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Sample records for antibiotics enter bacteria

  1. Antibiotic-Resistant Enteric Bacteria in Environmental Waters

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    Lisa M. Casanova

    2016-11-01

    Full Text Available Sources of antibiotic resistant organisms, including concentrated animal feeding operations (CAFOs, may lead to environmental surface and groundwater contamination with resistant enteric bacteria of public health concern. The objective of this research is to determine whether Salmonella, Escherichia coli, Yersinia enterocolitica, and enterococci resistant to clinically relevant antibiotics are present in surface and groundwater sources in two eastern North Carolina counties, Craven and Wayne. 100 surface and groundwater sites were sampled for Salmonella, E. coli, and enterococci, and the bacteria isolated from these samples were tested for susceptibility to clinically relevant antibiotics. Salmonella were detected at low levels in some surface but not groundwater. E. coli were in surface waters but not ground in both counties. Enterococci were present in surface water and a small number of groundwater sites. Yersinia was not found. Bacterial densities were similar in both counties. For Salmonella in surface water, the most frequent type of resistance was to sulfamethoxazole. There was no ciprofloxacin resistance. There were a few surface water E. coli isolates resistant to chloramphenicol, gentamicin, and ampicillin. Enterococci in surface water had very low levels of resistance to vancomycin, chloramphenicol, ampicillin, and streptomycin. E. coli and enterococci are present more frequently and at higher levels in surface water than Salmonella, but groundwater contamination with any of these organisms was rare, and low levels of resistance can be found sporadically. Resistant bacteria are relatively uncommon in these eastern N.C. surface and groundwaters, but they could pose a risk of human exposure via ingestion or primary contact recreation.

  2. The carriage of antibiotic resistance by enteric bacteria from imported tokay geckos (Gekko gecko) destined for the pet trade

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    Casey, Christine L. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Hernandez, Sonia M., E-mail: shernz@uga.edu [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Yabsley, Michael J. [Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States); Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602 (United States); Smith, Katherine F. [Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912 (United States); Sanchez, Susan [The Athens Veterinary Diagnostic Laboratory, Athens, GA 30602 (United States); The Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602 (United States)

    2015-02-01

    The emergence of antibiotic-resistant bacteria is a growing public health concern and has serious implications for both human and veterinary medicine. The nature of the global economy encourages the movement of humans, livestock, produce, and wildlife, as well as their potentially antibiotic-resistant bacteria, across international borders. Humans and livestock can be reservoirs for antibiotic-resistant bacteria; however, little is known about the prevalence of antibiotic-resistant bacteria harbored by wildlife and, to our knowledge, limited data has been reported for wild-caught reptiles that were specifically collected for the pet trade. In the current study, we examined the antibiotic resistance of lactose-positive Enterobacteriaceae isolates from wild-caught Tokay geckos (Gekko gecko) imported from Indonesia for use in the pet trade. In addition, we proposed that the conditions under which wild animals are captured, transported, and handled might affect the shedding or fecal prevalence of antibiotic resistance. In particular we were interested in the effects of density; to address this, we experimentally modified densities of geckos after import and documented changes in antibiotic resistance patterns. The commensal enteric bacteria from Tokay geckos (G. gecko) imported for the pet trade displayed resistance against some antibiotics including: ampicillin, amoxicillin/clavulanic acid, cefoxitin, chloramphenicol, kanamycin and tetracycline. There was no significant difference in the prevalence of antibiotic-resistant bacteria after experimentally mimicking potentially stressful transportation conditions reptiles experience prior to purchase. There were, however, some interesting trends observed when comparing Tokay geckos housed individually and those housed in groups. Understanding the prevalence of antibiotic resistant commensal enteric flora from common pet reptiles is paramount because of the potential for humans exposed to these animals to acquire antibiotic

  3. How beta-lactam antibiotics enter bacteria: a dialogue with the porins.

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    Chloë E James

    Full Text Available BACKGROUND: Multi-drug resistant (MDR infections have become a major concern in hospitals worldwide. This study investigates membrane translocation, which is the first step required for drug action on internal bacterial targets. beta-lactams, a major antibiotic class, use porins to pass through the outer membrane barrier of Gram-negative bacteria. Clinical reports have linked the MDR phenotype to altered membrane permeability including porin modification and efflux pump expression. METHODOLOGY/PRINCIPAL FINDINGS: Here influx of beta-lactams through the major Enterobacter aerogenes porin Omp36 is characterized. Conductance measurements through a single Omp36 trimer reconstituted into a planar lipid bilayer allowed us to count the passage of single beta-lactam molecules. Statistical analysis of each transport event yielded the kinetic parameters of antibiotic travel through Omp36 and distinguishable translocation properties of beta-lactams were quantified for ertapenem and cefepime. Expression of Omp36 in an otherwise porin-null bacterial strain is shown to confer increases in the killing rate of these antibiotics and in the corresponding bacterial susceptibility. CONCLUSIONS/SIGNIFICANCE: We propose the idea of a molecular "passport" that allows rapid transport of substrates through porins. Deciphering antibiotic translocation provides new insights for the design of novel drugs that may be highly effective at passing through the porin constriction zone. Such data may hold the key for the next generation of antibiotics capable of rapid intracellular accumulation to circumvent the further development MDR infections.

  4. Carriage of antibiotic-resistant enteric bacteria varies among sites in Galapagos reptiles.

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    Wheeler, Emily; Hong, Pei-Ying; Bedon, Lenin Cruz; Mackie, Roderick I

    2012-01-01

    Increased overlap between humans and wildlife populations has increased the risk for novel disease emergence. Detecting contacts with a high risk for transmission of pathogens requires the identification of dependable measures of microbial exchange. We evaluated antibiotic resistance as a molecular marker for the intensity of human-wildlife microbial connectivity in the Galápagos Islands. We isolated Escherichia coli and Salmonella enterica from the feces of land iguanas (Conolophus sp.), marine iguanas (Amblyrhynchus cristatus), giant tortoises (Geochelone nigra), and seawater, and tested these bacteria with the use of the disk diffusion method for resistance to 10 antibiotics. Antibiotic-resistant bacteria were found in reptile feces from two tourism sites (Isla Plaza Sur and La Galapaguera on Isla San Cristóbal) and from seawater close to a public use beach near Puerto Baquerizo Moreno on Isla San Cristóbal. No resistance was detected at two protected beaches on more isolated islands (El Miedo on Isla Santa Fe and Cape Douglas on Isla Fernandina) and at a coastal tourism site (La Lobería on Isla San Cristóbal). Eighteen E. coli isolates from three locations, all sites relatively proximate to a port town, were resistant to ampicillin, doxycycline, tetracycline, and trimethoprin/sulfamethoxazole. In contrast, only five S. enterica isolates showed a mild decrease in susceptibility to doxycycline and tetracycline from these same sites (i.e., an intermediate resistance phenotype), but no clinical resistance was detected in this bacterial species. These findings suggest that reptiles living in closer proximity to humans potentially have higher exposure to bacteria of human origin; however, it is not clear from this study to what extent this potential exposure translates to ongoing exchange of bacterial strains or genetic traits. Resistance patterns and bacterial exchange in this system warrant further investigation to understand better how human associations

  5. Antibiotic-Resistant Bacteria.

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    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

    A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

  6. Antibiotics from predatory bacteria

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    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  7. Mobility of Tylosin and Enteric Bacteria in Soil Columns

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    To maximize production, producers regularly use antibiotics as supplements in animal feed and water to increase weight gain and prevent diseases among their livestock, which may result in nonpoint source pollution of ground or surface waters. This study examined the leaching of the enteric bacteria ...

  8. Antibiotic resistance in probiotic bacteria

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    Miguel eGueimonde

    2013-07-01

    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.

  9. The antibiotics relo in bacteria resistance

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    Santana, Vinicius Canato; CESUMAR

    2007-01-01

    The paper explains how antibiotics help us to combat bacteriosis, and also presents a brief historical report about the emergence of the antibiotic era with the discovery of penicillin. It introduces the problem of bacteria resistance, and brings the concept of antibiotics and its that produce these substance, and brings the concept of antibiotics and its main function. It questions about the self-defense of the organisms that produce these substances. relates the bacteria structures attacked...

  10. Water quality indicators: bacteria, coliphages, enteric viruses.

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    Lin, Johnson; Ganesh, Atheesha

    2013-12-01

    Water quality through the presence of pathogenic enteric microorganisms may affect human health. Coliform bacteria, Escherichia coli and coliphages are normally used as indicators of water quality. However, the presence of above-mentioned indicators do not always suggest the presence of human enteric viruses. It is important to study human enteric viruses in water. Human enteric viruses can tolerate fluctuating environmental conditions and survive in the environment for long periods of time becoming causal agents of diarrhoeal diseases. Therefore, the potential of human pathogenic viruses as significant indicators of water quality is emerging. Human Adenoviruses and other viruses have been proposed as suitable indices for the effective identification of such organisms of human origin contaminating water systems. This article reports on the recent developments in the management of water quality specifically focusing on human enteric viruses as indicators.

  11. Antibiotic-Resistant Bacteria: There is Hope.

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    Offner, Susan

    1998-01-01

    Argues that reduction in the use of antibiotics would enable antibiotic-sensitive bacteria to flourish. Presents an activity designed to show students how a small, seemingly unimportant difference in doubling time can, over a period of time, make an enormous difference in population size. (DDR)

  12. Enteric Bacteria and Cancer Stem Cells

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    Jun Sun

    2011-01-01

    Full Text Available Intestinal bacteria can contribute to cell proliferation and cancer development, particularly in chronic infectious diseases in which bacteria and/or bacterial components might interfere with cell function. The number of microbial cells within the gut lumen is estimated to be 100 trillion, which is about 10-times larger than the number of eukaryotic cells in the human body. Because of the complexity of the gut flora, identifying the specific microbial agents related to human diseases remains challenging. Recent studies have demonstrated that the stemness of colon cancer cells is, in part, orchestrated by the microenvironment and is defined by high Wnt activity. In this review article, we will discuss recent progress with respect to intestinal stem cells, cancer stem cells, and the molecular mechanisms of enteric bacteria in the activation of the Wnt pathway. We will also discuss the roles of other pathways, including JAK-STAT, JNK, and Notch, in regulating stem cell niches during bacterial infections using Drosophila models. Insights gained from understanding how host-bacterial interaction during inflammation and cancer may serve as a paradigm for understanding the nature of self-renewal signals.

  13. Growth of bacteria in enteral feeding solutions.

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    Anderton, A

    1985-08-01

    Solutions of Clinifeed ISO, Triosorbon, Vivonex Standard (full- and half-strength) and Vivonex HN were experimentally contaminated with two strains each of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella aerogenes, Escherichia coli and Enterobacter cloacae at concentrations of 10(2)-10(3) organisms/ml. Samples were incubated at 4, 25 or 37 degrees C and viable counts were made at 0, 4, 8 and 24 h. No increase in numbers of any of the organisms was observed in any of the feeds during 24 h at 4 degrees C. All organisms multiplied rapidly in Clinifeed ISO and in Triosorbon at 25 and 37 degrees C. There was less rapid growth in half-strength Vivonex Standard at 25 degrees C, although at 37 degrees C all strains multiplied rapidly except for the two S. aureus strains, the growth of which was inhibited in half-strength Vivonex Standard at both 25 and 37 degrees C. In full-strength Vivonex Standard at 25 degrees C, only P. aeruginosa showed any increase in numbers during 24 h, whereas P. aeruginosa, K. aerogenes and E. cloacae all multiplied at 37 degrees C. None of the test organisms multiplied in full strength Vivonex HN at any of the temperatures studied. The results of the study show that bacteria survive and may multiply even in feeds with low pH and high osmolarity, and emphasise the importance of strict hygiene during the preparation and handling of all enteral feeds.

  14. Exposure of juvenile Leghorn chickens to lead acetate enhances antibiotic resistance in enteric bacterial flora.

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    Nisanian, M; Holladay, S D; Karpuzoglu, E; Kerr, R P; Williams, S M; Stabler, L; McArthur, J Vaun; Tuckfield, R Cary; Gogal, R M

    2014-04-01

    Heavy metals have been implicated for their ability to increase antibiotic resistance in bacteria collected from polluted waters, independent of antibiotic exposure. Specific-pathogen-free Leghorn chickens were therefore given Pb acetate in the drinking water to expose the enteric bacteria to Pb and to determine if antibiotic resistance changed in these bacteria. Concentrations of Pb used were 0.0, 0.01, 0.1, 1.0, or 10.0 mM; birds given the highest 2 concentrations showed signs of moribundity and dehydration and were removed from the study. Vent culture samples were collected for bacterial cultures on d 0 before Pb exposure, d 7 and 14, and then birds were euthanized by CO2 gas for necropsy on d 14, at which time intestinal contents were also collected for bacterial cultures. Fecal swabs but not intestinal samples from Pb-exposed birds contained isolates that had significantly elevated antibiotic resistance. Some of the isolates contained bacteria that were resistant to up to 20 antibiotics. These results suggest the need for repeated studies in chickens infected with zoonotic pathogens.

  15. Antibiotic-Resistant Bacteria Detected in Sewage Spill

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    ... medlineplus.gov/news/fullstory_160031.html Antibiotic-Resistant Bacteria Detected in Sewage Spill 'People need to be ... News) -- Sewer line breaks can release antibiotic-resistant bacteria that pose a public health threat, a new ...

  16. Different Subsets of Enteric Bacteria Induce and Perpetuate Experimental Colitis in Rats and Mice

    OpenAIRE

    Rath, Heiko C; Schultz, Michael; Freitag, René; Dieleman, Levinus A; Li, Fengling; Linde, Hans-Jörg; Schölmerich, Jürgen; Sartor, R. Balfour

    2001-01-01

    Resident bacteria are incriminated in the pathogenesis of experimental colitis and inflammatory bowel diseases. We investigated the relative roles of various enteric bacteria populations in the induction and perpetuation of experimental colitis. HLA-B27 transgenic rats received antibiotics (ciprofloxacin, metronidazole, or vancomycin-imipenem) in drinking water or water alone in either prevention or treatment protocols. Mice were treated similarly with metronidazole or vancomycin-imipenem bef...

  17. Bacteriophage biosensors for antibiotic-resistant bacteria.

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    Sorokulova, Irina; Olsen, Eric; Vodyanoy, Vitaly

    2014-03-01

    An increasing number of disease-causing bacteria are resistant to one or more anti-bacterial drugs utilized for therapy. Early and speedy detection of these pathogens is therefore very important. Traditional pathogen detection techniques, that include microbiological and biochemical assays are long and labor-intensive, while antibody or DNA-based methods require substantial sample preparation and purification. Biosensors based on bacteriophages have demonstrated remarkable potential to surmount these restrictions and to offer rapid, efficient and sensitive detection technique for antibiotic-resistant bacteria.

  18. Challenging the concept of bacteria subsisting on antibiotics.

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    Walsh, Fiona; Amyes, Sebastian G B; Duffy, Brion

    2013-06-01

    Antibiotic resistance concerns have been compounded by a report that soil bacteria can catabolise antibiotics, i.e. break down and use them as a sole carbon source. To date this has not been verified or reproduced, therefore in this study soil bacteria were screened to verify and reproduce this hypothesis. Survival in high concentrations of antibiotics was initially observed; however, on further analysis these bacteria either did not degrade the antibiotics or they used an intrinsic resistance mechanism (β-lactamases) to degrade the β-lactams, as demonstrated by high-performance liquid chromatography. These results did not verify or reproduce the hypothesis that bacteria subsist on antibiotics or catabolise antibiotics as previously reported. This study identified that bacteria with a catabolising phenotype did not degrade streptomycin or trimethoprim and therefore could not utilise the antibiotics as a nutrient source. Therefore, we conclude that soil bacteria do not catabolise antibiotics.

  19. Antimicrobial effect of Malaysian vegetables against enteric bacteria

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    Hassanain Al-Talib

    2016-03-01

    Conclusions: Garlic had excellent antimicrobial effects against enteric bacteria and was recommended to be given to patients with gastroenteritis. The other vegetables (pennywort, mint, parsley and celery showed no inhibitory effects on enteric bacteria but still can be used for its richness in vitamins and fibers. The performance of the well diffusion method was better than that of the disc diffusion method in detecting the antibacterial effects of green vegetables.

  20. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    KAUST Repository

    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.

  1. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes.

    Science.gov (United States)

    Hong, Pei-Ying; Al-Jassim, Nada; Ansari, Mohd Ikram; Mackie, Roderick I

    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.

  2. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    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.

  3. Antimicrobial effect of Malaysian vegetables against enteric bacteria

    Institute of Scientific and Technical Information of China (English)

    Hassanain Al-Talib; Norliana Dalila Mohamad Ali; Mohamed Harreez Suhaimi; Siti Shafika Nabila Rosli; Nurul Huda Othman; Nur Ain Sakinah Mansor; Amira Kartini Sulaiman Shah; Nurul Syuhada Ariffin; Alyaa Al-Khateeb

    2016-01-01

    Objective: To investigate the antibacterial activities of green vegetables(pennywort,mint, garlic, parsley and celery) against four common enteric bacteria [Salmonella enterica(ATCC 25957)(S. enterica), Shigella flexneri(ATCC 12022)(S. flexneri),Escherichia coli(ATCC 43889)(E. coli) and Enterobacter cloacae(ATCC 13047)(E. cloacae)] as an alternative medicine for controlling food borne diarrhea disease and the synergistic effect of green vegetables against those bacteria.Methods: Five common vegetables(pennywort, mint, garlic, parsley and celery) were purchased and extracted. The antimicrobial activities of these extracts were tested against four common enteric bacteria(S. enterica, S. flexneri, E. coli and E. cloacae). Ten different concentrations of the extracts(from 640 to 1.25 mg/m L) were prepared and used for the study. The minimal inhibitory concentration(MIC) was determined by the broth dilution method. The antimicrobial activities were assessed by using both well diffusion and disc diffusion methods.Results: Garlic extract showed excellent inhibitory effects on all enteric bacteria. Other plants(parsley, celery, mint and pennywort) were not effective against enteric bacteria.The MIC of garlic against S. flexneri and E. cloacae was 40 mg/m L. The MIC of S. enterica and E. coli were 20 and 10 mg/m L, respectively. The performance of the well diffusion method was better than that of the disc diffusion method with clear and sharp inhibition zones of tested bacteria against plant extracts.Conclusions: Garlic had excellent antimicrobial effects against enteric bacteria and was recommended to be given to patients with gastroenteritis. The other vegetables(pennywort, mint, parsley and celery) showed no inhibitory effects on enteric bacteria but still can be used for its richness in vitamins and fibers. The performance of the well diffusion method was better than that of the disc diffusion method in detecting the antibacterial effects of green vegetables.

  4. Bacteria resitnce to antibiotics: an analysis of hospital conduct

    OpenAIRE

    Oliveira, Andrea Luiza de; CESUMAR

    2007-01-01

    The objective of this paper is to identify the main medical-hospital practices that aggravate bacteria resistance and reflect the indiscriminate use of antibiotics leaging to hospital infections. To that aim, we present general concepts on antibiotic therapy. We analyse the development of induced bacteria resistance by the indiscriminate use of antibiotics, describing the genetic and biochemical resistance mechanisms. We focus on the incidence of bacteria resistance in hospital in relation to...

  5. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

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    Suresh Jaiswal et al.

    2012-03-01

    Full Text Available Drug resistant bacteria have been posing a major challenge to the effective control of bacterial infections for quite some time. One of the main causes of antibiotics drug resistance is antibiotic overuse, abuse, and in some cases, misuse, due to incorrect diagnosis. Bacterial antibiotic resistance is a significant issues faced by various industries, including the food and agricultural industries, the medical and veterinary profession and others. The potential for transfer of antibiotics resistance, or of potentially lethal antibiotic resistant bacteria, for example from a food animal to human consumer, is of particular concern. A method of controlling development and spread of antibiotic-resistant bacteria include changes in antibiotic usage and pattern of usage of different antibiotics. However, the ability of bacteria to adapt to antibiotic usage and to acquire resistance to existing and new antibiotics usage overcomes such conventional measures, and requires the continued development of alternative means of control of antibiotic resistance bacteria. Alternative means for overcoming the tendency of bacteria to acquire resistance to antibiotic control measures have taken various forms. This article explains one method evaluated for control, that is reducing or removing antibiotic resistance is so called “curing” of antibiotic resistance. Antibiotic resistance is formed in the chromosomal elements. Thus elimination of such drug-resistance plasmids results in loss of antibiotics resistance by the bacterial cell. “Curing” of a microorganism refers to the ability of the organism to spontaneously lose a resistance plasmid under the effect of particular compounds and environmental conditions, thus recovering the antibiotic sensitive state.

  6. Antibiotic resistance in bacteria from shrimp farming in mangrove areas.

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    Le, Tuan Xuan; Munekage, Yukihiro; Kato, Shin-ichiro

    2005-10-15

    Shrimp farming is a sufficiently large and mature industry to have an effective range of antimicrobial agents for most bacterial diseases in shrimp culture. However, at present, there exists great concern over the widespread use of antibiotics in aquaculture, which may result in residue of antibiotics in water and mud, and subsequently, the development of antibiotic resistance in bacteria in the environment. There is limited understanding about the effect of antibiotic residues on bacteria resistance in shrimp farming environment. Therefore, a study was conducted to investigate bacterial resistance to Norfloxacin (NFXC), Oxolinic Acid (OXLA), Trimethoprim (TMP) and Sulfamethoxazole (SMX), which were found in four shrimp farming locations in mangrove areas in Vietnam. Findings indicate that there is a relatively high incidence of bacteria resistance to these antibiotics observed in most of the studied sites, particularly to antibiotics with concentration of 0.1 microg/ml. Yet the relation between concentration of antibiotic residues and incidence of antibiotic resistance is not clearly defined. Among individual antibiotics, the incidence of resistance to TMP and SMX was higher than the others. Identification of bacteria isolated from mud samples by DNA analyzer shows that Bacillus and Vibrio are predominant among bacteria resistant to the antibiotics. The result of the study also indicates that these antibiotics in media degraded more rapidly due to the presence of resistant bacteria.

  7. THE AVAILABILITY OF Mytilus galloprovincialis FOR MONITORING ENTERIC BACTERIA

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    Nüket SĐVRĐ

    2012-01-01

    Full Text Available In this study, the usage of Mediterranean Mussel (Mytilus galloprovincialis Lamarck, 1819 as monitoring organism on enteric bacteria concentrations in heavily polluted marine environments and its use possibilities as water quality improving tool were investigated. The ability of the Mediterranean Mussel to accumulate and purge fecal coliform bacteria investigated in laboratory experiments. First, increase on bacteria concentration was observed on 1,5th hour and sharp decrease rate lasted until 10th hours after that period slow but steady declining bacteria concentration rate was observed and beginning bacteria concentration rate was reached within next 30- 50 hours. Time dependent bacteria concentration reduction has found statistically significant at p<0.001 (r-sq = 0.81. The investigation has also revealed that mussel farming could be established in the over polluted area which is the case only in the different discharge points in the sea.

  8. Alternatives to antibiotics to prevent necrotic enteritis in broiler chickens: a microbiologist’s perspective.

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    Delphine Louise Caly

    2015-12-01

    Full Text Available Since the 2006 European ban on the use of antibiotics as growth promoters in animal feed, numerous studies have been published describing alternative strategies to prevent diseases in animals. A particular focus has been on prevention of necrotic enteritis in poultry caused by Clostridium perfringens by the use of microbes or microbe-derived products. Microbes produce a plethora of molecules with antimicrobial properties and they can also have beneficial effects through interactions with their host. Here we review recent developments in novel preventive treatments against C. perfringens-induced necrotic enteritis in broiler chickens that employ yeasts, bacteria and bacteriophages or secondary metabolites and other microbial products in disease control.

  9. Demonstrating Effectiveness of Antibiotics Against Known Bacteria Strains

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    Keefe, Lois M.

    1977-01-01

    Procedures are described for showing the effectiveness of antibiotics (penicillin, ampicillin, and tetracycline) against a nonpathogenic bacteria strain (Bacillus cereus). Methods are outlined for preparing nutrient agar, sterilizing tubes, pouring agar plates, preparing antibiotic discs, and transferring antibiotic discs to agar plates. (CS)

  10. Diversity and antibiotic resistance of uropathogenic bacteria from Abidjan

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    J.-L.A. Moroh

    2014-03-01

    Conclusions: The diversity of uropathogenic bacteria obtained appeared to be a characteristic of sub-Saharan African countries. Their resistances to different antibiotics were following a dramatic trend. Waiting to be confronted with therapeutic dead end with the advent of multi-resistant bacteria, identifying the region-specific causes is crucial to adapt antibiotic therapy.

  11. Antibiotic susceptibility testing of the Gram-negative bacteria based on flow cytometry

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    Claude Saint-Ruf

    2016-07-01

    Full Text Available Rapidly treating infections with adequate antibiotics is of major importance. This requires a fast and accurate determination of the antibiotic susceptibility of bacterial pathogens. The most frequently used methods are slow because they are based on the measurement of growth inhibition. Faster methods, such as PCR-based detection of determinants of antibiotic resistance, do not always provide relevant information on susceptibility, particularly that which is not genetically based. Consequently, new methods, such as the detection of changes in bacterial physiology caused by antibiotics using flow cytometry and fluorescent viability markers, are being explored. In this study, we assessed whether Alexa Fluor® 633 Hydrazide (AFH, which targets carbonyl groups, can be used for antibiotic susceptibility testing. Carbonylation of cellular macromolecules, which increases in antibiotic-treated cells, is a particularly appropriate to assess for this purpose because it is irreversible. We tested the susceptibility of clinical isolates of Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, to antibiotics from the three classes: β-lactams, aminoglycosides and fluoroquinolones. In addition to AFH, we used TO-PRO®-3, which enters cells with damaged membranes and binds to DNA, and DiBAC4 (3, which enters cells with depolarized membranes. We also monitored antibiotic-induced morphological alterations of bacterial cells by analyzing light scattering signals. Although all tested dyes and light scattering signals allowed for the detection of antibiotic-sensitive cells, AFH proved to be the most suitable for the fast and reliable detection of antibiotic susceptibility.

  12. Antibiotic Susceptibility Testing of the Gram-Negative Bacteria Based on Flow Cytometry.

    Science.gov (United States)

    Saint-Ruf, Claude; Crussard, Steve; Franceschi, Christine; Orenga, Sylvain; Ouattara, Jasmine; Ramjeet, Mahendrasingh; Surre, Jérémy; Matic, Ivan

    2016-01-01

    Rapidly treating infections with adequate antibiotics is of major importance. This requires a fast and accurate determination of the antibiotic susceptibility of bacterial pathogens. The most frequently used methods are slow because they are based on the measurement of growth inhibition. Faster methods, such as PCR-based detection of determinants of antibiotic resistance, do not always provide relevant information on susceptibility, particularly that which is not genetically based. Consequently, new methods, such as the detection of changes in bacterial physiology caused by antibiotics using flow cytometry and fluorescent viability markers, are being explored. In this study, we assessed whether Alexa Fluor® 633 Hydrazide (AFH), which targets carbonyl groups, can be used for antibiotic susceptibility testing. Carbonylation of cellular macromolecules, which increases in antibiotic-treated cells, is a particularly appropriate to assess for this purpose because it is irreversible. We tested the susceptibility of clinical isolates of Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, to antibiotics from the three classes: β-lactams, aminoglycosides, and fluoroquinolones. In addition to AFH, we used TO-PRO®-3, which enters cells with damaged membranes and binds to DNA, and DiBAC4 (3), which enters cells with depolarized membranes. We also monitored antibiotic-induced morphological alterations of bacterial cells by analyzing light scattering signals. Although all tested dyes and light scattering signals allowed for the detection of antibiotic-sensitive cells, AFH proved to be the most suitable for the fast and reliable detection of antibiotic susceptibility.

  13. Influence of Chicken Manure Fertilization on Antibiotic-Resistant Bacteria in Soil and the Endophytic Bacteria of Pakchoi.

    Science.gov (United States)

    Yang, Qingxiang; Zhang, Hao; Guo, Yuhui; Tian, Tiantian

    2016-01-01

    Animal manure is commonly used as fertilizer for agricultural crops worldwide, even though it is believed to contribute to the spread of antibiotic resistance from animal intestines to the soil environment. However, it is unclear whether and how there is any impact of manure fertilization on populations and community structure of antibiotic-resistant endophytic bacteria (AREB) in plant tissues. To investigate the effect of manure and organic fertilizer on endophytic bacterial communities, pot experiments were performed with pakchoi grown with the following treatments: (1) non-treated; (2) chicken manure-treated and (3) organic fertilizer-treated. Manure or organic fertilizer significantly increased the abundances of total cultivable endophytic bacteria (TCEB) and AREB in pakchoi, and the effect of chicken manure was greater than that of organic fertilizer. Further, 16S rDNA sequencing and the phylogenetic analysis indicated that chicken manure or organic fertilizer application increased the populations of multiple antibiotic-resistant bacteria (MARB) in soil and multiple antibiotic-resistant endophytic bacteria (MAREB) in pakchoi. The identical multiple antibiotic-resistant bacterial populations detected in chicken manure, manure- or organic fertilizer-amended soil and the vegetable endophytic system were Brevundimonas diminuta, Brachybacterium sp. and Bordetella sp., suggesting that MARB from manure could enter and colonize the vegetable tissues through manure fertilization. The fact that some human pathogens with multiple antibiotic resistance were detected in harvested vegetables after growing in manure-amended soil demonstrated a potential threat to human health.

  14. Antibiotic Susceptibility of Commensal Bacteria from Human Milk.

    Science.gov (United States)

    Chen, Po-Wen; Tseng, Shu-Ying; Huang, Mao-Sheng

    2016-02-01

    Recent studies have focused on foodborne or commensal bacteria as vehicles of antibiotic resistance. However, the antibiotic resistance of milk bacteria from healthy donors is still vague in Taiwan. For this purpose, human milk samples were obtained from randomly recruited 19 healthy women between 3 and 360 days post-partum. Antibiotic susceptibility profile of bacteria from milk samples was determined. About 20 bacterial species were isolated from milk samples including Staphylococcus (6 species), Streptococcus (4 species), Enterococcus (2 species), Lactobacillus (1 species), and bacteria belonging to other genera (7 species). Some opportunistic or potentially pathogenic bacteria including Kluyvera ascorbata, Klebsiella oxytoca, Klebsiella pneumoniae, Acinetobacter baumannii, Actinomyces bovis, and Staphylococcus aureus were also isolated. Intriguingly, Staphylococcus isolates (22 strains) were resistant to 2–8 of 8 antibiotics, while Streptococcus isolates (3 strains) were resistant to 3–7 of 9 antibiotics, and members of the genus Enterococcus (5 strains) were resistant to 3–8 of 9 antibiotics. Notably, Staphylococcus lugdunensis, S. aureus, Streptococcus parasanguinis, Streptococcus pneumonia, and Enterococcus faecalis were resistant to vancomycin, which is considered as the last-resort antibiotic. Therefore, this study shows that most bacterial strains in human milk demonstrate mild to strong antibiotic resistance. Whether commensal bacteria in milk could serve as vehicles of antibiotic resistance should be further investigated.

  15. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

    OpenAIRE

    Suresh Jaiswal et al.

    2012-01-01

    Drug resistant bacteria have been posing a major challenge to the effective control of bacterial infections for quite some time. One of the main causes of antibiotics drug resistance is antibiotic overuse, abuse, and in some cases, misuse, due to incorrect diagnosis. Bacterial antibiotic resistance is a significant issues faced by various industries, including the food and agricultural industries, the medical and veterinary profession and others. The potential for transfer of antibiotics resi...

  16. The Shared Antibiotic Resistome of Soil Bacteria and Human Pathogens

    DEFF Research Database (Denmark)

    Forsberg, Kevin J.; Reyes, Alejandro; Wang, Bin

    2012-01-01

    From Farm to Clinic?Soil organisms have long been assumed to be an important source of antibiotic resistance genes, in part because of antibiotic-treated livestock and in part because of the natural ecology of antibiotic production in the soil. Forsberg et al. (p. 1107) developed a metagenomic...... protocol to assemble short-read sequence data after antibiotic selection experiments, using 12 different drugs in all antibiotic classes, and compared antibiotic resistance gene sequences between soil bacteria and clinically occurring pathogens. Sixteen sequences, representing seven gene products, were...

  17. The Evolution of Insertion Sequences within Enteric Bacteria

    OpenAIRE

    Lawrence, J G; Ochman, H.; Hartl, D. L.

    1992-01-01

    To identify mechanisms that influence the evolution of bacterial transposons, DNA sequence variation was evaluated among homologs of insertion sequences IS1, IS3 and IS30 from natural strains of Escherichia coli and related enteric bacteria. The nucleotide sequences within each class of IS were highly conserved among E. coli strains, over 99.7% similar to a consensus sequence. When compared to the range of nucleotide divergence among chromosomal genes, these data indicate high turnover and ra...

  18. Emergence of ciprofloxacin-resistant extended-spectrum β-lactamase-producing enteric bacteria in hospital wastewater and clinical sources.

    Science.gov (United States)

    Maheshwari, Meenu; Yaser, Nawar Hadi; Naz, Suraiya; Fatima, Mansha; Ahmad, Iqbal

    2016-06-01

    This study aimed to evaluate the incidence of ciprofloxacin-resistant extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and clinical sources. Enteric bacteria, mainly Escherichia coli, were isolated from clinical sources (urinary tract and gastrointestinal tract infections; 80 isolates) and hospital wastewater (103 isolates). The antibiotic resistance profile and ESBL production of the isolates were investigated by disc diffusion assay and combined disc diffusion test, respectively. Plasmid profiling was performed by agarose gel electrophoresis, and elimination of resistance markers was performed by a plasmid curing experiment. Antibiotic susceptibility testing revealed a high incidence of β-lactam resistance, being highest to ampicillin (88.0%) followed by amoxicillin, ceftriaxone, cefpodoxime, cefotaxime, aztreonam, cefepime and ceftazidime. Among the non-β-lactam antibiotics, the highest resistance was recorded to nalidixic acid (85.7%). Moreover, 50.8% of enteric bacteria showed resistance to ciprofloxacin. Among 183 total enteric bacteria, 150 (82.0%) exhibited multidrug resistance. ESBL production was detected in 78 isolates (42.6%). A significantly higher incidence of ciprofloxacin resistance was observed among ESBL-producing enteric bacteria both in clinical (P=0.0015) and environmental isolates (P=0.012), clearly demonstrating a close association between ESBL production and ciprofloxacin resistance. Plasmid profiling of selected ESBL-positive strains indicated the presence of one or more plasmids of varying sizes. Plasmid curing resulted in loss of ciprofloxacin and cefotaxime resistance markers simultaneously from selected ESBL-positive isolates, indicating the close relationship of these markers. This study revealed a common occurrence of ciprofloxacin-resistant ESBL-producing enteric bacteria both in hospital wastewater and clinical sources, indicating a potential public health threat.

  19. 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

    ). 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...

  20. Deoxyribonucleoside kinases activate nucleoside antibiotics in severely pathogenic bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Shannon, O.; Clausen, A.R.;

    2007-01-01

    Common bacterial pathogens are becoming progressively more resistant to traditional antibiotics, representing a major public-health crisis. Therefore, there is a need for a variety of antibiotics with alternative modes of action. In our study, several nucleoside analogs were tested against...... alternative for combating pathogenic bacteria....

  1. Antibiotics

    Science.gov (United States)

    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 ...

  2. Commensal enteric bacteria lipopolysaccharide impairs host defense against disseminated Candida albicans fungal infection.

    Science.gov (United States)

    Jiang, T T; Chaturvedi, V; Ertelt, J M; Xin, L; Clark, D R; Kinder, J M; Way, S S

    2015-07-01

    Commensal enteric bacteria maintain systemic immune responsiveness that protects against disseminated or localized infection in extra-intestinal tissues caused by pathogenic microbes. However, as shifts in infection susceptibility after commensal bacteria eradication have primarily been probed using viruses, the broader applicability to other pathogen types remains undefined. In sharp contrast to diminished antiviral immunity, we show commensal bacteria eradication bolsters protection against disseminated Candida albicans fungal infection. Enhanced antifungal immunity reflects more robust systemic expansion of Ly6G(hi)Ly6C(int) neutrophils, and their mobilization into infected tissues among antibiotic-treated compared with commensal bacteria-replete control mice. Reciprocally, depletion of neutrophils from expanded levels or intestinal lipopolysaccharide reconstitution overrides the antifungal protective benefits conferred by commensal bacteria eradication. This discordance in antifungal compared with antiviral immunity highlights intrinsic differences in how commensal bacteria control responsiveness for specific immune cell subsets, because pathogen-specific CD8(+) T cells that protect against viruses were suppressed similarly after C. albicans and influenza A virus infection. Thus, positive calibration of antiviral immunity by commensal bacteria is counterbalanced by restrained activation of other immune components that confer antifungal immunity.

  3. Antibiotic-resistant soil bacteria in transgenic plant fields.

    Science.gov (United States)

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy M; Simonet, Pascal

    2008-03-11

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-year culture of the transgenic Bt176 corn, which has a blaTEM marker gene, could have had on the soil bacterial community. The bla gene encoding resistance to ampicillin belongs to the beta-lactam antibiotic family, which is widely used in medicine but is readily compromised by bacterial antibiotic resistance. Our results indicate that soil bacteria are naturally resistant to a broad spectrum of beta-lactam antibiotics, including the third cephalosporin generation, which has a slightly stronger discriminating effect on soil isolates than other cephalosporins. These high resistance levels for a wide range of antibiotics are partly due to the polymorphism of bla genes, which occur frequently among soil bacteria. The blaTEM116 gene of the transgenic corn Bt176 investigated here is among those frequently found, thus reducing any risk of introducing a new bacterial resistance trait from the transgenic material. In addition, no significant differences were observed in bacterial antibiotic-resistance levels between transgenic and nontransgenic corn fields, although the bacterial populations were different.

  4. Stalking Antibiotic-Resistant Bacteria in Common Vegetables

    Science.gov (United States)

    Brock, David; Boeke, Caroline; Josowitz, Rebecca; Loya, Katherine

    2004-01-01

    The study developed a simple experimental protocol for studying antibiotic resistant bacteria that will allow students to determine the proportion of such bacteria found on common fruit and vegetable crops. This protocol can open up the world of environmental science and show how human behavior can dramatically alter ecosystems.

  5. Regulation and biosynthesis of carbapenem antibiotics in bacteria.

    Science.gov (United States)

    Coulthurst, Sarah J; Barnard, Anne M L; Salmond, George P C

    2005-04-01

    Carbapenem antibiotics are members of the beta-lactam family of antibiotics, the most important class of antibiotics currently in clinical use. They are active against many important Gram-positive and Gram-negative pathogens. One important feature of carbapenem antibiotics is their resistance to several beta-lactamases. Thienamycin, isolated from Streptomyces cattleya, was the first carbapenem described. Other well-studied carbapenems were isolated from the Gram-negative bacteria Erwinia carotovora subsp. carotovora, Serratia sp. strain ATCC39006 and Photorhabdus luminescens strain TT01. Here, we review the genetics and biochemistry of carbapenem production in these bacteria. Research into carbapenems could uncover a new repertoire of bioactive molecules and biosynthetic enzymes, and exploiting these novel enzymes could lead to development of new classes of antibiotics with useful chemotherapeutic activities.

  6. Antibiotic resistance shaping multi-level population biology of bacteria.

    Science.gov (United States)

    Baquero, Fernando; Tedim, Ana P; Coque, Teresa M

    2013-01-01

    Antibiotics have natural functions, mostly involving cell-to-cell signaling networks. The anthropogenic production of antibiotics, and its release in the microbiosphere results in a disturbance of these networks, antibiotic resistance tending to preserve its integrity. The cost of such adaptation is the emergence and dissemination of antibiotic resistance genes, and of all genetic and cellular vehicles in which these genes are located. Selection of the combinations of the different evolutionary units (genes, integrons, transposons, plasmids, cells, communities and microbiomes, hosts) is highly asymmetrical. Each unit of selection is a self-interested entity, exploiting the higher hierarchical unit for its own benefit, but in doing so the higher hierarchical unit might acquire critical traits for its spread because of the exploitation of the lower hierarchical unit. This interactive trade-off shapes the population biology of antibiotic resistance, a composed-complex array of the independent "population biologies." Antibiotics modify the abundance and the interactive field of each of these units. Antibiotics increase the number and evolvability of "clinical" antibiotic resistance genes, but probably also many other genes with different primary functions but with a resistance phenotype present in the environmental resistome. Antibiotics influence the abundance, modularity, and spread of integrons, transposons, and plasmids, mostly acting on structures present before the antibiotic era. Antibiotics enrich particular bacterial lineages and clones and contribute to local clonalization processes. Antibiotics amplify particular genetic exchange communities sharing antibiotic resistance genes and platforms within microbiomes. In particular human or animal hosts, the microbiomic composition might facilitate the interactions between evolutionary units involved in antibiotic resistance. The understanding of antibiotic resistance implies expanding our knowledge on multi

  7. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demaneche, S.; Sanguin, H.; Pote, J.; Navarro, Elisabeth; Bernillon, D.; Mavingui, P.; Wildi, W.; Vogel, T M; Simonet, P

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 110-successive-y...

  8. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy M.; Simonet, Pascal

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-ye...

  9. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demanèche, Sandrine; Sanguin, Hervé; Poté, John; Navarro, Elisabeth; Bernillon, Dominique; Mavingui, Patrick; Wildi, Walter; Vogel, Timothy,; Simonet, Pascal

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-y...

  10. Antibiotic Resistance Pattern of Gram-Negative Bacteria in Gorgan

    Directory of Open Access Journals (Sweden)

    Golsha, R. (MD

    2014-06-01

    Full Text Available Background and Objective: The excessive use of broad-spectrum antibiotics will lead to drug resistance of microorganism and specially nosocomial organisms. Because of high incidence of antibiotic resistance in hospitals, we aimed to study antibiotic resistance to gram negative bacteria. Material and Methods: This cross-sectional study was conducted on the data of biological samples (2006-2008, with positive culture result. Using antibiogram, microbial resistance to isolated microorganism was determined, and after culturing the samples, bacteria were identified by using differential media and antiserum. Then, antibiotic resistance was performed by disk diffusion. Results: The most common gram-negative microorganism obtained from all cultures was E.coli with the lowest drug resistance to Nitrofurantoin. Conclusion: Based on the results, antimicrobial resistance pattern is not the same in different places and furthermore it is ever changing. Therefore, further research is needed to be done to have an accurate pattern of antibiotic resistance to provide effective treatment regimens. Key words: Antibiotic Resistance; Disk Diffusion; Gram Negative Bacteria; Gorgan

  11. A bacteria antibiotic system in space (23-F ANTIBIO)

    Science.gov (United States)

    Tixador, Rene; Gasset, G.; Eche, B.; Moatti, N.; Lapchine, L.; Woldringh, C.; Toorop, P.; Moatti, J. P.; Delmotte, F.; Tap, G.

    1995-01-01

    In order to evaluate the effects of weightlessness and cosmic radiations on the bacteria resistance to antibiotics, the Antibio 23F experiment was undertaken onboard Discovery during the 1st International Microgravity Laboratory (IML-1) mission. The effects of various antibiotic concentrations (dihydrostreptomycin) on Escherichia coli growth and cell division behavior were studied. The antibiotic binding was investigated using a radioactive tracer (tritium). The results showed that microgravity did not affect E. coli cells in regards the growth and the cell division. The antibiotic added to the culture medium induced an inhibition of the cultures both in the flight and ground controls. However, the antibiotic was less efficient in flight. The behavior of bacteria was modified, and the exponential growth rate was increased in flight. The incorporation of radioactive antibiotics in flight was comparatively different to ground incorporation, which indicated some perturbations in antibiotic binding. The experiments performed in the 1 g centrifuge did not show any difference in the cultures developed on the static rack, and could support a radiative effect of cosmic radiation to explain the results.

  12. Off-label abuse of antibiotics by bacteria.

    Science.gov (United States)

    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.

  13. ANTIBIOTIC EXTRACT OF STREPTOMYCETES IN PATHOGEN BACTERIA

    Directory of Open Access Journals (Sweden)

    F. Gavazaj

    2011-04-01

    Full Text Available Streptomycetes usually inhabit soil and are important decomposers. They also produce more than half of the world's antibiotics, and are consequently invaluable in the medical field. The isolation of Streptomycetes has done for testing the antibiotic effect. In this study are used two kinds of soil from the locality of village Zhur, South of Kosova. Five extracts have been isolated. From the obtained samples the substance has been extracted, and it was tested in order to define the scale of inhibition for the development of some microbial cultures. Escherichia coli, Staphylococcus aureus and Pseudomonas have been chosen as testing cultures. The extraction of substances with microbial properties has been done by means of Augustine et al’s method while the test of the obtained extract has been done according to the gel diffusion method. The inhibition zones have been established as well. Thus we may suppose that those results will encourage further researches in this field in the other localities of Kosova.

  14. Antibiotic-resistant bacteria: a challenge for the food industry.

    Science.gov (United States)

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

    Antibiotic-resistant bacteria were first described in the 1940s, but whereas new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. At present, the paucity of new antimicrobials coming into the market has led to the problem of antibiotic resistance fast escalating into a global health crisis. Although the selective pressure exerted by the use of antibiotics (particularly overuse or misuse) has been deemed the major factor in the emergence of bacterial resistance to these antimicrobials, concerns about the role of the food industry have been growing in recent years and have been raised at both national and international levels. The selective pressure exerted by the use of antibiotics (primary production) and biocides (e.g., disinfectants, food and feed preservatives, or decontaminants) is the main driving force behind the selection and spread of antimicrobial resistance throughout the food chain. Genetically modified (GM) crops with antibiotic resistance marker genes, microorganisms added intentionally to the food chain (probiotic or technological) with potentially transferable antimicrobial resistance genes, and food processing technologies used at sub-lethal doses (e.g., alternative non-thermal treatments) are also issues for concern. This paper presents the main trends in antibiotic resistance and antibiotic development in recent decades, as well as their economic and health consequences, current knowledge concerning the generation, dissemination, and mechanisms of antibacterial resistance, progress to date on the possible routes for emergence of resistance throughout the food chain and the role of foods as a vehicle for antibiotic-resistant bacteria. The main approaches to prevention and control of the development, selection, and spread of antibacterial resistance in the food industry are also addressed.

  15. ANTIBIOTIC RESISTANT BACTERIA FROM HALIOTIS TUBERCULATA AND MYTILUS GALLOPROVINCIALIS

    Directory of Open Access Journals (Sweden)

    F. Conte

    2009-12-01

    Full Text Available The antibiotic resistance (AR of Gram negative bacteria from Haliotis tuberculata (Ht and Mytilus galloprovincialis (Mg was assessed. Essential differences between R profiles of Pseudomonas spp and of other strains was not observed. Strains AR from Ht and Mg was similar.

  16. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    Science.gov (United States)

    Kathleen, M. M.; Felecia, C.; Reagan, E. L.; Kasing, A.; Lesley, M.; Toh, S. C.

    2016-01-01

    The administration of antimicrobials in aquaculture provides a selective pressure creating a reservoir of multiple resistant bacteria in the cultured fish and shrimps as well as the aquaculture environment. The objective of this study was to determine the extent of antibiotic resistance in aquaculture products and aquaculture's surrounding environment in Sarawak, Malaysian Borneo. Ninety-four identified bacterial isolates constituted of 17 genera were isolated from sediment, water, and cultured organisms (fish and shrimp) in selected aquaculture farms. These isolates were tested for their antibiotic resistance against 22 antibiotics from several groups using the disk diffusion method. The results show that the highest resistance was observed towards streptomycin (85%, n = 20), while the lowest resistance was towards gentamicin (1.1%, n = 90). The multiple antibiotic resistant (MAR) index of the isolates tested ranged between 0 and 0.63. It was suggested that isolates with MAR index > 0.2 were recovered from sources with high risk of antibiotic resistant contamination. This study revealed low level of antibiotic resistance in the aquaculture bacterial isolates except for streptomycin and ampicillin (>50% resistance, n = 94) which have been used in the aquaculture industry for several decades. Antibiotic resistant patterns should be continuously monitored to predict the emergence and widespread of MAR. Effective action is needed to keep the new resistance from further developing and spreading.

  17. Countermeasures to Antibiotics Crisis: a Global Priority List of Antibiotic-Resistant Bacteria for Research and Development of New Antibiotics

    Directory of Open Access Journals (Sweden)

    Editorial

    2017-03-01

    Full Text Available On 27 Feb., 2017, the World Health Organization (WHO announced the first list of important antibiotic-resistant bacteria (http://www.who.int/mediacentre/news/releases/2017/bacteria-antibiotics-needed/en/, which tremendously threat human-being’s health. This list included 12 kinds of bacteria that were categorized into three priority tiers: Critical, High and Medium. In the first tier, Critical, three Gram negative bacteria were included: Acinetobacter baumannii with carbapenem-resistant, Pseudomonas aeruginosa with carbapenem-resistant; and Enterobacteriaceae with carbapenem-resistant, the third generation cephalosporin-resistant. In the second tier, High, six bacteria were suggested: Enterococcus faecium with vancomycin-resistant, Staphylococcus aureus with methicillin-resistant, vancomycin intermediate and resistant, Helicobacter pylori with clarithromycin-resistant, Campylobacter with fluoroquinolone-resistant, Salmonella spp. with fluoroquinolone-resistant, Neisseria gonorrhoeae with the third generation cephalosporin-resistant, fluoroquinolone-resistant. In the third tier, Medium, three bacteria were listed: Streptococcus pneumonia with penicillin-non-susceptible, Haemophilus influenza with ampicillin-resistant, and Shigella spp. with fluoroquinolone-resistant. This list was proposed by an expert panel, chaired by Dr. E. Tacconelli from Infectious Diseases, DZIF Center, Tübingen University, Germany and Dr. N. Magrini from EMP Department of WHO. This proposal recommended some key steps to countermeasure the challenges posed by multi-drug- and extensively drug-resistant bacteria, including research and development of new classes of antibiotics for the paediatric population, for preventing cross- and co-resistance to existing classes of antibiotics, and for oral formulations for community-acquired diseases with a high morbidity burden. This list will guide our future research and development of new antibiotics in future.

  18. Synergistic interaction of eugenol with antibiotics against Gram negative bacteria.

    Science.gov (United States)

    Hemaiswarya, S; Doble, M

    2009-11-01

    Eugenol, the principal chemical component of clove oil from Eugenia aromatica has been long known for its analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. The interaction of the eugenol with ten different hydrophobic and hydrophilic antibiotics was studied against five different Gram negative bacteria. The MIC of the combination was found to decrease by a factor of 5-1000 with respect to their individual MIC. This synergy is because of the membrane damaging nature of eugenol, where 1mM of its concentration is able to damage nearly 50% of the bacterial membrane. Eugenol was also able to enhance the activities of lysozyme, Triton X-100 and SDS in damaging the bacterial cell membrane. The hydrophilic antibiotics such as vancomycin and beta-lactam antibiotics which have a marginal activity on these gram negative bacteria exhibit an enhanced antibacterial activity when pretreated with eugenol. Reduced usage of antibiotics could be employed as a treatment strategy to slow down the onset of antibiotic resistance as well as decrease its toxicity. Experiments performed with human blood cells indicated that the concentration of eugenol used for the combination studies were below its cytotoxic values. Pharmacodynamic studies of the combinations need to be performed to decide on the effective dosage.

  19. Nanoformulated antibiotics: the next step for pathogenic bacteria control.

    Science.gov (United States)

    Saúde, Amanda Caroline Marques; Cherobim, Mariana Dornelles; Amaral, André Corrêa; Dias, Simoní Campos; Franco, Octávio Luiz

    2013-01-01

    The resistance of infectious bacteria to current antibiotics is a worldwide problem. Previous studies have demonstrated the efficacy of nanostructured molecules against pathogens as an innovative methodology for the development of novel drugs. Currently, 95% of properties limited pharmacies applicability such as low solubility, short half-life in the circulatory system, toxicity associated to controlled release and immunogenicity. Furthermore, nanobiotechnology provides a different perspective for modifying these properties and allows innovative drug development. In this context, this review aims to describe different methods, polymers, and drugs used to obtain and analyze nanostructures associated with antibiotics as an unconventional and innovative tool for bacterial control. Biotechnology provides a different perspective for modifying drug properties and allows innovative drug development. This review describes nanostructures in association with antibiotics as an unconventional and innovative tool for bacterial control.

  20. Bacteriophages as potential treatment option for antibiotic resistant bacteria.

    Science.gov (United States)

    Bragg, Robert; van der Westhuizen, Wouter; Lee, Ji-Yun; Coetsee, Elke; Boucher, Charlotte

    2014-01-01

    The world is facing an ever-increasing problem with antibiotic resistant bacteria and we are rapidly heading for a post-antibiotic era. There is an urgent need to investigate alterative treatment options while there are still a few antibiotics left. Bacteriophages are viruses that specifically target bacteria. Before the development of antibiotics, some efforts were made to use bacteriophages as a treatment option, but most of this research stopped soon after the discovery of antibiotics. There are two different replication options which bacteriophages employ. These are the lytic and lysogenic life cycles. Both these life cycles have potential as treatment options. There are various advantages and disadvantages to the use of bacteriophages as treatment options. The main advantage is the specificity of bacteriophages and treatments can be designed to specifically target pathogenic bacteria while not negatively affecting the normal microbiota. There are various advantages to this. However, the high level of specificity also creates potential problems, the main being the requirement of highly specific diagnostic procedures. Another potential problem with phage therapy includes the development of immunity and limitations with the registration of phage therapy options. The latter is driving research toward the expression of phage genes which break the bacterial cell wall, which could then be used as a treatment option. Various aspects of phage therapy have been investigated in studies undertaken by our research group. We have investigated specificity of phages to various avian pathogenic E. coli isolates. Furthermore, the exciting NanoSAM technology has been employed to investigate bacteriophage replication and aspects of this will be discussed.

  1. Bacteria-mediated effects of antibiotics on Daphnia nutrition.

    Science.gov (United States)

    Gorokhova, Elena; Rivetti, Claudia; Furuhagen, Sara; Edlund, Anna; Ek, Karin; Breitholtz, Magnus

    2015-05-05

    In polluted environments, contaminant effects may be manifested via both direct toxicity to the host and changes in its microbiota, affecting bacteria-host interactions. In this context, particularly relevant is exposure to antibiotics released into environment. We examined effects of the antibiotic trimethoprim on microbiota of Daphnia magna and concomitant changes in the host feeding. In daphnids exposed to 0.25 mg L(-1) trimethoprim for 24 h, the microbiota was strongly affected, with (1) up to 21-fold decrease in 16S rRNA gene abundance and (2) a shift from balanced communities dominated by Curvibacter, Aquabacterium, and Limnohabitans in controls to significantly lower diversity under dominance of Pelomonas in the exposed animals. Moreover, decreased feeding and digestion was observed in the animals exposed to 0.25-2 mg L(-1) trimethoprim for 48 h and then fed 14C-labeled algae. Whereas the proportion of intact algal cells in the guts increased with increased trimethoprim concentration, ingestion and incorporation rates as well as digestion and incorporation efficiencies decreased significantly. Thus, antibiotics may impact nontarget species via changes in their microbiota leading to compromised nutrition and, ultimately, growth. These bacteria-mediated effects in nontarget organisms may not be unique for antibiotics, but also relevant for environmental pollutants of various nature.

  2. Endophytic bacteria as a source of novel antibiotics: An overview

    Directory of Open Access Journals (Sweden)

    Ambrose Christina

    2013-01-01

    Full Text Available World human population is increasing with an alarming rate; and a variety of new types of health issues are popping up. For instance, increase in number of drug-resistant bacteria is a cause of concern. Research on antibiotics and other microbial natural products is pivotal in the global fight against the growing problem of antibiotic resistance. It is necessary to find new antibiotics to tackle this problem. The use of therapeutic plant species in traditional medicine is as old as mankind; and currently, it is strongly believed that all types of plant species across the plant kingdom do harbour endophytic bacteria (EB. The natural therapeutic compounds produced by EB do have several potential applications in pharmaceutical industry. The EB derived natural products such as Ecomycins, Pseudomycins, Munumbicins and Xiamycins are antibacterial, antimycotic and antiplasmodial. Some of these natural products have been reported to possess even antiviral (including Human Immunodeficiency Virus (HIV properties. Therefore, to deal with increasing number of drug-resistant pathogens EB could serve as a potential source of novel antibiotics.

  3. RpoE is a Putative Antibiotic Resistance Regulator of Salmonella enteric Serovar Typhi.

    Science.gov (United States)

    Xie, Xiaofang; Zhang, Haifang; Zheng, Yi; Li, Aiqing; Wang, Min; Zhou, Huiqin; Zhu, Xueming; Schneider, Zachary; Chen, Liang; Kreiswirth, Barry N; Du, Hong

    2016-04-01

    Bacterial antimicrobial resistance has been associated with the up regulation of genes encoding efflux pumps and the down regulation of genes encoding outer membrane proteins (OMPs). Gene expression in bacteria is primarily initiated by sigma factors (σ factors) such as RpoE, which plays an important role in responding to many environmental stresses. Here, we report the first observation that RpoE serves as an antibiotic resistance regulator in Salmonella enteric serovar Typhi (S. Typhi). In this study, we found that the rpoE mutant (ΔrpoE) of S. Typhi GIFU10007 has elevated resistance to several antimicrobial agents, including β-lactams, quinolones, and aminoglycosides. Genomic DNA microarray analysis was used to investigate the differential gene expression profiles between a wild type and rpoE mutant in response to ampicillin. The results showed that a total of 57 genes displayed differential expression (two-fold increase or decrease) in ΔrpoE versus the wild-type strain. The expressions of two outer membrane protein genes, ompF and ompC, were significantly down-regulated in ΔrpoE (six and seven-fold lower in comparison to wild-type strain) and RamA, a member of the efflux pump AraC/XylS family, was up-regulated about four-fold in the ΔrpoE. Our results suggest RpoE is a potential antimicrobial regulator in S. Typhi, controlling both the down regulation of the OMP genes and up-regulating the efflux system.

  4. Density-dependent adaptive resistance allows swimming bacteria to colonize an antibiotic gradient.

    Science.gov (United States)

    Hol, Felix J H; Hubert, Bert; Dekker, Cees; Keymer, Juan E

    2016-01-01

    During antibiotic treatment, antibiotic concentration gradients develop. Little is know regarding the effects of antibiotic gradients on populations of nonresistant bacteria. Using a microfluidic device, we show that high-density motile Escherichia coli populations composed of nonresistant bacteria can, unexpectedly, colonize environments where a lethal concentration of the antibiotic kanamycin is present. Colonizing bacteria establish an adaptively resistant population, which remains viable for over 24 h while exposed to the antibiotic. Quantitative analysis of multiple colonization events shows that collectively swimming bacteria need to exceed a critical population density in order to successfully colonize the antibiotic landscape. After colonization, bacteria are not dormant but show both growth and swimming motility under antibiotic stress. Our results highlight the importance of motility and population density in facilitating adaptive resistance, and indicate that adaptive resistance may be a first step to the emergence of genetically encoded resistance in landscapes of antibiotic gradients.

  5. The analysis of bacteria strains and sensitivity of bacteria to antibiotics in acute obstructive cholangitis with suppuration

    Institute of Scientific and Technical Information of China (English)

    顾彬

    2013-01-01

    Objective To analyze the changes of bacteria stains in acute obstructive cholangitis with suppuration(AOSC) and sensitivity of different bacteria strains to antibiotics in recent decade. Methods The data of bacterial

  6. Antibiotic susceptibility of different lactic acid bacteria strains.

    Science.gov (United States)

    Karapetkov, N; Georgieva, R; Rumyan, N; Karaivanova, E

    2011-12-01

    Five lactic acid bacteria (LAB) strains belonging to species Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis and Streptococcus thermophilus were tested for their susceptibility to 27 antibiotics. The minimum inhibitory concentrations of each antimicrobial were determined using a microdilution test. Among the strains a high susceptibility was detected for most of the cell-wall synthesis inhibitors (penicillins, cefoxitin and vancomycin) and resistance toward inhibitors of DNA synthesis (trimethoprim/sulfonamides and fluoroquinolones). Generally, the Lactobacillus strains were inhibited by antibiotics such as chloramphenicol, erythromycin and tetracycline at breakpoint levels lower or equal to the levels defined by the European Food Safety Authority. Despite the very similar profile of S. thermophilus LC201 to lactobacilli, the detection of resistance toward erythromycin necessitates the performance of additional tests in order to prove the absence of transferable resistance genes.

  7. Alternatives to antibiotics to prevent necrotic enteritis in broiler chickens: a microbiologist's perspective

    OpenAIRE

    Caly, Delphine L.; D'Inca, Romain; Auclair, Eric; Drider, Djamel

    2015-01-01

    Since the 2006 European ban on the use of antibiotics as growth promoters in animal feed, numerous studies have been published describing alternative strategies to prevent diseases in animals. A particular focus has been on prevention of necrotic enteritis in poultry caused by Clostridium perfringens by the use of microbes or microbe-derived products. Microbes produce a plethora of molecules with antimicrobial properties and they can also have beneficial effects through interactions with thei...

  8. Enabling Passive Immunization as an Alternative to Antibiotics for Controlling Enteric Infections in Production Animals

    DEFF Research Database (Denmark)

    Heegaard, Peter M. H.; Hald, Birthe; Madsen, M.

    massive use of antibiotics in food animals. Thus there is a pressing need for economically feasible, efficient, non-antibiotics based means for controlling the problem. Passive immunization has been known for decades as an efficient way of endowing humans or animals with short-term (weeks) immunity....... To control enteric infections by passive immunization a bolus of immunoglobulin may simply be administered orally. For this to work, large amounts of active immunoglobulins are needed. To be a real alternative to antibiotics the price of the immunoglobulin product needs to be low. We combined an efficient...... administered bovine immunoglobulin is currently being tested in a calf herd with persistent diarrhea problems. Furthermore, it was shown in a Campylobacter challenge model in chickens that caecal and faecal counts of Campylobacter were between 0.5 and 1.0 logs lower in birds when given 200 mg avian...

  9. “Infectious Supercarelessness” in Discussing Antibiotic-Resistant Bacteria

    Science.gov (United States)

    Greenspan, Neil S.

    2017-01-01

    Many bacterial pathogens are exhibiting resistance to increasing numbers of antibiotics making it much more challenging to treat the infections caused by these microbes. In many reports in the media and perhaps even in discussions among physicians and biomedical scientists, these bacteria are frequently referred to as “bugs” with the prefix “super” appended. This terminology has a high potential to elicit unjustified inferences and fails to highlight the broader evolutionary context. Understanding the full range of biological and evolutionary factors that influence the spread and outcomes of infections is critical to formulating effective individual therapies and public health interventions. Therefore, more accurate terminology should be used to refer these multidrug-resistant bacteria. PMID:28174759

  10. Enteritis

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001149.htm Enteritis To use the sharing features on this page, please enable JavaScript. Enteritis is inflammation of the small intestine. Causes Enteritis ...

  11. Synergistic Antibacterial Effect between Silibinin and Antibiotics in Oral Bacteria

    Directory of Open Access Journals (Sweden)

    Young-Soo Lee

    2012-01-01

    Full Text Available Silibinin is a composition of the silymarin group as a hepatoprotective agent, and it exhibits various biological activities, including antibacterial activity. In this study, the antibacterial activities of silibinin were investigated in combination with two antimicrobial agents against oral bacteria. Silibinin was determined with MIC and MBC values ranging from 0.1 to 3.2 and 0.2 to 6.4 μg/mL, ampicillin from 0.125 to 64 and 0.5 to 64 μg/mL, gentamicin from 2 to 256 and 4 to 512 μg/mL, respectively. The ranges of MIC50 and MIC90 were 0.025–0.8 μg/mL and 0.1–3.2 μg/mL, respectively. The antibacterial activities of silibinin against oral bacteria were assessed using the checkerboard and time-kill methods to evaluate the synergistic effects of treatment with ampicillin or gentamicin. The results were evaluated showing that the combination effects of silibinin with antibiotics were synergistic (FIC index <0.5 against all tested oral bacteria. Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after 2–6 h of treatment with the MBC of silibinin, regardless of whether it was administered alone or with ampicillin or gentamicin. These results suggest that silibinin combined with other antibiotics may be microbiologically beneficial and not antagonistic.

  12. A bioinformatic approach to understanding antibiotic resistance in intracellular bacteria through whole genome analysis

    OpenAIRE

    Biswas, S.(National Institute of Science Education and Research, Bhubaneswar, India); Raoult, Didier; Rolain, J. M.

    2008-01-01

    Intracellular bacteria survive within eukaryotic host cells and are difficult to kill with certain antibiotics. As a result, antibiotic resistance in intracellular bacteria is becoming commonplace in healthcare institutions. Owing to the lack of methods available for transforming these bacteria, we evaluated the mechanisms of resistance using molecular methods and in silico genome analysis. The objective of this review was to understand the molecular mechanisms of antibiotic resistance throug...

  13. A review of the influence of treatment strategies on antibiotic resistant bacteria and antibiotic resistance genes.

    Science.gov (United States)

    Sharma, Virender K; Johnson, Natalie; Cizmas, Leslie; McDonald, Thomas J; Kim, Hyunook

    2016-05-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARG) in the aquatic environment have become an emerging contaminant issue, which has implications for human and ecological health. This review begins with an introduction to the occurrence of ARB and ARG in different environmental systems such as natural environments and drinking water resources. For example, ARG or ARB with resistance to ciprofloxacin, sulfamethoxazole, trimethoprim, quinolone, vancomycin, or tetracycline (e.g., tet(A), tet(B), tet(C), tet(G), tet(O), tet(M), tet(W), sul I, and sul II) have been detected in the environment. The development of resistance may be intrinsic, may be acquired through spontaneous mutations (de novo), or may occur due to horizontal gene transfer from donor bacteria, phages, or free DNA to recipient bacteria. An overview is also provided of the current knowledge regarding inactivation of ARB and ARG, and the mechanism of the effects of different disinfection processes in water and wastewater (chlorination, UV irradiation, Fenton reaction, ozonation, and photocatalytic oxidation). The effects of constructed wetlands and nanotechnology on ARB and ARG are also summarized.

  14. Adaptive resistance to antibiotics in bacteria: a systems biology perspective.

    Science.gov (United States)

    Sandoval-Motta, Santiago; Aldana, Maximino

    2016-05-01

    Despite all the major breakthroughs in antibiotic development and treatment procedures, there is still no long-term solution to the bacterial antibiotic resistance problem. Among all the known types of resistance, adaptive resistance (AdR) is particularly inconvenient. This phenotype is known to emerge as a consequence of concentration gradients, as well as contact with subinhibitory concentrations of antibiotics, both known to occur in human patients and livestock. Moreover, AdR has been repeatedly correlated with the appearance of multidrug resistance, although the biological processes behind its emergence and evolution are not well understood. Epigenetic inheritance, population structure and heterogeneity, high mutation rates, gene amplification, efflux pumps, and biofilm formation have all been reported as possible explanations for its development. Nonetheless, these concepts taken independently have not been sufficient to prevent AdR's fast emergence or to predict its low stability. New strains of resistant pathogens continue to appear, and none of the new approaches used to kill them (mixed antibiotics, sequential treatments, and efflux inhibitors) are completely efficient. With the advent of systems biology and its toolsets, integrative models that combine experimentally known features with computational simulations have significantly improved our understanding of the emergence and evolution of the adaptive-resistant phenotype. Apart from outlining these findings, we propose that one of the main cornerstones of AdR in bacteria, is the conjunction of two types of mechanisms: one rapidly responding to transient environmental challenges but not very efficient, and another much more effective and specific, but developing on longer time scales. WIREs Syst Biol Med 2016, 8:253-267. doi: 10.1002/wsbm.1335 For further resources related to this article, please visit the WIREs website.

  15. Relationship between antibiotic- and disinfectant-resistance profiles in bacteria harvested from tap water.

    Science.gov (United States)

    Khan, Sadia; Beattie, Tara K; Knapp, Charles W

    2016-06-01

    Chlorination is commonly used to control levels of bacteria in drinking water; however, viable bacteria may remain due to chlorine resistance. What is concerning is that surviving bacteria, due to co-selection factors, may also have increased resistance to common antibiotics. This would pose a public health risk as it could link resistant bacteria in the natural environment to human population. Here, we investigated the relationship between chlorine- and antibiotic-resistances by harvesting 148 surviving bacteria from chlorinated drinking-water systems and compared their susceptibilities against chlorine disinfectants and antibiotics. Twenty-two genera were isolated, including members of Paenibacillus, Burkholderia, Escherichia, Sphingomonas and Dermacoccus species. Weak (but significant) correlations were found between chlorine-tolerance and minimum inhibitory concentrations against the antibiotics tetracycline, sulfamethoxazole and amoxicillin, but not against ciprofloxacin; this suggest that chlorine-tolerant bacteria are more likely to also be antibiotic resistant. Further, antibiotic-resistant bacteria survived longer than antibiotic-sensitive organisms when exposed to free chlorine in a contact-time assay; however, there were little differences in susceptibility when exposed to monochloramine. Irrespective of antibiotic-resistance, spore-forming bacteria had higher tolerance against disinfection compounds. The presence of chlorine-resistant bacteria surviving in drinking-water systems may carry additional risk of antibiotic resistance.

  16. Antibiotic resistance of lactic acid bacteria isolated from Chinese yogurts.

    Science.gov (United States)

    Zhou, N; Zhang, J X; Fan, M T; Wang, J; Guo, G; Wei, X Y

    2012-09-01

    The aim of this study was to evaluate the susceptibility of 43 strains of lactic acid bacteria, isolated from Chinese yogurts made in different geographical areas, to 11 antibiotics (ampicillin, penicillin G, roxithromycin, chloramphenicol, tetracycline, chlortetracycline, lincomycin, kanamycin, streptomycin, neomycin, and gentamycin). The 43 isolates (18 Lactobacillus bulgaricus and 25 Streptococcus thermophilus) were identified at species level and were typed by random amplified polymorphic DNA analysis. Thirty-five genotypically different strains were detected and their antimicrobial resistance to 11 antibiotics was determined using the agar dilution method. Widespread resistance to ampicillin, chloramphenicol, chlortetracycline, tetracyclines, lincomycin, streptomycin, neomycin, and gentamycin was found among the 35 strains tested. All of the Strep. thermophilus strains tested were susceptible to penicillin G and roxithromycin, whereas 23.5 and 64.7% of Lb. bulgaricus strains, respectively, were resistant. All of the Strep. thermophilus and Lb. bulgaricus strains were found to be resistant to kanamycin. The presence of the corresponding resistance genes in the resistant isolates was investigated through PCR, with the following genes detected: tet(M) in 1 Lb. bulgaricus and 2 Strep. thermophilus isolates, ant(6) in 2 Lb. bulgaricus and 2 Strep. thermophilus isolates, and aph(3')-IIIa in 5 Lb. bulgaricus and 2 Strep. thermophilus isolates. The main threat associated with these bacteria is that they may transfer resistance genes to pathogenic bacteria, which has been a major cause of concern to human and animal health. To our knowledge, the aph(3')-IIIa and ant(6) genes were found in Lb. bulgaricus and Strep. thermophilus for the first time. Further investigations are required to analyze whether the genes identified in Lb. bulgaricus and Strep. thermophilus isolates might be horizontally transferred to other species.

  17. Distribution and quantification of antibiotic resistant genes and bacteria across agricultural and non-agricultural metagenomes.

    Science.gov (United States)

    Durso, Lisa M; Miller, Daniel N; Wienhold, Brian J

    2012-01-01

    There is concern that antibiotic resistance can potentially be transferred from animals to humans through the food chain. The relationship between specific antibiotic resistant bacteria and the genes they carry remains to be described. Few details are known about the ecology of antibiotic resistant genes and bacteria in food production systems, or how antibiotic resistance genes in food animals compare to antibiotic resistance genes in other ecosystems. Here we report the distribution of antibiotic resistant genes in publicly available agricultural and non-agricultural metagenomic samples and identify which bacteria are likely to be carrying those genes. Antibiotic resistance, as coded for in the genes used in this study, is a process that was associated with all natural, agricultural, and human-impacted ecosystems examined, with between 0.7 to 4.4% of all classified genes in each habitat coding for resistance to antibiotic and toxic compounds (RATC). Agricultural, human, and coastal-marine metagenomes have characteristic distributions of antibiotic resistance genes, and different bacteria that carry the genes. There is a larger percentage of the total genome associated with antibiotic resistance in gastrointestinal-associated and agricultural metagenomes compared to marine and Antarctic samples. Since antibiotic resistance genes are a natural part of both human-impacted and pristine habitats, presence of these resistance genes in any specific habitat is therefore not sufficient to indicate or determine impact of anthropogenic antibiotic use. We recommend that baseline studies and control samples be taken in order to determine natural background levels of antibiotic resistant bacteria and/or antibiotic resistance genes when investigating the impacts of veterinary use of antibiotics on human health. We raise questions regarding whether the underlying biology of each type of bacteria contributes to the likelihood of transfer via the food chain.

  18. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria

    Science.gov (United States)

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater- and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hotspot for pr...

  19. Secular Trends in Nosocomial Bloodstream Infections : Antibiotic-Resistant Bacteria Increase the Total Burden of Infection

    NARCIS (Netherlands)

    Ammerlaan, H. S. M.; Harbarth, S.; Buiting, A. G. M.; Crook, D. W.; Fitzpatrick, F.; Hanberger, H.; Herwaldt, L. A.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Kola, A.; Kuchenbecker, R. S.; Lingaas, E.; Meessen, N.; Morris-Downes, M. M.; Pottinger, J. M.; Rohner, P.; dos Santos, R. P.; Seifert, H.; Wisplinghoff, H.; Ziesing, S.; Walker, A. S.; Bonten, M. J. M.

    2013-01-01

    Background. It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. Methods. We investigated temporal trends in annual incidence densit

  20. [From the discovery of antibiotics to emerging highly drug-resistant bacteria].

    Science.gov (United States)

    Meunier, Olivier

    2015-01-01

    The discovery of antibiotics has enabled serious infections to be treated. However, bacteria resistant to several families of antibiotics and the emergence of new highly drug-resistant bacteria constitute a public health issue in France and across the world. Actions to prevent their transmission are being put in place.

  1. Multidrug efflux pumps in Gram-negative bacteria and their role in antibiotic resistance.

    Science.gov (United States)

    Blair, Jessica M A; Richmond, Grace E; Piddock, Laura J V

    2014-01-01

    Gram-negative bacteria express a plethora of efflux pumps that are capable of transporting structurally varied molecules, including antibiotics, out of the bacterial cell. This efflux lowers the intracellular antibiotic concentration, allowing bacteria to survive at higher antibiotic concentrations. Overexpression of some efflux pumps can cause clinically relevant levels of antibiotic resistance in Gram-negative pathogens. This review discusses the role of efflux in resistance of clinical isolates of Gram-negative bacteria, the regulatory mechanisms that control efflux pump expression, the recent advances in our understanding of efflux pump structure and how inhibition of efflux is a promising future strategy for tackling multidrug resistance in Gram-negative pathogens.

  2. Enteral but not parenteral antibiotics enhance gut function and prevent necrotizing enterocolitis in formula-fed newborn preterm pigs

    DEFF Research Database (Denmark)

    Birck, Malene M; Nguyen, Duc Ninh; Cilieborg, Malene S;

    2016-01-01

    Preterm infants are susceptible to infection and necrotizing enterocolitis (NEC) and are often treated with antibiotics. Simultaneous administration of enteral and parenteral antibiotics during the first days after preterm birth prevents formula-induced NEC lesions in pigs but it is unknown which...... administration route is most effective. We hypothesized that only enteral antibiotics suppress gut bacterial colonization and NEC progression in formula-fed preterm pigs. Caesarean-delivered preterm pigs (90-92% of gestation) were fed increasing amounts of infant formula from birth to day 5, and given saline...... (CON) or antibiotics (ampicillin, gentamicin and metronidazole) via the enteral (ENT) or parenteral (PAR) route (n=16-17). NEC lesions, intestinal morphology, function, microbiology and inflammatory mediators were evaluated. NEC lesions were completely prevented in ENT pigs, while there were high...

  3. Do antibiotic residues in soils play a role in amplification and transmission of antibiotic resistant bacteria in cattle populations?

    Directory of Open Access Journals (Sweden)

    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.

  4. Ultraviolet disinfection of antibiotic resistant bacteria and their antibiotic resistance genes in water and wastewater.

    Science.gov (United States)

    McKinney, Chad W; Pruden, Amy

    2012-12-18

    Disinfection of wastewater treatment plant effluent may be an important barrier for limiting the spread of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). While ideally disinfection should destroy ARGs, to prevent horizontal gene transfer to downstream bacteria, little is known about the effect of conventional water disinfection technologies on ARGs. This study examined the potential of UV disinfection to damage four ARGs, mec(A), van(A), tet(A), and amp(C), both in extracellular form and present within a host ARBs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Escherichia coli SMS-3-5, and Pseudomonas aeruginosa 01, respectively. An extended amplicon-length quantitative polymerase chain reaction assay was developed to enhance capture of ARG damage events and also to normalize to an equivalent length of target DNA (∼1000 bp) for comparison. It was found that the two Gram-positive ARBs (MRSA and VRE) were more resistant to UV disinfection than the two Gram-negative ARBs (E. coli and P. aeruginosa). The two Gram-positive organisms also possessed smaller total genome sizes, which could also have reduced their susceptibility to UV because of fewer potential pyrimidine dimer targets. An effect of cell type on damage to ARGs was only observed in VRE and P. aeruginosa, the latter potentially because of extracellular polymeric substances. In general, damage of ARGs required much greater UV doses (200-400 mJ/cm² for 3- to 4-log reduction) than ARB inactivation (10-20 mJ/cm² for 4- to 5-log reduction). The proportion of amplifiable ARGs following UV treatment exhibited a strong negative correlation with the number of adjacent thymines (Pearson r 0.85; p disinfection technologies should be explored.

  5. Emerging antibiotic resistance in bacteria with special reference to India.

    Science.gov (United States)

    Raghunath, D

    2008-11-01

    The antibiotic era started in the 1940s and changed the profile of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic stress has been realized. The paper presents these subjects briefly to afford an overview. The epidemiology of antibiotic resistance is dealt with and community practices in different countries are described. The role of high antibiotic usage environments is indicated. The implication of the wide use of antibiotics in animals has been pointed out. Steadily increasing antibiotic resistance and decreasing numbers of newer antibiotics appear to point to a post-antibiotic period during which treatment of infections would become increasingly difficult. This article attempts to review the global antimicrobial resistance scene and juxtaposes it to the Indian experience. The prevalence in India of antibiotic resistance among major groups of pathogens is described. The factors that determine the prevalent high antibiotic resistance rates have been highlighted. The future research activity to ensure continued utility of antibiotics in the control of infections has been indicated.

  6. Emerging antibiotic resistance in bacteria with special reference to India

    Indian Academy of Sciences (India)

    D Raghunath

    2008-11-01

    The antibiotic era started in the 1940s and changed the profile of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic stress has been realized. The paper presents these subjects briefly to afford an overview. The epidemiology of antibiotic resistance is dealt with and community practices in different countries are described. The role of high antibiotic usage environments is indicated. The implication of the wide use of antibiotics in animals has been pointed out. Steadily increasing antibiotic resistance and decreasing numbers of newer antibiotics appear to point to a post-antibiotic period during which treatment of infections would become increasingly difficult. This article attempts to review the global antimicrobial resistance scene and juxtaposes it to the Indian experience. The prevalence in India of antibiotic resistance among major groups of pathogens is described. The factors that determine the prevalent high antibiotic resistance rates have been highlighted. The future research activity to ensure continued utility of antibiotics in the control of infections has been indicated.

  7. Impact of preoperative screening for rectal colonization with fluoroquinolone-resistant enteric bacteria on the incidence of sepsis following transrectal ultrasound guided prostate biopsy

    Science.gov (United States)

    Farrell, John J; Hicks, Jennifer L; Wallace, Stephanie E; Seftel, Allen D

    2017-01-01

    With the universal adoption of antibiotic prophylaxis prior to prostate biopsy, the current risk of post-biopsy infection (including sepsis) is study of preoperative rectal cultures to screen for rectal colonization with fluoroquinolone-resistant bacteria using ciprofloxacin-supplemented MacConkey agar culture media. To evaluate the feasibility and practicality of this test, one provider used the results of rectal swab cultures collected during the preoperative outpatient evaluation to adjust each patient’s preoperative antibiotic prophylaxis when fluoroquinolone-resistant enteric bacteria were detected, whereas two other providers continued usual preoperative care and empiric antimicrobial prophylaxis. Rectal colonization with fluoroquinolone-resistant bacteria was detected in 19/152 (12.5%) of patients. In our intention-to-treat analysis (N=268), the rate of post-biopsy sepsis was 3.6% lower in the group that was screened for rectal colonization with fluoroquinolone-resistant bacteria prior to transrectal prostate biopsy. The observed risk reduction in the rectal screening group trended toward, but did not achieve, statistical significance. We suggest that preoperative screening for rectal colonization with fluoroquinolone-resistant enteric bacteria may be a useful step toward mitigating post-prostate biopsy sepsis. PMID:28280717

  8. Emerging antibiotic resistance in bacteria with special reference to India

    OpenAIRE

    Raghunath, D.

    2008-01-01

    The antibiotic era started in the 1940s and changed the profi le of infectious diseases and human demography. The burgeoning classes and numbers promised much and elimination of this major cause of human (and animal) morbidity appeared possible. Bacterial antibiotic resistance which was observed soon after antibiotic introduction has been studied extensively. Diverse mechanisms have been demonstrated and the genetic basis elucidated. The resilience of the prokaryote ecosystems to antibiotic s...

  9. Enteral vancomycin and probiotic use for methicillin-resistant Staphylococcus aureus antibiotic-associated diarrhoea.

    Science.gov (United States)

    Sizemore, Elizabeth Nicole; Rivas, Kenya Maria; Valdes, Jose; Caballero, Joshua

    2012-07-27

    A geriatric patient status post intraabdominal surgery presented with persistent diarrhoea and heavy intestinal methicillin-resistant Staphylococcus aureus (MRSA) growth after multiple courses of antibiotic therapy. Additionally, swab cultures of the anterior nares tested positive for MRSA. In order to impede infection and prevent future complications, the patient received a 10-day course of vancomycin oral solution 250 mg every 6 h, 15-day course of Saccharomyces boulardii 250 mg orally twice daily and a 5-day course of topical mupirocin 2% twice daily intranasally. Diarrhoea ceased during therapy and repeat cultures 11 days after initiating therapy demonstrated negative MRSA growth from the stool and nares. Further repeat cultures 5 months later revealed negative MRSA growth in the stools and minimal MRSA growth in the nares. Overall, enteral vancomycin and probiotics successfully eradicated MRSA infection without intestinal recurrence. Although the results were beneficial treating MRSA diarrhoea for our patient, these agents remain highly controversial.

  10. Selection of antibiotic-resistant standard plate count bacteria during water treatment.

    Science.gov (United States)

    Armstrong, J L; Calomiris, J J; Seidler, R J

    1982-08-01

    Standard plate count (SPC) bacteria were isolated from a drinking-water treatment facility and from the river supplying the facility. All isolates were identified and tested for their resistance to six antibiotics to determine if drug-resistant bacteria were selected for as a consequence of water treatment. Among the isolates surviving our test procedures, there was a significant selection (P less than 0.05) of gram-negative SPC organisms resistant to two or more of the test antibiotics. These bacteria were isolated from the flash mix tank, where chlorine, alum, and lime are added to the water. Streptomycin resistance in particular was more frequent in this population as compared with bacteria in the untreated river water (P less than 0.01). SPC bacteria from the clear well, which is a tank holding the finished drinking water at the treatment facility, were also more frequently antibiotic resistant than were the respective river water populations. When 15.8 and 18.2% of the river water bacteria were multiply antibiotic resistant, 57.1 and 43.5%, respectively, of the SPC bacteria in the clear well were multiply antibiotic resistant. Selection for bacteria exhibiting resistance to streptomycin was achieved by chlorinating river water in the laboratory. We concluded that the selective factors operating in the aquatic environment of a water treatment facility can act to increase the proportion of antibiotic-resistant members of the SPC bacterial population in treated drinking water.

  11. A mathematical model for expected time to extinction of pathogenic bacteria through antibiotic

    Science.gov (United States)

    Ghosh, M. K.; Nandi, S.; Roy, P. K.

    2016-04-01

    Application of antibiotics in human system to prevent bacterial diseases like Gastritis, Ulcers, Meningitis, Pneumonia and Gonorrhea are indispensable. Antibiotics saved innumerable lives and continue to be a strong support for therapeutic application against pathogenic bacteria. In human system, bacterial diseases occur when pathogenic bacteria gets into the body and begin to reproduce and crowd out healthy bacteria. In this process, immature bacteria releases enzyme which is essential for bacterial cell-wall biosynthesis. After complete formation of cell wall, immature bacteria are converted to mature or virulent bacteria which are harmful to us during bacterial infections. Use of antibiotics as drug inhibits the bacterial cell wall formation. After application of antibiotics within body, the released bacterial enzyme binds with antibiotic molecule instead of its functional site during the cell wall synthesis in a competitive inhibition approach. As a consequence, the bacterial cell-wall formation as well as maturation process of pathogenic bacteria is halted and the disease is cured with lysis of bacterial cells. With this idea, a mathematical model has been developed in the present research investigation to review the inhibition of biosynthesis of bacterial cell wall by the application of antibiotics as drug in the light of enzyme kinetics. This approach helps to estimate the expected time to extinction of the pathogenic bacteria. Our mathematical approach based on the enzyme kinetic model for finding out expected time to extinction contributes favorable results for understanding of disease dynamics. Analytical and numerical results based on simulated findings validate our mathematical model.

  12. Reduced ability to detect surface-related biofilm bacteria after antibiotic exposure under in vitro conditions

    DEFF Research Database (Denmark)

    Ravn, Christen; Furustrand Tafin, Ulrika; Bétrisey, Bertrand

    2016-01-01

    -dependent drugs (i.e. daptomycin and ciprofloxacin) had a strong suppressive effect on bacterial growth and reduced the ability to detect planktonic and biofilm bacteria. Exposure to rifampin rapidly caused emergence of resistance. Our findings indicate that preoperative administration of antibiotics may have......Background and purpose - Antibiotic treatment of patients before specimen collection reduces the ability to detect organisms by culture. We investigated the suppressive effect of antibiotics on the growth of non-adherent, planktonic, and surface-related biofilm bacteria in vitro by using sonication...... heterogeneous effects on the ability to detect biofilm bacteria....

  13. The impact of different antibiotic regimens on the emergence of antimicrobial-resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Erika M C D'Agata

    Full Text Available BACKGROUND: The emergence and ongoing spread of antimicrobial-resistant bacteria is a major public health threat. Infections caused by antimicrobial-resistant bacteria are associated with substantially higher rates of morbidity and mortality compared to infections caused by antimicrobial-susceptible bacteria. The emergence and spread of these bacteria is complex and requires incorporating numerous interrelated factors which clinical studies cannot adequately address. METHODS/PRINCIPAL FINDINGS: A model is created which incorporates several key factors contributing to the emergence and spread of resistant bacteria including the effects of the immune system, acquisition of resistance genes and antimicrobial exposure. The model identifies key strategies which would limit the emergence of antimicrobial-resistant bacterial strains. Specifically, the simulations show that early initiation of antimicrobial therapy and combination therapy with two antibiotics prevents the emergence of resistant bacteria, whereas shorter courses of therapy and sequential administration of antibiotics promote the emergence of resistant strains. CONCLUSIONS/SIGNIFICANCE: The principal findings suggest that (i shorter lengths of antibiotic therapy and early interruption of antibiotic therapy provide an advantage for the resistant strains, (ii combination therapy with two antibiotics prevents the emergence of resistance strains in contrast to sequential antibiotic therapy, and (iii early initiation of antibiotics is among the most important factors preventing the emergence of resistant strains. These findings provide new insights into strategies aimed at optimizing the administration of antimicrobials for the treatment of infections and the prevention of the emergence of antimicrobial resistance.

  14. Antibiotic-resistant fecal bacteria, antibiotics, and mercury in surface waters of Oakland County, Michigan, 2005-2006

    Science.gov (United States)

    Fogarty, Lisa R.; Duris, Joseph W.; Crowley, Suzanne L.; Hardigan, Nicole

    2007-01-01

    Water samples collected from 20 stream sites in Oakland and Macomb Counties, Mich., were analyzed to learn more about the occurrence of cephalosporin-resistant Escherichia coli (E. coli) and vancomycin-resistant enterococci (VRE) and the co-occurrence of antibiotics and mercury in area streams. Fecal indicator bacteria concentrations exceeded the Michigan recreational water-quality standard of 300 E. coli colony forming units (CFU) per 100 milliliters of water in 19 of 35 stream-water samples collected in Oakland County. A gene commonly associated with enterococci from humans was detected in samples from Paint Creek at Rochester and Evans Ditch at Southfield, indicating that human fecal waste is a possible source of fecal contamination at these sites. E. coli resistant to the cephalosporin antibiotics (cefoxitin and/ or ceftriaxone) were found at all sites on at least one occasion. The highest percentages of E. coli isolates resistant to cefoxitin and ceftriaxone were 71 percent (Clinton River at Auburn Hills) and 19 percent (Sashabaw Creek near Drayton Plains), respectively. Cephalosporin-resistant E. coli was detected more frequently in samples from intensively urbanized or industrialized areas than in samples from less urbanized areas. VRE were not detected in any sample collected in this study. Multiple antibiotics (azithromycin, erythromycin, ofloxacin, sulfamethoxazole, and trimethoprim) were detected in water samples from the Clinton River at Auburn Hills, and tylosin (an antibiotic used in veterinary medicine and livestock production that belongs to the macrolide group, along with erythromycin) was detected in one water sample from Paint Creek at Rochester. Concentrations of total mercury were as high as 19.8 nanograms per liter (Evans Ditch at Southfield). There was no relation among percentage of antibiotic-resistant bacteria and measured concentrations of antibiotics or mercury in the water. Genetic elements capable of exchanging multiple antibiotic

  15. Resistance to antibiotics in Lacid acid bacteria - strain Lactococcus

    Directory of Open Access Journals (Sweden)

    Filipić Brankica

    2015-01-01

    Full Text Available Lactic acid bacteria (LAB are widely used in the food industry, especially in the production of fermented dairy products and meat. The most studied species among Lis Lactococcus lactis. L. lactis strains are of great importance in the production of fermented dairy products such as yogurt, butter, fresh cheese and some kind of semi-hard cheese. Although L. lactis acquired the „Generally Regarded As Safe“ (GRAS status, many investigations indicated that lactococci may act as reservoirs of antibiotic resistance genes, which could be transferred to other bacterial species in human gastrointestinal tract includ­ing pathogens. The genome analysis of L. lactis indicated the presence of at least 40 putative drug transporter genes, and only four multidrug resistance (MDR transporters are functionally characterized: LmrA, LmrP, LmrCD i CmbT. LmrA is the first described MDR transporter in prokaryotes. LmrCD is responsible for resistance to cholate, which is an integral part of human bile and LmrCD is important for intestinal survival of lactococci that are used as probiotics. Secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines. CmbT protein has an effect on the host cell resistance to lincomycin, sulfadiazine, streptomycin, rifampicin, puromycin and sulfametox­azole. Since the food chain is an important way of transmitting resistance genes in human and animal population, it is of great importance to study the mechanisms of resistance in lactococci and other LAB, intended for the food industry. [Projekat Ministarstva nauke Republike Srbije, br. 173019: Izučavanje gena i molekularnih mehanizama u osnovi probiotičke aktivnosti bakterija mlečne kiseline izolovanih sa područja Zapadnog Balkana

  16. In vitro efficacy of bioactive extracts of 15 medicinal plants against ESbetaL-producing multidrug-resistant enteric bacteria.

    Science.gov (United States)

    Ahmad, Iqbal; Aqil, Farrukh

    2007-01-01

    Alcoholic crude extracts and some fractions from 15 traditionally used Indian medicinal plants were investigated for their ability to inhibit the growth of extended spectrum beta-lactamases (ESbetaL)-producing multidrug-resistant enteric bacteria. The test bacteria Eschrichia coli and Shigella were resistant to 16-23 antibiotics with intermediate or resistance to beta-lactams (minimum inhibitory concentration (MIC) value range 16-1024 microg/ml). The crude plant extracts demonstrated zone of inhibition in the range of 11-29 mm against one or more test bacteria. On the basis of promising activity, 12 plants were selected to determine their efficacy in terms of MIC, which ranged from 0.64 mg/ml to 10.24 mg/ml. The extracts of Acorus calamus, Hemidesmus indicus, Holarrhena antidysenterica and Plumbago zeylanica demonstrated relatively high activity as compared to other plant extracts and were fractionated into acetone, ethyl acetate and methanol. Acetone fraction in most of the cases exhibited higher potency (low MIC value) as compared to ethyl acetate and methanol fraction. However, in Plumbago zeylanica, ethyl acetate fraction was most active. Synergistic interactions among crude extracts were demonstrated in the 12 different combinations against ESbetaL-producing E. coli (ESbetaL-02). Certain combinations exhibited significant synergy with enlargement of combined inhibition zone size by 5 mm. Interaction of crude extracts with five antibiotics (Tetracycline, ciprofloxacin, nalidixic acid, chloramphenicol and streptomycin) demonstrated synergistic interaction with tetracycline and ciprofloxacin by 10 and 3 plant extracts respectively. Phytochemical analysis and thin layer chromatography (TLC) bioautography of crude extracts showed the presence of alkaloids, phenols and flavonoids as active phytoconstituents. Most active fractions of four plants were subjected to Infrared spectroscopy and the major groups of compounds were detected. The plant extracts were further

  17. Differential sensitivity of pigmented and non-pigmented marine bacteria to metals and antibiotics

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; Chandramohan, D.; LokaBharathi, P.A.

    and Hg were less toxic to pigmented bacteria than Cd. Pigmented strains were resistant to antibiotics, particularly at higher concentrations. All the strains, irrespective of their pigments, showed multiple metal and drug resistance...

  18. Surveillance of Antibiotic-Resistant Bacteria from Wastewater Effluents Across the United States

    Science.gov (United States)

    This presentation will inform the audience of the purpose and importance of the antibiotic resistant bacteria surveillances that have been conducted to date. And an overview of why the EPA is looking into this problem in wastewater effluents.

  19. Molecular Characterization of Intrinsic and Acquired antibiotic resistance in lactic Acid bacteria and Bifidobacteria

    NARCIS (Netherlands)

    Ammor, M.S.; Flórez, A.B.; Hoek, van A.H.A.M.; Reyes-Gavilan, de los C.G.; Aarts, H.J.M.; Margolles, A.; Mayo, B.

    2008-01-01

    The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species

  20. A mathematical model for antibiotic control of bacteria in peritoneal dialysis associated peritonitis.

    Science.gov (United States)

    Calmelet, Colette; Hotchkiss, John; Crooke, Philip

    2014-12-01

    A study of the process of pharmacokinetics-pharmacodynamics (PKPD) of antibiotics and their interaction with bacteria during peritoneal dialysis associated peritonitis (PDAP) is presented. We propose a mathematical model describing the evolution of bacteria population in the presence of antibiotics for different peritoneal dialysis regimens. Using the model along with experimental data, clinical parameters, and physiological values, we compute variations in PD fluid distributions, drug concentrations, and number of bacteria in peritoneal and extra-peritoneal cavities. Scheduling algorithms for the PD exchanges that minimize bacteria count are investigated.

  1. Screening of antibiotic resistance determinants in Gram-negative bacteria isolated from environmental reservoirs

    OpenAIRE

    Carvalho, Sofia Rêgo de, 1988-

    2011-01-01

    Tese de mestrado. Biologia (Microbiologia Aplicada). Universidade de Lisboa, Faculdade de Ciências, 2011 Antibiotics are one of the most successful forms of chemotherapy and saved million of lives placing most bacterial infectious diseases under control. However, this success has been compromised the continuous selective pressure exerted by antibiotics use has resulted in multi-resistance bacteria bearing resistance mechanisms to several antibiotics. Nowadays, there is an increased recogni...

  2. Irrigation waters and pipe-based biofilms as sources for antibiotic-resistant bacteria.

    Science.gov (United States)

    Blaustein, Ryan A; Shelton, Daniel R; Van Kessel, Jo Ann S; Karns, Jeffrey S; Stocker, Matthew D; Pachepsky, Yakov A

    2016-01-01

    The presence of antibiotic-resistant bacteria in environmental surface waters has gained recent attention. Wastewater and drinking water distribution systems are known to disseminate antibiotic-resistant bacteria, with the biofilms that form on the inner-surfaces of the pipeline as a hot spot for proliferation and gene exchange. Pipe-based irrigation systems that utilize surface waters may contribute to the dissemination of antibiotic-resistant bacteria in a similar manner. We conducted irrigation events at a perennial stream on a weekly basis for 1 month, and the concentrations of total heterotrophic bacteria, total coliforms, and fecal coliforms, as well as the concentrations of these bacterial groups that were resistant to ampicillin and tetracycline, were monitored at the intake water. Prior to each of the latter three events, residual pipe water was sampled and 6-in. sections of pipeline (coupons) were detached from the system, and biofilm from the inner-wall was removed and analyzed for total protein content and the above bacteria. Isolates of biofilm-associated bacteria were screened for resistance to a panel of seven antibiotics, representing five antibiotic classes. All of the monitored bacteria grew substantially in the residual water between irrigation events, and the biomass of the biofilm steadily increased from week to week. The percentages of biofilm-associated isolates that were resistant to antibiotics on the panel sometimes increased between events. Multiple-drug resistance was observed for all bacterial groups, most often for fecal coliforms, and the distributions of the numbers of antibiotics that the total coliforms and fecal coliforms were resistant to were subject to change from week to week. Results from this study highlight irrigation waters as a potential source for antibiotic-resistant bacteria, which can subsequently become incorporated into and proliferate within irrigation pipe-based biofilms.

  3. Diversity and natural functions of antibiotics produced by beneficial and plant pathogenic bacteria

    NARCIS (Netherlands)

    Raaijmakers, J.M.; Mazzola, M.

    2012-01-01

    Soil- and plant-associated environments harbor numerous bacteria that produce antibiotic metabolites with specific or broad-spectrum activities against coexisting microorganisms. The function and ecological importance of antibiotics have long been assumed to yield a survival advantage to the produci

  4. Recycling antibiotics into GUMBOS: A new combination strategy to combat multi-drug resistant bacteria

    Science.gov (United States)

    The emergence of multi-drug resistant bacteria, coupled with the lack of new antibiotics in development, is fast evolving into a global crisis. New strategies utilizing existing antibacterial agents are urgently needed. We propose one such strategy in which four outmoded ß-lactam antibiotics (amp...

  5. Diversity and natural functions of antibiotics produced by beneficial and plant pathogenic bacteria.

    Science.gov (United States)

    Raaijmakers, Jos M; Mazzola, Mark

    2012-01-01

    Soil- and plant-associated environments harbor numerous bacteria that produce antibiotic metabolites with specific or broad-spectrum activities against coexisting microorganisms. The function and ecological importance of antibiotics have long been assumed to yield a survival advantage to the producing bacteria in the highly competitive but resource-limited soil environments through direct suppression. Although specific antibiotics may enhance producer persistence when challenged by competitors or predators in soil habitats, at subinhibitory concentrations antibiotics exhibit a diversity of other roles in the life history of the producing bacteria. Many processes modulated by antibiotics may be inherently critical to the producing bacterium, such as the acquisition of substrates or initiation of developmental changes that will ensure survival under stressful conditions. Antibiotics may also have roles in more complex interactions, including in virulence on host plants or in shaping the outcomes of multitrophic interactions. The innate functions of antibiotics to producing bacteria in their native ecosystem are just beginning to emerge, but current knowledge already reveals a breadth of activities well beyond the historical perspective of antibiotics as weaponry in microbial conflicts.

  6. Growth of soil bacteria, on penicillin and neomycin, not previously exposed to these antibiotics.

    Science.gov (United States)

    Zhang, Qichun; Dick, Warren A

    2014-09-15

    There is growing evidence that bacteria, in the natural environment (e.g. the soil), can exhibit naturally occurring resistance/degradation against synthetic antibiotics. Our aim was to assess whether soils, not previously exposed to synthetic antibiotics, contained bacterial strains that were not only antibiotic resistant, but could actually utilize the antibiotics for energy and nutrients. We isolated 19 bacteria from four diverse soils that had the capability of growing on penicillin and neomycin as sole carbon sources up to concentrations of 1000 mg L(-1). The 19 bacterial isolates represent a diverse set of species in the phyla Proteobacteria (84%) and Bacteroidetes (16%). Nine antibiotic resistant genes were detected in the four soils but some of these genes (i.e. tetM, ermB, and sulI) were not detected in the soil isolates indicating the presence of unculturable antibiotic resistant bacteria. Most isolates that could subsist on penicillin or neomycin as sole carbon sources were also resistant to the presence of these two antibiotics and six other antibiotics at concentrations of either 20 or 1000 mg L(-1). The potentially large and diverse pool of antibiotic resistant and degradation genes implies ecological and health impacts yet to be explored and fully understood.

  7. Enteral but not parenteral antibiotics enhance gut function and prevent necrotizing enterocolitis in formula-fed newborn preterm pigs.

    Science.gov (United States)

    Birck, Malene M; Nguyen, Duc Ninh; Cilieborg, Malene S; Kamal, Shamrulazhar S; Nielsen, Dennis S; Damborg, Peter; Olsen, John E; Lauridsen, Charlotte; Sangild, Per T; Thymann, Thomas

    2016-03-01

    Preterm infants are susceptible to infection and necrotizing enterocolitis (NEC) and are often treated with antibiotics. Simultaneous administration of enteral and parenteral antibiotics during the first days after preterm birth prevents formula-induced NEC lesions in pigs, but it is unknown which administration route is most effective. We hypothesized that only enteral antibiotics suppress gut bacterial colonization and NEC progression in formula-fed preterm pigs. Caesarean-delivered preterm pigs (90-92% of gestation) were fed increasing amounts of infant formula from birth to day 5 and given saline (CON) or antibiotics (ampicillin, gentamicin, and metronidazole) via the enteral (ENT) or parenteral (PAR) route (n = 16-17). NEC lesions, intestinal morphology, function, microbiology, and inflammatory mediators were evaluated. NEC lesions were completely prevented in ENT pigs, whereas there were high incidences of mild NEC lesions (59-63%) in CON and PAR pigs (P antibiotics reduces gut bacterial colonization, inflammation, and NEC lesions in newborn, formula-fed preterm pigs. Delayed colonization may support intestinal structure, function, and immunity in the immediate postnatal period of formula-fed preterm neonates.

  8. Molecular tools for the characterisation of antibiotic-resistant bacteria

    NARCIS (Netherlands)

    Aarts, H.J.M.; Boumedine, K.S.; Nesme, X.; Cloeckaert, A.

    2001-01-01

    This review will discuss a number of molecular tools which are currently used as well as some innovative approaches for the characterisation of antibiotic-resistant bacterial strains. Various methods involved in the detection and characterisation of genes and mutations associated with antibiotic res

  9. Health risks associated with the presence of antibiotic resistant bacteria in greywater

    Directory of Open Access Journals (Sweden)

    Juan Moretton

    2012-04-01

    Full Text Available The removal and disposal of waste from domestic activities is a major health problem in densely populated urban areas. In many areas of Greater Buenos Aires, greywater is disposed in open ditches and risk potential of this has not been adequately quantified. The aim of this study was to evaluate the prevalence of antibiotic-resistant bacteria and its resistance profile present in raw greywater obtained from a channel located in the area of Ingeniero Budge Buenos Aires Province. Thus, the prevalence of heterotrophic bacteria, Gram-negative bacteria resistant to beta-lactam antibiotics and vancomycin-resistant enterococci in greywater, their typing, and resistance to other antibiotics were determined. The prevalence of resistant bacteria was determined by the agar dilution method. Of all the antibiotics tested, the highest prevalence of resistant heterotrophic bacteria was detected with cephalothin (19% and ampicillin (8%. With regard to Gram-negative bacteria, the highest prevalence of resistance was given by coliforms ampicillin (34% and cephalothin (17%. A total of 38% of enterococci with low level resistance to vancomycin was detected. The multiresistant isolates were identified as Escherichia coli, Alcaligenes faecalis y Stenotrophomonas maltophilia. These results indicate that greywater can be considered as a reservoir of bacteria resistant to antibiotics, thus increasing their health risk.

  10. [Nonfermentative gram-negative bacteria: isolation rates and antibiotic sensitivity].

    Science.gov (United States)

    Bogomolova, N S; Bol'shakov, L V; Kuznetsova, S M; Oreshkina, T D

    2010-01-01

    The isolation rates of nonfermentative gram-negative bacteria (NFGNB) are analyzed in the inpatients treated at the B. V. Petrovsky Russian Surgery Research Center in 2005-2009 and antibiotic resistance trends in nosocomial strains of NFGNB are traced in the above period. The study of the etiological structure of nosocomial infections has shown that the past 2 years (2008 and 2009) were marked by a clear tendency for the preponderance of gram-positive coccal pathogens (46.8 and 53.9%) with a considerable (1.5-2-fold) reduction in the proportion of representatives of enterobacteria (31.5 and 24.5%) and NFGB (13.4 and 11.3%), but with an increase in the proportion of fungi up to 7.1 and 8.6%, respectively. Among the NFGNBs, P. aeruginosa remains ohe of the most common pathogens for nosocomial infections although its portion in the number of all etiologically significant microorganisms was substantially reduced (from 13% in 2005 to 4.6% in 2009). It continues to remain one of the most common causative agents for infections of the urinary tract (e.g., after renal transplantation) and upper and lower respiratory tract (e.g. nosocomial pneumonia) and for those developing after surgical interventions (postoperative wound suppuration discharged along the drainages, from a T-sized tube, etc.). Among the NFGNBs, Acinetobacter spp. was the second frequently isolated pathogen, the isolation rate for which also decreased from 7.9% in 2005 to 2.6% in 2009. Polymyxin B and carbapenems (imipenem, meropenem, and doripenem) showed the highest activity against the vast majority of the test strains; however, there was an absolutely clear declining trend in the proportion of carbapenem-sensitive strains among virtually all the NFGNBs under study. According to the proportion of imipenem-, meropenem-, and doripenem-sensitive nosocomial P. aeroginosa strains (66.7, 46.6, and 44.7%, respectively), doripenem had the least activity. Acinetobacter spp. strains sensitive to these drugs showed

  11. Photodynamic inactivation of antibiotic-resistant bacteria and biofilms by hematoporphyrin monomethyl ether.

    Science.gov (United States)

    Liu, Chengcheng; Hu, Min; Ma, Dandan; Lei, Jin'e; Xu, Jiru

    2016-02-01

    The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. A promising approach to killing antibiotic-resistant bacteria is photodynamic antimicrobial chemotherapy, which uses light in combination with a photosensitizer to induce a phototoxic reaction. We evaluated the photodynamic inactivation (PDI) efficiency of hematoporphyrin monomethyl ether (HMME) on antibiotic-resistant bacteria and biofilms. HMME exhibited no significant dark toxicity and provided dose-dependent inactivation of antibiotic-resistant bacteria and biofilms. After incubation with 100-μM HMME and irradiation with 72-J cm(-2) white light, 4.19-7.59 log10 reductions in survival were achieved in planktonic suspension. Antibiotic-resistant strains were as susceptible to PDI in biofilms as in planktonic suspensions, but the inactivation of bacterial cells in biofilms was attenuated. In addition, gram-positive bacterial strains and biofilms were more susceptible than gram-negative strains and biofilms to the PDI effect of HMME. Thus, HMME is a promising photosensitizer for the treatment of infectious diseases caused by antibiotic-resistant bacteria, especially gram-positive bacteria.

  12. Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.

    Directory of Open Access Journals (Sweden)

    Patrick Kaiser

    2014-02-01

    Full Text Available In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN, the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.

  13. Mobile antibiotic resistance - the spread of genes determining the resistance of bacteria through food products.

    Science.gov (United States)

    Godziszewska, Jolanta; Guzek, Dominika; Głąbski, Krzysztof; Wierzbicka, Agnieszka

    2016-07-07

    In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance.

  14. Antibiotic susceptibilities of bacteria isolated within the oral flora of Florida blacktip sharks: guidance for empiric antibiotic therapy.

    Science.gov (United States)

    Unger, Nathan R; Ritter, Erich; Borrego, Robert; Goodman, Jay; Osiyemi, Olayemi O

    2014-01-01

    Sharks possess a variety of pathogenic bacteria in their oral cavity that may potentially be transferred into humans during a bite. The aim of the presented study focused on the identification of the bacteria present in the mouths of live blacktip sharks, Carcharhinus limbatus, and the extent that these bacteria possess multi-drug resistance. Swabs were taken from the oral cavity of nineteen live blacktip sharks, which were subsequently released. The average fork length was 146 cm (±11), suggesting the blacktip sharks were mature adults at least 8 years old. All swabs underwent standard microbiological work-up with identification of organisms and reporting of antibiotic susceptibilities using an automated microbiology system. The oral samples revealed an average of 2.72 (±1.4) bacterial isolates per shark. Gram-negative bacteria, making up 61% of all bacterial isolates, were significantly (pshark gender or fork length with bacterial density or antibiotic resistance was observed. Antibiotics with the highest overall susceptibility rates included fluoroquinolones, 3rd generation cephalosporins and sulfamethoxazole/trimethoprim. Recommended empiric antimicrobial therapy for adult blacktip shark bites should encompass either a fluoroquinolone or combination of a 3rd generation cephalosporin plus doxycycline.

  15. Possible impact of treated wastewater discharge on incidence of antibiotic resistant bacteria in river water.

    Science.gov (United States)

    Iwane, T; Urase, T; Yamamoto, K

    2001-01-01

    Escherichia coli and coliform group bacteria resistant to seven antibiotics were investigated in the Tama River, a typical urbanized river in Tokyo, Japan, and at a wastewater treatment plant located on the river. The percentages of antibiotic resistance in the wastewater effluent were, in most cases, higher than the percentages in the river water, which were observed increasing downstream. Since the possible increase in the percentages in the river was associated with treated wastewater discharges, it was concluded that the river, which is contaminated by treated wastewater with many kinds of pollutants, is also contaminated with antibiotic resistant coliform group bacteria and E. coli. The percentages of resistant bacteria in the wastewater treatment plant were mostly observed decreasing during the treatment process. It was also demonstrated that the percentages of resistance in raw sewage are significantly higher than those in the river water and that the wastewater treatment process investigated in this study works against most of resistant bacteria in sewage.

  16. Antibiotic Resistance of Gram Negative Bacteria Isolated From Urine Cultures in Our Laboratory

    Directory of Open Access Journals (Sweden)

    Hakan Temiz

    2008-12-01

    Full Text Available In this study; we analyzed the antimicrobial susceptibility of Gram negative bacteria isolated from urine cultures in the Microbiology Laboratory of Dicle University Medical Faculty Hospital from January 2006 to December 2006; retrospectively. Escherichia coli and Klebsiella species were the most frequently isolated bacteria from both outpatients and hospitalized patients. The most effective antibiotics to these bacteria were carbapenems. These results were suggested to be useful for empirical treatment of urinary system infections in our hospital.

  17. Effects of temperature and antibiotics on persistence of antibiotic-resistant bacteria and antibiotic resistance genes in poultry litter

    Science.gov (United States)

    The effect of low, residual concentrations of antibiotics in manure and other environmental matrices is not well understood. It has been hypothesized that antibiotic concentrations below clinical MIC (minimal inhibitory concentrations) are still capable of selecting for resistance. The objective of ...

  18. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge.

    Science.gov (United States)

    Harlow, Brittany E; Lawrence, Laurie M; Flythe, Michael D

    2013-09-27

    Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects of common antibiotics on cellulolytic bacteria, lactobacilli, and AAD-associated pathogens in the feces of healthy horses. Fifteen horses were assigned to three treatment groups (blocked by age and sex): control (no antibiotics), trimethoprim-sulfadiazine (PO), or ceftiofur (IM). Fecal samples (n=8 per horse) were taken during dietary adaptation (3 weeks), antibiotic challenge (1 week), and withdrawal (1 week). Bacteria were enumerated by serial dilution and viable count. Cellulolytic bacteria decreased by >99% during administration of either antibiotic (Pantibiotic challenge period (PAntibiotic challenged horses also shed more salmonella than control horses (PAntibiotics had no effect on the number of Clostridium perfringens isolates. There was no detectable Clostridium difficile during adaptation or in any control horse. C. difficile increased (Pantibiotics, and were still detectable 1 week after withdrawal. These results indicate that antibiotics can disrupt the normal gastrointestinal microbiota and allow proliferation of Salmonella spp. and C. difficile.

  19. Recent investigations and updated criteria for the assessment of antibiotic resistance in food lactic acid bacteria.

    Science.gov (United States)

    Clementi, Francesca; Aquilanti, Lucia

    2011-12-01

    The worldwide use, and misuse, of antibiotics for about sixty years in the so-called antibiotic era, has been estimated in some one to ten million tons, a relevant part of which destined for non-therapeutic purposes such as growth promoting treatments for livestock or crop protection. As highly adaptable organisms, bacteria have reacted to this dramatic change in their environment by developing several well-known mechanisms of antibiotic resistance and are becoming increasingly resistant to conventional antibiotics. In recent years, commensal bacteria have become a cause of concern since they may act as reservoirs for the antibiotic resistance genes found in human pathogens. In particular, the food chain has been considered the main route for the introduction of animal and environment associated antibiotic resistant bacteria into the human gastrointestinal tract (GIT) where these genes may be transferred to pathogenic and opportunistic bacteria. As fundamental microbial communities in a large variety of fermented foods and feed, the anaerobe facultative, aerotolerant lactic acid bacteria (LAB) are likely to play a pivotal role in the resistance gene exchange occurring in the environment, food, feed and animal and human GIT. Therefore their antibiotic resistance features and their genetic basis have recently received increasing attention. The present article summarises the results of the latest studies on the most typical genera belonging to the low G + C branch of LAB. The evolution of the criteria established by European regulatory bodies to ensure a safe use of microorganisms in food and feed, including the assessment of their antibiotic resistance is also reviewed.

  20. An Antibiotic Selection System For Protein Overproducing Bacteria

    DEFF Research Database (Denmark)

    Rennig, Maja; Nørholm, Morten

    2015-01-01

    Introduction: Protein overproduction is a major bottleneck for analyses of membrane proteins and for the construction of cell factories. Screening for optimized protein production can be very time consuming. In this study we show that the coupling of antibiotic resistance to poorly produced...... that translationally couples the genes. Consequently, high expressing gene variants also allow for higher production of the coupled antibiotic resistance marker. Therefore, high expressing gene variants in a library can be determined either by plating the expression library on selection plates or by growing...... the library in a liquid culture, while both contain high concentrations of the inducible antibiotic.Results: We designed libraries for membrane proteins of E. coli, based on a recently published technique that promises enhanced protein production by optimizing the nucleotides between the Shine Dalgarno...

  1. Antibiotic Resistant Bacteria--What Everyone Needs To Know.

    Science.gov (United States)

    Pascoe, Neil; Felkner, Marilyn; Maldonado, Maria

    2003-01-01

    Notes the overuse of antibiotics and the resulting resistant bacterial strains. Describes how to control and prevent staphylococcal infections specifically, and almost all infectious diseases generally. Specific sections address: (1) what are staph infections; (2) preventing staph infections; (3) caring for wounds; and (4) controlling staph…

  2. The production and detoxification of a potent cytotoxin, nitric oxide, by pathogenic enteric bacteria.

    Science.gov (United States)

    Arkenberg, Anke; Runkel, Sebastian; Richardson, David J; Rowley, Gary

    2011-12-01

    The nitrogen cycle is based on several redox reactions that are mainly accomplished by prokaryotic organisms, some archaea and a few eukaryotes, which use these reactions for assimilatory, dissimilatory or respiratory purposes. One group is the Enterobacteriaceae family of Gammaproteobacteria, which have their natural habitats in soil, marine environments or the intestines of humans and other warm-blooded animals. Some of the genera are pathogenic and usually associated with intestinal infections. Our body possesses several physical and chemical defence mechanisms to prevent pathogenic enteric bacteria from invading the gastrointestinal tract. One response of the innate immune system is to activate macrophages, which produce the potent cytotoxin nitric oxide (NO). However, some pathogens have evolved the ability to detoxify NO to less toxic compounds, such as the neuropharmacological agent and greenhouse gas nitrous oxide (N₂O), which enables them to overcome the host's attack. The same mechanisms may be used by bacteria producing NO endogenously as a by-product of anaerobic nitrate respiration. In the present review, we provide a brief introduction into the NO detoxification mechanisms of two members of the Enterobacteriaceae family: Escherichia coli and Salmonella enterica serovar Typhimurium. These are discussed as comparative non-pathogenic and pathogenic model systems in order to investigate the importance of detoxifying NO and producing N₂O for the pathogenicity of enteric bacteria.

  3. Reduced ability to detect surface-related biofilm bacteria after antibiotic exposure under in vitro conditions

    DEFF Research Database (Denmark)

    Ravn, Christen; Furustrand Tafin, Ulrika; Bétrisey, Bertrand;

    2016-01-01

    Background and purpose - Antibiotic treatment of patients before specimen collection reduces the ability to detect organisms by culture. We investigated the suppressive effect of antibiotics on the growth of non-adherent, planktonic, and surface-related biofilm bacteria in vitro by using sonication......-dependent drugs (i.e. daptomycin and ciprofloxacin) had a strong suppressive effect on bacterial growth and reduced the ability to detect planktonic and biofilm bacteria. Exposure to rifampin rapidly caused emergence of resistance. Our findings indicate that preoperative administration of antibiotics may have...... and microcalorimetry methods. Patients and methods - Biofilms of Staphylococcus aureus, S. epidermidis, Escherichia coli, and Propionibacterium acnes were formed on porous glass beads and exposed for 24 h to antibiotic concentrations from 1 to 1,024 times the minimal inhibitory concentration (MIC) of vancomycin...

  4. Antimicrobial metallopolymers and their bioconjugates with conventional antibiotics against multidrug-resistant bacteria.

    Science.gov (United States)

    Zhang, Jiuyang; Chen, Yung Pin; Miller, Kristen P; Ganewatta, Mitra S; Bam, Marpe; Yan, Yi; Nagarkatti, Mitzi; Decho, Alan W; Tang, Chuanbing

    2014-04-02

    Bacteria are now becoming more resistant to most conventional antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), a complex of multidrug-resistant Gram-positive bacterial strains, has proven especially problematic in both hospital and community settings by deactivating conventional β-lactam antibiotics, including penicillins, cephalosporins, and carbapenems, through various mechanisms, resulting in increased mortality rates and hospitalization costs. Here we introduce a class of charged metallopolymers that exhibit synergistic effects against MRSA by efficiently inhibiting activity of β-lactamase and effectively lysing bacterial cells. Various conventional β-lactam antibiotics, including penicillin-G, amoxicillin, ampicillin, and cefazolin, are protected from β-lactamase hydrolysis via the formation of unique ion-pairs between their carboxylate anions and cationic cobaltocenium moieties. These discoveries could provide a new pathway for designing macromolecular scaffolds to regenerate vitality of conventional antibiotics to kill multidrug-resistant bacteria and superbugs.

  5. THAWING PROCEDURES FOR HOSPITAL-MADE ENTERAL FEEDINGS: SURVIVAL OF COLIFORM AND MESOPHILIC AEROBIC BACTERIA

    Directory of Open Access Journals (Sweden)

    KATHIA ROSSI ROLIM LOPES

    2009-07-01

    Full Text Available

    ABSTRACT: This study had the purpose to observe the effect of thawing procedures on survival of coliform and mesophilic aerobic bacteria in hospital-made enteral feedings. The samples are represented by three different lots. The tests were realized in three moments: immediately after the sample preparation and after freezing during 1 or 2 months. The thawing procedures were denominated convencional and alternative. The first, used by hospital, utilizes water bath at 50ºC, considering the time spent from the total thawing to its distribution in the infirmaries. The second was the fast thawing made by microwaving. The results showed that the reduction of the mesophiles and coliform was related to the time the samples were frozen. The results obtained indicate an advantage of the alternative method, which presented lower total and fecal coliform counts than the conventional one. KEYWORDS: Enteral feedings; thawing; food microbiology.

  6. Tracking acquired antibiotic resistance in commensal bacteria of Galapagos land iguanas: no man, no resistance.

    Directory of Open Access Journals (Sweden)

    Maria Cristina Thaller

    Full Text Available BACKGROUND: Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. METHODOLOGY/PRINCIPAL FINDINGS: Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i the abiotic conditions ensure to microbes good survival possibilities in the environment; ii the animal density and their habits favour microbial circulation between individuals; and iii there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. CONCLUSIONS/SIGNIFICANCE: Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.

  7. The culturable soil antibiotic resistome: a community of multi-drug resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Fiona Walsh

    Full Text Available Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes. We have identified and characterized multi-drug resistance (MDR mechanisms in the culturable soil antibiotic resistome and linked the resistance profiles to bacterial species. We isolated 412 antibiotic resistant bacteria from agricultural, urban and pristine soils. All isolates were multi-drug resistant, of which greater than 80% were resistant to 16-23 antibiotics, comprising almost all classes of antibiotic. The mobile resistance genes investigated, (ESBL, bla NDM-1, and plasmid mediated quinolone resistance (PMQR resistance genes were not responsible for the respective resistance phenotypes nor were they present in the extracted soil DNA. Efflux was demonstrated to play an important role in MDR and many resistance phenotypes. Clinically relevant Burkholderia species are intrinsically resistant to ciprofloxacin but the soil Burkholderia species were not intrinsically resistant to ciprofloxacin. Using a phenotypic enzyme assay we identified the antibiotic specific inactivation of trimethoprim in 21 bacteria from different soils. The results of this study identified the importance of the efflux mechanism in the soil resistome and variations between the intrinsic resistance profiles of clinical and soil bacteria of the same family.

  8. Co-occurrence of resistance to different antibiotics among aquatic bacteria

    Directory of Open Access Journals (Sweden)

    Voolaid Veiko

    2012-10-01

    Full Text Available Abstract Background Antibiotic resistance is not confined to pathogens, but is also widespread in various natural environments. In nature the microbes producing antibiotic compounds have been around for millions of years. Heavy use of antibiotics in medicine and veterinary practice may lead to the accumulation of resistance genes in microbial populations, followed by a rise in multiresistant bacteria. Results To test the extent of resistance among aquatic bacteria, we have collected 760 isolates resistant to at least one antibiotic. The phylogeny of the isolates covers a wide range of Proteobacteria, Actinobacteria and Bacteroidetes. In order to determine the extent of multiresistance, the isolates were tested on six antibiotics. As the growth rate of the different bacteria was highly variable, the classical medical resistance tests could not be used, and an alternative method considering the full growth curve was developed. In general, the overall resistances to different antibiotics could be explained by random, independent distribution. An exception to this was the resistances against tetracycline and chloramphenicol, which tended to occur in pairs. Conclusions We conclude that there is no massive spread of multiresistance determinants in the studied environment, although some specific cases can be found, awaiting for molecular characterization of the resistance mechanisms.

  9. Functional characterization of bacteria isolated from ancient arctic soil exposes diverse resistance mechanisms to modern antibiotics.

    Science.gov (United States)

    Perron, Gabriel G; Whyte, Lyle; Turnbaugh, Peter J; Goordial, Jacqueline; Hanage, William P; Dantas, Gautam; Desai, Michael M

    2015-01-01

    Using functional metagenomics to study the resistomes of bacterial communities isolated from different layers of the Canadian high Arctic permafrost, we show that microbial communities harbored diverse resistance mechanisms at least 5,000 years ago. Among bacteria sampled from the ancient layers of a permafrost core, we isolated eight genes conferring clinical levels of resistance against aminoglycoside, β-lactam and tetracycline antibiotics that are naturally produced by microorganisms. Among these resistance genes, four also conferred resistance against amikacin, a modern semi-synthetic antibiotic that does not naturally occur in microorganisms. In bacteria sampled from the overlaying active layer, we isolated ten different genes conferring resistance to all six antibiotics tested in this study, including aminoglycoside, β-lactam and tetracycline variants that are naturally produced by microorganisms as well as semi-synthetic variants produced in the laboratory. On average, we found that resistance genes found in permafrost bacteria conferred lower levels of resistance against clinically relevant antibiotics than resistance genes sampled from the active layer. Our results demonstrate that antibiotic resistance genes were functionally diverse prior to the anthropogenic use of antibiotics, contributing to the evolution of natural reservoirs of resistance genes.

  10. Coordinated Slowing of Metabolism in Enteric Bacteria under Nitrogen Limitation A Perspective

    CERN Document Server

    Wingreen, N S; Wingreen, Ned S.; Kustu, Sydney

    2001-01-01

    It is natural to ask how bacteria coordinate metabolism when depletion of an essential nutrient limits their growth, and they must slow their entire rate of biosynthesis. A major nutrient with a fluctuating abundance is nitrogen. The growth rate of enteric bacteria under nitrogen-limiting conditions is known to correlate with the internal concentration of free glutamine, the glutamine pool. Here we compare the patterns of utilization of L-glutamine and L-glutamate, the two central intermediates of nitrogen metabolism. Monomeric precursors of all of the cell's macromolecules -- proteins, nucleic acids, and surface polymers -- require the amide group of glutamine at the first dedicated step of biosynthesis. This is the case even though only a minority (~12%) of total cell nitrogen derives from glutamine. In contrast, the amino group of glutamate, which provides the remainder of cell nitrogen, is generally required late in biosynthetic pathways, e.g. in transaminase reactions for amino acid synthesis. We propose...

  11. A quorum sensing small volatile molecule promotes antibiotic tolerance in bacteria.

    Directory of Open Access Journals (Sweden)

    Yok-Ai Que

    Full Text Available Bacteria can be refractory to antibiotics due to a sub-population of dormant cells, called persisters that are highly tolerant to antibiotic exposure. The low frequency and transience of the antibiotic tolerant "persister" trait has complicated elucidation of the mechanism that controls antibiotic tolerance. In this study, we show that 2' Amino-acetophenone (2-AA, a poorly studied but diagnostically important small, volatile molecule produced by the recalcitrant gram-negative human pathogen Pseudomonas aeruginosa, promotes antibiotic tolerance in response to quorum-sensing (QS signaling. Our results show that 2-AA mediated persister cell accumulation occurs via alteration of the expression of genes involved in the translational capacity of the cell, including almost all ribosomal protein genes and other translation-related factors. That 2-AA promotes persisters formation also in other emerging multi-drug resistant pathogens, including the non 2-AA producer Acinetobacter baumannii implies that 2-AA may play an important role in the ability of gram-negative bacteria to tolerate antibiotic treatments in polymicrobial infections. Given that the synthesis, excretion and uptake of QS small molecules is a common hallmark of prokaryotes, together with the fact that the translational machinery is highly conserved, we posit that modulation of the translational capacity of the cell via QS molecules, may be a general, widely distributed mechanism that promotes antibiotic tolerance among prokaryotes.

  12. A quorum sensing small volatile molecule promotes antibiotic tolerance in bacteria.

    Science.gov (United States)

    Que, Yok-Ai; Hazan, Ronen; Strobel, Benjamin; Maura, Damien; He, Jianxin; Kesarwani, Meenu; Panopoulos, Panagiotis; Tsurumi, Amy; Giddey, Marlyse; Wilhelmy, Julie; Mindrinos, Michael N; Rahme, Laurence G

    2013-01-01

    Bacteria can be refractory to antibiotics due to a sub-population of dormant cells, called persisters that are highly tolerant to antibiotic exposure. The low frequency and transience of the antibiotic tolerant "persister" trait has complicated elucidation of the mechanism that controls antibiotic tolerance. In this study, we show that 2' Amino-acetophenone (2-AA), a poorly studied but diagnostically important small, volatile molecule produced by the recalcitrant gram-negative human pathogen Pseudomonas aeruginosa, promotes antibiotic tolerance in response to quorum-sensing (QS) signaling. Our results show that 2-AA mediated persister cell accumulation occurs via alteration of the expression of genes involved in the translational capacity of the cell, including almost all ribosomal protein genes and other translation-related factors. That 2-AA promotes persisters formation also in other emerging multi-drug resistant pathogens, including the non 2-AA producer Acinetobacter baumannii implies that 2-AA may play an important role in the ability of gram-negative bacteria to tolerate antibiotic treatments in polymicrobial infections. Given that the synthesis, excretion and uptake of QS small molecules is a common hallmark of prokaryotes, together with the fact that the translational machinery is highly conserved, we posit that modulation of the translational capacity of the cell via QS molecules, may be a general, widely distributed mechanism that promotes antibiotic tolerance among prokaryotes.

  13. Self-defensive layer-by-layer films with bacteria-triggered antibiotic release.

    Science.gov (United States)

    Zhuk, Iryna; Jariwala, Freneil; Attygalle, Athula B; Wu, Yong; Libera, Matthew R; Sukhishvili, Svetlana A

    2014-08-26

    We report on highly efficient, bioresponsive, controlled-release antibacterial coatings constructed by direct assembly of tannic acid (TA) with one of several cationic antibiotics (tobromycin, gentamicin, and polymyxin B) using the layer-by-layer (LbL) technique. These films exhibit a distinct “self-defense” behavior triggered by acidification of the immediate environment by pathogenic bacteria, such as Staphylococcus epidermidis (S. epidermidis) or Escherichia coli (E. coli). Films assembled using spin-assisted and dip-assisted techniques show drastically different morphology, thickness and pH-/bacteria-triggered antibiotic release characteristics. While dip-deposited films have rough surfaces with island-like, granular structures regardless of the film thickness, spin-assisted LbL assemblies demonstrate a transition from linear deposition of uniform 2D films to a highly developed 3D morphology for films thicker than ∼45 nm. Ellipsometry, UV–vis and mass spectrometry confirm that all coatings do not release antibiotics in phosphate buffered saline at pH 7.4 for as long as one month in the absence of bacteria and therefore do not contribute to the development of antibiotic resistance. These films do, however, release antibiotics upon pH lowering. The rate of triggered release can be controlled through the choice of assembled antibiotic and the assembly technique (spin- vs dip-deposition) and by the spinning rate used during deposition, which all affect the strength of TA–antibiotic binding. TA/antibiotic coatings as thin as 40 nm strongly inhibit S. epidermidis and E. coli bacterial growth both at surfaces and in surrounding medium, but support adhesion and proliferation of murine osteoblast cells. These coatings thus present a promising way to incorporate antibacterial agents at surfaces to prevent bacterial colonization of implanted biomedical devices.

  14. The Structure of Fitness Landscapes in Antibiotic-Resistant Bacteria

    Science.gov (United States)

    Deris, Barrett; Kim, Minsu; Zhang, Zhongge; Okano, Hiroyuki; Hermsen, Rutger; Gore, Jeff; Hwa, Terence

    2014-03-01

    To predict the emergence of antibiotic resistance, quantitative relations must be established between the fitness of drug-resistant organisms and the molecular mechanisms conferring resistance. We have investigated E. coli strains expressing resistance to translation-inhibiting antibiotics. We show that resistance expression and drug inhibition are linked in a positive feedback loop arising from an innate, global effect of drug-inhibited growth on gene expression. This feedback leads generically to plateau-shaped fitness landscapes and concomitantly, for strains expressing at least moderate degrees of drug resistance, gives rise to an abrupt drop in growth rates of cultures at threshold drug concentrations. A simple quantitative model of bacterial growth based on this innate feedback accurately predicts experimental observations without ad hoc parameter fitting. We describe how drug-inhibited growth rate and the threshold drug concentration (the minimum inhibitory concentration, or MIC) depend on the few biochemical parameters that characterize the molecular details of growth inhibition and drug resistance (e.g., the drug-target dissociation constant). And finally, we discuss how these parameters can shape fitness landscapes to determine evolutionary dynamics and evolvability.

  15. Prevalence of antibiotic-resistant bacteria in three different aquatic environments over three seasons.

    Science.gov (United States)

    Mohanta, Tandra; Goel, Sudha

    2014-08-01

    The objective of this study was to evaluate the impact of urbanization and seasonal changes on the prevalence of antibiotic-resistant bacteria in different aqueous environments. To this end, bacteria were isolated from three different water sources: the River Hooghly in Kolkata, River Kangsabati and groundwater from Kharagpur, West Bengal over three seasons: post-monsoon, winter and summer in 2012-2013. A total of 163 Gram-negative bacteria were isolated from the River Hooghly (n = 138), River Kangsabati (n = 13) and groundwater (n = 12). Antibiotic susceptibility testing was done using 12 antibiotic discs. The percentages of multiple antibiotic-resistant (MAR) bacteria at the three sampling locations were found to be 71.01 % (98/138) for River Hooghly, 15.38 % (2/13) for River Kangsabati and 8.33 % (1/12) for groundwater. Prevalence of MAR bacteria with respect to the three seasons were the following: 73.58 % in post-monsoon, 59.26 % in winter and 53.57 % in summer. Antibiotic resistance index (ARI) was calculated for each location and each season. In general, ARI values for all the River Hooghly samples were >0.2 while those for the River Kangsabati and groundwater in Kharagpur were always resistance in bacteria from the River Hooghly compared to the other two locations. In addition, percentage of MAR and ARI values followed the trend: post-monsoon > winter > summer. This may be due to the additional terrestrial resistants that get swept along with surface runoff during the monsoons.

  16. Methanobactin: a copper binding compound having antibiotic and antioxidant activity isolated from methanotrophic bacteria

    Science.gov (United States)

    DiSpirito, Alan A.; Zahn, James A.; Graham, David W.; Kim, Hyung J.; Alterman, Michail; Larive, Cynthia

    2007-04-03

    A means and method for treating bacterial infection, providing antioxidant activity, and chelating copper using a copper binding compound produced by methanotrophic bacteria is described. The compound, known as methanobactin, is the first of a new class of antibiotics having gram-positive activity. Methanobactin has been sequenced, and its structural formula determined.

  17. When It Comes to Antibiotics, Bacteria Show Some NO-how

    Institute of Scientific and Technical Information of China (English)

    Bhumit A. Patel; Brian R. Crane

    2010-01-01

    @@ Homologs to mammalian nitric oxide synthases are found in many mostly Gram-positive bacteria. In some genera such as bacilli, and staphylococci, these enzymes produce protects against oxidative damage, this effect has now been shown to provide an advantage against antibiotics that kill by increasing cellular levels of reactive oxygen species.

  18. Abundance and Distribution of Enteric Bacteria and Viruses in Coastal and Estuarine Sediments—a Review

    Science.gov (United States)

    Hassard, Francis; Gwyther, Ceri L.; Farkas, Kata; Andrews, Anthony; Jones, Vera; Cox, Brian; Brett, Howard; Jones, Davey L.; McDonald, James E.; Malham, Shelagh K.

    2016-01-01

    The long term survival of fecal indicator organisms (FIOs) and human pathogenic microorganisms in sediments is important from a water quality, human health and ecological perspective. Typically, both bacteria and viruses strongly associate with particulate matter present in freshwater, estuarine and marine environments. This association tends to be stronger in finer textured sediments and is strongly influenced by the type and quantity of clay minerals and organic matter present. Binding to particle surfaces promotes the persistence of bacteria in the environment by offering physical and chemical protection from biotic and abiotic stresses. How bacterial and viral viability and pathogenicity is influenced by surface attachment requires further study. Typically, long-term association with surfaces including sediments induces bacteria to enter a viable-but-non-culturable (VBNC) state. Inherent methodological challenges of quantifying VBNC bacteria may lead to the frequent under-reporting of their abundance in sediments. The implications of this in a quantitative risk assessment context remain unclear. Similarly, sediments can harbor significant amounts of enteric viruses, however, the factors regulating their persistence remains poorly understood. Quantification of viruses in sediment remains problematic due to our poor ability to recover intact viral particles from sediment surfaces (typically <10%), our inability to distinguish between infective and damaged (non-infective) viral particles, aggregation of viral particles, and inhibition during qPCR. This suggests that the true viral titre in sediments may be being vastly underestimated. In turn, this is limiting our ability to understand the fate and transport of viruses in sediments. Model systems (e.g., human cell culture) are also lacking for some key viruses, preventing our ability to evaluate the infectivity of viruses recovered from sediments (e.g., norovirus). The release of particle-bound bacteria and

  19. Study of frequency of bacteria isolated from blood culture and their antibiotic susceptibility pattern in a university hospital in Tehran

    OpenAIRE

    Hoorieh Saderi; Ali akbar Karimi; Marzieh Loni

    2009-01-01

    Introduction: Determining frequency of bacteria, isolated from blood culture and their antibiotic susceptibility patterns, has epidemiological significance and can help in selecting empirical therapy. This study was aimed to assess, the frequency of bacteria isolated from blood culture of patients suspected to bacteremia and their antibiotic susceptibility patterns. Methods: Culture of blood and determination of antibiotic susceptibility was done by standard methods. In this study, a variety ...

  20. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria.

    Science.gov (United States)

    Tängdén, Thomas

    2014-05-01

    Combination antibiotic therapy for Gram-negative sepsis is controversial. The present review provides a brief summary of the existing knowledge on combination therapy for severe infections with multidrug-resistant Pseudomonas spp., Acinetobacter spp., and Enterobacteriaceae. Empirical combination antibiotic therapy is recommended for severe sepsis and septic shock to reduce mortality related to inappropriate antibiotic treatment. Because definitive combination therapy has not been proven superior to monotherapy in meta-analyses, it is generally advised to de-escalate antibiotic therapy when the antibiotic susceptibility profile is known, although it cannot be excluded that some subgroups of patients might still benefit from continued combination therapy. Definitive combination therapy is recommended for carbapenemase-producing Enterobacteriaceae and should also be considered for severe infections with Pseudomonas and Acinetobacter spp. when beta-lactams cannot be used. Because resistance to broad-spectrum beta-lactams is increasing in Gram-negative bacteria and because no new antibiotics are expected to become available in the near future, the antibacterial potential of combination therapy should be further explored. In vitro data suggest that combinations can be effective even if the bacteria are resistant to the individual antibiotics, although existing evidence is insufficient to support the choice of combinations and explain the synergistic effects observed. In vitro models can be used to screen for effective combinations that can later be validated in animal or clinical studies. Further, in the absence of clinical evidence, in vitro data might be useful in supporting therapeutic decisions for severe infections with multidrug-resistant Gram-negative bacteria.

  1. Term-seq reveals abundant ribo-regulation of antibiotics resistance in bacteria.

    Science.gov (United States)

    Dar, Daniel; Shamir, Maya; Mellin, J R; Koutero, Mikael; Stern-Ginossar, Noam; Cossart, Pascale; Sorek, Rotem

    2016-04-01

    Riboswitches and attenuators are cis-regulatory RNA elements, most of which control bacterial gene expression via metabolite-mediated, premature transcription termination. We developed an unbiased experimental approach for genome-wide discovery of such ribo-regulators in bacteria. We also devised an experimental platform that quantitatively measures the in vivo activity of all such regulators in parallel and enables rapid screening for ribo-regulators that respond to metabolites of choice. Using this approach, we detected numerous antibiotic-responsive ribo-regulators that control antibiotic resistance genes in pathogens and in the human microbiome. Studying one such regulator in Listeria monocytogenes revealed an attenuation mechanism mediated by antibiotic-stalled ribosomes. Our results expose broad roles for conditional termination in regulating antibiotic resistance and provide a tool for discovering riboswitches and attenuators that respond to previously unknown ligands.

  2. Sulfhydryl variable-5 extended spectrum β-lactamase in nosocomial enteric bacteria causing sepsis in mexican children

    Directory of Open Access Journals (Sweden)

    Angélica Flores-Pérez

    2015-10-01

    Full Text Available Introduction: Enteric bacteria causing nosocomial infections are often resistant to third-generation cephalosporins due to the production of extended-spectrum β-lactamases (ESBLs. Objective: To describe and characterize the ESBLs pattern present in Klebsiella pneumoniae and Serratia marcescens strains, isolated as causative of nosocomial sepsis in pediatric patients at Instituto Nacional de Pediatría (National Institute of Pediatrics. Material and methods: We analyzed 94 strains of K. pneumoniae and 7 of S. marcescens isolated from clinical specimens from 2002-2005, causative of sepsis in a children’s hospital. We evaluated antibiotic susceptibility and detection of ESBL phenotypes by disk diffusion methods; ceftazidime-resistant isolates were further characterized by pulsed field gel electrophoresis (PFGE; and ESBLs were phenotypically and genotypically characterized by isoelectric focusing, polymerase chain reaction (PCR and sequencing. We also assed for presence of conjugative plasmids bearing the ESBL gene. Results: 51/94 (54% of K. pneumoniae isolates, and 5/7 (71% of S. marcescens isolates were resistant to ceftazidime; all carried a blaSHV-5 gene. All K. pneumoniae isolates had a distinct PFGE profile, yet all carried a ~48-Kb plasmid, that was conjugatively transferable to an Escherichia coli receptor, which expressed the resistance phenotype. On the other hand, all S. marcescens isolates had a similar PFGE profile, were unable to transfer the ceftazidime-resistance phenotype, and were isolated from the same ward in a short time-span suggesting an outbreak. Conclusions: The overall prevalence of ESBL-producing enteric bacteria in this hospital is high but similar to other Latin American reports. The sulfhydryl variable-5 (SHV-5 ESBL gene appears to reside in a highly mobile plasmid, capable of spreading among different K. pneumoniae clones and perhaps even to S. marcescens.

  3. Photodynamic inactivation of multidrug-resistant bacteria in hospital wastewaters: influence of residual antibiotics.

    Science.gov (United States)

    Almeida, Joana; Tomé, João P C; Neves, Maria G P M S; Tomé, Augusto C; Cavaleiro, José A S; Cunha, Ângela; Costa, Liliana; Faustino, Maria A F; Almeida, Adelaide

    2014-04-01

    One environmental concern related to hospital effluents is discharge of them without preliminary treatment. Antimicrobial photodynamic inactivation (PDI) may represent an alternative to the traditional expensive, unsafe and not always effective disinfection methods. The main goal of this work was to assess the efficiency of PDI on clinical multidrug-resistant (MDR) bacteria in hospital wastewaters in order to evaluate its potential use in treating hospital effluents. The efficiency of PDI was assessed using a cationic porphyrin as the photosensitizer (PS), four MDR bacteria either in phosphate buffered saline or in filtrated hospital wastewaters. The synergistic effect of PDI and antibiotics (ampicillin and chloramphenicol) was also evaluated, as well as the effect of the surfactant sodium dodecyl sulfate (SDS). The results show the efficient inactivation of MDR bacteria in PBS (reduction of 6-8 log after 270 min of irradiation at 40 W m(-2) with 5.0 μM of PS). In wastewater, the inactivation of the four MDR bacteria was again efficient and the decrease in bacterial survival starts even sooner. A faster decrease in bacterial survival occurred when PDI was combined with the addition of antibiotics, at sub-inhibitory and inhibitory concentrations, but the SDS did not affect the PDI efficiency. It can be concluded that PDI has potential to be an effective alternative for the inactivation of MDR bacteria in hospital wastewaters and that the presence of antibiotics may enhance its effectiveness.

  4. Study of frequency of bacteria isolated from blood culture and their antibiotic susceptibility pattern in a university hospital in Tehran

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    Hoorieh Saderi

    2009-12-01

    Full Text Available Introduction: Determining frequency of bacteria, isolated from blood culture and their antibiotic susceptibility patterns, has epidemiological significance and can help in selecting empirical therapy. This study was aimed to assess, the frequency of bacteria isolated from blood culture of patients suspected to bacteremia and their antibiotic susceptibility patterns. Methods: Culture of blood and determination of antibiotic susceptibility was done by standard methods. In this study, a variety of isolated bacteria types, antibiotic susceptibility, as well as age, sex and type of admission of patients were analyzed in a university hospital from 21 March, 2006 to 20 March, 2007. Results: During one year, blood culture was done for 5116 patients and bacteria were isolated in 912 cases (17.8%. Three most frequently groups of bacteria in blood cultures of patients were non-fermentative gram negative bacteria (Pseudomonas and Acintobacter spp, coliforms (Escherichia coli and enterobacter and klebsiella spp. and coagulase negative staphylococci, respectively, which were isolated in 63.4%, 17.0% and 12.8% of patients, and constituted 93.2% of positive blood cultures. Higher resistance was shown in bacteria isolated from inpatients compare to outpatients. Conclusion: This study showed the influence of age, sex and type of admission (outpatient or inpatient in a variety of isolated bacteria in blood culture. The result of this study were the same as the other studies in Iran and other countries in respect of the variety of isolated bacteria and antibiotic susceptibility and show increase of antibiotic resistance in these bacteria.

  5. A Multifunctional Subphthalocyanine Nanosphere for Targeting, Labeling, and Killing of Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Roy, Indranil; Shetty, Dinesh; Hota, Raghunandan; Baek, Kangkyun; Kim, Jeesu; Kim, Chulhong; Kappert, Sandro; Kim, Kimoon

    2015-12-01

    Developing a material that can combat antibiotic-resistant bacteria, a major global health threat, is an urgent requirement. To tackle this challenge, we synthesized a multifunctional subphthalocyanine (SubPc) polymer nanosphere that has the ability to target, label, and photoinactivate antibiotic-resistant bacteria in a single treatment with more than 99 % efficiency, even with a dose as low as 4.2 J cm(-2) and a loading concentration of 10 nM. The positively charged nanosphere shell composed of covalently linked SubPc units can increase the local concentration of photosensitizers at therapeutic sites. The nanosphere shows superior performance compared to corresponding monomers presumably because of their enhanced water dispersibility, higher efficiency of singlet-oxygen generation, and phototoxicity. In addition, this material is useful in fluorescence labeling of living cells and shows promise in photoacoustic imaging of bacteria in vivo.

  6. Bovine Muc1 inhibits binding of enteric bacteria to Caco-2 cells.

    Science.gov (United States)

    Parker, Phillip; Sando, Lillian; Pearson, Roger; Kongsuwan, Kritaya; Tellam, Ross L; Smith, Stuart

    2010-01-01

    Inhibition of bacterial adhesion to intestinal epithelial receptors by the consumption of natural food components is an attractive strategy for the prevention of microbial related gastrointestinal illness. We hypothesised that Muc1, a highly glycosylated mucin present in cows' milk, may be one such food component. Purified bovine Muc1 was tested for its ability to inhibit binding of common enteric bacterial pathogens to Caco-2 cells grown in vitro. Muc1 caused dose-dependent binding inhibition of Escherichia coli, Salmonella enterica serovar Typhimurium (S. Typhimurium), Staphylococcus aureus and Bacillus subtilis. This inhibition was more pronounced for the Gram negative compared with Gram positive bacteria. It was also demonstrated that Muc1, immobilised on a membrane, bound all these bacterial species in a dose-dependent manner, although there was greater interaction with the Gram negative bacteria. A range of monosaccharides, representative of the Muc1 oligosaccharide composition, were tested for their ability to prevent binding of E. coli and S. Typhimurium to Caco-2 cells. Inhibition was structure dependent with sialic acid, L(-) fucose and D(+) mannose significantly inhibiting binding of both Gram negative species. N-acetylglucosamine and N-acetylgalactosamine significantly inhibited binding of E. coli whilst galactose, one of the most abundant Muc1 monosaccharides, showed the strongest inhibition against S. Typhimurium. Treatment with sialidase significantly decreased the inhibitory properties of Muc1, demonstrating the importance of sialic acid in adhesion inhibition. It is concluded that bovine Muc1 prevents binding of bacteria to human intestinal cells and may have a role in preventing the binding of common enteropathogenic bacteria to human intestinal epithelial surfaces.

  7. Assessment of Antibiotic Resistant Commensal Bacteria in Food

    Science.gov (United States)

    2006-01-01

    vinegar, Italian dressing, lemon juice or HCl…………………………………………………………..……………………..….95 B.2. Treatment of celery using NaCl, boiling water, vinegar...Italian dressing, lemon juice , or HCl………………………………………..………………………………….…….….96 B.3. Comparison of multiplexing PCR versus conventional PCR...can be found in a multitude of bacteria important in food fermentation and food safety (35,36). Another common mechanism is enzyme modification

  8. The role of surveillance systems in confronting the global crisis of antibiotic-resistant bacteria

    Science.gov (United States)

    Perez, Federico; Villegas, Maria Virginia

    2015-01-01

    Purpose of Review It is widely accepted that infection control, advanced diagnostics, and novel therapeutics are crucial to mitigate the impact of antibiotic-resistant bacteria. The role of global, national and regional surveillance systems as part of the response to the challenge posed by antibiotic resistance is not sufficiently highlighted. We provide an overview of contemporary surveillance programs, with emphasis on Gram-negative bacteria. Recent Findings The World Health Organization and public health agencies in Europe and the United States recently published comprehensive surveillance reports. These highlight the emergence and dissemination of carbapenem-resistant Enterobacteriaceae (CRE) and other multidrug resistant Gram-negative bacteria. In Israel, public health action to control CRE, especially Klebsiella pneumoniae carbapenemase (KPC) producing-Klebsiella pneumoniae, has advanced together with a better understanding of its epidemiology. Surveillance models adapted to the requirements and capacities of each country are in development. Summary Robust surveillance systems are essential to combat antibiotic resistance, and need to emphasize a “One Health” approach. Refinements in surveillance will come from advances in bioinformatics and genomics that permit the integration of global and local information about antibiotic consumption in humans and animals, molecular mechanisms of resistance, and bacterial genotyping. PMID:26098505

  9. A new approach for the discovery of antibiotics by targeting non-multiplying bacteria: a novel topical antibiotic for staphylococcal infections.

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    Yanmin Hu

    Full Text Available In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.

  10. A new approach for the discovery of antibiotics by targeting non-multiplying bacteria: a novel topical antibiotic for staphylococcal infections.

    Science.gov (United States)

    Hu, Yanmin; Shamaei-Tousi, Alireza; Liu, Yingjun; Coates, Anthony

    2010-07-27

    In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.

  11. Recycling antibiotics into GUMBOS: a new combination strategy to combat multi-drug-resistant bacteria.

    Science.gov (United States)

    Cole, Marsha R; Hobden, Jeffery A; Warner, Isiah M

    2015-04-10

    The emergence of multi-drug-resistant bacteria, coupled with the lack of new antibiotics in development, is fast evolving into a global crisis. New strategies utilizing existing antibacterial agents are urgently needed. We propose one such strategy in which four outmoded β-lactam antibiotics (ampicillin, carbenicillin, cephalothin and oxacillin) and a well-known antiseptic (chlorhexidine di-acetate) were fashioned into a group of uniform materials based on organic salts (GUMBOS) as an alternative to conventional combination drug dosing strategies. The antibacterial activity of precursor ions (e.g., chlorhexidine diacetate and β-lactam antibiotics), GUMBOS and their unreacted mixtures were studied with 25 clinical isolates with varying antibiotic resistance using a micro-broth dilution method. Acute cytotoxicity and therapeutic indices were determined using fibroblasts, endothelial and cervical cell lines. Intestinal permeability was predicted using a parallel artificial membrane permeability assay. GUMBOS formed from ineffective β-lactam antibiotics and cytotoxic chlorhexidine diacetate exhibited unique pharmacological properties and profound antibacterial activity at lower concentrations than the unreacted mixture of precursor ions at equivalent stoichiometry. Reduced cytotoxicity to invasive cell types commonly found in superficial and chronic wounds was also observed using GUMBOS. GUMBOS show promise as an alternative combination drug strategy for treating wound infections caused by drug-resistant bacteria.

  12. Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian contaminated systems.

    Science.gov (United States)

    Oyetibo, Ganiyu O; Ilori, Matthew O; Adebusoye, Sunday Adekunle; Obayori, Oluwafemi S; Amund, Olukayode O

    2010-09-01

    Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd(2+), Co(2+), Ni(2+), Cr(6+), and Hg(2+)) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd(2+), 15 mM for Co(2+) and Ni(2+), 17 mM for Cr(6+), and 10 mM for Hg(2+). Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni(2+), P. aeruginosa resisted 10 mM Co(2+). To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.

  13. Fluoroquinolone-resistant enteric bacteria in sub-Saharan Africa: Clones, Implications and Research needs

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    Marie Anne Chattaway

    2016-04-01

    Full Text Available Fluoroquinolones came into widespread use in African countries in the early 2000s, after patents for the first generation of these drugs expired. By that time, quinolone antibacterial agents had been used intensively worldwide and resistant lineages of many bacterial species had evolved. We sought to understand which Gram negative enteric pandemic lineages have been reported from Africa, as well as the nature and transmission of any indigenous resistant clones. A systematic review of articles indexed in the Medline and AJOL literature databases was conducted. We report on the findings of 43 eligible studies documenting local or pandemic fluoroquinolone-resistant enteric clones in sub-Sahara African countries. Most reports are of invasive non-typhoidal Salmonella and Escherichia coli lineages and there have been three reports of cholera outbreaks caused by fluoroquinolone-resistant Vibrio cholerae O1. Fluoroquinolone-resistant clones have also been reported from commensals and animal isolates but there are few data for non-Enterobacteriaceae and almost none for difficult-to-culture Campylobacter spp. Fluoroquinolone-resistant lineages identified in African countries were universally resistant to multiple other classes of antibacterial agents. Although as many as 972 non-duplicate articles refer to fluoroquinolone resistance in enteric bacteria from Africa, most do not report on subtypes and therefore information on the epidemiology of fluoroquinolone-resistant clones is available from only a handful of countries in the subcontinent. When resistance is reported, resistance mechanisms and lineage information is rarely investigated. Insufficient attention has been given to molecular and sequence-based methods necessary for identifying and tracking resistant clones in Africa and more research is needed in this area.

  14. Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria.

    Science.gov (United States)

    Palaniappan, Kavitha; Holley, Richard A

    2010-06-15

    Plant-derived antibacterial compounds may be of value as a novel means for controlling antibiotic resistant zoonotic pathogens which contaminate food animals and their products. Individual activity of natural antimicrobials (eugenol, thymol, carvacrol, cinnamaldehyde, allyl isothiocyanate (AIT)) and activity when paired with an antibiotic was studied using broth microdilution and checkerboard methods. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interactions between the inhibitors. Bacteria tested were chosen because of their resistance to at least one antibiotic which had a known genetic basis. Substantial susceptibility of these bacteria toward the natural antimicrobials and a considerable reduction in the minimum inhibitory concentrations (MIC's) of the antibiotics were noted when paired combinations of antimicrobial and antibiotic were used. In the interaction study, thymol and carvacrol were found to be highly effective in reducing the resistance of Salmonella Typhimurium SGI 1 (tet A) to ampicillin, tetracycline, penicillin, bacitracin, erythromycin and novobiocin (FIC<0.4) and resistance of Streptococcus pyogenes ermB to erythromycin (FIC<0.5). With Escherichia coli N00 666, thymol and cinnamaldehyde were found to have a similar effect (FIC<0.4) in reducing the MIC's of ampicillin, tetracycline, penicillin, erythromycin and novobiocin. Carvacrol, thymol (FIC<0.3) and cinnamaldehyde (FIC<0.4) were effective against Staphylococcus aureus blaZ and in reducing the MIC's of ampicillin, penicillin and bacitracin. Allyl isothiocyanate (AIT) was effective in reducing the MIC of erythromycin (FIC<0.3) when tested against S. pyogenes. Fewer combinations were found to be synergistic when the decrease in viable population (log DP) was calculated. Together, fractional inhibitory concentrations < or = 0.5 and log DP<-1 indicated synergistic action between four natural antimicrobials and as many as three antibiotics

  15. Is screening patients for antibiotic-resistant bacteria justified in the Indian context?

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    S Bhattacharya

    2011-01-01

    Full Text Available Infection with multi-antibiotic-resistant bacteria is a common clinical problem in India. In some countries and centres, screening patients to detect colonisation by these organisms is used to determine specific interventions such as decolonisation treatment, prophylactic antibiotics prior to surgical interventions or for selection of empirical antibiotic therapy, and to isolate patients so that transmission of these difficult to treat organisms to other patients could be prevented. In India, there is no national guideline or recommendation for screening patients for multi-drug-resistant (MDR bacteria such as MRSA (methicillin-resistant Staphylococcus aureus, VRE (vancomycin-resistant enterococcus, ESBL (extended spectrum beta-lactamase or MBL (metallo-beta-lactamase producers. The present article discusses the relevance of screening patients for multi-antibiotic-resistant bacteria in the Indian context. Literature has been reviewed about antibiotic resistance in India, screening methodology, economic debate about screening. The percentages of strains from various hospitals in India which were reported to be MRSA was between 8 and 71%, those for ESBL between 19 and 60% and carbapenem-resistant Gram-negative bacilli between 5.3 and 59%. There exists culture-based technology for the detection of these resistant organisms from patient samples. For some pathogens, such as MRSA and VRE Polymerase chain reaction-based tests are also becoming available. Screening for MDR bacteria is an option which may be used after appraisal of the resources available, and after exploring possibility of implementing the interventions that may be required after a positive screening test result.

  16. Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram‐Negative Bacteria

    Science.gov (United States)

    Borselli, Diane; Blanchet, Marine; Bolla, Jean‐Michel; Muth, Aaron; Skruber, Kristen

    2017-01-01

    Abstract Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram‐negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU‐N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer‐membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de‐energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance. PMID:28098416

  17. Co-selection of antibiotic and heavy metal resistance in freshwater bacteria

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    Andrea Di Cesare

    2016-04-01

    Full Text Available Antibiotic resistant bacteria are found in most environments, especially in highly anthropized waters. A direct correlation between human activities (e.g., pollution and spread and persistence of antibiotic resistant bacteria (ARB and resistance genes (ARGs within the resident bacterial communities appears more and more obvious. Furthermore, the threat posed for human health by the presence of ARB and ARGs in these environments is enhanced by the risk of horizontal gene transfer of resistance genes to human pathogens. Although the knowledge on the spread of antibiotic resistances in waters is increasing, the understanding of the driving factors determining the selection for antibiotic resistance in the environment is still scarce. Antibiotic pollution is generally coupled with contamination by heavy metals (HMs and other chemicals, which can also promote the development of resistance mechanisms, often through co-selecting for multiple resistances. The co-selection of heavy metal resistance genes and ARGs in waters, sediments, and soils, increases the complexity of the ecological role of ARGs, and reduces the effectiveness of control actions. In this mini-review we present the state-of-the-art of the research on antibiotic- and HM-resistance and their connection in the environment, with a focus on HM pollution and aquatic environments. We review the spread and the persistence of HMs and/or ARB, and how it influences their respective gene co-selection. In the last chapter, we propose Lake Orta, a system characterized by an intensive HM pollution followed by a successful restoration of the chemistry of the water column, as a study-site to evaluate the spread and selection of HMs and antibiotic resistances in heavily disturbed environments.

  18. Antagonistic activity of antibiotic producing Streptomyces sp. against fish and human pathogenic bacteria

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    Nazmul Hossain

    2014-04-01

    Full Text Available In this study, attempts were made to isolate Streptomyces sp. from soil samples of two different regions of Bangladesh and evaluate their antagonistic activity against fish and human pathogenic bacteria. A total of 10 isolates were identified as Streptomyces sp. based on several morphological, physiological and biochemical tests. Cross streak method was used to observe the antagonistic activity of the Streptomyces sp. isolates against different fish pathogens belonging to the genus Aeromonas, Pseudomonas and Edwardsiella and human clinical isolates belonging to the genus Klebsiella, Salmonella and Streptococcus. Seven Streptomyces sp. isolates showed antagonism against both fish and human pathogenic bacteria. Four isolates viz., N24, N26, N28 and N47 showed broad spectrum of antagonistic activity (80-100% against all genera of fish and human pathogenic bacteria. The isolate N49 exhibited highest spectrum of antagonism against all fish pathogens (90-100% but comparatively lower degree of antagonism against human pathogens (50-60%. Rest of the two isolates (N21 and N23 showed variability in their antagonism. Results showed that broad spectrum antibiotic(s could be developed from the isolates N24, N26, N28 and N47against several human and fish pathogens. The isolate N49 could be a potential source of antibiotic, especially for fish pathogenic bacteria.

  19. Beyond bacteria: a study of the enteric microbial consortium in extremely low birth weight infants.

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    Mariam Susan LaTuga

    Full Text Available Extremely low birth weight (ELBW infants have high morbidity and mortality, frequently due to invasive infections from bacteria, fungi, and viruses. The microbial communities present in the gastrointestinal tracts of preterm infants may serve as a reservoir for invasive organisms and remain poorly characterized. We used deep pyrosequencing to examine the gut-associated microbiome of 11 ELBW infants in the first postnatal month, with a first time determination of the eukaryote microbiota such as fungi and nematodes, including bacteria and viruses that have not been previously described. Among the fungi observed, Candida sp. and Clavispora sp. dominated the sequences, but a range of environmental molds were also observed. Surprisingly, seventy-one percent of the infant fecal samples tested contained ribosomal sequences corresponding to the parasitic organism Trichinella. Ribosomal DNA sequences for the roundworm symbiont Xenorhabdus accompanied these sequences in the infant with the greatest proportion of Trichinella sequences. When examining ribosomal DNA sequences in aggregate, Enterobacteriales, Pseudomonas, Staphylococcus, and Enterococcus were the most abundant bacterial taxa in a low diversity bacterial community (mean Shannon-Weaver Index of 1.02 ± 0.69, with relatively little change within individual infants through time. To supplement the ribosomal sequence data, shotgun sequencing was performed on DNA from multiple displacement amplification (MDA of total fecal genomic DNA from two infants. In addition to the organisms mentioned previously, the metagenome also revealed sequences for gram positive and gram negative bacteriophages, as well as human adenovirus C. Together, these data reveal surprising eukaryotic and viral microbial diversity in ELBW enteric microbiota dominated bytypes of bacteria known to cause invasive disease in these infants.

  20. Antibiotic Resistance

    Science.gov (United States)

    ... lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able ... resistant to several common antibiotics. To help prevent antibiotic resistance Don't use antibiotics for viruses like colds ...

  1. Antibiotic Safety

    Science.gov (United States)

    ... are not effectively treated with an antibiotic • Viral gastroenteritis Bacterial infections should be treated with antibiotics. Some ... you antibiotics for a viral infection. Antibiotics kill bacteria, not viruses. • T ake all of your prescribed ...

  2. Bloodstream infections in intensive care unit patients: distribution and antibiotic resistance of bacteria

    Directory of Open Access Journals (Sweden)

    Russotto V

    2015-08-01

    Full Text Available Vincenzo Russotto,1 Andrea Cortegiani,1 Giorgio Graziano,2 Laura Saporito,2 Santi Maurizio Raineri,1 Caterina Mammina,2 Antonino Giarratano1 1Department of Biopathology and Medical Biotechnologies (DIBIMED, Section of Anaesthesia, Analgesia, Intensive Care and Emergency, Paolo Giaccone University Hospital, University of Palermo, Palermo, Italy; 2Department of Sciences for Health Promotion and Mother-Child Care, University of Palermo, Palermo, Italy Abstract: Bloodstream infections (BSIs are among the leading infections in critically ill patients. The case-fatality rate associated with BSIs in patients admitted to intensive care units (ICUs reaches 35%–50%. The emergence and diffusion of bacteria with resistance to antibiotics is a global health problem. Multidrug-resistant bacteria were detected in 50.7% of patients with BSIs in a recently published international observational study, with methicillin resistance detected in 48% of Staphylococcus aureus strains, carbapenem resistance detected in 69% of Acinetobacter spp., in 38% of Klebsiella pneumoniae, and in 37% of Pseudomonas spp. Prior hospitalization and antibiotic exposure have been identified as risk factors for infections caused by resistant bacteria in different studies. Patients with BSIs caused by resistant strains showed an increased risk of mortality, which may be explained by a higher incidence of inappropriate empirical therapy in different studies. The molecular genetic characterization of resistant bacteria allows the understanding of the most common mechanisms underlying their resistance and the adoption of surveillance measures. Knowledge of epidemiology, risk factors, mechanisms of resistance, and outcomes of BSIs caused by resistant bacteria may have a major influence on global management of ICU patients. The aim of this review is to provide the clinician an update on BSIs caused by resistant bacteria in ICU patients. Keywords: bloodstream infections, multidrug resistant

  3. THE STUDY OF ANTIBIOTIC- AND FAGOSENSITIVITY OF NOSOCOMIAL STRAINS BACTERIA ISOLATED FROM TRANSPLANTED PATIENTS

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    N. I. Gabrielan

    2011-01-01

    Full Text Available Antibiotic and fagosensitivity most etiologically important nosocomial strains of bacteria – Pseudomonas aeru- ginosa, Klebsiella pneumoniae, E. coli, Proteus spp., Staphylococcus spp. were studied. Multiple drug-resistant bacteria as gram-positive and gram-negative, isolated from 8 substrates, had been demonstrated. With regard to the sensitivity of Pseudomonas aeruginosa >40% was observed in 40–50% of the strains to aminoglycosides – aztreonam, amikacin, netilmicin, and only 23–25% of the strains – to gentamicin and levofloxacin (an average of antibiotic susceptibility was 27%. All strains of ESBL Klebsiella drew up and were sensitive only to imipenem, meropenem and aminoglycosides. Specific phages lysed 43–48% of the strains Pseudomonas aeruginosa and Klebsiella pneumoniae, E. coli, Pro- teus spp., multidrug resistant strains of Staphylococcus spp. It is proposed to introduce the use of phages in clinical practice. 

  4. Microfluidic cantilever detects bacteria and measures their susceptibility to antibiotics in small confined volumes

    Science.gov (United States)

    Etayash, Hashem; Khan, M. F.; Kaur, Kamaljit; Thundat, Thomas

    2016-10-01

    In the fight against drug-resistant bacteria, accurate and high-throughput detection is essential. Here, a bimaterial microcantilever with an embedded microfluidic channel with internal surfaces chemically or physically functionalized with receptors selectively captures the bacteria passing through the channel. Bacterial adsorption inside the cantilever results in changes in the resonance frequency (mass) and cantilever deflection (adsorption stress). The excitation of trapped bacteria using infrared radiation (IR) causes the cantilever to deflect in proportion to the infrared absorption of the bacteria, providing a nanomechanical infrared spectrum for selective identification. We demonstrate the in situ detection and discrimination of Listeria monocytogenes at a concentration of single cell per μl. Trapped Escherichia coli in the microchannel shows a distinct nanomechanical response when exposed to antibiotics. This approach, which combines enrichment with three different modes of detection, can serve as a platform for the development of a portable, high-throughput device for use in the real-time detection of bacteria and their response to antibiotics.

  5. CIEF separation, UV detection, and quantification of ampholytic antibiotics and bacteria from different matrices.

    Science.gov (United States)

    Horká, Marie; Vykydalová, Marie; Růžička, Filip; Šalplachta, Jiří; Holá, Veronika; Dvořáčková, Milada; Kubesová, Anna; Šlais, Karel

    2014-10-01

    The effect of antibiotics on the microbial cells and concentration of antibiotics in the human body is essential for the effective use of antimicrobial therapy. The capillary isoelectric focusing is a suitable technique for the separation and the detection of bacteria, and amphoteric substances from nature. However, the determination of isoelectric points of ampholytic antibiotics by conventional techniques is time consuming. For this reason, capillary isoelectric focusing seems to be appropriate as a simple and reliable way for establishing them. The separation conditions for the capillary isoelectric focusing of selected ampholytic antibiotics with known isoelectric points and pK as, ampicillin (pI 4.9), ciprofloxacin (pI 7.4), ofloxacin (pI 7.1), tetracycline (pI 5.4), tigecycline (pI 9.7), and vancomycin (pI 8.1), were found and optimized in the suitable pH ranges pH 2.0-5.3, 2.0-9.6, and 9.0-10.4. The established values of isoelectric points correspond with those found in the literature except tigecycline. Its pI was not found in the literature. As an example of a possible procedure for direct detection of both ampholytic antibiotics and bacteria, Staphylococcus epidermidis, in the presence of culture media or whole human blood, was found. The changes of the bacterial cells after their treatment with tetracycline were confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Capillary isoelectric focusing allows the fast and simple determination of isoelectric points of relevant antibiotics, their quantification from the environment, as well as studying their effectiveness on microorganisms in biological samples.

  6. Characterization of antibiotic resistance in commensal bacteria from an aquaculture ecosystem

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    Ying eHuang

    2015-09-01

    Full Text Available The objective of the study was to improve understanding of antibiotic resistance (AR ecology through characterization of antibiotic resistant commensal isolates associated with an aquaculture production system. A total of 4767 isolates non-susceptible to sulfamethoxazole/trimethoprim, tetracycline, erythromycin, or cefotaxime, originated from fish, feed, and environmental samples of an aquaculture farm with no known history of antibiotic applications were examined. Close to 80% of the isolates exhibited multi-drug resistance in media containing the corresponding antibiotics, and representative AR genes were detected in various isolates by PCR, with feed isolates had the highest positive rate detected. Identified AR gene carriers involve 18 bacterial genera. Selected AR genes led to acquired resistance in other bacteria by transformation. The AR traits in many isolates were stable in the absence of selective pressure. AR-rich feed and possibly environmental factors may contribute to AR in the aquaculture ecosystem. For Minimum Inhibitory Concentration test, Brain Heart Infusion medium was found more suitable for majority of the bacteria examined than cation-adjusted Mueller Hinton broth, with latter being the recommended medium for clinical isolates by standard protocol. The data indicated a need to update the methodology due to genetic diversity of microbiota for better understanding of the AR ecology.

  7. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria.

    Science.gov (United States)

    Li, Xian-Zhi; Plésiat, Patrick; Nikaido, Hiroshi

    2015-04-01

    The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.

  8. Biochemical characterization of systemic bacteria in bananas, sensitivity to antibiotics and plant phytotoxicity during shoot proliferation

    Directory of Open Access Journals (Sweden)

    Janiffe Peres de Oliveira

    2016-04-01

    Full Text Available The objective of this work was to characterize the biochemically systemic bacterial isolated from banana plants, to evaluate the bacterial sensitivity to antibiotics, and to determine the phytotoxicity of banana shoots during in vitro proliferation. Systemic bacteria belonging to the Klebsiella and Aeromonas genera were isolated from the “Maravilha” (FHIA 01 AAAB, “Preciosa” (PV 4285 AAAB and “Thap Maeo” (AAB varieties and were then characterized. Tests of shoot sensitivity to antibiotics were performed, and the minimum inhibitory concentration (MIC and phytotoxic effects of selected antibiotics to plants were determined. Among the 20 antibiotics evaluated, the strains showed sensitivity to cefaclor, cefalexin, cefalotin, nalidixic acid, chloramphenicol, and vancomycin. However, during MIC determination, the best results were obtained with cefaclor, vancomycin or nalidixic acid alone in concentrations ranging from 512 to 1,024 mg L-1. In culture medium, cefaclor at 1,024 mg L-1 was the only antibiotic to affect the multiplication and the shoot survival in culture.

  9. ANTIBIOTIC RESISTANCE IN LACTIC ACID BACTERIA ISOLATED FROM FERMENTED DAIRY PRODUCTS AND BOZA

    Directory of Open Access Journals (Sweden)

    Gamze Başbülbül

    2015-06-01

    Full Text Available In this study, the resistance of 83 strains of lactic acid bacteria isolated from Turkish cheese, yogurt, kefir and boza samples to 6 antibiotics (gentamicin, tetracycline, chloramphenicol, erythromycin, vancomycin and ciprofloxacin was evaluated. The 83 isolates were identified by 16S rRNA gene sequencing and according to BLAST comparisons with sequences in the data banks, those strains showing the highest similarities with the isolates were Enterococcus faecium (10, Lactococcus lactis subsp. Lactis (10, Lactobacillus fermentum (6, Lactobacillus plantarum (6, Lactobacillus coryniformis (7, Lactobacillus casei (13, Leuconostoc mesenteroides (14, Pediococcus pentosaceus (10, Weisella confusa (7. Antimicrobial resistance of strains to 6 antibiotics was determined using the agar dilution method. The antibiotic resistance among all the isolates was detected against chloramphenicol (31,3 % of the isolates, tetracycline (30,1 %, erythromycin (2,4 %, ciprofloxacin (2,41%, vancomycin (73,5 %, intrinsic resistance. Overall 19,3 % of the isolates showed resistance against multiple antibiotics. Antibiotic resistance genes were studied by PCR and the following genes were detected; tet(M gene in Lactobacillus fermentum (1, Lactobacillus plantarum (1, Pediococcus pentosaceus (5, Enterococcus faecium (2, Weisella confusa (4 and the vancomycin resistance gene van(A in one Weisella confusa strain.

  10. Synergistic effect and antibiofilm activity between the antimicrobial peptide coprisin and conventional antibiotics against opportunistic bacteria.

    Science.gov (United States)

    Hwang, In-sok; Hwang, Jae-Sam; Hwang, Ji Hong; Choi, Hyemin; Lee, Eunjung; Kim, Yangmee; Lee, Dong Gun

    2013-01-01

    Coprisin is a 43-mer defensin-like peptide from the dung beetle, Copris tripartitus. In this study, we tested its minimum inhibitory concentration and performed combination assays to confirm the antibacterial susceptibility of coprisin and synergistic effects with antibiotics. The synergistic effects were evaluated by testing the effects of coprisin in combination with ampicillin, vancomycin, and chloramphenicol. The results showed that coprisin possessed antibacterial properties and had synergistic activities with the antibiotics. To understand the synergistic mechanism(s), we conducted hydroxyl radical assays. Coprisin alone and in combination with antibiotics generated hydroxyl radicals, which are highly reactive oxygen forms and the major property of bactericidal agents. Furthermore, the antibiofilm effect of coprisin alone and in combination with antibiotics was investigated. Biofilm formation is the source of many relentless and chronic bacterial infections. The results indicated that coprisin alone and in combination with antibiotics also had antibiofilm activity. Therefore, we conclude that coprisin has the potential to be used as a combinatorial therapeutic agent for the treatment of infectious diseases caused by bacteria.

  11. Enteropathogenic Escherichia coli, Samonella, Shigella and Yersinia: cellular aspects of host-bacteria interactions in enteric diseases

    Directory of Open Access Journals (Sweden)

    Reis Roberta

    2010-07-01

    Full Text Available Abstract A successful infection of the human intestine by enteropathogenic bacteria depends on the ability of bacteria to attach and colonize the intestinal epithelium and, in some cases, to invade the host cell, survive intracellularly and disseminate from cell to cell. To accomplish these processes bacteria have evolved an arsenal of molecules that are mostly secreted by dedicated type III secretion systems, and that interact with the host, subverting normal cellular functions. Here we overview the most important molecular strategies developed by enteropathogenic Escherichia coli, Salmonella enterica, Shigella flexneri, and Yersinia enterocolitica to cause enteric infections. Despite having evolved different effectors, these four microorganisms share common host cellular targets.

  12. Occurrence and distribution of multiple antibiotic-resistant bacteria of Enterobacteriaceae family in waters of Veraval coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Maloo, A.; Borade, S.; Dhawde, R.; Gajbhiye, S.N.; Dastager, S.G.

    Current investigation was aimed to the assess occurrence and distribution of multiple antibiotic-resistant bacteria of the Enterobacteriaceae family in surface and bottom waters along the Veraval coast. Comparative prevalence of drug...

  13. Quantifying Cost-Effectiveness of Controlling Nosocomial Spread of Antibiotic-Resistant Bacteria : The Case of MRSA

    NARCIS (Netherlands)

    Wassenberg, Marjan W. M.; de Wit, G. Ardine; van Hout, Ben A.; Bonten, Marc J. M.

    2010-01-01

    Background: The costs and benefits of controlling nosocomial spread of antibiotic-resistant bacteria are unknown. Methods: We developed a mathematical algorithm to determine cost-effectiveness of infection control programs and explored the dynamical interactions between different epidemiological var

  14. Tissue Microbiome Profiling Identifies an Enrichment of Specific Enteric Bacteria in Opisthorchis viverrini Associated Cholangiocarcinoma

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    Kern Rei Chng

    2016-06-01

    Full Text Available Cholangiocarcinoma (CCA is the primary cancer of the bile duct system. The role of bile duct tissue microbiomes in CCA tumorigenesis is unestablished. To address this, sixty primary CCA tumors and matched normals, from both liver fluke (Opisthorchis viverrini associated (OVa, n = 28 and non-O. viverrini associated (non-OVa, n = 32 cancers, were profiled using high-throughput 16S rRNA sequencing. A distinct, tissue-specific microbiome dominated by the bacterial families Dietziaceae, Pseudomonadaceae and Oxalobacteraceae was observed in bile duct tissues. Systemic perturbation of the microbiome was noted in tumor and paired normal samples (vs non-cancer normals for several bacterial families with a significant increase in Stenotrophomonas species distinguishing tumors vs paired normals. Comparison of parasite associated (OVa vs non-associated (non-OVa groups identified enrichment for specific enteric bacteria (Bifidobacteriaceae, Enterobacteriaceae and Enterococcaceae. One of the enriched families, Bifidobacteriaceae, was found to be dominant in the O. viverrini microbiome, providing a mechanistic link to the parasite. Functional analysis and comparison of CCA microbiomes revealed higher potential for producing bile acids and ammonia in OVa tissues, linking the altered microbiota to carcinogenesis. These results define how the unique microbial communities resident in the bile duct, parasitic infections and the tissue microenvironment can influence each other, and contribute to cancer.

  15. Tissue Microbiome Profiling Identifies an Enrichment of Specific Enteric Bacteria in Opisthorchis viverrini Associated Cholangiocarcinoma.

    Science.gov (United States)

    Chng, Kern Rei; Chan, Sock Hoai; Ng, Amanda Hui Qi; Li, Chenhao; Jusakul, Apinya; Bertrand, Denis; Wilm, Andreas; Choo, Su Pin; Tan, Damien Meng Yew; Lim, Kiat Hon; Soetinko, Roy; Ong, Choon Kiat; Duda, Dan G; Dima, Simona; Popescu, Irinel; Wongkham, Chaisiri; Feng, Zhu; Yeoh, Khay Guan; Teh, Bin Tean; Yongvanit, Puangrat; Wongkham, Sopit; Bhudhisawasdi, Vajaraphongsa; Khuntikeo, Narong; Tan, Patrick; Pairojkul, Chawalit; Ngeow, Joanne; Nagarajan, Niranjan

    2016-06-01

    Cholangiocarcinoma (CCA) is the primary cancer of the bile duct system. The role of bile duct tissue microbiomes in CCA tumorigenesis is unestablished. To address this, sixty primary CCA tumors and matched normals, from both liver fluke (Opisthorchis viverrini) associated (OVa, n=28) and non-O. viverrini associated (non-OVa, n=32) cancers, were profiled using high-throughput 16S rRNA sequencing. A distinct, tissue-specific microbiome dominated by the bacterial families Dietziaceae, Pseudomonadaceae and Oxalobacteraceae was observed in bile duct tissues. Systemic perturbation of the microbiome was noted in tumor and paired normal samples (vs non-cancer normals) for several bacterial families with a significant increase in Stenotrophomonas species distinguishing tumors vs paired normals. Comparison of parasite associated (OVa) vs non-associated (non-OVa) groups identified enrichment for specific enteric bacteria (Bifidobacteriaceae, Enterobacteriaceae and Enterococcaceae). One of the enriched families, Bifidobacteriaceae, was found to be dominant in the O. viverrini microbiome, providing a mechanistic link to the parasite. Functional analysis and comparison of CCA microbiomes revealed higher potential for producing bile acids and ammonia in OVa tissues, linking the altered microbiota to carcinogenesis. These results define how the unique microbial communities resident in the bile duct, parasitic infections and the tissue microenvironment can influence each other, and contribute to cancer.

  16. Comparative study of enteric viruses, coliphages and indicator bacteria for evaluating water quality in a tropical high-altitude system

    Directory of Open Access Journals (Sweden)

    Mazari-Hiriart Marisa

    2009-10-01

    Full Text Available Abstract Background Bacteria used as indicators for pathogenic microorganisms in water are not considered adequate as enteric virus indicators. Surface water from a tropical high-altitude system located in Mexico City that receives rainwater, treated and non-treated wastewater used for irrigation, and groundwater used for drinking, was studied. Methods The presence of enterovirus, rotavirus, astrovirus, coliphage, coliform bacteria, and enterococci was determined during annual cycles in 2001 and 2002. Enteric viruses in concentrated water samples were detected by reverse transcriptase-polymerase chain reaction (RT-PCR. Coliphages were detected using the double agar layer method. Bacteria analyses of the water samples were carried out by membrane filtration. Results The presence of viruses and bacteria in the water used for irrigation showed no relationship between current bacterial indicator detection and viral presence. Coliphages showed strong association with indicator bacteria and enterovirus, but weak association with other enteric viruses. Enterovirus and rotavirus showed significant seasonal differences in water used for irrigation, although this was not clear for astrovirus. Conclusion Coliphages proved to be adequate faecal pollution indicators for the irrigation water studied. Viral presence in this tropical high-altitude system showed a similar trend to data previously reported for temperate zones.

  17. Bacteria isolated from a sugarcane agroecosystem: their potential production of polyhydroxyalcanoates and resistance to antibiotics

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    Lima Teresa Cristina S. de

    1999-01-01

    Full Text Available In this investigation, a sugarcane agroecosystem at a coastal tableland, in the northeast of Brazil, was screened to obtain bacteria strains able to synthesize poly-b-hydroxyalkanoates (PHA, using sucrose as the main carbon source. The potential to synthesize PHA was tested qualitatively by Sudan Black staining of colonies growing in different carbon sources: sucrose, glucose, fructose, propionate and cellulose. In a typical sugarcane crop management system, the plantation is burned before harvesting and vinasse, a byproduct of alcohol production, is used in a fertirrigation system causing, probably, selective pressures on the microbiota of natural environments. Eightytwo bacteria strains, belonging to 16 different genera and 35 different species, were isolated. The data showed that 11 strains (ca 13%, nine of which belonging to the genus Pseudomonas, presented a strong Sudan Black staining in several carbon sources tested and, simultaneously, showed multiple resistance to antibiotics. Resistance to antibiotics is an advantageous feature for the biotechnological production of PHAs. The total number of isolates with multiple resistance to antibiotics was 73, and 38% of them belong to the genus Pseudomonas. Among the isolates, ca 86% and 43% grew in the presence of 10-100 U/ml of penicillin and/or 100-300 mg/ml of virginiamycin, respectively. These antibiotics are utilized in the alcohol distillery we investigated. The results suggest that some agroecosystem environments could be considered as habitats where bacteria are submitted to nutritional unbalanced conditions, resulting in strains with potential ability to produce PHAs, and also, to an increase in the microbial diversity.

  18. [Profile and sensitivity to antibiotics of 2063 uropathogenic bacteria isolated in the center of Tunisia].

    Science.gov (United States)

    Boukadida, J; Boukadida, N; Elraii, S

    2002-03-01

    Current bacteriological data are very useful when making therapeutic decisions in cases of non complicated urinary tract infection. In this article, we present the data gathered by a university hospital laboratory in mid-Tunisia as well as the results of 17,829 urinary cytobacteriological examinations conducted in a multidisciplinary hospital during the year 2000. Urine was sowed on usual agar. All bacterium cultivating at least 10(5) bacteria reported to ml and at 37 degrees C in a normal atmosphere was retained; identification and sensitivity to antibiotics of the bacterium followed the recommendations of the French Society of Microbiology. We collected 2063 non-redundant bacteria of which 82.3% came from female samples. Gram negative rods were distinctly predominant with 92% of the whole bacterium and Escherichia coli represented 67% of the whole of the germs; Staphylococcus saprophyticus with 4.8% and Streptococcus agalactiae with 1% dominated Gram positive bacteria. The susceptibility of bacteria to the principal antibiotics used for the treatment of the urinary tract infection was characterised by the low percentage of sensitivity of the Gram negative rods to amoxicillin (41.2% of sensitivity for Escherichia coli and 22% for the Proteus sp), and by cotrimoxazole which preserved an activity between 63.8% for Escherichia coli and 94.7% for Staphylococcus saprophyticus. The highest percentage of sensitivity was achieved by gentamicine (99.4% of Escherichia coli and 98.9% of Staphylococcus saprophyticus) and fluoroquinolons (97.8% of Escherichia coli and 100% of Staphylococcus saprophyticus are sensible); furadoin was active on almost all Escherichia coli and Staphylococcus saprophyticus. Apart from natural resistance, colistin was constantly active. Escherichia coli and Staphylococcus saprophyticus were the major agents of the urinary tract infection. Gentamicin and fluoroquinolons showed themselves to be constantly active antibiotics. Nitrofurans and colistin

  19. Antibiotic resistance in bacteria isolated from vegetables with regards to the marketing stage (farm vs. supermarket).

    Science.gov (United States)

    Schwaiger, Karin; Helmke, Katharina; Hölzel, Christina Susanne; Bauer, Johann

    2011-08-15

    The aim of this study was to elucidate whether and to what extent fresh produce from Germany plays a role as a carrier and reservoir of antibiotic resistant bacteria. For this purpose, 1001 vegetables (fruit, root, bulbous vegetables, salads and cereals) were collected from 13 farms and 11 supermarkets in Germany and examined bacteriologically. Phenotypic resistance of Enterobacter cloacae (n=172); Enterobacter gergoviae (n=92); Pantoea agglomerans (n=96); Pseudomonas aeruginosa (n=295); Pseudomonas putida (n=106) and Enterococcus faecalis (n=100) against up to 30 antibiotics was determined by using the microdilution method. Resistance to ß-lactams was most frequently expressed by P. agglomerans and E. gergoviae against cefaclor (41% and 29%). Relatively high resistance rates were also observed for doxycycline (23%), erythromycin (21%) and rifampicin (65%) in E. faecalis, for spectinomycin (28%) and mezlocillin (12%) in E. cloacae, as well as for streptomycin (19%) in P. putida. In P. aeruginosa, relatively low resistance rates were observed for the aminoglycosides amikacin, apramicin, gentamicin, neomycin, netilmicin and tobramycin (4%); 11% was resistant to streptomycin. No glycopeptide-resistant enterococci were observed. Resistance rates of bacteria isolated from farm samples were higher than those of the retail markets whenever significant differences were observed. This suggests that expressing resistance is at the expense of bacterial viability, since vegetables purchased directly at the farm are probably fresher than at the supermarket, and they have not been exposed to stress factors. However, this should not keep the customer from buying directly at the farm, since the overall resistance rates were not higher than observed in bacteria from human or animal origin. Instead, peeling or washing vegetables before eating them raw is highly recommended, since it reduces not only the risk of contact with pathogens, but also that of ingesting and spreading

  20. Synergistic effects of antimicrobial peptide DP7 combined with antibiotics against multidrug-resistant bacteria

    Science.gov (United States)

    Wu, Xiaozhe; Li, Zhan; Li, Xiaolu; Tian, Yaomei; Fan, Yingzi; Yu, Chaoheng; Zhou, Bailing; Liu, Yi; Xiang, Rong; Yang, Li

    2017-01-01

    Antibiotic-resistant bacteria present a great threat to public health. In this study, the synergistic effects of antimicrobial peptides (AMPs) and antibiotics on several multidrug-resistant bacterial strains were studied, and their synergistic effects on azithromycin (AZT)-resistance genes were analyzed to determine the relationships between antimicrobial resistance and these synergistic effects. A checkerboard method was used to evaluate the synergistic effects of AMPs (DP7 and CLS001) and several antibiotics (gentamicin, vancomycin [VAN], AZT, and amoxicillin) on clinical bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli). The AZT-resistance genes (ermA, ermB, ermC, mefA, and msrA) were identified in the resistant strains using quantitative polymerase chain reaction. For all the clinical isolates tested that were resistant to different antibiotics, DP7 had high antimicrobial activity (≤32 mg/L). When DP7 was combined with VAN or AZT, the effect was most frequently synergistic. When we studied the resistance genes of the AZT-resistant isolates, the synergistic effect of DP7–AZT occurred most frequently in highly resistant strains or strains carrying more than two AZT-resistance genes. A transmission electron microscopic analysis of the S. aureus strain synergistically affected by DP7–AZT showed no noteworthy morphological changes, suggesting that a molecular-level mechanism plays an important role in the synergistic action of DP7–AZT. AMP DP7 plus the antibiotic AZT or VAN is more effective, especially against highly antibiotic-resistant strains. PMID:28356719

  1. Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation.

    Science.gov (United States)

    Bengtsson-Palme, Johan; Larsson, D G Joakim

    2016-01-01

    There are concerns that selection pressure from antibiotics in the environment may accelerate the evolution and dissemination of antibiotic-resistant pathogens. Nevertheless, there is currently no regulatory system that takes such risks into account. In part, this is due to limited knowledge of environmental concentrations that might exert selection for resistant bacteria. To experimentally determine minimal selective concentrations in complex microbial ecosystems for all antibiotics would involve considerable effort. In this work, our aim was to estimate upper boundaries for selective concentrations for all common antibiotics, based on the assumption that selective concentrations a priori need to be lower than those completely inhibiting growth. Data on Minimal Inhibitory Concentrations (MICs) were obtained for 111 antibiotics from the public EUCAST database. The 1% lowest observed MICs were identified, and to compensate for limited species coverage, predicted lowest MICs adjusted for the number of tested species were extrapolated through modeling. Predicted No Effect Concentrations (PNECs) for resistance selection were then assessed using an assessment factor of 10 to account for differences between MICs and minimal selective concentrations. The resulting PNECs ranged from 8 ng/L to 64 μg/L. Furthermore, the link between taxonomic similarity between species and lowest MIC was weak. This work provides estimated upper boundaries for selective concentrations (lowest MICs) and PNECs for resistance selection for all common antibiotics. In most cases, PNECs for selection of resistance were below available PNECs for ecotoxicological effects. The generated PNECs can guide implementation of compound-specific emission limits that take into account risks for resistance promotion.

  2. Antisense RNA regulation and application in the development of novel antibiotics to combat multidrug resistant bacteria.

    Science.gov (United States)

    Ji, Yinduo; Lei, Ting

    2013-01-01

    Despite the availability of antibiotics and vaccines, infectious diseases remain one of most dangerous threats to humans and animals. The overuse and misuse of antibacterial agents have led to the emergence of multidrug resistant bacterial pathogens. Bacterial cells are often resilient enough to survive in even the most extreme environments. To do so, the organisms have evolved different mechanisms, including a variety of two-component signal transduction systems, which allow the bacteria to sense the surrounding environment and regulate gene expression in order to adapt and respond to environmental stimuli. In addition, some bacteria evolve resistance to antibacterial agents while many bacterial cells are able to acquire resistance genes from other bacterial species to enable them to survive in the presence of toxic antimicrobial agents. The crisis of antimicrobial resistance is an unremitting menace to human health and a burden on public health. The rapid increase in antimicrobial resistant organisms and limited options for development of new classes of antibiotics heighten the urgent need to develop novel potent antibacterial therapeutics in order to combat multidrug resistant infections. In this review, we introduce the regulatory mechanisms of antisense RNA and significant applications of regulated antisense RNA interference technology in early drug discovery. This includes the identification and evaluation of drug targets in vitro and in vivo, the determination of mode of action for antibiotics and new antibacterial agents, as well as the development of peptide-nucleic acid conjugates as novel antibacterials.

  3. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    Science.gov (United States)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D’Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-03-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  4. Levels and treatment options for enteric and antibiotic resistant bacteria in sewage from Sisimiut, Greenland

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Gunnarsdottir, Ragnhildur; Andersen, Henrik Rasmus;

    2013-01-01

    marine environment negatively. Both peracetic acid treatment and UV-C radiation shows potential for disinfection of the wastewater after removal of solids >60μm. E-coli was most susceptible to peracetic acid treatment, while a maximum possible reduction of enterococci and coliforms of 2-3 size orders...

  5. Re-sensitizing drug-resistant bacteria to antibiotics by designing Antisense Therapeutics

    Science.gov (United States)

    Courtney, Colleen; Chatterjee, Anushree

    2014-03-01

    ``Super-bugs'' or ``multi-drug resistant organisms'' are a serious international health problem, with devastating consequences to patient health care. The Center for Disease Control has identified antibiotic resistance as one of the world's most pressing public health problems as a significant fraction of bacterial infections contracted are drug resistant. Typically, antibiotic resistance is encoded by ``resistance-genes'' which express proteins that carryout the resistance causing functions inside the bacterium. We present a RNA based therapeutic strategy for designing antimicrobials capable of re-sensitizing resistant bacteria to antibiotics by targeting labile regions of messenger RNAs encoding for resistance-causing proteins. We perform in silico RNA secondary structure modeling to identify labile target regions in an mRNA of interest. A synthetic biology approach is then used to administer antisense nucleic acids to our model system of ampicillin resistant Escherichia coli. Our results show a prolonged lag phase and decrease in viability of drug-resistant E. colitreated with antisense molecules. The antisense strategy can be applied to alter expression of other genes in antibiotic resistance pathways or other pathways of interest.

  6. Antibiotic Resistance Patterns in Enteric and Uropathogenic Strains of Escherichia Coli in Children

    Directory of Open Access Journals (Sweden)

    This paper should be cited as: Sedighi I, Alikhani MY, Nakhaee S, Karami P . [ Antibiotic Resistance Patterns in Enteric and Uropathogenic Strains of Escherichia Coli in Children ]. mlj goums . 201 4 ; 8 ( Suppl 4 : 42 - 48 [Article in Per sian] Sedi ghi, I. (MD

    2014-11-01

    Full Text Available Background and Objective: Escherichia coli is the most common cause of urinary tract infections in children and the leading cause of intra-abdominal infections (peritonitis and abscess followed intestinal injuries. Urinary tract infection, including cystitis and pyelonephritis, is a common childhood infection. E. coli causes more than 90 percent of the community acquired and 50% of hospital acquired urinary tract infections; therefore, the determination of E. coli antibiotic susceptibility is a paramount importance to clinical and epidemiological purposes. Material and Methods: In this cross-sectional study, 50 E. coli strains isolated from urine samples of children less than 7 years of age with urinary tract infections. They were compared for drug susceptibility testing by disc diffusion method with 50 strains of Escherichia coli isolated from stool samples of healthy children with the same age and sex pattern. Results: The actual amount of drug sensitivity of uropathogenic and intestinal Escherichia coli strains to amikacin was 94 and 100%, nitrofurantoin 90 and 88%, gentamicin 66 and 94%, cefixime 56 and 60%, nalidixic acid 38 and 44% and to cotrimoxazole 28 and 32%, respectively. Conclusion: the rate of resistance to gentamicin, Cefixime and nalidixic acid in urinary tract infection isolates were more than intestinal strains. The highest rate of drug resistance in urinary Escherichia coli isolates was associated with cotrimoxazole and the lowest one with amikacin.

  7. Effect of heating and aging of poultry litter on the persistence of enteric bacteria.

    Science.gov (United States)

    Wilkinson, K G; Tee, E; Tomkins, R B; Hepworth, G; Premier, R

    2011-01-01

    Food-borne illnesses have rarely been associated with the reuse of poultry litter as an organic fertilizer and soil amendment in agriculture. Yet farming practices in many countries have come under increased scrutiny because of heightened consumer awareness of food safety and environmental issues. This study was conducted to determine whether simple on-farm management practices could improve the microbiological safety of poultry litter. First, the effects of heat and moisture on the survival of Escherichia coli and Salmonella enterica serovar Typhimurium in poultry litter were investigated under laboratory conditions. Second, the persistence and regrowth of enteric bacteria were examined in poultry litter that had been aged for up to 12 wk in either a turned or static (unturned) windrow. Escherichia coli and Salmonella counts in poultry litter were reduced by >99% in 1 h at 55 or 65°C under laboratory conditions. At 35°C, both persisted longer under moist (65% wt/wt, wet basis) than dry (30% wt/wt) conditions. Poultry litter aged for 3 wk in a turned windrow, and up to 6 wk in a static windrow, supported increased E. coli densities when incubated in the laboratory at 37°C for 21 d. Peak temperatures >65°C were observed in both windrows within the first 3 wk of aging; after this point, the turned windrow was more consistently exposed to temperatures >45°C than the static windrow. By 12 wk, however, E. coli counts were very similar (3 to 3.6 log(10)) in the outside edge of both windrows. This study highlights the need for a better understanding of the interrelationship between spontaneous heating in organic waste streams, organic matter stabilization, and pathogen reduction.

  8. Quantitative relationship between antibiotic exposure and the acquisition and transmission of resistance in bacteria in the laboratory

    NARCIS (Netherlands)

    Händel, N.

    2015-01-01

    The worldwide emergence and spread of antibiotic resistant bacteria represent a major threat to human health care as the chance of therapy failure and costs for treatment increase. To curb the continuous rise of drug resistant bacteria worldwide, new strategies are urgently needed that counteract th

  9. Nanosilver-marine fungal chitosan as antibiotic synergizers against sepsis fish bacteria

    Directory of Open Access Journals (Sweden)

    Khouloud Mohamed Barakat

    2016-01-01

    Full Text Available Background and Objectives: Mortality is highly variable within population of cultured fish due to virulent bacteria causing fish septicemia. The use of nano-silver marine fungal chitosan as antibiotic synergisers could be an alternative in the treatment of sepsis fish pathogens.Materials and Methods: Different bulk chitosan solutions were prepared from the mycelia of four marine fungi (Aspergillus terreus, Aspergillus flavipes, Tricoderma hamatum and Fennellia flavipes and used as capping agents for silver nanoparticles. In vitro, the antibacterial activity of these preparations was determined against nine fish-sepsis causing bacteria, alone and in combination with nine antibiotics of choice used in aquaculture. Prepared fungal chitosans (CsF were characterized by yield of chistosan obtained, degree of deacetylation and viscosity.Results and Conclusion: The maximum yield of chitosan (28% was obtained from Aspergillus terreus. A. terreus chitosan (CsF, silver nanoparticles (AgNPs and chitosan-silver nanoparticles (CsF-AgNPs showed maximum activity at the minimum inhibitory concentrations average (MICAVG 27.2, 18.2 and 7.9 μg/ml, respectively. Combination of CsF –AgNPs with amikacin (Ak and rifampicin (RD reduced the MIC values by 96 and 94%, respectively, with fractional inhibitory concentration index (FICI = 0.42 and 0.50 as synergistic effect. It is promising to use CsF-AgNPs as enhancing agent in combination with antibiotics for fish sepsis therapy.Keywords: Marine fungal chitosan, nanosilver, bacterial sepsis, antibiotics, synergy

  10. Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages.

    Science.gov (United States)

    Fraqueza, Maria João

    2015-11-06

    Dry-fermented sausages are meat products highly valued by many consumers. Manufacturing process involves fermentation driven by natural microbiota or intentionally added starter cultures and further drying. The most relevant fermentative microbiota is lactic acid bacteria (LAB) such as Lactobacillus, Pediococcus and Enterococcus, producing mainly lactate and contributing to product preservation. The great diversity of LAB in dry-fermented sausages is linked to manufacturing practices. Indigenous starters development is considered to be a very promising field, because it allows for high sanitary and sensorial quality of sausage production. LAB have a long history of safe use in fermented food, however, since they are present in human gastrointestinal tract, and are also intentionally added to the diet, concerns have been raised about the antimicrobial resistance in these beneficial bacteria. In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance transmission from animal to human bacterial populations. The World Health Organization 2014 report on global surveillance of antimicrobial resistance reveals that this issue is no longer a future prediction, since evidences establish a link between the antimicrobial drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the possible sources and transmission routes of antibiotic resistant LAB of dry-fermented sausages, presenting LAB antibiotic resistance profile and related genetic determinants. Whenever LAB are used as starters in dry-fermented sausages processing, safety concerns regarding antimicrobial resistance should be addressed since antibiotic resistant genes could be mobilized and transferred to other bacteria.

  11. Microbiological air quality in some kindergartens and antibiotic resistance of bacteria of the Staphylococcus spp. genus

    Directory of Open Access Journals (Sweden)

    Łukasz Kubera

    2015-02-01

    Full Text Available Background: Microbiological contamination of the air and the acquisition of the antibiotic resistance by pathogenic bacteria is a growing phenomenon that has a substantial impact on the quality of our health. This problem applies mainly to public areas where we spend a large part of our lives. This study was focused on the microbiological analysis of the air in some kindergartens and antibiotic resistance of bacteria of the Stephylococcus spp. genus. The identification of the isolated mould fungi has been also made. Material and Methods: Air samples were collected from classrooms in the seasonal cycle in the mornings and afternoons using 2 methods, sedimentation and impact. Air samples collected outside the kindergartens served as controls. Air quality assessments were based on the groups of indicator microorganisms, according to Polish standards. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, using 8 different classes of antibiotics, in line with the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST. Results: The analyses show that, regardless of the method, the total number of heterothropic bacteria and staphylococci in the air of the analyzed kindergartens exceeded the allowable limits. There was no air pollution with the fungal infection. Based on the antibiogram, it was found that Staphylococcus spp. strains showed the highest sensitivity to chloramphenicol and the lowest to penicillin and gentamicin. Among the fungi moulds of the genus Cladosporium predominated. Conclusions: The results of the analyses highlight the need for regular health checks and further research to help identify biological factors that may significantly affect the quality of health of people living in public spaces. Med Pr 2015;66(1:49–56

  12. Multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS) for urinary tract infection (UTI) diagnosis

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-06-01

    The inappropriate use of antibiotics leads to antibiotic resistance, which is a major health care problem. The current method for determination of bacterial susceptibility to antibiotics requires overnight cultures. However most of the infections cannot wait for the results to receive treatment, so physicians administer general spectrum antibiotics. This results in ineffective treatments and aggravates the rising problem of antibiotic resistance. In this work, a rapid method for diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. The advantages of this novel method include its rapidness and efficiency which will potentially allow doctors to prescribe the most appropriate antibiotic for an infection. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Bacterial strains were diluted in order to reach the concentration of (2x105 cfu/ml), cells/ml which is equivalent to the minimum concentration found in urine samples from UTIs. Even though the concentration of bacteria was low, species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. This technique can be applied directly to urine samples, and with the enhancement provided by SERS, this method has the potential to be developed into a rapid method for same day UTI diagnosis and antibiogram.

  13. New rapid and simple methods for detection of bacteria and determination of their antibiotic susceptibility by using phage mutants.

    Science.gov (United States)

    Ulitzur, Nirit; Ulitzur, Shimon

    2006-12-01

    Three new methods applying a novel approach for rapid and simple detection of specific bacteria, based on plaque formation as the end point of the phage lytic cycle, are described. Different procedures were designed to ensure that the resulting plaques were derived only from infected target bacteria ("infectious centers"). (i) A pair of amber mutants that cannot form plaques at concentrations lower than their reversion rate underwent complementation in the tested bacteria; the number of plaques formed was proportional to the concentration of the bacteria that were coinfected by these phage mutants. (ii) UV-irradiated phages were recovered by photoreactivation and/or SOS repair mediated by target bacteria and plated on a recA uvrA bacterial lawn in the dark to avoid recovery of noninfecting phages. (iii) Pairs of temperature-sensitive mutants were allowed to coinfect their target bacteria at the permissive temperature, followed by incubation of the plates at the restrictive temperature to avoid phage infection of the host cells. This method allowed the omission of centrifuging and washing the infected cells. Only phages that recovered by recombination or complementation were able to form plaques. The detection limit was 1 to 10 living Salmonella or Escherichia coli O157 cells after 3 to 5 h. The antibiotic susceptibility of the target bacteria could also be determined in each of these procedures by preincubating the target bacteria with antibiotic prior to phage infection. Bacteria sensitive to the antibiotic lost the ability to form infectious centers.

  14. Similarities and differences in combined toxicity of sulfonamides and other antibiotics towards bacteria for environmental risk assessment.

    Science.gov (United States)

    Fang, Shuxia; Wang, Dali; Zhang, Xiaoxian; Long, Xi; Qin, Mengnan; Lin, Zhifen; Liu, Ying

    2016-07-01

    Antibiotics as a type of environmental contaminants are typically exposed to chemical mixtures over long periods of time, so chronic combined toxicity is the best way to perform an environmental risk assessment. In this paper, the individual and combined toxicity of sulfonamides (SAs), sulfonamide potentiators (SAPs), and doxycycline hyclate (DH) were tested on gram-positive (Bacillus subtilis, B. subtilis) and gram-negative (Escherichia coli, E. coli) bacteria. The individual toxicity of antibiotics on the two bacteria could be ranked in the same order: SAs antibiotics, which was likely due to both the different abilities of antibiotics to pass through the cell membrane and the varied capacities to bind target proteins between the two bacteria. In addition, the binary mixtures of SAs-SAPs, SAs-DH, and SAs-SAs exhibited synergistic, antagonistic, and additive effects on both of the bacteria but in different magnitudes as represented by the toxicity units (TU). And we found the different TU values were result from the different effective concentrations of antibiotic mixtures based on the approach of molecular docking and quantitative structure-activity relationships (QSARs). Moreover, from the results of risk assessment, it should be noted that the mixture of SAs and other antibiotics may pose a potential environmental risk assessment due to their combined action with the current environmentally realistic concentrations.

  15. Antibiotic Agents

    Science.gov (United States)

    ... Superbugs and Drugs" Home | Contact Us General Background: Antibiotic Agents What is an antibacterial and how are ... with the growth and reproduction of bacteria. While antibiotics and antibacterials both attack bacteria, these terms have ...

  16. Effect of betamethasone in combination with antibiotics on gram positive and gram negative bacteria.

    Science.gov (United States)

    Artini, M; Papa, R; Cellini, A; Tilotta, M; Barbato, G; Koverech, A; Selan, L

    2014-01-01

    Betamethasone is an anti-inflammatory steroid drug used in cases of anaphylactic and allergic reactions, of Alzheimer and Addison diseases and in soft tissue injuries. It modulates gene expression for anti-inflammatory activity suppressing the immune system response. This latter effect might decrease the effectiveness of immune system response against microbial infections. Corticosteroids, in fact, mask some symptoms of infection and during their use superimposed infections may occur. Thus, the use of glucocorticoids in patients with sepsis remains extremely controversial. In this study we analyzed the in vitro effect of a commercial formulation of betamethasone (Bentelan) on several Gram positive and Gram negative bacteria of clinical relevance. It was found to be an inhibitor of the growth of most of the strains examined. Also the effect of betamethasone in combination with some classes of antibiotics was evaluated. Antibiotic-steroid combination therapy is, in such cases, superior to antibiotic-alone treatment to impair bacterial growths. Such effect was essentially not at all observable on Staphylococcus aureus or Coagulase Negative Staphylococci (CoNS).

  17. Antagonism and Molecular Identification of an Antibiotic Bacterium BS04 Against Phytopathogenic Fungi and Bacteria

    Institute of Scientific and Technical Information of China (English)

    Xie Jing(谢晶); Ge Shaorong; Tao Yong; Gao Ping; Liu Kun; Liu Shigui

    2004-01-01

    Through a modified agar well diffusion assay, antagonism of bacterium BS04 is tested. The data show that BS04 has antibiotic activity against phytopathogenic fungi and bacteria, including Phoma wasabiae Yokogi, Cochlibolus Heterostrophu, Exserohilum Turcicum, Curuvularia Lunata (Walk) Boed, Thantephorus cucumris, Fusarium graminearum, Xanthomonas axonopodis pv. Citri (Hasse) Dye and Xanthomonas zingiberi (Uyeda) Savulescu. The products of bacterium BS04 can endure the treatment of a wide range of pH, and maintain the antibiotic activity after treatment of 100℃ for 30 min. The result suggests that bacterium BS04 has the potential as a promising biocontrol agent. In order to determine the taxonomic placement, the molecular identification of BS04 is performed. The comparative analysis of 16s rDNA sequences indicates that the 16s rDNA sequence of BS04 is highly homologous with sequences of typical Paenibacillus bacteria from the RPD library (from 92% to 99%). And the constructed phylogenetic tree by using maximum-likelihood method with Bootstrap Trial 1000 proves that BS04 is subjected to Paenibacillus polymyxa.

  18. Antibiotic Resistant Bacteria And Their Associated Resistance Genes in a Conventional Municipal Wastewater Treatment Plant

    KAUST Repository

    Aljassim, Nada I.

    2013-12-01

    With water scarcity as a pressing issue in Saudi Arabia and other Middle Eastern countries, the treatment and reuse of municipal wastewater is increasingly being used as an alternative water source to supplement country water needs. Standards are in place to ensure a safe treated wastewater quality, however they do not regulate pathogenic bacteria and emerging contaminants. Information is lacking on the levels of risk to public health associated with these factors, the efficiency of conventional treatment strategies in removing them, and on wastewater treatment in Saudi Arabia in general. In this study, a municipal wastewater treatment plant in Saudi Arabia is investigated to assess the efficiency of conventional treatment in meeting regulations and removing pathogens and emerging contaminants. The study found pathogenic bacterial genera, antibiotic resistance genes and antibiotic resistant bacteria, many of which were multi-resistant in plant discharges. It was found that although the treatments are able to meet traditional quality guidelines, there remains a risk from the discussed contaminants with wastewater reuse. A deeper understanding of this risk, and suggestions for more thorough guidelines and monitoring are needed.

  19. Antibiotic Resistance of Probiotic Strains of Lactic Acid Bacteria Isolated from Marketed Foods and Drugs

    Institute of Scientific and Technical Information of China (English)

    CHANG LIU; ZHUO-YANG ZHANG; KE DONG; JIAN-PING YUAN; XIAO-KUI GUO

    2009-01-01

    Objective To identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probioties. Methods Antimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR. Results Distribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis. Conclusion Antibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.

  20. Sewage sludge and liquid pig manure as possible sources of antibiotic resistant bacteria.

    Science.gov (United States)

    Hölzel, Christina S; Schwaiger, Karin; Harms, Katrin; Küchenhoff, Helmut; Kunz, Anne; Meyer, Karsten; Müller, Christa; Bauer, Johann

    2010-05-01

    Within the last decades, the environmental spread of antibiotic resistant bacteria has become a topic of concern. In this study, liquid pig manure (n=305) and sewage sludge (n=111) - used as agricultural fertilizers between 2002 and 2005 - were investigated for the presence of Escherichia coli, Enterococcus faecalis and Enterococcus faecium. Bacteria were tested for their resistance against 40 chemotherapeutics including several "reserve drugs". E. coli (n=613) from pig manure were at a significantly higher degree resistant to streptomycin, doxycycline, spectinomycin, cotrimoxazole, and chloramphenicol than E. coli (n=116) from sewage sludge. Enterococci (Ent. faecalis, n=387, and Ent. faecium, n=183) from pig manure were significantly more often resistant to high levels of doxycycline, rifampicin, erythromycin, and streptomycin than Ent. faecalis (n=44) and Ent. faecium (n=125) from sewage sludge. Significant differences in enterococcal resistance were also seen for tylosin, chloramphenicol, gentamicin high level, fosfomycin, clindamicin, enrofloxacin, moxifloxacin, nitrofurantoin, and quinupristin/dalfopristin. By contrast, aminopenicillins were more effective in enterococci from pig manure, and mean MIC-values of piperacillin+tazobactam and third generation cefalosporines were significantly lower in E. coli from pig manure than in E. coli from sewage sludge. 13.4% (E. coli) to 25.3% (Ent. faecium) of pig manure isolates were high-level multiresistant to substances from more than three different classes of antimicrobial agents. In sewage sludge, high-level-multiresistance reached from 0% (Ent. faecalis) to 16% (Ent. faecium). High rates of (multi-) resistant bacteria in pig manure emphasize the need for a prudent - cautious - use of antibiotics in farm animals.

  1. Ciprofloxacin residue and antibiotic-resistant biofilm bacteria in hospital effluent.

    Science.gov (United States)

    Ory, Jérôme; Bricheux, Geneviève; Togola, Anne; Bonnet, Jean Louis; Donnadieu-Bernard, Florence; Nakusi, Laurence; Forestier, Christiane; Traore, Ousmane

    2016-07-01

    Discharge of antimicrobial residues and resistant bacteria in hospital effluents is supposed to have strong impacts on the spread of antibiotic resistant bacteria in the environment. This study aimed to characterize the effluents of the Gabriel Montpied teaching hospital, Clermont-Ferrand, France, by simultaneously measuring the concentration of ciprofloxacin and of biological indicators resistant to this molecule in biofilms formed in the hospital effluent and by comparing these data to ciprofloxacin consumption and resistant bacterial isolates of the hospital. Determination of the measured environmental concentration of ciprofloxacin by spot sampling and polar organic chemical integrative (POCIS) sampling over 2 weeks, and comparison with predicted environmental concentrations produced a hazard quotient >1, indicating a potential ecotoxicological risk. A negative impact was also observed with whole hospital effluent samples using the Tetrahymena pyriformis biological model. During the same period, biofilms were formed within the hospital effluent, and analysis of ciprofloxacin-resistant isolates indicated that Gamma-Proteobacteria were numerous, predominantly Aeromonadaceae (69.56%) and Enterobacteriaceae (22.61%). Among the 115 isolates collected, plasmid-mediated fluoroquinolone-resistant genes were detected, with mostly aac(6')-lb-cr and qnrS. In addition, 60% of the isolates were resistant to up to six antibiotics, including molecules mostly used in the hospital (aminosides and third-generation cephalosporins). In parallel, 1247 bacteria isolated from hospitalized patients and resistant to at least one of the fluoroquinolones were collected. Only 5 of the 14 species identified in the effluent biofilm were also found in the clinical isolates, but PFGE typing of the Gram-negative isolates found in both compartments showed there was no clonality among the strains. Altogether, these data confirm the role of hospital loads as sources of pollution for wastewater

  2. Antibiotic resistance profiles among mesophilic aerobic bacteria in Nigerian chicken litter and associated antibiotic resistance genes1.

    Science.gov (United States)

    Olonitola, Olayeni Stephen; Fahrenfeld, Nicole; Pruden, Amy

    2015-05-01

    The effect of global antibiotic use practices in livestock on the emergence of antibiotic resistant pathogens is poorly understood. There is a paucity of data among African nations, which suffer from high rates of antibiotic resistant infections among the human population. Escherichia (29.5%), Staphylococcus (15.8%), and Proteus (15.79%) were the dominant bacterial genera isolated from chicken litter from four different farms in Zaria, Nigeria, all of which contain human pathogenic members. Escherichia isolates were uniformly susceptible to augmentin and cefuroxime, but resistant to sulfamethoxazole (54.5%), ampicillin (22.7%), ciprofloxacin (18.2%), cephalothin (13.6%) and gentamicin (13.6%). Staphylococcus isolates were susceptible to ciprofloxacin, gentamicin, and sulfamethoxazole, but resistant to tetracycline (86.7%), erythromycin (80%), clindamycin (60%), and penicillin (33.3%). Many of the isolates (65.4%) were resistant to multiple antibiotics, with a multiple antibiotic resistance index (MARI) ≥ 0.2. sul1, sul2, and vanA were the most commonly detected antibiotic resistance genes among the isolates. Chicken litter associated with antibiotic use and farming practices in Nigeria could be a public health concern given that the antibiotic resistant patterns among genera containing pathogens indicate the potential for antibiotic treatment failure. However, the MARI values were generally lower than reported for Escherichia coli from intensive poultry operations in industrial nations.

  3. Antibacterial activity of Thymus maroccanus and Thymus broussonetii essential oils against nosocomial infection - bacteria and their synergistic potential with antibiotics.

    Science.gov (United States)

    Fadli, Mariam; Saad, Asmaa; Sayadi, Sami; Chevalier, Jacqueline; Mezrioui, Nour-Eddine; Pagès, Jean-Marie; Hassani, Lahcen

    2012-03-15

    The aim of this study was to evaluate the antibacterial effect of the association between conventional antibiotics and essential oils (EOs) of endemic Moroccan thyme species, Thymus maroccanus and T. broussonetii, on antibiotic-resistant bacteria involved in nosocomial infections. Synergistic interactions between antibiotics (ciprofloxacin, gentamicin, pristinamycin, and cefixime) and EOs, and between T. maroccanus and T. Broussonetii EOs were determined by the checkerboard test. Serial dilutions of two antimicrobial agents were mixed together so that each row (and column) contained a fixed amount of the first agent and increasing amounts of the second one. The results indicate that the oils had a high inhibitory activity against tested bacteria, except for Pseudomonas aeruginosa. In parallel with the increase of cellular killing, the release of 260nm-absorbing materials from bacterial cells, treated with EOs, increased in response to oil concentration. Out of 80 combinations tested between EOs and antibiotics, 71% showed total synergism, 20% had partial synergistic interaction and 9% showed no effect. Combination with carvacrol, the major constituent of T. maroccanus and T. broussonetii, showed also an interesting synergistic effect in combination with ciprofloxacin. The effect on Gram-positive bacteria was more important than on Gram-negative bacteria. These findings are very promising since the use of these combinations for nosocomial infections treatment is likely to reduce the minimum effective dose of the antibiotics, thus minimizing their possible toxic side effects and treatment cost. However, further investigations are needed to assess the potential for therapeutic application.

  4. Utilization of Fenton-like reaction for antibiotics and resistant bacteria elimination in different parts of WWTP.

    Science.gov (United States)

    Mackuľak, Tomáš; Nagyová, Kristína; Faberová, Milota; Grabic, Roman; Koba, Olga; Gál, Miroslav; Birošová, Lucia

    2015-09-01

    Utilization of relatively low-cost modification of Fenton reaction for the elimination of selected antibiotics and resistant coliforms in different part of wastewater treatment plant (WWTP) was studied. The concentration of antibiotics and occurrence of resistant gems in different stages of WWTP in the capital city of Slovakia - Bratislava was analyzed by LC-MS/MS technique. Consequently, Fenton-like reaction was applied for the elimination of chemical and biological contaminants. Comparative study with classical Fenton reaction was also done. Very high concentrations of clarithromycin, ciprofloxacin and azithromycin in influent water were found. Coliform bacteria were predominantly resistant to ampicillin, ciprofloxacin and gentamicin. After the mechanical stage, the concentration of antibiotics in water was significantly decreased because of the sorption during this step. Biological step degraded 12 types of antibiotics. Analyses of effluent water showed very bad elimination of azithromycin (919ng/L) and clarithromycin (684ng/L). Contrary, ciprofloxacin was removed with very high efficiency (95%). The number of resistant bacteria was also significantly decreased in effluent water. In the case of Escherichia coli only ampicillin and gentamicin resistance bacteria were detected. Our results show that antibiotics as well as resistant bacteria were eliminated by the modification of classical Fenton reaction with high efficiency. The modification of the Fenton reaction can decrease the process wages, environmental impact. Moreover, the degradation process was easily controlled, monitored and tuned.

  5. Fate and transport of veterinary antibiotics, antibiotic-resistant bacteria, and antibiotic resistance gene from fields receiving poultry manure during storm events

    Science.gov (United States)

    Antimicrobials are used in production agriculture to treat disease and promote animal growth, but the presence of antibiotics in the environment raises concern about widespread antibiotic resistance. This study documents the occurrence and transport of tylosin, tetracycline, enterococci resistant to...

  6. Nontoxic colloidal particles impede antibiotic resistance of swarming bacteria by disrupting collective motion and speed

    Science.gov (United States)

    Lu, Shengtao; Liu, Fang; Xing, Bengang; Yeow, Edwin K. L.

    2015-12-01

    A monolayer of swarming B. subtilis on semisolid agar is shown to display enhanced resistance against antibacterial drugs due to their collective behavior and motility. The dynamics of swarming motion, visualized in real time using time-lapse microscopy, prevents the bacteria from prolonged exposure to lethal drug concentrations. The elevated drug resistance is significantly reduced when the collective motion of bacteria is judiciously disrupted using nontoxic polystyrene colloidal particles immobilized on the agar surface. The colloidal particles block and hinder the motion of the cells, and force large swarming rafts to break up into smaller packs in order to maneuver across narrow spaces between densely packed particles. In this manner, cohesive rafts rapidly lose their collectivity, speed, and group dynamics, and the cells become vulnerable to the drugs. The antibiotic resistance capability of swarming B. subtilis is experimentally observed to be negatively correlated with the number density of colloidal particles on the engineered surface. This relationship is further tested using an improved self-propelled particle model that takes into account interparticle alignment and hard-core repulsion. This work has pertinent implications on the design of optimal methods to treat drug resistant bacteria commonly found in swarming colonies.

  7. Transferable and non-transferable drug resistance in enteric bacteria from hospital and from general practice

    DEFF Research Database (Denmark)

    Møller, JK; Bak, AL; Bülow, P;

    1976-01-01

    Drug resistance to 8 different antibiotics in Enterobacteriaceae isolated from different hospitals and two groups of general practitioners was studied. Escherichia coli dominated among the 632 strains investigated. Drug resistance was found in 62% of the 512 hospital strains and in 38% of the 120...

  8. Occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing head and neck radiotherapy

    Directory of Open Access Journals (Sweden)

    Elerson Gaetti-Jardim Júnior

    2011-09-01

    Full Text Available The aim of this study was to evaluate the occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing radiotherapy (RT for treatment of head and neck cancer. Fifty patients receiving RT were examined before, during and 30 days after RT. Saliva, mucosa, and biofilm samples were collected and microorganisms were detected by culture and polymerase chain reaction (PCR. The most prevalent yeasts in patients submitted to RT were Candida albicans, C. tropicalis, C. krusei, C. glabrata and C. parapsilosis. Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, and Pseudomonas were the most frequently cultivated bacteria. Before RT, targeted bacteria were cultivated from 22.2% of edentulous patients and 16.6% of dentate patients; 30 days after RT, these microorganisms were recovered from 77.8% edentulous and 46.8% dentate patients. By PCR, these microorganisms were detected from all edentulous patients, 78.1% of dentate patients. The presence of Gram-negative enteric roads and fungi was particularly frequent in patients presenting mucositis level III or IV. Modifications in the oral environment due to RT treatment seem to facilitate the colonization of oral cavity by members of family Enterobacteriaceae, genera Enterococcus and Candida.

  9. Effects of reducing beta-lactam antibiotic pressure on intestinal colonization of antibiotic-resistant gram-negative bacteria

    NARCIS (Netherlands)

    S. Nijssen (Saskia); A.C. Fluit (Ad); D.A.M.C. van de Vijver (David); J. Top (Janetta); R.J.L. Willems (Rob); M.J.M. Bonten (Marc)

    2010-01-01

    textabstractBackground: We determined the effects of two antibiotic policies (predominance of either β-lactam antibiotics or fluroquinolones) on acquisition with third-generation cephalosporin-resistant Enterobacteriaceae (CRE) and fluoroquinolone-resistant CRE (FCRE) in two ICUs, with monitoring of

  10. Evaluation of new antibiotic cocktails against contaminating bacteria found in allograft tissues.

    Science.gov (United States)

    Serafini, Agnese; Riello, Erika; Trojan, Diletta; Cogliati, Elisa; Palù, Giorgio; Manganelli, Riccardo; Paolin, Adolfo

    2016-12-01

    Contamination of retrieved tissues is a major problem for allograft safety. Consequently, tissue banks have implemented decontamination protocols to eliminate microorganisms from tissues. Despite the widespread adoption of these protocols, few comprehensive studies validating such methods have been published. In this manuscript we compare the bactericidal activity of different antibiotic cocktails at different temperatures against a panel of bacterial species frequently isolated in allograft tissues collected at the Treviso Tissue Bank Foundation, a reference organization of the Veneto Region in Italy that was instituted to select, recover, process, store and distribute human tissues. We were able to identify at least two different formulations capable of killing most of the bacteria during prolonged incubation at 4 °C.

  11. Isolation of bacteria causing urinary tract infection and their antibiotic resistance profile

    Directory of Open Access Journals (Sweden)

    Leandro Antonio Soares

    2010-11-01

    Full Text Available Urinary tract infection (UTI is among the most frequent causes bringing male and female patients to the municipal health units in search of treatment. This paper aims at identifying the microorganisms responsible for this infection and at establishing their resistance profile against the antibiotics most commonly used in the municipal network. One hundred and twenty samples from patients clinically suspect to have UTI were collected and differentiated in CLED, MacConkey e chromogenic EC culture media in the Microbiology Laboratory I of the “Centro Universitário Positivo-UNICEP”. Positive samples were identified and characterized by antibiogram. 63,64% of the infections were caused by Escherichia coli and 18,18% by Staphylococcus aureus. More than 60% of the infections occurred in the age range from 12 to 33 years. The high number of samples found contaminated is an indicator for a certain difficulty in following the instructions for sample collection. Another relevant data is that 35,8% of the analyzed samples came from pregnant women. The antibiotics to which the bacteria responsible for UTI are sensitive are in great part not available at the Unified Health System but most of the isolated E.coli bacteria and 100% of Saureus showed sensitivity to the drugs Nitrofurantoin and Sulfametoxazole-trimetropim, which are available in the health units. With a compatible clinical picture, an empirical treatment with the referred drugs can be considered adequate, however post-therapy control examinations would be ideal for avoiding the appearance of resistant strains in the community.

  12. Comparison of different disinfection processes in the effective removal of antibiotic-resistant bacteria and genes.

    Science.gov (United States)

    Oh, Junsik; Salcedo, Dennis Espineli; Medriano, Carl Angelo; Kim, Sungpyo

    2014-06-01

    This study compared three different disinfection processes (chlorination, E-beam, and ozone) and the efficacy of three oxidants (H2O2, S2O(-)8, and peroxymonosulfate (MPS)) in removing antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in a synthetic wastewater. More than 30 mg/L of chlorine was needed to remove over 90% of ARB and ARG. For the E-beam method, only 1 dose (kGy) was needed to remove ARB and ARG, and ozone could reduce ARB and ARG by more than 90% even at 3 mg/L ozone concentration. In the ozone process, CT values (concentration × time) were compared for ozone alone and combined with different catalysts based on the 2-log removal of ARB and ARG. Ozone treatment yielded a value of 31 and 33 (mg·min)/L for ARB and ARGs respectively. On the other hand, ozone with persulfate yielded 15.9 and 18.5 (mg·min)/L while ozone with monopersulfate yielded a value of 12 and 14.5 (mg·min)/L. This implies that the addition of these catalysts significantly reduces the contact time to achieve a 2-log removal, thus enhancing the process in terms of its kinetics.

  13. [Production of hydrolases by lactic acid bacteria and bifidobacteria and their antibiotic resistance].

    Science.gov (United States)

    Novik, G I; Astanovich, N I; Riabaia, N E

    2007-01-01

    It was demonstrated that bifidobacteria and lactic acid bacteria B. adolescentis and Lactobacillus sp. synthesized extracellular enzymes cleaving glycoside bonds in the molecules of dextran, pectic acid, and soluble starch. The maximal production of extracellular beta-galactosidase by B. adolescentis 91-BIM and 94-BIM at a rate of 0.08 and 0.03 U/mg h was observed during the exponential growth phase at 5 and 12 h of cultivation, respectively. The cultures of bifidobacteria retained 60-70% of beta-galactosidase and alpha-amylase activities after six months of storage. The bifidobacterium strains studied were resistant to amphotericin and aminoglycosides (gentamicin, kanamycin, and netromycin). The lactam antibiotics (ampicillin, benzylpenicillin, bicillin 3, bicillin 5, and carbenicillin), the preparations inhibiting protein synthesis at the level of ribosomes (lincomycin), RNA polymerase inhibitors (rifampin), cephalosporin, and Maxipime inhibited the growth of bifidobacteria. Rifampin, erythromycin, amphotericin, Maxipime, Fortum, doxycycline, levomycetin, streptomycin, and the aminoglycosides netromycin, gentamicin, and kanamycin did not have an effect on the growth of Lactobacillus sp., whereas semisynthetic derivatives of penicillin, carbenicillin and ampicillin, inhibited its growth as well as Oxamp and lincomycin. The lactam antibiotics benzylpenicillin, bicillin 3, and bicillin 5 inhibited the growth of lactic acid bacilli by 30-90%.

  14. Evolution of peptidoglycan biosynthesis under the selective pressure of antibiotics in Gram-positive bacteria.

    Science.gov (United States)

    Mainardi, Jean-Luc; Villet, Régis; Bugg, Timothy D; Mayer, Claudine; Arthur, Michel

    2008-03-01

    Acquisition of resistance to the two classes of antibiotics therapeutically used against Gram-positive bacteria, the glycopeptides and the beta-lactams, has revealed an unexpected flexibility in the peptidoglycan assembly pathway. Glycopeptides select for diversification of the fifth position of stem pentapeptides because replacement of D-Ala by D-lactate or D-Ser at this position prevents binding of the drugs to peptidoglycan precursors. The substitution is generally well tolerated by the classical D,D-transpeptidases belonging to the penicillin-binding protein family, except by low-affinity enzymes. Total elimination of the fifth residue by a D,D-carboxypeptidase requires a novel cross-linking enzyme able to process the resulting tetrapeptide stems. This enzyme, an L,D-transpeptidase, confers cross-resistance to beta-lactams and glycopeptides. Diversification of the side chain of the precursors, presumably in response to the selective pressure of peptidoglycan endopeptidases, is controlled by aminoacyl transferases of the Fem family that redirect specific aminoacyl-tRNAs from translation to peptidoglycan synthesis. Diversification of the side chains has been accompanied by a parallel divergent evolution of the substrate specificity of the L,D-transpeptidases, in contrast to the D,D-transpeptidases, which display an unexpected broad specificity. This review focuses on the role of antibiotics in selecting or counter-selecting diversification of the structure of peptidoglycan precursors and their mode of polymerization.

  15. Evaluation of post-antibiotic effect in Gram-negative and Gram-positive bacteria

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    Elisa Tavella

    2008-03-01

    Full Text Available Although the postantibiotic effect (PAE is a well recognized phenomenon, the mechanism by which it is induced has not fully elucidated yet. It has been suggested that PAE is the time required by bacteria to synthesize proteins or mRNA characterized by a short half-life that are consumed during antibiotic treatment.This phenomenon is widely studied on Gram-positive cocci and Gram-negative rods, while information about Gram-positive rods and Gram-negative cocci are scanty.To gain new insights on the PAE, this study was addressed to evaluated the time required by Moraxella catarrhalis and Lactobacillus planctarum to resume their physiological growth rate after exposure to various antibiotics. Methods PAE was estimated in accordance with the method of Craig and Gudmundsson using the following drugs: penicillin, piperacillin-tazobactam, cefalotin, ceftazidime, imipenem, ciprofloxacin, gentamycin and azithromycin. Log-phase bacteria were exposed to drug at a concentration corresponding to 4 times the MIC value for 1h.The drug was inactivated by 1:1000 dilution. Bacterial counts were determined at time zero, immediately after drug dilution, and at each hour after removal for 6 - 7h by a pour-plate technique. The PAE was defined as the difference in time required by test and control cultures to increase by 1 log in CFU number. Results All drugs tested induced a PAE on the strains studied. M. catarrhalis registered PAE values ranging between 0,5 (gentamycin and 2 (ceftazidime, imipenem and azithromycin.With respect to L. plantarum a PAE between 0,8 (cefalotin and 3 hours (ciprofloxacin were detected. Conclusion. These findings demonstrated that all the drugs tested were able to induce a PAE on the strains tested.This observation differs from that observed on Gram-negative rods characterised by negative PAE values induced by penicillins and cephalosporins.This results might reflect the different target of these compounds on these Gram-positive rods or the

  16. Cultivation and qPCR detection of pathogenic and antibiotic resistant bacteria establishment in naive broiler houses

    Science.gov (United States)

    : Conventional commercial broiler production involves the rearing of more than 20,000 broilers in a single confined space, atop bedding material such as pine shavings or rice hulls, for approximately 6.5 weeks. This environment is known for harboring pathogens and antibiotic resistant bacteria, but ...

  17. Antibiotic resistant bacteria as bio-indicator of polluted effluent in the green turtles, Chelonia mydas in Oman.

    Science.gov (United States)

    Al-Bahry, Saif N; Mahmoud, Ibrahim Y; Al-Zadjali, Maheera; Elshafie, Abdulkader; Al-Harthy, Asila; Al-Alawi, Wafaa

    2011-03-01

    Antibiotic resistant bacteria were studied as bio-indicators of marine polluted effluents during egg-laying in green turtles. A non-invasive procedure for sampling oviductal fluid was used to test for exposure of turtles to pollution in Ras Al-Hadd, Oman, which is one of the most important nesting beaches in the world. Each sample was obtained by inserting a 15 cm sterile swab gently into the cloacal vent as the sphincter muscle is relaxed and the cloacal lining is unfolded to the outside. Forty turtles were sampled. A hundred and thirty-two species of bacteria from 7 genera were isolated. The dominant isolate was Citrobacter. Among the isolates 60.6% were multiple resistant to 15 tested antibiotics. The dominant resistance to antibiotics was ampicillin followed by streptomycin and sulphamethoxazole. Sampling oviductal fluid for resistant bacteria to antibiotics is valuable way to assess exposure to polluted effluents during feeding and migratory in turtles. Polluted effluents using bacteria as bio-indicator may influence reproductive potential in this endangered species.

  18. Effect of subtherapeutic administration of antibiotics on the prevalence of antibiotic-resistant Escherichia coli bacteria in feedlot cattle.

    Science.gov (United States)

    Alexander, T W; Yanke, L J; Topp, E; Olson, M E; Read, R R; Morck, D W; McAllister, T A

    2008-07-01

    Antibiotic-resistant Escherichia coli in 300 feedlot steers receiving subtherapeutic levels of antibiotics was investigated through the collection of 3,300 fecal samples over a 314-day period. Antibiotics were selected based on the commonality of use in the industry and included chlortetracycline plus sulfamethazine (TET-SUL), chlortetracycline (TET), virginiamycin, monensin, tylosin, or no antibiotic supplementation (control). Steers were initially fed a barley silage-based diet, followed by transition to a barley grain-based diet. Despite not being administered antibiotics prior to arrival at the feedlot, the prevalences of steers shedding TET- and ampicillin (AMP)-resistant E. coli were >40 and <30%, respectively. Inclusion of TET-SUL in the diet increased the prevalence of steers shedding TET- and AMP-resistant E. coli and the percentage of TET- and AMP-resistant E. coli in the total generic E. coli population. Irrespective of treatment, the prevalence of steers shedding TET-resistant E. coli was higher in animals fed grain-based compared to silage-based diets. All steers shed TET-resistant E. coli at least once during the experiment. A total of 7,184 isolates were analyzed for MIC of antibiotics. Across antibiotic treatments, 1,009 (13.9%), 7 (0.1%), and 3,413 (47.1%) E. coli isolates were resistant to AMP, gentamicin, or TET, respectively. In addition, 131 (1.8%) and 143 (2.0%) isolates exhibited potential resistance to extended-spectrum beta-lactamases, as indicated by either ceftazidime or cefpodoxime resistance. No isolates were resistant to ciprofloxacin. The findings of the present study indicated that subtherapeutic administration of tetracycline in combination with sulfamethazine increased the prevalence of tetracycline- and AMP-resistant E. coli in cattle. However, resistance to antibiotics may be related to additional environmental factors such as diet.

  19. Bacterial fitness shapes the population dynamics of antibiotic-resistant and -susceptible bacteria in a model of combined antibiotic and anti-virulence treatment

    Science.gov (United States)

    Ternent, Lucy; Dyson, Rosemary J.; Krachler, Anne-Marie; Jabbari, Sara

    2015-01-01

    Bacterial resistance to antibiotic treatment is a huge concern: introduction of any new antibiotic is shortly followed by the emergence of resistant bacterial isolates in the clinic. This issue is compounded by a severe lack of new antibiotics reaching the market. The significant rise in clinical resistance to antibiotics is especially problematic in nosocomial infections, where already vulnerable patients may fail to respond to treatment, causing even greater health concern. A recent focus has been on the development of anti-virulence drugs as a second line of defence in the treatment of antibiotic-resistant infections. This treatment, which weakens bacteria by reducing their virulence rather than killing them, should allow infections to be cleared through the body׳s natural defence mechanisms. In this way there should be little to no selective pressure exerted on the organism and, as such, a predominantly resistant population should be less likely to emerge. However, before the likelihood of resistance to these novel drugs emerging can be predicted, we must first establish whether such drugs can actually be effective. Many believe that anti-virulence drugs would not be powerful enough to clear existing infections, restricting their potential application to prophylaxis. We have developed a mathematical model that provides a theoretical framework to reveal the circumstances under which anti-virulence drugs may or may not be successful. We demonstrate that by harnessing and combining the advantages of antibiotics with those provided by anti-virulence drugs, given infection-specific parameters, it is possible to identify treatment strategies that would efficiently clear bacterial infections, while preventing the emergence of antibiotic-resistant subpopulations. Our findings strongly support the continuation of research into anti-virulence drugs and demonstrate that their applicability may reach beyond infection prevention. PMID:25701634

  20. Bacterial fitness shapes the population dynamics of antibiotic-resistant and -susceptible bacteria in a model of combined antibiotic and anti-virulence treatment.

    Science.gov (United States)

    Ternent, Lucy; Dyson, Rosemary J; Krachler, Anne-Marie; Jabbari, Sara

    2015-05-07

    Bacterial resistance to antibiotic treatment is a huge concern: introduction of any new antibiotic is shortly followed by the emergence of resistant bacterial isolates in the clinic. This issue is compounded by a severe lack of new antibiotics reaching the market. The significant rise in clinical resistance to antibiotics is especially problematic in nosocomial infections, where already vulnerable patients may fail to respond to treatment, causing even greater health concern. A recent focus has been on the development of anti-virulence drugs as a second line of defence in the treatment of antibiotic-resistant infections. This treatment, which weakens bacteria by reducing their virulence rather than killing them, should allow infections to be cleared through the body׳s natural defence mechanisms. In this way there should be little to no selective pressure exerted on the organism and, as such, a predominantly resistant population should be less likely to emerge. However, before the likelihood of resistance to these novel drugs emerging can be predicted, we must first establish whether such drugs can actually be effective. Many believe that anti-virulence drugs would not be powerful enough to clear existing infections, restricting their potential application to prophylaxis. We have developed a mathematical model that provides a theoretical framework to reveal the circumstances under which anti-virulence drugs may or may not be successful. We demonstrate that by harnessing and combining the advantages of antibiotics with those provided by anti-virulence drugs, given infection-specific parameters, it is possible to identify treatment strategies that would efficiently clear bacterial infections, while preventing the emergence of antibiotic-resistant subpopulations. Our findings strongly support the continuation of research into anti-virulence drugs and demonstrate that their applicability may reach beyond infection prevention.

  1. Antibiotic resistant bacteria/genes dissemination in lacustrine sediments highly increased following cultural eutrophication of Lake Geneva (Switzerland).

    Science.gov (United States)

    Thevenon, Florian; Adatte, Thierry; Wildi, Walter; Poté, John

    2012-02-01

    This study investigates faecal indicator bacteria (FIB), multiple antibiotic resistant (MAR), and antibiotic resistance genes (ARGs), of sediment profiles from different parts of Lake Geneva (Switzerland) over the last decades. MARs consist to expose culturable Escherichia coli (EC) and Enterococcus (ENT) to mixed five antibiotics including Ampicillin, Tetracycline, Amoxicillin, Chloramphenicol and Erythromycin. Culture-independent is performed to assess the distribution of ARGs responsible for, β-lactams (blaTEM; Amoxicillin/Ampicillin), Streptomycin/Spectinomycin (aadA), Tetracycline (tet) Chloramphenicol (cmlA) and Vancomycin (van). Bacterial cultures reveal that in the sediments deposited following eutrophication of Lake Geneva in the 1970s, the percentage of MARs to five antibiotics varied from 0.12% to 4.6% and 0.016% to 11.6% of total culturable EC and ENT, respectively. In these organic-rich bacteria-contaminated sediments, the blaTEM resistant of FIB varied from 22% to 48% and 16% to 37% for EC and ENT respectively, whereas the positive PCR assays responsible for tested ARGs were observed for EC, ENT, and total DNA from all samples. The aadA resistance gene was amplified for all the sediment samples, including those not influenced by WWTP effluent water. Our results demonstrate that bacteria MARs and ARGs highly increased in the sediments contaminated with WWTP effluent following the cultural eutrophication of Lake Geneva. Hence, the human-induced changing limnological conditions highly enhanced the sediment microbial activity, and therein the spreading of antibiotic resistant bacteria and genes in this aquatic environment used to supply drinking water in a highly populated area. Furthermore, the presence of the antibiotic resistance gene aadA in all the studied samples points out a regional dissemination of this emerging contaminant in freshwater sediments since at least the late nineteenth century.

  2. Antimicrobial resistance in bacteria from breeding dogs housed in kennels with differing neonatal mortality and use of antibiotics.

    Science.gov (United States)

    Milani, C; Corrò, M; Drigo, M; Rota, A

    2012-10-01

    This work examines the antimicrobial resistance of potentially pathogenic bacteria (Staphylococcus pseudintermedius, Streptococcus canis, Escherichia coli) found in the vaginal tract in prepartum mammary secretions and postpartum milk of bitches housed in breeding kennels (N = 20; 92 bitches). The kennels were divided into three categories: no routine antimicrobial administration around parturition (category 1); routine administration of one antibiotic around parturition (category 2); routine administration of multiple antimicrobials around parturition (category 3). Bacteriological cultures and antibiotic susceptibility tests were performed on vaginal specimens, prepartum mammary secretions, and postpartum milk. Stillbirths and neonatal deaths were recorded for each whelping and analyzed as "within-litter stillbirths" and "within-litter neonatal deaths" according to kennel category, by Pearson χ(2) test and the Kruskal-Wallis nonparametric test, respectively. The frequency of isolation and antimicrobial resistance of bacteria were analyzed according to kennel category by Pearson χ(2) test. Kennel category was not significantly associated with differing numbers of stillbirths or neonatal death events, nor was the frequency of isolation of potentially pathogenic bacteria in the three kennel categories significantly different. Kennel category 3 had a significantly higher frequency of isolation of multiresistant gram-positive bacterial strains. Our results show that intense administration of antibiotics to breeding bitches does not effectively reduce neonatal mortality; on the contrary, it induces multiresistance in potentially pathogenic bacteria. Breeders and veterinarians should be aware of the risk of selecting pathogenic bacteria by uncontrolled treatment in prepartum bitches.

  3. The Survey of Withani somnifera Extraction against Resistant Strains of Pseudomonas aeruginosa Bacteria to Selective Antibiotics

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    Mohammad Bokaeian

    2015-11-01

    Full Text Available Introduction:  Due  to  more  resistance  of  pathogenic  bacteria  to  new  and  current antibiotics  researchers  are  looking  to  find  the  agents  of  herbal  with  antimicrobial activities in order to replace chemical drugs.Methods:   The herbal extract of Withani somnifera was done by using a rotary vacuum,20 strains of Pseudomons aeruginosa were isolated from urinary infections hospitalized patients  in  city of Zabol  hospital.  The  MIC  Withani  somnifera  were  determined  by dilution method in various concentrations. Sensitivity of strains to multiple antibiotics was evaluated by standard disk diffusion Kirby-Bauer.Results:    The  result  showed  that  P.  aeruginosa  were  resistance  to  4  of the  agents including ampicillin  (85%, nitrofurantoin  (65%, nalidixic acid  (65%, ciprofloxacin (15% and for 5 strains of Pseudomonas showed MIC with activity of 100 ppm.Conclusion:   This  study  has  suggested  the  effect  of  winter  cherry  extract  on  P. aeruginosa in the in vitro assay. It s effectiveness of on in vivo system can be examined in future.

  4. Potential use of Bacillus thuringiensis bacteriocins to control antibiotic-resistant bacteria associated with mastitis in dairy goats.

    Science.gov (United States)

    Gutiérrez-Chávez, A J; Martínez-Ortega, E A; Valencia-Posadas, M; León-Galván, M F; de la Fuente-Salcido, N M; Bideshi, D K; Barboza-Corona, J E

    2016-01-01

    Mastitis caused by microbial infections in dairy goats reduces milk yield, modifies milk composition, and potentially contributes to morbidity in herds and consumers of dairy products. Microorganisms associated with mastitis in dairy goats are commonly controlled with antibiotics, but it is known that continued use of these chemical agents promotes antibiotic resistance among bacterial populations. Recently, it has been shown that bacteriocins of Bacillus thuringiensis inhibit growth of food-borne pathogens and also bacteria associated with bovine mastitis. However, there is no report on their ability to inhibit microorganisms linked to mastitis in dairy goats. In this study, using 16S rDNA and ITS regions of rDNA, we identified nine bacterial isolates and an encapsulated yeast associated with mastitis in dairy goats. Enterococcus durans, Brevibacillus sp., and Staphylococcus epidermidis 2 were resistant to, respectively, 75, ~67, ~42, and ~42 % of the antibiotics screened. In addition, 60 % of the bacterial isolates were resistant to penicillin, ampicillin, vancomycin, and dicloxacillin. Importantly, 60 % of the isolates were inhibited by the bacteriocins, but S. epidermidis 1, Enterobacter sp., Escherichia vulneris, and Cryptococcus neoformans were not susceptible to these antimicrobial peptides. Using Brevibacillus sp. and Staphylococcus chromogenes as indicator bacteria, we show that peptides of ~10 kDa that correspond to the molecular mass of bacteriocins used in this study are responsible for the inhibitory activity. Our results demonstrate that multiple antibiotic-resistant bacteria associated with subclinical mastitis in dairy goats from Guanajuato, Mexico, are susceptible to bacteriocins produced by B. thuringiensis.

  5. Antibiotic combinatorial approach utilized against extended spectrum beta-lactamase (ESBL bacteria isolates from Enugu, South Eastern Nigeria

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    Ruth A. Afunwa

    2014-04-01

    Full Text Available Introduction: Antibiotic options in the treatment of extended spectrum beta-lactamase (ESBL producing bacteria are very limited. The purpose of this study was to analyze several commonly applied antibiotics in quite various novel combinations for use against ESBL-producing bacteria isolates.Methods: Total of 460 samples of urine, throat and anal swab were collected from volunteers and patients from nursery, primary and secondary schools and from other individuals in the community. Hospital and community isolates comprised of 65% and 35% respectively. The identification and characterization of the isolates were done by standard culturing and in vitro antibiotic sensitivity procedures.Results: The antibiotic combination studies showed that the combination of gentamicin with the other antibiotics had predominantly synergistic effects. The percentage synergistic effect for the combinations of gentamicin/pefloxacin was 69%, gentamicin/[Amoxicillin and clavulanic acid] 72%, gentamicin/ceftriaxone 68%, gentamicin/cefuroxime 81.9%, and gentamicin/ciprofloxacin 80.6%, against the community and hospital derived ESBL producing organisms of both Enterobacteriaceae and Pseudomonas species.Conclusion: Good antimicrobial monitoring exercise and corresponding antimicrobial screening activities should work towards a dynamic approach to generate effective treatment options using combination therapy.

  6. Selective grazing from protist over enteric bacteria in an aquatic system

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, M. S.; Escalante, A. H.; Folabella, A. M.; Zamora, A. S.

    2009-07-01

    Its very clear that the grazing from protozoan can be an important source of mortality for the suspended bacteria, both in marine and freshwater environments. Considering that the presence of fecal contamination its a frequent phenomenon in this environments, and that Escherichia coli and members of Enterococcus genera are indicators of microbiology water quality, we analyze the effect of grazing from protozoan over E. coli and Enterococcus faecalis in de Los Padres Lagoon waters (Buenos Aires, Argentina) 37 degree centigrade 56'30'' S, 57 degree centigrade 44'30'' W). (Author)

  7. A novel combination approach of human polyclonal IVIG and antibiotics against multidrug-resistant Gram-positive bacteria

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    Sallam MM

    2016-12-01

    Full Text Available Mariam Madkour Sallam, Khaled Abou-Aisha, Mohamed El-Azizi Department of Microbiology, Immunology, and Biotechnology, Faculty of Pharmacy and Biotechnology, German University in Cairo, New Cairo City, Cairo, Egypt Background: Gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA and enterococci, have shown a remarkable ability to develop resistance to antimicrobial agents. Objective: We aimed to assess possible enhancement of the antimicrobial activity of vancomycin, amoxicillin, clarithromycin, and azithromycin by human polyclonal intravenous immunoglobulin G (IVIG against 34 multidrug-resistant (MDR bacterial isolates, including MRSA, Enterococcus faecium, and Enterococcus faecalis. Materials and methods: Double combinations of the antibiotics with the IVIG were assessed by checkerboard assay, where the interaction was evaluated with respect to the minimum inhibitory concentration (MIC of the antibiotics. The results of the checkerboard assay were verified in vitro using time-kill assay and in vivo using an invasive sepsis murine model. Results: The checkerboard assay showed that IVIG enhanced the antimicrobial activity of amoxicillin and clarithromycin against isolates from the three groups of bacteria, which were resistant to the same antibiotics when tested in the absence of IVIG. The efficacy of vancomycin against 15% of the tested isolates was enhanced when it was combined with the antibodies. Antagonism was demonstrated in 47% of the E. faecalis isolates when clarithromycin was combined with the IVIG. Synergism was proved in the time-kill assay when amoxicillin was combined with the antibodies; meanwhile, antagonism was not demonstrated in all tested combinations, even in combinations that showed such response in checkerboard assay. Conclusion: The suggested approach is promising and could be helpful to enhance the antimicrobial activity of not only effective antibiotics but also antibiotics that have

  8. A novel combination approach of human polyclonal IVIG and antibiotics against multidrug-resistant Gram-positive bacteria

    Science.gov (United States)

    Sallam, Mariam Madkour; Abou-Aisha, Khaled; El-Azizi, Mohamed

    2016-01-01

    Background Gram-positive bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA) and enterococci, have shown a remarkable ability to develop resistance to antimicrobial agents. Objective We aimed to assess possible enhancement of the antimicrobial activity of vancomycin, amoxicillin, clarithromycin, and azithromycin by human polyclonal intravenous immunoglobulin G (IVIG) against 34 multidrug-resistant (MDR) bacterial isolates, including MRSA, Enterococcus faecium, and Enterococcus faecalis. Materials and methods Double combinations of the antibiotics with the IVIG were assessed by checkerboard assay, where the interaction was evaluated with respect to the minimum inhibitory concentration (MIC) of the antibiotics. The results of the checkerboard assay were verified in vitro using time-kill assay and in vivo using an invasive sepsis murine model. Results The checkerboard assay showed that IVIG enhanced the antimicrobial activity of amoxicillin and clarithromycin against isolates from the three groups of bacteria, which were resistant to the same antibiotics when tested in the absence of IVIG. The efficacy of vancomycin against 15% of the tested isolates was enhanced when it was combined with the antibodies. Antagonism was demonstrated in 47% of the E. faecalis isolates when clarithromycin was combined with the IVIG. Synergism was proved in the time-kill assay when amoxicillin was combined with the antibodies; meanwhile, antagonism was not demonstrated in all tested combinations, even in combinations that showed such response in checkerboard assay. Conclusion The suggested approach is promising and could be helpful to enhance the antimicrobial activity of not only effective antibiotics but also antibiotics that have been proven to be ineffective against MDR bacteria. To our knowledge, this combinatorial approach against MDR bacteria, such as MRSA and enterococci, has not been investigated before. PMID:27994476

  9. Diversity and dynamics of antibiotic-resistant bacteria in cheese as determined by PCR denaturing gradient gel electrophoresis.

    Science.gov (United States)

    Flórez, Ana Belén; Mayo, Baltasar

    2015-12-01

    This work reports the composition and succession of tetracycline- and erythromycin-resistant bacterial communities in a model cheese, monitored by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Bacterial 16S rRNA genes were examined using this technique to detect structural changes in the cheese microbiota over manufacturing and ripening. Total bacterial genomic DNA, used as a template, was extracted from cultivable bacteria grown without and with tetracycline or erythromycin (both at 25 μg ml(-1)) on a non-selective medium used for enumeration of total and viable cells (Plate Count agar with Milk; PCA-M), and from those grown on selective and/or differential agar media used for counting various bacterial groups; i.e., lactic acid bacteria (de Man, Rogosa and Sharpe agar; MRSA), micrococci and staphylococci (Baird-Parker agar; BPA), and enterobacteria (Violet Red Bile Glucose agar; VRBGA). Large numbers of tetracycline- and erythromycin-resistant bacteria were detected in cheese samples at all stages of ripening. Counts of antibiotic-resistant bacteria varied widely depending on the microbial group and the point of sampling. In general, resistant bacteria were 0.5-1.0 Log10 units fewer in number than the corresponding susceptible bacteria. The PCR-DGGE profiles obtained with DNA isolated from the plates for total bacteria and the different bacterial groups suggested Escherichia coli, Lactococcus lactis, Enterococcus faecalis and Staphylococcus spp. as the microbial types resistant to both antibiotics tested. This study shows the suitability of the PCR-DGGE technique for rapidly identifying and tracking antibiotic resistant populations in cheese and, by extension, in other foods.

  10. Multiple Antibiotic Resistance and Heavy Metal Resistance Profile of Bacteria Isolated from Giant Freshwater Prawn (Macrobrachium rosenbergii) Hatchery

    Institute of Scientific and Technical Information of China (English)

    S W Lee; M Najiah; W Wendy; A Zahrol; M Nadirah

    2009-01-01

    In this article,antibiogram and heavy metal resistance profile of bacteria isolated from giant freshwater prawn (Macrobrachium rosenbergii) hatchery in Malaysia are described.Although giant freshwater prawn was introduced into Malaysia since the 1980s,there was no database information on antibiogram and heavy metal resistance profile of bacteria from giant freshwater prawn (M.rosenbergii) hatchery in Malaysia.Therefore,this study was carried out to determine the effectiveness of antibiotic and heavy metal resistance profile to control bacterial diseases in M.rosenbergii hatchery.The results can provide valuable information for local M.rosenbergii post-larval producer.Antibiotic sensitivity test was carried out by disk-diffusion method against 15 types of antibiotics as follows:oxolinic acid (2 μg),ampicillin (10 μg),erythromycin (15 μg),furazolidone (15 μg),lincomycin (15 μg),amoxicillin (25 μg),col istin sulphate (25 μg),doxycycline (30 μg),florfenicol (30 μg),flumequine (30 μg),nalidixic acid (30 μg),tetracycline (30 μg),oleandomyein (15 μg),fosfomycin (50 μg),and spiramycin (100 μg),whereas heavy metal resistance profile of the present bacterial isolates was determined by 2-fold agar dilution technique.In this study,5 types of bacteria were successfully isolated;they were Aeromonas spp.(n= 77),Escherichia coil (n = 73),Edwardsiella spp.(n = 62),Salmonella spp.(n= 75),and Vibrio spp.(n = 43).The result showed that furazolidone was the most effective antibiotic to control the bacteria isolated in this study,approximately 89.7% of the bacterial isolates were sensitive to this antibiotic.Multiple antibiotic resistance (MAR) index indicated that the hatchery water source and M.rosenbergii post-larval and sediment tanks were at high-risk exposure to the tested antibiotic.Furthermore,all the tested heavy metals (Cd2+,Cr6+ Hg2+,and Cu2+) failed to inhibit the growth of the bacterial isolates.Therefore,it indicated that the water source of the hatchery is

  11. The Role of Reactive Oxygen Species in Antibiotic-Induced Cell Death in Burkholderia cepacia Complex Bacteria.

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    Heleen Van Acker

    Full Text Available It was recently proposed that bactericidal antibiotics, besides through specific drug-target interactions, kill bacteria by a common mechanism involving the production of reactive oxygen species (ROS. However, this mechanism involving the production of hydroxyl radicals has become the subject of a lot of debate. Since the contribution of ROS to antibiotic mediated killing most likely depends on the conditions, differences in experimental procedures are expected to be at the basis of the conflicting results. In the present study different methods (ROS specific stainings, gene-expression analyses, electron paramagnetic resonance, genetic and phenotypic experiments, detection of protein carbonylation and DNA oxidation to measure the production of ROS upon antibiotic treatment in Burkholderia cepacia complex (Bcc bacteria were compared. Different classes of antibiotics (tobramycin, ciprofloxacin, meropenem were included, and both planktonic and biofilm cultures were studied. Our results indicate that some of the methods investigated were not sensitive enough to measure antibiotic induced production of ROS, including the spectrophotometric detection of protein carbonylation. Secondly, other methods were found to be useful only in specific conditions. For example, an increase in the expression of OxyR was measured in Burkholderia cenocepacia K56-2 after treatment with ciprofloxacin or meropenem (both in biofilms and planktonic cultures but not after treatment with tobramycin. In addition results vary with the experimental conditions and the species tested. Nevertheless our data strongly suggest that ROS contribute to antibiotic mediated killing in Bcc species and that enhancing ROS production or interfering with the protection against ROS may form a novel strategy to improve antibiotic treatment.

  12. Removal of total and antibiotic resistant bacteria in advanced wastewater treatment by ozonation in combination with different filtering techniques.

    Science.gov (United States)

    Lüddeke, Frauke; Heß, Stefanie; Gallert, Claudia; Winter, Josef; Güde, Hans; Löffler, Herbert

    2015-02-01

    Elimination of bacteria by ozonation in combination with charcoal or slow sand filtration for advanced sewage treatment to improve the quality of treated sewage and to reduce the potential risk for human health of receiving surface waters was investigated in pilot scale at the sewage treatment plant Eriskirch, Baden-Wuerttemberg/Germany. To determine the elimination of sewage bacteria, inflowing and leaving wastewater of different treatment processes was analysed in a culture-based approach for its content of Escherichia coli, enterococci and staphylococci and their resistance against selected antibiotics over a period of 17 month. For enterococci, single species and their antibiotic resistances were identified. In comparison to the established flocculation filtration at Eriskirch, ozonation plus charcoal or sand filtration (pilot-scale) reduced the concentrations of total and antibiotic resistant E. coli, enterococci and staphylococci. However, antibiotic resistant E. coli and staphylococci apparently survived ozone treatment better than antibiotic sensitive strains. Neither vancomycin resistant enterococci nor methicillin resistant Staphylococcus aureus (MRSA) were detected. The decreased percentage of antibiotic resistant enterococci after ozonation may be explained by a different ozone sensitivity of species: Enterococcus faecium and Enterococcus faecalis, which determined the resistance-level, seemed to be more sensitive for ozone than other Enterococcus-species. Overall, ozonation followed by charcoal or sand filtration led to 0.8-1.1 log-units less total and antibiotic resistant E. coli, enterococci and staphylococci, as compared to the respective concentrations in treated sewage by only flocculation filtration. Thus, advanced wastewater treatment by ozonation plus charcoal or sand filtration after common sewage treatment is an effective tool for further elimination of microorganisms from sewage before discharge in surface waters.

  13. [Investigation for Filamentous Bacteria Community Diversity in Activated Sludge Under Various Kinds and Concentration Conditions of Antibiotics].

    Science.gov (United States)

    Wang, Run-fang; Wang, Qin; Zhang, Hong; Qi, Rong

    2015-06-01

    Three kinds of synthetic antibiotic (spiramycin, oxytetracycline, streptomycin) wastewater were continuously treated by parallel aerobic biofilm reactors for 6 months, respectively. Sludge bulking phenomenon caused by overgrowth of filamentous bacteria was observed under long-term high rbCOD and high C/N conditions in all reactors as showed by the Eikelboom and Jenkins examinations. The qualitative analysis of filamentous bacterial population in the biofilm and suspended sludge using fluorescence in situ hybridization (FISH) showed that the dominated filamentous bacteria in the bioreactor were N. limicola II and Thiothrix II. Under conditions of different antibiotic concentrations (5 mg x L(-1), 25 mg x L(-1)), there was no obvious change in the COD removal efficiency of the parallel reactors, while the NH4+ -N concentration (about 20 mg x L(-1)) occurred under high streptomycin concentration. The filamentous bacteria abundance was reduced with the increasing antibiotic concentration, especially significant for N. limicola II. Terramycin had a significant inhibitory effect on filamentous bacteria population, followed by Streptomycin and Spiramycin.

  14. Antibiotic- and heavy-metal resistance in bacteria isolated from deep subsurface in El Callao region, Venezuela

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    Maura Lina Rojas Pirela

    2014-12-01

    Full Text Available The effect of contamination with mercury (Hg in the deep subsurface bacterial communities in the region of El Callao (Bolívar State, Venezuela was investigated. Bacterial communities from two deep levels (-288 m and -388 m in a gold mine were studied with the aim of describe the most relevant features of their colonizing indigenous culturable bacteria. Antibiotic and heavy metals resistance patterns, presence of the merA gene and plasmids in resistant isolates were evaluated. A high frequency of resistant indigenous bacteria to Hg and other heavy metals was found. From 76 Hg-resistant isolates tested 73.7 % were, in addition, resistant to ampicillin, 86.8% to chloramphenicol, 67.1 % for tetracycline, 56.6 % streptomycin, and 51.3 % kanamycin. Furthermore, it was found that 40.74 % (-328 mm and 26.53 % (-388 m of Hg-resistant bacteria were simultaneously resistant to both four and five of these antibiotics. The presence of low and high molecular weight plasmids was detected and, despite that isolated showed resistance to mercurial compounds, the presence of the gene merA was detected only in 71.05 % of strains. These results suggest that exposure to Hg could be a selective pressure on the proliferation of antibiotic-resistant bacteria and promote the preservation and propagation of these resistance genes. However, the existence of such resistances to these depths could also support the idea that antibiotic resistance in these bacteria is natural and has a more ancient origin than their exposure to Hg.

  15. Real-time investigation of antibiotics-induced oxidative stress and superoxide release in bacteria using an electrochemical biosensor.

    Science.gov (United States)

    Liu, Xiaobo; Marrakchi, Mouna; Jahne, Michael; Rogers, Shane; Andreescu, Silvana

    2016-02-01

    The involvement of oxidative stress in the mechanism of antibiotics-meditated cell death is unclear and subject to debate. The kinetic profile and a quantitative relationship between the release of reactive oxygen species (ROS), bacteria and antibiotic type remain elusive. Here we report direct measurements and analytical quantification of the release of superoxide radicals (O2(·-)), a major contributor to ROS, in antibiotics-treated bacterial cultures using a cytochrome c electrochemical biosensor. The specificity of electrochemical measurements was established by the addition of superoxide dismutase (SOD) which decreased the O2(·-) signal. Measurements using a general ROS-specific fluorescence dye and colony forming units (CFU) assays were performed side-by-side to determine the total ROS and establish the relationship between ROS and the degree of lethality. Exposure of Escherichia coli and Listeria monocytogenes cultures to antibiotics increased the release of O2(·-) radicals in a dose-dependent manner, suggesting that the transmembrane generation of ROS may occur as part of the antibiotic action. The study provides a quantitative methodology and fundamental knowledge to further explore the role of oxidative stress in antibiotics-meditated bacterial death and to assess physiological changes associated with the complex metabolic events related to oxidative stress and bacterial resistance.

  16. Co-selection of antibiotic and metal(loid) resistance in gram-negative epiphytic bacteria from contaminated salt marshes.

    Science.gov (United States)

    Henriques, Isabel; Tacão, Marta; Leite, Laura; Fidalgo, Cátia; Araújo, Susana; Oliveira, Cláudia; Alves, Artur

    2016-08-15

    The goal of this study was to investigate co-selection of antibiotic resistance in gram-negative epiphytic bacteria. Halimione portulacoides samples were collected from metal(loid)-contaminated and non-contaminated salt marshes. Bacterial isolates (n=137) affiliated with Vibrio, Pseudomonas, Shewanella, Comamonas, Aeromonas and with Enterobacteriaceae. Vibrio isolates were more frequent in control site while Pseudomonas was common in contaminated sites. Metal(loid) and antibiotic resistance phenotypes varied significantly according to site contamination, and multiresistance was more frequent in contaminated sites. However, differences among sites were not observed in terms of prevalence or diversity of acquired antibiotic resistance genes, integrons and plasmids. Gene merA, encoding mercury resistance, was only detected in isolates from contaminated sites, most of which were multiresistant to antibiotics. Results indicate that metal(loid) contamination selects for antibiotic resistance in plant surfaces. In salt marshes, antibiotic resistance may be subsequently transferred to other environmental compartments, such as estuarine water or animals, with potential human health risks.

  17. A single method for recovery and concentration of enteric viruses and bacteria from fresh-cut vegetables.

    Science.gov (United States)

    Sánchez, G; Elizaquível, P; Aznar, R

    2012-01-03

    Fresh-cut vegetables are prone to be contaminated with foodborne pathogens during growth, harvest, transport and further processing and handling. As most of these products are generally eaten raw or mildly treated, there is an increase in the number of outbreaks caused by viruses and bacteria associated with fresh vegetables. Foodborne pathogens are usually present at very low levels and have to be concentrated (i.e. viruses) or enriched (i.e. bacteria) to enhance their detection. With this aim, a rapid concentration method has been developed for the simultaneous recovery of hepatitis A virus (HAV), norovirus (NV), murine norovirus (MNV) as a surrogate for NV, Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enterica. Initial experiments focused on evaluating the elution conditions suitable for virus release from vegetables. Finally, elution with buffered peptone water (BPW), using a Pulsifier, and concentration by polyethylene glycol (PEG) precipitation were the methods selected for the elution and concentration of both, enteric viruses and bacteria, from three different types of fresh-cut vegetables by quantitative PCR (qPCR) using specific primers. The average recoveries from inoculated parsley, spinach and salad, were ca. 9.2%, 43.5%, and 20.7% for NV, MNV, and HAV, respectively. Detection limits were 132 RT-PCR units (PCRU), 1.5 50% tissue culture infectious dose (TCID₅₀), and 6.6 TCID₅₀ for NV, MNV, and HAV, respectively. This protocol resulted in average recoveries of 57.4%, 64.5% and 64.6% in three vegetables for E. coli O157:H7, L. monocytogenes and Salmonella with corresponding detection limits of 10³, 10² and 10³ CFU/g, respectively. Based on these results, it can be concluded that the procedure herein is suitable to recover, detect and quantify enteric viruses and foodborne pathogenic bacteria within 5 h and can be applied for the simultaneous detection of both types of foodborne pathogens in fresh-cut vegetables.

  18. Antibiotic resistance in lactic acid bacteria isolated from some pharmaceutical and dairy products

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    Gamal Fadl M. Gad

    2014-01-01

    Full Text Available A total of 244 lactic acid bacteria (LAB strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7% followed by Streptococcus spp. (65, 36.1% and Lactococcus spp. (27, 15%. Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus,8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M and/or erm(B]. PCR assays shows that some resistant strains harbor tet(M and/or erm(B resistance genes.

  19. Acute toxicity assessment of ANAMMOX substrates and antibiotics by luminescent bacteria test.

    Science.gov (United States)

    Ding, Shuang; Wu, Junwei; Zhang, Meng; Lu, Huifeng; Mahmood, Qaisar; Zheng, Ping

    2015-12-01

    Acute toxicities of anaerobic ammonia oxidation (ANAMMOX) substrates and four antibiotics from pharmaceutical wastewaters on ANAMMOX process were reported. Individual and joint acute toxicity assays were performed using 50% inhibitory concentration (IC50). Results showed that IC50 values and their 95% confidence interval of ammonium chloride (A), sodium nitrite (B), penicillin G-Na (C), polymyxin B sulfate (D), chloramphenicol (E) and kanamycin sulfate (F) were 2708.9 (2247.9-3169.9), 1475.4 (1269.9-1680.9), 5114.4 (4946.4-5282.4), 10.2 (1.8-18.6), 409.9 (333.7-486.1) and 5254.1 (3934.4-6573.8) mgL(-1) respectively, suggesting toxicities were in the order of D>E>B>A>C>F. Joint acute toxicities of bicomponent mixtures A and B, C and D, C and F, D and F were independent; D and E, E and F were additive while C and E were synergistic. Joint acute toxicities of multicomponent mixtures were synergistic or additive. Luminescent bacteria test is an easy and robust method for forecasting the feasibility of ANAMMOX process for pharmaceutical wastewater treatment.

  20. Monitoring of human enteric viruses and coliform bacteria in waters after urban flood in Jakarta, Indonesia.

    Science.gov (United States)

    Phanuwan, C; Takizawa, S; Oguma, K; Katayama, H; Yunika, A; Ohgaki, S

    2006-01-01

    Floodwaters in Kampung Melayu village, Jakarta, Indonesia, as well as river water and consumable water (including groundwater and tap water) samples in flooded and non-flooded areas, were quantitatively analysed to assess occurrence of viruses and total coliforms and E. coli as bacterial indicators after flooding event. High numbers of enterovirus, hepatitis A virus, norovirus (G1, G2) and adenovirus were detected at high concentration in floodwaters and waters sampled from Ciliwung River which runs across metropolitan Jakarta and is used widely for agriculture and domestic purposes by poor residents. One out of three groundwater wells in the flooded area was contaminated with all viruses tested while no viruses were found in groundwater samples in non-flooded areas and tap water samples. The results revealed that human enteric viruses, especially hepatitis A virus and adenovirus, were prevalent in Jakarta, Indonesia. This study suggested that flooding posed a higher risk of viral infection to the people through contamination of drinking water sources or direct contact with floodwaters.

  1. 食源性乳酸菌抗药性分析%Antibiotic resistance in food-associated lactic acid bacteria

    Institute of Scientific and Technical Information of China (English)

    孔健; 季明杰; 杨埔

    2011-01-01

    The emergence of antibiotic resistance in pathogens posed a major threat to human health because of abuses or misuse of antibiotics. Lactic acid bacteria ( LAB ) as starter cultures or probiotics were widely used in the production of fermented food and silage processes, and have acquired a "generally recognized as safe" (GRAS) status. However, recentiy it was demonstrated that antibiotic resistance genes from food-associated LAB strains were highly identical with those of pathogens, suggesting that LAB have the potential to serve as a host of antibiotic resistance genes with the risk of transferring the genes in cornmensal or pathogens in the intestinal gut. Antibiotic resistance genes were divided into intrinsic resistance and acquired resistance based on their transferability. Acquired resistance genes were often encoded by conjugative plasmids or conjugative transposons, which could enter into gastrointestinal tract through the consumption of fermented foods, and then transferred to the indigenous microflora and pathogens, furthermore resulted in the disease. This review will focus on the mechanism of resistance, detecting methods of antimicrobial susceptibility and gene horizontal transfer of antibiotic resistance in food-associated LAB.%抗生素的不合理使用导致病原菌耐药性已成为威胁人类健康的公共问题。乳酸菌在食品发酵、饲料青贮等领域具有悠久的应用历史,是公认的安全性菌株。但是研究发现,有些乳酸菌具有抗药性,根据抗药因子的可转移性,乳酸菌的抗药性可分为固有抗药性和外获抗药性。外获抗药性多由接合质粒或转座因子编码,这些抗药基因随发酵食品或益生菌剂进入肠道,是否与肠道共生菌或病原菌进行传递进而对机体带来危害引起了人们的关注。本文就食源性乳酸菌抗药性产生的分子机制、检测方法以及可能的抗药基因水平转移方式进行综述,以便对

  2. Antibiotics and heavy metals resistance patterns of Enterococcus faecalis and faecium bacteria isolated from the human and the livestock sources

    Directory of Open Access Journals (Sweden)

    Yaser Sharifi

    2015-12-01

    Full Text Available Background: Enterococci have emerged as a major cause of nosocomial infections and within this group, Enterococcus faecalis and Enterococcus faecium cause the majority of human and livestock enterococcal infections. In this article, we tried to determine antibiotics and metals resistance patterns of E. faecalis and E. faecium strains. Methods: One hundred sixty different strains of E. faecalis and E. faecium were collected from livestock sewage and the human fecal waste during 15 months. Then bacterial antibiotics sensitivity tests were carried out using the Agar disc diffusion method. Results: Generally, 100% of E. faecalis strains separated from human and livestock sources (i.e. sheep showed penicillin (P/ kanamycin (K/ nitrofurantoin (N/ loracarbef (L/ Ciprofloxacin (Cc/ ampicillin (AN/ nalidixic acid (NA/ sulfamethoxazole (S antibiotics resistance patterns. In addition, 55% of isolated E. faecium showed P/S/AN/NA antibiotics resistance patterns. Each strain showed a resistance to at least two aminoglycoside antibiotics. However, E. faecalis strains from human and the livestock sources showed 94% and 100% of resistance to nitrofurantoin, respectively. The effects of different metal concentrations was evaluated in both strains. The agar dilution method was applied in this stage. Hg at 0.05 mmol/L of minimum inhibitory concentration (MIC showed toxicity to both the human and livestock Enterococcus strains. Cadmium at 1 mmol/L and 0.5 mmol/L concentrations had the most toxicity to E. faecalis and E. faecium strains, respectively. Obviously, toxicity to bacteria is less than other metals. As a result, Zn/Ni/Cu/Co resistance pattern is suggested for both strains. Finally, antibiotics and heavy metals resistance patterns were monitored simultaneously. Conclusion: Almost all E. faecalis strains isolated from humans and livestock showed antibiotics and heavy metals resistance patterns of P/K/L/Cc/S/AN/NA/Zn/Cu/Co simultaneously. Moreover, 55% of E

  3. Inactivation/reactivation of antibiotic-resistant bacteria by a novel UVA/LED/TiO2 system.

    Science.gov (United States)

    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.

  4. Critical shortage of new antibiotics in development against multidrug-resistant bacteria-Time to react is now.

    Science.gov (United States)

    Freire-Moran, Laura; Aronsson, Bo; Manz, Chris; Gyssens, Inge C; So, Anthony D; Monnet, Dominique L; Cars, Otto

    2011-04-01

    Two commercial databases (Pharmaprojects and Adis Insight R&D) were queried for antibacterial agents in clinical development. Particular attention was given to antibacterial agents for systemic administration. For each agent, reviewers were requested to indicate whether its spectrum of activity covered a set of selected multidrug-resistant bacteria, and whether it had a new mechanism of action or a new target. In addition, PubMed was searched for antibacterial agents in development that appeared in review articles. Out of 90 agents that were considered to fulfil the inclusion criteria for the analysis, 66 were new active substances. Fifteen of these could be systemically administered and were assessed as acting via a new or possibly new mechanism of action or on a new or possibly new target. Out of these, 12 agents were assessed as having documented in vitro activity against antibiotic-resistant Gram-positive bacteria and only four had documented in vitro activity against antibiotic-resistant Gram-negative bacteria. Of these four, two acted on new or possibly new targets and, crucially, none acted via new mechanisms of action. There is an urgent need to address the lack of effective treatments to meet the increasing public health burden caused by multidrug-resistant bacteria, in particular against Gram-negative bacteria.

  5. Relatively high antibiotic resistance among heterotrophic bacteria from arctic fjord sediments than water - Evidence towards better selection pressure in the fjord sediments

    Science.gov (United States)

    Hatha, A. A. Mohamed; Neethu, C. S.; Nikhil, S. M.; Rahiman, K. M. Mujeeb; Krishnan, K. P.; Saramma, A. V.

    2015-12-01

    The objective of this study was to determine the prevalence of antibiotic resistance among aerobic heterotrophic bacteria and coliform bacteria from water and sediment of Kongsfjord. The study was based on the assumption that arctic fjord environments are relatively pristine and offer very little selection pressure for drug resistant mutants. In order to test the hypothesis, 200 isolates belonging to aerobic heterotrophic bacteria and 114 isolates belonging to coliforms were tested against 15 antibiotics belonging to 5 different classes such as beta lactams, aminoglycosides, quinolones, sulpha drugs and tetracyclines. Resistance to beta lactam and extended spectrum beta lactam (ESBL) antibiotics was considerably high and they found to vary significantly (p antibiotic resistance against ESBL's extent and diversity of antibiotic resistance (as revealed by multiple antibiotic resistance index and resistance patterns), was high in the aerobic heterotrophic bacteria. Most striking observation was that isolates from fjord sediments (both heterotrophic bacteria and coliforms) in general showed relatively high prevalence of antibiotic resistance against most of the antibiotics tested, indicating to better selection pressure for drug resistance mutants in the fjord sediments.

  6. Antimicrobial and Herbal Drug Resistance in Enteric Bacteria Isolated from Faecal Droppings of Common House Lizard/Gecko (Hemidactylus frenatus

    Directory of Open Access Journals (Sweden)

    Bhoj R. Singh

    2013-01-01

    Full Text Available From 194 faecal dropping samples of common house geckos collected from offices (60, houses (88, integrated farm units (IFS,18 and hostels, guest houses, and dining rooms of different canteen/mess (HGM, 28, 326 bacterial isolates of enteric bacteria belonging to 17 genera and 34 species were detected. Escherichia coli were the most frequently (39 isolated followed by Citrobacter freundii (33, Klebsiella pneumonia (27, Salmonella indica (12, Enterobacter gergoviae (12, and Ent. agglomerans (11. Other important bacteria isolated from gecko droppings were Listonella damsela (2, Raoultella terrigena (3, S. salamae (2, S. houtenae (3, Edwardsiella tarda (4, Edwardsiella hoshinae (1, and Klebsiella oxytoca (2. Of the 223 isolates tested for antimicrobial drug sensitivity, 27 (12.1% had multiple drug resistance (MDR. None of the salmonellae or edwardsiellae had MDR however, MDR strains were significantly more common among Escherichia spp. (P=1.9×10-5 and isolates from IFS units (P=3.58×10-23. The most effective herbal drug, Ageratum conyzoides extract, inhibited growth of only 27.8% of strains tested followed by ethanolic extract of Zanthoxylum rhetsa (13.9%, eucalyptus oil (5.4%, patchouli oil (5.4%, lemongrass oil (3.6%, and sandalwood oil (3.1%, and Artemisia vulgaris essential oil (3.1%.

  7. Antibacterial activity of the terrestrial fernLygodium flexuosum (L.) Sw. against multidrug resistant enteric- and uro-pathogenic bacteria

    Institute of Scientific and Technical Information of China (English)

    Nabakishore Nayak; Sibanarayan Rath; Monali P Mishra; Goutam Ghosh; Rabindra N Padhy

    2013-01-01

    Objective:To investigate antibacterial properties of the terrestrial fernLygodium flexuosum (L. flexuosum) obtained fromKalahandi district,Odisha against enteric- and uro-pathogenic bacteria isolated from clinical samples.Method:Frond-extracts ofL. flexuosum were obtained by the cold percolation method using four solvents, petroleum ether, chloroform, methanol and water.Antibacterial potencies of concentrated cold frond-extracts were tested by the agar-well diffusion method against7 multidrug resistant(MDR) bacteria of which,2 wereGram-positives, methicillin resistantStaphylococcus aureus(MRSA) and vancomycin resistantEnterococcus faecalis(VRE), and5Gram-negatives,Enterobacter aerogenes,Escherichia coli,Klebsiella pneumoniae, Pseudomonas aeruginosa andProteus mirabilis.Result:The cold-water frond-extract had the best antimicrobial activity against7MDR bacterial isolates, compared to extracts with other solvents.Values of zones of inhibition againstMRSA andP. mirabilis were the highest, 29 mm.Zones of inhibition againstVRE andP. aeruginosa were25 mm, while those were23 mm againstE. aerogenes andE. coli.The least size of zone of inhibition19 mm was recorded against K. pneumoniae.Minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC) values of active frond-extracts with water, chloroform, methanol, and petroleum ether were recorded.For the water extract, theMIC value1.562 mg/mL againstMRSA andP. mirabilis, but the value3.25 mg/mL againstVRE,E. aerogenes andP. aeruginosa, while the value of12.5 mg/mL againstK. pneumoniae were recorded.MBC values were the least with chloroform-extracts, with the range12.5 for6 bacteria, excludingP. aeruginosa for which, the value25 mg/mL was recorded asMBC.Conclusions:Phytochemical analysis of the water-extract ofL. flexuosum confirmed the presence of glycosides and carbohydrates, but alkaloids, terpenoids, steroids, saponins, tannins, and flavonoids were absent.L. flexuosum, being a fern, is a suitable non

  8. Isolation of Environmental Bacteria from Surface and Drinking Water in Mafikeng, South Africa, and Characterization Using Their Antibiotic Resistance Profiles

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    Suma George Mulamattathil

    2014-01-01

    Full Text Available The aim of this study was to isolate and identify environmental bacteria from various raw water sources as well as the drinking water distributions system in Mafikeng, South Africa, and to determine their antibiotic resistance profiles. Water samples from five different sites (raw and drinking water were analysed for the presence of faecal indicator bacteria as well as Aeromonas and Pseudomonas species. Faecal and total coliforms were detected in summer in the treated water samples from the Modimola dam and in the mixed water samples, with Pseudomonas spp. being the most prevalent organism. The most prevalent multiple antibiotic resistance phenotype observed was KF-AP-C-E-OT-K-TM-A. All organisms tested were resistant to erythromycin, trimethoprim, and amoxicillin. All isolates were susceptible to ciprofloxacin and faecal coliforms and Pseudomonas spp. to neomycin and streptomycin. Cluster analysis based on inhibition zone diameter data suggests that the isolates had similar chemical exposure histories. Isolates were identified using gyrB, toxA, ecfX, aerA, and hylH gene fragments and gyrB, ecfX, and hylH fragments were amplified. These results demonstrate that (i the drinking water from Mafikeng contains various bacterial species and at times faecal and total coliforms. (ii The various bacteria are resistant to various classes of antibiotics.

  9. Antibiotic Resistance Questions and Answers

    Science.gov (United States)

    ... on the Farm Get Smart About Antibiotics Week Antibiotic Resistance Questions and Answers Language: English Español (Spanish) ... a los antibióticos Questions about Bacteria, Viruses, and Antibiotics Q: What are bacteria and viruses? A: Bacteria ...

  10. LiF Reduces MICs of Antibiotics against Clinical Isolates of Gram-Positive and Gram-Negative Bacteria

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    H. C. Syed

    2012-01-01

    Full Text Available Antibiotic resistance is an ever-growing problem yet the development of new antibiotics has slowed to a trickle, giving rise to the use of combination therapy to eradicate infections. The purpose of this study was to evaluate the combined inhibitory effect of lithium fluoride (LiF and commonly used antimicrobials on the growth of the following bacteria: Enterococcus faecalis, Staphyloccoccus aureus, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Serratia marcescens, and Streptococcus pneumoniae. The in vitro activities of ceftazidime, sulfamethoxazole-trimethoprim, streptomycin, erythromycin, amoxicillin, and ciprofloxacin, doxycycline, alone or combined with LiF were performed by microdilution method. MICs were determined visually following 18–20 h of incubation at 37°C. We observed reduced MICs of antibiotics associated with LiF ranging from two-fold to sixteen-fold. The strongest decreases of MICs observed were for streptomycin and erythromycin associated with LiF against Acinetobacter baumannii and Streptococcus pneumoniae. An eight-fold reduction was recorded for streptomycin against S. pneumoniae whereas an eight-fold and a sixteen-fold reduction were obtained for erythromycin against A. baumannii and S. pneumoniae. This suggests that LiF exhibits a synergistic effect with a wide range of antibiotics and is indicative of its potential as an adjuvant in antibiotic therapy.

  11. A new approach to determine the susceptibility of bacteria to antibiotics directly from positive blood culture bottles in two hours.

    Science.gov (United States)

    March, Gabriel A; García-Loygorri, María C; Simarro, María; Gutiérrez, María P; Orduña, Antonio; Bratos, Miguel A

    2015-02-01

    The rapid identification and antibiotic susceptibility test of bacteria causing bloodstream infections are given a very high priority by clinical laboratories. In an effort to reduce the time required for performing antibiotic susceptibility test (AST), we have developed a new method to be applied from positive blood culture bottles. The design of method was performed using blood culture bottles prepared artificially with five strains which have a known susceptibility. An aliquot of the blood culture was subcultured in the presence of specific antibiotics and bacterial counts were monitored using the Sysmex UF-1000i flow cytometer at different times up to 180min. Receiver operating curve (ROC) analysis allowed us to find out the cut-off point for differentiating between sensitive and resistant strains to the tested antibiotic. This procedure was then validated against standard commercial methods on a total of 100 positive blood culture bottles from patients. First, bacterial identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) directly from positive blood culture bottles as we have previously reported. Secondly, antibiotic susceptibility test was performed in the same way that was carried out in artificially prepared blood culture bottles. Our results indicate that antibiotic susceptibility test can be determined as early as 120min since a blood culture bottle is flagged as positive. The essential agreement between our susceptibility test and commercial methods (E-test, MicroScan and Vitek) was 99%. In summary, we conclude that reliable results on bacterial identification and antibiotic susceptibility test performed directly from positive blood culture bottles can be obtained within 3h.

  12. Persistence of naturally occurring antibiotic resistance genes in the bacteria and bacteriophage fractions of wastewater.

    Science.gov (United States)

    Calero-Cáceres, William; Muniesa, Maite

    2016-05-15

    The emergence and prevalence of antibiotic resistance genes (ARGs) in the environment is a serious global health concern. ARGs from bacteria can be mobilized by mobile genetic elements, and recent studies indicate that phages and phage-derived particles, among others, could play a role in the spread of ARGs through the environment. ARGs are abundant in the bacterial and bacteriophage fractions of water bodies and for successful transfer of the ARGs, their persistence in these environments is crucial. In this study, three ARGs (blaTEM, blaCTX-M and sul1) that naturally occur in the bacterial and phage fractions of raw wastewater were used to evaluate the persistence of ARGs at different temperatures (4 °C, 22 °C and 37 °C) and pH values (3, 7 and 9), as well as after various disinfection treatments (thermal treatment, chlorination and UV) and natural inactivation in a mesocosm. Gene copies (GC) were quantified by qPCR; then the logarithmic reduction and significance of the differences between their numbers were evaluated. The ARGs persisted for a long time with minimal reductions after all the treatments. In general, they showed greater persistence in the bacteriophage fraction than in the bacterial fraction. Comparisons showed that the ARGs persisted under conditions that reduced culturable Escherichia coli and infectious coliphages below the limit of detection. The prevalence of ARGs, particularly in the bacteriophage fraction, poses the threat of the spread of ARGs and their incorporation into a new bacterial background that could lead to the emergence of new resistant clones.

  13. Antibacterial activity of some medicinal mangroves against antibiotic resistant pathogenic bacteria

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    Abeysinghe P

    2010-01-01

    Full Text Available The antibacterial activity of the leaves and bark of mangrove plants, Avicennia marina, A. officinalis, Bruguiera sexangula, Exoecaria agallocha, Lumnitzera racemosa, and Rhizophora apiculata was evaluated against antibiotic resistant pathogenic bacteria, Staphylococcus aureus and Proteus sp. Soxhlet extracts of petroleum ether, ethyl acetate, ethanol and water were prepared and evaluated the antibacterial activity using agar diffusion method. Most of the plant extracts showed promising antibacterial activity against both bacterial species. However, higher antibacterial activity was observed for Staphylococcus aureus than Proteus sp. The highest antibacterial activity was shown by ethyl acetate of mature leaf extracts of E. agallocha for Staphylococcus aureus. All ethyl acetate extracts showed higher inhibition against S. aureus while some extracts of chloroform, ethyl acetate and ethanol gave inhibition against Proteus sp. None of the petroleum ether and aqueous extracts showed inhibition against Proteus sp. All fresh plant materials did also show more antibacterial activity against both bacterial strains than did dried plant extracts. Antibacterial activity of fresh and dried plant materials reduced for both bacterial strains with time after extraction. Since L. racemosa and A. marina gave the best inhibition for bacterial species, they were used for further investigations. Charcoal treated plant extracts of L. racemosa and A. marina were able to inhibit both bacterial strains more than those of untreated plant extracts. Phytochemical screening of mature leaf, bark of L. racemosa and leaf extracts of A. marina has been carried out and revealed that leaf and bark contained alkaloids, steroids, triterpenoids and flavonoids. None of the above extracts indicate the presence of saponins and cardiac glycosides. Separated bands of extracts by TLC analysis showed antibacterial activity against S. aureus.

  14. Antibiotic resistance of Staphylococcus aureus isolated from enteral diets in a public hospital of Minas Gerais Resistência a antibióticos de Staphylococcus aureus isolados de dietas enterais em um hospital público de Minas Gerais

    Directory of Open Access Journals (Sweden)

    Nélio José de Andrade

    2007-10-01

    Full Text Available Enteral diets constitute an excellent means for microbial growth due to its composition rich in nutrients and its time of exposure to room temperature during application. Among the pathogenic bacteria there is the Staphylococcus aureus that is an opportunist microorganism found in the humans’ mucous membrane (buccal, nasal and oral. Samples of enteral diet after application as well as of the environment used for the preparation of the diets, were collected in a public hospital in Minas Gerais and analyzed for the presence of S. aureus. The contamination by S. aureus was evidenced in 83% of the enteral diet samples. As for the environment, the values found were in conformity with APHA recommendation. The isolated strains were submitted to the evaluation of the resistance to different antibiotics. Resistance was observed for tetracycline (100%, erythromycin (90,9%, chloramphenicol (59,1%, estreptomycin (22,72%, penicillin 18,8%, vancomycin (13,63%, ampicillin (13,63%, amoxilin (9,09% and gentamicin (4,54%. Due to the versatility in the resistance development to several antibiotics the S. aureus survives in hospital environments and can be diffused among patients. Dietas enterais constituem um excelente meio para crescimento microbiano, devido à sua composição rica em nutrientes e ao tempo de exposição à temperatura ambiente durante a administração. Dentre as bactérias patogênicas que podem ser encontradas nessas dietas, cita-se o Staphylococcus aureus, microrganismo oportunista encontrado na microbiota da membrana mucosa (bucal, nasal e oral em seres humanos. Amostras de dieta enteral pós-administração e do ambiente utilizado para o seu preparo foram coletadas em um hospital público e analisadas quanto à presença de S. aureus. A contaminação foi evidenciada em 83% das amostras de dietas enterais, e, quanto ao ambiente, os valores encontrados se apresentam de acordo com a recomendação da APHA. As cepas isoladas foram

  15. Analysis of enteric pathogenic bacteria survey of 2010 in Tongzhou District, Beijing%2010年北京市通州区肠道病原菌监测结果分析

    Institute of Scientific and Technical Information of China (English)

    陈立新; 刘秀军; 刘晓峰; 王宝兰; 饶丹

    2011-01-01

    目的 了解通州区腹泻病人的病原谱情况,为肠道传染病的防制工作和临床用药等提供参考依据.方法 在通州区的部分二级医院采集未用抗生素的腹泻病人粪便标本,进行流行病学调查,并进行霍乱弧菌、痢疾杆菌、副溶血弧菌、沙门氏菌和5种致泻性大肠埃希菌等细菌分离培养和鉴定.结果 共采集303份腹泻病人粪便标本,其中男性169例,女性134例,以幼儿和青年病例为主,20~39岁占48.5%,城市病例244例,占80.5%.共培养76株细菌,其中志贺氏菌13株(4.3%)、沙门氏菌17株(5.6%)、副溶血弧菌31株(10.2%)、产毒性大肠杆菌1株(0.3%)、其他肠道病原菌14株(4.6%),志贺氏菌、沙门氏菌、副溶血弧菌、产毒性大肠杆菌这4种主要肠道病原菌阳性率为20.5%,总肠道病原菌阳性率为25.1%.结论 通州区腹泻病例肠道病原菌种类繁多,应继续加强监测工作.%Objective To understand enteric pathogenic bacteria spectrum of diarrhea patients in Tongzhou, then put forward preventive and treatment work of enteric infectious disease. Methods Stool samples of unused antibiotics diarrhea patients in grade two hospitals were collected, and epidemiologic survey was conducted among these patients, enteric pathogenic bacteria of shegella salmonella vibrio parahaemolyticus e. coli etc were isolated and cultured. Results 303 stool samples of diarrhea patients were collected, 169 patients were male, 134 patients were female; most of the patients were children and youth from 20 to 39 years old, acounted 48.5% ; patients living in city were 244 cases (80.5% ); shegella 13 strains (4.3%), salmonella 17 strains (5.6%), vibrio parahaemolyticus 31 strains (10.2%), ETEC 1 strain (0.3%) and other enteric pathogenic bacteria 14 strains (4.6%) were cultured. There were 76 enteric pathogenic strains in total. The positive rate of main enteric pathogenic bacteria was 20. 5 percent, the total positive rate of enteric pathogenic

  16. Combination antibiotic therapy for multidrug-resistant Gram-negative bacteria

    OpenAIRE

    Tängdén, Thomas

    2014-01-01

    Combination antibiotic therapy for Gram-negative sepsis is controversial. The present review provides a brief summary of the existing knowledge on combination therapy for severe infections with multidrug-resistant Pseudomonas spp., Acinetobacter spp., and Enterobacteriaceae. Empirical combination antibiotic therapy is recommended for severe sepsis and septic shock to reduce mortality related to inappropriate antibiotic treatment. Because definitive combination therapy has not been proven supe...

  17. Limits to compensatory adaptation and the persistence of antibiotic resistance in pathogenic bacteria

    OpenAIRE

    MacLean, R. Craig; Vogwill, Tom

    2014-01-01

    Antibiotic resistance carries a fitness cost that could potentially limit the spread of resistance in bacterial pathogens. In spite of this cost, a large number of experimental evolution studies have found that resistance is stably maintained in the absence of antibiotics as a result of compensatory evolution. Clinical studies, on the other hand, have found that resistance in pathogen populations usually declines after antibiotic use is stopped, suggesting that compensatory adaptation is not ...

  18. Bacterial Diversity in Buffalo Meat and Bowel from Traditional Market and the Sensitivity of Some Bacteria to Irradiation and Antibiotics

    Directory of Open Access Journals (Sweden)

    Harsojo

    2015-08-01

    Full Text Available The population of buffaloes in Indonesia was 1.37 million in 2012, representing an increase of 5.5 % over its population the previous year. Buffaloes have been in Indonesia for such a long time, they have become a part of the lives of the majority of the Indonesian society. Research has been conducted to know the bacteria diversity in domestic buffalo meat and bowels from traditional markets in Pandeglang, Banten, in order to ascertain their safety based on their initial contamination and also to study the sensitivity of several of the bacteria to irradiation and antibiotics. The total bacterial was assessed by total plate count method as index of quality. The buffalo meat and bowel samples were taken from livers, intestines, lymph, lungs and tripe. Results showed that the contaminating bacteria were aerobic bacteria, coliform bacteria including Escherichia coli (E. coli, and Staphylococcus spp. in buffalo meat and bowel. The numbers of aerobic bacteria were in the 1.7×105- 2.3×106 CFU/g range, while the total coliform bacteria were in the 2.0×103- 6.8×104 CFU/g range. The total number of E. coli was in the 2.0×103- 6.0×104 CFU/g range, and Staphylococcus spp. was in the 2.0×104- 2.7×105 CFU/g range. No Salmonella was detected in any of the samples observed. The total coliform bacteria, E. coli, and Staphylococcus spp. in all buffalo meat and bowel samples exceeded the maximum numbers of microbes permitted by the Indonesian National Standard (SNI. The maximum of total coliform, E. coli, and Staphylococcus spp. permitted by SNI are 1.0×102, 1.0×10 and 1.0×102 CFU/g, respectively. The D10 values of S. aureus were in the 0.13 - 0.23 kGy range, while for E. coli they were in the 0.07 - 0.13 kGy range. The isolate of S. aureus from the lungs was the most resistant to cefoxitin, tetracycline, and amoxicillin antibiotics. The isolate of E. coli from buffalo bowels were almost sensitive to cefoxitin, tetracycline, and amoxicillin antibiotics.

  19. Antibiotic resistance patterns in fecal bacteria isolated from Christmas shearwater (Puffinus nativitatis) and masked booby (Sula dactylatra) at remote Easter Island.

    Science.gov (United States)

    Ardiles-Villegas, Karen; González-Acuña, Daniel; Waldenström, Jonas; Olsen, Björn; Hernández, Jorge

    2011-09-01

    Antibiotic use and its implications have been discussed extensively in the past decades. This situation has global consequences when antibiotic resistance becomes widespread in the intestinal bacterial flora of stationary and migratory birds. This study investigated the incidence of fecal bacteria and general antibiotic resistance, with special focus on extended spectrum beta-lactamase (ESBL) isolates, in two species of seabirds at remote Easter Island. We identified 11 species of bacteria from masked booby (Sula dactylatra) and Christmas shearwater (Puffinus nativitatis); five species of gram-negative bacilli, four species of Streptococcus (Enterococcus), and 2 species of Staphylococcus. In addition, 6 types of bacteria were determined barely to the genus level. General antibiotic susceptibility was measured in the 30 isolated Enterobacteriaceae to 11 antibiotics used in human and veterinary medicine. The 10 isolates that showed a phenotypic ESBL profile were verified by clavulanic acid inhibition in double mixture discs with cefpodoxime, and two ESBL strains were found, one strain in masked booby and one strain in Christmas shearwater. The two bacteria harboring the ESBL type were identified as Serratia odorifera biotype 1, which has zoonotic importance. Despite minimal human presence in the masked booby and Christmas shearwater habitats, and the extreme geographic isolation of Easter Island, we found several multiresistant bacteria and even two isolates with ESBL phenotypes. The finding of ESBLs has animal and public health significance and is of potential concern, especially because the investigation was limited in size and indicated that antibiotic-resistant bacteria now are distributed globally.

  20. Co-occurrence of antibiotic drugs, resistant bacteria and resistance genes in runoff from cattle feedlots

    Science.gov (United States)

    Agricultural uses of antibiotics raises concerns about the development of antibiotic resistance in food animals, and the potential to transmit resistance to human clinical settings via fecal contamination of surface and ground water. Although there is broad agreement that agricultural resistance can...

  1. Diarrhea-associated pathogens, lactobacilli and cellulolytic bacteria in equine feces: responses to antibiotic challenge

    Science.gov (United States)

    Antibiotics are important to equine medicine, but antibiotic-associated diarrhea (AAD) can lead to poor performance and even mortality. AAD is attributed to disruption of the hindgut microbiota, which permits proliferation of pathogenic microbes. The goal of this study was to evaluate the effects o...

  2. Antibacterial activity of plant extracts and phytochemicals on antibiotic-resistant bacteria

    OpenAIRE

    Nascimento,Gislene G. F.; Locatelli,Juliana; Freitas,Paulo C.; Silva,Giuliana L.

    2000-01-01

    The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant microorganisms. In addition, the possible synergistic effects when associated with antibiotics were studied. Extracts from the following plants were utilized: Achillea millifolium (yarrow), Caryophyllus aromaticus (clove), Melissa offficinalis (lemon-balm), Ocimun basilucum (basil), Psidium guajava (guava), Punica granatum (pomegranate), Rosmarinus officinalis (rosemary), Sa...

  3. [Investigation of Antibiotic Resistance of Indigenous Bacteria and Abundance of Class I Integron in Matrix of Constructed Wetlands of Different Configurations].

    Science.gov (United States)

    Mai, Xiao-bei; Tao, Ran; Yang, Yang; Zhang, Min; Lin, Jian-hua; Man, Ying

    2015-05-01

    Environmental indigenous bacteria (Staphylococcus and Pseudomonas) were isolated from 9 different constructed wetlands (CWs) in summer and winter. The antibiotic resistance analysis of the isolated bacteria was conducted by Kirby-Bauer disc agar diffusion method. And the quantitative PCR assay was used to quantify the abundance of class I integron (int1) in the matrix of CWs. The results indicated that over 84% of isolates among the 522 Staphylococcus strains and 543 Pseudomonas strains had antibiotic resistance and above 68% of isolates had multi-antibiotic resistance, the average of MRI index was 0.22. Antibiotic resistance of indigenous bacteria in CWs was at the same resistance level of human or animal bacteria in certain environment, indicating that indigenous bacteria from constructed wetlands had relatively high level of resistance. Staphylococcus and Pseudomonas strains had higher resistances to Ampicillin (AMP) and Sulfamethoxazole (SXT), and extremely low resistance rates of lower than 3% to Tetracycline (TE), Gentamicin (CN) and Ciprofloxacin (CIP). To Ceftazidime (CAZ) and Chloramphenicol (C), the two kinds of indigenous bacteria showed distinctly different resistances. Quantitative PCR revealed that the abundance of intl in CWs was 1.14 x 10(5)-5.66 x 10(5) copies · g(-1), and its relative abundance was 0.54%-3.68%. Both of season and wetland type had important impact on antibiotic resistance and abundance of int1. The antibiotic resistance rate and the multiple resistance index (MRI) for the indigenous bacteria and the abundance of int1 in summer were higher than those in winter. Among three types of CWs, the antibiotic resistance rate and the MRI value were the highest in the downward vertical flow, while the int1 abundance was the highest in the sub-surface flow. The research indicated that indigenous bacteria acquired antibiotic resistance due to long term exposure to antibiotics of certain concentrations and antibiotic-resistant intestinal

  4. Effects of silver nanoparticles in combination with antibiotics on the resistant bacteria Acinetobacter baumannii.

    Science.gov (United States)

    Wan, Guoqing; Ruan, Lingao; Yin, Yu; Yang, Tian; Ge, Mei; Cheng, Xiaodong

    2016-01-01

    Acinetobacter baumannii resistance to carbapenem antibiotics is a serious clinical challenge. As a newly developed technology, silver nanoparticles (AgNPs) show some excellent characteristics compared to older treatments, and are a candidate for combating A. baumannii infection. However, its mechanism of action remains unclear. In this study, we combined AgNPs with antibiotics to treat carbapenem-resistant A. baumannii (aba1604). Our results showed that single AgNPs completely inhibited A. baumannii growth at 2.5 μg/mL. AgNP treatment also showed synergistic effects with the antibiotics polymixin B and rifampicin, and an additive effect with tigecyline. In vivo, we found that AgNPs-antibiotic combinations led to better survival ratios in A. baumannii-infected mouse peritonitis models than that by single drug treatment. Finally, we employed different antisense RNA-targeted Escherichia coli strains to elucidate the synergistic mechanism involved in bacterial responses to AgNPs and antibiotics.

  5. Microbiological quality of ready-to-eat salads: an underestimated vehicle of bacteria and clinically relevant antibiotic resistance genes.

    Science.gov (United States)

    Campos, Joana; Mourão, Joana; Pestana, Nazaré; Peixe, Luísa; Novais, Carla; Antunes, Patrícia

    2013-09-16

    The increase demand for fresh vegetables is causing an expansion of the market for minimally processed vegetables along with new recognized food safety problems. To gain further insight on this topic we analyzed the microbiological quality of Portuguese ready-to-eat salads (RTS) and their role in the spread of bacteria carrying acquired antibiotic resistance genes, food products scarcely considered in surveillance studies. A total of 50 RTS (7 brands; split or mixed leaves, carrot, corn) were collected in 5 national supermarket chains in Porto region (2010). They were tested for aerobic mesophilic counts, coliforms and Escherichia coli counts as well as for the presence of Salmonella and Listeria monocytogenes. Samples were also plated in different selective media with/without antibiotics before and after enrichment. The E. coli, other coliforms and Enterococcus recovered were characterized for antibiotic resistance profiles and clonality with phenotypic and genetic approaches. A high number of RTS presented poor microbiological quality (86%--aerobic mesophilic counts, 74%--coliforms, 4%--E. coli), despite the absence of screened pathogens. In addition, a high diversity of bacteria (species and clones) and antibiotic resistance backgrounds (phenotypes and genotypes) were observed, mostly with enrichment and antibiotic selective media. E. coli was detected in 13 samples (n=78; all types and 4 brands; phylogenetic groups A, B1 and D; none STEC) with resistance to tetracycline [72%; tet(A) and/or tet(B)], streptomycin (58%; aadA and/or strA-strB), sulfamethoxazole (50%; sul1 and/or sul2), trimethoprim (50%; dfrA1 or dfrA12), ampicillin (49%; blaTEM), nalidixic acid (36%), ciprofloxacin (5%) or chloramphenicol (3%; catA). E. coli clones, including the widespread group D/ST69, were detected in different samples from the same brand or different brands pointing out to a potential cross-contamination. Other clinically relevant resistance genes were detected in 2 Raoultella

  6. Antibiotic susceptibility profile of bacteria isolated from natural sources of water from rural areas of East Sikkim

    Directory of Open Access Journals (Sweden)

    Shubra Poonia

    2014-01-01

    Full Text Available Background: Contamination of water, food, and environment with antibiotic-resistant bacteria poses a serious public health issue. Objective: The objective was to study the bacterial pollution of the natural sources of water in east Sikkim and to determine the antimicrobial profile of the bacterial isolates. Materials and Methods: A total of 225 samples, 75 each during winter, summer, and monsoon season were collected from the same source in every season for bacteriological analysis by membrane filtration method. Antibiotic susceptibility test was performed using standard disc diffusion method. Results: A total of 19 bacterial species of the genera Escherichia, Klebsiella, Proteus, Salmonella, Shigella, Enterobacter, Citrobacter, Morganella, Pseudomonas, Acinetobacter, Flavobacterium, and Serratia were isolated and their antimicrobial sensitivity tested. Generally, most bacterial isolates except Salmonella and Shigella species were found resistant to commonly used antibiotics such as ampicillin (57.5%, trimethoprim/sulfamethoxaole (39.1%, amoxicillin/clavulanic acid (37.4%, cefixime (34.5%, tetracycline (29.1%, ceftazidime (26.3%, ofloxacin (25.9%, amikacin (8.7%, and gentamicin (2.7% but sensitive to imipenem and piperacillin/tazobactam. Conclusion: Natural sources of water in east Sikkim are grossly contaminated with bacteria including enteropathogens. The consumption of untreated water from these sources might pose health risk to consumers.

  7. Evaluation of antibiotics as a methodological procedure to inhibit free-living and biofilm bacteria in marine zooplankton culture

    Directory of Open Access Journals (Sweden)

    Vanessa O. Agostini

    2016-01-01

    Full Text Available There is a problem with keeping culture medium completely or partially free from bacteria. The use of prokaryotic metabolic inhibitors, such as antibiotics, is suggested as an alternative solution, although such substances should not harm non-target organisms. Thus, the aim of this study was to assess the effectiveness of antibiotic treatments in inhibiting free-living and biofilm bacteria and their half-life in artificial marine environment using the copepod Acartia tonsa as bioindicador of non-harmful antibiotic combinations. Regarding to results, the application of 0.025 g L-1 penicillin G potassium + 0.08 g L-1 streptomycin sulphate + 0.04 g L-1 neomycin sulphate showed great potential for use in marine cultures and scientific experiments without lethal effects to non-target organisms. The effect of this combination starts within the first six hours of exposure and reduces up to 93 % the bacterial density, but the half-life is short, requiring replacement. No adverse changes in water quality were observed within 168 hours of exposure. As a conclusion, we can infer that this treatment was an effective procedure for zooplankton cultures and scientific experiments with the aim of measuring the role of free-living and biofilm in the marine community.

  8. Development of antibiotic-resistant strains for the enumeration of foodborne pathogenic bacteria in stored foods.

    Science.gov (United States)

    Blackburn, C D; Davies, A R

    1994-12-01

    Strains of Aeromonas spp., Salmonella enteritidis phage type 4, Salmonella typhimurium, verotoxigenic Escherichia coli O157:H7 (VTEC) and Yersinia enterocolitica resistant to streptomycin, nalidixic acid and a combination of both antibiotics were selected. When compared with the parent strains, most of the antibiotic-resistant strains had slightly slower growth rates at their optimum incubation temperature but the difference was reduced progressively when the temperature was lowered. Some antibiotic-resistant strains had considerably slower growth rates in the presence of the relevant antibiotic and these were not used further. Several agar and impedance media with added streptomycin and nalidixic acid were assessed for the enumeration of the antibiotic-resistant strains in artificially contaminated stored foods. Differential/selective media were required to enumerate low numbers of antibiotic-resistant strains in certain foods. The following agar and impedance media were selected: Aeromonas Agar (Ryan) for Aeromonas spp., Xylose Lysine Agar and Lysine Iron Cysteine Neutral Red Medium for Salmonella, Eosin Methylene Blue Agar and Coliform Medium for VTEC, and Yersinia Selective Agar without selective agents for Yersinia enterocolitica. The agar and impedance media have been used successfully to enumerate antibiotic-resistant strains inoculated into foods and stored at different temperatures.

  9. The soil resistome: a critical review on antibiotic resistance origins, ecology and dissemination potential in telluric bacteria.

    Science.gov (United States)

    Nesme, Joseph; Simonet, Pascal

    2015-04-01

    Soil is a large reservoir of microbial diversity and the majority of antimicrobial compounds used today in human and veterinary health care have been isolated from soil microorganisms. The Darwinian hypothesis of an 'arms-shields race' between antibiotic producers and resistant strains is often cited to explain antibiotic resistance gene determinants (ARGD) origins and diversity. ARGD abundance and antibiotic molecule exposure are, however, not systematically linked, and many other factors can contribute to resistance gene emergence, selection and dissemination in the environment. Soil is a heterogeneous habitat and represents a broad spectrum of different ecological niches. Soil harbours a large genetic diversity at small spatial scale, favouring exchange of genetic materials by means of horizontal gene transfer (HGT) that will contribute to ARGD dissemination between bacteria and eventually acquisition by pathogen genomes, therefore threatening antibiotic therapies. Our current knowledge on the extent of the soil resistome abundance and diversity has been greatly enhanced since the metagenomic revolution and help of high-throughput sequencing technologies. Different ecological hypotheses explaining their high prevalence in soil and questioning their transfer rate to pathogens, in respect to these recent experimental results, will be discussed in the present review.

  10. Long-term effects of antibiotics on the elimination of chemical oxygen demand, nitrification, and viable bacteria in laboratory-scale wastewater treatment plants.

    Science.gov (United States)

    Schmidt, Susan; Winter, Josef; Gallert, Claudia

    2012-10-01

    Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40 mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30 mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40 mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by ≤20 mg/L antibiotics. Addition of 30 mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40 mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2 × 10(6) to 8.2 × 10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4 × 10(6)-6.3 × 10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30 mg/L from the liquid was high for GM (70-90 %), much lower for VA, TMP, and CIP (0-50 %), and highly fluctuating for SMZ (0-95 %). The antibiotics were mainly adsorbed to the sludge and not biodegraded.

  11. Antibiotic resistance and extended-spectrum β-lactamases in isolated bacteria from seawater of Algiers beaches (Algeria).

    Science.gov (United States)

    Alouache, Souhila; Kada, Mohamed; Messai, Yamina; Estepa, Vanesa; Torres, Carmen; Bakour, Rabah

    2012-01-01

    The aim of the study was to evaluate bacterial antibiotic resistance in seawater from four beaches in Algiers. The most significant resistance rates were observed for amoxicillin and ticarcillin, whereas they were relatively low for ceftazidime, cefotaxime and imipenem. According to sampling sites, the highest resistance rates were recorded for 2 sites subjected to chemical and microbiological inputs (amoxicillin, 43% and 52%; ticarcillin, 19.6% and 47.7%), and for 2 sites relatively preserved from anthropogenic influence, resistance rates were lowest (amoxicillin, 1.5% and 16%; ticarcillin, 0.8% and 2.6%). Thirty-four bacteria resistant to imipenem (n=14) or cefotaxime (n=20) were identified as Pseudomonas aeruginosa (n=15), Pseudomonas fluorescens (7), Stenotrophomonas maltophilia (4), Burkholderia cepacia (2), Bordetella sp. (1), Pantoea sp. (1), Acinetobacter baumannii (1), Chryseomonas luteola (1), Ochrobactrum anthropi (1) and Escherichia coli (1). Screening for extended spectrum β-lactamase showed the presence of CTX-M-15 β-lactamase in the E. coli isolate, and the encoding gene was transferable in association with the IncI1 plasmid of about 50 kbp. Insertion sequence ISEcp1B was located upstream of the CTX-M-15 gene. This work showed a significant level of resistance to antibiotics, mainly among environmental saprophytic bacteria. Transmissible CTX-M-15 was detected in E. coli; this may mean that contamination of the environment by resistant bacteria may cause the spread of resistance genes.

  12. Detecting bacteria and Determining Their Susceptibility to Antibiotics by Stochastic Confinement in Nanoliter Droplets using Plug-Based Microfluidics

    Energy Technology Data Exchange (ETDEWEB)

    Boedicker, J.; Li, L; Kline, T; Ismagilov, R

    2008-01-01

    This article describes plug-based microfluidic technology that enables rapid detection and drug susceptibility screening of bacteria in samples, including complex biological matrices, without pre-incubation. Unlike conventional bacterial culture and detection methods, which rely on incubation of a sample to increase the concentration of bacteria to detectable levels, this method confines individual bacteria into droplets nanoliters in volume. When single cells are confined into plugs of small volume such that the loading is less than one bacterium per plug, the detection time is proportional to plug volume. Confinement increases cell density and allows released molecules to accumulate around the cell, eliminating the pre-incubation step and reducing the time required to detect the bacteria. We refer to this approach as stochastic confinement. Using the microfluidic hybrid method, this technology was used to determine the antibiogram - or chart of antibiotic sensitivity - of methicillin-resistant Staphylococcus aureus (MRSA) to many antibiotics in a single experiment and to measure the minimal inhibitory concentration (MIC) of the drug cefoxitin (CFX) against this strain. In addition, this technology was used to distinguish between sensitive and resistant strains of S. aureus in samples of human blood plasma. High-throughput microfluidic techniques combined with single-cell measurements also enable multiple tests to be performed simultaneously on a single sample containing bacteria. This technology may provide a method of rapid and effective patient-specific treatment of bacterial infections and could be extended to a variety of applications that require multiple functional tests of bacterial samples on reduced timescales.

  13. Detecting bacteria and determining their susceptibility to antibiotics by stochastic confinement in nanoliter droplets using plug-based microfluidics.

    Science.gov (United States)

    Boedicker, James Q; Li, Liang; Kline, Timothy R; Ismagilov, Rustem F

    2008-08-01

    This article describes plug-based microfluidic technology that enables rapid detection and drug susceptibility screening of bacteria in samples, including complex biological matrices, without pre-incubation. Unlike conventional bacterial culture and detection methods, which rely on incubation of a sample to increase the concentration of bacteria to detectable levels, this method confines individual bacteria into droplets nanoliters in volume. When single cells are confined into plugs of small volume such that the loading is less than one bacterium per plug, the detection time is proportional to plug volume. Confinement increases cell density and allows released molecules to accumulate around the cell, eliminating the pre-incubation step and reducing the time required to detect the bacteria. We refer to this approach as 'stochastic confinement'. Using the microfluidic hybrid method, this technology was used to determine the antibiogram - or chart of antibiotic sensitivity - of methicillin-resistant Staphylococcus aureus (MRSA) to many antibiotics in a single experiment and to measure the minimal inhibitory concentration (MIC) of the drug cefoxitin (CFX) against this strain. In addition, this technology was used to distinguish between sensitive and resistant strains of S. aureus in samples of human blood plasma. High-throughput microfluidic techniques combined with single-cell measurements also enable multiple tests to be performed simultaneously on a single sample containing bacteria. This technology may provide a method of rapid and effective patient-specific treatment of bacterial infections and could be extended to a variety of applications that require multiple functional tests of bacterial samples on reduced timescales.

  14. Impact of fertilizing with raw or anaerobically digested sewage sludge on the abundance of antibiotic-resistant coliforms, antibiotic resistance genes, and pathogenic bacteria in soil and on vegetables at harvest.

    Science.gov (United States)

    Rahube, Teddie O; Marti, Romain; Scott, Andrew; Tien, Yuan-Ching; Murray, Roger; Sabourin, Lyne; Zhang, Yun; Duenk, Peter; Lapen, David R; Topp, Edward

    2014-11-01

    The consumption of crops fertilized with human waste represents a potential route of exposure to antibiotic-resistant fecal bacteria. The present study evaluated the abundance of bacteria and antibiotic resistance genes by using both culture-dependent and molecular methods. Various vegetables (lettuce, carrots, radish, and tomatoes) were sown into field plots fertilized inorganically or with class B biosolids or untreated municipal sewage sludge and harvested when of marketable quality. Analysis of viable pathogenic bacteria or antibiotic-resistant coliform bacteria by plate counts did not reveal significant treatment effects of fertilization with class B biosolids or untreated sewage sludge on the vegetables. Numerous targeted genes associated with antibiotic resistance and mobile genetic elements were detected by PCR in soil and on vegetables at harvest from plots that received no organic amendment. However, in the season of application, vegetables harvested from plots treated with either material carried gene targets not detected in the absence of amendment. Several gene targets evaluated by using quantitative PCR (qPCR) were considerably more abundant on vegetables harvested from sewage sludge-treated plots than on vegetables from control plots in the season of application, whereas vegetables harvested the following year revealed no treatment effect. Overall, the results of the present study suggest that producing vegetable crops in ground fertilized with human waste without appropriate delay or pretreatment will result in an additional burden of antibiotic resistance genes on harvested crops. Managing human exposure to antibiotic resistance genes carried in human waste must be undertaken through judicious agricultural practice.

  15. Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.

    Science.gov (United States)

    El Salabi, Allaaeddin; Walsh, Timothey R; Chouchani, Chedly

    2013-05-01

    Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.

  16. H2O2 and/or TiO2 photocatalysis under UV irradiation for the removal of antibiotic resistant bacteria and their antibiotic resistance genes.

    Science.gov (United States)

    Guo, Changsheng; Wang, Kai; Hou, Song; Wan, Li; Lv, Jiapei; Zhang, Yuan; Qu, Xiaodong; Chen, Shuyi; Xu, Jian

    2017-02-05

    Inactivating antibiotic resistant bacteria (ARB) and removing antibiotic resistance genes (ARGs) are very important to prevent their spread into the environment. Previous efforts have been taken to eliminate ARB and ARGs from aqueous solution and sludges, however, few satisfying results have been obtained. This study investigated whether photocatalysis by TiO2 was able to reduce the two ARGs, mecA and ampC, within the host ARB, methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. The addition of H2O2 and matrix effect on the removal of ARB and ARGs were also studied. TiO2 thin films showed great effect on both ARB inactivation and ARGs removal. Approximately 4.5-5.0 and 5.5-5.8 log ARB reductions were achieved by TiO2 under 6 and 12mJ/cm(2) UV254 fluence dose, respectively. For ARGs, 5.8 log mecA reduction and 4.7 log ampC reduction were achieved under 120mJ/cm(2) UV254 fluence dose in the presence of TiO2. Increasing dosage of H2O2 enhanced the removal efficiencies of ARB and ARGs. The results also demonstrated that photocatalysis by TiO2 was capable of removing both intracellular and extracellular forms of ARGs. This study provided a potential alternative method for the removal of ARB and ARGs from aqueous solution.

  17. Odontogenic bacteria in periodontal disease and resistance patterns to common antibiotics used as treatment and prophylaxis in odontology in Spain.

    Science.gov (United States)

    Maestre, J R; Bascones, A; Sánchez, P; Matesanz, P; Aguilar, Lorenzo; Giménez, M J; Pérez-Balcabao, I; Granizo, J J; Prieto, J

    2007-03-01

    Resistance in streptococci or Gram-negative bacteria is associated with antibiotic consumption. Scarce information exists on the antibiotic susceptibility of bacterial isolates from patients with periodontitis in countries with high antibiotic consumption, as this is an area in which microbiological testing is not performed in daily practice. The present study was undertaken to explore the susceptibility of bacterial isolates in periodontitis to antibiotics prescribed in odontology in Spain as treatment for local infections or prophylaxis for distant focal infections. Periodontal samples were prospectively collected in 48 patients classified by pocket depth of or=4 mm. Species were identified by culture, selecting the five most frequent morphotypes per sample, and polymerase chain reaction (PCR). Susceptibility was determined by E-test. A total of 261 isolates were identified: 72.9% patients had Streptococcus oralis; 70.8% Streptococcus mitis; 60.4% Prevotella buccae; 39.6% Prevotella denticola; 37.5% Fusobacterium nucleatum; 35.4% Prevotella intermedia; 25% Capnocytophaga spp.; 23% Veillonella spp.; 22.9% Prevotella melaninogenica and Streptococcus sanguis; and resistance rates were 0% for amoxicillin, approximately 10% for clindamycin, 9-22% for tetracycline, and for azithromycin ranged from 18.2% for S. sanguis to 47.7% for S. mitis. Prevotella isolates were susceptible to amoxicillin-clavulanic acid, with amoxicillin resistance ranging from 17.1% in P. buccae to 26.3% in P. denticola. Metronidazole resistance was resistance ranged from 0 to 21.1%. beta-Lactamase production was positive in 54.1% Prevotella spp., 38.9% F. nucleatum, 30% Capnocytophaga spp., and 10% Veillonella spp. In this study, amoxicillin-clavulanic acid was the most active antibiotic against all species tested, followed by metronidazole in the case of anaerobes.

  18. Molecular modeling of Gram-positive bacteria peptidoglycan layer, selected glycopeptide antibiotics and vancomycin derivatives modified with sugar moieties.

    Science.gov (United States)

    Ślusarz, Rafał; Szulc, Monika; Madaj, Janusz

    2014-05-07

    Proper understanding of the mechanisms of binding to Gram-positive bacteria cell wall layers-especially to the peptidoglycan (PG) layer, seems to be crucial for proper development of new drug candidates which are effective against these bacteria. In this work we have constructed two different models of the Gram-positive bacteria PG layer: the layered and the scaffold models. PG conformational changes during geometry optimization, models relaxation, and molecular dynamics were described and discussed. We have found that the border surface of both PG layer models differs from the surface located away from the edge of models and the chains formed by disaccharide units prefer helix-like conformation. This curling of PG chains significantly affects the shape of antibiotic-accessible surface and the process is thus crucial for new drug development. Glycopeptide antibiotics effective against Gram-positive bacteria, such as vancomycin and its semisynthetic derivatives-oritavancin and telavancin, bind to d-alanyl-d-alanine stem termini on the peptidoglycan precursors of the cell wall. This binding inhibits cross-linking between the peptides and subsequently prevents cell wall synthesis. In this study some of the aspects of conformational freedom of vancomycin and restrictions from the modifications of vancomycin structure introduced into oritavancin and telavancin and five other vancomycin derivatives (with addition of 2-acetamido-2-deoxy-β-d-galactopyranosylamine, 2-acetamido-2-deoxy-β-d-glucopyranosylamine, 1-amine-1-deoxy-d-glucitol, 2-amino-2-deoxy-d-galactitol, or 2-amino-2-deoxy-d-glucitol to the C-terminal amino acid group in the vancomycin) are presented and discussed. The resulting molecular dynamics trajectories, root mean square deviation changes of aglycon and saccharide moieties as well as a comparative study of possible interactions with cyclic and chain forms of modified groups have been carried out, measured, and analyzed. Energetically advantageous

  19. The Role of Reactive Oxygen Species in Antibiotic-Mediated Killing of Bacteria.

    Science.gov (United States)

    Van Acker, Heleen; Coenye, Tom

    2017-01-12

    Recently, it was proposed that there is a common mechanism behind the activity of bactericidal antibiotics, involving the production of reactive oxygen species (ROS). However, the involvement of ROS in antibiotic-mediated killing has become the subject of much debate. In the present review, we provide an overview of the data supporting the ROS hypothesis; we also present data that explain the contradictory results often obtained when studying antibiotic-induced ROS production. For this latter aspect we will focus on the importance of taking the experimental setup into consideration and on the importance of some technical aspects of the assays typically used. Finally, we discuss the link between ROS production and toxin-antitoxin modules, and present an overview of implications for treatment.

  20. [Emerging and important antibiotic resistance in Gram negative bacteria: epidemiology, theory and practice].

    Science.gov (United States)

    Nordmann, P; Poirel, L

    2014-04-23

    Emerging and clinically-relevant antibiotic resistance mechanisms among Gram-negative rods are the extended-spectrum beta-lactamases (ESBL), carbapenemases, and 16S RNA methylases conferring resistance to aminoglycosides. Those resistance determinants do confer multiresistance to antibiotics. They are found in Enterobacteriaceae (especially community-acquired isolates, Pseudomonas aeruginosa and Acinetobacter baumannii). Detection of ESBL-producing and carbapenemase-producing isolates rely on the use of rapid diagnostic techniques that have to be performed when a reduced susceptibility to 3rd/4th generation cephalosporins or to carbapenems is observed, respectively. Only an early detection of those emerging resistance traits may contribute to limit their nosocomial spread and to optimize the antibiotic stewardship.

  1. In vitro synergistic effect of the CM11 antimicrobial peptide in combination with common antibiotics against clinical isolates of six species of multidrug-resistant pathogenic bacteria.

    Science.gov (United States)

    Amani, Jafar; Barjini, Kamal A; Moghaddam, Mehrdad M; Asadi, Asadollah

    2015-01-01

    During the last decades, increase of antibiotic resistance among pathogenic bacteria has been considered as a global concern. Therefore, it is important to find new antimicrobial agents and/or therapeutic strategies. In previous studies we investigated antibacterial activity of the CM11 peptide against multiple drug resistant clinical isolates of six bacteria species including Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Salmonella typhimurium. In this study, in order to reduce treatment costs and the cytotoxic effect of CM11 peptide, was analyzed its synergic interaction with selected antibiotics. In this reason, specific antibiotics for each bacterium were selected considering the guidelines of the "Clinical and Laboratory Standards Institute". Based on the results , using a checkerboard procedure through the broth microdilution method, MICs of antibiotic agents alone and in combination with the peptide were determined. In most cases, synergistic effects between CM11 peptide and selected antibiotics against six bacteria species were observed as partial synergy. However, for S. aureus and P. aeruginosaa synergic interaction between peptide and selective antibiotics was observed with penicillin and ceftazidime, respectively. For K. pneumoniae, synergic effect was observed when CM11 peptide was used in combination with norfloxacin and also the combination of peptide with norfloxacin showed synergic effect against A. baumannii. Combination between the CM11 peptide and ciprofloxacin showed synergic effect on E. coli while only partial synergy was observed for S. typhimurium in combination with cefotaxime and ceftazidime. These results suggest that when selected antibiotic used in combination with the CM11 peptide, the dose of some antibiotics, especially the dose independent antibiotics, may be reduced for eliminating drug resistant bacteria.

  2. Effects of silver nanoparticles in combination with antibiotics on the resistant bacteria Acinetobacter baumannii

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    Wan G

    2016-08-01

    Full Text Available Guoqing Wan,1,2 Lingao Ruan,2,3 Yu Yin,2,3 Tian Yang,2,3 Mei Ge,2 Xiaodong Cheng1,4 1School of Life Science and Technology, China Pharmaceutical University, Nanjing, 2Shanghai Laiyi Center for Biopharmaceutical R&D, 3School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China; 4Department of Integrative Biology & Pharmacology, The University of Texas Health Science Center, Houston, TX, USA Abstract: Acinetobacter baumannii resistance to carbapenem antibiotics is a serious clinical challenge. As a newly developed technology, silver nanoparticles (AgNPs show some excellent characteristics compared to older treatments, and are a candidate for combating A. baumannii infection. However, its mechanism of action remains unclear. In this study, we combined AgNPs with antibiotics to treat carbapenem-resistant A. baumannii (aba1604. Our results showed that single AgNPs completely inhibited A. baumannii growth at 2.5 µg/mL. AgNP treatment also showed synergistic effects with the antibiotics polymixin B and rifampicin, and an additive effect with tigecyline. In vivo, we found that AgNPs–antibiotic combinations led to better survival ratios in A. baumannii-infected mouse peritonitis models than that by single drug treatment. Finally, we employed different antisense RNA-targeted Escherichia coli strains to elucidate the synergistic mechanism involved in bacterial responses to AgNPs and antibiotics. Keywords: Acinetobacter baumannii, AgNPs, synergistic, antibiotic combination, anti­sense RNA 

  3. Antibiotic resistance profile of bacteria isolated from raw milk samples of cattle and buffaloes

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    Tahlina Tanzin

    2016-03-01

    Conclusion: Two different species of bacteria i.e., S. aureus and E. coli are contaminating with milk samples. The pathogenic bacteria can be controlled effectively by using Ciprofloxacin and Levofloxacin in the case of mastitis in cattle and buffaloes in Bangladesh. [J Adv Vet Anim Res 2016; 3(1.000: 62-67

  4. Darwinian and neo-Darwinian selection mechanisms in bacteria: Effects on antibiotic resistance

    Science.gov (United States)

    Darwin’s concept of survival of the fittest is as critical when applied to bacteria as it is to animals. Bacteria live in a highly competitive environment that is similar to the macrobiological world with its selective pressures. Neo-Darwinism views genes as selfish and as the ultimate unit of nat...

  5. Multi-antibiotic resistant bacteria in frozen food (ready to cook food) of animal origin sold in Dhaka, Bangladesh

    Institute of Scientific and Technical Information of China (English)

    Fouzia Sultana; Kamrunnahar; Hafsa Afroz; Afroz Jahan; Md Fakruddin; Suvamoy Datta

    2014-01-01

    Objective: To investigate the bacterial load and antibiotic resistance pattern of bacterial isolates obtained from (ready to cook) frozen food samples of animal origin in Dhaka, Bangladesh. Methods: A total of 20 samples of frozen ready to cook food of animal origin were purchased from different separate grocery stores in Dhaka, Bangladesh. Bacteria were isolated and identified based on the basis of biochemical properties. Results: A total of 57 isolates has been isolated from 20 samples, of them 35.08% were Gram positive and 64.92% were Gram negative organisms. Highest percentages of isolated organisms were Staphylococcocus spp. (24.56%), Alcaligene spp. (17.54%), Klebshiella spp. (12.28%) and the lowest percentages of organisms were Enterococcus spp., Actinobacillus spp. and Proteus spp. Antibiogram results clearly showed that levofloxacin and imipenem were the most effective drug against the isolates. The less effective antibiotics were chloramphenicol and nalidixic acid and resistance was highest against ciprofloxacin. The most contaminated food was chicken nuggets. Conclusions: This type of frozen food contaminated with multi-antibiotic resistant microorganisms can be potential vehicles for transmitting food-borne diseases.

  6. The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002

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    Mirović Veljko

    2004-01-01

    Full Text Available The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%, during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%. In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA fenotype. Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1% during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001. Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

  7. Antibiotic Resistance and Heavy Metals Tolerance in Gram-Negative Bacteria from Diseased American Bullfrog (Rana catesbeiana) Cultured in Malaysia

    Institute of Scientific and Technical Information of China (English)

    M Na-jian; S W Lee; W Wendy; L W Tee; M Nadirah; S H Faizah

    2009-01-01

    A total of 140 bacterial isolates have been successfully isolated from various organs of diseased American bullfrog (Rana catesbeiana) cultured in Malaysia. The most frequently isolated bacteria was Edwardsiella spp. (46 isolates) followed by Aeromonas spp. (33 isolates), Flavobacterium spp. (31 isolates), and Vibrio spp. (30 isolates). Majority of the bacterial isolates were found sensitive to furazolidone (85.0%), chloramphenicol (85.0%), oxolinic acid (90.0%), florfenicol (95.0%), and flumequine (97.5%). On the other hand, most of the bacterial isolates were resistant to oleandomycin (77.5%) and lincomycin (87.5%). Nitrofurantoin and flumequine can be inhibited the growth of all of Vibrio spp. whereas all isolates of Edwardsiella spp. were found sensitive to florfenicol and flumequine. Multiple antibiotic resistance (MAR) index were in range of 0.30-0.40, indicating that bacterial isolates from cultured bullfrogs may have received high risk exposure to the tested antibiotics. In addition, 90-100% of the isolates were resistant to copper, cadmium, and chromium. These results provided insight information on tolerance level of bacterial isolates from cultured bullfrogs to 21 antibiotics as well as heavy metals.

  8. Molecular characterization of antibiotic-resistant bacteria in contaminated chicken meat sold at supermarkets in Bangkok, Thailand.

    Science.gov (United States)

    Chaisatit, Chaiyaporn; Tribuddharat, Chanwit; Pulsrikarn, Chaiwat; Dejsirilert, Surang

    2012-01-01

    We assessed contamination by antibiotic-resistant bacteria in chicken meat obtained from supermarkets in Bangkok, Thailand. The prevalence of Salmonella enterica and Escherichia coli was 18.7% (14/75) and 53% (106/200), respectively. Most probable number (MPN) analysis showed that 56.7% of the samples (34/60) were in violation of the limit of allowable coliform bacteria in chicken meat, for which the maximum is 46,000 MPN/g. Multidrug-resistant phenotypes of both S. enterica and E. coli were found. The presence of class 1 integrons was demonstrated by polymerase chain reaction (PCR) and dot-blot hybridization. PCR showed that class 1 integrons were present in 42.9% (6/14) and 37.7% (40/106) of S. enterica and E. coli isolates, respectively. Resistance genes identified in this study were aadA2, aadA4, aadA22, and aadA23 (for aminoglycoside resistance); dfrA5 (for trimethoprim resistance), and lnuF (for lincosamide resistance). Four S. enterica isolates underwent multilocus sequence typing and the results were sequence type (ST) 50, ST 96, ST 1543, and ST 1549, which matched well with strains from many countries and reflected an international spread. Our study revealed that class 1 integrons have spread into community sources and might play an important role in horizontal antibiotic resistance gene transfer.

  9. Empiric combination antibiotic therapy is associated with improved outcome against sepsis due to Gram-negative bacteria: a retrospective analysis.

    Science.gov (United States)

    Micek, Scott T; Welch, Emily C; Khan, Junaid; Pervez, Mubashir; Doherty, Joshua A; Reichley, Richard M; Kollef, Marin H

    2010-05-01

    The optimal approach for empirical antibiotic therapy in patients with severe sepsis and septic shock remains controversial. A retrospective cohort study was conducted in the intensive care units of a university hospital. The data from 760 patients with severe sepsis or septic shock associated with Gram-negative bacteremia was analyzed. Among this cohort, 238 (31.3%) patients received inappropriate initial antimicrobial therapy (IIAT). The hospital mortality rate was statistically greater among patients receiving IIAT compared to those initially treated with an appropriate antibiotic regimen (51.7% versus 36.4%; P combination antibiotic regimen directed against Gram-negative bacteria (i.e., beta-lactam plus aminoglycoside or fluoroquinolone) were less likely to receive IIAT compared to monotherapy (22.2% versus 36.0%; P therapy from 89.7 to 94.2%. Similarly, the addition of an aminoglycoside would have increased the appropriate initial therapy for cefepime (83.4 to 89.9%) and piperacillin-tazobactam (79.6 to 91.4%). Logistic regression analysis identified IIAT (adjusted odds ratio [AOR], 2.30; 95% confidence interval [CI] = 1.89 to 2.80) and increasing Apache II scores (1-point increments) (AOR, 1.11; 95% CI = 1.09 to 1.13) as independent predictors for hospital mortality. In conclusion, combination empirical antimicrobial therapy directed against Gram-negative bacteria was associated with greater initial appropriate therapy compared to monotherapy in patients with severe sepsis and septic shock. Our experience suggests that aminoglycosides offer broader coverage than fluoroquinolones as combination agents for patients with this serious infection.

  10. Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria

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    Pirvu Lucia

    2016-01-01

    Full Text Available Epilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1 (S. epidermidis ATCC 12228 to very resistant (E. coli strains, E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.

  11. Antibiotic resistance of bacteria responsible of acute respiratory tract infections in children

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    Makhtar Camara

    2017-03-01

    Full Text Available Background and aims. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are the most common causative agents of acute respiratory tract infections (RTIs. The objective of this study was to assess their susceptibility to several antibiotics.Materials and methods. A total of 58 strains (16 S. pneumoniae, 19 H. influenzae and 23 M. catarrhalis were isolated from samples collected in two paediatric centres, and their susceptibility to commonly used antibiotics tested by E-test. Results. Among H. influenzae isolates, 10.5% were resistant to ampicillin (all β-lactamase-positive, and 88.9% were susceptible to cefaclor. High β-lactam resistance rates (penicillin: 31.3% and cephalosporins: 18.7 to 31.3% had been observed among S. pneumonia strains. Only 50% of isolates were susceptible to azithromycine. 91.3% of M. catarrhalis isolates β-lactamases producers were resistant to ampicillin while susceptible to the most tested antibiotics. Conclusions. Except M. catarrhalis β-lactamases producing strains, frequency of antibiotic resistance was mainly observed among S. pneumoniae, and to a lesser extent among H. influenzae clinical isolates, suggesting the need for continuous surveillance of antimicrobial resistance patterns in the management of RTIs.

  12. Longitudinal nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in indigenous Australian and Alaska native children with bronchiectasis.

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    Kim M Hare

    Full Text Available BACKGROUND: Indigenous children in Australia and Alaska have very high rates of chronic suppurative lung disease (CSLD/bronchiectasis. Antibiotics, including frequent or long-term azithromycin in Australia and short-term beta-lactam therapy in both countries, are often prescribed to treat these patients. In the Bronchiectasis Observational Study we examined over several years the nasopharyngeal carriage and antibiotic resistance of respiratory bacteria in these two PCV7-vaccinated populations. METHODS: Indigenous children aged 0.5-8.9 years with CSLD/bronchiectasis from remote Australia (n = 79 and Alaska (n = 41 were enrolled in a prospective cohort study during 2004-8. At scheduled study visits until 2010 antibiotic use in the preceding 2-weeks was recorded and nasopharyngeal swabs collected for culture and antimicrobial susceptibility testing. Analysis of respiratory bacterial carriage and antibiotic resistance was by baseline and final swabs, and total swabs by year. RESULTS: Streptococcus pneumoniae carriage changed little over time. In contrast, carriage of Haemophilus influenzae declined and Staphylococcus aureus increased (from 0% in 2005-6 to 23% in 2010 in Alaskan children; these changes were associated with increasing age. Moraxella catarrhalis carriage declined significantly in Australian, but not Alaskan, children (from 64% in 2004-6 to 11% in 2010. While beta-lactam antibiotic use was similar in the two cohorts, Australian children received more azithromycin. Macrolide resistance was significantly higher in Australian compared to Alaskan children, while H. influenzae beta-lactam resistance was higher in Alaskan children. Azithromycin use coincided significantly with reduced carriage of S. pneumoniae, H. influenzae and M. catarrhalis, but increased carriage of S. aureus and macrolide-resistant strains of S. pneumoniae and S. aureus (proportion of carriers and all swabs, in a 'cumulative dose-response' relationship

  13. Functional synergy of α-helical antimicrobial peptides and traditional antibiotics against Gram-negative and Gram-positive bacteria in vitro and in vivo.

    Science.gov (United States)

    Feng, Q; Huang, Y; Chen, M; Li, G; Chen, Y

    2015-01-01

    In this study, the antimicrobial activities based on the synergistic effects of traditional antibiotics (imipenem, cefepime, levofloxacin hydrochloride and vancomycin) and antimicrobial peptides (AMPs; PL-5, PL-31, PL-32, PL-18, PL-29 and PL-26), alone or in combination, against three Gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae and Staphylococcus epidermidis) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae) were investigated. In addition, the antimicrobial activity that was based on the synergistic effects of levofloxacin hydrochloride and PL-5 against Staphylococcus aureus in vivo was explored in a mouse infection model. Traditional antibiotics and AMPs showed significant synergistic effects on the antibacterial activities against the different Gram-positive and Gram-negative bacteria in vitro. A strong synergistic effect in the PL-5 and levofloxacin hydrochloride combination against Staphylococcus aureus was observed in the mouse infection model in vivo. The mechanism of synergistic action was due to the different targets of AMPs and traditional antibiotics. The combination of AMPs and traditional antibiotics can dramatically enhance antimicrobial activity and may help prevent or delay the emergence of antibiotic resistance. Thus, this combination therapy could be a promising approach to treat bacterial infections, particularly mixed infections and multi-antibiotic-resistant infections, in the clinics.

  14. Array based detection of antibiotic resistance genes in Gram negative bacteria isolated from retail poultry meat in the UK and Ireland.

    Science.gov (United States)

    McNeece, Grainne; Naughton, Violetta; Woodward, Martin J; Dooley, James S G; Naughton, Patrick J

    2014-06-02

    The use of antibiotics in birds and animals intended for human consumption within the European Union (EU) and elsewhere has been subject to regulation prohibiting the use of antimicrobials as growth promoters and the use of last resort antibiotics in an attempt to reduce the spread of multi-resistant Gram negative bacteria. Given the inexorable spread of antibiotic resistance there is an increasing need for improved monitoring of our food. Using selective media, Gram negative bacteria were isolated from retail chicken of UK-Intensively reared (n=27), Irish-Intensively reared (n=19) and UK-Free range (n=30) origin and subjected to an oligonucleotide based array system for the detection of 47 clinically relevant antibiotic resistance genes (ARGs) and two integrase genes. High incidences of β-lactamase genes were noted in all sample types, acc (67%), cmy (80%), fox (55%) and tem (40%) while chloramphenicol resistant determinants were detected in bacteria from the UK poultry portions and were absent in bacteria from the Irish samples. Denaturing Gradient Gel Electrophoresis (DGGE) was used to qualitatively analyse the Gram negative population in the samples and showed the expected diversity based on band stabbing and DNA sequencing. The array system proved to be a quick method for the detection of antibiotic resistance gene (ARG) burden within a mixed Gram negative bacterial population.

  15. Combined efficacy of biologically synthesized silver nanoparticles and different antibiotics against multidrug-resistant bacteria

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    Naqvi SZ

    2013-08-01

    Full Text Available Syed Zeeshan Haider Naqvi, Urooj Kiran, Muhammad Ishtiaq Ali, Asif Jamal, Abdul Hameed, Safia Ahmed, Naeem Ali Microbiology Research Laboratory, Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan Abstract: Biological synthesis of nanoparticles is a growing innovative approach that is relatively cheaper and more environmentally friendly than current physicochemical processes. Among various microorganisms, fungi have been found to be comparatively more efficient in the synthesis of nanomaterials. In this research work, extracellular mycosynthesis of silver nanoparticles (AgNPs was probed by reacting the precursor salt of silver nitrate (AgNO3 with culture filtrate of Aspergillus flavus. Initially, the mycosynthesis was regularly monitored by ultraviolet-visible spectroscopy, which showed AgNP peaks of around 400–470 nm. X-ray diffraction spectra revealed peaks of different intensities with respect to angle of diffractions (2θ corresponding to varying configurations of AgNPs. Transmission electron micrographs further confirmed the formation of AgNPs in size ranging from 5–30 nm. Combined and individual antibacterial activities of the five conventional antibiotics and AgNPs were investigated against eight different multidrug-resistant bacterial species using the Kirby–Bauer disk-diffusion method. The decreasing order of antibacterial activity (zone of inhibition in mm of antibiotics, AgNPs, and their conjugates against bacterial group (average was; ciprofloxacin + AgNPs (23 > imipenem + AgNPs (21 > gentamycin + AgNPs (19 > vancomycin + AgNPs (16 > AgNPs (15 > imipenem (14 > trimethoprim + AgNPs (14 > ciprofloxacin (13 > gentamycin (11 > vancomycin (4 > trimethoprim (0. Overall, the synergistic effect of antibiotics and nanoparticles resulted in a 0.2–7.0 (average, 2.8 fold-area increase in antibacterial activity, which clearly revealed that nanoparticles can be effectively used in

  16. Combined efficacy of biologically synthesized silver nanoparticles and different antibiotics against multidrug-resistant bacteria.

    Science.gov (United States)

    Naqvi, Syed Zeeshan Haider; Kiran, Urooj; Ali, Muhammad Ishtiaq; Jamal, Asif; Hameed, Abdul; Ahmed, Safia; Ali, Naeem

    2013-01-01

    Biological synthesis of nanoparticles is a growing innovative approach that is relatively cheaper and more environmentally friendly than current physicochemical processes. Among various microorganisms, fungi have been found to be comparatively more efficient in the synthesis of nanomaterials. In this research work, extracellular mycosynthesis of silver nanoparticles (AgNPs) was probed by reacting the precursor salt of silver nitrate (AgNO3) with culture filtrate of Aspergillus flavus. Initially, the mycosynthesis was regularly monitored by ultraviolet-visible spectroscopy, which showed AgNP peaks of around 400-470 nm. X-ray diffraction spectra revealed peaks of different intensities with respect to angle of diffractions (2θ) corresponding to varying configurations of AgNPs. Transmission electron micrographs further confirmed the formation of AgNPs in size ranging from 5-30 nm. Combined and individual antibacterial activities of the five conventional antibiotics and AgNPs were investigated against eight different multidrug-resistant bacterial species using the Kirby-Bauer disk-diffusion method. The decreasing order of antibacterial activity (zone of inhibition in mm) of antibiotics, AgNPs, and their conjugates against bacterial group (average) was; ciprofloxacin + AgNPs (23) . imipenem + AgNPs (21) > gentamycin + AgNPs (19) > vancomycin + AgNPs (16) > AgNPs (15) . imipenem (14) > trimethoprim + AgNPs (14) > ciprofloxacin (13) > gentamycin (11) > vancomycin (4) > trimethoprim (0). Overall, the synergistic effect of antibiotics and nanoparticles resulted in a 0.2-7.0 (average, 2.8) fold-area increase in antibacterial activity, which clearly revealed that nanoparticles can be effectively used in combination with antibiotics in order to improve their efficacy against various pathogenic microbes.

  17. Bactérias gram negativas resistentes a antimicrobianos em alimentos Gram-negative bacteria resistant to antibiotics in foods

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    José Cavalcante de Albuquerque Ribeiro Dias

    1985-12-01

    Full Text Available A partir de 154 espécimens de alimentos, representados por hortaliças (alface, leite e merenda escolar, obteve-se o isolamento e identificação de 400 amostras de bacilos Gram negativos. Esta amostragem se distribuiu em 339 enterobactérias (Escherichia, Shigella, Citrobacter, Klebsiella, Enterobacter, Serratia e Proteus e 61 de gêneros afins (Acinetobacter, Flavobacterium, Aeromonas e Pseudomonas. Submetendo-se as culturas aos antimicrobianos: sulfadiazina (Su, estreptomicina (Sm, tetraciclina (Tc, cloranfenicol (Cm, canamicina (Km, ampicilina (Ap, ácido nalidíxico (Nal e gentamicina (Gm, observou-se apenas seis estirpes sensíveis a todas as drogas e sensibilidade absoluta à Gm. A predominância dos modelos Su (27,6% e Su-Ap (39,6% incidiu nas enterobactérias, enquanto que, 18,0% para Ap e 9,8% para Su-Ap foram detectados nos gêneros afins. Para caracterização da resistência foram realizados testes de conjugação e a totalidade das culturas não revelou transferência para o gene que confere resistência ao ácido nalidíxico. Relevantes são as taxas de amostras R+ observadas nos bacilos entéricos, oscilando em torno de 90% (leite e merenda escolar e alface, em torno de 70%From 154 food samples, including vegetables (lettuce, milk and meals served at school it was possible to isolate and identify 400 Gram negative bacilli distributed among 339 enteric bacteria (Escherichia, Shigella, Citrobacter, Klebsiella, Enterobacter, Serratia and Proteus and other 61 non enteric bacilli (Acinetobacter, Flavobacterium, Aeromonas and Pseudomonas. Submitting this cultures to the drugs sulfadiazine (Su, streptomycin (Sm, tetracycline (Tc, chloramphenicol (Cm, kanamycin (Km, ampicillin (Ap, nalidixic acid (Nal and gentamycin (Gm it was observed only six stocks susceptible to all drugs and total sensibility to Gm. Among enteric bacteria the profiles Su (27,6% and Su-Ap (39,6% predominated, while for the non enteric bacilli percentages of 18.0 for

  18. Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria

    Directory of Open Access Journals (Sweden)

    Palloma Rodrigues Marinho

    2009-08-01

    Full Text Available Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3 isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

  19. Occurrence of yeasts, enterococci and other enteric bacteria in subgingival biofilm of HIV-positive patients with chronic gingivitis and necrotizing periodontitis.

    Science.gov (United States)

    Gaetti-Jardim Júnior, Elerson; Nakano, Viviane; Wahasugui, Thais C; Cabral, Fátima C; Gamba, Rosa; Avila-Campos, Mario Julio

    2008-04-01

    The purpose of this study was to determine the prevalence of enteric bacteria and yeasts in biofilm of 80 HIV-positive patients with plaque-associated gingivitis or necrotizing periodontitis. Patients were subjected to extra, intra oral and radiographic examinations. The oral hygiene, bleeding on probing, gingival conditions, and attachment loss were evaluated. Clinical specimens were collected from gingival crevices or periodontal pockets, transferred to VMGA III, diluted and transferred to Sabouraud Dextrose agar with 100 μg/ml of chloramphenicol, peptone water, EVA broth, EMB agar, SS agar, Bile esculin agar and Brilliant green agar. Isolation of yeasts was carried out at room temperature, for 3-7 days; and for the isolation of enteric microorganisms plates were incubated at 37°C, for 24-48 h. The yeasts identification was performed according to the carbon and nitrogen assimilation, fermentation of carbohydrates and germ tube formation. Bacteria were identified according to their colonial and cellular morphologies and biochemical tests. Yeasts were identified as Candida albicans and its occurrence was more common in patients with CD4+ below 200/mm(3) and was affected by the extension of periodontal involvement (P = 0.0345). Enteric bacteria recovered from clinical specimens were identified as Enterobacter sakazakii, Enterobacter cloacae, Serratia liquefaciens, Klebsiella oxytoca and Enterococcus sp. Enterobacteriaceae and enterococci were detected in 32.5% of clinical samples from patients with necrotizing periodontitis. In conclusion, non-oral pathogenic bacteria and C. albicans were more prevalent in periodontal sites of HIV-positive patients with necrotizing periodontitis and chronic gingivitis.

  20. Antimicrobial Activity and Antibiotic Sensitivity of Three Isolates of Lactic Acid Bacteria From Fermented Fish Product, Budu

    Directory of Open Access Journals (Sweden)

    Liasi, S. A.

    2009-01-01

    Full Text Available Three isolates of lactic acid bacteria (LAB from the fermented food product, Budu, were identified as genus lactobacillus (Lactobacillus casei LA17, Lactobacillus plantarum LA22 and L. paracasei LA02, and the highest population was Lb. paracasei LA02. The antibacterial agent produced by the isolates inhibited the growth of a range of gram-positive and gram-negative microorganisms. Antimicrobial sensitivity test to 18 different types of antibiotic were evaluated using the disc diffusion method. Inhibition zone diameter was measured and calculated from the means of five determinations and expressed in terms of resistance or susceptibility. All the LAB isolates were resistant to colestin sulphate, streptomycin, amikacin, norfloxacin, nalidixic acid, mecillinam, sulphanethoxazole/ trimethoprim, kanamycin, neomycin, bacitracin and gentamycin but susceptible to erythromycin, penicillin G, chloramphenicol, tetracycline, ampicillin and nitrofurantion.

  1. A Comprehensive Insight into Tetracycline Resistant Bacteria and Antibiotic Resistance Genes in Activated Sludge Using Next-Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Kailong Huang

    2014-06-01

    Full Text Available In order to comprehensively investigate tetracycline resistance in activated sludge of sewage treatment plants, 454 pyrosequencing and Illumina high-throughput sequencing were used to detect potential tetracycline resistant bacteria (TRB and antibiotic resistance genes (ARGs in sludge cultured with different concentrations of tetracycline. Pyrosequencing of 16S rRNA gene revealed that tetracycline treatment greatly affected the bacterial community structure of the sludge. Nine genera consisting of Sulfuritalea, Armatimonas, Prosthecobacter, Hyphomicrobium, Azonexus, Longilinea, Paracoccus, Novosphingobium and Rhodobacter were identified as potential TRB in the sludge. Results of qPCR, molecular cloning and metagenomic analysis consistently indicated that tetracycline treatment could increase both the abundance and diversity of the tet genes, but decreased the occurrence and diversity of non-tetracycline ARG, especially sulfonamide resistance gene sul2. Cluster analysis showed that tetracycline treatment at subinhibitory concentrations (5 mg/L was found to pose greater effects on the bacterial community composition, which may be responsible for the variations of the ARGs abundance. This study indicated that joint use of 454 pyrosequencing and Illumina high-throughput sequencing can be effectively used to explore ARB and ARGs in the environment, and future studies should include an in-depth investigation of the relationship between microbial community, ARGs and antibiotics in sewage treatment plant (STP sludge.

  2. In Vitro Biofilm Formation by Uropathogenic Bacteria and their Antibiotic Susceptibility Pattern

    Directory of Open Access Journals (Sweden)

    Somya Verma

    2016-07-01

    Full Text Available Background: Uropathogens have an ability to form biofilm in urinary tract. Microorganisms growing in biofilm are associated with chronic and recurrent UTI. They are highly resistant to a variety of antimicrobial agents. There are different phenotypic methods to detect biofilm production like Tube Adherence Method (TAM, Congo Red Agar Method (CRAM, Tissue Culture Plate Method (TCPM, etc. Aim and Objectives: The purpose of the study was to observe biofilm formation by uropathogens, their antibiotic resistance pattern and to correlate biofilm formation with drug resistance. Material and Methods: Total 168 isolates were collected from urine over six months. They were subjected to AST by Kirby Bauer disc diffusion method. Detection of biofilm production was done by TAM, CRAM, and TCPM. Results: Escherichia coli was the commonest isolate. Of the 68 clinical isolates, 54% were positive for biofilm production by TAM, 58% by CRAM, and 66% by TCPM. Compared to non-biofilm producers higher antibiotic resistance was observed among biofilm producers. TCPM was found to be more accurate. Conclusion: E. coli was the most frequent isolate. Biofilm producers were found to be resistant for multiple drugs. TCPM was found to be more quantitative and reliable

  3. Decellularized human amniotic membrane: more is needed for an efficient dressing for protection of burns against antibiotic-resistant bacteria isolated from burn patients.

    Science.gov (United States)

    Gholipourmalekabadi, M; Bandehpour, M; Mozafari, M; Hashemi, A; Ghanbarian, H; Sameni, M; Salimi, M; Gholami, M; Samadikuchaksaraei, A

    2015-11-01

    Human amniotic membranes (HAMs) have attracted the attention of burn surgeons for decades due to favorable properties such as their antibacterial activity and promising support of cell proliferation. On the other hand, as a major implication in the health of burn patients, the prevalence of bacteria resistant to multiple antibiotics is increasing due to overuse of antibiotics. The aim of this study was to investigate whether HAMs (both fresh and acellular) are an effective antibacterial agent against antibiotic-resistant bacteria isolated from burn patients. Therefore, a HAM was decellularized and tested for its antibacterial activity. Decellularization of the tissue was confirmed by hematoxylin and eosin (H&E) and 4,6-diamidino-2-phenylindole (DAPI) staining. In addition, the cyto-biocompatibility of the acellular HAM was proven by the cell viability test (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide, MTT) and scanning electron microscopy (SEM). The resistant bacteria were isolated from burns, identified, and tested for their susceptibility to antibiotics using both the antibiogram and polymerase chain reaction (PCR) techniques. Among the isolated bacteria, three blaIMP gene-positive Pseudomonas aeruginosa strains were chosen for their high resistance to the tested antibiotics. The antibacterial activity of the HAM was also tested for Klebsiella pneumoniae (American Type Culture Collection (ATCC) 700603) as a resistant ATCC bacterium; Staphylococcus aureus (mecA positive); and three standard strains of ATCC bacteria including Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27833), and S. aureus (ATCC 25923). Antibacterial assay revealed that only the latter three bacteria were susceptible to the HAM. All the data obtained from this study suggest that an alternative strategy is required to complement HAM grafting in order to fully protect burns from nosocomial infections.

  4. 后抗生素时代我们如何征服细菌?%How to conquer bacteria in post-antibiotic era?

    Institute of Scientific and Technical Information of China (English)

    郭晓奎

    2012-01-01

    The occurrence of antibiotic resistant bacteria, especially pan-drug resistant bacteria may make no antibiotics available for the treatment of infectious diseases, which will lead to the emerge of post-antibiotic era. It is imperative to find new antibacterial drugs or strategies to solve the increasingly serious problem of drug resistance. The invention status and application prospect of new-type antibiotics, antimicrobial peptide, bacteriophage and traditional Chinese medicine preparation are introduced in this paper, which may provide reference for the exploration of antibacterial drugs to conquer bacteria in post-antibiotic era.%耐药性“超级细菌”的出现,将使我们重新步入无抗生素可用的时代,即“后抗生素时代”.面对日益严重的细菌耐药性,寻找新的抗菌药物及治疗方案已成为目前急需解决的难题.文章阐述新型抗生素、抗菌肽、噬菌体和中药制剂的研究开发及应用前景,为后抗生素时代针对耐药细菌,特别是超级细菌的抗感染药物的研究提供思路.

  5. Antibiotic-producing bacteria from the sea surface microlayer in the Trondheim fjord, Norway

    OpenAIRE

    Hakvåg, Sigrid

    2009-01-01

    The marine environment has so far been poorly utilized in the search for (producers of) novel antimicrobial compounds. Marine bioprospecting might therefore be a promising field of research for the pharmaceutical industry as an alternative to terrestrial sources and synthetic production of pharmaceuticals.In this project, over 4000 cultivable isolates have been isolated from different locations in the Trondheim fjord and along the coast of Trøndelag, Norway. Over 1000 of these bacteria were i...

  6. First study on antimicriobial activity and synergy between isothiocyanates and antibiotics against selected Gram-negative and Gram-positive pathogenic bacteria from clinical and animal source.

    Science.gov (United States)

    Dias, Carla; Aires, Alfredo; Bennett, Richard N; Rosa, Eduardo A S; Saavedra, Maria J

    2012-05-01

    The emergence of new diseases and the resurgence of several infections that were controlled in the past, associated with recent increase of bacterial resistance have created the necessity for more studies towards to the development of new antimicrobials and new treatment strategies. The aim of the present study was to evaluate the in vitro synergy between different classes of important glucosinolates hydrolysis products-isothiocyanates with antibiotics (gentamycin and vancomycin), against important pathogenic bacteria: Escherichia coli, Enterococcus faecalis, Listeria monocytogenes, Pseudomonas aeruginosa and Staphylococcus aureus. A disc diffusion method was used to evaluate the antibacterial activity. The antimicrobial activity of phytochemicals and combinations between gentamycin, vancomycin and phytochemicals were quantitatively assessed by measuring the inhibitory halos. The results showed a selective antimicrobial effect of isothiocyanates, and this effect was strictly related with their chemical structure. In general the benzylisothiocyanate was the most effective compound against both Gram-positive and Gram-negative bacteria. The Listeria monocytogenes and Staphylococcus aureus were the bacteria most affected either by the phytochemicals alone or by the combination phytochemical-antibiotic. The bacteria Pseudomonas aeruginosa was the less affected pathogen. The most important synergism detected occurred between the commercial antibiotics with benzylisothiocyanate and 2-phenylethylisothiocyanate. In conclusion, some isothiocyanates are effective inhibitors of in vitro bacterial growth, and they can act synergistically with antibiotics.

  7. Studies of Antibiotic Resistance of Beta-Lactamase Bacteria under Different Nutrition Limitations at the Single-Cell Level.

    Science.gov (United States)

    Wang, Ying; Ran, Min; Wang, Jun; Ouyang, Qi; Luo, Chunxiong

    2015-01-01

    Drug resistance involves many biological processes, including cell growth, cell communication, and cell cooperation. In the last few decades, bacterial drug resistance studies have made substantial progress. However, a major limitation of the traditional resistance study still exists: most of the studies have concentrated on the average behavior of enormous amounts of cells rather than surveying single cells with different phenotypes or genotypes. Here, we report our study of beta-lactamase bacterial drug resistance in a well-designed microfluidic device, which allows us to conduct more controllable experiments, such as controlling the nutrient concentration, switching the culture media, performing parallel experiments, observing single cells, and acquiring time-lapse images. By using GFP as a beta-lactamase indicator and acquiring time-lapse images at the single-cell level, we observed correlations between the bacterial heterogeneous phenotypes and their behavior in different culture media. The feedback loop between the growth rate and the beta-lactamase production suggests that the beta-lactamase bacteria are more resistant in a rich medium than in a relatively poor medium. In the poorest medium, the proportion of dormant cells may increase, which causes a lower death rate in the same generation. Our work may contribute to assaying the antibiotic resistance of pathogenic bacteria in heterogeneous complex media.

  8. Control of multi-resistant bacteria and ventilator-associated pneumonia: is it possible with changes in antibiotics?

    Directory of Open Access Journals (Sweden)

    Elisa M. Jukemura

    2007-08-01

    Full Text Available Potent antimicrobial agents have been developed as a response to the development of antibiotic-resistant bacteria, which especially affect patients with prolonged hospitalization in Intensive Care Units (ICU and who had been previously treated with antimicrobials, especially third-generation cephalosporins.This study was to determine how changes in the empirical treatment of infections in ICU patients affect the incidence of Gram-negative bacteria species and their susceptibility to antimicrobials, and examine the impact of these changes on nosocomial infections. A prospective interventional study was performed in a university hospital during two periods: 1 First period (September 1999 to February 2000; and 2 Second period (August 2000 to December 2000; empirical treatment was changed from ceftriaxone and/or ceftazidime in the first period to piperacillin/tazobactam in the second. ICU epidemiological and infection control rates, as well as bacterial isolates from upper airways were analyzed. Ceftazidime consumption dropped from 34.83 to 0.85 DDD/1000 patients per day (p=0.004. Piperacillin/tazobactam was originally not available; its consumption reached 157.07 DDD/1000 patients per day in the second period (p=0.0002. Eighty-seven patients and 66 patients were evaluated for upper airway colonization in the first and second periods, respectively. There was a significant decrease in the incidence of K. pneumoniae (p=0.004 and P. mirabilis (p=0.036, restoration of K. pneumoniae susceptibility to cephalosporins (p<0.0001 and reduction of ventilator-associated pneumonia rates (p<0.0001. However, there was an increase in P. aeruginosa incidence (p=0.005 and increases in ceftazidime (p=0.003 and meropenem (p<0.0001 susceptibilities. Changing antimicrobial selective pressure on multi-resistant Gram-negative bacteria helps control ventilator-associated pneumonia and decreases antimicrobial resistance.

  9. Antibacterial activity of the terrestrial fern Lygodium flexuosum (L. Sw. against multidrug resistant enteric- and uro-pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Nabakishore Nayak

    2013-01-01

    Conclusions: Phytochemical analysis of the water-extract of L. flexuosum confirmed the presence of glycosides and carbohydrates, but alkaloids, terpenoids, steroids, saponins, tannins, and flavonoids were absent. L. flexuosum, being a fern, is a suitable non-microbial source of antimicrobial for MDR strains of major enteric and uro-pathogens.

  10. Antibiotic resistance and assessment of food-borne pathogenic bacteria in frozen foods.

    Science.gov (United States)

    Baek, Eunhye; Lee, Dokyung; Jang, Seok; An, Hyangmi; Kim, Mijin; Kim, Kyungjae; Lee, Kangoh; Ha, Namjoo

    2009-12-01

    One hundred ninety-three frozen food samples collected in Korea various public bazaars from October 2006 to September 2007. Staphylococci were detected in 21.8% of frozen food samples. Staphylococcus aureus was isolated from 17 (8.8%) samples. Other staphylococci isolates were identified as S. warneri (7.8%), S. epidermidis (2.1%), S. xylosus (1.6%), S. eguorum (1%), and S. vitulinus (0.5%). Additionally, the antimicrobial susceptibility of 42 staphylococcal isolates to ten different antimicrobial agents was determined. The staphylococcal isolates demonstrated antimicrobial resistance to mupirocin (31%) oxacillin (14.3%), gentamicin (9.5%), teicoplanin (7.1%) and ciprofloxacin (7.1%). Most of the staphylococcal isolates showed high-level resistance to mupirocin (MIC(90), >128 microg/mL). Fortunately, most of the isolates were susceptible to vancomycin. The total bacteria and Escherichia coli count were tested to investigate the microbiological quality of frozen foods. From 193 frozen food samples, 43 (22.3%), 34 (17.6%) and 19 (9.8%) samples were shown to be of unacceptable quality due to total bacteria, coliform and E. coli counts, respectively.

  11. Artemisia princeps Inhibits Biofilm Formation and Virulence-Factor Expression of Antibiotic-Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Na-Young Choi

    2015-01-01

    Full Text Available In this study, we used ethanol extract of A. princeps and investigated its antibacterial effects against MRSA. Ethanol extract of A. princeps significantly inhibited MRSA growth and organic acid production during glucose metabolism at concentrations greater than 1 mg/mL (P < 0.05. MRSA biofilm formation was observed using scanning electron microscopy (SEM and safranin staining. A. princeps extract was found to inhibit MRSA biofilm formation at concentrations higher than 2 mg/mL significantly (P < 0.05. Bactericidal effects of the A. princeps were observed using confocal laser microscopy, which showed that A. princeps was bactericidal in a dose-dependent manner. Using real-time PCR, expression of mecA, an antibiotic-resistance gene of MRSA, was observed, along with that of sea, agrA, and sarA. A. princeps significantly inhibited mecA, sea, agrA, and sarA, mRNA expression at the concentrations greater than 1 mg/mL (P < 0.05. The phytochemical analysis of A. princeps showed a relatively high content of organic acids and glycosides. The results of this study suggest that the ethanol extract of A. princeps may inhibit proliferation, acid production, biofilm formation, and virulence gene expressions of MRSA, which may be related to organic acids and glycosides, the major components in the extract.

  12. Forgotten antibiotics

    DEFF Research Database (Denmark)

    Pulcini, Céline; Bush, Karen; Craig, William A

    2012-01-01

    disease specialists in Europe, the United States, Canada, and Australia. An international expert panel selected systemic antibacterial drugs for their potential to treat infections caused by resistant bacteria or their unique value for specific criteria. Twenty-two of the 33 selected antibiotics were...... available in fewer than 20 of 38 countries. Economic motives were the major cause for discontinuation of marketing of these antibiotics. Fourteen of 33 antibiotics are potentially active against either resistant Gram-positive or Gram-negative bacteria. Urgent measures are then needed to ensure better...

  13. Quantification of enteric viruses, pathogen indicators, and Salmonella bacteria in class B anaerobically digested biosolids by culture and molecular methods.

    Science.gov (United States)

    Wong, Kelvin; Onan, Brandon M; Xagoraraki, Irene

    2010-10-01

    The most common class B biosolids in the United States are generated by mesophilic anaerobic digestion (MAD), and MAD biosolids have been used for land application. However, the pathogen levels in MAD biosolids are still unclear, especially with respect to enteric viruses. In this study, we determined the occurrence and the quantitative levels of enteric viruses and indicators in 12 MAD biosolid samples and of Salmonella enterica in 6 MAD biosolid samples. Three dewatered biosolid samples were also included in this study for purposes of comparison. Human adenoviruses (HAdV) had the highest gene levels and were detected more frequently than other enteric viruses. The gene levels of noroviruses (NV) reported were comparable to those of enteroviruses (EV) and human polyomaviruses (HPyV). The occurrence percentages of HAdV, HAdV species F, EV, NV GI, NV GII, and HPyV in MAD samples were 83, 83, 42, 50, 75, and 58%, respectively. No hepatitis A virus was detected. Infectious HAdV was detected more frequently than infectious EV, and all infectious HAdV were detected when samples were propagated in A549 cells. Based on most-probable-number (MPN) analysis, A549 cells were more susceptible to biosolid-associated viruses than BGM cells. All indicator levels in MAD biosolids were approximately 10(4) MPN or PFU per gram (dry), and the dewatered biosolids had significantly higher indicator levels than the MAD biosolids. Only two MAD samples tested positive for Salmonella enterica, where the concentration was below 1.0 MPN/4 g. This study provides a broad comparison of the prevalence of different enteric viruses in MAD biosolids and reports the first detection of noroviruses in class B biosolids. The observed high quantitative and infectivity levels of adenoviruses in MAD biosolids indicate that adenovirus is a good indicator for the evaluation of sludge treatment efficiency.

  14. Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate

    Science.gov (United States)

    Fongaro, Gislaine; García-González, María C.; Hernández, Marta; Kunz, Airton; Barardi, Célia R. M.; Rodríguez-Lázaro, David

    2017-01-01

    Enteric pathogens from biofertilizer can accumulate in the soil, subsequently contaminating water and crops. We evaluated the survival, percolation and leaching of model enteric pathogens in clay and sandy soils after biofertilization with swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174 in clay soil was significantly lower than in sandy soil (iT90 values of 10.520 ± 0.600 vs. 21.270 ± 1.100 and 12.040 ± 0.010 vs. 43.470 ± 1.300, respectively) and PhiX-174 showed faster percolation and leaching in sandy soil than clay soil (iT90 values of 0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated more slowly than E. coli O157:H7 (iT90 values of 9.340 ± 0.200 vs. 6.620 ± 0.500 and 11.900 ± 0.900 vs. 10.750 ± 0.900 in clay and sandy soils, respectively), such that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful microbial biomarker of depth contamination and leaching in clay and sandy soil and that bacteriophage could be used as an indicator of enteric pathogen persistence. Our study contributes to development of predictive models for enteric pathogen behavior in soils, and for potential water and food contamination associated with biofertilization, useful for risk management and mitigation in swine digestate recycling. PMID:28197137

  15. An investigation into the removal of Salmonella and enteric indicator bacteria from the separated liquid fraction of raw or anaerobically digested pig manure using novel on-farm woodchip biofilters.

    Science.gov (United States)

    McCarthy, G; Lawlor, P G; Carney, K N; Zhan, X; Gutierrez, M; Gardiner, G E

    2015-05-01

    The objective was to investigate the removal of Salmonella and enteric indicator bacteria from the liquid fraction of raw and anaerobically digested (AD) pig manure in woodchip biofilters over a 14 week (98 day) period. Antibiotic susceptible Salmonella Infantis was detected in one influent material (liquid fraction of raw manure) on two occasions but was not found in the effluent at any time point. Furthermore, mean coliform reductions of 56% were observed in the biofilters treating the liquid fraction of raw manure. However, a mean increase of 228% was found in those treating the liquid from AD manure, despite the fact that the microbial challenge to these biofilters was lower. In addition, relatively high coliform counts were still present in the effluent from both biofilter treatments, especially in the systems treating the liquid fraction of AD manure. However, findings for Escherichia coli and Enterococcus were more promising, with reductions observed for both treatments (10 and 18.5% for E. coli and 71 and 87% for Enterococcus). Moreover, E. coli and Enterococcus were at, or just above, the limit of detection in the final effluents. Overall, although, there are no microbial limits for discharge or washwaters, the woodchip filter effluent would appear safe for discharge to waterways or use on-farm as regards Salmonella, E. coli and Enterococcus but not coliform. In conclusion, woodchip biofilters offer potential as a low-cost sustainable novel treatment option for the removal of pathogens from the liquid fraction of pig manure.

  16. Nonmedical Uses of Antibiotics: Time to Restrict Their Use?

    Directory of Open Access Journals (Sweden)

    Richard William Meek

    2015-10-01

    Full Text Available The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.

  17. Nonmedical Uses of Antibiotics: Time to Restrict Their Use?

    Science.gov (United States)

    Meek, Richard William; Vyas, Hrushi; Piddock, Laura Jane Violet

    2015-10-01

    The global crisis of antibiotic resistance has reached a point where, if action is not taken, human medicine will enter a postantibiotic world and simple injuries could once again be life threatening. New antibiotics are needed urgently, but better use of existing agents is just as important. More appropriate use of antibiotics in medicine is vital, but the extensive use of antibiotics outside medical settings is often overlooked. Antibiotics are commonly used in animal husbandry, bee-keeping, fish farming and other forms of aquaculture, ethanol production, horticulture, antifouling paints, food preservation, and domestically. This provides multiple opportunities for the selection and spread of antibiotic-resistant bacteria. Given the current crisis, it is vital that the nonmedical use of antibiotics is critically examined and that any nonessential use halted.

  18. Studies on the ecology of aquatic bacteria of the lower Niger Delta: multiple antibiotic resistance among the standard plate count organisms.

    Science.gov (United States)

    Ogan, M T; Nwiika, D E

    1993-05-01

    The ecology of multiple antibiotic resistant (MAR) bacteria in the fresh-waters of the lower Niger Delta was studied in the Port Harcourt area, Rivers State. On the basis of decreasing pollution levels three zones, A, B, C, were recognized. Cell recovery by two viable count media, casein-peptone-starch (CPS) and plate count (PC) agar containing chloramphenicol, tetracycline, penicillin, streptomycin or ampicillin were compared in an initial study. Higher numbers of antibiotic resistant (AR) bacteria were recovered on CPS containing tetracycline, penicillin, streptomycin and ampicillin from the faecally-polluted New Calabar River (zone A) than on SPC agar containing similar antibiotics but the reverse was observed for forest stream (zone B) samples. Differences between the two media were also observed at individual sample sites. The proportions of strains of AR bacteria resistant to their primary isolation antibiotic varied from 55% (zone B) to 72% in the least polluted Isiokpo and Elele-Alimini streams (zone C), for ampicillin, and mostly count media without antibiotics included mainly species of Bacillus (12) and enterobacteria (18). Between five and 10 strains were resistant to > or = three antibiotics; seven were resistant to all five. The antibiograms of most strains were variable and depended on the method of drug application (discs or incorporation into agar), media and temperature of incubation (25 degrees, 37 degrees or 44.5 degrees C). Twenty-one strains were consistently resistant to ampicillin by the two methods; 10 to 19 were consistent for chloramphenicol, tetracycline and penicillin.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. The Comparison of Antagonistic Effects of Normal Vaginal Lactobacilli and Some Commonly used Antibiotics on Isolated Bacteria of Uterine Infections in Dairy Cows

    Directory of Open Access Journals (Sweden)

    Pouya Dini

    2012-12-01

    Full Text Available Uterine infections are one of the major reproductive complications during postpartum. The antibiotics and antiseptic agents used in the treatment of postpartum infections have residues in food, induce bacterial resistance, increase the financial costs and cause failure in defense mechanism of host. On the other hand, nowadays the administration of probiotics is considered as an alternative method for the prevention and treatment of infections. Therefore, preventive treatment with probiotic product could decrease the usage of antibiotic and bring advantages in dairy farm systems. The objective of this study was screening of the antagonistic properties of isolated vaginal Lactic Acid Bacteria (LAB against the most prevalent bacteria in uterine infections in order to investigate their probiotic potentials as an alternative approach for prevention of uterine infections. LAB were isolated from sampling of cranial part of vagina during estrus phase and luteal phase of Holstein dairy cattle and pathogens bacteria were isolated from merits and endometritis specimens which referred to our veterinary laboratory. The antagonistic activity of isolated LAB against uterine pathogens was tested by Agar spot test. Antibiotic susceptibilities of pathogenic strains to commonly used antibiotics were investigated by using disc diffusion method. Inhibition zones around both the probiotic spots and the antibiotic discs were classified to weak, moderate and strong categories and their antagonistic efficacies were compared. Isolated LAB had antagonistic effects against all the pathogenic strains including both gram negative and gram positive, Arcanobacterium pyogenes and Pseudomonas aeroginosa were the most sensitive bacteria (with 12.60 and 14 mm an average inhibition zone, respectively. LAB had the least antagonistic effects on Clostridium perfringens (3.6 mm of an average inhibition zone. Comparing the antagonistic efficacies, the percentages of overall

  20. 环境中抗药细菌及其抗药基因的研究进展%Antibiotic Resistant Bacteria and Its Antibiotic Resistant Genes in Environment :A Review

    Institute of Scientific and Technical Information of China (English)

    郭美婷; 袁青彬; 杨健

    2012-01-01

    Worldwide overuse of antibiotics has induced antibiotic resistance of bacteria and genes in environment. Antibiotic resistant bacteria (ARB)and its antibiotic resistant genes (ARGs)are gaining more attention as emerging contaminants. The generation mechanism of ARB and ARGs, as well as their occurrence and abundance in environment were summarized. And removal of these two contaminants was analyzed as well. Necessity to make relative research in China was also proposed.%抗生素的大量使用,诱发环境中的细菌和基因产生了抗药性.环境中的抗药细菌及其抗药基因被列为“新型污染物”逐渐引起了人们的关注.为此,文章介绍了环境中抗药细菌及其抗药基因的产生机制,总结了其在环境中的浓度和分布状况,分析了污水处理厂对抗药细菌及其抗药基因的去除特性,并指出在我国开展相关研究的必要性.

  1. Distribution of 1 037 strains of pathogenic bacteria and antibiotic resistance of the main pathogenic bacteria analysis%1037株病原菌分布及其主要病原菌耐药情况分析

    Institute of Scientific and Technical Information of China (English)

    潘开拓; 姜朝新; 王陈龙; 黄燕新; 曾令恒; 曾庆洋

    2013-01-01

      目的分析佛山市南海区第三人民医院检出的病原菌分布及其主要病原菌耐药情况,为临床合理用药和控制医院感染提供依据.方法采用法国生物梅里埃公司ATB微生物鉴定仪对2010年1月至2011年12月从该院患者的各类标本中分离的1037株病原菌进行鉴定,药敏试验采用琼脂纸片扩散法及法国生物梅里埃ATB药敏板条.结果检出病原菌以革兰阴性杆菌为主占58.4%、革兰阳性球菌次之占27.3%,真菌占13.2%,除真菌外的其他主要病原菌的抗菌药物耐药率普遍较高.结论医院容易发生医院感染,应加强其病原菌分布及其抗菌药物耐药情况监测,以指导临床合理用药,降低医院感染率.%Objective To analyze the distribution of pathogenic bacteria isolated from our hospital and the an-tibiotic resistance of the main pathogenic bacteria ,to provide a basis for clinical rational drug use and control the hos-pital infection .Methods 1 037 strains of pathogenic bacteria separated from patients in our hospital during Jan 2010-Dec 2011 were identified by ATB biomerieux from France and detected the antibiotic resistance by Kirby-Bauer(K-B) agar tape diffusion and drug sensitivity test tape of ATB biomerieux from France .Results The Gram-negative bacte-ria(58 .4% ) were the main pathogenic bacteria ,as followed by Gram-positive bacteria(27 .3% ) ,and fungi(13 .2% ) . The antibiotic resistance rates of the main pathogenic bacteria except fungi were high .Conclusion Patients easily suffered hospital infection ,it should strengthen the monitoring of the distribution of pathogenic bacteria and their an-tibiotic resistance so as to help the doctors to choose the antibiotics reasonably and reduce the rate of hospital infec-tion .

  2. Association of Pattern of Bacteria Sensitivity During the Empirical Antibiotics Use to the Achievement of Clinical Outcome in Pediatric Patients with Pneumonia

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    Vesara A. Gatera

    2014-12-01

    Full Text Available Pneumonia is one of infectious diseases that require a comprehensive and effective effort in its treatment, including in the use of empirical antibiotics. The use of empirical antibiotics should be based on patterns of sensitivity toward bacteria. The aim of this study was to evaluate the use of antibiotics based on the sensitivity patterns by clinical outcomes as the goal of treatment. This study was conducted in Hasan Sadikin Hospital Bandung in October–December 2013 using a retrospective cross-sectional study design. Secondary data were obtained from medical records during January 2011–December 2012. This study consisted of 24 patients with positive culture test and received antibiotic prescription. The results showed the percentage of the use of cefotaxime-ampicillin (37.5%, cefotaxime (33.3%, ceftriaxone (20.8%, and Ampicillin (8.4%. The most influential antibiotics for achieving clinical outcome using 95% confidence level is combination of cefotaxime-ampiciline (P=0.044 with 77.7% sensitivity level. This study suggested that the pattern of antibiotic sensitivity affected the clinical outcomes of pediatric patients with pneumonia.

  3. Tryptophan-containing lipopeptide antibiotics derived from polymyxin B with activity against Gram positive and Gram negative bacteria.

    Science.gov (United States)

    Grau-Campistany, Ariadna; Manresa, Ángeles; Pujol, Montserrat; Rabanal, Francesc; Cajal, Yolanda

    2016-02-01

    Resistance to all known antibiotics is a growing concern worldwide, and has renewed the interest in antimicrobial peptides, a structurally diverse class of amphipathic molecules that essentially act on the bacterial membrane. Propelled by the antimicrobial potential of this compound class, we have designed three new lipopeptides derived from polymyxin B, sp-34, sp-96 and sp-100, with potent antimicrobial activity against both Gram positive and Gram negative bacteria. The three peptides bind with high affinity to lipopolysaccharide as demonstrated by monolayer penetration and dansyl-displacement. The interaction with the cytoplasmic membrane has been elucidated by biophysical experiments with model membranes of POPG or POPE/POPG (6:4), mimicking the Gram positive and Gram negative bacterial membrane. Trp-based fluorescence experiments including steady-state, quenching, anisotropy and FRET, reveal selectivity for anionic phospholipids and deep insertion into the membrane. All three lipopeptides induce membrane fusion and leakage from anionic vesicles, a process that is favored by the presence of POPE. The molecules bind to zwitterionic POPC vesicles, a model of the eukaryotic membrane, but in a different way, with lower affinity, less penetration into the bilayer and no fusion or permeabilization of the membrane. Results in model membranes are consistent with flow cytometry experiments in Escherichia coli and Staphylococcus aureus using a membrane potential sensitive dye (bis-oxonol) and a nucleic acid dye (propidium iodide), suggesting that the mechanism of action is based on membrane binding and collapse of membrane integrity by depolarization and permeabilization.

  4. Distribution of tetracycline- and tylosin-resistance genes in bacteria from soils exposed to swine effluent

    Science.gov (United States)

    The application of animal waste from large-scale production facilities to cropland is a common means of manure disposal and nutrient recycling. In addition to the high nutrient load, antibiotic residues and antibiotic-resistant bacteria enter into the environment through this process. As yet, it i...

  5. Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters.

    Science.gov (United States)

    Cheng, Dan; Yu, Mengqun; Fu, Fei; Han, Weiye; Li, Gan; Xie, Jianping; Song, Yang; Swihart, Mark T; Song, Erqun

    2016-01-01

    Food poisoning and infectious diseases caused by pathogenic bacteria such as Staphylococcus aureus (SA) are serious public health concerns. A method of specific, sensitive, and rapid detection of such bacteria is essential and important. This study presents a strategy that combines aptamer and antibiotic-based dual recognition units with magnetic enrichment and fluorescent detection to achieve specific and sensitive quantification of SA in authentic specimens and in the presence of much higher concentrations of other bacteria. Aptamer-coated magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters (AuNCs@Van) were prepared by a simple one-step process and used for sensitive quantification of SA in the range of 32-10(8) cfu/mL with the detection limit of 16 cfu/mL via a fluorescence intensity measurement. And using this strategy, about 70 cfu/mL of SA in complex samples (containing 3 × 10(8) cfu/mL of other different contaminated bacteria) could be successfully detected. In comparison to prior studies, the developed strategy here not only simplifies the preparation procedure of the fluorescent probes (AuNCs@Van) to a great extent but also could sensitively quantify SA in the presence of much higher concentrations of other bacteria directly with good accuracy. Moreover, the aptamer and antibiotic used in this strategy are much less expensive and widely available compared to common-used antibodies, making it cost-effective. This general aptamer- and antibiotic-based dual recognition strategy, combined with magnetic enrichment and fluorescent detection of trace bacteria, shows great potential application in monitoring bacterial food contamination and infectious diseases.

  6. 7-(1-Methyl-3-Pyrrolyl--4,6-Dinitrobenzofuroxan Reduces the Frequency of Antibiotic Resistance Mutations Induced by Ciprofloxacin in Bacteria

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    Vladimir A. Chistyakov

    2016-09-01

    Full Text Available The aim of the present study was to investigate biological properties of the novel nitrobenzoxadiazole derivative 7-(1-methyl-3-pyrrolyl--4,6-dinitrobenzofuroxan. Materials and Methods: We used a bioluminescent test based on a set of lux-biosensors, which are genetically modified E.coli strains able to react on different types of factors that can induce an SOS-response with light emission. The spontaneous and induced mutation frequencies of antibiotic resistance in E. coli were determined by methods of classical genetics of microorganisms. Results: 7-(1-methyl-3-pyrrolyl--4,6-dinitrobenzofuroxan demonstrated inhibition of SOS-response in a biosensor model system and significantly reduced the frequency of spontaneous mutations and mutations induced by ciprofloxacin of antibiotic resistance. Conclusion: Based on our data, we can recommend using compound-1 as a starting point for the development of drugs that block mutagenesis associated with the emergence of antibiotic-resistant bacteria.

  7. Identification of Enterococcus faecalis bacteria resistant to heavy metals and antibiotics in surface waters of the Mololoa River in Tepic, Nayarit, Mexico.

    Science.gov (United States)

    Mondragón, Verónica Alejandra; Llamas-Pérez, Dámaris F; González-Guzmán, Gladis E; Márquez-González, Antonio R; Padilla-Noriega, Roberto; Durán-Avelar, Ma de Jesús; Franco, Bernardo

    2011-12-01

    Heavy metal and antibiotic resistance have been shown to have a strong correlation in nature, and their inter-relation is an important subject of study. We report an analysis of surface waters of the Mololoa River in the municipality of Tepic, state of Nayarit, Mexico. This river has two distinctive sources of contamination: sewage waters and trash confinements. Our findings demonstrate a correlation between the river flow pattern and resistance to heavy metals or to heavy metals and antibiotics in isolated bacteria of the genus Enterococcus, specifically Enterococcus faecalis. The Mololoa River provides a model to study the relationship between water flow and generation of biodiversity, and more importantly, it constitutes a model for studying genetic diversity of bacteria affecting human health.

  8. In vitro antibacterial screening of six proline-based cyclic dipeptides in combination with β-lactam antibiotics against medically important bacteria.

    Science.gov (United States)

    Kumar, S Nishanth; Lankalapalli, Ravi S; Kumar, B S Dileep

    2014-05-01

    The in vitro synergistic antibacterial activity of six proline-based cyclic dipeptides [cyclo(D-Pro-L-Leu), cyclo(L-Pro-L-Met), cyclo(D-Pro-L-Phe), cyclo(L-Pro-L-Phe), cyclo(L-Pro-L-Tyr), and cyclo(L-Pro-D-Tyr)] in combination imipenem and ceftazidime was investigated in the present manuscript. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the cyclic dipeptides were compared with those of the standard antibiotics (imipenem and ceftazidime). The synergistic antibacterial activities of cyclic dipeptides with imipenem or ceftazidime were assessed using the checkerboard and time-kill methods. The results of the present study showed that the combined effect of six cyclic dipeptides with imipenem predominantly recorded synergistic interaction (FIC index bacteria was completely attenuated after 12-24 h of treatment with a 50:50 ratio of proline-based cyclic dipeptides and antibiotics. These synergistic effects have a potential role in delaying the development of resistance as the antibacterial activity is achieved with the very low concentrations of cyclic dipeptides and antibiotics. The cytotoxicity of cyclic dipeptides was tested against VERO cell line (African green monkey kidney cell line), and no cytotoxicity was recorded for cyclic dipeptides up to 100 μg/mL. These findings suggest that combination of cyclic dipeptides and antibiotics might be a good strategy for the individualization of novel templates for the development of new antimicrobial agents or combinations of drugs for antimicrobial chemotherapy. Moreover, these combinations may lead to the development of a new and vital antimicrobial combination against the infections caused by pathogenic bacteria. The in vitro synergistic activity of cyclic dipeptides with antibiotics against medically important bacteria is reported here for the first time.

  9. Phage-Based Fluorescent Biosensor Prototypes to Specifically Detect Enteric Bacteria Such as E. coli and Salmonella enterica Typhimurium.

    Directory of Open Access Journals (Sweden)

    Manon Vinay

    Full Text Available Water safety is a major concern for public health and for natural environment preservation. We propose to use bacteriophages to develop biosensor tools able to detect human and animal pathogens present in water. For this purpose, we take advantage of the highly discriminating properties of the bacteriophages, which specifically infect their bacterial hosts. The challenge is to use a fluorescent reporter protein that will be synthesized, and thus detected, only once the specific recognition step between a genetically modified temperate bacteriophage and its bacterial host has occurred. To ensure the accuracy and the execution speed of our system, we developed a test that does not require bacterial growth, since a simple 1-hour infection step is required. To ensure a high sensitivity of our tool and in order to detect up to a single bacterium, fluorescence is measured using a portable flow cytometer, also allowing on-site detection. In this study, we have constructed and characterized several "phagosensor" prototypes using the HK620 bacteriophage and its host Escherichia coli TD2158 and we successfully adapted this method to Salmonella detection. We show that the method is fast, robust and sensitive, allowing the detection of as few as 10 bacteria per ml with no concentration nor enrichment step. Moreover, the test is functional in sea water and allows the detection of alive bacteria. Further development will aim to develop phagosensors adapted on demand to the detection of any human or animal pathogen that may be present in water.

  10. 613株病原菌分布及其主要耐药情况分析%Distribution of 613 Strains of Pathogenic Bacteria and Antibiotic Resistance of the Main Pathogenic Bacteria analysis

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Objective To analyze the distribution of pathogenic bacteria isolated from our hospital and the antibiotic resistance of the main pathogenic bacteria ,to provide a basis for clinical rational drug use and control the hospital infection .Methods 613 strains of pathogenic bacteria separated from patients in our hospital during June to December of 2012 were identifited by Hengxing bacteria analysis and detected the antibiotic resistance by Kirby-Bauer(K-B) agar tapediffusion. Results We gather 613 strains in last year of 2012,there were 417 strains Gram-negative bacteria (68%),128 strains Gram-positive bacteria(20.8%),and 68 strains fungi(13.2%), obviously the antibiotic resistance of pathogenic bacteria was higer than first half year.Conclusion It is necessary to reasonably use antibiotics,strengthen the awareness of bacteria culture and strictly comply the standards of diagnosis and antibiotic use so as to prevent the antibiotic resistanc of pathogenic bacteria. Gram-negative bacteria was the main pathogenic bacteria,clinician should ware the infection of Gram-negative bacteria.%  目的分析故城县医院检出的病原菌分布及其主要病原菌的耐药情况,为临床合理用药和控制医院感染提供参考。方法采用恒星细菌分析系统对2012年6月至2012年12月分离的613株病原菌进行鉴定,药敏试验采用琼脂纸片扩散法。结果2012年下半年共收集非重复临床分离菌株613株,其中革兰阴性菌417株占68%,革兰阳性菌128株占20.8%,真菌68株占11.2%,除真菌外其他病原菌的耐药率较之上半年都明显增加。结论应完善抗菌药物的规范使用,加强细菌培养意识,严格控制医院感染病例的诊断和用药标准,预防抗菌药物耐药率的快速产生。革兰阴性杆菌在住院患者感染中占主要地位,临床医师应警惕革兰阴性菌引起的感染。

  11. The Impact of Efflux Pump Inhibitors on the Activity of Selected Non-Antibiotic Medicinal Products against Gram-Negative Bacteria

    Directory of Open Access Journals (Sweden)

    Agnieszka E. Laudy

    2017-01-01

    Full Text Available The potential role of non-antibiotic medicinal products in the treatment of multidrug-resistant Gram-negative bacteria has recently been investigated. It is highly likely that the presence of efflux pumps may be one of the reasons for the weak activity of non-antibiotics, as in the case of some non-steroidal anti-inflammatory drugs (NSAIDs, against Gram-negative rods. The activity of eight drugs of potential non-antibiotic activity, active substance standards, and relevant medicinal products were analysed with and without of efflux pump inhibitors against 180 strains of five Gram-negative rod species by minimum inhibitory concentration (MIC value determination in the presence of 1 mM MgSO4. Furthermore, the influence of non-antibiotics on the susceptibility of clinical strains to quinolones with or without PAβN (Phe-Arg-β-naphthylamide was investigated. The impacts of PAβN on the susceptibility of bacteria to non-antibiotics suggests that amitriptyline, alendronate, nicergoline, and ticlopidine are substrates of efflux pumps in Gram-negative rods. Amitriptyline/Amitriptylinum showed the highest direct antibacterial activity, with MICs ranging 100–800 mg/L against all studied species. Significant decreases in the MIC values of other active substances (acyclovir, atorvastatin, and famotidine tested with pump inhibitors were not observed. The investigated non-antibiotic medicinal products did not alter the MICs of quinolones in the absence and in the presence of PAβN to the studied clinical strains of five groups of species.

  12. Enhanced simultaneous PEC eradication of bacteria and antibiotics by facilely fabricated high-activity {001} facets TiO2 mounted onto TiO2 nanotubular photoanode.

    Science.gov (United States)

    Li, Guiying; Nie, Xin; Chen, Jiangyao; Wong, Po Keung; An, Taicheng; Yamashita, Hiromi; Zhao, Huijun

    2016-09-15

    Biohazards and coexisted antibiotics are two groups of emerging contaminants presented in various aquatic environments. They can pose serious threat to the ecosystem and human health. As a result, inactivation of biohazards, degradation of antibiotics, and simultaneous removal of them are highly desired. In this work, a novel photoanode with a hierarchical structured {001} facets exposed nano-size single crystals (NSC) TiO2 top layer and a perpendicularly aligned TiO2 nanotube array (NTA) bottom layer (NSC/NTA) was successfully fabricated. The morphology and facets of anatase TiO2 nanoparticles covered on the top of NTA layer could be controlled by adjusting precalcination temperature and heating rate as the pure NTA was clamped with glasses. Appropriate recalcination can timely remove surface F from {001} facets, and the photocatalytic activity of the resultant photoanode was subsequently activated. NSC/NTA photoanode fabricated under 500 °C precalcination with 20 °C min(-1) followed by 550 °C recalcination possessed highest photoelectrocatalytic efficiency to simultaneously remove bacteria and antibiotics. Results suggest that two-step calcination is necessary for fabrication of high photocatalytic activity NSC/NTA photoanode. The capability of simultaneous eradication of bacteria and antibiotics shows great potential for development of a versatile approach to effectively purify various wastewaters contaminated with complex pollutants.

  13. Enhancement of antibacterial activity of capped silver nanoparticles in combination with antibiotics, on model gram-negative and gram-positive bacteria.

    Science.gov (United States)

    Kora, Aruna Jyothi; Rastogi, Lori

    2013-01-01

    The nanoparticles used in this study were prepared from AgNO3 using NaBH4 in the presence of capping agents such as citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone. The formed nanoparticles were characterized with UV-Vis, TEM, and XRD. The generation of silver nanoparticles was confirmed from the appearance of yellow colour and an absorption maximum between 399 and 404 nm. The produced nanoparticles were found to be spherical in shape and polydisperse. For citrate, SDS, and PVP capped nanoparticles, the average particle sizes were 38.3 ± 13.5, 19.3 ± 6.0, and 16.0 ± 4.8 nm, respectively. The crystallinity of the nanoparticles in FCC structure is confirmed from the SAED and XRD patterns. Also, the combined antibacterial activity of these differently capped nanoparticles with selected antibiotics (streptomycin, ampicillin, and tetracycline) was evaluated on model Gram-negative and Gram-positive bacteria, employing disc diffusion assay. The activity of the tested antibiotics was enhanced in combination with all the stabilized nanoparticles, against both the Gram classes of bacteria. The combined effects of silver nanoparticles and antibiotics were more prominent with PVP capped nanoparticles as compared to citrate and SDS capped ones. The results of this study demonstrate potential therapeutic applications of silver nanoparticles in combination with antibiotics.

  14. Enhancement of Antibacterial Activity of Capped Silver Nanoparticles in Combination with Antibiotics, on Model Gram-Negative and Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Aruna Jyothi Kora

    2013-01-01

    Full Text Available The nanoparticles used in this study were prepared from AgNO3 using NaBH4 in the presence of capping agents such as citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone. The formed nanoparticles were characterized with UV-Vis, TEM, and XRD. The generation of silver nanoparticles was confirmed from the appearance of yellow colour and an absorption maximum between 399 and 404 nm. The produced nanoparticles were found to be spherical in shape and polydisperse. For citrate, SDS, and PVP capped nanoparticles, the average particle sizes were 38.3±13.5, 19.3±6.0, and 16.0±4.8 nm, respectively. The crystallinity of the nanoparticles in FCC structure is confirmed from the SAED and XRD patterns. Also, the combined antibacterial activity of these differently capped nanoparticles with selected antibiotics (streptomycin, ampicillin, and tetracycline was evaluated on model Gram-negative and Gram-positive bacteria, employing disc diffusion assay. The activity of the tested antibiotics was enhanced in combination with all the stabilized nanoparticles, against both the Gram classes of bacteria. The combined effects of silver nanoparticles and antibiotics were more prominent with PVP capped nanoparticles as compared to citrate and SDS capped ones. The results of this study demonstrate potential therapeutic applications of silver nanoparticles in combination with antibiotics.

  15. Contamination of sulfonamide antibiotics and sulfamethazine-resistant bacteria in the downstream and estuarine areas of Jiulong River in Southeast China.

    Science.gov (United States)

    Ou, Danyun; Chen, Bin; Bai, Renao; Song, Puqing; Lin, Heshan

    2015-08-01

    Surface water samples from downstream and estuarine areas of Jiulong River were collected in August 2011 and May 2012 for detecting sulfonamide antibiotic residues and isolating sulfamethazine-resistant bacteria. Sulfamethazine was detected in all samples in May 2012 at an average concentration of 78.3 ng L(-1), which was the highest among the nine sulfonamide antibiotics determined. Sulfamethazine-resistant bacteria (SRB) were screened using antibiotic-containing agar plates. The SRB average abundance in the samples was 3.69 × 10(4) and 2.17 × 10(3) CFUs mL(-1) in August 2011 and May 2012, respectively, and was positively correlated to sulfamethazine concentration in May 2012. The 16S rRNA gene sequencing of all the 121 SRB isolates revealed high diversity. Furthermore, the SRB isolates exhibited multidrug resistance, with 48.7% showing resistance to at least three antibiotics. The abundance and persistence of highly diverse SRB and their multidrug resistance are likely to demonstrate the transferable pressure from coastal environments on public health.

  16. Differential interleukin-10 (IL-10) and IL-23 production by human blood monocytes and dendritic cells in response to commensal enteric bacteria.

    Science.gov (United States)

    Manuzak, Jennifer; Dillon, Stephanie; Wilson, Cara

    2012-08-01

    Human peripheral blood contains antigen-presenting cells (APC), including dendritic cells (DC) and monocytes, that may encounter microbes that have translocated from the intestine to the periphery in disease states like HIV-1 infection and inflammatory bowel disease. We investigated the response of DC and monocytes in peripheral blood mononuclear cells (PBMC) to a panel of representative commensal enteric bacteria, including Escherichia coli, Enterococcus sp., and Bacteroides fragilis. All three bacteria induced significant upregulation of the maturation and activation markers CD40 and CD83 on myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC). However, only mDC produced cytokines, including interleukin-10 (IL-10), IL-12p40/70, and tumor necrosis factor alpha (TNF-α), in response to bacterial stimulation. Cytokine profiles in whole PBMC differed depending on the stimulating bacterial species: B. fragilis induced production of IL-23, IL-12p70, and IL-10, whereas E. coli and Enterococcus induced an IL-10-predominant response. mDC and monocyte depletion experiments indicated that these cell types differentially produced IL-10 and IL-23 in response to E. coli and B. fragilis. Bacteroides thetaiotaomicron did not induce levels of IL-23 similar to those of B. fragilis, suggesting that B. fragilis may have unique proinflammatory properties among Bacteroides species. The addition of recombinant human IL-10 to PBMC cultures stimulated with commensal bacteria abrogated the IL-23 response, whereas blocking IL-10 significantly enhanced IL-23 production, suggesting that IL-10 controls the levels of IL-23 produced. These results indicate that blood mDC and monocytes respond differentially to innate stimulation with whole commensal bacteria and that IL-10 may play a role in controlling the proinflammatory response to translocated microbes.

  17. Isolation of multiple drug-resistant enteric bacteria from feces of wild Western Lowland Gorilla (Gorilla gorilla gorilla) in Gabon.

    Science.gov (United States)

    Mbehang Nguema, Pierre Philippe; Okubo, Torahiko; Tsuchida, Sayaka; Fujita, Shiho; Yamagiwa, Juichi; Tamura, Yutaka; Ushida, Kazunari

    2015-05-01

    Prevalence of drug-resistant bacteria in wildlife can reveal the actual level of anthropological burden on the wildlife. In this study, we isolated two multiple drug-resistant strains, GG6-2 and GG6-1-1, from 27 fresh feces of wild western lowland gorillas in Moukalaba-Doudou National Park, Gabon. Isolates were identified as Achromobacter xylosoxidans and Providencia sp., respectively. Minimum inhibitory concentrations of the following 12 drugs-ampicillin (ABPC), cefazolin (CEZ), cefotaxime (CTX), streptomycin (SM), gentamicin (GM), kanamycin (KM), tetracycline (TC), nalidixic acid (NA), ciprofloxacin (CPFX), colistin (CL), chloramphenicol (CP) and trimethoprim (TMP)-were determined. Isolate GG6-2 was resistant to all antimicrobials tested and highly resistant to CTX, SM, TC, NA and TMP. Isolate GG6-1-1 was resistant to ABPC, CEZ, TC, CL, CP and TMP.

  18. Inactivation by solar photo-Fenton in pet bottles of wild enteric bacteria of natural well water: Absence of re-growth after one week of subsequent storage

    OpenAIRE

    Ndounla, J.; Spuhler, D.; Kenfack, S.; Wethe, J.; Pulgarin, C

    2013-01-01

    Iron photo-assisted inactivation of wild enteric bacteria (total coliforms/E. coil and Salmonella spp.) was carried out in water from the Sahelian wells having different pH (W1:4.9 and W2: 6.3) and a natural iron content of 0.07 mg/L We evaluate the efficiency of the disinfection on different systems containing both or only one Fenton reagent (H2O2/Fe-2.): (i) H2O2/Fe2+/hv, (ii) Fe2+/hv, (iii) H2O2/hv, and (iv) only light irradiation (hv) at lab and field scale. Generally, 0.6 mg/L of Fe2+ an...

  19. Community analysis of chronic wound bacteria using 16S rRNA gene-based pyrosequencing: impact of diabetes and antibiotics on chronic wound microbiota.

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    Lance B Price

    Full Text Available BACKGROUND: Bacterial colonization is hypothesized to play a pathogenic role in the non-healing state of chronic wounds. We characterized wound bacteria from a cohort of chronic wound patients using a 16S rRNA gene-based pyrosequencing approach and assessed the impact of diabetes and antibiotics on chronic wound microbiota. METHODOLOGY/PRINCIPAL FINDINGS: We prospectively enrolled 24 patients at a referral wound center in Baltimore, MD; sampled patients' wounds by curette; cultured samples under aerobic and anaerobic conditions; and pyrosequenced the 16S rRNA V3 hypervariable region. The 16S rRNA gene-based analyses revealed an average of 10 different bacterial families in wounds--approximately 4 times more than estimated by culture-based analyses. Fastidious anaerobic bacteria belonging to the Clostridiales family XI were among the most prevalent bacteria identified exclusively by 16S rRNA gene-based analyses. Community-scale analyses showed that wound microbiota from antibiotic treated patients were significantly different from untreated patients (p = 0.007 and were characterized by increased Pseudomonadaceae abundance. These analyses also revealed that antibiotic use was associated with decreased Streptococcaceae among diabetics and that Streptococcaceae was more abundant among diabetics as compared to non-diabetics. CONCLUSIONS/SIGNIFICANCE: The 16S rRNA gene-based analyses revealed complex bacterial communities including anaerobic bacteria that may play causative roles in the non-healing state of some chronic wounds. Our data suggest that antimicrobial therapy alters community structure--reducing some bacteria while selecting for others.

  20. Inactivation of natural enteric bacteria in real municipal wastewater by solar photo-Fenton at neutral pH.

    Science.gov (United States)

    Ortega-Gómez, E; Esteban García, B; Ballesteros Martín, M M; Fernández Ibáñez, P; Sánchez Pérez, J A

    2014-10-15

    This study analyses the use of the solar photo-Fenton treatment in compound parabolic collector photo-reactors at neutral pH for the inactivation of wild enteric Escherichia coli and total coliform present in secondary effluents of a municipal wastewater treatment plant (SEWWTP). Control experiments were carried out to find out the individual effects of mechanical stress, pH, reactants concentration, and UVA radiation as well as the combined effects of UVA-Fe and UVA-H2O2. The synergistic germicidal effect of solar-UVA with 50 mg L(-1) of H2O2 led to complete disinfection (up to the detection limit) of total coliforms within 120 min. The disinfection process was accelerated by photo-Fenton, achieving total inactivation in 60 min reducing natural bicarbonate concentration found in the SEWWTP from 250 to 100 mg L(-1) did not give rise to a significant enhancement in bacterial inactivation. Additionally, the effect of hydrogen peroxide and iron dosage was evaluated. The best conditions were 50 mg L(-1) of H2O2 and 20 mg L(-1) of Fe(2+). Due to the variability of the SEWWTP during autumn and winter seasons, the inactivation kinetic constant varied between 0.07 ± 0.04 and 0.17 ± 0.04 min(-1). Moreover, the water treated by solar photo-Fenton fulfilled the microbiological quality requirement for wastewater reuse in irrigation as per the WHO guidelines and in particular for Spanish legislation.

  1. Antibiotics produced by marine bacteria and the evaluation of their activity; Kaiyo saikin no seisansuru kosei busshitsu to sono kassei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, K.

    1997-09-10

    Researches continue into physiologically active substances metabolized by marine bacteria and, in this report, some that exhibit antibacterial activity (antibiotics) are introduced. A detailed description is given of a new, peculiar antibiotic named Koromicin discovered in this project. Since a number of terrestrial bacteria have already been investigated, marine halophiles, especially those adhering to large seaweed in eutrophic environments, are taken up in this paper. This is because they are easy to culture. Many are collected in Japan and South-Sea islands, and some are selected for culture in view of their capability for producing active substances. Active compounds are extracted from them, refined, isolated, and their structures are determined. It is found that many of the thus-obtained compounds are those that have already been isolated from marine creatures in the past, but this verifies the effectiveness of selecting the marine bacteria as the source from which to collect physiologically active substances. Koromicin discovered in this process is unique in that it impedes the growth of marine Gram-negative bacteria only. 11 refs., 4 figs., 2 tabs.

  2. Preliminary survey of antibiotic-resistant fecal indicator bacteria and pathogenic Escherichia coli from river-water samples collected in Oakland County, Michigan, 2003

    Science.gov (United States)

    Fogarty, Lisa R.; Duris, Joseph W.; Aichele, Stephen S.

    2005-01-01

    A preliminary study was done in Oakland County, Michigan, to determine the concentration of fecal indicator bacteria (fecal coliform bacteria and enterococci), antibiotic resistance patterns of these two groups, and the presence of potentially pathogenic Escherichia coli (E. coli). For selected sites, specific members of these groups [E. coli, Enterococcus faecium (E. faecium) and Enterococcus faecalis (E. faecalis)] were isolated and tested for levels of resistance to specific antibiotics used to treat human infections by pathogens in these groups and for their potential to transfer these resistances. In addition, water samples from all sites were tested for indicators of potentially pathogenic E. coli by three assays: a growth-based assay for sorbitol-negative E. coli, an immunological assay for E. coli O157, and a molecular assay for three virulence and two serotype genes. Samples were also collected from two non-urbanized sites outside of Oakland County. Results from the urbanized Oakland County area were compared to those from these two non-urbanized sites. Fecal indicator bacteria concentrations exceeded State of Michigan recreational water-quality standards and (or) recommended U.S. Environmental Protection Agency (USEPA) standards in samples from all but two Oakland County sites. Multiple-antibiotic-resistant fecal coliform bacteria were found at all sites, including two reference sites from outside the county. Two sites (Stony Creek and Paint Creek) yielded fecal coliform isolates resistant to all tested antibiotics. Patterns indicative of extended-spectrum-β-lactamase (ESBL)- producing fecal coliform bacteria were found at eight sites in Oakland County and E. coli resistant to clinically significant antibiotics were recovered from the River Rouge, Clinton River, and Paint Creek. Vancomycin-resistant presumptive enterococci were found at six sites in Oakland County and were not found at the reference sites. Evidence of acquired antibiotic resistances was

  3. Antibiotic resistance and multidrug-resistant efflux pumps expression in lactic acid bacteria isolated from pozol, a nonalcoholic Mayan maize fermented beverage.

    Science.gov (United States)

    Wacher-Rodarte, Maria Del Carmen; Trejo-Muñúzuri, Tanya Paulina; Montiel-Aguirre, Jesús Fernando; Drago-Serrano, Maria Elisa; Gutiérrez-Lucas, Raúl L; Castañeda-Sánchez, Jorge Ismael; Sainz-Espuñes, Teresita

    2016-05-01

    Pozol is a handcrafted nonalcoholic Mayan beverage produced by the spontaneous fermentation of maize dough by lactic acid bacteria. Lactic acid bacteria (LAB) are carriers of chromosomal encoded multidrug-resistant efflux pumps genes that can be transferred to pathogens and/or confer resistance to compounds released during the fermentation process causing food spoiling. The aim of this study was to evaluate the antibiotic sensibility and the transcriptional expression of ABC-type efflux pumps in LAB isolated from pozol that contributes to multidrug resistance. Analysis of LAB and Staphylococcus (S.) aureus ATCC 29213 and ATCC 6538 control strains to antibiotic susceptibility, minimal inhibitory concentration (MIC), and minimal bactericidal concentration (MBC) to ethidium bromide were based in "standard methods" whereas the ethidium bromide efflux assay was done by fluorometric assay. Transcriptional expression of efflux pumps was analyzed by RT-PCR. LAB showed antibiotic multiresistance profiles, moreover, Lactococcus (L.) lactis and Lactobacillus (L.) plantarum displayed higher ethidium bromide efflux phenotype than S. aureus control strains. Ethidium bromide resistance and ethidium bromide efflux phenotypes were unrelated with the overexpression of lmrD in L. lactics, or the underexpression of lmrA in L. plantarum and norA in S. aureus. These findings suggest that, moreover, the analyzed efflux pumps genes, other unknown redundant mechanisms may underlie the antibiotic resistance and the ethidium bromide efflux phenotype in L. lactis and L. plantarum. Phenotypic and molecular drug multiresistance assessment in LAB may improve a better selection of the fermentation starter cultures used in pozol, and to control the antibiotic resistance widespread and food spoiling for health safety.

  4. Quantitative proteomic view associated with resistance to clinically important antibiotics in Gram-positive bacteria: A systematic review

    Directory of Open Access Journals (Sweden)

    Chang-Ro eLee

    2015-08-01

    Full Text Available The increase of methicillin-resistant Staphylococcus aureus (MRSA and vancomycin-resistant Enterococcus (VRE poses a worldwide and serious health threat. Although new antibiotics, such as daptomycin and linezolid, have been developed for the treatment of infections of Gram-positive pathogens, the emergence of daptomycin-resistant and linezolid-resistant strains during therapy has now increased clinical treatment failures. In the past few years, studies using quantitative proteomic methods have provided a considerable progress in understanding antibiotic resistance mechanisms. In this review, to understand the resistance mechanisms to four clinically important antibiotics (methicillin, vancomycin, linezolid, and daptomycin used in the treatment of Gram-positive pathogens, we summarize recent advances in studies on resistance mechanisms using quantitative proteomic methods, and also examine proteins playing an important role in the bacterial mechanisms of resistance to the four antibiotics. Proteomic researches can identify proteins whose expression levels are changed in the resistance mechanism to only one antibiotic, such as LiaH in daptomycin resistance and PrsA in vancomycin resistance, and many proteins simultaneously involved in resistance mechanisms to various antibiotics. Most of resistance-related proteins, which are simultaneously associated with resistance mechanisms to several antibiotics, play important roles in regulating bacterial envelope biogenesis or compensating for the fitness cost of antibiotic resistance. Therefore,

  5. Identification of 8-methyladenosine as the modification catalyzed by the radical SAM methyltransferase Cfr that confers antibiotic resistance in bacteria

    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...

  6. Detection and Antibiotic Susceptibility Pattern of Biofilm Producing Gram Positive and Gram Negative Bacteria Isolated From a Tertiary Care Hospital of Pakistan

    Directory of Open Access Journals (Sweden)

    Iqbal, M.

    2011-01-01

    Full Text Available Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST, Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA. Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production, was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54% slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.

  7. Improved in vitro evaluation of novel antimicrobials: potential synergy between human plasma and antibacterial peptidomimetics, AMPs and antibiotics against human pathogenic bacteria

    DEFF Research Database (Denmark)

    Citterio, Linda; Franzyk, Henrik; Palarasah, Yaseelan;

    2016-01-01

    Stable peptidomimetics mimicking natural antimicrobial peptides (AMPs) have emerged as a promising class of potential novel antibiotics. In the present study, we aimed at determining whether the antibacterial activity of two α-peptide/β-peptoid peptidomimetics against a range of bacterial pathogens...... was affected by conditions mimicking in vivo settings. Their activity was enhanced to an unexpected degree in the presence of human blood plasma for thirteen pathogenic Gram-positive and Gram-negative bacteria. MIC values typically decreased 2- to 16-fold in the presence of a human plasma concentration...... treatments might be lower than traditionally deduced from MICs determined in laboratory media. Thus, antibiotics previously considered too toxic could be developed into usable last-resort drugs, due to ensuing lowered risk of side effects. In contrast, the activity of the compounds was significantly...

  8. Antibiotic resistance monitoring: the Spanish programme. The VAV Network. Red de Vigilancia de Resistencias Antibióticas en Bacterias de Origen Veterinario.

    Science.gov (United States)

    Moreno, M A; Domínguez, L; Teshager, T; Herrero, I A; Porrero, M C

    2000-05-01

    Antimicrobial resistance is a problem in modern public health and antimicrobial use and especially misuse, the most important selecting force for bacterial antibiotic resistance. As this resistance must be monitored we have designed the Spanish network 'Red de Vigilancia de Resistencias Antibióticas en Bacterias de Origen Veterinario'. This network covers the three critical points of veterinary responsibility, bacteria from sick animals, bacteria from healthy animals and bacteria from food animals. Key bacteria, antimicrobials and animal species have been defined for each of these groups along with laboratory methods for testing antimicrobial susceptibility and for data analysis and reporting. Surveillance of sick animals was first implemented using Escherichia coli as the sentinel bacterium. Surveillance of E. coli and Enterococcus faecium from healthy pigs was implemented in 1998. In July 1999, data collection on Salmonella spp. was initiated in poultry slaughterhouses. Additionally, the prevalence of vancomycin resistant E. faecium was also monitored. This network has specific topics of interest related to methods of determining resistance, analysis and reporting of data, methods of use for veterinary practitioners and collaboration with public health authorities.

  9. Assessment of 2,2,6,6-tetramethyl-4-piperidinol-based amine N-halamine-labeled silica nanoparticles as potent antibiotics for deactivating bacteria.

    Science.gov (United States)

    Li, Chenghao; Hou, Jingjing; Huang, Zhen; Zhao, Tianyi; Xiao, Linghan; Gao, Ge; Harnoode, Chokto; Dong, Alideertu

    2015-02-01

    Novel potent antibiotics, amine N-halamine-labeled silica nanoparticles (ANHLS NPs) based on 2,2,6,6-tetramethyl-4-piperidinol (TMP), were skillfully synthesized via the encapsulation of silica nanoparticles with amine N-halamine polymer for effective killing pathogenic bacteria. The particle size and coating thickness of amine N-halamine of ANHLS NPs were well controlled by tuning size of silica NPs and polymer encapsulation period, respectively. Effect of chlorination time on the oxidative chlorine content in ANHLS NPs was well elucidated by the aid of the modified iodometric/thiosulfate technique. Antimicrobial action of the ANHLS NPs on bacterial strain was evaluated using Staphylococcus aureus and Escherichia coli as model pathogenic bacteria. Bactericidal assessment showed that the ANHLS NPs exerted powerful bactericidal capability toward both two model bacteria. Time-kill assay demonstrated the significance of the oxidative chlorine content and contact time on antibacterial behavior. Size effect experiment displayed the decisive role of the size in controlling the biocidal activity. Plausible antibacterial mechanism of the ANHLS NPs against pathogenic bacteria was also discussed. Such a systematic investigation of the ANHLS NPs provides us a novel idea of making them the promising candidates for deactivating bacteria or even disease control.

  10. Unsaturated fatty acid, cis-2-decenoic acid, in combination with disinfectants or antibiotics removes pre-established biofilms formed by food-related bacteria.

    Science.gov (United States)

    Sepehr, Shayesteh; Rahmani-Badi, Azadeh; Babaie-Naiej, Hamta; Soudi, Mohammad Reza

    2014-01-01

    Biofilm formation by food-related bacteria and food-related pathogenesis are significant problems in the food industry. Even though much disinfection and mechanical procedure exist for removal of biofilms, they may fail to eliminate pre-established biofilms. cis-2 decenoic acid (CDA), an unsaturated fatty acid messenger produced by Pseudomonas aeruginosa, is reportedly capable of inducing the dispersion of established biofilms by multiple types of microorganisms. However, whether CDA has potential to boost the actions of certain antimicrobials is unknown. Here, the activity of CDA as an inducer of pre-established biofilms dispersal, formed by four main food pathogens; Staphylococcus aureus, Bacillus cereus, Salmonella enterica and E. coli, was measured using both semi-batch and continuous cultures bioassays. To assess the ability of CDA combined biocides treatments to remove pre-established biofilms formed on stainless steel discs, CFU counts were performed for both treated and untreated cultures. Eradication of the biofilms by CDA combined antibiotics was evaluated using crystal violet staining. The effect of CDA combined treatments (antibiotics and disinfectants) on biofilm surface area and bacteria viability was evaluated using fluorescence microscopy, digital image analysis and LIVE/DEAD staining. MICs were also determined to assess the probable inhibitory effects of CDA combined treatments on the growth of tested microorganisms' planktonic cells. Treatment of pre-established biofilms with only 310 nM CDA resulted in at least two-fold increase in the number of planktonic cells in all cultures. While antibiotics or disinfectants alone exerted a trivial effect on CFU counts and percentage of surface area covered by the biofilms, combinational treatments with both 310 nM CDA and antibiotics or disinfectants led to approximate 80% reduction in biofilm biomass. These data suggests that combined treatments with CDA would pave the way toward developing new strategies

  11. Antibiotic Resistance of Bacteria Involved in Urinary Infections in Brazil: A Cross-Sectional and Retrospective Study

    Directory of Open Access Journals (Sweden)

    Wellington Francisco Rodrigues

    2016-09-01

    Full Text Available Empirical and prolonged antimicrobial treatment of urinary tract infections caused by Escherichia coli is associated with the emergence of bacterial resistance, and not all countries have strict policies against the indiscriminate use of drugs in order to prevent resistance. This cross-sectional and retrospective study (2010–2015 aimed to evaluate the sensitivity and resistance of patient-derived E. coli to different drugs broadly used to treat urinary infections in Brazil: ampicillin + sulbactam, cephalothin, ciprofloxacin, norfloxacin, and nitrofurantoin. We obtained 1654 E. coli samples from ambulatory patients with disease symptoms of the urinary tract from a Brazilian public hospital. While all antibiotics were effective in killing E. coli to a large degree, nitrofurantoin was the most effective, with fewer samples exhibiting antibiotic resistance. We assessed the costs of generic and brand name versions of each antibiotic. Nitrofurantoin, the most effective antibiotic, was the cheapest, followed by the fluoroquinolones (ciprofloxacin and norfloxacin, ampicillin + sulbactam and, lastly, cephalothin. Finally, assessment of antibiotic resistance to fluoroquinolones over the study period and extrapolation of the data led to the conclusion that these antibiotics could no longer be effective against E. coli-based urinary infections in approximately 20 years if their indiscriminate use in empirical treatment continues.

  12. Antibiotic Resistance of Bacteria Involved in Urinary Infections in Brazil: A Cross-Sectional and Retrospective Study

    Science.gov (United States)

    Rodrigues, Wellington Francisco; Miguel, Camila Botelho; Nogueira, Ana Paula Oliveira; Ueira-Vieira, Carlos; Paulino, Tony De Paiva; Soares, Siomar De Castro; De Resende, Elisabete Aparecida Mantovani Rodrigues; Lazo-Chica, Javier Emilio; Araújo, Marcelo Costa; Oliveira, Carlo José

    2016-01-01

    Empirical and prolonged antimicrobial treatment of urinary tract infections caused by Escherichia coli is associated with the emergence of bacterial resistance, and not all countries have strict policies against the indiscriminate use of drugs in order to prevent resistance. This cross-sectional and retrospective study (2010–2015) aimed to evaluate the sensitivity and resistance of patient-derived E. coli to different drugs broadly used to treat urinary infections in Brazil: ampicillin + sulbactam, cephalothin, ciprofloxacin, norfloxacin, and nitrofurantoin. We obtained 1654 E. coli samples from ambulatory patients with disease symptoms of the urinary tract from a Brazilian public hospital. While all antibiotics were effective in killing E. coli to a large degree, nitrofurantoin was the most effective, with fewer samples exhibiting antibiotic resistance. We assessed the costs of generic and brand name versions of each antibiotic. Nitrofurantoin, the most effective antibiotic, was the cheapest, followed by the fluoroquinolones (ciprofloxacin and norfloxacin), ampicillin + sulbactam and, lastly, cephalothin. Finally, assessment of antibiotic resistance to fluoroquinolones over the study period and extrapolation of the data led to the conclusion that these antibiotics could no longer be effective against E. coli-based urinary infections in approximately 20 years if their indiscriminate use in empirical treatment continues. PMID:27649224

  13. Characterization and sensitivity to antibiotics of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units

    Directory of Open Access Journals (Sweden)

    Manuel Medell

    2012-02-01

    Full Text Available OBJECTIVE: This observational study described the characterization of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units. The demonstration of isolated microorganism resistance to antibiotics and a time-trend analysis of infection comparing a 48-month period were also other objectives. METHOD: Semi-quantitative assays of 1254 samples taken from 741 ventilated patients were performed, while pathogens were identified using the Enterotube II assay and VITEK 2 Compact equipment. Bacterial resistance to antibiotics was assessed by the Kirby-Bauer disc diffusion method and time-trend analysis of infection was based on data recorded by hospital microbiology laboratories. RESULTS: The most prevalent isolated bacteria from the patient's lower respiratory tract were with Gram-negative bacteria (67.8% mostly represented by: Acinetobacter spp. (25.2%, Pseudomonas spp. (18.3% and Klebsiellas spp. (9.4%. Acinetobacter spp. showed moderate high to very high resistance to ceftriaxone (CRO, gentamicin (CN, amikacin (AK, meropenem (MRP, aztreonam (ATM and piperacillin/tazobactam (TZP. Some isolates of Acinetobacter spp. resistant to colistin (CS were identified in this patient population. Pseudomonas spp. and Klebsiella spp. were very highly resistant to ampicillin/sublactam (AMS and with moderate or low resistance to CRO, ATM, MRP, AK, CN and TZP. A decrease in the Pseudomonas spp. prevalence rate was observed, whereas an increase in Acinetobacter spp. and Klebsiella spp. prevalence rates were observed in a 48-month period. CONCLUSION: This research corroborated that these nosocomial infections are a relevant medical problem in our context. The most prevalent bacterial infections in the lower respiratory tract of ventilated patients were by Acinetobacter spp., Pseudomonas spp. and Klebsiella spp. The panel of antibiotics used as preventive therapy was not the solution of infections and probably induced

  14. Intense association of non-culturable endophytic bacteria with antibiotic-cleansed in vitro watermelon and their activation in degenerating cultures.

    Science.gov (United States)

    Thomas, Pious

    2011-12-01

    The study was undertaken with a view to unravel the source of bacterial colony growth observed in a section of micropropagated triploid watermelon cultures that were supposedly cleansed of the associated endophytic bacteria through antibiotic treatment, and thereafter maintained under stringent sterility checks to prevent lateral intrusion of contaminants. Five different bacteria were retrieved from colony growth-displaying watermelon cultures that were previously treated with gentamycin and five isolates from cefazolin-treated stocks with the organisms showing tolerance to the respective antibiotic. These watermelon cultures were in degeneration phase (over 6 months after the previous sub-culturing), while the actively maintained counterpart stocks appeared healthy with no colony growth on different bacteriological media during tissue-screenings. The latter cultures, however, revealed abundant motile, tetrazolium-stained bacterial cells in microscopy, suggesting tissue colonization by non-culturable endophytes. PCR screening on healthy cultures endorsed tissue colonization by different bacterial phylogenic groups. A few organisms could be activated to cultivation from healthy watermelon stocks through host tissue extract supplementation, which also enhanced the growth of all the organisms. The study indicated that a fraction of antibiotic-tolerant bacteria survived intra-tissue in non-culturable form during the preceding cleansing activity, multiplied to substantial numbers thereafter, and turned cultivable in degenerating cultures contributed by tissue breakdown products. This study brings out the existence of a deep endophyte association in tissue cultures which is not easily dissociable. It also signifies the utility of in vitro system for investigations into plant-endophyte association and to bring normally non-culturable novel organisms to cultivation facilitating their future exploitation.

  15. Natural hot spots for gain of multiple resistances: arsenic and antibiotic resistances in heterotrophic, aerobic bacteria from marine hydrothermal vent fields.

    Science.gov (United States)

    Farias, Pedro; Espírito Santo, Christophe; Branco, Rita; Francisco, Romeu; Santos, Susana; Hansen, Lars; Sorensen, Soren; Morais, Paula V

    2015-04-01

    Microorganisms are responsible for multiple antibiotic resistances that have been associated with resistance/tolerance to heavy metals, with consequences to public health. Many genes conferring these resistances are located on mobile genetic elements, easily exchanged among phylogenetically distant bacteria. The objective of the present work was to isolate arsenic-, antimonite-, and antibiotic-resistant strains and to determine the existence of plasmids harboring antibiotic/arsenic/antimonite resistance traits in phenotypically resistant strains, in a nonanthropogenically impacted environment. The hydrothermal Lucky Strike field in the Azores archipelago (North Atlantic, between 11°N and 38°N), at the Mid-Atlantic Ridge, protected under the OSPAR Convention, was sampled as a metal-rich pristine environment. A total of 35 strains from 8 different species were isolated in the presence of arsenate, arsenite, and antimonite. ACR3 and arsB genes were amplified from the sediment's total DNA, and 4 isolates also carried ACR3 genes. Phenotypic multiple resistances were found in all strains, and 7 strains had recoverable plasmids. Purified plasmids were sequenced by Illumina and assembled by EDENA V3, and contig annotation was performed using the "Rapid Annotation using the Subsystems Technology" server. Determinants of resistance to copper, zinc, cadmium, cobalt, and chromium as well as to the antibiotics β-lactams and fluoroquinolones were found in the 3 sequenced plasmids. Genes coding for heavy metal resistance and antibiotic resistance in the same mobile element were found, suggesting the possibility of horizontal gene transfer and distribution of theses resistances in the bacterial population.

  16. Isolation and identification of antibiotics resistant bacteria from fresh milk%鲜牛奶中耐药性细菌的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    张晓梅; 杨洪江

    2012-01-01

    Objective: Isolation and identification of antibiotics resistant bacteria in fresh milk. Methods: Luria-Bertani plates containing tetracycline (16 μg/mL), ciprofloxacin (4 μg/mL) or gentamicin (16 μg/ mL) were used in isolating the antibiotics resistant bacteria from samples. K-B disk diffusion method was used to confirm the resistant phenotypes. Blood agar plates were used in hemolysis assay. 16S rRNA analysis method was used to identify the isolates. Results: 30 fresh milk samples collected from Zhangjiakou were screened for antibiotic resistant bacteria. The screening results showed that 23 (76.67%) samples had isolates resistant to more than one antibiotic, 7(23.33%) samples had isolates resistant tomore than two antibiotics, and 1 (3.33%) sample had isolates resistant to three antibiotics tested. Totally, 37 strains were isolated resistant to tetracycline, 8 strains were isolated resistant to ciprofloxacin, and 7 strains were isolated resistant to gentamicin. Six strains (two from each antibiotic resistant bacteria group) were randomLy selected for 16S rRNA analysis and they were identified as Serratia marcescens (1), Pseudomonas aeruginosa (2), Acinetobacter junii (1), Cronobacter sakazakii (1) and Staphylococcus aureus (1). Hemolysis test results showed that 3 strains with a-hemolytic phenotype, 1 strains with 13-hemolytic phenotype, and 2 strains with y-hemolytic phenotype. Furthermore, antibiotic resistant phenotypes of the six isolates were validated K-B disk diffusion method and only one isolate sensitive to gentamicin. Conclusion: Fresh milk is the reservoir of a variety of antibiotics resistant bacteria, antibiotic plates can be used for preliminary screening of antibiotics resistant bacteria from fresh milk samples.%目的:分离鉴定鲜牛奶中耐药性细菌的分布。方法:利用含有四环素(16μg/mL)、环丙沙星(4μg/mL)或庆大霉素(16μg/mL)的Luria-Bertani

  17. Bacteria, phages and pigs: the effects of in-feed antibiotics on the microbiome at different gut locations.

    Science.gov (United States)

    Looft, Torey; Allen, Heather K; Cantarel, Brandi L; Levine, Uri Y; Bayles, Darrell O; Alt, David P; Henrissat, Bernard; Stanton, Thaddeus B

    2014-08-01

    Disturbance of the beneficial gut microbial community is a potential collateral effect of antibiotics, which have many uses in animal agriculture (disease treatment or prevention and feed efficiency improvement). Understanding antibiotic effects on bacterial communities at different intestinal locations is essential to realize the full benefits and consequences of in-feed antibiotics. In this study, we defined the lumenal and mucosal bacterial communities from the small intestine (ileum) and large intestine (cecum and colon) plus feces, and characterized the effects of in-feed antibiotics (chlortetracycline, sulfamethazine and penicillin (ASP250)) on these communities. 16S rRNA gene sequence and metagenomic analyses of bacterial membership and functions revealed dramatic differences between small and large intestinal locations, including enrichment of Firmicutes and phage-encoding genes in the ileum. The large intestinal microbiota encoded numerous genes to degrade plant cell wall components, and these genes were lacking in the ileum. The mucosa-associated ileal microbiota harbored greater bacterial diversity than the lumen but similar membership to the mucosa of the large intestine, suggesting that most gut microbes can associate with the mucosa and might serve as an inoculum for the lumen. The collateral effects on the microbiota of antibiotic-fed animals caused divergence from that of control animals, with notable changes being increases in Escherichia coli populations in the ileum, Lachnobacterium spp. in all gut locations, and resistance genes to antibiotics not administered. Characterizing the differential metabolic capacities and response to perturbation at distinct intestinal locations will inform strategies to improve gut health and food safety.

  18. Application of real-time PCR to determination of combined effect of antibiotics on Bacteria, Methanogenic Archaea, Archaea in anaerobic sequencing batch reactors.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2015-06-01

    This study evaluated the long-term effects of erythromycin-tetracycline-sulfamethoxazole (ETS) and sulfamethoxazole-tetracycline (ST) antibiotic combinations on the microbial community and examined the ways in which these antimicrobials impact the performance of anaerobic reactors. Quantitative real-time PCR was used to determine the effect that different antibiotic combinations had on the total and active Bacteria, Archae and Methanogenic Archae. Three primer sets that targeted metabolic genes encoding formylterahydrofolate synthetase, methyl-coenzyme M reductase and acetyl-coA synthetase were also used to determine the inhibition level on the mRNA expression of the homoacetogens, methanogens and specifically acetoclastic methanogens, respectively. These microorganisms play a vital role in the anaerobic degradation of organic waste and targeting these gene expressions offers operators or someone at a treatment plant the potential to control and the improve the anaerobic system. The results of the investigation revealed that acetogens have a competitive advantage over Archaea in the presence of ETS and ST combinations. Although the efficiency with which methane production takes place and the quantification of microbial populations in both the ETS and ST reactors decreased as antibiotic concentrations increased, the ETS batch reactor performed better than the ST batch reactor. According to the expression of genes results, the syntrophic interaction of acetogens and methanogens is critical to the performance of the ETS and ST reactors. Failure to maintain the stability of these microorganisms resulted in a decrease in the performance and stability of the anaerobic reactors.

  19. Improved in vitro evaluation of novel antimicrobials: potential synergy between human plasma and antibacterial peptidomimetics, AMPs and antibiotics against human pathogenic bacteria.

    Science.gov (United States)

    Citterio, Linda; Franzyk, Henrik; Palarasah, Yaseelan; Andersen, Thomas Emil; Mateiu, Ramona Valentina; Gram, Lone

    2016-01-01

    Stable peptidomimetics mimicking natural antimicrobial peptides (AMPs) have emerged as a promising class of potential novel antibiotics. In the present study, we aimed at determining whether the antibacterial activity of two α-peptide/β-peptoid peptidomimetics against a range of bacterial pathogens was affected by conditions mimicking in vivo settings. Their activity was enhanced to an unexpected degree in the presence of human blood plasma for thirteen pathogenic Gram-positive and Gram-negative bacteria. MIC values typically decreased 2- to 16-fold in the presence of a human plasma concentration that alone did not damage the cell membrane. Hence, MIC and MBC data collected in these settings appear to represent a more appropriate basis for in vivo experiments preceding clinical trials. In fact, concentrations of peptidomimetics and peptide antibiotics (e.g. polymyxin B) required for in vivo treatments might be lower than traditionally deduced from MICs determined in laboratory media. Thus, antibiotics previously considered too toxic could be developed into usable last-resort drugs, due to ensuing lowered risk of side effects. In contrast, the activity of the compounds was significantly decreased in heat-inactivated plasma. We hypothesize that synergistic interactions with complement proteins and/or clotting factors most likely are involved.

  20. Whole blood-mediated endothelial permeability and adhesion molecule expression: a model study into the effects of bacteria and antibiotics.

    NARCIS (Netherlands)

    Nooteboom, A.; Linden, C.J. van der; Hendriks, T.

    2005-01-01

    AIM: To investigate whether the inflammatory response of cultured endothelial cells, as induced by conditioned plasma, depends on the bacterial species or type of antibiotic used for incubation with whole blood. MATERIALS AND METHODS: Blood from healthy volunteers was stimulated ex vivo with differe

  1. Investigating the Antibiotic Resistance Problem.

    Science.gov (United States)

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

    Seeks to give teachers useful information on the extent of the problem of antibiotic-resistant bacteria, mechanisms bacteria use to resist antibiotics, the causes of the emergence of antibiotic-resistant organisms, and practices that can prevent or reverse this trend. Contains 19 references. (DDR)

  2. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    NARCIS (Netherlands)

    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

    2016-01-01

    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

  3. 872株临床常见病原菌分布及其耐药性%Distribution and antibiotics resistance of 872 clinical pyogenic bacteria

    Institute of Scientific and Technical Information of China (English)

    朱晓娟; 查赟峰

    2011-01-01

    目的:研究医院临床常见病原菌分布特点及其对常用抗生素的耐药性.方法:采集临床标本分离致病菌,用Vitek-32全自动微生物分析仪及纸片扩散法对分离菌进行鉴定及药敏试验.结果:共分离到872株致病菌,以大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、肺炎克雷伯菌为多见,其中金黄色葡萄球菌对临床多种常用抗生素耐药率超过80%.但是全部革兰阳性球菌对万古霉索敏感.革兰阴性杆菌对氨苄西林、哌拉西林、头孢唑啉和庆大霉素等耐药率较高.结论:湖州的致病细菌耐药现象严重.%Objective:To research distribution of common bacteria in hospital and to detect their resistence of antibiotics.Methods: The identification of bacteria and bacteria susceptibility test were performing automatic bio analysis - Vitek - 32 and Kirby - Bauer method. Results: There were 872 strains was isolated, the common organisms were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. The resistance to common antibiotics of Staphylococcus aureus was more than 80%. But Vancomycin was still effective to all Gram positive coccus. Gram negative bacillus had higher resistance against the Amicillin, Piperacillin, ciprofloxacin and Gentamicin. Conclusion: Bacterial resistance in Huzhou was very serious.

  4. Cryptosporidium enteritis

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/000617.htm Cryptosporidium enteritis To use the sharing features on this page, please enable JavaScript. Cryptosporidium enteritis is an infection of the small intestine that ...

  5. 新生儿感染性肺炎的病原菌状况分析%Investigation of pathogenic bacteria and antibiotic susceptibility in neonatal infective pneumonia

    Institute of Scientific and Technical Information of China (English)

    卓少宏; 伍成峰; 马兴灶; 詹世产

    2012-01-01

    Objective To investigate the pathogenic bateria of neonatal infective pneumonia in Shantou area. Method The identification of bacteria and susceptibility test were performed by AMS VITEK-60. Reslut Gram-negative bacteria were the prominent pathogens, which accounted for 92.81% (142/153) of the pathogens in neonatal infective pneumonia. The most common pathogens were Klebsialla pneumonia. There were less pathogens of Gram-positive bacteria found in the neonatal infective pneumonia. The resistance rates of Gram-negative bacteria to cephalosporins and aminoglycosides were significantly higher than to imipenem and fluroguinlones. Conclusion Klebsialla pneumonia is the prominent pathogen of neonatal infective pneumonia in Shantou area. The first choices of antibiotics in treating Gram-negative bacteria infection are imipenem, cefotetan and ciprofloxacin. Use of antibiotics in clinical therapy should be based on the results of susceptibility of pathogens.%目的 了解本地区新生儿感染性肺炎的病原菌的菌种、构成比及耐药情况,探索临床合理选用抗生素.方法 细菌鉴定及药敏试验采用VITEK-60全自动细菌鉴定仪.结果 本地区新生儿感染性肺炎的病原菌主要为革兰阴性杆菌(92.81%),其中以肺炎克雷伯菌最为常见,革兰阳性球菌感染较少(7.19%).革兰阴性杆菌对头孢二代、三代和氨基糖苷类抗生素的耐药率均较高,对喹诺酮类抗生素耐药率较低.亚胺培南具有良好的抗菌活性.结论 肺炎克雷伯菌是本地区新生儿感染性肺炎的主要病原菌.经验性治疗用药可首选亚胺培南、头孢替坦、环丙沙星等,建议临床根据药敏结果选用抗生素.

  6. N-Heterocyclic molecule-capped gold nanoparticles as effective antibiotics against multi-drug resistant bacteria

    Science.gov (United States)

    Feng, Yan; Chen, Wenwen; Jia, Yuexiao; Tian, Yue; Zhao, Yuyun; Long, Fei; Rui, Yukui; Jiang, Xingyu

    2016-07-01

    We demonstrate that N-heterocyclic molecule-capped gold nanoparticles (Au NPs) have broad-spectrum antibacterial activity. Optimized antibacterial activity can be achieved by using different initial molar ratios (1 : 1 and 10 : 1) of N-heterocyclic prodrugs and the precursor of Au NPs (HAuCl4). This work opens up new avenues for antibiotics based on Au NPs.We demonstrate that N-heterocyclic molecule-capped gold nanoparticles (Au NPs) have broad-spectrum antibacterial activity. Optimized antibacterial activity can be achieved by using different initial molar ratios (1 : 1 and 10 : 1) of N-heterocyclic prodrugs and the precursor of Au NPs (HAuCl4). This work opens up new avenues for antibiotics based on Au NPs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03317b

  7. Antibiotic resistance in faecal bacteria isolated from horses receiving virginiamycin for the prevention of pasture-associated laminitis

    OpenAIRE

    2011-01-01

    International audience; , a major cause of potentially life-threatening hospital-acquired human infections, can be resistant to several antimicrobials, such that streptogramin quinupristin-dalfopristin (Q/D) is one of the few antibiotics still effective. Consequently use of the streptogramin virginiamycin as an animal growth promoter was banned in the EU in 1999 as some believed this contributed to the emergence of Q/D resistant E. . Virginiamycin is advocated for preventing equine pasture-as...

  8. Biodegradation of 2,4-dichlorophenoxyacetic acid by bacteria with highly antibiotic-resistant pattern isolated from wheat field soils in Kurdistan, Iran.

    Science.gov (United States)

    Karami, Solmaz; Maleki, Afshin; Karimi, Ebrahim; Poormazaheri, Helen; Zandi, Shiva; Davari, Behrooz; Salimi, Yahya Zand; Gharibi, Fardin; Kalantar, Enayatollah

    2016-12-01

    Recently, there has been increasing interest to clean up the soils contaminated with herbicide. Our aim was to determine the bioremediation of 2,4-dichlorophenoxyacetic acid (2,4-D) from wheat fields which have a long history of herbicide in Sanandaj. Based on our literature survey, this study is the first report to isolate and identify antimicrobial resistant bacteria from polluted wheat field soils in Sanandaj which has the capacity to degrade 2,4-D. From 150 2,4-D-exposed soil samples, five different bacteria were isolated and identified based on biochemical tests and 16S ribosomal RNA (rRNA). Pseudomonas has been the most frequently isolated genus. By sequencing the 16S rRNA gene of the isolated bacteria, the strains were detected and identified as a member of the genus Pseudomonas sp, Entrobacter sp, Bacillus sp, Seratia sp, and Staphylococcus sp. The sequence of Sanandaj 1 isolate displayed 87% similarity with the 16S rRNA gene of a Pseudomonas sp (HE995788). Similarly, all the isolates were compared to standard strains based on 16S rRNA. Small amounts of 2,4-D could be transmitted to a depth of 10-20 cm; however, in the depth of 20-40 cm, we could not detect the 2,4-D. The isolates were resistant to various antibiotics particularly, penicillin, ampicillin, and amoxicillin.

  9. Detection of antibiotic-resistant bacteria endowed with antimicrobial activity from a freshwater lake and their phylogenetic affiliation

    Directory of Open Access Journals (Sweden)

    Zothanpuia

    2016-06-01

    Full Text Available Antimicrobial resistance poses a serious challenge to global public health. In this study, fifty bacterial strains were isolated from the sediments of a freshwater lake and were screened for antibiotic resistance. Out of fifty isolates, thirty-three isolates showed resistance against at least two of the selected antibiotics. Analysis of 16S rDNA sequencing revealed that the isolates belonged to ten different genera, namely Staphylococcus(n = 8, Bacillus(n = 7, Lysinibacillus(n = 4, Achromobacter(n=3, bacterium(n = 3, Methylobacterium(n = 2, Bosea(n = 2, Aneurinibacillus(n = 2, Azospirillum(n = 1, Novosphingobium(n = 1. Enterobacterial repetitive intergenic consensus (ERIC and BOX-PCR markers were used to study the genetic relatedness among the antibiotic resistant isolates. Further, the isolates were screened for their antimicrobial activity against bacterial pathogens viz., Staphylococcus aureus(MTCC-96, Pseudomonas aeruginosa(MTCC-2453 and Escherichia coli(MTCC-739, and pathogenic fungi viz., Fusarium proliferatum (MTCC-286, Fusarium oxysporum (CABI-293942 and Fusarium oxy. ciceri (MTCC-2791. In addition, biosynthetic genes (polyketide synthase II (PKS-II and non-ribosomal peptide synthetase (NRPS were detected in six and seven isolates, respectively. This is the first report for the multifunctional analysis of the bacterial isolates from a wetland with biosynthetic potential, which could serve as potential source of useful biologically active metabolites.

  10. Enteric microbiota leads to new therapeutic strategies for ulcerative colitis.

    Science.gov (United States)

    Chen, Wei-Xu; Ren, Li-Hua; Shi, Rui-Hua

    2014-11-14

    Ulcerative colitis (UC) is a leading form of inflammatory bowel disease that involves chronic relapsing or progressive inflammation. As a significant proportion of UC patients treated with conventional therapies do not achieve remission, there is a pressing need for the development of more effective therapies. The human gut contains a large, diverse, and dynamic population of microorganisms, collectively referred to as the enteric microbiota. There is a symbiotic relationship between the human host and the enteric microbiota, which provides nutrition, protection against pathogenic organisms, and promotes immune homeostasis. An imbalance of the normal enteric microbiota composition (termed dysbiosis) underlies the pathogenesis of UC. A reduction of enteric microbiota diversity has been observed in UC patients, mainly affecting the butyrate-producing bacteria, such as Faecalibacterium prausnitzii, which can repress pro-inflammatory cytokines. Many studies have shown that enteric microbiota plays an important role in anti-inflammatory and immunoregulatory activities, which can benefit UC patients. Therefore, manipulation of the dysbiosis is an attractive approach for UC therapy. Various therapies targeting a restoration of the enteric microbiota have shown efficacy in treating patients with active and chronic forms of UC. Such therapies include fecal microbiota transplantation, probiotics, prebiotics, antibiotics, helminth therapy, and dietary polyphenols, all of which can alter the abundance and composition of the enteric microbiota. Although there have been many large, randomized controlled clinical trials assessing these treatments, the effectiveness and safety of these bacteria-driven therapies need further evaluation. This review focuses on the important role that the enteric microbiota plays in maintaining intestinal homeostasis and discusses new therapeutic strategies targeting the enteric microbiota for UC.

  11. Antibiotic Resistance

    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...

  12. Antibiotic-Resistant Gonorrhea (ARG)

    Science.gov (United States)

    ... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Basic Information Recommend on Facebook Tweet ... Page Surveillance Trends and Treatment Challenges Laboratory Issues Antibiotic resistance (AR) is the ability of bacteria to ...

  13. Biomonitoring marine habitats in reference to antibiotic resistant bacteria and ampicillin resistance determinants from oviductal fluid of the nesting green sea turtle, Chelonia mydas.

    Science.gov (United States)

    Al-Bahry, S N; Al-Zadjali, M A; Mahmoud, I Y; Elshafie, A E

    2012-06-01

    During the egg-laying process, oviductal fluid was collected using a non-invasive procedure from the cloacal vent of the green turtles. Forty-two independent isolates of antibiotic-resistant bacteria from 11 genera were obtained from 20 turtles during nesting. The dominant isolate was Citrobacter (52.4%), followed by Pseudomonas, Proteus, Enterobacter, Salmonella, Escherichia coli, Shigella, Edwardsiella, Morganella, Providencia and Arcomobacter. Most of the isolates were resistant to ampicillin. Ampicillin-resistant isolates showed variations in their resistance for the following classes of β-lactamases: extended-spectrum β-lactamases (EBSLs), AmpC type β-lactamases C (AmpC), and screen-positive β-lactamase. None of the isolates produced metallo β-lactamase. Some ampicillin-resistant genes were detected by multiplex polymerase chain reaction (PCR) only. Inhibitor based test (IBT) categorized some isolates as AmpC β-lactamase producers. β-Lactamase genes were detected from a few strains. The sequencing of those genes revealed the presence of cephamycinase (CMY) and AmpC β-lactamases. The oviductal fluid was used in this study as a source of bacterial antibiotic-resistant determinants for biomonitoring marine turtles exposed to contaminated effluents. This data can be of value in understanding the decline of this endangered species as a result of exposure to marine pollution which is threatening their survival.

  14. Anti-adhesion and antibiotic modulatory evaluation of grapefruit (Citrus paradisi juice and seed extract on bacteria isolated from urine and catheter

    Directory of Open Access Journals (Sweden)

    Michael Oluwole Osungunna

    2016-02-01

    Full Text Available Context: The in vivo use of grapefruit seed in the treatment of urinary tract infections (UTIs has been reported but the mechanism of action is yet to be explained. Aims: Evaluate the anti-adhesion and antibiotic modulatory activities of grapefruit seed extract and juice as their possible mechanisms of action. Methods: Sub-inhibitory concentrations of 2.5 and 5 mg/mL as well as 10.3 and 5.15 mg/mL of grapefruit seed extract and juice respectively were evaluated for modulatory activity of ciprofloxacin, streptomycin and nalidixic acid against one hundred and twenty seven bacterial isolates from mid-stream urine (MSU (100, catheter-stream urine (CSU (14 and catheter tips (CT (13 using the agar dilution method. Anti-adhesion activity of grapefruit seed extract and juice at sub-inhibitory concentrations of 2.5 and 1.03 mg/mL respectively was evaluated against twenty three (23 moderately adherent bacterial isolates from MSU (10, CSU (7 and CT (6 using the tissue culture plate method. Results: The results revealed that grapefruit juice (5.15 mg/mL showed more effect on nalidixic acid activity than seed extract (2.5 mg/mL. Grapefruit juice showed more anti-adhesion activity than grapefruit seed extract at the concentration tested. Conclusions: The study concluded that grapefruit seed extract and juice had anti-adhesion and antibiotic modulatory effects on bacteria associated with UTIs.

  15. Antibiotic Resistance of Bacteria in Effluents of Municipal Wastewater Treatnent Plants%城市污水处理厂所出水中的细菌对抗生素耐性的研究

    Institute of Scientific and Technical Information of China (English)

    陈朝琼

    2012-01-01

    为研究城市污水厂所出水中的一般细菌对抗生素的耐性.在成都市选取了2座有代表性的污水厂,检测分析其出水中的细菌分别对6种抗生素(青霉素、头孢氨苄、环丙沙星、四环素、庆大霉素、阿奇霉素)的抗性菌浓度、比例、及半抑制浓度.结果表明:2座污水厂出水的细菌总数随着抗生素浓度的增加而减少;青霉素和头孢氨苄对细菌总数的影响较小,四环素和环丙沙星对细菌总数的影响较大.青霉素的抗性菌浓度最高,A、B厂分别高达6.5×104、2×104 CFU/mL,B厂的四环素抗性菌浓度最低为8.9 ×102 CFU/mL.A、B污水厂出水中细菌的庆大霉素抗性水平最高,其半抑制浓度分别高达28.1 mg/L和25.4 mg/L.2座污水厂出水细菌的抗生素半抑制浓度高于污水中的抗生素浓度,低浓度的抗生素是抗性菌稳定存在的重要因素,因此应该谨慎抗生素的使用,降低抗性菌的环境污染风险.%Prevalence of antibiotic-resistant bacteria in wastewater effluents was concerned as an emerging contaminant. To estimate antibiotic resistance of bacteria in effluents of municipal wastewater treatment plants (WWTP), antibiotic tolerance, proportion of antibiotic-resistant bacteria, and hemi-inhibitory concentrations of six antibiotics (Penicillin, Cefalexin, Ciprofloxacin, Tetracycline, Gentamicin and Azithromycin) were determined at two wastewater treatment plants in Chengdu. The results showed that the total bacterial counts decreased along with the increase of antibiotic concentration, and the variations of Penicillin and Cefalexin were relatively higher than that of Tetracycline and Ciprofloxacin. Moreover, the concentrations of Ampicillin-resistant bacteria were highest to 6.5×104 and 7.2 ×104 CFU/mL in WWTP-A and WWTP-B, respectively, and the lowest antibiotic-resistant bacteria concentration was also as high as 8.9 CFU/mL. The hemi-inhibitory concentration of Gentamicin was highest in the 6

  16. Molecular mechanisms of antibiotic resistance.

    Science.gov (United States)

    Blair, Jessica M A; Webber, Mark A; Baylay, Alison J; Ogbolu, David O; Piddock, Laura J V

    2015-01-01

    Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.

  17. Distribution and Antibiotic Sensitivity of Bacteria Isolated from Patients with Biliary Tract Disorders%胆道细菌感染的分布及药敏分析

    Institute of Scientific and Technical Information of China (English)

    刘适; 蔡瑞云; 李浩

    2012-01-01

    Objective To investigate the distribution of bacteria isolated from inpatients with biliary tract disorders (BTD) and their sensitivities to common antibiotics. Methods We retrospectively analyzed drug sensitivity results of 280 bacterial strains isolated from the bile samples of the inpatients with BTD in the People's Hospital of Hunan Province from January 1, 2011 to June 30, 2012. Results Altogether 195 strains of Gram - negative bacteria were isolated from the bile samples, and the top three bacteria were Escherkhia coli {21.9% , 78/195), Klebsiella pneumoniae (13. 9% , 39/195), and Pseudomonas aeruginosa (7.9% , 22/195). 83 strains of Gram - positive bacteria were isolated from the samples, and the top three bacteria were Enterococcus faecalis (10. 4% , 29/83), Enterococcus faecium (4.6% , 13/83), Streptococcus mutans (4.6% , 13/83). And 2 strains of Candida albicans were isolated from the samples. The Gram - negative bacteria were mostly sensitive to carbapenems and amikacin, while the Gram - negative bacteria were mostly sensitive to glycopeptides, nitrofurans and carbapenems. Conclusions The bacterial distribution and their sensitivities to antibiotics in the inpatients with BTD have been changed. It is necessary to perform bile culture so as to guide reasonable clinical prescription and reduce the production of drug-resistant strains.%目的 了解湖南省人民医院住院病人胆道感染细菌分布及其对目前常用抗生素的敏感性. 方法 对2011年1月1日-2012年6月30日245例胆道疾病患者胆汁培养阳性所检出的280株细菌及其药敏试验结果进行回顾性分析. 结果 检出革兰阴性细菌(G-菌)195株(69.6%),其中大肠杆菌78株(27.9%)、肺炎克雷伯菌39株(13.9%)和铜绿假单胞菌22株(7.9%)分列前三位;革兰阳性球菌(G+球菌)83株(29.6%),其中粪肠球菌29株(10.4%)、屎肠球菌13株(4.6%)和变异链球菌13株(4.6%)分列前三位;真菌(白色念珠菌)2株(0

  18. Chemical warfare: Leaf-cutting ants defend themselves and their gardens against parasite attack by deploying antibiotic secreting bacteria.

    Science.gov (United States)

    Samuels, Richard Ian; Mattoso, Thalles Cardoso; Moreira, Denise D O

    2013-03-01

    Leaf-cutting ants are well known for their highly complex social organization, which provides them with a strong defense against parasites invading their colonies. Besides this attribute, these insects have morphological, physiological and structural characteristics further reinforcing the defense of their colonies. With the discovery of symbiotic bacteria present on the integument of leaf-cutting ants, a new line of defense was proposed and considered to be specific for the control of a specialized fungal parasite of the ants' fungus gardens (Escovopsis). However, recent studies have questioned the specificity of the integumental bacteria, as they were also found to inhibit a range of fungi, including entomopathogens. The microbiota associated with the leaf-cutting ant gardens has also been proposed as another level of chemical defense, protecting the garden from parasite invasion. Here we review the chemical defense weaponry deployed by leaf-cutting ants against parasites of their fungus gardens and of the ants themselves.

  19. Strategy for rapid identification and antibiotic susceptibility testing of gram-negative bacteria directly recovered from positive blood cultures using the Bruker MALDI Biotyper and the BD Phoenix system.

    Science.gov (United States)

    Wimmer, Jana L; Long, S Wesley; Cernoch, Patricia; Land, Geoffrey A; Davis, James R; Musser, James M; Olsen, Randall J

    2012-07-01

    Decreasing the time to species identification and antibiotic susceptibility determination of strains recovered from patients with bacteremia significantly decreases morbidity and mortality. Herein, we validated a method to identify Gram-negative bacteria directly from positive blood culture medium using the Bruker MALDI Biotyper and to rapidly perform susceptibility testing using the BD Phoenix.

  20. Impact of urban contamination of the La Paz River basin on thermotolerant coliform density and occurrence of multiple antibiotic resistant enteric pathogens in river water, irrigated soil and fresh vegetables.

    Science.gov (United States)

    Poma, Violeta; Mamani, Nataniel; Iñiguez, Volga

    2016-01-01

    La Paz River in Andean highlands is heavily polluted with urban run-off and further contaminates agricultural lowlands and downstream waters at the Amazon watershed. Agricultural produce at this region is the main source of vegetables for the major Andean cities of La Paz and El Alto. We conducted a 1 year study, to evaluate microbial quality parameters and occurrence of multiple enteropathogenic bacteria (Enterohemorrhagic E. coli-EHEC, Enteroinvasive E. coli or Shigella-EIEC/Shigella, Enteroaggregative E. coli-EAEC, Enteropathogenic E. coli-EPEC Enterotoxigenic E. coli-ETEC and Salmonella) and its resistance to 11 antibiotics. Four sampling locations were selected: a fresh mountain water reservoir (un-impacted, site 1) and downstream sites receiving wastewater discharges (impacted, sites 2-4). River water (sites 1-4, N = 48), and soil and vegetable samples (site 3, N = 24) were collected during dry (April-September) and rainy seasons (October-March). Throughout the study, thermotolerant coliform density values at impacted sites greatly exceeded the guidelines for recreational and agricultural water uses. Seasonal differences were found for thermotolerant coliform density during dry season in water samples nearby a populated and hospital compound area. In contrast to the un-impacted site, where none of the tested enteropathogens were found, 100 % of surface water, 83 % of soil and 67 % of vegetable samples at impacted sites, were contaminated with at least one enteropathogen, being ETEC and Salmonella the most frequently found. ETEC isolates displayed different patterns of toxin genes among sites. The occurrence of enteropathogens was associated with the thermotolerant coliform density. At impacted sites, multiple enteropathogens were frequently found during rainy season. Among isolated enteropathogens, 50 % were resistant to at least two antibiotics, with resistance to ampicillin, nalidixic acid, trimethoprim-sulfamethoxazole and tetracycline commonly

  1. Recent progress in development of antibiotics against Gram-negative bacteria%抗革兰阴性细菌感染抗生素的研发新进展

    Institute of Scientific and Technical Information of China (English)

    徐泽奇; 徐泽宇

    2013-01-01

    Multidrug-resistant (MDR) bacterial infections,especially those caused by Gram-negative pathogens,have emerged to be one of the world's greatest health threats.However,not only have recent decades shown a steady decline in the number of approved antimicrobial agents but a disappointing discovery also void.The development of novel antibiotics to treat MDR Gram-negative bacteria has been stagnated over the last half century.Though few compounds have shown activities in vitro,in animal models or even in clinical studies,the global antibiotic pipeline is not encouraging.There are a plethora of unexpected challenges that may arise and cannot always be solved to cause promising drugs to fail.This review intends to summarize recent research and development activities to meet the inevitable challenge in restricting the proliferation of MDR Gram-negative bacteria,with focus on compounds that have entered into clinical development stage.In addition to new analogues of existing antibiotic molecules,attention is also directed to alternative strategies to develop antibacterial agents with novel mechanisms of action.%多药耐药(MDR)的细菌感染,尤其是MDR革兰阴性细菌感染,已经成为全球公共健康最大的威胁之一.然而,新型有效的抗生素研发并没有伴随MDR细菌的增加而增加.数十年来,新批准的抗生素数量在不断减少,治疗MDR革兰阴性细菌感染的抗生素研发在半个多世纪以来更是一直停滞不前.因此,从市场和国民生活安全的角度考虑,对新型抗生素研发的需求就显得非常迫切.虽然目前有一些化合物在体外测试、或在动物模型、甚至在临床研究中显示出一定的活性,但距离批准全面临床应用还较远.所以,全球新型的抗革兰阴性细菌感染的抗生素的供应并不乐观.本文总结了最近几年来国内外针对革兰阴性细菌感染,特别是那些己进入临床试验阶段抗生素的研发进展.除了现有抗生素的衍生

  2. Feeding untreated and pasteurized waste milk and bulk milk to calves: effects on calf performance, health status and antibiotic resistance of faecal bacteria.

    Science.gov (United States)

    Aust, V; Knappstein, K; Kunz, H-J; Kaspar, H; Wallmann, J; Kaske, M

    2013-12-01

    Non-saleable milk (waste milk, WM) is contaminated with an undefined spectrum of potentially harmful pathogens and antimicrobial residues. The objective of this study was to determine the impact of feeding bulk milk (BM) or WM - both pasteurized or not - on calf performance, health and the antibiotic resistance of specific faecal bacteria. A total of 114 calves from a large-scale dairy were housed outdoors in individual hutches and were randomly assigned to one of four feeding groups. The calves were fed either WM, pasteurized WM (pWM), BM or pasteurized BM (pBM) from day 3 to 56 of life. Milk samples taken from the pasteurizer and calves' nipple buckets were investigated at regular intervals for total plate count and counts of thermoduric bacteria, coliforms and mastitis pathogens. Faecal samples were taken on days 2, 14, 28 and 56 of life from randomly selected calves of the WM, pWM and BM groups (each N = 8-9) and processed to obtain from each sample preferably two isolates of Escherichia (E.) coli and Enterococcus spp. respectively. Isolates were tested for their antimicrobial susceptibility to 25 antimicrobial agents by broth microdilution. Daily weight gain, milk and calf starter intake and health parameters did not differ significantly between the calves of the four feeding groups. The proportion of resistant E. coli isolates was significantly higher in calves fed WM and in calves fed pWM (most pronounced for cephalosporins) than in calves receiving BM. No differences in resistance were found for Enterococus spp. Thus, the concerns for selecting resistant faecal bacteria by feeding WM seem to be justified. Nonetheless, pasteurized WM of cows not treated with antimicrobials represents an acceptable feed for young calves.

  3. Abundances of tetracycline, sulphonamide and beta-lactam antibiotic resistance genes in conventional wastewater treatment plants (WWTPs) with different waste load

    DEFF Research Database (Denmark)

    Laht, Mailis; Karkman, Antti; Voolaid, Veiko;

    2014-01-01

    Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs), an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs) were quantified using qPCR in three WWTPs of decreasing capacity located...... in the relative abundance of resistance genes, while the raw abundances fell by several orders of magnitude. Standard water quality variables (biological oxygen demand, total phosphorus and nitrogen, etc.) were weakly related or unrelated to the relative abundance of resistance genes. Based on our results we...... conclude that there is neither considerable enrichment nor purification of antibiotic resistance genes in studied conventional WWTPs....

  4. Abundances of tetracycline, sulphonamide and beta-lactam antibiotic resistance genes in conventional wastewater treatment plants (WWTPs) with different waste load

    DEFF Research Database (Denmark)

    Laht, Mailis; Karkman, Antti; Voolaid, Veiko

    2014-01-01

    Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs), an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs) were quantified using qPCR in three WWTPs of decreasing capacity located...... conclude that there is neither considerable enrichment nor purification of antibiotic resistance genes in studied conventional WWTPs....... in Helsinki, Tallinn, and Tartu, respectively: sulphonamide resistance genes (sul1 and sul2), tetracycline resistance genes (tetM and tetC), and resistance genes for extended spectrum beta-lactams (blaoxa-58, blashv-34, and blactx-m-32). To avoid inconsistencies among qPCR assays we normalised the ARG...

  5. Radiation enteritis

    Science.gov (United States)

    Radiation enteropathy; Radiation-induced small bowel injury; Post-radiation enteritis ... Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells. The therapy ...

  6. Antibiotic resistance in faecal bacteria isolated from horses receiving virginiamycin for the prevention of pasture-associated laminitis.

    Science.gov (United States)

    Menzies-Gow, N J; Young, N J

    2011-09-28

    Enterococcus faecium, a major cause of potentially life-threatening hospital-acquired human infections, can be resistant to several antimicrobials, such that streptogramin quinupristin-dalfopristin (Q/D) is one of the few antibiotics still effective. Consequently use of the streptogramin virginiamycin as an animal growth promoter was banned in the EU in 1999 as some believed this contributed to the emergence of Q/D resistant E. faecium. Virginiamycin is advocated for preventing equine pasture-associated laminitis, but its effect on equine faecal bacterial Q/D resistance has not been determined. Faecal samples were obtained from horses receiving virginiamycin, horses co-grazing and horses not exposed to virginiamycin. Streptogramin resistant E. faecium were cultured from 70% (21/30) of animals treated with virginiamycin, 75% (18/24) of co-grazing animals and 69% (11/16) of animals not exposed. ermB and vatD genes were detected using real time PCR in 63% and 66% of animals treated with virginiamycin, 75% and 71% of co-grazing animals and 63% and 69% of animals not exposed. Antimicrobial resistance genes were present only in samples which had cultured Q/D resistant E. faecium. There was no significant difference between groups with respect to antimicrobial resistance. The gene load of vatD was significantly (p=0.04) greater in unexposed animals compared to those treated with virginiamycin. The use of virginiamycin to prevent pasture-associated laminitis does not appear to be related to an increased Q/D resistance frequency. However, in view of the high frequency of resistance within all groups, the horse is a reservoir of Q/D resistant genes and clones that potentially could be transferred transiently to humans.

  7. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    DEFF Research Database (Denmark)

    Leibovici, Leonard; Paul, Mical; Garner, Paul

    2016-01-01

    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......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...

  8. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    Science.gov (United States)

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

  9. Qualitative Analysis of a Antibiotic-resistant Bacteria Model with Different Respond Function%具有不同功能反应函数的抗药性细菌模型的定性分析

    Institute of Scientific and Technical Information of China (English)

    高宇坤; 曼合布拜·热合木

    2015-01-01

    The spread of antibiotic resistance is studied through a mathematical model. We compute the basic repro-duction number Ri, the bacteria-free stead state, two boundaries stead state which we define as existence of wild strain of bacteria while the antibiotic resistant mutants dies out, and the positive stead state when the wild strain of bacteria and the antibiotic resistant mutants persists in the two population for specific conditions. We also determine stability criteria for the bacteria-free stead state, boundaries stead state and the positive stead state. Numerical results are provided to illustrate theoretical results and the further insight of the dynamics of the models.%通过数学模型研究了抗生素耐药性的传播。计算了基本再生数,得到了无菌平衡点,两个边界平衡点(表示抗生素的突变体消失)和正平衡点(表示野生菌株和抗生素的突变体)持久存在的条件。建立了判定无菌平衡点、边界平衡点及正平衡点稳定的准则。通过数值模拟进一步观察了模型的动力学行为并验证了理论分析结果的正确性。

  10. Identification of lactic acid bacteria in commercial yogurt and their antibiotic resistance%市售酸奶中乳酸菌的鉴定与耐药性

    Institute of Scientific and Technical Information of China (English)

    秦宇轩; 李晶; 王秋涯; 高可心; 朱宝利; 律娜

    2013-01-01

    [Objective] To identify lactic acid bacteria (LAB) in commercial yogurts and investigate their antibiotic resistance.[Methods] LABs were cultured from 5 yogurt brands and the isolates were identified at the species level by 16S rRNA sequence.Genotyping was performed by repetitive extragenic palindromic PCR (rep-PCR).The sensitivity to 7 antibiotics was tested for all LAB isolates by Kirby-Bauer paper diffusion (K-B method).Meanwhile,9 antibiotic resistance genes(ARGs),including erythromycin resistance genes (ermA and ermB) and tetracycline resistance genes (tetM,tetK,tetS,tetQ,tetO,tetL and tetW),were detected by PCR amplification in the identified LAB isolates.The PCR products were confirmed by sequencing.[Results] Total 100 LABs were isolated,including 23 Lactobacillus delbrueckii ssp.bulgaricus,26 Lactobacillus casei,30 Streptococcus thermophilus,5 Lactobacillus acidophilus,6 Lactobacillus plantarum,and 10 Lactobacillus paracasei.The drug susceptibility test shows that all 100 isolates were resistant to gentamicin and streptomycin,42 isolates were resistant to vancomycin,and on the contrary all were sensitive to cefalexin,erythromycin,tetracycline and oxytetracycline.Moreover,5 ARGs were found in the 28 sequencing confirmed isolates,ermB gene was detected in 8 isolates,tet K in 4 isolates,tetL in 2 isolates,tetM in 4 isolates,tetO in 2 isolates.erm A,tet S,tet Q and tet W genes were not detected in the isolates.Antibiotic resistance genes were found in 53.57% (15/28) sequenced isolates,2-3 antibiotic resistance genes were detected in 4 isolates of L.delbrueckii ssp.bulgaricus.[Conclusions] Some LABs were not labeled in commercial yogurt products.Antibiotic resistance genes tend to be found in the starter culture of L.delbrueckii ssp.Bulgaricus and S.thermophilus.All the LAB isolates were sensitive to erythromycin and tetracycline,even though some carried erythromycin and/or tetracycline resistance genes.We proved again that LAB could carry antibiotic resistance

  11. Killing of Mycolic Acid-Containing Bacteria Aborted Induction of Antibiotic Production by Streptomyces in Combined-Culture.

    Science.gov (United States)

    Asamizu, Shumpei; Ozaki, Taro; Teramoto, Kanae; Satoh, Katsuya; Onaka, Hiroyasu

    2015-01-01

    Co-culture of Streptomyces with mycolic acid-containing bacteria (MACB), which we termed "combined-culture," alters the secondary metabolism pattern in Streptomyces and has been a useful method for the discovery of bioactive natural products. In the course of our investigation to identify the inducing factor(s) of MACB, we previously observed that production of pigments in Streptomyces lividans was not induced by factors such as culture extracts or mycolic acids. Although dynamic changes occurred in culture conditions because of MACB, the activation of pigment production by S. lividans was observed in a limited area where both colonies were in direct contact. This suggested that direct attachment of cells is a requirement and that components on the MACB cell membrane may play an important role in the response by S. lividans. Here we examined whether this response was influenced by dead MACB that possess intact mycolic acids assembled on the outer cell membrane. Formaldehyde fixation and γ-irradiation were used to prepare dead cells that retain their shape and mycolic acids of three MACB species: Tsukamurella pulmonis, Rhodococcus erythropolis, and Rhodococcus opacus. Culturing tests verified that S. lividans does not respond to the intact dead cells of three MACB. Observation of combined-culture by scanning electron microscopy (SEM) indicated that adhesion of live MACB to S. lividans mycelia were a significant interaction that resulted in formation of co-aggregation. In contrast, in the SEM analysis, dead cells were not observed to adhere. Therefore, direct attachment by live MACB cells is proposed as one of the possible factors that causes Streptomyces to alter its specialized metabolism in combined-culture.

  12. Killing of Mycolic Acid-Containing Bacteria Aborted Induction of Antibiotic Production by Streptomyces in Combined-Culture.

    Directory of Open Access Journals (Sweden)

    Shumpei Asamizu

    Full Text Available Co-culture of Streptomyces with mycolic acid-containing bacteria (MACB, which we termed "combined-culture," alters the secondary metabolism pattern in Streptomyces and has been a useful method for the discovery of bioactive natural products. In the course of our investigation to identify the inducing factor(s of MACB, we previously observed that production of pigments in Streptomyces lividans was not induced by factors such as culture extracts or mycolic acids. Although dynamic changes occurred in culture conditions because of MACB, the activation of pigment production by S. lividans was observed in a limited area where both colonies were in direct contact. This suggested that direct attachment of cells is a requirement and that components on the MACB cell membrane may play an important role in the response by S. lividans. Here we examined whether this response was influenced by dead MACB that possess intact mycolic acids assembled on the outer cell membrane. Formaldehyde fixation and γ-irradiation were used to prepare dead cells that retain their shape and mycolic acids of three MACB species: Tsukamurella pulmonis, Rhodococcus erythropolis, and Rhodococcus opacus. Culturing tests verified that S. lividans does not respond to the intact dead cells of three MACB. Observation of combined-culture by scanning electron microscopy (SEM indicated that adhesion of live MACB to S. lividans mycelia were a significant interaction that resulted in formation of co-aggregation. In contrast, in the SEM analysis, dead cells were not observed to adhere. Therefore, direct attachment by live MACB cells is proposed as one of the possible factors that causes Streptomyces to alter its specialized metabolism in combined-culture.

  13. 家养禽类肠道可培养细菌抗生素抗性的种类、数量和分布%Diversity and distribution of antibiotic resistance for gut culturable bacteria from domestic poultry

    Institute of Scientific and Technical Information of China (English)

    周俊雄; 马荣琴; 李冬松; 田容川; 李敏昱; 罗艺彬; 刘平平; 田宝玉

    2016-01-01

    The wide-use, misuse and even abuse of antibiotics in recent years have led to an increase in the resistance of environ-mental and pathogenic microorganisms to antibiotics. In this study, diversity and ecological distribution of antibiotic resistances for culturable intestinal bacteria from domestic poultry, including chicken, duck and pigeon, were investigated using traditional micro-culture and replica plating techniques. Results showed that all the isolated bacteria were resistant to at least 1 of the 10 tested antibi-otics. Proportions of bacteria which were resistant to greater than or equal to 5 antibiotics were 75%, 58.9% and 97.4% for chicken, duck and pigeon, respectively. And 66 out of 192 ( 34%) isolates were resistant to all the antibiotics. Moreover, a variety of bacteri-a, with the highest overall proportion in pigeon and lowest in duck, showed resistance to nalidixic acid, tetracyyline, clindamycin, sulfadiazine and erythromycin. In order to identify bacteria that presentd high and multi-drug antibiotic resistance, 16S rRNA genes of 8 representative strains were amplified and followed by phylogenetic analysis. It turned out that the bacteria were grouped into the branch of Escherichia coli under the family of Enterobacterium. Referring to database from National Center of Biotechnology Informa-tion ( NCBI) , sequences with 99% similarity with the 8 strains were widely distributed in a variety of environment, including soil, animal host and pathogenic bacteria. Results indicated that culturable gut bacteria from domestic poultry was a potential source of an-tibiotic resistance for environmental microbiota and human pathogenic bacteria.%采用微生物培养和影印法对家养禽类鸡、鸭和肉鸽肠道可培养细菌抗生素抗性的种类、数量和分布进行了调查.结果表明:在调查的鸡、鸭和肉鸽3种禽类中,肠道可培养细菌抗生素抗性的分布非常普遍,所有测试细菌至少可以抗一种抗生素,抗5

  14. Antibiotics: Miracle Drugs

    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 you’ve 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.

  15. Demographics of antibiotic persistence

    DEFF Research Database (Denmark)

    Steiner, Ulrich; Kollerova, Silvia; Jouvet, Lionel

    2016-01-01

    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...... cultures, rather than the individual level. Here, we used individual level bacteria data to confirm previous studies in how fast cells switch into a persistence stage, but our results challenge the fundamental idea that persistence comes with major costs of reduced growth (cell elongation) and division due...... even play a more prominent role for the evolution of resistance and failures of medical treatment by antibiotics as currently assumed....

  16. Eosinofil enteritis

    DEFF Research Database (Denmark)

    Gjersøe, P; Rasmussen, S N; Hansen, B F

    2000-01-01

    We present a case of eosinophilic enteritis in a 45 year-old male with clinical and radiological signs of stenotic inflammatory ileal disease. A diagnosis of Crohn's disease was considered. He developed small bowel obstruction and sixty cm of obstructed ileum was resected. Histopathological...... examination revealed the diagnosis of eosinophilic enteritis primarily localized to the tunica muscularis. One year postoperatively he relapsed and small bowel X-ray demonstrated 1 m narrow and irregular ileum. He was treated with mesalamine, azathioprine, and cromoglicate, went into remission and fares well...

  17. 2010年医院临床分离细菌的耐药性监测%Surveillance of antibiotic resistance of clinically isolated bacteria in 2010

    Institute of Scientific and Technical Information of China (English)

    李玉瑭; 于超; 杜亭亭; 刘培; 阎世坤; 肖颖; 曹倩; 周亚滨

    2012-01-01

    , gram-negative bacteria were dominated, accounting for 57. 25%; Acinetobacter baumannii was resistant to various antibiotics in general, the drug resistance rate to ampicillin was 99. 13% ;in contrast, the drug resistance rates of Pseudomonas aeruginosa to minocycline and sulfa drugs, the drug resistance rates to β-lactam, multiple peptide, aminoglycoside antibiotics were around 30. 00%; Escherichia coli was resistant to β-lactam antibiotics in general, the resistance rate to cefoxitin was 12. 04%, piperacillin/tazobactam 3. 14%-, cefoperazone/sulbactam 6. 28%; Staphylococcus aureus was resistant to various antibiotics, the drug resistance rate to β-lactam antibiotics were higher than 90. 00%, sulbactam/ampicillin 81.12%; no strains of vancomycin-resistant S. aureus were detected. CONCLUSION It is necessary to reasonably use antibiotics, strengthen the awareness of bacterial culture and strictly comply the standards of diagnosis so as to improve the quality of clinical anti-infection.

  18. Enteric viruses

    Science.gov (United States)

    Characteristic clinical signs associated with viral enteritis in young poultry include diarrhea, anorexia, litter eating, ruffled feathers, and poor growth. Intestines may have lesions; intestines are typically dilated and are filled with fluid and gaseous contents. The sequela to clinical disease...

  19. Antibiotics resistance of two non-fermentative bacteria%两种非发酵菌对多种抗菌药物耐药性的分析

    Institute of Scientific and Technical Information of China (English)

    方欢; 张军; 李刚; 袁轶群; 丁柳美

    2011-01-01

    OBJECTIVE To periodically investigate resistance variation of Pseudomonas aeruginosa (PAE) and Acinetobacter baumannii (ABA), correlation between resistance and antimicrobials consumption, and correlations among antimicrobials resistance of each non-fermentative bacteria. METHODS Results of antimicrobials sensitive test as well as DDDS of antibiotic were gathered and counted every quarter, and the data were analysed with the statistics method of Spearman rank correlation. RESULTS PAE kept a relatively high sensitivity to most antimicrobials, and ABA expressed an increasing ratio of drug resistance. For PAE, FEP DDDS was positively correlated to its resistance and the SXT resistance (r= 0. 767,0. 772), and Fluoroquinolone DDDS was positively correlated to IMP resistance (r=0. 689). For ABA, CMZ DDDS were positively correlated to IMP, MEM, GEN and CTX resistance (r=0. 711,0. 711,0. 767 and 0.8). Cephalomycin DDDS were positively correlated to IMP,MEM,and GEN and AMK resistance (r=0. 826,0. 788,0. 633 and 0. 642). FEP DDDS were correlated to CXM,CAZ, PIP and SXT DDDs (r= 0. 709,0. 697,0. 818 and 0. 782). There were only FEP and SXT resistance without correlation to other antimicrobials resistance for PAE. For ABA just CMZ resistance had no correlation to others. CONCLUSION The doses of antibiotics can influence both their own resistance rates and the resistances to other antibiotics. The increasing resistance rate can not be prevented by using the single antibiotics to nonfermentative bacteria. The drug resistant genes, which can transmit horizontally through strains, can directly cause drug resistance, besides the reasonable application of antibiotics. We must control the nosocomail infection and implement the strict isolation and disinfection system to control the increasing drug resistant rate.%目的 了解铜绿假单胞菌(PAE)和鲍氏不动杆菌(ABA)耐药的变化,探讨抗菌药物用药情况与耐药性之间关系,为合理使用

  20. Antibiotic resistance of Clostridium perfringens isolates from broiler chickens in Egypt.

    Science.gov (United States)

    Osman, K M; Elhariri, M

    2013-12-01

    The use of antibiotic feed additives in broiler chickens results in a high prevalence of resistance among their enteric bacteria, with a consequent emergence of antibiotic resistance in zoonotic enteropathogens. Despite growing concerns about the emergence of antibiotic-resistant strains, which show varying prevalences in different geographic regions, little work has been done to investigate this issue in the Middle East. This study provides insight into one of the world's most common and financially crippling poultry diseases, necrotic enteritis caused by Clostridium perfringens. The study was designed to determine the prevalence of antibiotic resistance in C. perfringens isolates from clinical cases of necrotic enteritis in broiler chickens in Egypt. A total of 125 isolates were obtained from broiler flocks in 35 chicken coops on 17 farms and were tested using the disc diffusion method. All 125 isolates were resistant to gentamicin, streptomycin, oxolinic acid, lincomycin, erythromycin and spiramycin. The prevalence of resistance to other antibiotics was also high: rifampicin (34%), chloramphenicol (46%), spectinomycin (50%), tylosin-fosfomycin (52%), ciprofloxacin (58%), norfloxacin (67%), oxytetracycline (71%), flumequine (78%), enrofloxacin (82%), neomycin (93%), colistin (94%), pefloxacin (94%), doxycycline (98%) and trimethoprim-sulfamethoxazole (98%). It is recommended that C. perfringens infections in Egypt should be treated with antibiotics for which resistant isolates are rare at present; namely, amoxicillin, ampicillin, cephradine, fosfomycin and florfenicol.

  1. Review article: antibiotics and probiotics in inflammatory bowel disease.

    Science.gov (United States)

    Kruis, W

    2004-10-01

    Treatment with antibiotics in inflammatory bowel disease has a long tradition and is widely used. The indications for antibiotic therapy are wide ranging, from specific situations such as abscesses or fistulae, to patients with severe disease (as an unspecific 'protective' measure), and to address the hypothesis that the enteric flora as a whole, or specific microorganisms such as mycobacteria, are involved in the pathogenesis of inflammatory bowel disease. The best-studied single antibiotic compound is metronidazole. However, overall, the scientific basis for the use of antibiotics is limited, which may reflect a lack of interest from sponsors within the pharmaceutical industry. Despite this weak evidence base, antibiotics are a globally established therapeutic tool in inflammatory bowel disease. Growing evidence from human and animal studies points towards a pivotal pathogenetic role of intestinal bacteria in inflammatory bowel disease. In view of these experimental findings, clinical trials have been undertaken to elucidate the therapeutic effects of probiotics in inflammatory bowel disease. Probiotics are viable nonpathogenic microorganisms which confer health benefits to the host by improving the microbial balance of the indigenous microflora. So far, of the many candidates, one specific strain (Escherichia coli Nissle 1917) and a mixture of eight different bacteria have demonstrated convincing therapeutic efficacy in controlled studies. Maintenance therapy in ulcerative colitis and prevention therapy, as well as the treatment of pouchitis, have emerged as areas in which probiotic therapy offers a valid therapeutic alternative to current treatments. Further investigations may detect additional clinically effective probiotics and other clinical indications.

  2. Antibiotic sensitivity of bacterial strains isolated from newborn infants Sensibilidad a los antibióticos de bacterias aisladas de neonatos hospitalizados

    Directory of Open Access Journals (Sweden)

    Alvaro Uribe

    1990-02-01

    Full Text Available

    Eighty nine bacterial strains isolated from newborn infants hospitalized at a Special Care Unit in Medellin, Colombia, were studied. The sensitivity of each one was determined by the Minimallnhibitory Concentration method against 21 antibiotics; a high frequency of resistance was found toward gentamycin, netilmycin, oxacillin, penicillin G and ampicillin, that are often employed as initial therapy in newborn infants; on the other hand both Gram positive and Gram negative bacteria exhibited high percentages of sensitivity against quinolones; aztreonam and third generation cephalosporins were also highly effective against Gram negative bacilli. On the basis of this new information the need to restate therapeutic conducts in the case of serious bacterial neonatal infections is emphasized.

    Se estudiaron 89 cepas bacterianas aisladas de neonatos hospitalizados en la sala de cuidados especiales de la Fundación Hospitalaria San Vicente de Paúl, de Medellín; a cada una se le determinó la sensibilidad frente a 21 antibióticos por el método de la concentración inhibitoria mínima (CIM; se halló una alta frecuencia de resistencia hacia la gentamicina, la netilmicina, la oxacilina y la ampicilina que se usan a menudo en esta institución como terapia inicial en las infecciones del recién nacido; por otra parte se demostraron altos porcentajes de sensibilidad hacia las quinolonas tanto de las bacterias gram positivas como de las gram negativas; contra estas últimas también fueron muy efectivos el aztreonam y las cefalosporinas de tercera generación. A la luz de esta nueva información se llama la atención hacia la necesidad de revaluar las normas de la antibioterapia en las infecciones graves del recién nacido.

  3. Development of a Rapid Reverse Blot Hybridization Assay for Detection of Clinically Relevant Antibiotic Resistance Genes in Blood Cultures Testing Positive for Gram-Negative Bacteria

    Science.gov (United States)

    Wang, Hye-young; Yoo, Gilsung; Kim, Juwon; Uh, Young; Song, Wonkeun; Kim, Jong Bae; Lee, Hyeyoung

    2017-01-01

    Rapid and accurate identification of the causative pathogens of bloodstream infections is crucial for the prompt initiation of appropriate antimicrobial therapy to decrease the related morbidity and mortality rates. The aim of this study was to evaluate the performance of a newly developed PCR-reverse blot hybridization assay (REBA) for the rapid detection of Gram-negative bacteria (GNB) and their extended-spectrum β-lactamase (ESBL), AmpC β-lactamase, and carbapenemase resistance genes directly from the blood culture bottles. The REBA-EAC (ESBL, AmpC β-lactamase, carbapenemase) assay was performed on 327 isolates that were confirmed to have an ESBL producer phenotype, 200 positive blood culture (PBCs) specimens, and 200 negative blood culture specimens. The concordance rate between the results of REBA-EAC assay and ESBL phenotypic test was 94.2%. The sensitivity, specificity, positive predictive value, and negative predictive value of the REBA-EAC assay for GNB identification in blood culture specimens were 100% (95% CI 0.938–1.000, P < 0.001), 100% (95% CI 0.986–1.000, P < 0.001), 100% (95% CI 0.938–1.000, P < 0.001), and 100% (95% CI 0.986–1.000, P < 0.001), respectively. All 17 EAC-producing GNB isolates from the 73 PBCs were detected by the REBA-EAC assay. The REBA-EAC assay allowed easy differentiation between EAC and non-EAC genes in all isolates. Moreover, the REBA-EAC assay was a rapid and reliable method for identifying GNB and their β-lactamase resistance genes in PBCs. Thus, this assay may provide essential information for accelerating therapeutic decisions to achieve earlier appropriate antibiotic treatment during the acute phase of bloodstream infection. PMID:28232823

  4. Development of a Rapid Reverse Blot Hybridization Assay for Detection of Clinically Relevant Antibiotic Resistance Genes in Blood Cultures Testing Positive for Gram-Negative Bacteria.

    Science.gov (United States)

    Wang, Hye-Young; Yoo, Gilsung; Kim, Juwon; Uh, Young; Song, Wonkeun; Kim, Jong Bae; Lee, Hyeyoung

    2017-01-01

    Rapid and accurate identification of the causative pathogens of bloodstream infections is crucial for the prompt initiation of appropriate antimicrobial therapy to decrease the related morbidity and mortality rates. The aim of this study was to evaluate the performance of a newly developed PCR-reverse blot hybridization assay (REBA) for the rapid detection of Gram-negative bacteria (GNB) and their extended-spectrum β-lactamase (ESBL), AmpC β-lactamase, and carbapenemase resistance genes directly from the blood culture bottles. The REBA-EAC (ESBL, AmpC β-lactamase, carbapenemase) assay was performed on 327 isolates that were confirmed to have an ESBL producer phenotype, 200 positive blood culture (PBCs) specimens, and 200 negative blood culture specimens. The concordance rate between the results of REBA-EAC assay and ESBL phenotypic test was 94.2%. The sensitivity, specificity, positive predictive value, and negative predictive value of the REBA-EAC assay for GNB identification in blood culture specimens were 100% (95% CI 0.938-1.000, P < 0.001), 100% (95% CI 0.986-1.000, P < 0.001), 100% (95% CI 0.938-1.000, P < 0.001), and 100% (95% CI 0.986-1.000, P < 0.001), respectively. All 17 EAC-producing GNB isolates from the 73 PBCs were detected by the REBA-EAC assay. The REBA-EAC assay allowed easy differentiation between EAC and non-EAC genes in all isolates. Moreover, the REBA-EAC assay was a rapid and reliable method for identifying GNB and their β-lactamase resistance genes in PBCs. Thus, this assay may provide essential information for accelerating therapeutic decisions to achieve earlier appropriate antibiotic treatment during the acute phase of bloodstream infection.

  5. Microbiological culture simplified using anti-O12 monoclonal antibody in TUBEX test to detect Salmonella bacteria from blood culture broths of enteric fever patients.

    Science.gov (United States)

    Nugraha, Jusak; Marpaung, Ferdy R; Tam, Frankie C H; Lim, Pak Leong

    2012-01-01

    Definitive diagnosis of infectious diseases, including food poisoning, requires culture and identification of the infectious agent. We described how antibodies could be used to shorten this cumbersome process. Specifically, we employed an anti-Salmonella lipopolysaccharide O12 monoclonal antibody in an epitope-inhibition 10-min test (TUBEX TP) to detect O12⁺Salmonella organisms directly from routine blood culture broths. The aim is to obviate the need to subculture the broth and subsequently identify the colonies. Thus, blood from 78 young outpatients suspected of having enteric fever was incubated in an enrichment broth, and after 2 or 4 days, broth samplings were examined by TUBEX TP as well as by conventional agar culture and identification. TUBEX TP was performed before the culture results. Eighteen isolates of S. Typhi (15 after 2 days) and 10 isolates of S. Paratyphi A (4 after 2 days) were obtained by conventional culture. Both these Salmonella serotypes, the main causes of enteric fever, share the O12 antigen. In all instances where either of these organisms was present (cultured), TUBEX TP was positive (score 4 [light blue]--to--score 10 [dark blue]; negative is 0 [pink-colored]) i.e. 100% sensitive. Identification of the specific Salmonella serotype in TUBEX-positive cases was achieved subsequently by conventional slide agglutination using appropriate polyclonal antisera against the various serotypes. Twelve Escherichia coli, 1 Alcaligenes spp. and 1 Enterobacter spp. were isolated. All of these cases, including all the 36 culture-negative broths, were TUBEX-negative i.e. TUBEX TP was 100% specific. In a separate study using known laboratory strains, TUBEX TF, which detects S. Typhi but not S. Paratyphi A via the O9 antigen, was found to efficiently complement TUBEX TP as a differential test. Thus, TUBEX TP and TUBEX TF are useful adjuncts to conventional culture because they can save considerable time (>2 days), costs and manpower.

  6. Microbiological culture simplified using anti-O12 monoclonal antibody in TUBEX test to detect Salmonella bacteria from blood culture broths of enteric fever patients.

    Directory of Open Access Journals (Sweden)

    Jusak Nugraha

    Full Text Available Definitive diagnosis of infectious diseases, including food poisoning, requires culture and identification of the infectious agent. We described how antibodies could be used to shorten this cumbersome process. Specifically, we employed an anti-Salmonella lipopolysaccharide O12 monoclonal antibody in an epitope-inhibition 10-min test (TUBEX TP to detect O12⁺Salmonella organisms directly from routine blood culture broths. The aim is to obviate the need to subculture the broth and subsequently identify the colonies. Thus, blood from 78 young outpatients suspected of having enteric fever was incubated in an enrichment broth, and after 2 or 4 days, broth samplings were examined by TUBEX TP as well as by conventional agar culture and identification. TUBEX TP was performed before the culture results. Eighteen isolates of S. Typhi (15 after 2 days and 10 isolates of S. Paratyphi A (4 after 2 days were obtained by conventional culture. Both these Salmonella serotypes, the main causes of enteric fever, share the O12 antigen. In all instances where either of these organisms was present (cultured, TUBEX TP was positive (score 4 [light blue]--to--score 10 [dark blue]; negative is 0 [pink-colored] i.e. 100% sensitive. Identification of the specific Salmonella serotype in TUBEX-positive cases was achieved subsequently by conventional slide agglutination using appropriate polyclonal antisera against the various serotypes. Twelve Escherichia coli, 1 Alcaligenes spp. and 1 Enterobacter spp. were isolated. All of these cases, including all the 36 culture-negative broths, were TUBEX-negative i.e. TUBEX TP was 100% specific. In a separate study using known laboratory strains, TUBEX TF, which detects S. Typhi but not S. Paratyphi A via the O9 antigen, was found to efficiently complement TUBEX TP as a differential test. Thus, TUBEX TP and TUBEX TF are useful adjuncts to conventional culture because they can save considerable time (>2 days, costs and manpower.

  7. Discovery research: the scientific challenge of finding new antibiotics.

    Science.gov (United States)

    Livermore, David M

    2011-09-01

    The dwindling supply of new antibiotics largely reflects regulatory and commercial challenges, but also a failure of discovery. In the 1990s the pharmaceutical industry abandoned its classical ways of seeking antibiotics and instead adopted a strategy that combined genomics with high-throughput screening of existing compound libraries. Too much emphasis was placed on identifying targets and molecules that bound to them, and too little emphasis was placed on the ability of these molecules to permeate bacteria, evade efflux and avoid mutational resistance; moreover, the compound libraries were systematically biased against antibiotics. The sorry result is that no antibiotic found by this strategy has yet entered clinical use and many major pharmaceutical companies have abandoned antibiotic discovery. Although a raft of start-up companies-variously financed by venture capital, charity or public money--are now finding new antibiotic compounds (some of them very promising in vitro or in early trials), their development through Phase III depends on financial commitments from large pharmaceutical companies, where the discouraging regulatory environment and the poor likely return on investment remain paramount issues.

  8. 污水处理厂削减耐药菌与抗性基因的研究进展%State-of-the-art removal of antibiotic resistance bacteria (ARB) and antibiotic resistance gene (ARG) in wastewater treatment plants (WWTPs)

    Institute of Scientific and Technical Information of China (English)

    佟娟; 魏源送

    2012-01-01

    长期滥用抗生素导致细菌耐药性增强,并使抗性广泛传播.污水处理厂既是耐药菌(antibiotic resistance bacteria,ARB)与抗性基因(antibiotic resistance gene,ARG)的储存库,排放的污水与污泥是向自然环境中传播抗性的重要污染源,也是削减ARB和ARG及控制抗性传播的重要环节.本文总结了天然水体中的耐药菌和抗性基因污染现状,分析了近年来耐药菌与抗性基因在污水/污泥处理过程中的转归与去除方面的研究进展,同时对将来的重点研究方向提出展望,以期为今后耐药菌和抗性基因的污染控制提供参考.%The abuse and overuse of antibiotics lead to increasing bacterial resistance to actibiotics and extensive dissemination of resistance. As a reservoir for antibiotic resistance bacteria (ARB) and antibiotic resistance gene (ARG) , the effluent and biosolids of wastewater treatment plants (WWTPs) are the important contamination sources for the antibiotic resistance dissemination. Meanwhile, WWTPs play an important role in controlling of resistance dissemination. The purpose of this paper is to summarize pollution status of antibiotic resistance in the aquatic environment, to thoroughly review the advances of removing ARB and ARG during WWTP treating processes, and to propose the future research direction.

  9. Antibiotics Quiz

    Science.gov (United States)

    ... on the Farm Get Smart About Antibiotics Week Antibiotics Quiz Recommend on Facebook Tweet Share Compartir Try ... right of the answer you think is correct. Antibiotic Quiz Widget Copy the code for this widget, ...

  10. 医院感染细菌的临床分布及耐药性分析%Clinical distribution and antibiotic resistance analysis on bacteria of nosocomial infection

    Institute of Scientific and Technical Information of China (English)

    陈映; 乔岩; 赵燕

    2013-01-01

    Objective To investigate the distribution and antibiotic resistance of hospitalized infection bacteria in clinical departments and specimens. Methods French biology-bioMerieux ATB bacterial identification system, susceptibility detection instrument and supporting microbial detection reagent were applied for bacterial identification and susceptibility testing. The distribution of bacterial infection and antibiotic resistance data from January 2011 to December 2011 were analyzed, respectively. Results Among 455 bacteria, Escherichia coli, Klebsiella pneumoniae, Candida albicans, Staphylococcus epidermidis, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus were the seven major infection bacteria, accounting for 68. 13% of the total detected bacteria. Methicillin-resistant Staphylococcus aureus ( MRSA ) and Staphylococcus epidermidis ( MRSE ) were with 46. 43% and 75. 68% detection, no vancomycin-resistant and teicoplain-resistant Staphylococcus aureus were detected. There were 38 cases with multiple antibiotic resistant bacteria with positive rate as 8. 35% . There was 37. 93% ( 11/29 ) Acinetobacter baumannii detected as pan-resistant bacteria. The sources of bacterial were mainly from respiratory medicine and intensive care unit ( ICU ). Sputum samples had the highest positive bacteria with 178 ( 39. 12% ). Conslusions That conducting regular surveillance of antibiotic resistance could help analyze changes of antibiotic resistant of hospital bacteria, providing a theoretical basis for the clinical experience of drug use.%目的 了解医院感染细菌在临床科室和标本中的分布及耐药情况.方法 回顾性分析2011年1月~2011年12月本院感染菌的分布及耐药情况.使用法国生物-梅里埃ATB细菌鉴定系统,应用药敏测试仪及配套微生物检测试剂进行细菌鉴定和药敏试验.结果 本研究分离的455株感染菌中,大肠埃希菌、肺炎克雷伯菌、白假丝酵母菌、表皮葡萄球菌、

  11. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions.

    Science.gov (United States)

    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.

  12. Selection of antibiotic resistance at very low antibiotic concentrations.

    Science.gov (United States)

    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.

  13. Ease with VITEK 2 systems, biomerieux in identification of non-lactose fermenting bacteria including their antibiotic drug susceptibility: our experience

    Directory of Open Access Journals (Sweden)

    Susmitha Simgamsetty

    2016-03-01

    Results: Out of the 186 strains, 50 strains were isolated from tracheal aspirate, 47 from pus/wound infections, 43 from blood cultures, 25 from urine, 20 from sputum and one from central line tip. The VITEK-2 compact system identified all the strains with a level of 95-99% probability. Most of the strains were identified as Pseudomonas aeruginosa followed by Acientobacter baumannii. Pseudomonas aeruginosa strains were most susceptible to Meropenem (72% and least susceptible to Cefuroxime and Trimethoprim/Sulfamethoxazole (0% while Sphingomonas paucimobilis showed resistance to all the antibiotics tested. Conclusions: Care in detection, evaluation of effective antibiotic options, and judicious use of antibiotics by instituting antibiotic policy for combination therapy and rigorous infection control measures will help us to fight against these multidrug resistant NFGNB during the effective management of patients. [Int J Res Med Sci 2016; 4(3.000: 813-817

  14. Beta-lactam antibiotics prevent Salmonella-mediated bovine encephalopathy regardless of the β-lactam resistance status of the bacteria.

    Science.gov (United States)

    Xiong, Nalee; Brewer, Matt T; Anderson, Kristi L; Watrous, Gwyneth K; Weeks, Katherine E; Barnhill, Alison E; Day, Tim A; Kimber, Michael J; Carlson, Steve A

    2012-06-01

    This study assessed the capacity of β-lactam antibiotics to prevent salmonella-mediated encephalopathy in calves given the putative neuroprotective effects of these drugs of increasing glutamate export from the brain. Both ampicillin and ceftiofur prevented the development of encephalopathy despite resistance of the inoculated Salmonella enterica serovar Saint-Paul isolate to both drugs. A glutamate receptor antagonist also prevented this salmonella-mediated encephalopathy. Glutamate exporters were hyper-expressed in the presence of β-lactam antibiotics while a glutamate export inhibitor obviated the effects of these antibiotics, demonstrating a neuroprotective effect through glutamate export from the brain. The findings indicate that β-lactam antibiotics remain an important treatment option for this atypical form of bovine salmonellosis.

  15. Controlling antibiotic resistance in the ICU

    NARCIS (Netherlands)

    Derde, L.P.G.

    2013-01-01

    Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (V

  16. Antibiotics and antibiotic resistance in agroecosystems: Cultural methods and gaps in knowledge

    Science.gov (United States)

    Varying cultural methodologies are used in assessment of antibiotic resistance in environmental samples. Culture based methods commonly involve isolation of target bacteria on general or selective media, and assessing growth in response to specific concentrations of antibiotics. Though time consumin...

  17. 小儿心脏监护病房病原菌分布及超广谱β-内酰胺酶阳性菌的耐药性分析%Distribution of pathogenic bacteria and antibiotic resistance of ESBLs (+)bacteria in CICU

    Institute of Scientific and Technical Information of China (English)

    王保存; 丁力; 张峰

    2016-01-01

    目的:监测、分析小儿心脏监护病房(CICU)病原菌分布特点及超广谱β-内酰胺酶阳性菌[ESBLs(+)]的耐药状况,为指导临床合理用药提供理论依据。方法回顾性分析 CICU 分离的病原菌及耐药性。结果送检各类标本共计1192份,检测出病原菌124株(10.4%),主要来源于呼吸道(74株,59.7%),其中革兰阴性菌62株(50.0%)、革兰阳性菌50株(40.3%)、真菌12株(9.7%)。ESBLs(+)菌共24株(19.4%),均检自肺炎克雷伯菌及大肠埃希菌,对青霉素类、头孢菌素、氨曲南的耐药率高,对氨基糖苷类、喹诺酮类、碳氢霉烯类的耐药率低。结论CICU 病原菌多来源于呼吸道,ESBLs(+)菌的检出率高、耐药严重,应加强监测病原菌分布及耐药性,指导临床合理应用抗菌药物。%Objective To monitor and analyze the distribution of pathogenic bacteria and antibiotic resistance of ESBLs (+)bacteria in CICU of Anhui Provincial Children’s Hospital,in order to provide the theoretical basis for rational use of antibiotics in clinical prac-tice.Methods A retrospective analysis was made of pathogenic bacteria separated in CICU from January 2011 to December 2015 and of their antibiotic resistance.Results From a total of 1 192 samples,the detected pathogenic bacteria were 124 strains (10.4%), mainly derived from the respiratory tract (74 strains,59.7%).Among them,there were 62 strains (50.0%)of gram-negative bacteria, 50 strains (40.3%)of gram positive bacteria and 12 strains (9.7%)of fungus.ESBLs (+)bacteria,a total of 24 strains (19.4%), were both from pneumonia klebsiella bacteria and e.Coli,which were highly resistant to penicillin,cephalosporin and aztreonam,but were lowly resistant to aminoglycoside,quinolone and hydrocarbon alkene.Conclusions Pathogenic bacteria in CICU were mainly de-rived from respiratory tract.The detection rate of ESBLs (+)bacteria was

  18. Gut colonization of extended-spectrum β-lactamase-producing antibiotic-resistant bacteria in premature infants and its concordance with nosocomial sepsis%早产儿肠道产超广谱β-内酰胺酶耐药菌定植及其与医院感染脓毒症的符合情况

    Institute of Scientific and Technical Information of China (English)

    蔡文红; 杨长仪; 王俐萍; 林秀凤; 修文龙; 林惠姿; 石惠英; 林述玲

    2016-01-01

    Objective To investigate the characteristics and risk factors of extended-spectrum β-lactamase (ESBLs)-producing antibiotic-resistant bacterial gut colonization in premature infants and to explore its concordance with nosocomial sepsis.Methods A prospective surveillance was performed in Fujian Provincial Maternity and Children's Health Hospital from May 2013 to May 2014.Preterm infants(gestational age < 36 weeks,admission within 24 h of birth and hospitalization time ≥ 14 d)were enrolled,and rectal swabs were collected for ESBLs-producing antibiotic-resistant bacteria culture,on the 1 st,3 rd,7th day after birth,and every 7 days until the 28th day or discharge.The clinical data and the results of blood culture were collected,and statistical analysis was performed.Results A total of 300 patients were enrolled in this study,of whom 221 patients (73.7%) were identified as gut colonization with ESBLs-producing bacteria,but the most common was ESBLs-producing klebsiella pneumoniae.No ESBLs-producing bacteria colonized in the gut on the first day after birth,and ESBLs-producing bacteria gut colonization mainly appeared in the first 2 weeks after birth.Multivariate Logistic regression indentified:the use of antenatal antibiotics(OR =2.091,95% CI:1.089-4.014) was the independent risk factor for ESBLs-producing bacterial gut colonization in premature infants on the 3rd day after birth,the age of first enteral feeding after birth ≥72 h (OR =3.356,95% CI:1.540-7.312) was the independent risk factor on the 7 th day,gestational age < 34 weeks (OR =4.011,95 % CI:1.864-8.629),birth weight ≤ 1 500 g(OR =7.271,95% CI:3.301-16.016) and hospitalization in neonatal intensive care unit (NICU) after birth(OR =2.675,95% CI:1.135-6.303)were the independent risk factors on the 14th day,birthweight ≤ 1 500 g(OR =58.371,95% CI:6.517-522.854) was the independent risk factor on the 21th day,using of the third generation cephalosporin(OR =48.000,95% CI:2

  19. 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

  20. Bacterial Colonization and Antibiotic Resistance in a Prospective Cohort of Newborn Infants During the First Year of Life

    Science.gov (United States)

    Stange, Kurt C.; Jacobs, Michael R.; Weiss, Judith K.; Bajaksouzian, Saralee; Bonomo, Robert A.

    2016-01-01

    Background. Infants are virtually sterile at birth and frequently use antibiotics; our objective was to (1) characterize the longitudinal colonization with bacterial pathogens and associated antibiotic resistance in a cohort of community-dwelling infants in Northeast Ohio and (2) describe longitudinal concurrent antibiotic and daycare exposures. Methods. For 35 newborns, nasopharyngeal swabs were cultured for Streptococcus pneumoniae, anterior nasal for Staphylococcus aureus, and perirectal for extended-spectrum beta-lactamase (ESBL)-producing Gram-negative enteric bacteria, at 3-month intervals for 12 months. Infant and household antibiotics and daycare exposure were assessed longitudinally. Results. Thirteen infants received perinatal or nursery antibiotics. By 3 months, at least 22 were colonized with Gram-negative bacteria; 2 with S pneumoniae (type 19A, resistant; 15C, susceptible), 5 with methicillin-susceptible S aureus. By 12 months, at least 22 of 35 infants received antibiotics, 20 had household members with antibiotics, and 12 attended daycare; 7 more had household members with daycare exposure. The ESBL-producing organisms were not identified. At least 10 infants were colonized at some time with an antibiotic-resistant organism, 3 more with pathogens displaying intermediate resistance. Pathogen colonization and resistance were intermittent and inconsistent. Conclusions. In a community-based cohort followed from birth, early antibiotic and daycare exposures are common, especially considering perinatal maternal exposures. Colonization patterns of Gram-negative bacteria, S pneumoniae, S aureus, and resistant pneumococci are strikingly dynamic. Further research can identify key areas for potential interventions to maximize clinical antibiotic outcomes while minimizing future resistance. PMID:27957505

  1. L型菌慢性泌尿系感染诊断及抗生素运用%Diagnosis of L model bacteria in chronic urinary tract infection and antibiotic use

    Institute of Scientific and Technical Information of China (English)

    杨葵

    2012-01-01

    OBJECTIVE To explore L model bacteria in the urinary tract infection situation and the resistance to antibiotics, to provide scientific bases for clinical diagnosis and treatment. METHODS Used improved Kagan culture medium (L model flat) to separate and cultivate urine, which were from the clinical urinary tract infections patients. RESULTS From 128 patients' urine samples, we found that the detection rate of bacteria infection with L model bacteria was 82.8% (106/128), and the rate of ordinary cultivating bacteria was 66.4% (85/128). Among them, the separating rate of bacteria infection with L model bacteria in chronic urinary tract infection of patients was 93.8% (90/96), the rate of L model bacteria was 19.8% (19/96), and the rate of bacteria infection was 74.0% (71/96). CONCLUSION The highest antibiotic resistance is in penicillin class (penicillin G), the followed cephalosporin (ceftriaxone sodium, cefazolin, cefotaxime) , aminoglycoside (gentamicin, amikacin, tobramycin) and erythromycin; while vancomycin, chloromycetin and neomycina are with low antibiotic resistance. In chronic urinary tract infections, patients should also be detected bacteria and L model bacteria, and we should combine using drugs according to antimicrobial susceptibility test, to sterilize and prevent it from transforming to L model.%目的 探讨L型细菌在泌尿系的感染情况及其抗生素的耐药性,为临床诊治提供科学依据.方法 用改良Kagan培养基(L型平板)对临床泌尿系感染者的尿液进行分离培养,并对所获得的L型细菌进行药物敏感试验.结果 从128例患者的尿液标本中,检出L型伴细菌型感染率为82.8% (106/128),普通培养细菌检出率为66.4% (85/128).其中,慢性泌尿系感染L型伴细菌型分离率93.8% (90/96),L型细菌分离率19.8% (19/96),共19株,细菌型分离率为74.0% (71/96).结论 对抗生素而言,耐药性最高的是青霉素类(青霉素G),其次依次为头孢菌素类(头孢三

  2. 中药饮片对多重抗生素耐药细菌的抑菌作用%The bacteriostasis of Chinese medicine in multiple antibiotic-resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    李君华

    2014-01-01

    Objective To analyze and detect the antibacterial effect of Chinese medicine on multiple antibiotic resistant bacteria .Methods Agar dilution method was used to analysis the antimicrobial effect of water decoction of 24 Chinese medicines on multiple antibiotic escherichia coli resistant bacteria and sensitive strain .Results To the most Chinese medicine,there was no significant difference in the inhibitory effect between sensitive strain and resistant bacteria ,except forsythia,cassia seed and licorice.Conclusion Only a little of Chinese medicine was difference in the bacteriostasis as to the sensitive bacteria and drug resistance bacteria .While drug resistance bacteria was more sensitivity than the sensitive bacteria to the traditional Chinese medicine .The Chinese medicine treatment may have a more advantages in the treatment of bacterial infections.%目的:分析检测中药饮片对多重抗生素耐药细菌的抑菌作用。方法选用稀释法,分析检测24种常用中药饮片的水煎液对大肠杆菌的多重抗生素耐药菌种和敏感菌种的抑菌效果。结果大多数中药对敏感菌和耐药菌的抑菌效果没有明显差别,其中只有连翘、决明子和甘草表现出明显的抑菌差别。并且,耐药菌相对于敏感菌来说对中药更为敏感。结论只有少数中药对敏感菌和耐药菌的抑菌效果存在差别,同时耐药菌比敏感菌对中药的敏感度更高,提示中药治疗细菌感染疾病可能会更具优越性。

  3. Antibiotic resistance in Salmonella

    NARCIS (Netherlands)

    Vo, A.T.T.

    2007-01-01

    Immediately after their introduction in the beginning of the fourties of the previous century, the agents used to combat infectious diseases caused by bacteria were regarded with suspicion, but not long thereafter antibiotics had the status of miracle drugs. For decades mankind has lived under the i

  4. Marine echinoderms as reservoirs of antimicrobial resistant bacteria

    Directory of Open Access Journals (Sweden)

    Catarina Marinho

    2014-06-01

    Full Text Available Echinoderms are benthic animals that play an important ecological role in marine communities occupying diverse trophic levels in the marine food chains. The majority of echinoderms feed on small particles of edible matter, although they can eat many kinds of food (Clark, 1968. Although, some echinoderms species has been facing an emerging demand for human consumption, particularly in Asian and Mediterranean cuisine, where these animals can be eaten raw (Kelly, 2005; Micael et al., 2009. Echinoderms own an innate immune mechanism that allows them to defend themselves from high concentrations of bacteria, viruses and fungus they are often exposed, on marine sediment (Janeway and Medzhitov, 1998, Cooper, 2003. The most frequent genera of gut bacteria in echinoderms are Vibrio, Pseudomonas, Flavobacterium, and Aeromonas; nevertheless Enterococcus spp. and Escherichia coli are also present (Harris, 1993; Marinho et al., 2013. Moreover, fecal resistant bacteria found in the aquatic environment might represent an index of marine pollution (Foti et al., 2009, Kummerer, 2009. Several studies had been lead in order to identify environmental reservoirs for antibiotic-resistant bacteria in populations of fish, echinoderms and marine mammals, and they all support the thesis that these animals may serve as reservoirs since they had acquired resistant microbial species (Johnson et al., 1998, Marinho et al., 2013, Miranda and Zemelman, 2001. However, to our knowledge, there are only available in bibliography one study of antimicrobial resistant bacteria isolated from marine echinoderms (Marinho et al., 2013, which stats that their provenience in this environment is still unclear. Antimicrobial resistance outcomes from the intensive use of antimicrobial drugs in human activities associated with various mechanisms for bacteria genetic transfer (Barbosa and Levy, 2000, Coque et al., 2008. Antibiotic-resistant bacteria enter into water environments where they are

  5. Antibiotic Resistance of Bacteria to 6 Antibiotics in Secondary Effluents of Municipal Wastewater Treatment Plants%污水处理厂二级出水中总异养菌群对6种抗生素的耐受性研究

    Institute of Scientific and Technical Information of China (English)

    陆孙琴; 李轶; 黄晶晶; 魏斌; 胡洪营

    2011-01-01

    以北京市2座污水处理厂二级出水为研究对象,通过考察总异养菌群、抗性菌比例、浓度及抗生素对细菌的半抑制浓度,研究了二级出水中一般细菌对青霉素、氨苄青霉素、头孢氨苄、氯霉素、四环素和利福平6种抗生素在不同浓度下的耐受性.结果表明,2座污水处理厂出水中青霉素、氨苄青霉素、头孢氨苄和氯霉素抗性菌比例较四环素和利福平高.当抗生素浓度为32mg.L-1时,污水处理厂G二级出水中头孢氨苄抗性菌比例最高为59%,而污水处理厂Q二级出水中氯霉素抗性菌比例最高为44%.头孢氨苄抗性菌在污水处理厂G、Q出水中的浓度分别高达4.0×103 CFU.mL-1和3.5×104 CFU.mL-1,而氯霉素抗性菌浓度分别高达4.9×102 CFU.mL-1和4.6×104 CFU.mL-1.污水处理厂G中异养菌对头孢氨苄的耐受能力最强,其半抑制浓度〉32 mg.L-1;污水处理厂Q中,异养菌对氯霉素的耐受能力最强,其半抑制浓度为23.1 mg.L-1.污水处理厂二级出水中部分抗生素抗性菌污染严重,且稳定存在于低浓度抗生素的处理出水.%Prevalence of antibiotic-resistant bacteria in wastewater effluents is concerned as an emerging contaminant.To estimate antibiotic resistance in secondary effluents of municipal wastewater treatment plants,antibiotic tolerance of heterotrophic bacteria,proportion of antibiotic-resistant bacteria and hemi-inhibitory concentrations of six antibiotics(penicillin,ampicillin,cefalexin,chloramphenicol,tetracycline and rifampicin) were determined at two wastewater treatment plants(WWTPs)in Beijing.The results showed that proportions of ampicillin-resistant bacteria in WWTP-G and chloramphenicol-resistant bacteria in WWTP-Q were highest to 59% and 44%,respectively.The concentrations of ampicillin-resistant bacteria in the effluents of WWTP-G and WWTP-Q were as high as 4.0×103 CFU·mL-1 and 3.5×104 CFU·mL-1,respectively;the concentrations of chloramphenicol

  6. Effects of environmental conditions on the morphologic change of Pseudomonas aeruginosa and its association with antibiotic resistance in burn patients

    Directory of Open Access Journals (Sweden)

    Mohsen Moghoofei

    2015-12-01

    Full Text Available Introduction: Pseudomonas aeruginosa is an aerobic gram-negative bacteria, which causes hospital infections. Bacteria under stress, such as lack of food, pH and osmotic pressure change and antibiotic stress transforms its morphology to coccoid form. In the bacill form due to changes in the peptidoglycan cell wall, membrane lipids and decreased metabolic activity, bacteria resistant to antibiotics. Due to an increase in mortality in burn patients and important problem of antibiotic resistance in P.aeruginosa the researcher decided to study the factors affecting on morphologic change to coccoid form. Materials and methods: In this study P.aeruginosa strains obtained from clinical samples of burned patients (8 samples were taken from the wound by Infectious Disease Specialist and standard strain ATCC 27853 were used. Samples were confirmed by biochemical tests and PCR by 16srDNA primer. Then bacteria were put under lack of food and antibiotic stress invitro. After that bacterial morphology was examined on different days by digital DP 72-BX 51 microscope to 60 days. After induction coccoid forms, bacterial viability was confirmed by flow cytometry. Results: Bacteria begin to change morphology from 5 days for antibiotic stress and 10 days for other stress. Changing morphology was initially elongate bacilli, U shape and finally the coccoid form was seen. Discussion and conclusion: Changing morphology of bacilli to coccoid bacteria that are the result of stress on the bacteria which enter the body can lead to bacterial resistance to antibiotics and have grave consequences for the patient.

  7. Prescribing antibiotics in general practice:

    DEFF Research Database (Denmark)

    Sydenham, Rikke Vognbjerg; Pedersen, Line Bjørnskov; Plejdrup Hansen, Malene

    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......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...

  8. Antibiotic resistance breakers: can repurposed drugs fill the antibiotic discovery void?

    Science.gov (United States)

    Brown, David

    2015-12-01

    Concern over antibiotic resistance is growing, and new classes of antibiotics, particularly against Gram-negative bacteria, are needed. However, even if the scientific hurdles can be overcome, it could take decades for sufficient numbers of such antibiotics to become available. As an interim solution, antibiotic resistance could be 'broken' by co-administering appropriate non-antibiotic drugs with failing antibiotics. Several marketed drugs that do not currently have antibacterial indications can either directly kill bacteria, reduce the antibiotic minimum inhibitory concentration when used in combination with existing antibiotics and/or modulate host defence through effects on host innate immunity, in particular by altering inflammation and autophagy. This article discusses how such 'antibiotic resistance breakers' could contribute to reducing the antibiotic resistance problem, and analyses a priority list of candidates for further investigation.

  9. Distribution and antibiotic resistance of pathogenic bacteria causing lower respiratory tract infection in ICU%ICU下呼吸道感染病原菌分布与耐药现状分析

    Institute of Scientific and Technical Information of China (English)

    金晓冰; 邓敏; 邹俊宁; 江新姣; 吴艳艳

    2011-01-01

    目的 了解重症监护病房(ICU)患者下呼吸道感染的病原菌分布和耐药谱,为临床治疗提供依据. 方法 入选2008年1月-2009年6月入住ICU下呼吸道感染患者,进行深部痰液病原菌培养,分析病原菌分布情况和耐药性. 结果 革兰阴性杆菌是下呼吸道感染的主要病原菌,占66.9%,以鲍氏不动杆菌占优势,为31.6%;革兰阳性球菌占10.3%,以金黄色葡萄球菌为主,占8.1%;真菌感染占22.8%,除真菌耐药率较低外,其他病原菌均有较高耐药性,多药耐药鲍氏不动杆菌检出率达69.8%. 结论 ICU下呼吸道感染病原菌的菌群分布发生了变化,真菌感染率上升,多药耐药菌增多,临床医师需密切关注分离菌的变迁及耐药情况,合理使用抗菌药物.%OBJECTIVE To investigate the distribution and antibiotic resistance status of pathogenic bacteria from lower respiratory tract in patients of intensive care unit (ICU) in hospital, and provide basis for rational selection of clinical drugs. METHODS Totally 89 cases of lower respiratory infection admitted to the ICU from Jan 2008 to Jun 2009 were reviewed. Pathogens in the sputum were isolated and indenified,and the distribution of pathogenic bactieria and their drug resistance profile were analyzed. RESULTS 66. 9 % of pathogenic bacteria were Gramnegative ones, among which Acinetobater baumannii occupy 31.6 %, 10.3 % were Gram-positive bacteria, Staphylococcus aureus (8. 1 %)was the most prominent bacteria. Fungi accounted for 22.8%. All pathogenic bacteria showed high resistance to the antibiotics but fungi. Multi-drug resistant (MDR) Acinetobater baumannii were test out with 69.8 % occurrence. CONCLUSION The pathogenic bacteria and their resistance to the antibiotic have been changed in ICU. The fungal infection rate is increased and there is an increasing trend in the detection rate of MDR. Clinicians should pay close attention to the changes and resistance of pathogenic bacteria and

  10. Insights into the structure, function and evolution of the radical-SAM 23S rRNA methyltransferase Cfr that confers antibiotic resistance in bacteria

    DEFF Research Database (Denmark)

    Karminska, K. H.; Purta, E.; Hansen, L .H.

    2010-01-01

    The Cfr methyltransferase confers combined resistance to five classes of antibiotics that bind to the peptidyl tranferase center of bacterial ribosomes by catalyzing methylation of the C-8 position of 23S rRNA nucleotide A2503. The same nucleotide is targeted by the housekeeping methyltransferase...... of a 4Fe-4S cluster, a SAM molecule coordinated to the iron-sulfur cluster (SAM1) and a SAM molecule that is the putative methyl group donor (SAM2). All mutations at predicted functional sites affect Cfr activity significantly as assayed by antibiotic susceptibility testing and primer extension analysis...

  11. Impacts of Gut Bacteria on Human Health and Diseases

    Directory of Open Access Journals (Sweden)

    Yu-Jie Zhang

    2015-04-01

    Full Text Available Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by 1014 microbes, ten times more than the human cells. Gut bacteria play an important role in human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function. However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle. Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases.

  12. Synergistic bactericidal effects of low-frequency ultrasound and antibiotics against bacteria%低频超声与抗菌药物协同增效研究进展

    Institute of Scientific and Technical Information of China (English)

    刘旭; 蔡芸; 白艳; 朱亚萍; 王睿

    2013-01-01

    It is difficult to eradicate bacteria completely with single antibiotic because of serious drug resistance. The combination of low-frequency ultrasound technology and antibiotics could enhance the bactericidal or bacteriostatic effect of antibiotics on both planktonic bacteria and bacterial biofilm. The primary mechanism may be cavitation effect. Currently, low-frequency ultrasound technology has been applied to local infection treatment. As a non-invasive and targeted therapy, low-frequency ultrasound technology has great potential use in clinic. In addition, the low-frequency ultrasound technology has advantage on gene transfection and inhibition of bacterial resistance by changing the genes.%  细菌耐药日益严重,单一抗菌药物难以完全杀灭耐药菌。应用低频超声技术联合抗菌药物,无论是对于浮游态菌还是生物被膜态菌,都能增强抗菌药物的杀菌或抑菌作用。其机制主要为空化效应。目前,低频超声技术已探索性应用于人体局部感染治疗中。作为一种可靶向治疗的非侵入性疗法,低频超声具有很大的临床应用潜能。此外,低频超声技术在基因转染上具有优势,并可通过改变基因来影响细菌耐药性。

  13. Progress in the Fight Against Multidrug-Resistant Bacteria? A Review of U.S. Food and Drug Administration-Approved Antibiotics, 2010-2015.

    Science.gov (United States)

    Deak, Dalia; Outterson, Kevin; Powers, John H; Kesselheim, Aaron S

    2016-09-06

    A weak antibiotic pipeline and the increase in drug-resistant pathogens have led to calls for more new antibiotics. Eight new antibiotics were approved by the U.S. Food and Drug Administration (FDA) between January 2010 and December 2015: ceftaroline, fidaxomicin, bedaquiline, dalbavancin, tedizolid, oritavancin, ceftolozane-tazobactam, and ceftazidime-avibactam. This study evaluates the development course and pivotal trials of these antibiotics for their innovativeness, development process, documented patient outcomes, and cost. Data sources were FDA approval packages and databases (January 2010 to December 2015); the Red Book (Truven Health Analytics); Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations (FDA); and supplementary information from company filings, press releases, and media reports. Four antibiotics were approved for acute bacterial skin and skin-structure infection. Seven had similar mechanisms of action to those of previously approved drugs. Six were initially developed by small to midsized companies, and 7 are currently marketed by 1 of 3 large companies. The drugs spent a median of 6.2 years in clinical trials (interquartile range [IQR], 5.4 to 8.8 years) and 8 months in FDA review (IQR, 7.5 to 8 months). The median number of patients enrolled in the pivotal trials was 666 (IQR, 553 to 739 patients; full range, 44 to 1005 patients), and median trial duration was 18 months (IQR, 15 to 22 months). Seven drugs were approved on the basis of pivotal trials evaluating noninferiority. One drug demonstrated superiority on an exploratory secondary end point, 2 showed decreased efficacy in patients with renal insufficiency, and 1 showed increased mortality compared with older drugs. Seven of the drugs are substantially more expensive than their trial comparators. Limitations are that future research may show benefit to patients, new drugs from older classes may show superior effectiveness in specific patient populations, and

  14. 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.

  15. Third generation cephalosporin resistant Enterobacteriaceae and multidrug resistant gram-negative bacteria causing bacteremia in febrile neutropenia adult cancer patients in Lebanon, broad spectrum antibiotics use as a major risk factor, and correlation with poor prognosis

    Directory of Open Access Journals (Sweden)

    Rima eMoghnieh

    2015-02-01

    Full Text Available Bacteremia remains a major cause of life-threatening complications in patients receiving anticancer chemotherapy. The spectrum and susceptibility profiles of causative microorganisms differ with time and place. Data from Lebanon are scarce. We aim at evaluating the epidemiology of bacteremia in cancer patients in a university hospital in Lebanon, emphasizing antibiotic resistance and risk factors of multi-drug resistant organism (MDRO-associated bacteremia.This is a retrospective study of 75 episodes of bacteremia occurring in febrile neutropenic patients admitted to the hematology-oncology unit at Makassed General Hospital, Lebanon, from October 2009-January 2012.It corresponds to epidemiological data on bacteremia episodes in febrile neutropenic cancer patients including antimicrobial resistance and identification of risk factors associated with third generation cephalosporin resistance (3GCR and MDRO-associated bacteremia. Out of 75 bacteremias, 42.7% were gram-positive (GP, and 57.3% were gram-negative (GN. GP bacteremias were mostly due to methicillin-resistant coagulase negative staphylococci (28% of total bacteremias and 66% of GP bacteremias. Among the GN bacteremias, Escherichia coli (22.7% of total, 39.5% of GN organisms and Klebsiellapneumoniae(13.3% of total, 23.3% of GN organisms were the most important causative agents. GN bacteremia due to 3GC sensitive (3GCS bacteria represented 28% of total bacteremias, while 29% were due to 3GCR bacteria and 9% were due to carbapenem-resistant organisms. There was a significant correlation between bacteremia with MDRO and subsequent intubation, sepsis and mortality. Among potential risk factors, only broad spectrum antibiotic intake >4 days before bacteremia was found to be statistically significant for acquisition of 3GCR bacteria. Using carbapenems or piperacillin/ tazobactam>4 days before bacteremia was significantly associated with the emergence of MDRO (p value<0.05.

  16. Bacteriocins - a viable alternative to antibiotics?

    Science.gov (United States)

    Cotter, Paul D; Ross, R Paul; Hill, Colin

    2013-02-01

    Solutions are urgently required for the growing number of infections caused by antibiotic-resistant bacteria. Bacteriocins, which are antimicrobial peptides produced by certain bacteria, might warrant serious consideration as alternatives to traditional antibiotics. These molecules exhibit significant potency against other bacteria (including antibiotic-resistant strains), are stable and can have narrow or broad activity spectra. Bacteriocins can even be produced in situ in the gut by probiotic bacteria to combat intestinal infections. Although the application of specific bacteriocins might be curtailed by the development of resistance, an understanding of the mechanisms by which such resistance could emerge will enable researchers to develop strategies to minimize this potential problem.

  17. Avaliação da resistência a antibióticos de bactérias isoladas de efluente hospitalar = Evaluation of resistance to antibiotics of bacteria isolated from hospital effluents

    Directory of Open Access Journals (Sweden)

    Elenice Tavares Abreu

    2010-01-01

    Full Text Available O uso intensivo de antibióticos está entre as principais causas de resistência bacteriana. O objetivo deste estudo foi investigar se o esgoto do Hospital Universitário Regional de Maringá (HUM apresentava bactérias patogênicas resistentes a antibióticos. Asamostras foram coletadas em dois pontos, um de todo o hospital e outro do Hemocentro. Foram semeados 100 μL nas diluições 10-2, 10-3 e 10-4 nos meios de culturas Ágar Mac Conkey, Ágar Salmonella-Shigella, Ágar Manitol Salgado e Ágar Sabouraud Dextrose. As amostras foram submetidas à identificação bacteriana e ao antibiograma. A identificação bacteriana se baseou na bacterioscopia por coloração de Gram e provas bioquímicas. Os antibiogramas foram feitos de acordo com a metodologia de difusão de disco em Ágar Müeller-Hinton, e foram utilizados 12 antibióticos nesses testes. Foram isoladas eidentificadas 39 amostras, e dentre estas, 18 espécies apresentaram resistência e moderada resistência pelo menos para um dos antibióticos. Bactérias isoladas e identificadas como K. pneumoniae, E.coli, K. pneumoniae, E. cloacae e C. freundii apresentaram resistência para quase todos os antibióticos testados. Verificou-se que o HUM lança, na rede pública coletora de esgoto, bactérias com multirresistência a determinados antibióticos. Portanto, torna-se necessária a implantação de sistema eficiente de tratamento de efluentes no HUM. The massive use of antibiotics is among the leading causes of bacterial resistance. The objective of this study is to investigate whether the sewage of the Maringá Regional University Hospital (HUM has pathogenic bacteria resistant to antibiotics. The samples were collected at two sites, one from the entire hospital and the other from the blood bank. 100 mL were inserted in dilutions of 10-2, 10-3 and 10-4 in cultures Mac Conkey Agar, Salmonella-Shigella Agar, Mannitol Salt Agar and Sabouraud Dextrose Agar. The samples were subjected to

  18. 泡菜中乳酸菌的分离及其发酵液抑菌活性研究%Study on the Isolation of the Lactic Acid Bacteria from Pickled Vegetable and Its Antibiotic Activity

    Institute of Scientific and Technical Information of China (English)

    陈静; 朱强; 朱明

    2011-01-01

    [ Objective ] The reference for the production of the ferment of pure lactic acid bacteria and the improvement of traditional lactic acid fermentation was provided through the research on the isolation of the lactic acid bacteria from pickled vegetable and the formation of its antibiotic material. [ Method] The bacterium for acid formation was isolated from the pickled vegetable by means of the medium of lactic acid isolation and the product was identified based on the experiment in acid formation and morphologic/biochemical character. The antibiotic activity of the supernatant was tested. [ Result] 11 bacterium strains were isolated from pickled vegetable and the experiment in the acid-producing of the strain indicated that the strain: J-4, J-5, J-9 and J-11, was better strain. The preliminary identification of morphologic/biochemical character indicated that 4 bacterium strains belonged to lactic acid bacteria spp. The experiment in antibiotic activity of the supernatant indicated that the four bacterium strains was with stronger antibiotic activity, among which, the strain: J-4, had broad-spectrum antibiotic activity.[ Conclusion] The research could provide the inspiration and reference value of development and application of the fermentation and antibacterial factor of lactic acid bacteria.%[目的]从泡菜中分离筛选优势乳酸菌并时其产抑菌物质进行研究,为生产纯菌乳酸茵发酵剂、改进传统乳酸发酵食品生产提供参考.[方法]利用乳酸菌分离培养基从泡菜中分离产酸菌,并通过产酸试验、形态学及生化特性判断是否为乳酸菌属;取发酵上清液进行抑菌活性研究.[结果]从泡菜中分离获得11株产酸菌,产酸试验表明J-4、J-5、J-9、J-11为优势产酸菌;通过形态学及生化特性,初步鉴定4株产酸菌均为乳酸杆菌属;发酵上清液抑菌试验表明,4株菌均具有较强的抑菌活性,其中,J-4还具有广谱抑菌活性.[结论]研究对于纯种发

  19. Distribution and drug resistance of enteric pathogenic bacteria in Fengtai, Beijing,2010-2012%2010-2012年北京市丰台区感染性腹泻病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    封会茹; 曲梅; 耿荣; 秦萌; 余红; 尉秀霞; 赵伟; 邢洪光; 杨军勇

    2013-01-01

    coli. The time, population and serotype distributions of the pathogens were analyzed by statistical methods. The susceptibility of 140 strains of pathogens to antibiotics was tested by Kirby-Bauer method recommended by US Clinical and Laboratory Standards Institute. Results Totally 357 strains of pathogens were isolated from 1108 specimens (32. 22%). V. parahaemolyticus was predominant, accounting for 50. 98% , followed by Salmonella (18.49% ). The seasonality of the positive detection of pathogens was obvious, the detection rate was high during July-September. The differences in detection rate in different age groups were statistical significant ( P < 0. 05 ). The difference in positive rate of V. parahaemolyticus between males and females was statistical significant (P < 0. 01). The major serotype of V. parahaemolyticus was O3K6, the major serotype of Shigella was Shigella Sonnei and the major serotype of Salmonella were Salmonella Enteritidis and Salmonella senftenberg. The sensitivity of different pathogens to antibiotics varied. Most isolated strains were highly sensitive to cefoxitin, amoxicillin-clavulanic acid and aztreonam. Conclusion V. parahaemolyticus and Salmonella were the main pathogenic bacteria causing infectious diarrhea in Fengtai. The pathogen spectrum had changed. Different pathogenic bacterium had different resistance to antibiotics. The active surveillance of these pathogenic bacteria should be strengthened.

  20. Research Advance of Communicating Molecule of Antibiotic Resistance among Bacteria%细菌间耐药性交换分子的研究进展

    Institute of Scientific and Technical Information of China (English)

    李利山; 王晓敏; 刘燕霏; 杨建德

    2015-01-01

    The continuous increase of antibiotic resistance usually causes failing treatment and brings serious problems to treat microbial infections. It is reviewed some small molecules that mediated inter-cellular communication of antibiotic resistance, in particular involving putrescine, indole and ammonia, and so as to provide references for developing inhibitors to those molecules.%细菌耐药性的不断增强常常引起抗菌素治疗失败,给治疗微生物感染带来严重的问题。本文介绍了一些细菌间耐药性交换的分子,如腐胺、吲哚和氨等,以期为研究细菌间耐药性交换分子的抑制剂提供依据。

  1. Using an Adenosine Triphosphate Bioluminescent Assay to Determine Effective Antibiotic Combinations against Carbapenem-Resistant Gram Negative Bacteria within 24 Hours.

    Directory of Open Access Journals (Sweden)

    Yiying Cai

    Full Text Available Current in vitro combination testing methods involve enumeration by bacterial plating, which is labor-intensive and time-consuming. Measurement of bioluminescence, released when bacterial adenosine triphosphate binds to firefly luciferin-luciferase, has been proposed as a surrogate for bacterial counts. We developed an ATP bioluminescent combination testing assay with a rapid turnaround time of 24h to determine effective antibiotic combinations.100 strains of carbapenem-resistant (CR GNB [30 Acinetobacter baumannii (AB, 30 Pseudomonas aeruginosa (PA and 40 Klebsiella pneumoniae (KP] were used. Bacterial suspensions (105 CFU/ml were added to 96-well plates containing clinically achievable concentrations of multiple single and two-antibiotic combinations. At 24h, the luminescence intensity of each well was measured. Receiver operator characteristic curves were plotted to determine optimal luminescence threshold (TRLU to discriminate between inhibitory/non-inhibitory combinations when compared to viable plating. The unweighted accuracy (UA [(sensitivity + specificity/2] of TRLU values was determined. External validation was further done using 50 additional CR-GNB.Predictive accuracies of TRLU were high for when all antibiotic combinations and species were collectively analyzed (TRLU = 0.81, UA = 89%. When individual thresholds for each species were determined, UA remained high. Predictive accuracy was highest for KP (TRLU = 0.81, UA = 91%, and lowest for AB (TRLU = 0.83, UA = 87%. Upon external validation, high overall accuracy (91% was observed. The assay distinguished inhibitory/non-inhibitory combinations with UA of 80%, 94% and 93% for AB, PA and KP respectively.We developed an assay that is robust at identifying useful combinations with a rapid turn-around time of 24h, and may be employed to guide the timely selection of effective antibiotic combinations.

  2. 具有脉冲加药的双菌株模型的动力学分析%Dynamical Analysis of a Two-Strain Bacteria Model with Impulsive Antibiotic Effect

    Institute of Scientific and Technical Information of China (English)

    闫超; 王稳地; 曾豪; 芶知学

    2016-01-01

    建立了一个考虑脉冲注射抗生素药物的四维双菌株动力学模型,得到了脉冲加药的双菌株模型的基本再生数,证明了无菌平衡点的局部渐近稳定和全局吸引,得到无菌平衡点是全局渐近稳定的。此外,还得到了菌株1、菌株2的一致持续生存条件。%In this paper ,a 4‐dimensional chemostat model of two‐strain bacteria with impulsive antibiotic effect is proposed .By defining the spectral radius of a next infection operator in the periodic system to de‐scribe the basic reproduction number ,the bacteria‐free equilibrium is shown to be globally asymptotically stable by proving that the equilibrium is globally attractive and locally asymptotically stable .Moreover , the conditions of uniform persistence of Bacteria 1 and Bacteria 2 are given .

  3. Certain surfactants significantly enhance the activity of antibiotics in the mouse model of MTB and drug resistant MTB infection and effectively remove the bacteria from a pulmonary cavity in human ex-vivo study.

    Science.gov (United States)

    Risin, Semyon A; Hunter, Robert L; Kobak, Mikhail; Ariel, Boris; Vishnevsky, Boris; Erokhin, Vladislav; Demikhova, Olga; Bocharova, Irina; Stoops, James K

    2014-01-01

    Surfactants have the potential to overcome natural resistance of MTB to antibiotics which is mediated by barriers that impede the penetration of drugs to their targets. A major component of this barrier is trehalose dimycolate (TDM) which surrounds the bacteria with a thick lipid shield. In this study dodecyl maltoside (DDM) was evaluated for this purpose. This surfactant is an excellent cellular permeabilizing agent with associated low toxicity. The administration of the surfactant as an aerosol into the lungs of the infected mice achieved a 5-10 times enhancement of the isoniazid (INH) treatment gauged by the reduction of the colony forming units. This study also established proof of principle that surfactants alone applied as an aerosol can reduce the bacteria count in lungs infected with MTB. The potential of the surfactant in the therapy of human cavitary TB was also investigated using a surgically removed lung from a patient with extreme drug resistant MTB (XDR-TB). A cavity in this lung was flushed with DDM solution ex-vivo. The procedure readily removed the bacteria, excessive amounts of TDM and necrotic tissue from the cavity. These studies demonstrate that DDM can disrupt the layers of TDM and free embedded MTB and, consequently, surfactants have promise as a proficient modality for the treatment of pulmonary MTB.

  4. Avian necrotic enteritis: Experimental models, climate change, and vaccine development

    Science.gov (United States)

    This review summarizes recent developments in disease models, pathogenesis, host immunity, risk factors, and vaccine development for Clostridium perfringens infection of poultry and necrotic enteritis (NE). The increasing trends of legislative restrictions and voluntary removal of antibiotic growth...

  5. How honey kills bacteria

    NARCIS (Netherlands)

    P.H.S. Kwakman; A.A. te Velde; L. de Boer; D. Speijer; C.M.J.E. Vandenbroucke-Grauls; S.A.J. Zaat

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria t

  6. Antibiotics in agroecosystems: Introduction to the special section

    Science.gov (United States)

    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, ...

  7. Reducing Parental Demand for Antibiotics by Promoting Communication Skills

    Science.gov (United States)

    Alder, Stephen C.; Trunnell, Eric P.; White, George L., Jr.; Lyon, Joseph L.; Reading, James P.; Samore, Matthew H.; Magill, Michael K.

    2005-01-01

    Antibiotic-resistant strains of bacteria are continuing to emerge as high rates of antibiotic use persist. Children are among the highest users of antibiotics, with parents influencing physician decision-making regarding antibiotic prescription. An intervention based on Social Cognitive Theory (SCT) to reduce parents' expectations for antibiotics…

  8. Antibiotic resistance of common pathogenic bacteria causing clinical Infection in geriatric department%老年病科患者临床感染细菌耐药性分析

    Institute of Scientific and Technical Information of China (English)

    徐卫刚; 沈瑜; 浦裕美; 徐伟民

    2011-01-01

    OBJECTIVE To analysis the distribution and antibiotic resistance of commom pathogenic bacteria in the patients with Clinical infection in Geriatrics Dept. METHODS An investigation of all bacteriology specimens was carried out in 2009. Microbial sensitivity tests were performed by K-B disk diffusion method and the data was analyzed by WHONET5.4. RESULTS The bacteriology detection rate of patients in Geriatrics Dept was 51.5 %.The top three clinical isolates of Gram-positive cocci were Staphylococcus aureus, Enterococcus faecalis and E.faecium, which were 100.0% sensitive to vancomycin. The top 3 Enterobacteriaceae bacteria were E. coli, Klebsiella pneumoniae and P. aeruginosa. Enterobacteriaceae was most sensitive to imipenem. Cefoperazone/sulbactam, which was inferior to carbapenem, was the most sensitive antibiotic. The detection rates of ESBLsproducing E. col i and K. pneumoniae were 48% and 18. 3%, respectively. The detection rate of MRSA was 62.8%. The drug sensitivity of the antibiotics which were added enzyme inhibitors to E. coli and K. pneumoniae was significantly higher than that without adding. CONCLUSIONS The antibiotic resistance of the pathogenic bacteria is very high in geriatrics department. Cefoperazone/sulbactam and vancomycin are the ideal antibiotics.%目的 探讨老年病科临床感染常见病原菌分布及耐药状况. 方法 对2009年老年病科所有细菌送检标本进行专项分析,药敏采用K-B纸片法,WHONET 5.4软件进行统计. 结果 老年病科患者细菌学检出率低,为51.5%;排在前3位的革兰阳性球菌分别是金黄色葡萄球菌(10.0%)、粪肠球菌(1.9%)、屎肠球菌(1.6%)均对万古霉素100.0%敏感,排在前3位的革兰阴性菌主要为大肠埃希菌(28.8%)、肺炎克雷伯菌(16.6%)、铜绿假单胞菌(16.4%)其对亚胺培南敏感率最高,头孢哌酮/舒巴坦是仅次于碳青霉烯类外最敏感的抗菌药物;产超广谱β-内酰胺酶的大肠埃希菌和肺炎克

  9. Antibacterial activity of plant extracts and phytochemicals on antibiotic-resistant bacteria Atividade de extratos vegetais e fitofármacos sobre bactérias resistentes a antibióticos

    Directory of Open Access Journals (Sweden)

    Gislene G. F. Nascimento

    2000-10-01

    Full Text Available The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant microorganisms. In addition, the possible synergistic effects when associated with antibiotics were studied. Extracts from the following plants were utilized: Achillea millifolium (yarrow, Caryophyllus aromaticus (clove, Melissa offficinalis (lemon-balm, Ocimun basilucum (basil, Psidium guajava (guava, Punica granatum (pomegranate, Rosmarinus officinalis (rosemary, Salvia officinalis (sage, Syzygyum joabolanum (jambolan and Thymus vulgaris (thyme. The phytochemicals benzoic acid, cinnamic acid, eugenol and farnesol were also utilized. The highest antimicrobial potentials were observed for the extracts of Caryophyllus aromaticus and Syzygyum joabolanum, which inhibited 64.2 and 57.1% of the tested microorganisms, respectively, with higher activity against antibiotic-resistant bacteria (83.3%. Sage and yarrow extracts did not present any antimicrobial activity. Association of antibiotics and plant extracts showed synergistic antibacterial activity against antibiotic-resistant bacteria. The results obtained with Pseudomonas aeruginosa was particularly interesting, since it was inhibited by clove, jambolan, pomegranate and thyme extracts. This inhibition was observed with the individual extracts and when they were used in lower concentrations with ineffective antibiotics.Foi avaliada a atividade antimicrobiana de extratos vegetais e fitofármacos frente a microrganismos sensíveis e resistentes a antibióticos, bem como observado o possível efeito sinérgico da associação entre antibióticos e extratos vegetais. Foram utilizados os extratos de plantas cujo nomes populares são: tomilho, alecrim, cravo-da-Índia, jambolão, erva cidreira, romã, goiaba, sálvia, manjericão e mil-folhas, e ainda os fitofármacos, ácido benzóico, ácido cinâmico, eugenol e farnesol. Na avaliação da atividade antimicrobiana através do m

  10. Aminoglycoside-Resistant Bacteria and Rational Selection for Antibiotic-Producing Strain%细菌对氨基糖苷类抗生素的耐药性与抗生素产生菌的推理选育

    Institute of Scientific and Technical Information of China (English)

    陈代杰; 李燕

    2001-01-01

    The mechanisms of aminoglycoside-resistant bacteria including inactive enzymes and ribosome or ribosomal protein modification are briefly reviewed. The rational selection for antibiotic-produ-cing strain according to its resistant mechanisms is also discussed.%简要阐述氨基糖苷类抗生素耐药菌通过产生各种钝化酶来修饰活性分子的耐药机制,以及由抗生素作用靶位核糖体或核蛋白发生改变产生的耐药机制。同时,对抗生素产生菌的耐药机制以及利用这些机制进行抗生素产生菌推理选育也作了介绍。

  11. Etiological study of enteric viruses and bacteria in adult diarrhea in Chongqing area%重庆地区成人感染性腹泻病原学分析

    Institute of Scientific and Technical Information of China (English)

    娄茜; 孙滨; 张再宽; 张秀瑜; 王云英; 黄长武; 陈维贤

    2012-01-01

    目的 研究重庆地区成人感染性腹泻患者的病原学特点.方法 采用MICROSCAN系统进行粪便细菌培养,用ELISA和多重PCR方法进行病毒检测.结果 130例腹泻标本中,检出细菌阳性17例,包括沙门菌属7例,志贺菌属5例,副溶血弧菌3例和嗜水气单胞菌2例.病毒检测中,单重感染30例,双重感染10例,三重感染1例.A组轮状病毒检出率为3.85% (5/130),B轮状病毒检出率为3.85% (5/130),C组轮状病毒检出率为15.4% (20/130),诺如病毒检出率为9.23% (12/130),星状病毒检出率为4.62%(6/130),札如病毒检出率为3.08% (4/130),腺病毒检出率为0.77%(1/130).结论 重庆地区成人腹泻患者中,沙门菌和志贺菌为细菌感染的主要菌种,轮状病毒和诺如病毒为病毒感染的主要病原体.%Objective To study the etiologic characteristics of enteric viruses and bacteria in adult diarrhea in Chongqing area. Methods Bacteria were isolated from feces specimens and indentified by MICROSCAN system. Viruses were detected with ELISA and multiple polymerase chain reactions ( PCR). Results A total of 17 strains of pathogenic bacteria were isolated from 130 specimens, including 7 strains of Salmonella, 5 strains of Shigella, 3 strains of vice Hemolysis vibrio and 2 strains of Aeromonas hydrophilia. Among the virus detection results, the positive rates for Rotavirus A, Rotavirus B, Rotavirus C, Norovirus, Astrovirus, Sapporo like virus and Adenovirus were 3. 85% (5/130) , 3. 85% (5/130) , 15.4% (20/130) , 9.23% (12/130), 4.62% (6/130), 3.08% (4/130) and 0. 77% (1/130), respectively. Conclusion The prevalent pathogens for adult diarrhea in Chongqing area are Salmonella, Shigella, Rotavirus and Norovirus.

  12. 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...

  13. CURRENT ISSUES REGARDING ENDOCRINE DISRUPTING CHEMICALS AND ANTIBIOTIC RESISTANCE

    Science.gov (United States)

    Recently public concern has increased regarding industrial and environmental substances that may have adverse hormonal effects in human and wildlife populations. This concern has also been expanded to include antibiotic-resistant bacteria and the presence of various antibiotics a...

  14. [Action of antibiotics as signalling molecules].

    Science.gov (United States)

    Bulgakova, V G; Vinogradova, K A; Orlova, T I; Kozhevin, P A; Polin, A N

    2014-01-01

    It was thought that antibiotics should be produced by soil microorganisms to inhibit the growth of competitors in natural habitats. Yet it has been shown that antibiotics at subinhibitory concentrations may have a role as signalling molecules providing cell-to-cell communication in bacteria in the environment. Antibiotics modulate gene transcription and regulate gene expression in microbial populations. Subinhibitory concentrations of antibiotics may cause a number of phenotypic and genotypic changes in microorganisms. These transcription changes are dependent on the interaction of antibiotics with macromolecular receptors such as ribosome or RNA-polymerase. Antibiotic signalling and quorum-sensing system are important regulatory mechanisms in bacteria. It was demonstrated that antibiotics interfered with quorum-sensing system.

  15. Analysis of Distribution and Antibiotic Resistance of Pathogenic Bacteria of Blood Cultures in Newborns in Nanjing Area%南京地区新生儿血培养病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    张晓洁; 邱胜丰; 葛高霞; 黎青

    2012-01-01

    目的:了解南京地区新生儿败血症病原菌分布及其耐药情况,为临床合理选择抗生素提供参考.方法:收集2009年1月-2011年9月我院住院新生儿血培养标本1546例,分析其病原菌分布及耐药性.结果:1 546例新生儿血培养标本共检出细菌186株,总阳性率为12.03%,因无临床表现支持而被视为假菌血症者7例,污染率为3.76%(7/186).其中革兰阳性茵129株,占总分离菌的72.07%,革兰阳性菌以凝固酶阴性葡萄球菌为主,占革兰阳性茵的76.74%,占总分离菌的55.31%;革兰阴性菌50株,占总分离菌的27.93%,革兰阴性菌以肺炎克雷伯茵居多,占革兰阴性菌的42.00%,占总分离菌的11.73%.革兰阳性菌对抗生素耐药率最高的为青霉素,其次为红霉素,对万古霉素、哌拉西林/他唑巴坦、阿米卡星以及左氧氟沙星表现了较低的耐药率;革兰阴性菌对抗生素耐药率最高的为氨苄西林,其次为哌拉西林、头孢唑林、氨曲南,对亚胺培南、头孢吡肟、阿米卡星、左氧氟沙星以及加酶抑制剂的复合制剂表现了较低的耐药率.结论:凝固酶阴性葡萄球菌是南京地区近2年新生儿败血症最常见的病原菌,其次为肺炎克雷伯菌,对常用抗生素均有不同程度的耐药.%OBJECTIVE: To investigate distribution and antibiotic resistance of pathogens causing neonatal septicemia and to provide evidence for reasonable use of antibiotics in clinic in Nanjing area. METHODS: 1546 neonatal blood samples were collect-ed from our hospital during Jan. 2009 -Sept. 2011. The distribution and antibiotic resistance of pathogens causing neonatal septice-mia were analyzed. RESULTS: 186 pathogenic strains were isolated from 1546 specimens and the positive rate was 12.03%. 7 cas-es were considered as false bacteremia due to non-clinical support, in which contamination rate was 3.76% (7/186). Among them, 129 strains were Gram-positive bacteria (72.07% ) , and the

  16. How to Manage Infections Caused by Antibiotic Resistant Gram-negative Bacteria - EBMT Educational Meeting from the Severe Aplastic Anaemia and Infectious Diseases Working Parties, Naples, Italy, 2014.

    Science.gov (United States)

    Mikulska, Małgorzata

    2015-02-23

    Multidrug resistant (MDR) Gram-negative bacteria are increasingly frequent in hematopoietic stem cell transplant (HSCT) recipients, yet their prevalence is highly variable among transplant centres. Thus, the knowledge of local epidemiology is mandatory for deciding the most appropriate management protocols. Empirical therapy of febrile neutropenia should be individualized. Either escalation or de-escalation strategy could be chosen, based on local epidemiology, individual risk factors for infection due to resistant strains, such as previous infection or colonization with a resistant pathogen, and clinical presentation. De-escalation approach is recommended in case of severe clinical presentation in patients who are at high risk of drug-resistant infection. Targeted therapy of MDR Gram-negatives, in particular carbapenem-resistant strains, calls for a combination treatment, usually including colistin. No large randomized trials exist in this setting. Local epidemiology dictates which resistant bacteria should be routinely screened for, and infection control precautions are mandatory to limit the spread of resistant strains. Antimicrobial stewardship, with the aim of the best possible management of bacterial infections, should be put in place in every transplant centre. In conclusion, infections caused by resistant Gram-negative bacteria in HSCT population warrant currently particular attention in order to limit their negative impact on transplant outcomes.

  17. 尿路感染的病原菌及其药敏分析%Pathogenic Bacteria and Their Antibiotic Susceptibility Analysis of Urinary Tract Infection

    Institute of Scientific and Technical Information of China (English)

    肖洁; 黄泳璋

    2012-01-01

    目的:分析不同年龄组尿路感染的细菌病原学分布及耐药状况,为临床合理使用抗生素提供依据.方法:回顾性分析2010 年1月至2010 年12 月本院门、急诊和住院部送检的中段尿标本培养及药敏结果,并根据年龄不同分为小儿组(6 个月~13 岁),成人组(14 岁~64 岁)和老年组(65 岁以上).结果:中段尿培养阳性标本570 例,其中革兰阴性杆菌感染占82.11%(468/570),革兰阳性球菌占17.89%(102/570).成人组和老年组中大肠埃希菌和克雷伯菌的比例与小儿组相似(P>0.05); 而小儿组的铜绿假单胞菌的比例显著高于成人组和老年组(P or =65 years old).Results:Gram negative bacterial accounted for 82.11%, Gram positive bacterial for 17.89%. Escherichia coli and Klebsiella pneumoniae were the common bacterial in adults and seniors and in children, while P.aeruginosa was more common in children. Imipenem showed the best activity against most gram negative bacterial .followed by Cefoperazone+Sulbactam. The most susceptible antibiotic for Gram positive bacterial was vancomycin, followed by imipenem. Almost all gram negative bacterial showed resistant to ampicillin and most of gram positive bacterial were resistant to Erythrocin.Conclusion:Gram negative bacterial are the most common pathogenic organisms in urinary tract infection in this study. But the proportion of pathogenic agents is different among different age groups. The antibiotics resistance is severe. So, bacterial culture of urine should be examined before initiation antibiotics treatment for urinary tract infection.

  18. Resistance to antibiotics in Gram-negative bacteria isolated from broiler carcasses Resistência a antibióticos em bactérias Gram-negativas isoladas de carcaças de frangos

    Directory of Open Access Journals (Sweden)

    M.A.S. Moreira

    2002-02-01

    Full Text Available One hundred and ninety-seven isolates of Gram-negative bacteria, comprising 10 genera, were isolated from poultry carcasses at a processing plant in order to investigate resistance to low levels of antibiotics. The samples were taken just after evisceration and before inspection. Most of the isolates were of Samonella and Escherichia. Other genera present were Enterobacter, Serratia, Klebsiella, Kluyvera, Erwinia, Citrobacter, Pseudomonas and Aeromonas. Distinct profiles of antibiotic resistance were detected. Resistance to more than two antibiotics predominated and spanned several classes of antibiotics. Salmonellae and escherichiae were mainly resistant to the aminoglycosides, followed by tetracycline, nitrofuran, sulpha, macrolide, chloramphenicol, quinolones and beta-lactams. Most isolates were sensitive to 30mug/ml olaquindox, the growth promoter in use at the time of sampling. However, many were resistant to a level of 10mug/ml and 13mug/ml olaquindox, levels present in the gut due to the dilution in the feed. The results suggest a possible role of low level administration of antibiotics to broilers in selecting multi-resistant bacteria in vivo.Para verificar a resistência a baixos níveis de antibióticos foram obtidos e identificados 197 isolados de bactérias Gram negativas pertencentes a 10 gêneros. Os isolados foram coletados em abatedouro industrial, imediatamente após a evisceração e antes do serviço de inspeção. Salmonella e Escherichia foram os gêneros identificados com maior freqüência. Os demais gêneros foram Aeromonas, Enterobacter, Serratia, Klebsiella, Citrobacter, Erwinia, Kluyvera, Pseudomonas e Aeromonas. Diferentes perfis de resistência a antibióticos foram detectados. A resistência a mais de dois antibióticos foi freqüente na maioria dos isolados e incluiu diversas classes de antibióticos. As bactérias dos gêneros Salmonella e Escherichia apresentaram maior percentagem de isolados resistentes

  19. [THE ROLE OF (p)ppGpp MOLECULES IN FORMATION OF "STRICT RESPONSE" IN BACTERIA AND BIOSYNTHESIS OF ANTIBIOTICS AND MORPHOLOGICAL DIFFERENTIATION IN ACTINOMYCETES].

    Science.gov (United States)

    Klymyshin, D; Stephanyshyn, O; Fedorenko, V

    2016-01-01

    Strict response is a pleiotropic physiological response of cells caused by lack of aminoacetylated tRNAs. Experimentally, this response occurs due to the lack of amino acids in the environment and the limitation of tRNA aminoacylation even in the presence of the corresponding amino acids in the cell. Many features of this response indicate its dependence on the accumulation of ppGpp molecules. There is a correlation between the growth rate of actinomycetes and biosynthesis of their secondary metabolites. Introduction of additional relA gene copies of ppGpp synthetase can affect the production of antibiotics in streptomycetes. The article presents the authors' own experimental data, dedicated to the influence of heterologous relA gene expression in Streptomyces nogalater cells.

  20. Clinical, serological, microbiological, and outcome study of 200 cases of short duration fever without prior exposure to