found at most sampling sites; its highest values were recorded in the Jihlava River (up to 979.8 µg.kg(-1) dry matter). Other frequently detected sulfonamides were sulfamethoxazole and sulfamerazine. Most other sulfonamides were under the limit of detection or limit of quantification. Monitoring of antibiotic residues in the environment, especially in the aquatic ecosystem, is a current topic due to the growing worldwide use in both human and veterinary medicine. According to obtained results, we document the pollution of selected rivers and water reservoir by particular sulfonamides which basically reflects their application in veterinary medicine.
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Multi-residue method for the determination of antibiotics and some of their metabolites in seafood.
Serra-Compte, Albert; Álvarez-Muñoz, Diana; Rodríguez-Mozaz, Sara; Barceló, Damià
2017-06-01
The presence of antibiotics in seafood for human consumption may pose a risk for consumers. A methodology for the analysis of antibiotics in seafood based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction, followed by detection and quantification using liquid chromatography coupled to mass spectrometry was developed. The analytical method was evaluated for the determination of 23 antibiotics (including parent compounds and some metabolites) in fish, mussels and clams. Recoveries ranged between 30% and 70% for most of the compounds and method detection and quantification limits (MDLs and MQLs) were between 0.01 and 0.31 ng/g dry weigh (dw) and 0.02-1.03 ng/g (dw) respectively. Real seafood samples were analysed using this method. Nine antibiotics were found at levels above MDLs; however none of them exceed the maximum residue limits (MRL) established by the authorities. Tetracycline was the most ubiquitous compound, presenting also the highest concentration: 5.63 ng/g (dw) in fish from Netherlands. In addition, an alternative technique based on microbial growth inhibition was explored as semiquantitative detection method of antibiotics in seafood. This methodology could be applied as a fast screening technique for the detection of macrolides and β-lactams in seafood but further research is needed for other antibiotics families. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Fejzić, Nihad; Begagić, Muris; Šerić-Haračić, Sabina; Smajlović, Muhamed
2014-01-01
Beta lactam antibiotics are widely used in therapy of cattle, particularly for the treatment of mastitis. Over 95% of residue testing in dairies in Bosnia and Herzegovina is for Beta lactams. The aim of this paper is to compare the efficacy of three most common screening tests for Beta lactam residues in cow’s milk in our country. The tests used in the study are SNAP β Lactam test (Idexx), Rosa Charm β Lactam test (Charm Sciences) and Inhibition MRL test (A&M). Study samples included: standardized concentrations of penicillin solution (0, 2, 3, 4, 5 and 6 ppb). In addition we tested milk samples from three equal size study groups (not receiving any antibiotic therapy, treated with Beta lactams for mastitis and treated with Beta lactams for diseases other than mastitis). Sensitivity and specificity were determined for each test, using standard penicillin concentrations with threshold value set at concentration of 4 ppb (Maximum residue level – MLR). Additionally we determined proportions of presumably false negative and false positive results for each test using results of filed samples testing. Agreement of test results for each test pair was assessed through Kappa coefficients interpreted by Landis-Koch scale. Detection level of all tests was shown to be well below MRL. This alongside with effects of natural inhibitors in milk contributed to finding of positive results in untreated and treated animals after the withholding period. Screening tests for beta lactam residues are important tools for ensuring that milk for human consumption is free from antibiotics residues. PMID:25172975
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Directory of Open Access Journals (Sweden)
Thomas R. Aunins
2018-03-01
Full Text Available Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under
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Aunins, Thomas R; Erickson, Keesha E; Prasad, Nripesh; Levy, Shawn E; Jones, Angela; Shrestha, Shristi; Mastracchio, Rick; Stodieck, Louis; Klaus, David; Zea, Luis; Chatterjee, Anushree
2018-01-01
Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under extreme stress
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Aunins, Thomas R.; Erickson, Keesha E.; Prasad, Nripesh; Levy, Shawn E.; Jones, Angela; Shrestha, Shristi; Mastracchio, Rick; Stodieck, Louis; Klaus, David; Zea, Luis; Chatterjee, Anushree
2018-01-01
Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under extreme stress
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Antibiotic residues and resistance in the environment
Pikkemaat, M.G.; Yassin, H.; Fels-Klerkx, H.J.; Berendsen, B.J.A.
2016-01-01
Antibiotic usage has benefited the animal industry and helped providing affordable animal proteins to the growing human population. However, since extensive use of antibiotics results in the inhibition of susceptible organisms while selecting for the resistant ones, agricultural use is contributing
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Antibiotic Stimulation of a Bacillus subtilis Migratory Response
Liu, Yongjin; Kyle, Steven
2018-01-01
ABSTRACT Competitive interactions between bacteria reveal physiological adaptations that benefit fitness. Bacillus subtilis is a Gram-positive species with several adaptive mechanisms for competition and environmental stress. Biofilm formation, sporulation, and motility are the outcomes of widespread changes in a population of B. subtilis. These changes emerge from complex, regulated pathways for adapting to external stresses, including competition from other species. To identify competition-specific functions, we cultured B. subtilis with multiple species of Streptomyces and observed altered patterns of growth for each organism. In particular, when plated on agar medium near Streptomyces venezuelae, B. subtilis initiates a robust and reproducible mobile response. To investigate the mechanistic basis for the interaction, we determined the type of motility used by B. subtilis and isolated inducing metabolites produced by S. venezuelae. Bacillus subtilis has three defined forms of motility: swimming, swarming, and sliding. Streptomyces venezuelae induced sliding motility specifically in our experiments. The inducing agents produced by S. venezuelae were identified as chloramphenicol and a brominated derivative at subinhibitory concentrations. Upon further characterization of the mobile response, our results demonstrated that subinhibitory concentrations of chloramphenicol, erythromycin, tetracycline, and spectinomycin all activate a sliding motility response by B. subtilis. Our data are consistent with sliding motility initiating under conditions of protein translation stress. This report underscores the importance of hormesis as an early warning system for potential bacterial competitors and antibiotic exposure. IMPORTANCE Antibiotic resistance is a major challenge for the effective treatment of infectious diseases. Identifying adaptive mechanisms that bacteria use to survive low levels of antibiotic stress is important for understanding pathways to
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Antibiotic residues in Brazilian UHT milk: a screening study Resíduos de antibióticos em leite UHT
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Gilberto Poggio Fonseca
2009-06-01
Full Text Available The aim of this research was to carry out a screening study to check the incidence of antimicrobial residues in Brazilian UHT milk according to rapid yoghurt method. Of the 100 (100% samples analysed, 96 (96% showed no traces of antibiotic residues while 4 (4% indicated probable presence of antibiotic residues. The results suggest that the Brazilian Sanitary Surveillance Agency should apply continuous monitoring programs in order to obtain a safe product offering no health risks to consumers.O objetivo deste trabalho é realizar um estudo preliminar para verificar a presença de resíduos de antibióticos em leite UHT disponíveis no mercado brasileiro, utilizando o método rápido do iogurte. Das 100 (100% amostras analisadas, 96 (96% indicaram negativas, sugerindo ausência de resíduos de antibióticos, enquanto 4 (4% mostraram-se positivas. Os resultados sugerem a necessidade de contínuo monitoramento deste parâmetro por parte da Vigilância Sanitária com o objetivo de oferecer um produto seguro, sem riscos para saúde do consumidor.
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International Nuclear Information System (INIS)
2016-08-01
Awareness of food safety is rising among consumers, and many importing countries implement food control regulations to guarantee the quality and safety of imported foods for their consumers. Many developing countries have also taken steps to put in place control systems that encourage responsible use of veterinary medicines to combat possible drug resistance, control drug residues and ensure compliance with international and national standards. However, these countries still require the necessary know-how and skills to protect local consumers and to access international markets. One significant constraint is the capacity of laboratory services to generate surveillance data using reliable and cost effective analytical methods validated to national and international standards. The IAEA coordinated research project (CRP) on the Development of Radiometric and Allied Analytical Methods to Strengthen National Residue Control Programmes for Antibiotic and Anthelmintic Veterinary Drug Residues was initiated in 2009 to conduct work on robust nuclear and related technologies suitable for the screening and confirmatory analysis of residues of veterinary medicines, including antimicrobials and anthelmintics commonly used in animal production, with public health and trade significance. The CRP also explored mechanisms to enhance networking among research institutions involved in research on pharmacologically active veterinary drug residues in food (primarily) and environmental samples. The project was implemented by the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture between 2009 and 2014 and involved eleven research contracts and one technical contract, five research agreements and one institution. The CRP was a continuation of the CRP on the Development of Strategies for the Effective Monitoring of Veterinary Drug Residues in Livestock and Livestock Products in Developing Countries and the key findings are also summarized in this publication.
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Quadruplex gold immunochromatogaraphic assay for four families of antibiotic residues in milk.
Zhou, Jinyu; Nie, Wei; Chen, Yiqiang; Yang, Chunjiang; Gong, Lu; Zhang, Chi; Chen, Qian; He, Lidong; Feng, Xiaoyu
2018-08-01
In this study, we developed a quadruplex gold immunochromatogaraphic assay (GICA) for the simultaneous determination of four families of antibiotics including β-lactams, tetracyclines, streptomycin and chloramphenicol in milk. For qualitative analysis, the visual cut-off values were measured to be 2-100 ng/mL, 16-32 ng/mL, 50 ng/mL and 2.4 ng/mL for β-lactams, tetracyclines, streptomycin and chloramphenicol, respectively. For quantitative analysis, the detection ranges were 0.13-1 ng/mL for penicillin G, 0.13-8 ng/mL for tetracycline, 0.78-25 ng/mL for streptomycin, 0.019-1.2 ng/mL for chloramphenicol in milk respectively, with linear correlation coefficients higher than 0.97. The spiked experiment indicated that the mean recoveries ranged from 84.5% to 107.6% with coefficient of variations less than 16.2%, and real sample analysis revealed that the GICA can produce consistent results with instrumental analysis. These results demonstrated that this novel immunoassay is a promising approach for rapidly screening common antibiotic residues in milk. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Genome-wide dynamics of a bacterial response to antibiotics that target the cell envelope
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Tran Ngat
2011-05-01
Full Text Available Abstract Background A decline in the discovery of new antibacterial drugs, coupled with a persistent rise in the occurrence of drug-resistant bacteria, has highlighted antibiotics as a diminishing resource. The future development of new drugs with novel antibacterial activities requires a detailed understanding of adaptive responses to existing compounds. This study uses Streptomyces coelicolor A3(2 as a model system to determine the genome-wide transcriptional response following exposure to three antibiotics (vancomycin, moenomycin A and bacitracin that target distinct stages of cell wall biosynthesis. Results A generalised response to all three antibiotics was identified which involves activation of transcription of the cell envelope stress sigma factor σE, together with elements of the stringent response, and of the heat, osmotic and oxidative stress regulons. Attenuation of this system by deletion of genes encoding the osmotic stress sigma factor σB or the ppGpp synthetase RelA reduced resistance to both vancomycin and bacitracin. Many antibiotic-specific transcriptional changes were identified, representing cellular processes potentially important for tolerance to each antibiotic. Sensitivity studies using mutants constructed on the basis of the transcriptome profiling confirmed a role for several such genes in antibiotic resistance, validating the usefulness of the approach. Conclusions Antibiotic inhibition of bacterial cell wall biosynthesis induces both common and compound-specific transcriptional responses. Both can be exploited to increase antibiotic susceptibility. Regulatory networks known to govern responses to environmental and nutritional stresses are also at the core of the common antibiotic response, and likely help cells survive until any specific resistance mechanisms are fully functional.
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Taxing Meat: Taking Responsibility for One's Contribution to Antibiotic Resistance.
Giubilini, Alberto; Birkl, Patrick; Douglas, Thomas; Savulescu, Julian; Maslen, Hannah
2017-04-01
Antibiotic use in animal farming is one of the main drivers of antibiotic resistance both in animals and in humans. In this paper we propose that one feasible and fair way to address this problem is to tax animal products obtained with the use of antibiotics. We argue that such tax is supported both by (a) deontological arguments, which are based on the duty individuals have to compensate society for the antibiotic resistance to which they are contributing through consumption of animal products obtained with the use of antibiotics; and (b) a cost-benefit analysis of taxing such animal products and of using revenue from the tax to fund alternatives to use of antibiotics in animal farming. Finally, we argue that such a tax would be fair because individuals who consume animal products obtained with the use of antibiotics can be held morally responsible, i.e. blameworthy, for their contribution to antibiotic resistance, in spite of the fact that each individual contribution is imperceptible.
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Environmental pollution by antibiotics and by antibiotic resistance determinants
International Nuclear Information System (INIS)
Martinez, Jose Luis
2009-01-01
Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.
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Environmental pollution by antibiotics and by antibiotic resistance determinants
Energy Technology Data Exchange (ETDEWEB)
Martinez, Jose Luis, E-mail: jlmtnez@cnb.csic.e [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)
2009-11-15
Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.
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DNA-Aptamers Binding Aminoglycoside Antibiotics
Directory of Open Access Journals (Sweden)
Nadia Nikolaus
2014-02-01
Full Text Available Aptamers are short, single stranded DNA or RNA oligonucleotides that are able to bind specifically and with high affinity to their non-nucleic acid target molecules. This binding reaction enables their application as biorecognition elements in biosensors and assays. As antibiotic residues pose a problem contributing to the emergence of antibiotic-resistant pathogens and thereby reducing the effectiveness of the drug to fight human infections, we selected aptamers targeted against the aminoglycoside antibiotic kanamycin A with the aim of constructing a robust and functional assay that can be used for water analysis. With this work we show that aptamers that were derived from a Capture-SELEX procedure targeting against kanamycin A also display binding to related aminoglycoside antibiotics. The binding patterns differ among all tested aptamers so that there are highly substance specific aptamers and more group specific aptamers binding to a different variety of aminoglycoside antibiotics. Also the region of the aminoglycoside antibiotics responsible for aptamer binding can be estimated. Affinities of the different aptamers for their target substance, kanamycin A, are measured with different approaches and are in the micromolar range. Finally, the proof of principle of an assay for detection of kanamycin A in a real water sample is given.
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Phenotypic Profiling of Antibiotic Response Signatures in Escherichia coli Using Raman Spectroscopy
Athamneh, A. I. M.; Alajlouni, R. A.; Wallace, R. S.; Seleem, M. N.
2014-01-01
Identifying the mechanism of action of new potential antibiotics is a necessary but time-consuming and costly process. Phenotypic profiling has been utilized effectively to facilitate the discovery of the mechanism of action and molecular targets of uncharacterized drugs. In this research, Raman spectroscopy was used to profile the phenotypic response of Escherichia coli to applied antibiotics. The use of Raman spectroscopy is advantageous because it is noninvasive, label free, and prone to automation, and its results can be obtained in real time. In this research, E. coli cultures were subjected to three times the MICs of 15 different antibiotics (representing five functional antibiotic classes) with known mechanisms of action for 30 min before being analyzed by Raman spectroscopy (using a 532-nm excitation wavelength). The resulting Raman spectra contained sufficient biochemical information to distinguish between profiles induced by individual antibiotics belonging to the same class. The collected spectral data were used to build a discriminant analysis model that identified the effects of unknown antibiotic compounds on the phenotype of E. coli cultures. Chemometric analysis showed the ability of Raman spectroscopy to predict the functional class of an unknown antibiotic and to identify individual antibiotics that elicit similar phenotypic responses. Results of this research demonstrate the power of Raman spectroscopy as a cellular phenotypic profiling methodology and its potential impact on antibiotic drug development research. PMID:24295982
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Taxing Meat: Taking Responsibility for One’s Contribution to Antibiotic Resistance
Giubilini, Alberto; Birkl, Patrick; Douglas, Thomas; Savulescu, Julian; Maslen, Hannah
2018-01-01
Antibiotic use in animal farming is one of the main drivers of antibiotic resistance both in animals and in humans. In this paper we propose that one feasible and fair way to address this problem is to tax animal products obtained with the use of antibiotics. We argue that such tax is supported both by (a) deontological arguments, which are based on the duty individuals have to compensate society for the antibiotic resistance to which they are contributing through consumption of animal products obtained with the use of antibiotics; and (b) a cost-benefit analysis of taxing such animal products and of using revenue from the tax to fund alternatives to use of antibiotics in animal farming. Finally, we argue that such a tax would be fair because individuals who consume animal products obtained with the use of antibiotics can be held morally responsible, i.e. blameworthy, for their contribution to antibiotic resistance, in spite of the fact that each individual contribution is imperceptible. PMID:29515330
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Directory of Open Access Journals (Sweden)
Wim Reybroeck
Full Text Available Two Pseudomonas strains, identified as closely related to Pseudomonas tolaasii, were isolated from milk of a farm with frequent false-positive Delvotest results for screening putative antibiotic residues in raw milk executed as part of the regulatory quality programme. Growth at 5 to 7°C of these isolates in milk resulted in high lipolysis and the production of bacterial inhibitors. The two main bacterial inhibitors have a molecular weight of 1168.7 and 1140.7 Da respectively, are heat-tolerant and inhibit Geobacillus stearothermophilus var. calidolactis, the test strain of most of the commercially available microbiological inhibitor tests for screening of antibiotic residues in milk. Furthermore, these bacterial inhibitors show antimicrobial activity against Staphylococcus aureus, Bacillus cereus and B. subtilis and also interfere negatively with yoghurt production. Following their isolation and purification with RP-HPLC, the inhibitors were identified by NMR analysis as cyclic lipodepsipeptides of the viscosin group. Our findings bring to light a new challenge for quality control in the dairy industry. By prolonging the refrigerated storage of raw milk, the keeping quality of milk is influenced by growth and metabolic activities of psychrotrophic bacteria such as pseudomonads. Besides an increased risk of possible spoilage of long shelf-life milk, the production at low temperature of natural bacterial inhibitors may also result in false-positive results for antibiotic residue screening tests based on microbial inhibitor assays thus leading to undue production loss.
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Antibiotics in agroecosystems: Introduction to the special section
The presence of antibiotic drug residues, antibiotic resistant bacteria, and antibiotic resistance genes in agroecosystems has become a significant area of research in recent years, and is a growing public health concern. While antibiotics are utilized for human medicine and agricultural practices, ...
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Murai, Atsushi; Kitahara, Kazuki; Okumura, Shouta; Kobayashi, Misato; Horio, Fumihiko
2016-02-01
Recent studies have emphasized the crucial role of gut microbiota in triggering and modulating immune response. We aimed to determine whether the modification of gut microbiota by oral co-administration of two antibiotics, ampicillin and neomycin, would lead to changes in the antibody response to antigens in chickens. Neonatal chickens were given or not given ampicillin and neomycin (0.25 and 0.5 g/L, respectively) in drinking water. At 2 weeks of age, the chicks were muscularly or orally immunized with antigenic keyhole limpet hemocyanin (KLH), and then serum anti-KLH antibody levels were examined by ELISA. In orally immunized chicks, oral antibiotics treatment enhanced antibody responses (IgM, IgA, IgY) by 2-3-fold compared with the antibiotics-free control, while the antibiotics did not enhance antibody responses in the muscularly immunized chicks. Concomitant with their enhancement of antibody responses, the oral antibiotics also lowered the Lactobacillus species in feces. Low doses of antibiotics (10-fold and 100-fold lower than the initial trial), which failed to change the fecal Lactobacillus population, did not modify any antibody responses when chicks were orally immunized with KLH. In conclusion, oral antibiotics treatment enhanced the antibody response to orally exposed antigens in chickens. This enhancement of antibody response was associated with a modification of the fecal Lactobacillus content, suggesting a possible link between gut microbiota and antibody response in chickens. © 2015 Japanese Society of Animal Science.
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Segment-specific responses of intestinal epithelium transcriptome to in-feed antibiotics in pigs.
Yu, Kaifan; Mu, Chunlong; Yang, Yuxiang; Su, Yong; Zhu, Weiyun
2017-10-01
Despite widespread use of antibiotics for treatment of human diseases and promotion of growth of agricultural animals, our understanding of their effects on the host is still very limited. We used a model in which pigs were fed with or without a cocktail of antibiotics and found, based on the denaturing gradient gel electrophoresis (DGGE) patterns, that the fecal bacteria from the treatment and control animals were distinct. Furthermore, the total bacterial population in the feces tended to be decreased by the antibiotic treatment ( P = 0.07), and the counts of Lactobacillus and Clostridium XIVa were significantly reduced ( P epithelium, we assessed gene expression profiles of the jejunum and ileum and their response to antibiotic administration. The results indicate that in-feed antibiotics increased expression of genes involved in immune functions in both the jejunum and ileum, some of which were clustered in the coexpression network. Gene ontology terms of metabolic processes were altered predominantly in the jejunum but not in the ileum. Notably, antibiotics diminished intestinal segment-specific transcriptional changes, especially for genes associated with metabolic functions. This study reveals segment-specific responses of host intestinal epithelium to in-feed antibiotics, which can be a valuable resource for deciphering antibiotic-microbiota-host interactions. Copyright © 2017 the American Physiological Society.
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Directory of Open Access Journals (Sweden)
Martin Levkut, ml.
2011-04-01
Full Text Available The aim of the present study was to evaluate the microbial growth inhibition test Total antibiotics for the screening of lasalocid residues in the tissues of broiler chickens after its oral administration in medicated feed. The residues were investigated throughout the 5-day withdrawal period /WP/ and also on day 6 representing the first day following the WP. All broiler chicken tissues were positive for lasalocid. The breast muscle was positive (the presence of residues at/above the detection limit /LOD/ of method up to day 1 of the WP, the thigh muscle, gizzard, heart, skin and fat up to day 3 of the WP and the liver and kidneys up to day 4 of the WP. When evaluating the dubious results (the presence of residues just below the LOD of method, the breast muscle was suspect positive up to day 3 of the WP and the gizzard, skin and fat up to day 4 of the WP. No positive or dubious results were detected on day 5 of the WP. The LOD of Bacillus stearothermophilus var. calidolactis for maduramycin was 500 µg.l-1.doi:10.5219/140
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Residues of veterinary antibiotics in manures from feedlot livestock in eight provinces of China.
Zhao, Ling; Dong, Yuan Hua; Wang, Hui
2010-02-01
The residue levels of selected fluoroquinolones, sulfonamides and tetracyclines in 143 animal dung samples collected in 2007 from large-scale livestock and poultry feedlots in 8 provinces were determined by using ultrasonic extraction and liquid chromatography. Recoveries from spiked pig dung samples (spike level=1mg/kg) ranged from 73.9 to 102.0% for fluoroquinolones, from 81.6 to 92.3% for sulfonamides, and from 57.2 to 72.6% for tetracyclines. Relative standard deviations of the recoveries were less than 10% within the same day. Method quantification limits were measured from 0.031 to 0.150 mg/kg for fluoroquinolones, from 0.023 to 0.082 mg/kg for sulfonamides, and 0.091 to 0.182 mg/kg for tetracyclines in spiked pig manure samples. Analysis of 61 pig, 54 chicken and 28 cow dung samples collected in China revealed that in pig and cow dung, up to 33.98 and 29.59 mg/kg ciprofloxacin, 33.26 and 46.70 mg/kg enrofloxacin, 59.06 and 59.59 mg/kg oxytetracycline, and 21.06 and 27.59 mg/kg chlortetracycline could be detected, respectively. A maximum concentration of 99.43 mg/kg fleroxacin, 225.45 mg/kg norfloxacin, 45.59 mg/kg ciprofloxacin and 1420.76 mg/kg enrofloxacin could be detected in chicken dung. No appreciable sulfonamide antibiotic concentrations (less than 10mg/kg) were found in any animal dung, and only sulfadimidine was observed, at a maximum concentration of 6.04 mg/kg, in chicken dung. Both enrofloxacin and chlortetracycline were detected with a very high occurrence in three animal manure samples. The residue levels for most antibiotics showed significant statistical differences among the sampling districts and the animal species. Copyright 2009 Elsevier B.V. All rights reserved.
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Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee
2013-07-01
Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.
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Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk
International Nuclear Information System (INIS)
Beltrán, M.C.; Althaus, R.L.; Molina, A.; Berruga, M.I.; Molina, M.P.
2015-01-01
The use of antibiotics to treat mastitis and other infectious diseases in dairy sheep and goats is a widespread practice nowadays that can, when not properly applied, result in the contamination of the milk supply. Spanish legislation establishes the control of the presence of antibiotic residues in sheep and goat’s milk using screening methods that detect, at least, beta-lactam drugs. Microbial inhibitor tests using Geobacillus stearothermophilus var. calidolactis and specific receptor-binding assays are most widely employed for this purpose. The detection rates of screening tests routinely used in Spain have been calculated considering the frequency of use of veterinary drugs commonly applied in ovine and caprine livestock to treat and prevent mastitis as well as the test sensitivity toward these substances at safety levels. In general, the use of a single test allows detecting 62.8-82.4% of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of methods were found when goat's milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90% in some cases (81.5-90.1% for sheep and 84.7-92.6% for goats). However, the periodical use of screening tests able to detect quinolones, macrolides or aminoglycosides would be recommended to carry out more efficient screening and ensure the safety of milk and dairy products from sheep and goats. (Author)
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Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk
Energy Technology Data Exchange (ETDEWEB)
Beltrán, M.C.; Althaus, R.L.; Molina, A.; Berruga, M.I.; Molina, M.P.
2015-07-01
The use of antibiotics to treat mastitis and other infectious diseases in dairy sheep and goats is a widespread practice nowadays that can, when not properly applied, result in the contamination of the milk supply. Spanish legislation establishes the control of the presence of antibiotic residues in sheep and goat’s milk using screening methods that detect, at least, beta-lactam drugs. Microbial inhibitor tests using Geobacillus stearothermophilus var. calidolactis and specific receptor-binding assays are most widely employed for this purpose. The detection rates of screening tests routinely used in Spain have been calculated considering the frequency of use of veterinary drugs commonly applied in ovine and caprine livestock to treat and prevent mastitis as well as the test sensitivity toward these substances at safety levels. In general, the use of a single test allows detecting 62.8-82.4% of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of methods were found when goat's milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90% in some cases (81.5-90.1% for sheep and 84.7-92.6% for goats). However, the periodical use of screening tests able to detect quinolones, macrolides or aminoglycosides would be recommended to carry out more efficient screening and ensure the safety of milk and dairy products from sheep and goats. (Author)
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Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk
Directory of Open Access Journals (Sweden)
M. Carmen Beltrán
2015-03-01
Full Text Available The use of antibiotics to treat mastitis and other infectious diseases in dairy sheep and goats is a widespread practice nowadays that can, when not properly applied, result in the contamination of the milk supply. Spanish legislation establishes the control of the presence of antibiotic residues in sheep and goat’s milk using screening methods that detect, at least, beta-lactam drugs. Microbial inhibitor tests using Geobacillus stearothermophilus var. calidolactis and specific receptor-binding assays are most widely employed for this purpose. The detection rates of screening tests routinely used in Spain have been calculated considering the frequency of use of veterinary drugs commonly applied in ovine and caprine livestock to treat and prevent mastitis as well as the test sensitivity toward these substances at safety levels. In general, the use of a single test allows detecting 62.8-82.4% of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of methods were found when goat’s milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90% in some cases (81.5-90.1% for sheep and 84.7-92.6% for goats. However, the periodical use of screening tests able to detect quinolones, macrolides or aminoglycosides would be recommended to carry out more efficient screening and ensure the safety of milk and dairy products from sheep and goats.
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Wu, Ying; Cui, Erping; Zuo, Yiru; Cheng, Weixiao; Chen, Hong
2018-03-07
The prevalence and persistence of antibiotic resistance genes in wastewater treatment plants (WWTPs) is of growing interest, and residual sludge is among the main sources for the release of antibiotic resistance genes (ARGs). Moreover, heavy metals concentrated in dense microbial communities of sludge could potentially favor co-selection of ARGs and metal resistance genes (MRGs). Residual sludge treatment is needed to limit the spread of resistance from WWTPs into the environment. This study aimed to explore the fate of ARGs and MRGs during thermophilic two-phase (acidogenic/methanogenic phase) anaerobic digestion by metagenomic analysis. The occurrence and abundance of mobile genetic elements were also determined based on the SEED database. Among the 27 major ARG subtypes detected in feed sludge, large reductions (> 50%) in 6 ARG subtypes were achieved by acidogenic phase (AP), while 63.0% of the ARG subtypes proliferated in the following methanogenic phase (MP). In contrast, a 2.8-fold increase in total MRG abundance was found in AP, while the total abundance during MP decreased to the same order of magnitude as in feed sludge. The distinct dynamics of ARGs and MRGs during the two-phase anaerobic digestion are noteworthy, and more specific treatments are required to limit their proliferation in the environment.
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Hurtaud-Pessel, D; Jagadeshwar-Reddy, T; Verdon, E
2011-10-01
A liquid chromatography-high resolution mass spectrometry (LC-HRMS) method was developed for screening meat for a wide range of antibiotics used in veterinary medicine. Full-scan mode under high resolution mass spectral conditions using an LTQ-Orbitrap mass spectrometer with resolving power 60,000 full width at half maximum (FWHM) was applied for analysis of the samples. Samples were prepared using two extraction protocols prior to LC-HRMS analysis. The scope of the method focuses on screening the following main families of antibacterial veterinary drugs: penicillins, cephalosporins, sulfonamides, macrolides, tetracyclines, aminoglucosides and quinolones. Compounds were successfully identified in spiked samples from their accurate mass and LC retention times from the acquired full-scan chromatogram. Automated data processing using ToxId software allowed rapid treatment of the data. Analyses of muscle tissues from real samples collected from antibiotic-treated animals was carried out using the above methodology and antibiotic residues were identified unambiguously. Further analysis of the data for real samples allowed the identification of the targeted antibiotic residues but also non-targeted compounds, such as some of their metabolites.
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Gaudin, V; Hedou, C; Rault, A; Verdon, E
2010-07-01
The STAR protocol is a Five Plate Test (FPT) developed several years ago at the Community Reference Laboratory (CRL) for the screening of antimicrobial residues in milk and muscle. This paper presents the validation of this method according to European Decision 2002/657/EC and to an internal guideline for validation. A validation protocol based on 'simulated tissues' and on a list of 16 representative antimicrobials to be validated was implemented in our laboratory during several months for the STAR protocol. The performance characteristics of the method were determined (specificity, detection capabilities CCbeta, applicability, ruggedness). In conclusion, the STAR protocol is applicable to the broad-spectrum detection of antibiotic residues in muscles of different animal species (pig, cattle, sheep, poultry). The method has good specificity (false-positive rate = 4%). The detection capabilities were determined for 16 antibiotics from different families in relation to their respective maximum residue limit (MRL): beta-lactams (penicillins and cephalosporins 8 MRL) and florfenicol (MRL). The two objectives of this study were met: firstly, to validate the STAR protocol according to European Decision 2002/657/EC, then to demonstrate that the validation guideline developed to implement this decision is applicable to microbiological plate tests even for muscle. The use of simulated tissue appeared a good compromise between spiked discs with antibiotic solutions and incurred tissues. In addition, the choice of a list of representative antibiotics allowed the reduction of the scope of the validation, which was already costly in time and effort.
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Analysis of antibiotics from liquid sample using electrospray ionization-ion mobility spectrometry
International Nuclear Information System (INIS)
Li Shu; Jia Jian; Gao Xiaoguang; He Xiuli; Li Jianping
2012-01-01
Highlights: ► The reduced mobilities of 18 antibiotics are determined. ► Establishing antibiotic mass-mobility correlation using (12,4) potential model. ► Multi-component characteristics of antibiotics can be revealed using ESI-IMS. ► Most mixtures of antibiotics can be analyzed using ESI-IMS. ► The detection limit of amoxicillin is 70 pg. - Abstract: The recent findings of antibiotic residues in aquatic environment at trace level have gained much concern for the detrimental effect on ecological and human health due to bacterial resistance. Here, the feasibility of using electrospray ionization ion mobility spectrometry (ESI-IMS) for analysis antibiotics in liquid sample is demonstrated. Reduced mobilities and collision cross sections of 18 antibiotics are experimentally measured and compared with theoretical values according to mass-mobility correlation. Gentamicin is used as an example to investigate the capability of ESI-IMS for multi-component analysis of antibiotics. Mixtures of antibiotics at different concentrations are analyzed. The estimated detection limit for amoxicillin is 0.7 mg L −1 (70 pg) and the linear range of response maintains over two orders. This method will be a potential technique for the analysis of antibiotics in aquatic environment.
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Gaudin, Valérie; Hedou, Celine; Soumet, Christophe; Verdon, Eric
2016-01-01
The Evidence Investigator™ system (Randox, UK) is a biochip and semi-automated system. The microarray kit II (AM II) is capable of detecting several compounds belonging to different families of antibiotics: quinolones, ceftiofur, thiamphenicol, streptomycin, tylosin and tetracyclines. The performance of this innovative system was evaluated for the detection of antibiotic residues in new matrices, in muscle of different animal species and in aquaculture products. The method was validated according to the European Decision No. EC/2002/657 and the European guideline for the validation of screening methods, which represents a complete initial validation. The false-positive rate was equal to 0% in muscle and in aquaculture products. The detection capabilities CCβ for 12 validated antibiotics (enrofloxacin, difloxacin, ceftiofur, desfuroyl ceftiofur cysteine disulfide, thiamphenicol, florfenicol, tylosin, tilmicosin, streptomycin, dihydrostreptomycin, tetracycline, doxycycline) were all lower than the respective maximum residue limits (MRLs) in muscle from different animal origins (bovine, ovine, porcine, poultry). No cross-reactions were observed with other antibiotics, neither with the six detected families nor with other families of antibiotics. The AM II kit could be applied to aquaculture products but with higher detection capabilities from those in muscle. The detection capabilities CCβ in aquaculture products were respectively at 0.25, 0.10 and 0.5 of the respective MRL in aquaculture products for enrofloxacin, tylosin and oxytetracycline. The performance of the AM II kit has been compared with other screening methods and with the performance characteristics previously determined in honey.
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Optimization and Validation of kit of detection Antibiotics on Honey
International Nuclear Information System (INIS)
Hamza, Malek
2013-01-01
According to the Codex Alimentarius and the European Commission Directive each food has a maximum residual antibiotic (MRLs) however, for honey is still no limit set. Among the main methods that guarantee the detection of antibiotic residues include the Premi Test which is a qualitative method for the detection of antibiotics in honey, but it remains a non-specific method for this matrix and long enough (three hours of incubation). Through this work, we were able to develop and optimize a new kit called Honey test. This kit is able to detect the presence of antibiotic residues in honey by a bacterial strain radio-resistant called D.ra. The duration of treatment is only 30 minutes, requiring incubation at 37 Degree C and treatment with UV at 366 nm. This work will be the subject of a national patent.
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Ankomah, Peter; Levin, Bruce R
2014-06-10
The successful treatment of bacterial infections is the product of a collaboration between antibiotics and the host's immune defenses. Nevertheless, in the design of antibiotic treatment regimens, few studies have explored the combined action of antibiotics and the immune response to clearing infections. Here, we use mathematical models to examine the collective contribution of antibiotics and the immune response to the treatment of acute, self-limiting bacterial infections. Our models incorporate the pharmacokinetics and pharmacodynamics of the antibiotics, the innate and adaptive immune responses, and the population and evolutionary dynamics of the target bacteria. We consider two extremes for the antibiotic-immune relationship: one in which the efficacy of the immune response in clearing infections is directly proportional to the density of the pathogen; the other in which its action is largely independent of this density. We explore the effect of antibiotic dose, dosing frequency, and term of treatment on the time before clearance of the infection and the likelihood of antibiotic-resistant bacteria emerging and ascending. Our results suggest that, under most conditions, high dose, full-term therapy is more effective than more moderate dosing in promoting the clearance of the infection and decreasing the likelihood of emergence of antibiotic resistance. Our results also indicate that the clinical and evolutionary benefits of increasing antibiotic dose are not indefinite. We discuss the current status of data in support of and in opposition to the predictions of this study, consider those elements that require additional testing, and suggest how they can be tested.
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Directory of Open Access Journals (Sweden)
Petroianu Andy
1998-01-01
Full Text Available The side effects of antibiotics have been extensively described during the last decades, however, their role on digestive motility must be better investigated. Following a line of research, the influence of penicillin, chloranfenicol tetracycline and gentamicine on longitudinal smooth muscle responses to acetylcholine and histamine were studied on guinea-pig ileum. There were no differences between the responses before and after the addition of each antibiotic. Further investigations must be performed in order to find a possible influence of antibiotics on digestive motility.
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Chuah, Li-Oon; Effarizah, M E; Goni, Abatcha Mustapha; Rusul, Gulam
2016-06-01
Catfish is one of the most cultivated species worldwide. Antibiotics are usually used in catfish farming as therapeutic and prophylactic agents. In the USA, only oxytetracycline, a combination of sulfadimethoxine and ormetoprim, and florfenicol are approved by the Food Drug Administration for specific fish species (e.g., catfish and salmonids) and their specific diseases. Misuse of antibiotics as prophylactic agents in disease prevention, however, is common and contributes in the development of antibiotic resistance. Various studies had reported on antibiotic residues and/or resistance in farmed species, feral fish, water column, sediments, and, in a lesser content, among farm workers. Ninety percent of the world aquaculture production is carried out in developing countries, which lack regulations and enforcement on the use of antibiotics. Hence, efforts are needed to promote the development and enforcement of such a regulatory structure. Alternatives to antibiotics such as antibacterial vaccines, bacteriophages and their lysins, and probiotics have been applied to curtail the increasing emergence of antibiotic-resistant bacteria due to the imprudent application of antibiotics in aquaculture.
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Quantification of Drive-Response Relationships Between Residues During Protein Folding.
Qi, Yifei; Im, Wonpil
2013-08-13
Mutual correlation and cooperativity are commonly used to describe residue-residue interactions in protein folding/function. However, these metrics do not provide any information on the causality relationships between residues. Such drive-response relationships are poorly studied in protein folding/function and difficult to measure experimentally due to technical limitations. In this study, using the information theory transfer entropy (TE) that provides a direct measurement of causality between two times series, we have quantified the drive-response relationships between residues in the folding/unfolding processes of four small proteins generated by molecular dynamics simulations. Instead of using a time-averaged single TE value, the time-dependent TE is measured with the Q-scores based on residue-residue contacts and with the statistical significance analysis along the folding/unfolding processes. The TE analysis is able to identify the driving and responding residues that are different from the highly correlated residues revealed by the mutual information analysis. In general, the driving residues have more regular secondary structures, are more buried, and show greater effects on the protein stability as well as folding and unfolding rates. In addition, the dominant driving and responding residues from the TE analysis on the whole trajectory agree with those on a single folding event, demonstrating that the drive-response relationships are preserved in the non-equilibrium process. Our study provides detailed insights into the protein folding process and has potential applications in protein engineering and interpretation of time-dependent residue-based experimental observables for protein function.
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Overexpression of antibiotic resistance genes in hospital effluents over time.
Rowe, Will P M; Baker-Austin, Craig; Verner-Jeffreys, David W; Ryan, Jim J; Micallef, Christianne; Maskell, Duncan J; Pearce, Gareth P
2017-06-01
Effluents contain a diverse abundance of antibiotic resistance genes that augment the resistome of receiving aquatic environments. However, uncertainty remains regarding their temporal persistence, transcription and response to anthropogenic factors, such as antibiotic usage. We present a spatiotemporal study within a river catchment (River Cam, UK) that aims to determine the contribution of antibiotic resistance gene-containing effluents originating from sites of varying antibiotic usage to the receiving environment. Gene abundance in effluents (municipal hospital and dairy farm) was compared against background samples of the receiving aquatic environment (i.e. the catchment source) to determine the resistome contribution of effluents. We used metagenomics and metatranscriptomics to correlate DNA and RNA abundance and identified differentially regulated gene transcripts. We found that mean antibiotic resistance gene and transcript abundances were correlated for both hospital ( ρ = 0.9, two-tailed P hospital effluent samples. High β-lactam resistance gene transcript abundance was related to hospital antibiotic usage over time and hospital effluents contained antibiotic residues. We conclude that effluents contribute high levels of antibiotic resistance genes to the aquatic environment; these genes are expressed at significant levels and are possibly related to the level of antibiotic usage at the effluent source. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.
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Phenotypic and gene expression responses of E. coli to antibiotics during spaceflight
Zea, Luis
Bacterial susceptibility to antibiotics has been shown in vitro to be reduced during spaceflight; however, the underlying mechanisms responsible for this outcome are not fully understood. In particular, it is not yet clear whether this observed response is due to increased drug resistance (a microbial defense response) or decreased drug efficacy (a microgravity biophysical mass transport effect). To gain insight into the differentiation between these two potential causes, an investigation was undertaken onboard the International Space Station (ISS) in 2014 termed Antibiotic Effectiveness in Space-1 (AES-1). For this purpose, E. coli was challenged with two antibiotics, Gentamicin Sulfate and Colistin Sulfate, at concentrations higher than those needed to inhibit growth on Earth. Phenotypic parameters (cell size, cell envelope thickness, population density and lag phase duration) and gene expression were compared between the spaceflight samples and ground controls cultured in varying levels of drug concentration. It was observed that flight samples proliferated in antibiotic concentrations that were inhibitory on Earth, growing on average to a 13-fold greater concentration than matched 1g controls. Furthermore, at the highest drug concentrations in space, E. coli cells were observed to aggregate into visible clusters. In spaceflight, cell size was significantly reduced, translating to a decrease in cell surface area to about one half of the ground controls. Smaller cell surface area can in turn proportionally reduce the rate of antibiotic molecules reaching the cell. Additionally, it was observed that genes --- in some cases more than 2000 --- were overexpressed in space with respect to ground controls. Up-regulated genes include poxB, which helps catabolize glucose into organic acids that alter acidity around and inside the cell, and the gadABC family genes, which confer resistance to extreme acid conditions. The next step is to characterize the mechanisms behind
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Analysis of antibiotics from liquid sample using electrospray ionization-ion mobility spectrometry
Energy Technology Data Exchange (ETDEWEB)
Shu, Li; Jian, Jia; Xiaoguang, Gao; Xiuli, He [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); Li Jianping, E-mail: jpli@mail.ie.ac.cn [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)
2012-03-30
Highlights: Black-Right-Pointing-Pointer The reduced mobilities of 18 antibiotics are determined. Black-Right-Pointing-Pointer Establishing antibiotic mass-mobility correlation using (12,4) potential model. Black-Right-Pointing-Pointer Multi-component characteristics of antibiotics can be revealed using ESI-IMS. Black-Right-Pointing-Pointer Most mixtures of antibiotics can be analyzed using ESI-IMS. Black-Right-Pointing-Pointer The detection limit of amoxicillin is 70 pg. - Abstract: The recent findings of antibiotic residues in aquatic environment at trace level have gained much concern for the detrimental effect on ecological and human health due to bacterial resistance. Here, the feasibility of using electrospray ionization ion mobility spectrometry (ESI-IMS) for analysis antibiotics in liquid sample is demonstrated. Reduced mobilities and collision cross sections of 18 antibiotics are experimentally measured and compared with theoretical values according to mass-mobility correlation. Gentamicin is used as an example to investigate the capability of ESI-IMS for multi-component analysis of antibiotics. Mixtures of antibiotics at different concentrations are analyzed. The estimated detection limit for amoxicillin is 0.7 mg L{sup -1} (70 pg) and the linear range of response maintains over two orders. This method will be a potential technique for the analysis of antibiotics in aquatic environment.
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Sustained release of antibiotics from injectable and thermally responsive polypeptide depots.
Adams, Samuel B; Shamji, Mohammed F; Nettles, Dana L; Hwang, Priscilla; Setton, Lori A
2009-07-01
Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to undergo in situ depot formation at body temperature. ELPs were modified to enable loading with the antibiotics, cefazolin, and vancomycin, followed by induction of the phase transition in vitro. Cefazolin and vancomycin concentrations were monitored, as well as bioactivity of the released antibiotics, to test an ability of the ELP depot to provide for prolonged release of bioactive drugs. Further tests of formulation viscosity were conducted to test suitability as an injectable drug carrier. Results demonstrate sustained release of therapeutic concentrations of bioactive antibiotics by the ELP, with first-order time constants for drug release of approximately 25 h for cefazolin and approximately 500 h for vancomycin. These findings illustrate that an injectable, in situ forming ELP depot can provide for sustained release of antibiotics with an effect that varies across antibiotic formulation. ELPs have important advantages for drug delivery, as they are known to be biocompatible, biodegradable, and elicit no known immune response. These benefits suggest distinct advantages over currently used carriers for antibiotic drug delivery in orthopedic applications. (c) 2008 Wiley Periodicals, Inc.
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Ha, Jing; Song, Ge; Ai, Lian-Feng; Li, Jian-Chen
2016-04-01
A new method using solid phase extraction (SPE) combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of six polyether antibiotics, including lasalocid, salinomycin, monensin, narasin, madubamycin and nigericin residues, in foods of animal origin. The samples were extracted with acetonitrile and purified by ENVI-Carb SPE columns after comparing the impurity effect and maneuverability of several SPE cartridges. Subsequently, the analytes were separated on a Hypersil Gold column (2.1×150mm, 5μm) and analyzed by MS/MS detection. The limit of quantization (LOQ) for milk and chicken was 0.4μg/kg, and for chicken livers and eggs, it was 1μg/kg. The linearity was satisfactory with a correlation coefficient of >0.9995 at concentrations ranging from 2 to 100μg/L. The average recoveries of the analytes fortified at three levels ranged from 68.2 to 114.3%, and the relative standard deviations ranged from 4.5 to 12.1%. The method was suitable for quantitative analysis and confirmation of polyether antibiotic residues in foods of animal origin. Copyright © 2016 Elsevier B.V. All rights reserved.
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Hong, Pei-Ying; Al-Jassim, Nada; Ansari, Mohd Ikram; Mackie, Roderick I.
2013-01-01
Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water. PMID:27029309
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Directory of Open Access Journals (Sweden)
Roderick I. Mackie
2013-07-01
Full Text Available Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.
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Hong, Pei-Ying; Aljassim, Nada I.; Ansari, Mohd Ikram; Mackie, Roderick
2013-01-01
Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.
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Hong, Pei-Ying
2013-07-31
Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.
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The U.S. Food and Drug Administration sets tolerances for veterinary drug residues in muscle, but does not specify which type of muscle should be analyzed. In order to determine if antibiotic residue levels are dependent on muscle type, 7 culled dairy cows were dosed with Penicillin G (Pen G) from ...
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Directory of Open Access Journals (Sweden)
Weiwei Ye
2017-05-01
Full Text Available The wide abuse of antibiotics has accelerated bacterial multiresistance, which means there is a need to develop tools for rapid detection and characterization of bacterial response to antibiotics in the management of infections. In the study, an electrochemical biosensor based on nanoporous alumina membrane and graphene quantum dots (GQDs was developed for bacterial response to antibiotics detection. Anti-Salmonella antibody was conjugated with amino-modified GQDs by glutaraldehyde and immobilized on silanized nanoporous alumina membranes for Salmonella bacteria capture. The impedance signals across nanoporous membranes could monitor the capture of bacteria on nanoporous membranes as well as bacterial response to antibiotics. This nanoporous membrane and GQD-based electrochemical biosensor achieved rapid detection of bacterial response to antibiotics within 30 min, and the detection limit could reach the pM level. It was capable of investigating the response of bacteria exposed to antibiotics much more rapidly and conveniently than traditional tools. The capability of studying the dynamic effects of antibiotics on bacteria has potential applications in the field of monitoring disease therapy, detecting comprehensive food safety hazards and even life in hostile environment.
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McKinney, C.W.; Loftin, K.A.; Meyer, M.T.; Davis, J.G.; Pruden, A.
2010-01-01
Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and su/(II)] ARGsin a broad cross-section of livestock lagoons within the same semiarid western watershed. ARGs were monitored for one year in the water and the settled solids of eight lagoon systems by quantitative polymerase chain reaction. In addition, antibiotic residues and various bulk water quality constituents were analyzed. It was found that the lagoons of the chicken layer operation had the lowest concentrations of both tet and sul ARGs and low total antibiotic concentrations, whereas su ARGs were highest in the swine lagoons, which generally corresponded to the highest total antibiotic concentrations. A marginal benefit of organic and small dairy operations also was observed compared to conventional and large dairies, respectively. In all lagoons, su ARGs were observed to be generally more recalcitrant than tet ARGs. Also, positive correlations of various bulk water quality constituents were identified with tet ARGs but not sul ARGs. Significant positive correlations were identified between several metals and tet ARGs, but Pearson's correlation coefficients were mostly lower than those determined between antibiotic residues and ARGs. This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities. ?? 2010 American Chemical Society.
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Microbial endogenous response to acute inhibitory impact of antibiotics.
Pala-Ozkok, I; Kor-Bicakci, G; Çokgör, E U; Jonas, D; Orhon, D
2017-06-13
Enhanced endogenous respiration was observed as the significant/main response of the aerobic microbial culture under pulse exposure to antibiotics: sulfamethoxazole, tetracycline and erythromycin. Peptone mixture and acetate were selected as organic substrates to compare the effect of complex and simple substrates. Experiments were conducted with microbial cultures acclimated to different sludge ages of 10 and 2 days, to visualize the effect of culture history. Evaluation relied on modeling of oxygen uptake rate profiles, reflecting the effect of all biochemical reactions associated with substrate utilization. Model calibration exhibited significant increase in values of endogenous respiration rate coefficient with all antibiotic doses. Enhancement of endogenous respiration was different with antibiotic type and initial dose. Results showed that both peptone mixture and acetate cultures harbored resistance genes against the tested antibiotics, which suggests that biomass spends cellular maintenance energy for activating the required antibiotic resistance mechanisms to survive, supporting higher endogenous decay rates. [Formula: see text]: maximum growth rate for X H (day -1 ); K S : half saturation constant for growth of X H (mg COD/L); b H : endogenous decay rate for X H (day -1 ); k h : maximum hydrolysis rate for S H1 (day -1 ); K X : hydrolysis half saturation constant for S H1 (mg COD/L); k hx : maximum hydrolysis rate for X S1 (day -1 ); K XX : hydrolysis half saturation constant for X S1 (mg COD/L); k STO : maximum storage rate of PHA by X H (day -1 ); [Formula: see text]: maximum growth rate on PHA for X H (day -1 ); K STO : half saturation constant for storage of PHA by X H (mg COD/L); X H1 : initial active biomass (mg COD/L).
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Bacteriocins - exploring alternatives to antibiotics in mastitis treatment.
Pieterse, Reneé; Todorov, Svetoslav D
2010-07-01
Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease.
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International Nuclear Information System (INIS)
Hu Xiangang; Zhou Qixing; Luo Yi
2010-01-01
The residue of antibiotics is becoming an intractable environmental problem in many organic vegetable bases. However, their residual levels and distribution are still obscure. This work systematically analyzed the occurrence and migration of typical veterinary antibiotics in organic vegetable bases, northern China. The results showed that there was no obvious geographical difference in antibiotic distribution between soil and manure. A simple migration model can be easy and quick to predict the accumulation of antibiotics in soil. Antibiotics were mainly taken up through water transport and passive absorption in vegetables. The distribution of antibiotics in a plant was in the sequence leaf > stem > root, and performed biological accumulation. The residues of antibiotics in all samples in winter were significantly higher than those in summer. Overall, this work can lay the foundation for understanding ecological risk of antibiotics and their potential adverse effects on human health by food chain. - The residues of typical veterinary antibiotics from manure were detected and migrated in soil, vegetables and groundwater of organic vegetable bases.
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Behavior of antibiotics and antibiotic resistance genes in eco-agricultural system: A case study
International Nuclear Information System (INIS)
Cheng, Weixiao; Li, Jianan; Wu, Ying; Xu, Like; Su, Chao; Qian, Yanyun; Zhu, Yong-Guan; Chen, Hong
2016-01-01
Highlights: • TetQ had the highest relative abundance and tetG was the most persistent gene. • The anaerobic digestion has no effective removal of most ARGs. • The abundance of ARGs in soils and fishpond was higher than that of control system. • Positive correlations were observed between the total ARGs and TN, TP and TOC. - Abstract: This study aims to determine abundance and persistence of antibiotics and antibiotic resistance genes (ARGs) in eco-agricultural system (EAS), which starts from swine feces to anaerobic digestion products, then application of anaerobic digestion solid residue (ADSR) and anaerobic digestion liquid residue (ADLR) to the soil to grow ryegrass, one of swine feed. Oxytetracycline had the highest concentration in manure reaching up to 138.7 mg/kg. Most of antibiotics could be effectively eliminated by anaerobic digestion and removal rates ranged from 11% to 86%. ARGs abundance fluctuated within EAS. TetQ had the highest relative abundance and the relative abundance of tetG had the least variation within the system, which indicates that tetG is persistent in the agricultural environment and requires more attention. Compared to the relative abundance in manure, tetC and tetM increased in biogas residue while three ribosomal protection proteins genes (tetO, tetQ, tetW) decreased (p 0.05). Most ARGs in downstream components (soils and fishpond) of EAS showed significantly higher relative abundance than the control agricultural system (p < 0.05), except for tetG and sulI.
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Bohm, Detlef A; Stachel, Carolin S; Gowik, Petra
2012-07-01
The presented multi-method was developed for the confirmation of 37 antibiotic substances from the six antibiotic groups: macrolides, lincosamides, quinolones, tetracyclines, pleuromutilines and diamino-pyrimidine derivatives. All substances were analysed simultaneously in a single analytical run with the same procedure, including an extraction with buffer, a clean-up by solid-phase extraction, and the measurement by liquid chromatography tandem mass spectrometry in ESI+ mode. The method was validated on the basis of an in-house validation concept with factorial design by combination of seven factors to check the robustness in a concentration range of 5-50 μg kg(-1). The honeys used were of different types with regard to colour and origin. The values calculated for the validation parameters-decision limit CCα (range, 7.5-12.9 μg kg(-1)), detection capability CCβ (range, 9.4-19.9 μg kg(-1)), within-laboratory reproducibility RSD(wR) (tylvalosin with 21.4 %), repeatability RSD(r) (tylvalosin with 21.1%), and recovery (range, 92-106%)-were acceptable and in agreement with the criteria of Commission Decision 2002/657/EC. The validation results showed that the method was applicable for the residue analysis of antibiotics in honey to substances with and without recommended concentrations, although some changes had been tested during validation to determine the robustness of the method.
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Mathieu, Aurélie; Fleurier, Sébastien; Frénoy, Antoine; Dairou, Julien; Bredeche, Marie-Florence; Sanchez-Vizuete, Pilar; Song, Xiaohu; Matic, Ivan
2016-09-27
A better understanding of the impact of antibiotics on bacteria is required to increase the efficiency of antibiotic treatments and to slow the emergence of resistance. Using Escherichia coli, we examined how bacteria exposed to sublethal concentrations of ampicillin adjust gene expression patterns and metabolism to simultaneously deal with the antibiotic-induced damage and maintain rapid growth. We found that the treated cells increased energy production, as well as translation and macromolecular repair and protection. These responses are adaptive, because they confer increased survival not only to lethal ampicillin treatment but also to non-antibiotic lethal stresses. This robustness is modulated by nutrient availability. Because different antibiotics and other stressors induce the same set of responses, we propose that it constitutes a general core hormetic stress response. It is plausible that this response plays an important role in the robustness of bacteria exposed to antibiotic treatments and constant environmental fluctuations in natural environments. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
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Multiclass determination and confirmation of antibiotic residues in honey using LC-MS/MS.
Lopez, Mayda I; Pettis, Jeffery S; Smith, I Barton; Chu, Pak-Sin
2008-03-12
A multiclass method has been developed for the determination and confirmation in honey of tetracyclines (chlortetracycline, doxycycline, oxytetracycline, and tetracycline), fluoroquinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, and sarafloxacin), macrolides (tylosin), lincosamides (lincomycin), aminoglycosides (streptomycin), sulfonamides (sulfathiazole), phenicols (chloramphenicol), and fumagillin residues using liquid chromatography tandem mass spectrometry (LC-MS/MS). Erythromycin (a macrolide) and monensin (an ionophore) can be detected and confirmed but not quantitated. Honey samples (approximately 2 g) are dissolved in 10 mL of water and centrifuged. An aliquot of the supernatant is used to determine streptomycin. The remaining supernatant is filtered through a fine-mesh nylon fabric and cleaned up by solid phase extraction. After solvent evaporation and sample reconstitution, 15 antibiotics are assayed by LC-MS/MS using electrospray ionization (ESI) in positive ion mode. Afterward, chloramphenicol is assayed using ESI in negative ion mode. The method has been validated at the low part per billion levels for most of the drugs with accuracies between 65 and 104% and coefficients of variation less than 17%. The evaluation of matrix effects caused by honey of different floral origin is presented.
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Bacteriocins: exploring alternatives to antibiotics in mastitis treatment
Directory of Open Access Journals (Sweden)
Reneé Pieterse
2010-10-01
Full Text Available Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease.
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Antimicrobial residues in tissues and eggs of laying hens at Chittagong, Bangladesh
Directory of Open Access Journals (Sweden)
Ariful Islam
2016-12-01
Full Text Available Aim: Antimicrobial residue in animal food products is an important index of food safety. Antimicrobial residues could result from chemotherapeutic or chemoprophylactic use of drugs in food animals. This occurrence of residue in animal food products has received enormous worldwide attention from some local, international, and public health agencies. A crosssectional study was conducted from July to December 2009 to detect the antibiotic residues in tissues and eggs of laying hens at Chittagong of Bangladesh. Materials and Methods: Microbial inhibition test (MIT and thin layer chromatography (TLC methods were used to detect antibacterial residues in poultry tissues (liver, kidney, breast, and thigh muscles and eggs. The bacteria and pH of the MIT method were as follows: Bacillus subtilis on test agar medium with a pH of 7.2, Bacillus cereus with a pH of 6.0, and Escherichia coli at pH with an 8.0. Results: The overall prevalence of antibiotic residues detected by MIT was 64% in liver, 63% in kidney, 56% in breast muscle, 50% in thigh muscle, and 60% in eggs. There was significant variation in results between MIT and TLC (p<0.05. Tetracycline residues were found in 48% in liver, 24% in kidneys, 20% in thigh muscles, 26% in breast muscles, and 36% in eggs. Ciprofloxacin residues were found 46% in liver, 42% in kidneys, 34% in thigh muscles, 30% in breast muscles, and 30% in eggs. Enrofloxacin residues were found 40% in livers, 36% in kidneys, 24% in thigh muscles, 20% in breast muscles, and 26% in eggs. Amoxicillin residues were found 48% in livers, 30% in kidneys, 26% in thigh muscles, 22% in breast muscles, and 24% in eggs. The most frequently detected antibiotic residues by both MIT and TLC were found in liver tissue, tetracycline (48%, ciprofloxacin (46%, enrofloxacin (40%, and amoxicillin (42% were found in liver. Breast muscle tissue was least likely to contain antibiotic residues (24%. Tetracycline (p=0.01 and amoxicillin (p=0.03 residues had
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DEFF Research Database (Denmark)
Munck, Christian
morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...... of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I...... to rationally design drug combinations that limit the evolution of antibiotic resistance due to counteracting evolutionary trajectories. My results highlight that an in-depth knowledge about the genetic responses to the individual antimicrobial compounds enables the prediction of responses to drug combinations...
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Semedo, M.; Song, B.; Sparrer, T.; Crozier, C.; Tobias, C. R.; Phillips, R. L.
2015-12-01
Agroecosystems are major contributors of nitrous oxide (N2O) emissions. Denitrification and nitrification are the primary pathways of N2O emission in soils. However, there is uncertainty regarding the organisms responsible for N2O production. Bacteria were previously considered the only microbial N2O source, however, current studies indicate that fungi also produce N2O by denitrification. Denitrifying bacteria can be a source or sink of N2O depending on the presence and expression of nitrous oxide reductase genes (nosZ), encoding for the enzyme converting N2O to N2. Fungal denitrification may produce only N2O as an end product due to missing the nosZ gene. Animal manures applied to agricultural fields can transfer antibiotics to soils as a result of antibiotic use in the livestock industry. These antibiotics target mostly bacteria and may promote fungal growth. The growth inhibition of denitrifying bacteria may favor fungal denitrifiers potentially enhancing N2O emissions. Our objective is to examine the effects of antibiotic exposure and manure fertilization on the microbial communities responsible for N2 and N2O production in grasslands. Soil slurry incubations were conducted with tetracycline at different concentrations. A mesocosm experiment was also performed with soil cores exposed to tetracycline and cow manure. Production of N2O and N2 was measured using gas chromatography with electron capture detector (GC-ECD) and isotope ratio mass spectrometry (IRMS), respectively. Antibiotic inhibition of soil N2 production was found to be dose dependent, reaching up to 80% inhibition with 1g Kg-1 of tetracycline treatment, while N2O production was enhanced up to 8 times. These results suggest higher fungal denitrification with a concomitant decrease in bacterial denitrification after antibiotic exposure. We also found higher N2O fluxes in the soil mesocosms treated with manure plus tetracycline. Quantitative PCR (qPCR) will be conducted to examine the changes in
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Chlortetracycline and Oxytetracycline Residues in Poultry Tissues and Eggs
Meredith, W. E.; Weiser, H. H.; Winter, A. R.
1965-01-01
A pad-plate method of assaying residual amounts of chlortetracycline (CTC) and oxytetracycline (OTC) using Bacillus cereus 213 was used to determine amounts of antibiotic left in tissues and eggs of poultry fed 1,000 and 200 ppm of CTC and OTC in basal feed mixtures. The effects of various methods of cooking the tissues and eggs and the potentiating effect of terephthalic acid (TPA) were studied. It was found that normal methods of roasting, frying, and autoclaving poultry tissue destroyed all residual CTC and OTC, even with the potentiating effect of TPA. The largest amounts of residual antibiotic were found in the liver, then breast, and then thigh tissue when assayed for CTC. Tissue assays for CTC revealed that it was not taken up as extensively as CTC and the largest amounts were found in the liver, then breast. OTC residue was seldom found in the thigh tissue. Terephthalic acid in 0.5% concentration increased the concentration found in all cases. Cooking by poaching and scrambling eggs did not destroy the antibiotic in all cases. PMID:14264853
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Presence and biological activity of antibiotics used in fuel ethanol and corn co-product production.
Compart, D M Paulus; Carlson, A M; Crawford, G I; Fink, R C; Diez-Gonzalez, F; Dicostanzo, A; Shurson, G C
2013-05-01
Antibiotics are used in ethanol production to control bacteria from competing with yeast for nutrients during starch fermentation. However, there is no published scientific information on whether antibiotic residues are present in distillers grains (DG), co-products from ethanol production, or whether they retain their biological activity. Therefore, the objectives of this study were to quantify concentrations of various antibiotic residues in DG and determine whether residues were biologically active. Twenty distillers wet grains and 20 distillers dried grains samples were collected quarterly from 9 states and 43 ethanol plants in the United States. Samples were analyzed for DM, CP, NDF, crude fat, S, P, and pH to describe the nutritional characteristics of the samples evaluated. Samples were also analyzed for the presence of erythromycin, penicillin G, tetracycline, tylosin, and virginiamycin M1, using liquid chromatography and mass spectrometry. Additionally, virginiamycin residues were determined, using a U.S. Food and Drug Administration-approved bioassay method. Samples were extracted and further analyzed for biological activity by exposing the sample extracts to 10(4) to 10(7) CFU/mL concentrations of sentinel bacterial strains Escherichia coli ATCC 8739 and Listeria monocytogenes ATCC 19115. Extracts that inhibited bacterial growth were considered to have biological activity. Physiochemical characteristics varied among samples but were consistent with previous findings. Thirteen percent of all samples contained low (≤1.12 mg/kg) antibiotic concentrations. Only 1 sample extract inhibited growth of Escherichia coli at 10(4) CFU/mL, but this sample contained no detectable concentrations of antibiotic residues. No extracts inhibited Listeria monocytogenes growth. These data indicate that the likelihood of detectable concentrations of antibiotic residues in DG is low; and if detected, they are found in very low concentrations. The inhibition in only 1 DG
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Dietary risk ranking for residual antibiotics in cultured aquatic products around Tai Lake, China.
Song, Chao; Li, Le; Zhang, Cong; Qiu, Liping; Fan, Limin; Wu, Wei; Meng, Shunlong; Hu, Gengdong; Chen, Jiazhang; Liu, Ying; Mao, Aimin
2017-10-01
Antibiotics are widely used in aquaculture and therefore may be present as a dietary risk in cultured aquatic products. Using the Tai Lake Basin as a study area, we assessed the presence of 15 antibiotics in 5 widely cultured aquatic species using a newly developed dietary risk ranking approach. By assigning scores to each factor involved in the ranking matrices, the scores of dietary risks per antibiotic and per aquatic species were calculated. The results indicated that fluoroquinolone antibiotics posed the highest dietary risk in all aquatic species. Then, the total scores per aquatic species were summed by all 15 antibiotic scores of antibiotics, it was found that Crab (Eriocheir sinensis) had the highest dietary risks. Finally, the most concerned antibiotic category and aquatic species were selected. This study highlighted the importance of dietary risk ranking in the production and consumption of cultured aquatic products around Tai Lake. Copyright © 2017 Elsevier Inc. All rights reserved.
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Behavior of antibiotics and antibiotic resistance genes in eco-agricultural system: A case study
Energy Technology Data Exchange (ETDEWEB)
Cheng, Weixiao; Li, Jianan; Wu, Ying; Xu, Like; Su, Chao; Qian, Yanyun [Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhu, Yong-Guan [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Hong, E-mail: chen_hong@zju.edu.cn [Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)
2016-03-05
Highlights: • TetQ had the highest relative abundance and tetG was the most persistent gene. • The anaerobic digestion has no effective removal of most ARGs. • The abundance of ARGs in soils and fishpond was higher than that of control system. • Positive correlations were observed between the total ARGs and TN, TP and TOC. - Abstract: This study aims to determine abundance and persistence of antibiotics and antibiotic resistance genes (ARGs) in eco-agricultural system (EAS), which starts from swine feces to anaerobic digestion products, then application of anaerobic digestion solid residue (ADSR) and anaerobic digestion liquid residue (ADLR) to the soil to grow ryegrass, one of swine feed. Oxytetracycline had the highest concentration in manure reaching up to 138.7 mg/kg. Most of antibiotics could be effectively eliminated by anaerobic digestion and removal rates ranged from 11% to 86%. ARGs abundance fluctuated within EAS. TetQ had the highest relative abundance and the relative abundance of tetG had the least variation within the system, which indicates that tetG is persistent in the agricultural environment and requires more attention. Compared to the relative abundance in manure, tetC and tetM increased in biogas residue while three ribosomal protection proteins genes (tetO, tetQ, tetW) decreased (p < 0.05), with other genes showing no significant change after anaerobic fermentation (p > 0.05). Most ARGs in downstream components (soils and fishpond) of EAS showed significantly higher relative abundance than the control agricultural system (p < 0.05), except for tetG and sulI.
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Jenks, Daniel B; Ehrlich, Ygal; Spolnik, Kenneth; Gregory, Richard L; Yassen, Ghaeth H
2016-10-01
We investigated the residual antibiofilm effects of different concentrations of double antibiotic paste (DAP) applied on radicular dentin for 1 or 4 weeks. Dentin samples were prepared (n=120), sterilized and pretreated for 1 or 4 weeks with the clinically used concentration of DAP (500mg/mL), low concentrations of DAP (1, 5 or 50mg/mL) loaded into a methylcellulose system, calcium hydroxide (Ca(OH) 2 ), or placebo paste. After the assigned treatment time, treatment pastes were rinsed off and the samples were kept independently in phosphate buffered saline for 3 weeks. Pretreated dentin samples were then inoculated with Enterococcus faecalis and bacterial biofilms were allowed to grow for an additional 3 weeks. Biofilms were then retrieved from dentin using biofilm disruption assays, diluted, spiral plated, and quantified. Fisher's Exact and Wilcoxon rank sum tests were used for statistical comparisons (α=0.05). Dentin pretreatment for 4 weeks with 5, 50 or 500mg/mL of DAP demonstrated significantly higher residual antibiofilm effects and complete eradication of E. faecalis biofilms in comparison to a 1 week pretreatment with similar concentrations. However, dentin pretreated with 1mg/mL of DAP or Ca(OH) 2 did not provide a substantial residual antibiofilm effect regardless of the application time. Dentin pretreatment with 5mg/mL of DAP or higher for 4 weeks induced significantly higher residual antibiofilm effects in comparison to a 1 week pretreatment with the same concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Heather K Allen
Full Text Available Functional metagenomic analysis of soil metagenomes is a method for uncovering as-yet unidentified mechanisms for antibiotic resistance. Here we report an unconventional mode by which a response regulator derived from a soil metagenome confers resistance to the β-lactam antibiotic carbenicillin in Escherichia coli. A recombinant clone (βlr16 harboring a 5,169 bp DNA insert was selected from a metagenomic library previously constructed from a remote Alaskan soil. The βlr16 clone conferred specific resistance to carbenicillin, with limited increases in resistance to other tested antibiotics, including other β-lactams (penicillins and cephalosporins, rifampin, ciprofloxacin, erythromycin, chloramphenicol, nalidixic acid, fusidic acid, and gentamicin. Resistance was more pronounced at 24°C than at 37°C. Zone-of-inhibition assays suggested that the mechanism of carbenicillin resistance was not due to antibiotic inactivation. The DNA insert did not encode any genes known to confer antibiotic resistance, but did have two putative open reading frames (ORFs that were annotated as a metallopeptidase and a two-component response regulator. Transposon mutagenesis and subcloning of the two ORFs followed by phenotypic assays showed that the response regulator gene was necessary and sufficient to confer the resistance phenotype. Quantitative reverse transcriptase PCR showed that the response regulator suppressed expression of the ompF porin gene, independently of the small RNA regulator micF, and enhanced expression of the acrD, mdtA, and mdtB efflux pump genes. This work demonstrates that antibiotic resistance can be achieved by the modulation of gene regulation by heterologous DNA. Functional analyses such as these can be important for making discoveries in antibiotic resistance gene biology and ecology.
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Bacteriocins – Exploring Alternatives to Antibiotics in Mastitis Treatment
Pieterse, Reneé; Todorov, Svetoslav D.
2010-01-01
Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease. PMID:24031528
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Boi, Paola; Manti, Anita; Pianetti, Anna; Sabatini, Luigia; Sisti, Davide; Rocchi, Marco Bruno; Bruscolini, Francesca; Galluzzi, Luca; Papa, Stefano
2015-01-01
In this study, we check for the presence of specific resistance genes by polymerase chain reaction (PCR) and then we used flow cytometry (FCM) to evaluate antibiotic-induced effects in different strains of Escherichia coli (E. coli). The presence of resistance genes was investigated by PCR in 10 strains of E. coli isolated from Foglia River. Bacterial responses to different antibiotics were also tested with FCM techniques by evaluating both the degree of decrease in viability and the light scatter changes in all of the strains. PCR revealed that only one strain exhibits the presence of one resistance gene. Despite this, analyses of strains using FCM evidenced the presence of viable subpopulations after antibiotic treatment. Furthermore, analyses of scatter signals revealed profound changes in the Forward Scatter and Side Scatter of the bacterial populations as a consequence of antibiotic exposure, confirming the viability and membrane potential data. The riverine strains were in general less sensitive to antibiotics than the reference strain (ATCC 25922). Antibiotic resistance is a widespread phenomena. The multiparametric approach based on FCM used in this study, providing results about different aspects (cell viability, membrane potential, light scatter changes), may overcome the limitation of PCR and could represent an adequate method for the evaluation of bacteria responses to antibiotic exposure. © 2014 International Clinical Cytometry Society.
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Directory of Open Access Journals (Sweden)
Federica Chiappori
Full Text Available DnaK, the bacterial homolog of human Hsp70, plays an important role in pathogens survival under stress conditions, like antibiotic therapies. This chaperone sequesters protein aggregates accumulated in bacteria during antibiotic treatment reducing the effect of the cure. Although different classes of DnaK inhibitors have been already designed, they present low specificity. DnaK is highly conserved in prokaryotes (identity 50-70%, which encourages the development of a unique inhibitor for many different bacterial strains. We used the DnaK of Acinetobacter baumannii as representative for our analysis, since it is one of the most important opportunistic human pathogens, exhibits a significant drug resistance and it has the ability to survive in hospital environments. The E.coli DnaK was also included in the analysis as reference structure due to its wide diffusion. Unfortunately, bacterial DnaK and human Hsp70 have an elevated sequence similarity. Therefore, we performed a differential analysis of DnaK and Hsp70 residues to identify hot spots in bacterial proteins that are not present in the human homolog, with the aim of characterizing the key pharmacological features necessary to design selective inhibitors for DnaK. Different conformations of DnaK and Hsp70 bound to known inhibitor-peptides for DnaK, and ineffective for Hsp70, have been analysed by molecular dynamics simulations to identify residues displaying stable and selective interactions with these peptides. Results achieved in this work show that there are some residues that can be used to build selective inhibitors for DnaK, which should be ineffective for the human Hsp70.
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Effect of Gamma Rays on Antibiotic Residues in Slaughtered Animals
International Nuclear Information System (INIS)
El Hifnawi, H.N.; Zahran, D.A.
2008-01-01
A modified 4-plate test was used to screen 200 meat and chicken tissue samples from retail outlets in Egypt. This test prescribes the use of a thin layer of agar medium which cause higher sensitivities for aqueous solutions of antibiotics.Inhibition zones were compared with those obtained by the standard solution. All examined samples were positive on the 4 plates seeded with Bacillus subtilis and Micrococcus luteus at different ph values. By exposure to gamma rays (1, 1.5 and 2 kGy) the inhibition zones obtained for all tested samples showed tendency towards decreasing the antibiotic concentrations when these samples were exposed to 1.5 and 2 kGy after 45 days post-irradiation storage
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Yoo, Ji-Sun; Oh, Gyeong-Seok; Ryoo, Sungweon; Roe, Jung-Hye
2016-01-01
Antibiotic-producing streptomycetes are rich sources of resistance mechanisms against endogenous and exogenous antibiotics. An ECF sigma factor ?R (SigR) is known to govern the thiol-oxidative stress response in Streptomyces coelicolor. Amplification of this response is achieved by producing an unstable isoform of ?R called ?R?. In this work, we present evidence that antibiotics induce the SigR regulon via a redox-independent pathway, leading to antibiotic resistance. The translation-inhibiti...
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Lin, Y. F.; Yannarell, A. C.; Mackie, R. I.; Krapac, I. G.; Chee-Sanford, J. S.; Koike, S.
2008-12-01
The use of antibiotics at concentrated animal feeding operations (CAFOs) for disease prevention, disease treatment, and growth promotion can contribute to the spread of antibiotic compounds, their breakdown products, and antibiotic resistant bacteria and/or the genes that confer resistance. In addition, constitutive use of antibiotics at sub-therapeutic levels can select for antibiotic resistance among the bacteria that inhabit animal intestinal tracts, onsite manure treatment facilities, and any environments receiving significant inputs of manure (e.g. through waste lagoon leakage or fertilizer amendments to farm soils). If the antibiotic resistant organisms persist in these new environments, or if they participate in genetic exchanges with the native microflora, then CAFOs may constitute a significant reservoir for the spread of antibiotic resistance to the environment at large. Our results have demonstrated that leakage from waste treatment lagoons can influence the presence and persistence of tetracycline resistance genes in the shallow aquifer adjacent to swine CAFOs, and molecular phylogeny allowed us to distinguish "native" tetracycline resistance genes in control groundwater wells from manure-associated genes introduced from the lagoon. We have also been able to detect the presence of erythromycin resistance genes in CAFO surface and groundwater even though erythromycin is strictly reserved for use in humans and thus is not utilized at any of these sites. Ongoing research, including modeling of particle transport in groundwater, will help to determine the potential spatial and temporal extent of CAFO-derived antibiotic resistance.
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Neut, D; van de Belt, H; van Horn, [No Value; van der Mei, HC; Busscher, HJ
In infected joint arthroplasty, high local levels of antibiotics are achieved through temporary implantation of non-biodegradable gentamicin-loaded polymethylmethacrylate beads. Despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow
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Ibrahim, Heba K; Abdel-Moety, Mona M; Abdel-Gawad, Sherif A; Al-Ghobashy, Medhat A; Kawy, Mohamed Abdel
2017-03-01
Realistic implementation of ion selective electrodes (ISEs) into environmental monitoring programs has always been a challenging task. This could be largely attributed to difficulties in validation of ISE assay results. In this study, the electrochemical response of amoxicillin trihydrate (AMX), ciprofloxacin hydrochloride (CPLX), trimethoprim (TMP), and norfloxacin (NFLX) was studied by the fabrication of sensitive membrane electrodes belonging to two types of ISEs, which are polyvinyl chloride (PVC) membrane electrodes and glassy carbon (GC) electrodes. Linear response for the membrane electrodes was in the concentration range of 10 -5 -10 -2 mol/L. For the PVC membrane electrodes, Nernstian slopes of 55.1, 56.5, 56.5, and 54.0 mV/decade were achieved over a pH 4-8 for AMX, CPLX, and NFLX, respectively, and pH 3-6 for TMP. On the other hand, for GC electrodes, Nernstian slopes of 59.1, 58.2, 57.0, and 58.2 mV/decade were achieved over pH 4-8 for AMX, CPLX, and NFLX, respectively, and pH 3-6 for TMP. In addition to assay validation to international industry standards, the fabricated electrodes were also cross-validated relative to conventional separation techniques; high performance liquid chromatography (HPLC), and thin layer chromatography (TLC)-densitometry. The HPLC assay was applied in concentration range of 0.5-10.0 μg/mL, for all target analytes. The TLC-densitometry was adopted over a concentration range of 0.3-1.0 μg/band, for AMX, and 0.1-0.9 μg/band, for CPLX, NFLX, and TMP. The proposed techniques were successfully applied for quantification of the selected drugs either in pure form or waste water samples obtained from pharmaceutical plants. The actual waste water samples were subjected to solid phase extraction (SPE) for pretreatment prior to the application of chromatographic techniques (HPLC and TLC-densitometry). On the other hand, the fabricated electrodes were successfully applied for quantification of the antibiotic residues in actual
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Antibiotics usefulness and choice in BPCO acute exacerbation
Bruno Tartaglino
2005-01-01
Although the debate on the role of bacterial infections and antibiotic treatment in AE-COPD remains open, there is evidence that the persistence of bacteria after acute exacerbation (residual bacterial colony) influences the frequency and severity of subsequent acute exacerbation and that antibiotic treatment that induces faster and more complete eradication produces better clinical outcomes. New aspects must now be considered, given that COPD is a chronic illness subject to acute exacerbatio...
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Evans, Scott R; Rubin, Daniel; Follmann, Dean; Pennello, Gene; Huskins, W Charles; Powers, John H; Schoenfeld, David; Chuang-Stein, Christy; Cosgrove, Sara E; Fowler, Vance G; Lautenbach, Ebbing; Chambers, Henry F
2015-09-01
Clinical trials that compare strategies to optimize antibiotic use are of critical importance but are limited by competing risks that distort outcome interpretation, complexities of noninferiority trials, large sample sizes, and inadequate evaluation of benefits and harms at the patient level. The Antibacterial Resistance Leadership Group strives to overcome these challenges through innovative trial design. Response adjusted for duration of antibiotic risk (RADAR) is a novel methodology utilizing a superiority design and a 2-step process: (1) categorizing patients into an overall clinical outcome (based on benefits and harms), and (2) ranking patients with respect to a desirability of outcome ranking (DOOR). DOORs are constructed by assigning higher ranks to patients with (1) better overall clinical outcomes and (2) shorter durations of antibiotic use for similar overall clinical outcomes. DOOR distributions are compared between antibiotic use strategies. The probability that a randomly selected patient will have a better DOOR if assigned to the new strategy is estimated. DOOR/RADAR represents a new paradigm in assessing the risks and benefits of new strategies to optimize antibiotic use. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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Directory of Open Access Journals (Sweden)
Dimitrios Bitas
2018-02-01
Full Text Available Milk-producing animals are typically kept stationary in overcrowded large-scale farms and in most cases under unsanitary conditions, which promotes the development of infections. In order to maintain sufficient health status among the herd or promote growth and increase production, farmers administer preventative antibiotic doses to the animals through their feed. However, many antibiotics used in cattle farms are intended for the treatment of bacterial infections in humans. This results in the development of antibiotic-resistant bacteria which pose a great risk for public health. Additionally, antibiotic residues are found in milk and dairy products, with potential toxic effects for the consumers. Hence the need of antibiotic residues monitoring in milk arises. Analytical methods were developed for the determination of antibiotics in milk, with key priority given to the analyte extraction and preconcentration step. Extraction can benefit from the production of molecularly imprinted polymers (MIPs that can be applied as sorbents for the extraction of specific antibiotics. This review focuses on the principals of molecular imprinting technology and synthesis methods of MIPs, as well as the application of MIPs and MIPs composites for the chromatographic determination of various antibiotic categories in milk found in the recent literature.
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Tantiyavarong, Pichaya; Traitanon, Opas; Chuengsaman, Piyatida; Patumanond, Jayanton; Tasanarong, Adis
2016-01-01
Background. Patients with peritoneal dialysis-related peritonitis usually have different responses to initial antibiotic treatment. This study aimed to explore the patterns of response by using the changes of dialysate white blood cell count on the first five days of the initial antibiotic treatment. Materials and Methods. A retrospective cohort study was conducted. All peritoneal dialysis-related peritonitis episodes from January 2014 to December 2015 were reviewed. We categorized the patterns of antibiotic response into 3 groups: early response, delayed response, and failure group. The changes of dialysate white blood cell count for each pattern were determined by multilevel regression analysis. Results. There were 644 episodes in 455 patients: 378 (58.7%) of early response, 122 (18.9%) of delayed response, and 144 (22.3%) of failure episodes. The patterns of early, delayed, and failure groups were represented by the average rate reduction per day of dialysate WBC of 68.4%, 34.0%, and 14.2%, respectively (p value patterns, which were categorized by types of responses, have variable rates of WBC declining. Clinicians should focus on the delayed response and failure patterns in order to make a decision whether to continue medical therapies or to aggressively remove the peritoneal catheter.
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Czech Academy of Sciences Publication Activity Database
Křen, Vladimír; Řezanka, Tomáš
2008-01-01
Roč. 32, č. 5 (2008), s. 858-889 ISSN 0168-6445 R&D Projects: GA MŠk(CZ) LC06010; GA AV ČR IAA400200503 Institutional research plan: CEZ:AV0Z50200510 Keywords : glycosides * sweet antibiotics * aglycone Subject RIV: CE - Biochemistry Impact factor: 7.963, year: 2008
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Current perspectives on the dynamics of antibiotic resistance in different reservoirs.
Caniça, Manuela; Manageiro, Vera; Jones-Dias, Daniela; Clemente, Lurdes; Gomes-Neves, Eduarda; Poeta, Patrícia; Dias, Elsa; Ferreira, Eugénia
2015-09-01
Antibiotic resistance consists of a dynamic web. In this review, we describe the path by which different antibiotic residues and antibiotic resistance genes disseminate among relevant reservoirs (human, animal, and environmental settings), evaluating how these events contribute to the current scenario of antibiotic resistance. The relationship between the spread of resistance and the contribution of different genetic elements and events is revisited, exploring examples of the processes by which successful mobile resistance genes spread across different niches. The importance of classic and next generation molecular approaches, as well as action plans and policies which might aid in the fight against antibiotic resistance, are also reviewed. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
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Siedlewicz, Grzegorz; Białk-Bielińska, Anna; Borecka, Marta; Winogradow, Aleksandra; Stepnowski, Piotr; Pazdro, Ksenia
2018-04-01
Concentrations of selected antibiotic compounds from different groups were measured in sediment samples (14 analytes) and in near-bottom water samples (12 analytes) collected in 2011-2013 from the southern Baltic Sea (Polish coastal zone). Antibiotics were determined at concentration levels of a few to hundreds of ng g -1 d.w. in sediments and ng L -1 in near-bottom waters. The most frequently detected compounds were sulfamethoxazole, trimethoprim, oxytetracycline in sediments and sulfamethoxazole and trimethoprim in near-bottom waters. The occurrence of the identified antibiotics was characterized by spatial and temporal variability. A statistically important correlation was observed between sediment organic matter content and the concentrations of sulfachloropyridazine and oxytetracycline. Risk assessment analyses revealed a potential high risk of sulfamethoxazole contamination in near-bottom waters and of contamination by sulfamethoxazole, trimethoprim and tetracyclines in sediments. Both chemical and risk assessment analyses show that the coastal area of the southern Baltic Sea is highly exposed to antibiotic residues. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Ju, Tingting; Shoblak, Yasmeen; Gao, Yanhua; Yang, Kaiyuan; Fouhse, Janelle; Finlay, B Brett; So, Yee Wing; Stothard, Paul; Willing, Benjamin P
2017-09-01
Antibiotics are important for treating bacterial infection; however, efficacies and side effects of antibiotics vary in medicine and experimental models. A few studies have correlated microbiota composition variations with health outcomes in response to antibiotics; however, no study has demonstrated causality. We had noted variation in colonic expression of C-type lectins, regenerating islet-derived protein 3β (Reg3β) and Reg3γ, after metronidazole treatment in a mouse model. To investigate the effects of specific variations in the preexisting microbiome on host response to antibiotics, mice harboring a normal microbiota were allocated to 4 treatments in a 2-by-2 factorial arrangement with or without commensal Escherichia coli and with or without metronidazole in drinking water. E. coli colonized readily without causing a notable shift in the microbiota or host response. Metronidazole administration reduced microbiota biodiversity, indicated by decreased Chao1 and Shannon index values, and altered microbiota composition. However, the presence of E. coli strongly affected metronidazole-induced microbiota shifts. Remarkably, this single commensal bacterium in the context of a complex population led to variations in host responses to metronidazole treatment, including increased expression of antimicrobial peptides Reg3β and Reg3γ and intestinal inflammation indicated by tumor necrosis factor alpha levels. Similar results were obtained from 2-week antibiotic exposure and with additional E. coli isolates. The results of this proof-of-concept study indicate that even minor variations in initial commensal microbiota can drive shifts in microbial composition and host response after antibiotic administration. As well as providing an explanation for variability in animal models using antibiotics, the findings encourage the development of personalized medication in antibiotic therapies. IMPORTANCE This work provides an understanding of variability in studies where
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Strategies to Minimize Antibiotic Resistance
Directory of Open Access Journals (Sweden)
Sang Hee Lee
2013-09-01
Full Text Available Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs and various data such as pharmacokinetic (PK and pharmacodynamic (PD properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST, clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care, the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing. The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics.
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Botanical alternatives to antibiotics for use in organic poultry production.
Diaz-Sanchez, Sandra; D'Souza, Doris; Biswas, Debrabrata; Hanning, Irene
2015-06-01
The development of antibiotic resistant pathogens has resulted from the use of sub-therapeutic concentrations of antibiotics delivered in poultry feed. Furthermore, there are a number of consumer concerns regarding the use of antibiotics in food animals including residue contamination of poultry products and antibiotic resistant bacterial pathogens. These issues have resulted in recommendations to reduce the use of antibiotics as growth promoters in livestock in the United States. Unlike conventional production, organic systems are not permitted to use antibiotics. Thus, both conventional and organic poultry production need alternative methods to improve growth and performance of poultry. Herbs, spices, and various other plant extracts are being evaluated as alternatives to antibiotics and some do have growth promoting effects, antimicrobial properties, and other health-related benefits. This review aims to provide an overview of herbs, spices, and plant extracts, currently defined as phytobiotics as potential feed additives. © 2015 Poultry Science Association Inc.
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Nicholson, Wayne L.; Fajardo-Cavazos, Patricia
2015-01-01
Comparisons of spaceflight stress responses in Bacillus subtilis spores and Staphylococcus epidermidis cells to ground-based controls will be conducted to uncover alterations in their antibiotic susceptibility.
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Torres-Barceló, Clara; Kojadinovic, Mila; Moxon, Richard; MacLean, R Craig
2015-10-07
Exposure to antibiotics induces the expression of mutagenic bacterial stress-response pathways, but the evolutionary benefits of these responses remain unclear. One possibility is that stress-response pathways provide a short-term advantage by protecting bacteria against the toxic effects of antibiotics. Second, it is possible that stress-induced mutagenesis provides a long-term advantage by accelerating the evolution of resistance. Here, we directly measure the contribution of the Pseudomonas aeruginosa SOS pathway to bacterial fitness and evolvability in the presence of sublethal doses of ciprofloxacin. Using short-term competition experiments, we demonstrate that the SOS pathway increases competitive fitness in the presence of ciprofloxacin. Continued exposure to ciprofloxacin results in the rapid evolution of increased fitness and antibiotic resistance, but we find no evidence that SOS-induced mutagenesis accelerates the rate of adaptation to ciprofloxacin during a 200 generation selection experiment. Intriguingly, we find that the expression of the SOS pathway decreases during adaptation to ciprofloxacin, and this helps to explain why this pathway does not increase long-term evolvability. Furthermore, we argue that the SOS pathway fails to accelerate adaptation to ciprofloxacin because the modest increase in the mutation rate associated with SOS mutagenesis is offset by a decrease in the effective strength of selection for increased resistance at a population level. Our findings suggest that the primary evolutionary benefit of the SOS response is to increase bacterial competitive ability, and that stress-induced mutagenesis is an unwanted side effect, and not a selected attribute, of this pathway. © 2015 The Authors.
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International Nuclear Information System (INIS)
Gesell, Jennifer; Zasloff, Michael; Opella, Stanley J.
1997-01-01
Magainin2 is a 23-residue antibiotic peptide that disrupts the ionic gradient across certain cell membranes. Two-dimensional 1H NMR spectroscopy was used to investigate the structure of the peptide in three of the membrane environments most commonly employed in biophysical studies. Sequence-specific resonance assignments were determined for the peptide in perdeuterated dodecylphosphocholine (DPC) and sodium dodecylsulfate micelles and confirmed for the peptide in 2,2,2-trifluoroethanol solution. The secondary structure is shown to be helical in all of the solvent systems. The NMR data were used as a set of restraints for a simulated annealing protocol that generated a family of three-dimensional structures of the peptide in DPC micelles, which superimposed best between residues 4 and 20. For these residues, the mean pairwise rms difference for the backbone atoms is 0.47 ± 0.10A from the average structure. The calculated peptide structures appear to be curved,with the bend centered at residues Phe12 and Gly13
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Directory of Open Access Journals (Sweden)
VDA Murarolli
2014-09-01
Full Text Available This study aimed to evaluate diets supplemented with prebiotic, probiotic and symbiotic as an alternative to antibiotics on the performance and immune response against the virus of Newcastle disease in broiler chickens. 1,400 one-day old male Cobb 500 chicks were raised until 42 days old in a completely randomized design with 2x2+1 factorial scheme with seven replications. The treatments were: diet without supplementation (base diet - BD, BD + prebiotic, BD + probiotic, BD + symbiotic (prebiotic + probiotic, and BD + antibiotic. The parameters evaluated were performance and antibody serum titers against Newcastle disease. No antibiotic effect was observed on performance. The symbiotic provided better results for weight gain and feed:gain ratio until 21 days old than isolated additives. At 28 days old, the broilers fed diets with prebiotic presented better feed: gain ratio. In the same period (28 d-old, there was an antibody production increase against the Newcastle disease virus in the group supplemented with prebiotic. It can be concluded that the utilization of symbiotic in broiler chickens' diets can substitute performance enhancing antibiotics. The inclusion of prebiotic in the diet improves feed: gain ratio at 1-28 days old. The chickens' immune response increases at 28 days against the Newcastle disease virus in the group supplemented with prebiotic.
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Samanidou, Victoria; Michaelidou, Katia; Kabir, Abuzar; Furton, Kenneth G
2017-06-01
Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Alavi, Nadali; Babaei, Ali Akbar; Shirmardi, Mohammad; Naimabadi, Abolfazl; Goudarzi, Gholamreza
2015-11-01
Tetracyclines (TCs), a class of antibiotics with a broad spectrum, are the most frequently used antibiotics in animal production. The major concern is that the widespread use of the antibiotics may lead to the emergence of new strains of bacteria that are resistant to these antibiotics. The objective of this study was to determine the residual levels of oxytetracycline and tetracycline in 80 animal manure samples that were collected from the livestock and poultry feedlots in Khuzestan Province. The residual levels of the antibiotics in the samples were extracted by using solid-phase extraction (SPE) method and subsequently were measured by liquid chromatography. Recoveries from the spiked poultry manure samples ranged from 65 to 113% for tetracycline and 86 to 132% for oxytetracycline. Relative standard deviations of the recoveries were less than 5.7% within the same day. Method detection limit (MDL) measured for oxytetracycline and tetracycline in the manure were 0.011 and 0.01 mg/kg, respectively. Analysis of the collected 50 chickens and 30 cow manure samples showed that the highest concentration of tetracycline was related to Behbahan City (5.36 mg/kg) and the lowest concentration was detected for Ramhormoz (0.05 mg/kg). The highest and lowest concentrations of oxytetracycline were respectively observed for Behbahan (13.77 mg/kg) and Ramhormoz (0.047 mg/kg). Based on the results, in chicken manure, there was significant statistical difference between the residual TC concentrations among five cities (p(value) oxytetracyclin (OTC) residual concentrations among five cities (p(value) > 0.05).
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Antibiotics in Canadian poultry productions and anticipated alternatives
Directory of Open Access Journals (Sweden)
Moussa Sory Diarra
2014-06-01
Full Text Available The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics in feed (growth promoters need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily spread within microbial communities. In Canada, poultry production involves more than 2,600 regulated chicken producers. There are several antibiotics approved as feed additives available for poultry farmers. Feed recipes and mixtures greatly vary geographically and from one farm to another, making links between use of a specific antibiotic feed additive and production yields or selection of specific antibiotic-resistant bacteria difficult to establish. Many on-farm studies have revealed the widespread presence of antibiotic-resistant bacteria in broiler chickens. While sporadic reports linked the presence of antibiotic-resistant organisms to the use of feed supplemented with antibiotics, no recent studies could clearly demonstrate the benefit of antimicrobial growth promoters on performance and production yields. With modern biosecurity and hygienic practices, there is a genuine concern that intensive utilization of antibiotics or use of antimicrobial growth promoters in feed might no longer be useful. Public pressure and concerns about food and environmental safety (antibiotic residues, antibiotic-resistant pathogens have driven researchers to actively look for alternatives to antibiotics. Some of the alternatives include pre- and probiotics, organic acids and essential oils. We will describe here the properties of some bioactive molecules, like those found in cranberry, which have shown interesting polyvalent antibacterial and immuno
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A preliminary study on the phytoremediation of antibiotic contaminated sediment.
Hoang, Thuy Thi Thanh; Tu, Loan Thi Cam; Le Nga, Phi; Dao, Quoc Phu
2013-01-01
In Vietnam's coastal wetlands, fluoroquinolones, a widely used class of antibiotics in shrimp farming, are frequently detected in sediments of former shrimp farms. This phenomenon could lead to negative impacts on the aquatic ecosystem, since the antibiotic residues could induce changes in the microorganism communities of the water body. The potential of native wetland plants (Acrostichum aureum L. and Rhizophora apiculata Blume Fl. Javae) for phytoremediation of fluoroquinolones (ciprofloxacin and norfloxacin) was investigated. The half-life for each antibiotic was estimated at approximately 10 days in the planted sediment. With respect to the accumulation of ciprofloxacin and norfloxacin in plants, these antibiotics were found mainly in roots. Antibiotic translocation from root to stem and leaves occurred at a low rate. The results showed that A. aureum and R. apiculata can be valuable for the phytoremediation of antibiotic-contaminated sediments. Additionally, the initialfindings of the presence of resistant bacteria indicated that bacteria could play a role in facilitating the phytodegradation.
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Schweitzer, V A; van Smeden, M; Postma, D F; Oosterheert, J J; Bonten, M J M; van Werkhoven, C H
2017-12-01
The Response Adjusted for Days of Antibiotic Risk (RADAR) statistic was proposed to improve the efficiency of trials comparing antibiotic stewardship strategies to optimize antibiotic use. We studied the behaviour of RADAR in a non-inferiority trial in which a β-lactam monotherapy strategy (n = 656) was non-inferior to fluoroquinolone monotherapy (n = 888) for patients with moderately severe community-acquired pneumonia. Patients were ranked according to clinical outcome, using five or eight categories, and antibiotic use. RADAR was calculated as the probability that the β-lactam group had a more favourable ranking than the fluoroquinolone group. To investigate the sensitivity of RADAR to detrimental clinical outcome we simulated increasing rates of 90-day mortality in the β-lactam group and performed the RADAR and non-inferiority analysis. The RADAR of the β-lactam group compared with the fluoroquinolone group was 60.3% (95% CI 57.9%-62.7%) using five and 58.4% (95% CI 56.0%-60.9%) using eight clinical outcome categories, all in favour of β-lactam. Sample sizes for RADAR were 38% (250/653) and 89% (580/653) of the non-inferiority sample size calculation, using five or eight clinical outcome categories, respectively. With simulated mortality rates, loss of non-inferiority of the β-lactam group occurred at a relative risk of 1.125 in the conventional analysis, whereas using RADAR the β-lactam group lost superiority at a relative risk of mortality of 1.25 and 1.5, with eight and five clinical outcome categories, respectively. RADAR favoured β-lactam over fluoroquinolone therapy for community-acquired pneumonia. Although RADAR required fewer patients than conventional non-inferiority analysis, the statistic was less sensitive to detrimental outcomes. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
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Huang, David T; Angus, Derek C; Chang, Chung-Chou H; Doi, Yohei; Fine, Michael J; Kellum, John A; Peck-Palmer, Octavia M; Pike, Francis; Weissfeld, Lisa A; Yabes, Jonathan; Yealy, Donald M
2017-08-29
Overuse of antibiotics is a major public health problem, contributing to growing antibiotic resistance. Procalcitonin has been reported to be commonly elevated in bacterial, but not viral infection. Multiple European trials found procalcitonin-guided care reduced antibiotic use in lower respiratory tract infection, with no apparent harm. However, applicability to US practice is limited due to trial design features impractical in the US, between-country differences, and residual safety concerns. The Procalcitonin Antibiotic Consensus Trial (ProACT) is a multicenter randomized trial to determine the impact of a procalcitonin antibiotic prescribing guideline, implemented with basic reproducible strategies, in US patients with lower respiratory tract infection. We describe the trial methods using the Consolidated Standards of Reporting Trials (CONSORT) framework, and the rationale for key design decisions, including choice of eligibility criteria, choice of control arm, and approach to guideline implementation. ClinicalTrials.gov NCT02130986 . Registered May 1, 2014.
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Peng, Xianzhi; Tan, Jianhua; Tang, Caiming; Yu, Yiyi; Wang, Zhendi
2008-01-01
A feasible method has been optimized to simultaneously determine multiclass antibiotic residues, including sulfonamides, fluoroquinolones, trimethoprim, and chloramphenicol in urban riverine water and wastewater by off-line solid phase extraction and high-performance liquid chromatography coupled with a diode-array ultraviolet detector and a fluorescence detector. Internal standard and standard addition methods were used in combination to identify and quantify these antibiotics to compensate for the matrix interference. The method quantification limits (MQLs) were determined to be 0.035 to 0.100 microg/L and 0.100 to 0.300 microg/L for the riverine water and wastewater, respectively. Recoveries of the investigated antibiotics ranged from 63 to 126%. Sulfamethoxazole was the most frequently detected antibiotic residue in Guangzhou section of the Major Pearl River, South China, with a maximum level of 0.510 microg/L. Fluoroquinolone antibiotics were relatively less detected with a maximum level of 0.459 microg/L. The maximum concentration of sulfamethoxazole reached 5.597 microg/L in the raw wastewater from a large-scale sewage treatment plant in Guangzhou city. Around 30% of sulfamethoxazole might survive the primary clarification and biotreatment processes in the sewage treatment plant. None of the investigated antibiotics have been found above MQLs in the final effluent after chlorine disinfection.
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Drug and chemical residues in domestic animals.
Mussman, H C
1975-02-01
Given the large number of chemical substances that may find their way into the food supply, a system is needed to monitor their presence. The U. S. Department of Agriculture's Meat and Poultry Inspection Program routinely tests for chemical residues in animals coming to slaughter. Pesticides, heavy metals, growth promotants (hormones and hormonelike agents), and antibiotics are included. Samples are taken statistically so that inferences as to national incidence of residues can be drawn. When a problem is identified, a more selective sampling is designed to help follow up on the initial regulatory action. In testing for pesticides, only DDT and dieldrin are found with any frequency and their levels are decreasing; violative residues of any chlorinated hydrocarbon are generally a result of an industrial accident rather than agricultural usage. Analyses for heavy metals have revealed detectable levels of mercury, lead, and others, but none at levels that are considered a health hazard. Of the hormone or hormonelike substances, only diethylstilbestrol has been a residue problem and its future is uncertain. The most extensive monitoring for veterinary drugs is on the antimicrobials, including sulfonamides, streptomycin, and the tetracycline group of antibiotics that constitute the bulk of the violations; their simultaneous use prophylactically and therapeutically has contributed to the problem in certain cases. A strong, well-designed user education program on proper application of pesticides, chemicals, and veterinary drugs appears to be one method of reducing the incidence of unwanted residues.
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Directory of Open Access Journals (Sweden)
Neil eSegil
2015-05-01
Full Text Available Aminoglycoside antibiotics are the drug of choice for treating many bacterial infections, but their administration results in hearing loss in nearly one fourth of the patients who receive them. Several biochemical pathways have been implicated in aminoglycoside antibiotic ototoxicity; however, little is known about how hair cells respond to aminoglycoside antibiotics at the transcriptome level. Here we have investigated the genome-wide response to the aminoglycoside antibiotic gentamicin. Using organotypic cultures of the perinatal organ of Corti, we performed RNA sequencing using cDNA libraries obtained from FACS-purified hair cells. Within 3 hours of gentamicin treatment, the messenger RNA level of more than three thousand genes in hair cells changed significantly. Bioinformatic analysis of these changes highlighted several known signal transduction pathways, including the JNK pathway and the NF-κB pathway, in addition to genes involved in the stress response, apoptosis, cell cycle control, and DNA damage repair. In contrast, only 698 genes, mainly involved in cell cycle and metabolite biosynthetic processes, were significantly affected in the non-hair cell population. The gene expression profiles of hair cells in response to gentamicin share a considerable similarity with those previously observed in gentamicin-induced nephrotoxicity. Our findings suggest that previously observed early responses to gentamicin in hair cells in specific signaling pathways are reflected in changes in gene expression. Additionally, the observed changes in gene expression of cell cycle regulatory genes indicate a disruption of the postmitotic state, which may suggest an alternative pathway regulating gentamicin-induced hair cell death. This work provides a more comprehensive view of aminoglycoside antibiotic ototoxicity, and thus contribute to identifying potential pathways or therapeutic targets to alleviate this important side effect of aminoglycoside
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Antibiotics, pediatric dysbiosis, and disease.
Vangay, Pajau; Ward, Tonya; Gerber, Jeffrey S; Knights, Dan
2015-05-13
Antibiotics are by far the most common medications prescribed for children. Recent epidemiological data suggests an association between early antibiotic use and disease phenotypes in adulthood. Antibiotic use during infancy induces imbalances in gut microbiota, called dysbiosis. The gut microbiome's responses to antibiotics and its potential link to disease development are especially complex to study in the changing infant gut. Here, we synthesize current knowledge linking antibiotics, dysbiosis, and disease and propose a framework for studying antibiotic-related dysbiosis in children. We recommend future studies into the microbiome-mediated effects of antibiotics focused on four types of dysbiosis: loss of keystone taxa, loss of diversity, shifts in metabolic capacity, and blooms of pathogens. Establishment of a large and diverse baseline cohort to define healthy infant microbiome development is essential to advancing diagnosis, interpretation, and eventual treatment of pediatric dysbiosis. This approach will also help provide evidence-based recommendations for antibiotic usage in infancy. Copyright © 2015 Elsevier Inc. All rights reserved.
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Microbial screening methods for detection of antibiotic residues in slaughter animals
Pikkemaat, M.G.
2009-01-01
Monitoring of food products from animal origin for the presence of antimicrobial residues is preferably done using microbial screening methods because of their high cost-effectiveness. Traditionally applied methods fail to detect the maximum residue limits which were established when EU Council
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Mechanisms of Antibiotic Resistance
Munita, Jose M.; Arias, Cesar A.
2015-01-01
Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have emerged not only in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic “attack” is the prime example of bacterial adaptation and the pinnacle of evolution. “Survival of the fittest” is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice providing specific examples in relevant bacterial pathogens. PMID:27227291
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International Nuclear Information System (INIS)
Zhu, Xiangdong; Yang, Shijun; Wang, Liang; Liu, Yuchen; Qian, Feng; Yao, Wenqing; Zhang, Shicheng; Chen, Jianmin
2016-01-01
Antibiotic mycelial fermentation residues (AMFRs), which are emerging solid pollutants, have been recognized as hazardous waste in China since 2008. Nitrogen (N), which is an environmental sensitivity element, is largely retained in AMFR samples derived from fermentation substrates. Pyrolysis is a promising technology for the treatment of solid waste. However, the outcomes of N element during the pyrolysis of AMFRs are still unknown. In this study, the conversion of N element during the pyrolysis of AMFRs was tracked using XPS (X-ray photoelectron spectroscopy) and online TG-FTIR-MS (Thermogravimetry-Fourier transform infrared-Mass spectrometry) technology. In the AMFR sample, organic amine-N, pyrrolic-N, protein-N, pyridinic-N, was the main N-containing species. XPS results indicated that pyrrolic-N and pyridinic-N were retained in the AMFR-derived pyrolysis char. More stable species, such as N-oxide and quaternary-N, were also produced in the char. TG-FTIR-MS results indicated that NH_3 and HCN were the main gaseous species, and their contents were closely related to the contents of amine-N and protein-N, and pyrrolic-N and pyridinic-N of AMFRs, respectively. Increases in heating rate enhanced the amounts of NH_3 and HCN, but had less of an effect on the degradation degree of AMFRs. N-containing organic compounds, including amine-N, nitrile-N and heterocyclic-N, were discerned from the AMFR pyrolysis process. Their release range was extended with increasing of heating rate and carbon content of AMFR sample. This work will help to take appropriate measure to reduce secondary pollution from the treatment of AMFRs. - Highlights: • Hazardous AMFR material was treated by slow pyrolysis reaction. • TG-FTIR-MS were used to study the N conversion for pyrolysis gas and bio-oil. • NH_3 and HCN were observed as the main N-containing gas species. • XPS were used to study the N conversion for pyrolysis char. • Stable species, such as N-oxide and quaternary-N, were
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Liu, Xiaoxing; Xie, Shuyu; Ni, Tengteng; Chen, Dongmei; Wang, Xu; Pan, Yuanhu; Wang, Yulian; Huang, Lingli; Cheng, Guyue; Qu, Wei; Liu, Zhenli; Tao, Yanfei; Yuan, Zonghui
2017-06-01
Carbon nanotubes-magnetic nanoparticles, comprising ferroferric oxide nanoparticles and carbon nanotubes, were prepared through a simple one-step synthesis method and subsequently applied to magnetic solid-phase extraction for the determination of polyether antibiotic and s-triazine drug residues in animal food coupled with liquid chromatography with tandem mass spectrometry. The nanocomposites were characterized by transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The components within the nanocomposites endowed the material with high extraction performance and manipulative convenience. Compared with carbon nanotubes, the as-prepared carbon nanotubes-magnetic nanoparticles showed better extraction and separation efficiencies for polyether antibiotics and s-triazine drugs thanks to the contribution of the iron-containing magnetic nanoparticles. Various experimental parameters affecting the extraction efficiency had been investigated in detail. Under the optimal conditions, the good linearity ranging from 1 to 200 μg/kg for diclazuril, toltrazuril, toltrazuril sulfone, lasalocid, monensin, salinomycin, narasin, nanchangmycin, and maduramicin, low limits of detection ranging from 1 to 5 μg/kg, and satisfactory spiked recoveries (77.1-91.2%, with the inter relative standard deviation values from 4.0 to 12.2%) were shown. It was confirmed that this novel method was an efficient pretreatment and enrichment procedure and could be successfully applied for extraction and determination of polyether and s-triazine drug residues in complex matrices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Antibiotic research and development: business as usual?
Harbarth, S; Theuretzbacher, U; Hackett, J
2015-01-01
The global burden of antibiotic resistance is tremendous and, without new anti-infective strategies, will continue to increase in the coming decades. Despite the growing need for new antibiotics, few pharmaceutical companies today retain active antibacterial drug discovery programmes. One reason is that it is scientifically challenging to discover new antibiotics that are active against the antibiotic-resistant bacteria of current clinical concern. However, the main hurdle is diminishing economic incentives. Increased global calls to minimize the overuse of antibiotics, the cost of meeting regulatory requirements and the low prices of currently marketed antibiotics are strong deterrents to antibacterial drug development programmes. New economic models that create incentives for the discovery of new antibiotics and yet reconcile these incentives with responsible antibiotic use are long overdue. DRIVE-AB is a €9.4 million public-private consortium, funded by the EU Innovative Medicines Initiative, that aims to define a standard for the responsible use of antibiotics and to develop, test and recommend new economic models to incentivize investment in producing new anti-infective agents. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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Yan, Caixia; Yang, Yi; Zhou, Junliang; Liu, Min; Nie, Minghua; Shi, Hao; Gu, Lijun
2013-04-01
The occurrence and distribution of five groups of antibiotics were investigated in the surface water of Yangtze Estuary over four seasons. Of the 20 antibiotics, only sulfamerazine was not detected at all sampling sites, indicating widespread occurrence of antibiotic residues in the study area. Detection frequencies and concentrations of antibiotics were generally higher in January, indicating that low flow conditions and low temperature might enhance the persistence of antibiotics in water. Antibiotic levels varied with location, with the highest concentrations being observed around river discharge and sewage outfall. Furthermore, a positive correlation between total antibiotic and DOC concentrations revealed the significant role played by DOC. Risk assessment based on single compound exposure showed that sulfapyridine and sulfamethoxazole could cause medium risk to daphnid in the Yangtze Estuary. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Electromagnetic interactions between antibiotics and bacteria
Abdul-Moqueet, Mohammad M.
The effect of weak electromagnetic fields on the interaction of the antibiotic erythromycin on E.coli has been studied. Erythromycin is a first derivative antibiotic which is bacteriostatic in nature. E.coli's structure has been well studied and provides a baseline for understanding the interaction. Electromagnetic fields are shown to influence the growth curve of bacterium depending on the field's geometry. The theoretical model discussed in this thesis describes the interaction using a two-fluid model. The basis of this two-fluid model has been tested and shown that the concentration of antibiotics in the fluid environment is proportional to the response seen by the bacterium. The response of the bacterium has been determined using optical density measurements from which the behavior of the antibiotic-cell system has been studied.
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Thal, Johannes; Steffen, Monika; Meier, Bianca; Schneider, Elisabeth; Adriany, Ansgar; Usleber, Ewald
2011-01-01
The aim of this study was to develop and evaluate an enzyme immunoassay (EIA) for the cephalosporin antibiotic in milk, in combination with a new microbiological test system (brilliant black reduction test, BRT-P). Polyclonal antibodies against cefquinome were produced in rabbits, using cefquinome-keyhole limpet hemocyanine as the immunogen. These antibodies and a cefquinome-glucose oxidase conjugate were used in a competitive indirect EIA. The detection limit for cefquinome in milk was 1.5 ng ml(-1), recoveries were 80-128% at 4-40 ng ml(-1). Cross-reactivities with other cephalosporins/penicillins were all <1%. The EIA was used to determine cefquinome in incurred raw milk, the BRT-P (detection limit ≈ 20 ng ml(-1)) and a receptor assay (ßeta-s.t.a.r., detection limit ≈ 15 ng ml(-1)) were used in parallel. Five lactating cows, suffering from clinical mastitis, were treated with cefquinome by simultaneous intramammary and intramuscular injection. Cefquinome residues (maximum 10-27 μg ml(-1)) were most exclusively found in the udder quarter which was treated intramammary, residue levels in the other three quarters were low (<20 ng ml(-1)). Even in milk from intramammary-dosed quarters, residue levels fell below European Union maximum residue level (MRL, 20 μg kg(-1)) 2 days before the end of the withdrawal period. EIA, BRT-P, and ßeta-s.t.a.r. results showed acceptable agreement for milk samples, but the newly developed EIA is superior in aspects of sensitivity. In conclusion, this is the first one description of immunoassay and microbiological tests capable to determine cefquinome in milk at the MRL in incurred sample material.
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2014-01-01
Antibiotic resistance continues to spread even as society is experiencing a market failure of new antibiotic research and development (R&D). Scientific, economic, and regulatory barriers all contribute to the antibiotic market failure. Scientific solutions to rekindle R&D include finding new screening strategies to identify novel antibiotic scaffolds and transforming the way we think about treating infections, such that the goal is to disarm the pathogen without killing it or modulate the host response to the organism without targeting the organism for destruction. Future economic strategies are likely to focus on ‘push’ incentives offered by public-private partnerships as well as increasing pricing by focusing development on areas of high unmet need. Such strategies can also help protect new antibiotics from overuse after marketing. Regulatory reform is needed to re-establish feasible and meaningful traditional antibiotic pathways, to create novel limited-use pathways that focus on highly resistant infections, and to harmonize regulatory standards across nations. We need new antibiotics with which to treat our patients. But we also need to protect those new antibiotics from misuse when they become available. If we want to break the cycle of resistance and change the current landscape, disruptive approaches that challenge long-standing dogma will be needed. PMID:25043962
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DEFF Research Database (Denmark)
Knudsen, Gitte Maegaard; Fromberg, Arvid; Ng, Yin
2016-01-01
The human pathogenic bacterium Listeria monocytogenes is exposed to antibiotics both during clinical treatment and in its saprophytic lifestyle. As one of the keys to successful treatment is continued antibiotic sensitivity, the purpose of this study was to determine if exposure to sublethal...... antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... in Imo1179 (eutE) encoding an aldehyde oxidoreductase where rerouting caused increased ethanol production was tolerant to three of four antibiotics tested. This shift in metabolism could be a survival strategy in response to antibiotics to avoid generation of ROS production from respiration by oxidation...
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Raivio, Tracy L; Leblanc, Shannon K D; Price, Nancy L
2013-06-01
The Cpx envelope stress response mediates adaptation to stresses that cause envelope protein misfolding. Adaptation is partly conferred through increased expression of protein folding and degradation factors. The Cpx response also plays a conserved role in the regulation of virulence determinant expression and impacts antibiotic resistance. We sought to identify adaptive mechanisms that may be involved in these important functions by characterizing changes in the transcriptome of two different Escherichia coli strains when the Cpx response is induced. We show that, while there is considerable strain- and condition-specific variability in the Cpx response, the regulon is enriched for proteins and functions that are inner membrane associated under all conditions. Genes that were changed by Cpx pathway induction under all conditions were involved in a number of cellular functions and included several intergenic regions, suggesting that posttranscriptional regulation is important during Cpx-mediated adaptation. Some Cpx-regulated genes are centrally involved in energetics and play a role in antibiotic resistance. We show that a number of small, uncharacterized envelope proteins are Cpx regulated and at least two of these affect phenotypes associated with membrane integrity. Altogether, our work suggests new mechanisms of Cpx-mediated envelope stress adaptation and antibiotic resistance.
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Poole, Keith
2017-10-01
Environmental influences on antibiotic activity and resistance can wreak havoc with in vivo antibiotic efficacy and, ultimately, antimicrobial chemotherapy. In nature, bacteria encounter a variety of metal ions, particularly copper (Cu) and zinc (Zn), as contaminants in soil and water, as feed additives in agriculture, as clinically-used antimicrobials, and as components of human antibacterial responses. Importantly, there is a growing body of evidence for Cu/Zn driving antibiotic resistance development in metal-exposed bacteria, owing to metal selection of genetic elements harbouring both metal and antibiotic resistance genes, and metal recruitment of antibiotic resistance mechanisms. Many classes of antibiotics also form complexes with metal cations, including Cu and Zn, and this can hinder (or enhance) antibiotic activity. This review highlights the ways in which Cu/Zn influence antibiotic resistance development and antibiotic activity, and in so doing impact in vivo antibiotic efficacy. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Antibiotics usefulness and choice in BPCO acute exacerbation
Directory of Open Access Journals (Sweden)
Bruno Tartaglino
2005-10-01
Full Text Available Although the debate on the role of bacterial infections and antibiotic treatment in AE-COPD remains open, there is evidence that the persistence of bacteria after acute exacerbation (residual bacterial colony influences the frequency and severity of subsequent acute exacerbation and that antibiotic treatment that induces faster and more complete eradication produces better clinical outcomes. New aspects must now be considered, given that COPD is a chronic illness subject to acute exacerbations of varying frequencies and that acute exacerbations correspond to functional respiratory deterioration. One of the parameters that is currently acquiring clinical relevance is the interval free of infection (IFI, the period that elapses between one acute exacerbation and the next, caused by bacterial infection. Another guiding concept in the choice of antibiotic treatment is that not all patients benefit in the same way; those requiring more aggressive treatment are most likely to be those with FEV1 < 50%, frequent exacerbations (> 3/year treated with antibiotics, relevant co-morbidity, under chronic steroid treatment, etc., for these patients it is recommended to administer antibiotics active on the three most common pathogens (in particular H. influenzae, considering the resistance acquired in recent years, and on Pseudomomias aeruginosa.
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Yao, Linlin; Wang, Yanxin; Tong, Lei; Deng, Yamin; Li, Yonggang; Gan, Yiqun; Guo, Wei; Dong, Chuangju; Duan, Yanhua; Zhao, Ke
2017-01-01
The occurrence of 14 antibiotics (fluoroquinolones, tetracyclines, macrolides and sulfonamides) in groundwater and surface water at Jianghan Plain was investigated during three seasons. The total concentrations of target compounds in the water samples were higher in spring than those in summer and winter. Erythromycin was the predominant antibiotic in surface water samples with an average value of 1.60μg/L, 0.772μg/L and 0.546μg/L respectively in spring, summer and winter. In groundwater samples, fluoroquinolones and tetracyclines accounted for the dominant proportion of total antibiotic residues. The vertical distributions of total antibiotics in groundwater samples from three different depths boreholes (10m, 25m, and 50m) exhibited irregular fluctuations. Consistently decreasing of antibiotic residues with increasing of depth was observed in four (G01, G02, G03 and G05) groundwater sampling sites over three seasons. However, at the sampling sites G07 and G08, the pronounced high concentrations of total antibiotic residues were detected in water samples from 50m deep boreholes instead of those at upper aquifer in winter sampling campaign, with the total concentrations of 0.201μg/L and 0.100μg/L respectively. The environmental risks posed by the 14 antibiotics were assessed by using the methods of risk quotient and mixture risk quotient for algae, daphnids and fish in surface water and groundwater. The results suggested that algae might be the aquatic organism most sensitive to the antibiotics, with the highest risk levels posed by erythromycin in surface water and by ciprofloxacin in groundwater among the 14 antibiotics. In addition, the comparison between detected antibiotics in groundwater samples and the reported effective concentrations of antibiotics on denitrification by denitrifying bacteria, indicating this biogeochemical process driven by microorganisms won't be inhibitory influenced by the antibiotic residues in groundwater. Copyright © 2016
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Gebhardt, Michael J; Shuman, Howard A
2017-05-15
A critical component of bacterial pathogenesis is the ability of an invading organism to sense and adapt to the harsh environment imposed by the host's immune system. This is especially important for opportunistic pathogens, such as Acinetobacter baumannii , a nutritionally versatile environmental organism that has recently gained attention as a life-threatening human pathogen. The emergence of A. baumannii is closely linked to antibiotic resistance, and many contemporary isolates are multidrug resistant (MDR). Unlike many other MDR pathogens, the molecular mechanisms underlying A. baumannii pathogenesis remain largely unknown. We report here the characterization of two recently identified virulence determinants, GigA and GigB, which comprise a signal transduction pathway required for surviving environmental stresses, causing infection and antibiotic resistance. Through transcriptome analysis, we show that GigA and GigB coordinately regulate the expression of many genes and are required for generating an appropriate transcriptional response during antibiotic exposure. Genetic and biochemical data demonstrate a direct link between GigA and GigB and the nitrogen phosphotransferase system (PTS Ntr ), establishing a novel connection between a novel stress response module and a well-conserved metabolic-sensing pathway. Based on the results presented here, we propose that GigA and GigB are master regulators of a global stress response in A. baumannii , and coupling this pathway with the PTS Ntr allows A. baumannii to integrate cellular metabolic status with external environmental cues. IMPORTANCE Opportunistic pathogens, including Acinetobacter baumannii , encounter many harsh environments during the infection cycle, including antibiotic exposure and the hostile environment within a host. While the development of antibiotic resistance in A. baumannii has been well studied, how this organism senses and responds to environmental cues remain largely unknown. Herein, we
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Zhou, Y; Ma, L-Y; Zhao, X; Tian, S-H; Sun, L-Y; Cui, Y-M
2015-08-01
The use of prophylactic antibiotics in clean operations was routine in China before 2011. Along with the appeal for using antibiotics rationally by WHO in 2011, China launched a national special rectification scheme on clinical use of antibiotics from April that year. The scheme, aimed at achieving rational use of antibiotics, made pharmacists part of the responsible medical team. Our objective was to describe the impacts of pharmacist intervention on the use of antibiotics, particularly in urology clean operations. Pharmacists participated in antibiotic stewardship programmes of the hospital and urological clinical work and conducted real-time interventions at the same time from 2011 to 2013. Data on the use of antibiotics between 2010 and 2013 in urology were collected. Comparison of the 2013 data with those of 2010 showed that antibiotic use density [AUD= DDDs*100/(The number of patients who were treated the same period*Average days in hospital). DDDs = Total drug consumption (g)/DDD. DDD is the Defined Daily Dose] decreased by 57·8(58·8%); average antibiotic cost decreased by 246·94 dollars; the cost of antibiotics as a percentage of total drug cost decreased by 27·7%; the rate of use of antibiotics decreased from 100% to 7·3%. The study illustrates how an antibiotic stewardship programme with pharmacist participation including real-time interventions can promote improved antibiotic-prescribing and significantly decrease costs. © 2015 John Wiley & Sons Ltd.
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Qiao, Li'na; Qian, Sihua; Wang, Yuhui; Yan, Shifeng; Lin, Hengwei
2018-03-26
Fluorescent carbon dots (CDs) have received considerable attention in recent years due to their superior optical properties. To take further advantages of these unique features, herein, a CDs-based "lab-on-a-nanoparticle" approach for the detection and discrimination of antibiotics is developed. The sensing platform was designed based on the different channel's fluorescence recoveries or further quenching of the full-color emissive CDs (F-CDs) and metal ion ensembles upon the addition of antibiotics. The F-CDs exhibited unusually comparable emission intensity nearly across the entire visible spectrum even as the excitation wavelength is shifted, making it very suitable for the construction of multi-channel sensing systems. The sensing platform was fabricated on the basis of the competing interaction of metal ions with the F-CDs and antibiotics. Three metal ions (i.e., Cu 2+ , Ce 3+ and Eu 3+ ) can efficiently quench the fluorescence of the F-CDs. Upon the addition of antibiotics, the fluorescent intensities either recovered at different emission wavelengths or were further quenched to various degrees. The fluorescence response patterns at different emission wavelength were characteristic for each antibiotic and can be quantitatively differentiated by standard statistical methods (e.g., hierarchical clustering analysis and principal component analysis). Moreover, as an example, the proposed method was applied for quantitative detection of oxytetracycline with a limit of detection to be 0.06 μm. Finally, the sensing system was successfully employed for residual antibiotics detection and identification in real food samples. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Differential transcriptional response to antibiotics by Pseudomonas putida DOT-T1E
DEFF Research Database (Denmark)
Molina-Santiago, Carlos; Daddaoua, Abdelali; Gómez Lozano, María
2015-01-01
Multi-drug resistant bacteria are a major threat to humanity, especially because the current battery of known antibiotics is not sufficient to combat infections produced by these microbes. Therefore, the study of how current antibiotics act and how bacteria defend themselves against antibiotics i...
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Directory of Open Access Journals (Sweden)
M.H Movassagh
2014-11-01
Full Text Available Antibiotic residues in milk have a potential hazard for the consumer and may cause allergic reactions, interference in the intestinal flora that result in development of resistant populations of bacteria, thereby rendering antibiotic treatment ineffective. The aim of this study was to determine neomycin residues in pasteurized milk in East-Azarbaijan province. For this, a total of 200 samples of pasteurized milk produced by five dairy processing establishments of East Azarbaijan province was randomly collected. The samples were obtained over the spring and autumn (100 samples for each season of 2010. First, antibiotic residues were determined by Copan milk test. Afterwards, the competitive ELISA assay was used for the determination of neomycin concentration in positive samples. Of all samples, neomycin residues were observed in 9 and 13 samples and the mean neomycin residues amount were 43.20 ± 8.10 and 26.63±2.08 µg/L in spring and autumn, respectively. According to the limit of neomycin (1500 µg/l in cow raw milk in Iran, despite all the remaining drugs in pasteurized milk, in any of the samples exceeded level of neomycin was not observed.Based on the results, continuousmonitoringofantibiotic residues inmilk samples is recommended.
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Occurrence of antibiotics as emerging contaminant substances in aquatic environment.
Milić, Nataša; Milanović, Maja; Letić, Nevena Grujić; Sekulić, Maja Turk; Radonić, Jelena; Mihajlović, Ivana; Miloradov, Mirjana Vojinović
2013-01-01
The occurrence of pharmaceutical residues in the environment has become a subject of growing concern. Due to the constant input of the emerging contaminants in the surface water via wastewater which leads to the long-term adverse effects on the aquatic and terrestrial organisms, special attention is being paid to their presence in the aquatic environment. Most of the emerging substances, especially pharmaceuticals, could not be completely removed using the wastewater treatment. Pharmaceuticals are usually water soluble and poorly degradable. They can pass through all natural filtrations and then reach the groundwater and, finally, the drinking water. The trace levels of antibiotics could have a negative impact on the environment and public health because of their inherent bioactivity. This article is an overview of the presence of the antibiotic residual concentrations, methods and levels of detection and possible risks to both health and environment.
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Effect of irradiation on oxytetracycline residues in poultry meat
Energy Technology Data Exchange (ETDEWEB)
Mazurowski, P [Warsaw Agricultural University, Faculty of Veterinary Medicine, Department of Food Hygiene, Warsaw (Poland)
1994-12-31
The purpose of the study was an evaluation of the effect of ionizing radiation on detection of oxytetracycline residues in poultry meat. Oxytetracycline was chosen as a representative of tetracyclines which are often applied in poultry for therapeutical reasons. The experiment was conducted using both broiler meat treated by oxytetracycline and slurry of broiler meat containing appropriate concentration of this antibiotic. A traditional microbiological method for determination of antibiotics antimicrobial activity was used. A significant decrease of oxytetracycline concentration in meat slurry as a result of irradiation was noted. A dose of 1 kGy reduced concentration of tetracycline to ca 40% and a dose of 3 kGy reduced it to ca 3%. In ground poultry meat a dose of 1 kGy reduced this antibiotic concentration to 70%, a dose of 3 kGy reduced oxytetracycline concentration to 35% and a 5 kGy dose reduced it up to ca 18% of initial concentration. It can be concluded that irradiation of poultry meat with radurization doses can cause some difficulties in detection of tetracycline residues in meat using traditional microbiological methods of detection. (author).
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Effect of irradiation on oxytetracycline residues in poultry meat
International Nuclear Information System (INIS)
Mazurowski, P.
1994-01-01
The purpose of the study was an evaluation of the effect of ionizing radiation on detection of oxytetracycline residues in poultry meat. Oxytetracycline was chosen as a representative of tetracyclines which are often applied in poultry for therapeutical reasons. The experiment was conducted using both broiler meat treated by oxytetracycline and slurry of broiler meat containing appropriate concentration of this antibiotic. A traditional microbiological method for determination of antibiotics antimicrobial activity was used. A significant decrease of oxytetracycline concentration in meat slurry as a result of irradiation was noted. A dose of 1 kGy reduced concentration of tetracycline to ca 40% and a dose of 3 kGy reduced it to ca 3%. In ground poultry meat a dose of 1 kGy reduced this antibiotic concentration to 70%, a dose of 3 kGy reduced oxytetracycline concentration to 35% and a 5 kGy dose reduced it up to ca 18% of initial concentration. It can be concluded that irradiation of poultry meat with radurization doses can cause some difficulties in detection of tetracycline residues in meat using traditional microbiological methods of detection. (author)
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Zhang, Yu; Xie, Jianping; Liu, Miaomiao; Tian, Zhe; He, Zhili; van Nostrand, Joy D; Ren, Liren; Zhou, Jizhong; Yang, Min
2013-10-15
It is widely demonstrated that antibiotics in the environment affect microbial community structure. However, direct evidence regarding the impacts of antibiotics on microbial functional structures in wastewater treatment systems is limited. Herein, a high-throughput functional gene array (GeoChip 3.0) in combination with quantitative PCR and clone libraries were used to evaluate the microbial functional structures in two biological wastewater treatment systems, which treat antibiotic production wastewater mainly containing oxytetracycline. Despite the bacteriostatic effects of antibiotics, the GeoChip detected almost all key functional gene categories, including carbon cycling, nitrogen cycling, etc., suggesting that these microbial communities were functionally diverse. Totally 749 carbon-degrading genes belonging to 40 groups (24 from bacteria and 16 from fungi) were detected. The abundance of several fungal carbon-degrading genes (e.g., glyoxal oxidase (glx), lignin peroxidase or ligninase (lip), manganese peroxidase (mnp), endochitinase, exoglucanase_genes) was significantly correlated with antibiotic concentrations (Mantel test; P functional genes have been enhanced by the presence of antibiotics. However, from the fact that the majority of carbon-degrading genes were derived from bacteria and diverse antibiotic resistance genes were detected in bacteria, it was assumed that many bacteria could survive in the environment by acquiring antibiotic resistance and may have maintained the position as a main player in nutrient removal. Variance partitioning analysis showed that antibiotics could explain 24.4% of variations in microbial functional structure of the treatment systems. This study provides insights into the impacts of antibiotics on microbial functional structure of a unique system receiving antibiotic production wastewater, and reveals the potential importance of the cooperation between fungi and bacteria with antibiotic resistance in maintaining the
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International Nuclear Information System (INIS)
Gust, M.; Gélinas, M.; Fortier, M.; Fournier, M.; Gagné, F.
2012-01-01
The separate and combined in vitro toxic effects of antibiotics (ciprofloxacin, erythromycin, novobiocin, oxytetracycline, sulfamethazole and trimethoprim) commonly found in urban wastewater effluents were assessed on the immune parameters of Elliptio complanata at environmentally relevant concentrations. The observed responses were then compared to those produced by the physicochemical-treated wastewater effluent of a major city before and after the removal of microorganisms. Most of the selected antibiotics, separately and as mixture, induced changes in immune responses. The removal of microorganisms and fine particles from the effluent increased or decreased the resulting immunotoxic effects, depending of the observed parameter. The immunotoxic effects of erythromycin, sulfamethoxazole and trimethoprim were closely associated to the antibiotic mixture and the filtered effluent. In conclusion, the data revealed that the removal of fine particles and microorganisms from municipal effluents can alter the toxic nature of the effluent that is closely associated with the cumulative effects of antibiotics. - Highlights: ► Environmental concentrations of antibiotics induce the immune response in mussels. ► Antibiotic mixture also modulate the immune response. ► Urban effluent, both filtered and unfiltered also increase the immune response. ► Filtered effluent, antibiotic mixture and 3 antibiotics induced similar responses. - Environmentally relevant concentration of antibiotics and filtered urban effluent similarly modulate the in vitro immune response of mussels’ hemocytes.
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Energy Technology Data Exchange (ETDEWEB)
Gust, M [Fluvial Ecosystem Research, Environment Canada, 105 McGill St., Montreal, Quebec H2Y 2E7 (Canada); IRSTEA, UR MAEP, Laboratoire d' ecotoxicologie, 3 bis quai Chauveau, 69009 Lyon (France); Gelinas, M [Fluvial Ecosystem Research, Environment Canada, 105 McGill St., Montreal, Quebec H2Y 2E7 (Canada); Fortier, M; Fournier, M [INRS - Institut Armand-Frappier, 531 Blvd. des Prairies, Laval, Quebec H7V 1B7 (Canada); Gagne, F [Fluvial Ecosystem Research, Environment Canada, 105 McGill St., Montreal, Quebec H2Y 2E7 (Canada); INRS - Institut Armand-Frappier, 531 Blvd. des Prairies, Laval, Quebec H7V 1B7 (Canada)
2012-10-15
The separate and combined in vitro toxic effects of antibiotics (ciprofloxacin, erythromycin, novobiocin, oxytetracycline, sulfamethazole and trimethoprim) commonly found in urban wastewater effluents were assessed on the immune parameters of Elliptio complanata at environmentally relevant concentrations. The observed responses were then compared to those produced by the physicochemical-treated wastewater effluent of a major city before and after the removal of microorganisms. Most of the selected antibiotics, separately and as mixture, induced changes in immune responses. The removal of microorganisms and fine particles from the effluent increased or decreased the resulting immunotoxic effects, depending of the observed parameter. The immunotoxic effects of erythromycin, sulfamethoxazole and trimethoprim were closely associated to the antibiotic mixture and the filtered effluent. In conclusion, the data revealed that the removal of fine particles and microorganisms from municipal effluents can alter the toxic nature of the effluent that is closely associated with the cumulative effects of antibiotics. - Highlights: Black-Right-Pointing-Pointer Environmental concentrations of antibiotics induce the immune response in mussels. Black-Right-Pointing-Pointer Antibiotic mixture also modulate the immune response. Black-Right-Pointing-Pointer Urban effluent, both filtered and unfiltered also increase the immune response. Black-Right-Pointing-Pointer Filtered effluent, antibiotic mixture and 3 antibiotics induced similar responses. - Environmentally relevant concentration of antibiotics and filtered urban effluent similarly modulate the in vitro immune response of mussels' hemocytes.
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Directory of Open Access Journals (Sweden)
E. Zumelzu
2015-01-01
Full Text Available The persistent adhesion of salmon muscle to food container walls after treatment with urea solution was observed. This work evaluated the diffusion of antibiotics from the salmon muscle to the polyethylene terephthalate (PET coating protecting the electrolytic chromium coated steel (ECCS plates. New aquaculture production systems employ antibiotics such as florfenicol, florfenicol amine, oxytetracycline, and erythromycin to control diseases. The introduction of antibiotics is a matter of concern regarding the effects on human health and biodiversity. It is important to determine their impact on the adhesion of postmortem salmon muscle to can walls and the surface and structural changes affecting the functionality of multilayers. This work characterized the changes occurring in the multilayer PET polymer and steel of containers by electron microscopy, 3D atomic force microscopy (3D-AFM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectroscopy (FT-IR analyses. A robust mass spectrometry methodology was employed to determine the presence of antibiotic residues. No evidence of antibiotics was observed on the protective coating in the range between 0.001 and 2.0 ng/mL; however, the presence of proteins, cholesterol, and alpha-carotene was detected. This in-depth profiling of the matrix-level elements is relevant for the use of adequate materials in the canning export industry.
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Chiesa, Luca Maria; Nobile, Maria; Panseri, Sara; Arioli, Francesco
2017-11-15
The antibiotic overuse in zoothechnics, due to prophylactic and therapeutic treatments, or to their growth-promoting activity, is a major cause for the onset of widespread antibiotic resistance. Of particular relevance to this study, is the antibiotic abuse in pig breeding. Despite the comprehensive literature on residue controls in pig muscle, data on pig urine, a non-invasive, on-farm collectable matrix, are lacking. Therefore, we validated an HPLC-MS/MS method to detect 29 antimicrobials from eight classes and applied it to 43 anonymous pig urine and muscle paired samples and fulfilled the parameters in agreement with the Commission Decision 2002/657/UE. The analytical limits were moreover much lower than the maximum residue limits (MRLs) required by the Commission Regulation 37/2010/UE. In the samples, antibiotics were usually detected at higher frequencies and concentrations in urine than muscle. Urine proved a useful tool to detect antibiotic administration and their excessive use in pig farming is depicted. Copyright © 2017. Published by Elsevier Ltd.
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An antibiotic's journey from marketing authorization to use, Norway.
Årdal, Christine; Blix, Hege Salvesen; Plahte, Jens; Røttingen, John-Arne
2017-03-01
Here we describe in detail marketing authorization and reimbursement procedures for medicinal products in Norway, with particular reference to nine novel antibiotics that received marketing authorization between 2005 and 2015. The description illustrates that, in places like Norway, with effective antibiotic stewardship policies and an associated low prevalence of antibiotic-resistant bacterial infection, there is little need for newer, more expensive antibiotics whose therapeutic superiority to existing compounds has not been demonstrated. Since resistance begins to emerge as soon as an antibiotic is used, Norway's practice of leaving newer antibiotics on the shelf is consistent with the goal of prolonging the effectiveness of newer antibiotics. An unintended consequence is that the country has signalled to the private sector that there is little commercial value in novel antibiotics, which may nevertheless still be needed to treat rare or emerging infections. Every country aims to improve infection control and to promote responsible antibiotic use. However, as progress is made, antibiotic-resistant bacteria should become less common and, consequently, the need for, and the commercial value of, novel antibiotics will probably be reduced. Nevertheless, antibiotic innovation continues to be essential. This dilemma will have to be resolved through the introduction of alternative reward systems for antibiotic innovation. The DRIVE-AB (Driving re-investment in research and development and responsible antibiotic use) research consortium in Europe has been tasked with identifying ways of meeting this challenge.
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Vasani, Roshan B; Szili, Endre J; Rajeev, Gayathri; Voelcker, Nicolas H
2017-07-04
Chronic wounds are a major socio-economic problem. Bacterial infections in such wounds are a major contributor to lack of wound healing. An early indicator of wound infection is an increase in pH of the wound fluid. Herein, we describe the development of a pH-responsive drug delivery device that can potentially be used for wound decontamination in situ and on-demand in response to an increase in the pH of the wound environment. The device is based on a porous silicon film that provides a reservoir for encapsulation of an antibiotic within the pores. Loaded porous silicon is capped with dual plasma polymer layers of poly(1,7-octadiene) and poly(acrylic acid), which provide a pH-responsive barrier for on-demand release of the antibiotic. We demonstrate that release of the antibiotic is inhibited in aqueous buffer at pH 5, whereas the drug is released in a sustainable manner at pH 8. Importantly, the released drug was bacteriostatic against the Pseudomonas aeruginosa wound pathogen. In the future, incorporation of the delivery device into wound dressings could potentially be utilized for non-invasive decontamination of wounds. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Diwan, Vishal; Stålsby Lundborg, Cecilia; Tamhankar, Ashok J
2013-01-01
The presence of antibiotics in the environment and their subsequent impact on resistance development has raised concerns globally. Hospitals are a major source of antibiotics released into the environment. To reduce these residues, research to improve knowledge of the dynamics of antibiotic release from hospitals is essential. Therefore, we undertook a study to estimate seasonal and temporal variation in antibiotic release from two hospitals in India over a period of two years. For this, 6 sampling sessions of 24 hours each were conducted in the three prominent seasons of India, at all wastewater outlets of the two hospitals, using continuous and grab sampling methods. An in-house wastewater sampler was designed for continuous sampling. Eight antibiotics from four major antibiotic groups were selected for the study. To understand the temporal pattern of antibiotic release, each of the 24-hour sessions were divided in three sub-sampling sessions of 8 hours each. Solid phase extraction followed by liquid chromatography/tandem mass spectrometry (LC-MS/MS) was used to determine the antibiotic residues. Six of the eight antibiotics studied were detected in the wastewater samples. Both continuous and grab sampling methods indicated that the highest quantities of fluoroquinolones were released in winter followed by the rainy season and the summer. No temporal pattern in antibiotic release was detected. In general, in a common timeframe, continuous sampling showed less concentration of antibiotics in wastewater as compared to grab sampling. It is suggested that continuous sampling should be the method of choice as grab sampling gives erroneous results, it being indicative of the quantities of antibiotics present in wastewater only at the time of sampling. Based on our studies, calculations indicate that from hospitals in India, an estimated 89, 1 and 25 ng/L/day of fluroquinolones, metronidazole and sulfamethoxazole respectively, might be getting released into the
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Bacterial Response to Antibiotic Gradients in a Porous Microfluidic Device
Deng, J.; Shechtman, L. A.; Sanford, R. A.; Dong, Y.; Werth, C. J.; Fouke, B. W.
2015-12-01
Microorganisms in nature have evolved survival strategies to cope with a wide variety of environmental stresses, including gradients in temperature, pH, substrate availability and aqueous chemistry. Microfluidic devices provide a consistently reliable real-time means to quantitatively measure, control and reproduce the dynamic nature of these stresses. As an example, accelerated adaptation from genetic mutations have been observed in E. coli as it responds to gradients of Ciprofloxacin (Zhang et. al. 2011). However, the mechanisms by which bacteria respond to antibiotic gradients, as well as the effect of changes in how the stressor is applied, have not been systematically studied. In this study, newly designed and fabricated microfluidic devices with porous media have been utilized to determine the chemical stress fields that enhance adaptation and thus to test how E. coli bacterial communities adapt to antibiotic stresses. By applying antibiotic and nutrient into inlet channels adjacent to either side of the porous media inoculated with E. coli, a gradient of antibiotic was formed. Hydrogel barriers were selectively photo-polymerized in between of the inlet channels and the porous media to prevent any undesired convection. Hence, chemical solute can only be transported by diffusion, creating a reproducible antibiotic gradient over the porous media. The bacteria were also constrained by the hydrogel boundary barriers from escaping the porous media. Preliminary results suggest that E. coli moves freely with respect to Ciprofloxacin concentrations. In addition, and unexpectedly, the E. coli colonies exhibit a concentric pulsed growth front radiating away from the point of inoculation within the micromodel ecosystem and pulse over the porous media containing antibiotic. The bacteria at the growth front grow into long filaments (up to 100μm) while the bacteria in the inner concentric area are normal size. We hypothesize that the frontier bacteria, which are first
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Feng, Aixin; Cao, Yupeng; Wang, Heng; Zhang, Zhengang
2018-01-01
In order to reveal the quantitative control of the residual stress on the surface of metal materials, the relevant theoretical and experimental studies were carried out to investigate the dynamic response of metal thin plates and the formation mechanism of residual stress induced by laser shock wave. In this paper, the latest research trends on the surface residual stress of laser shock processing technology were elaborated. The main progress of laser shock wave propagation mechanism and dynamic response, laser shock, and surface residual stress were discussed. It is pointed out that the multi-scale characterization of laser and material, surface residual stress and microstructure change is a new hotspot in laser shock strengthening technology.
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Zhu, Xian-Dong; Zhang, Kun; Wang, Yu; Long, Wei-Wei; Sa, Rong-Jian; Liu, Tian-Fu; Lü, Jian
2018-02-05
A Zn(II)-based fluorescent metal-organic framework (MOF) was synthesized and applied as a highly sensitive and quickly responsive chemical sensor for antibiotic detection in simulated wastewater. The fluorescent chemical sensor, denoted FCS-1, exhibited enhanced fluorescence derived from its highly ordered, 3D MOF structure as well as excellent water stability in the practical pH range of simulated antibiotic wastewater (pH = 3.0-9.0). Remarkably, FCS-1 was able to effectively detect a series of sulfonamide antibiotics via photoinduced electron transfer that caused detectable fluorescence quenching, with fairly low detection limits. Two influences impacting measurements related to wastewater treatment and water quality monitoring, the presence of heavy-metal ions and the pH of solutions, were studied in terms of fluorescence quenching, which was nearly unaffected in sulfonamide-antibiotic detection. Additionally, the effective detection of sulfonamide antibiotics was rationalized by the theoretical computation of the energy bands of sulfonamide antibiotics, which revealed a good match between the energy bands of FCS-1 and sulfonamide antibiotics, in connection with fluorescence quenching in this system.
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Evaluation of a microbiological indicator test for antibiotic detection in ewe and goat milk.
Comunian, R; Paba, A; Dupré, I; Daga, E S; Scintu, M F
2010-12-01
Antibiotics are widely used for therapeutic and prophylactic purposes in dairy animals. The presence of residual antibiotics in milk could cause potentially serious problems in human health and have technological implication in the manufacturing of dairy products. The aim of this study was to evaluate Delvotest Accelerator (DSM Food Specialties, Delft, the Netherlands), a new system for a fully automated microbial test to detect antibiotic residues in ewe and goat milk. Forty-three samples of raw, whole, refrigerated bulk-tank milk samples (22 of ewe milk and 21 of goat milk) were analyzed during the whole lactation period. Four concentrations of 4 antibiotics were diluted in milk: penicillin G at 1, 2, 3, and 4 μg/L; sulfadiazine at 25, 50, 100, and 200 μg/L; tetracycline at 50, 100, 200, and 400 μg/L; and gentamicin at 25, 50, 100, and 200 μg/L. The detection limit of the Delvotest Accelerator was calculated as the range of antibiotic concentrations within which 95% of positive result lie. The range of detection limit of penicillin G and sulfadiazine was easily detected by Delvotest Accelerator at or below the European Union maximum residue limits, both for ewe and goat milk samples. In contrast, the system showed a lower ability to detect tetracycline and gentamicin both for ewe and goat milk samples. Very low percentages of false-positive outcomes were obtained. Lactation phase did not seem to be a crucial factor affecting the ability of the Delvotest Accelerator to detect spiked milk samples. A higher detection ability was observed for goat milk samples compared with ewe milk samples. A negative correlation between the percentage of positive milk samples detected and milk fat, protein, and lactose contents was observed for gentamicin only. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
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Kim, Chansik; Ryu, Hong-Duck; Chung, Eu Gene; Kim, Yongseok; Lee, Jae-Kwan
2018-07-01
Medically important (MI) antibiotics are defined by the United States Food and Drug Administration as drugs containing certain active antimicrobial ingredients that are used for the treatment of human diseases or enteric pathogens causing food-borne diseases. The presence of MI antibiotic residues in environmental water is a major concern for both aquatic ecosystems and public health, particularly because of their potential to contribute to the development of antimicrobial-resistant microorganisms. In this article, we present a review of global trends in the sales of veterinary MI antibiotics and the analytical methodologies used for the simultaneous determination of antibiotic residues in environmental water. According to recently published government reports, sales volumes have increased steadily, despite many countries having adopted strategies for reducing the consumption of antibiotics. Global attention needs to be directed urgently at establishing new management strategies for reducing the use of MI antimicrobial products in the livestock industry. The development of standardized analytical methods for the detection of multiple residues is required to monitor and understand the fate of antibiotics in the environment. Simultaneous analyses of antibiotics have mostly been conducted using high-performance liquid chromatography-tandem mass spectrometry with a solid-phase extraction (SPE) pretreatment step. Currently, on-line SPE protocols are used for the rapid and sensitive detection of antibiotics in water samples. On-line detection protocols must be established for the monitoring and screening of unknown metabolites and transformation products of antibiotics in environmental water. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Synthetic membrane-targeted antibiotics.
Vooturi, S K; Firestine, S M
2010-01-01
Antimicrobial resistance continues to evolve and presents serious challenges in the therapy of both nosocomial and community-acquired infections. The rise of resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA) and vancomycin-resistant enterococci (VRE) suggests that antimicrobial resistance is an inevitable evolutionary response to antimicrobial use. This highlights the tremendous need for antibiotics against new bacterial targets. Agents that target the integrity of bacterial membrane are relatively novel in the clinical armamentarium. Daptomycin, a lipopeptide is a classical example of membrane-bound antibiotic. Nature has also utilized this tactic. Antimicrobial peptides (AMPs), which are found in all kingdoms, function primarily by permeabilizing the bacterial membrane. AMPs have several advantages over existing antibiotics including a broad spectrum of activity, rapid bactericidal activity, no cross-resistance with the existing antibiotics and a low probability for developing resistance. Currently, a small number of peptides have been developed for clinical use but therapeutic applications are limited because of poor bioavailability and high manufacturing cost. However, their broad specificity, potent activity and lower probability for resistance have spurred the search for synthetic mimetics of antimicrobial peptides as membrane-active antibiotics. In this review, we will discuss the different classes of synthetic membrane-bound antibiotics published since 2004.
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Directory of Open Access Journals (Sweden)
Lizeth Mariel Casarrubias-Torres
2018-01-01
Full Text Available Mid-infrared spectroscopy and chemometric analysis were tested to determine tetracycline's residues in cow's milk. Cow's milk samples (n = 30 were spiked with tetracycline, chlortetracycline, and oxytetracycline in the range of 10-400 µg/l. Chemometric models to quantify each of the tetracycline's residues were developed by applying Partial Components Regression and Partial Least Squares algorithms. The Soft Independent Modeling of Class Analogy model was used to differentiate between pure milk and milk sample with tetracycline residues. The best models for predicting the levels of these antibiotics were obtained using Partial Least Square 1 algorithm (coefficient of determination between 0.997-0.999 and the standard error of calibration from 1.81 to 2.95. The Soft Independent Modeling of Class Analogy model showed well-separated groups allowing classification of milk samples and milk sample with antibiotics. The obtained results demonstrate the great analytical potential of chemometrics coupled with mid-infrared spectroscopy for the prediction of antibiotic in cow's milk at a concentration of microgram per litre (µg/l. This technique can be used to verify the safety of the milk rapidly and reliably.
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Ecological and Clinical Consequences of Antibiotic Subsistence by Environmental Microbes
DEFF Research Database (Denmark)
Dantas, Gautam; Sommer, Morten Otto Alexander
2011-01-01
This chapter contains sections titled: Introduction Environmental Origins of Resistance: The Producer Hypothesis Resistome of other Soil Bacteria: Response to the Producers? Early Reports of Antibiotic Catabolism by Soil Bacteria The Antibiotic Subsistome: Who and how much? Antibiotic Subsistence...... as a Scavenger Phenotype Ecological Consequences of the Antibiotic Subsistome Investigating Connections Between Subsistomes and Resistomes Metagenomic Functional Selections for Discovering Genes Enabling Antibiotic Subsistence and Resistance Antibiotic Subsistence by Pathogenic Bacteria Concluding Remarks...
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Miyata, M; Ihara, I; Yoshid, G; Toyod, K; Umetsu, K
2011-01-01
In animal husbandry, antibiotics are widely used to treat and prevent diseases or to promote growth. The use of antibiotics for domestic animals enables to promote safety of livestock products and enhance productivity. Tetracycline antibiotics (TCs) are one of the primarily used groups of antibiotics for cattle and swine. However, the unintentional spreading of antibiotics from animal waste to the environment may leave out drug residues, promoting resistant strains of bacteria, and will adversely affect the ecosystem and human health. To prevent the spread of veterinary antibiotics in the environment, it is required to treat residual antibiotics in livestock wastewater. In this study, we investigated the electrochemical oxidation of TCs to treat livestock wastewater. The concentrations of TCs in aqueous solutions were reduced from 100 mg/L to less than 0.6 mg/L by 6 h of electrochemical treatment using a Ti/IrO2 anode with Na2SO4 electrolyte. The concentration of oxytetracycline (OTC) in livestock wastewater was also reduced from 100 mg/L to less than 0.7 mg/L by the same treatment. Thus, the electrochemical oxidation using a Ti/IrO2 anode with Na2SO4 electrolyte was found to be effective for degradation of TCs. The results suggest that the electrochemical oxidation method is a promising treatment for TCs in livestock wastewater.
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Off-label abuse of antibiotics by bacteria.
Viswanathan, V K
2014-01-01
Antibiotics and antibiotic resistance made news on several fronts in the past year. Many public health organizations, including the CDC, used terms such as "crisis", "catastrophic consequences", and "nightmare scenario" to highlight the rapid emergence and spread of antibiotic resistance. A report from the Pew Commission on Industrial Farm Animal Production, on the fifth anniversary of the publication of its landmark 2008 report, noted that state and federal legislative efforts to limit non-therapeutic use of antibiotics in animal production were thwarted by drug and food animal industries. In its lobbying disclosures, the Farm Bureau stated that such efforts to limit use of animal antibiotics were "based on emotion and no credible peer reviewed science." Meanwhile, there have been inexorable advances in our understanding of the molecular mechanisms by which antibiotics induce diversity and resistance in bacteria. This article reviews one study that probed the role of the bacterial general stress response in sub-inhibitory antibiotic-induced mutagenesis and antibiotic resistance.
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Chloramphenicol Use and Prevalence of its Residues in Broiler ...
African Journals Online (AJOL)
Semi-structured questionnaires were administered to 75 poultry farmers to assess the use of antibiotics in poultry and the presence of chloramphenicol in chicken eggs and meat randomly obtained from broiler farms and commercial egg outlets were screened for chloramphenicol residues using ELISA technique.
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Hamscher, Gerd; Pawelzick, Heike Theresia; Sczesny, Silke; Nau, Heinz; Hartung, Jörg
2003-01-01
Pig-house dust originates from feed, bedding, feces, and the animals themselves. If the animals receive drugs such as antibiotics, residues of these substances may occur in manure, in the air, or on surfaces of the respective animal house. In a retrospective study, we investigated dust samples collected during two decades from the same piggery for the occurrence of various antibiotics. In 90% of these samples, we detected up to five different antibiotics, including tylosin, various tetracycli...
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Antibiotics impact plant traits, even at small concentrations
Deloy, Andrea; Volkert, Anna Martina; Leonhardt, Sara Diana; Pufal, Gesine
2017-01-01
Abstract Antibiotics of veterinary origin are released to agricultural fields via grazing animals or manure. Possible effects on human health through the consumption of antibiotic exposed crop plants have been intensively investigated. However, information is still lacking on the effects of antibiotics on plants themselves, particularly on non-crop species, although evidence suggests adverse effects of antibiotics on growth and performance of plants. This study evaluated the effects of three major antibiotics, penicillin, sulfadiazine and tetracycline, on the germination rates and post-germinative traits of four plant species during ontogenesis and at the time of full development. Antibiotic concentrations were chosen as to reflect in vivo situations, i.e. concentrations similar to those detected in soils. Plant species included two herb species and two grass species, and represent two crop-species and two non-crop species commonly found in field margins, respectively. Germination tests were performed in climate chambers and effects on the remaining plant traits were determined in greenhouse experiments. Results show that antibiotics, even in small concentrations, significantly affect plant traits. These effects include delayed germination and post-germinative development. Effects were species and functional group dependent, with herbs being more sensitive to antibiotics then grasses. Responses were either negative or positive, depending on plant species and antibiotic. Effects were generally stronger for penicillin and sulfadiazine than for tetracycline. Our study shows that cropland species respond to the use of different antibiotics in livestock industry, for example, with delayed germination and lower biomass allocation, indicating possible effects on yield in farmland fertilized with manure containing antibiotics. Also, antibiotics can alter the composition of plant species in natural field margins, due to different species-specific responses, with unknown
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Directory of Open Access Journals (Sweden)
Olumide Ajibola
2018-04-01
Full Text Available This study set out to evaluate self-medicated antibiotics and knowledge of antibiotic resistance among undergraduate students and community members in northern Nigeria. Antibiotic consumption pattern, source of prescription, illnesses commonly treated, attitude towards antibiotics, and knowledge of antibiotic resistance were explored using a structured questionnaire. Responses were analyzed and summarized using descriptive statistics. Of the 1230 respondents from undergraduate students and community members, prescription of antibiotics by a physician was 33% and 57%, respectively, amongst undergraduate students and community members. We tested the respondents’ knowledge of antibiotic resistance (ABR and found that undergraduate students displayed less knowledge that self-medication could lead to ABR (32.6% and 42.2% respectively. Self-medication with antibiotics is highly prevalent in Northwest Nigeria, with most medicines being purchased from un-licensed stores without prescription from a physician. We also observed a significant gap in respondents’ knowledge of ABR. There is an urgent need for public health authorities in Nigeria to enforce existing laws on antibiotics sales and enlighten the people on the dangers of ABR.
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Ho, Yu Bin; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid
2014-08-01
Repeated applications of animal manure as fertilizer are normal agricultural practices that may release veterinary antibiotics and hormones into the environment from treated animals. Broiler manure samples and their respective manure-amended agricultural soil samples were collected in selected locations in the states of Selangor, Negeri Sembilan and Melaka in Malaysia to identify and quantify veterinary antibiotic and hormone residues in the environment. The samples were analyzed using ultrasonic extraction followed by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The broiler manure samples were found to be contaminated with at least six target analytes, namely, doxycycline, enrofloxacin, flumequine, norfloxacin, trimethoprim and tylosin. These analytes were detected in broiler manure samples with maximum concentrations reaching up to 78,516 μg kg(-1) dry weight (DW) (doxycycline). For manure-amended agricultural soil samples, doxycycline and enrofloxacin residues were detected in every soil sample. The maximum concentration of antibiotic detected in soil was 1331 μg kg(-1) DW (flumequine). The occurrence of antibiotics and hormones in animal manure at high concentration poses a risk of contaminating agricultural soil via fertilization with animal manure. Some physico-chemical parameters such as pH, total organic carbon (TOC) and metal content played a considerable role in the fate of the target veterinary antibiotics and progesterone in the environment. It was suggested that these parameters can affect the adsorption of pharmaceuticals to solid environmental matrices. Copyright © 2014 Elsevier B.V. All rights reserved.
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Wyrsch, Ethan R; Roy Chowdhury, Piklu; Chapman, Toni A; Charles, Ian G; Hammond, Jeffrey M; Djordjevic, Steven P
2016-01-01
Contamination of waste effluent from hospitals and intensive food animal production with antimicrobial residues is an immense global problem. Antimicrobial residues exert selection pressures that influence the acquisition of antimicrobial resistance and virulence genes in diverse microbial populations. Despite these concerns there is only a limited understanding of how antimicrobial residues contribute to the global problem of antimicrobial resistance. Furthermore, rapid detection of emerging bacterial pathogens and strains with resistance to more than one antibiotic class remains a challenge. A comprehensive, sequence-based genomic epidemiological surveillance model that captures essential microbial metadata is needed, both to improve surveillance for antimicrobial resistance and to monitor pathogen evolution. Escherichia coli is an important pathogen causing both intestinal [intestinal pathogenic E. coli (IPEC)] and extraintestinal [extraintestinal pathogenic E. coli (ExPEC)] disease in humans and food animals. ExPEC are the most frequently isolated Gram negative pathogen affecting human health, linked to food production practices and are often resistant to multiple antibiotics. Cattle are a known reservoir of IPEC but they are not recognized as a source of ExPEC that impact human or animal health. In contrast, poultry are a recognized source of multiple antibiotic resistant ExPEC, while swine have received comparatively less attention in this regard. Here, we review what is known about ExPEC in swine and how pig production contributes to the problem of antibiotic resistance.
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Póvoa, Pedro; Martin-Loeches, Ignacio; Ramirez, Paula; Bos, Lieuwe D.; Esperatti, Mariano; Silvestre, Joana; Gili, Gisela; Goma, Gemma; Berlanga, Eugenio; Espasa, Mateu; Gonçalves, Elsa; Torres, Antoni; Artigas, Antonio
2017-01-01
Purpose: Our aim was to evaluate the role of biomarker kinetics in the assessment of ventilator-associated pneumonia (VAP) response to antibiotics. Materials and methods: We performed a prospective, multicenter, observational study to evaluate in 37 microbiologically documented VAP, the kinetics of
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Li, Xiaoyu; Wang, Lili; Zhen, Yuhong; Li, Shuying; Xu, Yongping
2015-01-01
In recent years, the use of in-feed antibiotics for growth and disease prevention in livestock production has been under severe scrutiny. The use and misuse of in-feed antibiotics has led to problems with drug residues in animal products and increased bacterial resistance. Chicken egg yolk antibodies (IgY) have attracted considerable attention as an alternative to antibiotics to maintain swine health and performance. Oral administration of IgY possesses many advantages over mammalian IgG such...
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Cranendonk, Duncan R.; Opmeer, Brent C.; Prins, Jan M.; Wiersinga, W. Joost
2014-01-01
Recommended therapy duration for patients hospitalized with cellulitis is 10-14 days. Unnecessary use of antibiotics is one of the key factors driving resistance. Recent studies have shown that antibiotic therapy for cellulitis in outpatients can safely be shortened, despite residual inflammation.
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Antibiotics: Precious Goods in Changing Times.
Sass, Peter
2017-01-01
Antibiotics represent a first line of defense of diverse microorganisms, which produce and use antibiotics to counteract natural enemies or competitors for nutritional resources in their nearby environment. For antimicrobial activity, nature has invented a great variety of mechanisms of antibiotic action that involve the perturbation of essential bacterial structures or biosynthesis pathways of macromolecules such as the bacterial cell wall, DNA, RNA, or proteins, thereby threatening the specific microbial lifestyle and eventually even survival. However, along with highly inventive modes of antibiotic action, nature also developed a comparable set of resistance mechanisms that help the bacteria to circumvent antibiotic action. Microorganisms have evolved specific adaptive responses that allow appropriately reacting to the presence of antimicrobial agents, ensuring survival during antimicrobial stress. In times of rapid development and spread of antibiotic (multi-)resistance, we need to explore new, resistance-breaking strategies to counteract bacterial infections. This chapter intends to give an overview of common antibiotics and their target pathways. It will also discuss recent advances in finding new antibiotics with novel modes of action, illustrating that nature's repertoire of innovative new antimicrobial agents has not been fully exploited yet, and we still might find new drugs that help to evade established antimicrobial resistance strategies.
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Energy Technology Data Exchange (ETDEWEB)
Cam Van, Do Thi
2013-08-01
Compost and residues from biogas plant have been increasingly recognized as potting substrates in horticulture. To investigate the suitability of both materials to grow salt tolerant plants in 2010 a pot experiment was conducted in the greenhouse of INRES-Plant nutrition, University of Bonn. Ryegrass (Lolium perenne L.), rape (Brassica napus) and sunflower (Helianthus annuus) were chosen as experimental plants. To reduce the high salt content compost and residues from biogas plant were leached. To improve physical characteristics of raw materials, additives including Perlite, Styromull, Hygromull, Lecaton, Peat, Cocofiber were incorporated into compost or residues from biogas plant with the volumetric ratio of 4:1. Plant growth (DM) and nutrient uptake (N, P, K, Mg, Ca, Na and S) of the experimental plants grown in compost-based or residue-based substrates with and without additives and standard soil as a control were determined. Preliminary results reveal that origin compost and residues from biogas plant without leaching are suitable potting substrates for those plants. For compost leaching may not be recommended while for residues from biogas plant the effect of leaching was not distinct and needs further investigations. The incorporation of additives into the basic materials partially resulted in higher plant dry matter yield and nutrient uptake. However, differences between the additives on both parameters were mainly insignificant. Incorporation of Hygromull or Peat, especially into residues from biogas plant favored plant growth and enhanced total nutrient uptake. In 2011, pot experiments were continued with the salt-sensitive ornamental plants, Pelargonium (Pelargonium zonale Toro) and Salvia (Salvia splendens). Two separate experiments were carried out for the mixtures of compost and additives (SPS standard soil type 73 based on Peat, Hygromull or Cocofiber) with different volumetric ratios (4:1, 1:1, 1:4) and the mixtures of Peat incorporated with small
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Novel polyketones with pendant imidazolium groups as nanodispersants of hydrophobic antibiotics
Araya-Hermosilla, Esteban; Orellana, Sandra L.; Toncelli, Claudio; Picchioni, Francesco; Moreno-Villoslada, Ignacio
2015-01-01
In this work, we present a new method to nanodisperse the pH-sensitive antibiotics oxolinic acid and flumequine by the use of a pH-sensitive synthetic polyketone derivative with amphiphilic characteristics. The pH-sensitive polymer bears imidazolium residues on pendant groups as weak acids, and its
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Antibiotics prescription in Nigerian dental healthcare services.
Azodo, C C; Ojehanon, P I
2014-09-01
Inappropriate antibiotics prescription in dental healthcare delivery that may result in the emergence of antibiotic-resistant bacteria, is a worldwide concern. The objective of the study was to determine the antibiotics knowledge and prescription patterns among dentists in Nigeria. A total of 160 questionnaires were distributed to dentists attending continuing education courses organized by two organizations in Southern and Northern parts of Nigeria. Data analysis was done using SPSS version 17.0. A total of 146 questionnaires were returned, properly filled, out of 160 questionnaires, giving an overall response rate 91.3%. The clinical factors predominantly influenced the choice of therapeutic antibiotics among the respondents. In this study, the most commonly prescribed antibiotics among the respondents was a combination of amoxicillin and metronidazole. Of the respondents, 136 (93.2%) of them considered antibiotic resistance as a major problem in Nigeria and 102 (69.9%) have experienced antibiotics resistance in dental practice. The major reported conditions for prophylactic antibiotics among the respondents were diabetic mellitus, HIV/AIDS, history of rheumatic fever, other heart anomalies presenting with heart murmur and presence of prosthetic hip. The knowledge of adverse effects of antibiotics was greatest for tooth discoloration which is related to tetracycline. Data from this study revealed the most commonly prescribed antibiotics as a combination of amoxicillin and metronidazole. There existed gaps in prophylactic antibiotic prescription, consideration in the choice of therapeutic antibiotics and knowledge of adverse effects of antibiotics among the studied dentists.
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Directory of Open Access Journals (Sweden)
Zuzana Gondová
2014-10-01
Full Text Available The study compares two existing microbiological inhibition tests, Screening Test for Antibiotic Residues (STAR and Premi®Test with two recently introduced tests, Nouws Antibiotic Test (NAT and Total Antibiotics for the screening of antimicrobial residues in the tissues of food-producing animals. In the negative or positive sample classification based on inhibition of the growth of test strain sensitive to many antibiotics and sulphonamides, out of 142 samples obtained from slaughterhouses and retail operations, 39 samples yielded a positive result in one or more tests: 4 samples in four tests, 14 samples in three tests, 13 samples in two tests, and 8 samples in one test. As for the numbers of observed positive samples, the descending sequence of tests was: STAR, Total Antibiotics, Premi®Test, NAT. The growth inhibition was observed in three out of seven test strains, namely Bacillus cereus ATCC 11778, Kocuria rhizophila ATCC 9341, and Bacillus stearothermophilus var. calidolactis. Considering the test strains sensitivity and no inhibition on the Bacillus pumilus NCIMB 10822 NAT test plates, our preliminary conclusion is that the animal samples are suspected for the presence of tetracycline, macrolide, and b-lactam antibiotics.
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Directory of Open Access Journals (Sweden)
Sushovan Dam
2017-12-01
Full Text Available Antibiotic resistant Gram-negative bacteria are a serious threat for public health. The permeation of antibiotics through their outer membrane is largely dependent on porin, changes in which cause reduced drug uptake and efficacy. Escherichia coli produces two major porins, OmpF and OmpC. MicF and MicC are small non-coding RNAs (sRNAs that modulate the expression of OmpF and OmpC, respectively. In this work, we investigated factors that lead to increased production of MicC. micC promoter region was fused to lacZ, and the reporter plasmid was transformed into E. coli MC4100 and derivative mutants. The response of micC–lacZ to antimicrobials was measured during growth over a 6 h time period. The data showed that the expression of micC was increased in the presence of β-lactam antibiotics and in an rpoE depleted mutant. Interestingly, the same conditions enhanced the activity of an ompN–lacZ fusion, suggesting a dual transcriptional regulation of micC and the quiescent adjacent ompN. Increased levels of OmpN in the presence of sub-inhibitory concentrations of chemicals could not be confirmed by Western blot analysis, except when analyzed in the absence of the sigma factor σE. We suggest that the MicC sRNA acts together with the σE envelope stress response pathway to control the OmpC/N levels in response to β-lactam antibiotics.
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Directory of Open Access Journals (Sweden)
Firooz Fadaeifard
2015-09-01
Full Text Available Florfenicol is a broad-spectrum antibiotic, widely used in veterinary medicine. The aim of this study was to determine florfenicol residues in the muscle and liver of cultured rainbow trout in Iran by ELISA. The samples were collected from three areas (Kiar, Ardal, and Koohrang, considered as areas with high production of trout in the western part of Iran. Sampling was completed during the spring and summer of 2011. All of the samples were categorized into three weight groups (below 50g, 50 to150g and over 150g and five individuals were randomly selected from fish belonged to each weigh group, and then collected samples sent for determination of antibiotic residues. The highest and the lowest antibiotic residues were 31.42±53.52 ng g-1 (>150 g fish and 10.35±2.33 ng g-1 (<50 g fish for liver samples and 48.84±50.36 ng g-1 (50-150 g fish and 18.20±15.41 ng g-1 (> 150 g fish for muscle samples, respectively. In different areas, the highest antibiotic levels were found in Koohrang and Ardal with mean of 37.00±63.61 and 15.33±10.45 ng g-1 for liver samples and 40.74±40.80 and 28.24±45.91ng g-1 for muscle samples. The results indicated that florfenicol residues are lower than the maximum permissible level has been announced by the European Union.
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Reclamation of Herb Residues Using Probiotics and Their Therapeutic Effect on Diarrhea
Directory of Open Access Journals (Sweden)
Fanjing Meng
2017-01-01
Full Text Available Residues from herbal medicine processing in pharmaceutical plants create a large amount of waste (herb residues, which consists mainly of environmental pollution and medicinal waste. In order to resolve this problem, probiotics of Bacillus (B. subtilis, Aspergillus (A. oryzae, and Lactobacillus (L. plantarum M3 are selected to reuse herb residue of Jianweixiaoshi tablets (JT, and an antibiotic-associated diarrhea (AAD mouse model was established to evaluate the therapeutic effects of the herb residue fermentation supernatant. Our results indicated that the fermentation supernatant had scavenged 77.8% of 2,2-diphenyl-1-picrylhydrazyl (DPPH, 78% of O2•−, 36.7% of •OH, 39% of Fe2+ chelation, and 716 mg/L reducing power. The inhibition zones for Salmonella (S. typhimurium, S. enteritidis, Shigella (Sh. flexneri, Escherichia (E. coli, Listeria (L. monocytogenes, Sh. dysenteriae 301, and Staphylococcus (S. aureus were 17, 14, 19, 18, 20, 19, and 20 mm, respectively. The in vivo results indicated that the fermentation supernatant resulted in a high diarrhea inhibition rate (56%, p<0.05, greatly enhanced the disruption of bacterial diversity caused by antibiotics, and restored the dominant position of L. johnsonii in the treatment and recovery stages. Therefore, the combination of the herb residue and probiotics suggests a potential to explore conversion of these materials for the possible development of therapies for AAD.
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Decline in extractable antibiotics in manure-based composts during composting.
Kim, K-R; Owens, G; Ok, Y S; Park, W-K; Lee, D B; Kwon, S-I
2012-01-01
A wide variety of antibiotics have been detected in natural water samples and this is of potential concern because of the adverse environmental effects of such antibiotic residues. One of the main sources of antibiotics effluence to the surrounding environment is livestock manures which often contain elevated concentrations of veterinary antibiotics (VAs) which survive digestion in the animal stomach following application in animal husbandry practices. In Korea, livestock manures are normally used for compost production indicating that there is potential for antibiotic release to the environment through compost application to agricultural lands. Therefore, reduction of the amount of VAs in composts is crucial. The purpose of this study was to understand the influence of the composting process and the components of the compost on the levels of three common classes of antibiotics (tetracyclines, sulfonamides, and macrolides). Composted materials at different stages of composting were collected from compost manufacturing plants and the variation in antibiotic concentrations was determined. Three different antibiotics, chlortetracycline (CTC), sulfamethazine (SMZ), and tylosin (TYL) at three different concentrations (2, 10, and 20mgkg(-1)) were also applied to a mixture of pig manure and sawdust and the mixtures incubated using a laboratory scale composting apparatus to monitor the changes in antibiotic concentrations during composting together with the physicochemical properties of the composts. During composting, in both field and lab-scale investigations, the concentrations of all three different antibiotics declined below the relevant Korean guideline values (0.8mgkg(-1) for tetracyclines, 0.2mgkg(-1) for sulfonamides and 1.0mgkg(-1) for macrolides). The decline of tetracycline and sulfonamide concentrations was highly dependent on the presence of sawdust while there was no influence of sawdust on TYL decline. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Antibiotic and Anti-Inflammatory Therapies for Cystic Fibrosis
Chmiel, James F.; Konstan, Michael W.; Elborn, J. Stuart
2013-01-01
Cystic fibrosis (CF) lung disease is characterized by chronic bacterial infection and an unremitting inflammatory response, which are responsible for most of CF morbidity and mortality. The median expected survival has increased from 38 yr now. This dramatic improvement, although not great enough, is due to the development of therapies directed at secondary disease pathologies, especially antibiotics. The importance of developing treatments directed against the vigorous inflammatory response was realized in the 1990s. New therapies directed toward the basic defect are now visible on the horizon. However, the impact of these drugs on downstream pathological consequences is unknown. It is likely that antibiotics and anti-inflammatory drugs will remain an important part of the maintenance regimen for CF in the foreseeable future. Current and future antibiotic and anti-inflammatory therapies for CF are reviewed. PMID:23880054
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DEFF Research Database (Denmark)
Petersen, Jens; Thomsen, Ingrid Kaag; Mattson, L
2012-01-01
Knowledge of the cumulated effect of long-continued nitrogen (N) inputs is important for both agronomic and environmental reasons. However, only little attention has been paid to estimate the crop response to mineral fertilizer N residues. Before interpreting estimates for the crop response...
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Directory of Open Access Journals (Sweden)
Jeevanandan V.
2016-09-01
Full Text Available The Total Antibiotics test is a microbial inhibition test which has been recently introduced for the detection of antibiotics in meat. The aim of this study was to determine whether it would be suitable for the detection of coccidiostats in poultry meat. A comparison with the Premi®Test was assessed also for the suitability of the detection of coccidiostats in poultry meat. A selection of poultry meat samples of different organ parts were assessed with 14 samples from Slovakian farms that had previously been tested for coccidiostats by the Veterinary and Food Institute in Košice. In addition, another 8 samples from varied Slovakian supermarkets such as Lidl, Billa and Tesco with samples of chicken or duck meat, were tested. Each prepared sample was added to the Total Antibiotics kit tubes and incubated. The samples from all sources showed a mixture of positive and negative results for the detection of coccidiostats.
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Interventions on Metabolism: Making Antibiotic-Susceptible Bacteria
Directory of Open Access Journals (Sweden)
Fernando Baquero
2017-11-01
Full Text Available Antibiotics act on bacterial metabolism, and antibiotic resistance involves changes in this metabolism. Interventions on metabolism with drugs might therefore modify drug susceptibility and drug resistance. In their recent article, Martin Vestergaard et al. (mBio 8:e01114-17, 2017, https://doi.org/10.1128/mBio.01114-17 illustrate the possibility of converting intrinsically resistant bacteria into susceptible ones. They reported that inhibition of a central metabolic enzyme, ATP synthase, allows otherwise ineffective polymyxin antibiotics to act on Staphylococcus aureus. The study of the intrinsic resistome of bacterial pathogens has shown that several metabolic genes, including multigene transcriptional regulators, contribute to antibiotic resistance. In some cases, these genes only marginally increase antibiotic resistance, but reduced levels of susceptibility might be critical in the evolution or resistance under low antibiotic concentrations or in the clinical response of highly resistant bacteria. Drug interventions on bacterial metabolism might constitute a critical adjuvant therapy in combination with antibiotics to ensure susceptibility of pathogens with intrinsic or acquired antimicrobial resistance.
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Antibiotics used most commonly to treat animals in Europe
De Briyne, N.; Atkinson, J.; Pokludová, L.; Borriello, S. P.
2014-01-01
The Heads of Medicines Agencies and the Federation of Veterinarians of Europe undertook a survey to gain an insight into European prescribing of antibiotics for animals, in particular to highlight the diseases for which antibiotics are most commonly said to be prescribed and which different classes, including human critically important antibiotics (CIAs). The survey was completed by 3004 practitioners from 25 European countries. Many older antibiotics (eg, penicillins, tetracyclines) are cited most frequently as the prescribed classes to treat the main food producing species. The frequency of citation of non-CIAs predominates. CIAs are mostly frequently cited to be prescribed for: urinary diseases in cats (62 per cent), respiratory diseases in cattle (45 per cent), diarrhoea in cattle and pigs (respectively 29 per cent and 34 per cent), locomotion disorders in cattle (31 per cent), postpartum dysgalactia syndrome complex in pigs (31 per cent) and dental disease in dogs (36 per cent). Clear ‘preferences’ between countries can be observed between antibiotic classes. The use of national formularies and guidance helps to drive responsible use of antibiotics and can significantly reduce the extent of use of CIAs. A more widespread introduction of veterinary practice antibiotic prescribing policies and monitoring obedience to these should ensure more widespread compliance with responsible use guidelines. PMID:24899065
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Kurenbach, Brigitta; Marjoshi, Delphine; Amábile-Cuevas, Carlos F; Ferguson, Gayle C; Godsoe, William; Gibson, Paddy; Heinemann, Jack A
2015-03-24
Biocides, such as herbicides, are routinely tested for toxicity but not for sublethal effects on microbes. Many biocides are known to induce an adaptive multiple-antibiotic resistance phenotype. This can be due to either an increase in the expression of efflux pumps, a reduced synthesis of outer membrane porins, or both. Exposures of Escherichia coli and Salmonella enterica serovar Typhimurium to commercial formulations of three herbicides-dicamba (Kamba), 2,4-dichlorophenoxyacetic acid (2,4-D), and glyphosate (Roundup)-were found to induce a changed response to antibiotics. Killing curves in the presence and absence of sublethal herbicide concentrations showed that the directions and the magnitudes of responses varied by herbicide, antibiotic, and species. When induced, MICs of antibiotics of five different classes changed up to 6-fold. In some cases the MIC increased, and in others it decreased. Herbicide concentrations needed to invoke the maximal response were above current food maximum residue levels but within application levels for all herbicides. Compounds that could cause induction had additive effects in combination. The role of soxS, an inducer of the AcrAB efflux pump, was tested in β-galactosidase assays with soxS-lacZ fusion strains of E. coli. Dicamba was a moderate inducer of the sox regulon. Growth assays with Phe-Arg β-naphtylamide (PAβN), an efflux pump inhibitor, confirmed a significant role of efflux in the increased tolerance of E. coli to chloramphenicol in the presence of dicamba and to kanamycin in the presence of glyphosate. Pathways of exposure with relevance to the health of humans, domestic animals, and critical insects are discussed. Increasingly common chemicals used in agriculture, domestic gardens, and public places can induce a multiple-antibiotic resistance phenotype in potential pathogens. The effect occurs upon simultaneous exposure to antibiotics and is faster than the lethal effect of antibiotics. The magnitude of the
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Antibiotic control measures in Dutch secondary care hospitals.
Schouten, J.A.; Hulscher, M.E.J.L.; Natsch, S.S.; Grol, R.P.T.M.; Meer, J.W.M. van der
2005-01-01
Control measures for the use of antibiotics are essential because of the potential harmful consequences of side effects. Various methods have been developed to help curb undesirable antibiotic prescription. We performed a survey in Dutch secondary care hospitals (response rate 73%) to make an
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Directory of Open Access Journals (Sweden)
Borović Branka
2013-01-01
Full Text Available Antibiotic residues when present in animal tissues, through food chain, can enter human body, causing allergic reactions or facilitating the development of resistant bacterial strains. In order to determine the presence of antibiotics in animal tissues, it is appropriate to use convenient, reliable and sensitive methods. Microbiological methods applied for the detection of antibiotic residues in primary products of animal origin are based on the sensitivity of specific bacterial strains to a particular group of antibiotics. Regulatives on the amount of pesticides, metals and metalloids and other toxic substances, chemotherapeutics, anabolics and other substances which can be found in food ("Off. Gazette", No. 5/92, 11/92 - corr. and 32/02, state that milk and milk products can be used in commercial purposes only if not contain antibiotics in quantities that can be detected by reference methods. The applied method is modified STAR (Screening test for detection of antibiotics protocol, regulated by the CRL (Community Reference Laboratory Fougeres, France, in which the initial validation of the method had been carried out. In accordance with the demands of Regulative Commission EC No657/2002, the sensitivity of modified STAR protocol for beta lactam antibiotics group was examined , that is, there was carried out a contracted validation of the method, which initial validation had been performed at CRL. In a couple of series of experiments, 20 blank samples of raw cow milk originating from animals not treated by antibiotics, had been examined. By the beginning of the experiment samples were stored in a freezer at -20ºC. Samples of raw cow milk enriched by working solutions of seven beta-lactam antibiotics, in order to obtain concentrations at the level of 0.5, 1 and 1.5 MRL (Maximmum Residue Limit for each given antibiotic (Commission Regulation EC No. 37/2010. For detection of beta-lactam antibiotics, there was used Kundrat agar test with
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Wallace, Joshua S; Garner, Emily; Pruden, Amy; Aga, Diana S
2018-05-01
Manure treatment technologies are rapidly developing to minimize eutrophication of surrounding environments and potentially decrease the introduction of antibiotics and antibiotic resistant genes (ARGs) into the environment. While laboratory and pilot-scale manure treatment systems boast promising results, antibiotic and ARG removals in full-scale systems receiving continuous manure input have not been evaluated. The effect of treatment on ARGs is similarly lacking. This study examines the occurrence and transformation of sulfonamides, tetracyclines, tetracycline degradation products, and related ARGs throughout a full-scale advanced anaerobic digester (AAD) receiving continuous manure and antibiotic input. Manure samples were collected throughout the AAD system to evaluate baseline antibiotic and ARG input (raw manure), the effect of hygenization (post-pasteurized manure) and anaerobic digestion (post-digestion manure) on antibiotic and ARG levels. Antibiotics were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the ARGs tet(O), tet(W), sul1 and sul2 were analyzed by quantitative polymerase chain reaction (Q-PCR). Significant reductions in the concentrations of chlortetracycline, oxytetracycline, tetracycline and their degradation products were observed in manure liquids following treatment (p < 0.001), concomitant to significant increases in manure solids (p < 0.001). These results suggest sorption is the major removal route for tetracyclines during AAD. Significant decreases in the epimer-to-total residue ratios for chlortetracycline and tetracycline in manure solids further indicate degradation is desorption-limited. Moreover, sul1 and sul2 copies decreased significantly (p < 0.001) following AAD in the absence of sulfonamide antibiotics, while tetracyclines-resistant genes remained unchanged. A cross-sectional study of dairy farms utilizing natural aeration and liquid-solid separation treatments was additionally performed
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Smolders, E.A.A.
2007-01-01
On nine milk cattle companies with cows, two with goats and one with sheep, which none of them do not or hardly uses antibiotics, animal health and management have been examined. Reasons not to use antibiotics have to do with resistance, residues, healthier livestock, less stress and economic
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Transfer of antibiotic resistant bacteria from animals to man
DEFF Research Database (Denmark)
Wegener, Henrik Caspar; Aarestrup, Frank Møller; Gerner-Smidt, P.
1999-01-01
for animals either for therapy or for growth promotion. Antibiotic resistance in zoonotic bacteria constitute a public health hazard, primarily through the increased risk of treatment failures. This paper describes the zoonotic bacteria, salmonella, campylobacter, yersinia and enterohaemorrhagic E. coli (EHEC......Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used......). Infections with these agents do not generally require antibiotic therapy, but in some cases antibiotics are essential to obtain a successful cure. The levels and types of resistance observed in zoonotic bacteria in some countries, especially the increasing levels of fluoroquinolone resistance in salmonella...
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International Nuclear Information System (INIS)
Ladd, T.I.; Schmiel, D.; Nickel, J.C.; Costerton, J.W.
1987-01-01
A 14 C-radiorespirometric assay was used to show the sensitivity of fixed-film (sessile), catheter-associated and free-living (planktonic) cells of Pseudomonas aeruginosa to varying concentrations (100 micrograms/mL to 1000 micrograms/mL) tobramycin sulfate. This strain of P. aeruginosa has an MIC of 0.6 microgram/ml and an MBC of 50 micrograms/mL when tested by conventional methods. When 14 C-glutamic acid was used as a substrate in this radiorespirometric assay, it could be completed in less than one hour and planktonic samples showed a significant reduction in mineralization activity (evolution of 14 CO 2 ) within eight hours of the antibiotic challenge. These changes in respiratory activity appeared to be dose and time dependent. Within 18 hr. at 1000 micrograms/mL, there was no significant residual respiratory activity in planktonic samples. Some residual respiratory activity was detected, however, in samples exposed to 100 micrograms/mL for 36 hours. The mineralization activity of sessile catheter-associated bacteria was unaffected by four hr. and eight hr. exposures to 1000 micrograms/mL of the antibiotic. A significant reduction in respiratory activity was recorded in catheter samples exposed for 18 hr. or more at each concentration examined. Unlike the planktonic samples, however, the antibiotic challenge failed to eradicate the metabolic activity of the attached bacteria. Antibiotic stressed, catheter-associated bacteria transferred to a post-exposure enrichment broth showed a limited ability to re-establish respiratory activity. This apparent recovery was limited to antibiotic exposures less than 24 hr. and was not observed in planktonic samples. The radioisotopic assay is a non-culture method which can be used to assess the antibiotic sensitivity of both planktonic bacteria and in situ biofilm populations
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Xu, Jian; Xu, Yan; Wang, Hongmei; Guo, Changsheng; Qiu, Huiyun; He, Yan; Zhang, Yuan; Li, Xiaochen; Meng, Wei
2015-01-01
The extensive use of antibiotics has caused the contamination of both antibiotics and antibiotic resistance genes (ARGs) in the environment. In this study, the abundance and distribution of antibiotics and ARGs from a sewage treatment plant (STP) and its effluent-receiving river in Beijing China were characterized. Three classes of antibiotics including tetracycline, sulfonamide and quinolone were quantified by LC-MS/MS. In the secondary effluent they were detected at 195, 2001 and 3866 ng L(-1), respectively, which were higher than in the receiving river water. A total of 13 ARGs (6 tet genes: tetA, tetB, tetE, tetW, tetM and tetZ, 3 sulfonamide genes: sul1, sul2 and sul3, and 4 quinolone genes: gryA, parC, qnrC and qnrD) were determined by quantitative PCR. For all ARGs, sulfonamide resistance genes were present at relatively high concentrations in all samples, with the highest ARG concentration above 10(-1). ARGs remained relatively stable along each sewage treatment process. The abundances of detected ARGs from the STP were also higher than its receiving river. Bivariate correlation analysis showed that relative tet gene copies (tetB/16S-rRNA and tetW/16S-rRNA) were strongly correlated with the concentrations of tetracycline residues (r(2)>0.8, pgenes. A negative correlation between the relative abundance of quinolone resistance gene (qnrC/16S-rRNA) and the concentrations of enrofloxacin (ENR) was also determined. The difference of ARGs levels in the raw influent and secondary effluent suggested that the STP treatment process may induce to increase the abundance of resistance genes. The results showed that the sewage was an important repository of the resistance genes, which need to be effectively treated before discharge into the natural water body. Copyright © 2014 Elsevier Ltd. All rights reserved.
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[Antibiotic resistance: A global crisis].
Alós, Juan-Ignacio
2015-12-01
The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
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Treatment of acute otitis media - challenges in the era of antibiotic resistance.
Dagan, R
2000-12-08
The last decade is characterized by the increase in antibiotic resistance among respiratory bacterial pathogens in the presence of only modest progress in the development of new antibacterial agents to overcome this resistance. A series of recent studies show clearly that the increased resistance among the main AOM pathogens (namely Streptococcus pneumoniae and Haemophilus influenzae) is associated with a dramatic decrease in bacteriologic response to antibiotic treatment, which in turn has an impact on clinical response. Thus, the individual patient is affected by the increasing antibiotic resistance. Moreover, the society as a whole is now also affected because the carriage and spread of antibiotic resistant AOM pathogens is remarkably impacted by antibiotic treatment. New studies show the remarkable ability of antibiotics to rapidly promote nasopharyngeal carriage and spread of antibiotic-resistant AOM pathogens. In these studies, the increase in carriage of antibiotic resistant S. pneumoniae is shown already after 3-4 days from initiation of antibiotic treatment and may last for weeks to months after treatment. Children carrying antibiotic-resistant organisms transmit those organisms to their family and to their day care centers and thus a vicious cycle is created in which increased antibiotic resistance with decreased response leads to increased antibiotic use, which in turn leads to further increase in resistance. New antibiotics are not likely to improve this situation. It is clear that the challenge in the next decade is to prevent AOM rather than to treat it. Efforts to prevent AOM include improved environmental factors, immunization with bacterial and viral vaccines and some creative measures such as prevention of colonization and attachment to epithelium of AOM pathogens. Whether these efforts will prove successful or, even if successful, will only modify the clinical and bacteriologic picture presenting new challenges, only time will tell.
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Antibiotic use as a tragedy of the commons: a cross-sectional survey.
O'Brien, Kieran S; Blumberg, Seth; Enanoria, Wayne T A; Ackley, Sarah; Sippl-Swezey, Nicolas; Lietman, Thomas M
2014-01-01
Many believe antibiotic use results in a tragedy of the commons, since overuse may lead to antibiotic resistance and limiting use would benefit society. In contrast, mass antibiotic treatment programs are thought to result in community-wide benefits. A survey was conducted to learn the views of infectious disease experts on the individual- and societal-level consequences of antibiotic use. The survey instrument was designed to elicit opinions on antibiotic use and resistance. It was sent via SurveyMonkey to infectious disease professionals identified through literature searches. Descriptive statistics were used to analyze the data. A total of 1,530 responses were received for a response rate of 9.9%. Nearly all participants believed antibiotic use could result in a tragedy of the commons, at least in certain circumstances (96.0%). Most participants did not believe mass antibiotic treatment programs could produce societal benefits in an antibiotic-free society (91.4%) or in the United States (94.2%), though more believed such programs would benefit antibiotic-free societies compared to the United States (P antibiotic use can result in a tragedy of the commons and do not believe that mass treatment programs benefit individuals or society.
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Asgari, Ali; Dehestani, Pouya; Poruraminaie, Iman
2018-02-01
Shot peening is a well-known process in applying the residual stress on the surface of industrial parts. The induced residual stress improves fatigue life. In this study, the effects of shot peening parameters such as shot diameter, shot speed, friction coefficient, and the number of impacts on the applied residual stress will be evaluated. To assess these parameters effect, firstly the shot peening process has been simulated by finite element method. Then, effects of the process parameters on the residual stress have been evaluated by response surface method as a statistical approach. Finally, a strong model is presented to predict the maximum residual stress induced by shot peening process in AISI 4340 steel. Also, the optimum parameters for the maximum residual stress are achieved. The results indicate that effect of shot diameter on the induced residual stress is increased by increasing the shot speed. Also, enhancing the friction coefficient magnitude always cannot lead to increase in the residual stress.
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Directory of Open Access Journals (Sweden)
Christy Manyi-Loh
2018-03-01
Full Text Available Due to the increased demand of animal protein in developing countries, intensive farming is instigated, which results in antibiotic residues in animal-derived products, and eventually, antibiotic resistance. Antibiotic resistance is of great public health concern because the antibiotic-resistant bacteria associated with the animals may be pathogenic to humans, easily transmitted to humans via food chains, and widely disseminated in the environment via animal wastes. These may cause complicated, untreatable, and prolonged infections in humans, leading to higher healthcare cost and sometimes death. In the said countries, antibiotic resistance is so complex and difficult, due to irrational use of antibiotics both in the clinical and agriculture settings, low socioeconomic status, poor sanitation and hygienic status, as well as that zoonotic bacterial pathogens are not regularly cultured, and their resistance to commonly used antibiotics are scarcely investigated (poor surveillance systems. The challenges that follow are of local, national, regional, and international dimensions, as there are no geographic boundaries to impede the spread of antibiotic resistance. In addition, the information assembled in this study through a thorough review of published findings, emphasized the presence of antibiotics in animal-derived products and the phenomenon of multidrug resistance in environmental samples. This therefore calls for strengthening of regulations that direct antibiotic manufacture, distribution, dispensing, and prescription, hence fostering antibiotic stewardship. Joint collaboration across the world with international bodies is needed to assist the developing countries to implement good surveillance of antibiotic use and antibiotic resistance.
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Manyi-Loh, Christy; Mamphweli, Sampson; Meyer, Edson; Okoh, Anthony
2018-03-30
Due to the increased demand of animal protein in developing countries, intensive farming is instigated, which results in antibiotic residues in animal-derived products, and eventually, antibiotic resistance. Antibiotic resistance is of great public health concern because the antibiotic-resistant bacteria associated with the animals may be pathogenic to humans, easily transmitted to humans via food chains, and widely disseminated in the environment via animal wastes. These may cause complicated, untreatable, and prolonged infections in humans, leading to higher healthcare cost and sometimes death. In the said countries, antibiotic resistance is so complex and difficult, due to irrational use of antibiotics both in the clinical and agriculture settings, low socioeconomic status, poor sanitation and hygienic status, as well as that zoonotic bacterial pathogens are not regularly cultured, and their resistance to commonly used antibiotics are scarcely investigated (poor surveillance systems). The challenges that follow are of local, national, regional, and international dimensions, as there are no geographic boundaries to impede the spread of antibiotic resistance. In addition, the information assembled in this study through a thorough review of published findings, emphasized the presence of antibiotics in animal-derived products and the phenomenon of multidrug resistance in environmental samples. This therefore calls for strengthening of regulations that direct antibiotic manufacture, distribution, dispensing, and prescription, hence fostering antibiotic stewardship. Joint collaboration across the world with international bodies is needed to assist the developing countries to implement good surveillance of antibiotic use and antibiotic resistance.
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Antibiotics are powerful medicines that fight bacterial infections. Used properly, antibiotics can save lives. They either kill bacteria or ... natural defenses can usually take it from there. Antibiotics do not fight infections caused by viruses, such ...
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Inactivation/reactivation of antibiotic-resistant bacteria by a novel UVA/LED/TiO2 system.
Xiong, Pei; Hu, Jiangyong
2013-09-01
In this study, an effective photocatalytic disinfection system was established using the newly emerged high power UVA/LED lamp. Crystallizing dish coated with TiO2 was prepared by 32-times impregnation-drying processes, and served as the supporting container for water samples. This study focused on the application of this UVA/LED system for the photocatalytic disinfection of selected antibiotic-resistant bacteria, Escherichia coli ATCC 700891. The disinfection performances were studied under various light intensities and illumination modes. Results show that higher light intensity could reach more significant inactivation of E. coli ATCC 700891. With the same UV dose, log-removal of antibiotic-resistant bacteria decreased with circle time in the studied range, while increased with duty circle. A "residual disinfecting effect" was found in the following dark period for bacteria collected at different phases of photocatalytic process. Residual disinfecting effect was found not significant for bacteria with 30 min periodic illumination. While residual disinfecting effect could kill almost all bacteria after 90 min UV periodic illumination within the following 240 min dark period. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Children as agents of change in combatting antibiotic resistance.
Molnar, Andreea
2017-01-01
Antibiotic resistance is a worldwide problem and changes are needed in the way antibiotics are used. The value of engaging children as key contributors in health care campaigns to increase the appropriate use of antibiotics has not been fully recognized. Little is known about how to design educational materials for children in order to enable them to be agents of change in their communities. Science education needs to improve the way it engages children so as to give them the tools needed to make responsible decisions on antibiotic use.
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Guzmán-Valdivia, Gilberto
2008-12-01
Accidental rupture of the gallbladder is an event which occurs in up to 20% of laparoscopic cholecystectomies, mainly in those where dissection is difficult, or during extraction when the gallbladder is withdrawn directly through the laparoscope port. It has been commonly assumed that contamination by bile in the abdominal cavity could be a cause of infection and lead to the formation of a residual abscess or even to surgical wound infection. It is common practice, therefore, for the surgeon to prescribe the application of an antibiotic at the moment when gallbladder perforation occurs. To compare 2 groups of similar patients, to determine whether administration of antibiotics, started during surgery, is actually useful in reducing the risk of residual abscess or infection in the surgical wound. The study considered a total of 166 patients who had suffered accidental perforation of the gallbladder during elective laparoscopic cholecystectomy. This total was divided at random into 2 groups: group A (80 patients) who received a dose of 1 g of Cefotaxime at the moment of gallbladder rupture, followed by 2 more doses at intervals of 8 hours in the immediate postoperative period; and group B (86 patients) who did not receive any antibiotic treatment at all. The dependent variables observed were surgical wound infection and residual abscess: and the control variables were age, sex, length of operation time, intercurrent illnesses, and American Society of Anesthesiologists (ASA) classification. Two patients (2.5%) in group A developed a surgical wound infection, against 3 cases (3.4%) in group B, the result having no statistical significance. No patients developed residual abscess. In a multivariant analysis, the following were identified as independent factors significantly associated with the onset of surgical wound infection (Pgallbladder during laparoscopic cholecystectomy is not necessary. In the case of patients with diabetes mellitus, those who are older than 60
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Directory of Open Access Journals (Sweden)
Taheri M.
2015-09-01
Full Text Available Background: Drug resistance is widely believed to be an increasingly serious threat to global public health. We have previously reported that short term exposure of microorganisms to diagnostic ultrasound waves could significantly alter their sensitivity to antibiotics. In our previous studies, Klebsiella pneumoniae showed major differences in the sensitivity to antibiotics in exposed and non-exposed samples. This study was aimed at investigating the alteration of antibiotic resistance of Klebsiella pneumonia, after exposure to Wi-Fi 2.4 GHz electromagnetic radiofrequency radiation. Materials and Methods: In this in vitro study, three replicate agar plates were used for each test. The antibiotic susceptibility test was carried out using disc diffusion method on Mueller Hinton agar plates and the inhibition zones in both control and exposed groups were measured. A common Wi-Fi router was used in this study as the radiofrequency exposure source. Irradiated samples were exposed to Wi-Fi radiofrequency radiation for 3, 4.5 and 8 hours. Results: Statistically significant variations of sensitivity to antibiotics were found for all studied antibiotics after 4.5 hours of RF exposure, compared to non-exposed bacteria. Interestingly, the mean diameters of the inhibition zones after 3 hours of exposure were less than those exposed for 4.5 hours. Following this rise in the sensitivity to antibiotics, a fall was observed in the bacteria exposed for 8 hours for all studied antibiotics. Conclusion: The findings of this study show a statistically significant rise in the sensitivity of Klebsiella pneumoniae to different antibiotics after 4.5 hours of exposure to 2.4 GHz Wi-Fi radiation, followed by a fall after 8 hours of exposure. These observations can be interpreted by the concept of non-linearity in the responses of Klebsiella pneumoniae to different antibiotics after exposure to electromagnetic radiofrequency radiation. As in this study a minimum level of
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Zhang, Chunhui; Ning, Ke; Zhang, Wenwen; Guo, Yuanjie; Chen, Jun; Liang, Chen
2013-04-01
Increased attention is currently being directed towards the potential negative effects of antibiotics and other PPCPs discharged into the aquatic environment via municipal WWTP secondary effluents. A number of analytical methods, such as high performance liquid chromatography technologies, including a high performance liquid chromatography-fluorescence method (HPLC-FLD), high performance liquid chromatography-UV detection method (HPLC-UV) and high performance liquid chromatography-mass spectrometry method (HPLC-MS), have been suggested as determination technologies for antibiotic residues in water. In this study, we implement a HPLC-MS/MS combined method to detect and analyze antibiotics in WWTP secondary effluent and apply a horizontal subsurface flow constructed wetland (CW) as an advanced wastewater treatment for removing antibiotics in the WWTP secondary effluent. The results show that there were 2 macrolides, 2 quinolones and 5 sulfas in WWTP secondary effluent among all the 22 antibiotics considered. After the CW advanced treatment, the concentration removal efficiencies and removal loads of 9 antibiotics were 53-100% and 0.004-0.7307 μg m(-2) per day, respectively.
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Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards
Directory of Open Access Journals (Sweden)
Noori Al-Waili
2012-01-01
Full Text Available Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's pathogens. Many cases of infant botulisms have been attributed to contaminated honey. Honey may be very toxic when produced from certain plants. Ingestion of honey without knowing its source and safety might be problematic. Honey should be labeled to explore its origin, composition, and clear statement that it is free from contaminants. Honey that is not subjected for analysis and sterilization should not be used in infants, and should not be applied to wounds or used for medicinal purposes. This article reviews the extent and health impact of honey contamination and stresses on the introduction of a strict monitoring system and validation of acceptable minimal concentrations of pollutants or identifying maximum residue limits for bee products, in particular, honey.
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Effects of Long Term Antibiotic Therapy on Human Oral and Fecal Viromes.
Abeles, Shira R; Ly, Melissa; Santiago-Rodriguez, Tasha M; Pride, David T
2015-01-01
Viruses are integral members of the human microbiome. Many of the viruses comprising the human virome have been identified as bacteriophage, and little is known about how they respond to perturbations within the human ecosystem. The intimate association of phage with their cellular hosts suggests their communities may change in response to shifts in bacterial community membership. Alterations to human bacterial biota can result in human disease including a reduction in the host's resilience to pathogens. Here we report the ecology of oral and fecal viral communities and their responses to long-term antibiotic therapy in a cohort of human subjects. We found significant differences between the viral communities of each body site with a more heterogeneous fecal virus community compared with viruses in saliva. We measured the relative diversity of viruses, and found that the oral viromes were significantly more diverse than fecal viromes. There were characteristic changes in the membership of oral and fecal bacterial communities in response to antibiotics, but changes in fecal viral communities were less distinguishing. In the oral cavity, an abundance of papillomaviruses found in subjects on antibiotics suggests an association between antibiotics and papillomavirus production. Despite the abundance of papillomaviruses identified, in neither the oral nor the fecal viromes did antibiotic therapy have any significant impact upon overall viral diversity. There was, however, an apparent expansion of the reservoir of genes putatively involved in resistance to numerous classes of antibiotics in fecal viromes that was not paralleled in oral viromes. The emergence of antibiotic resistance in fecal viromes in response to long-term antibiotic therapy in humans suggests that viruses play an important role in the resilience of human microbial communities to antibiotic disturbances.
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Residual stress concerns in containment analysis
International Nuclear Information System (INIS)
Costantini, F.; Kulak, R. F.; Pfeiffer, P. A.
1997-01-01
The manufacturing of steel containment vessels starts with the forming of flat plates into curved plates. A steel containment structure is made by welding individual plates together to form the sections that make up the complex shaped vessels. The metal forming and welding process leaves residual stresses in the vessel walls. Generally, the effect of metal forming residual stresses can be reduced or virtually eliminated by thermally stress relieving the vesseL In large containment vessels this may not be practical and thus the residual stresses due to manufacturing may become important. The residual stresses could possibly tiect the response of the vessel to internal pressurization. When the level of residual stresses is significant it will affect the vessel's response, for instance the yielding pressure and possibly the failure pressure. The paper will address the effect of metal forming residual stresses on the response of a generic pressure vessel to internal pressurization. A scoping analysis investigated the effect of residual forming stresses on the response of an internally pressurized vessel. A simple model was developed to gain understanding of the mechanics of the problem. Residual stresses due to the welding process were not considered in this investigation
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Antibiotics and the resistant microbiome
DEFF Research Database (Denmark)
Sommer, Morten; Dantas, Gautam
2011-01-01
. Less appreciated are the concomitant changes in the human microbiome in response to these assaults and their contribution to clinical resistance problems. Studies have shown that pervasive changes to the human microbiota result from antibiotic treatment and that resistant strains can persist for years....... Additionally, culture-independent functional characterization of the resistance genes from the microbiome has demonstrated a close evolutionary relationship between resistance genes in the microbiome and in pathogens. Application of these techniques and novel cultivation methods are expected to significantly...... expand our understanding of the interplay between antibiotics and the microbiome....
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Tacconelli, Evelina; Carrara, Elena; Savoldi, Alessia; Harbarth, Stephan; Mendelson, Marc; Monnet, Dominique L; Pulcini, Céline; Kahlmeter, Gunnar; Kluytmans, Jan; Carmeli, Yehuda; Ouellette, Marc; Outterson, Kevin; Patel, Jean; Cavaleri, Marco; Cox, Edward M; Houchens, Chris R; Grayson, M Lindsay; Hansen, Paul; Singh, Nalini; Theuretzbacher, Ursula; Magrini, Nicola
2018-03-01
The spread of antibiotic-resistant bacteria poses a substantial threat to morbidity and mortality worldwide. Due to its large public health and societal implications, multidrug-resistant tuberculosis has been long regarded by WHO as a global priority for investment in new drugs. In 2016, WHO was requested by member states to create a priority list of other antibiotic-resistant bacteria to support research and development of effective drugs. We used a multicriteria decision analysis method to prioritise antibiotic-resistant bacteria; this method involved the identification of relevant criteria to assess priority against which each antibiotic-resistant bacterium was rated. The final priority ranking of the antibiotic-resistant bacteria was established after a preference-based survey was used to obtain expert weighting of criteria. We selected 20 bacterial species with 25 patterns of acquired resistance and ten criteria to assess priority: mortality, health-care burden, community burden, prevalence of resistance, 10-year trend of resistance, transmissibility, preventability in the community setting, preventability in the health-care setting, treatability, and pipeline. We stratified the priority list into three tiers (critical, high, and medium priority), using the 33rd percentile of the bacterium's total scores as the cutoff. Critical-priority bacteria included carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa, and carbapenem-resistant and third-generation cephalosporin-resistant Enterobacteriaceae. The highest ranked Gram-positive bacteria (high priority) were vancomycin-resistant Enterococcus faecium and meticillin-resistant Staphylococcus aureus. Of the bacteria typically responsible for community-acquired infections, clarithromycin-resistant Helicobacter pylori, and fluoroquinolone-resistant Campylobacter spp, Neisseria gonorrhoeae, and Salmonella typhi were included in the high-priority tier. Future development strategies should focus on
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Directory of Open Access Journals (Sweden)
Jae-Sik Jeon
2017-01-01
Full Text Available Background: Approximately 50% of the world population is infected with Helicobacter pylori, which corresponds to a high infection rate. Furthermore, the incidence of antibiotic-resistant H. pylori has increased with the recent rise in use of antibiotics for H. pylori elimination, suggesting growing treatment failures. Aim: The study was aimed to assess the use of residual samples from rapid urease test (RUT for biomolecular testing as an effective and accurate method to detect antibiotic-resistant H. pylori. Settings and Design: This study was a retrospective study performed using data obtained from medical records of previously isolated H. pylori strains. Materials and Methods: RUT was conducted for 5440 biopsy samples from individuals who underwent health examination in South Korea. Subsequently, 469 RUT residual samples were randomly selected and subjected to polymerase chain reaction (PCR to detect antibiotic-resistant H. pylori. Statistical Analysis Used: The Chi-square test was used to analyse categorical data. P < 0.05 was considered statistically significant. Results: The results showed a concordance between the results of PCR and conventional RUT in 450 of 469 samples, suggesting that the H. pylori PCR test is a time- and cost-effective detection method. Conclusions: This study demonstrated that PCR test can aid physicians to prescribe the appropriate antibiotics at the time of diagnosis, thus preventing the reduction in H. pylori eradication due to antibiotic resistance, averting progression to serious diseases and increasing the treatment success rate.
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Tong, Changlun; Zhuo, Xiajun; Guo, Yun
2011-07-13
A sensitive liquid chromatography-fluorescence detection method, combined with one-step solid-phase extraction, was established for detecting the residual levels of the four typical fluoroquinolone antibiotics (ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin) in influent, effluent, and surface waters from Hangzhou, China. For the various environmental water matrices, the overall recoveries were from 76.8 to 122%, and no obvious interferences of matrix effect were observed. The limit of quantitation of this method was estimated to be 17 ng/L for ciprofloxacin and norfloxacin, 20 ng/L for ofloxacin, and 27 ng/L for enrofloxacin. All of the four typical fluoroquinolone antibiotics were found in the wastewaters and surface waters. The residual contents of the four typical fluoroquinolone antibiotics in influent, effluent, and surface water samples are 108-1405, 54-429, and 7.0-51.6 ng/L, respectively. The removal rates of the selected fluoroquinolone antibiotics were 69.5 (ofloxacin), 61.3 (norfloxacin), and 50% (enrofloxacin), indicating that activated sludge treatment is effective except for ciprofloxacin and necessary to remove these fluoroquinolone antibiotics in municipal sewage. The risk to the aquatic environment was estimated by a ratio of measured environmental concentration and predicted no-effect concentration. At the concentrations, these fluoroquinolone antibiotics were found in influent, effluent, and surface waters, and they should not pose a risk for the aquatic environment.
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Kim, Chansik; Ryu, Hong-Duck; Chung, Eu Gene; Kim, Yongseok
2018-05-01
The use of antibiotics and their occurrence in the environment have received significant attention in recent years owing to the generation of antibiotic-resistant bacteria. Antibiotic residues in water near livestock farming areas should be monitored to establish effective strategies for reducing the use of veterinary antibiotics. However, environmental water contamination resulting from veterinary antibiotics has not been studied extensively. In this work, we developed an analytical method for the simultaneous determination of multiple classes of veterinary antibiotic residues in environmental water using on-line solid-phase extraction (SPE)-high performance liquid chromatography (HPLC)-high resolution mass spectrometry (HRMS). Eighteen popular antibiotics (eight classes) were selected as target analytes based on veterinary antibiotics sales in South Korea in 2015. The developed method was validated by calibration-curve linearities, precisions, relative recoveries, and method detection limits (MDLs)/limits of quantification (LOQs) of the selected antibiotics, and applied to the analysis of environmental water samples (groundwater, river water, and wastewater-treatment-plant effluent). All calibration curves exhibited r 2 > 0.995 with MDLs ranging from 0.2 to 11.9 ng/L. Relative recoveries were between 50 and 150% with coefficients of variation below 20% for all analytes (spiked at 500 ng/L) in groundwater and river water samples. Relative standard deviations (RSDs) of standard-spiked samples were lower than 7% for all antibiotics. The on-line SPE system eliminates human-based SPE errors and affords excellent method reproducibility. Amoxicillin, ampicillin, clopidol, fenbendazole, flumequine, lincomycin, sulfadiazine, and trimethoprim were detected in environmental water samples in concentrations ranging from 1.26 to 127.49 ng/L. The developed method is a reliable analytical technique for the potential routine monitoring of veterinary antibiotics
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Directory of Open Access Journals (Sweden)
Morgan E. Milton
2018-02-01
Full Text Available 2-aminoimidazole (2-AI compounds inhibit the formation of bacterial biofilms, disperse preformed biofilms, and re-sensitize multidrug resistant bacteria to antibiotics. 2-AIs have previously been shown to interact with bacterial response regulators, but the mechanism of interaction is still unknown. Response regulators are one part of two-component systems (TCS. TCSs allow cells to respond to changes in their environment, and are used to trigger quorum sensing, virulence factors, and antibiotic resistance. Drugs that target the TCS signaling process can inhibit pathogenic behavior, making this a potent new therapeutic approach that has not yet been fully exploited. We previously laid the groundwork for the interaction of the Acinetobacter baumannii response regulator BfmR with an early 2-AI derivative. Here, we further investigate the response regulator/2-AI interaction and look at a wider library of 2-AI compounds. By combining molecular modeling with biochemical and cellular studies, we expand on a potential mechanism for interaction between response regulators and 2-AIs. We also establish that Francisella tularensis/novicida, encoding for only three known response regulators, can be a model system to study the interaction between 2-AIs and response regulators. We show that knowledge gained from studying Francisella can be applied to the more complex A. baumannii system, which contains over 50 response regulators. Understanding the impact of 2-AIs on response regulators and their mechanism of interaction will lead to the development of more potent compounds that will serve as adjuvant therapies to broad-range antibiotics.
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Effects of six selected antibiotics on plant growth and soil microbial and enzymatic activities
International Nuclear Information System (INIS)
Liu Feng; Ying Guangguo; Tao Ran; Zhao Jianliang; Yang Jifeng; Zhao Lanfeng
2009-01-01
The potential impact of six antibiotics (chlortetracycline, tetracycline and tylosin; sulfamethoxazole, sulfamethazine and trimethoprim) on plant growth and soil quality was studied by using seed germination test on filter paper and plant growth test in soil, soil respiration and phosphatase activity tests. The phytotoxic effects varied between the antibiotics and between plant species (sweet oat, rice and cucumber). Rice was most sensitive to sulfamethoxazole with the EC10 value of 0.1 mg/L. The antibiotics tested inhibited soil phosphatase activity during the 22 days' incubation. Significant effects on soil respiration were found for the two sulfonamides (sulfamethoxazole and sulfamethazine) and trimethoprim, whereas little effects were observed for the two tetracyclines and tylosin. The effective concentrations (EC10 values) for soil respiration in the first 2 days were 7 mg/kg for sulfamethoxazole, 13 mg/kg for sulfamethazine and 20 mg/kg for trimethoprim. Antibiotic residues in manure and soils may affect soil microbial and enzyme activities. - Terrestrial ecotoxicological effects of antibiotics are related to their sorption and degradation behavior in soil.
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Effects of six selected antibiotics on plant growth and soil microbial and enzymatic activities
Energy Technology Data Exchange (ETDEWEB)
Liu Feng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Tao Ran; Zhao Jianliang; Yang Jifeng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhao Lanfeng [College of Resource and Environmental Science, South China Agricultural University, Guangzhou 510642 (China)
2009-05-15
The potential impact of six antibiotics (chlortetracycline, tetracycline and tylosin; sulfamethoxazole, sulfamethazine and trimethoprim) on plant growth and soil quality was studied by using seed germination test on filter paper and plant growth test in soil, soil respiration and phosphatase activity tests. The phytotoxic effects varied between the antibiotics and between plant species (sweet oat, rice and cucumber). Rice was most sensitive to sulfamethoxazole with the EC10 value of 0.1 mg/L. The antibiotics tested inhibited soil phosphatase activity during the 22 days' incubation. Significant effects on soil respiration were found for the two sulfonamides (sulfamethoxazole and sulfamethazine) and trimethoprim, whereas little effects were observed for the two tetracyclines and tylosin. The effective concentrations (EC10 values) for soil respiration in the first 2 days were 7 mg/kg for sulfamethoxazole, 13 mg/kg for sulfamethazine and 20 mg/kg for trimethoprim. Antibiotic residues in manure and soils may affect soil microbial and enzyme activities. - Terrestrial ecotoxicological effects of antibiotics are related to their sorption and degradation behavior in soil.
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Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance
Directory of Open Access Journals (Sweden)
Geoffrey Ivan Scott
2016-04-01
Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No
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The multifaceted roles of antibiotics and antibiotic resistance in nature
Directory of Open Access Journals (Sweden)
Saswati eSengupta
2013-03-01
Full Text Available Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic-resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic-resistance in pathogens. In the natural milieu, antibiotics are often found to be present in subinhibitory concentrations acting as signalling molecules supporting quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell and so on. The evolutionary and ecological aspects of antibiotics and antibiotic-resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behaviour of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and genes that confer resistance to antibiotics in
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Timpel, Patrick; Gurke, Robert; Marx, Conrad; Knoth, Holger; Fauler, Joachim
2016-02-01
Antibiotics are essential for the successful treatment of bacterial infections. Recently, the increasing number of resistant bacteria and the occurrence of residues of antibiotics in the environment has become the focus of scientific interest. The aim of the cooperative project ANTI-Resist was to investigate the release of antibiotics and the occurrence and distribution of antibiotic resistance in the urban waste water system of the city of Dresden.This article presents the main results of the secondary data analysis for the determination of outpatient and inpatient antibiotic consumption and provides an insight into the complexity of the topic antibiotics in waste water.Based on the data of outpatient prescriptions provided by the AOK PLUS for the period 2005 to 2013, thirteen focus substances were identified to estimate antibiotic consumption. Furthermore, delivery data from the pharmacies of three hospitals in Dresden were available.Depending on the substances investigated, seasonality and age dependency were determined. The results at a regional level were mostly in good accordance with general trends throughout Germany. It should be noted that the total amount of antibiotics used remained nearly constant over the whole period investigated, but the prescription of fluoroquinolones increased. This must be questioned when taking into account the increasingly critical situation in the treatment of Gram-negative bacteria in particular. Examinations of waste water conducted indicated that sewage treatment plants are not able to remove antibiotics or their metabolites completely from waste water. The residues are released into surface waters via the treatment plants. The impact cannot be assessed at the moment and further investigations are necessary.
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Selection of antibiotic resistance at very low antibiotic concentrations.
Sandegren, Linus
2014-05-01
Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.
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Directory of Open Access Journals (Sweden)
Chang Lin-Li
2010-07-01
Full Text Available Abstract Background Q fever is a zoonosis distributed worldwide that is caused by Coxiella burnetii infection and the defervescence usually occurs within few days of appropriate antibiotic therapy. Whether the changes of cytokine levels are associated with acute Q fever with persistent fever despite antibiotic therapy had not been investigated before. Case Presentation We report a rare case of acute Q fever granulomatous hepatitis remained pyrexia despite several antibiotic therapy and 6-day course of oral prednisolone. During the 18-month follow-up, the investigation of the serum cytokines profile and procalcitonin (PCT revealed that initially elevated levels of interleukin-2 (IL-2, IL-8, IL-10, and PCT decreased gradually, but the IL-6 remained in low titer. No evidence of chronic Q fever was identified by examinations of serum antibodies against C. burnetii and echocardiography. Conclusions The changes of cytokine levels may be associated with acute Q fever with poor response to treatment and PCT may be an indicator for monitoring the response to treatment.
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Mo, Charlie Y; Manning, Sara A; Roggiani, Manuela; Culyba, Matthew J; Samuels, Amanda N; Sniegowski, Paul D; Goulian, Mark; Kohli, Rahul M
2016-01-01
The bacterial SOS response is a DNA damage repair network that is strongly implicated in both survival and acquired drug resistance under antimicrobial stress. The two SOS regulators, LexA and RecA, have therefore emerged as potential targets for adjuvant therapies aimed at combating resistance, although many open questions remain. For example, it is not well understood whether SOS hyperactivation is a viable therapeutic approach or whether LexA or RecA is a better target. Furthermore, it is important to determine which antimicrobials could serve as the best treatment partners with SOS-targeting adjuvants. Here we derived Escherichia coli strains that have mutations in either lexA or recA genes in order to cover the full spectrum of possible SOS activity levels. We then systematically analyzed a wide range of antimicrobials by comparing the mean inhibitory concentrations (MICs) and induced mutation rates for each drug-strain combination. We first show that significant changes in MICs are largely confined to DNA-damaging antibiotics, with strains containing a constitutively repressed SOS response impacted to a greater extent than hyperactivated strains. Second, antibiotic-induced mutation rates were suppressed when SOS activity was reduced, and this trend was observed across a wider spectrum of antibiotics. Finally, perturbing either LexA or RecA proved to be equally viable strategies for targeting the SOS response. Our work provides support for multiple adjuvant strategies, while also suggesting that the combination of an SOS inhibitor with a DNA-damaging antibiotic could offer the best potential for lowering MICs and decreasing acquired drug resistance. IMPORTANCE Our antibiotic arsenal is becoming depleted, in part, because bacteria have the ability to rapidly adapt and acquire resistance to our best agents. The SOS pathway, a widely conserved DNA damage stress response in bacteria, is activated by many antibiotics and has been shown to play central role in
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Overexpression of antibiotic resistance genes in hospital effluents over time
Rowe, Will P. M.; Baker-Austin, Craig; Verner-Jeffreys, David W.; Ryan, Jim J.; Micallef, Christianne; Maskell, Duncan J.; Pearce, Gareth P.
2017-01-01
$\\textbf{Objectives}$: Effluents contain a diverse abundance of antibiotic resistance genes that augment the resistome of receiving aquatic environments. However, uncertainty remains regarding their temporal persistence, transcription and response to anthropogenic factors, such as antibiotic usage. We present a spatiotemporal study within a river catchment (River Cam, UK) that aims to determine the contribution of antibiotic resistance gene-containing effluents originating from sites of varyi...
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Antibiotics Susceptibility Pattern of Pseudomonas aeruginosa ...
African Journals Online (AJOL)
ABSTRACT: This work investigated the prevalence and antibiotics sensitivity of Pseudomonas aeruginosa isolated from ... skin triggers coagulation and an acute inflammatory response ... agents with anti-pseudomonal activity, life-threatening.
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Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R
2017-08-01
A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.
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Paenibacillus polymyxa PKB1 produces variants of polymyxin B-type antibiotics.
Shaheen, Mohamed; Li, Jingru; Ross, Avena C; Vederas, John C; Jensen, Susan E
2011-12-23
Polymyxins are cationic lipopeptide antibiotics active against many species of Gram-negative bacteria. We sequenced the gene cluster for polymyxin biosynthesis from Paenibacillus polymyxa PKB1. The 40.8 kb gene cluster comprises three nonribosomal peptide synthetase-encoding genes and two ABC transporter-like genes. Disruption of a peptide synthetase gene abolished all antibiotic production, whereas deletion of one or both transporter genes only reduced antibiotic production. Computational analysis of the peptide synthetase modules suggested that the enzyme system produces variant forms of polymyxin B (1 and 2), with D-2,4-diaminobutyrate instead of L-2,4-diaminobutyrate in amino acid position 3. Two antibacterial metabolites were resolved by HPLC and identified by high-resolution mass spectrometry and MS/MS sequencing as the expected variants 3 and 4 of polymyxin B(1) (1) and B(2) (2). Stereochemical analysis confirmed the presence of both D-2,4-diaminobutyrate and L-2,4-diaminobutyrate residues. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Selection of antibiotic resistance at very low antibiotic concentrations
Sandegren, Linus
2014-01-01
Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are fou...
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COUPLING OF MEMBRANE BIOREACTOR AND OZONATION FOR REMOVAL OF ANTIBIOTICS FROM HOSPITAL WASTEWATER
Directory of Open Access Journals (Sweden)
Bui Xuan Thanh
2016-02-01
Full Text Available Antibiotic residues in the environment and their potential toxic effects have been considered as one of the emerging research area in the environmental field. Their continuous introduction in our environment may increase their negative impacts on human health. In this study, the eliminations of antibiotic such as Norfloxacin (NOR, Ciprofloxacin (CIP, Ofloxacin (OFL and Sulfamethoxazole (SMZ in wastewater of hospital were processed by membrane bioreactor (MBR coupled with ozonation process. In particular, the MBR was applied for the antibiotic removals followed by ozonation process as a post-treatment stage to create an adequate integration to enhance removal efficiency. Achieved results after MBR treatment showed that the removal efficiency of NOR, CIP, OFL and SMZ were 90 ± 4.0% , 83 ± 13% , 81 ± 13 % and 39 ± 6%, respectivley. In addition, those antibiotic matters were continously removed by ozonation process with the removal efficiency of 87±9.0% , 83±1.0% , 81±2.3% and 66±2.3% for NOR, CIP, OFL and SMZ, respectively. In summary, antibiotics could be basically limited by the combination of MBR and ozonation before discharging in aquatic environment.
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van Limburg, Maarten; Sinha, Bhanu; Lo-Ten-Foe, Jerome R; van Gemert-Pijnen, Julia Ewc
2014-01-01
BACKGROUND: Antibiotic resistance is a global threat to patient safety and care. In response, hospitals start antibiotic stewardship programs to optimise antibiotic use. Expert-based guidelines recommend strategies to implement such programs, but local implementations may differ per hospital.
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Inhaled Antibiotics for Gram-Negative Respiratory Infections
Fraidenburg, Dustin R.; Scardina, Tonya
2016-01-01
SUMMARY Gram-negative organisms comprise a large portion of the pathogens responsible for lower respiratory tract infections, especially those that are nosocomially acquired, and the rate of antibiotic resistance among these organisms continues to rise. Systemically administered antibiotics used to treat these infections often have poor penetration into the lung parenchyma and narrow therapeutic windows between efficacy and toxicity. The use of inhaled antibiotics allows for maximization of target site concentrations and optimization of pharmacokinetic/pharmacodynamic indices while minimizing systemic exposure and toxicity. This review is a comprehensive discussion of formulation and drug delivery aspects, in vitro and microbiological considerations, pharmacokinetics, and clinical outcomes with inhaled antibiotics as they apply to disease states other than cystic fibrosis. In reviewing the literature surrounding the use of inhaled antibiotics, we also highlight the complexities related to this route of administration and the shortcomings in the available evidence. The lack of novel anti-Gram-negative antibiotics in the developmental pipeline will encourage the innovative use of our existing agents, and the inhaled route is one that deserves to be further studied and adopted in the clinical arena. PMID:27226088
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DEFF Research Database (Denmark)
Giessing, Anders; Jensen, Søren Skov; Rasmussen, Anette
2009-01-01
The Cfr methyltransferase confers combined resistance to five different classes of antibiotics that bind to the peptidyl transferase center of bacterial ribosomes. The Cfr-mediated modification has previously been shown to occur on nucleotide A2503 of 23S rRNA and has a mass corresponding......,8-dimethyladenosine. The mutation of single conserved cysteine residues in the radical SAM motif CxxxCxxC of Cfr abolishes its activity, lending support to the notion that the Cfr modification reaction occurs via a radical-based mechanism. Antibiotic susceptibility data confirm that the antibiotic resistance...
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van Limburg, A.H.M.; Sinha, Bhanu; Lo-Ten-Foe, Jerome R.; van Gemert-Pijnen, Julia E.W.C.
2014-01-01
Background Antibiotic resistance is a global threat to patient safety and care. In response, hospitals start antibiotic stewardship programs to optimise antibiotic use. Expert-based guidelines recommend strategies to implement such programs, but local implementations may differ per hospital. Earlier
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Antibiotic alternatives: the substitution of antibiotics in animal husbandry?
Cheng, Guyue; Hao, Haihong; Xie, Shuyu; Wang, Xu; Dai, Menghong; Huang, Lingli; Yuan, Zonghui
2014-01-01
It is a common practice for decades to use of sub-therapeutic dose of antibiotics in food-animal feeds to prevent animals from diseases and to improve production performance in modern animal husbandry. In the meantime, concerns over the increasing emergence of antibiotic-resistant bacteria due to the unreasonable use of antibiotics and an appearance of less novelty antibiotics have prompted efforts to develop so-called alternatives to antibiotics. Whether or not the alternatives could really ...
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Handling Time-dependent Variables : Antibiotics and Antibiotic Resistance
Munoz-Price, L. Silvia; Frencken, Jos F.; Tarima, Sergey; Bonten, Marc
2016-01-01
Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods,
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Multiple Pathways of Genome Plasticity Leading to Development of Antibiotic Resistance
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Didier Mazel
2013-05-01
Full Text Available The emergence of multi-resistant bacterial strains is a major source of concern and has been correlated with the widespread use of antibiotics. The origins of resistance are intensively studied and many mechanisms involved in resistance have been identified, such as exogenous gene acquisition by horizontal gene transfer (HGT, mutations in the targeted functions, and more recently, antibiotic tolerance through persistence. In this review, we focus on factors leading to integron rearrangements and gene capture facilitating antibiotic resistance acquisition, maintenance and spread. The role of stress responses, such as the SOS response, is discussed.
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Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf
2015-01-01
The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from aquatic environment, yet the persistence of these antibiotics is of concern and might lead to chronic exposure of aquatic organisms as well as humans. PMID:26135396
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Directory of Open Access Journals (Sweden)
Hao Zhang
2017-11-01
Full Text Available Antibiotic contamination in agroecosystems may cause serious problems, such as the proliferation of various antibiotic resistant bacteria and the spreading of antibiotic resistance genes (ARGs in the environment or even to human beings. However, it is unclear whether environmental antibiotics, antibiotic resistant bacteria, and ARGs can directly enter into, or occur in, the endophytic systems of plants exposed to pollutants. In this study, a hydroponic experiment exposing pakchoi (Brassica chinensis L. to tetracycline, cephalexin, and sulfamethoxazole at 50% minimum inhibitory concentration (MIC levels and MIC levels, respectively, was conducted to explore plant growth, antibiotic uptake, and the development of antibiotic resistance in endophytic systems. The three antibiotics promoted pakchoi growth at 50% MIC values. Target antibiotics at concentrations ranging from 6.9 to 48.1 µg·kg−1 were detected in the treated vegetables. Additionally, the rates of antibiotic-resistant endophytic bacteria to total cultivable endophytic bacteria significantly increased as the antibiotics accumulated in the plants. The detection and quantification of ARGs indicated that four types, tetX, blaCTX-M, and sul1 and sul2, which correspond to tetracycline, cephalexin, and sulfamethoxazole resistance, respectively, were present in the pakchoi endophytic system and increased with the antibiotic concentrations. The results highlight a potential risk of the development and spread of antibiotic resistance in vegetable endophytic systems.
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Zhang, Hao; Li, Xunan; Yang, Qingxiang; Sun, Linlin; Yang, Xinxin; Zhou, Mingming; Deng, Rongzhen; Bi, Linqian
2017-11-03
Antibiotic contamination in agroecosystems may cause serious problems, such as the proliferation of various antibiotic resistant bacteria and the spreading of antibiotic resistance genes (ARGs) in the environment or even to human beings. However, it is unclear whether environmental antibiotics, antibiotic resistant bacteria, and ARGs can directly enter into, or occur in, the endophytic systems of plants exposed to pollutants. In this study, a hydroponic experiment exposing pakchoi ( Brassica chinensis L.) to tetracycline, cephalexin, and sulfamethoxazole at 50% minimum inhibitory concentration (MIC) levels and MIC levels, respectively, was conducted to explore plant growth, antibiotic uptake, and the development of antibiotic resistance in endophytic systems. The three antibiotics promoted pakchoi growth at 50% MIC values. Target antibiotics at concentrations ranging from 6.9 to 48.1 µg·kg -1 were detected in the treated vegetables. Additionally, the rates of antibiotic-resistant endophytic bacteria to total cultivable endophytic bacteria significantly increased as the antibiotics accumulated in the plants. The detection and quantification of ARGs indicated that four types, tet X, bla CTX-M , and sul 1 and sul 2, which correspond to tetracycline, cephalexin, and sulfamethoxazole resistance, respectively, were present in the pakchoi endophytic system and increased with the antibiotic concentrations. The results highlight a potential risk of the development and spread of antibiotic resistance in vegetable endophytic systems.
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Fighting antibiotic resistance in the intensive care unit using antibiotics.
Plantinga, Nienke L; Wittekamp, Bastiaan H J; van Duijn, Pleun J; Bonten, Marc J M
2015-01-01
Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.
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Weber, T E; Schinckel, A P; Houseknecht, K L; Richert, B T
2001-10-01
An experiment was conducted to determine the efficacy of dietary conjugated linoleic acid (CLA) as a growth promotant in weanling swine. Weanling pigs (n = 192; 7.6 kg and 29 d of age) were randomly assigned to four treatments that were arranged as a 2 x 2 factorial. Concentrations of dietary CLA (0 or 0.6%) and antibiotics (+/-) constituted the main effect variables. Dietary CLA treatments consisted of a 1% addition of an oil containing 60% CLA isomers or 1% soybean oil, and dietary antibiotic treatments were antibiotics or no antibiotics. The experimental diets were fed for 9 wk in four phases (1, wk 1; 2, wk 2 and 3; 3, wk 4 through 6; and 4, wk 7 through 9), after which all pigs were fed identical medicated diets for the duration of the finishing phase. Live weights were recorded at wk 17 postweaning and at marketing to determine any residual effects of dietary treatments on finisher ADG and days to market. Medicated diets fed during phases 1 and 2 contained 55 mg carbadox/kg; during phase 3 contained 299 mg tilmicosin/kg; and during phase 4 contained 110 mg tylosin and 110 mg sulfamethazine/kg. Pigs fed medicated diets had higher overall ADG than pigs fed unmedicated diets for wk 0 through 9 (P pigs fed medicated diets than for pigs fed unmedicated diets during phase 1 (P residual effects of nursery CLA or antibiotics on finisher ADG and days to market. Blood samples collected from a subset of pigs (n = 72) at the completion of phases 2, 3, and 4 were assayed for serum IGF-I and antibody concentrations to porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae. There was a tendency for pigs fed medicated diets to have greater IGF-I concentrations than pigs fed unmedicated diets at the completion of phase 4 (P Pigs fed CLA had greater antibody titers (P pigs fed diets without CLA. These results indicate that feeding 0.6% dietary CLA did not enhance growth performance in weanling swine and that the use of dietary antibiotics can
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Surveillance of antibiotic resistance
Johnson, Alan P.
2015-01-01
Surveillance involves the collection and analysis of data for the detection and monitoring of threats to public health. Surveillance should also inform as to the epidemiology of the threat and its burden in the population. A further key component of surveillance is the timely feedback of data to stakeholders with a view to generating action aimed at reducing or preventing the public health threat being monitored. Surveillance of antibiotic resistance involves the collection of antibiotic susceptibility test results undertaken by microbiology laboratories on bacteria isolated from clinical samples sent for investigation. Correlation of these data with demographic and clinical data for the patient populations from whom the pathogens were isolated gives insight into the underlying epidemiology and facilitates the formulation of rational interventions aimed at reducing the burden of resistance. This article describes a range of surveillance activities that have been undertaken in the UK over a number of years, together with current interventions being implemented. These activities are not only of national importance but form part of the international response to the global threat posed by antibiotic resistance. PMID:25918439
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Menz, Jakob; Müller, Julia; Olsson, Oliver; Kümmerer, Klaus
2018-06-05
There are growing concerns that antibiotic pollution impacts environmental microbiota and facilitates the propagation of antibiotic resistance. However, the prediction or analytical determination of bioavailable concentrations of antibiotics in soil is still subject to great uncertainty. Biological assays are increasingly recognized as valuable complementary tools that allow a more direct determination of the residual antibiotic activity. This study assessed the bioavailability of structurally diverse antibiotics at a soil-water interface applying activity-based analyses in conjunction with equilibrium partitioning (EqP) modeling. The activity against Gram-positive and Gram-negative bacteria of nine antibiotics from different classes was determined in the presence and absence of standard soil (LUFA St. 2.2). The addition of soil affected the activity of different antibiotics to highly varying degrees. Moreover, a highly significant correlation ( p < 0.0001) between the experimentally observed and the EqP-derived log EC 50 (half-maximal effective concentration) values was observed. The innovative experimental design of this study provided new insights on the bioavailability of antibiotics at soil-water interfaces. EqP appears to be applicable to a broad range of antibiotics for the purpose of screening-level risk assessment. However, EqP estimates cannot replace soil-specific ecotoxicity testing in higher-tier assessments, since their accuracy is still compromised by a number of factors.
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Analysis of Infiltration-Suction Response in Unsaturated Residual Soil Slope in Gelugor, Penang
Ashraf Mohamad Ismail, Mohd; Hasliza Hamzah, Nur; Min, Ng Soon; Hazreek Zainal Abidin, Mohd; Tajudin, Saiful Azhar Ahmad; Madun, Aziman
2018-04-01
Rainfall infiltration on residual soil slope may impair slope stability by altering the pore-water pressure in the soil. A study has been carried out on unsaturated residual soil slope in Gelugor, Penang to determine the changes in matric suction of residual soils at different depth due to rainwater infiltration. The sequence of this study includes the site investigation, field instrumentation, laboratory experiment and numerical modeling. Void ratio and porosity of soil were found to be decreasing with depth while the bulk density and dry density of soil increased due to lower porosity of soil at greater depth. Soil infiltration rate and matric suction of all depths decrease with the increase of volumetric water content as well as the degree of saturation. Numerical modeling was used to verify and predict the relationship between infiltration-suction response and degree of saturation. Numerical models can be used to integrate the rainfall scenarios into quantitative landslide hazard assessments. Thus, development plans and mitigation measures can be designed for estimated impacts from hazard assessments based on collected data.
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Addressing resistance to antibiotics in systematic reviews of antibiotic interventions
Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This
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Directory of Open Access Journals (Sweden)
Georgios Chrysos
2017-01-01
Full Text Available Excessive antibiotic consumption and misuse is one of the main factors responsible for the emergence of antibiotic-resistant bacteria and has been associated with increased health care costs. Active intervention is necessary in changing antimicrobial prescribing practices. The Infection Control Committee and the administration of our hospital decided to implement an antibiotic stewardship program beginning in January 2016 in order to reduce inappropriate antibiotic use and to combat antibiotic resistance through improved prescribing practices. The antimicrobial stewardship team includes an ID specialist, physicians, infection control nurses, a microbiologist and a pharmacist who are responsible for the implementation of the program. Preauthorization by an ID specialist and prospective review is necessary for all pharmacy orders of antibiotics under restriction. Pre-intervention, we collected Pharmacy and hospital data regarding antibiotic consumption and numbers of patient-days for the years 2013-2015. We calculated antibiotic use in Defined Daily Doses (DDDs/100 patient-days. After one year, the antibiotic stewardship program was effective in reducing consumption of most antibiotics. The result of the implementation of the program in our hospital was a reduction about 17% of antibiotic DDDs/100 patient-days and about 21% of the antibiotic cost/100 patient-days. Education is an essential element of our program in order to influence prescribing behavior. Lectures and brochures are used to supplement strategies. Antibiotic stewardship programs have been shown from many studies to improve patient outcomes, reduce antibiotic resistance and save money.
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DEFF Research Database (Denmark)
Jørgensen, Thomas J. D.; Delforge, D; Remacle, J
1999-01-01
In solution, the antibiotics of the vancomycin group bind stereospecifically to peptides with the C-terminal sequence: -L-Lys-D-Ala-D-Ala, Substitution by a L-Ala at either of the two C-terminal residues causes a dramatic decrease in the binding affinity to the antibiotics. This solution behavior...... is clearly reflected in electrospray ionization (ESI) mass spectra obtained from equimolar mixtures of an antibiotic, an isotopically labelled peptide ligand and an unlabelled peptide stereoisomer. Using collision-induced dissociation (CID) we have probed the gas phase stability of isomeric (1:1) noncovalent...
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Pan, Xueni; Slater, Mel; Beacco, Alejandro; Navarro, Xavi; Bellido Rivas, Anna I; Swapp, David; Hale, Joanna; Forbes, Paul Alexander George; Denvir, Catrina; Hamilton, Antonia F de C; Delacroix, Sylvie
2016-01-01
Dealing with insistent patient demand for antibiotics is an all too common part of a General Practitioner's daily routine. This study explores the extent to which portable Immersive Virtual Reality technology can help us gain an accurate understanding of the factors that influence a doctor's response to the ethical challenge underlying such tenacious requests for antibiotics (given the threat posed by growing anti-bacterial resistance worldwide). It also considers the potential of such technology to train doctors to face such dilemmas. Twelve experienced GPs and nine trainees were confronted with an increasingly angry demand by a woman to prescribe antibiotics to her mother in the face of inconclusive evidence that such antibiotic prescription is necessary. The daughter and mother were virtual characters displayed in immersive virtual reality. The specific purposes of the study were twofold: first, whether experienced GPs would be more resistant to patient demands than the trainees, and second, to investigate whether medical doctors would take the virtual situation seriously. Eight out of the 9 trainees prescribed the antibiotics, whereas 7 out of the 12 GPs did so. On the basis of a Bayesian analysis, these results yield reasonable statistical evidence in favor of the notion that experienced GPs are more likely to withstand the pressure to prescribe antibiotics than trainee doctors, thus answering our first question positively. As for the second question, a post experience questionnaire assessing the participants' level of presence (together with participants' feedback and body language) suggested that overall participants did tend towards the illusion of being in the consultation room depicted in the virtual reality and that the virtual consultation taking place was really happening.
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Directory of Open Access Journals (Sweden)
Xueni Pan
Full Text Available Dealing with insistent patient demand for antibiotics is an all too common part of a General Practitioner's daily routine. This study explores the extent to which portable Immersive Virtual Reality technology can help us gain an accurate understanding of the factors that influence a doctor's response to the ethical challenge underlying such tenacious requests for antibiotics (given the threat posed by growing anti-bacterial resistance worldwide. It also considers the potential of such technology to train doctors to face such dilemmas.Twelve experienced GPs and nine trainees were confronted with an increasingly angry demand by a woman to prescribe antibiotics to her mother in the face of inconclusive evidence that such antibiotic prescription is necessary. The daughter and mother were virtual characters displayed in immersive virtual reality. The specific purposes of the study were twofold: first, whether experienced GPs would be more resistant to patient demands than the trainees, and second, to investigate whether medical doctors would take the virtual situation seriously.Eight out of the 9 trainees prescribed the antibiotics, whereas 7 out of the 12 GPs did so. On the basis of a Bayesian analysis, these results yield reasonable statistical evidence in favor of the notion that experienced GPs are more likely to withstand the pressure to prescribe antibiotics than trainee doctors, thus answering our first question positively. As for the second question, a post experience questionnaire assessing the participants' level of presence (together with participants' feedback and body language suggested that overall participants did tend towards the illusion of being in the consultation room depicted in the virtual reality and that the virtual consultation taking place was really happening.
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Pan, Xueni; Slater, Mel; Beacco, Alejandro; Navarro, Xavi; Bellido Rivas, Anna I.; Swapp, David; Hale, Joanna; Forbes, Paul Alexander George; Denvir, Catrina; de C. Hamilton, Antonia F.; Delacroix, Sylvie
2016-01-01
Background Dealing with insistent patient demand for antibiotics is an all too common part of a General Practitioner’s daily routine. This study explores the extent to which portable Immersive Virtual Reality technology can help us gain an accurate understanding of the factors that influence a doctor’s response to the ethical challenge underlying such tenacious requests for antibiotics (given the threat posed by growing anti-bacterial resistance worldwide). It also considers the potential of such technology to train doctors to face such dilemmas. Experiment Twelve experienced GPs and nine trainees were confronted with an increasingly angry demand by a woman to prescribe antibiotics to her mother in the face of inconclusive evidence that such antibiotic prescription is necessary. The daughter and mother were virtual characters displayed in immersive virtual reality. The specific purposes of the study were twofold: first, whether experienced GPs would be more resistant to patient demands than the trainees, and second, to investigate whether medical doctors would take the virtual situation seriously. Results Eight out of the 9 trainees prescribed the antibiotics, whereas 7 out of the 12 GPs did so. On the basis of a Bayesian analysis, these results yield reasonable statistical evidence in favor of the notion that experienced GPs are more likely to withstand the pressure to prescribe antibiotics than trainee doctors, thus answering our first question positively. As for the second question, a post experience questionnaire assessing the participants’ level of presence (together with participants’ feedback and body language) suggested that overall participants did tend towards the illusion of being in the consultation room depicted in the virtual reality and that the virtual consultation taking place was really happening. PMID:26889676
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Predicting the dynamics of bacterial growth inhibition by ribosome-targeting antibiotics
Greulich, Philip; Doležal, Jakub; Scott, Matthew; Evans, Martin R.; Allen, Rosalind J.
2017-12-01
Understanding how antibiotics inhibit bacteria can help to reduce antibiotic use and hence avoid antimicrobial resistance—yet few theoretical models exist for bacterial growth inhibition by a clinically relevant antibiotic treatment regimen. In particular, in the clinic, antibiotic treatment is time-dependent. Here, we use a theoretical model, previously applied to steady-state bacterial growth, to predict the dynamical response of a bacterial cell to a time-dependent dose of ribosome-targeting antibiotic. Our results depend strongly on whether the antibiotic shows reversible transport and/or low-affinity ribosome binding (‘low-affinity antibiotic’) or, in contrast, irreversible transport and/or high affinity ribosome binding (‘high-affinity antibiotic’). For low-affinity antibiotics, our model predicts that growth inhibition depends on the duration of the antibiotic pulse, and can show a transient period of very fast growth following removal of the antibiotic. For high-affinity antibiotics, growth inhibition depends on peak dosage rather than dose duration, and the model predicts a pronounced post-antibiotic effect, due to hysteresis, in which growth can be suppressed for long times after the antibiotic dose has ended. These predictions are experimentally testable and may be of clinical significance.
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International Nuclear Information System (INIS)
Vashista, M.; Paul, S.
2011-01-01
The Barkhausen Noise Analysis (BNA) technique has been utilised to assess surface integrity of steels. But the BNA technique is not very successful in evaluating surface integrity of ground steels that exhibit poor micro-magnetic response. A new approach has been proposed for the processing of BN signal and two newly proposed parameters, namely 'count' and 'event', have been shown to correlate linearly with the residual stress upon grinding, with judicious choice of user defined 'threshold', even when the micro-magnetic response of the work material is poor. In the present study, residual stress induced upon conventional plunge surface grinding of hardened bearing steel has been investigated along with unhardened bearing steel for benchmarking. Moreover, similar correlation has been established, when primarily compressive stress is induced upon high speed grinding using cBN wheel with moderately deep cut suppressing the micro-magnetic response from the ground medium carbon steel as the work material. - Highlights: → The problem of work materials exhibiting poor BN response and poor Barkhausen Noise response is identified. → A novel signal processing strategy is introduced to address the issue of poor micro-magnetic response of some ferromagnetic material. → Potential of newly introduced BN parameters has been studied. → These two BN parameters exhibited linear correlation with residual stress for work material with poor micro-magnetic response.
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Abscess of residual lobe after pulmonary resection for lung cancer.
Ligabue, Tommaso; Voltolini, Luca; Ghiribelli, Claudia; Luzzi, Luca; Rapicetta, Cristian; Gotti, Giuseppe
2008-04-01
Abscess of the residual lobe after lobectomy is a rare but potentially lethal complication. Between January 1975 and December 2006, 1,460 patients underwent elective pulmonary lobectomy for non-small-cell lung cancer at our institution. Abscess of the residual lung parenchyma occurred in 5 (0.3%) cases (4 bilobectomies and 1 lobectomy). Postoperative chest radiography showed incomplete expansion and consolidation of residual lung parenchyma. Flexible bronchoscopy revealed persistent bronchial occlusion from purulent secretions and/or bronchial collapse. Computed tomography in 3 patients demonstrated lung abscess foci. Surgical treatment included completion right pneumonectomy in 3 patients and a middle lobectomy in one. Complications after repeat thoracotomy comprised contralateral pneumonia and sepsis in 1 patient. Residual lobar abscess after lobectomy should be suspected in patients presenting with fever, leukocytosis, bronchial obstruction and lung consolidation despite antibiotic therapy, physiotherapy and bronchoscopy. Computed tomography is mandatory for early diagnosis. Surgical resection of the affected lobe is recommended.
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Application of Stable Isotope in Detection of Veterinary Drug Residues
International Nuclear Information System (INIS)
Wang Wei; Liu Zhanfeng; Du Xiaoning
2010-01-01
In recent years, there has happened a series of significant food safety events worldwide, which lower down consumers' confidence in food safety, and they are taking increasing care about the sources of their foods. The safety problem of animal-origin foods has become a global topic for discussion. Therefore, it is a pressing task to establish a precise, sensitive and reliable method for analyzing veterinary drug residue. An introduction of the present status regarding veterinary drug residue analysis was made in the paper, and it briefly summarized the limit of detection (LOD) and quantification (LOQ) which could be reached in veterinary drug residue analysis by isotopic internal standard method domestically and abroad. The paper also made a review of the progress in applied research of stable isotope labeled compound in veterinary drug residue analysis of, such as, antibiotic medicines, furans and sulfonamides. The paper elucidated the great importance of the application of stable isotopes in the sane development of China's food safety system. (authors)
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Directory of Open Access Journals (Sweden)
Hsin-Chun Lee
2018-04-01
Full Text Available Antibiotics have been widely used in the treatment of livestock diseases. However, the emergence of issues related to drug resistance prompted governments to enact a series of laws regulating the use of antibiotics in livestock. Following control of the problem of drug resistant bacteria, public attention has shifted to the recurring incidence of human health and safety issues caused by residual veterinary drugs in livestock products. To guarantee the safety and hygiene of meat, milk, and eggs from food-producing animals, governments and relevant agencies established laws and regulations for the use of veterinary drugs. It is, therefore, necessary to monitor the content of residual drugs in livestock products at regular intervals to assess whether the regulations have resulted in the effective management of food product safety, and to prevent and manage sudden problems related to this issue. A 2011–2015 livestock product post-marketing monitoring program launched by the Taiwan Food and Drug Administration (TFDA inspected 1487 livestock products. Over the past 5 years, there were 34 samples identified that did not conform to the regulations; these samples included residue drugs such as β-agonists, chloramphenicols, β-lactam antibiotics, sulfa drugs, enrofloxacin, and lincomycin. Inspections of commercial livestock products with the consistent cooperation of agricultural authorities did not detect the drugs that were banned by the government, whereas the detection of other drugs decreased annually with an increase in the post-market monitoring sample size. In the future, the TFDA will continue to monitor the status of residual veterinary drugs in commercial livestock products, adjust the sampling of food products annually according to monitoring results, and closely cooperate with agricultural authorities on source management. Keywords: Agricultural authorities, Livestock products, Post-market monitoring, Veterinary drug residues
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Johnson, Quentin R; Lindsay, Richard J; Nellas, Ricky B; Fernandez, Elias J; Shen, Tongye
2015-02-24
Understanding allosteric mechanisms is essential for the physical control of molecular switches and downstream cellular responses. However, it is difficult to decode essential allosteric motions in a high-throughput scheme. A general two-pronged approach to performing automatic data reduction of simulation trajectories is presented here. The first step involves coarse-graining and identifying the most dynamic residue-residue contacts. The second step is performing principal component analysis of these contacts and extracting the large-scale collective motions expressed via these residue-residue contacts. We demonstrated the method using a protein complex of nuclear receptors. Using atomistic modeling and simulation, we examined the protein complex and a set of 18 glycine point mutations of residues that constitute the binding pocket of the ligand effector. The important motions that are responsible for the allostery are reported. In contrast to conventional induced-fit and lock-and-key binding mechanisms, a novel "frustrated-fit" binding mechanism of RXR for allosteric control was revealed.
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Combating Antibiotic Resistance
... Bacteria Phasing Out Certain Antibiotic Use in Farm Animals FDA: Cutting-Edge Technology Sheds Light on Antibiotic Resistance For More Information Antibiotics and Antibiotic Resistance Antimicrobial Resistance Information for Consumers and Health Professionals CDC: ...
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International Nuclear Information System (INIS)
Wang, Jilu; Mao, Daqing; Mu, Quanhua; Luo, Yi
2015-01-01
This study investigated the characteristics of 10 subtypes of antibiotic resistance genes (ARGs) for sulfonamide, tetracycline, β-lactam and macrolide resistance and the class 1 integrase gene (intI1). In total, these genes were monitored in 24 samples across each stage of five full-scale pharmaceutical wastewater treatment plants (PWWTPs) using qualitative and real-time quantitative polymerase chain reactions (PCRs). The levels of typical ARG subtypes in the final effluents ranged from (2.08 ± 0.16) × 10 3 to (3.68 ± 0.27) × 10 6 copies/mL. The absolute abundance of ARGs in effluents accounted for only 0.6%–59.8% of influents of the five PWWTPs, while the majority of the ARGs were transported to the dewatered sludge with concentrations from (9.38 ± 0.73) × 10 7 to (4.30 ± 0.81) × 10 10 copies/g dry weight (dw). The total loads of ARGs discharged through dewatered sludge was 7–308 folds higher than that in the raw influents and 16–638 folds higher than that in the final effluents. The proliferation of ARGs mainly occurs in the biological treatment processes, such as conventional activated sludge, cyclic activated sludge system (CASS) and membrane bio-reactor (MBR), implying that significant replication of certain subtypes of ARGs may be attributable to microbial growth. High concentrations of antibiotic residues (ranging from 0.14 to 92.2 mg/L) were detected in the influents of selected wastewater treatment systems and they still remain high residues in the effluents. Partial correlation analysis showed significant correlations between the antibiotic concentrations and the associated relative abundance of ARG subtypes in the effluent. Although correlation does not prove causation, this study demonstrates that in addition to bacterial growth, the high antibiotic residues within the pharmaceutical WWTPs may influence the proliferation and fate of the associated ARG subtypes. - Highlights: • The ARGs in final discharges were 7–308 times higher than
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Energy Technology Data Exchange (ETDEWEB)
Wang, Jilu [College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071 (China); Mao, Daqing, E-mail: mao@tju.edu.cn [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China); Mu, Quanhua [College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071 (China); Luo, Yi, E-mail: luoy@nankai.edu.cn [College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071 (China)
2015-09-01
This study investigated the characteristics of 10 subtypes of antibiotic resistance genes (ARGs) for sulfonamide, tetracycline, β-lactam and macrolide resistance and the class 1 integrase gene (intI1). In total, these genes were monitored in 24 samples across each stage of five full-scale pharmaceutical wastewater treatment plants (PWWTPs) using qualitative and real-time quantitative polymerase chain reactions (PCRs). The levels of typical ARG subtypes in the final effluents ranged from (2.08 ± 0.16) × 10{sup 3} to (3.68 ± 0.27) × 10{sup 6} copies/mL. The absolute abundance of ARGs in effluents accounted for only 0.6%–59.8% of influents of the five PWWTPs, while the majority of the ARGs were transported to the dewatered sludge with concentrations from (9.38 ± 0.73) × 10{sup 7} to (4.30 ± 0.81) × 10{sup 10} copies/g dry weight (dw). The total loads of ARGs discharged through dewatered sludge was 7–308 folds higher than that in the raw influents and 16–638 folds higher than that in the final effluents. The proliferation of ARGs mainly occurs in the biological treatment processes, such as conventional activated sludge, cyclic activated sludge system (CASS) and membrane bio-reactor (MBR), implying that significant replication of certain subtypes of ARGs may be attributable to microbial growth. High concentrations of antibiotic residues (ranging from 0.14 to 92.2 mg/L) were detected in the influents of selected wastewater treatment systems and they still remain high residues in the effluents. Partial correlation analysis showed significant correlations between the antibiotic concentrations and the associated relative abundance of ARG subtypes in the effluent. Although correlation does not prove causation, this study demonstrates that in addition to bacterial growth, the high antibiotic residues within the pharmaceutical WWTPs may influence the proliferation and fate of the associated ARG subtypes. - Highlights: • The ARGs in final discharges were 7
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Kesel, Sara; Mader, Andreas; Höfler, Carolin; Mascher, Thorsten; Leisner, Madeleine
2013-01-01
Two-component signal transduction systems are one means of bacteria to respond to external stimuli. The LiaFSR two-component system of Bacillus subtilis consists of a regular two-component system LiaRS comprising the core Histidine Kinase (HK) LiaS and the Response Regulator (RR) LiaR and additionally the accessory protein LiaF, which acts as a negative regulator of LiaRS-dependent signal transduction. The complete LiaFSR system was shown to respond to various peptide antibiotics interfering with cell wall biosynthesis, including bacitracin. Here we study the response of the LiaFSR system to various concentrations of the peptide antibiotic bacitracin. Using quantitative fluorescence microscopy, we performed a whole population study analyzed on the single cell level. We investigated switching from the non-induced 'OFF' state into the bacitracin-induced 'ON' state by monitoring gene expression of a fluorescent reporter from the RR-regulated liaI promoter. We found that switching into the 'ON' state occurred within less than 20 min in a well-defined switching window, independent of the bacitracin concentration. The switching rate and the basal expression rate decreased at low bacitracin concentrations, establishing clear heterogeneity 60 min after bacitracin induction. Finally, we performed time-lapse microscopy of single cells confirming the quantitative response as obtained in the whole population analysis for high bacitracin concentrations. The LiaFSR system exhibits an immediate, heterogeneous and graded response to the inducer bacitracin in the exponential growth phase.
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Lankelma, Jacqueline M; Cranendonk, Duncan R; Belzer, Clara; de Vos, Alex F; de Vos, Willem M; van der Poll, Tom; Wiersinga, W Joost
2017-09-01
The gut microbiota is essential for the development of the intestinal immune system. Animal models have suggested that the gut microbiota also acts as a major modulator of systemic innate immunity during sepsis. Microbiota disruption by broad-spectrum antibiotics could thus have adverse effects on cellular responsiveness towards invading pathogens. As such, the use of antibiotics may attribute to immunosuppression as seen in sepsis. We aimed to test whether disruption of the gut microbiota affects systemic innate immune responses during endotoxemia in healthy subjects. In this proof-of-principle intervention trial, 16 healthy young men received either no treatment or broad-spectrum antibiotics (ciprofloxacin, vancomycin and metronidazole) for 7 days, after which all were administered lipopolysaccharide intravenously to induce a transient sepsis-like syndrome. At various time points, blood and faeces were sampled. Gut microbiota diversity was significantly lowered by the antibiotic treatment in all subjects. Clinical parameters, neutrophil influx, cytokine production, coagulation activation and endothelial activation during endotoxemia were not different between antibiotic-pretreated and control individuals. Antibiotic treatment had no impact on blood leucocyte responsiveness to various Toll-like receptor ligands and clinically relevant causative agents of sepsis ( Streptococcus pneumoniae, Klebsiella pneumoniae, Escherichia coli ) during endotoxemia. These findings suggest that gut microbiota disruption by broad-spectrum antibiotics does not affect systemic innate immune responses in healthy subjects during endotoxemia in humans, disproving our hypothesis. Further research is needed to test this hypothesis in critically ill patients. These data underline the importance of translating findings in mice to humans. ClinicalTrials.gov (NCT02127749; Pre-results). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a
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On the feasibility of a CENTA-based biosensor to measure antibiotics concentration in milk
Ferrari, Luca; Rovati, Luigi; Costi, Maria Paola; Venturelli, Alberto; Luciani, Rosaria; Cattini, Stefano
2017-07-01
In veterinary practice antibiotics are used and abused all over the world both to treat diseases and prevent infections and, to increase feed efficiency thus promoting growth in food producing animals. With more than 30 years history, β-lactam antibiotics are nowadays one of the most important group of antibiotics in veterinary medicine. In this paper we investigate the possibility to realize a measurement method suitable for field testing and we propose a competitive biosensor based on a relatively low-cost chromogenic cephalosporin (CENTA) for the quantitative analysis of β-lactams concentration in milk. In particular, the reported preliminary study has been focused on cloxacillin and the reported results indicates that the method is potentially able to detect cloxacillin at a concentration of about one order of magnitude lower than the maximal residue limits (MRL) set by the European Commission.
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Dental students′ compliance with antibiotic prescribing guidelines for dental infections in children
Directory of Open Access Journals (Sweden)
Yee Chen Wong
2016-01-01
Full Text Available Context: To investigate the antibiotic prescribing training received by dental students, clinical experience in treating child patients, awareness of antibiotic prescribing guidelines, preparedness in antibiotic prescribing, and compliance with antibiotic prescribing guidelines for the management of dental infections in children. Methods: This was a cross-sectional study involving final year dentals students from Malaysian and Asian dental schools. A self-administered questionnaire consisting of five clinical case scenarios was e-mailed to all final year students at selected dental schools. Students′ responses were compared for each clinical case scenario with the prescribing guidelines of the American Academy of Pediatric Dentistry and the American Dental Association. Compliance in each scenario was tested for association with their preparedness in antibiotic prescribing, previous training on antibiotic prescribing and awareness of antibiotic prescribing guidelines using Chi-square test. Data collected were analyzed using SPSS statistics version 20. Results: A total of 108 completed responses were received. About 74 (69% students were from Malaysian dental schools. The compliance rate with prescribing guidelines ranged from 15.7% to 43.5%. Those attending Malaysian dental schools (47.3% and those who had treated child patient more often (46.3% were more likely (P < 0.05 to be aware of the guidelines. Those who had received antibiotic prescribing training (21.3% were more likely to think they were well prepared in antibiotic prescribing (P < 0.05. Conclusions: Final year dental students had low awareness and compliance with antibiotic prescribing guidelines. Further research is needed to investigate how compliance with the guidelines may be enhanced.
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Directory of Open Access Journals (Sweden)
Fausto Scoppetta
2017-09-01
Full Text Available Antibiotic use in food-producing animals has considerable impact on public health, especially with respect to the development and spread of antibiotic resistance. Pigs represent one of the main species in which antibiotics are frequently used for different purposes. Surveillance of antibiotic consumption and dose appropriateness, through novel approaches based on defined daily doses, is strongly needed to assess farms’ antibiotic risk, in terms of spread of antibiotic resistance and possibile presence of residues in meat. In this study, antibiotic consumption was monitored in 14 swine reproduction farms, together with managerial, structural, and health aspects. Most of the controlled farms (65% were classified as at medium antibiotic risk, 21% at high antibiotic risk, and 14% at low antibiotic risk. Critical aspects of antibiotic administration concerned treatments for suckling and weaner piglets, oral antibiotic administration, treatment and diagnosis of gastroenteric infections, and use of critically important antimicrobials for human medicine, especially colistin. These aspects could be considered critical aspects of antibiotic use in from-farrow-to-wean/finish swine farms in the Umbria region and must be controlled to minimize risks. Even though a small number of farms in Umbria region are at high antibiotic risk, the risk of antibiotic resistance should be minimized, and management and biosecurity of the farms should be improved by extending the use of antimicrobial susceptibility tests and optimizing the diagnostic methods for infectious diseases. Furthermore, farmers’ and veterinarians’ knowledge of antibiotic resistance should be improved and the prudent use of antibiotics encouraged to prevent the development and spread of resistant microorganisms.
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Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination.
Jia, Shuyu; Shi, Peng; Hu, Qing; Li, Bing; Zhang, Tong; Zhang, Xu-Xiang
2015-10-20
For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.
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Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis
International Nuclear Information System (INIS)
2016-01-01
Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples
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Obesity in the United States—dysbiosis from exposure to low-dose antibiotics?
Directory of Open Access Journals (Sweden)
Lee W Riley
2013-12-01
Full Text Available The rapid increase in obesity prevalence in the United States in the last 20 years is unprecedented and not well explained. Here, we explore a hypothesis that the obesity epidemic may be driven by population-wide chronic exposures to low-residue antibiotics that have increasingly entered the American food chain over the same time period. We propose this hypothesis based on two recent bodies of published reports—1 those that provide evidence for the spread of antibiotics into the American food chain, and 2 those that examine the relationship between the gut microbiota and body physiology. The livestock use of antimicrobial agents has sharply increased in the US over the same 20-year period of the obesity epidemic, especially with the expansion of intensified livestock production, such as the concentrated animal feeding operations (CAFOs. Observational and experimental studies support the idea that changes in the intestinal microbiota exert a profound effect on body physiology. We propose that chronic exposures to low-residue antimicrobial drugs in food could disrupt the equilibrium state of intestinal microbiota and cause dysbiosis that can contribute to changes in body physiology. The obesity epidemic in the United States may be partly driven by the mass exposure of Americans to food containing low-residue antimicrobial agents. While this hypothesis cannot discount the impact of diet and other factors associated with obesity, we believe studies are warranted to consider this possible driver of the epidemic.
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A Biomathematical Model of Pneumococcal Lung Infection and Antibiotic Treatment in Mice.
Schirm, Sibylle; Ahnert, Peter; Wienhold, Sandra; Mueller-Redetzky, Holger; Nouailles-Kursar, Geraldine; Loeffler, Markus; Witzenrath, Martin; Scholz, Markus
2016-01-01
Pneumonia is considered to be one of the leading causes of death worldwide. The outcome depends on both, proper antibiotic treatment and the effectivity of the immune response of the host. However, due to the complexity of the immunologic cascade initiated during infection, the latter cannot be predicted easily. We construct a biomathematical model of the murine immune response during infection with pneumococcus aiming at predicting the outcome of antibiotic treatment. The model consists of a number of non-linear ordinary differential equations describing dynamics of pneumococcal population, the inflammatory cytokine IL-6, neutrophils and macrophages fighting the infection and destruction of alveolar tissue due to pneumococcus. Equations were derived by translating known biological mechanisms and assuming certain response kinetics. Antibiotic therapy is modelled by a transient depletion of bacteria. Unknown model parameters were determined by fitting the predictions of the model to data sets derived from mice experiments of pneumococcal lung infection with and without antibiotic treatment. Time series of pneumococcal population, debris, neutrophils, activated epithelial cells, macrophages, monocytes and IL-6 serum concentrations were available for this purpose. The antibiotics Ampicillin and Moxifloxacin were considered. Parameter fittings resulted in a good agreement of model and data for all experimental scenarios. Identifiability of parameters is also estimated. The model can be used to predict the performance of alternative schedules of antibiotic treatment. We conclude that we established a biomathematical model of pneumococcal lung infection in mice allowing predictions regarding the outcome of different schedules of antibiotic treatment. We aim at translating the model to the human situation in the near future.
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The expression of antibiotic resistance genes in antibiotic-producing bacteria.
Mak, Stefanie; Xu, Ye; Nodwell, Justin R
2014-08-01
Antibiotic-producing bacteria encode antibiotic resistance genes that protect them from the biologically active molecules that they produce. The expression of these genes needs to occur in a timely manner: either in advance of or concomitantly with biosynthesis. It appears that there have been at least two general solutions to this problem. In many cases, the expression of resistance genes is tightly linked to that of antibiotic biosynthetic genes. In others, the resistance genes can be induced by their cognate antibiotics or by intermediate molecules from their biosynthetic pathways. The regulatory mechanisms that couple resistance to antibiotic biosynthesis are mechanistically diverse and potentially relevant to the origins of clinical antibiotic resistance. © 2014 John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Anthony Ayodeji Adegoke
2016-12-01
Full Text Available The increasing threat to global health posed by antibiotic resistance remains of serious concern. Human health remains at higher risk due to several reported therapeutic failures to many life threatening drug resistant microbial infections. The resultant effects have been prolonged hospital stay, higher cost of alternative therapy, increased mortality, etc. This opinionated review considers the two main concerns in integrated human health risk assessment (i.e., residual antibiotics and antibiotic resistant genes in various compartments of human environment, as well as clinical dynamics associated with the development and transfer of antibiotic resistance (AR. Contributions of quorum sensing, biofilms, enzyme production, and small colony variants in bacteria, among other factors in soil, water, animal farm and clinical settings were also considered. Every potential factor in environmental and clinical settings that brings about AR needs to be identified for the summative effects in overall resistance. There is a need to embrace coordinated multi-locational approaches and interrelationships to track the emergence of resistance in different niches in soil and water versus the hospital environment. The further integration with advocacy, legislation, enforcement, technological innovations and further research input and recourse to WHO guidelines on antibiotic policy would be advantageous towards addressing the emergence of antibiotic resistant superbugs.
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Wright, Gerard D
2010-08-01
Antibiotics are essential for the treatment of bacterial infections and are among our most important drugs. Resistance has emerged to all classes of antibiotics in clinical use. Antibiotic resistance has, proven inevitable and very often it emerges rapidly after the introduction of a drug into the clinic. There is, therefore, a great interest in understanding the origins, scope and evolution of antibiotic resistance. The review discusses the concept of the antibiotic resistome, which is the collection of all genes that directly or indirectly contribute to antibiotic resistance. The review seeks to assemble current knowledge of the resistome concept as a means of understanding the totality of resistance and not just resistance in pathogenic bacteria. The concept of the antibiotic resistome provides a framework for the study and understanding of how resistance emerges and evolves. Furthermore, the study of the resistome reveals strategies that can be applied in new antibiotic discoveries.
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Antibiotic use and resistance in animals: Belgian initiatives.
Daeseleire, Els; De Graef, Evelyne; Rasschaert, Geertrui; De Mulder, Thijs; Van den Meersche, Tina; Van Coillie, Els; Dewulf, Jeroen; Heyndrickx, Marc
2016-05-01
The widespread use of antibiotics in animals is causing concerns about the growing risk for development and the spread of antibiotic-resistant bacteria. Antibiotic consumption is higher in animals than in humans as reported in a joint publication of EFSA (European Food Safety Agency), ECDC (European Centre for Disease Prevention and Control), and EMA (European Medicines Agency) using data from 2011 and 2012. Both in humans and animals, positive associations between the consumption of antibiotics and resistant bacteria are observed. Responsible use of antibiotics in humans and animals should therefore be promoted. In this paper some general aspects of antibiotic resistance such as microbiological versus clinical resistance, intrinsic versus acquired resistance, resistance mechanisms, and transfer of resistance are briefly introduced. In 2012, the Belgian Center of Expertise on Antimicrobial Consumption and Resistance in Animals (AMCRA) was founded. Its mission is to collect and analyze all data related to antibiotic use and resistance in animals in Belgium and to communicate these findings in a neutral and objective manner. One of AMCRA's 10 objectives is a 50% reduction in antibiotic consumption in veterinary medicine in Belgium by 2020. The aim of this paper is to report on the achievements of this national project. The Institute for Agricultural and Fisheries Research (ILVO, Merelbeke-Melle), in collaboration with Ghent University, is currently working on three nationally funded projects on antibiotic resistance in animal husbandry. In the first project, an in vitro model is used to study the influence of low antibiotic concentrations due to carry-over after production and usage of medicated feed on the development of resistance in the pig gut. Part of that project is to develop a quantitative risk assessment model. A second project focuses on tracking excreted antibiotics used in pig rearing and their influence on the development of antibiotic resistance in pig
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Mogre, Aalap; Sengupta, Titas; Veetil, Reshma T.; Ravi, Preethi; Seshasayee, Aswin Sai Narain
2014-01-01
Evolution of bacteria under sublethal concentrations of antibiotics represents a trade-off between growth and resistance to the antibiotic. To understand this trade-off, we performed in vitro evolution of laboratory Escherichia coli under sublethal concentrations of the aminoglycoside kanamycin over short time durations. We report that fixation of less costly kanamycin-resistant mutants occurred earlier in populations growing at lower sublethal concentration of the antibiotic, compared with those growing at higher sublethal concentrations; in the latter, resistant mutants with a significant growth defect persisted longer. Using deep sequencing, we identified kanamycin resistance-conferring mutations, which were costly or not in terms of growth in the absence of the antibiotic. Multiple mutations in the C-terminal end of domain IV of the translation elongation factor EF-G provided low-cost resistance to kanamycin. Despite targeting the same or adjacent residues of the protein, these mutants differed from each other in the levels of resistance they provided. Analysis of one of these mutations showed that it has little defect in growth or in synthesis of green fluorescent protein (GFP) from an inducible plasmid in the absence of the antibiotic. A second class of mutations, recovered only during evolution in higher sublethal concentrations of the antibiotic, deleted the C-terminal end of the ATP synthase shaft. This mutation confers basal-level resistance to kanamycin while showing a strong growth defect in the absence of the antibiotic. In conclusion, the early dynamics of the development of resistance to an aminoglycoside antibiotic is dependent on the levels of stress (concentration) imposed by the antibiotic, with the evolution of less costly variants only a matter of time. PMID:25281544
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Addressing resistance to antibiotics in systematic reviews of antibiotic interventions
DEFF Research Database (Denmark)
Leibovici, Leonard; Paul, Mical; Garner, Paul
2016-01-01
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies....... This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should...... controlled trials or systematic reviews....
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Hsin-Chun Lee; Chi-Min Chen; Jen-Ting Wei; Hsiu-Yi Chiu
2018-01-01
Antibiotics have been widely used in the treatment of livestock diseases. However, the emergence of issues related to drug resistance prompted governments to enact a series of laws regulating the use of antibiotics in livestock. Following control of the problem of drug resistant bacteria, public attention has shifted to the recurring incidence of human health and safety issues caused by residual veterinary drugs in livestock products. To guarantee the safety and hygiene of meat, milk, and egg...
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Immunostimulation asa method limiting unnecessary antibiotic therapy
Directory of Open Access Journals (Sweden)
Agnieszka Szczukocka-Zych
2015-12-01
Full Text Available Recurring respiratory tract infections are typical of childhood. This results from the fact that children are exposed to pathogens, usually in groups of people, and from the immaturity of the immune system. Most upper and lower respiratory tract infections are caused by viruses. Nevertheless, antibiotics, which target bacteria, are often prescribed. Antibiotic overuse leads to increased microbial resistance to these drugs, resulting in their inefficacy. Improper treatment of respiratory infections with antibiotics ultimately leads to treatment failure. An increase in antibiotic resistance of many bacterial strains is becoming a serious global problem and makes treatment much more difficult. It is a responsibility of each physician to use antibiotics properly and implement adequate prevention of recurring respiratory tract infections. For many years, it has been attempted to find effective agents that improve immunity in children. The pharmaceutical market offers various preparations advertised as immunostimulants, such as bacterial lysates, vitamins, dietary supplements, probiotics or herbal, animal and homeopathic products. The role of immunomodulatory substances is to promote the immune system to fight pathogens, reduce the frequency of infections and decrease the demand for antibiotics. Unfortunately, most immunomodulators do not have sufficiently reliable clinical trials that would confirm their efficacy.
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Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf
2015-01-01
The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks to the aquatic environment, yet the persistence of these antibiotics is of concern and might lead to
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Hamscher, Gerd; Pawelzick, Heike Theresia; Sczesny, Silke; Nau, Heinz; Hartung, Jörg
2003-10-01
Pig-house dust originates from feed, bedding, feces, and the animals themselves. If the animals receive drugs such as antibiotics, residues of these substances may occur in manure, in the air, or on surfaces of the respective animal house. In a retrospective study, we investigated dust samples collected during two decades from the same piggery for the occurrence of various antibiotics. In 90% of these samples, we detected up to five different antibiotics, including tylosin, various tetracyclines, sulfamethazine, and chloramphenicol, in total amounts up to 12.5 mg/kg dust. High dust exposure in animal confinement buildings is believed to be a respiratory health hazard because of the high content of microorganisms, endotoxins, and allergens. Further risks may arise from the inhalation of dust contaminated with a cocktail of antibiotics. Apart from that, our data provide first evidence for a new route of entry for veterinary drugs in the environment.
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Impact of reclaimed water irrigation on antibiotic resistance in public parks, Beijing, China
International Nuclear Information System (INIS)
Wang, Feng-Hua; Qiao, Min; Lv, Zhen-E; Guo, Guang-Xia; Jia, Yan; Su, Yu-Hong; Zhu, Yong-Guan
2014-01-01
The abundance and distribution of antibiotics and antibiotic resistance genes (ARGs) in soils from six parks using reclaimed water in Beijing, China, were characterized. Three classes of commonly used antibiotics (tetracycles, quinolones, and sulfonamides) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The highest concentrations of tetracyclines and quinolones were 145.2 μg kg −1 and 79.2 μg kg −1 , respectively. Detected tetG, tetW, sulI, and sulII genes were quantified by quantitative PCR. ARGs exhibited various abundances for different park soils. The integrase gene (intI1) as an indicator of horizontal gene transfer potential was also detected in high abundance, and had significant positive correlation with tetG, sulI, and sulII genes, suggesting that intI1 may be involved in ARGs dissemination. Both sulII and intI1 clones had high homology with some classes of pathogenic bacteria, such as Klebsiella oxytoca, Acinetobacter baumannii, Shigella flexneri, which could trigger potential public health concern. Highlights: • Reclaimed water irrigation could increase the concentration of antibiotics and ARGs in urban park soils. • ARGs can be persistent in the irrigated park soils, even without antibiotic selection pressure. • Both sulII and intI1 clones had high homology with some classes of pathogenic bacteria. -- The release of residual antibiotics and ARGs from reclaimed water could result in the proliferation of ARGs in irrigated park soils
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Adesokan, Hezekiah K; Agada, Charity A; Adetunji, Victoria O; Akanbi, Ibikunle M
2013-01-01
After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.
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Directory of Open Access Journals (Sweden)
Hezekiah K. Adesokan
2013-07-01
Full Text Available After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA. The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38 were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline and 0.017% (penicillin-G of the acceptable daily intake (ADI. Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised.
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Action and resistance mechanisms of antibiotics: A guide for clinicians
Directory of Open Access Journals (Sweden)
Garima Kapoor
2017-01-01
Full Text Available Infections account for a major cause of death throughout the developing world. This is mainly due to the emergence of newer infectious agents and more specifically due to the appearance of antimicrobial resistance. With time, the bacteria have become smarter and along with it, massive imprudent usage of antibiotics in clinical practice has resulted in resistance of bacteria to antimicrobial agents. The antimicrobial resistance is recognized as a major problem in the treatment of microbial infections. The biochemical resistance mechanisms used by bacteria include the following: antibiotic inactivation, target modification, altered permeability, and “bypass” of metabolic pathway. Determination of bacterial resistance to antibiotics of all classes (phenotypes and mutations that are responsible for bacterial resistance to antibiotics (genetic analysis are helpful. Better understanding of the mechanisms of antibiotic resistance will help clinicians regarding usage of antibiotics in different situations. This review discusses the mechanism of action and resistance development in commonly used antimicrobials.
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The Role of Antibiotics in Modulating Virulence in Staphylococcus aureus.
Hodille, Elisabeth; Rose, Warren; Diep, Binh An; Goutelle, Sylvain; Lina, Gerard; Dumitrescu, Oana
2017-10-01
Staphylococcus aureus is often involved in severe infections, in which the effects of bacterial virulence factors have great importance. Antistaphylococcal regimens should take into account the different effects of antibacterial agents on the expression of virulence factors and on the host's immune response. A PubMed literature search was performed to select relevant articles on the effects of antibiotics on staphylococcal toxin production and on the host immune response. Information was sorted according to the methods used for data acquisition (bacterial strains, growth models, and antibiotic concentrations) and the assays used for readout generation. The reported mechanisms underlying S. aureus virulence modulation by antibiotics were reviewed. The relevance of in vitro observations is discussed in relation to animal model data and to clinical evidence extracted from case reports and recommendations on the management of toxin-related staphylococcal diseases. Most in vitro data point to a decreased level of virulence expression upon treatment with ribosomally active antibiotics (linezolid and clindamycin), while cell wall-active antibiotics (beta-lactams) mainly increase exotoxin production. In vivo studies confirmed the suppressive effect of clindamycin and linezolid on virulence expression, supporting their utilization as a valuable management strategy to improve patient outcomes in cases of toxin-associated staphylococcal disease. Copyright © 2017 American Society for Microbiology.
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Antibiotic use in childhood alters the gut microbiota and predisposes to overweight
Directory of Open Access Journals (Sweden)
Katri Korpela
2016-06-01
Full Text Available A correlation between the use of antibiotics in early life and the excessive weight gain in later childhood has been shown in several large cohort studies all over the world. One hypothesis explaining this association is the pervasive impact that antibiotics may have on the intestinal microbiota, and this has been supported by recent mouse studies. Studies have shown dramatic changes in the intestinal microbiota of adults in response to oral antibiotic treatments. However, little is known about the impact of antibiotics on the intestinal microbiota of children, although antibiotics account for the majority of the medication prescribed to children in Western countries.
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Attitudes of pharmacists and physicians to antibiotic policies in hospitals.
Adu, A; Simpson, J M; Armour, C L
1999-06-01
Antibiotic therapy in hospitals has substantial impact on patient outcome and the pharmacy drug budget. Antibiotic policies have been implemented by some hospitals to improve the quality of patient outcome and cost of antibiotic therapy. Antibiotic policies impose certain requirements on pharmacists and physicians. Pharmacists' and physicians' attitudes to and opinions about antibiotic policies are likely to affect the usefulness of such policies. To determine the attitudes of pharmacists and physicians to antibiotic policies in New South Wales (NSW) hospitals. Pharmacists and physicians in NSW public hospitals were surveyed to determine their attitudes to and opinions on antibiotic policies. A simple one-stage cluster sample of 241 pharmacists and a two-stage cluster sample of 701 physicians were obtained. Factor analysis was used to identify the attitudinal dimensions. General linear modelling was used to investigate the effects of predictor variables on outcome variables. The response rates were 91% and 77% for pharmacists and physicians, respectively. Factor analysis identified three dimensions of attitude to antibiotic policies: that they encourage rational antibiotic use; that they improve the quality of antibiotic prescribing and that they are associated with some problems. The reliability of these factors (Cronbach's alpha) ranged from 0.71 to 0.74, and was 0.90 for the overall attitude scale. Pharmacists and physicians had a positive overall attitude to antibiotic policies. Whereas physicians recognize that antibiotic policies improve the quality of prescribing, this was highly correlated with identification of problems (alpha = 0.71). In urban hospitals, pharmacists were more likely than physicians to associate antibiotics with problems. There was a positive overall attitude to hospital antibiotic policies expressed by pharmacists and physicians.
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Amino acid residues that contribute to substrate specificity of class A beta-lactamase SME-1.
Majiduddin, Fahd K; Palzkill, Timothy
2005-08-01
Carbapenem antibiotics are used as antibiotics of last resort because they possess a broad spectrum of antimicrobial activity and are not easily hydrolyzed by beta-lactamases. Recently, class A enzymes, such as the SME-1, NMC-A, and IMI-1 beta-lactamases, have been identified with the capacity to hydrolyze carbapenem antibiotics. Traditional class A beta-lactamases, such as TEM-1 and SHV-1, are unable to hydrolyze carbapenem antibiotics and exhibit some differences in sequence from those that are able to hydrolyze carbapenem antibiotics. The positions that differ may contribute to the unique substrate specificity of the class A carbapenemase SME-1. Codons in the SME-1 gene representing residues 104, 105, 132, 167, 237, and 241 were randomized by site-directed mutagenesis, and functional mutants were selected for the ability to hydrolyze imipenem, ampicillin, or cefotaxime. Although several positions are important for hydrolysis of beta-lactam antibiotics, no single position was found to uniquely contribute to carbapenem hydrolysis. The results of this study support a model whereby the carbapenemase activity of SME-1 is due to a highly distributed set of interactions that subtly alter the structure of the active-site pocket.
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Amino Acid Residues That Contribute to Substrate Specificity of Class A β-Lactamase SME-1
Majiduddin, Fahd K.; Palzkill, Timothy
2005-01-01
Carbapenem antibiotics are used as antibiotics of last resort because they possess a broad spectrum of antimicrobial activity and are not easily hydrolyzed by β-lactamases. Recently, class A enzymes, such as the SME-1, NMC-A, and IMI-1 β-lactamases, have been identified with the capacity to hydrolyze carbapenem antibiotics. Traditional class A β-lactamases, such as TEM-1 and SHV-1, are unable to hydrolyze carbapenem antibiotics and exhibit some differences in sequence from those that are able to hydrolyze carbapenem antibiotics. The positions that differ may contribute to the unique substrate specificity of the class A carbapenemase SME-1. Codons in the SME-1 gene representing residues 104, 105, 132, 167, 237, and 241 were randomized by site-directed mutagenesis, and functional mutants were selected for the ability to hydrolyze imipenem, ampicillin, or cefotaxime. Although several positions are important for hydrolysis of β-lactam antibiotics, no single position was found to uniquely contribute to carbapenem hydrolysis. The results of this study support a model whereby the carbapenemase activity of SME-1 is due to a highly distributed set of interactions that subtly alter the structure of the active-site pocket. PMID:16048956
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Are we eliminating cures with antibiotic abuse? A study among dentists.
Goud, S R; Nagesh, L; Fernandes, S
2012-01-01
The theme of "World Health Day 2011" is "combat drug resistance- No action today, No cure tomorrow" which is very pertinent. The present study emphatically demonstrates the current issues related to the overwhelming concerns regarding indiscriminate use of antibiotics, leading to a bleak tomorrow where cures may be few. To know the prescription pattern of antibiotics for various dental procedures by dental practitioners. A pretested questionnaire was used which contained two sections pertaining to prescription of antibiotics for healthy and medically compromised patients during various dental procedures, with therapeutic and prophylactic considerations. Questionnaire response rate of 66.6% was observed. Amoxicillin emerged as the most preferred antibiotic for dental procedures both as a therapeutic and a prophylactic drug. 50% of the endodontists and 40% of the general dentists opted to prescribe antibiotics during root canal therapy where ideally operative intervention would have sufficed. Overuse of antibiotics for routine scaling and extraction was observed. The dental profession as a whole needs to acquire a deeper understanding of the global effects of superfluous antibiotic prescription. Antibiotics when judiciously used are precise life-saving drugs.
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Bistable Bacterial Growth Rate in Response to Antibiotics with Low Membrane Permeability
Elf, Johan; Nilsson, Karin; Tenson, Tanel; Ehrenberg, Måns
2006-12-01
We demonstrate that growth rate bistability for bacterial cells growing exponentially at a fixed external antibiotic concentration can emerge when the cell wall permeability for the drug is low and the growth rate sensitivity to the intracellular drug concentration is high. Under such conditions, an initially high growth rate can remain high, due to dilution of the intracellular drug concentration by rapid cell volume increase, while an initially low growth rate can remain low, due to slow cell volume increase and insignificant drug dilution. Our findings have implications for the testing of novel antibiotics on growing bacterial strains.
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Otero, Fátima; Tamayo, María; Santiso, Rebeca; Gosálvez, Jaime; Bou, Germán; Fernández, José Luis
2017-04-01
A novel assay for rapid determination of resistance to antibiotic inhibitors of protein synthesis was developed for the gram-positive pathogens, Enterococcus faecalis and Streptococcus pneumoniae. To this purpose, a lytic response was obtained by a brief incubation with lysozyme or a mixture of lysozyme, Triton X-100, and EDTA for E. faecalis (n = 82) and S. pneumoniae (n = 51), respectively. Lysis was quantified by visualizing the released nucleoids. Antibiotic-susceptible bacteria treated with Clinical and Laboratory Standards Institute (CLSI) breakpoint doses of erythromycin, azithromycin, or doxycycline that inhibited protein synthesis demonstrated a large reduction of lysed cells with respect to the control, that is, without antibiotics. However, cell lysis prevention was much lower in nonsusceptible strains, with unsuccessful inhibition of protein synthesis. ROC analysis showed that a reduction value of ≥35.6% and ≥40.4% discriminates susceptible and nonsusceptible strains for erythromycin and for doxycycline, respectively, in E. faecalis, whereas ≥20.0% is adequate for both macrolides and doxycycline in S. pneumoniae. Resistant stains were identified in 90-120 min with sensitivity and specificity between 91.7% and 100%. This is a proof of concept that evaluation of the lytic response may be a rapid and efficient test for determination of resistance to antibiotic inhibitors of protein synthesis.
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Wen, Xin; Wang, Yan; Zou, Yongde; Ma, Baohua; Wu, Yinbao
2018-01-01
Biodegradation of antibiotic residues in the environment by microorganisms may lead to the generation of antibiotic resistance genes (ARGs), which are of great concern to human health. The aim of this study was to determine whether there is a relationship between the ability to degrade antibiotic doxycycline (DOX) and the development of resistance genes in microorganisms. We isolated and identified ten bacterial strains from a vegetable field that had received long-term manure application as fertilizer and were capable of surviving in a series of DOX concentrations (25, 50, 80, and 100mg/L). Our results showed no evidential correlation between DOX degradation ability and the development of resistance genes among the isolated microorganisms that had high DOX degradation capability (P > 0.05). This was based on the fact that Escherichia sp. and Candida sp. were the most efficient bacterial strains to degrade DOX (92.52% and 91.63%, respectively), but their tetracycline resistance genes showed a relatively low risk of antibiotic resistance in a 7-day experiment. Moreover, the tetM of the ribosomal protection protein genes carried by these two preponderant bacteria was five-fold higher than that carried by other isolates (P genes of three isolates, except for Escherichia sp. and Candida sp., showed remarkable negative correlations (P < 0.05), mainly because tetG markedly increased during the DOX degradation process. Our results concluded that the biodegradation of antibiotic residues may not necessarily lead to the development of ARGs in the environment. In addition, the two bacteria that we isolated, namely, Escherichia sp. and Candida sp., are potential candidates for the engineering of environmentally friendly bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.
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Ghiga, I; Stålsby Lundborg, C
2016-01-01
Antibiotic resistance is a serious global public health problem directly correlated to high antibiotic consumption. Romania is one of the European countries with the highest rates of antibiotic consumption, non-prescription antibiotics use and resistance of several pathogens to antibiotics. Pharmacists are an important stakeholder in respect to antibiotic management and context specific research on this topic is needed. The aim of the research is to increase the understanding of how community pharmacists in Romania perceive their roles in respect to antibiotic consumption and antibiotic resistance. Semi-structured interviews with 18 pharmacists were conducted to explore the perceptions and attitudes of pharmacists towards their roles on antibiotics consumption and antibiotic resistance. Manifest and latent qualitative content analysis was used to analyse interview transcripts. Three sub-themes emerged from the analysis. 'Maintaining equilibrium between ethics, law and economy' expresses how pharmacists often feel when trying to fulfil their duties considering all the dimensions of the pharmacist profession.' Antibiotic resistance problem rooted in a low social capital environment' reflects the pharmacists' perceptions of the deep causes of antibiotic resistance and the underlying problems that perpetuate the status quo and impact their role in relation to this problem. Wanting to fulfil their educational role illustrates how the pharmacists feel they could best contribute to improving the present situation. The overarching theme 'Undervalued medicines' professionals struggling with agency related and structural barriers to meet their deontological duties'- meaning the ethical responsibilities that come with the pharmacy practice, reflects that the pharmacists see their roles as being challenged by several barriers. A health system and societal context perspective is helpful in order to understand the pharmacists' roles in respect to antibiotic consumption and
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Improving antibiotic use in daily hospital practice : The antibiotic checklist
van Daalen, F.V.
2018-01-01
Better use of current antibiotic agents is necessary to help control antimicrobial resistance (AMR). Antibiotic stewardship programs (ASPs) are introduced to coordinate activities to measure and improve appropriate antibiotic use in daily hospital practice. This thesis shows how the introduction of
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Continuous infusion of antibiotics in critically ill patients.
Smuszkiewicz, Piotr; Szałek, Edyta; Tomczak, Hanna; Grześkowiak, Edmund
2013-02-01
Antibiotics are the most commonly used drugs in intensive care unit patients and their supply should be based on pharmacokinetic/pharmacodynamic rules. The changes that occur in septic patients who are critically ill may be responsible for subtherapeutic antibiotic concentrations leading to poorer clinical outcomes. Evolving in time the disturbed pathophysiology in severe sepsis (high cardiac output, glomerular hyperfiltration) and therapeutic interventions (e.g. haemodynamically active drugs, mechanical ventilation, renal replacement therapy) alters antibiotic pharmacokinetics mainly through an increase in the volume of distribution and altered drug clearance. The lack of new and efficacious drugs and increased bacterial resistance are current problems of contemporary antibiotic therapy. Although intermittent administration is a standard clinical practice, alternative methods of antibiotic administration are sought, which may potentialise effects and reduce toxicity as well as contribute to inhibition of bacterial resistance. A wide range of studies prove that the application of continuous infusion of time-dependent antibiotics (beta-lactams, glycopeptides) is more rational than standard intermittent administration. However, there are also studies which do not confirm the advantage of one method over the other. In spite of controversy the continuous administration of this group of antibiotics is common practice, because the results of both studies point to the higher efficacy of this method in critically ill patients. Authors reviewed the literature to determine whether any clinical benefits exist for administration of time-dependent antibiotics by continuous infusion. Definite specification of the clinical advantage of administration this way over standard dosage requires a large-scale multi-centre randomised controlled trial.
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In vivo Host Environment Alters Pseudomonas aeruginosa Susceptibility to Aminoglycoside Antibiotics
Pan, Xiaolei; Dong, Yuanyuan; Fan, Zheng; Liu, Chang; Xia, Bin; Shi, Jing; Bai, Fang; Jin, Yongxin; Cheng, Zhihui; Jin, Shouguang; Wu, Weihui
2017-01-01
During host infection, Pseudomonas aeruginosa coordinately regulates the expression of numerous genes to adapt to the host environment while counteracting host clearance mechanisms. As infected patients take antibiotics, the invading bacteria encounter antibiotics in the host milieu. P. aeruginosa is highly resistant to antibiotics due to multiple chromosomally encoded resistant determinants. And numerous in vitro studies have demonstrated the regulatory mechanisms of antibiotic resistance related genes in response to antibiotics. However, it is not well-known how host environment affects bacterial response to antibiotics. In this study, we found that P. aeruginosa cells directly isolated from mice lungs displayed higher susceptibility to tobramycin than in vitro cultured bacteria. In vitro experiments demonstrated that incubation with A549 and differentiated HL60 (dHL60) cells sensitized P. aeruginosa to tobramycin. Further studies revealed that reactive oxygen species produced by the host cells contributed to the increased bacterial susceptibility. At the same concentration of tobramycin, presence of A549 and dHL60 cells resulted in higher expression of heat shock proteins, which are known inducible by tobramycin. Further analyses revealed decreased membrane potential upon incubation with the host cells and modification of lipopolysaccharide, which contributed to the increased susceptibility to tobramycin. Therefore, our results demonstrate that contact with host cells increased bacterial susceptibility to tobramycin. PMID:28352614
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Dynamic Response and Residual Helmet Liner Crush Using Cadaver Heads and Standard Headforms.
Bonin, S J; Luck, J F; Bass, C R; Gardiner, J C; Onar-Thomas, A; Asfour, S S; Siegmund, G P
2017-03-01
Biomechanical headforms are used for helmet certification testing and reconstructing helmeted head impacts; however, their biofidelity and direct applicability to human head and helmet responses remain unclear. Dynamic responses of cadaver heads and three headforms and residual foam liner deformations were compared during motorcycle helmet impacts. Instrumented, helmeted heads/headforms were dropped onto the forehead region against an instrumented flat anvil at 75, 150, and 195 J. Helmets were CT scanned to quantify maximum liner crush depth and crush volume. General linear models were used to quantify the effect of head type and impact energy on linear acceleration, head injury criterion (HIC), force, maximum liner crush depth, and liner crush volume and regression models were used to quantify the relationship between acceleration and both maximum crush depth and crush volume. The cadaver heads generated larger peak accelerations than all three headforms, larger HICs than the International Organization for Standardization (ISO), larger forces than the Hybrid III and ISO, larger maximum crush depth than the ISO, and larger crush volumes than the DOT. These significant differences between the cadaver heads and headforms need to be accounted for when attempting to estimate an impact exposure using a helmet's residual crush depth or volume.
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Social interaction, noise and antibiotic-mediated switches in the intestinal microbiota.
Directory of Open Access Journals (Sweden)
Vanni Bucci
Full Text Available The intestinal microbiota plays important roles in digestion and resistance against entero-pathogens. As with other ecosystems, its species composition is resilient against small disturbances but strong perturbations such as antibiotics can affect the consortium dramatically. Antibiotic cessation does not necessarily restore pre-treatment conditions and disturbed microbiota are often susceptible to pathogen invasion. Here we propose a mathematical model to explain how antibiotic-mediated switches in the microbiota composition can result from simple social interactions between antibiotic-tolerant and antibiotic-sensitive bacterial groups. We build a two-species (e.g. two functional-groups model and identify regions of domination by antibiotic-sensitive or antibiotic-tolerant bacteria, as well as a region of multistability where domination by either group is possible. Using a new framework that we derived from statistical physics, we calculate the duration of each microbiota composition state. This is shown to depend on the balance between random fluctuations in the bacterial densities and the strength of microbial interactions. The singular value decomposition of recent metagenomic data confirms our assumption of grouping microbes as antibiotic-tolerant or antibiotic-sensitive in response to a single antibiotic. Our methodology can be extended to multiple bacterial groups and thus it provides an ecological formalism to help interpret the present surge in microbiome data.
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Directory of Open Access Journals (Sweden)
Guannan Mao
2018-05-01
Full Text Available Residual chlorine is often required to remain present in public drinking water supplies during distribution to ensure water quality. It is essential to understand how bacteria respond to long-term chlorine exposure, especially with the presence of assimilable organic carbon (AOC. This study aimed to investigate the effects of chlorination on Pseudomonas aeruginosa in low AOC medium by both conventional plating and culture-independent methods including flow cytometry (FCM and quantitative PCR (qPCR. In a simulated chlorinated system using a bioreactor, membrane damage and DNA damage were measured by FCM fluorescence fingerprint. The results indicated membrane permeability occurred prior to DNA damage in response to chlorination. A regrowth of P. aeruginosa was observed when the free chlorine concentration was below 0.3 mg/L. The bacterial response to long-term exposure to a constant low level of free chlorine (0.3 mg/L was subsequently studied in detail. Both FCM and qPCR data showed a substantial reduction during initial exposure (0–16 h, followed by a plateau where the cell concentration remained stable (16–76 h, until finally all bacteria were inactivated with subsequent continuous chlorine exposure (76–124 h. The results showed three-stage inactivation kinetics for P. aeruginosa at a low chlorine level with extended exposure time: an initial fast inactivation stage, a relatively stable middle stage, and a final stage with a slower rate than the initial stage. A series of antibiotic resistance tests suggested long-term exposure to low chlorine level led to the selection of antibiotic-resistant P. aeruginosa. The combined results suggest that depletion of residual chlorine in low AOC medium systems could reactivate P. aeruginosa, leading to a possible threat to drinking water safety.
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Mazer-Amirshahi, Maryann; Pourmand, Ali; May, Larissa
2017-01-01
Millions of patients are evaluated every year in the emergency department (ED) for bacterial infections. Emergency physicians often diagnose and prescribe initial antibiotic therapy for a variety of bacterial infections, ranging from simple urinary tract infections to severe sepsis. In life-threatening infections, inappropriate choice of initial antibiotic has been shown to increase morbidity and mortality. As such, initiation of appropriate antibiotic therapy on the part of the emergency physician is critical. Increasing rates of antibiotic resistance, drug allergies, and antibiotic shortages further complicates the choice of antibiotics. Patients may have a history of prior resistant infections or culture data indicating that common first-line antibiotics used in the ED may be ineffective. In recent years, there have been several new antibiotic approvals as well as renewed interest in second and third line antibiotics because of the aforementioned concerns. In addition, several newly approved antibiotics have the advantage of being administered once weekly or even as a single infusion, which has the potential to decrease hospitalizations and healthcare costs. This article reviews newly approved antibiotics and antibiotics used to treat resistant infections with a focus on implications for emergency medicine. Copyright © 2016 Elsevier Inc. All rights reserved.
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Impact of antibiotics on necrotizing enterocolitis and antibiotic-associated diarrhea
Silverman, Michael A.; Konnikova, Liza; Gerber, Jeffrey S.
2017-01-01
Summary Antibiotics induce changes or dysbiosis of the intestinal microbiome. These antibiotic-induce changes may contribute to the pathogenesis of necrotizing enterocolitis (NEC) and antibiotic-associated diarrhea (AAD). Studies are beginning to unravel the contribution of specific groups of microbes to these diseases—most notably Gammaproteobacteria for NEC and bile acid- and carbohydrate-metabolizing microbes for AAD. Antibiotic-associated diarrhea occurs when antibiotic treatment induces diarrhea by altering the metabolic function of the patient’s intestinal microbiota leading to either an osmotic or infectious diarrhea, most notably Clostridium difficile infection (CDI). Antibiotic therapy impairs the host microbiota’s ability to resist colonization or expansion of pathogenic bacteria. In the case of CDI, there is growing evidence that microbiota-mediated bile acid metabolism is critical in the pathogenesis of this infection. Probiotics or other microbiota-targeted therapies may provide effective strategies to prevent and treat NEC and AAD. PMID:28164853
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Patient knowledge and perception of antibiotics: A questionnaire survey in primary care
DEFF Research Database (Denmark)
Sydenham, Rikke Vognbjerg; Plejdrup Hansen, Malene; Bruun Lauridsen, Gitte
2015-01-01
of antibiotics. Objectives: This study aimed to study patient knowledge and perceptions of antibiotic treatment and to explore possible associations between patient gender, age, and educational level and accurate knowledge of antibiotics. Design/Methods: As part of an Audit Project Odense project a questionnaire...... survey was conducted during winter 2014. Patients aged ≥18 years consulting their GP with symptoms of ARI were requested to fill in a questionnaire on knowledge and perception of antibiotic treatment. Socio-demographic information was obtained. Results: 361 patients completed the questionnaire (response...... rate 64%). 75% recognized that antibiotics are effective against bacteria and not against virus. Overuse of antibiotics was acknowledged by 80% of respondents as an important factor in the development of resistant bacteria. Female gender was the only patient characteristic significantly associated...
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Hartog, den L.A.; Smits, C.H.M.; Hendriks, W.H.
2016-01-01
The rapid development of antimicrobial resistance (AMR) in human health care urges the need for effective strategies to reduce antibiotic use in animal production. The Netherlands and Denmark have already implemented successful strategies to reduce antibiotic usage in animal production. Part of the
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DEFF Research Database (Denmark)
Malo, Sara; José Rabanaque, María; Feja, Cristina
2014-01-01
Heavy antibiotic users are those individuals with the highest exposure to antibiotics. They play an important role as contributors to the increasing risk of antimicrobial resistance. We applied different methods to identify and characterize the group of heavy antibiotic users in Spain as well...... as their exposure to antibiotics. Data on outpatient prescribing of antimicrobials (ATC J01) in 2010 were obtained from a prescription database covering Aragón (northeastern Spain). The antimicrobial consumption at the individual level was analysed both according to the volume of DDD and the number of packages...... purchased per year. Heavy antibiotic users were identified according to Lorenz curves and characterized by age, gender, and their antimicrobial prescription profile. Lorenz curves demonstrated substantial differences in the individual use of antimicrobials. Heavy antibiotic users (5% of individuals...
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Addressing resistance to antibiotics in systematic reviews of antibiotic interventions.
Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David
2016-09-01
Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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Shift in antibiotic prescribing patterns in relation to antibiotic expenditure in paediatrics
Kimpen, JLL; van Houten, M.A.
In paediatrics, antibiotics are among the most commonly prescribed drugs. Because of an overall rise in health care costs, lack of uniformity in drug prescribing and the emergence of antibiotic resistance, monitoring and control of antibiotic use is of growing concern and strict antibiotic policies
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Mazón-Suástegui, José Manuel; García-Bernal, Milagro; Saucedo, Pedro Enrique; Campa-Córdova, Ángel; Abasolo-Pacheco, Fernando
2017-02-01
Mortality from vibriosis in mollusk production is attributed to pathogenic bacteria, particularly Vibrio alginolyticus. Use of increasingly potent antibiotics has led to bacterial resistance and increased pathogenicity. Alternatives in sanitation, safety, and environmental sustainability are currently under analysis. To-date, homeopathy has been investigated in aquaculture of freshwater fish, but not in marine mollusks. The effect of the homeopathic complexes in the growth, survival, and immune response of the Catarina scallop Argopecten ventricosus were assessed. A bioassay to assess the potential of homeopathy in improving cultivation of juvenile A. ventricosus was conducted for 21 days, with a final challenge of 120 h with V. alginolyticus. The experimental design included two homeopathic formulas The homeopathic complex Passival, consisting of Passiflora incarnata 30 CH, Valeriana officinalis 30 CH, Ignatia amara 30 CH and Zincum valerianicum 30 CH plus Phosphoricum acid 30 CH (treatment TH1) or Silicea terra 30 CH (TH2), two antibiotics (ampicillin = AMP, oxytetracycline = OXY), and two reference treatments (without homeopathic or antibiotic treatment = CTRL, ethanol 30° GL = ETH). Additionally, a negative control CTRL- (untreated/uninfected) is included in the challenge test. Juvenile scallops (4.14 ± 0.06 mm, 13.33 mg wet weight) were cultivated in 4 L tanks provided with aerated, filtered (1 μm), and UV-sterilized seawater that was changed every third day. They were fed a blend of the microalgae Isochrysis galbana and Chaetoceros calcitrans (150,000 cells mL -1 twice a day). All treatments were directly added to the tank water and then 500 mL challenge units were inoculated with 1 × 10 7 CFU/mL (LD 50 ) of V. alginolyticus. Juveniles grew significantly larger and faster in height and weight with TH2 compared to the ETH and CTRL (P homeopathy is a viable treatment for this mollusk to reduce use of antibiotics in scallops and its
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Podolsky, Scott H; Bud, Robert; Gradmann, Christoph; Hobaek, Bård; Kirchhelle, Claas; Mitvedt, Tore; Santesmases, María Jesús; Thoms, Ulrike; Berild, Dag; Kveim Lie, Anne
2015-01-01
Antibiotic development and usage, and antibiotic resistance in particular, are today considered global concerns, simultaneously mandating local and global perspectives and actions. Yet such global considerations have not always been part of antibiotic policy formation, and those who attempt to formulate a globally coordinated response to antibiotic resistance will need to confront a history of heterogeneous, often uncoordinated, and at times conflicting reform efforts, whose legacies remain apparent today. Historical analysis permits us to highlight such entrenched trends and processes, helping to frame contemporary efforts to improve access, conservation and innovation. © 2015 American Society of Law, Medicine & Ethics, Inc.
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Lee, Hsin-Chun; Chen, Chi-Min; Wei, Jen-Ting; Chiu, Hsiu-Yi
2018-04-01
Antibiotics have been widely used in the treatment of livestock diseases. However, the emergence of issues related to drug resistance prompted governments to enact a series of laws regulating the use of antibiotics in livestock. Following control of the problem of drug resistant bacteria, public attention has shifted to the recurring incidence of human health and safety issues caused by residual veterinary drugs in livestock products. To guarantee the safety and hygiene of meat, milk, and eggs from food-producing animals, governments and relevant agencies established laws and regulations for the use of veterinary drugs. It is, therefore, necessary to monitor the content of residual drugs in livestock products at regular intervals to assess whether the regulations have resulted in the effective management of food product safety, and to prevent and manage sudden problems related to this issue. A 2011-2015 livestock product post-marketing monitoring program launched by the Taiwan Food and Drug Administration (TFDA) inspected 1487 livestock products. Over the past 5 years, there were 34 samples identified that did not conform to the regulations; these samples included residue drugs such as β-agonists, chloramphenicols, β-lactam antibiotics, sulfa drugs, enrofloxacin, and lincomycin. Inspections of commercial livestock products with the consistent cooperation of agricultural authorities did not detect the drugs that were banned by the government, whereas the detection of other drugs decreased annually with an increase in the post-market monitoring sample size. In the future, the TFDA will continue to monitor the status of residual veterinary drugs in commercial livestock products, adjust the sampling of food products annually according to monitoring results, and closely cooperate with agricultural authorities on source management. Copyright © 2017. Published by Elsevier B.V.
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Crystal and molecular structure of the membrane-active antibiotic enniatin C
International Nuclear Information System (INIS)
Tishchenko, G.N.; Zhukhlistova, N.E.
2000-01-01
The crystal structure of the cyclic hexadepsipeptide antibiotic enniatin C c[-(L-MeLeu-D-Hyi) 3 -], C 34 H 59 N 3 O 9 , was established by X-ray structure analysis (sp. gr. P2 1 , a = 20.205(5) A, b = 8.702(2) A, c 25.587(6) A, γ = 97.0(5) deg., V = 4465.3(18) A 3 , Z = 4, R = 0.089 for 3601 reflections with I > 2σ(I)). The unit cell contains two independent molecules of enniatin C, one ethanol molecule disordered over two positions, and approximately two water molecules occupying four positions and forming hydrogen bonds with each other. The independent antibiotic molecules adopt virtually identical conformations similar to those observed in the structures of enniatin B and its Na,Ni-complex. These conformations are characterized by alternating upward and downward orientations of the carbonyl groups and pseudoequatorial orientations of side radicals. The Leu residues have stretched conformations. The N-methylamide groups of the independent antibiotic molecules face each other, whereas the molecules are displaced by approximately 8.4 A with respect to each other along the mean planes of the rings
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Characterization of Antibiotics and Antibiotic Resistance Genes on an Ecological Farm System
Directory of Open Access Journals (Sweden)
Songhe Zhang
2015-01-01
Full Text Available There is a growing concern worldwide about the prevalence of antibiotics and antibiotic resistance genes (ARGs on the farm. In this study, we investigated the distribution of seven antibiotics and ten ARGs in fresh and dried pig feces, in biogas slurry, and in grape-planting soil from an ecological farm. Antibiotics including sulfamethazine, norfloxacin, ofloxacin, tetracycline, oxytetracycline, and chlortetracycline were detected in these samples (except for sulfamethoxazole in dried feces. In general, antibiotics levels in samples were in the sequence: biogas slurry > fresh feces > soil or dried feces. Results of ecological risk assessments revealed that among the seven antibiotics chlortetracycline showed the highest ecological risk. Among the ten ARGs, sulI and tetO were the most prevalent on this ecological farm. There were positive correlations between certain ARGs and the corresponding antibiotics on this ecological farm. Therefore, continuous monitoring of antibiotics and their corresponding ARGs should be conducted in the agroecosystem near the concentrated animal farming operation systems.
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Access to antibiotics in New Delhi, India: implications for antibiotic policy.
Kotwani, Anita; Holloway, Kathleen
2013-01-01
The present survey was conducted to investigate the price and availability of a basket of 24 essential antibiotics and eight high-end antibiotics at various levels of health care in public and private sector in National Capital Territory of Delhi, India using standardized WHO/HAI methodology. DATA ON PROCUREMENT PRICE AND AVAILABILITY WAS COLLECTED FROM THREE PUBLIC HEALTHCARE PROVIDERS IN THE STATE: the federal (central) government, state government and Municipal Corporation of Delhi (MCD). Overall a total of 83 public facilities, 68 primary care, 10 secondary cares and 5 tertiary care facilities were surveyed. Data was also collected from private retail (n = 40) and chain pharmacies (n = 40) of a leading corporate house. Prices were compared to an international reference price (expressed as median price ratio-MPR). PUBLIC SECTOR: Delhi state government has its essential medicine list (Delhi state EML) and was using Delhi state EML 2007 for procurement; the other two agencies had their own procurement list. All the antibiotics procured including second and third generation antibiotics except for injections were available at primary care facilities. Antibiotic available were on the basis of supply rather than rationality or the Delhi state EML and none was 100% available. There was sub-optimal availability of some essential antibiotics while other non-essential ones were freely available. Availability of antibiotics at tertiary care facilities was also sub-optimal. Private sector: Availability of antibiotics was good. For most of the antibiotics the most expensive and popular trade names were often available. High-end antibiotics, meropenam, gemifloxacin, and moxifloxacin were commonly available. In retail pharmacies some newer generation non-essential antibiotics like gemifloxacin were priced lower than the highest-priced generic of amoxicillin + clavulanic acid, azithromycin, and cefuroxime aexitl. Inappropriate availability and pricing of newer
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Christou, Anastasis; Agüera, Ana; Bayona, Josep Maria; Cytryn, Eddie; Fotopoulos, Vasileios; Lambropoulou, Dimitra; Manaia, Célia M; Michael, Costas; Revitt, Mike; Schröder, Peter; Fatta-Kassinos, Despo
2017-10-15
The use of reclaimed wastewater (RWW) for the irrigation of crops may result in the continuous exposure of the agricultural environment to antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). In recent years, certain evidence indicate that antibiotics and resistance genes may become disseminated in agricultural soils as a result of the amendment with manure and biosolids and irrigation with RWW. Antibiotic residues and other contaminants may undergo sorption/desorption and transformation processes (both biotic and abiotic), and have the potential to affect the soil microbiota. Antibiotics found in the soil pore water (bioavailable fraction) as a result of RWW irrigation may be taken up by crop plants, bioaccumulate within plant tissues and subsequently enter the food webs; potentially resulting in detrimental public health implications. It can be also hypothesized that ARGs can spread among soil and plant-associated bacteria, a fact that may have serious human health implications. The majority of studies dealing with these environmental and social challenges related with the use of RWW for irrigation were conducted under laboratory or using, somehow, controlled conditions. This critical review discusses the state of the art on the fate of antibiotics, ARB and ARGs in agricultural environment where RWW is applied for irrigation. The implications associated with the uptake of antibiotics by plants (uptake mechanisms) and the potential risks to public health are highlighted. Additionally, knowledge gaps as well as challenges and opportunities are addressed, with the aim of boosting future research towards an enhanced understanding of the fate and implications of these contaminants of emerging concern in the agricultural environment. These are key issues in a world where the increasing water scarcity and the continuous appeal of circular economy demand answers for a long-term safe use of RWW for irrigation. Copyright © 2017 Elsevier
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Dispensing of non-prescribed antibiotics in Jordan
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Almaaytah A
2015-09-01
Full Text Available Ammar Almaaytah,1 Tareq L Mukattash,2 Julia Hajaj2 1Department of Pharmaceutical Technology, 2Department of Clinical Pharmacy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan Objective: Current regulations in Jordan state that antibiotics cannot be sold without a medical prescription. This study aimed to assess the percentage of pharmacies that dispense antibiotics without a medical prescription in the Kingdom of Jordan and identify and highlight the extent and seriousness of such practices among Jordanian pharmacies. Methods: A prospective study was performed, and five different clinical scenarios were simulated at pharmacies investigated including sore throat, otitis media, acute sinusitis, diarrhea, and urinary tract infection in childbearing-aged women. Three levels of demand were used to convince the pharmacists to sell an antibiotic. Results: A total of 202 total pharmacies in Jordan were visited in the present study. The majority of pharmacies (74.3% dispensed antibiotics without prescription with three different levels of demand. The percentage of pharmacies dispensing antibiotics without a prescription for the sore throat scenario was 97.6%, followed by urinary tract infection (83.3%, diarrhea (83%, and otitis media (68.4%. The lowest percentage of antibiotic dispensing was for the acute sinusitis simulation at 48.5%. Among the pharmacies that dispensed antibiotics, the pharmacists provided an explanation as the number of times per day the drug should be taken in 95.3% of the cases, explained the duration of treatment in 25.7%, and inquired about allergies prior to the sale of the antibiotic in only 17.3%. Only 52 pharmacies (25.7% refused to dispense any kind of antibiotics, the majority (61.5% of this refusal response came from acute sinusitis cases, while the minority (2.4% came from the sore throat cases. Conclusion: The results of this study demonstrate that antibiotics continue to be dispensed
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Labeling of antibiotics for infection diagnosis
International Nuclear Information System (INIS)
Benitez, A.; Roca, M.; Martin-Comin, J.
2006-01-01
The high impact of infection on daily clinical practice has promoted research into better and more accurate diagnostic and therapeutic methods. Localizing inflammation/infection with nuclear medicine techniques began over 40 years ago. Today, 6 7G a-scintigraphy, 9 9mT c-nanocolloid, 1 11I n and 9 9mT c in vitro labeled leukocytes, and monoclonal anti granulocyte antibodies are widely available for this purpose. While these methods are useful for localizing inflammation, they cannot always differentiate septic from aseptic processes. The ideal properties of an agent for diagnosing infection include: high specificity, early diagnosis, rapid blood clearance, ease of preparation, low toxicity, biodistribution appropriate for the disease under study, absence of immunologic response and low cost. A novel approach to infection diagnosis is the use of radiolabelled antibiotics. Antibiotics localize in the infectious focus, where they are frequently taken up and metabolized by microorganisms. The majority of the various antibiotics studied so far are those of the quinolones group (ciprofloxacin, sparfloxacin, enrofloxacin, levofloxacin, norfloxacin and ofloxacin). More recently, the labeling of ceftizoxime, a semisynthetic third generation cephalosporin, has been reported. The relevant features of labeled antibiotics in research and/or clinical infection diagnosis are the focus of this article
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Surgeon preferences regarding antibiotic prophylaxis for ballistic fractures.
Marecek, Geoffrey S; Earhart, Jeffrey S; Gardner, Michael J; Davis, Jason; Merk, Bradley R
2016-06-01
Scant evidence exists to support antibiotic use for low velocity ballistic fractures (LVBF). We therefore sought to define current practice patterns. We hypothesized that most surgeons prescribe antibiotics for LVBF, prescribing is not driven by institutional protocols, and that decisions are based on protocols utilized for blunt trauma. A web-based questionnaire was emailed to the membership of the Orthopaedic Trauma Association (OTA). The questionnaire included demographic information and questions about LVBF treatment practices. Two hundred and twenty surgeons responded. One hundred and fifty-four (70 %) respondents worked at a Level-1 trauma center, 176 (80 %) had received fellowship education in orthopaedic trauma and 104 (47 %) treated at least 10 ballistic fractures annually. Responses were analyzed with SAS 9.3 for Windows (SAS Institute Inc, Cary, NC). One hundred eighty-six respondents (86 %) routinely provide antibiotics for LVBF. Those who did not were more apt to do so for intra-articular fractures (8/16, 50 %) and pelvic fractures with visceral injury (10/16, 63 %). Most surgeons (167, 76 %) do not believe the Gustilo-Anderson classification applies to ballistic fractures, and (20/29, 70 %) do not base their antibiotic choice on the classification system. Few institutions (58, 26 %) have protocols guiding antibiotic use for LVBF. Routine antibiotic use for LVBF is common; however, practice is not dictated by institutional protocol. Although antibiotic use generally follows current blunt trauma guidelines, surgeons do not base their treatment decisions the Gustilo-Anderson classification. Given the high rate of antibiotic use for LVBF, further study should focus on providing evidence-based treatment guidelines.
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Directory of Open Access Journals (Sweden)
Teresa A Figueiredo
2012-01-01
Full Text Available The glutamic acid residues of the peptidoglycan of Staphylococcus aureus and many other bacteria become amidated by an as yet unknown mechanism. In this communication we describe the identification, in the genome of S. aureus strain COL, of two co-transcribed genes, murT and gatD, which are responsible for peptidoglycan amidation. MurT and GatD have sequence similarity to substrate-binding domains in Mur ligases (MurT and to the catalytic domain in CobB/CobQ-like glutamine amidotransferases (GatD. The amidation of glutamate residues in the stem peptide of S. aureus peptidoglycan takes place in a later step than the cytoplasmic phase--presumably the lipid phase--of the biosynthesis of the S. aureus cell wall precursor. Inhibition of amidation caused reduced growth rate, reduced resistance to beta-lactam antibiotics and increased sensitivity to lysozyme which inhibited culture growth and caused degradation of the peptidoglycan.
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Responses of the Murine Myeloid Colony-Forming Cell to Ansamycin Antibiotics
Horoszewicz, Julius S.; Carter, William A.
1974-01-01
The in vitro susceptibility of murine myeloid colony-forming cells to the antiproliferative activities of three ansamycin antibiotics was determined. These cells were found to be 10- to 40-fold more susceptible than the corresponding human ones. PMID:4151701
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Prophylactic antibiotics versus post- operative antibiotics in herniorraphy
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Abedulla Khan Kayamkani
2015-07-01
Full Text Available Postoperative surgical site infections are a major source of illness. Infection results in longer hospital stay and higher costs. Uses of preoperative antibiotics have been standardized and are being used routinely in most clinical surgeries and include controversial areas like breast surgery and herniorraphy. Objective of the study is to find out the benefit of prophylactic use of antibiotics in the management of herniorraphy.This project was carried out in a multispeciality tertiary care teaching hospital from 1st-30th April in 2002. Group 1 patients were treated prophylactically half an hour before surgery with single dose of I.V. antibiotics (injection. Ampicillin 1gm + injection. Gentamicin 80mg. Group 2 patients were treated post surgery with capsule. Ampicillin 500mg 4 times a day for 7 days and injection. Gentamicin twice a day for first 4 days. In case of group 1 patients only one out of 20 patients (5% was infected. Whereas in-group 2 patients 5 out of 20 patients (25% were infected. The cost of prophylactic antibiotic treatment was Rs. 25.56 per patient. The postoperative antibiotic treatment cost was Rs. 220.4 per patient. That means postoperative treatment is around 8.62 times costlier than prophylactic treatment. From this study it is evident that prophylactic (preoperative treatment is better than postoperative treatment with antibiotics.
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Survival of Bactericidal Antibiotic Treatment by a Persister Subpopulation of Listeria monocytogenes
DEFF Research Database (Denmark)
Knudsen, Gitte Maegaard; Ng, Yin; Gram, Lone
2013-01-01
Listeria monocytogenes can cause the serious infection listeriosis, which despite antibiotic treatment has a high mortality. Understanding the response of L. monocytogenes to antibiotic exposure is therefore important to ensure treatment success. Some bacteria survive antibiotic treatment...... by formation of persisters, which are a dormant antibiotic-tolerant subpopulation. The purpose of this study was to determine whether L. monocytogenes can form persisters and how bacterial physiology affects the number of persisters in the population. A stationary-phase culture of L. monocytogenes was adjusted...... that eradication of persisters is possible. Our study adds L. monocytogenes to the list of bacterial species capable of surviving bactericidal antibiotics in a dormant stage, and this persister phenomenon should be borne in mind when developing treatment regimens....
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Genetic Mechanisms of Antibiotic Resistance and the Role of Antibiotic Adjuvants.
Pontes, Daniela Santos; de Araujo, Rodrigo Santos Aquino; Dantas, Natalina; Scotti, Luciana; Scotti, Marcus Tullius; de Moura, Ricardo Olimpio; Mendonca-Junior, Francisco Jaime Bezerra
2018-01-01
The ever increasing number of multidrug-resistant microorganism pathogens has become a great and global public health threat. Antibiotic mechanisms of action and the opposing mechanisms of resistance are intimately associated, but comprehension of the biochemical and molecular functions of such drugs is not a simple exercise. Both the environment, and genetic settings contribute to alterations in phenotypic resistance (natural bacterial evolution), and make it difficult to control the emergence and impacts of antibiotic resistance. Under such circumstances, comprehension of how bacteria develop and/or acquire antibiotic resistance genes (ARG) has a critical role in developing propositions to fight against these superbugs, and to search for new drugs. In this review, we present and discuss both general information and examples of common genetic and molecular mechanisms related to antibiotic resistance, as well as how the expression and interactions of ARGs are important to drug resistance. At the same time, we focus on the recent achievements in the search for antibiotic adjuvants, which help combat antibiotic resistance through deactivation of bacterial mechanisms of action such as β-lactamases. Recent advances involving the use of anti-resistance drugs such as: efflux pump inhibitors; anti-virulence drugs; drugs against quorum sensing; and against type II/III secretion systems are revealed. Such antibiotic adjuvants (as explored herein) collaborate against the problems of antibiotic resistance, and may restore or prolong the therapeutic activity of known antibiotics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
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Chau Nguyen Dang Giang
Full Text Available The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX, 4 ng L-1 sulfadiazine (SDZ, 17 ng L-1 trimethoprim (TRIM, and 12 ng L-1 enrofloxacin (ENRO. These concentrations were lower than the predicted no effect concentrations (PNECs and minimum inhibitory concentrations (MICs, suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks
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Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis (Spanish Edition)
International Nuclear Information System (INIS)
2017-01-01
Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples
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Manual of Standard Operating Procedures for Veterinary Drug Residue Analysis (French Edition)
International Nuclear Information System (INIS)
2017-01-01
Laboratories are crucial to national veterinary drug residue monitoring programmes. However, one of the main challenges laboratories encounter is obtaining access to relevant methods of analysis. Thus, in addition to training, providing technical advice and transferring technology, the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture has resolved to develop clear and practical manuals to support Member State laboratories. The Coordinated Research Project (CRP) on Development of Radiometric and Allied Analytical Methods to Strengthen Residue Control Programs for Antibiotic and Anthelmintic Veterinary Drug Residues has developed a number of analytical methods as standard operating procedures (SOPs), which are now compiled here. This publication contains SOPs on chromatographic and spectrometric techniques, as well as radioimmunoassay and associated screening techniques, for various anthelmintic and antimicrobial veterinary drug residue analysis. Some analytical method validation protocols are also included. The publication is primarily aimed at food and environmental safety laboratories involved in testing veterinary drug residues, including under organized national residue monitoring programmes. It is expected to enhance laboratory capacity building and competence through the use of radiometric and complementary tools and techniques. The publication is also relevant for applied research on residues of veterinary drugs in food and environmental samples
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Directory of Open Access Journals (Sweden)
Miao Yu
2018-05-01
Full Text Available In modern swine husbandry systems, antibiotics have been used as growth promoters for piglets during suckling or weaning period. However, while early colonization of intestinal microbiota has been regarded crucial for the host’s later life performance and well-being, little is known about the impact of antibiotics on intestinal microbiota in suckling piglets. The present study aimed to investigate the effects of early antibiotics exposure on gut microbiota and microbial metabolism of suckling piglets. Sixteen litters of suckling piglets were fed a creep feed diet with (Antibiotic or without (Control antibiotics from postnatal days 7–23 (n = 8. The ileal and cecal digesta were obtained for microbial composition and microbial metabolites analysis. The results showed that the antibiotics significantly altered the bacterial community composition by decreasing (P < 0.05 the diversity and richness in the ileum. The antibiotics significantly reduced the abundance of Lactobacillus in both the ileum and cecum, increased the abundance of Streptococcus, unclassified Enterococcaceae, unclassified Fusobacteriales, and Corynebacterium in the ileum, and the abundance of unclassified Ruminococcaceae and unclassified Erysipelotrichaceae in the cecum. The antibiotics decreased (P < 0.05 ileal lactate concentration and cecal concentration of total short-chain fatty acids (SCFAs. But the antibiotics enhanced protein fermentation (P < 0.05 in the ileum and cecum, as ileal concentrations of putrescine and cadaverine, and cecal concentrations of isobutyrate, isovalerate, putrescine, cadaverine, spermine, and spermidine were significantly increased (P < 0.05. These results indicated that early antibiotics exposure significantly altered the microbial composition of suckling piglets toward a vulnerable and unhealthy gut environment. The findings provide a new insight on the antibiotics impact on neonates and may provide new framework for designing alternatives to the
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Self-medication practices with antibiotics among Chinese university students.
Zhu, X; Pan, H; Yang, Z; Cui, B; Zhang, D; Ba-Thein, W
2016-01-01
Self-medication with antibiotics (SMA) is a serious global health problem. We sought to investigate SMA behaviors and risk factors among Chinese university students, and further explore the association between SMA practices and adverse drug events (ADEs). Cross-sectional study. An online survey was conducted at Jiangsu University (JSU) in eastern China in July 2011 using a pretested questionnaire. Out of 2608 website visitors, 1086 participated in the survey (response rate: 41.6%), 426 respondents were excluded for not being a JSU student or repeat participation, 660 (2.2% of JSU students) were included in analysis, and 316 students (47.9%) had a lifetime history of SMA. Among self-treated students, 43.5% believed that antibiotic was suitable for viral infections, 65.9% had more than one SMA episode in the previous year, 73.5% self-medicated with at least two different antibiotics, 57.1% and 64.4% changed antibiotic dosage and antibiotics during the course, respectively. Female gender, older age, and prior knowledge of antibiotics (PKA) were identified as independent risk factors of SMA. There was no difference between students with and without PKA regarding SMA frequency, use of polyantibiotics, and switching antibiotic dosage or antibiotics. ADEs happened to 13.3% of self-medicated students. Frequent change of dosage and simultaneous use of the same antibiotic with different names were independent risk practices associated with an ADE. Our findings substantiate high SMA prevalence among Chinese university students. Older age and PKA are independent SMA risk factors common to Chinese university students and female gender is exclusive SMA risk factor for JSU students. Poor SMA practices are associated with ADEs. Strict regulations on antibiotic sales and public education reinforced by further health care reform are recommended. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Directory of Open Access Journals (Sweden)
Antonio C. Pignatari
2013-06-01
Full Text Available Inappropriate antibiotic use in normally self-limiting acute respiratory tract infections (RTIs, such as sore throat and the common cold, is a global problem and an important factor for increasing levels of antibiotic resistance. A new group of international experts—the Global Respiratory Infection Partnership (GRIP—is committed to addressing this issue, with the interface between primary care practitioners and their patients as their core focus. To combat the overuse of antibiotics in the community, and facilitate a change from prescribing empiric antibiotic treatment towards cautious deferment combined with symptomatic relief, there is a need to introduce and enhance evidence-based dialogue between primary care practitioners and their patients. Communication with patients should focus on the de-medicalisation of self-limiting viral infections, which can be achieved via a coherent globally endorsed framework outlining the rationale for appropriate antibiotic use in acute RTIs in the context of antibiotic stewardship and conservancy. The planned framework is intended to be adaptable at a country level to reflect local behaviours, cultures and healthcare systems, and has the potential to serve as a model for change in other therapeutic areas.
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Ribosomal Antibiotics: Contemporary Challenges
Directory of Open Access Journals (Sweden)
Tamar Auerbach-Nevo
2016-06-01
Full Text Available Most ribosomal antibiotics obstruct distinct ribosomal functions. In selected cases, in addition to paralyzing vital ribosomal tasks, some ribosomal antibiotics are involved in cellular regulation. Owing to the global rapid increase in the appearance of multi-drug resistance in pathogenic bacterial strains, and to the extremely slow progress in developing new antibiotics worldwide, it seems that, in addition to the traditional attempts at improving current antibiotics and the intensive screening for additional natural compounds, this field should undergo substantial conceptual revision. Here, we highlight several contemporary issues, including challenging the common preference of broad-range antibiotics; the marginal attention to alterations in the microbiome population resulting from antibiotics usage, and the insufficient awareness of ecological and environmental aspects of antibiotics usage. We also highlight recent advances in the identification of species-specific structural motifs that may be exploited for the design and the creation of novel, environmental friendly, degradable, antibiotic types, with a better distinction between pathogens and useful bacterial species in the microbiome. Thus, these studies are leading towards the design of “pathogen-specific antibiotics,” in contrast to the current preference of broad range antibiotics, partially because it requires significant efforts in speeding up the discovery of the unique species motifs as well as the clinical pathogen identification.
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Antibiotics and Breastfeeding.
de Sá Del Fiol, Fernando; Barberato-Filho, Silvio; de Cássia Bergamaschi, Cristiane; Lopes, Luciane Cruz; Gauthier, Timothy P
2016-01-01
During the breastfeeding period, bacterial infections can occur in the nursing mother, requiring the use of antibiotics. A lack of accurate information may lead health care professionals and mothers to suspend breastfeeding, which may be unnecessary. This article provides information on the main antibiotics that are appropriate for clinical use and the interference of these antibiotics with the infant to support medical decisions regarding the discontinuation of breastfeeding. We aim to provide information on the pharmacokinetic factors that interfere with the passage of antibiotics into breast milk and the toxicological implications of absorption by the infant. Publications related to the 20 most frequently employed antibiotics and their transfer into breast milk were evaluated. The results demonstrate that most antibiotics in clinical use are considered suitable during breastfeeding; however, the pharmacokinetic profile of each drug must be observed to ensure the resolution of the maternal infection and the safety of the infant. © 2016 S. Karger AG, Basel.
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Lee, Boeun; Tam, Idy; Weigel, Bernard; Breeze, Janis L; Paulus, Jessica K; Nelson, Jason; Allison, Genève M
2015-08-01
β-Lactam antibiotics are commonly used in outpatient parenteral antimicrobial therapy (OPAT), but data regarding outcomes of long-term therapy are limited. The purpose of this study was to compare treatment success, readmission and antibiotic switch rates in patients treated with β-lactam antibiotics as OPAT. We carried out a retrospective review of all patients, discharged from Tufts Medical Center with cefazolin, ceftriaxone, ertapenem or oxacillin, between January 2009 and June 2013. A competing risks analysis was used to compare the cumulative incidence of first occurrence of treatment success, antibiotic switch and 30 day readmission for each drug. Four hundred patients were identified (cefazolin n = 38, ceftriaxone n = 104, ertapenem n = 128 and oxacillin n = 130). Baseline demographics were similar. Treatment success rates were higher for ceftriaxone and ertapenem (cefazolin 61%, ceftriaxone 81%, ertapenem 73% and oxacillin 58%; P antibiotic switches were accomplished without readmission. Adverse drug events (ADEs) were the most common reason for outpatient antibiotic switches (31/37, 84%). The ADE rate was higher for the oxacillin group (cefazolin 2.0 versus ceftriaxone 1.5 versus ertapenem 2.9 versus oxacillin 8.4 per 1000 OPAT days; P antibiotics is effective, but antibiotic switches for adverse events were more frequent with oxacillin use. Clinicians should be cognizant of the risk of readmissions and ADEs in OPAT patients, as the value of OPAT lies in reducing patient morbidity and readmissions by managing ADEs and preventing clinical failures. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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DEFF Research Database (Denmark)
Ashbolt, Nicholas J.; Amézquita, Alejandro; Backhaus, Thomas
2013-01-01
to enable human health risk assessments (HHRA) that focus on the role of the environment in the failure of antibiotic treatment caused by antibiotic-resistant pathogens. Methods: The authors participated in a workshop held 4-8 March 2012 in Québec, Canada, to define the scope and objectives...... of an environmental assessment of antibiotic-resistance risks to human health. We focused on key elements of environmental-resistance-development "hot spots," exposure assessment (unrelated to food), and dose response to characterize risks that may improve antibiotic-resistance management options. Discussion: Various...... novel aspects to traditional risk assessments were identified to enable an assessment of environmental antibiotic resistance. These include a) accounting for an added selective pressure on the environmental resistome that, over time, allows for development of antibiotic-resistant bacteria (ARB); b...
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Directory of Open Access Journals (Sweden)
Collin M. Blakely
2015-04-01
Full Text Available Although oncogene-targeted therapy often elicits profound initial tumor responses in patients, responses are generally incomplete because some tumor cells survive initial therapy as residual disease that enables eventual acquired resistance. The mechanisms underlying tumor cell adaptation and survival during initial therapy are incompletely understood. Here, through the study of EGFR mutant lung adenocarcinoma, we show that NF-κB signaling is rapidly engaged upon initial EGFR inhibitor treatment to promote tumor cell survival and residual disease. EGFR oncogene inhibition induced an EGFR-TRAF2-RIP1-IKK complex that stimulated an NF-κB-mediated transcriptional survival program. The direct NF-κB inhibitor PBS-1086 suppressed this adaptive survival program and increased the magnitude and duration of initial EGFR inhibitor response in multiple NSCLC models, including a patient-derived xenograft. These findings unveil NF-κB activation as a critical adaptive survival mechanism engaged by EGFR oncogene inhibition and provide rationale for EGFR and NF-κB co-inhibition to eliminate residual disease and enhance patient responses.
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Centers for Disease Control (CDC) Podcasts
The overuse of antibiotics has led to the development of resistance among bacteria, making antibiotics ineffective in treating certain conditions. This podcast discusses the importance of talking to your healthcare professional about whether or not antibiotics will be beneficial if you've been diagnosed with an infectious disease.
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Centers for Disease Control (CDC) Podcasts
2015-04-16
The overuse of antibiotics has led to the development of resistance among bacteria, making antibiotics ineffective in treating certain conditions. This podcast discusses the importance of talking to your healthcare professional about whether or not antibiotics will be beneficial if youâve been diagnosed with an infectious disease. Created: 4/16/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program. Date Released: 4/16/2015.
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Respiratory Infections and Antibiotic Usage in Common Variable Immunodeficiency.
Sperlich, Johannes M; Grimbacher, Bodo; Workman, Sarita; Haque, Tanzina; Seneviratne, Suranjith L; Burns, Siobhan O; Reiser, Veronika; Vach, Werner; Hurst, John R; Lowe, David M
Patients with common variable immunodeficiency (CVID) suffer frequent respiratory tract infections despite immunoglobulin replacement and are prescribed significant quantities of antibiotics. The clinical and microbiological nature of these exacerbations, the symptomatic triggers to take antibiotics, and the response to treatment have not been previously investigated. To describe the nature, frequency, treatment, and clinical course of respiratory tract exacerbations in patients with CVID and to describe pathogens isolated during respiratory tract exacerbations. We performed a prospective diary card exercise in 69 patients with CVID recruited from a primary immunodeficiency clinic in the United Kingdom, generating 6210 days of symptom data. We collected microbiology (sputum microscopy and culture, atypical bacterial PCR, and mycobacterial culture) and virology (nasopharyngeal swab multiplex PCR) samples from symptomatic patients with CVID. There were 170 symptomatic exacerbations and 76 exacerbations treated by antibiotics. The strongest symptomatic predictors for commencing antibiotics were cough, shortness of breath, and purulent sputum. There was a median delay of 5 days from the onset of symptoms to commencing antibiotics. Episodes characterized by purulent sputum responded more quickly to antibiotics, whereas sore throat and upper respiratory tract symptoms responded less quickly. A pathogenic virus was isolated in 56% of respiratory exacerbations and a potentially pathogenic bacteria in 33%. Patients with CVID delay and avoid treatment of symptomatic respiratory exacerbations, which could result in structural lung damage. However, viruses are commonly represented and illnesses dominated by upper respiratory tract symptoms respond poorly to antibiotics, suggesting that antibiotic usage could be better targeted. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.
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Immunology-Based Techniques for the Detection of Veterinary Drug Residues in Foods
Reig, Milagro; Toldrá, Fidel
Veterinary drugs are used in farm animals, via the feed or the drinking water, to prevent the outbreak of diseases or even for the treatment of diseases. However, the growth of animals may be promoted through the use of hormones and antibiotics. Depending on the type of residue and the application and washing conditions, these substances or its metabolites may remain in meat and other foods of animal origin and may cause adverse effects on consumers’ health. This is the main reason why its use is strictly regulated or even banned (case of the European Union) in different countries. Antibiotics typically used for growth promotion include chloramphenicol, nitrofurans, and enrofloxacin but others like sulphonamides, macrolides etc. may also be used (Reig & Toldrá, 2007).
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Incentives for new antibiotics: the Options Market for Antibiotics (OMA) model.
Brogan, David M; Mossialos, Elias
2013-11-07
Antimicrobial resistance is a growing threat resulting from the convergence of biological, economic and political pressures. Investment in research and development of new antimicrobials has suffered secondary to these pressures, leading to an emerging crisis in antibiotic resistance. Current policies to stimulate antibiotic development have proven inadequate to overcome market failures. Therefore innovative ideas utilizing market forces are necessary to stimulate new investment efforts. Employing the benefits of both the previously described Advanced Market Commitment and a refined Call Options for Vaccines model, we describe herein a novel incentive mechanism, the Options Market for Antibiotics. This model applies the benefits of a financial call option to the investment in and purchase of new antibiotics. The goal of this new model is to provide an effective mechanism for early investment and risk sharing while maintaining a credible purchase commitment and incentives for companies to ultimately bring new antibiotics to market. We believe that the Options Market for Antibiotics (OMA) may help to overcome some of the traditional market failures associated with the development of new antibiotics. Additional work must be done to develop a more robust mathematical model to pave the way for practical implementation.
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Assessing the Risk of Probiotic Dietary Supplements in the Context of Antibiotic Resistance
Directory of Open Access Journals (Sweden)
Min Zheng
2017-05-01
Full Text Available Probiotic bacteria are known to harbor intrinsic and mobile genetic elements that confer resistance to a wide variety of antibiotics. Their high amounts in dietary supplements can establish a reservoir of antibiotic resistant genes in the human gut. These resistant genes can be transferred to pathogens that share the same intestinal habitat thus resulting in serious clinical ramifications. While antibiotic resistance of probiotic bacteria from food, human and animal sources have been well-documented, the resistant profiles of probiotics from dietary supplements have only been recently studied. These products are consumed with increasing regularity due to their health claims that include the improvement of intestinal health and immune response as well as prevention of acute and antibiotic-associated diarrhea and cancer; but, a comprehensive risk assessment on the spread of resistant genes to human health is lacking. Here, we highlight recent reports of antibiotic resistance of probiotic bacteria isolated from dietary supplements, and propose complementary strategies that can shed light on the risks of consuming such products in the context of a global widespread of antibiotic resistance. In concomitant with a broader screening of antibiotic resistance in probiotic supplements is the use of computational simulations, live imaging and functional genomics to harvest knowledge on the evolutionary behavior, adaptations and dynamics of probiotics studied in conditions that best represent the human gut including in the presence of antibiotics. The underlying goal is to enable the health benefits of probiotics to be exploited in a responsible manner and with minimal risk to human health.
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Activation of Antibiotic Production in Bacillus spp. by Cumulative Drug Resistance Mutations.
Tojo, Shigeo; Tanaka, Yukinori; Ochi, Kozo
2015-12-01
Bacillus subtilis strains produce a wide range of antibiotics, including ribosomal and nonribosomal peptide antibiotics, as well as bacilysocin and neotrehalosadiamine. Mutations in B. subtilis strain 168 that conferred resistance to drugs such as streptomycin and rifampin resulted in overproduction of the dipeptide antibiotic bacilysin. Cumulative drug resistance mutations, such as mutations in the mthA and rpsL genes, which confer low- and high-level resistance, respectively, to streptomycin, and mutations in rpoB, which confer resistance to rifampin, resulted in cells that overproduced bacilysin. Transcriptional analysis demonstrated that the enhanced transcription of biosynthesis genes was responsible for the overproduction of bacilysin. This approach was effective also in activating the cryptic genes of Bacillus amyloliquefaciens, leading to actual production of antibiotic(s). Copyright © 2015, American Society for Microbiology. All Rights Reserved.
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Antibiotic resistance: current issues and future strategies
Directory of Open Access Journals (Sweden)
Giancarlo Scarafile
2016-09-01
Full Text Available The antibiotic resistance (antimicrobial resistance – AMR and the particular emergence of multi-resistant bacterial strains, is a problem of clinical relevance involving serious threats to public health worldwide. From early this decade, a lot of studies have demonstrated a significant increase in the rates of antibiotic resistance by bacterial pathogens responsible for nosocomial and community infections all over the world. The AMR leads to a reduced drug efficacy in the treatment options available and therefore, to an increase in mortality rates. The original causes of the phenomenon are: environmental factors which favor a mutation of the genetic bacterial inheritance, thereby inhibiting the active ingredient of the antibiotics; unsuitable administering of antibiotics in veterinary, incorrect taking both in hospitals and at home and, lately, lack of investments in the development of new drugs. The alarming epidemiological data prompted the World Health Organization (WHO in 2011 to coin the slogan "No action today, no cure tomorrow" in order to immediately implement a new strategy to improve the use of available drugs and to accelerate the introduction of new ones through a new phase of research involving private and public institutions. The European Union has stressed that the surveillance is considered an essential factor for an effective response to this problem but it has also highlighted that the results produced have been lower than expectations because of serious shortcomings such as lack of methodological standards, insufficient data sharing and no coordination among European countries. In Italy the situation is much more troubling; in fact, according to the Ministry of Health, 5000-7000 yearly deaths are deemed due to nosocomial infections, with an annual cost of more than 100 million €.These figures explain how the fight against infections is far from being won. The purpose of this review is to analyze the basic causes of the
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How type 1 fimbriae help Escherichia coli to evade extracellular antibiotics.
Avalos Vizcarra, Ima; Hosseini, Vahid; Kollmannsberger, Philip; Meier, Stefanie; Weber, Stefan S; Arnoldini, Markus; Ackermann, Martin; Vogel, Viola
2016-01-05
To survive antibiotics, bacteria use two different strategies: counteracting antibiotic effects by expression of resistance genes or evading their effects e.g. by persisting inside host cells. Since bacterial adhesins provide access to the shielded, intracellular niche and the adhesin type 1 fimbriae increases bacterial survival chances inside macrophages, we asked if fimbriae also influenced survival by antibiotic evasion. Combined gentamicin survival assays, flow cytometry, single cell microscopy and kinetic modeling of dose response curves showed that type 1 fimbriae increased the adhesion and internalization by macrophages. This was caused by strongly decreased off-rates and affected the number of intracellular bacteria but not the macrophage viability and morphology. Fimbriae thus promote antibiotic evasion which is particularly relevant in the context of chronic infections.
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Determination of antibiotic compounds in water by on-line SPE-LC/MSD.
Choi, Keun-Joo; Kim, Sang-Goo; Kim, Chang-won; Kim, Seung-Hyun
2007-01-01
This study attempts to provide an improved approach for the analysis of antibiotics, which normally exist at low concentration in complex matrices such as receiving streams of wastewater treatment plant discharge. The analytical method developed in this study combines an existing pretreatment technique of solid-phase extraction (SPE) with liquid chromatography mass spectrometry (LC/MSD) through on-line connection. The on-line connection suppressed the target loss by keeping the cartridge from drying, which resulted in improvement of the recovery and saving of the analytical time. For the on-line solid-phase extraction of 10 ml water samples, recoveries were between 74.3% and 116.5% and average LOQ was 0.11 microg l(-1) for the sulfonamide antibiotics (SA) and 0.09 microg l(-1) for the tetracycline antibiotics (TA). Application of the developed method for the analysis of fourteen antibiotics revealed that several antibiotics were detected at concentrations above the LOQ in ARW. Treated and untreated sewage and agricultural wastewater were mostly responsible for the antibiotics contamination of the river. Antibiotics were detected at much higher concentrations in the agricultural wastewater sample than in the sewage sample, implying substantial use of antibiotics in the agricultural industry. Wastewater treatment was generally effective in separation of the antibiotics tested in this study. The extent of the treatment depended on the type of antibiotics. Hydrophobic antibiotics were more effectively separated from the solution than hydrophilic antibiotics.
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Role of antibiotics for treatment of inflammatory bowel disease.
Nitzan, Orna; Elias, Mazen; Peretz, Avi; Saliba, Walid
2016-01-21
Inflammatory bowel disease is thought to be caused by an aberrant immune response to gut bacteria in a genetically susceptible host. The gut microbiota plays an important role in the pathogenesis and complications of the two main inflammatory bowel diseases: Crohn's disease (CD) and ulcerative colitis. Alterations in gut microbiota, and specifically reduced intestinal microbial diversity, have been found to be associated with chronic gut inflammation in these disorders. Specific bacterial pathogens, such as virulent Escherichia coli strains, Bacteroides spp, and Mycobacterium avium subspecies paratuberculosis, have been linked to the pathogenesis of inflammatory bowel disease. Antibiotics may influence the course of these diseases by decreasing concentrations of bacteria in the gut lumen and altering the composition of intestinal microbiota. Different antibiotics, including ciprofloxacin, metronidazole, the combination of both, rifaximin, and anti-tuberculous regimens have been evaluated in clinical trials for the treatment of inflammatory bowel disease. For the treatment of active luminal CD, antibiotics may have a modest effect in decreasing disease activity and achieving remission, and are more effective in patients with disease involving the colon. Rifamixin, a non absorbable rifamycin has shown promising results. Treatment of suppurative complications of CD such as abscesses and fistulas, includes drainage and antibiotic therapy, most often ciprofloxacin, metronidazole, or a combination of both. Antibiotics might also play a role in maintenance of remission and prevention of post operative recurrence of CD. Data is more sparse for ulcerative colitis, and mostly consists of small trials evaluating ciprofloxacin, metronidazole and rifaximin. Most trials did not show a benefit for the treatment of active ulcerative colitis with antibiotics, though 2 meta-analyses concluded that antibiotic therapy is associated with a modest improvement in clinical symptoms
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Hirokawa, Fumitoshi; Hayashi, Michihiro; Miyamoto, Yoshiharu; Asakuma, Mitsuhiro; Shimizu, Tetsunosuke; Komeda, Koji; Inoue, Yoshihiro; Uchiyama, Kazuhisa; Nishimura, Yasuichiro
2013-07-01
Antibiotic prophylaxis is frequently administered after liver resection to prevent postoperative infections. However, very few studies have examined the usefulness of antibiotic prophylaxis after liver resection. A randomized controlled trial was conducted to evaluate the postoperative antibiotic prophylaxis in patients after liver resection. A total of 241 patients scheduled to undergo liver resection were randomly assigned to the non-postoperative antibiotic group (n = 95) or the antibiotic group (n = 95). The antibiotic group was given flomoxef sodium every 12 hours for 3 days after the operation. The end point was signs of infection, surgical site infection, or infectious complications. There were no significant differences between the 2 groups in signs of infection (21.3% vs 25.5%, P = .606), the incidence of systemic inflammatory response syndrome (11.7% vs 17.0%, P = .406), infectious complications (7.5% vs 17.0%, P = .073), surgical site infection (10.6% vs 13.8%, P = .657), and remote site infection (2.1% vs 8.5%, P = .100). Postoperative antibiotic prophylaxis cannot prevent postoperative infections after liver resection, and it is thought that antibiotic prophylaxis is unnecessary and costly. Copyright © 2013 Elsevier Inc. All rights reserved.
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Wang, Hsin-Ju; Chen, Yea-Huey Melody; Chen, Kuan-Liang
2016-01-01
The purpose of this report is to present conservative treatment for two immature premolars with apical periodontitis. A triple antibiotic paste was used to disinfect the root canal systems for revascularization. In both cases, residual vital pulp tissue was noted in the root canal system after the opening of each premolar. The canals in both cases were irrigated with copious sodium hypochlorite solution and medicated with a paste consisting of ciprofloxacin, metronidazole, and minocycline. Th...
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Romme Christensen, Jeppe; Komori, Mika; von Essen, Marina Rode; Ratzer, Rikke; Börnsen, Lars; Bielekova, Bibi; Sellebjerg, Finn
2018-05-01
Development of treatments for progressive multiple sclerosis (MS) is challenged by the lack of sensitive and treatment-responsive biomarkers of intrathecal inflammation. To validate the responsiveness of cerebrospinal fluid (CSF) inflammatory biomarkers to treatment with natalizumab and methylprednisolone in progressive MS and to examine the relationship between CSF inflammatory and tissue damage biomarkers. CSF samples from two open-label phase II trials of natalizumab and methylprednisolone in primary and secondary progressive MS. CSF concentrations of 20 inflammatory biomarkers and CSF biomarkers of axonal damage (neurofilament light chain (NFL)) and demyelination were analysed using electrochemiluminescent assay and enzyme-linked immunosorbent assay (ELISA). In all, 17 natalizumab- and 23 methylprednisolone-treated patients had paired CSF samples. CSF sCD27 displayed superior standardised response means and highly significant decreases during both natalizumab and methylprednisolone treatment; however, post-treatment levels remained above healthy donor reference levels. Correlation analyses of CSF inflammatory biomarkers and NFL before, during and after treatment demonstrated that CSF sCD27 consistently correlates with NFL. These findings validate CSF sCD27 as a responsive and sensitive biomarker of intrathecal inflammation in progressive MS, capturing residual inflammation after treatment. Importantly, CSF sCD27 correlates with NFL, consistent with residual inflammation after anti-inflammatory treatment being associated with axonal damage.
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[Virulence and its relationship to antibiotic resistance].
Joly-Guillou, M L
1998-12-01
PATHOGENIC ISLANDS: Certain DNA blocks inserted into the chromosome of most Gram negative bacteria originated in pathogens found in plants. VIRULENCE-ANTIBIOTIC INTERACTIONS: During the invasive phase, the bacterial cell covers itself with adhesins which facilitate its adherence to tissues. The bacterial cell produces a fibronectin which protects its defense systems. Antibiotics favor bacterial resistance by increasing the expression of surface adhesins and fibronectin production. PENICILLIN RESISTANT PNEUMOCOCCI: Experimental models have demonstrated that mortality in mice and host resistance to pneumococcal infection are related to the type of capsule and not to antibiotic resistance. QUORUM SENSING: The bacterial inoculum regulates the production of virulence factors in vivo via quorum sensing. This regulation can play an important role in Pseudomonas aeruginosa infections. ACINETOBACTER BAUMANNI VIRULENCE: Long poorly understood, factors favoring A. baumanni virulence appear to result from bacterial production of IROMPs in the extracellular growth medium in response to iron depletion during the exponential growth phase.
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Dubreil, Estelle; Gautier, Sophie; Fourmond, Marie-Pierre; Bessiral, Mélaine; Gaugain, Murielle; Verdon, Eric; Pessel, Dominique
2017-04-01
An approach is described to validate a fast and simple targeted screening method for antibiotic analysis in meat and aquaculture products by LC-MS/MS. The strategy of validation was applied for a panel of 75 antibiotics belonging to different families, i.e., penicillins, cephalosporins, sulfonamides, macrolides, quinolones and phenicols. The samples were extracted once with acetonitrile, concentrated by evaporation and injected into the LC-MS/MS system. The approach chosen for the validation was based on the Community Reference Laboratory (CRL) guidelines for the validation of screening qualitative methods. The aim of the validation was to prove sufficient sensitivity of the method to detect all the targeted antibiotics at the level of interest, generally the maximum residue limit (MRL). A robustness study was also performed to test the influence of different factors. The validation showed that the method is valid to detect and identify 73 antibiotics of the 75 antibiotics studied in meat and aquaculture products at the validation levels.
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World alliance against antibiotic resistance: The WAAAR declaration against antibiotic resistance.
Carlet, Jean
2015-01-01
We must change how antibiotics are used and adopt proactive strategies, similar to those used to save endangered species. Preservation of the efficacy of antibiotics and to stabilization of antibiotic-susceptible bacterial ecosystems should be global goals. Copyright © 2014 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.
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Sensor histidine kinase is a β-lactam receptor and induces resistance to β-lactam antibiotics.
Li, Lu; Wang, Qiyao; Zhang, Hui; Yang, Minjun; Khan, Mazhar I; Zhou, Xiaohui
2016-02-09
β-Lactams disrupt bacterial cell wall synthesis, and these agents are the most widely used antibiotics. One of the principle mechanisms by which bacteria resist the action of β-lactams is by producing β-lactamases, enzymes that degrade β-lactams. In Gram-negative bacteria, production of β-lactamases is often induced in response to the antibiotic-associated damage to the cell wall. Here, we have identified a previously unidentified mechanism that governs β-lactamase production. In the Gram-negative enteric pathogen Vibrio parahaemolyticus, we found a histidine kinase/response regulator pair (VbrK/VbrR) that controls expression of a β-lactamase. Mutants lacking either VbrK or VbrR do not produce the β-lactamase and are no longer resistant to β-lactam antibiotics. Notably, VbrK autophosphorylation is activated by β-lactam antibiotics, but not by other lactams. However, single amino acid substitutions in the putative periplasmic binding pocket of VbrK leads its phosphorylation in response to both β-lactam and other lactams, suggesting that this kinase is a β-lactam receptor that can directly detect β-lactam antibiotics instead of detecting the damage to cell wall resulting from β-lactams. In strong support of this idea, we found that purified periplasmic sensor domain of VbrK binds penicillin, and that such binding is critical for VbrK autophosphorylation and β-lactamase production. Direct recognition of β-lactam antibiotics by a histidine kinase receptor may represent an evolutionarily favorable mechanism to defend against β-lactam antibiotics.
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Allahverdiyev, Adil M; Kon, Kateryna Volodymyrivna; Abamor, Emrah Sefik; Bagirova, Malahat; Rafailovich, Miriam
2011-11-01
The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria.
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Determination of tylosin residues in pig tissues using high-performance liquid chromatography.
De Liguoro, M; Anfossi, P; Angeletti, R; Montesissa, C
1998-06-01
In accordance with the maximum residue limit of 100 micrograms kg-1 established by EU legislation, a simple and sensitive high-performance liquid chromatographic (HPLC) method was developed for the measurement of tylosin residues in pig tissues (fat, kidney, liver and muscle). Tylosin, a macrolide antibiotic, is extracted with water-methanol and cleaned-up by solid-phase extraction (SPE) on cation-exchange cartridges using methanol elution. Tylosin was determined by reversed-phase HPLC with UV detection at 280 nm and the mean recovery from pig tissues fortified in the range 50-200 micrograms kg-1 was 70-85%, with intra- and inter-day RSDs in the ranges 3.4-9.1 and 3.9-10.1% respectively.
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Antibiotics for acute otitis media in children.
Venekamp, Roderick P; Sanders, Sharon L; Glasziou, Paul P; Del Mar, Chris B; Rovers, Maroeska M
2015-06-23
Acute otitis media (AOM) is one of the most common diseases in early infancy and childhood. Antibiotic use for AOM varies from 56% in the Netherlands to 95% in the USA, Canada and Australia. This is an update of a Cochrane review first published in The Cochrane Library in Issue 1, 1997 and previously updated in 1999, 2005, 2009 and 2013. To assess the effects of antibiotics for children with AOM. We searched CENTRAL (2015, Issue 3), MEDLINE (1966 to April week 3, 2015), OLDMEDLINE (1958 to 1965), EMBASE (January 1990 to April 2015), Current Contents (1966 to April 2015), CINAHL (2008 to April 2015) and LILACS (2008 to April 2015). Randomised controlled trials (RCTs) comparing 1) antimicrobial drugs with placebo and 2) immediate antibiotic treatment with expectant observation (including delayed antibiotic prescribing) in children with AOM. Two review authors independently assessed trial quality and extracted data. For the review of antibiotics against placebo, 13 RCTs (3401 children and 3938 AOM episodes) from high-income countries were eligible and had generally low risk of bias. The combined results of the trials revealed that by 24 hours from the start of treatment, 60% of the children had recovered whether or not they had placebo or antibiotics. Pain was not reduced by antibiotics at 24 hours (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.78 to 1.01) but almost a third fewer had residual pain at two to three days (RR 0.70, 95% CI 0.57 to 0.86; number needed to treat for an additional beneficial outcome (NNTB) 20). A quarter fewer had pain at four to seven days (RR 0.76, 95% CI 0.63 to 0.91; NNTB 16) and two-thirds fewer had pain at 10 to 12 days (RR 0.33, 95% CI 0.17 to 0.66; NNTB 7) compared with placebo. Antibiotics did reduce the number of children with abnormal tympanometry findings at two to four weeks (RR 0.82, 95% CI 0.74 to 0.90; NNTB 11), at six to eight weeks (RR 0.88, 95% CI 0.78 to 1.00; NNTB 16) and the number of children with tympanic
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An antibiotic-responsive mouse model of fulminant ulcerative colitis.
Directory of Open Access Journals (Sweden)
Silvia S Kang
2008-03-01
Full Text Available BACKGROUND: The constellation of human inflammatory bowel disease (IBD includes ulcerative colitis and Crohn's disease, which both display a wide spectrum in the severity of pathology. One theory is that multiple genetic hits to the host immune system may contribute to the susceptibility and severity of IBD. However, experimental proof of this concept is still lacking. Several genetic mouse models that each recapitulate some aspects of human IBD have utilized a single gene defect to induce colitis. However, none have produced pathology clearly distinguishable as either ulcerative colitis or Crohn's disease, in part because none of them reproduce the most severe forms of disease that are observed in human patients. This lack of severe IBD models has posed a challenge for research into pathogenic mechanisms and development of new treatments. We hypothesized that multiple genetic hits to the regulatory machinery that normally inhibits immune activation in the intestine would generate more severe, reproducible pathology that would mimic either ulcerative colitis or Crohn's disease. METHODS AND FINDINGS: We generated a novel mouse line (dnKO that possessed defects in both TGFbetaRII and IL-10R2 signaling. These mice rapidly and reproducibly developed a disease resembling fulminant human ulcerative colitis that was quite distinct from the much longer and more variable course of pathology observed previously in mice possessing only single defects. Pathogenesis was driven by uncontrolled production of proinflammatory cytokines resulting in large part from T cell activation. The disease process could be significantly ameliorated by administration of antibodies against IFNgamma and TNFalpha and was completely inhibited by a combination of broad-spectrum antibiotics. CONCLUSIONS: Here, we develop to our knowledge the first mouse model of fulminant ulcerative colitis by combining multiple genetic hits in immune regulation and demonstrate that the resulting
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Systemic antibiotics in periodontics.
Slots, Jørgen
2004-11-01
This position paper addresses the role of systemic antibiotics in the treatment of periodontal disease. Topical antibiotic therapy is not discussed here. The paper was prepared by the Research, Science and Therapy Committee of the American Academy of Periodontology. The document consists of three sections: 1) concept of antibiotic periodontal therapy; 2) efficacy of antibiotic periodontal therapy; and 3) practical aspects of antibiotic periodontal therapy. The conclusions drawn in this paper represent the position of the American Academy of Periodontology and are intended for the information of the dental profession.
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Directory of Open Access Journals (Sweden)
nasrin choubkar
2014-02-01
Full Text Available Antibiotics use to increase the immune and wound healing in many animals. But due to the residual effects of a drug, Antibiotics and used to increase the immune response and propolis wound healing is aquadic animals. But due to their residual, researchers are looking to replace them with natural materials. One of these natural materials that has many health benefits is bee propolis. The aim of this study was to evaluate the effect of different concentrations of propolis on wound healing and immune system response in common carp (Cyprinus carpio. Propolis extracts were prepared from Kashan Barij essence with different concentrations of 0 , 2 , 5 and 10% with carrier substances (to dissolve the propolis in water, and were evaluated on wound healing and immune response and survival of common carp on a 21 –day cycle of short baths once a day . The results showed that, compared with the control group (0%, the use of bee propolis in concentration of 2% has statistically significant difference on wound healing and immune system response in common carp. The use of higher concentrations of propolis healed wound, but increased the number of blood cells (red blood cells, neutrophils, and eosinophils and increased mortality of fish, so it is better to use lower concentrations of propolis in fish. The use bee propolis as additive in water is effective in low concentrations and stimulates the immune system.
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DEFF Research Database (Denmark)
Pulcini, Céline; Bush, Karen; Craig, William A
2012-01-01
In view of the alarming spread of antimicrobial resistance in the absence of new antibiotics, this study aimed at assessing the availability of potentially useful older antibiotics. A survey was performed in 38 countries among experts including hospital pharmacists, microbiologists, and infectious...
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Optimizing Antibiotic Use in Nursing Homes Through Antibiotic Stewardship.
Sloane, Philip D; Huslage, Kirk; Kistler, Christine E; Zimmerman, Sheryl
2016-01-01
Antibiotic stewardship is becoming a requirement for nursing homes. Programs should be interdisciplinary and multifaceted; should have support from nursing home administrators; and should aim to promote antibiotics only when needed, not just in case. Recommended components include use of evidence-based guidelines; ongoing monitoring of antibiotic prescriptions, cultures, and study results; monitoring of health outcomes; use of nursing home-specific antibiograms; regular reporting and feedback to medical providers and nurses; and education of residents and families. ©2016 by the North Carolina Institute of Medicine and The Duke Endowment. All rights reserved.
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Effect of Vibration on Bacterial Growth and Antibiotic Resistance
Juergensmeyer, Elizabeth A.; Juergensmeyer, Margaret A.
2004-01-01
The purpose of this research grant was to provide a fundamental, systematic investigation of the effects of oscillatory acceleration on bacterial proliferation and their responses to antibiotics in a liquid medium.
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Interaction of antibiotics on pipecuronium-induced neuromuscular blockade.
de Gouw, N E; Crul, J F; Vandermeersch, E; Mulier, J P; van Egmond, J; Van Aken, H
1993-01-01
To measure the interaction of two antibiotics (clindamycin and colistin) on neuromuscular blockade induced by pipecuronium bromide (a new long-acting, steroidal, nondepolarizing neuromuscular blocking drug). Prospective, randomized, placebo-controlled study. Inpatient gynecologic and gastroenterologic service at a university medical center. Three groups of 20 ASA physical status I and II patients with normal kidney and liver function, taking no medication, and undergoing elective surgery under general anesthesia. Anesthesia was induced with propofol and alfentanil intravenously (IV) and maintained with a propofol infusion and 60% nitrous oxide in oxygen. Pipecuronium bromide 50 micrograms/kg was administered after reaching a stable baseline of single-twitch response. At 25% recovery of pipecuronium-induced neuromuscular blockade, patients received one of two antibiotics, clindamycin 300 mg or colistin 1 million IU, or a placebo. The recovery index (RI, defined as time from 25% to 75% recovery of neuromuscular blockade) was measured using the single-twitch response of the adductor pollicis muscle with supramaximal stimulation of the ulnar nerve at the wrist. RI after administration of an antibiotic (given at 25% recovery) was measured and compared with RI of the control group using Student's unpaired t-test. Statistical analyses of the results showed a significant prolongation of the recovery time (from 25% to 75% recovery) of 40 minutes for colistin. When this type of antibiotic is used during anesthesia with pipercuronium as a muscle relaxant, one must be aware of a significant prolongation of an already long-acting neuromuscular blockade and (although not observed in this study) possible problems in antagonism.
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Directory of Open Access Journals (Sweden)
Chhorvoin Om
2017-03-01
Full Text Available Abstract Background Antibiotic misuse is widespread in resource-limited countries such as Cambodia where the burden of infectious diseases is high and access to antibiotics is unrestricted. We explored healthcare seeking behaviour related to obtaining antibiotics and drivers of antibiotic misuse in the Cambodian community. Methods In-depth interviews were held with family members of patients being admitted in hospitals and private pharmacies termed pharmacy attendants in the catchment areas of the hospitals. Nurses who run community primary healthcare centres located within the hospital catchment areas were invited to attend focus group discussions. Nvivo version 10 was used to code and manage thematic data analysis. Results We conducted individual interviews with 35 family members, 7 untrained pharmacy attendants and 3 trained pharmacists and 6 focus group discussions with 30 nurses. Self-medication with a drug-cocktail was widespread and included broad-spectrum antibiotics for mild illness. Unrestricted access to antibiotics was facilitated by various community enablers including pharmacies or drug outlets, nurse suppliers and unofficial village medical providers referred to as “village Pett” whose healthcare training has historically been in the field and not at university. These enablers supplied the community with various types of antibiotics including broad spectrum fluoroquinolones and cephalosporins. When treatment was perceived to be ineffective patients would prescriber-shop various suppliers who would unfailingly provide them with antibiotics. The main driver of the community’s demand for antibiotics was a mistaken belief in the benefits of antibiotics for a common cold, high temperature, pain, malaria and ‘Roleak’ which includes a broad catch-all for perceived inflammatory conditions. For severe illnesses, patients would attend a community healthcare centre, hospital, or when their finances permitted, a private prescriber
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Wu, Siva; Li, Xiaojin; Gunawardana, Manjula; Maguire, Kathleen; Guerrero-Given, Debbie; Schaudinn, Christoph; Wang, Charles; Baum, Marc M.; Webster, Paul
2014-01-01
Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. PMID:25007395
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[Antibiotics: present and future].
Bérdy, János
2013-04-14
The author discuss the up to date interpretation of the concept of antibiotics and antibiotic research, as well as the present role of various natural, semisynthetic and synthetic antibiotic compounds in various areas of the human therapy. The origin and the total number of all antibiotics and applied antibiotics in the practice, as well as the bioactive microbial metabolites (antibiotics) in other therapeutical, non-antibiotic fields (including agriculture) are also reviewed. The author discusses main problems, such as increasing (poly)resistance, virulence of pathogens and the non-scientific factors (such as a decline of research efforts and their sociological, economic, financial and regulatory reasons). A short summary of the history of Hungarian antibiotic research is also provided. The author briefly discusses the prospects in the future and the general advantages of the natural products over synthetic compounds. It is concluded that new approaches for the investigation of the unlimited possibilities of the living world are necessary. The discovery of new types or simply neglected (micro)organisms and their biosynthetic capabilities, the introduction of new biotechnological and genetic methods (genomics, metagenom, genome mining) are absolutely required in the future.
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[Hygienic substantiation of the permissible levels for tetracycline-group antibiotics in food].
Onishchenko, G G; Sheveleva, S A; Khotimchenko, S A
2012-01-01
For the purpose of justification of the hygienic standard for tetracycline-group antibiotics in the food production established in the Russian Federation at more rigid level, than maximum and admissible levels (MAL) of the Codex Alimentarius Commission, the analysis of data of literature on negative nature of impact of low concentration of these antibiotics on an organism and the environmental conditions and risk for health has been performed. Inadequacy of the accepted admissible daily dose (ADD) accepted by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) on action on selection of resistant E. coli in intestines, for the wide contingent of consumers in connection with ignoring of obvious factors of uncertainty (gastrointestinal dysbiosis, age and individual variations in the microbiota of people synergy with other antibiotics residues in food and indirect impact on an organism through microflora from the natural habitat (resistance genes, modified causative organisms with altered properties).. By the analysis of information received with the use of modern molecular and genetic methods, the role of Subinhibitory concentrations (sub-MICs) of tetracyclines as biologically active substances, signaling molecules which, without causing obvious negative consequences in a macroorganism, serve as a major factor of regulation of a transcription in microorganisms and activation of a horizontal gene transfer coding resistance, transferred on conjugative transposons of Tn916-Tn1545 family. Reasonable scientific data on a dominating contribution of minor levels of tetracyclines in globalization in the nature of the most adverse transmissive type of the antibiotic resistance interfaced to formation new bacterial pathotypes, as consequences of irrationally high scales of application in agriculture and strengthened impact on microbic ecosystems of live organisms and objects of habitat are presented. For minimization of this mediated risk for health the need of
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Antibiotic resistance - the interplay between antibiotic use in animals and human beings
DEFF Research Database (Denmark)
Singer, R.S.; Finch, R.; Wegener, Henrik Caspar
2003-01-01
Antibiotic-resistant bacteria were first identified in the 1940s, but while new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. Today, the excessive use of antibiotics compounded by the paucity of new agents on the market has...... meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance....... There is a growing concern over the transmission of resistant bacteria via the food chain. Many questions will be difficult to resolve, such as how do you distinguish the fraction of resistance in human beings that originated from animals? If we wait to see evidence that a significant amount of antibiotic resistance...
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Occurrence of antibiotics in mussels and clams from various FAO areas.
Chiesa, Luca Maria; Nobile, Maria; Malandra, Renato; Panseri, Sara; Arioli, Francesco
2018-02-01
Filter feeders, like mussels and clams, are suitable bioindicators of environmental pollution. These shellfish, when destined for human consumption, undergo a depuration step that aims to nullify their pathogenic microorganism load and decrease chemical contamination. Nevertheless, the lack of contamination by drugs may not be guaranteed. Antimicrobials are a class of drugs of particular concern due to the increasing phenomenon of antibiotic resistance. Their use in breeding and aquaculture is a major cause of this. We developed a multiclass method for the HPLC-MS/MS analysis of 29 antimicrobials, validated according to the Commission Decision 2002/657/UE guidelines, and applied it to 50 mussel and 50 clam samples derived from various Food and Agricultural Organisation marine zones. The results obtained, indicate a negligible presence of antibiotics. Just one clam sample showed the presence of oxytetracycline at a concentration slightly higher than the European Union Maximum residue limit set for fish. Copyright © 2017. Published by Elsevier Ltd.
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Antibiotic use during the intracoelomic implantation of electronic tags into fish
Mulcahy, D.M.
2011-01-01
The use of antibiotics, in particular, the use of a single dose of antibiotics during electronic tag implantation is of unproven value, and carries with it the potential for the development of antibiotic resistance in bacteria and the alteration of the immune response of the fish. Antibiotic use during electronic tag implantation must conform to relevant drug laws and regulations in the country where work is being done, including the requirements for withdrawal times before human consumption is a possibility. Currently, the choice of antibiotics (most often tetracycline or oxytetracycline) and the use of a single dose of the drug are decisions made without knowledge of the basic need for antibiotic usage and of the bacteria involved in infections that occur following electronic tag implantation. Correct perioperative use of an antibiotic is to apply the drug to the animal before surgery begins, to assure serum and tissue levels of the drug are adequate before the incision is made. However, the most common perioperative application of antibiotics during implantation of an electronic tag is to delay the administration of the drug, injecting it into the coelom after the electronic tag is inserted, just prior to closure of the incision. There is little empirical evidence that the present application of antibiotics in fish being implanted with electronic tags is of value. Improvements should first be made to surgical techniques, especially the use of aseptic techniques and sterilized instruments and electronic tags, before resorting to antibiotics. ?? 2010 Springer Science+Business Media B.V.(outside the USA).
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Antibiotic use in dentistry: A cross-sectional survey from a developing country
Directory of Open Access Journals (Sweden)
Sivaramakrishnan Gowri
2015-01-01
Full Text Available Introduction: Antimicrobial resistance is a well-known entity and the most common factor leading to this is the irrational use of antibiotics. Several studies from the West have substantiated the irrational use of antibiotics in dentistry. Aims: The aim was to assess the knowledge, attitude, and practice (KAP of antimicrobial drug use among dental fraternity in a tertiary care teaching dental college and hospital. Materials and methods: A cross-sectional survey of various dental fraternities using a structured validated questionnaire. The study was initiated following approval from Institutional Ethics Committee and interns, junior residents and faculty members of various departments in dentistry were enrolled after obtaining written informed consent. A structured validated questionnaire was developed to assess the above-mentioned objectives. Statistical analysis: Descriptive statistics was used for representing each category of response and kappa statistics were used to assess the reliability in the initial cohort. Chi-square test for independence was used to evaluate the difference in proportion between different professional cadres. Results: A total of 120 participants were recruited out of which 81.6% (98/120 of the participants accepted their frequent antibiotic usage. The most common dental indication of antibiotics among dentists was post dental extraction, attributing to 30.8% (37/120, followed by dental abscess 21.6% (26/120 and 60% (72/120 prescribed antibiotics after most minor surgical procedures. Surprisingly, 37.5% (45/120 of the participants opined that they use antibiotics against viral infection. Regarding the spectrum of antibiotic usage, 74.1% (89/120 preferred broad spectrum instead of narrow spectrum 25.8% (31/120. The commonly prescribed antibiotics were amoxicillin 71.7% (86/120, metronidazole 33.3% (40/120, amoxicillin with clavulanic acid 26.6% (32/120. A total of (43/120 35.8% opted generic name for mentioning the
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Demographics of antibiotic persistence
DEFF Research Database (Denmark)
Kollerova, Silvia; Jouvet, Lionel; Steiner, Ulrich
Persister cells, cells that can survive antibiotic exposure but lack heritable antibiotic resistance, are assumed to play a crucial role for the evolution of antibiotic resistance. Persistence is a stage associated with reduced metabolic activity. Most previous studies have been done on batch...... even play a more prominent role for the evolution of resistance and failures of medical treatment by antibiotics as currently assumed....
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You, Di; Yao, Li-Li; Huang, Dan; Escalante-Semerena, Jorge C; Ye, Bang-Ce
2014-09-01
Reversible lysine acetylation (RLA) is used by cells of all domains of life to modulate protein function. To date, bacterial acetylation/deacetylation systems have been studied in a few bacteria (e.g., Salmonella enterica, Bacillus subtilis, Escherichia coli, Erwinia amylovora, Mycobacterium tuberculosis, and Geobacillus kaustophilus), but little is known about RLA in antibiotic-producing actinomycetes. Here, we identify the Gcn5-like protein acetyltransferase AcuA of Saccharopolyspora erythraea (SacAcuA, SACE_5148) as the enzyme responsible for the acetylation of the AMP-forming acetyl coenzyme A synthetase (SacAcsA, SACE_2375). Acetylated SacAcsA was deacetylated by a sirtuin-type NAD(+)-dependent consuming deacetylase (SacSrtN, SACE_3798). In vitro acetylation/deacetylation of SacAcsA enzyme was studied by Western blotting, and acetylation of lysine residues Lys(237), Lys(380), Lys(611), and Lys(628) was confirmed by mass spectrometry. In a strain devoid of SacAcuA, none of the above-mentioned Lys residues of SacAcsA was acetylated. To our knowledge, the ability of SacAcuA to acetylate multiple Lys residues is unique among AcuA-type acetyltransferases. Results from site-specific mutagenesis experiments showed that the activity of SacAcsA was controlled by lysine acetylation. Lastly, immunoprecipitation data showed that in vivo acetylation of SacAcsA was influenced by glucose and acetate availability. These results suggested that reversible acetylation may also be a conserved regulatory posttranslational modification strategy in antibiotic-producing actinomycetes. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
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Clinical decision making in restorative dentistry, endodontics, and antibiotic prescription.
Zadik, Yehuda; Levin, Liran
2008-01-01
The purpose of this study was to evaluate the influence of geographic location of graduation (Israel, Eastern Europe, Latin America) on decision making regarding management of dental caries, periapical lesions, and antibiotic prescribing routines. A questionnaire was given to ninety-eight general practitioners regarding demographic and work habits. Photographs of lesions were shown on a screen. Participants reported recommended treatment and whether they would routinely prescribe antibiotics following regular endodontic treatment, retreatment, and impacted third molar surgical extraction in healthy patients. There was a 94 percent (n=92) response rate, of which eighty-five responses were used in the data analysis. Surgical treatment of asymptomatic enamel caries lesions was not recommended by most of the subjects, and surgery was recommended for DEJ caries lesions in low or moderate caries risk patients, both without significant differences between geographic regions of dental school graduation. Israelis had a lower frequency of retreatment in asymptomatic teeth that demonstrated periapical radiolucency with post restoration (without crown) compared to Latin Americans and East Europeans. Most of the participants would not retreat asymptomatic teeth that demonstrated periapical radiolucency with post and crown. After third molar surgery, 46 percent of participants routinely prescribed antibiotics. Significantly more Latin American graduates prescribed antibiotics following endodontic treatment, retreatment, and third molar extractions (pantibiotics) and overtreatment (caries) among young practitioners reflect failure of undergraduate education in proper use of antibiotics and management of the carious lesions according to the patient's clinical presentation and caries risk assessment rather than routinely undertaking surgical caries treatment.
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van Daalen, Frederike Vera; Lagerburg, Anouk; de Kort, Jaclyn; Sànchez Rivas, Elena; Geerlings, Suzanne Eugenie
2017-01-01
No interventions have yet been implemented to improve antibiotic use on Aruba. In the Netherlands, the introduction of an antibiotic checklist resulted in more appropriate antibiotic use in nine hospitals. The aim of this study was to introduce the antibiotic checklist on Aruba, test its
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Amézquita, Alejandro; Backhaus, Thomas; Borriello, Peter; Brandt, Kristian K.; Collignon, Peter; Coors, Anja; Finley, Rita; Gaze, William H.; Heberer, Thomas; Lawrence, John R.; Larsson, D.G. Joakim; McEwen, Scott A.; Ryan, James J.; Schönfeld, Jens; Silley, Peter; Snape, Jason R.; Van den Eede, Christel; Topp, Edward
2013-01-01
Background: Only recently has the environment been clearly implicated in the risk of antibiotic resistance to clinical outcome, but to date there have been few documented approaches to formally assess these risks. Objective: We examined possible approaches and sought to identify research needs to enable human health risk assessments (HHRA) that focus on the role of the environment in the failure of antibiotic treatment caused by antibiotic-resistant pathogens. Methods: The authors participated in a workshop held 4–8 March 2012 in Québec, Canada, to define the scope and objectives of an environmental assessment of antibiotic-resistance risks to human health. We focused on key elements of environmental-resistance-development “hot spots,” exposure assessment (unrelated to food), and dose response to characterize risks that may improve antibiotic-resistance management options. Discussion: Various novel aspects to traditional risk assessments were identified to enable an assessment of environmental antibiotic resistance. These include a) accounting for an added selective pressure on the environmental resistome that, over time, allows for development of antibiotic-resistant bacteria (ARB); b) identifying and describing rates of horizontal gene transfer (HGT) in the relevant environmental “hot spot” compartments; and c) modifying traditional dose–response approaches to address doses of ARB for various health outcomes and pathways. Conclusions: We propose that environmental aspects of antibiotic-resistance development be included in the processes of any HHRA addressing ARB. Because of limited available data, a multicriteria decision analysis approach would be a useful way to undertake an HHRA of environmental antibiotic resistance that informs risk managers. Citation: Ashbolt NJ, Amézquita A, Backhaus T, Borriello P, Brandt KK, Collignon P, Coors A, Finley R, Gaze WH, Heberer T, Lawrence JR, Larsson DG, McEwen SA, Ryan JJ, Schönfeld J, Silley P, Snape JR
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Directory of Open Access Journals (Sweden)
Tomson Göran
2010-09-01
Full Text Available Abstract Background Studies indicate that antibiotics are sold against regulation and without prescription in private drugstores in rural Tanzania. The objective of the study was to explore and describe antibiotics sale and dispensing practices and link it to drugseller knowledge and perceptions of antibiotics and antibiotic resistance. Methods Exit customers of private drugstores in eight districts were interviewed about the drugstore encounter and drugs bought. Drugsellers filled in a questionnaire with closed- and open-ended questions about antibiotics and resistance. Data were analyzed using mixed quantitative and qualitative methods. Results Of 350 interviewed exit customers, 24% had bought antibiotics. Thirty percent had seen a health worker before coming and almost all of these had a prescription. Antibiotics were dispensed mainly for cough, stomachache, genital complaints and diarrhea but not for malaria or headache. Dispensed drugs were assessed as relevant for the symptoms or disease presented in 83% of all cases and 51% for antibiotics specifically. Non-prescribed drugs were assessed as more relevant than the prescribed. The knowledge level of the drugseller was ranked as high or very high by 75% of the respondents. Seventy-five drugsellers from three districts participated. Seventy-nine percent stated that diseases caused by bacteria can be treated with antibiotics but 24% of these also said that antibiotics can be used for treating viral disease. Most (85% said that STI can be treated with antibiotics while 1% said the same about headache, 4% general weakness and 3% 'all diseases'. Seventy-two percent had heard of antibiotic resistance. When describing what an antibiotic is, the respondents used six different kinds of keywords. Descriptions of what antibiotic resistance is and how it occurs were quite rational from a biomedical point of view with some exceptions. They gave rise to five categories and one theme: Perceiving antibiotic
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Sanhueza, Loreto; Melo, Ricardo; Montero, Ruth; Maisey, Kevin; Mendoza, Leonora; Wilkens, Marcela
2017-01-01
Synergy could be an effective strategy to potentiate and recover antibiotics nowadays useless in clinical treatments against multi-resistant bacteria. In this study, synergic interactions between antibiotics and grape pomace extract that contains high concentration of phenolic compounds were evaluated by the checkerboard method in clinical isolates of Staphylococcus aureus and Escherichia coli. To define which component of the extract is responsible for the synergic effect, phenolic compounds were identified by RP-HPLC and their relative abundance was determined. Combinations of extract with pure compounds identified there in were also evaluated. Results showed that the grape pomace extract combined with representatives of different classes of antibiotics as β-lactam, quinolone, fluoroquinolone, tetracycline and amphenicol act in synergy in all S. aureus and E. coli strains tested with FICI values varying from 0.031 to 0.155. The minimal inhibitory concentration (MIC) was reduced 4 to 75 times. The most abundant phenolic compounds identified in the extract were quercetin, gallic acid, protocatechuic acid and luteolin with relative abundance of 26.3, 24.4, 16.7 and 11.4%, respectively. All combinations of the extract with the components also showed synergy with FICI values varying from 0.031 to 0.5 and MIC reductions of 4 to 125 times with both bacteria strains. The relative abundance of phenolic compounds has no correlation with the obtained synergic effect, suggesting that the mechanism by which the synergic effect occurs is by a multi-objective action. It was also shown that combinations of grape pomace extract with antibiotics are not toxic for the HeLa cell line at concentrations in which the synergistic effect was observed (47 μg/mL of extract and 0.6-375 μg/mL antibiotics). Therefore, these combinations are good candidates for testing in animal models in order to enhance the effect of antibiotics of different classes and thus restore the currently unused
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Directory of Open Access Journals (Sweden)
Loreto Sanhueza
Full Text Available Synergy could be an effective strategy to potentiate and recover antibiotics nowadays useless in clinical treatments against multi-resistant bacteria. In this study, synergic interactions between antibiotics and grape pomace extract that contains high concentration of phenolic compounds were evaluated by the checkerboard method in clinical isolates of Staphylococcus aureus and Escherichia coli. To define which component of the extract is responsible for the synergic effect, phenolic compounds were identified by RP-HPLC and their relative abundance was determined. Combinations of extract with pure compounds identified there in were also evaluated. Results showed that the grape pomace extract combined with representatives of different classes of antibiotics as β-lactam, quinolone, fluoroquinolone, tetracycline and amphenicol act in synergy in all S. aureus and E. coli strains tested with FICI values varying from 0.031 to 0.155. The minimal inhibitory concentration (MIC was reduced 4 to 75 times. The most abundant phenolic compounds identified in the extract were quercetin, gallic acid, protocatechuic acid and luteolin with relative abundance of 26.3, 24.4, 16.7 and 11.4%, respectively. All combinations of the extract with the components also showed synergy with FICI values varying from 0.031 to 0.5 and MIC reductions of 4 to 125 times with both bacteria strains. The relative abundance of phenolic compounds has no correlation with the obtained synergic effect, suggesting that the mechanism by which the synergic effect occurs is by a multi-objective action. It was also shown that combinations of grape pomace extract with antibiotics are not toxic for the HeLa cell line at concentrations in which the synergistic effect was observed (47 μg/mL of extract and 0.6-375 μg/mL antibiotics. Therefore, these combinations are good candidates for testing in animal models in order to enhance the effect of antibiotics of different classes and thus restore the
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Rahube, Teddie O; Marti, Romain; Scott, Andrew; Tien, Yuan-Ching; Murray, Roger; Sabourin, Lyne; Duenk, Peter; Lapen, David R; Topp, Edward
2016-07-01
Sewage sludge recovered from wastewater treatment plants contains antibiotic residues and is rich in antibiotic resistance genes, selected for and enriched in the digestive tracts of human using antibiotics. The use of sewage sludge as a crop fertilizer constitutes a potential route of human exposure to antibiotic resistance genes through consumption of contaminated crops. Several gene targets associated with antibiotic resistance (catA1, catB3, ereA, ereB, erm(B), str(A), str(B), qnrD, sul1, and mphA), mobile genetic elements (int1, mobA, IncW repA, IncP1 groups -α, -β, -δ, -γ, -ε), and bacterial 16S rRNA (rrnS) were quantified by qPCR from soil and vegetable samples obtained from unamended and sludge-amended plots at an experimental field in London, Ontario. The qPCR data reveals an increase in abundance of gene targets in the soil and vegetables samples, indicating that there is potential for additional crop exposure to antibiotic resistance genes carried within sewage sludge following field application. It is therefore advisable to allow an appropriate delay period before harvesting of vegetables for human consumption.
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Berglund, Björn
2015-01-01
Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs). Horizontal gene transfer (HGT) events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment. PMID:26356096
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Directory of Open Access Journals (Sweden)
A Javadi
2011-11-01
Full Text Available The purpose of this study was to determine the effects of different cooking processes such as boiling, roasting and microwaving on enrofloxacin residues in muscle, liver and gizzard tissues of broiler chickens. Each of chicks was fed by routine diet and water with %0.05 of enrofloxacine for consecutive 5 days .Then; three locations including breast muscle, liver and gizzard were sampled aseptically from each carcass. Enrofloxacin residue was analyzed using microbial method by plates seeded with Escherichia coli. After doing different phases of the test on raw samples, the positive raw samples cooked by various cooking procedures and we surveyed cooked samples with similar method again for present of residue. The results were show reduction in concentration of enrofloxacin residue after different cooking processes. The most reduction of the residue in cooked meat and gizzard samples related to boiling process and roasting process for cooked liver samples and the highest detectable amount of residue belonged to microwaving process in all cooked samples. Regarding to the results of this study, we can conclude that cooking processes can’t annihilate total amounts of these drug and it can only decrease their amounts and the most of residue in boiling process excreted from tissue to cooking fluid.
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Castillo, UF; Strobel, GA; Ford, EJ; Hess, WM; Porter, H; Jensen, JB; Albert, H; Robison, R; Condron, MAM; Teplow, DB; Stevens, D; Yaver, D
2002-01-01
Munumbicins A, B, C and D are newly described antibiotics with a wide spectrum of activity against many human as well as plant pathogenic fungi and bacteria, and a Plasmodium sp. These compounds were obtained from Streptomyces NRRL 3052, which is endophytic in the medicinal plant snakevine (Kennedia nigriscans), native to the Northern Territory of Australia. This endophyte was cultured, the broth was extracted with an organic solvent and the contents of the residue were purified by bioassay-g...
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Montemurro, Pasqualina; Mariggiò, Maria A; Barbuti, Giovanna; Cassano, Amalia; Vincenti, Alessandra; Serio, Gabriella; Guerra, Lorenzo; Diana, Anna; Santostasi, Teresa; Polizzi, Angela; Fumarulo, Ruggiero; Casavola, Valeria; Manca, Antonio; Conese, Massimo
2012-12-01
It is not known whether antibiotic therapy for lung disease in cystic fibrosis (CF) has an influence on circulating polymorphonuclear neutrophil (PMN) function and apoptosis. Blood PMNs were obtained from 14 CF patients before and after antibiotic treatment for an acute exacerbation, and from 10 healthy controls. PMNs were evaluated for production of reactive oxygen species (ROS) by spectrophotometry, of cytokines in the conditioned medium by ELISA, and apoptotic response by cytofluorimetry. ROS and interleukin (IL)-8 were produced at higher levels by CF PMNs pre-therapy than control PMNs under basal conditions. IL-8 levels further increased after therapy. Early apoptotic response was higher in CF PMNs pre-therapy than in control PMNs, and this pattern did not change after antibiotic treatment. Circulating PMNs are primed in CF acute patients. Further studies are needed to consider PMN-produced IL-8 as a biomarker to evaluate response to antibiotic therapy in CF patients. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
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Zhu, Xiangdong; Yang, Shijun; Wang, Liang; Liu, Yuchen; Qian, Feng; Yao, Wenqing; Zhang, Shicheng; Chen, Jianmin
2016-04-01
Antibiotic mycelial fermentation residues (AMFRs), which are emerging solid pollutants, have been recognized as hazardous waste in China since 2008. Nitrogen (N), which is an environmental sensitivity element, is largely retained in AMFR samples derived from fermentation substrates. Pyrolysis is a promising technology for the treatment of solid waste. However, the outcomes of N element during the pyrolysis of AMFRs are still unknown. In this study, the conversion of N element during the pyrolysis of AMFRs was tracked using XPS (X-ray photoelectron spectroscopy) and online TG-FTIR-MS (Thermogravimetry-Fourier transform infrared-Mass spectrometry) technology. In the AMFR sample, organic amine-N, pyrrolic-N, protein-N, pyridinic-N, was the main N-containing species. XPS results indicated that pyrrolic-N and pyridinic-N were retained in the AMFR-derived pyrolysis char. More stable species, such as N-oxide and quaternary-N, were also produced in the char. TG-FTIR-MS results indicated that NH3 and HCN were the main gaseous species, and their contents were closely related to the contents of amine-N and protein-N, and pyrrolic-N and pyridinic-N of AMFRs, respectively. Increases in heating rate enhanced the amounts of NH3 and HCN, but had less of an effect on the degradation degree of AMFRs. N-containing organic compounds, including amine-N, nitrile-N and heterocyclic-N, were discerned from the AMFR pyrolysis process. Their release range was extended with increasing of heating rate and carbon content of AMFR sample. This work will help to take appropriate measure to reduce secondary pollution from the treatment of AMFRs. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Immuno-modulation and anti-inflammatory benefits of antibiotics: the example of tilmicosin.
Buret, André G
2010-01-01
Exaggerated immune responses, such as those implicated in severe inflammatory reactions, are costly to the metabolism. Inflammation and pro-inflammatory mediators negatively affect production in the food animal industry by reducing growth, feed intake, reproduction, milk production, and metabolic health. An ever-increasing number of findings have established that antibiotics, macrolides in particular, may generate anti-inflammatory effects, including the modulation of pro-inflammatory cytokines and the alteration of neutrophil function. The effects are time- and dose-dependent, and the mechanisms responsible for these phenomena remain incompletely understood. Recent studies, mostly using the veterinary macrolide tilmicosin, may have shed new light on the mode of action of some macrolides and their anti-inflammatory properties. Indeed, research findings demonstrate that this compound, amongst others, induces neutrophil apoptosis, which in turn provides anti-inflammatory benefits. Studies using tilmicosin model systems in vitro and in vivo demonstrate that this antibiotic has potent immunomodulatory effects that may explain why at least parts of its clinical benefits are independent of anti-microbial effects. More research is needed, using this antibiotic and others that may have similar properties, to clarify the biological mechanisms responsible for antibiotic-induced neutrophil apoptosis, and how this, in turn, may provide enhanced clinical benefits. Such studies may help establish a rational basis for the development of novel, efficacious, anti-microbial compounds that generate anti-inflammatory properties in addition to their antibacterial effects.
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Shao, Sicheng; Hu, Yongyou; Cheng, Jianhua; Chen, Yuancai
2018-05-28
Antimicrobial and antibiotics resistance caused by misuse or overuse of antibiotics exposure is a growing and significant threat to global public health. The spread and horizontal transfer of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) by the selective pressure of antibiotics in an aquatic environment is a major public health issue. To develop a better understanding of potential ecological risks die to antibiotics and ARGs, this study mainly summarizes research progress about: (i) the occurrence, concentration, fate, and potential ecological effects of antibiotics and ARGs in various aquatic environments, (ii) the threat, spread, and horizontal gene transfer (HGT) of ARGs, and (iii) the relationship between antibiotics, ARGs, and ARB. Finally, this review also proposes future research direction on antibiotics and ARGs.
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Adverse consequences of neonatal antibiotic exposure.
Cotten, Charles M
2016-04-01
Antibiotics have not only saved lives and improved outcomes, but they also influence the evolving microbiome. This review summarizes reports on neonatal infections and variation in antibiotic utilization, discusses the emergence of resistant organisms, and presents data from human neonates and animal models demonstrating the impact of antibiotics on the microbiome, and how microbiome alterations impact health. The importance of antibiotic stewardship is also discussed. Infections increase neonatal morbidity and mortality. Furthermore, the clinical presentation of infections can be subtle, prompting clinicians to empirically start antibiotics when infection is a possibility. Antibiotic-resistant infections are a growing problem. Cohort studies have identified extensive center variations in antibiotic usage and associations between antibiotic exposures and outcomes. Studies of antibiotic-induced microbiome alterations and downstream effects on the developing immune system have increased our understanding of the mechanisms underlying the associations between antibiotics and adverse outcomes. The emergence of resistant microorganisms and recent evidence linking antibiotic practice variations with health outcomes has led to the initiation of antibiotic stewardship programs. The review encourages practitioners to assess local antibiotic use with regard to local microbiology, and to adopt steps to reduce infections and use antibiotics wisely.
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Petit, F.; Berthe, T.; Oberle, K.; Denamur, E.; Clermont, O.; Leclercq, R.; Cattoir, V.; Budzinski, H.
2013-12-01
The spread of antibiotic-resistant faecal bacteria and their corresponding genes in water environment, as a result of the overuse of antibiotics, have become an ecological and a public problem. The aim of this multidisciplinary research program (FLASH) -associating chemists, hydrologists, clinical and environmental microbiologists- was to determine to what extent the hospital effluent have an ecological impact on the downstream aquatic environment. For this purpose, fate of Escherichia coli (distribution of phylogenetic groups, antibiotic resistance, integrons- 342 strains) and Enterococci (diversity, antibiotic resistance, genes ermB, mefA, clonal complex 17- 235 strains ) was analyzed in water and sediments along a medical center - WWTP - river - estuary continuum, during a high epidemiologic period in the North west of France. A multi-residue chemical methodology was developed in order to detect low levels of 34 antibiotics in water. To link occurrence of antibiotic-resistant bacteria in water and antibiotic prescription, we use the data collection from the hospital and the antibiotics sales information. In the medical center, the main prescribed antibiotic (amoxicillin) was weakly found in effluents. Along the continuum, contamination of water by antibiotics decreased from 160μg.L-1 (cefotaxim) in hospital effluents to 1ng.L-1 (ofloxacin) in the river. These concentrations were too low to exert a selective pressure (mg.L-1) on antibiotic-resistant bacteria. In same samples, occurrences of antibiotic-resistant E. coli and those harboring a class 1 integrons decreased significantly (p-value E. coli isolates, multiresistant to antibiotic, was observed in water microcosm experiment (E. coli and the corresponding antibiotic-resistance genes are submitted to the particle dynamics and are deposited on mudflats. Among Enterococcus populations, E. faecium was mainly isolated (from 89% to 98%). All E. faecium isolates from medical center effluents were multiply
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Herrmann, Markus; Nkuiya, Bruno
2017-06-01
This paper designs a bio-economic model to examine the use of substitute antibiotic drugs (analogs) sold by an industry that has open access to the resource of the antibiotic class's susceptibility (treatment effectiveness). Antibiotics are characterized by different expected recovery rates and production costs, which in conjunction with the class's treatment susceptibility determines their relative effectiveness. Our analysis reveals that the high-quality antibiotic drug loses its comparative advantage over time making the low-quality drug the treatment of last resort in the market equilibrium and the social optimum when antibiotic susceptibility cannot replenish. However, when antibiotic susceptibility is renewable, both antibiotics may be used in the long run, and the comparative advantage of the high-quality drug may be restored in the social optimum that allows lowering infection in the long run. We develop the optimal tax/subsidy scheme that would induce antibiotic producers under open access to behave optimally and account for the social cost of infection and value of antibiotic susceptibility. We show that the welfare loss associated with the uncorrected open-access allocation is highest; when the resource of antibiotic susceptibility is non-renewable, high morbidity costs are incurred by individuals, and low social discount rates apply. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
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Directory of Open Access Journals (Sweden)
Marianne Frieri
2017-07-01
Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department
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Glycopeptide antibiotic biosynthesis.
Yim, Grace; Thaker, Maulik N; Koteva, Kalinka; Wright, Gerard
2014-01-01
Glycopeptides such as vancomycin, teicoplanin and telavancin are essential for treating infections caused by Gram-positive bacteria. Unfortunately, the dwindled pipeline of new antibiotics into the market and the emergence of glycopeptide-resistant enterococci and other resistant bacteria are increasingly making effective antibiotic treatment difficult. We have now learned a great deal about how bacteria produce antibiotics. This information can be exploited to develop the next generation of antimicrobials. The biosynthesis of glycopeptides via nonribosomal peptide assembly and unusual amino acid synthesis, crosslinking and tailoring enzymes gives rise to intricate chemical structures that target the bacterial cell wall. This review seeks to describe recent advances in our understanding of both biosynthesis and resistance of these important antibiotics.
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Directory of Open Access Journals (Sweden)
Siva Wu
Full Text Available Non-typeable Haemophilus influenzae (NTHi is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10 µg/mL of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended.
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Antibiotic use in early childhood and the development of asthma.
Wickens, K; Pearce, N; Crane, J; Beasley, R
1999-06-01
Recent investigations have focused on the role of infections in infancy in promoting or protecting against the subsequent development of asthma. A related hypothesis concerns the possible role of medical responses to infections, including the widespread use of antibiotics. We chose children at Rudolf Steiner schools to test this latter hypothesis because a significant proportion of parents rejects the use of conventional treatments, including antibiotics. Seventy-five per cent (n = 456) of parents of children aged 5-10 years attending Rudolf Steiner schools throughout New Zealand completed questionnaires which included questions on the use of antibiotics and a history of asthma and wheeze in their children. After controlling for potential confounders, antibiotic use was significantly associated with having a history of asthma (OR = 2.74, 95% CI: 1.10-6.85) or wheeze (OR = 1. 86, 95% CI: 1.06-3.26) but not with current wheeze (OR = 1.08, 95% CI: 0.54-2-16). The adjusted odds ratio for asthma was 4.05 (95% CI: 1.55-10.59) if antibiotics were used in the first year of life and 1. 64 (95% CI: 0.60-4.46) if antibiotics had been used only after the first year of life when compared with children who had never used antibiotics. The number of courses of antibiotics during the first year of life was also associated with increased odds ratios for asthma: 2.27 (95% CI: 1.14-4.51) for one to two courses and 4.02 (95% CI: 1.57-10.31) for three or more courses when compared with no antibiotic use in the first year of life. Although not significant, the association of antibiotics and hay fever (OR = 1.99 [95% CI: 0. 93-4.26]) was of a similar strength to the association of antibiotics with a history of wheeze. Antibiotics were not significantly associated with eczema (OR = 1.23 [95% CI: 0.71-2.13]). Antibiotic use in infancy may be associated with an increased risk of developing asthma. Further study is required to determine the reasons for this association.
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Zeng, Dongping; Lin, Zhoumeng; Fang, Binghu; Li, Miao; Gehring, Ronette; Riviere, Jim E; Zeng, Zhenling
2017-01-01
Mequindox (MEQ) is a quinoxaline-N,N-dioxide antibiotic used in food-producing animals. MEQ residue in animal-derived foods is a food safety concern. The tissue distribution of MEQ and its marker residue 1,4-bisdesoxymequindox (M1) were determined in swine following oral gavage or intramuscular
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International Nuclear Information System (INIS)
Ansari, S.H.; Nasim, S.; Ahmed, A.; Irfan, M.; Ishaque, A.; Farzana, T.; Panjwani, V.K.; Taj, M.; Shamsi, T.S.
2006-01-01
To find the in-vitro sensitivity data and clinical response in order to determine the changes required in empiric antibiotic therapy for management of febrile neutropenia in paediatric patients undergoing peripheral blood stem cell transplantation. All patients were treated according to institutional protocol for febrile neutropenia. Empirical antibiotics include Ceftriaxone and Amikacin. In non-responders, changes made included Imipenem and Amikacin, Piperacillin Tazobactum/Tiecoplanin or Vancomycin/Cloxacilin/Ceftazidime. In non-responders, amphotaracin was added until recovery. Out of 52 patients, 5 did not develop any fever; in the remaining 47 patients there were 57 episodes of febrile neutropenia. The mean days of febrile episodes were 4.71 (range 3-8). Fever of unknown origin (FUO) occurred in 31 (54.3%) episodes. Microbiologically documented infection (MDI) occurred in 17 (29.8%) episodes of fever. Clinically documented infection (CDI) occurred in 9 (15.7%) episodes. Gram-negative organisms were isolated in 10 while gram-positive organisms in 7. Klebseilla, S. aureus were the most common isolates. Empirical therapy was effective in 12 of the 33 (36%) episodes. Out of 28, 26 (92%) responded to Imipenem/Amikacin as second line therapy while those who received any other second line combination, only 11 out of 22 (50%) showed response. Systemic Amphotericin was used in 4 patients, 2 responded. Infection related mortality rate was 4%. (author)
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Thermus Thermophilus as a Model System for the Study of Ribosomal Antibiotic Resistance
Gregory, Steven T.
2018-03-01
Ribosomes are the intracellular ribonucleoprotein machines responsible for the translation of mRNA sequence into protein sequence. As an essential cell component, the ribosome is the target of numerous antibiotics that bind to critical functional sites to impair protein synthesis. Mutations causing resistance to antibiotics arise in antibiotic binding sites, and an understanding of the basis of resistance will be an essential component of efforts to develop new antibiotics by rational drug design. We have identified a number of antibiotic-resistance mutations in ribosomal genes of the thermophilic bacterium Thermus thermophilus. This species offers two primary advantages for examining the structural basis of antibiotic-resistance, in particular, its potential for genetic manipulation and the suitability of its ribosomes for analysis by X-ray crystallography. Mutations we have identified in this organism are in many instances identical to those found in other bacterial species, including important pathogens, a result of the extreme conservation of ribosome functional sites. Here I summarize the advantages of this organism as a model system to study antibiotic-resistance mechanisms at the molecular level.
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Haenssgen, MJ; Charoenboon, N; Zanello, G; Mayxay, M; Reed-Tsochas, F; Jones, COH; Kosaikanont, R; Praphattong, P; Manohan, P; Lubell, Y; Newton, PN; Keomany, S; Wertheim, HFL; Lienert, J; Xayavong, T
2018-01-01
Background Antimicrobial resistance (AMR) is a global health priority. Leading UK and global strategy papers to fight AMR recognise its social and behavioural dimensions, but current policy responses to improve the popular use of antimicrobials (eg, antibiotics) are limited to education and awareness-raising campaigns. In response to conceptual, methodological and empirical weaknesses of this approach, we study people’s antibiotic-related health behaviour through three research questions. ...
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Awareness of antibiotic use and antimicrobial resistance in the Iraqi community in Jordan.
Darwish, Dana A; Abdelmalek, Suzanne; Abu Dayyih, Wael; Hamadi, Salim
2014-05-14
Antimicrobial resistance is a serious global health concern. It has considerable implications on societies' health and resources. In Jordan, there is a large Iraqi community due to the ongoing turmoil in Iraq. Unfortunately, health awareness and practices of this community are under-investigated due to scarcity of research. This paper assesses the awareness of antibiotic use and antimicrobial resistance in the Iraqi community residing in Amman, Jordan. Their level of interaction with health care professionals regarding antibiotics and differences in their antibiotic use between Iraq and Jordan are also discussed. A cross-sectional questionnaire-based survey involving randomly selected Iraqis residing in Amman, Jordan was conducted. The study involved 508 participants. Sixty-two percent of participants agreed with buying antibiotics without a prescription, 29% agreed with obtaining antibiotics from friends or relatives, and 46% agreed with keeping leftover antibiotics for future use. Furthermore, 60% disagreed with not completing an antibiotic course and almost 90% of the sample listed viral diseases as an indication for antibiotics. Forty-four percent of participants abided by physicians' instructions on antibiotic use. Half of the participants believed that pharmacists provided instructions on antibiotics all the time, whereas physicians were perceived to do so by 29% of participants. Gaps exist in knowledge of antibiotic use and reasons for antimicrobial resistance among Iraqis residing in Jordan. These gaps should serve in planning educational campaigns to raise the community's awareness of responsible antibiotic use. Law enforcement to restrict access to antibiotics is also pivotal to tackle their misuse.
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History of Antibiotics Research.
Mohr, Kathrin I
2016-01-01
For thousands of years people were delivered helplessly to various kinds of infections, which often reached epidemic proportions and have cost the lives of millions of people. This is precisely the age since mankind has been thinking of infectious diseases and the question of their causes. However, due to a lack of knowledge, the search for strategies to fight, heal, and prevent the spread of communicable diseases was unsuccessful for a long time. It was not until the discovery of the healing effects of (antibiotic producing) molds, the first microscopic observations of microorganisms in the seventeenth century, the refutation of the abiogenesis theory, and the dissolution of the question "What is the nature of infectious diseases?" that the first milestones within the history of antibiotics research were set. Then new discoveries accelerated rapidly: Bacteria could be isolated and cultured and were identified as possible agents of diseases as well as producers of bioactive metabolites. At the same time the first synthetic antibiotics were developed and shortly thereafter, thousands of synthetic substances as well as millions of soil borne bacteria and fungi were screened for bioactivity within numerous microbial laboratories of pharmaceutical companies. New antibiotic classes with different targets were discovered as on assembly line production. With the beginning of the twentieth century, many of the diseases which reached epidemic proportions at the time-e.g., cholera, syphilis, plague, tuberculosis, or typhoid fever, just to name a few, could be combatted with new discovered antibiotics. It should be considered that hundred years ago the market launch of new antibiotics was significantly faster and less complicated than today (where it takes 10-12 years in average between the discovery of a new antibiotic until the launch). After the first euphoria it was quickly realized that bacteria are able to develop, acquire, and spread numerous resistance mechanisms
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DEFF Research Database (Denmark)
Luo, Gang; Li, Bing; Li, Li-Guan
2017-01-01
resistance genes (MRGs). The total abundance of ARGs in all the samples varied from 7 × 10-3 to 1.08 × 10-1 copy of ARG/copy of 16S-rRNA gene, and the samples obtained from thermophilic biogas reactors had a lower total abundance of ARGs, indicating the superiority of thermophilic anaerobic digestion......Digested residues from biogas plants are often used as biofertilizers for agricultural crops cultivation. The antibiotic resistance genes (ARGs) in digested residues pose a high risk to public health due to their potential spread to the disease-causing microorganisms and thus reduce...... the susceptibility of disease-causing microorganisms to antibiotics in medical treatment. A high-throughput sequencing (HTS)-based metagenomic approach was used in the present study to investigate the variations of ARGs in full-scale biogas reactors and the correlations of ARGs with microbial communities and metal...
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Mohammadi, Z; Abbott, P V
2009-07-01
Antibiotics are a valuable adjunctive to the armamentarium available to health professionals for the management of bacterial infections. During endodontic treatment and when managing trauma to the teeth, antibiotics may be applied systemically (orally and/or parenterally) or locally (i.e. intra-dentally via irrigants and medicaments). Due to the potential risk of adverse effects following systemic application, and the ineffectiveness of systemic antibiotics in necrotic pulpless teeth and the periradicular tissues, the local application of antibiotics may be a more effective mode for delivery in endodontics. The aim of this article was to review the history, rationale and applications of antibiotic-containing irrigants and medicaments in endodontics and dental traumatology. The search was performed from 1981 to 2008 and was limited to English-language papers. The keywords searched on Medline were 'Antibiotics AND endodontics', 'Antibiotics AND root canal irrigation', 'Antibiotics AND intra-canal medicament', 'Antibiotics AND Dental trauma' and 'Antibiotics AND root resorption'. The reference section of each article was manually searched to find other suitable sources of information. It seems that local routes of antibiotic administration are a more effective mode than systemic applications. Various antibiotics have been tested in numerous studies and each has some advantages. Tetracyclines are a group of bacteriostatic antibiotics with antibacterial substantivity for up to 12 weeks. They are typically used in conjunction with corticosteroids and these combinations have anti-inflammatory, anti-bacterial and anti-resorptive properties, all of which help to reduce the periapical inflammatory reaction including clastic-cell mediated resorption. Tetracyclines have also been used as part of irrigating solutions but the substantivity is only for 4 weeks. Clindamycin and a combination of three antibiotics (metronidazole, ciprofloxacin and minocycline) have also been
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Neut, C; Mahieux, S; Dubreuil, L J
2017-11-01
The main goal of this study was to determine the in vitro susceptibility of strains collected from marketed probiotics to antibiotics used to treat community-acquired infections. The minimum inhibitory concentrations (MICs) of 16 antibiotics were determined using a gradient strip (E test) or the agar dilution method for fidaxomicin. The probiotics demonstrated various antibiotic patterns. Bacterial probiotics are generally susceptible to most prescribed antibiotics orally administered, whereas yeast probiotics, such as Saccharomyces boulardii, are resistant. Special attention must be paid to co-prescriptions of antibiotics and probiotics to ensure that the probiotic strain is not susceptible. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
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DEFF Research Database (Denmark)
Madsbad, S; Hilsted, J; Krarup, T
1982-01-01
Hormonal, metabolic and cardiovascular responses to insulin induced hypoglycaemia were investigated in seven Type 1 (insulin-dependent) diabetic patients with residual B cell function, eight Type 1 diabetic patients without B cell function and six healthy subjects. No differences were found between...... the diabetic groups regarding nadir of glucose and rate of recovery to normoglycaemia. The patients with residual B cell function had a glucagon response to hypoglycaemia which was close to that of normal subjects. In patients without B cell function, the glucagon response to hypoglycaemia was present, albeit...... significantly smaller than in the patients with preserved B cell function (0.025 ng/ml, range 0.007-0.042 versus 0.054 ng/ml, range 0.029-0.087). The group without B cell function had signs of an exaggerated rate of lipolysis and ketogenesis compared with the patients with B cell function and the normal...
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Directory of Open Access Journals (Sweden)
Katrien eVan't Hooft
2016-02-01
Full Text Available The current and expected growth of the world’s population warrants an increased production of high quality animal protein. Dairy farming is regarded as one of the important ways of satisfying this need to meet the growing demand for milk, especially in developing countries. The focus on crossbreeding and increasing the productivity of dairy cattle has, besides enhanced milk production, also resulted in an increased use of agro-chemicals, mainly antibiotics and anti-parasite drugs. The residues of these agro-chemicals, if not managed properly, could leak into the environment, affecting natural processes, biodiversity and soil life. Public health can also be affected due to residues in milk and meat, especially in countries with insufficient food quality controls. These processes contribute to the growing global threat to human and animal health posed by multi-resistant microbes. This article discusses the differences and similarities of dairy farming, and the effect on public and environmental health, between the Netherlands, India, Ethiopia and Uganda, emphasizing the strategies that have been developed during the E-Motive exchange project to reduce the use of antibiotics and other chemicals in dairy farming. Proposed solutions include raising consciousness about the risk of antibiotics and their effect on food quality, and implementing the 5-layer approach for reducing the use of antibiotics and other chemicals. This approach is based on improving animal and farm management, revitalizing ethno veterinary knowledge and the use of medicinal plants, genetic improvement through strategic use of local breeds, establishing quality control systems in the dairy chain, and extra payment to farmers for residue-free milk.
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Aldrin, Magne; Raastad, Ragnhild; Tvete, Ingunn Fride; Berild, Dag; Frigessi, Arnoldo; Leegaard, Truls; Monnet, Dominique L; Walberg, Mette; Müller, Fredrik
2013-04-15
Association between previous antibiotic use and emergence of antibiotic resistance has been reported for several microorganisms. The relationship has been extensively studied, and although the causes of antibiotic resistance are multi-factorial, clear evidence of antibiotic use as a major risk factor exists. Most studies are carried out in countries with high consumption of antibiotics and corresponding high levels of antibiotic resistance, and currently, little is known whether and at what level the associations are detectable in a low antibiotic consumption environment. We conduct an ecological, retrospective study aimed at determining the impact of antibiotic consumption on antibiotic-resistant Pseudomonas aeruginosa in three hospitals in Norway, a country with low levels of antibiotic use. We construct a sophisticated statistical model to capture such low signals. To reduce noise, we conduct our study at hospital ward level. We propose a random effect Poisson or binomial regression model, with a reparametrisation that allows us to reduce the number of parameters. Inference is likelihood based. Through scenario simulation, we study the potential effects of reduced or increased antibiotic use. Results clearly indicate that the effects of consumption on resistance are present under conditions with relatively low use of antibiotic agents. This strengthens the recommendation on prudent use of antibiotics, even when consumption is relatively low. Copyright © 2012 John Wiley & Sons, Ltd.
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Zhao, Lei; Li, Hongru; Zhu, Ziwen; Wakefield, Mark R; Fang, Yujiang; Ye, Ying
2017-06-01
Acinetobacter baumannii has been becoming a great challenge to clinicians due to their resistance to almost all available antibiotics. In this study, we sequenced the genome from a multiple antibiotics resistant Acinetobacter baumannii stain which was named A. baumannii-1isolated from China by SMRT sequencing technology to explore its potential mechanisms to antibiotic resistance. We found that several mechanisms might contribute to the antibiotic resistance of Acinetobacter baumannii. Specifically, we found that SNP in genes associated with nucleotide excision repair and ABC transporter might contribute to its resistance to multiple antibiotics; we also found that specific genes associated with bacterial DNA integration and recombination, DNA-mediated transposition and response to antibiotics might contribute to its resistance to multiple antibiotics; Furthermore, specific genes associated with penicillin and cephalosporin biosynthetic pathway and specific genes associated with CHDL and MBL β-lactamase genes might contribute to its resistance to multiple antibiotics. Thus, the detailed mechanisms by which Acinetobacter baumannii show extensive resistance to multiple antibiotics are very complicated. Such a study might be helpful to develop new strategies to control Acinetobacter baumannii infection. Copyright © 2017 Elsevier B.V. All rights reserved.
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Antibiotic modulation of capsular exopolysaccharide and virulence in Acinetobacter baumannii.
Directory of Open Access Journals (Sweden)
Edward Geisinger
2015-02-01
Full Text Available Acinetobacter baumannii is an opportunistic pathogen of increasing importance due to its propensity for intractable multidrug-resistant infections in hospitals. All clinical isolates examined contain a conserved gene cluster, the K locus, which determines the production of complex polysaccharides, including an exopolysaccharide capsule known to protect against killing by host serum and to increase virulence in animal models of infection. Whether the polysaccharides determined by the K locus contribute to intrinsic defenses against antibiotics is unknown. We demonstrate here that mutants deficient in the exopolysaccharide capsule have lowered intrinsic resistance to peptide antibiotics, while a mutation affecting sugar precursors involved in both capsule and lipopolysaccharide synthesis sensitizes the bacterium to multiple antibiotic classes. We observed that, when grown in the presence of certain antibiotics below their MIC, including the translation inhibitors chloramphenicol and erythromycin, A. baumannii increases production of the K locus exopolysaccharide. Hyperproduction of capsular exopolysaccharide is reversible and non-mutational, and occurs concomitantly with increased resistance to the inducing antibiotic that is independent of the presence of the K locus. Strikingly, antibiotic-enhanced capsular exopolysaccharide production confers increased resistance to killing by host complement and increases virulence in a mouse model of systemic infection. Finally, we show that augmented capsule production upon antibiotic exposure is facilitated by transcriptional increases in K locus gene expression that are dependent on a two-component regulatory system, bfmRS. These studies reveal that the synthesis of capsule, a major pathogenicity determinant, is regulated in response to antibiotic stress. Our data are consistent with a model in which gene expression changes triggered by ineffectual antibiotic treatment cause A. baumannii to transition
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Antibiotics and Antibiotic Resistance
... all that ails you. Antibiotics, also known as antimicrobial drugs, are drugs that fight infections caused by bacteria. ... Information for Consumers and Health Professionals Information by drug class Antimicrobial Resistance Animal and Veterinary Related Resources Further information ...
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Directory of Open Access Journals (Sweden)
Martina Vallin
Full Text Available In 2006, a study investigating knowledge and attitudes regarding antibiotic use and resistance in Sweden, indicated high level of knowledge but also areas in need of improvement.(i To provide an update on the knowledge and attitudes to antibiotic use and resistance of the Swedish population, and (ii to identify which groups within the population are in particular need of improved knowledge or attitudes.A questionnaire was sent by post in 2013 to 2,500 randomly-selected individuals aged 18-74, living in Sweden. Latent class analyses were conducted to group respondents based on their responses. The association between socio-demographic characteristics and the probability of belonging to each latent class was assessed.The response rate was 57%. Ninety-four per cent of the responders knew that bacteria could become resistant to antibiotics and the majority answered correctly to the questions regarding antibiotic resistance development. The respondents expressed confidence in doctors who decided not to prescribe antibiotics. Three latent classes related to 'knowledge regarding antibiotic use and resistance', two regarding 'attitudes towards antibiotic accessibility and infection prevention' and three regarding 'attitudes towards antibiotic use and effects' were revealed. Men, younger and more educated people were more knowledgeable but males had a less restrictive attitude. Respondents with high levels of knowledge on antibiotics were more likely to have appropriate restrictive attitudes to antibiotics.Knowledge on antibiotic use and resistance is maintained high and has improved in Sweden compared to 2006. People with lower education and elderly are especially in need of improved knowledge about antibiotic use and resistance.
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Bacterial cheating limits antibiotic resistance
Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff
2012-02-01
The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.
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Short-term effect of antibiotics on human gut microbiota.
Directory of Open Access Journals (Sweden)
Suchita Panda
Full Text Available From birth onwards, the human gut microbiota rapidly increases in diversity and reaches an adult-like stage at three years of age. After this age, the composition may fluctuate in response to external factors such as antibiotics. Previous studies have shown that resilience is not complete months after cessation of the antibiotic intake. However, little is known about the short-term effects of antibiotic intake on the gut microbial community. Here we examined the load and composition of the fecal microbiota immediately after treatment in 21 patients, who received broad-spectrum antibiotics such as fluoroquinolones and β-lactams. A fecal sample was collected from all participants before treatment and one week after for microbial load and community composition analyses by quantitative PCR and pyrosequencing of the 16S rRNA gene, respectively. Fluoroquinolones and β-lactams significantly decreased microbial diversity by 25% and reduced the core phylogenetic microbiota from 29 to 12 taxa. However, at the phylum level, these antibiotics increased the Bacteroidetes/Firmicutes ratio (p = 0.0007, FDR = 0.002. At the species level, our findings unexpectedly revealed that both antibiotic types increased the proportion of several unknown taxa belonging to the Bacteroides genus, a Gram-negative group of bacteria (p = 0.0003, FDR<0.016. Furthermore, the average microbial load was affected by the treatment. Indeed, the β-lactams increased it significantly by two-fold (p = 0.04. The maintenance of or possible increase detected in microbial load and the selection of Gram-negative over Gram-positive bacteria breaks the idea generally held about the effect of broad-spectrum antibiotics on gut microbiota.
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McArthur, J Vaun; Dicks, Christian A; Bryan, A Lawrence; Tuckfield, R Cary
2017-09-01
Environmental reservoirs of antibiotic resistant bacteria are poorly understood. Understanding how the environment selects for resistance traits in the absence of antibiotics is critical in developing strategies to mitigate this growing menace. Indirect or co-selection of resistance by environmental pollution has been shown to increase antibiotic resistance. However no attention has been given to the effects of low-level ionizing radiation or the interactions between radiation and heavy metals on the maintenance or selection for antibiotic resistance (AR) traits. Here we explore the effect of radiation and copper on antibiotic resistance. Bacteria were collected from biofilms in two ponds - one impacted by low-level radiocesium and the other an abandoned farm pond. Through laboratory controlled experiments we examined the effects of increasing concentrations of copper on the incidence of antibiotic resistance. Differences were detected in the resistance profiles of the controls from each pond. Low levels (0.01 mM) of copper sulfate increased resistance but 0.5 mM concentrations of copper sulfate depressed the AR response in both ponds. A similar pattern was observed for levels of multiple antibiotic resistance per isolate. The first principal component response of isolate exposure to multiple antibiotics showed significant differences among the six isolate treatment combinations. These differences were clearly visualized through a discriminant function analysis, which showed distinct antibiotic resistance response patterns based on the six treatment groups. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Antibiotics and antibiotic resistance in agroecosystems: State of the science
We propose a simple causal model depicting relationships involved in dissemination of antibiotics and antibiotic resistance in agroecosystems and potential effects on human health, functioning of natural ecosystems, and agricultural productivity. Available evidence for each causal link is briefly su...
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Molecular study on some antibiotic resistant genes in Salmonella spp. isolates
Nabi, Ari Q.
2017-09-01
Studying the genes related with antimicrobial resistance in Salmonella spp. is a crucial step toward a correct and faster treatment of infections caused by the pathogen. In this work Integron mediated antibiotic resistant gene IntI1 (Class I Integrase IntI1) and some plasmid mediated antibiotic resistance genes (Qnr) were scanned among the isolated non-Typhoid Salmonellae strains with known resistance to some important antimicrobial drugs using Sybr Green real time PCR. The aim of the study was to correlate the multiple antibiotics and antimicrobial resistance of Salmonella spp. with the presence of integrase (IntI1) gene and plasmid mediated quinolone resistant genes. Results revealed the presence of Class I Integrase gene in 76% of the isolates with confirmed multiple antibiotic resistances. Moreover, about 32% of the multiple antibiotic resistant serotypes showed a positive R-PCR for plasmid mediated qnrA gene encoding for nalidixic acid and ciprofloxacin resistance. No positive results could be revealed form R-PCRs targeting qnrB or qnrS. In light of these results we can conclude that the presence of at least one of the qnr genes and/or the presence of Integrase Class I gene were responsible for the multiple antibiotic resistance to for nalidixic acid and ciprofloxacin from the studied Salmonella spp. and further studies required to identify the genes related with multiple antibiotic resistance of the pathogen.
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Metabolic profiling for detection of Staphylococcus aureus infection and antibiotic resistance.
Directory of Open Access Journals (Sweden)
Henrik Antti
Full Text Available Due to slow diagnostics, physicians must optimize antibiotic therapies based on clinical evaluation of patients without specific information on causative bacteria. We have investigated metabolomic analysis of blood for the detection of acute bacterial infection and early differentiation between ineffective and effective antibiotic treatment. A vital and timely therapeutic difficulty was thereby addressed: the ability to rapidly detect treatment failures because of antibiotic-resistant bacteria. Methicillin-resistant Staphylococcus aureus (MRSA and methicillin-sensitive S. aureus (MSSA were used in vitro and for infecting mice, while natural MSSA infection was studied in humans. Samples of bacterial growth media, the blood of infected mice and of humans were analyzed with combined Gas Chromatography/Mass Spectrometry. Multivariate data analysis was used to reveal the metabolic profiles of infection and the responses to different antibiotic treatments. In vitro experiments resulted in the detection of 256 putative metabolites and mice infection experiments resulted in the detection of 474 putative metabolites. Importantly, ineffective and effective antibiotic treatments were differentiated already two hours after treatment start in both experimental systems. That is, the ineffective treatment of MRSA using cloxacillin and untreated controls produced one metabolic profile while all effective treatment combinations using cloxacillin or vancomycin for MSSA or MRSA produced another profile. For further evaluation of the concept, blood samples of humans admitted to intensive care with severe sepsis were analyzed. One hundred thirty-three putative metabolites differentiated severe MSSA sepsis (n = 6 from severe Escherichia coli sepsis (n = 10 and identified treatment responses over time. Combined analysis of human, in vitro, and mice samples identified 25 metabolites indicative of effective treatment of S. aureus sepsis. Taken together, this
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Directory of Open Access Journals (Sweden)
Farhana Khanam
2015-04-01
Full Text Available Children bear a large burden of typhoid fever caused by Salmonella enterica serotype Typhi (S. Typhi in endemic areas. However, immune responses and clinical findings in children are not well defined. Here, we describe clinical and immunological characteristics of young children with S. Typhi bacteremia, and antimicrobial susceptibility patterns of isolated strains.As a marker of recent infection, we have previously characterized antibody-in-lymphocyte secretion (TPTest during acute typhoid fever in adults. We similarly assessed membrane preparation (MP IgA responses in young children at clinical presentation, and then 7-10 days and 21-28 days later. We also assessed plasma IgA, IgG and IgM responses and T cell proliferation responses to MP at these time points. We compared responses in young children (1-5 years with those seen in older children (6-17 years, adults (18-59 years, and age-matched healthy controls.We found that, compared to age-matched controls patients in all age cohorts had significantly more MP-IgA responses in lymphocyte secretion at clinical presentation, and the values fell in all groups by late convalescence. Similarly, plasma IgA responses in patients were elevated at presentation compared to controls, with acute and convalescent IgA and IgG responses being highest in adults. T cell proliferative responses increased in all age cohorts by late convalescence. Clinical characteristics were similar in all age cohorts, although younger children were more likely to present with loss of appetite, less likely to complain of headache compared to older cohorts, and adults were more likely to have ingested antibiotics. Multi-drug resistant strains were present in approximately 15% of each age cohort, and 97% strains had resistance to nalidixic acid.This study demonstrates that S. Typhi bacteremia is associated with comparable clinical courses, immunologic responses in various age cohorts, including in young children, and that TPTest
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Antibiotic misuse in children by the primary care physicians--an Indian experience.
Basu, S; Chatterjee, M; Chandra, P Kumar; Basu, S
2008-03-01
To determine the misuse of antibiotics in the Pediatric outpatients department' (OPD) of a busy teaching hospital and to ascertain the probable reasons behind it. Over a 6 months period, new cases primarily treated with antibiotics by Medical Officers (first contact physicians in Peadiatric Medicine and Surgery OPD) were recruited in the study after obtaining written consent from the parents. Various errors of antibiotic usage were noted. All Medical Officers were asked to fill up a preformed questionnaire and the parents/guardians were interviewed on their ideas about antibiotics. Data were analyzed by the statistical software SPSS 10. Antibiotics were prescribed in 2427 (84.9%) new patients. Misuse of antibiotics was documented in 36.8% patients (no indication in 35.3%, improper selection in 17.9% and incorrect dosage in 7.7%). All medical officers were aware that they overuse antibiotics. The various reasons sited were demand of the parents, reluctance to counsel due to patient overload, free supply of medicines from OPD and sympathetic grounds as follow up visits were uncertain. Majority of the parents/attendants belonged to poor socioeconomic status and did not have any idea regarding antibiotics. All parents wanted quick relief without hospitalization and only 2.3% were willing to revisit the OPD for the same illness. Both medical officers and parents felt that base line investigations were unnecessary. Antibiotic misuse is quite common in this part of the world. Irrational use was mostly seen in over-prescribing and improper selection of antibiotic. Poor socio-economic status and overcrowding of patients in OPD were the main responsible factors.
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Radioactive material in residues of health services residues
International Nuclear Information System (INIS)
Costa R, A. Jr.; Recio, J.C.
2006-01-01
The work presents the operational actions developed by the one organ responsible regulator for the control of the material use radioactive in Brazil. Starting from the appearance of coming radioactive material of hospitals and clinical with services of nuclear medicine, material that that is picked up and transported in specific trucks for the gathering of residuals of hospital origin, and guided one it manufactures of treatment of residuals of services of health, where they suffer radiological monitoring before to guide them for final deposition in sanitary embankment, in the city of Sao Paulo, Brazil. The appearance of this radioactive material exposes a possible one violation of the norms that govern the procedures and practices in that sector in the country. (Author)
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El Zowalaty, Mohamed E; Belkina, Tatiana; Bahashwan, Saleh A; El Zowalaty, Ahmed E; Tebbens, Jurjen Duintjer; Abdel-Salam, Hassan A; Khalil, Adel I; Daghriry, Safaa I; Gahtani, Mona A; Madkhaly, Fatimah M; Nohi, Nahed I; Khodari, Rafaa H; Sharahili, Reem M; Dagreery, Khlood A; Khormi, Mayisah; Habibah, Sarah Abuo; Medrba, Bayan A; Gahtani, Amal A; Hifthi, Rasha Y; Zaid, Jameelah M; Amshan, Arwa W; Alneami, Alqasim A; Noreddin, Ayman; Vlček, Jiří
2016-10-01
Background Inappropriate use of antibiotics is a public health problem of great concern. Objective To evaluate knowledge of antibiotics, race, gender and age as independent risk factors for self-medication. Setting Residents and population from different regions of Saudi Arabia. Methods We conducted a cross sectional survey study among residents. Data were collected between June 2014 to May, 2015 from 1310 participants and data were recorded anonymously. The questionnaire was randomly distributed by interview of participants and included sociodemographic characteristics, antibiotics knowledge, attitudes and behavior with respect to antibiotics usage. Main outcome measure Population aggregate scores on questions and data were analyzed using univariate logistic regression to evaluate the influence of variables on self-prescription of antibiotics. Results The response rate was 87.7 %. A cumulative 63.6 % of participants reported to have purchased antibiotics without a prescription from pharmacies; 71.1 % reported that they did not finish the antibiotic course as they felt better. The availability of antibiotics without prescription was found to be positively associated with self-medication (OR 0.238, 95 % CI 0.17-0.33). Of those who used prescribed or non-prescribed antibiotics, 44.7 % reported that they kept left-over antibiotics from the incomplete course of treatment for future need. Interestingly, 62 % of respondents who used drugs without prescription agreed with the statement that antibiotics should be access-controlled prescribed by a physician. We also found significant association between storage, knowledge/attitudes and education. Conclusions The overall level of awareness on antibiotics use among residents in Saudi Arabia is low. This mandates public health awareness intervention programs to be implemented on the use of antibiotics.
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Stulik, Lukas; Hudcova, Jana; Craven, Donald E; Nagy, Gabor; Nagy, Eszter
2017-04-15
Airway-colonization by Staphylococcus aureus predisposes to the development of ventilator-associated tracheobronchitis (VAT) and ventilator-associated pneumonia (VAP). Despite extensive antibiotic treatment of intensive care unit patients, limited data are available on the efficacy of antibiotics on bacterial airway colonization and/or prevention of infections. Therefore, microbiologic responses to antibiotic treatment were evaluated in ventilated patients. Results of semiquantitative analyses of S. aureus burden in serial endotracheal-aspirate (ETA) samples and VAT/VAP diagnosis were correlated to antibiotic treatment. Minimum inhibitory concentrations of relevant antibiotics using serially collected isolates were evaluated. Forty-eight mechanically ventilated patients who were S. aureus positive by ETA samples and treated with relevant antibiotics for at least 2 consecutive days were included in the study. Vancomycin failed to reduce methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) burden in the airways. Oxacillin was ineffective for MSSA colonization in approximately 30% of the patients, and responders were typically coadministered additional antibiotics. Despite antibiotic exposure, 15 of the 39 patients (approximately 38%) colonized only by S. aureus and treated with appropriate antibiotic for at least 2 days still progressed to VAP. Importantly, no change in antibiotic susceptibility of S. aureus isolates was observed during treatment. Staphylococcus aureus colonization levels inversely correlated with the presence of normal respiratory flora. Antibiotic treatment is ineffective in reducing S. aureus colonization in the lower airways and preventing VAT or VAP. Staphylococcus aureus is in competition for colonization with the normal respiratory flora. To improve patient outcomes, alternatives to antibiotics are urgently needed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of
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Fighting antibiotic resistance in the intensive care unit using antibiotics
Plantinga, Nienke L.; Wittekamp, Bastiaan H J; Van Duijn, Pleun J.; Bonten, Marc J M
2015-01-01
Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to
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Distribution, diversity, and activity of antibiotic-producing Pseudomonas spp.
Souza, de J.T.
2002-01-01
Bacteria of the genus Pseudomonas are potential biocontrol agents of plant diseases caused by various fungi and oomycetes. Antibiotic production is an important trait responsible for the activity of several Pseudomonas
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Centers for Disease Control (CDC) Podcasts
2015-04-15
This podcast provides a brief background about antibiotics and quick tips to help prevent antibiotic resistance. Created: 4/15/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program. Date Released: 4/16/2015.
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Prescribing antibiotics in general practice:
DEFF Research Database (Denmark)
Sydenham, Rikke Vognbjerg; Pedersen, Line Bjørnskov; Plejdrup Hansen, Malene
Objectives The majority of antibiotics are prescribed from general practice. The use of broad-spectrum antibiotics increases the risk of development of bacteria resistant to antibiotic treatment. In spite of guidelines aiming to minimize the use of broad-spectrum antibiotics we see an increase...... in the use of these agents. The overall aim of the project is to explore factors influencing the decision process and the prescribing behaviour of the GPs when prescribing antibiotics. We will study the impact of microbiological testing on the choice of antibiotic. Furthermore the project will explore how...... the GPs’ prescribing behaviour is influenced by selected factors. Method The study consists of a register-based study and a questionnaire study. The register-based study is based on data from the Register of Medicinal Product Statistics (prescribed antibiotics), Statistics Denmark (socio-demographic data...
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Antibiotic use and microbiome function.
Ferrer, Manuel; Méndez-García, Celia; Rojo, David; Barbas, Coral; Moya, Andrés
2017-06-15
Our microbiome should be understood as one of the most complex components of the human body. The use of β-lactam antibiotics is one of the microbiome covariates that influence its composition. The extent to which our microbiota changes after an antibiotic intervention depends not only on the chemical nature of the antibiotic or cocktail of antibiotics used to treat specific infections, but also on the type of administration, duration and dose, as well as the level of resistance that each microbiota develops. We have begun to appreciate that not all bacteria within our microbiota are vulnerable or reactive to different antibiotic interventions, and that their influence on both microbial composition and metabolism may differ. Antibiotics are being used worldwide on a huge scale and the prescription of antibiotics is continuing to rise; however, their effects on our microbiota have been reported for only a limited number of them. This article presents a critical review of the antibiotics or antibiotic cocktails whose use in humans has been linked to changes in the composition of our microbial communities, with a particular focus on the gut, oral, respiratory, skin and vaginal microbiota, and on their molecular agents (genes, proteins and metabolites). We review the state of the art as of June 2016, and cover a total of circa 68 different antibiotics. The data herein are the first to compile information about the bacteria, fungi, archaea and viruses most influenced by the main antibiotic treatments prescribed nowadays. Copyright © 2016 Elsevier Inc. All rights reserved.
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Chen, Jun; Wei, Xiao-Dong; Liu, You-Sheng; Ying, Guang-Guo; Liu, Shuang-Shuang; He, Liang-Ying; Su, Hao-Chang; Hu, Li-Xin; Chen, Fan-Rong; Yang, Yong-Qiang
2016-09-15
This study aimed to assess removal potential of antibiotics and antibiotic resistance genes (ARGs) in raw domestic wastewater by various mesocosm-scale horizontal subsurface-flow constructed wetlands (CWs) planted Cyperus alternifolius L. with different design parameters. Twelve CWs with three hydraulic loading rates (HLR 10, 20 and 30cm/day) and four substrates (oyster shell, zeolite, medical stone and ceramic) were set up in order to select the best optimized wetland. The result showed that 7 target antibiotics compounds including erythromycin-H2O, lincomycin, monensin, ofloxacin, sulfamerazine, sulfamethazine and novobiocin were detected, and all selected 18 genes (three sulfonamide resistance genes (sul1, sul2 and sul3), four tetracycline resistance genes (tetG, tetM, tetO and tetX), two macrolide resistance genes (ermB and ermC), three quinolone resistance genes (qnrB, qnrD and qnrS) and four chloramphenicol resistance genes (cmlA, fexA, fexB and floR)) and two integrase genes (int1 and int2) were positively detected in the domestic wastewaters. The aqueous removal rates of the total antibiotics ranged from17.9 to 98.5%, while those for the total ARGs varied between 50.0 and 85.8% by the mesocosm-scale CWs. After considering their aqueous removal rates in combination with their mass removals, the CW with zeolite as the substrate and HLR of 20cm/day was selected as the best choice. Combined chemical and biological analyses indicate that both microbial degradation and physical sorption processes were responsible for the fate of antibiotics and ARGs in the wetlands. The findings from this study suggest constructed wetlands could be a promising technology for the removal of emerging contaminants such as antibiotics and ARGs in domestic wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.
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[Antibiotic treatment for prevention of infectious complications in joint replacement].
Jahoda, D; Nyc, O; Pokorný, D; Landor, I; Sosna, A
2006-04-01
Prophylactic antibiotic treatment is mandatory in every operation involving an orthopedic implant. Carefully selected and correctly administered antibiotics can provide effective protection of the implant from bacterial colonization. The prevention of deep wound infection in joint replacement includes several procedures and measures which constitute three basic groups: 1) Promotion of patient's ability to resist infection (careful pre-operative preparation, elimination of potential infectious loci, good nutritional status, etc). 2) Optimal conditions for the operative wound (surgical technique, prophylactic antibiotics). 3) Reduction of the number of bacteria brought in the wound (control measures, super-sterile operating theatres). Clear rules for the system of prophylactic antibiotic treatment should be adopted. A program in which responsibility for antibiotic administration was shifted from the nursing staff to the anesthesiologist in the operating theatre showed improved outcomes and reduced costs. Poor timing of prophylactic antibiotic administration is one of the basic mistakes. If the wound happened to be contaminated during surgery, the first three post-operative hours would be most decisive for the development of infection. An effective bactericidal concentration of antibiotic should be present in tissues and serum immediately after surgery has begun. Therefore the appropriate time for antibiotic application is before a skin incision is made, and not after the operation has started; the highest serum and bone tissue levels appear 20 to 30 min. after intravenous antibiotic injection. To allow antibiotics to reach target tissues, they should be introduced at least 10 min. before tourniquet application. For long surgical procedures or when blood loss is high, an additional dose of antibiotics is recommended during the operation. If a sample for bacterial cultivation is required, antibiotic administration is postponed until during surgery. However, this is
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Vancomycin Molecular Interactions: Antibiotic and Enantioselective Mechanisms
Ward, Timothy J.; Gilmore, Aprile; Ward, Karen; Vowell, Courtney
Medical studies established that vancomycin and other related macrocyclic antibiotics have an enhanced antimicrobial activity when they are associated as dimers. The carbohydrate units attached to the vancomycin basket have an essential role in the dimerization reaction. Covalently synthesized dimers were found active against vancomycin-resistant bacterial strains. A great similarity between antibiotic potential and enantioselectivity was established. A covalent vancomycin dimer was studied in capillary electrophoresis producing excellent chiral separation of dansyl amino acids. Balhimycin is a macrocyclic glycopeptide structurally similar to vancomycin. The small differences are, however, responsible for drastic differences in enantioselectivity in the same experimental conditions. Contributions from studies examining vancomycin's mechanism for antimicrobial activity have substantially aided our understanding of its mechanism in chiral recognition.
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Weber, Zhanni; Ariano, Robert; Lagacé-Wiens, Philippe; Zelenitsky, Sheryl
2016-12-01
Given the overall prevalence and poor prognosis of Staphylococcus aureus bloodstream infections (BSIs), the study of treatment strategies to improve patient outcomes is important. The aim of this study was to conduct a multifaceted antibiotic treatment analysis of methicillin-sensitive S. aureus (MSSA) BSI and to characterise optimal early antibiotic therapy (within the first 7 days of drawing the index blood culture) for this serious infection. Antibiotic selection was categorised as optimal targeted (intravenous cloxacillin or cefazolin), optimal broad (piperacillin/tazobactam or meropenem), adequate (vancomycin) or inadequate (other antibiotics or oral therapy). A TSE (timing, selection, exposure) score was developed to comprehensively characterise early antibiotic therapy, where higher points corresponded to prompt initiation, optimal antibiotic selection and longer exposure (duration). Amongst 71 cases of complicated MSSA-BSI, end-of-treatment (EOT) response (i.e. clinical cure) was improved when at least adequate antibiotic therapy was initiated within 24 h [71.7% (33/46) vs. 48.0% (12/25); P = 0.047]. Clinical cure was also more likely when therapy included ≥4 days of optimal targeted antibiotics within the first 7 days [74.4% (29/39) vs. 50.0% (16/32); P = 0.03]. The TSE score was an informative index of early antibiotic therapy, with EOT cure documented in 72.0% (36/50) compared with 42.9% (9/21) of cases with scores above and below 15.2, respectively (P = 0.02). In multivariable analysis, lower Charlson comorbidity index, presence of BSI on admission, and optimising early antibiotic therapy, as described above, were associated with clinical cure in patients with MSSA-BSI. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.
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Farm factors associated with the use of antibiotics in pig production.
van der Fels-Klerx, H J; Puister-Jansen, L F; van Asselt, E D; Burgers, S L G E
2011-06-01
The aim of this study was to investigate farm-level economic and technical factors that are associated with the use of antibiotics on pig farms. Identification of such factors, like farm size and net farm result, may help to increase epidemiological knowledge and to specify farm advice and policy making to reduce inappropriate use of antibiotics. The study used over 300 farm-year records collected during 2004 to 2007 from pig farms in the Netherlands. Data included economic and technical factors as well as antibiotic administration. Data were statistically analyzed for factors associated with antibiotic use, both for fattening pig and sow farms (piglets only), separately. The response variable was the average number of daily dosages per average pig year. Statistical analysis was performed on 16 and 19 potential explanatory factors for the fattening pig and sow farms, respectively. The results showed that, both on the fattening pig and sow farms, the average use of antibiotics increased from 2004 to 2006, but decreased during 2007, but the effect of year was not significant (P > 0.05). Use of antibiotics varied between individual farms. Large farm repeatability for the use of antibiotics in the different years was found. Factors associated (P antibiotics included: farm system, number of pigs, and population density in the region of the farm (for sow farms only). As these factors are easy to collect and to register, they can be used to specify farm advice and investigation, as well as for policy making. The majority of the technical and economic factors were not significantly (P > 0.05) related to the on-farm use of antibiotics. Therefore, it is recommended to focus future research on the potential role of socioeconomic factors associated with antibiotic use on pig farms.
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Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.
2011-01-01
Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.
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Comparing the sensitivity of chlorophytes, cyanobacteria, and diatoms to major-use antibiotics.
Guo, Jiahua; Selby, Katherine; Boxall, Alistair B A
2016-10-01
The occurrence of antibiotic residues in the aquatic environment is an emerging concern. In contrast to daphnia and fish, algae are known to be particularly sensitive to antibiotic exposure. However, to date, a systematic evaluation of the sensitivity of different algal species to antibiotics has not been performed. The aim of the present study was therefore to explore the sensitivity of a battery of algal species toward antibiotic exposures. The present study investigated the growth inhibition effects of 3 major-use antibiotics, tylosin, lincomycin, and trimethoprim, on 7 algal species from the chlorophyte, cyanobacteria, and diatom groups. Based on median effective concentration (EC50) values, cyanobacteria (EC50 = 0.095-0.13 μmol/L) were found to be the most sensitive group to lincomycin followed by chlorophytes (EC50 = 7.36-225.73 μmol/L) and diatoms (EC50 > 225.73 μmol/L). Cyanobacteria were also the most sensitive group to tylosin (EC50 = 0.09-0.092 μmol/L), but, for this compound, diatoms (EC50 = 1.33-5.7 μmol/L) were more sensitive than chlorophytes (EC50 = 4.14-81.2 μmol/L). Diatoms were most sensitive to trimethoprim (EC50 = 7.36-74.61 μmol/L), followed by cyanobacteria (EC50 = 315.78-344.45 μmol/L), and chlorophytes (EC50 > 344.45 μmol/L) for trimethoprim. Although these results partly support the current approach to regulatory environmental risk assessment (whereby cyanobacterial species are recommended for use with antibiotic compounds), they indicate that for some antibiotics this group might not be the most appropriate test organism. It is therefore suggested that environmental risk assessments consider data on 3 algal groups (chlorophytes, cyanobacteria, and diatoms) and use test species from these groups, which are consistently found to be the most sensitive (Pseudokirchneriella subcapitata, Anabaena flos-aquae, and Navicula pelliculosa). Environ Toxicol Chem 2016;35:2587-2596. © 2016 SETAC.
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Immuno-modulation and anti-inflammatory benefits of antibiotics: The example of tilmicosin
Buret, André G.
2010-01-01
Exagerated immune responses, such as those implicated in severe inflammatory reactions, are costly to the metabolism. Inflammation and pro-inflammatory mediators negatively affect production in the food animal industry by reducing growth, feed intake, reproduction, milk production, and metabolic health. An ever-increasing number of findings have established that antibiotics, macrolides in particular, may generate anti-inflammatory effects, including the modulation of pro-inflammatory cytokines and the alteration of neutrophil function. The effects are time- and dose-dependent, and the mechanisms responsible for these phenomena remain incompletely understood. Recent studies, mostly using the veterinary macrolide tilmicosin, may have shed new light on the mode of action of some macrolides and their anti-inflammatory properties. Indeed, research findings demonstrate that this compound, amongst others, induces neutrophil apoptosis, which in turn provides anti-inflammatory benefits. Studies using tilmicosin model systems in vitro and in vivo demonstrate that this antibiotic has potent immunomodulatory effects that may explain why at least parts of its clinical benefits are independent of anti-microbial effects. More research is needed, using this antibiotic and others that may have similar properties, to clarify the biological mechanisms responsible for antibiotic-induced neutrophil apoptosis, and how this, in turn, may provide enhanced clinical benefits. Such studies may help establish a rational basis for the development of novel, efficacious, anti-microbial compounds that generate anti-inflammatory properties in addition to their antibacterial effects. PMID:20357951
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Collignon, A; Sandré, C; Barc, M-C
2010-09-01
Saccharomyces boulardii is a non-pathogenic yeast with biotherapeutic properties that has been used successfully to prevent and to treat various infectious and antibiotic-associated diarrheas. The intestinal microbiota is responsible for colonization resistance and immune response to pathogens but can be disrupted by antibiotics and lose its barrier effect. Dendritic cells (DCs) are professional antigen-presenting cells of the immune system with the ability to initiate a primary immune response or immune tolerance. In a human microbiota-associated mouse model, we evaluated the influence of S. boulardii on the composition of the microbiota and on the properties of dendritic cells in normal homeostatic conditions and after antibiotic-induced stress. The DCs were derived from splenic precursors. Membrane antigen expression and phagocytosis of FITC-latex beads by DCs were evaluated by flow cytometry. The molecular analysis of the microbiota was performed with fluorescence in situ hybridization (FISH) combined with flow cytometry or confocal microscopy using group specific 16S rRNA targeted probes. This evaluation was conducted during and after a 7-day oral treatment with amoxicillin-clavulanic acid alone and in combination with the administration of the yeast. The antibiotic treatment increased the phagocytic activity of DCs. Their antigen presenting function (MHC class II antigen and CD 86 costimulatory molecule membrane expression) was up-regulated. This reflects a functional activation of DCs. In the presence of S. boulardii, the modification of membrane antigen expression was down regulated. To correlate these modifications to the microbiota disruption, we analyzed in parallel the composition of the intestinal microbiota. As previously shown, the amoxicillin-clavulanic acid treatment, both alone and with S. boulardii, did not quantitatively alter the total microbiota. In contrast, after one day of the antibiotic treatment the Clostridium coccoides group decreased
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Probiotic approach to prevent antibiotic resistance.
Ouwehand, Arthur C; Forssten, Sofia; Hibberd, Ashley A; Lyra, Anna; Stahl, Buffy
2016-01-01
Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it.
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International Nuclear Information System (INIS)
Malik, M.A.; Shaukat, G.A.; Ahmed, M.S.
1990-01-01
Three types of antibiotics S, X and F characteristically bioactive against staphylococcic, xanthomonas and fungi are elaborated by Bacillus Subtilis AECL 69 when grown in molasses peptone malt extract sucrose. No antibiotic production was observed when molasses was omitted from the growth medium. A mineral salt mixture was devised that could replace molasses and restore the production of antibiotics. Influence of various carbohydrates on the production of antibiotics was also studied. Mannose and mannitol had inhibitory effect on the antibiotic production. (author)
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DEFF Research Database (Denmark)
Price, Lance B.; Newland, Jason; Bole, Aparna
edical and public health organizations around the world agree that more prudent use of antibiotics in human medicine and in livestock production is paramount to slow the spread of antibiotic resistance. Of particular concern is the widespread use of antibiotics important to human medicine in food...... animals. In the U.S., such use accounts for 70% of all sales of medically important antibiotics. It is against this backdrop that 12 antibiotic resistance experts from the fields of infectious disease medicine, veterinary medicine, microbiology, epidemiology and public health joined to craft a policy...... roadmap to help move the U.S. forward in addressing the contribution of livestock antibiotic use to the growing global threat of antibiotic resistance. The policy roadmap consists of 11 core policy recommendations that are aimed at a broad set of stakeholders: federal, state and local policymakers, food...
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Structural studies of the mechanism for biosensing antibiotics in a fluorescein-labeled β-lactamase
Directory of Open Access Journals (Sweden)
Wong Kwok-Yin
2011-03-01
Full Text Available Abstract Background β-lactamase conjugated with environment-sensitive fluorescein molecule to residue 166 on the Ω-loop near its catalytic site is a highly effective biosensor for β-lactam antibiotics. Yet the molecular mechanism of such fluorescence-based biosensing is not well understood. Results Here we report the crystal structure of a Class A β-lactamase PenP from Bacillus licheniformis 749/C with fluorescein conjugated at residue 166 after E166C mutation, both in apo form (PenP-E166Cf and in covalent complex form with cefotaxime (PenP-E166Cf-cefotaxime, to illustrate its biosensing mechanism. In the apo structure the fluorescein molecule partially occupies the antibiotic binding site and is highly dynamic. In the PenP-E166Cf-cefatoxime complex structure the binding and subsequent acylation of cefotaxime to PenP displaces fluorescein from its original location to avoid steric clash. Such displacement causes the well-folded Ω-loop to become fully flexible and the conjugated fluorescein molecule to relocate to a more solvent exposed environment, hence enhancing its fluorescence emission. Furthermore, the fully flexible Ω-loop enables the narrow-spectrum PenP enzyme to bind cefotaxime in a mode that resembles the extended-spectrum β-lactamase. Conclusions Our structural studies indicate the biosensing mechanism of a fluorescein-labelled β-lactamase. Such findings confirm our previous proposal based on molecular modelling and provide useful information for the rational design of β-lactamase-based biosensor to detect the wide spectrum of β-lactam antibiotics. The observation of increased Ω-loop flexibility upon conjugation of fluorophore may have the potential to serve as a screening tool for novel β-lactamase inhibitors that target the Ω-loop and not the active site.
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Effect of residual stress on the nanoindentation response of (100) copper single crystal
International Nuclear Information System (INIS)
Zhu, Li-na; Xu, Bin-shi; Wang, Hai-dou; Wang, Cheng-biao
2012-01-01
Experimental measurements were used to investigate the effect of residual stress on the nanoindentation of (100) copper single crystal. Equi-biaxial tensile and compressive stresses were applied to the copper single crystal using a special designed apparatus. It was found that residual stresses greatly affected peak load, curvature of the loading curve, elastically recovered depth, residual depth, indentation work, pile-up amount and contact area. The Suresh and Giannakopoulos and Lee and Kwon methods were used to calculate the residual stresses from load-depth data and morphology observation of nanoindents using atomic force microscopy. Comparison of the obtained results with stress values from strain gage showed that the residual stresses analyzed from the Suresh and Giannakopoulos model agreed well with the applied stresses. -- Highlights: ► Residual stresses greatly affected various nanoindentation parameters. ► The contact area can be accurately measured from AFM observation. ► The residual stresses analyzed from the S and G model agreed well with applied stresses.
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Antibiotics produced by Streptomyces.
Procópio, Rudi Emerson de Lima; Silva, Ingrid Reis da; Martins, Mayra Kassawara; Azevedo, João Lúcio de; Araújo, Janete Magali de
2012-01-01
Streptomyces is a genus of Gram-positive bacteria that grows in various environments, and its shape resembles filamentous fungi. The morphological differentiation of Streptomyces involves the formation of a layer of hyphae that can differentiate into a chain of spores. The most interesting property of Streptomyces is the ability to produce bioactive secondary metabolites, such as antifungals, antivirals, antitumorals, anti-hypertensives, immunosuppressants, and especially antibiotics. The production of most antibiotics is species specific, and these secondary metabolites are important for Streptomyces species in order to compete with other microorganisms that come in contact, even within the same genre. Despite the success of the discovery of antibiotics, and advances in the techniques of their production, infectious diseases still remain the second leading cause of death worldwide, and bacterial infections cause approximately 17 million deaths annually, affecting mainly children and the elderly. Self-medication and overuse of antibiotics is another important factor that contributes to resistance, reducing the lifetime of the antibiotic, thus causing the constant need for research and development of new antibiotics. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.
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Redox-Active Antibiotics Control Gene Expression and Community Behavior in Divergent Bacteria
Dietrich, Lars E. P.; Teal, Tracy K.; Price-Whelan, Alexa; Newman, Dianne K.
2008-01-01
It is thought that bacteria excrete redox-active pigments as antibiotics to inhibit competitors. In Pseudomonas aeruginosa, the endogenous antibiotic pyocyanin activates SoxR, a transcription factor conserved in Proteo- and Actinobacteria. In Escherichia coli, SoxR regulates the superoxide stress response. Bioinformatic analysis coupled with gene expression studies in P. aeruginosa and Streptomyces coelicolor revealed that the majority of SoxR regulons in bacteria lack the genes required for ...
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Directory of Open Access Journals (Sweden)
Quadri Luis EN
2006-10-01
Full Text Available Abstract Background Quorum sensing is a form of cell-to-cell communication that allows bacteria to control a wide range of physiological processes in a population density-dependent manner. Production of peptide antibiotics is one of the processes regulated by quorum sensing in several species of Gram-positive bacteria, including strains of Carnobacterium maltaromaticum. This bacterium and its peptide antibiotics are of interest due to their potential applications in food preservation. The molecular bases of the quorum sensing phenomenon controlling peptide antibiotic production in C. maltaromaticum remain poorly understood. The present study was aimed at gaining a deeper insight into the molecular mechanism involved in quorum sensing-mediated regulation of peptide antibiotic (bacteriocin production by C. maltaromaticum. We report the functional analyses of the CS (autoinducer-CbnK (histidine protein kinase-CbnR (response regulator three-component regulatory system and the three regulated promoters involved in peptide antibiotic production in C. maltaromaticum LV17B. Results CS-CbnK-CbnR system-dependent activation of carnobacterial promoters was demonstrated in both homologous and heterologous hosts using a two-plasmid system with a β-glucuronidase (GusA reporter read-out. The results of our analyses support a model in which the CbnK-CbnR two-component signal transduction system is necessary and sufficient to transduce the signal of the peptide autoinducer CS into the activation of the promoters that drive the expression of the genes required for production of the carnobacterial peptide antibiotics and the immunity proteins that protect the producer bacterium. Conclusions The CS-CbnK-CbnR triad forms a three-component regulatory system by which production of peptide antibiotics by C. maltaromaticum LV17B is controlled in a population density-dependent (or cell proximity-dependent manner. This regulatory mechanism would permit the bacterial
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Systems, not pills: The options market for antibiotics seeks to rejuvenate the antibiotic pipeline.
Brogan, David M; Mossialos, Elias
2016-02-01
Over the past decade, there has been a growing recognition of the increasing growth of antibiotic resistant bacteria and a relative decline in the production of novel antibacterial therapies. The combination of these two forces poses a potentially grave threat to global health, in both developed and developing countries. Current market forces do not provide appropriate incentives to stimulate new antibiotic development, thus we propose a new incentive mechanism: the Options Market for Antibiotics. This mechanism, modelled on the principle of financial call options, allows payers to buy the right, in early stages of development, to purchase antibiotics at a discounted price if and when they ever make it to market approval. This paper demonstrates the effect of such a model on the expected Net Present Value of a typical antibacterial project. As part of an integrated strategy to confront the impending antibiotic crisis, the Options Market for Antibiotics may effectively stimulate corporate and public investment into antibiotic research and development. Copyright © 2016. Published by Elsevier Ltd.
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Energy Technology Data Exchange (ETDEWEB)
Korshunov, V.M.; Pinegin, B.V.; Ivanova, N.P.; Mal' tsev, V.N.
1982-05-01
Broad-spectrum antibiotics are used to treat intestinal dysbacteriosis of diverse etiology, including postradiation dysbacteriosis. Antibiotic therapy is instrumental in decontaminating the intestine. In addition to pathogenic microorganisms, there is disappearance of lactobacilli and bifidobacteria which perform several important and useful functions. For this reason, in addition to antibiotics, bifidobacterial preparations are used to restore the microbial cenosis and administration thereof is started after antibiotics are discontinued. There are some flaws to deferred administration of bifidobacteria, since the process of colonization of the intestine with commercial bifidobacterial preparations is rather lengthy, and there is slow elevation of bididobacterium level in the intestinal tract, whereas exogenous recontamination of the intestine by conditionally pathogenic bacteria is possible after antibiotic therapy is discontinued. On the other hand, use of antibiotics alone could, in turn, be the cause of intestinal dysbacteriosis. Our objective was to eliminate intestinal dysbacteriosis in irradiated animals by means of combining antibiotics and preparations of bifidobacteria resistant to these antibiotics, and thus prolong the life of these animals.
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International Nuclear Information System (INIS)
Korshunov, V.M.; Pinegin, B.V.; Ivanova, N.P.; Maltsev, V.N.
1982-01-01
Elimination of intestinal dysbacteriosis in irradiated animals by combining antibiotics and peparations of bifidobacteria resistant to these antibiotics prolonging the life of these animals was investigated. Broad spectrum antibiotics are used to treat intestinal dysbacteriosis. Bifidobacterial preparations are used to restore the microbial cenosis and their administration is started after antibiotics are discontinued. There are some flaws to deferred administration of bifidobacteria, since the process of colonization of the intestine with commercial bifidobacterial preparations is rather lengthy, and there is slow elevation of bifidobacterium level in the intestinal tract, whereas exogenous recontamination of the intestine by conditionally pathogenic bacteria is possible after antibiotic therapy is discontinued. Use of antibiotics alone could be the cause of intestinal dysbacteriosis
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Abeyrathne, Chathurika D; Huynh, Duc H; Mcintire, Thomas W; Nguyen, Thanh C; Nasr, Babak; Zantomio, Daniela; Chana, Gursharan; Abbott, Iain; Choong, Peter; Catton, Mike; Skafidas, Efstratios
2016-03-21
The Gram-positive bacterium, Staphylococcus aureus (S. aureus), is a major pathogen responsible for a variety of infectious diseases ranging from cellulitis to more serious conditions such as septic arthritis and septicaemia. Timely treatment with appropriate antibiotic therapy is essential to ensure clinical defervescence and to prevent further complications such as infective endocarditis or organ impairment due to septic shock. To date, initial antibiotic choice is empirical, using a "best guess" of likely organism and sensitivity- an approach adopted due to the lack of rapid identification methods for bacteria. Current culture based methods take up to 5 days to identify the causative bacterial pathogen and its antibiotic sensitivity. This paper provides proof of concept for a biosensor, based on interdigitated electrodes, to detect the presence of S. aureus and ascertain its sensitivity to flucloxacillin rapidly (within 2 hours) in a cost effective manner. The proposed method is label-free and uses non-faradic measurements. This is the first study to successfully employ interdigitated electrodes for the rapid detection of antibiotic resistance. The method described has important potential outcomes of faster definitive antibiotic treatment and more rapid clinical response to treatment.
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Strzępa, Anna; Majewska-Szczepanik, Monika; Lobo, Francis M; Wen, Li; Szczepanik, Marian
2017-07-01
Medical advances in the field of infection therapy have led to an increasing use of antibiotics, which, apart from eliminating pathogens, also partially eliminate naturally existing commensal bacteria. It has become increasingly clear that less exposure to microbiota early in life may contribute to the observed rise in "immune-mediated" diseases, including autoimmunity and allergy. We sought to test whether the change of gut microbiota with the broad spectrum antibiotic enrofloxacin will modulate contact sensitivity (CS) in mice. Natural gut microbiota were modified by oral treatment with enrofloxacin prior to sensitization with trinitrophenyl chloride followed by CS testing. Finally, adoptive cell transfers were performed to characterize the regulatory cells that are induced by microbiota modification. Oral treatment with enrofloxacin suppresses CS and production of anti-trinitrophenyl chloride IgG1 antibodies. Adoptive transfer experiments show that antibiotic administration favors induction of regulatory cells that suppress CS. Flow cytometry and adoptive transfer of purified cells show that antibiotic-induced suppression of CS is mediated by TCR αβ + CD4 + CD25 + FoxP3 + Treg, CD19 + B220 + CD5 + IL-10 + , IL-10 + Tr1, and IL-10 + TCR γδ + cells. Treatment with the antibiotic induces dysbiosis characterized by increased proportion of Clostridium coccoides (cluster XIVa), C coccoides-Eubacterium rectale (cluster XIVab), Bacteroidetes, and Bifidobacterium spp, but decreased segmented filamentous bacteria. Transfer of antibiotic-modified gut microbiota inhibits CS, but this response can be restored through oral transfer of control gut bacteria to antibiotic-treated animals. Oral treatment with a broad spectrum antibiotic modifies gut microbiota composition and promotes anti-inflammatory response, suggesting that manipulation of gut microbiota can be a powerful tool to modulate the course of CS. Copyright © 2017 American Academy of Allergy, Asthma & Immunology
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A study of antibiotic prescribing
DEFF Research Database (Denmark)
Jaruseviciene, L.; Radzeviciene-Jurgute, R.; Jurgutis, A.
2012-01-01
Background. Globally, general practitioners (GPs) write more than 90% of all antibiotic prescriptions. This study examines the experiences of Lithuanian and Russian GPs in antibiotic prescription for upper respiratory tract infections, including their perceptions of when it is not indicated...... clinically or pharmacologically. Methods. 22 Lithuanian and 29 Russian GPs participated in five focus group discussions. Thematic analysis was used to analyse the data. Results. We identified four main thematic categories: patients' faith in antibiotics as medication for upper respiratory tract infections......; patient potential to influence a GP's decision to prescribe antibiotics for upper respiratory tract infections; impediments perceived by GPs in advocating clinically grounded antibiotic prescribing with their patients, and strategies applied in physician-patient negotiation about antibiotic prescribing...
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Antibiotic prevention of postcataract endophthalmitis
DEFF Research Database (Denmark)
Kessel, Line; Flesner, Per; Andresen, Jens
2015-01-01
Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL......, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one...... with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to one...
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Tahrani, Leyla; Mehri, Ines; Reyns, Tim; Anthonissen, Roel; Verschaeve, Luc; Khalifa, Anis Bel Haj; Loco, Joris Van; Abdenaceur, Hassen; Mansour, Hedi Ben
2018-05-01
The UPLC MS/MS analysis showed the presence of the two antibiotics in the pharmaceutical industry discharges during 3 months; norfloxacin and spiramycin which were quantified with the mean concentrations of 226.7 and 84.2 ng mL -1 , respectively. Sixteen resistant isolates were obtained from the pharmaceutical effluent and identified by sequencing. These isolates belong to different genera, namely Citrobacter, Acinetobacter, Pseudomonas, Delftia, Shewanella, and Rheinheimera. The antibiotic resistance phenotypes of these isolates were determined (27 tested antibiotics-discs). All the studied isolates were found resistant to amoxicillin and gentamicin, and 83.33% of isolates were resistant to ciprofloxacin. Multiple antibiotic resistances were revealed against β-lactams, quinolones, and aminoglycosides families. Our overall results suggest that the obtained bacterial isolates may constitute potential candidates for bioremediation and can be useful for biotechnological applications. Genotoxic effects were assessed by a battery of biotests; the pharmaceutical wastewater was genotoxic according to the bacterial Vitotox test and micronuclei test. Genotoxicity was also evaluated by the comet test; the tail DNA damages reached 38 and 22% for concentrated sample (10×) and non-concentrated sample (1×), respectively. However, the histological sections of kidney and liver's mice treated by pharmaceutical effluent showed normal histology and no visible structural effects or alterations as cytolysis, edema, or ulcerative necrosis were observed. Residual antibiotics can reach water environment through wastewater and provoke dissemination of the antibiotics resistance and induce genotoxic effects.
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Kidney inhibition swab (KIS) tests, recently adapted by the US FSIS for antibiotics on-site screening, were employed to evaluate the depletion of penicillin-G residues from kidney, liver, muscle, serum, and urine of sows after intramuscular (IM) penicillin-G procaine administration. Sows (n=130; 22...
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The Bacillus subtilis GntR family repressor YtrA responds to cell wall antibiotics.
Salzberg, Letal I; Luo, Yun; Hachmann, Anna-Barbara; Mascher, Thorsten; Helmann, John D
2011-10-01
The transglycosylation step of cell wall synthesis is a prime antibiotic target because it is essential and specific to bacteria. Two antibiotics, ramoplanin and moenomycin, target this step by binding to the substrate lipid II and the transglycosylase enzyme, respectively. Here, we compare the ramoplanin and moenomycin stimulons in the Gram-positive model organism Bacillus subtilis. Ramoplanin strongly induces the LiaRS two-component regulatory system, while moenomycin almost exclusively induces genes that are part of the regulon of the extracytoplasmic function (ECF) σ factor σ(M). Ramoplanin additionally induces the ytrABCDEF and ywoBCD operons, which are not part of a previously characterized antibiotic-responsive regulon. Cluster analysis reveals that these two operons are selectively induced by a subset of cell wall antibiotics that inhibit lipid II function or recycling. Repression of both operons requires YtrA, which recognizes an inverted repeat in front of its own operon and in front of ywoB. These results suggest that YtrA is an additional regulator of cell envelope stress responses.
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Bacterial Enzymes and Antibiotic Resistance- Oral Presentation
Energy Technology Data Exchange (ETDEWEB)
Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)
2015-08-25
By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.
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Lv, Bing; Zhou, Zhongliang; Xu, Guiping; Yang, Dingkun; Wu, Lina; Shen, Qian; Jiang, Minghuan; Wang, Xiao; Zhao, Guilan; Yang, Shimin; Fang, Yu
2014-07-01
To evaluate the knowledge, attitude and behaviours of university students on the use of antibiotics. A knowledge-attitude-practice questionnaire was developed and distributed to undergraduate students of Xi'an Jiaotong University, comprising 18 schools/colleges in Shaanxi Province, western China. Chi-square test and logistic regression analysis were applied to identify risk factors associated with self-medication with antibiotics. Of the 731 respondents (response rate = 73.1%), 294 (40.2%) had self-medicated with antibiotics in the past 6 months. Most of the antibiotics (59.2%) for self-medication were purchased without prescription in retail pharmacies. The median score of students' knowledge about antibiotics was 4 (IQR: 3-6) of a maximum possible score of 10. Students had moderately accurate beliefs towards antibiotics. More than half of the students (56.5%) were storing antibiotics frequently. During self-medication, 16.7% of students claimed to have experienced adverse reactions, and 30.6% had used antibiotics to prevent common colds. The majority preferred to use broad-spectrum antibiotics, and nearly half preferred intravenous antibiotics. Over 44% of students had changed antibiotic dosage, and 36.5% had switched to another antibiotic during the treatment course. Logistic regression analysis identified college and home town as independent risk factors for self-medication with antibiotics (P students had inadequate knowledge, moderately accurate beliefs and inappropriate practices concerning antibiotics, and a high rate of self-medication. This highlights the need for focused educational intervention and stricter governmental regulation concerning antibiotic use and sale in retail pharmacies. © 2014 John Wiley & Sons Ltd.
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New business models for antibiotic innovation.
So, Anthony D; Shah, Tejen A
2014-05-01
The increase in antibiotic resistance and the dearth of novel antibiotics have become a growing concern among policy-makers. A combination of financial, scientific, and regulatory challenges poses barriers to antibiotic innovation. However, each of these three challenges provides an opportunity to develop pathways for new business models to bring novel antibiotics to market. Pull-incentives that pay for the outputs of research and development (R&D) and push-incentives that pay for the inputs of R&D can be used to increase innovation for antibiotics. Financial incentives might be structured to promote delinkage of a company's return on investment from revenues of antibiotics. This delinkage strategy might not only increase innovation, but also reinforce rational use of antibiotics. Regulatory approval, however, should not and need not compromise safety and efficacy standards to bring antibiotics with novel mechanisms of action to market. Instead regulatory agencies could encourage development of companion diagnostics, test antibiotic combinations in parallel, and pool and make transparent clinical trial data to lower R&D costs. A tax on non-human use of antibiotics might also create a disincentive for non-therapeutic use of these drugs. Finally, the new business model for antibiotic innovation should apply the 3Rs strategy for encouraging collaborative approaches to R&D in innovating novel antibiotics: sharing resources, risks, and rewards.
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Bogialli, Sara; Coradazzi, Cristina; Di Corcia, Antonio; Lagana, Aldo; Sergi, Manuel
2007-01-01
A rapid, specific, and sensitive procedure for determining residues of 4 widely used tetracycline antibiotics and 3 of their 4-epimers in cheese is presented. The method is based on the matrix solid-phase dispersion (MSPD) technique followed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). After dispersing samples of mozzarella, asiago, parmigiano, gruyere, emmenthal, and camembert on sand, target compounds were eluted from the MSPD column by passing through it 6 mL water heated at 70 degrees C. After acidification and filtration, 200 microL of the aqueous extract was directly injected into the LC column. For analyte identification and quantification, MS data acquisition was performed in the multireaction monitoring mode, selecting 2 precursor ion-to-product ion transitions for each target compound. Hot water appeared to be an efficient extractant, because absolute recoveries were no lower than 78%. Using demeclocycline as a surrogate analyte, recoveries of analyte added to the 6 types of cheeses at the 30 ng/g level were 96-117%, with relative standard deviation (RSD) not higher than 9%. Statistical analysis of the mean recovery data showed that the extraction efficiency was not dependent on the type of cheese analyzed. This result indicates that this method could be applied to other cheese types not considered here. At the lowest concentration considered, i.e., 10 ng/g, the accuracy of the method ranged between 90 and 107%, with RSDs not larger than 12%. Based on a signal-to-noise ratio of 10, limits of quantitation were estimated to be 1-2 ng/g.
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International Nuclear Information System (INIS)
Wang, Yi; Zhang, Dun
2012-01-01
Graphical abstract: The antibiotic anion released from Mg–Al LDHs provides a controlled release antibacterial activity against the growth of Micrococcus lysodeikticus in 3.5% NaCl solution. Highlights: ► Antibiotic anion intercalated LDHs were synthesized and characterized. ► The ion-exchange one is responsible for the release process. ► The diffusion through particle is the release rate limiting step. ► LDHs loaded with antibiotic anion have high antibacterial capabilities. -- Abstract: Antibiotic–inorganic clay composites including four antibiotic anions, namely, benzoate (BZ), succinate (SU), benzylpenicillin (BP), and ticarcillin (TC) anions, intercalated Mg–Al layered double hydroxides (LDHs) were synthesized via ion-exchange. Powder X-ray diffraction and Fourier transform infrared spectrum analyses showed the successful intercalation of antibiotic anion into the LDH interlayer. BZ and BP anions were accommodated in the interlayer region as a bilayer, whereas SU and TC anions were intercalated in a monolayer arrangement. Kinetic simulation of the release data indicated that ion-exchange was responsible for the release process, and the diffusion through the particles was the rate-limiting step. The antibacterial capabilities of LDHs loaded with antibiotic anion toward Micrococcus lysodeikticus growth were analyzed using a turbidimetric method. Significant high inhibition rate was observed when LDH nanohybrid was introduced in 3.5% NaCl solution. Therefore, this hybrid material may be applied as nanocontainer in active antifouling coating for marine equipment.
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de Souza, Alessandra A; Ionescu, Michael; Baccari, Clelia; da Silva, Aline M; Lindow, Steven E
2013-06-01
Eal is an EAL domain protein in Xylella fastidiosa homologous to one involved in resistance to tobramycin in Pseudomonas aeruginosa. EAL and HD-GYP domain proteins are implicated in the hydrolysis of the secondary messenger bis-(3'-5')-cyclic dimeric GMP (cyclic di-GMP). Cell density-dependent communication mediated by a Diffusible Signal Factor (DSF) also modulates cyclic di-GMP levels in X. fastidiosa, thereby controlling the expression of virulence genes and genes involved in insect transmission. The possible linkage of Eal to both extrinsic factors such as antibiotics and intrinsic factors such as quorum sensing, and whether both affect virulence, was thus addressed. Expression of eal was induced by subinhibitory concentrations of tobramycin, and an eal deletion mutant was more susceptible to this antibiotic than the wild-type strain and exhibited phenotypes similar to those of an rpfF deletion mutant blocked in DSF production, such as hypermotility, reduced biofilm formation, and hypervirulence to grape. Consistent with that, the rpfF mutant was more susceptible than the wild-type strain to tobramycin. Therefore, we propose that cell-cell communication and antibiotic stress can apparently lead to similar modulations of cyclic di-GMP in X. fastidiosa, resulting in similar phenotypes. However, the effect of cell density is dominant compared to that of antibiotic stress, since eal is suppressed by RpfF, which may prevent inappropriate behavioral changes in response to antibiotic stress when DSF accumulates.
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Dissemination of antibiotic resistance genes from antibiotic producers to pathogens
DEFF Research Database (Denmark)
Jiang, Xinglin; Ellabaan, Mostafa M Hashim; Charusanti, Pep
2017-01-01
It has been hypothesized that some antibiotic resistance genes (ARGs) found in pathogenic bacteria derive from antibiotic-producing actinobacteria. Here we provide bioinformatic and experimental evidence supporting this hypothesis. We identify genes in proteobacteria, including some pathogens...... and experimentally test a 'carry-back' mechanism for the transfer, involving conjugative transfer of a carrier sequence from proteobacteria to actinobacteria, recombination of the carrier sequence with the actinobacterial ARG, followed by natural transformation of proteobacteria with the carrier-sandwiched ARG. Our...... results support the existence of ancient and, possibly, recent transfers of ARGs from antibiotic-producing actinobacteria to proteobacteria, and provide evidence for a defined mechanism....
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Antibiotic Prescription in Danish General Practice
DEFF Research Database (Denmark)
Sydenham, Rikke Vognbjerg; Plejdrup Hansen, Malene; Pedersen, Line Bjørnskov
2016-01-01
1. Background & Aim The overall aim of the project is to describe antibiotic consumption in Danish general practice with emphasis on specific types of antibiotics. The project will shed light on the impact of microbiological diagnostic methods (MDM) on the choice of antibiotic and the project...... will explore how the GPs prescription behaviour is influenced by selected factors. Antibiotics are essential when treating potentially lethal infections. An increasing development of resistant bacteria is considered one of the primary threats to public health. The majority of antibiotics (90%) are prescribed...... from general practice. The prescription of broad-spectrum antibiotics can cause unnecessary side effects for the individual and increases the risk of development of bacteria resistant to antibiotic treatment. Both the prescription of broad-spectrum antibiotics and the level of resistant bacteria...
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Consumer attitudes and use of antibiotics.
Vanden Eng, Jodi; Marcus, Ruthanne; Hadler, James L; Imhoff, Beth; Vugia, Duc J; Cieslak, Paul R; Zell, Elizabeth; Deneen, Valerie; McCombs, Katherine Gibbs; Zansky, Shelley M; Hawkins, Marguerite A; Besser, Richard E
2003-09-01
Recent antibiotic use is a risk factor for infection or colonization with resistant bacterial pathogens. Demand for antibiotics can be affected by consumers' knowledge, attitudes, and practices. In 1998-1999, the Foodborne Diseases Active Surveillance Network (FoodNet( conducted a population-based, random-digit dialing telephone survey, including questions regarding respondents' knowledge, attitudes, and practices of antibiotic use. Twelve percent had recently taken antibiotics; 27% believed that taking antibiotics when they had a cold made them better more quickly, 32% believed that taking antibiotics when they had a cold prevented more serious illness, and 48% expected a prescription for antibiotics when they were ill enough from a cold to seek medical attention. These misguided beliefs and expectations were associated with a lack of awareness of the dangers of antibiotic use; 58% of patients were not aware of the possible health dangers. National educational efforts are needed to address these issues if patient demand for antibiotics is to be reduced.
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Sustained Release of Antibiotics from Injectable and Thermally Responsive Polypeptide Depots
Adams, Samuel B.; Shamji, Mohammed F.; Nettles, Dana L.; Hwang, Priscilla; Setton, Lori A.
2009-01-01
Biodegradable polymeric scaffolds are of interest for delivering antibiotics to local sites of infection in orthopaedic applications, such as bone and diarthrodial joints. The objective of this study was to develop a biodegradable scaffold with ease of drug loading in aqueous solution, while providing for drug depot delivery via syringe injection. Elastin-like polypeptides (ELPs) were used for this application, biopolymers of repeating pentapeptide sequences that were thermally triggered to u...
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DEFF Research Database (Denmark)
Kleif, Jakob; Rasmussen, Louise; Fonnes, Siv
2017-01-01
BACKGROUND: Prolonging post-operative antibiotic treatment beyond 3 days does not seem to reduce the incidence of post-operative abscess formation or wound infection after surgery for complicated appendicitis. The route of administration seems to be based on an empirical basis. Using enteral...... antibiotics could reduce length of stay and reduce overall costs. We aimed to examine whether treatment with enteral antibiotics during the first three post-operative days is non-inferior to intravenous antibiotics regarding intra-abdominal abscess formation or wound infection after surgery for complicated...... of surgery. Route of antibiotic administration for the first three post-operative days was registered for all patients. RESULTS: A total of 1141 patients were included in the study. The overall risk of developing an intra-abdominal abscess was 6.7% (95% CI 5.2%; 8.1%), and the risk of wound infection was 1...
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The determinants of the antibiotic resistance process.
Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I
2009-01-01
The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. We conducted a MedLine search using the key words "determinants", "antibiotic", and "antibiotic resistance" to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.
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Strieker, Matthias; Kopp, Florian; Mahlert, Christoph; Essen, Lars-Oliver; Marahiel, Mohamed A
2007-03-20
Non-ribosomally synthesized lipopeptide antibiotics of the daptomycin type are known to contain unnatural beta-modified amino acids, which are essential for bioactivity. Here we present the biochemical and structural basis for the incorporation of 3-hydroxyasparagine at position 9 in the 11-residue acidic lipopeptide lactone calcium-dependent antibiotic (CDA). Direct hydroxylation of l-asparagine by AsnO, a non-heme Fe(2+)/alpha-ketoglutarate-dependent oxygenase encoded by the CDA biosynthesis gene cluster, was validated by Fmoc derivatization of the reaction product and LC/MS analysis. The 1.45, 1.92, and 1.66 A crystal structures of AsnO as apoprotein, Fe(2+) complex, and product complex, respectively, with (2S,3S)-3-hydroxyasparagine and succinate revealed the stereoselectivity and substrate specificity of AsnO. The comparison of native and product-complex structures of AsnO showed a lid-like region (residues F208-E223) that seals the active site upon substrate binding and shields it from sterically demanding peptide substrates. Accordingly, beta-hydroxylated asparagine is synthesized prior to its incorporation into the growing CDA peptide. The AsnO structure could serve as a template for engineering novel enzymes for the synthesis of beta-hydroxylated amino acids.
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Blanco, Guillermo; Lemus, Jesús A; Grande, Javier
2009-05-01
The spread of pathogens in the environment due to human activities (pathogen pollution) may be involved in the emergence of many diseases in humans, livestock and wildlife. When manure from medicated livestock and urban effluents is spread onto agricultural land, both residues of antibiotics and bacteria carrying antibiotic resistance may be introduced into the environment. The transmission of bacterial resistance from livestock and humans to wildlife remains poorly understood even while wild animals may act as reservoirs of resistance that may be amplified and spread in the environment. We determined bacterial resistance to antibiotics in wildlife using the red-billed chough Pyrrhocorax pyrrhocorax as a potential bioindicator of soil health, and evaluated the role of agricultural manuring with waste of different origins in the acquisition and characteristics of such resistance. Agricultural manure was found to harbor high levels of bacterial resistance to multiple antibiotics. Choughs from areas where manure landspreading is a common agricultural practice harbor a high bacterial resistance to multiple antibiotics, resembling the resistance profile found in the waste (pig slurry and sewage sludge) used in each area. The transfer of bacterial resistance to wildlife should be considered as an important risk for environmental health when agricultural manuring involves fecal material containing multiresistant enteric bacteria including pathogens from livestock operations and urban areas. The assessment of bacterial resistance in wild animals may be valuable for the monitoring of environmental health and for the management of emergent infectious diseases influenced by the impact of different human activities in the environment.
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When and How to Take Antibiotics
... bacterial balance, it may cause stomach upsets, diarrhea, vaginal infections, or other problems. If you take antibiotics unnecessarily ... before taking antibiotics? Antibiotics often lead to a vaginal yeast infection. Because antibiotics kill the normal bacteria in the ...
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Structure of polysaccharide antibiotics
International Nuclear Information System (INIS)
Matutano, L.
1966-01-01
Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author) [fr
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Di Cerbo, A; Palatucci, A T; Rubino, V; Centenaro, S; Giovazzino, A; Fraccaroli, E; Cortese, L; Ruggiero, G; Guidetti, G; Canello, S; Terrazzano, G
2016-04-01
Antibiotics are widely used in zoo technical and veterinary practices as feed supplementation to ensure wellness of farmed animals and livestock. Several evidences have been suggesting both the toxic role for tetracyclines, particularly for oxytetracycline (OTC). This potential toxicity appears of great relevance for human nutrition and for domestic animals. This study aimed to extend the evaluation of such toxicity. The biologic impact of the drug was assessed by evaluating the proinflammatory effect of OTC and their bone residues on cytokine secretion by in vitro human peripheral blood lymphocytes. Our results showed that both OTC and OTC-bone residues significantly induced the T lymphocyte and non-T cell secretion of interferon (IFN)-γ, as cytokine involved in inflammatory responses in humans as well as in animals. These results may suggest a possible implication for new potential human and animal health risks depending on the entry of tetracyclines in the food-processing chain. © 2015 The Authors Journal of Biochemical and Molecular Toxicology Published Wiley Periodicals, Inc.
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Directory of Open Access Journals (Sweden)
Sharvari Vijaykumar Gaidhani
2014-01-01
Full Text Available Background & objectives: Available literature shows paucity of reports describing antibiotic and metal resistance profile of biofilm forming clinical isolates of Acinetobacter haemolyticus. The present study was undertaken to evaluate the antibiotic and metal resistance profile of Indian clinical isolate of A. haemolyticus MMC 8 isolated from human pus sample in planktonic and biofilm form. Methods: Antibiotic susceptibility and minimum inhibitory concentration were determined employing broth and agar dilution techniques. Biofilm formation was evaluated quantitatively by microtiter plate method and variation in complex architecture was determined by scanning electron microscopy. Minimum biofilm inhibiting concentration was checked by Calgary biofilm device. Results: Planktonic A. haemolyticus MMC 8 was sensitive to 14 antibiotics, AgNO 3 and HgC1 2 resistant to streptomycin and intermediately resistant to netilmycin and kanamycin. MMC 8 exhibited temporal variation in amount and structure of biofilm. There was 32 - 4000 and 4 - 256 fold increase in antibiotic and metal salt concentration, respectively to inhibit biofilm over a period of 72 h as against susceptible planktonic counterparts. Total viable count in the range of 10 5 -10 6 cfu / ml was observed on plating minimum biofilm inhibiting concentration on Muller-Hinton Agar plate without antimicrobial agents. Biofilm forming cells were several folds more resistant to antibiotics and metal salts in comparison to planktonic cells. Presence of unaffected residual cell population indicated presence of persister cells. Interpretation & conclusions: The results indicate that biofilm formation causes enhanced resistance against antibiotics and metal salts in otherwise susceptible planktonic A. haemolyticus MMC 8.
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Gao, Pengfei; Ma, Chen; Sun, Zheng; Wang, Lifeng; Huang, Shi; Su, Xiaoquan; Xu, Jian; Zhang, Heping
2017-08-03
Reducing antibiotics overuse in animal agriculture is one key in combat against the spread of antibiotic resistance. Probiotics are a potential replacement of antibiotics in animal feed; however, it is not clear whether and how probiotics and antibiotics differ in impact on physiology and microbial ecology of host animals. Host phenotype and fecal microbiota of broilers with either antibiotics or probiotics as feed additive were simultaneously sampled at four time points from birth to slaughter and then compared. Probiotic feeding resulted in a lower feed conversion ratio (FCR) and induced the highest level of immunity response, suggesting greater economic benefits in broiler farming. Probiotic use but not antibiotic use recapitulated the characteristics of age-dependent development of gut microbiota in the control group. The maturation of intestinal microbiota was greatly accelerated by probiotic feeding, yet significantly retarded and eventually delayed by antibiotic feeding. LP-8 stimulated the growth of many intestinal Lactobacillus spp. and led to an altered bacterial correlation network where Lactobacillus spp. are negatively correlated with 14 genera and positively linked with none, yet from the start antibiotic feeding featured a less-organized network where such inter-genera interactions were fewer and weaker. Consistently, microbiota-encoded functions as revealed by metagenome sequencing were highly distinct between the two groups. Thus, "intestinal microbiota maturation index" was proposed to quantitatively compare impact of feed additives on animal microecology. Our results reveal a tremendous potential of probiotics as antibiotics' substitute in poultry farming.
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[Usage of antibiotics in hospitals].
Ternák, G; Almási, I
1996-12-29
The authors publish the results of a survey conducted among hospital records of patients discharged from eight inpatient's institutes between 1-31st of January 1995 to gather information on the indications and usage of antibiotics. The institutes were selected from different part of the country to represent the hospital structure as much as possible. Data from the 13,719 documents were recorded and analysed by computer program. It was found that 27.6% of the patients (3749 cases) received antibiotic treatment. 407 different diagnosis and 365 different surgical procedures (as profilaxis) were considered as indications of antibiotic treatment (total: 4450 indications for 5849 antibiotic treatment). The largest group of patients receiving antibiotics was of antibiotic profilaxis (24.56%, 1093 cases), followed by lower respiratory tract infections (19.89%, 849 cases), uroinfections (10.53%, 469 cases) and upper respiratory tract infections. Relatively large group of patients belonged to those who had fever or subfebrility without known reason (7.35%, 327 cases) and to those who did not have any proof in their document indicating the reasons of antibiotic treatment (6.4%, 285 cases). We can not consider the antibiotic indications well founded in those groups of patients (every sixth or every fifth cases). The most frequently used antibiotics were of [2-nd] generation cefalosporins. The rate of nosocomial infections were found as 6.78% average. The results are demonstrated on diagrams and table.
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Antibiotics in late clinical development.
Fernandes, Prabhavathi; Martens, Evan
2017-06-01
Most pharmaceutical companies have stopped or have severely limited investments to discover and develop new antibiotics to treat the increasing prevalence of infections caused by multi-drug resistant bacteria, because the return on investment has been mostly negative for antibiotics that received marketing approved in the last few decades. In contrast, a few small companies have taken on this challenge and are developing new antibiotics. This review describes those antibiotics in late-stage clinical development. Most of them belong to existing antibiotic classes and a few with a narrow spectrum of activity are novel compounds directed against novel targets. The reasons for some of the past failures to find new molecules and a path forward to help attract investments to fund discovery of new antibiotics are described. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
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Wang, Yanhong; Yu, Zhenhua; Li, Yansheng; Wang, Guanghua; Liu, Junjie; Liu, Judong; Liu, Xiaobing; Jin, Jian
2017-12-31
As the chemical quality of crop residue is likely to be affected by elevated CO 2 (eCO 2 ), residue amendments may influence soil organic carbon (SOC) sequestration. However, in Mollisols, the dynamics of the SOC fractions in response to amendment with wheat residue produced under eCO 2 and the corresponding microbial community composition remain unknown. Such investigation is essential to residue management, which affects the soil quality and productivity of future farming systems. To narrow this knowledge gap, 13 C-labeled shoot and root residue derived from ambient CO 2 (aCO 2 ) or eCO 2 were amended into Mollisols and incubated for 200days. The soil was sampled during the incubation period to determine the residue-C retained in the three SOC fractions, i.e., coarse intra-aggregate particulate organic C (coarse iPOC), fine iPOC and mineral-associated organic C (MOC). The soil bacterial community was assessed using a MiSeq sequencing instrument. The results showed that the increase in SOC concentrations attributable to the application of the wheat residue primarily occurred in the coarse iPOC fraction. Compared with the aCO 2 -derived shoot residue, the amendment of eCO 2 -derived shoot residue resulted in greater SOC concentrations, whereas no significant differences (P>0.05) were observed between the aCO 2 - and eCO 2 -derived roots. Principal coordinates analysis (PCoA) showed that the residue amendment significantly (P≤0.05) altered the bacterial community composition compared with the non-residue amendment. Additionally, the bacterial community in the aCO 2 -derived shoot treatment differed from those in the other residue treatments until day 200 of the incubation period. The eCO 2 -derived shoot treatment significantly increased (P≤0.05) the relative abundances of the genera Acidobacteriaceae_(Subgroup_1)_uncultured, Bryobacter, Candidatus_Solibacter, Gemmatimonas and Nitrosomonadaceae_uncultured, whereas the opposite trend was observed in Nonomuraea
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Update on the combination effect of macrolide antibiotics in community-acquired pneumonia.
Emmet O'Brien, M; Restrepo, Marcos I; Martin-Loeches, Ignacio
2015-09-01
Community-acquired pneumonia (CAP) is a leading cause of death from an infectious cause worldwide. Guideline-concordant antibiotic therapy initiated in a timely manner is associated with improved treatment responses and patient outcomes. In the post-antibiotic era, much of the morbidity and mortality of CAP is as a result of the interaction between bacterial virulence factors and host immune responses. In patients with severe CAP, or who are critically ill, there is a lot of emerging observational evidence demonstrating improved survival rates when treatment using combination therapy with a β-lactam and a macrolide is initiated, as compared to other antibiotic regimes without a macrolide. Macrolides in combination with a β-lactam antibiotic provide broader coverage for the atypical organisms implicated in CAP, and may contribute to antibacterial synergism. However, it has been postulated that the documented immunomodulatory effects of macrolides are the primary mechanism for improved patient outcomes through attenuation of bacterial virulence factors and host systemic inflammatory responses. Despite concerns regarding the limitations of observational evidence and the lack of confirmatory randomized controlled trials, the potential magnitude of mortality benefits estimated at 20-50% cannot be overlooked. In light of recent data from a number of trials showing that combination treatment with a macrolide and a suitable second agent is justified in all patients with severe CAP, such treatment should be obligatory for those admitted to an intensive care setting. Copyright © 2015 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.
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Antibiotic Resistant Salmonella and Vibrio Associated with Farmed Litopenaeus vannamei
Directory of Open Access Journals (Sweden)
Sanjoy Banerjee
2012-01-01
Full Text Available Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed individual and multiple antibiotic resistance patterns. Five Vibrio species having individual and multiple antibiotic resistance were also identified. They were Vibrio cholerae (18.3%, V. mimicus (16.7%, V. parahaemolyticus (10%, V. vulnificus (6.7%, and V. alginolyticus (1.7%. Farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of shrimp.
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Antibiotic Resistance in Foodborne Pathogens
Walsh, Ciara; Duffy, Geraldine
2013-01-01
Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...
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Metabolic regulation of mycobacterial growth and antibiotic sensitivity.
Directory of Open Access Journals (Sweden)
Seung-Hun Baek
2011-05-01
Full Text Available Treatment of chronic bacterial infections, such as tuberculosis (TB, requires a remarkably long course of therapy, despite the availability of drugs that are rapidly bacteriocidal in vitro. This observation has long been attributed to the presence of bacterial populations in the host that are "drug-tolerant" because of their slow replication and low rate of metabolism. However, both the physiologic state of these hypothetical drug-tolerant populations and the bacterial pathways that regulate growth and metabolism in vivo remain obscure. Here we demonstrate that diverse growth-limiting stresses trigger a common signal transduction pathway in Mycobacterium tuberculosis that leads to the induction of triglyceride synthesis. This pathway plays a causal role in reducing growth and antibiotic efficacy by redirecting cellular carbon fluxes away from the tricarboxylic acid cycle. Mutants in which this metabolic switch is disrupted are unable to arrest their growth in response to stress and remain sensitive to antibiotics during infection. Thus, this regulatory pathway contributes to antibiotic tolerance in vivo, and its modulation may represent a novel strategy for accelerating TB treatment.
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ANTIBIOTIC THERAPY OF ABSCESS OF THE LUNG AND BRONCHIECTASIS
Hewitt, William L.
1952-01-01
Since the fusospirochetal group of bacteria are the commonest etiologic agents in abscess of the lung, aqueous crystalline penicillin is the agent of first choice in the majority of cases. Streptomycin is indicated for a small group of cases in which Klebsiella is the etiologic agent. Aureomycin, chloramphenicol or terramycin may produce an excellent therapeutic response either initially or after therapeutic failure with penicillin. Administration of antibiotics by inhalation should be carried out in conjunction with systemic forms of treatment. In the treatment of bronchiectasis, the antibiotics are most useful in the control of acute exacerbations of pulmonary infection which punctuate the course of this disease. PMID:14935877
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Use of antibiotics in the treatment of Crohn's disease.
Scribano, Maria Lia; Prantera, Cosimo
2013-02-07
Many data coming from animal models and clinical observations support an involvement of intestinal microbiota in the pathogenesis of Crohn's disease (CD). It is hypothesized in fact, that the development of chronic intestinal inflammation is caused by an abnormal immune response to normal flora in genetically susceptible hosts. The involvement of bacteria in CD inflammation has provided the rationale for including antibiotics in the therapeutic armamentarium. However, randomized controlled trials have failed to demonstrate an efficacy of these drugs in patients with active uncomplicated CD, even if a subgroup of patients with colonic location seems to get benefit from antibiotics. Nitroimidazole compounds have been shown to be efficacious in decreasing CD recurrence rates in operated patients, and the use of metronidazole and ciprofloxacin is recommended in perianal disease. However, the appearance of systemic side effects limits antibiotic long-term employment necessary for treating a chronic relapsing disease. Rifaximin, characterized by an excellent safety profile, has provided promising results in inducing remission of CD.
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MECHANISM OF ACTION OF ANTIBIOTICS WHICH INHIBIT SYNTHESIS OF BACTERIAL CELL WALL
Directory of Open Access Journals (Sweden)
Indira Mujezinović
2013-03-01
Full Text Available Bacterial cell possess a cell wall, which is a main difference from mammalian cells. Its basic function is to provide the strength of bacteria, keeps its shape and provides an unusually high internal osmotic pressure. Synthesis of (construction of bacterial cell wall occurs in at least three phases. All of these three phases can be influence by a variety of antibiotics in way to inhibit its synthesis. The most important drugs that act in this manner are ß-lactam antibiotics (penicillins, cephalosporins, cephamycins and other ß-lactams. They interfere with the synthesis of the bacterial cell wall peptidoglycan. After attachment to penicillin binding proteins (PBP on bacteria, they inhibit the transpeptidation enzyme that cross-links the peptide chain attached to the backbone of the peptidoglycan. The final bactericidal event is the inactivation of an inhibitor of autolytic enzymes in the cell wall, wich leads to lysis of the bacteria. Vancomycin inhibits the release of the building block unit from the carrier, thus preventing its addition to the growing end of the peptidoglycan. Cycloserine, which is a structural analogue of D-alanine, prevents the addition of the two terminal alanine residue to the initial tripeptide side-chain on N-acetylmuramic acid by competitive inhibition. Bacitracin interferes with the regeneration of the lipid carrier by blocking its dephosphorylation. Key words: bacterial cell wall, paptidoglycan, antibiotics, ß-lactams
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Antibiotic prophylaxis in obstetric procedures.
van Schalkwyk, Julie; Van Eyk, Nancy
2010-09-01
To review the evidence and provide recommendations on antibiotic prophylaxis for obstetrical procedures. Outcomes evaluated include need and effectiveness of antibiotics to prevent infections in obstetrical procedures. Published literature was retrieved through searches of Medline and The Cochrane Library on the topic of antibiotic prophylaxis in obstetrical procedures. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and articles published from January 1978 to June 2009 were incorporated in the guideline. Current guidelines published by the American College of Obstetrics and Gynecology were also incorporated. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care (Table 1). Implementation of this guideline should reduce the cost and harm resulting from the administration of antibiotics when they are not required and the harm resulting from failure to administer antibiotics when they would be beneficial. SUMMARY STATEMENTS: 1. Available evidence does not support the use of prophylactic antibiotics to reduce infectious morbidity following operative vaginal delivery. (II-1) 2. There is insufficient evidence to argue for or against the use of prophylactic antibiotics to reduce infectious morbidity for manual removal of the placenta. (III) 3. There is insufficient evidence to argue for or against the use of
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De Briyne, N; Atkinson, J; Pokludová, L; Borriello, S P; Price, S
2013-11-16
The Heads of Medicines Agencies and the Federation of Veterinarians of Europe undertook a survey to gain a better insight into the decision-making process of veterinarians in Europe when deciding which antibiotics to prescribe. The survey was completed by 3004 practitioners from 25 European countries. Analysis was to the level of different types of practitioner (food producing (FP) animals, companion animals, equines) and country for Belgium, Czech Republic, France, Germany, Spain, Sweden and the UK. Responses indicate no single information source is universally considered critical, though training, published literature and experience were the most important. Factors recorded which most strongly influenced prescribing behaviour were sensitivity tests, own experience, the risk for antibiotic resistance developing and ease of administration. Most practitioners usually take into account responsible use warnings. Antibiotic sensitivity testing is usually performed where a treatment failure has occurred. Significant differences were observed in the frequency of sensitivity testing at the level of types of practitioners and country. The responses indicate a need to improve sensitivity tests and services, with the availability of rapid and cheaper testing being key factors.