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Sample records for antibiotics enter bacteria

  1. 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

    enterococci, the wastewater is very strong, suggesting a potential hygienic risk. In addition, a high fraction of antibiotic resistant bacteria and an increased toxicity in the sub-stream from the hospital, suggest that this stream contains toxic compounds, possibly antibiotic of nature that may affect the...... the presence of Total coliforms, Escherichia coli (Ecoli), enterococci, streptococci, antibiotic resistant enteric bacteria, and toxicity in sewage from two sewer outlets in Sisimiut, West-Greenland, as well as in a sub-stream from the local hospital. According to the content of streptococci and...... local Arctic 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...

  2. Incidence and transferability of antibiotic resistance in the enteric bacteria isolated from hospital wastewater

    Directory of Open Access Journals (Sweden)

    Mohammad Zubair Alam

    2013-09-01

    Full Text Available This study reports the occurrence of antibiotic resistance and production of β-lactamases including extended spectrum beta-lactamases (ESβL in enteric bacteria isolated from hospital wastewater. Among sixty-nine isolates, tested for antibiotic sensitivity, 73.9% strains were resistant to ampicillin followed by nalidixic acid (72.5%, penicillin (63.8%, co-trimoxazole (55.1%, norfloxacin (53.6%, methicillin (52.7%, cefuroxime (39.1%, cefotaxime (23.2% and cefixime (20.3%. Resistance to streptomycin, chloramphenicol, nitrofurantoin, tetracycline, and doxycycline was recorded in less than 13% of the strains. The minimum inhibitory concentration (MIC showed a high level of resistance (800-1600 µg/mL to one or more antibiotics. Sixty three (91% isolates produced β-lactamases as determined by rapid iodometric test. Multiple antibiotic resistances were noted in both among ESβL and non-ESβL producers. The β-lactamases hydrolyzed multiple substrates including penicillin (78.8% isolates, ampicillin (62.3%, cefodroxil (52.2%, cefotoxime (21.7% and cefuroxime (18.8%. Fifteen isolates producing ESβLs were found multidrug resistant. Four ESβL producing isolates could transfer their R-plasmid to the recipient strain E. coli K-12 with conjugation frequency ranging from 7.0 x 10-3 to 8.8 x 10-4. The findings indicated that ESβL producing enteric bacteria are common in the waste water. Such isolates may disseminate the multiple antibiotic resistance traits among bacterial community through genetic exchange mechanisms and thus requires immediate attention.

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

    Science.gov (United States)

    Casey, Christine L; Hernandez, Sonia M; Yabsley, Michael J; Smith, Katherine F; Sanchez, Susan

    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

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Science.gov (United States)

    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

  7. Acid resistance in enteric bacteria.

    OpenAIRE

    Gorden, J; Small, P L

    1993-01-01

    Shigella species require a uniquely small inoculum for causing dysentery. One explanation for the low infective dose is that Shigella species are better able to survive the acidic conditions encountered in the stomach than are other enteric pathogens. We have tested Shigella species, Escherichia coli, and Salmonella species for the ability to survive at pH 2.5 for at least 2 h. Most isolates of Shigella and E. coli survived this treatment, whereas none of the Salmonella isolates were able to ...

  8. Antibiotics and antibiotic-resistant bacteria in waters associated with a hospital in Ujjain, India

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    Marothi Yogyata

    2010-07-01

    Full Text Available Abstract Background Concerns have been raised about the public health implications of the presence of antibiotic residues in the aquatic environment and their effect on the development of bacterial resistance. While there is information on antibiotic residue levels in hospital effluent from some other countries, information on antibiotic residue levels in effluent from Indian hospitals is not available. Also, concurrent studies on antibiotic prescription quantity in a hospital and antibiotic residue levels and resistant bacteria in the effluent of the same hospital are few. Therefore, we quantified antibiotic residues in waters associated with a hospital in India and assessed their association, if any, with quantities of antibiotic prescribed in the hospital and the susceptibility of Escherichia coli found in the hospital effluent. Methods This cross-sectional study was conducted in a teaching hospital outside the city of Ujjain in India. Seven antibiotics - amoxicillin, ceftriaxone, amikacin, ofloxacin, ciprofloxacin, norfloxacin and levofloxacin - were selected. Prescribed quantities were obtained from hospital records. The samples of the hospital associated water were analysed for the above mentioned antibiotics using well developed and validated liquid chromatography/tandem mass spectrometry technique after selectively isolating the analytes from the matrix using solid phase extraction. Escherichia coli isolates from these waters were tested for antibiotic susceptibility, by standard Kirby Bauer disc diffusion method using Clinical and Laboratory Standard Institute breakpoints. Results Ciprofloxacin was the highest prescribed antibiotic in the hospital and its residue levels in the hospital wastewater were also the highest. In samples of the municipal water supply and the groundwater, no antibiotics were detected. There was a positive correlation between the quantity of antibiotics prescribed in the hospital and antibiotic residue levels in

  9. Antibiotic-Resistant Bacteria Detected in Sewage Spill

    Science.gov (United States)

    ... 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 ...

  10. Growth of bacteria in enteral feeding solutions.

    Science.gov (United States)

    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. PMID:3927003

  11. Alternatives to Antibiotics to Prevent Necrotic Enteritis in Broiler Chickens: A Microbiologist's Perspective.

    Science.gov (United States)

    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 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. PMID:26648920

  12. Antibiotic-resistant bacteria in wild primates: increased prevalence in baboons feeding on human refuse.

    OpenAIRE

    Rolland, R M; Hausfater, G; Marshall, B.; Levy, S B

    1985-01-01

    We examined three groups of wild baboons (Papio cynocephalus) in Amboseli National Park, Kenya, to determine the prevalence of aerobic antibiotic-resistant fecal bacteria in nonhuman primates with and without contact with human refuse. Using standard isolation and replica plating techniques, we found only low numbers of antibiotic-resistant gram-negative enteric bacteria in two groups of baboons leading an undisturbed existence in their natural habitat and having limited or no contact with hu...

  13. 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.

  14. 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.

  15. Transfer of antibiotic resistant bacteria from animals to man

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar; Aarestrup, Frank Møller; Gerner-Smidt, P.; Bager, Flemming

    Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used ...

  16. 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.

  17. Antibiotic resistance of lactic acid bacteria

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    Bulajić Snežana

    2008-01-01

    Full Text Available Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolates. Also, the choice of media is problematic, as well as the specification of MIC breakpoint values as a result of the large species variation and the possible resulting variation in MIC values between species and genera. The current investigations in this field showed that we might end up with a range of different species- or genus-specific breakpoint values that may further increase the current complexity. Another problem associated with safety determinations of starter strains is that once a resistance phenotype and an associated resistance determinant have been identified, it becomes difficult to show that this determinant is not transferable, especially if the resistance gene is not located on a plasmid and no standard protocols for showing genetic transfer are available. Encountering those problems, the QPS system should allow leeway for the interpretations of results, especially when these relate to the methodology for resistance phenotype determinations, determinations of MIC breakpoints for certain genera, species, or strains, the nondeterminability of a genetic basis of a resistance phenotype and the transferability of resistance genes.

  18. [Antibiotic resistance of bacteria to 6 antibiotics in secondary effluents of municipal wastewater treatment plants].

    Science.gov (United States)

    Lu, Sun-Qin; Li, Yi; Huang, Jing-Jing; Wei, Bin; Hu, Hong-Ying

    2011-11-01

    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 x 10(3) CFU x mL(-1) and 3.5 x 10(4) CFU x mL(-1), respectively; the concentrations of chloramphenicol-resistant bacteria were 4.9 x 10(2) CFU x mL(-1) and 4.6 x 10(4) CFU x mL(-1), respectively. The data also indicated that the hemi-inhibitory concentrations of heterotrophic bacteria to 6 antibiotics were much higher than common concentrations of antibiotics in sewages, which suggested that antibiotic-resistant bacteria could exist over a long period in the effluents with low concentrations of antibiotics. Antibiotic-resistant bacteria could be a potential microbial risk during sewage effluent reuse or emission into environmental waters. PMID:22295644

  19. 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.

  20. Characterization of antibiotic-resistant bacteria in rendered animal products.

    Science.gov (United States)

    Hofacre, C L; White, D G; Maurer, J J; Morales, C; Lobsinger, C; Hudson, C

    2001-01-01

    Antibiotics are used in food animal production to treat diseases and also to improve performance. Antibiotics are not used on all farms, and antibiotic resistance is occasionally found on farms that do not use antibiotics. Rendered animal protein products are often included in poultry feeds and could potentially serve as a source of antibiotic-resistant bacteria. One hundred sixty-five rendered animal protein products from cattle, poultry, and fish were aseptically collected from poultry feed mills. Fifty-five percent of the poultry meal samples had detectable levels of gram-negative bacteria ranging from 40 to 10,440 colony-forming units/g of sample. Poultry meal and meat and bone meal had the greatest number of samples with bacteria resistant to five or more antibiotics. A high percentage of feed samples (85%) contained bacteria resistant to amoxicillin, ampicillin, clavulanic acid, or cephalothin, whereas few samples contained bacteria resistant to ciprofloxacin, kanamycin, or trimethoprim/sulfamethoxazole. Acinetobacter calcoaceticus, Citrobacter freundii, and Enterobacter cloacae were the most commonly isolated antibiotic-resistant bacteria. Isolation for Salmonella was also performed, with 14% of the meat and bone meal samples containing Salmonella sp. Only one of the meat and bone meal isolates, Salmonella livingstone, was resistant to five or more antibiotics. Many of the antibiotic-resistant bacteria contained integrons, genetic elements that mediate multiple drug resistance. PMID:11785899

  1. 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. PMID:26494365

  2. Antibiotic resistance in food lactic acid bacteria--a review.

    Science.gov (United States)

    Mathur, Shalini; Singh, Rameshwar

    2005-12-15

    Antibiotics are a major tool utilized by the health care industry to fight bacterial infections; however, bacteria are highly adaptable creatures and are capable of developing resistance to antibiotics. Consequently, decades of antibiotic use, or rather misuse, have resulted in bacterial resistance to many modern antibiotics. This antibiotic resistance can cause significant danger and suffering for many people with common bacterial infections, those once easily treated with antibiotics. For several decades studies on selection and dissemination of antibiotic resistance have focused mainly on clinically relevant species. However, recently many investigators have speculated that commensal bacteria including lactic acid bacteria (LAB) may act as reservoirs of antibiotic resistance genes similar to those found in human pathogens. The main threat associated with these bacteria is that they can transfer resistance genes to pathogenic bacteria. Genes conferring resistance to tetracycline, erythromycin and vancomycin have been detected and characterized in Lactococcus lactis, Enterococci and, recently, in Lactobacillus species isolated from fermented meat and milk products. A number of initiatives have been recently launched by various organizations across the globe to address the biosafety concerns of starter cultures and probiotic microorganisms. The studies can lead to better understanding of the role played by the dairy starter microorganisms in horizontal transfer of antibiotic resistance genes to intestinal microorganisms and food-associated pathogenic bacteria. PMID:16289406

  3. 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. PMID:27507962

  4. Epigenetic regulation of enteric neurotransmission by gut bacteria.

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    Tor eSavidge

    2016-01-01

    Full Text Available The Human Microbiome Project defined microbial community interactions with the human host, and provided important molecular insight into how epigenetic factors can influence intestinal ecosystems. Given physiological context, changes in gut microbial community structure are increasingly found to associate with alterations in enteric neurotransmission and disease. At present, it is not known whether shifts in microbial community dynamics represent cause or consequence of disease pathogenesis. The discovery of bacterial-derived neurotransmitters suggests further studies are needed to establish their role in enteric neuropathy. This mini-review highlights recent advances in bacterial communications to the autonomic nervous system and discusses emerging epigenetic data showing that diet, probiotic and antibiotic use may regulate enteric neurotransmission through modulation of microbial communities. Because of its limited scope, a particular emphasis is placed on bacterial regulation of enteric nervous system function in the intestine.

  5. Epigenetic Regulation of Enteric Neurotransmission by Gut Bacteria.

    Science.gov (United States)

    Savidge, Tor C

    2015-01-01

    The Human Microbiome Project defined microbial community interactions with the human host, and provided important molecular insight into how epigenetic factors can influence intestinal ecosystems. Given physiological context, changes in gut microbial community structure are increasingly found to associate with alterations in enteric neurotransmission and disease. At present, it is not known whether shifts in microbial community dynamics represent cause or consequence of disease pathogenesis. The discovery of bacterial-derived neurotransmitters suggests further studies are needed to establish their role in enteric neuropathy. This mini-review highlights recent advances in bacterial communications to the autonomic nervous system and discusses emerging epigenetic data showing that diet, probiotic and antibiotic use may regulate enteric neurotransmission through modulation of microbial communities. A particular emphasis is placed on bacterial metabolite regulation of enteric nervous system function in the intestine. PMID:26778967

  6. Antimicrobial effect of Malaysian vegetables against enteric bacteria

    OpenAIRE

    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...

  7. Probing minority population of antibiotic-resistant bacteria.

    Science.gov (United States)

    Huang, Tianxun; Zheng, Yan; Yan, Ya; Yang, Lingling; Yao, Yihui; Zheng, Jiaxin; Wu, Lina; Wang, Xu; Chen, Yuqing; Xing, Jinchun; Yan, Xiaomei

    2016-06-15

    The evolution and spread of antibiotic-resistant pathogens has become a major threat to public health. Advanced tools are urgently needed to quickly diagnose antibiotic-resistant infections to initiate appropriate treatment. Here we report the development of a highly sensitive flow cytometric method to probe minority population of antibiotic-resistant bacteria via single cell detection. Monoclonal antibody against TEM-1 β-lactamase and Alexa Fluor 488-conjugated secondary antibody were used to selectively label resistant bacteria green, and nucleic acid dye SYTO 62 was used to stain all the bacteria red. A laboratory-built high sensitivity flow cytometer (HSFCM) was applied to simultaneously detect the side scatter and dual-color fluorescence signals of single bacteria. By using E. coli JM109/pUC19 and E. coli JM109 as the model systems for antibiotic-resistant and antibiotic-susceptible bacteria, respectively, as low as 0.1% of antibiotic-resistant bacteria were accurately quantified. By monitoring the dynamic population change of a bacterial culture with the administration of antibiotics, we confirmed that under the antimicrobial pressure, the original low population of antibiotic-resistant bacteria outcompeted susceptible strains and became the dominant population after 5hours of growth. Detection of antibiotic-resistant infection in clinical urine samples was achieved without cultivation, and the bacterial load of susceptible and resistant strains can be faithfully quantified. Overall, the HSFCM-based quantitative method provides a powerful tool for the fundamental studies of antibiotic resistance and holds the potential to provide rapid and precise guidance in clinical therapies. PMID:26852201

  8. 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 ...

  9. Plasmid Mediated Antibiotic Resistance in Isolated Bacteria From Burned Patients

    OpenAIRE

    Beige, Fahimeh; Baseri Salehi, Majid; Bahador, Nima; Mobasherzadeh, Sina

    2014-01-01

    Background: Nowadays, the treatment of burned patients is difficult because of the high frequency of infection with antibiotic resistance bacteria. Objectives: This study was conducted to evaluate the level of antibiotic resistance in Gram-negative bacteria and its relation with the existence of plasmid. Materials and Methods: The samples were collected from two hundred twenty hospitalized burned patients in Isfahan burn hospital during a three-month period (March 2012 to June 2012). The samp...

  10. 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

    . coli (EHEC). 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...

  11. Plasmid encoded antibiotic resistance: acquisition and transfer of antibiotic resistance genes in bacteria.

    Science.gov (United States)

    Bennett, P M

    2008-03-01

    Bacteria have existed on Earth for three billion years or so and have become adept at protecting themselves against toxic chemicals. Antibiotics have been in clinical use for a little more than 6 decades. That antibiotic resistance is now a major clinical problem all over the world attests to the success and speed of bacterial adaptation. Mechanisms of antibiotic resistance in bacteria are varied and include target protection, target substitution, antibiotic detoxification and block of intracellular antibiotic accumulation. Acquisition of genes needed to elaborate the various mechanisms is greatly aided by a variety of promiscuous gene transfer systems, such as bacterial conjugative plasmids, transposable elements and integron systems, that move genes from one DNA system to another and from one bacterial cell to another, not necessarily one related to the gene donor. Bacterial plasmids serve as the scaffold on which are assembled arrays of antibiotic resistance genes, by transposition (transposable elements and ISCR mediated transposition) and site-specific recombination mechanisms (integron gene cassettes).The evidence suggests that antibiotic resistance genes in human bacterial pathogens originate from a multitude of bacterial sources, indicating that the genomes of all bacteria can be considered as a single global gene pool into which most, if not all, bacteria can dip for genes necessary for survival. In terms of antibiotic resistance, plasmids serve a central role, as the vehicles for resistance gene capture and their subsequent dissemination. These various aspects of bacterial resistance to antibiotics will be explored in this presentation. PMID:18193080

  12. Antibiotic concentration and antibiotic-resistant bacteria in two shallow urban lakes after stormwater event.

    Science.gov (United States)

    Zhang, Songhe; Pang, Si; Wang, PeiFang; Wang, Chao; Han, Nini; Liu, Bin; Han, Bing; Li, Yi; Anim-Larbi, Kwaku

    2016-05-01

    Stormwater runoff is generally characterized as non-point source pollution. In the present study, antibiotic concentration and antibiotic susceptibilities of cultivable heterotrophic bacteria were investigated in two small shallow urban lakes before and after strong storm event. Several antibiotics, lactose-fermenting bacteria and cultivable heterotrophic bacteria concentrations increased in surface water and/or surface sediment of two small urban lakes (Lake Xuanwu and Wulongtan) after strong storm event. In general, the frequencies of bacteria showing resistance to nine antibiotics increased after storm event. Based on the 16S rRNA genes of 50 randomly selected isolates from each water sample of two lakes, Aeromonas and Bacillus were dominant genera in samples from two lakes, while genera Proteus and Lysinibacillus were the third abundant genera in Lake Xuanwu and Wulongtu, respectively. Presences of nine antibiotic resistance genes (ARGs) in the 100 isolates were detected and most of these isolates harbored at least two ARGs with different functions. The detection frequency of ARGs in Gram-negative isolates was higher than that in Gram-positive isolates. The most prevalent integron in 100 isolates was int(II) (n = 28), followed by int(I) (n = 17) and int(III) (n = 17). Our results indicate that strong storm events potentially contribute to the transfer of ARGs and antibiotic-resistant bacteria from land-sewer system to the urban Lakes. PMID:26865482

  13. 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

  14. Rifaximin: A Unique Gastrointestinal-Selective Antibiotic for Enteric Diseases

    Science.gov (United States)

    Koo, Hoonmo L.; DuPont, Herbert L.

    2014-01-01

    Purpose of review Rifaximin is gaining attention for its potential activity in a multitude of gastrointestinal diseases. We review the unique pharmaceutical properties of this antibiotic and the published evidence in the literature regarding the use of rifaximin for different gastrointestinal disorders. Recent findings Rifaximin is a gastrointestinal-selective antibiotic with a broad spectrum of antimicrobial activity, an excellent safety profile, minimal drug interactions, and negligible impact on the intestinal microbiome. Rifaximin is currently approved in the United States for the treatment of travelers’ diarrhea caused by noninvasive diarrheagenic Escherichia coli and is approved in more than 30 other countries for a variety of gastrointestinal disorders. Considerable research with this medication has been conducted for the treatment and prevention of travelers’ diarrhea, the treatment of portal systemic encephalopathy, Clostridium difficile infection, small bowel intestinal overgrowth, irritable bowel syndrome, inflammatory bowel disease, pouchitis, and colonic diverticular disease. Summary Rifaximin is effective for the treatment of travelers’ diarrhea and can be considered as the treatment of choice for uncomplicated travelers’ diarrhea. When invasive travelers’ diarrhea pathogens are suspected, an alternative antibiotic should be administered. Rifaximin appears promising as a chemoprophylaxis for travelers’ diarrhea and as a treatment of portal systemic encephalopathy. This antibiotic may be effective for other gastrointestinal diseases, but more well-designed clinical studies are needed to confirm its efficacy for these off-label indications. Future studies will determine whether the development of significant bacterial resistance will limit rifaximin use. PMID:19881343

  15. Plasmid-Encoded Multidrug Resistance of Salmonella typhi and some Enteric Bacteria in and around Kolkata, India: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Nishith Kumar Pal

    2005-02-01

    Full Text Available The present study investigates the occurrence of R-plasmid in Salmonella typhi isolates from enteric fever cases in and around Kolkata (1991-2001, India following in vitro conjugation experiments, isolation of plasmid DNAs and agarose gel electrophoretic analysis. The multidrug resistant (MDR S. typhi strains contained a transferable plasmid conferring resistance to ampicillin, chloramphenicol, cotrimoxazole and tetracycline. The plasmid encoding ACCoT-resistance of Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were conjugative and co-migrated with the plasmid of MDR S. typhi isolates. The antibiotic sensitive S. typhi isolates did not contain any plasmid. Thus the findings of the present study confirmed the instability of the R-plasmid in S. typhi, and that the antibiotic sensitive S. typhi strains acquired the R-plasmid from other enteric bacteria such as E. coli, K. pneumoniae and P.vulgaris to undergo a suitable adaptation for survival in the changing antibiotic environment.

  16. Metagenomic Insights into Transferable Antibiotic Resistance in Oral Bacteria.

    Science.gov (United States)

    Sukumar, S; Roberts, A P; Martin, F E; Adler, C J

    2016-08-01

    Antibiotic resistance is considered one of the greatest threats to global public health. Resistance is often conferred by the presence of antibiotic resistance genes (ARGs), which are readily found in the oral microbiome. In-depth genetic analyses of the oral microbiome through metagenomic techniques reveal a broad distribution of ARGs (including novel ARGs) in individuals not recently exposed to antibiotics, including humans in isolated indigenous populations. This has resulted in a paradigm shift from focusing on the carriage of antibiotic resistance in pathogenic bacteria to a broader concept of an oral resistome, which includes all resistance genes in the microbiome. Metagenomics is beginning to demonstrate the role of the oral resistome and horizontal gene transfer within and between commensals in the absence of selective pressure, such as an antibiotic. At the chairside, metagenomic data reinforce our need to adhere to current antibiotic guidelines to minimize the spread of resistance, as such data reveal the extent of ARGs without exposure to antimicrobials and the ecologic changes created in the oral microbiome by even a single dose of antibiotics. The aim of this review is to discuss the role of metagenomics in the investigation of the oral resistome, including the transmission of antibiotic resistance in the oral microbiome. Future perspectives, including clinical implications of the findings from metagenomic investigations of oral ARGs, are also considered. PMID:27183895

  17. 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. PMID:24637595

  18. ANTIBIOTIC RESISTANT BACTERIA FROM HALIOTIS TUBERCULATA AND MYTILUS GALLOPROVINCIALIS

    OpenAIRE

    F. Conte; Longo, S.; Malaspina, A.

    2009-01-01

    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.

  19. Antibiotic resistome of bacteria isolated from bat guano

    Czech Academy of Sciences Publication Activity Database

    Volná, Lucie; Kyselková, Martina; Chroňáková, Alica; Petrásek, Jiří; Jirout, Jiří; Elhottová, Dana

    Košice : Pavol Jozef Šafárik University in Košice, 2012. s. 111-112. [International Conference on Subterranean Biology /21./. 02.09.2012-07.09.2012, Košice] Institutional support: RVO:60077344 Keywords : antibiotic resistome * bacteria * bat guano Subject RIV: EH - Ecology, Behaviour

  20. Combination of essential oils and antibiotics reduce antibiotic resistance in plasmid-conferred multidrug resistant bacteria.

    Science.gov (United States)

    Yap, Polly Soo Xi; Lim, Swee Hua Erin; Hu, Cai Ping; Yiap, Beow Chin

    2013-06-15

    In this study we investigated the relationship between several selected commercially available essential oils and beta-lactam antibiotics on their antibacterial effect against multidrug resistant bacteria. The antibacterial activity of essential oils and antibiotics was assessed using broth microdilution. The combined effects between essential oils of cinnamon bark, lavender, marjoram, tea tree, peppermint and ampicillin, piperacillin, cefazolin, cefuroxime, carbenicillin, ceftazidime, meropenem, were evaluated by means of the checkerboard method against beta-lactamase-producing Escherichia coli. In the latter assays, fractional inhibitory concentration (FIC) values were calculated to characterize interaction between the combinations. Substantial susceptibility of the bacteria toward natural antibiotics and a considerable reduction in the minimum inhibitory concentrations (MIC) of the antibiotics were noted in some paired combinations of antibiotics and essential oils. Out of 35 antibiotic-essential oil pairs tested, four of them showed synergistic effect (FIC≤0.5) and 31 pairs showed no interaction (FIC>0.5-4.0). The preliminary results obtained highlighted the occurrence of a pronounced synergistic relationship between piperacillin/cinnamon bark oil, piperacillin/lavender oil, piperacillin/peppermint oil as well as meropenem/peppermint oil against two of the three bacteria under study with a FIC index in the range 0.26-0.5. The finding highlighted the potential of peppermint, cinnamon bark and lavender essential oils being as antibiotic resistance modifying agent. Reduced usage of antibiotics could be employed as a treatment strategy to decrease the adverse effects and possibly to reverse the beta-lactam antibiotic resistance. PMID:23537749

  1. 2nd U.S. Case of Bacteria Resistant to Last-Resort Antibiotic

    Science.gov (United States)

    ... news/fullstory_159807.html 2nd U.S. Case of Bacteria Resistant to Last-Resort Antibiotic Scientists concerned it ... the United States who was infected with a bacteria that is resistant to an antibiotic of last ...

  2. Frequency of Antibiotic Resistance Patterns in Bacteria Isolated from Children

    Directory of Open Access Journals (Sweden)

    Esmaeili, R.

    2014-06-01

    Full Text Available Background and Objective: Bacterial infectioins in particular meningitis, pneumonia and septicemia are still some of the most causes of mortalities in children.The aim of present study was to identify the most common bacterial agents causing infectionis in children under 14 and detection of antibiotic resistance paterns. Material and Methods: During two years,1897samples were obtained from the patients suspected bacterial infectioins. They were investigated for bacterial cultures, age, sex and antibiogram patterns. The species were identified by biochemical and serological methods. Results: Of 1897 samples, 563 (29.6% had positve bacterial culture. Of these 74.7% were gram negative and 25.3% gram positive . The most common species were Escherichia coli(34.1%, Staphylococcus aureus (17.1%, Psuedomonas aeroginosa (12.4%, Kelebsiella (11% and Staphylococcus epidermidis (5.7%. The most effective antibiotics against both gram positive and gram negative bacteria were ceftriaoxne, nitrofurantoin, nalidixic acid, amikacin and gentamycin. Conclusion: The gram negative bacteria in particular Escherichia coli, Psuedomonas aeroginosa and Kelebsiella are the predominant causes of bacterial infections in children under 14 in these regions. Most species showed a high relative resisitance to routine antibiotics such as ampicillin, trimethoprim and chloramphenicol. Key Words: Bacteria; Infection; Children; Antibiotic

  3. 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. PMID:19540744

  4. [Sensitivity of bacteria to antibiotics (Zurich, 2000)].

    Science.gov (United States)

    Zbinden, R; Pfyffer, G E; Wüst, J

    2001-12-13

    This paper describes the frequency of susceptibility of Gram-negative and Gram-positive bacteria against antibacterial agents. Data are based on all susceptibility tests performed at the Department of Medical Microbiology of the University of Zurich in 2000. The evaluation of the results from 1987 to 2000 shows that susceptibilities against the antimicrobial agents tested have not markedly changed with the following exceptions: 7% of Staphylococcus aureus are resistant against methicillin, 8% of pneumococci have a reduced susceptibility to penicillin, 1% is resistant to penicillin, and 10% are resistant to macrolides. 9% of group A streptococci are resistant to macrolides. Quinolone resistance is markedly high in the medical practice with 10% of E. coli strains and 32% of Campylobacter sp. Strains of Klebsiella pneumoniae and E. coli producing extended spectrum betalactamases are isolated occasionally. Of all strains of Mycobacterium tuberculosis isolated from clinical specimens in 2000, 4% were multi-drug resistant. The tables may be a help for the physician in his decision for a "calculated chemotherapy" of bacterial infections. PMID:11793839

  5. Fate of antibiotic resistant cultivable heterotrophic bacteria and antibiotic resistance genes in wastewater treatment processes.

    Science.gov (United States)

    Zhang, Songhe; Han, Bing; Gu, Ju; Wang, Chao; Wang, Peifang; Ma, Yanyan; Cao, Jiashun; He, Zhenli

    2015-09-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants of environmental concern. Heterotrophic bacteria in activated sludge have an important role in wastewater treatment plants (WWTPs). However, the fate of cultivable heterotrophic ARB and ARGs in WWPTs process remains unclear. In the present study, we investigated the antibiotic-resistant phenotypes of cultivable heterotrophic bacteria from influent and effluent water of three WWTPs and analysed thirteen ARGs in ARB and in activated sludge from anoxic, anaerobic and aerobic compartments. From each influent or effluent sample of the three plants, 200 isolates were randomly tested for susceptibility to 12 antibiotics. In these samples, between 5% and 64% isolates showed resistance to >9 antibiotics and the proportion of >9-drug-resistant bacteria was lower in isolates from effluent than from influent. Eighteen genera were identified in 188 isolates from influent (n=94) and effluent (n=94) of one WWTP. Six genera (Aeromonas, Bacillus, Lysinibacillus, Microbacterium, Providencia, and Staphylococcus) were detected in both influent and effluent samples. Gram-negative and -positive isolates dominated in influent and effluent, respectively. The 13 tetracycline-, sulphonamide-, streptomycin- and β-lactam-resistance genes were detected at a higher frequency in ARB from influent than from effluent, except for sulA and CTX-M, while in general, the abundances of ARGs in activated sludge from two of the three plants were higher in aerobic compartments than in anoxic ones, indicating abundant ARGs exit in the excess sledges and/or in uncultivable bacteria. These findings may be useful for elucidating the effect of WWTP on ARB and ARGs. PMID:25950407

  6. Laser based enhancement of susceptibility of bacteria to antibiotic

    Science.gov (United States)

    Reznick, Yana; Banin, Ehud; Lipovsky, Anat; Lubart, Rachel; Zalevsky, Zeev

    2012-03-01

    Our objective is to test the effect of pulsed (Q-switched) and continuous wave (CW) laser light at wavelength of 532nm on the viability of free-living stationary phase bacteria with and without gentamicin (an antibiotic) treatment. Free living stationary phase gram negative bacteria (Pseudomonas aeruginosa strain PAO1) was immersed in Luria Broth (LB) solution and exposed to Q-switched and CW lasers with and without the addition of the antibiotic gentamicin. Cell viability was determined at different time points. Laser treatment alone did not reduce cell viability compared to untreated control and the gentamicin treatment alone only resulted in a 0.5 log reduction in the viable count for P. aeruginosa. The combined laser and gentamicin treatment, however, resulted in a synergistic effect and viability was reduced by 8 log's for P. aeruginosa PAO1.

  7. 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. PMID:24619620

  8. [Gram-negative bacteria resistant to antibiotics in foods].

    Science.gov (United States)

    Dias, J C; Hofer, E

    1985-01-01

    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 Ap and 9.8 for Su-Ap were detected. Aiming to better characterization of resistance, experiments of conjugation were made with standard strains of Escherichia coli K 12. Great concern was raised by the recognition of these cultures due to the elevated R+ taxes for the enteric bacilli that were close to 90% (milk and food at school) and about 70% in relation to lettuce. PMID:3837834

  9. Antibiotic resistance among aquatic bacteria in natural freshwater environments of Korea.

    Science.gov (United States)

    Kim, Tae Woon; Joung, Yochan; Han, Ji-Hye; Jung, Wonwha; Kim, Seung Bum

    2015-12-01

    The taxonomic diversity and antibiotic resistance among freshwater bacterial communities in the major water bodies of Korea was examined using 437 penicillin-resistant, and 110 tetracycline-resistant bacterial isolates. Based on 16S rRNA gene sequence analysis, most isolates were assigned to Proteobacteria, which was then followed by Bacteroidetes. Strains of Aeromonas were found as the most abundant penicillin-resistant populations, whereas those affiliated to diverse species including enteric groups were found as the most abundant tetracycline-resistant populations. Most strains exhibited multiple antibiotic resistance, and all tested strains were resistant to penicillin and hygromycin. High levels of resistance were observed for antibiotics acting on cell wall synthesis, whereas low levels were for those acting on DNA replication or transcription in general. It is apparent from this study that penicillin resistance is widespread among environmental bacteria, although the antibiotic has been generally non-detectable in the environment. It is also likely from the taxonomic composition of the resistant communities that various sources including terrestrial animals and humans may contribute to antibiotic resistance in the freshwater environment. PMID:26608770

  10. Prevalence of Antibiotic-Resistant Bacteria on Rectal Swabs and Factors Affecting Resistance to Antibiotics in Patients Undergoing Prostate Biopsy

    OpenAIRE

    Kim, Jong Beom; Jung, Seung Il; Hwang, Eu Chang; Kwon, Dong Deuk

    2014-01-01

    Purpose The prevalence of antibiotic-resistant bacteria on rectal swabs in patients undergoing transrectal ultrasound (TRUS)-guided prostate biopsy and the factors affecting resistance to antibiotics were evaluated. Materials and Methods Two hundred twenty-three men who underwent TRUS-guided prostate biopsy from November 2011 to December 2012 were retrospectively evaluated. Rectal swabs were cultured on MacConkey agar to identify antibiotic-resistant bacteria in rectal flora before TRUS-guide...

  11. Antibiotic contamination and occurrence of antibiotic-resistant bacteria in aquatic environments of northern Vietnam.

    Science.gov (United States)

    Hoa, Phan Thi Phuong; Managaki, Satoshi; Nakada, Norihide; Takada, Hideshige; Shimizu, Akiko; Anh, Duong Hong; Viet, Pham Hung; Suzuki, Satoru

    2011-07-01

    The ubiquitous application and release of antibiotics to the environment can result in bacterial antibiotic resistance, which in turn can be a serious risk to humans and other animals. Southeast Asian countries commonly apply an integrated recycling farm system called VAC (Vegetable, Aquaculture and Caged animal). In the VAC environment, antibiotics are released from animal and human origins, which would cause antibiotic-resistant bacteria (ARB). This study evaluated occurrence of ARB in the VAC environment in northern Vietnam, with quantitative analysis of antibiotic pollution. We found that sulfonamides were commonly detected at all sites. In dry season, while sulfamethazine was a major contaminant in pig farm pond (475-6662 ng/l) and less common in city canal and aquaculture sites, sulfamethoxazole was a major one in city canal (612-4330 ng/l). Erythromycin (154-2246 ng/l) and clarithromycin (2.8-778 ng/ml) were the common macrolides in city canal, but very low concentrations in pig farm pond and aquaculture sites. High frequencies of sulfamethoxazole-resistant bacteria (2.14-94.44%) were found whereas the occurrence rates of erythromycin-resistant bacteria were lower (Aeromonas were the major genera. Twenty three of 25 genera contained sul genes. This study showed specific contamination patterns in city and VAC environments and concluded that ARB occurred not only within contaminated sites but also those less contaminated. Various species can obtain resistance in VAC environment, which would be reservoir of drug resistance genes. Occurrence of ARB is suggested to relate with rainfall condition and horizontal gene transfer in diverse microbial community. PMID:21669325

  12. 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

  13. Coexistence of Antibiotic-Producing and Antibiotic-Sensitive Bacteria in Biofilms Is Mediated by Resistant Bacteria▿ †

    OpenAIRE

    Narisawa, Naoki; Haruta, Shin; Arai, Hiroyuki; Ishii, Masaharu; Igarashi, Yasuo

    2008-01-01

    Antibiotic-sensitive bacteria have been found to coexist with antibiotic-producing bacteria in biofilms, but little is known about how the former develop in such an environment. Here we isolated pyocyanin-sensitive bacteria belonging to the genus Brevibacillus from a biofilm derived from soil extract and based on the preestablished biofilm of a pyocyanin producer, Pseudomonas aeruginosa strain P1. In addition, pyocyanin-resistant strains belonging to the genus Raoultella were isolated from th...

  14. 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.

  15. A comparison of fluoroquinolones versus other antibiotics for treating enteric fever: meta-analysis

    OpenAIRE

    Thaver, Durrane; Zaidi, Anita K M; Critchley, Julia; Azmatullah, Asma; Madni, Syed Ali; Bhutta, Zulfiqar A.

    2009-01-01

    Objectives To review evidence supporting use of fluoroquinolones as first line agents over other antibiotics for treating typhoid and paratyphoid fever (enteric fever). Design Meta-analysis of randomised controlled trials. Data sources Cochrane Infectious Diseases Group specialised register, CENTRAL (issue 4, 2007), Medline (1966-2007), Embase (1974-2007), LILACS (1982-2007), selected conferences, reference lists, and ongoing trial register (November 2007). Review methods Trials comparing flu...

  16. Antibiotic Resistance of Isolated Bacteria from Urban and Hospital Wastewaters in Hamadan City

    OpenAIRE

    Karimi, M; A.M Ebrahimzadeh Namvar; R Shokoohi; M. Hadi; M Solaimany Aminabad

    2011-01-01

    "nBackground and Objectives: widely use of antibiotics as therapy and uncontrolled discharge of them to receiving waters increased the percentages of antibiotic resistant bacteria in various environments which may cause problems in therapy. The aim of this study was to investigate the antibiotic resistance of E. coli, K. pneumoniae and P. aeruginosa bacteria isolated from urban and hospital wastewaters. Nine antibiotics namely Chloramphenicol, Ciprofloxacin, Trimethoprim Sulfamethoxazol, Gent...

  17. Carriage of antibiotic-resistant bacteria by healthy children.

    Science.gov (United States)

    Millar, M R; Walsh, T R; Linton, C J; Zhang, S; Leeming, J P; Bennett, P M

    2001-05-01

    The frequency of carriage of antibiotic-resistant bacteria in healthy 7- and 8-year-old children in Bristol was studied. Children born in Avon between 1 April 1991 and 31 December 1992, attending the Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC) 7 year follow-up clinic, formed the study population. Carriage was estimated using mouth and stool samples. None of 105 children on whom information was available had received tetracycline, chloramphenicol, ciprofloxacin or an extended-spectrum cephalosporin in the previous year. Staphylococcus aureus was isolated from mouthwashes from 200 (37.1%) of 539 children sampled. Six (3%) of the isolates were resistant to chloramphenicol or tetracycline and four (2%) were methicillin resistant. Haemophilus spp. were isolated from 369 (72%) of 513 samples and 63 (17%) were ampicillin resistant, 49 (13.3%) were erythromycin resistant and seven (1.9%) were tetracycline resistant. Branhamella catarrhalis was isolated from 333 (74%) of 450 samples. Twenty-eight (8.4%) were erythromycin resistant and 14 (4.2%) strains were tetracycline resistant. Group A beta-haemolytic streptococci were isolated from 17 of 507 children sampled. One (5.9%) was tetracycline resistant. Stool samples were returned from 335 (62%) of 539 children from whom they were requested. Eleven per cent of samples yielded Gram-negative bacilli with high-level resistance to chloramphenicol, which was frequently linked to resistance to ampicillin, spectinomycin and streptomycin. Isolates demonstrating resistance to the third-generation cephalosporin ceftazidime were recovered from 17 subjects (3.2%). Six (35%) of 17 isolates possessed extended-spectrum beta-lactamases. Healthy children carry bacteria resistant to antibiotics to which children are not usually exposed. Resistance to ceftazidime, chloramphenicol and tetracycline may be co-selected by exposure to other antibiotics used in children or may be acquired from family members, pets, other children or

  18. Antibiotic Resistance of Enterococci and Coliform Bacteria in Dairy Products from Commercial Farms

    OpenAIRE

    Ivana Nováková; Miroslava Kačániová; Henrieta Arpášová; Peter Haščík; Simona Kunová; Juraj Čuboň

    2010-01-01

    The aim of this study was to determine the prevalence and antibiotic resistance of enterococci and coliform bacteria isolated from sheep and cows cheese from commercial farms. Susceptibilities of isolated enterococci and coliform bacteria were tested using the disk diffusion method. The bacteria were tested on antibiotics enrofloxacin, sulphonamides, tetracycline and streptomycin. All isolates of Enterococcus strains were resistant of all used antibiotics. The similar results were detected of...

  19. 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. PMID:26775188

  20. 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. PMID:26966812

  1. 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. PMID:27103502

  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 Muusfeldt; Nguyen, Duc Ninh; Cilieborg, Malene Skovsted;

    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...

  3. 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...

  4. 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

  5. Effect of bile salts on the DNA and membrane integrity of enteric bacteria.

    Science.gov (United States)

    Merritt, Megan E; Donaldson, Janet R

    2009-12-01

    Enteric bacteria are able to resist the high concentrations of bile encountered throughout the gastrointestinal tract. Here we review the current mechanisms identified in the enteric bacteria Salmonella, Escherichia coli, Bacillus cereus and Listeria monocytogenes to resist the dangerous effects of bile. We describe the role of membrane transport systems, and their connection with DNA repair pathways, in conferring bile resistance to these enterics. We discuss the findings from recent investigations that indicate bile tolerance is dependent upon being able to resist the detergent properties of bile at both the membrane and DNA level. PMID:19762477

  6. 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)

    DouglasRubenCall

    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.

  7. Resistance of Bacteria Isolated from Otamiri River to Heavy Metals and Some Selected Antibiotics

    OpenAIRE

    I.C. Mgbemena; J.C. Nnokwe; L.A. Adjeroh; N.N. Onyemekara

    2012-01-01

    This study is aimed at determining the resistance of bacteria to heavy metals and some antibiotics. The ability of aquatic bacteria isolates from Otamiri River at Ihiagwa in Owerri North, Imo State to tolerate or resist the presence of certain selected heavy metals: Pb+, Zn2+ and Fe2+ and some antibiotics was investigated. Identification tests for the bacteria isolates from Otamiri River revealed them to belong to the genera Pseudomonas, Aeromonas, Bacillus, Escherichia, Micrococcus and Prote...

  8. 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.

  9. Antibiotics influence on lactic acid bacteria inhibiting gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Andreja Čanžek Majhenič

    2001-04-01

    Full Text Available Lactic acid bacteria (LAB are common inhabitants of the gastrointestinal (GI tract and have important role in maintaining the equilibrium of GI flora, which can be influenced by various factors like diets, antimicrobials and stress. Minimal inhibitory concentrations (MIC and minimal bactericidal concentrations (MBC of 6 antibiotics, commonly used in human medicine for 8 selected lactobacilli strains were determined by macrodilution and microdilution methods in liquid media and by diffusion method on agar plates. The effects of Penicillin G and Ampicillin on intestinal LAB were tested in vivoon mice as well. Lactobacilli were sensitive to Penicillin G, (penicillines and their derivatives and Erythromycin (macrolides by in vitro testing. Clyndamycin (pyranosid showed moderate inhibitory effect. All lactobacilli strains were resistant to Kanamycin and Neomycin (aminoglycosides, while L. salivarius IM 124 has shown extra resistance to Erythromycin and Clyndamycin. The influence of orally administered Ampicillin showed no significant influence on LAB count in mice faeces. The effect of Penicillin G on mice LAB total count was significant, while no effect of orally administered lactobacilli was determined.

  10. 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.

  11. 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 pr...

  12. 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 (p<0.001) more common than gram-positive bacteria (39%). The most common organisms were Vibrio spp. (28%), various coagulase-negative Staphylococcus spp. (16%), and Pasteurella spp. (12%). The overall resistance rate was 12% for all antibiotics tested with nearly 43% of bacteria resistant to at least one antibiotic. Multi-drug resistance was seen in 4% of bacteria. No association between shark 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. PMID:25110948

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

    Directory of Open Access Journals (Sweden)

    Nathan R Unger

    Full Text Available 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 (p<0.001 more common than gram-positive bacteria (39%. The most common organisms were Vibrio spp. (28%, various coagulase-negative Staphylococcus spp. (16%, and Pasteurella spp. (12%. The overall resistance rate was 12% for all antibiotics tested with nearly 43% of bacteria resistant to at least one antibiotic. Multi-drug resistance was seen in 4% of bacteria. No association between shark 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.

  14. Modified broth-disk method for testing the antibiotic susceptibility of anaerobic bacteria.

    Science.gov (United States)

    Wilkins, T D; Thiel, T

    1973-03-01

    The most commonly used method for testing the antibiotic susceptibility of aerobic and facultative bacteria is the disk diffusion method. However, some anaerobic bacteria do not grow well enough in anaerobic jars for performance of disk diffusion tests. A modification of the broth-disk method of Schneierson allowed us to determine antibiotic susceptibility in a completely anaerobic environment. Commercial antibiotic disks were added anaerobically to tubes of prereduced brain heart infusion broth to achieve a concentration of each antibiotic approximating that attainable in blood. The tubes were then inoculated and incubated for 18 h. Resistance or susceptibility to each antibiotic was determined according to the amount of growth in each tube as compared with a control culture without the antibiotic. There was good correlation between results obtained by this broth-disk method and minimal inhibitory concentrations. PMID:4790595

  15. 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

  16. 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...

  17. 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.

  18. 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

  19. The incidence of antibiotic resistant bacteria in chicken and pork / Eugénie van Wijk

    OpenAIRE

    Van Wijk, Eugénie

    2003-01-01

    The emergence of antibiotic resistance in important human pathogens has globally become a public health concern. Consumption of contaminated meat and meat products constitute a major route for the transmission of antibiotic resistant organisms and the dissemination of resistance genes in the human environment. The aim of this study was to determine the level of antibiotic resistance in potentially pathogenic bacteria associated with pork, chicken meat, chicken manure, chicken f...

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

    OpenAIRE

    Bhattacharya, S.

    2011-01-01

    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,...

  1. 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. PMID:26703979

  2. 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...

  3. Antibiotic Resistance of Isolated Bacteria from Urban and Hospital Wastewaters in Hamadan City

    Directory of Open Access Journals (Sweden)

    M Karimi

    2011-04-01

    Full Text Available "nBackground and Objectives: widely use of antibiotics as therapy and uncontrolled discharge of them to receiving waters increased the percentages of antibiotic resistant bacteria in various environments which may cause problems in therapy. The aim of this study was to investigate the antibiotic resistance of E. coli, K. pneumoniae and P. aeruginosa bacteria isolated from urban and hospital wastewaters. Nine antibiotics namely Chloramphenicol, Ciprofloxacin, Trimethoprim Sulfamethoxazol, Gentamycin, Ceftizoxime, Nalidixic Acid, Ceftazidime, Ceftriaxon and Cefalexin were investigated in this study."nMaterials and Methods: through a cross-sectional descriptive study the isolation of bacteria from hospital and urban wastewater samples was performed by microbiological identification techniques. The resistance to nine antibiotics was tested by application of the standard disc diffusion technique and zone-size interpretation chart of Kirby-Baeur. Non-parametric Mann-Whitney test was used to assessing two environments differences."nResults: The resistance percentage of E. coli to studied antibiotics was significantly less (ranged from 1.81 to 51.02% than the resistance percentage of P. aeroginosa (ranged from 3.57 to 61.76 and K. pneumoniae (ranged from 6.45 to 91.83%. the highest resistance to antibiotics studied was for K. pneumonia in comparison with others. E. coli, K. pneumonia and P. aeroginosa bacteria showed the highest resistance to CAZ, SXT and CN, respectively. The study showed the resistance rate in hospital wastewater is more than urban wastewater."nConclusion: Easy access and uncontrolled usage of antibiotics cause discharge of antibiotics to wastewaters and consequently diminish the drugs' effectiveness. High concentration of antibiotic and diversity in wastewater of hospital in comparison with urban wastewater causes to transfer resistant agents between bacteria and increased the multiple resistances.

  4. 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.

  5. 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.

  6. 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.

  7. Kinetics and Strain Specificity of Rhizosphere and Endophytic Colonization by Enteric Bacteria on Seedlings of Medicago sativa and Medicago truncatula

    OpenAIRE

    Dong, Yuemei; Iniguez, A. Leonardo; Brian M M Ahmer; Triplett, Eric W.

    2003-01-01

    The presence of human-pathogenic, enteric bacteria on the surface and in the interior of raw produce is a significant health concern. Several aspects of the biology of the interaction between these bacteria and alfalfa (Medicago sativa) seedlings are addressed here. A collection of enteric bacteria associated with alfalfa sprout contaminations, along with Escherichia coli K-12, Salmonella enterica serotype Typhimurium strain ATCC 14028, and an endophyte of maize, Klebsiella pneumoniae 342, we...

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

    OpenAIRE

    KATHIA ROSSI ROLIM LOPES; IZABEL BRANDãO STREIT; ROSA HELENA LUCHESE; MARCO ANTôNIO ZACHIA AYUB

    2009-01-01

    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 5...

  9. 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

  10. 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...... membrane proteins of Escherichia coli can be used as a fast and simple selection system for protein overproduction.Methods: We designed an expression plasmid encoding the gene of interest and an additional, inducible antibiotic resistance marker. Both genes were linked by a hairpin structure 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...

  11. Multidrug resistance and transferability of blaCTX-M among extended-spectrum β-lactamase-producing enteric bacteria in biofilm.

    Science.gov (United States)

    Maheshwari, Meenu; Ahmad, Iqbal; Althubiani, Abdullah Safar

    2016-09-01

    This study aimed to investigate the occurrence of biofilm-forming extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and to evaluate their antibiotic resistance behaviour and transferability of the plasmid-encoded blaCTX-M gene in biofilm. ESBL production was confirmed using the combined disc test and Etest. Amplification of blaCTX-M was performed by PCR. Antibiotic susceptibility was evaluated using the disc diffusion assay and broth dilution method. Transfer of blaCTX-M in planktonic and biofilm state was performed by broth mating and filter mating experiments, respectively. Among 110 enteric bacteria, 24 (21.8%) isolates belonging to Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were found to produce ESBL and formed varying levels of biofilm in vitro. Presence of blaCTX-M was detected in 18 (75%) ESBL-producing isolates. A many fold increase in resistance to antibiotics was observed in biofilm. Among ESBL-producers, seven isolates could transfer the blaCTX-M gene by conjugation, with transfer frequencies ranging from 2.22×10(-4) to 7.14×10(-2) transconjugants/recipient cell in the planktonic state and from 3.04×10(-3) to 9.15×10(-1) in biofilm. The transfer frequency of blaCTX-M was significantly higher in biofilm compared with the planktonic state, and co-transfer of ciprofloxacin resistance was also detected in five isolates. This study demonstrates that biofilm-forming ESBL-producing enteric bacteria with a greater transfer frequency of resistance genes will lead to frequent dissemination of β-lactam and fluoroquinolone resistance genes in environmental settings. The emergence and spread of such multidrug resistance is a serious threat to animal and public health. PMID:27530857

  12. Zonulin Regulates Intestinal Permeability and Facilitates Enteric Bacteria Permeation in Coronary Artery Disease.

    Science.gov (United States)

    Li, Chuanwei; Gao, Min; Zhang, Wen; Chen, Caiyu; Zhou, Faying; Hu, Zhangxu; Zeng, Chunyu

    2016-01-01

    Several studies have reported an association between enteric bacteria and atherosclerosis. Bacterial 16S ribosomal RNA (rRNA) gene belong to Enterobacteriaceae have been detected in atherosclerotic plaques. How intestinal bacteria go into blood is not known. Zonulin reversibly modulate intestinal permeability (IP), the circulating zonulin levels were increased in diabetes, obesity, all of which are risk factors for atherosclerosis. It is unclear whether the circulating zonulin levels were changed in coronary artery disease (CAD) patients and modulate IP. The 16S rRNA gene of bacteria in blood sample was checked by 454 pyrosequencing. The zonulin levels were determined by enzyme-linked immunosorbent assay (ELISA) methods. The distribution of zonulin was detected by confocal immunofluorescence microscopy. Bacteria and Caco-2 cell surface micro-structure were checked by transmission electron microscopy. A high diversity of bacterial 16S rRNA gene can be detected in samples from CAD patients, most of them (99.4%) belong to Enterobacteriaceaes, eg. Rahnella. The plasma zonulin levels were significantly higher in CAD patients. Pseudomonas fluorescens exposure significantly increased zonulin expression and decreased IP in a time dependent manner. The elevated zonulin increase IP and may facilitate enteric translocation by disassembling the tight junctions, which might explain the observed high diversity of bacterial 16S rRNA genes in blood samples. PMID:27353603

  13. 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…

  14. Formation of an adduct between fosfomycin and glutathione: a new mechanism of antibiotic resistance in bacteria.

    OpenAIRE

    Arca, P; Rico, M; Braña, A F; Villar, C J; Hardisson, C; Suárez, J E

    1988-01-01

    Plasmid-borne resistance to fosfomycin in bacteria is due to modification of the antibiotic molecule by a glutathione S-transferase that catalyzes the formation of a covalent bond between the sulfhydryl residue of the cysteine in glutathione and the C-1 of fosfomycin. This reaction results in opening of the epoxide ring of the antibiotic to form an inactive adduct, the structure of which was confirmed by nuclear magnetic resonance. Dialyzed extracts prepared from resistant Escherichia coli st...

  15. Microarray-Based Detection of 90 Antibiotic Resistance Genes of Gram-Positive Bacteria

    OpenAIRE

    Perreten, Vincent; Vorlet-Fawer, Lorianne; Slickers, Peter; Ehricht, Ralf; Kuhnert, Peter; Frey, Joachim

    2005-01-01

    A disposable microarray was developed for detection of up to 90 antibiotic resistance genes in gram-positive bacteria by hybridization. Each antibiotic resistance gene is represented by two specific oligonucleotides chosen from consensus sequences of gene families, except for nine genes for which only one specific oligonucleotide could be developed. A total of 137 oligonucleotides (26 to 33 nucleotides in length with similar physicochemical parameters) were spotted onto the microarray. The mi...

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

    OpenAIRE

    Janiffe Peres de Oliveira; Jonny Everson Scherwinski-Pereira

    2016-01-01

    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 ...

  17. Antibiotic resistance in triclosan heterotrophic plate count bacteria from sewage water / Ilsé Coetzee

    OpenAIRE

    Coetzee, Ilsé

    2015-01-01

    The concentration of triclosan in antiseptics, disinfectants and preservatives in products exceeds the minimal lethal levels. Extensive use of triclosan and antibiotics results in bacterial resistance to their active ingredients. The precise relationship between use and resistance, however, has been challenging to define. The aim of the study was to identify and determine antibiotic resistance profiles of triclosan tolerant heterotrophic plate count bacteria isolates from sewag...

  18. 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.

  19. 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.

  20. 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.

  1. Results of Antibiotic Sensitivity Tests of Bacteria Causing Acute Otitis Media

    Directory of Open Access Journals (Sweden)

    M Khajeh Karameddini

    2000-07-01

    Full Text Available In a period of 12 months 241 children (2-12 years old with Otitis Media were examined. 98 bacteria were isolated from Otitis Media discharge and tested for sensitivity against 13 generic antibiotics. The disk-agar diffusion and macrodilution both methods were used for these tests. Staphylococcus aureus had the highest and streptococcus pneumonia the lowest rate of occurrence. Otitis Media cases caused by merely a single bacterium were 12 fold more than those caused by two bacteria and 4 fold more than those caused by more than two bacteria. The antibacterial efficacy of carbenicillin, gentamicin, kanamycin and amikacin was higher than that of other antibiotics in disk-agar diffusion method. The MIC rates of cefoperazone against four most frequently encountered bacteria were higher than that of Mezlocillin.

  2. 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.

  3. Calcined Eggshell Waste for Mitigating Soil Antibiotic-Resistant Bacteria/Antibiotic Resistance Gene Dissemination and Accumulation in Bell Pepper.

    Science.gov (United States)

    Ye, Mao; Sun, Mingming; Feng, Yanfang; Li, Xu; Schwab, Arthur P; Wan, Jinzhong; Liu, Manqiang; Tian, Da; Liu, Kuan; Wu, Jun; Jiang, Xin

    2016-07-13

    The combined accumulation of antibiotics, heavy metals, antibiotic-resistant bacteria (ARB)/antibiotic resistance genes (ARGs) in vegetables has become a new threat to human health. This is the first study to investigate the feasibility of calcined eggshells modified by aluminum sulfate as novel agricultural wastes to impede mixed contaminants from transferring to bell pepper (Capsicum annuum L.). In this work, calcined eggshell amendment mitigated mixed pollutant accumulation in bell pepper significantly, enhanced the dissipation of soil tetracycline, sulfadiazine, roxithromycin, and chloramphenicol, decreased the water-soluble fractions of antibiotics, and declined the diversity of ARB/ARGs inside the vegetable. Moreover, quantitative polymerase chain reaction analysis detected that ARG levels in the bell pepper fruits significantly decreased to 10(-10) copies/16S copies, indicating limited risk of ARGs transferring along the food chain. Furthermore, the restoration of soil microbial biological function suggests that calcined eggshell is an environmentally friendly amendment to control the dissemination of soil ARB/ARGs in the soil-vegetable system. PMID:27333280

  4. Heavy metal and antibiotic resistance in bacteria isolated from the environment of swine farms

    International Nuclear Information System (INIS)

    The aim of the present study was to determine the level of heavy metal resistance and antibiotic resistance patterns of bacterial isolates from environment of swine farms in China. A total of 284 bacteria were isolated, 158 from manure, 62 from soil and 64 from wastewater in different swine farm samples. All the isolates were tested for resistant against eight heavy metals. From the total of 284 isolates, maximum bacterial isolates were found to be resistant to Zn/sup 2+/ (98.6%) followed by Cu/sup 2+/ (97.5%), Cd/sup 2+/ (68.3%), Mn/sup 2+/ (60.2%), Pb/sup 2+/(51.4%), Ni/sup 2+/(41.5%) and Cr/sup 2+/(45.1%). However, most of the isolates were sensitive to Co/sup 2+/. Meanwhile,all the isolates were tested for sensitively to nine antibiotics. The results shows that most isolates were sensitive to cefoxitin and oxacillin, but resistance to tetracycline, ampicillin, gentamicin, amikacin, erythromycin, clindamycin were widespread. Multiple resistant to metals and antibiotics were also observed in this study. Most isolates were tolerant to different concentrations of various heavy metals and antibiotics. Our results confirmed that environment of swine farms in China has a significant proportion of heavy metal and antibiotic resistant bacteria, and these bacteria constitute a potential risk for swine health and public health. (author)

  5. [Distribution and removal of anaerobic antibiotic resistant bacteria during mesophilic anaerobic digestion of sewage sludge].

    Science.gov (United States)

    Tong, Juan; Wang, Yuan-Yue; Wei Yuan, Song

    2014-10-01

    Sewage sludge is one of the major sources that releasing antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARG) into the environment since it contains large amount of ARB, but there is little information about the fate of the anaerobic ARB in the anaerobic digestion of sewage sludge. Therefore, the distribution, removal and seasonal changes of tetracycline and β-lactam antibiotics resistant bacteria in the mesophilic egg-shaped digesters of a municipal wastewater treatment plant were investigated for one year in this study. Results showed that there were higher amounts of ARB and higher resistance rate of β-lactam antibiotics than that of tetracycline antibiotics in the sewage sludge. All ARB could be significantly reduced during the mesophilic anaerobic digestion process by 1.48-1.64 log unit (P < 0.05). Notably, the ampicillin and cephalothin resistance rates were significantly increased after anaerobic digestion by 12.0% and 14.3%, respectively (P < 0.05). The distribution of ARB in the sewage sludge had seasonal change characteristics. Except for chlorotetracycline resistant bacteria, there were more ARB in the sewage sludge in cold season than in warm season (P < 0.05). PMID:25693388

  6. [Antibiotic resistance--an ambivalence of attitudes. As of now, the bacteria are in advantage].

    Science.gov (United States)

    Sköld, O

    1995-09-13

    The value of the precious medical asset that antibiotics constitute is contimualby being eroded by the spread of resistance. For some time that bacterial world has been adapting itself to contend with the toxic assault of man-made poisons, antibiotics, by developing resistance in a very rapid process of evolutionary changes occurring before our very eyes. This evolutionary adaptation is an example of natural genetic engineering entailing an interchange between bacteria of genes conferring antibiotic resistance. Trimethoprim resistance is an example where numerous genes of unknown origin (some closely interrelated), expressing drug-resistant dihydrofolate reductases, move among human commensals and pathogens. They have been shown to move as gene cassettes in and out of the recently characterised integron structure occurring in many pathogens. They are also carried by various transposons such as Tn7, or Tn5393 originally observed in a plant pathogen, Erwinia amylovora. Betalactam resistance is another example of natural genetic engineering, where new betalactamases are continually emerging, and individual enzyme substrate specificity is modified by point mutation. At present, betalactamase mutants resistant to all commercially available betalactams, including clavulanic acid used in combination with betalactam antibiotics, are to be found in clinical isolates. Thus, currently bacteria seem to be triumphing in the running battle between the pharmaceutical industry and the bacterial world, the former introducing one new antibiotic variant after another, to which bacteria promptly develop resistance by manipulating their own genomes. PMID:7674727

  7. 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...

  8. Evolution of Coenzyme B(12) Synthesis among Enteric Bacteria: Evidence for Loss and Reacquisition of a Multigene Complex

    OpenAIRE

    Lawrence, J. G.; Roth, J R

    1996-01-01

    We have examined the distribution of cobalamin (coenzyme B(12)) synthetic ability and cobalamin-dependent metabolism among enteric bacteria. Most species of enteric bacteria tested synthesize cobalamin under both aerobic and anaerobic conditions and ferment glycerol in a cobalamin-dependent fashion. The group of species including Escherichia coli and Salmonella typhimurium cannot ferment glycerol. E. coli strains cannot synthesize cobalamin de novo, and Salmonella spp. synthesize cobalamin on...

  9. 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.

  10. The Study of Blood Culture for Prevalent Bacteria and Antibiotic Resistance on Hospitalized Patients

    Directory of Open Access Journals (Sweden)

    H Alaodolei

    2007-06-01

    Full Text Available Background: Bacteremia means invasion of bacteria to coronary- arthery system. One third of these cases lead to septicemia and in 40-50% cases, it causes patient’s death. Therefore information about resistance and prevalent of bacteria isolated from blood culture is important for deciding about suitable therapeutic management. Methods: This retrospective study was done on all positive blood cultures for typing and detecting of antibiotic resistance during 2001- 2005. Data was analyzed by statistical procedure. Results: In 252 (4.35% of studied blood cultures, the most prevalent bacteries were Staph. epidermidis (35.2% and E. Coli (18.5%. The greatest and the least resistance antibiotics were βLactam (75.2% and glycopeptide (7.8% groups, respectively. Conclusion: With regard to antibiotic resistance increased during these years, awaring of the last changes about it in every therapeutic center is necessary.

  11. Efficacy of Locally Isolated Lactic Acid Bacteria Against Antibiotic-Resistant Uropathogens

    Science.gov (United States)

    Manzoor, Asma; Ul-Haq, Ikram; Baig, Shahjhan; Qazi, Javed Iqbal; Seratlic, Sanja

    2016-01-01

    Background: Antibiotic resistance represents a serious global health threat to public health, so infections such as pneumonia and urinary tract infection (UTI) are becoming harder to treat. Therefore, it is necessary to develop an action plan to restrain the problem of antibiotic resistance. One approach in UTI control could be the use of lactobacilli because these indigenous inhabitants in human intestine have been found to play an important role in protecting the host from various infections. Objectives: We sought to check the efficacy of locally isolated Lactobacillus species to eradicate antibiotic-resistant pathogenic bacteria causing UTI. Materials and Methods: Lactic acid bacteria isolated from spoiled fruits and vegetables and grown in MRS medium were screened against multi-drug-resistant Candida albicans, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus fecalis. Results: Fifty-four lactic acid bacteria were isolated from spoiled fruits and vegetables, of which 11 Gram-positive and catalase-negative Lactobacillus isolates were identified by carbohydrate assimilation profiles as Lactobacillus acidophilus, L. paracasei, L. delbrueckii, L. casei, L. helveticus, L. brevis, L. salivarius, L. fermentum, L. rhamnosus, L. animalis, and L. plantarum. The latter organism had the highest abundance of all the samples, so its isolates were also verified through 16S rRNA gene sequencing. The isolated Lactobacilli were screened against multi-drug-resistant uropathogens, viz. C. albicans, P. aeruginosa, K. pneumoniae, E. fecalis, and E. coli. The growth inhibition zone (GIZ) was over 10 mm against all the uropathogenic test organisms, where L. fermentum and L. plantarum strains demonstrated remarkable inhibitory activities against E. coli and E. faecalis, with a GIZ up to 28 mm. The susceptibility test to 16 antibiotics showed multidrug resistance (3 to 5 antibiotics) among all the tested uropathogens. Conclusions: The obtained results

  12. Use of a radiorespirometric assay for testing the antibiotic sensitivity of catheter-associated bacteria

    International Nuclear Information System (INIS)

    A 14C-radiorespirometric assay was used to show the sensitivity of fixed-film (sessile), catheter-associated and free-living (planktonic) cells of Pseudomonas aeruginosa to varying concentrations (100 micrograms/mL to 1000 micrograms/mL) tobramycin sulfate. This strain of P. aeruginosa has an MIC of 0.6 microgram/ml and an MBC of 50 micrograms/mL when tested by conventional methods. When 14C-glutamic acid was used as a substrate in this radiorespirometric assay, it could be completed in less than one hour and planktonic samples showed a significant reduction in mineralization activity (evolution of 14CO2) within eight hours of the antibiotic challenge. These changes in respiratory activity appeared to be dose and time dependent. Within 18 hr. at 1000 micrograms/mL, there was no significant residual respiratory activity in planktonic samples. Some residual respiratory activity was detected, however, in samples exposed to 100 micrograms/mL for 36 hours. The mineralization activity of sessile catheter-associated bacteria was unaffected by four hr. and eight hr. exposures to 1000 micrograms/mL of the antibiotic. A significant reduction in respiratory activity was recorded in catheter samples exposed for 18 hr. or more at each concentration examined. Unlike the planktonic samples, however, the antibiotic challenge failed to eradicate the metabolic activity of the attached bacteria. Antibiotic stressed, catheter-associated bacteria transferred to a post-exposure enrichment broth showed a limited ability to re-establish respiratory activity. This apparent recovery was limited to antibiotic exposures less than 24 hr. and was not observed in planktonic samples. The radioisotopic assay is a non-culture method which can be used to assess the antibiotic sensitivity of both planktonic bacteria and in situ biofilm populations

  13. Non-invasive determination of conjugative transfer of plasmids bearing antibiotic-resistance genes in biofilm-bound bacteria: effects of substrate loading and antibiotic selection

    OpenAIRE

    Ma, Hongyan; Bryers, James D.

    2012-01-01

    Biofilms cause much of all human microbial infections. Attempts to eradicate biofilm-based infections rely on disinfectants and antibiotics. Unfortunately, biofilm bacteria are significantly less responsive to antibiotic stressors than their planktonic counterparts. Sublethal doses of antibiotics can actually enhance biofilm formation. Here, we have developed a non-invasive microscopic image analyses to quantify plasmid conjugation within a developing biofilm. Corroborating destructive sample...

  14. Antibiotic Susceptibility Pattern of Aerobic and Anaerobic Bacteria Isolated From Surgical Site Infection of Hospitalized Patients

    Science.gov (United States)

    Akhi, Mohammad Taghi; Ghotaslou, Reza; Beheshtirouy, Samad; Asgharzadeh, Mohammad; Pirzadeh, Tahereh; Asghari, Babak; Alizadeh, Naser; Toloue Ostadgavahi, Ali; Sorayaei Somesaraei, Vida; Memar, Mohammad Yousef

    2015-01-01

    Background: Surgical Site Infections (SSIs) are infections of incision or deep tissue at operation sites. These infections prolong hospitalization, delay wound healing, and increase the overall cost and morbidity. Objectives: This study aimed to investigate anaerobic and aerobic bacteria prevalence in surgical site infections and determinate antibiotic susceptibility pattern in these isolates. Materials and Methods: One hundred SSIs specimens were obtained by needle aspiration from purulent material in depth of infected site. These specimens were cultured and incubated in both aerobic and anaerobic condition. For detection of antibiotic susceptibility pattern in aerobic and anaerobic bacteria, we used disk diffusion, agar dilution, and E-test methods. Results: A total of 194 bacterial strains were isolated from 100 samples of surgical sites. Predominant aerobic and facultative anaerobic bacteria isolated from these specimens were the members of Enterobacteriaceae family (66, 34.03%) followed by Pseudomonas aeruginosa (26, 13.4%), Staphylococcus aureus (24, 12.37%), Acinetobacter spp. (18, 9.28%), Enterococcus spp. (16, 8.24%), coagulase negative Staphylococcus spp. (14, 7.22%) and nonhemolytic streptococci (2, 1.03%). Bacteroides fragilis (26, 13.4%), and Clostridium perfringens (2, 1.03%) were isolated as anaerobic bacteria. The most resistant bacteria among anaerobic isolates were B. fragilis. All Gram-positive isolates were susceptible to vancomycin and linezolid while most of Enterobacteriaceae showed sensitivity to imipenem. Conclusions: Most SSIs specimens were polymicrobial and predominant anaerobic isolate was B. fragilis. Isolated aerobic and anaerobic strains showed high level of resistance to antibiotics. PMID:26421133

  15. Anthrax lethal toxin disrupts intestinal barrier function and causes systemic infections with enteric bacteria.

    Directory of Open Access Journals (Sweden)

    Chen Sun

    Full Text Available A variety of intestinal pathogens have virulence factors that target mitogen activated protein kinase (MAPK signaling pathways, including Bacillus anthracis. Anthrax lethal toxin (LT has specific proteolytic activity against the upstream regulators of MAPKs, the MAPK kinases (MKKs. Using a murine model of intoxication, we show that LT causes the dose-dependent disruption of intestinal epithelial integrity, characterized by mucosal erosion, ulceration, and bleeding. This pathology correlates with an LT-dependent blockade of intestinal crypt cell proliferation, accompanied by marked apoptosis in the villus tips. C57BL/6J mice treated with intravenous LT nearly uniformly develop systemic infections with commensal enteric organisms within 72 hours of administration. LT-dependent intestinal pathology depends upon its proteolytic activity and is partially attenuated by co-administration of broad spectrum antibiotics, indicating that it is both a cause and an effect of infection. These findings indicate that targeting of MAPK signaling pathways by anthrax LT compromises the structural integrity of the mucosal layer, serving to undermine the effectiveness of the intestinal barrier. Combined with the well-described immunosuppressive effects of LT, this disruption of the intestinal barrier provides a potential mechanism for host invasion via the enteric route, a common portal of entry during the natural infection cycle of Bacillus anthracis.

  16. Effect of Oxytetracycline-Medicated Feed on Antibiotic Resistance of Gram-Negative Bacteria in Catfish Ponds

    OpenAIRE

    DePaola, A.; Peller, J. T.; Rodrick, G E

    1995-01-01

    The effect of oxytetracycline-medicated feeds on antibiotic resistance in gram-negative bacteria from fish intestines and water in catfish ponds was investigated. In experiments in the fall and spring, using ponds with no previous history of antibiotic usage, percentages of tetracycline-resistant bacteria in catfish intestines obtained from medicated ponds increased significantly after 10 days of treatment. In the fall, resistance of the intestinal and aquatic bacteria returned to pretreatmen...

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Recycling Antibiotics into GUMBOS: A New Combination Strategy to Combat Multi-Drug-Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Marsha R. Cole

    2015-04-01

    Full Text Available 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.

  19. Anaerobic ammonium-oxidizing bacteria gain antibiotic resistance during long-term acclimatization.

    Science.gov (United States)

    Zhang, Zheng-Zhe; Zhang, Qian-Qian; Guo, Qiong; Chen, Qian-Qian; Jiang, Xiao-Yan; Jin, Ren-Cun

    2015-09-01

    Three broad-spectrum antibiotics, amoxicillin (AMX), florfenicol (FF) and sulfamethazine (SMZ), that inhibit bacteria via different target sites, were selected to evaluate the acute toxicity and long-term effects on anaerobic ammonium oxidation (anammox) granules. The specific anammox activity (SAA) levels reduced by approximately half within the first 3 days in the presence of antibiotics but no nitrite accumulation was observed in continuous-flow experiments. However, the SAA levels and heme c content gradually recovered as the antibiotic concentrations increased. Extracellular polymeric substances (EPS) analysis suggested that anaerobic ammonium-oxidizing bacteria gradually developed a better survival strategy during long-term acclimatization, which reduced the antibiotic stress via increased EPS secretion that provided a protective 'cocoon.' In terms of nitrogen removal efficiency, anammox granules could resist 60 mg-AMX L(-1), 10 mg-FF L(-1) and 100 mg-SMZ L(-1). This study supported the feasibility of using anammox granules to treat antibiotic-containing wastewater. PMID:26111629

  20. Analysis of antibiotic resistance in bacteria isolated from the surface microlayer and underlying water of an estuarine environment.

    Science.gov (United States)

    Azevedo, Juliana S N; Araújo, Susana; Oliveira, Cláudia S; Correia, António; Henriques, Isabel

    2013-02-01

    We compared the prevalence of cultivable antibiotic-resistant bacteria and resistance genes in the surface microlayer (SML) and underlying waters (UW) of an estuary. Prevalence of resistant bacteria was determined in antibiotic-supplemented agar. Bacterial isolates from the UW (n=91) and SML (n=80), selected in media without antibiotic, were characterized concerning susceptibility against nine antibiotics. The presence of genes bla(TEM), bla(OXA-B), bla(SHV), bla(IMP), tet(A), tet(B), tet(E), tet(M), cat, sul1, sul2, sul3, aadA, IntI1, IntI2, and IntI3 was assessed by PCR. The variable regions of integrons were sequenced. Ampicillin- and streptomycin-resistant bacteria were significantly more prevalent in SML. Resistance levels among the bacterial collections were generally low, preventing detection of significant differences between SML and UW. The tet(E) gene was detected in two Aeromonas isolates and tet(M) was detected in a Pseudomonas isolate. Gene sul1 was amplified from three Aeromonas isolates. Prevalence of intI genes was 2.11%. Cassette arrays contained genes encoding resistance to aminoglycosides and chloramphenicol. A higher prevalence of antibiotic-resistant bacteria in the SML, although only detectable when bacteria were selected in antibiotic-supplemented agar, suggests that SML conditions select for antibiotic resistance. Results also showed that antibiotic resistance was uncommon among estuarine bacteria and the resistance mechanisms are probably predominantly intrinsic. PMID:23067198

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Reprogrammable microbial cell-based therapeutics against antibiotic-resistant bacteria.

    Science.gov (United States)

    Hwang, In Young; Koh, Elvin; Kim, Hye Rim; Yew, Wen Shan; Chang, Matthew Wook

    2016-07-01

    The discovery of antimicrobial drugs and their subsequent use has offered an effective treatment option for bacterial infections, reducing morbidity and mortality over the past 60 years. However, the indiscriminate use of antimicrobials in the clinical, community and agricultural settings has resulted in selection for multidrug-resistant bacteria, which has led to the prediction of possible re-entrance to the pre-antibiotic era. The situation is further exacerbated by significantly reduced antimicrobial drug discovery efforts by large pharmaceutical companies, resulting in a steady decline in the number of new antimicrobial agents brought to the market in the past several decades. Consequently, there is a pressing need for new antimicrobial therapies that can be readily designed and implemented. Recently, it has become clear that the administration of broad-spectrum antibiotics can lead to collateral damage to the human commensal microbiota, which plays several key roles in host health. Advances in genetic engineering have opened the possibility of reprogramming commensal bacteria that are in symbiotic existence throughout the human body to implement antimicrobial drugs with high versatility and efficacy against pathogenic bacteria. In this review, we discuss recent advances and potentialities of engineered bacteria in providing a novel antimicrobial strategy against antibiotic resistance. PMID:27449598

  3. Cooperative Electrostatic Polymer-Antibiotic Nanoplexes

    OpenAIRE

    Vadala, Timothy Patrick

    2010-01-01

    Many pathogenic bacteria can enter phagocytic cells and replicate in them, and these intracellular bacteria are difficult to treat because the recommended antibiotics do not transport into the cells efficiently. Examples include food-borne bacteria such as Salmonella and Listeria as well as more toxic bacteria such as Brucella and the Mycobacteria that lead to tuberculosis. Current treatments utilize aminoglycoside antibiotics that are polar and positively charged and such drugs do not ente...

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

    Directory of Open Access Journals (Sweden)

    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. 

  5. Direct laser light enhancement of susceptibility of bacteria to gentamicin antibiotic

    Science.gov (United States)

    Reznick, Yana; Banin, Ehud; Lipovsky, Anat; Lubart, Rachel; Zalevsky, Zeev

    2011-11-01

    ObjectivesTo test the effect of pulsed (Q-switched) and continuous wave (CW) laser light at wavelength of 532 nm on the viability of free-living stationary phase bacteria with and without gentamicin (an antibiotic) treatment. MethodsFree living stationary phase gram negative bacteria ( Pseudomonas aeruginosa strain PAO1) was immersed in Luria Broth (LB) solution and exposed to Q-switched and CW lasers with and without the addition of the antibiotic gentamicin. Cell viability was determined at different time points. ResultsLaser treatment alone did not reduce cell viability compared to untreated control and the gentamicin treatment alone only resulted in a 0.5 log reduction in the viable count for P. aeruginosa. The combined laser and gentamicin treatment, however, resulted in a synergistic effect and viability was reduced by 8 logs for P. aeruginosa PAO1. ConclusionsCombination of laser light with gentamicin shows an improved efficacy against P. aeruginosa.

  6. Single-cell protein induction dynamics reveals a period of vulnerability to antibiotics in persister bacteria.

    Science.gov (United States)

    Gefen, Orit; Gabay, Chana; Mumcuoglu, Michael; Engel, Giora; Balaban, Nathalie Q

    2008-04-22

    Phenotypic variability in populations of cells has been linked to evolutionary robustness to stressful conditions. A remarkable example of the importance of cell-to-cell variability is found in bacterial persistence, where subpopulations of dormant bacteria, termed persisters, were shown to be responsible for the persistence of the population to antibiotic treatments. Here, we use microfluidic devices to monitor the induction of fluorescent proteins under synthetic promoters and characterize the dormant state of single persister bacteria. Surprisingly, we observe that protein production does take place in supposedly dormant bacteria, over a narrow time window after the exit from stationary phase. Only thereafter does protein production stop, suggesting that differentiation into persisters fully develops over this time window and not during starvation, as previously believed. In effect, we observe that exposure of bacteria to antibiotics during this time window significantly reduces persistence. Our results point to new strategies to fight persistent bacterial infections. The quantitative measurement of single-cell induction presented in this study should shed light on the processes leading to the dormancy of subpopulations in different systems, such as in subpopulations of viable but nonculturable bacteria, or those of quiescent cancer cells. PMID:18427112

  7. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters

    Science.gov (United States)

    Miller, Jennifer H.; Novak, John T.; Knocke, William R.; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1—a Pseudomonas sp.) and thermophilic (Iso T10—a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457–0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130–0.486, P = 0.075–0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and

  8. Survival of Antibiotic Resistant Bacteria and Horizontal Gene Transfer Control Antibiotic Resistance Gene Content in Anaerobic Digesters.

    Science.gov (United States)

    Miller, Jennifer H; Novak, John T; Knocke, William R; Pruden, Amy

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) vs. their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1-a Pseudomonas sp.) and thermophilic (Iso T10-a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts and quantitative polymerase chain reaction (QPCR) of their corresponding tetracycline ARGs. In batch studies, spiked ARB plate counts returned to baseline (thermophilic) or 1-log above baseline (mesophilic) while levels of the ARG present in the spiked isolate [tet(G)] remained high in mesophilic batch reactors. To compare results under semi-continuous flow conditions with natural influent variation, tet(O), tet(W), and sul1 ARGs, along with the intI1 integrase gene, were monitored over a 9-month period in the raw feed sludge and effluent sludge of lab-scale thermophilic and mesophilic anaerobic digesters. sul1 and intI1 in mesophilic and thermophilic digesters correlated positively (Spearman rho = 0.457-0.829, P < 0.05) with the raw feed sludge. There was no correlation in tet(O) or tet(W) ratios in raw sludge and mesophilic digested sludge or thermophilic digested sludge (Spearman rho = 0.130-0.486, P = 0.075-0.612). However, in the thermophilic digester, the tet(O) and tet(W) ratios remained consistently low over the entire monitoring period. We conclude that the influent sludge microbial composition can influence the ARG content of a digester, apparently as a result of differential survival or death of ARBs or horizontal gene transfer of genes between raw sludge ARBs and the digester microbial community. Notably, mesophilic digestion was more susceptible to ARG intrusion than thermophilic digestion, which may be attributed to a higher rate of ARB survival and/or horizontal gene

  9. Fluoroquinolone-Resistant Enteric Bacteria in Sub-Saharan Africa: Clones, Implications and Research Needs.

    Science.gov (United States)

    Chattaway, Marie A; Aboderin, Aaron O; Fashae, Kayode; Okoro, Chinyere K; Opintan, Japheth A; Okeke, Iruka N

    2016-01-01

    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. PMID:27148238

  10. Single-cell protein induction dynamics reveals a period of vulnerability to antibiotics in persister bacteria

    OpenAIRE

    Gefen, Orit; Gabay, Chana; Mumcuoglu, Michael; Engel, Giora; Balaban, Nathalie Q.

    2008-01-01

    Phenotypic variability in populations of cells has been linked to evolutionary robustness to stressful conditions. A remarkable example of the importance of cell-to-cell variability is found in bacterial persistence, where subpopulations of dormant bacteria, termed persisters, were shown to be responsible for the persistence of the population to antibiotic treatments. Here, we use microfluidic devices to monitor the induction of fluorescent proteins under synthetic promoters and characterize ...

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

    OpenAIRE

    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); Alikhani, MY. (PhD); Nakhaee, S. (MD); Karami, P. (MSc

    2014-01-01

    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 i...

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. Gramicidin A Mutants with Antibiotic Activity against Both Gram-Positive and Gram-Negative Bacteria.

    Science.gov (United States)

    Zerfas, Breanna L; Joo, Yechaan; Gao, Jianmin

    2016-03-17

    Antimicrobial peptides (AMPs) have shown potential as alternatives to traditional antibiotics for fighting infections caused by antibiotic-resistant bacteria. One promising example of this is gramicidin A (gA). In its wild-type sequence, gA is active by permeating the plasma membrane of Gram-positive bacteria. However, gA is toxic to human red blood cells at similar concentrations to those required for it to exert its antimicrobial effects. Installing cationic side chains into gA has been shown to lower its hemolytic activity while maintaining the antimicrobial potency. In this study, we present the synthesis and the antibiotic activity of a new series of gA mutants that display cationic side chains. Specifically, by synthesizing alkylated lysine derivatives through reductive amination, we were able to create a broad selection of structures with varied activities towards Staphylococcus aureus and methicillin-resistant S. aureus (MRSA). Importantly, some of the new mutants were observed to have an unprecedented activity towards important Gram-negative pathogens, including Escherichia coli, Klebsiella pneumoniae and Psuedomonas aeruginosa. PMID:26918268

  17. Resistance to antibiotics in heterotrophic bacteria as a result of environmental pollution

    Directory of Open Access Journals (Sweden)

    Maria Bartoszewic

    2014-12-01

    Full Text Available Introduction. The aim of the study was to investigate resistance to selected antibiotics in Escherichia coli and Enterococcus faecalis strains that were isolated from water collected from ten streams within the administrative boundaries of the city of Sopot. Material and methods. 114 E. coli strains and 57 E. faecalis strains were studied. Antibiotic resistance was determined by the disc diffusion method using antibiotic-impregnated discs. Results. The isolated E. coli strains were resistant to chloramphenicol (21%, cefepime (51%, tetracycline (41%, imipenem (35%, cephazoline (62% and gentamicin (90%. E. faecalis isolates showed resistance to erythromycin (75%, chloramphenicol (21% and imipenem (33%. The relationship between the level of antibiotic resistance, the origin of water sample and the level of water contamination with E. coli and Enterococcus faecalis bacteria in the investigated streams was analyzed. Conclusions. Based on the obtained results, it was determined that multi-drug resistant bacterial strains of E. coli and E. faecalis are present in the investigated surface waters.

  18. Enteric bacteria and osmotic stress: intracellular potassium glutamate as a secondary signal of osmotic stress?

    Science.gov (United States)

    Booth, I R; Higgins, C F

    1990-06-01

    Enteric bacteria have evolved an impressive array of mechanisms that allow the cell to grow at widely different external osmotic pressures. These serve two linked functions; firstly, they allow the cell to maintain a relatively constant turgor pressure which is essential for cell growth; and secondly they permit changes in cytoplasmic composition such that the accumulation of intracellular osmolytes required to restore turgor pressure does not impair enzyme function. The primary event in turgor regulation is the controlled accumulation of potassium and its counterion glutamate. At high external osmolarities the cytoplasmic levels of potassium glutamate can impair enzyme function. Rapid growth is therefore dependent upon secondary responses, principally the accumulation of compatible solutes, betaine (N-trimethylglycine), proline and trehalose. The accumulation of these solutes is achieved by the controlled activity of transport systems and enzymes in response to changes in external osmotic pressure. It has been proposed that the accumulation of potassium glutamate during turgor regulation acts as a signal for the activation of these systems [1,2]. This brief review will examine the evidence that control over the balance of cytoplasmic osmolytes is achieved by sensing of the intracellular potassium (and glutamate) concentration. PMID:1974769

  19. Ozone treatment of conditioned wastewater selects antibiotic resistance genes, opportunistic bacteria, and induce strong population shifts.

    Science.gov (United States)

    Alexander, Johannes; Knopp, Gregor; Dötsch, Andreas; Wieland, Arne; Schwartz, Thomas

    2016-07-15

    An ozone treatment system was investigated to analyze its impact on clinically relevant antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs). A concentration of 0.9±0.1g ozone per 1g DOC was used to treat conventional clarified wastewater. PCR, qPCR analyses, Illumina 16S Amplicon Sequencing, and PCR-DGGE revealed diverse patterns of resistances and susceptibilities of opportunistic bacteria and accumulations of some ARGs after ozone treatment. Molecular marker genes for enterococci indicated a high susceptibility to ozone. Although they were reduced by almost 99%, they were still present in the bacterial population after ozone treatment. In contrast to this, Pseudomonas aeruginosa displayed only minor changes in abundance after ozone treatment. This indicated different mechanisms of microorganisms to cope with the bactericidal effects of ozone. The investigated ARGs demonstrated an even more diverse pattern. After ozone treatment, the erythromycin resistance gene (ermB) was reduced by 2 orders of magnitude, but simultaneously, the abundance of two other clinically relevant ARGs increased within the surviving wastewater population (vanA, blaVIM). PCR-DGGE analysis and 16S-Amplicon-Sequencing confirmed a selection-like process in combination with a substantial diversity loss within the vital wastewater population after ozone treatment. Especially the PCR-DGGE results demonstrated the survival of GC-rich bacteria after ozone treatment. PMID:27058129

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

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    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

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

    Science.gov (United States)

    Fraqueza, Maria João

    2015-11-01

    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. PMID:26002560

  2. 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.

  3. 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.

  4. Metal and antibiotic-resistance in psychrotrophic bacteria from Antarctic marine waters

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A; Chandramohan, D.

    genes in Escherichia coli. J. Bacteriol 171, 3458-3464. Smibert, R.M. and Krieg, N.R. (1981). General characterization In: Manual of methods for general bacteriology edt: Gerhardt P., Murray R.G.E., Costilow R.N. Nester E.W. Wood W.A. Krieg N... and antibiotic-resistance in psychrotrophic bacteria from Antarctic Marine waters Maria-Judith De Souza? , Shanta Nair, P.A. Loka bharathi and D. Chandramohan Abstract: In the wake of the findings that Antarctic krills concentrate heavy metals at ppm...

  5. Food Safety Hazards Related to Emerging Antibiotic Resistant Bacteria in Cultured Freshwater Fishes of Kolkata, India

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    T. Jawahar Abraham

    2011-02-01

    Full Text Available Association of opportunistic human bacterial pathogens in cultured freshwater fishes of Kolkata, India and their sensitivity to broad spectrum antibiotics was investigated. Both indigenous and non-indigenous human bacterial pathogens such as Aeromonas hydrophila, A. caviae, Edwardsiella tarda, Escherichia coli, Pseudomonas spp. and Vibrio parahaemolyticus were isolated from freshwater fishes of Kolkata. These strains were highly resistant to oxytetracycline (62% and nitrofurantoin (46%, and sensitive to ciprofloxacin (91% and chloramphenicol (89%. Multiple Antibiotic Resistance (MAR was high in catfishes (76% followed by miscellaneous fishes (66% and sewage-fed farm grown carps (55%. Among the bacterial species, the MAR was high in Ed. tarda (86%. More than 50% of the strains of A. hydrophila, A. caviae, E. coli, Pseudomonas spp., V. parahaemolyticus and unidentified Gram positive rods exhibited MAR. The results suggested that there is added risk of antibacterial resistance developing in the emerging human bacterial pathogens from freshwater aquaculture and of such antibiotic resistant bacterial pathogens entering the food chain.

  6. Monitoring and Comparison of Antibiotic Resistant Bacteria and Their Resistance Genes in Municipal and Hospital Wastewaters

    Directory of Open Access Journals (Sweden)

    Rahim Aali

    2014-01-01

    Full Text Available Background: Human exposure to antibiotic resistant bacteria (ARB is a public health concern which could occur in a number of ways. Wastewaters seem to play an important role in the dissemination of bacteria and antibiotic resistant genes (ARGs in our environment. The aim of this study was to evaluate the occurrence of three groups of ARB and their resistance genes in hospital and municipal wastewaters (MWs as possible sources. Methods: A total of 66 samples were collected from raw MWs and hospital wastewaters (HWs and final effluents of related wastewater treatment plants (WWTPs. Samples were analyzed for the detection of three groups of ARB including gentamicin (GM, chloramphenicol (CHL and ceftazidime resistant bacteria and their ARGs (aac (3-1, cmlA1 and ctx-m-32, respectively. Results: The mean concentration of GM, CHL and ceftazidime resistant bacteria in raw wastewater samples was 1.24 × 10 7 , 3.29 × 10 7 and 5.54 × 10 7 colony forming unit/100 ml, respectively. There is a variation in prevalence of different groups of ARB in MWs and HWs. All WWTPs decreased the concentration of ARB. However, high concentration of ARB was found in the final effluent of WWTPs. Similar to ARB, different groups of ARGs were found frequently in both MWs and HWs. All genes also detected with a relative high frequency in effluent samples of MWs WWTPs. Conclusions: Discharge of final effluent from conventional WWTPs is a potential route for dissemination of ARB and ARGs into the natural environment and poses a hazard to environmental and public health.

  7. The Goldilocks Principle and Rapid Evolution of Antibiotic Resistance in Bacteria

    Science.gov (United States)

    Zhang, Qiucen; Austin, Robert

    2011-03-01

    Goldilocks sampled the three bear's wares for the ``just right'' combination of taste, fit and comfort. Like Goldilocks's need for the just right parameters, evolution proceeds most rapidly when there is the just right combination of a large number of mutants and rapid fixation of the mutants. We show here using a two-dimensional micro-ecology that it is possible to fix resistance to the powerful antibiotic ciprofloxacin (Cipro) in wild-type E. coli in 10 hours through a combination of extremely high population gradients, which generate rapid fixation, convolved with the just right level of antibiotic which generates a large number of mutants and the motility of the organism. Although evolution occurs in well-stirred chemostats without such Goldilocks conditions, natural environments are rarely well stirred in nature.For complex environments such as the Galapagos Islands, spatial population gradients and movement of mutants along these population gradients can be as important as genomic heterogeneity in setting the speed of evolution. The design of our micro-ecology is unique in that it provides two overlapping gradients, one an emergent and self generated bacterial population gradient due to food restriction and the other a mutagenic antibiotic gradient. Further, it exploits the motility of the bacteria moving across these gradients to drive the rate of resistance to Cipro to extraordinarily high rates. The research described was supported by Award Number U54CA143803 from the National Cancer Institute.

  8. Pandrug-resistant Gram-negative bacteria: the dawn of the post-antibiotic era?

    Science.gov (United States)

    Falagas, Matthew E; Bliziotis, Ioannis A

    2007-06-01

    The evolving problem of antimicrobial resistance in Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae has led to the emergence of clinical isolates susceptible to only one class of antimicrobial agents and eventually to pandrug-resistant (PDR) isolates, i.e. resistant to all available antibiotics. We reviewed the available evidence from laboratory and clinical studies that reported on polymyxin-resistant and/or PDR P. aeruginosa, A. baumannii or K. pneumoniae clinical isolates. Eleven laboratory studies reported on isolates with resistance to polymyxins, three of which (including two surveillance studies) also included data regarding PDR isolates. In addition, two clinical studies (from Central and Southern Europe) reported on the clinical characteristics and outcomes of patients infected with PDR isolates. These data suggest that polymyxin-resistant or PDR P. aeruginosa, A. baumannii and K. pneumoniae clinical isolates are currently relatively rare. However, they have important global public health implications because of the therapeutic problems they pose. The fears for the dawn of a post-antibiotic era appear to be justified, at least for these three Gram-negative bacteria. We must increase our efforts to preserve the activity of available antibiotics, or at least expand as much as possible the period of their use, whilst intense research efforts should be focused on the development and introduction into clinical practice of new antimicrobial agents. PMID:17306965

  9. High-throughput screening of antibiotic-resistant bacteria in picodroplets.

    Science.gov (United States)

    Liu, X; Painter, R E; Enesa, K; Holmes, D; Whyte, G; Garlisi, C G; Monsma, F J; Rehak, M; Craig, F F; Smith, C A

    2016-04-26

    The prevalence of clinically-relevant bacterial strains resistant to current antibiotic therapies is increasing and has been recognized as a major health threat. For example, multidrug-resistant tuberculosis and methicillin-resistant Staphylococcus aureus are of global concern. Novel methodologies are needed to identify new targets or novel compounds unaffected by pre-existing resistance mechanisms. Recently, water-in-oil picodroplets have been used as an alternative to conventional high-throughput methods, especially for phenotypic screening. Here we demonstrate a novel microfluidic-based picodroplet platform which enables high-throughput assessment and isolation of antibiotic-resistant bacteria in a label-free manner. As a proof-of-concept, the system was used to isolate fusidic acid-resistant mutants and estimate the frequency of resistance among a population of Escherichia coli (strain HS151). This approach can be used for rapid screening of rare antibiotic-resistant mutants to help identify novel compound/target pairs. PMID:27033300

  10. 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.

  11. 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.

  12. 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.

  13. Assessment of copper and zinc salts as selectors of antibiotic resistance in Gram-negative bacteria.

    Science.gov (United States)

    Becerra-Castro, Cristina; Machado, Rita A; Vaz-Moreira, Ivone; Manaia, Célia M

    2015-10-15

    Some metals are nowadays considered environmental pollutants. Although some, like Cu and Zn, are essential for microorganisms, at high concentrations they can be toxic or exert selective pressures on bacteria. This study aimed to assess the potential of Cu or Zn as selectors of specific bacterial populations thriving in wastewater. Populations of Escherichia coli recovered on metal-free and metal-supplemented culture medium were compared based on antibiotic resistance phenotype and other traits. In addition, the bacterial groups enriched after successive transfers in metal-supplemented culture medium were identified. At a concentration of 1mM, Zn produced a stronger inhibitory effect than Cu on the culturability of Enterobacteriaceae. It was suggested that Zn selected populations with increased resistance prevalence to sulfamethoxazole or ciprofloxacin. In non-selective culture media, Zn or Cu selected for mono-species populations of ubiquitous Betaproteobacteria and Flavobacteriia, such as Ralstonia pickettii or Elizabethkingia anophelis, yielding multidrug resistance profiles including resistance against carbapenems and third generation cephalosporins, confirming the potential of Cu or Zn as selectors of antibiotic resistant bacteria. PMID:26057541

  14. Bacteriophage and lytic enzymes - can they help us in the war with antibiotic resistant bacteria

    International Nuclear Information System (INIS)

    Drug-resistant pathogens are a growing menace to all people, regardless of age, or socioeconomic background. They endanger people industrial societies like the United States, as well as in less developed nations and are even causing problems in military field hospitals. From Streptococcus pneumoniae to Staphylococcus, C. difficile, and multidrug-resistant TB, the list is growing. The threat of engineered microorganisms further complicates the interaction between man and Mother Nature. Additionally, although antibiotics were specifically designed for treating human health emergencies, their use for raising livestock animals has expanded. In the US, large amounts of antibiotics are routinely mixed into feed in order to promote growth rather than combat disease and as prophylactic treatment to offset unnatural diets and unhealthy living conditions. U.S.-raised animals in the 1950s received 2 million pounds per year of antibiotics in their feed compared to 50 million pounds today-a 2,500-percent increase. A large percentage of these drugs pass into the environment. In fact, prior to 1995, when fluoroquinolones were first approved to treat poultry, very few fluoroquinolone-resistant Campylobacter were found in people with foodborne diseases in the United States. After the approval, however, many more fluoroquinolone-resistant bacteria were found in humans and in poultry from slaughter plants and retail stores. The threat to our food supply becomes a threat to security. What can be done? One approach is to treat bacterial diseases by the use of bacteriophages. Phages are very small viruses that destroy by lysing select bacteria. The idea of using phage as a therapy for infectious bacterial diseases was first proposed by d'Herelle around World War I and over 80 years bacteriophage has been a key tool of healthcare professionals within Eastern Europe. More recently professionals in the USA and Western Europe have isolated and developed specific lytic components which have

  15. Distinction between intact and antibiotic-inactivated bacteria by real-time PCR after treatment with propidium monoazide.

    Science.gov (United States)

    Kobayashi, Hideo; Oethinger, Margret; Tuohy, Marion J; Hall, Gerri S; Bauer, Thomas W

    2010-09-01

    One limitation to the use of the polymerase chain reaction (PCR) to identify orthopedic infections has been apparent false-positive results, possibly due to the detection of dead bacteria. We recently showed that the use of DNA-binding agent propidium monoazide (PMA) could distinguish viable from heat-inactivated bacteria, and, in this study, we investigated whether the same technique can be applied to bacteria killed by two antibiotics with distinctly different mechanisms of action, a test of greater clinical relevance than thermal inactivation. Staphylococcus aureus and S. epidermidis were inactivated by vancomycin and gentamicin and treated with PMA or left untreated before DNA extraction. The threshold cycle difference of antibiotic-treated bacteria with and without PMA pretreatment was investigated with PCR primers for the 16S rDNA and tuf genes. Our results indicated that PMA effectively inhibited detection by PCR of bacteria, which had been inactivated by either vancomycin or gentamicin. The effect was statistically significant at 24 h after treatment (C(t) difference consistently >3; p 4; p cells (C(t) difference 1-2). Vancomycin had a stronger effect on the C(t) value than gentamicin, reflecting the different mechanism of action of each antibiotic. Techniques of this type may help reduce clinically false-positive PCR results caused by the detection of dead bacteria, and may be especially useful in patients who have received antibiotics, such as patients undergoing the second stage of a two-stage revision for infected arthroplasty. PMID:20186836

  16. Antibiotic susceptibility patterns of isolated bacteria from bile fluids of patients with gallstone disease in Isfahan city (Iran

    Directory of Open Access Journals (Sweden)

    Fatemi Seyed-Masih

    2015-01-01

    Full Text Available Bacterial infections are one of the important agents in the creation of gallstones in the gallbladder. In recent years the spread of antibiotic-resistant bacteria such as extended-spectrum β-lactamases (ESBL is increasing and of concern in hospitalized patients worldwide. The purpose of this study was to investigate the antibiotic susceptibility patterns of isolated bacteria from the bile specimens of patients with chronic and acute cholecystitis who had been operated by single-incision laparoscopic cholecystectomy (SILC in Isfahan (Iran 2 using an antibiogram susceptibility test and molecular technique. The bile fluids of 91 patients were obtained from the Al-Zahra hospital and were cultured on specific media for the isolation of Gram-negative and positive bacteria and the disk diffusion test was done to determine the antibiotic susceptibility patterns of isolated bacteria. Finally, bacterial DNA was extracted from the bile samples and polymerase chain reaction (PCR was performed to investigate extended-spectrum β-lactamases genes. The bacteria Escherichia coli, Klebsiella pneumoniae, Proteus spp. and Staphylococcus aureus were detected in bile specimens cultured with high frequency, and the results showed that biliary infection increased with aging in patients with gallstone disease operated by SILC. The results showed a high frequency of ESBL genes including TEM, SHV, and CTX-M in isolated bacteria (especially Escherichia coli and Klebsiella spp.. Thus, evaluating the antibiotic susceptibility patterns and screening of ESBLs bacteria in patients with gallstones are essential. Prescribing suitable drugs, designing good strategies, and informing the medical community could decrease bile infection and antibiotic-resistant bacteria in clinical centers and hospitals.

  17. 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. PMID:20303077

  18. 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

  19. Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana) raised in Malaysia

    OpenAIRE

    Lee SW; M. Najiah; W Wendy; M Nadirah; SH Faizah

    2009-01-01

    A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana) raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3%) cases of sensitivity and 61 (7.3%) cases of partial sensitivity. Meanwhile, 297 (35.4%) bacterial isolates were registe...

  20. Spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics

    OpenAIRE

    Naik Subhash R; Ranjan Piyush; Ghoshal Uday C; Ghoshal Ujjala; Ayyagari Archana

    2003-01-01

    Abstract Background Various causes of malabsorption syndrome (MAS) are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (SIBO). Frequency, nature and antibiotic sensitivity of SIBO in patients with MAS are not well understood. Methods Jejunal aspirates of 50 consecutive patients with MAS were cultured for bacteria and colony counts and antibiotic sensitivity were performed. Twelve patients with irritable bowel syndrome were studied as controls. Results Cu...

  1. Microbiological and biochemical studies on certain antibiotic-resistant bacteria isolated from certain clinical specimens

    International Nuclear Information System (INIS)

    Infection is a dynamic process involving invasion of the body by pathogenic microorganisms and reactions of the tissues to microorganisms and their toxins. Pathogenic microorganisms isolated from clinical samples are of great threat to human health.The outcome of an infection depends on the virulence of the pathogen and the relative degree of resistance or susceptibility to antimicrobial chemotherapy. Antimicrobial agents interfere with specific processes that are essential for growth and division.Development of antibiotic resistance in bacteria is a problem of great concern. The high prevalence of resistant bacteria seems to be related to uncontrolled usage of antibiotics. B-lactamases are the most common cause of bacterial resistance to B-lactam antimicrobial agents, and it is one of the most important reason for increasing the resistance in pathogenic bacteria against some antibiotics especially those acting on inhibition of cell wall synthesis. One hundred and seven clinical samples and specimens were collected from public, private hospitals and National Cancer Institute (NCI) in Cairo, Egypt. Out of them 72 cases positive for microbial infection. Twelve cases were showed mixed infection. Eighty four isolates of pathogenic bacteria and yeast were collected from single and mixed culture. Susceptibilities of the isolates to 20 different antimicrobial agents were determined according to Kirby-Bauer method. Nine multi-drug resistant gram-negative bacterial strains were identified by (Micro Scan WalkAway 96 SI System). Six of them urine isolates, 2 wound (pus) isolates and one sputum isolate. The identified strains were exposed to in-vitro gamma irradiation at dose level of 24.4 Gy, which is biologically equivalent to the fractionated multiple therapeutic dose used in the protocol of cancer treatment of some patients. The antimicrobial susceptibility of the nine multi-drug resistant strains were carried out by disk diffusion method before and after irradiation

  2. 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...

  3. 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.

  4. The role of bacteria in lactational mastitis and some considerations of the use of antibiotic treatment

    Directory of Open Access Journals (Sweden)

    Hall-Lord Marie

    2008-04-01

    Full Text Available Abstract Background The role of bacterial pathogens in lactational mastitis remains unclear. The objective of this study was to compare bacterial species in breast milk of women with mastitis and of healthy breast milk donors and to evaluate the use of antibiotic therapy, the symptoms of mastitis, number of health care contacts, occurrence of breast abscess, damaged nipples and recurrent symptoms in relation to bacterial counts. Methods In this descriptive study, breast milk from 192 women with mastitis (referred to as cases and 466 breast milk donors (referred to as controls was examined bacteriologically and compared using analytical statistics. Statistical analyses were also carried out to test for relationships between bacteriological content and clinical symptoms as measured on scales, prescription of antibiotics, the number of care contacts, occurrence of breast abscess and recurring symptoms. Results Five main bacterial species were found in both cases and controls: coagulase negative staphylococci (CNS, viridans streptococci, Staphylococcus aureus (S. aureus, Group B streptococci (GBS and Enterococcus faecalis. More women with mastitis had S. aureus and GBS in their breast milk than those without symptoms, although 31% of healthy women harboured S. aureus and 10% had GBS. There were no significant correlations between bacterial counts and the symptoms of mastitis as measured on scales. There were no differences in bacterial counts between those prescribed and not prescribed antibiotics or those with and without breast abscess. GBS in breast milk was associated with increased health care contacts (p = 0.02. Women with ≥ 107 cfu/L CNS or viridans streptococci in their breast milk had increased odds for damaged nipples (p = 0.003. Conclusion Many healthy breastfeeding women have potentially pathogenic bacteria in their breast milk. Increasing bacterial counts did not affect the clinical manifestation of mastitis; thus bacterial counts in

  5. 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

  6. The Relative Contributions of Physical Structure and Cell Density to the Antibiotic Susceptibility of Bacteria in Biofilms

    OpenAIRE

    Kirby, Amy E.; Garner, Kimberly; Levin, Bruce R.

    2012-01-01

    For many bacterial infections, noninherited mechanisms of resistance are responsible for extending the term of treatment and in some cases precluding its success. Among the most important of these noninherited mechanisms of resistance is the ability of bacteria to form biofilms. There is compelling evidence that bacteria within biofilms are more refractory to antibiotics than are planktonic cells. Not so clear, however, is the extent to which this resistance can be attributed to the structure...

  7. Kinetics and strain specificity of rhizosphere and endophytic colonization by enteric bacteria on seedlings of Medicago sativa and Medicago truncatula.

    Science.gov (United States)

    Dong, Yuemei; Iniguez, A Leonardo; Ahmer, Brian M M; Triplett, Eric W

    2003-03-01

    The presence of human-pathogenic, enteric bacteria on the surface and in the interior of raw produce is a significant health concern. Several aspects of the biology of the interaction between these bacteria and alfalfa (Medicago sativa) seedlings are addressed here. A collection of enteric bacteria associated with alfalfa sprout contaminations, along with Escherichia coli K-12, Salmonella enterica serotype Typhimurium strain ATCC 14028, and an endophyte of maize, Klebsiella pneumoniae 342, were labeled with green fluorescent protein, and their abilities to colonize the rhizosphere and the interior of the plant were compared. These strains differed widely in their endophytic colonization abilities, with K. pneumoniae 342 and E. coli K-12 being the best and worst colonizers, respectively. The abilities of the pathogens were between those of K. pneumoniae 342 and E. coli K-12. All Salmonella bacteria colonized the interiors of the seedlings in high numbers with an inoculum of 10(2) CFU, although infection characteristics were different for each strain. For most strains, a strong correlation between endophytic colonization and rhizosphere colonization was observed. These results show significant strain specificity for plant entry by these strains. Significant colonization of lateral root cracks was observed, suggesting that this may be the site of entry into the plant for these bacteria. At low inoculum levels, a symbiosis mutant of Medicago truncatula, dmi1, was colonized in higher numbers on the rhizosphere and in the interior by a Salmonella endophyte than was the wild-type host. Endophytic entry of M. truncatula appears to occur by a mechanism independent of the symbiotic infections by Sinorhizobium meliloti or mycorrhizal fungi. PMID:12620870

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

    Directory of Open Access Journals (Sweden)

    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

  9. [A comparative study of various evaluation methods of the antibiotic sensitivity of strict anaerobic bacteria of the subgingival flora].

    Science.gov (United States)

    Kamagate, A; Kone, D; Coulibaly, N T; Brou, E; Sixou, M

    2001-09-01

    The study on the sensitiveness of slow-growing anaerobes bacteria to antibiotics is delicate when you consider the technical motives that make it difficult to transpose the standard methods frequently used in microbiological laboratories. The three main methods used to determine susceptibility to antibiotics are: disk-diffusion test, antibiotics containing microdilution plates and ATB ANA (bioMérieux). The aim of this study is to compare the effectiveness of each of these methods on severe anaerobes bacteria isolated in sub-gingival flora of patients suffering from developing periodontitis (rapidly progressive periodontitis, refractory periodontitis, active stage of adult chronic periodontitis). The observed bacteria are: Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus micros. Antibiotics used are: ampicilline, amoxicilline, tetracycline, erythromycine, metronidazole. The comparison of the minimal inhibitory concentrations (M.I.C) of each of these methods has permitted to show a strict correlation in the results observed with these three methods, if only the growth of the severe anaerobes bacteria on agar medium does not exceed 72 hours. PMID:11808376

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. A laminated polymer film formulation for enteric delivery of live vaccine and probiotic bacteria

    OpenAIRE

    de Barros, João M. S.; Scherer, Timothy; Charalampopoulos, Dimitris; Khutoryanskiy, Vitaliy V.; Edwards, Alexander D.

    2014-01-01

    Live bacterial cells (LBC) are administered orally as attenuated vaccines, to deliver biopharmaceutical agents, and as probiotics to improve gastrointestinal health. However, LBC present unique formulation challenges and must survive gastrointestinal antimicrobial defenses including gastric acid after administration. We present a simple new formulation concept, termed Polymer Film Laminate (PFL). LBC are ambient dried onto cast acid-resistant enteric polymer films that are then laminated toge...

  13. 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 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. PMID:27334345

  14. 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. PMID:26022411

  15. Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana raised in Malaysia

    Directory of Open Access Journals (Sweden)

    SW Lee

    2009-01-01

    Full Text Available A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3% cases of sensitivity and 61 (7.3% cases of partial sensitivity. Meanwhile, 297 (35.4% bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0%. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Antibiotic Resistance

    Science.gov (United States)

    Antibiotics are medicines that fight bacterial infections. Used properly, they can save lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able to resist the effects of an antibiotic. Using antibiotics can lead to resistance. ...

  18. 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. PMID:26241491

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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. PMID:27210560

  2. Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value.

    Science.gov (United States)

    Igbeneghu, Oluwatoyin A; Abdu, Abdulrasheed B

    2014-06-01

    Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers. PMID:25076655

  3. Evaluation of antibiotics against the bacteria, Candidatus Liberibacter for control of citrus Huanglongbing

    OpenAIRE

    Zhang, Muqing; Guo, Ying; Powell, Charles A.; Duan, Yongping

    2014-01-01

    Citrus Huanglongbing (HLB) is one of the most serious diseases of citrus worldwide. The present study was undertaken to screen antibiotics against Candidatus Liberibacter asiaticus (Las) while simultaneously assessing phytotoxicity to citrus. Twenty-eight antibiotics from ten classes of medical-antibiotics and three agricultural-antibiotics were tested for in vivo activities against HLB bacterium using the previously optimized graft-based chemotherapy method (Zhang et al., 2012). First, sampl...

  4. Interactions Between Bacteria and the Gut Mucosa: Do Enteric Neurotransmitters Acting on the Mucosal Epithelium Influence Intestinal Colonization or Infection?

    Science.gov (United States)

    Green, Benedict T; Brown, David R

    2016-01-01

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include enteric neurons, whose activity is influenced by bacterial pathogens, and their secreted products. Neurotransmitters appear to influence epithelial associations with bacteria in the intestinal lumen. For example, internalization of Salmonella enterica and Escherichia coli O157:H7 into the Peyer's patch mucosa of the small intestine is altered after the inhibition of neural activity with saxitoxin, a neuronal sodium channel blocker. Catecholamine neurotransmitters, such as dopamine and norepinephrine, also alter bacterial internalization in Peyer's patches. In the large intestine, norepinephrine increases the mucosal adherence of E. coli. These neurotransmitter actions are mediated by well-defined catecholamine receptors situated on the basolateral membranes of epithelial cells rather than through direct interactions with luminal bacteria. Investigations of the involvement of neuroepithelial communication in the regulation of interactions between the intestinal mucosa and luminal bacteria will provide novel insights into the mechanisms underlying bacterial colonization and pathogenesis at mucosal surfaces. PMID:26589216

  5. 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)

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

    International Nuclear Information System (INIS)

    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. 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

  8. Antibiotics.

    Science.gov (United States)

    Hariprasad, Seenu M; Mieler, William F

    2016-01-01

    The Endophthalmitis Vitrectomy Study (EVS) provided ophthalmologists with evidence-based management strategies to deal with endophthalmitis for the first time. However, since the completion of the EVS, numerous unresolved issues remain. The use of oral antibiotics has important implications for the ophthalmologist, particularly in the prophylaxis and/or management of postoperative, posttraumatic, or bleb-associated bacterial endophthalmitis. One can reasonably conclude that significant intraocular penetration of an antibiotic after oral administration may be a property unique to the newer-generation fluoroquinolones. Prophylactic use of mupirocin nasal ointment resulted in significant reduction of conjunctival flora with or without preoperative topical 5% povidone-iodine preparation. Ocular fungal infections have traditionally been very difficult to treat due to limited therapeutic options both systemically and intravitreally. Because of its broad spectrum of coverage, low MIC90 levels for the organisms of concern, good tolerability, and excellent bioavailability, voriconazole through various routes of administration may be useful to the ophthalmologist in the primary treatment of or as an adjunct to the current management of ocular fungal infections. PMID:26501865

  9. Antibiotics supplemented culture media can eliminate non-specific bacteria from human semen during sperm preparation for intra uterine insemination

    Directory of Open Access Journals (Sweden)

    D. M. A. B. Dissanayake

    2014-01-01

    Full Text Available Rationale: Bacterial flora can be isolated from many semen samples of subfertile males. Bacteriospermia can compromise the outcome of intra uterine insemination (IUI by contaminating the post-processed sperm sample. Objectives: The objective of the present study is to determine the efficacy of penicillin and streptomycin in eliminating the bacteria from semen samples in the sperm processing procedure, and to assess the effects of antibiotics on sperm motility, survivability, and pregnancy rates. Design and Settings: A prospectively controlled study was carried out using couples undergoing IUI with their informed consent. Intervention: Sperm processing using the swim-up technique in penicillin and streptomycin supplemented culture medium. Subjects And Methods: Couples were consecutively allocated in two groups for sperm processing (a Group AB+ (antibiotics supplemented culture medium, n = 33 and (b Group AB− (antibiotic free culture medium, n = 33. Semen culture was performed before and after sperm processing. Sperm motility was assessed immediately after processing and after 24 h of incubation. Results: Bacterial isolates were found in 20 (60.6% and 22 (66.1% of samples before processing in Groups AB+ and AB− respectively. Addition of antibiotics resulted in completely eliminating non-specific bacteria from semen samples without affecting sperm motility. In vitro survival rate of sperm enhanced in AB+ group compared with AB− group (motile sperm after 24 h, 62.21% (standard deviation [SD]: 37.27 versus 41.36% (SD: 30.78, P = 0.012. Pregnancy rate, was comparable between two groups (9% in Group AB+ vs. 6% in Group AB−, P = 0.45. Conclusion: Penicillin streptomycin combination could completely eliminate non-specific bacteria from semen samples during sperm processing in this population. The types of antibiotics and dosage used did not seem to have any harmful effects on human sperm.

  10. 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.

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

    OpenAIRE

    Kailong Huang; Junying Tang; Xu-Xiang Zhang; Ke Xu; Hongqiang Ren

    2014-01-01

    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 cons...

  12. Frequency and Antibiotic Susceptibility Pattern of Amp C Beta Lactamase Producing Bacteria Isolated from a Tertiary Care Hospital of Pakistan

    OpenAIRE

    Afreenish Hassan; Javaid Usman; Fatima Kaleem; Maria Omair; Ali Khalid; Muhammad Iqabal

    2011-01-01

    Objective: Amp C beta lactamases are cephalosporinases which hydrolyze cephamycins and are poorlyinhibited by clavulanic acid. Amp C beta lactamases confer resistance to a wide variety of antibiotics andpose both diagnostic and therapeutic challenges, The objective was to detect the frequency and antibioticsusceptibility pattern of Amp C beta lactamase producing bacteria isolated from a tertiary care hospital ofPakistan.Methodology: Organisms were isolated from various clinical specimens. Fir...

  13. Antibacterial Activities of Selected Cameroonian Plants and Their Synergistic Effects with Antibiotics against Bacteria Expressing MDR Phenotypes

    Directory of Open Access Journals (Sweden)

    Stephen T. Lacmata

    2012-01-01

    Full Text Available The present work was designed to assess the antibacterial properties of the methanol extracts of some Cameroonian medicinal plants and the effect of their associations with currently used antibiotics on multidrug resistant (MDR Gram-negative bacteria overexpressing active efflux pumps. The antibacterial activities of twelve methanol extracts of medicinal plants were evaluated using broth microdilution. The results of this test showed that three extracts Garcinia lucida with the minimal inhibitory concentrations (MIC varying from 128 to 512 μg/mL, Garcinia kola (MIC of 256 to 1024 μg/mL, and Picralima nitida (MIC of 128 to 1024 μg/mL were active on all the twenty-nine studied bacteria including MDR phenotypes. The association of phenylalanine arginine β-naphthylamide (PAβN or efflux pumps inhibitor to different extracts did not modify their activities. At the concentration of MIC/2 and MIC/5, the extracts of P. nitida and G. kola improved the antibacterial activities of some commonly used antibiotics suggesting their synergistic effects with the tested antibiotics. The results of this study suggest that the tested plant extracts and mostly those from P. nitida, G. lucida and G. kola could be used alone or in association with common antibiotics in the fight of bacterial infections involving MDR strains.

  14. Sustainability of Water Reclamation: Long-Term Recharge with Reclaimed Wastewater Does Not Enhance Antibiotic Resistance in Sediment Bacteria

    Directory of Open Access Journals (Sweden)

    Jean E. McLain

    2014-03-01

    Full Text Available Wastewater reclamation for municipal irrigation is an increasingly attractive option for extending water supplies. However, public health concerns include the potential for development of antibiotic resistance (AR in environmental bacteria after exposure to residual pharmaceuticals in reclaimed water. Though scientific studies have reported high levels of AR in soils irrigated with wastewater, these works often fail to address the soil resistome, or the natural occurrence of AR. This study compared AR patterns in sediment Enterococcus isolated from water storage basins containing either reclaimed water or groundwater in central Arizona. Resistance to 16 antibiotics was quantified in isolates to a depth of 30 cm. Results reveal high levels of resistance to certain antibiotics, including lincomycin, ciprofloxacin, and erythromycin, exists in sediments regardless of the water source (groundwater, reclaimed water, and higher AR was not detectable in reclaimed water sediments. Furthermore, multiple-antibiotic-resistance (MAR was substantially reduced in isolates from reclaimed water sediments, compared to freshwater sediment isolates. Comparing the development of AR in sediment bacteria at these two sites will increase awareness of the environmental and public health impacts of using reclaimed water for irrigation of municipal areas, and illustrates the necessity for control sites in studies examining AR development in environmental microbiota.

  15. 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

    2012-01-01

    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. PMID:22036077

  16. Enhanced antibiotic multi-resistance in nasal and faecal bacteria after agricultural use of streptomycin.

    Science.gov (United States)

    Scherer, Alexandre; Vogt, Hans-Rudolf; Vilei, Edy M; Frey, Joachim; Perreten, Vincent

    2013-01-01

    Streptomycin is used in arboriculture to control fire blight. Using sheep as a model, multidrug-resistant bacteria in mammals were found to be selected after the intentional release of streptomycin into the environment. Escherichia coli and Staphylococcus spp. were isolated from the faeces and nasal cavities, respectively, of sheep grazing on a field sprayed with streptomycin at concentrations used in orchards (test group) and on a field without streptomycin (control group). Before the application of streptomycin, the percentage of streptomycin-resistant E. coli isolates in faeces was 15.8% in the control group and 14.7% in the test group. After the application of streptomycin, the overall number of streptomycin-resistant E. coli isolates was significantly higher in the test group (39.9%) than in the control group (22.3%). Streptomycin-resistant Staphylococcus isolates were only detected after the application of streptomycin. Streptomycin resistance was frequently associated with resistance to sulfamethoxazole, ampicillin, tetracycline and chloramphenicol and less frequently to cefotaxime in E. coli, and to tetracycline, fusidic acid and tiamulin in Staphylococcus spp. This study shows that the application of low concentrations of streptomycin on grass, as occurs during the spraying of orchards, selects for multidrug-resistant nasal and enteric bacterial flora, including extended-spectrum beta-lactamase-producing E. coli. PMID:23157680

  17. 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. PMID:17037154

  18. Killing of enteric bacteria in drinking water by a copper device for use in the home: laboratory evidence.

    Science.gov (United States)

    Sudha, V B Preethi; Singh, K Ojit; Prasad, S R; Venkatasubramanian, Padma

    2009-08-01

    Water inoculated with 500-1000 colony forming units/ml of Escherichia coli, Salmonella Typhi and Vibrio cholerae was stored overnight at room temperature in copper pots or in glass bottles containing a copper coil devised by us. The organisms were no longer recoverable when cultured on conventional media, by contrast with water stored in control glass bottles under similar conditions. The amount of copper leached into the water after overnight storage in a copper pot or a glass bottle with a copper device was less than 475 parts per billion, which is well within the safety limits prescribed by the WHO. The device is inexpensive, reusable, easy to maintain, durable, does not need energy to run and appears to be safe. It has the potential to be used as a household water purification method for removing enteric bacteria, especially in developing countries. PMID:19230946

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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. PMID:26978717

  2. Natural Hot Spots for Gain of Multiple Resistances: Arsenic and Antibiotic Resistances in Heterotrophic, Aerobic Bacteria from Marine Hydrothermal Vent Fields

    OpenAIRE

    Farias, Pedro; Espírito Santo, Christophe; Branco, Rita; Francisco, Romeu; Santos, Susana; Hansen, Lars; Sorensen, Soren; Morais, Paula V.

    2015-01-01

    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...

  3. The frequency of antibiotic-resistant bacteria in homes differing in their use of surface antibacterial agents.

    Science.gov (United States)

    Marshall, Bonnie M; Robleto, Eduardo; Dumont, Theresa; Levy, Stuart B

    2012-10-01

    Antibacterial agents are common in household cleaning and personal care products, but their long-range impacts on commensal and pathogenic household bacteria are largely unknown. In a one-time survey of 38 households from Boston, MA [19] and Cincinnati, OH [18], 13 kitchen and bathroom sites were sampled for total aerobic bacteria and screened for gram phenotype and susceptibility to six antibiotic drug families. The overall bacterial titers of both user (2 or more antibacterial cleaning or personal care products) and non-user (0 or 1 product) rooms were similar with sponges and sink drains consistently showing the highest overall titers and relatively high titers of antibiotic-resistant bacteria. The mean frequency of resistant bacteria ranged from ≤20 % to as high as 45 % and multi-drug resistance was common. However, no significant differences were noted between biocide users and non-users. The frequency of pathogen recovery was similar in both user and non-user groups. PMID:22752336

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

    Science.gov (United States)

    Singh, Bhoj R; Singh, Vidya; Ebibeni, N; Singh, Raj K

    2013-01-01

    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%). PMID:24223595

  5. 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...

  6. 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

  7. Antibiotic resistance in bacteria isolated from freshwater aquacultures and prediction of the persistence and toxicity of antimicrobials in the aquatic environment.

    Science.gov (United States)

    Lim, Seung J; Jang, Eunhee; Lee, Sang-Hun; Yoo, Byeong-Hak; Kim, Sun-Kyoung; Kim, Tak-Hyun

    2013-01-01

    The occurrence of antibiotic-resistant bacteria isolated from freshwater aquaculture effluents was investigated. The bacterial strains were collected from four different freshwater aquaculture effluents (catfish, trout, eel, and loach). Based on sequence of 16S rRNA, a total of 20 bacterial strains was isolated and one half of the isolated bacteria were Aeromonas sp. The antimicrobial sensitivity test was performed using the disc diffusion method. Individual antibiotic-resistant bacteria to antimicrobials were 41.7% and multiple antibiotic resistant bacteria were 58.3%. The disinfection of antibiotic-resistant bacteria by electron beam (E-beam) irradiation was carried out using an electron accelerator. Antibiotic-resistant bacteria were effectively disinfected by E-beam irradiation. The isolated bacteria were completely disinfected at a dose of less than 2 kGy. The persistence and toxicity of each antimicrobial in the aquatic environment was estimated due to the human health and ecosystems. In order to estimate the persistence and toxicity of antimicrobials in the aquatic environment, two quantitative structure activity relationship (QSAR) models were used. The persistence and toxicity of each antimicrobial were influenced on its hydrophobicity. In addition, QSAR models showed that isoelectric point and hydrogen bonding acceptor are key parameters to estimate the persistence and toxicity of antimicrobials in the aquatic environment. PMID:23452215

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

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    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.

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

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    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.

  10. Effect of biochar amendment on the control of soil sulfonamides, antibiotic-resistant bacteria, and gene enrichment in lettuce tissues.

    Science.gov (United States)

    Ye, Mao; Sun, Mingming; Feng, Yanfang; Wan, Jinzhong; Xie, Shanni; Tian, Da; Zhao, Yu; Wu, Jun; Hu, Feng; Li, Huixin; Jiang, Xin

    2016-05-15

    Considering the potential threat of vegetables growing in antibiotic-polluted soil with high abundance of antibiotic-resistant genes (ARGs) against human health through the food chain, it is thus urgent to develop novel control technology to ensure vegetable safety. In the present work, pot experiments were conducted in lettuce cultivation to assess the impedance effect of biochar amendment on soil sulfonamides (SAs), antibiotic-resistant bacteria (ARB), and ARG enrichment in lettuce tissues. After 100 days of cultivation, lettuce cultivation with biochar amendment exhibited the greatest soil SA dissipation as well as the significant improvement of lettuce growth indices, with residual soil SAs mainly existing as the tightly bound fraction. Moreover, the SA contents in roots and new/old leaves were reduced by one to two orders of magnitude compared to those without biochar amendment. In addition, isolate counts for SA-resistant bacterial endophytes in old leaves and sul gene abundances in roots and old leaves also decreased significantly after biochar application. However, neither SA resistant bacteria nor sul genes were detected in new leaves. It was the first study to demonstrate that biochar amendment can be a practical strategy to protect lettuce safety growing in SA-polluted soil with rich ARB and ARGs. PMID:26896719

  11. 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. PMID:22622431

  12. Spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics

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    Naik Subhash R

    2003-05-01

    Full Text Available Abstract Background Various causes of malabsorption syndrome (MAS are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (SIBO. Frequency, nature and antibiotic sensitivity of SIBO in patients with MAS are not well understood. Methods Jejunal aspirates of 50 consecutive patients with MAS were cultured for bacteria and colony counts and antibiotic sensitivity were performed. Twelve patients with irritable bowel syndrome were studied as controls. Results Culture revealed growth of bacteria in 34/50 (68% patients with MAS and 3/12 controls (p 2 to 1015 (median 105 in MAS and 100 to 1000 (median 700 CFU/ml in controls (p 0.003. 21/50 (42% patients had counts ≥105 CFU/ml in MAS and none of controls (p Escherichia coli respectively. The isolated bacteria were more often sensitive to quinolones than to tetracycline (ciprofloxacin: 39/47 and norfloxacin: 34/47 vs. tetracycline 19/47, Conclusions SIBO is common in patients with MAS due to various causes and quinolones may be the preferred treatment. This needs to be proved further by a randomized controlled trial.

  13. Bacteria isolated from pristine high altitude environments in the Argentinean Andean wetlands: plasmid profile and multiple antibiotic resistance

    International Nuclear Information System (INIS)

    Full text: Andean wetlands, placed in the North-Western Argentine at 4,600 m altitude, are attractive for both, environmental and biotechnology studies. Most of these wetlands are completely remote and inaccessible, having a high salinity and metal contents, a wide range of daily temperature changes, and an important intensity of solar UV-B radiation. Bacteria isolated from these environments were identified by 16SrDNA sequence and resulted in Gram-positive colored bacteria. Interesting features, to our knowledge never reported so far from bacteria isolates from these pristine high altitude lake-environments, such as similar plasmids profiles and multiple antibiotic resistances are the focus of this work. At least two plasmids were found in all isolates studied by using modifications of the alkaline Iysis method. Their preliminary characterization in this work includes size, incompatibility group through PCR, genetic transference to suitable hosts by transformation and conjugation, and studies of possible relationships of them with antibiotic resistances. (author)

  14. 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.

  15. Fate of antibiotic resistance bacteria and genes during enhanced anaerobic digestion of sewage sludge by microwave pretreatment.

    Science.gov (United States)

    Tong, Juan; Liu, Jibao; Zheng, Xiang; Zhang, Junya; Ni, Xiaotang; Chen, Meixue; Wei, Yuansong

    2016-10-01

    The fate of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) were investigated during the sludge anaerobic digestion (AD) with microwave-acid (MW-H), microwave (MW) and microwave-H2O2-alkaline (MW-H2O2) pretreatments. Results showed that combined MW pretreatment especially for the MW-H pretreatment could efficiently reduce the ARB concentration, and most ARG concentrations tended to attenuate during the pretreatment. The subsequent AD showed evident removal of the ARB, but most ARGs were enriched after AD. Only the concentration of tetX kept continuous declination during the whole sludge treatment. The total ARGs concentration showed significant correlation with 16S rRNA during the pretreatment and AD. Compared with unpretreated sludge, the AD of MW and MW-H2O2 pretreated sludge presented slightly better ARB and ARGs reduction efficiency. PMID:26970692

  16. Induction of changes in antibiotic susceptibility of certain Bacteria using gamma radiation

    International Nuclear Information System (INIS)

    Antibiotic sensitivity tests of cultures isolated from environment of high radiation intensity of the facility were studied. Standard strains of ATCC, NTCC and those from air of clean area in the vicinity of the facility were used for comparison. The following isolated cultures from the environment of the radiation facility were studied in the present work B. Cereus, B. Licheniformis and Staph Aureus. Antibiotic sensitivity tests were performed before and after exposure to radiation doses in the range from 0.1 kGy to 2.5 kGy depending on the radiation resistance of the studied strain. The obtained results showed changes in the antibiotic sensitivities of the studied isolates after their exposure to certain doses of gamma radiation. These induced changes were found to have similar trend for all strains except in the case of Staph Aureus with the antibiotic tetracycline

  17. Antibiotic Resistance Patterns of Gram-Negative Psychrotrophic Bacteria from Bulk Tank Milk.

    Science.gov (United States)

    Decimo, Marilù; Silvetti, Tiziana; Brasca, Milena

    2016-04-01

    Bacterial resistance to antibiotics is a major global health problem and resistance of Pseudomonadaceae and Enterobacteriaceae is a serious concern. We investigated the prevalence of drug-resistance in a total of 80 psychrotrophic strains from bulk milk belonging to Pseudomonas genus (n. 63) and Enterobacteriaceae group (n. 17). All the strains were tested against 16 antibiotics. Pseudomonas were further investigated for their sensitivity against 12 additional antibiotics. Pseudomonas showed a high susceptibility toward fluoroquinolones, aminoglycosides, and piperacillin and, to a lesser extent, to imipenem, ceftazidime, cefepime. Thirty-five out of 63 Pseudomonas strains were susceptible to meropenem, while among antibiotics for which recommended breakpoints are not yet available, 55% of Pseudomonas strains had no inhibition halo in presence of nitrofurantoin, highlighting a resistance toward this drug. The results obtained in this study indicate a high efficiency of fluoroquinolones, chloramphenicol (94%), and kanamycin (76%) for Enterobacteriaceae while a high prevalence of resistant strains was found to ampicillin (13/17). Serratia marcescens is highly susceptible to fluoroquinolones, chloramphenicol, and kanamycin. Moreover, mupirocin seems to be the new antibiotic with the less efficacy for Enterobacteriaceae, with 41% of strains without halo, pointing out an important resistance. Further knowledge on resistance to known and new antibiotics among Pseudomonas species and Enterobacteriaceae of milk origin was acquired. PMID:26910385

  18. Synergistic activity of biocides and antibiotics on resistant bacteria from organically produced foods.

    Science.gov (United States)

    Fernández Fuentes, Miguel Angel; Abriouel, Hikmate; Gadea, Rebeca; Pérez Pulido, Rubén; Gálvez, Antonio; Ortega, Elena

    2014-10-01

    Synergism between biocides and antibiotics was investigated in 20 biocide and antibiotic-resistant bacterial strains that were previously isolated from organically produced foods, according to their antimicrobial resistance profiles. Most of the antibiotic/biocide combinations yielded synergistic interactions, reducing the inhibitory concentrations of biocides and antibiotics by 4- to 16-fold. Among enterococci, synergism with biocides was detected for amoxicillin (AM), cefuroxime (CX), erythromycin (EM), ciprofloxacin (CP), and trimethoprim/sulphametoxazol (T/S). Among staphylococci, interactions were synergistic (AM) and either synergistic or indifferent (CX and EM, depending on biocide). Among the three methicillin-resistant Staphylococcus aureus clinical strains included in the study, the combinations of methicillin and triclosan or hexachlorophene acted synergistically in all strains, but interactions were either synergistic or indifferent for the other biocides, depending on the strain. All combinations tested were synergistic for Lactobacillus (AM, CX, EM, and CP) and Micrococcus (AM, EM). In Salmonella, interactions were indifferent (AM, CX, EM, and CP) or synergistic (T/S). Synergism with biocides was also detected in Klebsiella isolates (AM, CX, and T/S), Enterobacter sp. (AM, CX, EM, and T/S), Pantoea (AM, CX, EM, CP, and T/S), and Chryseobacterium sp. (EM). These results suggest that combinations of biocides and antibiotics may open new possibilities to combat antimicrobial resistance. PMID:24660956

  19. Isolation and characterization of antibiotic-resistant bacteria from pharmaceutical industrial wastewaters.

    Science.gov (United States)

    Tahrani, Leyla; Soufi, Leila; Mehri, Ines; Najjari, Afef; Hassan, Abdenaceur; Van Loco, Joris; Reyns, Tim; Cherif, Ameur; Ben Mansour, Hedi

    2015-12-01

    Contamination of surface waters in underdeveloped countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks which may represent a significant dissemination mechanism of antibiotic resistance genes among pathogenic bacterial populations. The present study aims to determine the multi-drug resistance patterns among isolated and identified bacterial strains in a pharmaceutical wastewater effluent in north Tunisia. Fourteen isolates were obtained and seven of them were identified. These isolates belong to different genera namely, Pseudomonas, Acinetobacter, Exiguobacterium, Delftia and Morganella. Susceptibility patterns of these isolates were studied toward commonly used antibiotics in Tunisia. All the identified isolates were found to have 100% susceptibility against colistin sulfate and 100% resistance against amoxicillin. Among the 11 antibiotics tested, six patterns of multi-drug resistance were obtained. The potential of the examined wastewater effluent in spreading multi-drug resistance and the associated public health implications are discussed. PMID:26343496

  20. Evaluation of Antibacterial Activity of Aqueous Extracts of Onion and some Antibiotics on a Number of Important Bacteria in Terms of Food Hygiene

    Directory of Open Access Journals (Sweden)

    Anzabi Younes

    2014-10-01

    Full Text Available Objective: The purpose of this study was to evaluate the antibacterial effect of edible onion plant and a number of common antibiotics in the case of some important bacteria regarding food hygiene. Materials and Methods: The sensitivity or resistance of standard strains of 9 important species of transmissible pathogenic bacteria, through food in laboratory Mueller Hinton agar medium and using blank paper discs containing onion extract, 9 standard synthetic chemicals, and antibiotics by agar disk diffusion method (disk diffusion agar, were investigated. Results: The findings of this study showed that, of the 9 species of bacteria tested, the aqueous extract of onion only has relatively small antibacterial activity on the 2 species of Staphylococcus aureus and clostridium perfringens. Statistical analysis of the results also indicated that there was no significant relationship among the different antibiotics used and the edible onion aqueous extract, and the resistance or susceptibility of isolates. Moreover, there was a difference between different antibiotics tested in this study and aqueous extract of onion, regarding the number of resistant bacteria, and intermediate and moderate susceptibility, and susceptibility to the antibacterial compounds. Conclusion: It seems that the aqueous extract of onions cannot be used as an alternative to commonly used antibiotics to fight important bacteria in terms food hygiene.

  1. 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 

  2. 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.

  3. 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.

  4. 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.

  5. 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

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

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    Pirvu Lucia

    2016-03-01

    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.

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

    Czech Academy of Sciences Publication Activity Database

    Horká, Marie; Vykydalová, Marie; Růžička, F.; Šalplachta, Jiří; Holá, V.; Dvořáčková, M.; Kubesová, Anna; Šlais, Karel

    2014-01-01

    Roč. 406, č. 25 (2014), s. 6285-6296. ISSN 1618-2642 R&D Projects: GA MV VG20112015021 Institutional support: RVO:68081715 Keywords : capillary isoelectric focusing with UV detection * ampholytic antibiotics * Staphylococcus epidermidis Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 3.436, year: 2014 http://hdl.handle.net/11104/0236550

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

    OpenAIRE

    Horká, M. (Marie); Vykydalová, M. (Marie); Růžička, F.; Šalplachta, J. (Jiří); Holá, V.; Dvořáčková, M.; Kubesová, A. (Anna); Šlais, K. (Karel)

    2014-01-01

    The isoelectric points of some ampholytic antibiotics dissolved in water or growth medium were found by capillary isoelectric focusing and the influence of selected antimicrobials on S. epidermidis re-suspended in medium or human blood was monitored by this electrophoretic technique or MALDI-TOF MS.

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

    Directory of Open Access Journals (Sweden)

    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

  10. ANTIMICROBIAL RESISTANCE AMONG ENTERIC BACTERIA ISOLATED FROM HUMAN AND ANIMAL WASTES AND IMPACTED SURFACE WATERS: COMPARISON WITH NARMS FINDINGS

    Science.gov (United States)

    Human infection with bacteria exhibiting mono or multiple antimicrobial resistance (MAR) has been a growing problem in the US, and studies have implicated livestock as a source of MAR bacteria primarily through foodborne transmission routes. However, waterborne transmission of...

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

    OpenAIRE

    Tahlina Tanzin; K. H. M. Nazmul Hussain Nazir; Mst. Nusrat Zahan; Md. Shafiullah Parvej; Khalada Zesmin; Md. Tanvir Rahman

    2016-01-01

    Objectives: The objective of this study was to isolate and identify Staphylococcus aureus and Escherichia coli from raw milk samples of cattle and buffalo, and to evaluate the antibiotic sensitivity pattern. Materials and methods: A total of 34 milk samples were collected twice from 17 different healthy cattle (n=14) and buffaloes (n=3) at one-month interval, and analyzed in laboratory by staining, cultural and biochemical characteristics followed by polymerase chain reaction targeting nu...

  12. The effect of bacteria on diatom community structure - The 'antibiotics' approach

    Digital Repository Service at National Institute of Oceanography (India)

    DeCosta, P.M.; Anil, A.C.

    (1997). The Most Probable Number of diatoms in the sediment sample (MPN g -1 wet sediment) was calculated by counting the positive wells in three consecutive dilutions and interpreting that value using the statistical MPN table provided by Throndsen... (1978). The diatom density (cm -3 wet sediment) was obtained by multiplying the MPN with the apparent specific gravity of the wet sediment (Imai and Itakura, 1999), which was determined separately. 2.4. Quantification of antibiotic...

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. Mannitol enhances antibiotic sensitivity of persister bacteria in Pseudomonas aeruginosa biofilms.

    Directory of Open Access Journals (Sweden)

    Nicolas Barraud

    Full Text Available The failure of antibiotic therapies to clear Pseudomonas aeruginosa lung infection, the key mortality factor for cystic fibrosis (CF patients, is partly attributed to the high tolerance of P. aeruginosa biofilms. Mannitol has previously been found to restore aminoglycoside sensitivity in Escherichia coli by generating a proton-motive force (PMF, suggesting a potential new strategy to improve antibiotic therapy and reduce disease progression in CF. Here, we used the commonly prescribed aminoglycoside tobramycin to select for P. aeruginosa persister cells during biofilm growth. Incubation with mannitol (10-40 mM increased tobramycin sensitivity of persister cells up to 1,000-fold. Addition of mannitol to pre-grown biofilms was able to revert the persister phenotype and improve the efficacy of tobramycin. This effect was blocked by the addition of a PMF inhibitor or in a P. aeruginosa mutant strain unable to metabolise mannitol. Addition of glucose and NaCl at high osmolarity also improved the efficacy of tobramycin although to a lesser extent compared to mannitol. Therefore, the primary effect of mannitol in reverting biofilm associated persister cells appears to be an active, physiological response, associated with a minor contribution of osmotic stress. Mannitol was tested against clinically relevant strains, showing that biofilms containing a subpopulation of persister cells are better killed in the presence of mannitol, but a clinical strain with a high resistance to tobramycin was not affected by mannitol. Overall, these results suggest that in addition to improvements in lung function by facilitating mucus clearance in CF, mannitol also affects antibiotic sensitivity in biofilms and does so through an active, physiological response.

  17. How Often Are Antibiotic-Resistant Bacteria Said to "Evolve" in the News?

    Science.gov (United States)

    Singh, Nina; Sit, Matthew T; Chung, Deanna M; Lopez, Ana A; Weerackoon, Ranil; Yeh, Pamela J

    2016-01-01

    Media plays an important role in informing the general public about scientific ideas. We examine whether the word "evolve," sometimes considered controversial by the general public, is frequently used in the popular press. Specifically, we ask how often articles discussing antibiotic resistance use the word "evolve" (or its lexemes) as opposed to alternative terms such as "emerge" or "develop." We chose the topic of antibiotic resistance because it is a medically important issue; bacterial evolution is a central player in human morbidity and mortality. We focused on the most widely-distributed newspapers written in English in the United States, United Kingdom, Canada, India, and Australia. We examined all articles that focused primarily on the evolution of antibiotic resistance, were published in 2014 or earlier, and were accessible in online archives, for a total of 1639 articles. The total years examined per newspaper ranged from 5 to 37 years with a median of 27 years, and the overall range was 1978-2014. We quantified how many articles included the term "evolve" and analyzed how this varied with newspaper, country, and time. We found that an overall rate of 18% of articles used the term "evolve" but with significant variation among countries. Newspapers in the United Kingdom had the highest rate (24%), more than double of those in India (9%), the country with the lowest rate. These frequencies were lower than those found in scientific papers from both evolutionary journals and biomedical journals. There were no statistically significant changes in frequency and no trends when "evolve" usage was compared against variables such as newspaper circulation, liberal/conservative bias, time, and state evolution acceptance in U.S. newspapers. This study highlights the globally low usage of the word "evolve" in the popular press. We suggest this low usage may affect public understanding and acceptance of evolutionary concepts. PMID:26934595

  18. Innovating nanosensing technique to detect living bacteria and reveal resistance to antibiotics

    International Nuclear Information System (INIS)

    Full text: Bacterial pathogens are a major concern for health issues, it is crucial to detect and identify them with the shortest time delay as possible. Usually, once a bacterial infection is suspected, a time consuming procedure dependent on the bacterial growth rate concludes to a diagnosis. In this study, we present a new technique that is capable of characterizing bacterial sensitivity to antibiotics in unmatched time scales (minutes). The experimental set-up is based on AFM technology. The device has already shown promising results with strains such as Escherichia coli, Staphyloccocus aureus, Lactococcus lactis and many others are being tested. (author)

  19. 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.

  20. Occurrence of antibiotic and metal resistance in bacteria from organs of river fish

    International Nuclear Information System (INIS)

    Bacterial populations in some organs, viz., liver, spleen, kidney, gill, and arborescent organ of the catfish Clarias batrachus were enumerated followed by determination of resistance for antibiotics and metals. The total viable counts in these organs, observed, were 2.24x104, 2.08x104, 1.44x104, 1.23x104, and 6.40x103 colony-forming units/mL, respectively. The random bacterial isolates from these fish organs showed resistance in decreasing order for colistin (98%), ampicillin (82%), gentamycin (34%), carbenicillin (28%), tetracyline (20%), streptomycin (12%), and ciprofloxacin (02%). Most of the isolates exhibited an increasing order of tolerance for the metals (μg/mL) copper (100), lead (200), manganese (400), cadmium (200), and chromium (50), with minimum inhibitory concentration (MIC) ranging from <50 to 1600 μg/mL. These observations indicate that the significant occurrence of bacterial population in organs of fish with high incidence of resistance for antibiotics and metals may pose risk to fish fauna and public health

  1. 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.

  2. Salmonella Newport as Reported by the Animal Arm of the National Antimicrobial Resistance Monitoring System Enteric Bacteria (NARMS)

    Science.gov (United States)

    Introduction: Since the early 1990’s there has been increasing awareness and concern regarding the development of antimicrobial resistance among bacteria of public health significance. Reports targeting zoonotic bacteria, and in particular Salmonella species, suggest that resistance is trending upw...

  3. New Role for FDA-Approved Drugs in Combating Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Andersson, Jourdan A; Fitts, Eric C; Kirtley, Michelle L; Ponnusamy, Duraisamy; Peniche, Alex G; Dann, Sara M; Motin, Vladimir L; Chauhan, Sadhana; Rosenzweig, Jason A; Sha, Jian; Chopra, Ashok K

    2016-06-01

    Antibiotic resistance in medically relevant bacterial pathogens, coupled with a paucity of novel antimicrobial discoveries, represents a pressing global crisis. Traditional drug discovery is an inefficient and costly process; however, systematic screening of Food and Drug Administration (FDA)-approved therapeutics for other indications in humans offers a rapid alternative approach. In this study, we screened a library of 780 FDA-approved drugs to identify molecules that rendered RAW 264.7 murine macrophages resistant to cytotoxicity induced by the highly virulent Yersinia pestis CO92 strain. Of these compounds, we identified 94 not classified as antibiotics as being effective at preventing Y. pestis-induced cytotoxicity. A total of 17 prioritized drugs, based on efficacy in in vitro screens, were chosen for further evaluation in a murine model of pneumonic plague to delineate if in vitro efficacy could be translated in vivo Three drugs, doxapram (DXP), amoxapine (AXPN), and trifluoperazine (TFP), increased animal survivability despite not exhibiting any direct bacteriostatic or bactericidal effect on Y. pestis and having no modulating effect on crucial Y. pestis virulence factors. These findings suggested that DXP, AXPN, and TFP may modulate host cell pathways necessary for disease pathogenesis. Finally, to further assess the broad applicability of drugs identified from in vitro screens, the therapeutic potential of TFP, the most efficacious drug in vivo, was evaluated in murine models of Salmonella enterica serovar Typhimurium and Clostridium difficile infections. In both models, TFP treatment resulted in increased survivability of infected animals. Taken together, these results demonstrate the broad applicability and potential use of nonantibiotic FDA-approved drugs to combat respiratory and gastrointestinal bacterial pathogens. PMID:27067323

  4. Isolation and antibiotic susceptibility of bacteria from foot infections in the patients with diabetes mellitus type I and type II in the district of Kancheepuram, Tamil Nadu, India

    Directory of Open Access Journals (Sweden)

    Kannan Iyanar

    2014-04-01

    Conclusion: The present study has given the data of various bacteria encountered in the diabetic foot ulcer in the district of Kancheepuram, Tamil Nadu, India and its antibiotic sensitivity pattern. The results clearly reveal that there is no definite aetiology in diabetic foot infections. Many patients presented the infection with the involvement of many bacteria. Further it is evident that many bacteria are multi drug resistant and thus complicating the management of diabetic foot infections. [Int J Res Med Sci 2014; 2(2.000: 457-461

  5. 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...

  6. Prevalence and Antibiotic Resistance of Gram-Negative Pathogenic Bacteria Species Isolated from Periplaneta americana and Blattella germanica in Varanasi, India.

    Directory of Open Access Journals (Sweden)

    D Leshan Wannigama

    2014-06-01

    Full Text Available Cockroaches are among the medically important pests found within the human habitations that cause serious public health problems. They may harbor a number of pathogenic bacteria on the external surface with antibiotic resistance. Hence, they are regarded as major microbial vectors. This study investigates the prevalence and antibiotic resistance of Gram-negative pathogenic bacteria species isolated from Periplaneta americana and Blattella germanica in Varanasi, India.Totally, 203 adult cockroaches were collected form 44 households and 52 food-handling establishments by trapping. Bacteriological examination of external surfaces of Pe. americana and Bl. germanica were carried out using standard method and antibiotics susceptibility profiles of the isolates were determined using Kirby-Bauer disc diffusion methods.Among the places, we found that 54% had cockroache infestation in households and 77% in food- handling establishments. There was no significant different between the overall bacteria load of the external surface in Pe. americana (64.04% and Bl. germanica (35.96%. However the predominant bacteria on cockroaches were Klebsiella pneumonia, Escherichia coli, Enterobacter aerogenes, and Pseudomonas aeruginosa. However, Kl. pneumoniae and Ps. aeruginosa were the most prevalent, drug-resistant strains were isolated from the cockroaches with 100% resistance to sulfamethoxazole/trimethoprim and ampicillin. For individual strains of bacteria, Escherichia coli was found to have multi-resistance to four antibiotic tested, Citrobacter freundii four, Enterobacter aerogenes and Proteus mirabilis to three.Cockroaches are uniformly distributed in domestic environment, which can be a possible vector for transmission of drug-resistant bacteria and food-borne diseases.

  7. 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.

  8. 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. PMID:26444324

  9. 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

  10. Interactions between bacteria and the intestinal mucosa: Do enteric neurotransmitters acting on epithelium cells influence mucosal colonization or infection?

    Science.gov (United States)

    The mechanisms governing the ability of bacteria to adhere to and colonize human and animal hosts in health and disease are still incompletely understood. Throughout the extensive mucosal surfaces of the body that are in contact with the external environment, epithelial cells represent the first po...

  11. 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. PMID:26641108

  12. Impact of Gut Colonization by Antibiotic-Resistant Bacteria on the Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation: A Retrospective, Single-Center Study.

    Science.gov (United States)

    Bilinski, Jaroslaw; Robak, Katarzyna; Peric, Zinaida; Marchel, Halina; Karakulska-Prystupiuk, Ewa; Halaburda, Kazimierz; Rusicka, Patrycja; Swoboda-Kopec, Ewa; Wroblewska, Marta; Wiktor-Jedrzejczak, Wieslaw; Basak, Grzegorz W

    2016-06-01

    Gut colonization by antibiotic-resistant bacteria may underlie hard-to-treat systemic infections. There is also accumulating evidence on the immunomodulatory function of gut microbiota after allogeneic stem cell transplantation (alloSCT) and its impact on graft-versus-host disease (GVHD). We investigated the epidemiology and clinical impact of gut colonization after alloSCT and retrospectively analyzed data on 107 alloSCTs performed at a single transplant center. Pretransplant microbiology screening identified colonization in 31% of cases. Colonization had a negative impact on overall survival after alloSCT in univariate (34% versus 74% at 24 months, P antibiotic-resistant bacteria decreases the overall survival of patients undergoing alloSCT by increasing nonrelapse mortality and the incidences of systemic infection and acute GVHD. PMID:26900084

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

    OpenAIRE

    MBEHANG NGUEMA, Pierre Philippe; Okubo, Torahiko; TSUCHIDA, Sayaka; FUJITA, Shiho; YAMAGIWA, Juichi; TAMURA, Yutaka; Ushida, Kazunari

    2015-01-01

    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 (...

  14. Antigen sampling by intestinal M cells is the principal pathway initiating mucosal IgA production to commensal enteric bacteria

    Science.gov (United States)

    Rios, D; Wood, M B; Li, J; Chassaing, B; Gewirtz, A T; Williams, I R

    2016-01-01

    Secretory IgA (SIgA) directed against gut resident bacteria enables the mammalian mucosal immune system to establish homeostasis with the commensal gut microbiota after weaning. Germinal centers (GCs) in Peyer's patches (PPs) are the principal inductive sites where naive B cells specific for bacterial antigens encounter their cognate antigens and receive T-cell help driving their differentiation into IgA-producing plasma cells. We investigated the role of antigen sampling by intestinal M cells in initiating the SIgA response to gut bacteria by developing mice in which receptor activator of nuclear factor-κB ligand (RANKL)-dependent M-cell differentiation was abrogated by conditional deletion of Tnfrsf11a in the intestinal epithelium. Mice without intestinal M cells had profound delays in PP GC maturation and emergence of lamina propria IgA plasma cells, resulting in diminished levels of fecal SIgA that persisted into adulthood. We conclude that M-cell-mediated sampling of commensal bacteria is a required initial step for the efficient induction of intestinal SIgA. PMID:26601902

  15. Isolation and antibiotic susceptibility of bacteria from foot infections in the patients with diabetes mellitus type I and type II in the district of Kancheepuram, Tamil Nadu, India

    OpenAIRE

    Kannan Iyanar; Premavathy R. K.; Sambandam Cecilia; Jayalakshmi M.; Sruthi Priyadarsini S.; Shantha S

    2014-01-01

    Background: Diabetic foot infections are important cause of morbidity and mortality among persons with diabetes mellitus. The reported prevalence rates in India range from 0.9 and ndash;8.3%. Diabetes foot lesions are the leading cause of non-traumatic amputations worldwide. A study has been conducted to isolate and find the antibiotic susceptibility pattern of the bacteria from diabetic foot infections from the patients of Kancheepuram district, Tamil Nadu, India. Methods: Sixty patients ...

  16. 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. PMID:27314556

  17. Substrate specificity of the OqxAB multidrug resistance pump in Escherichia coli and selected enteric bacteria

    DEFF Research Database (Denmark)

    Hansen, Lars Hestbjerg; Jensen, Lars Bogø; Sørensen, Heidi Iskou;

    2007-01-01

    Objectives: A plasmid-encoded multidrug eff lux pump, OqxAB, identified in Escherichia coli of porcine origin, was tested for substrate specificity against selected antibiotics, detergents and disinfectants. The ability of horizontal transfer to food-borne pathogens of the Enterobacteriaceae family...... Typhimurium, Klebsiella pneumoniae, Kluyvera sp. and Enterobacter aerogrenes was investigated. The effect of the presence of the OqxAB pump on susceptibility for selected compounds was investigated using broth dilution assays. Results: The OqxAB pump conferred antimicrobial resistance or reduced....... Conclusions: The plasmid-encoded OqxAB pump has a wide substrate specificity and can be transferred between Enterobacteriaceae conferring reduced susceptibility to a multitude of substrates. These results could indicate some dependence on the outer membrane proteins present in the different species....

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

    Directory of Open Access Journals (Sweden)

    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.

  19. PATTERN AND ANTIBIOTIC SUSCEPTIBILITY OF BACTERIA ISOLATED IN CLINICALLY SUSPECTED CASES OF ACUTE PYOGENIC MENINGITIS IN CHILDREN IN KRH, GWALIOR

    Directory of Open Access Journals (Sweden)

    Dutt

    2014-05-01

    Full Text Available This study was conducted in Department of Pediatrics, Kamla Raja Hospital Gwalior, (MP, during a period of a year September 2011 to August 2012. It was prospective and investigational study. Two hundred cases were enrolled for the study confirmed by either CSF r/m and or CSF c/s. Their history, complete physical examination and investigation like CSF, RBS, Blood c/s and Urine c/s were sent. Out of 200, male were 66% and female were 34% making a ratio of 1.9:1. Maximum cases were below the age group of 6year (80%. About 60% cases were from the rural area and 40% from urban area. More cases found in the months of May, Jun and July (45%. Commonest manifestations were fever (96%, irritability/ lethargy (88%, vomiting (80%, convulsion (75%, unconsciousness (53% and headache (31%. Signs of meningeal irritation were neck rigidity (57%; kerning’s sign (51%, brudzinki’s sign (45% and photophobia (28%. Anterior fontanel Bulging were found in (30% cases. Sensitivity of gram stain of the CSF was 88%. Culture was found positive in 35%. Out of 70 cases of culture positive 52 cases were gram negative and 18 cases were gram positive. Bacteria isolated from CSF were common below 3 years age group and there was very less difference in sex distribution. The bacteria isolated from the CSF culture were pseudomonas, Klebsiella, Acinetobacter, Streptococci pneumonia, Staph. Aureus, E.coli, Gm –ve bacilli, Citrobacter, Proteus, Enterobacter. Overall sensitivity pattern were for meropenem (90%, vancomycin (87.5%, ceftriaxone (85.7%, Amikacin (85.7%, Ceftazidime (82.2%, Piperacillin-Tazobactam (81.4%, Amoxyclav (77.1%, Cefotaxime (70%, Gentamicin (70%, and Netilmicin (70%. Blood and urine culture were positive 5% and 2% respectively. Case fatality rate was 11.5%. Acute bacterial meningitis in children has a considerable mortality, morbidity and serious long term sequelae therefore neurodevelopmental follow up and therapy should begin early. The study concluded that

  20. Antibiotic susceptibility of coagulase-negative staphylococci isolated from very low birth weight babies: comprehensive comparisons of bacteria at different stages of biofilm formation

    Directory of Open Access Journals (Sweden)

    Garland Suzanne M

    2010-05-01

    Full Text Available Abstract Background Coagulase-negative staphylococci are major causes of bloodstream infections in very low birth weight babies cared for in Neonatal Intensive Care Units. The virulence of these bacteria is mainly due to their ability to form biofilms on indwelling medical devices. Biofilm-related infections often fail to respond to antibiotic chemotherapy guided by conventional antibiotic susceptibility tests. Methods Coagulase-negative staphylococcal blood culture isolates were grown in different phases relevant to biofilm formation: planktonic cells at mid-log phase, planktonic cells at stationary phase, adherent monolayers and mature biofilms and their susceptibilities to conventional antibiotics were assessed. The effects of oxacillin, gentamicin, and vancomycin on preformed biofilms, at the highest achievable serum concentrations were examined. Epifluorescence microscopy and confocal laser scanning microscopy in combination with bacterial viability staining and polysaccharide staining were used to confirm the stimulatory effects of antibiotics on biofilms. Results Most coagulase-negative staphylococcal clinical isolates were resistant to penicillin G (100%, gentamicin (83.3% and oxacillin (91.7% and susceptible to vancomycin (100%, ciprofloxacin (100%, and rifampicin (79.2%. Bacteria grown as adherent monolayers showed similar susceptibilities to their planktonic counterparts at mid-log phase. Isolates in a biofilm growth mode were more resistant to antibiotics than both planktonic cultures at mid-log phase and adherent monolayers; however they were equally resistant or less resistant than planktonic cells at stationary phase. Moreover, for some cell-wall active antibiotics, concentrations higher than conventional MICs were required to prevent the establishment of planktonic cultures from biofilms. Finally, the biofilm-growth of two S. capitis isolates could be enhanced by oxacillin at the highest achievable serum concentration. Conclusion

  1. 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. PMID:25649412

  2. 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. PMID:27247772

  3. Epidemiology and potential land-sea transfer of enteric bacteria from terrestrial to marine species in the Monterey Bay Region of California.

    Science.gov (United States)

    Oates, Stori C; Miller, Melissa A; Byrne, Barbara A; Chouicha, Nadira; Hardin, Dane; Jessup, David; Dominik, Clare; Roug, Annette; Schriewer, Alexander; Jang, Spencer S; Miller, Woutrina A

    2012-07-01

    Marine mammals are at risk for infection by fecal-associated zoonotic pathogens when they swim and feed in polluted nearshore marine waters. Because of their tendency to consume 25-30% of their body weight per day in coastal filter-feeding invertebrates, southern sea otters (Enhydra lutris nereis) can act as sentinels of marine ecosystem health in California. Feces from domestic and wildlife species were tested to determine prevalence, potential virulence, and diversity of selected opportunistic enteric bacterial pathogens in the Monterey Bay region. We hypothesized that if sea otters are sentinels of coastal health, and fecal pollution flows from land to sea, then sea otters and terrestrial animals might share the same enteric bacterial species and strains. Twenty-eight percent of fecal samples tested during 2007-2010 were positive for one or more potential pathogens. Campylobacter spp. were isolated most frequently, with an overall prevalence of 11%, followed by Vibrio cholerae (9%), Salmonella spp. (6%), V. parahaemolyticus (5%), and V. alginolyticus (3%). Sea otters were found positive for all target bacteria, exhibiting similar prevalences for Campylobacter and Salmonella spp. but greater prevalences for Vibrio spp. when compared to terrestrial animals. Fifteen Salmonella serotypes were detected, 11 of which were isolated from opossums. This is the first report of sea otter infection by S. enterica Heidelberg, a serotype also associated with human clinical disease. Similar strains of S. enterica Typhimurium were identified in otters, opossums, and gulls, suggesting the possibility of land-sea transfer of enteric bacterial pathogens from terrestrial sources to sea otters. PMID:22740531

  4. 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.

  5. Unsaturated fatty acid, cis-2-decenoic acid, in combination with disinfectants or antibiotics removes pre-established biofilms formed by food-related bacteria.

    Directory of Open Access Journals (Sweden)

    Shayesteh Sepehr

    Full Text Available 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

  6. Characterization and sensitivity to antibiotics of bacteria isolated from the lower respiratory tract of ventilated patients hospitalized in intensive care units

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    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

  7. 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

  8. A 980nm driven photothermal ablation of virulent and antibiotic resistant Gram-positive and Gram-negative bacteria strains using Prussian blue nanoparticles.

    Science.gov (United States)

    Maaoui, Houcem; Jijie, Roxana; Pan, Guo-Hui; Drider, Djamel; Caly, Delphine; Bouckaert, Julie; Dumitrascu, Nicoleta; Chtourou, Radouane; Szunerits, Sabine; Boukherroub, Rabah

    2016-10-15

    A 980nm laser-driven antimicrobial photothermal therapy using poly(vinylpyrrolidone) -coated Prussian Blue nanoparticles (PVP/PB NPs) is demonstrated. This approach allows an efficient eradication of a virulent strain of Gram-negative Escherichia coli (E. coli) associated with urinary tract infection as well as for the ablation of antibiotic resistant pathogens such as methicillin resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) E. coli. Interestingly the 980nm irradiation exhibits minimal effect on mammalian cells up to a PVP/PB NPs concentration of 50μgmL(-1), while at this concentration bacteria are completely eradicated. This feature is certainly very promising for the selective targeting of bacteria over mammalian cells. PMID:27405072

  9. Isolation of antibiotic-resistant pathogenic and potentially pathogenic bacteria from carpets of mosques in Tripoli, Libya

    OpenAIRE

    Rahouma, Amal; Elghamoudi, Abdunabi; Nashnoush, Halima; Belhaj, Khalifa; Tawil, Khaled; Ghenghesh, Khalifa Sifaw

    2010-01-01

    Objective: Isolation of potentially pathogenic bacteria from carpets in hospitals has been reported earlier, but not from carpets in mosques. The aim of the present study is to determine the pathogenic and potentially pathogenic bacteria that may exist on the carpets of mosques in Tripoli, Libya. Methods: Dust samples from carpets were collected from 57 mosques in Tripoli. Samples were examined for pathogenic bacteria using standard bacteriological procedures. Susceptibility of isolated bacte...

  10. Non-fermentative gram-negative bacteria in hospital tap water and water used for haemodialysis and bronchoscope flushing: prevalence and distribution of antibiotic resistant strains.

    Science.gov (United States)

    Vincenti, Sara; Quaranta, Gianluigi; De Meo, Concetta; Bruno, Stefania; Ficarra, Maria Giovanna; Carovillano, Serena; Ricciardi, Walter; Laurenti, Patrizia

    2014-11-15

    This study provides a detailed description of the distribution of non-fermentative gram-negative bacteria (NFGNB) collected in water sources (tap water and water used for haemodialysis and bronchoscope flushing) from different wards of a tertiary care hospital. The aim is to identify risk practices for patients or to alert clinicians to the possible contamination of environment and medical devices. The resistance profile of NFGNB environmental isolates has shown that more than half (55.56%) of the strains isolated were resistant to one or more antibiotics tested in different antimicrobial categories. In particular, 38.89% of these strains were multidrug resistant (MDR) and 16.67% were extensively drug resistant (XDR). The most prevalent bacterial species recovered in water samples were Pseudomonas aeruginosa, Pseudomonas fluorescens, Ralstonia pickettii and Stenotrophomonas maltophilia. Analysis of antibiotic resistance rates has shown remarkable differences between Pseudomonadaceae (P. aeruginosa and P. fluorescens) and emerging pathogens, such as S. maltophilia and R. pickettii. Multidrug resistance can be relatively common among nosocomial isolates of P. aeruginosa, which represent the large majority of clinical isolates; moreover, our findings highlight that the emergent antibiotic resistant opportunistic pathogens, such as R. pickettii and S. maltophilia, isolated from hospital environments could be potentially more dangerous than other more known waterborne pathogens, if not subjected to surveillance to direct the decontamination procedures. PMID:25173861

  11. 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 to an a...

  12. 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...

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

    OpenAIRE

    Yaser Sharifi; Azadeh Abedzadeh; Atieh Salighe; Naser Kalhor; Mohammad Khodadad Motlagh; Ali Javadi

    2015-01-01

    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. T...

  14. Etiology and antibiotic susceptibility patterns of bacteria collected from urinary tract infections in the ASL3 in Genoa

    Directory of Open Access Journals (Sweden)

    Manuela Fedele

    2010-06-01

    Full Text Available An epidemiological study addressed to identify the pathogens collected from urine samples and their antibiotic susceptibility patterns was conducted. From January 2008 to May 2009 56,435 urine samples were processed in the Clinical Microbiological Laboratory of the ASL3 in Genoa. Materials and methods. Urine samples were firstly screened by automated equipment Uroquik (ALIFAX.All urine cultures with microbial ≥105 CFU / ml were seeded on Chromagar Orientation (BD and incubated at 37 ° C °.The identification of the isolates and the evaluation of their susceptibility to antibiotics were determined by the automated system Vitek 2 (bioMérieux. Results. About 33% (18,543 of the urine samples gave positive results.The number and frequency of the microorganisms collected was: 13,379 (72% Gram-negative including 9179 (69% E.coli, 1382 (10% Klebsiella spp, 1209 (9% Proteus spp, 445 (3% Pseudomonas spp, and other species 1164 (9%, 4942 (27% Gram positive which included 3615 (73% Enterococcus spp, 821 (17% Staphylococcus spp, 506 (10% Streptococcus spp and 222 (1% fungi. In E. coli the incidence of susceptible strains ranged between 90-96% for gentamicin, fosfomycin, nitrofurantoin, piperacillin-tazobactam, between 87-89% for the cefepime, cefotaxime, ceftazidime, about 70% for quinolones ciprofloxacin, norfloxacin, and trimethoprim-sulfamethoxazole, 62% for piperacillin, about 50% to ampicillin. For Klebsiella spp and Proteus spp the percentage of susceptible strains ranged from 95-99% to piperacillin-tazobactam, gentamicin, and respectively 93% and between 68-52% for third-generation cephalosporins cefotaxime and ceftazidime and fluoroquinolones ciprofloxacin and norfloxacin. Conclusions. Present findings indicate that among the Enterobacteriaceae, E. coli, cause most of UTI and in vitro resulted susceptible various antibiotics.There was an increased resistance to fluoroquinolones among community-acquired E. coli and Proteus spp.A periodical

  15. Antibiotic resistance in faecal bacteria isolated from horses receiving virginiamycin for the prevention of pasture-associated laminitis

    OpenAIRE

    Menzies-Gow, N.J.; Young, N. J.

    2011-01-01

    Abstract 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 preve...

  16. Detection of antibiotic-resistant bacteria endowed with antimicrobial activity from a freshwater lake and their phylogenetic affiliation

    Science.gov (United States)

    Zothanpuia; Passari, Ajit K.; Gupta, Vijai K.

    2016-01-01

    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. PMID:27330861

  17. Fate of Antibiotics and Antibiotic Resistance during Digestion and Composting: A Review.

    Science.gov (United States)

    Youngquist, Caitlin P; Mitchell, Shannon M; Cogger, Craig G

    2016-03-01

    Antibiotics and antibiotic-resistant bacteria (ARB) enter the environment through municipal and agricultural waste streams and pose a potential risk to human and livestock health through either direct exposure to antibiotic-resistant pathogens or selective pressure on the soil microbial community. This review summarizes current literature on the fate of antibiotics, ARB, and antibiotic resistance genes (ARGs) during anaerobic digestion and composting of manure and wastewater residuals. Studies have shown that removal of antibiotics varies widely during mesophilic anaerobic digestion, even within the same class of antibiotics. Research on ARB shows a wide range of removal under mesophilic conditions, with nearly complete removal under thermophilic conditions. Research on 16 antibiotics in 11 different studies using both bench-scale and farm-scale composting systems demonstrates that composting significantly reduces levels of extractable antibiotics in livestock manure in nearly all cases. Calculated half-lives ranged from 0.9 to 16 d for most antibiotics. There is more limited evidence that levels of ARB are also reduced by composting. Studies of the fate of ARGs show mixed evidence for removal during both mesophilic and thermophilic anaerobic digestion and during thermophilic composting. Antibiotic resistance genes are DNA structures, so they may persist until the DNA structure is degraded, yet the bacterium may have been rendered nonviable long before the DNA is completely degraded. Additional research would be of value to determine optimum anaerobic digestion and composting conditions for removal of ARB and to increase understanding of the fate of ARGs during anaerobic digestion and composting. PMID:27065401

  18. Kinetic inhibition of the extracellular protease of Shigella dysenteriae by the volatile oil from camellia sinensis and its effects on pathogenic bacteria in comparison with standard antibiotics

    Directory of Open Access Journals (Sweden)

    Folorunso Olufemi Samuel

    2013-04-01

    Full Text Available Context: In spite of great advances observed in modern medicine, plants still make an important contribution to health care. Hence, there is need for unrelenting effort in the exploration of the health benefit of medicinal plants. Purpose: This work was designed to determine the role of the volatile oil of Camellia sinensis on the extracellular protease, which is one of the major virulent factors in the pathogenesis of Shigella dysenteriae and its antibacterial effects on eight other enteric bacterial as compared with the antibiotics Finding: The total antimicrobial effect of the volatile oil (355.0 mm was significantly higher (p<0.05 than the antibiotics tested (203.0 mm. The minimum inhibitory and bactericidal concentrations of the oils revealed Escherichia coli as the most sensitive. However, relatively higher concentrations of the oils is required to achieve similar sensitivity against Salmonella and Shigella species. The activity of the partially purified extracellular protease, which is one of the virulence factors of Shigella dysenteriae was inhibited by the oil from different parts of the plant especially the leaf. The activity of this enzyme increased steadily between pH 7.0 – 8.0 and 40 – 50 oC. Summary: The volatile oils possessed antimicrobial activity and showed both competitive and noncompetitive kinetic inhibition of the extracellular protease of Shigella dysenteriae. Implication: The inhibitory action of the oil on protease from Shigella dysenteriae suggests the possible mode of action. Volatile oil from Camellia sinensis, especially the leaf, may be an important source of antibiotic against these organisms particularly Shigella dysenteriae.

  19. Enhancement of the antibiotic activity of aminoglycosides by extracts from Anadenanthera colubrine (Vell.) Brenan var. cebil against multi-drug resistant bacteria.

    Science.gov (United States)

    Barreto, Humberto M; Coelho, Kivia M R N; Ferreira, Josie H L; Dos Santos, Bernadete H C; de Abreu, Aislan P L; Coutinho, Henrique D M; da Silva, Romezio A C; de Sousa, Taciana O; Citó, Antonia M das G L; Lopes, José A D

    2016-06-01

    The aim of this work was to evaluate the antimicrobial activity of ethanol (EEAC) and hexane (HFAC) extracts from the stem bark of Anadenanthera colubrina (Vell.) Brenan var. cebil alone or in combination with aminoglycosides against multi-drug resistant (MDR) bacteria. Minimal inhibitory concentrations (MICs) of the extracts were determined by using microdilution assay. For the evaluation of extracts as modulators of antibiotic resistance, MICs of neomycin and amikacin were determined in presence or absence of each compound at sub-inhibitory concentrations. Both EEAC and HFAC did not show antimicrobial activity against MDR strains tested. However, the addition of EEAC and HFAC enhanced the activity of neomycin and amikacin against Staphylococcus aureus SA10 strain. When the natural products were replaced by chlorpromazine, the same effect was observed. Anadenanthera colubrine var. cebil may be a source of phytochemicals able to potentiate the aminoglycoside activity against MDR S. aureus by the inhibition of efflux pump. PMID:26158209

  20. Epidemiological study on distribution and antibiotic susceptibility patterns of Enterobacteriaceae and non-fermenting bacteria, isolated in Liguria and in a neighbouring area

    Directory of Open Access Journals (Sweden)

    Elisabetta Maioli

    2008-06-01

    Full Text Available Introduction. An epidemiological study addressed to identify gram-negative bacteria, isolated from laboratories in a Northern area of Italy, and their antibiotic resistance patterns was conducted. Methods. Twelve laboratories distributed on Ligurian territory or neighbouring areacollected all consecutive gram-negative isolates belonging to the Enterobacteriaceae family and non-fermenter group for 2 months and sent them to a reference laboratory. Results. A total of 1880 pathogens were collected, including 899 and 981 strains isolated from nosocomial- and community-acquired infections, respectively. Escherichia coli (63.3% of total was the most frequently isolated pathogen followed by Pseudomonas aeruginosa (9.6%, Proteus mirabilis (8.9% and Klebsiella pneumoniae (5.4%. Nosocomial samples were collected mainly from patients in general medicine wards (19.9% and healthcare settings (14.1%. Urine was the most common clinical sample (79.9% of the total. Other samples were sputum and bronchoaspirates (8%, skin wounds including those from decubitus (5.3% and blood (4.1%. E. coli and P. mirabilis were collected mainly from urinary tract infection while P. aeruginosa appears more involved in respiratory or other infections. Considering the resistance to representative classes of antibiotics, it was higher (% for piperacillin-tazobactam in P. mirabilis (30.3, for ceftazidime in Enterobacter aerogenes (40.8 and in Providencia stuartii (40, for imipenem and amikacin in P. aeruginosa (16.2 and 13.7 respectively, for ciprofloxacin in P. stuartii (66.6 and in P. mirabilis (44.7 than in others bacteria. Conclusions. The increasing age of the population in general medical wards and healthcare settings is associated with urinary tract and bedsore infections. E. coli confirms its epidemiologic and pathogenic role, but P. mirabilis and P. aeruginosa are emerging as alternativechallenges.

  1. Antibacterial and anti-biofilm activities of melittin and colistin, alone and in combination with antibiotics against Gram-negative bacteria.

    Science.gov (United States)

    Dosler, Sibel; Karaaslan, Elif; Alev Gerceker, A

    2016-04-01

    In vitro antibacterial and anti-biofilm activities of antimicrobial cationic peptides (AMPs) - melittin and colistin - both alone and in combination with antibiotics were evaluated against clinical isolates of Gram-negative bacteria. Minimum inhibitory concentration (MIC) and fractional inhibitory concentration (FIC) index were determined by the microbroth dilution and chequerboard techniques, respectively. The time-kill curve (TKC) method was used for determining the bactericidal activities of AMPs alone and in combination. Measurements of anti-biofilm activities were performed spectrophotometrically for both inhibition of attachment and 24-hour biofilm formation at MIC or subMIC. According to MIC90 values, the most active agents against Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae were colistin, imipenem and ciprofloxacin, respectively. In combination studies, synergistic effects were mostly seen with colistin-imipenem against E. coli and K. pneumoniae (50 and 54%, respectively), colistin-ciprofloxacin against P. aeruginosa (77%). In TKC studies, synergism was observed with almost all expected combinations, even more frequently than chequerboard method. All of the antimicrobial agents were able to inhibit attachment and 24-hour biofilm formation between 0-57% at 1/10 × MIC and 7-73% at 1 × or 1/10 × MIC, respectively. AMPs seem to be a good candidate for antimicrobial chemotherapy with their antibacterial and anti-biofilm activities as a single agent or in combination with antibiotics. PMID:25801062

  2. 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

  3. The role of the outer membrane of Gram-negative bacteria in antibiotic resistance: Ajax' shield or Achilles' heel?

    Science.gov (United States)

    Page, Malcolm G P

    2012-01-01

    There has been an enormous increase in our knowledge of the fundamental steps in the biosynthesis and assembly of the outer membrane of Gram-negative bacteria. Lipopolysaccharide is a major component of the outer membrane of Gram-negative bacteria as is peptidoglycan. Porins, efflux pumps and other transport proteins of the outer membrane are also present. It is clear that there are numerous essential proteins that have the potential to be targets for novel antimicrobial agents. Progress, however, has been slow. Much of the emphasis has been on cytoplasmic processes that were better understood earlier on, but have the drawback that two penetration barriers, with different permeability properties, have to be crossed. With the increased understanding of the late-stage events occurring in the periplasm, it may be possible to shift focus to these more accessible targets. Nevertheless, getting drugs across the outer membrane will remain a challenge to the ingenuity of the medicinal chemist. PMID:23090596

  4. Understanding Antibiotic Resistance

    OpenAIRE

    Goulart-Touma, Christiane

    2014-01-01

    The evolution of antibiotic resistance among bacteria threatens our continued ability to treat infectious diseases. The need for sustainable strategies to cure bacterial infections has never been greater. So far, all attempts to restore susceptibility after resistance arises have been unsuccessful, including restrictions on prescribing antibiotics (Andersson DI et al.2011) and antibiotic cycling (Andersson DI et al. 2005, Bergstrom CT et al. 2004). Part of the problem may be that those effor...

  5. 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

  6. Antibiotic resistance in wild birds

    OpenAIRE

    Bonnedahl, Jonas; Järhult, Josef D.

    2014-01-01

    Wild birds have been postulated as sentinels, reservoirs, and potential spreaders of antibiotic resistance. Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds. There is evidence suggesting that wild birds can spread resistant bacteria through migration and that resistant bacteria can be transmitted from birds to humans and vice versa. Through further...

  7. Campylobacter pylori-associated gastritis: attempts to eradicate the bacteria by various antibiotics and anti-ulcer regimens.

    Science.gov (United States)

    Glupczynski, Y; Burette, A; Nyst, J F; De Prez, C; De Koster, E; Deltenre, M

    1988-01-01

    The efficacy of various antimicrobial and anti-ulcer agents on the eradication of Campylobacter pylori in patients with antral gastritis or duodenal ulcers was investigated by several open studies or double-blind, placebo-controlled protocols. Among the anti-ulcer agents, ranitidine, cimetidine or sucraflate had no effect on C. pylori. Colloidal bismuth subcitrate achieved clearance of C. pylori in 40% of treated patients at the end of therapy but a high relapse rate (14/16 patients) was observed after a 6-month follow-up period. The antibacterial agents doxycycline, minocycline, ofloxacin, clindamycin, paromomycin and nifuroxazide failed to eradicate C. pylori in most patients. By contrast, short term elimination of C. pylori could be achieved in more than 90% of patients treated with amoxycillin. However, relapse occurred as a rule in all amoxycillin-treated patients within one month after therapy. Overall, we observed no correlation between the in-vitro activity of the different antibacterial agents and their in vivo efficacy. Development of resistance during therapy does not seem to account for this discrepancy since it occurred only with ofloxacin. On the basis of these results, we conclude that long term eradication of C. pylori from the gastric antrum cannot be achieved after monotherapy either with antibiotics or with bismuth salts. PMID:2979039

  8. 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.

  9. 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

  10. A Chemical-Genomic Screen of Neglected Antibiotics Reveals Illicit Transport of Kasugamycin and Blasticidin S.

    Science.gov (United States)

    Shiver, Anthony L; Osadnik, Hendrik; Kritikos, George; Li, Bo; Krogan, Nevan; Typas, Athanasios; Gross, Carol A

    2016-06-01

    Fighting antibiotic resistance requires a deeper understanding of the genetic factors that determine the antibiotic susceptibility of bacteria. Here we describe a chemical-genomic screen in Escherichia coli K-12 that was designed to discover new aspects of antibiotic resistance by focusing on a set of 26 antibiotics and other stresses with poorly characterized mode-of-action and determinants of resistance. We show that the screen identifies new resistance determinants for these antibiotics including a common signature from two antimicrobials, kasugamycin and blasticidin S, used to treat crop diseases like rice blast and fire blight. Following this signature, we further investigated the mechanistic basis for susceptibility to kasugamycin and blasticidin S in E. coli using both genetic and biochemical approaches. We provide evidence that these compounds hijack an overlapping set of peptide ABC-importers to enter the bacterial cell. Loss of uptake may be an underappreciated mechanism for the development of kasugamycin resistance in bacterial plant pathogens. PMID:27355376

  11. A Chemical-Genomic Screen of Neglected Antibiotics Reveals Illicit Transport of Kasugamycin and Blasticidin S.

    Directory of Open Access Journals (Sweden)

    Anthony L Shiver

    2016-06-01

    Full Text Available Fighting antibiotic resistance requires a deeper understanding of the genetic factors that determine the antibiotic susceptibility of bacteria. Here we describe a chemical-genomic screen in Escherichia coli K-12 that was designed to discover new aspects of antibiotic resistance by focusing on a set of 26 antibiotics and other stresses with poorly characterized mode-of-action and determinants of resistance. We show that the screen identifies new resistance determinants for these antibiotics including a common signature from two antimicrobials, kasugamycin and blasticidin S, used to treat crop diseases like rice blast and fire blight. Following this signature, we further investigated the mechanistic basis for susceptibility to kasugamycin and blasticidin S in E. coli using both genetic and biochemical approaches. We provide evidence that these compounds hijack an overlapping set of peptide ABC-importers to enter the bacterial cell. Loss of uptake may be an underappreciated mechanism for the development of kasugamycin resistance in bacterial plant pathogens.

  12. High Antibiotic Consumption

    DEFF Research Database (Denmark)

    Malo, Sara; José Rabanaque, María; Feja, Cristina;

    2014-01-01

    a high proportion of antibiotics not recommended as first choice in primary health care. In conclusion, heavy antibiotic users consisted mainly of children and old adults. Inappropriate overuse of antibiotics (high quantity, high frequency, and inappropriate antibiotic choice) leads to a substantial...... individuals with highest consumption) were responsible for 21% of the total DDD consumed and received ≥6 packages per year. Elderly adults (≥60 years) and small children (0-9 years) were those exposed to the highest volume of antibiotics and with the most frequent exposure, respectively. Heavy users received...... risk of the emergence and spread of resistant bacteria, and interventions to reduce overuse of antibiotics should therefore primarily be targeted children and elderly people....

  13. Evaluation of Statens Serum Institut Enteric Medium for Detection of Enteric Pathogens

    OpenAIRE

    Blom, Marianne; Meyer, Aase; Gerner-Smidt, Peter; Gaarslev, Knud; Espersen, Frank

    1999-01-01

    The efficacy of the Statens Serum Institut (SSI) enteric medium for isolation and direct identification of enteric pathogens was evaluated. Six different biochemical reactions can be read by using the SSI enteric medium, allowing direct identification of a range of enteric pathogens. All 248 gram-negative bacterial species that were tested grew on the SSI enteric medium. Only 10 of 248 bacteria (4%) showed discrepant results in the biochemical reactions, and none of these were enteric pathoge...

  14. 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. PMID:24761735

  15. Danger of Antibiotic Overuse (For Parents)

    Science.gov (United States)

    ... don’t work against them. This is called bacterial resistance or antibiotic resistance. Treating these resistant bacteria requires ... child gets sick? To minimize the risk of bacterial resistance, keep these tips in mind: Take antibiotics only ...

  16. The Prevalence and Risk Factors in Associated to Antibiotic Resistance of Bacteria from Diarrhoeal Patients in Bac Ninh Hospital Northern Viet Nam

    OpenAIRE

    2005-01-01

    Background: Antibiotic resistance has become a worldwide problem. Recently, there has been a global increase in infections caused by microorganisms resistant to multiple antibiotics. This has led to increases in morbidity and mortality and increased the cost of health care, which threatens to become unaffordable in developing countries. Behavioural factors, particularly the misuse of antibiotics; and lack of infection control practices in communities are the most common factors which lead to ...

  17. A compositional shift in the soil microbiome induced by tetracycline, sulfamonomethoxine and ciprofloxacin entering a plant-soil system.

    Science.gov (United States)

    Lin, Hui; Jin, Danfeng; Freitag, Thomas E; Sun, Wanchun; Yu, Qiaogang; Fu, Jianrong; Ma, Junwei

    2016-05-01

    Antibiotics entering the soil likely disturb the complex regulatory network of the soil microbiome, which is closely associated with soil quality and ecological function. This study investigated the effects of tetracycline (TC), sulfamonomethoxine (SMM), ciprofloxacin (CIP) and their combination (AM) on the bacterial community in a soil-microbe-plant system and identified the main bacterial responders. Antibiotic effects on the soil microbiome depended on antibiotic type and exposure time. TC resulted in an acute but more rapidly declining effect on soil microbiome while CIP and SMM led to a delayed antibiotic effect. The soil exposed to AM presented a highly similar bacterial structure to that exposed to TC rather than to SMM and CIP. TC, SMM and CIP had their own predominantly impacted taxonomic groups that include both resistance and sensitive bacteria. The antibiotic sensitive responders predominantly distributed within the phylum Proteobacteria. The potential bacteria resistant to each antibiotic exhibited phyla preference to some extent, particularly those resistant to TC. CIP and SMM resistance in soil was increased with exposure time while TC resistance gave the opposite result. Overall, the work extended the understanding of antibiotic effects on soil microbiome after introduced into the soil during greenhouse vegetable cultivation. PMID:26952272

  18. Eosinofil enteritis

    DEFF Research Database (Denmark)

    Gjersøe, P; Rasmussen, S N; Hansen, B F

    2000-01-01

    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...

  19. 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...

  20. Antibiotics Quiz

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  1. 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

  2. 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

  3. Frequency and correlation of some enteric indicator bacteria and Salmonella in ready-to-eat raw vegetable salads from Mexican restaurants.

    Science.gov (United States)

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Castro-Rosas, Javier

    2013-08-01

    Data about Salmonella presence in ready-to-eat raw vegetable salads (REVS) consumed in restaurants or sold as REVS in México is not available. The objective of the study was to measure the frequency of coliform bacteria (CB), fecal coliform (FC), Escherichia coli, and Salmonella in REVS from different types of restaurants and determine the correlations of CB, FC, and E. coli versus Salmonella from frequencies and concentration data. The REVS were purchased from 3 types of restaurants: national chain restaurants (A1 , A2 ); local restaurants (B1 , B2 ); and small restaurants in local markets (C1 , C2 , C3 ). Two restaurants for each A and B, and 3 for C, were included. Forty REVS were purchased at each A and B restaurant, and 20 at each C restaurant. CB were tested by plate count using violet red bile agar, FC and E. coli were detected by the most probable number method and E. coli confirmed using IMViC test; conventional method of culture was used for Salmonella. Of 220 analyzed samples, 100% had CB, 95.5% had FC, 83.2% had E. coli, and 6.8% had Salmonella. E. coli frequency was equal to or exceeded 75% in all the cases: 75% (A1 , C1 , C2 ), 80% (B2 ), 85% (B1 , C3 ), and 100% (A2 ). Salmonella frequency was equal to or exceeded 2.5% in all cases: 2.5% (A1 ), 5% (B2 , C2 ), 7.5% (B1 ), and 10% (A2 , C1 , C3 ). No correlation was observed between FC or E. coli versus Salmonella in the analyzed salads. All the tested salads were of poor quality microbiologically, and microbiological quality did not differ between the restaurants types. PMID:23957408

  4. Phenotypic Resistance to Antibiotics

    Directory of Open Access Journals (Sweden)

    Jose L. Martinez

    2013-04-01

    Full Text Available The development of antibiotic resistance is usually associated with genetic changes, either to the acquisition of resistance genes, or to mutations in elements relevant for the activity of the antibiotic. However, in some situations resistance can be achieved without any genetic alteration; this is called phenotypic resistance. Non-inherited resistance is associated to specific processes such as growth in biofilms, a stationary growth phase or persistence. These situations might occur during infection but they are not usually considered in classical susceptibility tests at the clinical microbiology laboratories. Recent work has also shown that the susceptibility to antibiotics is highly dependent on the bacterial metabolism and that global metabolic regulators can modulate this phenotype. This modulation includes situations in which bacteria can be more resistant or more susceptible to antibiotics. Understanding these processes will thus help in establishing novel therapeutic approaches based on the actual susceptibility shown by bacteria during infection, which might differ from that determined in the laboratory. In this review, we discuss different examples of phenotypic resistance and the mechanisms that regulate the crosstalk between bacterial metabolism and the susceptibility to antibiotics. Finally, information on strategies currently under development for diminishing the phenotypic resistance to antibiotics of bacterial pathogens is presented.

  5. [Prophylactic antibiotics in neurosurgery].

    Science.gov (United States)

    Iacob, G; Iacob, Simona; Cojocaru, Inimioara

    2007-01-01

    Because of a low risk of infection (around 2-3%), prophylactic use of antibiotics in neurosurgery is a controversial issue. Some neurosurgeons consider that there are strong arguments against the use of antimicrobials (promotion of antibiotic-resistant strains of bacteria, superinfection and adverse drug reactions) and meticulous aseptic techniques could be more usefully than prophylactic antibiotics. On the other hand, despite of being rare, the consequences of a neurosurgical infection can be dramatic and may result in a rapid death, caused by meningitis, cerebritis, abscess formation or sepsis. Clinical studies emphasized that the most important factors influencing the choice of antibiotic prophylaxis in neurosurgery is the patient's immune status, virulence of the pathogens and the type of surgery ("clean contaminated"--procedure that crosses the cranial sinuses, "clean non-implant"--procedure that does not cross the cranial sinuses, CSF shunt surgery, skull fracture). Prophylaxis has become the standard of care for contaminated and clean-contaminated surgery, also for surgery involving insertion of artificial devices. The antibiotic (first/second generation of cephalosporins or vancomycin in allergic patients) should recover only the cutaneous possibly contaminating flora (S. aureus, S. epidermidis) and should be administrated 30' before the surgical incision, intravenously in a single dose. Most studies pointed that identification of the risk factors for infections, correct asepsis and minimal prophylactic antibiotic regimen, help neurosurgeons to improve patient care and to decrease mortality without selecting resistant bacteria. PMID:18293694

  6. Widespread antibiotic resistance of diarrheagenic Escherichia coli and Shigella species

    Directory of Open Access Journals (Sweden)

    Azam Fatahi Sadeghabadi

    2014-01-01

    Full Text Available Background: Antibiotic resistance of enteric pathogens particularly Shigella species, is a critical world-wide problem and monitoring their resistant pattern is essential, because the choice of antibiotics is absolutely dependent on regional antibiotic susceptibility patterns. During summer 2013, an unusual increase in number of diarrheal diseases was noticed in Isfahan, a central province of Iran. Therefore, the antibiotic resistance of diarrheagenic Escherichia coli and Shigella species isolated were evaluated. Materials and Methods: According to the guideline on National Surveillance System for Foodborn Diseases, random samples from patients with acute diarrhea were examined in local laboratories of health centers and samples suspicious of Shigella spp. were further assessed in referral laboratory. Isolated pathogens were identified by standard biochemical and serologic tests and antibiotic susceptibility testing was carried out by disc diffusion method. Results: A total of 1086 specimens were obtained and 58 samples suspicious of Shigella were specifically evaluated. The most prevalent isolated pathogen was Shigella sonnei (26/58 followed by E. coli (25/58 and Shigella flexneri (3/58. A large number of isolated bacteria were resistant to co-trimoxazole (Shigella spp: 100%, E. coli: 80%, azithromycin (Shigella spp: 70.4%, E. coli: 44.0%, ceftriaxone (Shigella spp: 88.9%, E. coli: 56.0% and cefixime (Shigella spp: 85.2%, E. coli: 68.0%. About88.3% of S. sonnei isolates, one S. flexneri isolate, and 56% of E. coli strains were resistant to at least three antibiotic classes (multidrug resistant. Conclusion: Due to high levels of resistance to recommended and commonly used antibiotics for diarrhea, continuous monitoring of antibiotic resistance seems essential for determining best options of empirical therapy.

  7. From Bench-Top to Bedside: A Prospective In Vitro Antibiotic Combination Testing (iACT) Service to Guide the Selection of Rationally Optimized Antimicrobial Combinations against Extensively Drug Resistant (XDR) Gram Negative Bacteria (GNB)

    Science.gov (United States)

    Lim, Tze-Peng; Teo, Jocelyn Qi-Min; Lee, Winnie; Kurup, Asok; Koh, Tse-Hsien; Tan, Thuan-Tong; Kwa, Andrea L.

    2016-01-01

    Introduction Combination therapy is increasingly utilized against extensively-drug resistant (XDR) Gram negative bacteria (GNB). However, choosing a combination can be problematic as effective combinations are often strain-specific. An in vitro antibiotic combination testing (iACT) service, aimed to guide the selection of individualized and rationally optimized combination regimens within 48 hours, was developed. We described the role and feasibility of the iACT service in guiding individualized antibiotic combination selection in patients with XDR-GNB infections. Methods A retrospective case review was performed in two Singapore hospitals from April 2009–June 2014. All patients with XDR-GNB and antibiotic regimen guided by iACT for clinical management were included. The feasibility and role of the prospective iACT service was evaluated. The following patient outcomes were described: (i) 30-day in-hospital all-cause and infection-related mortality, (ii) clinical response, and (iii) microbiological eradication in patients with bloodstream infections. Results From 2009–2014, the iACT service was requested by Infectious Disease physicians for 39 cases (20 P. aeruginosa, 13 A. baumannii and 6 K. pneumoniae). Bloodstream infection was the predominant infection (36%), followed by pneumonia (31%). All iACT recommendations were provided within 48h from request for the service. Prior to iACT-guided therapy, most cases were prescribed combination antibiotics empirically (90%). Changes in the empiric antibiotic regimens were recommended in 21 (54%) cases; in 14 (36%) cases, changes were recommended as the empiric regimens were found to be non-bactericidal in vitro. In 7 (18%) cases, the number of antibiotics used in combination empirically was reduced by the iACT service. Overall, low 30-day infection-related mortality (15%) and high clinical response (82%) were observed. Microbiological eradication was observed in 79% of all bloodstream infections. Conclusions The i

  8. 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.

  9. Targeting Antibiotic Resistance.

    Science.gov (United States)

    Chellat, Mathieu F; Raguž, Luka; Riedl, Rainer

    2016-06-01

    Finding strategies against the development of antibiotic resistance is a major global challenge for the life sciences community and for public health. The past decades have seen a dramatic worldwide increase in human-pathogenic bacteria that are resistant to one or multiple antibiotics. More and more infections caused by resistant microorganisms fail to respond to conventional treatment, and in some cases, even last-resort antibiotics have lost their power. In addition, industry pipelines for the development of novel antibiotics have run dry over the past decades. A recent world health day by the World Health Organization titled "Combat drug resistance: no action today means no cure tomorrow" triggered an increase in research activity, and several promising strategies have been developed to restore treatment options against infections by resistant bacterial pathogens. PMID:27000559

  10. 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

  11. Antibiotic resistance in lactic acid bacteria and Micrococcaceae/Staphylococcaceae isolates from artisanal raw milk cheeses, and potential implications on cheese making.

    Science.gov (United States)

    Rodríguez-Alonso, P; Fernández-Otero, C; Centeno, J A; Garabal, J I

    2009-08-01

    Antibiotic susceptibility against 19 antimicrobial agents was evaluated in isolates of the genera Lactococcus (46 isolates), Leuconostoc (22), Lactobacillus (19), Staphylococcus (8), Enterococcus (7), and Microccoccus/Kocuria (5) obtained from the predominant microflora of nonrecent and recent types of artisanal raw cow's milk cheeses. Beta-lactams showed broad activity against all genera, although leuconostocs and lactobacilli were highly resistant to oxacillin (80% to 95.5%). Resistance to aminoglycosides was frequent for lactococci and enterococci (particularly for streptomycin), whereas lower rates of resistance were detected for lactobacilli and leuconostocs. Technologically interesting traits for the food industry were distributed among isolates that showed different degrees of resistance to common antibiotics. However, isolates showing resistance to less than 2 antibiotics were mainly those with properties of greatest technological interest (acidifying activity, proteolytic/lipolytic activities, or diacetyl production). PMID:19723213

  12. 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)

    Kaminska, Katarzyna H; Purta, Elzbieta; Hansen, Lykke H; Bujnicki, Janusz M; Vester, Birte; Long, Katherine S

    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...... 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...

  13. Environmental pollution by antibiotics and by antibiotic resistance determinants

    International Nuclear Information System (INIS)

    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.

  14. Studies on the chemical control of psychrophilic bacterial spoilage of fish. 2 - The effect of antibiotics on the growth of psycrophilic bacteria isolated from marine fish

    OpenAIRE

    Anand, C.P.; Rudra Setty, T.M.

    1981-01-01

    Among the various antibiotics tried, tetracyclines particularly chlorotetracycline (CTC), chloramphenicol and chlorostrep were found to be fairly effective at 8 and 10 p.p.m. levels. The order of sensitivity to CTC among the six genera studied was found to be Achromobacter

  15. 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.; Bujnicki, J. M.; Vester, B.; Long, Katherine

    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...

  16. 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.

  17. 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

  18. Antibiotic sensitivity of bacterial strains isolated from newborn infants Sensibilidad a los antibióticos de bacterias aisladas de neonatos hospitalizados

    OpenAIRE

    Alvaro Uribe; Rafael J. Manotas Cabarcas

    1990-01-01

    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 inf...

  19. Reservoirs of antibiotic-resistant enterobacteriaceae among animals sympatric to humans in Senegal: extended-spectrum beta-lactamases in bacteria in a black rat (Rattus rattus)

    Czech Academy of Sciences Publication Activity Database

    Literák, I.; Dolejská, M.; Čížek, A.; Djigo, CH. A. T.; Konečný, Adam; Koubek, Petr

    2009-01-01

    Roč. 3, č. 11 (2009), s. 751-754. ISSN 1996-0808 R&D Projects: GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Keywords : antibiotic s * resistance * Escherichia * Enterobacter * rat * Senegal Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 0.407, year: 2009 http://www.academicjournals.org/ajmr/PDF/Pdf2009/Nov/Literak%20et%20al.pdf

  20. Inducible xylitol dehydrogenases in enteric bacteria.

    OpenAIRE

    Doten, R C; Mortlock, R P

    1985-01-01

    Morganella morganii ATCC 25829, Providencia stuartii ATCC 25827, Serratia marcescens ATCC 13880, and Erwinia sp. strain 4D2P were found to induce a xylitol dehydrogenase when grown on a xylitol-containing medium. The xylitol dehydrogenases were partially purified from the four strains, and those from M. morganii ATCC 25829, P. stuartii ATCC 25827, and S. marcescens ATCC 13880 were all found to oxidize xylitol to D-xylulose. These three enzymes had KmS for xylitol of 7.1 to 16.4 mM and molecul...

  1. 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…

  2. 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

  3. Antibiotic Resistance Common in Kids' Urinary Tract Infections

    Science.gov (United States)

    ... nlm.nih.gov/medlineplus/news/fullstory_157809.html Antibiotic Resistance Common in Kids' Urinary Tract Infections Researchers ... coli bacteria are now failing to respond to antibiotic treatment, a new review warns. The culprit, according ...

  4. Stenotrophomonas maltophilia D457R Contains a Cluster of Genes from Gram-Positive Bacteria Involved in Antibiotic and Heavy Metal Resistance

    OpenAIRE

    Alonso, Ana; Sanchez, Patricia; Martínez, José L.

    2000-01-01

    A cluster of genes involved in antibiotic and heavy metal resistance has been characterized from a clinical isolate of the gram-negative bacterium Stenotrophomonas maltophilia. These genes include a macrolide phosphotransferase (mphBM) and a cadmium efflux determinant (cadA), together with the gene cadC coding for its transcriptional regulator. The cadC cadA region is flanked by a truncated IS257 sequence and a region coding for a bin3 invertase. Despite their presence in a gram-negative bact...

  5. Anti-adhesion and antibiotic modulatory evaluation of grapefruit (Citrus paradisi) juice and seed extract on bacteria isolated from urine and catheter

    OpenAIRE

    Michael Oluwole Osungunna; Grace O. Onawunmi

    2016-01-01

    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 activit...

  6. Negative Cross-Communication among Wheat Rhizosphere Bacteria: Effect on Antibiotic Production by the Biological Control Bacterium Pseudomonas aureofaciens 30-84

    OpenAIRE

    Morello, J. E.; Pierson, E.A.; Pierson, L S

    2004-01-01

    Phenazine antibiotic production in the biological control bacterium Pseudomonas aureofaciens 30-84 is regulated in part via the PhzR/PhzI N-acyl homoserine lactone (AHL) system. Previous work showed that a subpopulation of the wheat rhizosphere community positively affected phenazine gene expression in strain 30-84 via AHL signals (E. A. Pierson, D. W. Wood, J. A. Cannon, F. M. Blachere, and L. S. Pierson III, Mol. Plant-Microbe Interact. 11:1078-1084, 1998). In the present work, a second sub...

  7. Antibiotics in dental practice

    OpenAIRE

    2007-01-01

    The oral cavity and it surrounding tissue are habitats for many bacteria. Therefore a rationale for the use of antibacterial agents rises. During my time as a dental student, me often meet conditions were antibiotics are pointed out as the treatment of chose, as indicated or not recommended. According to Norwegian drug regulations (Tørisen 2007) dentists have: The right to requisition necessary medical agents in connection with dental treatment and prevention and treatment of diseases in the...

  8. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.;

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...... to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum...

  9. Functional metagenomics for the investigation of antibiotic resistance

    OpenAIRE

    Mullany, Peter

    2014-01-01

    Antibiotic resistance is a major threat to human health and well-being. To effectively combat this problem we need to understand the range of different resistance genes that allow bacteria to resist antibiotics. To do this the whole microbiota needs to be investigated. As most bacteria cannot be cultivated in the laboratory, the reservoir of antibiotic resistance genes in the non-cultivatable majority remains relatively unexplored. Currently the only way to study antibiotic resistance in thes...

  10. Assessment of Bacterial Antibiotic Resistance Transfer in the Gut

    OpenAIRE

    Susanne Schjørring; Krogfelt, Karen A.

    2011-01-01

    We assessed horizontal gene transfer between bacteria in the gastrointestinal (GI) tract. During the last decades, the emergence of antibiotic resistant strains and treatment failures of bacterial infections have increased the public awareness of antibiotic usage. The use of broad spectrum antibiotics creates a selective pressure on the bacterial flora, thus increasing the emergence of multiresistant bacteria, which results in a vicious circle of treatments and emergence of new antibiotic res...

  11. Elimination of indigenous endophytic bacteria in Eucalyptus urophylla by heat and antibiotics treatment%热处理和抗生素对桉树固有内生细菌去除的研究

    Institute of Scientific and Technical Information of China (English)

    宋艳祥; 王玉凤; 冉隆贤

    2011-01-01

    In order to obtain endophytic bacteria free seedlings of Eucalyptus urophylla , three methods were applied to eliminate or inhibit the indigenous endophytic bacteria in E. Urophylla, I. E. , heat treatment of the seeds of E. Urophylla at stable and variated high temperatures, heat treatment of seedlings from tissue culture of E. Urophylla combined with apical meristem culture, and antibiotics treatment of the seedlings grown in tissue culture. A differential staining procedure was used to detect the existence of endophytic bacteria and hemacytometer counting method was used to study the bacterial population. The results showed that there was no obvious effect in the elimination of endophytic bacteria by heat treatment of the seeds, and the bacteria in root of treated seedlings had a bit more population than that of control. However, the bacteria in stem and leaf of treated seedlings had less population than those of control. After the heat treatment of seedlings combined with shoot-tip culture, the endophytic bacteria can be removed effectively as the temperature increased daily, with less number compared with control. And when it reached 40 ℃ , the bacterial growth was inhibited largely. Heat treatment at 37 ℃ reduced the number of indigenous bacteria at 20th and 21st day, with a population of 5. 33 × 108 CFU/g and 4. 02 × 108 CFU/g, respectively, and only about one seventh of the number of control at 3. 43 × 109 CFU/g. When the temperature for heat treatment reached 40 ℃ , the number of bacteria decreased to 1. 63×108 CFU/g, occupied only one forty-seventh of the bacteria number of control at 7. 70 × 109CFU/g, indicating that treatment with higher temperature at 37 ℃ and 40℃ could significantly reduce the number of bacteria in seedlings grown in vitro culture. The population of the endophytic bacteria of E. Urophylla increased obviously after growing in the MS supplemented with antibiotics, I. E. , oxytetracycline, tetra-cycline and cephamycins

  12. Deliberations on the impact of antibiotic contamination on dissemination of antibiotic resistance genes in aquatic environments

    OpenAIRE

    Berglund, Björn

    2014-01-01

    The great success of antibiotics in treating bacterial infectious diseases has been hampered by the increasing prevalence of antibiotic resistant bacteria. Not only does antibiotic resistance threaten to increase the difficulty in treating bacterial infectious diseases, but it could also make medical procedures such as routine surgery and organ transplantations very dangerous to perform. Traditionally, antibiotic resistance has been regarded as a strictly clinical problem and studies of the p...

  13. Antibiotic Resistance in Wastewater : Methicillin-resistant Staphylococcus aureus (MRSA)and antibiotic resistance genes

    OpenAIRE

    Börjesson, Stefan

    2009-01-01

    A large part of the antibiotics consumed ends up in wastewater, and in the wastewater the antibiotics may exert selective pressure for or maintain resistance among microorganisms. Antibiotic resistant bacteria and genes encoding antibiotic resistance are commonly detected in wastewater, often at higher rates and concentrations compared to surface water. Wastewater can also provide favourable conditions for the growth of a diverse bacterial community, which constitutes a basis for the selectio...

  14. Origin of diderm (Gram-negative) bacteria: antibiotic selection pressure rather than endosymbiosis likely led to the evolution of bacterial cells with two membranes

    OpenAIRE

    Gupta, Radhey S.

    2011-01-01

    The prokaryotic organisms can be divided into two main groups depending upon whether their cell envelopes contain one membrane (monoderms) or two membranes (diderms). It is important to understand how these and other variations that are observed in the cell envelopes of prokaryotic organisms have originated. In 2009, James Lake proposed that cells with two membranes (primarily Gram-negative bacteria) originated from an ancient endosymbiotic event involving an Actinobacteria and a Clostridia (...

  15. Ecological antibiotic policy.

    Science.gov (United States)

    Høiby, N

    2000-09-01

    Development of resistance to antibiotics is a major problem worldwide. The normal oropharyngeal flora, the intestinal flora and the skin flora play important roles in this development. Within a few days after the onset of antibiotic therapy, resistant Escherichia coli, Haemophilus influenzae and Staphylococcus epidermidis can be detected in the normal flora of volunteers or patients. Horizontal spread of the resistance genes to other species, e.g. Salmonella spp., Staphylococcus aureus and Streptococcus pneumoniae, occurs by conjugation or transformation. An ecologically sound antibiotic policy favours the use of antibiotics with little or no impact on the normal flora. Prodrug antibiotics which are not active against the bacteria in the mouth and the intestine (before absorption) and which are not excreted to a significant degree via the intestine, saliva or skin are therefore preferred. Prodrugs such as pivampicillin, bacampicillin, pivmecillinam and cefuroxime axetil are favourable from an ecological point of view. Experience from Scandinavia supports this, since resistance to mecillinam after 20 years of use is low (about 5%) and stable. PMID:11051626

  16. [A report on a clinical experience of which has successfully made several antibiotics-resistant bacteria (MRSA etc.) negative on a bedsore].

    Science.gov (United States)

    Nakanishi, T

    1992-02-01

    At the treatment of a bedsore of which had been resistant to various sorts of antibiotics, the mixture of several drugs was used for the treatment of its bedsore. Those drugs from which were used as the drugs-mixture, are 1% liquid of Pioctanin (C24H28N3Cl). 600 mg of Ascorbic acid, 9 mg of Pantothenic calcium and 20mg of hydrochloric Amitriptyline, respectively. The drugs-mixture, as mentioned above, has been scattered over its bedsore before the usual traditional treatment. After that, the bedsore has been treated by Gebencream (1% Cream of Sulfadiazine silver) as usually. Since a few days after that, Pseudomonas aeruginosa has never been able to be found on its bedsore at all. After a month, Staphylococcus aureus, Enterococcus faecalis and Serratia marcescens, which had been resistant to many antibioticus till that, cannot be found at all, too. PMID:1523942

  17. Distribution and antibiotic resistance analysis of fermentable sugars bacteria strains isolated from inpatients from 2008 to 2010%2008-2010年住院患者不发酵糖菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    林晓; 黄东煜; 张昕; 赵建铭; 林宇岚; 林其昌

    2013-01-01

    目的 了解福建医科大学附属第一医院2008年1月1日至2010年12月31日临床分离不发酵糖菌分布及其对所测抗菌药物的耐药性,以引起临床医师和医院感染管理部门的关注,指导临床合理用药.方法 收集2008年1月1日至2010年12月31日我院住院患者临床分离的不发酵糖菌,采用法国生物梅里埃公司VITEK 2全自动细菌鉴定仪器检测,采用纸片扩散法(Kirby-Bauer法)进行抗菌药物的药敏试验,并对数据进行统计分析.结果 3年临床分离的不发酵糖菌共2 651株,其中铜绿假单胞菌1 268株,不动杆菌属1119株,嗜麦芽窄食单胞菌264株.铜绿假单胞菌对碳青霉烯类抗生素的耐药率在上升,达到19.5%~28.8%.不动杆菌耐药性更强,目前仅有米诺环素、头孢哌酮/舒巴坦、阿米卡星的耐药率<30%,碳青霉烯类、喹诺酮类及氨苄西林/舒巴坦等抗菌药物的耐药率已经超过50%.嗜麦芽窄食单胞菌耐药率变化不大,对哌拉西林/他唑巴坦、复方新诺明、米诺环素等敏感率超过90%.结论 3年来我院住院患者临床分离不发酵糖菌占总的临床分离菌的比例波动于36.9%~40.6%,铜绿假单胞菌、不动杆菌属始终占据临床分离菌的前两位,不动杆菌耐药性逐年上升,铜绿假单胞菌对碳青霉烯类抗生素敏感性在下降,值得临床医师高度重视,定期开展细菌分布及耐药性监测,了解其动态变化,对合理应用抗菌药物有重要指导意义,同时院感部门应加强消毒隔离工作,防止耐药菌医院内传播.%Objective To investigate the distribution and antibiotic resistance of fermentable sugars bacteria strains collected in the First Hospital affiliated to Fujian Medical University from January 1,2008 to December 31,2010,attract the attention of clinicians and hospital infection control department,and guide the rational antimicrobial therapy.Methods All the fermentable sugars bacteria strains

  18. The Prehistory of Antibiotic Resistance.

    Science.gov (United States)

    Perry, Julie; Waglechner, Nicholas; Wright, Gerard

    2016-01-01

    Antibiotic resistance is a global problem that is reaching crisis levels. The global collection of resistance genes in clinical and environmental samples is the antibiotic "resistome," and is subject to the selective pressure of human activity. The origin of many modern resistance genes in pathogens is likely environmental bacteria, including antibiotic producing organisms that have existed for millennia. Recent work has uncovered resistance in ancient permafrost, isolated caves, and in human specimens preserved for hundreds of years. Together with bioinformatic analyses on modern-day sequences, these studies predict an ancient origin of resistance that long precedes the use of antibiotics in the clinic. Understanding the history of antibiotic resistance is important in predicting its future evolution. PMID:27252395

  19. Prevalence of Mastitis Resulted from Bacteria of Enterobacteriaceae Group (Coli Forms and Determining Their Antibiotic Sensitivity in Traditional Farms of Sarab City, Iran

    Directory of Open Access Journals (Sweden)

    Mahdi Yeganehzad

    2011-01-01

    Full Text Available Mastitis in livestock means transformation and pathogenesis in udder tissue which may affect one or all quarter of cattle and lead to non-usable of the milk. Although, mastitis may be seen in all livestock, it is of high economical importance in dairy cattles. The studies reveal that notwithstanding disease agent, mastitis is more prevalent in most countries. Coli form bacteria are opportunist. All environmental resource which are in contact with udder are considered as important for pathogenicity of organism. When udder gland is infected, Escherichia coli bacterium propagates at high numbers and produces a strong endotoxin resulting in edema and mastitis. About 1000 dairy cattles of traditional farms of Sarab and its surrounding villages were considered as understudy statistical population out of which 752 were lactating cattles. Preparing milk samples of these cattles according to the following stages, the samples were studied measuring individual cell count of milk samples of understudycattles conducting CMT (California Mastitis Test for cows′ milk whose cell count in over than 150000 in mL sterile sampling from milk of quarter whose CMT result were positive and transferring the samples to bacteriology laboratory centrifuging milk and culture sample from deposit and cream resulted in the culture media conducting of differential tests for colonies related to Enterobacteriaceae of positive suspected lactose in order to determine species and genus of the isolated bacteria conducting of antibiogram test.

  20. Prediction of mixture toxicity from the hormesis of a single chemical: A case study of combinations of antibiotics and quorum-sensing inhibitors with gram-negative bacteria.

    Science.gov (United States)

    Wang, Ting; Wang, Dali; Lin, Zhifen; An, Qingqing; Yin, Chunsheng; Huang, Qinghui

    2016-05-01

    The 50% effect level of a single chemical in the real environment is almost impossible to determine at the low exposure concentration, and the prediction of the concentration of a mixture at the 50% effect level from the concentration of a single chemical at the low effect level is even more difficult. The current literature does not address this problem. Thus, to determine solutions for this question, single/mixture chronic toxicities of sulfonamides (SAs) and quorum-sensing inhibitors (QSIs) were determined using Gram-negative bacteria (Vibrio fischeri and E. coli.) and Gram-positive bacteria (B. subtilis) as the target organisms. The results showed that the joint effects of SAs and QSIs were primarily antagonistic responses. In addition, the toxicity mechanisms of mixtures of SAs and QSIs were investigated further, and the results revealed that the chronic joint effects were primarily an antagonistic response due to the QSI competing against acyl-homoserine lactones (AHL) for luxR in V. fischeri and SdiA in E. coli generated by the SAs, leading to negative effects exerted by the QSI-luxR or QSI-SdiA complexes on luxI in V. fischeri or FtsZ in E. coli. This phenomenon eventually weakened the stimulatory effect caused by the SAs. Based on the mixture toxicity mechanism, the relationship between the mixture toxicity and the simulation effect was formulated. PMID:26901472

  1. Coping with antibiotic resistance: combining nanoparticles with antibiotics and other antimicrobial agents.

    Science.gov (United States)

    Allahverdiyev, Adil M; Kon, Kateryna Volodymyrivna; Abamor, Emrah Sefik; Bagirova, Malahat; Rafailovich, Miriam

    2011-11-01

    The worldwide escalation of bacterial resistance to conventional medical antibiotics is a serious concern for modern medicine. High prevalence of multidrug-resistant bacteria among bacteria-based infections decreases effectiveness of current treatments and causes thousands of deaths. New improvements in present methods and novel strategies are urgently needed to cope with this problem. Owing to their antibacterial activities, metallic nanoparticles represent an effective solution for overcoming bacterial resistance. However, metallic nanoparticles are toxic, which causes restrictions in their use. Recent studies have shown that combining nanoparticles with antibiotics not only reduces the toxicity of both agents towards human cells by decreasing the requirement for high dosages but also enhances their bactericidal properties. Combining antibiotics with nanoparticles also restores their ability to destroy bacteria that have acquired resistance to them. Furthermore, nanoparticles tagged with antibiotics have been shown to increase the concentration of antibiotics at the site of bacterium-antibiotic interaction, and to facilitate binding of antibiotics to bacteria. Likewise, combining nanoparticles with antimicrobial peptides and essential oils generates genuine synergy against bacterial resistance. In this article, we aim to summarize recent studies on interactions between nanoparticles and antibiotics, as well as other antibacterial agents to formulate new prospects for future studies. Based on the promising data that demonstrated the synergistic effects of antimicrobial agents with nanoparticles, we believe that this combination is a potential candidate for more research into treatments for antibiotic-resistant bacteria. PMID:22029522

  2. Swollen hindgut syndrome (SHG of tiger shrimp Penaeus monodon (Crustacea, Malacostraca, Penaeidae post larvae: Identification of causing pathogenic bacteria and their sensitivity to some antibiotics

    Directory of Open Access Journals (Sweden)

    Sheikh Aftabuddin

    2011-01-01

    Full Text Available Swollen Hindgut syndrome (SHG of black tiger shrimp Penaeus monodon Fabricius, 1798post larvae has been reported from Bangladesh shrimp hatcheries in recent years. At present SHG is abudding problem causing significant economic loss to the shrimp hatcheries in Bangladesh. Unlike therapid mortalities associated with viral disease such as white spot syndrome and yellow head virus,progression of SHG is gradual leading to low level mortalities without affecting swimming activity. Thesign of SHG are a bloated or swollen in hind gut area, with the posterior digestive tract convolutingthrough the last abdominal segment. This syndrome tends to occur at later PL stages, typically afterPL10. Two types of Vibrio spp. were isolated from the swollen hindgut syndrome post larvae, identified asVibrio harveyi (Johnson and Shunk 1936and Vibrio alginolyticus (Miyamoto, Nakamura & Takizawa1961. Among these V. alginolyticus was dominant to V. harveyi. The bacterial isolates showed sensitiveto oxytetracycline (OTC, norfloxacin and ciprofloxacin and resistant to penicillin, ampicillin andamoxycillin. The luminous V. harveyi showed resistant to many antibiotics and susceptibility to only twodrugs. The cause of swollen hindgut syndrome (SHG was probably bacterial infections and poor waterquality, possibly heavy metal i.e. iron, the presence of toxic substances from chemical prophylactics andlow quality or diseased nauplii.

  3. Bacterial infections: antibiotics and decontamination.

    Science.gov (United States)

    Gould, Dinah

    Infectious disease is caused by bacteria, viruses, fungi, protozoa and micro-organisms including the mycoplasmas, rickettsiae and chlamydiae. Most of the infections commonly encountered in the UK are caused either by bacteria or viruses. This article describes bacterial structure and function to explain how antibiotics work and the processes of decontamination such as cleaning, disinfection and sterilisation, which are important in infection control. PMID:15224613

  4. Antibiotics May Blunt Breast-Feeding's Benefits

    Science.gov (United States)

    ... fighting infection because of the immunity offered in mother's milk," said Dr. William Muinos, a pediatric gastroenterologist at Nicklaus Children's Hospital in Miami. Antibiotics kill the bacteria in the gut, he said. "If ...

  5. Stop the Spread of Superbugs: Help Fight Drug Resistant Bacteria

    Science.gov (United States)

    ... the Spread of Superbugs Help Fight Drug-Resistant Bacteria For nearly a century, bacteria-fighting drugs known as antibiotics have helped to control and destroy many of the harmful bacteria that can make us sick. But in recent ...

  6. Antibiotic Resistance

    Science.gov (United States)

    ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Information by Audience For Women Antibiotic Resistance Share Tweet Linkedin Pin it More ...

  7. Mining metagenomic datasets for antibiotic resistance genes

    Science.gov (United States)

    Antibiotics are medicines that are used to kill, slow down, or prevent the growth of susceptible bacteria. They became widely used in the mid 20th century for controlling disease in humans, animals, and plants, and for a variety of industrial purposes. Antibiotic resistance is a broad term. There ...

  8. Antibiotic tolerance and resistance in biofilms

    DEFF Research Database (Denmark)

    Ciofu, Oana; Tolker-Nielsen, Tim

    One of the most important features of microbial biofilms is their tolerance to antimicrobial agents and components of the host immune system. The difficulty of treating biofilm infections with antibiotics is a major clinical problem. Although antibiotics may decrease the number of bacteria in...

  9. Synthesis and mode of action of hydrophobic derivatives of the glycopeptide antibiotic eremomycin and des-(N-methyl-D-leucyl)eremomycin against glycopeptide-sensitive and -resistant bacteria.

    Science.gov (United States)

    Printsevskaya, Svetlana S; Pavlov, Andrey Y; Olsufyeva, Evgenia N; Mirchink, Elena P; Isakova, Elena B; Reznikova, Marina I; Goldman, Robert C; Branstrom, Arthur A; Baizman, Eugene R; Longley, Clifford B; Sztaricskai, Ferenc; Batta, Gyula; Preobrazhenskaya, Maria N

    2002-03-14

    Des-(N-methyl-D-leucyl)eremomycin was obtained by Edman degradation of eremomycin. Derivatives with a hydrophobic substituent at the exterior of the molecule were then synthesized, and their antibacterial activities were compared with similar derivatives of eremomycin. Comparison of derivatives of eremomycin containing the n-decyl or p-(p-chlorophenyl)benzyl substituent in the eremosamine moiety (N') and n-decyl or p-(p-chlorophenyl)benzylamides with similar derivatives of eremomycin possessing the damaged peptide core (a defective binding pocket) showed that compounds of both types are almost equally active against glycopeptide-resistant strains of enterococci (GRE), whereas eremomycin derivatives are more active against staphylococci. Hydrophobic 7d-alkylaminomethylated derivatives of eremomycin (9, 10) demonstrated similar antibacterial properties. Since the basic mode of action of glycopeptide antibiotics involves binding to cell wall intermediates terminating in -D-Ala-D-Ala and this interaction is seriously decreased in the hexapeptide derivatives (lacking the critical N-methyl-D-leucine), we suggest that these hydrophobic derivatives may inhibit peptidoglycan synthesis in the absence of dipeptide binding. NMR binding experiments using Ac-D-Ala-D-Ala show that binding constants of these hexapeptide derivativies are decreased in comparison with the corresponding heptapeptides with intact binding pocket. This is in agreement with the decreased biological activity of the hexapeptide derivatives against vancomycin-sensitive strains in comparison with the activity of parent compounds. Binding to the lactate cell wall analogue Ac-D-Ala-D-Lac with decylamide of eremomycin 8 was not observed, demonstrating that the interaction with this target in GRE does not occur. While hydrophobic glycopeptide derivatives retain the ability to inhibit the synthesis of peptidoglycan in manner of natural glycopeptides, biochemical investigation supports the hypothesis that they

  10. Detection of residues antibiotics in food using a microbiological method

    International Nuclear Information System (INIS)

    Antibiotics are effective therapeutic agents because of their property of selective bacterial toxicity which helps controlling infections. Animals, just like humans, can be treated with antibiotics. This use of antibiotics can lead to the development of resistance. Resistant strains may cause severe infections in humans and animals. In addition, antibiotic residues might represent a problem for human health. Our objective is to develop a microbiological method for the detection of antibiotic residues in poultry(muscle, liver,...). For this purpose, antibiotic sensitive bacteria and selective agar media were used. An inhibition growth zone surrounds each of the food samples containing antibiotic residues after a prescribed incubation time. (Author). 23 refs

  11. Emergence and dissemination of antibiotic resistance: a global problem.

    Science.gov (United States)

    Choudhury, R; Panda, S; Singh, D V

    2012-01-01

    Antibiotic resistance is a major problem in clinical health settings. Interestingly the origin of many of antibiotic resistance mechanisms can be traced back to non-pathogenic environmental organisms. Important factors leading to the emergence and spread of antibiotic resistance include absence of regulation in the use of antibiotics, improper waste disposal and associated transmission of antibiotic resistance genes in the community through commensals. In this review, we discussed the impact of globalisation on the transmission of antibiotic resistance genes in bacteria through immigration and export/import of foodstuff. The significance of surveillance to define appropriate use of antibiotics in the clinic has been included as an important preventive measure. PMID:23183460

  12. ANTIMICROBIAL PEPTIDES: AN EFFECTIVE ALTERNATIVE FOR ANTIBIOTIC THERAPY

    Directory of Open Access Journals (Sweden)

    KK PULICHERLA

    2013-01-01

    Full Text Available Extensive use of classical antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence has suggested that cationic antimicrobial peptides (AMP’s are of greatest potential to represent a new class of antibiotics. These peptides have a good scope in current antibiotic research. During the past two decades several AMPs have been isolated from a wide variety of animals (both vertebrates and invertebrates, and plants as well as from bacteria and fungi. These are relatively small (<10kDa, cationic and amphipathic peptides of variable length, sequence and structure. These peptides exhibit broad-spectrum activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, protozoa, yeast, fungi and viruses. Most of these peptides are believed to act by disrupting the plasma membrane leading to the lysis of the cell. Antimicrobial peptides encompass a wide variety of structural motifs such as α -helical peptides, β -sheet peptides, looped peptides and extended peptides. Preparations enriched by a specific protein are rarely easily obtained from natural host cells. Hence, recombinant protein production is frequently the sole applicable procedure. Several fusion strategies have been developed for the expression and purification of small antimicrobial peptides (AMPs in recombinant bacterial expression systems which were produced by cloning. This article aims to review in brief the sources of antimicrobial peptides, diversity in structural features, mode of action, production strategies and insight into the current data on their antimicrobial activity followed by a brief comment on the peptides that have entered clinical trials.

  13. 2011年汉中市中心医院细菌耐药性监测分析%Analysis of Bacteria Antibiotic Resistance in Hanzhong Centre Hospital in 2011

    Institute of Scientific and Technical Information of China (English)

    何宝明; 柏莹; 汤进; 黄晓霞

    2012-01-01

    目的 了解2011年临床分离菌株对常用抗生素的耐药情况.方法 细菌鉴定与药敏实验采用全自动细菌鉴定仪,手工鉴定系统以及纸片扩散法.实验及判读标准均按美国临床实验室标准化协会推荐的进行.结果 2011年细菌培养标本14 701例,分离菌株3643株,革兰阴性菌占71%,革兰阳性菌占29%.前5位的细菌为:大肠埃希菌、肺炎克雷伯菌、鲍曼不动杆菌、金黄色葡萄球菌、铜绿假单胞菌.其中耐药菌种大肠埃希菌产超广谱β内酰胺酶占54.7%,肺炎克雷伯菌产β内酰胺酶占50.7%,多重耐药鲍曼不动杆菌占36.40%,耐甲氧西林金黄色葡萄球菌占32.20%,多重耐药铜绿假单胞菌占7.70%.结论 常见葡萄球菌、链球菌对红霉素都有较高的耐药性.分离到对万古霉素耐药的溶血葡萄球菌(5.7%).大肠埃希菌、肺炎克雷伯菌、奇异变形杆菌都对亚胺培南保持较高的敏感性,而阴沟肠杆菌则有1%的耐药率.%Objective To investigate the antibiotic resistance status of bacteria isolated from the hospital in 2011. Methods Bacterial identification and antibiotic testing were carried out by automatic system, manual identification and K-B method was done according to CLS1. Results A total of 3643 bacteria were isolated from 14701 samples in 2011 , Gram-negative bacteria accounted for 71% , (Tram-positive bacteria accounted for 29% . The top five were E. coli,K. pneumoniae , Acinetobacter baumannii, Staphylococcus aureus, and Pseudomonas aeruginosa. In (Tram negative bacilli, ESBLs was up to 54. 7% . In K. pneumoniae, ESBLs was up to 50. 7% , MDR Acinetobacter baumannii, MRS A, MDR pseudomonas aeruginosa were 36. 40% , 32. 20% ,7. 70% . Conclusion Common ataphylococcus and streptococcus showed a high resistance to eryth-romycin ; Staphylococcus haemolyticus showed 5.7% resistance to vancomycin ;E. coli,K. pneumoniae ,Proteus mirabilis showed a high susceptibility to imipenem, while enterobacter

  14. Efforts to slacken antibiotic resistance: Labeling meat products from animals raised without antibiotics in the United States.

    Science.gov (United States)

    Centner, Terence J

    2016-09-01

    As bacteria and diseases spread due to climatic change, greater amounts of antibiotics will be used thereby exacerbating the problem of antibiotic resistance. To help slacken the development of resistant bacteria, the medical community is attempting to reduce unnecessary and excessive usage of antibiotics. One of the targets is the use of antibiotics for enhancing animal growth and promoting feed efficiency in the production of food animals. While governments can adopt regulations prohibiting nontherapeutic uses of antibiotics in food animals and strategies to reduce antibiotic usage, another idea is to publicize when antibiotics are used in food animal production by allowing labeled meat products. This paper builds upon existing labeling and marketing efforts in the United States to show how a government can develop a verified antibiotic-free labeling program that would allow consumers to purchase meat products from animals that had never received antibiotics. PMID:27236477

  15. Pharmacodynamics of TD-1792, a novel glycopeptide-cephalosporin heterodimer antibiotic used against Gram-positive bacteria, in a neutropenic murine thigh model.

    Science.gov (United States)

    Hegde, Sharath S; Okusanya, Olanrewaju O; Skinner, Robert; Shaw, Jeng-Pyng; Obedencio, Glenmar; Ambrose, Paul G; Blais, Johanne; Bhavnani, Sujata M

    2012-03-01

    TD-1792 is a novel glycopeptide-cephalosporin heterodimer investigational antibiotic that displays potent bactericidal effects against clinically relevant Gram-positive organisms in vitro. The present studies evaluated the in vivo pharmacokinetics (PK) and pharmacodynamics (PD) of TD-1792 in the neutropenic murine thigh infection animal model. TD-1792, dosed subcutaneously (SC), produced dose-dependent reduction in the thigh bacterial burden of several organisms, including methicillin-susceptible and -resistant strains of Staphylococcus aureus and Staphylococcus epidermidis (MSSA, MRSA, MSSE, MRSE, respectively), penicillin-susceptible strains of Streptococcus pneumoniae (PSSP), Streptococcus pyogenes, and vancomycin-intermediate-susceptible Staphylococcus aureus (VISA). In single-dose efficacy studies, the 1-log(10) CFU kill effective dose (ED(1-log kill)) estimates for TD-1792 ranged from 0.049 to 2.55 mg/kg of body weight administered SC, and the bacterial burden was reduced by up to 3 log(10) CFU/g from pretreatment values. Against S. aureus ATCC 33591 (MRSA), the total 24-h log(10) stasis dose (ED(stasis)) and ED(1-logkill) doses for TD-1792 were 0.53 and 1.11 mg/kg/24 h, respectively, compared to 23.4 and 54.6 mg/kg/24 h for vancomycin, indicating that TD-1762 is 44- to 49-fold more potent than vancomycin. PK-PD analysis of data from single-dose and dose-fractionation studies for MRSA (ATCC 33591) demonstrated that the total-drug 24-h area under the concentration-time curve-to-MIC ratio (AUC/MIC ratio) was the best predictor of efficacy (r(2) = 0.826) compared to total-drug maximum plasma concentration of drug-to-MIC ratio (Cmax/MIC ratio; r(2) = 0.715) and percent time that the total-drug plasma drug concentration remains above the MIC (%Time>MIC; r(2) = 0.749). The magnitudes of the total-drug AUC/MIC ratios associated with net bacterial stasis, a 1-log(10) CFU reduction from baseline and near maximal effect, were 21.1, 37.2, and 51.8, respectively. PK

  16. Antibiotic Resistance in Multidrug-Resistant Gram-Negative Bacteria from Burn Wards%烧伤病房革兰阴性多重耐药菌耐药性分析

    Institute of Scientific and Technical Information of China (English)

    庞宗超; 李惠斌

    2015-01-01

    目的:分析烧伤病房革兰阴性多重耐药菌的病原菌分布及耐药性,为临床合理应用抗生素提供依据,并探讨多重耐药菌的防控策略。方法应用 VITEK2-compact全自动微生物鉴定及药敏分析系统对临沂市人民医院烧伤整形科2012年1月至2014年1月送检标本分离的菌株进行菌种鉴定,采用 K-B纸片扩散法进行药敏试验,统计分析革兰阴性多重耐药菌的分布情况及其对抗菌药物的耐药情况。结果共检出130株革兰阴性多重耐药菌,创面分泌物为其主要标本来源,占81.54%,其次为痰液,占12.30%。菌株分布以鲍曼不动杆菌和大肠埃希菌为主,分别占38.46%(50/130)、29.23%(38/130)。大肠埃希菌和肺炎克雷伯菌产超广谱β-内酰胺酶(ESBLs)菌株分离率为89.47%(34/38)、87.50%(14/16)。耐碳青霉烯类抗生素鲍曼不动杆菌(CR-AB)对除替加环素、左氧氟沙星之外的所有测试抗菌药物均呈现高度耐药,耐药率在90%~100%之间;肺炎克雷伯菌和大肠埃希菌对碳青霉烯类抗生素、含酶抑制剂的复合制剂、替加环素耐药率均小于20%,而对氨基糖苷类、第三代头孢菌素类、喹诺酮类抗生素耐药率较高。铜绿假单胞菌和阴沟肠杆菌仅对丁胺卡那霉素有较高敏感性。结论革兰阴性多重耐药菌对常用抗菌药物表现出较高耐药性,应及时制定防控策略,缓解细菌耐药性。%Objective To analyze the distribution and antibiotic resistance of multidrug-resist-ant gram-negative bacteria from burn wards,and to provide a basis for rational use of antibiotics and prevention and control of multidrug-resistant bacteria.Methods VITEK2-compact automatic microorganism system and drug sensitivity analyzer were used to identify the pathogens isolated from specimens from patients hospitalized in Department of Burn and Plastic Surgery of Linyi

  17. Cognitive Impairment by Antibiotic-Induced Gut Dysbiosis: Analysis of Gut Microbiota-Brain Communication

    Science.gov (United States)

    Fröhlich, Esther E.; Farzi, Aitak; Mayerhofer, Raphaela; Reichmann, Florian; Jačan, Angela; Wagner, Bernhard; Zinser, Erwin; Bordag, Natalie; Magnes, Christoph; Fröhlich, Eleonore; Kashofer, Karl; Gorkiewicz, Gregor; Holzer, Peter

    2016-01-01

    Emerging evidence indicates that disruption of the gut microbial community (dysbiosis) impairs mental health. Germ-free mice and antibiotic-induced gut dysbiosis are two approaches to establish causality in gut microbiota-brain relationships. However, both models have limitations, as germ-free mice display alterations in blood-brain barrier and brain ultrastructure and antibiotics may act directly on the brain. We hypothesized that the concerns related to antibiotic-induced gut dysbiosis can only adequately be addressed if the effect of intragastric treatment of adult mice with multiple antibiotics on (i) gut microbial community, (ii) metabolite profile in the colon, (iii) circulating metabolites, (iv) expression of neuronal signaling molecules in distinct brain areas and (v) cognitive behavior is systematically investigated. Of the antibiotics used (ampicillin, bacitracin, meropenem, neomycin, vancomycin), ampicillin had some oral bioavailability but did not enter the brain. 16S rDNA sequencing confirmed antibiotic-induced microbial community disruption, and metabolomics revealed that gut dysbiosis was associated with depletion of bacteria-derived metabolites in the colon and alterations of lipid species and converted microbe-derived molecules in the plasma. Importantly, novel object recognition, but not spatial, memory was impaired in antibiotic-treated mice. This cognitive deficit was associated with brain region-specific changes in the expression of cognition-relevant signaling molecules, notably brain-derived neurotrophic factor, N-methyl-D-aspartate receptor subunit 2B, serotonin transporter and neuropeptide Y system. We conclude that circulating metabolites and the cerebral neuropeptide Y system play an important role in the cognitive impairment and dysregulation of cerebral signaling molecules due to antibiotic-induced gut dysbiosis. PMID:26923630

  18. Cognitive impairment by antibiotic-induced gut dysbiosis: Analysis of gut microbiota-brain communication.

    Science.gov (United States)

    Fröhlich, Esther E; Farzi, Aitak; Mayerhofer, Raphaela; Reichmann, Florian; Jačan, Angela; Wagner, Bernhard; Zinser, Erwin; Bordag, Natalie; Magnes, Christoph; Fröhlich, Eleonore; Kashofer, Karl; Gorkiewicz, Gregor; Holzer, Peter

    2016-08-01

    Emerging evidence indicates that disruption of the gut microbial community (dysbiosis) impairs mental health. Germ-free mice and antibiotic-induced gut dysbiosis are two approaches to establish causality in gut microbiota-brain relationships. However, both models have limitations, as germ-free mice display alterations in blood-brain barrier and brain ultrastructure and antibiotics may act directly on the brain. We hypothesized that the concerns related to antibiotic-induced gut dysbiosis can only adequately be addressed if the effect of intragastric treatment of adult mice with multiple antibiotics on (i) gut microbial community, (ii) metabolite profile in the colon, (iii) circulating metabolites, (iv) expression of neuronal signaling molecules in distinct brain areas and (v) cognitive behavior is systematically investigated. Of the antibiotics used (ampicillin, bacitracin, meropenem, neomycin, vancomycin), ampicillin had some oral bioavailability but did not enter the brain. 16S rDNA sequencing confirmed antibiotic-induced microbial community disruption, and metabolomics revealed that gut dysbiosis was associated with depletion of bacteria-derived metabolites in the colon and alterations of lipid species and converted microbe-derived molecules in the plasma. Importantly, novel object recognition, but not spatial, memory was impaired in antibiotic-treated mice. This cognitive deficit was associated with brain region-specific changes in the expression of cognition-relevant signaling molecules, notably brain-derived neurotrophic factor, N-methyl-d-aspartate receptor subunit 2B, serotonin transporter and neuropeptide Y system. We conclude that circulating metabolites and the cerebral neuropeptide Y system play an important role in the cognitive impairment and dysregulation of cerebral signaling molecules due to antibiotic-induced gut dysbiosis. PMID:26923630

  19. Clostridium difficile enteritis in a patient after total proctocolectomy

    OpenAIRE

    Peacock, Oliver; Speake, William; Shaw, Aidan; Goddard, Andrew

    2009-01-01

    Clostridium difficile infection is associated with antibiotic therapy and usually limited to the colonic mucosa. However, it is also a rare cause of enteritis, with only a few cases reported in the literature. In the present report, the case of a 30-year-old woman with Clostridium difficile enteritis who previously had a panproctocolectomy with end ileostomy for severe ulcerative colitis is described. Previously reported cases of Clostridium difficile enteritis are also reviewed. Previous ant...

  20. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  1. Pantoea agglomerans strain EH318 produces two antibiotics that inhibit Erwinia amylovora in vitro.

    Science.gov (United States)

    Wright, S A; Zumoff, C H; Schneider, L; Beer, S V

    2001-01-01

    Pantoea agglomerans (synonym: Erwinia herbicola) strain Eh318 produces through antibiosis a complex zone of inhibited growth in an overlay seeded with Erwinia amylovora, the causal agent of fire blight. This zone is caused by two antibiotics, named pantocin A and B. Using a genomic library of Eh318, two cosmids, pCPP702 and pCPP704, were identified that conferred on Escherichia coli the ability to inhibit growth of E. amylovora. The two cosmids conferred different antibiotic activities on E. coli DH5alpha and had distinct restriction enzyme profiles. A smaller, antibiotic-conferring DNA segment from each cosmid was cloned. Each subclone was characterized and mutagenized with transposons to generate clones that were deficient in conferring pantocin A and B production, respectively. Mutated subclones were introduced into Eh318 to create three antibiotic-defective marker exchange mutants: strain Eh421 (pantocin A deficient); strain Eh439 (pantocin B deficient), and Eh440 (deficient in both pantocins). Cross-hybridization results, restriction maps, and spectrum-of-activity data using the subclones and marker exchange mutants, supported the presence of two distinct antibiotics, pantocin A and pantocin B, whose biosynthetic genes were present in pCPP702 and pCPP704, respectively. The structure of pantocin A is unknown, whereas that of pantocin B has been determined as (R)-N-[((S)-2-amino-propanoylamino)-methyl]-2-methanesulfonyl-s uccina mic acid. The two pantocins mainly affect other enteric bacteria, based on limited testing. PMID:11133457

  2. Widespread antibiotic resistance of diarrheagenic Escherichia coli and Shigella species

    OpenAIRE

    Azam Fatahi Sadeghabadi; Ali Ajami; Reza Fadaei; Masoud Zandieh; Elham Heidari; Mahmoud Sadeghi; Behrooz Ataei; Shervin Ghaffari Hoseini

    2014-01-01

    Background: Antibiotic resistance of enteric pathogens particularly Shigella species, is a critical world-wide problem and monitoring their resistant pattern is essential, because the choice of antibiotics is absolutely dependent on regional antibiotic susceptibility patterns. During summer 2013, an unusual increase in number of diarrheal diseases was noticed in Isfahan, a central province of Iran. Therefore, the antibiotic resistance of diarrheagenic Escherichia coli and Shigella species iso...

  3. Medical and Personal Care Applications of Bacteriocins Produced by Lactic Acid Bacteria

    Science.gov (United States)

    Dicks, L. M. T.; Heunis, T. D. J.; van Staden, D. A.; Brand, A.; Noll, K. Sutyak; Chikindas, M. L.

    The frequent use of antibiotics has led to a crisis in the antibiotic ­resistance of pathogens associated with humans and animals. Antibiotic resistance and the emergence of multiresistant bacterial pathogens have led to the investigation of alternative antimicrobial agents to treat and prevent infections in both humans and animals. Research on antimicrobial peptides, with a special interest on bacteriocins of lactic acid bacteria, is entering a new era with novel applications other than food preservation. Many scientists are now focusing on the application of these peptides in medicinal and personal care products. However, it is difficult to assess the success of such ventures due to the dearth of information that has been published and the lack of clinical trials.

  4. [Antibiotic sensitivity to epidemic strains of Vibrio cholerae and Shigella dysenteriae 1 isolated in Rwandan refugee camps in Zaire].

    Science.gov (United States)

    Cavallo, J D; Niel, L; Talarmin, A; Dubrous, P

    1995-01-01

    Multiresistance or epidemic enteric bacteria to antibiotics greatly complicates treatment, and in some cases prophylaxis, of severe invasive gastroenteritis. During the summer of 1994, two epidemics of diarrhea, one due to Vibrio cholerae and the other to Shigella dysenteriae 1 isolated from the Goma and Bukavu camps was determined by measurement of the Agar Minimal Inhibitory Concentration. Multiresistance to tetracyclins, aminopenicillins, trimethoprimsulfamethoxazole, and nifuroxazide was observed. After intensive treatment mutant forms of both bacteria resistant to nalidixic acid rapidly appeared. Only fluoroquinolones remained active on these mutant strains, but the availability of this agent in Africa is restricted due to cost. The most effective way of preventing resistance is to limit the spread of enteric infections by health education and improvement of hygiene. This can be difficult during wartime. PMID:8830219

  5. Effective Phages as Green Antimicrobial Agents Against Antibiotic-Resistant Hospital Escherichia coli

    OpenAIRE

    Rahmani, Rana; Zarrini, Gholamreza; Sheikhzadeh, Farzam; Aghamohammadzadeh, Naser

    2015-01-01

    Background: Bacteriophages are viruses that attack bacteria and lead to their lysis in an efficient and highly specific manner. These natural enemies of bacteria were used as therapeutic agents before the advent of antibiotics. Currently, with the rapid spread of multi-drug resistant bacteria, phage therapy can be an effective alternative treatment for antibiotic resistant bacteria. Objectives: This study evaluated the effectiveness of bacteriophages in removing antibiotic-resistant clinical ...

  6. STUDIES ON ANTIMICROBIAL ACTIVITY AND PHYTOCHEMICAL ANALYSIS OF CITRUS FRUIT JUICES AGAINST SELECTED ENTERIC PATHOGENS

    Directory of Open Access Journals (Sweden)

    Bansode.D.S.

    2012-11-01

    Full Text Available The present study was carried out to find out the antimicrobial activity and phytochemical study of citrus fruit juices viz. Lemon (Citrus limon and Orange (Citrus ourantium against medically important selected enteric pathogens. As microorganisms are becoming resistant to present day antibiotics, our study focuses on antimicrobial activity and phytochemical study of Citrus fruit juices against selected enteric pathogens. Biological active compounds present in the medicinal important fruit juices have always been of great interest to scientist. These compounds, not only play an important physiological and etiological role, but are also of commercial interest because of their multitude application in the food and pharmaceutical industries. In the present study, the Lemon and Orange fruit juices were subjected to screening against enteric pathogens, E.coli, Salmonella paratyphy B, and Shigella sonnei. Antimicrobial analysis was done by using agar well diffusion method against selected enteric bacteria. The MIC values were determined by using U.V. Spectrophotometer. The fresh crude Lemon fruit juice produced the highest antimicrobial activity against Salmonella para.B and Shigella sonnei followed by E.coli and fresh crude Orange fruit juice produced the highest antimicrobial activity against Shigella sonnei and Salmonella para.B. followed by E.coli. The antimicrobial activity of standard antibiotic Ampicillin was studied in comparison with Lemon and Orange fruit juices. The Minimum inhibitory concentration observed at 25% conc. of lemon juice against Salmonella paratyphy B, and Shigella sonnei and 25% concentration of orange juice against Shigella sonnei. The phytochemical analysis showed the presence of phenols, flavonoids, glycosides, steroid, saponin, and reducing sugar in citrus fruit juices.

  7. Aerobic digestion reduces the quantity of antibiotic resistance genes in residual municipal wastewater solids

    OpenAIRE

    Burch, Tucker R.; Sadowsky, Michael J.; LaPara, Timothy M.

    2013-01-01

    Numerous initiatives have been undertaken to circumvent the problem of antibiotic resistance, including the development of new antibiotics, the use of narrow spectrum antibiotics, and the reduction of inappropriate antibiotic use. We propose an alternative but complimentary approach to reduce antibiotic resistant bacteria (ARB) by implementing more stringent technologies for treating municipal wastewater, which is known to contain large quantities of ARB and antibiotic resistance genes (ARGs)...

  8. Molecular characterization and antibiotic specificities of multidrug transporters in Lactoccus lactis

    NARCIS (Netherlands)

    Putman, Monique

    2000-01-01

    Many infectious diseases caused by various pathogenic bacteria can often successfully be treated with antibiotics. however, a major drawback of the widespread use of antibiotics is the selection of antibiotic resistant bacteria. Consequently, bacterial diseases that were believed to be controlled, a

  9. Differential transcriptional response to antibiotics by Pseudomonas putida DOT-T1E

    DEFF Research Database (Denmark)

    Molina-Santiago, Carlos; Daddaoua, Abdelali; Gómez Lozano, María;

    2015-01-01

    Multi-drug resistant bacteria are a major threat to humanity, especially because the current battery of known antibiotics is not sufficient to combat infections produced by these microbes. Therefore, the study of how current antibiotics act and how bacteria defend themselves against antibiotics i...

  10. A Survey of the Epidemiology and Antibiotic Resistance Patterns of Enteropathogens Isolates in an Iranian Hospital

    Directory of Open Access Journals (Sweden)

    Mirjafari Tafti

    2016-02-01

    Full Text Available Background Infectious diarrhea is one of the most frequent diseases among children, especially in developing countries. Objectives The aim of this study was to determine the etiological agents and drug resistance patterns of common enteric pathogens isolated in an Iranian 1000-bed tertiary care hospital. Patients and Methods In a retrospective study, we analyzed the etiology and drug resistance patterns of enteric pathogens associated with diarrheal cases. The study was carried out in the Milad hospital of Tehran over two years, from April of 2012 to January of 2014. Stool specimens from patients with diarrhea (n = 7321 were examined for enteric pathogens using routine microbiological culture methods. Strains of Salmonella, Shigella, and enteric pathogenic E. coli (EPEC were serotyped and their susceptibility to commonly used antimicrobial agents was determined by a disk diffusion method, as recommended by the clinical and laboratory standards institute (CLSI guidelines. Results Enteric pathogens were isolated from 310 (4.23% of the patients. The most frequently isolated microorganisms included enteropathogenic E. coli (EPEC, Salmonella, and Shigella spp. The majority of the isolates of EPEC were resistant to commonly used antibiotics such as ampicillin (85.61%, cefixime (79.41%, and nalidixic acid. Resistance among other enteric pathogens was also prevalent. About 45.70% of the Salmonella isolates were resistant to chloramphenicol, and 87.95% were resistant to sulfamethoxazole/trimethoprim. Resistance of the Shigella isolates to nalidixic acid in comparison to the resistance recorded in previous studies was higher. Conclusions The results show that enteric bacteria, including EPEC, Salmonella spp., and Shigella spp. are the major causative agents of diarrhea in the hospital. The emergence of antimicrobial resistance among enteric pathogens is an important problem for public health. Considering the threat of emerging antimicrobial resistance

  11. The Agricultural Antibiotic Carbadox Induces Phage-mediated Gene Transfer in Salmonella

    Directory of Open Access Journals (Sweden)

    Bradley L. Bearson

    2014-02-01

    Full Text Available Antibiotics are used for disease therapeutic or preventative effects in humans and animals, as well as for enhanced feed conversion efficiency in livestock. Antibiotics can also cause undesirable effects in microbial populations, including selection for antibiotic resistance, enhanced pathogen invasion, and stimulation of horizontal gene transfer. Carbadox is a veterinary antibiotic used in the U.S. during the starter phase of swine production for improved feed efficiency and control of swine dysentery and bacterial swine enteritis. Carbadox has been shown in vitro to induce phage-encoded Shiga toxin in Shiga toxin-producing Escherichia coli and a phage-like element transferring antibiotic resistance genes in Brachyspira hyodysenteriae, but the effect of carbadox on prophages in other bacteria is unknown. This study examined carbadox exposure on prophage induction and genetic transfer in Salmonella enterica serovar Typhimurium, a human foodborne pathogen that frequently colonizes swine without causing disease. S. Typhimurium LT2 exposed to carbadox induced prophage production, resulting in bacterial cell lysis and release of virions that were visible by electron microscopy. Carbadox induction of phage-mediated gene transfer was confirmed by monitoring the transduction of a sodCIII::neo cassette in the Fels-1 prophage from LT2 to a recipient Salmonella strain. Furthermore, carbadox frequently induced generalized transducing phages in multidrug-resistant phage type DT104 and DT120 isolates, resulting in the transfer of chromosomal and plasmid DNA that included antibiotic resistance genes. Our research indicates that exposure of Salmonella to carbadox induces prophages that can transfer virulence and antibiotic resistance genes to susceptible bacterial hosts. Carbadox-induced, phage-mediated gene transfer could serve as a contributing factor in bacterial evolution during animal production, with prophages being a reservoir for bacterial fitness

  12. New record of Pterotaenia fasciata (Wiedemann) (Diptera, Ulidiidae) in Brazil, a probably mechanical vector of enteric bacteria Novo registro de Pterotaenia fasciata (Wiedemann) (Diptera, Ulidiidae) no Brasil, um provável vetor mecânico de enterobactérias

    OpenAIRE

    Anderson Sena Barnabe; Gabriel Zorello Laporta; Marcia Zorello Laporta; Carlos José Einicker Lamas

    2007-01-01

    Pterotaenia fasciata is commonly recorded in rural areas in Argentina, but during a Diptera survey study developed in a reservoir which retains storm water from polluted canals in an urban area of Taboão da Serra municipality, SP, Brazil, we could capture P. fasciata adults. Enteric bacteria Escherichia coli T. Escherich, 1885 and Proteus sp. were isolated from P. fasciata collected in traps inside the reservoir and around it. Fecal coliforms and E. coli were found in the water of the reservo...

  13. Systems, not pills: The options market for antibiotics seeks to rejuvenate the antibiotic pipeline.

    Science.gov (United States)

    Brogan, David M; Mossialos, Elias

    2016-02-01

    Over the past decade, there has been a growing recognition of the increasing growth of antibiotic resistant bacteria and a relative decline in the production of novel antibacterial therapies. The combination of these two forces poses a potentially grave threat to global health, in both developed and developing countries. Current market forces do not provide appropriate incentives to stimulate new antibiotic development, thus we propose a new incentive mechanism: the Options Market for Antibiotics. This mechanism, modelled on the principle of financial call options, allows payers to buy the right, in early stages of development, to purchase antibiotics at a discounted price if and when they ever make it to market approval. This paper demonstrates the effect of such a model on the expected Net Present Value of a typical antibacterial project. As part of an integrated strategy to confront the impending antibiotic crisis, the Options Market for Antibiotics may effectively stimulate corporate and public investment into antibiotic research and development. PMID:26808335

  14. Environmental dissemination of antibiotic resistance genes and correlation to anthropogenic contamination with antibiotics

    Directory of Open Access Journals (Sweden)

    Björn Berglund

    2015-09-01

    Full Text Available Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs. Horizontal gene transfer (HGT events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment.

  15. Prevalence of Tetracycline Resistance Genes in Oral Bacteria

    OpenAIRE

    Villedieu, A.; Diaz-Torres, M. L.; Hunt, N; McNab, R; Spratt, D. A.; Wilson, M.; Mullany, P.

    2003-01-01

    Tetracycline is a broad-spectrum antibiotic used in humans, animals, and aquaculture; therefore, many bacteria from different ecosystems are exposed to this antibiotic. In order to determine the genetic basis for resistance to tetracycline in bacteria from the oral cavity, saliva and dental plaque samples were obtained from 20 healthy adults who had not taken antibiotics during the previous 3 months. The samples were screened for the presence of bacteria resistant to tetracycline, and the tet...

  16. Protective role of E. coli outer membrane vesicles against antibiotics.

    Science.gov (United States)

    Kulkarni, Heramb M; Nagaraj, R; Jagannadham, Medicharla V

    2015-12-01

    The outer membrane vesicles (OMVs) from bacteria are known to posses both defensive and protective functions and thus participate in community related functions. In the present study, outer membrane vesicles have been shown to protect the producer bacterium and two other bacterial species from the growth inhibitory effects of some antibiotics. The OMVs isolated from E. coli MG1655 protected the bacteria against membrane-active antibiotics colistin, melittin. The OMVs of E. coli MG1655 could also protect P. aeruginosa NCTC6751 and A. radiodioresistens MMC5 against these membrane-active antibiotics. However, OMVs could not protect any of these bacteria against the other antibiotics ciprofloxacin, streptomycin and trimethoprim. Hence, OMVs appears to protect the bacterial community against membrane-active antibiotics and not other antibiotics, which have different mechanism of actions. The OMVs of E. coli MG1655 sequester the antibiotic colistin, whereas their protein components degrade the antimicrobial peptide melittin. Proteomic analysis of OMVs revealed the presence of proteases and peptidases which appear to be involved in this process. Thus, the protection of bacteria by OMVs against antibiotics is situation dependent and the mechanism differs for different situations. These studies suggest that OMVs of bacteria form a common defense for the bacterial community against specific antibiotics. PMID:26640046

  17. 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...... abundances with 16S rRNA gene abundances while assessing if the respective genes increased or decreased during treatment. ARGs were detected in most samples; sul1, sul2, and tetM were detected in all samples. Statistically significant differences (adjusted p<0.01) between the inflow and effluent were...... detected in only four cases. Effluent values for blaoxa-58 and tetC decreased in the two larger plants while tetM decreased in the medium-sized plant. Only blashv-34 increased in the effluent from the medium-sized plant. In all other cases the purification process caused no significant change in the...

  18. Analysis of antibiotic consumption in burn patients.

    Science.gov (United States)

    Soleymanzadeh-Moghadam, Somayeh; Azimi, Leila; Amani, Laleh; Rastegar Lari, Aida; Alinejad, Faranak; Rastegar Lari, Abdolaziz

    2015-01-01

    Infection control is very important in burn care units, because burn wound infection is one of the main causes of morbidity and mortality among burn patients. Thus, the appropriate prescription of antibiotics can be helpful, but unreasonable prescription can have detrimental consequences, including greater expenses to patients and community alike. The aim of this study was to determine the effect of antibiotic therapy on the emergence of antibiotic-resistant bacteria. 525 strains of Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus aureus were isolated from 335 hospitalized burn patients. Antibiotic susceptibility tests were performed after identification the strains. The records of patients were audited to find the antibiotic used. The results indicated that P. aeruginosa is the most prevalent Gram-negative bacteria. Further, it showed a relation between abuse of antibiotics and emergence of antibiotic resistance. Control of resistance to antibiotics by appropriate prescription practices not only facilitates prevention of infection caused by multi-drug resistant (MDR) microorganisms, but it can also decrease the cost of treatment. PMID:26124986

  19. Analysis of antibiotic consumption in burn patients

    Directory of Open Access Journals (Sweden)

    Soleymanzadeh-Moghadam, Somayeh

    2015-06-01

    Full Text Available Infection control is very important in burn care units, because burn wound infection is one of the main causes of morbidity and mortality among burn patients. Thus, the appropriate prescription of antibiotics can be helpful, but unreasonable prescription can have detrimental consequences, including greater expenses to patients and community alike. The aim of this study was to determine the effect of antibiotic therapy on the emergence of antibiotic-resistant bacteria. 525 strains of and were isolated from 335 hospitalized burn patients. Antibiotic susceptibility tests were performed after identification the strains. The records of patients were audited to find the antibiotic used.The results indicated that is the most prevalent Gram-negative bacteria. Further, it showed a relation between abuse of antibiotics and emergence of antibiotic resistance. Control of resistance to antibiotics by appropriate prescription practices not only facilitates prevention of infection caused by multi-drug resistant (MDR microorganisms, but it can also decrease the cost of treatment.

  20. Experimental Evolution of Antibiotic Resistance in Bacteria

    Science.gov (United States)

    Krist, Amy C.; Showsh, Sasha A.

    2007-01-01

    Evolution is typically measured as a change in allele or genotype frequencies over one or more generations. Consequently, evolution is difficult to show experimentally in a semester-long lab course because most organisms have longer generation times than 15 weeks. In this article, the authors present an experiment to demonstrate and study…

  1. Antibacterial activity of plant extracts and phytochemicals on antibiotic-resistant bacteria Atividade de extratos vegetais e fitofármacos sobre bactérias resistentes a antibióticos

    OpenAIRE

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

    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...

  2. How should we be determining background and baseline antibiotic resistance levels in agroecosystem research?

    Science.gov (United States)

    Although historically antibiotic resistance has occurred naturally in environmental bacteria, many questions remain regarding the specifics of how humans and animals contribute to the development and spread of antibiotic resistance in agroecosystems. Additional research is necessary to completely u...

  3. Study on the application of performance management to enhance administration of antibiotics and depress drug-resistant bacteria%绩效管理措施在加强抗菌药物管理控制院内耐药菌感染中的应用效果研究

    Institute of Scientific and Technical Information of China (English)

    周勇

    2012-01-01

    目的 探讨绩效管理措施对医院合理使用抗菌药物管理控制院内耐药菌感染的效果.方法 在抗菌药物使用管理中实施绩效管理措施,制定绩效考核标准,加强监管和教育,对耐药流行菌趋势分析,指导临床合理用药.结果 应用绩效管理措施后,抗菌药物使用率由59.01%下降为43.00%,院内感染率由9.00%下降为4.40%.流行菌中的耐药菌株比例明显降低.结论 应用绩效管理措施可以加强医院抗菌药物管理,控制医院耐药菌流行和提高医院感染管理科学水平.%OBJECTIVE To explore application of performance management to enhance administration of antibiotics and depress drug resistant bacteria in hospital. METHODS The performance management was applied in the proper administration of antibiotics usage. It included perfected regulation system, established the standard of the performance management, enhanced monitoring, analyzed the popular trend of drug-resistant bacteria, educated the medical staff and guided their appropriate antibiotics usage. RESULTS After taking the performance management in the administration of antibiotics, the rate of the antibiotics usage decreased from 59.01% to 43.00% and the rate of hospital infection decreased from 9.00% to 4.40%. The drug-resistant bacteria ratio obviously repressed in hospital. CONCLUSION Application of the performance management in the proper administration of antibiotics usage is effective.

  4. Antibiotic Agents

    Science.gov (United States)

    ... either as public health or as non-public health antimicrobial agents. What is the difference between bacteriostats, sanitizers, disinfectants ... bacteria, however, there is considerable controversy surrounding their health benefits. The ... producing agents (Table of Antibacterials) have been used for many ...

  5. Beyond Antibiotics?

    Directory of Open Access Journals (Sweden)

    LE Nicolle

    2006-01-01

    Full Text Available The AMMI Canada meeting in March 2006 hosted a symposium exploring the potential alternatives to antibiotics for the prevention and treatment of infection. Four papers summarizing talks from that session are published in this issue of the Journal (1-4. These reviews address the scientific underpinnings for a number of proposed concepts, and summarize the current status of clinical use. The approaches - probiotics, bacteriophage therapy, and manipulation of innate immunity - are all intriguing but are still removed from immediate practical applications.

  6. Minocycline: far beyond an antibiotic

    OpenAIRE

    Garrido-Mesa, N; Zarzuelo, A; Gálvez, J

    2013-01-01

    Minocycline is a second-generation, semi-synthetic tetracycline that has been in therapeutic use for over 30 years because of its antibiotic properties against both gram-positive and gram-negative bacteria. It is mainly used in the treatment of acne vulgaris and some sexually transmitted diseases. Recently, it has been reported that tetracyclines can exert a variety of biological actions that are independent of their anti-microbial activity, including anti-inflammatory and anti-apoptotic acti...

  7. Antibiotics and the burn patient.

    Science.gov (United States)

    Ravat, François; Le-Floch, Ronan; Vinsonneau, Christophe; Ainaud, Pierre; Bertin-Maghit, Marc; Carsin, Hervé; Perro, Gérard

    2011-02-01

    Infection is a major problem in burn care and especially when it is due to bacteria with hospital-acquired multi-resistance to antibiotics. Moreover, when these bacteria are Gram-negative organisms, the most effective molecules are 20 years old and there is little hope of any new product available even in the distant future. Therefore, it is obvious that currently available antibiotics should not be misused. With this aim in mind, the following review was conducted by a group of experts from the French Society for Burn Injuries (SFETB). It examined key points addressing the management of antibiotics for burn patients: when to use or not, time of onset, bactericidia, combination, adaptation, de-escalation, treatment duration and regimen based on pharmacokinetic and pharmacodynamic characteristics of these compounds. The authors also considered antibioprophylaxis and some other key points such as: infection diagnosis criteria, bacterial inoculae and local treatment. French guidelines for the use of antibiotics in burn patients have been designed up from this work. PMID:20510518

  8. Characterization of Escherichia coli Isolates from an Urban Lake Receiving Water from a Wastewater Treatment Plant in Mexico City: Fecal Pollution and Antibiotic Resistance.

    Science.gov (United States)

    Rosas, Irma; Salinas, Eva; Martínez, Leticia; Cruz-Córdova, Ariadnna; González-Pedrajo, Bertha; Espinosa, Norma; Amábile-Cuevas, Carlos F

    2015-10-01

    The presence of enteric bacteria in water bodies is a cause of public health concerns, either by directly causing water- and food-borne diseases, or acting as reservoirs for antibiotic resistance determinants. Water is used for crop irrigation; and sediments and aquatic plants are used as fertilizing supplements and soil conditioners. In this work, the bacterial load of several micro-environments of the urban lake of Xochimilco, in Mexico City, was characterized. We found a differential distribution of enteric bacteria between the water column, sediment, and the rhizoplane of aquatic plants, with human fecal bacteria concentrating in the sediment, pointing to the need to assess such bacterial load for each micro-environment, for regulatory agricultural purposes, instead of only the one of the water, as is currently done. Resistance to tetracycline, ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole was common among Escherichia coli isolates, but was also differentially distributed, being again higher in sediment isolates. A distinct distribution of chloramphenicol minimum inhibitory concentrations (MIC) among these isolates suggests the presence of a local selective pressure favoring lower MICs than those of isolates from treated water. Fecal bacteria of human origin, living in water bodies along with their antibiotic resistance genes, could be much more common than typically considered, and pose a higher health risk, if assessments are only made on the water column of such bodies. PMID:26198413

  9. The HIV-Associated Enteric Microbiome Has Gone Viral.

    Science.gov (United States)

    Palmer, Brent E; Li, Sam X; Lozupone, Catherine A

    2016-03-01

    HIV infection is associated with dramatic alterations in enteric bacteria, but little is known about other microbiome components. In this issue of Cell Host & Microbe, studies by Monaco et al. (2016) and Handley et al. (2016) reveal an under-appreciated role of the enteric virome in HIV-associated gastroenteritis and pathogenesis. PMID:26962936

  10. Phages limit the evolution of bacterial antibiotic resistance in experimental microcosms

    OpenAIRE

    Zhang, Quan-Guo; Buckling, Angus

    2012-01-01

    The evolution of multi-antibiotic resistance in bacterial pathogens, often resulting from de novo mutations, is creating a public health crisis. Phages show promise for combating antibiotic-resistant bacteria, the efficacy of which, however, may also be limited by resistance evolution. Here, we suggest that phages may be used as supplements to antibiotics in treating initially sensitive bacteria to prevent resistance evolution, as phages are unaffected by most antibiotics and there should be ...

  11. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    Energy Technology Data Exchange (ETDEWEB)

    Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

    2010-06-15

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  12. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    International Nuclear Information System (INIS)

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  13. Intensive Care Unit Infections and Antibiotic Use

    OpenAIRE

    Ayşegül Yeşilkaya; Hande Arslan

    2011-01-01

    Burn wound infections is the leading cause of morbidity and mortality in burn trauma patients. Although burn wound is sterile at the beginning, because of risk factors such as prolonged hospital stay, immunesuppression and burn affecting large body surface area, colonisation firstly with Staphylococcus aureus and then Pseudomonas aeruginosa will occur later. Delay in wound closure and treatment with broad-spectrum antibiotic will result wound colonisation with antibiotic-resistant bacteria. T...

  14. Antibiotics promote aggregation within aquatic bacterial communities

    OpenAIRE

    Corno, Gianluca; Coci, Manuela; Giardina, Marco; Plechuk, Sonia; Campanile, Floriana; Stefani, Stefania

    2014-01-01

    The release of antibiotics (AB) into the environment poses several threats for human health due to potential development of AB-resistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and ...

  15. Antibiotics promote aggregation within aquatic bacterial communities

    OpenAIRE

    ManuelaCoci; MarcoGiardina

    2014-01-01

    The release of antibiotics (AB) into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and p...

  16. Antibiotic research and development: business as usual?

    Science.gov (United States)

    Harbarth, S; Theuretzbacher, U; Hackett, J

    2015-01-01

    The global burden of antibiotic resistance is tremendous and, without new anti-infective strategies, will continue to increase in the coming decades. Despite the growing need for new antibiotics, few pharmaceutical companies today retain active antibacterial drug discovery programmes. One reason is that it is scientifically challenging to discover new antibiotics that are active against the antibiotic-resistant bacteria of current clinical concern. However, the main hurdle is diminishing economic incentives. Increased global calls to minimize the overuse of antibiotics, the cost of meeting regulatory requirements and the low prices of currently marketed antibiotics are strong deterrents to antibacterial drug development programmes. New economic models that create incentives for the discovery of new antibiotics and yet reconcile these incentives with responsible antibiotic use are long overdue. DRIVE-AB is a €9.4 million public-private consortium, funded by the EU Innovative Medicines Initiative, that aims to define a standard for the responsible use of antibiotics and to develop, test and recommend new economic models to incentivize investment in producing new anti-infective agents. PMID:25673635

  17. What Is Enteral Nutrition?

    Science.gov (United States)

    ... a Clinician Press Room Career Center Advertising and Sponsorship Join / Renew Donate Online Store Certification Claim CE Credits Clinical Nutrition Week eLearning Center Professional Development Webinars Calendar of Events What Is Enteral Nutrition ...

  18. The 'liaisons dangereuses' between iron and antibiotics.

    Science.gov (United States)

    Ezraty, Benjamin; Barras, Frédéric

    2016-05-01

    The decline in the rate of new antibiotic discovery is of growing concern, and new antibacterial strategies must now be explored. This review brings together research in two fields (metals in biology and antibiotics) in the hope that collaboration between scientists working in these two areas will lead to major advances in understanding and the development of new approaches to tackling microbial pathogens. Metals have been used as antiseptics for centuries. In this review, we focus on iron, an essential trace element that can nevertheless be toxic to bacteria. We review the many situations in which iron and antibiotics have combinatorial effects when used together. Understanding the molecular relationships between iron and antibiotics, from pure chemistry to gene reprogramming via biochemical competition, is important not only to increase basic knowledge, but also for the development of treatments against pathogens, with a view to optimizing antibiotic efficacy. PMID:26945776

  19. Bacteriocins: exploring alternatives to antibiotics in mastitis treatment

    Directory of Open Access Journals (Sweden)

    Reneé Pieterse

    2010-10-01

    Full Text Available Mastitis is considered to be the most costly disease affecting the dairy industry. Management strategies involve the extensive use of antibiotics to treat and prevent this disease. Prophylactic dosages of antibiotics used in mastitis control programmes could select for strains with resistance to antibiotics. In addition, a strong drive towards reducing antibiotic residues in animal food products has lead to research in finding alternative antimicrobial agents. In this review we have focus on the pathogenesis of the mastitis in dairy cows, existing antibiotic treatments and possible alternative for application of bacteriocins from lactic acid bacteria in the treatment and prevention of this disease.

  20. Influence of Antibiotics Added in Milk over Yogurth Quality

    Directory of Open Access Journals (Sweden)

    Cornelia Vintila

    2010-10-01

    Full Text Available Large spectrum antibiotics used in different cow diseases leads to their release in milk altering its proprieties during processing. Knowing the inhibitory effect of antibiotics upon lactic bacteria development and multiplying we followed the effect of gentamycin, a large spectrum antibiotic added in different doses in milk used for yogurth processing. In our research, besides the effect of antibiotica we followed also the influence of milk fat content upon milk clotting time, while antibiotics added in milk incease the clotting time of yogurth. Clotting density deceases proportional with the dosis of antibiotics added to milk.

  1. Cooperative Antibiotic Resistance in a Multi-Drug Environment

    Science.gov (United States)

    Yurtsev, Eugene; Dai, Lei; Gore, Jeff

    2013-03-01

    The emergence of antibiotic resistance in bacteria is a significant health concern. A frequent mechanism of antibiotic resistance involves the production of an enzyme which inactivates the antibiotic. By inactivating the antibiotic, resistant cells can ``share'' their resistance with other cells in the bacterial population, suggesting that it may be possible to observe cooperation between strains that inactivate different antibiotics. Here, we experimentally track the population dynamics of two E. coli strains in the presence of two different antibiotics. We find that together the strains are able to grow in antibiotic concentrations that inhibit growth of either of the strains individually. We observe that even when there is stable coexistence between the two strains, the population size of each strain can undergo large oscillations. We expect that our results will provide insight into the evolution of antibiotic resistance and the evolutionary origin of phenotypic diversity and cooperative behaviors.

  2. Understanding Antibiotic Use in Minya District, Egypt: Physician and Pharmacist Prescribing and the Factors Influencing Their Practices

    OpenAIRE

    Dooling, Kathleen L.; Amr Kandeel; Hicks, Lauri A.; Waleed El-Shoubary; Khaled Fawzi; Yasser Kandeel; Ahmad Etman; Anna Leena Lohiniva; Maha Talaat

    2014-01-01

    Overuse of antibiotics has contributed to the emergence of antibiotic-resistant bacteria globally. In Egypt, patients can purchase antibiotics without a prescription, and we hypothesized frequent inappropriate antibiotic prescribing and dispensing. We interviewed physicians (n = 236) and pharmacists (n = 483) and conducted focus groups in Minya, Egypt, to assess attitudes and practices regarding antibiotic prescribing for outpatient acute respiratory infections (ARI). Antibiotics were reporte...

  3. Facts about Antibiotic Resistance

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  4. Antibiotic / Antimicrobial Resistance Glossary

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  5. Recent government regulations in the United States seek to ensure the effectiveness of antibiotics by limiting their agricultural use.

    Science.gov (United States)

    Centner, Terence J

    2016-09-01

    The development of bacteria resistant to antibiotics is viewed as a medical health threat. Because thousands of people die every year due to antibiotic-resistant bacteria, efforts are underway to reduce antibiotic usage which in turn will reduce the development of antibiotic-resistant bacteria. In the United States, the use of antibiotics in the production of food animals to enhance animal growth has been identified as contributing to resistance. In 2015, a veterinary feed directive was adopted by the U.S. federal government prohibiting nontherapeutic uses of antibiotics in food animals that should reduce usage. The continued usage of antibiotics by producers for preventing disease may mean the directive is insufficient to reduce nontherapeutic antibiotic administration. This may lead some consumers to seek meat products from animals raised without antibiotics. A governmentally-sponsored labeling program could encourage reduction in antibiotic usage. PMID:27182666

  6. 南京市4个污水处理厂的活性污泥中细菌的分离鉴定和抗生素耐药性分析%Isolation and Identification of Bacteria in the Activated Sludge from Four Sewage Treatment Plants in Nanjing City and Its Antibiotic Resistance Analysis

    Institute of Scientific and Technical Information of China (English)

    葛峰; 郭坤; 周广灿; 张会娟; 刘济宁; 戴亦军

    2012-01-01

    通过16S rDNA序列分析对南京CN、CE、JN和JM这4个污水处理厂的活性污泥中分离的细菌进行鉴定,采用Kirby-Bauer纸片琼脂扩散法分析细菌的抗生素耐药性,目的是阐明该地区污水处理厂活性污泥中细菌抗生素耐药性现状,探索污水及污泥的潜在环境风险.4个污水处理厂分别分离到7、9、8和11株菌落形态不同的细菌,上述35株细菌分属25个种,17个属.抗生素耐药性分析显示,97.1%的菌株具有抗生素耐药性,80%菌株具有多重耐药性.分离菌株对氨苄西林、卡那霉素、氯霉素、链霉素、庆大霉素、四环素、红霉素和大观霉素的耐药率分别为71.4%、37.1%、37.1%、57.1%、34.3%、68.6%、94.3%和65.7%.结果表明活性污泥中细菌耐药性严重;不同菌株间的耐药性分析显示,危害水产养殖业的病原菌气单胞菌具有严重的多重耐药性,所有芽孢杆菌对氯霉素、链霉素和庆大霉素敏感;污水处理厂应加强出水的消杀工作,避免二次污染.%Bacteria were isolated from the activated sludge of CN,CE,JN and JM Sewage Treatment Plants(STPs) in Nanjing city and identified by 16S rDNA sequence analysis.The antibiotic resistance analysis of the isolated bacteria was conducted by Kirby-Bauer Disc Agar Diffusion Method.The objective of this study is to clarify the current state of bacteria antibiotic resistance from the four STPs and analyze the potential environmental risk of the produced waste water and the sludge.The 7,9,8 and 11 bacterial strains with different morphology were respectively isolated from the above four sample sites,which belonged to 25 species and 17 genera.Antibiotic resistance analysis indicated that 97.1% of isolates had antibiotic resistance and 80% of isolates had multi-antibiotic resistance.The drug resistance rates were 71.4%,37.1%,37.1%,57.1%,34.3%,68.6%,94.3% and 65.7% of ampicillin(AM),kanamycin(KAN),chloromycetin

  7. RecA Inhibitors Potentiate Antibiotic Activity and Block Evolution of Antibiotic Resistance.

    Science.gov (United States)

    Alam, Md Kausar; Alhhazmi, Areej; DeCoteau, John F; Luo, Yu; Geyer, C Ronald

    2016-03-17

    Antibiotic resistance arises from the maintenance of resistance mutations or genes acquired from the acquisition of adaptive de novo mutations or the transfer of resistance genes. Antibiotic resistance is acquired in response to antibiotic therapy by activating SOS-mediated DNA repair and mutagenesis and horizontal gene transfer pathways. Initiation of the SOS pathway promotes activation of RecA, inactivation of LexA repressor, and induction of SOS genes. Here, we have identified and characterized phthalocyanine tetrasulfonic acid RecA inhibitors that block antibiotic-induced activation of the SOS response. These inhibitors potentiate the activity of bactericidal antibiotics, including members of the quinolone, β-lactam, and aminoglycoside families in both Gram-negative and Gram-positive bacteria. They reduce the ability of bacteria to acquire antibiotic resistance mutations and to transfer mobile genetic elements conferring resistance. This study highlights the advantage of including RecA inhibitors in bactericidal antibiotic therapies and provides a new strategy for prolonging antibiotic shelf life. PMID:26991103

  8. Dietary lactose and its effects on the disease necrotic enteritis

    Science.gov (United States)

    Clostridium perfringens (CP) is the etiologic agent of Necrotic enteritis (NE) and is ubiquitous in nature. The incidence of NE has increased in poultry flocks that have stopped using antibiotic growth promoters. The mechanisms of colonization of CP and the factors involved in onset of NE are not ...

  9. Bacteria, Phages and Septicemia

    OpenAIRE

    Gaidelytė, Aušra; Vaara, Martti; Bamford, Dennis H.

    2007-01-01

    The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such ph...

  10. Patient knowledge and perception of antibiotics: A questionnaire survey in primary care

    DEFF Research Database (Denmark)

    Sydenham, Rikke Vognbjerg; Plejdrup Hansen, Malene; Lauridsen, Gitte Bruun;

    2015-01-01

    antibiotics. Objectives: This study aimed to study patient knowledge and perceptions of antibiotic treatment and to explore possible associations between patient gender, age, and educational level and accurate knowledge of antibiotics. Design/Methods: As part of an Audit Project Odense project a questionnaire...... rate 64%). 75% recognized that antibiotics are effective against bacteria and not against virus. Overuse of antibiotics was acknowledged by 80% of respondents as an important factor in the development of resistant bacteria. Female gender was the only patient characteristic significantly associated with...... important factor in the development of resistant bacteria. Points for discussion: To what extent does patient knowledge and perception on antibiotics influence the GP when considering prescribing antibiotics? How can knowledge of patient perception of ARIs and antibiotics be helpful in the consultation room?...

  11. Photodynamic inactivation of antibiotic-resistant pathogens

    International Nuclear Information System (INIS)

    Nowadays methicillin-resistant strain Staphylococcus aureus (MRSA) is one of the most widespread multiresistant bacteria. Photodynamic inactivation (PDI) of microorganisms by photosensitizers (PS) may be an effective and alternative therapeutic option against antibiotic resistant bacteria. The effectiveness of new PS cationic porphyrin Zn-TBut4PyP was tested on two strains of S. aureus (MRSA and methicillin-sensitive S. aureus). It is shown that Zn-TBut4PyP has high photodynamic activity against both strains

  12. U.S. Officials Confirm Superbug Resistant to All Antibiotics

    Science.gov (United States)

    ... E. coli was genetically resistant to the drug colistin. Colistin, an older antibiotic, fell out of favor in ... if carbapenem-resistant bacteria also gain resistance to colistin, it could leave doctors with no treatment options ...

  13. Topical and oral antibiotics for acne vulgaris.

    Science.gov (United States)

    Del Rosso, James Q

    2016-06-01

    Antibiotics, both oral and topical, have been an integral component of the management of acne vulgaris (AV) for approximately 6 decades. Originally thought to be effective for AV due to their ability to inhibit proliferation of Propionibacterium acnes, it is now believed that at least some antibiotics also exert anti-inflammatory effects that provide additional therapeutic benefit. To add, an increase in strains of P acnes and other exposed bacteria that are less sensitive to antibiotics used to treat AV have emerged, with resistance directly correlated geographically with the magnitude of antibiotic use. Although antibiotics still remain part of the therapeutic armamentarium for AV treatment, current recommendations support the following when used to treat AV: 1) monotherapy use should be avoided; 2) use benzoyl peroxide concomitantly to reduce emergence of resistant P acnes strains; 3) oral antibiotics should be used in combination with a topical regimen for moderate-to-severe inflammatory AV; and 4) use oral antibiotics over a limited duration to achieve control of inflammatory AV with an exit plan in place to discontinue their use as soon as possible. When selecting an oral antibiotic to treat AV, potential adverse effects are important to consider. PMID:27416309

  14. Resistance to last-resort antibiotics in natural environments

    OpenAIRE

    Tacão, Marta Cristina Oliveira Martins

    2014-01-01

    Last-resort antibiotics are the final line of action for treating serious infections caused by multiresistant strains. Over the years the prevalence of resistant bacteria has been increasing. Natural environments are reservoirs of antibiotic resistance, highly influenced by human-driven activities. The importance of aquatic systems on the evolution of antibiotic resistance is highlighted from the assumption that clinically-relevant resistance genes have originated in strains ...

  15. Influence of Antibiotics Added in Milk over Yogurth Quality

    OpenAIRE

    Cornelia Vintila; Adela Marcu; Teodor Vintila; Daniela Roxana Vintilă; Adrian Marcu

    2010-01-01

    Large spectrum antibiotics used in different cow diseases leads to their release in milk altering its proprieties during processing. Knowing the inhibitory effect of antibiotics upon lactic bacteria development and multiplying we followed the effect of gentamycin, a large spectrum antibiotic added in different doses in milk used for yogurth processing. In our research, besides the effect of antibiotica we followed also the influence of milk fat content upon milk clotting time, while antibioti...

  16. Some aspects of genetic control of antibiotic biosynthesis in Streptomyces

    OpenAIRE

    М. P. Teplitskaya; I. E. Sokolova

    2005-01-01

    These work contain a review of basic hypotheses and experimental information in relation to the problem of antibiotic synthesis regulation by the bacteria of the Streptomyces family. Data on cluster organization of antibiotics biosynthesis genes in these microorganisms were generalized. The examples of the positive and negative specific control of antibiotic production genes were resulted. Except for it, proofs that confirm participation of a few genes of more high level in the process of ini...

  17. Antibiotic Susceptibilities of Acinetobacter Baumanii Strains Isolated from Clinical Samples

    OpenAIRE

    Harun Aðca

    2013-01-01

         Aim :  In this study it was aimed to investigate the antibiotic susceptibilities of Acinetobacter baumanii strains isolated from various clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. Material and Method: All of the cultures were examined for the agent and antibiotic susceptibilities. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD) system was used. Antibiotic susce...

  18. Radioactivity measurements for determining bacterial increase and sensibility to antibiotics

    International Nuclear Information System (INIS)

    The authors elaborated a sensitive and objective measuring method for determining the bacteria increase in biological material and the sensibility to antibiotics. When 14C glucose is added to the medium as the single source of sugar, the respiratory carbon dioxide formed by the bacteria reflects the rate of increase. The released 14C dioxide can be measured continuously without loss to the environment and the degree of bacterial infection and the antibiotic activity, respectively, can be determined. (author)

  19. Prophylaxis for infective endocarditis: antibiotic sensitivity of dental plaque.

    OpenAIRE

    MacFarlane, T W; McGowan, D. A.; Hunter, K; MacKenzie, D.

    1983-01-01

    The antibiotic sensitivity pattern of bacteria isolated from bacteraemia after dental extraction was compared with that of bacteria isolated from dental plaque samples from the same patient. The results supported the current practice of using penicillin and erythromycin empirically for prophylaxis. The prediction of the most appropriate antibiotic for prophylaxis using dental plaque samples was most accurate when the minimum inhibitory concentration (MIC) of plaque isolates were used. It appe...

  20. Antibiotic resistance in urban aquatic environments: can it be controlled?

    OpenAIRE

    Manaia, Célia; Macedo, Gonçalo; Fatta-Kassinos, Despo; Nunes, Olga

    2016-01-01

    Over the last decade, numerous evidences have contributed to establish a link between the natural and humanimpacted environments and the growing public health threat that is the antimicrobial resistance. In the environment, in particular in areas subjected to strong anthropogenic pressures, water plays a major role on the transformation and transport of contaminants including antibiotic residues, antibioticresistant bacteria, and antibiotic resistance genes. Therefore, ...

  1. Diversity and natural functions of antibiotices produced by beneficial and pathogenic soil bacteria

    Science.gov (United States)

    Soil and plant-associated environments harbor numerous bacterial species that produce antibiotic metabolites. Many of these bacteria have been exploited for the discovery of clinical antibiotics and other therapeutics. In the field of plant pathology, antibiotic-producing bacteria are used as a reso...

  2. Antibiotics in Canadian poultry productions and anticipated alternatives

    Directory of Open Access Journals (Sweden)

    Moussa Sory Diarra

    2014-06-01

    Full Text Available The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics in feed (growth promoters need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily spread within microbial communities. In Canada, poultry production involves more than 2,600 regulated chicken producers. There are several antibiotics approved as feed additives available for poultry farmers. Feed recipes and mixtures greatly vary geographically and from one farm to another, making links between use of a specific antibiotic feed additive and production yields or selection of specific antibiotic-resistant bacteria difficult to establish. Many on-farm studies have revealed the widespread presence of antibiotic-resistant bacteria in broiler chickens. While sporadic reports linked the presence of antibiotic-resistant organisms to the use of feed supplemented with antibiotics, no recent studies could clearly demonstrate the benefit of antimicrobial growth promoters on performance and production yields. With modern biosecurity and hygienic practices, there is a genuine concern that intensive utilization of antibiotics or use of antimicrobial growth promoters in feed might no longer be useful. Public pressure and concerns about food and environmental safety (antibiotic residues, antibiotic-resistant pathogens have driven researchers to actively look for alternatives to antibiotics. Some of the alternatives include pre- and probiotics, organic acids and essential oils. We will describe here the properties of some bioactive molecules, like those found in cranberry, which have shown interesting polyvalent antibacterial and immuno

  3. Antibiotics in Canadian poultry productions and anticipated alternatives.

    Science.gov (United States)

    Diarra, Moussa S; Malouin, François

    2014-01-01

    The use of antibiotics in food-producing animals has significantly increased animal health by lowering mortality and the incidence of diseases. Antibiotics also have largely contributed to increase productivity of farms. However, antibiotic usage in general and relevance of non-therapeutic antibiotics (growth promoters) in feed need to be reevaluated especially because bacterial pathogens of humans and animals have developed and shared a variety of antibiotic resistance mechanisms that can easily be spread within microbial communities. In Canada, poultry production involves more than 2600 regulated chicken producers who have access to several antibiotics approved as feed additives for poultry. Feed recipes and mixtures vary greatly geographically and from one farm to another, making links between use of a specific antibiotic feed additive and production yields or selection of specific antibiotic-resistant bacteria difficult to establish. Many on-farm studies have revealed the widespread presence of antibiotic-resistant bacteria in broiler chickens. While some reports linked the presence of antibiotic-resistant organisms to the use of feed supplemented with antibiotics, no recent studies could clearly demonstrate the benefit of antimicrobial growth promoters on performance and production yields. With modern biosecurity and hygienic practices, there is a genuine concern that intensive utilization of antibiotics or use of antimicrobial growth promoters in feed might no longer be useful. Public pressure and concerns about food and environmental safety (antibiotic residues, antibiotic-resistant pathogens) have driven researchers to actively look for alternatives to antibiotics. Some of the alternatives include pre- and probiotics, organic acids and essential oils. We will describe here the properties of some bioactive molecules, like those found in cranberry, which have shown interesting polyvalent antibacterial and immuno-stimulatory activities. PMID:24987390

  4. Entering a community dialogue.

    Science.gov (United States)

    Britt, Teri; Player, Kathy; Parsons, Kathleen; Stover, Deanna

    2004-01-01

    Entering a new, unstructured community is facilitated when existing members embrace the thoughts, ideas, and experiences of new members. Watson's Caring Healing Model, including the caritas conscious and transpersonal caring components, provides a framework for understanding the experience of being a new community member (e.g., a "newbie") in the Global Nursing Exchange. PMID:14986502

  5. Future of enteral nutrition.

    OpenAIRE

    Silk, D. B.

    1986-01-01

    Although there has been agreement that enteral nutrition remains an excellent means of providing nutritional support to malnourished patients with normal or near normal gastrointestinal function, it is clear that areas of controversy do exist, and attention needs to be directed towards these in the future.

  6. Enteral approaches in malabsorption.

    Science.gov (United States)

    Avitzur, Yaron; Courtney-Martin, Glenda

    2016-04-01

    Enteral autonomy and freedom from parenteral nutrition dependency is the ultimate therapeutic goal in children with intestinal failure. This can be achieved following attainment of bowel adaptation in conditions such as short bowel syndrome. Enteral nutrition is a major therapeutic cornerstone in the management of children with intestinal failure. It promotes physiological development, bowel adaptation and enhances weaning from parenteral nutrition. The optimal method of delivery, type of nutrients, timing of initiation, promotion of feeds and transition to solid food in children with short bowel syndrome are debated. Lack of high quality human data hampers evidence based conclusions and impacts daily practices in the field. Clinical approaches and therapeutic decisions are regularly influenced by expert opinion and center practices. This review summarizes the physiological principles, medical evidence and practice recommendations on enteral nutrition approaches in short bowel syndrome and provides a practical framework for daily treatment of this unique group of patients. Oral and tube feeding, bolus and continuous feeding, type of nutrients, formulas, trace elements and solid food options are reviewed. Future collaborative multicenter, high quality clinical trials are needed to support enteral nutrition approaches in intestinal failure. PMID:27086892

  7. Colistin : Revival of an Old Polymyxin Antibiotic

    NARCIS (Netherlands)

    Dijkmans, Anneke C.; Wilms, Erik B.; Kamerling, Ingrid M. C.; Birkhoff, Willem; Ortiz-Zacarias, Natalia V.; van Nieuwkoop, Cees; Verbrugh, Henri A.; Touw, Daan J.

    2015-01-01

    Colistin (polymyxin E) is a positively charged deca-peptide antibiotic that disrupts the integrity of the outer membrane of the cell wall of gram-negative bacteria by binding to the lipid A moiety of lipopolysaccharides, resulting in cell death. The endotoxic activity of lipopolysaccharides is simul

  8. Conjugative Plasmid Transfer in Gram-Positive Bacteria

    OpenAIRE

    Grohmann, Elisabeth; Muth, Günther; Espinosa, Manuel

    2003-01-01

    Conjugative transfer of bacterial plasmids is the most efficient way of horizontal gene spread, and it is therefore considered one of the major reasons for the increase in the number of bacteria exhibiting multiple-antibiotic resistance. Thus, conjugation and spread of antibiotic resistance represents a severe problem in antibiotic treatment, especially of immunosuppressed patients and in intensive care units. While conjugation in gram-negative bacteria has been studied in great detail over t...

  9. Antibiotics for the treatment of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Ogrendik M

    2013-12-01

    Full Text Available Mesut OgrendikDivision Physical Therapy and Rheumatology, Nazilli State Hospital, Nazilli, TurkeyAbstract: Antibiotic treatment for rheumatoid arthritis (RA commenced in the 1930s with the use of sulfasalazine. Later, tetracyclines were successfully used for the treatment of RA. In double-blind and randomized studies, levofloxacin and macrolide antibiotics (including clarithromycin and roxithromycin were also shown to be effective in the treatment of RA. There have been several reports in the literature indicating that periodontal pathogens are a possible cause of RA. Oral bacteria are one possible cause of RA. In this review, we aimed to investigate the effects of different antibiotics in RA treatment.Keywords: oral bacteria, treatment, disease-modifying antirheumatic drugs, periodontitis

  10. "Practical knowledge" and perceptions of antibiotics and antibiotic resistance among drugsellers in Tanzanian private drugstores

    Directory of Open Access Journals (Sweden)

    Tomson Göran

    2010-09-01

    Full Text Available Abstract Background Studies indicate that antibiotics are sold against regulation and without prescription in private drugstores in rural Tanzania. The objective of the study was to explore and describe antibiotics sale and dispensing practices and link it to drugseller knowledge and perceptions of antibiotics and antibiotic resistance. Methods Exit customers of private drugstores in eight districts were interviewed about the drugstore encounter and drugs bought. Drugsellers filled in a questionnaire with closed- and open-ended questions about antibiotics and resistance. Data were analyzed using mixed quantitative and qualitative methods. Results Of 350 interviewed exit customers, 24% had bought antibiotics. Thirty percent had seen a health worker before coming and almost all of these had a prescription. Antibiotics were dispensed mainly for cough, stomachache, genital complaints and diarrhea but not for malaria or headache. Dispensed drugs were assessed as relevant for the symptoms or disease presented in 83% of all cases and 51% for antibiotics specifically. Non-prescribed drugs were assessed as more relevant than the prescribed. The knowledge level of the drugseller was ranked as high or very high by 75% of the respondents. Seventy-five drugsellers from three districts participated. Seventy-nine percent stated that diseases caused by bacteria can be treated with antibiotics but 24% of these also said that antibiotics can be used for treating viral disease. Most (85% said that STI can be treated with antibiotics while 1% said the same about headache, 4% general weakness and 3% 'all diseases'. Seventy-two percent had heard of antibiotic resistance. When describing what an antibiotic is, the respondents used six different kinds of keywords. Descriptions of what antibiotic resistance is and how it occurs were quite rational from a biomedical point of view with some exceptions. They gave rise to five categories and one theme: Perceiving antibiotic

  11. Emergence and dissemination of antibiotic resistance: A global problem

    Directory of Open Access Journals (Sweden)

    R Choudhury

    2012-01-01

    Full Text Available Antibiotic resistance is a major problem in clinical health settings. Interestingly the origin of many of antibiotic resistance mechanisms can be traced back to non-pathogenic environmental organisms. Important factors leading to the emergence and spread of antibiotic resistance include absence of regulation in the use of antibiotics, improper waste disposal and associated transmission of antibiotic resistance genes in the community through commensals. In this review, we discussed the impact of globalisation on the transmission of antibiotic resistance genes in bacteria through immigration and export/import of foodstuff. The significance of surveillance to define appropriate use of antibiotics in the clinic has been included as an important preventive measure.

  12. Occurrence of yeasts, enterococci and other enteric bacteria in subgingival biofilm of HIV-positive patients with chronic gingivitis and necrotizing periodontitis Ocorrência de leveduras, enterococos e outras bactérias entéricas no biofilme subgengival de pacientes HIV-positivos com gengivite crônica e periodontite necrosante

    Directory of Open Access Journals (Sweden)

    Elerson Gaetti-Jardim Júnior

    2008-06-01

    Full Text Available 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 37ºC, 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/mm³ 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.O objetivo desse estudo foi avaliar a ocorrência de bactérias entéricas e leveduras no biofilme subgengival de pacientes HIV-positivos com gengivite crônica ou periodontite necrosante. Os pacientes foram submetidos a exame clínico e radiogr

  13. Effect analysis of Bacillus subtilis two (Live) enteric-coated capsules combined with Bacillus licheniformis capsule in the treatment of antibiotic associated diarrhea%枯草杆菌二联活菌肠溶胶囊联合地衣芽胞杆菌活菌胶囊治疗老年抗生素相关性腹泻的效果分析

    Institute of Scientific and Technical Information of China (English)

    袁宏伟

    2015-01-01

    Objective To explore the clinical effect of Bacillus subtilis two (Live) enteric-coated capsules combined with Bacillus licheniformis capsule in the treatment of antibiotic associated diarrhea. Methods 120 patients with an-tibiotic associated diarrhea in our hospital from February 2013 to February 2014 were selected,and were divided into three groups based on random number table,Bacillus subtilis two (Live) enteric-coated capsules group,Bacillus licheni-formis capsule group,and joint application of Bacillus subtilis two (Live) enteric-coated capsules and Bacillus licheni-formis capsule group.The therapeutic effects among three groups were compared. Results The cure rate of joint applica-tion of Bacillus subtilis two (Live) enteric-coated capsules and Bacillus licheniformis capsule group was higher than that of Bacillus subtilis two (Live) enteric-coated capsules group and Bacillus licheniformis capsule group,the differ-ence was significant (χ2=8.26,P=0.02).The number of diarrhea in healed patients of joint application of Bacillus subtilis two (Live) enteric-coated capsules and Bacillus licheniformis capsule group was less than that of Bacillus subtilis two (Live) enteric-coated capsules group and Bacillus licheniformis capsule group,the difference was significant (F=91.03, P=0.00). Conclusion Both Bacillus subtilis two (Live) enteric-coated capsules and Bacillus licheniformis capsule are classified into probiotics,and have some effect on treating senile associated diarrhea caused by antibiotics.Joint applica-tion of the two drugs displays remarkable effect on treating antibiotic associated diarrhea,and plays a certain assistant role in clinical treatment.%目的:探讨枯草杆菌二联活菌肠溶胶囊联合地衣芽胞杆菌活菌胶囊对老年抗生素相关性腹泻的临床疗效。方法收集2013年2月~2014年2月本院老年抗生素相关性腹泻患者120例,根据随机数字表法分为枯草杆菌二联活菌肠溶胶囊组、地衣芽胞杆

  14. Antibiotics in Wastewater of a Rural and an Urban Hospital before and after Wastewater Treatment, and the Relationship with Antibiotic Use—A One Year Study from Vietnam

    OpenAIRE

    Lien, La Thi Quynh; Hoa, Nguyen Quynh; Chuc, Nguyen Thi Kim; Thoa, Nguyen Thi Minh; Phuc, Ho Dang; Diwan, Vishal; Dat, Nguyen Thanh; Tamhankar, Ashok J.; Lundborg, Cecilia Stålsby

    2016-01-01

    Hospital effluents represent an important source for the release of antibiotics and antibiotic resistant bacteria into the environment. This study aims to determine concentrations of various antibiotics in wastewater before and after wastewater treatment in a rural hospital (60 km from the center of Hanoi) and in an urban hospital (in the center of Hanoi) in Vietnam, and it aims to explore the relationship between antibiotic concentrations in wastewater before wastewater treatment and quantit...

  15. Sensitivity of antibiotic resistant and antibiotic susceptible Escherichia coli, Enterococcus and Staphylococcus strains against ozone.

    Science.gov (United States)

    Heß, Stefanie; Gallert, Claudia

    2015-12-01

    Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role. PMID:26608763

  16. Priorities for antibiotic resistance surveillance in Europe

    DEFF Research Database (Denmark)

    Fluit, A. C.; van der Bruggen, J. T.; Aarestrup, Frank Møller; Verhoef, J.; Jansen, W. T. M.

    2006-01-01

    Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. To achieve this, surveillance studies must have standardised methodologies, be longitud......Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. To achieve this, surveillance studies must have standardised methodologies, be...... various reservoirs of antibiotic-resistant bacteria, such as hospitalised patients, nursing homes, the community, animals and food. Two studies that could serve as examples of tailored programmes are the European Antimicrobial Resistance Surveillance System (EARSS), which collects resistance data during...... development of antibiotic resistance....

  17. Manipulation of the Quorum Sensing Signal AI-2 Affects the Antibiotic-Treated Gut Microbiota

    Directory of Open Access Journals (Sweden)

    Jessica Ann Thompson

    2015-03-01

    Full Text Available The mammalian gut microbiota harbors a diverse ecosystem where hundreds of bacterial species interact with each other and their host. Given that bacteria use signals to communicate and regulate group behaviors (quorum sensing, we asked whether such communication between different commensal species can influence the interactions occurring in this environment. We engineered the enteric bacterium, Escherichia coli, to manipulate the levels of the interspecies quorum sensing signal, autoinducer-2 (AI-2, in the mouse intestine and investigated the effect upon antibiotic-induced gut microbiota dysbiosis. E. coli that increased intestinal AI-2 levels altered the composition of the antibiotic-treated gut microbiota, favoring the expansion of the Firmicutes phylum. This significantly increased the Firmicutes/Bacteroidetes ratio, to oppose the strong effect of the antibiotic, which had almost cleared the Firmicutes. This demonstrates that AI-2 levels influence the abundance of the major phyla of the gut microbiota, the balance of which is known to influence human health.

  18. Exposure to phages has little impact on the evolution of bacterial antibiotic resistance on drug concentration gradients

    OpenAIRE

    Zhang, Quan-Guo

    2014-01-01

    The use of phages for treating bacterial pathogens has recently been advocated as an alternative to antibiotic therapy. Here, we test a hypothesis that bacteria treated with phages may show more limited evolution of antibiotic resistance as the fitness costs of resistance to phages may add to those of antibiotic resistance, further reducing the growth performance of antibiotic-resistant bacteria. We did this by studying the evolution of phage-exposed and phage-free Pseudomonas fluorescens cul...

  19. Antibiotic usage and resistance in different regions of the Dutch community

    NARCIS (Netherlands)

    Bruinsma, N; Filius, PMG; De Smet, PAGM; Degener, J; Endtz, P; Van den Bogaard, AE; Stobberingh, EE

    2002-01-01

    Regional differences of antibiotic use and antibiotic resistance in the fecal indicator bacteria Escherichia coli and enterococci were determined in different cities in the south, west, and north of The Netherlands. In 1999, differences in antibiotic consumption were observed between the different r

  20. Genotypic Detection of Antibiotic Resistance in "Escherichia Coli.": A Classroom Exercise

    Science.gov (United States)

    Longtin, Sarah; Guilfoile, Patrick; Asper, Andrea

    2004-01-01

    Bacterial antibiotic resistance remains a problem of clinical importance. Current microbiological methods for determining antibiotic resistance are based on culturing bacteria, and may require up to 48 hours to complete. Molecular methods are increasingly being developed to speed the identification of antibiotic resistance and to determine its…

  1. Restricted use of antibiotics in organic pig farming

    DEFF Research Database (Denmark)

    Aabo, Søren; Jensen, Annette Nygaard

    2013-01-01

    Can the restricted use of antibiotics in organic pig farming be documented to provide a safer, high quality meat product with less antibiotic resistant bacteria? The project SafeOrganic aims to document that the restricted use of antimicrobials in organic pig production leads to lower levels...... of antibiotic resistant bacteria compared with the level in conventional pigs. However, the project will also address the risk of losing this quality parameter, due to a widespread practice of slaughtering organic pigs together with conventional pigs, implying a risk of cross-contamination....

  2. Magnetic isotope effect of magnesium (25)Mg on E. coli resistance to antibiotics.

    Science.gov (United States)

    Letuta, U G; Vekker, A S; Kornilova, T A; Gryaznov, A A; Cheplakov, I A

    2016-07-01

    Effects of synergism and antagonism of antibacterial drugs and magnetic isotope of magnesium (25)Mg on antibiotic resistance of bacteria E. coli were discovered. Fourteen antibiotics from seven different groups were tested. The increase in antibiotic resistance in the presence of the ion (25)Mg(2+) was discovered in E. coli cells incubated with quinolones/fluoroquinolones, indicating the inhibiting effect of the magnetic moments of nuclei (25)Mg on DNA synthesis. The change in antibiotic resistance was also detected in bacteria affected by magnesium (25)Mg and certain antibiotics from aminoglycoside and lincosamide groups. PMID:27599512

  3. Resistant bacteria in stem cell transplant recipients

    Directory of Open Access Journals (Sweden)

    Nucci Marcio

    2002-01-01

    Full Text Available Bacterial infections account for most infections in hematopoietic stem cell transplant recipients. While early mortality reduced dramatically with the introduction of the concept of empirical antibiotic therapy in neutropenic patients, no effect of prophylaxis on the mortality was observed in many studies. On the other hand, antibiotic prophylaxis has resulted in the emergence of resistance among bacteria. In addition, the choice of the antibiotic regimen for empirical therapy and the practices of antibiotic therapy during neutropenia may result in a significant shift in the pattern of bacterial infections. The use of quinolones and vancomycin as prophylaxis, and of carbapenems and vancomycin in the empirical antibiotic therapy, are associated with the appearance of resistant Gram-positive and Gram-negative bacteria. Therefore, hematologists must be aware of the impact of these practices on the emergence of infections due to multi-resistant pathogens, since these infections may be associated with increased mortality.

  4. Enhanced uptake of antibiotic resistance genes in the presence of nanoalumina.

    Science.gov (United States)

    Ding, Chengshi; Pan, Jie; Jin, Min; Yang, Dong; Shen, Zhiqiang; Wang, Jingfeng; Zhang, Bin; Liu, Weili; Fu, Jialun; Guo, Xuan; Wang, Daning; Chen, Zhaoli; Yin, Jing; Qiu, Zhigang; Li, Junwen

    2016-10-01

    Nanomaterial pollution and the spread of antibiotic resistance genes (ARGs) are global public health and environmental concerns. Whether nanomaterials could aid the transfer of ARGs released from dead bacteria into live bacteria to cause spread of ARGs is still unknown. Here, we demonstrated that nano-Al2O3 could significantly promote plasmid-mediated ARGs transformation into Gram-negative Escherichia coli strains and into Gram-positive Staphylococcus aureus; however, bulk Al2O3 did not have this effect. Under suitable conditions, 7.4 × 10(6) transformants of E. coli and 2.9 × 10(5) transformants of S. aureus were obtained from 100 ng of a pBR322-based plasmid when bacteria were treated with nano-Al2O3. Nanoparticles concentrations, plasmid concentrations, bacterial concentrations, interaction time between the nanomaterial and bacterial cells and the vortexing time affected the transformation efficiency. We also explored the mechanisms underlying this phenomenon. Using fluorescence in situ hybridization and scanning electron microscopy, we found that nano-Al2O3 damaged the cell membrane to produce pores, through which plasmid could enter bacterial cells. Results from reactive oxygen species (ROS) assays, genome-wide expression microarray profiling and quantitative real-time polymerase chain reactions suggested that intracellular ROS damaged the cell membrane, and that an SOS response promoted plasmid transformation. Our results indicated the environmental and health risk resulting from nanomaterials helping sensitive bacteria to obtain antibiotic resistance. PMID:26946995

  5. EFFECT OF WASTEWATER DISINFECTANTS ON SURVIVAL OF R-FACTOR COLIFORM BACTERIA

    Science.gov (United States)

    The objectives of the study were to determine the incidence of antibiotic resistance among coliform bacteria in a secondary waste-water treatment facility and to determine whether various alternative disinfection procedures would select for or against antibiotic resistant colifor...

  6. In vitro and in vivo bactericidal activity of Vitex negundo leaf extract against diverse multidrug resistant enteric bacterial pathogens

    Institute of Scientific and Technical Information of China (English)

    Muhammad Kamruzzaman; S.M. Nayeemul Bari; Shah M. Faruque

    2013-01-01

    Objective: To investigate in vitro and in vivo antibacterial potentials of Vitex negundo (V. negundo) leaf extracts against diverse enteric pathogens. Methods: Water and methanol extracts of V. negundo leaves were evaluated against enteric bacterial pathogens by using standard disc diffusion, viable bacterial cell count methods, determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). Results: Methanol extract of V. negundo leaves showed potent antibacterial activity (inhibition zone: 9.9-22.6 mm, MIC:200-3 200 μg/mL, MBC: 200-6 400 μg/mL) against all the pathogenic enteric bacteria (Vibriocholerae , Vibrio parahaemolyticus, Vibrio mimicus, Echerichia coli, Shigella spps., and Aeromonas spps) tested. Methanol extract of V. negundo leaves showed potent bactericidal activity both in vitro laboratory conditions (MBC, 200-400 μg/mL) and in the intestinal environment (Dose, 1-2 mg/mL) of infant mice against pathogenic Vibrio cholerae, the major causative agent of cholera. Furthermore, assays using the mice cholera model showed that V. negundo methanol extract can protect mice from Vibrio cholerae infection and significantly decrease the mortality rate (P<0.0001). Conclusions: For the first time we showed that methanol extract of V. negundo leaves exhibited strong vibriocidal activity both in vitro and in vivo conditions. Therefore, it will be useful to identify and isolate the active compounds of this extract that could be a good alternative of antibiotics to treat cholera.

  7. Integron involvement in environmental spread of antibiotic resistance

    Directory of Open Access Journals (Sweden)

    ThibaultStalder

    2012-04-01

    Full Text Available The spread of antibiotic-resistant bacteria is a growing problem and a public health issue. In recent decades, various genetic mechanisms involved in the spread of resistance genes among bacteria have been identified. Integrons -- genetic elements that acquire, exchange and express genes embedded within gene cassettes (GC -- are one of these mechanisms. Integrons are widely distributed, especially in Gram-negative bacteria; they are carried by mobile genetic elements, plasmids and transposons, which promote their spread within bacterial communities. Initially studied mainly in the clinical setting for their involvement in antibiotic resistance, their role in the environment is now an increasing focus of attention. The aim of this review is to provide an in-depth analysis of recent studies of antibiotic-resistance integrons in the environment, highlighting their potential involvement in antibiotic resistance outside the clinical context. We will focus particularly on the impact of human activities (agriculture, industries, wastewater treatment, etc..

  8. Antagonistic self-sensing and mate-sensing signaling controls antibiotic-resistance transfer

    OpenAIRE

    Chatterjee, Anushree; Cook, Laura C. C.; Shu, Che-Chi; Chen, Yuqing; Manias, Dawn A.; Ramkrishna, Doraiswami; Dunny, Gary M.; Hu, Wei-Shou

    2013-01-01

    Conjugation is one of the most common ways bacteria acquire antibiotic resistance, contributing to the emergence of multidrug-resistant “superbugs.” Bacteria of the genus Enterococcus faecalis are highly antibiotic-resistant nosocomial pathogens that use the mechanism of conjugation to spread antibiotic resistance between resistance-bearing donor cells and resistance-deficient recipient cells. Here, we report a unique quorum sensing-based communication system that uses two antagonistic signal...

  9. Lytic phages obscure the cost of antibiotic resistance in Escherichia coli

    OpenAIRE

    Tazzyman, Samuel J; Hall, Alex R

    2014-01-01

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under pha...

  10. Antimicrobial decision making for enteric diseases of cattle.

    Science.gov (United States)

    Smith, Geof

    2015-03-01

    Diarrhea in neonatal and adult cattle is common and can be caused by several etiologic agents. As diagnostic testing is not always readily available, practitioners must often decide on a course of treatment based on knowledge of the likely pathogen and their own clinical experience. Antimicrobials have long been used to treat diarrhea in adults and neonates; however, there is increased pressure to prevent unnecessary use of antibiotics in food animal species. This article reviews existing data on the use of antibiotics given to cattle with enteric diseases to decide when they are necessary and which antimicrobials should be used. PMID:25705025

  11. Antibiotic Application and Emergence of Multiple Antibiotic Resistance (MAR) in Global Catfish Aquaculture.

    Science.gov (United States)

    Chuah, Li-Oon; Effarizah, M E; Goni, Abatcha Mustapha; Rusul, Gulam

    2016-06-01

    Catfish is one of the most cultivated species worldwide. Antibiotics are usually used in catfish farming as therapeutic and prophylactic agents. In the USA, only oxytetracycline, a combination of sulfadimethoxine and ormetoprim, and florfenicol are approved by the Food Drug Administration for specific fish species (e.g., catfish and salmonids) and their specific diseases. Misuse of antibiotics as prophylactic agents in disease prevention, however, is common and contributes in the development of antibiotic resistance. Various studies had reported on antibiotic residues and/or resistance in farmed species, feral fish, water column, sediments, and, in a lesser content, among farm workers. Ninety percent of the world aquaculture production is carried out in developing countries, which lack regulations and enforcement on the use of antibiotics. Hence, efforts are needed to promote the development and enforcement of such a regulatory structure. Alternatives to antibiotics such as antibacterial vaccines, bacteriophages and their lysins, and probiotics have been applied to curtail the increasing emergence of antibiotic-resistant bacteria due to the imprudent application of antibiotics in aquaculture. PMID:27038482

  12. Effect of leukocyte hydrolases on bacteria

    International Nuclear Information System (INIS)

    Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites

  13. The Artistry of Bacterial Colonies and the Antibiotic Crisis

    Science.gov (United States)

    Golding, Ido; Ben-Jacob, Eshel

    Since the beginning of massive usage of antibiotics during World War II we have witnessed a dramatic evolutionary event - the emergence of multiple drug resistant bacteria. The bacteria are capable of developing antibiotic resistance at a higher rate than scientists develop new drugs [1, and references therein. See also the UN's World Health Report 1996]. We seem to be loosing a crucial battle on our health. To reverse this course of events, we have to "outsmart" the bacteria by taking new avenues of study which will lead to the development of novel strategies to fight them.

  14. Antibiotic resistance: are we all doomed?

    Science.gov (United States)

    Collignon, P

    2015-11-01

    Antibiotic resistance is a growing and worrying problem associated with increased deaths and suffering for people. Overall, there are only two factors that drive antimicrobial resistance, and both can be controlled. These factors are the volumes of antimicrobials used and the spread of resistant micro-organisms and/or the genes encoding for resistance. The One Health concept is important if we want to understand better and control antimicrobial resistance. There are many things we can do to better control antimicrobial resistance. We need to prevent infections. We need to have better surveillance with good data on usage patterns and resistance patterns available across all sectors, both human and agriculture, locally and internationally. We need to act on these results when we see either inappropriate usage or resistance levels rising in bacteria that are of concern for people. We need to ensure that food and water sources do not spread multi-resistant micro-organisms or resistance genes. We need better approaches to restrict successfully what and how antibiotics are used in people. We need to restrict the use of 'critically important' antibiotics in food animals and the entry of these drugs into the environment. We need to ensure that 'One Health' concept is not just a buzz word but implemented. We need to look at all sectors and control not only antibiotic use but also the spread and development of antibiotic resistant bacteria - both locally and internationally. PMID:26563691

  15. Strengthening Control of Antibiotics

    Institute of Scientific and Technical Information of China (English)

    EthelLu

    2005-01-01

    IT is a well-known fact that buy-ng guns is much easier than purchasing antibiotics in the United States. In China, however, the situation is different. According to a recent WHO survey,about 80 percent of Chinese inpatients take antibiotic medicines, and 58 percent of them are prescribed multifunctional antibiotics,

  16. Know When Antibiotics Work

    Centers for Disease Control (CDC) Podcasts

    2015-04-15

    This podcast provides a brief background about antibiotics and quick tips to help prevent antibiotic resistance.  Created: 4/15/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program.   Date Released: 4/16/2015.

  17. Antibiotic resistant in microorganisms

    Science.gov (United States)

    Antimicrobial agents are necessary for use in veterinary medicine including the production of food producing animals. Antibiotic use is indicated for the treatment of bacterial target organisms and/or disease for which the antibiotic was developed. However, an unintended consequence of antibiotic ...

  18. Insects Represent a Link between Food Animal Farms and the Urban Environment for Antibiotic Resistance Traits

    OpenAIRE

    Zurek, Ludek; Ghosh, Anuradha

    2014-01-01

    Antibiotic-resistant bacterial infections result in higher patient mortality rates, prolonged hospitalizations, and increased health care costs. Extensive use of antibiotics as growth promoters in the animal industry represents great pressure for evolution and selection of antibiotic-resistant bacteria on farms. Despite growing evidence showing that antibiotic use and bacterial resistance in food animals correlate with resistance in human pathogens, the proof for direct transmission of antibi...

  19. The Use of Machine Learning Methodologies to Analyse Antibiotic and Biocide Susceptibility in Staphylococcus aureus

    OpenAIRE

    Coelho, Joana Rosado; Carriço, João André; Knight, Daniel; Martínez, Jose-Luis; Morrissey, Ian; Oggioni, Marco Rinaldo; Freitas, Ana Teresa

    2013-01-01

    Background The rise of antibiotic resistance in pathogenic bacteria is a significant problem for the treatment of infectious diseases. Resistance is usually selected by the antibiotic itself; however, biocides might also co-select for resistance to antibiotics. Although resistance to biocides is poorly defined, different in vitro studies have shown that mutants presenting low susceptibility to biocides also have reduced susceptibility to antibiotics. However, studies with natural bacterial is...

  20. Enteral nutrition - child - managing problems

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000164.htm Enteral nutrition - child - managing problems To use the sharing features ... trouble breathing, call 911. References Mcclave SA. Enteral nutrition. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  1. How to Fight Back Against Antibiotic Resistance

    DEFF Research Database (Denmark)

    Dantas, Gautam; Sommer, Morten

    2014-01-01

    Mapping the exchange of genes between pathogens and nonpathogens offers new ways to understand and manage the spread of drug-resistant strains. In reality, the development of new antibiotics is only part of the solution, as pathogens will inevitably develop resistance to even the most promising new...... compounds. To save the era of antibiotics, scientists must figure out what it is about bacterial pathogens that makes resistance inevitable. Although most studies on drug resistance have focused on disease causing pathogens, recent efforts have shifted attention to the resistomes of nonpathogenic bacteria...

  2. Sampling and Pooling Methods for Capturing Herd Level Antibiotic Resistance in Swine Feces using qPCR and CFU Approaches

    DEFF Research Database (Denmark)

    Schmidt, Gunilla Veslemøy; Mellerup, Anders; Christiansen, Lasse Engbo;

    2015-01-01

    The aim of this article was to define the sampling level and method combination that captures antibiotic resistance at pig herd level utilizing qPCR antibiotic resistance gene quantification and culture-based quantification of antibiotic resistant coliform indicator bacteria. Fourteen qPCR assays...... for commonly detected antibiotic resistance genes were developed, and used to quantify antibiotic resistance genes in total DNA from swine fecal samples that were obtained using different sampling and pooling methods. In parallel, the number of antibiotic resistant coliform indicator bacteria was...... determined in the same swine fecal samples. The results showed that the qPCR assays were capable of detecting differences in antibiotic resistance levels in individual animals that the coliform bacteria colony forming units (CFU) could not. Also, the qPCR assays more accurately quantified antibiotic...

  3. Entering the Anthropocene

    Science.gov (United States)

    Vince, Gaia

    2016-04-01

    There is growing evidence that we are now entering a new geological age defined by human influence on the planet, the Anthropocene. Millions of years from now, a stripe in the accumulated layers of rock on Earth's surface will reveal our human fingerprint just as we can see evidence of dinosaurs in rocks of the Jurassic, or the explosion of life that marks the Cambrian. There is now no part of the planet untouched by human influence. The realisation that we wield such planetary power requires a quite extraordinary shift in perception, fundamentally toppling the scientific, cultural and religious philosophies that define our place in the world. This session explores these issues and examines our new relationship with nature now that we so strongly influence the biosphere. And this session will look at what the impacts of our planetary changes mean for us, and how we might deal with the consequences of the Anthropocene we have created.

  4. Antibiotic Selection Pressure and Macrolide Resistance in Nasopharyngeal Streptococcus pneumoniae: A Cluster-Randomized Clinical Trial

    OpenAIRE

    Skalet, Alison H; Vicky Cevallos; Berhan Ayele; Teshome Gebre; Zhaoxia Zhou; Jorgensen, James H.; Mulat Zerihun; Dereje Habte; Yared Assefa; Emerson, Paul M.; Gaynor, Bruce D.; Porco, Travis C.; Lietman, Thomas M.; Keenan, Jeremy D.

    2010-01-01

    Editors' Summary Background In 1928, Alexander Fleming discovered penicillin, the first antibiotic (a drug that kills bacteria). By the early 1940s, scientists were able to make large quantities of penicillin and, in the following decades, several other classes of powerful antibiotics were discovered. For example, erythromycin—the first macrolide antibiotic—was developed in the early 1950s. For a time, it looked like bacteria and the diseases that they cause had been defeated. But bacteria ra...

  5. Squalamine: an aminosterol antibiotic from the shark.

    Science.gov (United States)

    Moore, K S; Wehrli, S; Roder, H; Rogers, M; Forrest, J N; McCrimmon, D; Zasloff, M

    1993-02-15

    In recent years, a variety of low molecular weight antibiotics have been isolated from diverse animal species. These agents, which include peptides, lipids, and alkaloids, exhibit antibiotic activity against environmental microbes and are thought to play a role in innate immunity. We report here the discovery of a broad-spectrum steroidal antibiotic isolated from tissues of the dogfish shark Squalus acanthias. This water-soluble antibiotic, which we have named squalamine, exhibits potent bactericidal activity against both Gram-negative and Gram-positive bacteria. In addition, squalamine is fungicidal and induces osmotic lysis of protozoa. The chemical structure of the antibiotic 3 beta-N-1-(N-[3-(4-aminobutyl)]- 1,3-diaminopropane)-7 alpha,24 zeta-dihydroxy-5 alpha-cholestane 24-sulfate has been determined by fast atom bombardment mass spectroscopy and NMR. Squalamine is a cationic steroid characterized by a condensation of an anionic bile salt intermediate with spermidine. The discovery of squalamine in the shark implicates a steroid as a potential host-defense agent in vertebrates and provides insights into the chemical design of a family of broad-spectrum antibiotics. PMID:8433993

  6. Identification and Characterization of the fis Operon in Enteric Bacteria

    OpenAIRE

    Beach, Michael B.; Osuna, Robert

    1998-01-01

    The small DNA binding protein Fis is involved in several different biological processes in Escherichia coli. It has been shown to stimulate DNA inversion reactions mediated by the Hin family of recombinases, stimulate integration and excision of phage λ genome, regulate the transcription of several different genes including those of stable RNA operons, and regulate the initiation of DNA replication at oriC. fis has also been isolated from Salmonella typhimurium, and the genomic sequence of Ha...

  7. Antibiotic resistance - the interplay between antibiotic use in animals and human beings

    DEFF Research Database (Denmark)

    Singer, R.S.; Finch, R.; Wegener, Henrik Caspar; Bywater, R.; Walters, J.; Lipsitch, M.

    2003-01-01

    meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance....... There is a growing concern over the transmission of resistant bacteria via the food chain. Many questions will be difficult to resolve, such as how do you distinguish the fraction of resistance in human beings that originated from animals? If we wait to see evidence that a significant amount of...... antibiotic resistance really does come through the food chain, will it be too late for action? In this forum, we present different perspectives from both human and animal medicine, to better understand the complexity of the problem of antibiotic resistance and examine the challenges that lie ahead....

  8. Enteric bacterial pathogens in children with diarrhea in Niger: diversity and antimicrobial resistance.

    Directory of Open Access Journals (Sweden)

    Céline Langendorf

    Full Text Available Although rotavirus is the leading cause of severe diarrhea among children in sub-Saharan Africa, better knowledge of circulating enteric pathogenic bacteria and their antimicrobial resistance is crucial for prevention and treatment strategies.As a part of rotavirus gastroenteritis surveillance in Maradi, Niger, we performed stool culture on a sub-population of children under 5 with moderate-to-severe diarrhea between April 2010 and March 2012. Campylobacter, Shigella and Salmonella were sought with conventional culture and biochemical methods. Shigella and Salmonella were serotyped by slide agglutination. Enteropathogenic Escherichia coli (EPEC were screened by slide agglutination with EPEC O-typing antisera and confirmed by detection of virulence genes. Antimicrobial susceptibility was determined by disk diffusion. We enrolled 4020 children, including 230 with bloody diarrhea. At least one pathogenic bacterium was found in 28.0% of children with watery diarrhea and 42.2% with bloody diarrhea. Mixed infections were found in 10.3% of children. EPEC, Salmonella and Campylobacter spp. were similarly frequent in children with watery diarrhea (11.1%, 9.2% and 11.4% respectively and Shigella spp. were the most frequent among children with bloody diarrhea (22.1%. The most frequent Shigella serogroup was S. flexneri (69/122, 56.5%. The most frequent Salmonella serotypes were Typhimurimum (71/355, 20.0%, Enteritidis (56/355, 15.8% and Corvallis (46/355, 13.0%. The majority of putative EPEC isolates was confirmed to be EPEC (90/111, 81.1%. More than half of all Enterobacteriaceae were resistant to amoxicillin and co-trimoxazole. Around 13% (46/360 Salmonella exhibited an extended-spectrum beta-lactamase phenotype.This study provides updated information on enteric bacteria diversity and antibiotic resistance in the Sahel region, where such data are scarce. Whether they are or not the causative agent of diarrhea, bacterial infections and their antibiotic

  9. Public Beliefs about Antibiotics, Infection and Resistance: A Qualitative Study

    Directory of Open Access Journals (Sweden)

    Helen Madden

    2013-11-01

    Full Text Available We aimed to gain an in-depth understanding of public views and ways of talking about antibiotics. Four focus groups were held with members of the public. In addition, 39 households were recruited and interviews, diaries of medicine taking, diaries of any contact with medication were used to explore understanding and use of medication. Discussions related to antibiotics were identified and analyzed. Participants in this study were worried about adverse effects of antibiotics, particularly for recurrent infections. Some were concerned that antibiotics upset the body’s “balance”, and many used strategies to try to prevent and treat infections without antibiotics. They rarely used military metaphors about infection (e.g., describing bacteria as invading armies but instead spoke of clearing infections. They had little understanding of the concept of antibiotic resistance but they thought that over-using antibiotics was unwise because it would reduce their future effectiveness. Previous studies tend to focus on problems such as lack of knowledge, or belief in the curative powers of antibiotics for viral illness, and neglect the concerns that people have about antibiotics, and the fact that many people try to avoid them. We suggest that these concerns about antibiotics form a resource for educating patients, for health promotion and social marketing strategies.

  10. NANOTECHNOLOGICAL SOLUTION FOR IMPROVING THE ANTIBIOTIC EFFICIENCY AGAINST BIOFILMS DEVELOPED BY GRAM-NEGATIVE BACTERIAL STRAINS

    Directory of Open Access Journals (Sweden)

    Keng-Shiang Huang

    2013-03-01

    Full Text Available At present bacteria involved in biofilm associated infections display the highest rates of antibiotic resistance among pathogenic bacteria, which made that treatment options to be limited, and determined the researchers to find out alternative treatments to antibiotics. In the recent years nanomaterials gained much attention in medicine, particularly in the fight to bacteria resistant to antibiotics by acting as drug delivery devices. Magnetic iron oxide nanoparticles (MNPs have raised much interest during the recent years due to their potential applications in medicine. In the present study we synthesized MNPd functionalized with antibiotics for the study of their antimicrobial and anti-biofilm properties against Escherichia coli and Pseudomonas aeruginosa, two Gram-negative bacteria, frequently resistant to antibiotics, involved in biofilm infections in order to investigate their capacity to serve as potential drug delivery systems in the fight to these important opportunist pathogens.

  11. Enhancement of antibiotic effect via gold:silver-alloy nanoparticles

    International Nuclear Information System (INIS)

    A strategy for the development of novel antimicrobials is to combine the stability and pleiotropic effects of inorganic compounds with the specificity and efficiency of organic compounds, such as antibiotics. Here we report on the use of gold:silver-alloy (Au:Ag-alloy) nanoparticles, obtained via a single-step citrate co-reduction method, combined to conventional antibiotics to enhance their antimicrobial effect on bacteria. Addition of the alloy nanoparticles considerably decreased the dose of antibiotic necessary to show antimicrobial effect, both for bacterial cells growing in rich medium in suspension and for bacterial cells resting in a physiological buffer on a humid cellulose surface. The observed effect was more pronounced than the sum of the individual effects of the nanoparticles and antibiotic. We demonstrate the enhancement effect of Au:Ag-alloy nanoparticles with a size distribution of 32.5 ± 7.5 nm mean diameter on the antimicrobial effect of (i) kanamycin on Escherichia coli (Gram-negative bacterium), and (ii) a β-lactam antibiotic on both a sensitive and resistant strain of Staphylococcus aureus (Gram-positive bacterium). Together, these results may pave the way for the combined use of nanoparticle–antibiotic conjugates towards decreasing antibiotic resistance currently observed for certain bacteria and conventional antibiotics.

  12. Enhancement of antibiotic effect via gold:silver-alloy nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Moreira dos Santos, Margarida, E-mail: margarida.santos@fct.unl.pt; Queiroz, Margarida Joao; Baptista, Pedro V. [Universidade Nova de Lisboa, CIGMH, Departamento Ciencias da Vida, Faculdade de Ciencias e Tecnologia (Portugal)

    2012-05-15

    A strategy for the development of novel antimicrobials is to combine the stability and pleiotropic effects of inorganic compounds with the specificity and efficiency of organic compounds, such as antibiotics. Here we report on the use of gold:silver-alloy (Au:Ag-alloy) nanoparticles, obtained via a single-step citrate co-reduction method, combined to conventional antibiotics to enhance their antimicrobial effect on bacteria. Addition of the alloy nanoparticles considerably decreased the dose of antibiotic necessary to show antimicrobial effect, both for bacterial cells growing in rich medium in suspension and for bacterial cells resting in a physiological buffer on a humid cellulose surface. The observed effect was more pronounced than the sum of the individual effects of the nanoparticles and antibiotic. We demonstrate the enhancement effect of Au:Ag-alloy nanoparticles with a size distribution of 32.5 {+-} 7.5 nm mean diameter on the antimicrobial effect of (i) kanamycin on Escherichia coli (Gram-negative bacterium), and (ii) a {beta}-lactam antibiotic on both a sensitive and resistant strain of Staphylococcus aureus (Gram-positive bacterium). Together, these results may pave the way for the combined use of nanoparticle-antibiotic conjugates towards decreasing antibiotic resistance currently observed for certain bacteria and conventional antibiotics.

  13. DNA Integrity and Shock Wave Transformation Efficiency of Bacteria and Fungi

    Science.gov (United States)

    Loske, Achim M.; Campos-Guillén, Juan; Fernández, Francisco; Pastrana, Xóchitl; Magaña-Ortíz, Denis; Coconi-Linares, Nancy; Ortíz-Vázquez, Elizabeth; Gómez-Lim, Miguel

    Delivery of DNA into bacteria and fungi is essential in medicine and biotechnology to produce metabolites, enzymes, antibiotics and proteins. So far, protocols to genetically transform bacteria and fungi are inefficient and have low reproducibility.

  14. Differential resistance and the importance of antibiotic production in Acromyrmex echinatior leaf-cutting ant castes towards the entomopathogenic fungus Aspergillus nomius

    DEFF Research Database (Denmark)

    Poulsen, Michael; Hughes, William Owen Hamar; Boomsma, Jacobus Jan

    2006-01-01

    Paired exocrine metapleural glands are present in almost all ants and produce compounds with antibiotic properties towards a variety of pathogenic fungi and bacteria. In Acromyrmex leaf-cutting ants, small workers have relatively large metapleural glands compared to large workers, and thus harbour...... approximately half the number of gland cells of large workers, despite being only one-fifteenth their body mass. Here we present results showing that when the two worker castes of A. echinatior are treated with spores of the pathogenic fungus Aspergillus nomius in doses that correspond to the difference in...... glands in small workers makes this caste particularly well adapted to preventing pathogenic microorganisms from entering the colony....

  15. A Survey and Analysis of the American Public's Perceptions and Knowledge About Antibiotic Resistance.

    Science.gov (United States)

    Carter, Rebecca R; Sun, Jiayang; Jump, Robin L P

    2016-09-01

    Background.  Little is known about the American public's perceptions or knowledge about antibiotic-resistant bacteria or antibiotic misuse. We hypothesized that although many people recognize antibiotic resistance as a problem, they may not understand the relationship between antibiotic consumption and selection of resistant bacteria. Methods.  We developed and tested a survey asking respondents about their perceptions and knowledge regarding appropriate antibiotic use. Respondents were recruited with the Amazon Mechanical Turk crowdsourcing platform. The survey, carefully designed to assess a crowd-sourced population, asked respondents to explain "antibiotic resistance" in their own words. Subsequent questions were multiple choice. Results.  Of 215 respondents, the vast majority agreed that inappropriate antibiotic use contributes to antibiotic resistance (92%), whereas a notable proportion (70%) responded neutrally or disagreed with the statement that antibiotic resistance is a problem. Over 40% of respondents indicated that antibiotics were the best choice to treat a fever or a runny nose and sore throat. Major themes from the free-text responses included that antibiotic resistance develops by bacteria, or by the infection, or the body (ie, an immune response). Minor themes included antibiotic overuse and antibiotic resistance caused by bacterial adaptation or an immune response. Conclusions.  Our findings indicate that the public is aware that antibiotic misuse contributes to antibiotic resistance, but many do not consider it to be an important problem. The free-text responses suggest specific educational targets, including the difference between an immune response and bacterial adaptation, to increase awareness and understanding of antibiotic resistance. PMID:27382598

  16. Frontline antibiotic therapy.

    Science.gov (United States)

    MacGowan, Alasdair; Albur, Maha

    2013-06-01

    The need to use front-line antibiotics wisely has never been greater. Antibiotic resistance and multi-drug resistant infection, driven by antibiotic use, remain major public health and professional concerns. To overcome these infection problems, use of older antibiotics active against multi drug-resistant pathogens is increasing - for example, colistin, fosfomycin, pivmecillinam, pristinamycin, temocillin and oral tetracyclines. The number of new antibacterials reaching clinical practice has reduced significantly in the last 20 years, most being focused on therapy of Gram-positive infection - eg linezolid, daptomycin, telavancin and ceftaroline. Recent guidance on antibiotic stewardship in NHS trusts in England is likely to provide a backdrop to antibiotic use in hospitals in the next 5 years. PMID:23760700

  17. Carriage of ESBL (extended spectrum beta-lactamases) - producing bacteria - knowledge, emotional impact and risk assessment

    OpenAIRE

    Wiklund, Susanne

    2015-01-01

    Antibiotic-resistant bacteria, such as ESBL-producing Enterobacteriaceae, have become a growing public health threat. The overall aim of this thesis was to explore how the increasing prevalence of ESBL-producing bacteria affects different groups among the Swedish population. Paper I described the knowledge and understanding of antibiotic-resistant bacteria, and of the risk of becoming a carrier of such bacteria, among ninety-five Swedish travelers before travel to high-risk areas. A questionn...

  18. New antibiotic agents for bloodstream infections.

    Science.gov (United States)

    Vergidis, Paschalis I; Falagas, Matthew E

    2008-11-01

    Infections due to multidrug-resistant pathogens have shown a dramatic worldwide increase in prevalence. Bloodstream infections (BSIs) represent an important cause of morbidity and mortality in hospitalised patients. Research in the field led to the introduction of several novel antibiotic agents in the fight against bacterial pathogens. New antibiotics used against Gram-positive bacteria, mainly meticillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, include daptomycin, linezolid, quinupristin/dalfopristin and semisynthetic lipoglycopeptides. Among the Gram-negative bacteria, extended-spectrum beta-lactamase-producing Enterobacteriaceae as well as highly resistant Pseudomonas and Acinetobacter isolates are of particular concern. Doripenem is a recently approved carbapenem. Polymyxins are reconsidered as valuable therapeutic options for Gram-negative infections. Tigecycline, a glycylcycline, and ceftobiprole, a novel cephalosporin under investigation, have activity both against Gram-positive and Gram-negative organisms. In addition to the above agents, alternative treatment approaches that require further investigation have also been introduced into clinical practice. These include antibiotic lock therapy and continuous intravenous administration of antibiotics. In this article, we review the above treatment options for BSIs based on current clinical evidence. Comparative trials specifically focusing on patients with bacteraemia were generally not performed; however, a proportion of patients from the reported studies did have bacteraemia. PMID:18723329

  19. Resurrecting the intestinal microbiota to combat antibiotic-resistant pathogens.

    Science.gov (United States)

    Pamer, Eric G

    2016-04-29

    The intestinal microbiota, which is composed of diverse populations of commensal bacterial species, provides resistance against colonization and invasion by pathogens. Antibiotic treatment can damage the intestinal microbiota and, paradoxically, increase susceptibility to infections. Reestablishing microbiota-mediated colonization resistance after antibiotic treatment could markedly reduce infections, particularly those caused by antibiotic-resistant bacteria. Ongoing studies are identifying commensal bacterial species that can be developed into next-generation probiotics to reestablish or enhance colonization resistance. These live medicines are at various stages of discovery, testing, and production and are being subjected to existing regulatory gauntlets for eventual introduction into clinical practice. The development of next-generation probiotics to reestablish colonization resistance and eliminate potential pathogens from the gut is warranted and will reduce health care-associated infections caused by highly antibiotic-resistant bacteria. PMID:27126035

  20. Antibiotic resistance via the food chain: Fact or fiction?

    Directory of Open Access Journals (Sweden)

    Sabiha Y. Essack

    2010-09-01

    Full Text Available The mechanisms that bacteria use to acquire additional genetic material, including genes coding for antibiotic resistance, are principally the secondary pathways that have been described as transformation and conjugation pathways. The farming industry often is reported as a hotspot for antibiotic-resistance reservoirs. In this review, we consider the exposure of food animals during the course of their lifespans to preventative, therapeutic or prophylactic treatment with antibiotic agents. In this context, zoonotic bacteria are commonly recognised as a potential threat to human health, with therapeutic treatment of pathogenic organisms on farms increasing the likelihood of selective antibiotic pressure influencing the commensal flora of the intestines. Existing literature indicates, however, that the effective impact on human health of such interventions in the food production process is still subject to debate.

  1. Effect of Clostridium perfringens infection and antibiotic administration on microbiota in the small intestine of broiler chickens.

    Science.gov (United States)

    Fasina, Yewande O; Newman, Molli M; Stough, Joshua M; Liles, Mark R

    2016-02-01

    The etiological agent of necrotic enteritis (NE) is Clostridium perfringens (CP), which is an economically significant problem for broiler chicken producers worldwide. Traditional use of in-feed antibiotic growth promoters to control NE disease have resulted in the emergence of antibiotic resistance in CP strains. Identification of probiotic bacteria strains as an alternative to antibiotics for the control of intestinal CP colonization is crucial. Two experiments were conducted to determine changes in intestinal bacterial assemblages in response to CP infection and in-feed bacitracin methylene disalicylate (BMD) in broiler chickens. In each experiment conducted in battery-cage or floor-pen housing, chicks were randomly assigned to the following treatment groups: 1) BMD-supplemented diet with no CP challenge (CM), 2) BMD-free control diet with no CP challenge (CX), 3) BMD-supplemented diet with CP challenge (PCM), or 4) BMD-free control diet with CP challenge (PCX). The establishment of CP infection was confirmed, with the treatment groups exposed to CP having a 1.5- to 2-fold higher CP levels (P chicken intestine. Future studies should explore the potential to use commensal strains of unknown Clostridiales, Lactobacillaceae, Enterobacteriaceae, Streptococcaceae, and Enterococcaceae in effective probiotic formulations for the control of CP and NE disease. PMID:26567176

  2. Structure of polysaccharide antibiotics

    International Nuclear Information System (INIS)

    Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author)

  3. Current status of the application of antibiotic-loaded bone cements in primary arthroplasty%初次关节置换中抗生素骨水泥的应用现状

    Institute of Scientific and Technical Information of China (English)

    王晓楠; 王金成

    2013-01-01

    Infection is considered to be a serious complication of artificial arthroplasty. Accordingly, infection control becomes a research focus in recent years. In order to reduce its incidence, many doctors use antibiotic-loaded bone cements in primary arthroplasty, especially in those special cases, such as surgery with a long period, or with a high risk of pollution, revision surgery, and for patients with idiopathic or acquired immunodeficiency, patients with rheumatoid diseases or systemic lupus erythematosus, patients treated with radiotherapy or chemotherapy, obese patients, diabetic patients, especially patients with poor glucose control, and patients with previous joint infection or malignancy. However, there exists such problems as higher costs and a single kind of antibiotics in use. At the same time, the release time of antibiotics in bone cements is limited, which determines that the infection is mainly prevented in the introduced pathway after artificial arthroplasty. So it is uncertain whether all types of bacteria entering the human body through the introduced pathway can be included by the antibacterial spectrum of antibiotics in bone cements, and further experiments and studies are needed for doctors to verify the results. In this article, we reviewed the application of antibiotic-loaded bone cements in primary arthroplasty for reference.

  4. The determination of resistance to ertapenem and other antibiotics with ESBL product of Enterobacteriaceae isolated from urine samples

    OpenAIRE

    Aytekin Çıkman; Nadire Seval Gündem; Barış Gülhan; Merve Aydın; Mehmet Parlak; Yasemin Bayram

    2014-01-01

    Objective: Enterobacteriaceae is the most frequently isolated bacteria in urinary system infections. This study investigated the antibiotic susceptibility including ertapenem and extended-spectrum beta-lactamase production of bacteria belons to Enterobacteriaceae isolated from the urinary culture. Methods: Enterobacteriaceae strains, identified by using conventional methods in our laboratory between January 2012 and March 2012, were included the study. The antibiotic susceptibilities were...

  5. Frontiers in Squid Reproduction: Prospecting for New Antibiotics

    OpenAIRE

    Epel, David

    2002-01-01

    Many strains of disease-causing bacteria have become resistant to antibiotics, leading those in the medical profession to search for new sources of drugs. Although most antibiotics have been derived from terrestrial life, it is the marine world that may provide the pharmaceutical industry with the next generation of medicines. The biochemistries of seemingly simple marine organisms such as blue-green algae, sponges and squid are inspiring new ideas for drug development.

  6. Antibiotic, Pesticide, and Microbial Contaminants of Honey: Human Health Hazards

    OpenAIRE

    Noori Al-Waili; Khelod Salom; Ahmed Al-Ghamdi; Mohammad Javed Ansari

    2012-01-01

    Agricultural contamination with pesticides and antibiotics is a challenging problem that needs to be fully addressed. Bee products, such as honey, are widely consumed as food and medicine and their contamination may carry serious health hazards. Honey and other bee products are polluted by pesticides, heavy metals, bacteria and radioactive materials. Pesticide residues cause genetic mutations and cellular degradation and presence of antibiotics might increase resistant human or animal's patho...

  7. Alternatives to Antibiotics in Animal Agriculture: An Ecoimmunological View

    OpenAIRE

    Yongming Sang; Frank Blecha

    2014-01-01

    Ecological immunology (or ecoimmunology) is a new discipline in animal health and immunology that extends immunologists’ views into a natural context where animals and humans have co-evolved. Antibiotic resistance and tolerance (ART) in bacteria are manifested in antibiosis-surviving subsets of resisters and persisters. ART has emerged though natural evolutionary consequences enriched by human nosocomial and agricultural practices, in particular, wide use of antibiotics that overwhelms other ...

  8. Removal of Antibiotics by “Green” Clay Sorbents

    OpenAIRE

    Dordio, A. V.; Miranda, Susana; Carvalho, A.J. Palace

    2014-01-01

    Contamination of water resources with pharmaceuticals has been one of the top concerns of environmental sciences in the latest years [1], the matter having received very significant media coverage recently [2]. Antibiotics in particular have been gathering considerable attention and are amongst the most serious worries due to the development of antibiotic resistant bacteria as result of prolonged exposure [1, 2]. Because most wastewater treatment plants were only designed for removing bulk po...

  9. Antibiotics can ameliorate circulatory complications of liver cirrhosis

    DEFF Research Database (Denmark)

    Madsen, Bjørn Stæhr; Schaffalitzky de Muckadell, Ove B

    2011-01-01

    Livercirrhosis can be complicated by a hyperdynamic circulatory syndrome. This is due to translocation of bacteria and bacterial product (bacterial DNA and endotoxins), which stimulate the splanchnic nitric oxide synthase and leads to splanchnic vasodilatation and haemodynamic derangement. This...... review focuses on how broad spectrum antibiotics can ameliorate the haemodynamic consequences of bacterial translocation. It is possible that the use of broad spectrum antibiotics in the future may be used to prevent other complications of liver cirrhosis than spontaneous bacterial peritonitis and...

  10. Overview on the Current Antibiotic Containing Agents Used in Endodontics

    OpenAIRE

    Ramta Bansal; Aditya Jain

    2014-01-01

    Antibiotics are systemically and locally used extensively in endodontics. However, local antibiotic application mode is considered more effective than systemic administration. The local mode enables the dentist to target bacteria in every nook and corner of root canal system, which is otherwise beyond reach if targeted by instrumentation or conventional root canal treatment protocols. Therefore, they are an important adjunct to conventional treatment of root canal. The present study reviews t...

  11. A Simple Model of Tetracycline Antibiotic Resistance in the Aquatic Environment (with Application to the Poudre River

    Directory of Open Access Journals (Sweden)

    Sarah Sanchez

    2011-02-01

    Full Text Available Antibiotic resistance is a major concern, yet it is unclear what causes the relatively high densities of resistant bacteria in the anthropogenically impacted environment. There are various possible scenarios (hypotheses: (A Input of resistant bacteria from wastewater and agricultural sources is significant, but they do not grow in the environment; (B Input of resistant bacteria is negligible, but the resistant bacteria (exogenous or endogenous grow due to the selection pressure of the antibiotic; (C Exogenous bacteria transfer the resistance to the endogenous bacteria and those grow. This paper presents a simple mechanistic model of tetracycline resistance in the aquatic environment. It includes state variables for tetracyclines, susceptible and resistant bacteria, and particulate and dissolved organic matter in the water column and sediment bed. The antibiotic partitions between freely dissolved, dissolved organic matter (DOM-bound and solids-bound phases, and decays. Bacteria growth is limited by DOM, inhibited by the antibiotic (susceptible bacteria only and lower due to the metabolic cost of carrying the resistance (resistant bacteria only. Resistant bacteria can transfer resistance to the susceptible bacteria (conjugation and lose the resistance (segregation. The model is applied to the Poudre River and can reproduce the major observed (literature data patterns of antibiotic concentration and resistance. The model suggests observed densities of resistant bacteria in the sediment bed cannot be explained by input (scenario A, but require growth (scenarios B or C.

  12. Antibiotic resistance genes detected in the marine sponge Petromica citrina from Brazilian coast.

    Science.gov (United States)

    Laport, Marinella Silva; Pontes, Paula Veronesi Marinho; Dos Santos, Daniela Silva; Santos-Gandelman, Juliana de Fátima; Muricy, Guilherme; Bauwens, Mathieu; Giambiagi-deMarval, Marcia; George, Isabelle

    2016-01-01

    Although antibiotic-resistant pathogens pose a significant threat to human health, the environmental reservoirs of the resistance determinants are still poorly understood. This study reports the detection of resistance genes (ermB, mecA, mupA, qnrA, qnrB and tetL) to antibiotics among certain culturable and unculturable bacteria associated with the marine sponge Petromica citrina. The antimicrobial activities elicited by P. citrina and its associated bacteria are also described. The results indicate that the marine environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria. PMID:27287338

  13. An Investigation about the Antibiotic Resistance of the Pathogenic Bacteria and Epidemiological Analysis in the Burn Unit from 2011-2013%2011-2013年中南大学湘雅三医院烧伤科病房致病菌耐药情况及流行病学分析

    Institute of Scientific and Technical Information of China (English)

    蒲虹妃; 贺全勇; 罗成群; 朱颉

    2014-01-01

    目的:总结2011-2013年中南大学湘雅三医院烧伤科病房致病菌的分布及耐药情况,为临床提供最新的流行病学资料,以优化临床用药方案。方法收集2011年1月-2013年12月烧伤科送检的1240例患者的2025份标本的细菌培养及药敏检测资料,并与1995-2000年烧伤科送检标本的细菌培养及药敏检测结果进行对比分析。结果近3年烧伤科检出病原菌以革兰阴性菌为主,检出率最高者为铜绿假单胞菌,其次为鲍曼不动杆菌、金黄色葡萄球菌。铜绿假单胞菌对多黏菌素B耐药率最低,为48.4%;鲍曼不动杆菌对替加环素耐药率最低,为48.8%;金黄色葡萄球菌对万古霉素耐药率最低,为5.3%。与1995-2000年的检测结果相比,革兰阴性菌检出率呈上升趋势,革兰阳性菌及真菌检出率呈下降趋势,且优势菌及其抗菌谱变化较大。结论中南大学湘雅三医院烧伤科病房近年来的细菌学分布有所变化,整体上呈现出多重耐药、高耐药性的特征,对临床控制和治疗耐药菌株感染提出了严峻的考验。%Obj ective Sum up the distribution of the pathogenic bacteria and the situation of antibiotic resistance during 2011-2013 in wards of the Burns Department of the Third Xiangya Hospital of Central South University to provide the latest epidemiological data , so as to optimize the regimen of clinical treatment .Method The data of bacteria culture and drug resistance profile of 2025 specimens from 1240 patients of burns department during 2011 to 2013 , was collected and analyzed in comparison with the counterpart data of 1995-2000 .Results The dominant detected bacteria in burns de-partment were Gram negative bacteria in recent 3 years.The top one is pseudomonas aeruginosa , followed by acinetobacter-baumannii and staphylococcus aureus .The lowest drug resistant ratio is:Pseudomonas aeruginosato polymyxin B , 48.4 %;Acinetobacterbaumannii to

  14. From the application of antibiotics to antibiotic residues in liquid manures and digestates: A screening study in one European center of conventional pig husbandry.

    Science.gov (United States)

    Widyasari-Mehta, Arum; Hartung, Susen; Kreuzig, Robert

    2016-07-15

    In conventional pig husbandry, antibiotics are frequently applied. Together with excreta, antibiotic residues enter liquid manures finally used as organic soil fertilizers or input materials for biogas plants. Therefore, this first screening study was performed to survey the application patterns of antibiotics from fall 2011 until spring 2013. Manures and digestates were then analyzed for selected antibiotic residues from spring 2012 to 2013. The data analysis of veterinary drug application documents revealed the use of 34 different antibiotics belonging to 11 substance classes at 21 farms under study. Antibiotics, particularly tetracyclines, frequently administered to larger pig groups were detected in manure samples up to higher mg kg(-1) dry weight (DW) concentrations. Antibiotic residues in digestates, furthermore, show that a full removal capacity cannot be guaranteed through the anaerobic digestion process in biogas plants. PMID:27088209

  15. Probiotic bacteria in prevention and treatment of diarrhea

    OpenAIRE

    Jasmina Havranek; Šimun Zamberlin; Iva Dolenčić Špehar; Tamara Prtilo; Milna Tudor; Dubravka Samaržija

    2009-01-01

    Probiotic bacteria have beneficial effects in prevention and treatment of different diseases. The results of preventive and therapeutic effect of probiotic bacteria on diarrhea during last ten years are shown in this paper. The greatest preventive and therapeutic effect of probiotic bacteria was identified for acute diarrhea in children caused by rotaviruses. Significant, but slightly lower effect of probiotic bacteria was proved for antibiotic associated diarrhea. Positive effect in preventi...

  16. Methanotrophic bacteria.

    OpenAIRE

    Hanson, R S; Hanson, T. E.

    1996-01-01

    Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehy...

  17. Adaptive Landscapes of Resistance Genes Change as Antibiotic Concentrations Change.

    Science.gov (United States)

    Mira, Portia M; Meza, Juan C; Nandipati, Anna; Barlow, Miriam

    2015-10-01

    Most studies on the evolution of antibiotic resistance are focused on selection for resistance at lethal antibiotic concentrations, which has allowed the detection of mutant strains that show strong phenotypic traits. However, solely focusing on lethal concentrations of antibiotics narrowly limits our perspective of antibiotic resistance evolution. New high-resolution competition assays have shown that resistant bacteria are selected at relatively low concentrations of antibiotics. This finding is important because sublethal concentrations of antibiotics are found widely in patients undergoing antibiotic therapies, and in nonmedical conditions such as wastewater treatment plants, and food and water used in agriculture and farming. To understand the impacts of sublethal concentrations on selection, we measured 30 adaptive landscapes for a set of TEM β-lactamases containing all combinations of the four amino acid substitutions that exist in TEM-50 for 15 β-lactam antibiotics at multiple concentrations. We found that there are many evolutionary pathways within this collection of landscapes that lead to nearly every TEM-genotype that we studied. While it is known that the pathways change depending on the type of β-lactam, this study demonstrates that the landscapes including fitness optima also change dramatically as the concentrations of antibiotics change. Based on these results we conclude that the presence of multiple concentrations of β-lactams in an environment result in many different adaptive landscapes through which pathways to nearly every genotype are available. Ultimately this may increase the diversity of genotypes in microbial populations. PMID:26113371

  18. Detection of antibiotic resistance in probiotics of dietary supplements

    KAUST Repository

    Wong, Aloysius Tze

    2015-09-14

    Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

  19. Antibiotic use and its consequences for the normal microbiome.

    Science.gov (United States)

    Blaser, Martin J

    2016-04-29

    Anti-infectives, including antibiotics, are essentially different from all other drugs; they not only affect the individual to whom they are given but also the entire community, through selection for resistance to their own action. Thus, their use resides at the intersection of personal and public health. Antibiotics can be likened to a four-edged sword against bacteria. The first two edges of the antibiotic sword were identified immediately after their discovery and deployment in that they not only benefit an individual in treating their infection but also benefit the community in preventing the spread of that infectious agent. The third edge was already recognized by Alexander Fleming in 1945 in his Nobel acceptance speech, which warned about the cost to the community of antibiotic resistance that would inevitably evolve and be selected for during clinical practice. We have seen this cost mount up, as resistance curtails or precludes the activities of some of our most effective drugs for clinically important infections. But the fourth edge of the antibiotic sword remained unappreciated until recently, i.e., the cost that an antibiotic exerts on an individual's own health via the collateral damage of the drug on bacteria that normally live on or in healthy humans: our microbiota. These organisms, their genes, metabolites, and interactions with one another, as well as with their host collectively, represent our microbiome. Our relationship with these symbiotic bacteria is especially important during the early years of life, when the adult microbiome has not yet formed. PMID:27126037

  20. Bacteria-Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen-Chi; Tolker-Nielsen, Tim;

    2014-01-01

    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... material is demonstrated by the bacteria‐triggered release of antibiotics to control bacterial populations and signaling molecules to modulate quorum sensing. The self‐regulating system provides the basis for the development of device‐relevant polymeric materials, which only release antibiotics in...... dependency of the titer of bacteria surrounding the medical device....