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Sample records for multiple antibiotic resistant

  1. Multiple antibiotic resistance in Rhizobium japonicum.

    PubMed

    Cole, M A; Elkan, G H

    1979-05-01

    A total of 48 strains of the soil bacterium Rhizobium japonicum were screened for their response to several widely used antibiotics. Over 60% of the strains were resistant to chloramphenicol, polymyxin B, and erythromycin, and 47% or more of the strains were resistant to neomycin and penicillin G, when tested by disk assay procedures. The most common grouping of resistances in strains was simultaneous resistance to tetracycline, penicillin G, neomycin, chloramphenicol, and streptomycin (25% of all strains tested). The occurrence of multiple drug resistance in a soil bacterium that is not a vertebrate pathogen suggests that chemotherapeutic use of antibiotics is not required for the development of multiple drug resistance. PMID:485137

  2. [Factors of multiple resistance to antibiotics in nodule bacteria].

    PubMed

    Pariĭskaia, A N; Gorelova, O P

    1976-01-01

    Multiple resistance to antibiotics (penicillin, levomycetin, neomycin, tetracycline) was found in 15% of collection strains of nodule bacteria and in strains isolated from natural environment. PMID:1050635

  3. Antibiotic Resistance

    MedlinePlus

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

  4. Antibiotic Resistance

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Antibiotic Resistance Share Tweet Linkedin Pin it More sharing options ... these products really help. To Learn More about Antibiotic Resistance Get Smart About Antibiotics (Video) Fact Sheets and ...

  5. Resistance-resistant antibiotics.

    PubMed

    Oldfield, Eric; Feng, Xinxin

    2014-12-01

    New antibiotics are needed because drug resistance is increasing while the introduction of new antibiotics is decreasing. We discuss here six possible approaches to develop 'resistance-resistant' antibiotics. First, multitarget inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy owing to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, repurposing existing drugs can lead to combinations of multitarget therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and, in some cases, suggest that sensitivity to existing antibiotics may be restored in otherwise drug-resistant organisms.

  6. Emergence of a Potent Multidrug Efflux Pump Variant That Enhances Campylobacter Resistance to Multiple Antibiotics

    PubMed Central

    Yao, Hong; Shen, Zhangqi; Wang, Yang; Deng, Fengru; Liu, Dejun; Naren, Gaowa; Dai, Lei; Su, Chih-Chia; Wang, Bing; Wang, Shaolin; Wu, Congming; Yu, Edward W.

    2016-01-01

    ABSTRACT Bacterial antibiotic efflux pumps are key players in antibiotic resistance. Although their role in conferring multidrug resistance is well documented, the emergence of “super” efflux pump variants that enhance bacterial resistance to multiple drugs has not been reported. Here, we describe the emergence of a resistance-enhancing variant (named RE-CmeABC) of the predominant efflux pump CmeABC in Campylobacter, a major zoonotic pathogen whose resistance to antibiotics is considered a serious antibiotic resistance threat in the United States. Compared to the previously characterized CmeABC transporters, RE-CmeABC is much more potent in conferring Campylobacter resistance to antibiotics, which was shown by increased MICs and reduced intracellular accumulation of antibiotics. Structural modeling suggests that sequence variations in the drug-binding pocket of CmeB possibly contribute to the enhanced efflux function. Additionally, RE-CmeABC expands the mutant selection window of ciprofloxacin, enhances the emergence of antibiotic-resistant mutants, and confers exceedingly high-level resistance to fluoroquinolones, an important class of antibiotics for clinical therapy of campylobacteriosis. Furthermore, RE-CmeABC is horizontally transferable, shifts antibiotic MIC distribution among clinical isolates, and is increasingly prevalent in Campylobacter jejuni isolates, suggesting that it confers a fitness advantage under antimicrobial selection. These findings reveal a new mechanism for enhanced multidrug resistance and an effective strategy utilized by bacteria for adaptation to selection from multiple antibiotics. PMID:27651364

  7. Association of metal tolerance with multiple antibiotic resistance of bacteria isolated from drinking water

    SciTech Connect

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

    1984-06-01

    Bacterial isolates from the drinking water system of an Oregon coastal community were examined to assess the association of metal tolerance with multiple antibiotic resistance. Positive correlations between tolerance to high levels of Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and multiple antibiotic resistance were noted among bacteria from distribution waters but not among bacteria from raw waters. Tolerances to higher levels of Al/sup 3 +/ and Sn/sup 2 +/ were demonstrated more often by raw water isolates which were not typically multiple antibiotic resistant. A similar incidence of tolerance to Cd/sup 2 +/ was demonstrated by isolates of both water types and was not associated with multiple antibiotic resistance. These results suggest that simultaneous selection phenomena occurred in distribution water for bacteria which exhibited unique patterns of tolerance to Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and antibiotic resistance.

  8. Resistance-Resistant Antibiotics

    PubMed Central

    Oldfield, Eric; Feng, Xinxin

    2014-01-01

    New antibiotics are needed because as drug resistance is increasing, the introduction of new antibiotics is decreasing. Here, we discuss six possible approaches to develop ‘resistance-resistant’ antibiotics. First, multi-target inhibitors in which a single compound inhibits more than one target may be easier to develop than conventional combination therapies with two new drugs. Second, inhibiting multiple targets in the same metabolic pathway is expected to be an effective strategy due to synergy. Third, discovering multiple-target inhibitors should be possible by using sequential virtual screening. Fourth, re-purposing existing drugs can lead to combinations of multi-target therapeutics. Fifth, targets need not be proteins. Sixth, inhibiting virulence factor formation and boosting innate immunity may also lead to decreased susceptibility to resistance. Although it is not possible to eliminate resistance, the approaches reviewed here offer several possibilities for reducing the effects of mutations and in some cases suggest that sensitivity to existing antibiotics may be restored, in otherwise drug resistant organisms. PMID:25458541

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

    PubMed

    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.

  10. Multiple antibiotic resistant Escherichia coli from a tropical rain forest stream

    SciTech Connect

    Carrasco, C.E.; Alvarez, H.J.; Ortiz, N.; Bisbal, M.; Arias, W.; Baerga, C.; Hazen, T.C.

    1988-12-31

    High densities of fecal coliforms were obtained from a pristine site and sewage contaminated site in a tropical rain forest watershed in Puerto Rico. Confirmation of fecal coliform isolates as Escherichia coli was significantly lower than for temperate waters. Antibiotic resistance and multiple antibiotic resistance were common for isolates at both sites; however, the site receiving sewage effluent had a greater proportion of multiple antibiotic resistant isolates. R. plasmids were recovered from 4 MAR isolates, 2 from each site. All recovered plasmids were approximately 1 kilobase. The recovered plasmid were also capable of transforming E. coli HB101 in vitro. The high concentrations of enterobacteriaceae, small R-plasmid size, R-plasmid transformability, and long term survival of fecal origin bacteria in tropical freshwater environments give increasing importance to adequate sewage treatment, and better indicator monitoring methods for tropical areas.

  11. Targeting Antibiotic Resistance

    PubMed Central

    Chellat, Mathieu F.; Raguž, Luka

    2016-01-01

    Abstract 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

  12. Mathematical modelling of bacterial resistance to multiple antibiotics and immune system response.

    PubMed

    Daşbaşı, Bahatdin; Öztürk, İlhan

    2016-01-01

    Resistance of developed bacteria to antibiotic treatment is a very important issue, because introduction of any new antibiotic is after a little while followed by the formation of resistant bacterial isolates in the clinic. The significant increase in clinical resistance to antibiotics is a troubling situation especially in nosocomial infections, where already defenseless patients can be unsuccessful to respond to treatment, causing even greater health issue. Nosocomial infections can be identified as those happening within 2 days of hospital acceptance, 3 days of discharge or 1 month of an operation. They influence 1 out of 10 patients admitted to hospital. Annually, this outcomes in 5000 deaths only in UK with a cost to the National Health Service of a billion pounds. Despite these problems, antibiotic therapy is still the most common method used to treat bacterial infections. On the other hand, it is often mentioned that immune system plays a major role in the progress of infections. In this context, we proposed a mathematical model defining population dynamics of both the specific immune cells produced according to the properties of bacteria by host and the bacteria exposed to multiple antibiotics synchronically, presuming that resistance is gained through mutations due to exposure to antibiotic. Qualitative analysis found out infection-free equilibrium point and other equilibrium points where resistant bacteria and immune system cells exist, only resistant bacteria exists and sensitive bacteria, resistant bacteria and immune system cells exist. As a result of this analysis, our model highlights the fact that when an individual's immune system weakens, he/she suffers more from the bacterial infections which are believed to have been confined or terminated. Also, these results was supported by numerical simulations.

  13. Characterization of a multiple antibiotic resistance plasmid from Haemophilus ducreyi.

    PubMed Central

    Willson, P J; Albritton, W L; Slaney, L; Setlow, J K

    1989-01-01

    Plasmid pLS88 from a clinical isolate of Haemophilus ducreyi encoded resistance determinants for sulfonamides and streptomycin related to those of RSF1010 and for kanamycin related to Tn903 but lacked the inverted repeats of the transposon. Its host range included Haemophilus influenzae, Actinobacillus pleuropneumoniae, and Escherichia coli; and it was compatible with pDM2 and RSF1010. Images PMID:2684012

  14. Facts about Antibiotic Resistance

    MedlinePlus

    ... Trends and Cost Español: Datos breves Facts about Antibiotic Resistance Antibiotic resistance has been called one of the world’s most ... antibiotic use is a key strategy to control antibiotic resistance. Antibiotic resistance in children is of particular concern ...

  15. High levels of multiple metal resistance and its correlation to antibiotic resistance in environmental isolates of Acinetobacter.

    PubMed

    Dhakephalkar, P K; Chopade, B A

    1994-01-01

    Forty strains of Acinetobacter were isolated from different environmental sources. All the strains were classified into four genospecies, i.e., A. baumannii (33 isolates), A. calcoaceticus (three isolates), A. junii (three isolates) and A. genospecies3 (one isolate). Susceptibility of these 40 strains to salts of 20 heavy metals and 18 antibiotics was tested by the agar dilution method. All environmental isolates of Acinetobacter were resistant to multiple metal ions (minimum 13 metal ions) while all but one of the strains were resistant to multiple antibiotics (minimum four antibiotics). The maximum number of strains were found to be sensitive to mercury (60% strains) while all strains were resistant to copper, lead, boron and tungsten even at 10 mM concentration. Salts of these four metal ions may be added to the growth medium to facilitate selective isolation of Acinetobacter. Rifampicin and nalidixic acid were the most toxic antibiotics, inhibiting 94.5 and 89.5% of the acinetobacters, respectively. A. genospecies3 was found to be the most resistant species, tolerating high concentrations of all the 20 metal ions and also to a greater number of antibiotics than any other species of Acinetobacter tested. An inhibitory concentration (10 mM) of Ni(2+) and Zn(2+) was observed to inhibit the growth of all of the clinical isolates but allowed the growth of the environmental isolates, facilitating the differentiation between pathogenic and non-pathogenic acinetobacters. PMID:8118175

  16. Pneumococcal resistance to antibiotics.

    PubMed Central

    Klugman, K P

    1990-01-01

    The geographic distribution of pneumococci resistant to one or more of the antibiotics penicillin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline appears to be expanding, and there exist foci of resistance to chloramphenicol and rifampin. Multiply resistant pneumococci are being encountered more commonly and are more often community acquired. Factors associated with infection caused by resistant pneumococci include young age, duration of hospitalization, infection with a pneumococcus of serogroup 6, 19, or 23 or serotype 14, and exposure to antibiotics to which the strain is resistant. At present, the most useful drugs for the management of resistant pneumococcal infections are cefotaxime, ceftriaxone, vancomycin, and rifampin. If the strains are susceptible, chloramphenicol may be useful as an alternative, less expensive agent. Appropriate interventions for the control of resistant pneumococcal outbreaks include investigation of the prevalence of resistant strains, isolation of patients, possible treatment of carriers, and reduction of usage of antibiotics to which the strain is resistant. The molecular mechanisms of penicillin resistance are related to the structure and function of penicillin-binding proteins, and the mechanisms of resistance to other agents involved in multiple resistance are being elucidated. Recognition is increasing of the standard screening procedure for penicillin resistance, using a 1-microgram oxacillin disk. PMID:2187594

  17. Conjugal Transfer of Plasmid-Borne Multiple Antibiotic Resistance in Streptococcus faecalis var. zymogenes

    PubMed Central

    Jacob, Alan E.; Hobbs, Susan J.

    1974-01-01

    A strain of Streptococcus faecalis var. zymogenes, designated JH1, had high-level resistance to the antibiotics streptomycin, kanamycin, neomycin, erythromycin, and tetracycline. These resistances were lost en bloc from approximately 0.1% of cells grown in nutrient broth at 45 C. The frequency of resistance loss was not increased by growth in the presence of the “curing” agents acriflavine or acridine orange, but after prolonged storage in nutrient agar 17% of cells became antibiotic sensitive. Covalently closed circular deoxyribonucleic acid (DNA) molecules were isolated from the parental strain and from antibiotic-sensitive segregants by using cesium chloride-ethidium bromide gradients. DNA molecular species were identified by using neutral sucrose gradients. Strain JH1 contained two covalently closed circular DNA species of molecular weights 50 × 106 and 38 × 106. An antibiotic-sensitive segregant, strain JH1-9, had lost the larger molecular species. A second sensitive segregant, strain JH1-5, had also lost the larger molecular species but a new molecular species of approximate molecular weight 6 × 106 was present. The antibiotic resistances that were curable from the parental strain were transferred to antibiotic-sensitive strains of S. faecalis and to strain JH1-9, during mixed incubation in nutrient broth at 37 C. Data to be described are interpreted to suggest that the transfer is by a conjugal mechanism. Analysis of the plasmid species in recipient clones showed that all had received the plasmid of molecular weight 50 × 106. Strain JH1-5 was not a good recipient. Analysis of one successful recipient clone of JH1-5 revealed that it had gained the 50 × 106 molecular weight plasmid but lost the 6 × 106 molecular weight species. These data are interpreted to mean that the multiple antibiotic resistance is borne by a transferable plasmid of 50 × 106 molecular weight, and that in clone JH1-5 this plasmid suffered a large deletion leaving only a 6

  18. Multiple antibiotic resistance in Pseudomonas aeruginosa: evidence for involvement of an efflux operon.

    PubMed Central

    Poole, K; Krebes, K; McNally, C; Neshat, S

    1993-01-01

    An outer membrane protein of 50 kDa (OprK) was overproduced in a siderophore-deficient mutant of Pseudomonas aeruginosa capable of growth on iron-deficient minimal medium containing 2,2'-dipyridyl (0.5 mM). The expression of OprK in the mutant (strain K385) was associated with enhanced resistance to a number of antimicrobial agents, including ciprofloxacin, nalidixic acid, tetracycline, chloramphenicol, and streptonigrin. OprK was inducible in the parent strain by growth under severe iron limitation, as provided, for example, by the addition of dipyridyl or ZnSO4 to the growth medium. The gene encoding OprK (previously identified as ORFC) forms part of an operon composed of three genes (ORFABC) implicated in the secretion of the siderophore pyoverdine. Mutants defective in ORFA, ORFB, or ORFC exhibited enhanced susceptibility to tetracycline, chloramphenicol, ciprofloxacin, streptonigrin, and dipyridyl, consistent with a role for the ORFABC operon in multiple antibiotic resistance in P. aeruginosa. Sequence analysis of ORFC (oprK) revealed that its product is homologous to a class of outer membrane proteins involved in export. Similarly, the products of ORFA and ORFB exhibit homology to previously described bacterial export proteins located in the cytoplasmic membrane. These data suggest that ORFA-ORFB-oprK (ORFC)-dependent drug efflux contributes to multiple antibiotic resistance in P. aeruginosa. We propose, therefore, the designation mexAB (multiple efflux) for ORFAB. Images PMID:8226684

  19. Antibiotics and Resistance: Glossary

    MedlinePlus

    ... induced by natural or human activity on the ecology and living organisms. Ecology The study of the relationships and interactions between ... antibiotics The Cost of Resistance Science of Resistance Ecology Antibiotics in Agriculture Antibacterial Agents Glossary References Web ...

  20. Reversibility of antibiotic resistance

    PubMed Central

    2014-01-01

    Although theoretically attractive, the reversibility of resistance has proven difficult in practice, even though antibiotic resistance mechanisms induce a fitness cost to the bacterium. Associated resistance to other antibiotics and compensatory mutations seem to ameliorate the effect of antibiotic interventions in the community. In this paper the current understanding of the concepts of reversibility of antibiotic resistance and the interventions performed in hospitals and in the community are reviewed. PMID:24836051

  1. Multiple Pathways of Genome Plasticity Leading to Development of Antibiotic Resistance

    PubMed Central

    Baharoglu, Zeynep; Garriss, Geneviève; Mazel, Didier

    2013-01-01

    The emergence of multi-resistant bacterial strains is a major source of concern and has been correlated with the widespread use of antibiotics. The origins of resistance are intensively studied and many mechanisms involved in resistance have been identified, such as exogenous gene acquisition by horizontal gene transfer (HGT), mutations in the targeted functions, and more recently, antibiotic tolerance through persistence. In this review, we focus on factors leading to integron rearrangements and gene capture facilitating antibiotic resistance acquisition, maintenance and spread. The role of stress responses, such as the SOS response, is discussed. PMID:27029305

  2. High prevalence of multiple-antibiotic-resistant (MAR) Escherichia coli in river bed sediments of the Apies River, South Africa.

    PubMed

    Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

    2015-10-01

    This study aimed at investigating the presence of antibiotic-resistant Escherichia coli in river bed sediments of the Apies River, Gauteng, South Africa, in order to better inform health management decisions designed to protect users of the river. Overall, 180 water and sediment samples were collected at 10 sites along the Apies River from January to February 2014. E. coli was enumerated using the Colilert® 18/Quanti-Tray® 2000 (IDEXX). Isolates were purified by streaking on eosin methylene blue agar followed by the indole test. Pure E. coli isolates were tested for resistance to nine antibiotics by the Kirby-Bauer disc diffusion method. Over 98% of the isolates were resistant to at least one of the antibiotics tested. The highest resistance was observed against nitrofurantoin (sediments) and ampicillin (water). Over 80% of all resistant isolates showed multiple antibiotic resistance (resistance to ≥3 antibiotics). The abundance of E. coli in the sediments not only adds to the evidence that sediments are a reservoir for bacteria and possibly other pathogens including antibiotic-resistant bacteria but also suggests that antibiotic-resistant genes could be transferred to pathogens due to the high prevalence of multiple-antibiotic-resistant (MAR) strains of E. coli observed in the sediment. Using untreated water from the Apies River following resuspension for drinking and other household purposes could pose serious health risks for users. Our results suggest that river bed sediments could serve as reservoirs for MAR bacteria including pathogens under different climatic conditions and their analysis could provide information of public health concerns.

  3. High prevalence of multiple-antibiotic-resistant (MAR) Escherichia coli in river bed sediments of the Apies River, South Africa.

    PubMed

    Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

    2015-10-01

    This study aimed at investigating the presence of antibiotic-resistant Escherichia coli in river bed sediments of the Apies River, Gauteng, South Africa, in order to better inform health management decisions designed to protect users of the river. Overall, 180 water and sediment samples were collected at 10 sites along the Apies River from January to February 2014. E. coli was enumerated using the Colilert® 18/Quanti-Tray® 2000 (IDEXX). Isolates were purified by streaking on eosin methylene blue agar followed by the indole test. Pure E. coli isolates were tested for resistance to nine antibiotics by the Kirby-Bauer disc diffusion method. Over 98% of the isolates were resistant to at least one of the antibiotics tested. The highest resistance was observed against nitrofurantoin (sediments) and ampicillin (water). Over 80% of all resistant isolates showed multiple antibiotic resistance (resistance to ≥3 antibiotics). The abundance of E. coli in the sediments not only adds to the evidence that sediments are a reservoir for bacteria and possibly other pathogens including antibiotic-resistant bacteria but also suggests that antibiotic-resistant genes could be transferred to pathogens due to the high prevalence of multiple-antibiotic-resistant (MAR) strains of E. coli observed in the sediment. Using untreated water from the Apies River following resuspension for drinking and other household purposes could pose serious health risks for users. Our results suggest that river bed sediments could serve as reservoirs for MAR bacteria including pathogens under different climatic conditions and their analysis could provide information of public health concerns. PMID:26419380

  4. Multiple antibiotic resistance of heterotrophic bacteria isolated from Siberian lakes subjected to differing degrees of anthropogenic impact.

    PubMed

    Lobova, Tatiana I; Feil, Edward J; Popova, Lyudmila Yu

    2011-12-01

    The antibiotic resistance profiles of 150 heterotrophic bacterial isolates recovered from two lakes in Southern Siberia was determined to examine the effect of anthropogenic disturbance on aquatic ecosystems. Resistance was detected in at least one strain for seven of the eight antibiotics tested, the exception being amikacin. Resistance to antibiotics predominated in the areas of the lakes likely to be under highest anthropogenic disturbance. Resistance was more frequently observed among isolates recovered from within the proximity to a tourist resort (Lake Shira; 63% of bacteria with multiple antibiotic resistance (MAR) in the resort part), or the shore line (Lake Shunet; 100% of bacteria with MAR) than among isolates from the center of each lake; 42.5% of bacteria with MAR from Lake Shira and 25%/75% of bacteria are resistant to three/four antibiotics consequently from Lake Shunet. Plasmid profiles were determined from a sample of 37 multiply resistant bacteria, and between one and four plasmids were isolated from each isolate; the plasmids ranged in size from 2.3 to 23.1 kb. These observations are consistent with anthropogenic disturbance playing one of the key roles in the dissemination of antibiotic resistance in the aquatic ecosystems.

  5. Plasmid metagenomics reveals multiple antibiotic resistance gene classes among the gut microbiomes of hospitalised patients.

    PubMed

    Jitwasinkul, Tossawan; Suriyaphol, Prapat; Tangphatsornruang, Sithichoke; Hansen, Martin Asser; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes; Permpikul, Chairat; Rongrungruang, Yong; Tribuddharat, Chanwit

    2016-09-01

    Antibiotic resistance genes are rapidly spread between pathogens and the normal flora, with plasmids playing an important role in their circulation. This study aimed to investigate antibiotic resistance plasmids in the gut microbiome of hospitalised patients. Stool samples were collected from seven inpatients at Siriraj Hospital (Bangkok, Thailand) and were compared with a sample from a healthy volunteer. Plasmids from the gut microbiomes extracted from the stool samples were subjected to high-throughput DNA sequencing (GS Junior). Newbler-assembled DNA reads were categorised into known and unknown sequences (using >80% alignment length as the cut-off), and ResFinder was used to classify the antibiotic resistance gene pools. Plasmid replicon modules were used for plasmid typing. Forty-six genes conferring resistance to several classes of antibiotics were identified in the stool samples. Several antibiotic resistance genes were shared by the patients; interestingly, most were reported previously in food animals and healthy humans. Four antibiotic resistance genes were found in the healthy subject. One gene (aph3-III) was identified in the patients and the healthy subject and was related to that in cattle. Uncommon genes of hospital origin such as blaTEM-124-like and fosA, which confer resistance to extended-spectrum β-lactams and fosfomycin, respectively, were identified. The resistance genes did not match the patients' drug treatments. In conclusion, several plasmid types were identified in the gut microbiome; however, it was difficult to link these to the antibiotic resistance genes identified. That the antibiotic resistance genes came from hospital and community environments is worrying. PMID:27530840

  6. Plasmid metagenomics reveals multiple antibiotic resistance gene classes among the gut microbiomes of hospitalised patients.

    PubMed

    Jitwasinkul, Tossawan; Suriyaphol, Prapat; Tangphatsornruang, Sithichoke; Hansen, Martin Asser; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes; Permpikul, Chairat; Rongrungruang, Yong; Tribuddharat, Chanwit

    2016-09-01

    Antibiotic resistance genes are rapidly spread between pathogens and the normal flora, with plasmids playing an important role in their circulation. This study aimed to investigate antibiotic resistance plasmids in the gut microbiome of hospitalised patients. Stool samples were collected from seven inpatients at Siriraj Hospital (Bangkok, Thailand) and were compared with a sample from a healthy volunteer. Plasmids from the gut microbiomes extracted from the stool samples were subjected to high-throughput DNA sequencing (GS Junior). Newbler-assembled DNA reads were categorised into known and unknown sequences (using >80% alignment length as the cut-off), and ResFinder was used to classify the antibiotic resistance gene pools. Plasmid replicon modules were used for plasmid typing. Forty-six genes conferring resistance to several classes of antibiotics were identified in the stool samples. Several antibiotic resistance genes were shared by the patients; interestingly, most were reported previously in food animals and healthy humans. Four antibiotic resistance genes were found in the healthy subject. One gene (aph3-III) was identified in the patients and the healthy subject and was related to that in cattle. Uncommon genes of hospital origin such as blaTEM-124-like and fosA, which confer resistance to extended-spectrum β-lactams and fosfomycin, respectively, were identified. The resistance genes did not match the patients' drug treatments. In conclusion, several plasmid types were identified in the gut microbiome; however, it was difficult to link these to the antibiotic resistance genes identified. That the antibiotic resistance genes came from hospital and community environments is worrying.

  7. Control of infection with multiple antibiotic resistant bacteria in a hospital renal unit: the value of plasmid characterization.

    PubMed Central

    Reed, C. S.; Barrett, S. P.; Threlfall, E. J.; Cheasty, T.

    1995-01-01

    An outbreak of infections due to multiple antibiotic-resistant bacteria took place over a period of approximately 18 months in a renal unit. Strains of Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Citrobacter spp. and Pseudomonas spp. were involved, and a variety of antibiotic resistances was encountered. Closely related plasmids encoding resistance to aztreonam, ceftazidime and piperacillin, possibly derived from an archetypal plasmid of 105 kb were found in the majority of isolates examined. After limiting the use of aztreonam the incidence of new patient isolates of multiple-resistant organisms was greatly reduced. This study demonstrated how molecular studies can contribute to the control of an outbreak situation in a hospital unit by providing an impetus to reduce the use of specific antibiotics. Images Fig. 2 PMID:7641839

  8. [Correlation between multiple antibiotic resistance and heavy-metal tolerance among some E.coli strains isolated from polluted waters].

    PubMed

    Lazăr, Veronica; Cernat, Ramona; Balotescu, Carmen; Cotar, Ani; Coipan, Elena; Cojocaru, Cristina

    2002-01-01

    Self-transmissible plasmids conferring multiple antibiotic resistance are wide-spread in coliforms populations. In soil and water, multiple antibiotic resistance is clearly associated with resistance/tolerance to heavy-metals (Hg2+, Cu2+, Pb2+, Zn2+, Ca2+). For different genera the genes for heavy-metals resistance are often plasmid encoded. Since these genes are clustered on the same plasmids, heavy-metals and drugs are environmental factors which exert a selective pressure for the populations of these plasmid-harboring bacteria. The aim of this preliminary study was to find possible correlation between resistance genotype determined by genetic analysis and antibiotic and heavy-metal resistance patterns of 12 E. coli strains isolated from chronically polluted waters. Antimicrobial susceptibility testing was performed for ampicillin, tetracycline, gentamycin, kanamycin, chloramphenicol, ceftazidime and cefotaxime by standard disk diffusion Kirby-Bauer method following NCCLS recommendations. These antibiotics were chosen because of their wide-spread use and importance in the treatment of Gram-negative bacterial infections. MICs values of antibiotics and heavy-metals were determined by dilution method in Mueller-Hinton broth using an inoculum of about 1-2 x 10(8) CFU/ml. The concentration range for antimicrobials and heavy-metals salts (CuSO4, CdCl2, Co(NO3)2, Cr(NO3)3, HgCl2, NiCl2 and ZnSO4) was 0.06-64 [symbol: see text] g/ml, 0.5-256 [symbol: see text] g/ml respectively. Plasmid DNA was isolated from E. coli strains by an alkaline lysis. Genetic characterization was performed by agarose gel electrophoresis and spectrophotometric analysis. All strains are multiple antibiotic resistant, 16% of them being resistant to 3, 4 and 6 antibiotics, 32% to 5 and 8% to all 7 antibiotics, respectively. Multiple tolerance to high levels of Cd2+, Cu2+, Cr3+ and Ni2+ was common among multiple antibioresistant strains. Screening for plasmids relieved the presence of several

  9. Antibiotic Resistance Questions and Answers

    MedlinePlus

    ... on the Farm Get Smart About Antibiotics Week Antibiotic Resistance Questions and Answers Language: English Español (Spanish) Recommend ... Many ear infections Top of Page Questions about Antibiotic Resistance Examples of How Antibiotic Resistance Spreads Click for ...

  10. A multiple antibiotic-resistant enterobacter cloacae strain isolated from a bioethanol fermentation facility.

    PubMed

    Murphree, Colin A; Li, Qing; Heist, E Patrick; Moe, Luke A

    2014-09-17

    An Enterobacter cloacae strain (E. cloacae F3S3) that was collected as part of a project to assess antibiotic resistance among bacteria isolated from bioethanol fermentation facilities demonstrated high levels of resistance to antibiotics added prophylactically to bioethanol fermentors. PCR assays revealed the presence of canonical genes encoding resistance to penicillin (ampC) and erythromycin (ermG). Assays measuring biofilm formation under antibiotic stress indicated that erythromycin induced biofilm formation in E. cloacae F3S3. Planktonic growth and biofilm formation were observed at a high ethanol content, indicating E. cloacae F3S3 can persist in a bioethanol fermentor under the highly variable environmental conditions found in fermentors. PMID:24941895

  11. Genetic relationship between soxRS and mar loci in promoting multiple antibiotic resistance in Escherichia coli.

    PubMed Central

    Miller, P F; Gambino, L F; Sulavik, M C; Gracheck, S J

    1994-01-01

    Multiple antibiotic resistance in Escherichia coli has typically been associated with mutations at the mar locus, located at 34 min on the E. coli chromosome. A new mutant, marC, isolated on the basis of a Mar phenotype but which maps to the soxRS (encoding the regulators of the superoxide stress response) locus located at 92 min, is described here. This mutant shares several features with a known constitutive allele of the soxRS gene, prompting the conclusion that it is a highly active allele of this gene. The marC mutation has thus been given the designation soxR201. This new mutant was used to examine the relationship between the mar and sox loci in promoting antibiotic resistance. The results of these studies indicate that full antibiotic resistance resulting from the soxR201 mutation is partially dependent on an intact mar locus and is associated with an increase in the steady-state level of mar-specific mRNA. In addition, paraquat treatment of wild-type cells is shown to increase the level of antibiotic resistance in a dose-dependent manner that requires an intact soxRS locus. Conversely, overexpression of MarA from a multicopy plasmid results in weak activation of a superoxide stress response target gene. These findings are consistent with a model in which the regulatory factors encoded by the marA and soxS genes control the expression of overlapping sets of target genes, with MarA preferentially acting on targets involved with antibiotic resistance and SoxS directed primarily towards components of the superoxide stress response. Furthermore, compounds frequently used to induce the superoxide stress response, including paraquat, menadione, and phenazine methosulfate, differ with respect to the amount of protection provided against them by the antibiotic resistance response. Images PMID:7986007

  12. Antibiotic-Resistant Bacteria.

    ERIC Educational Resources Information Center

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

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

  13. High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment.

    PubMed

    Ozaktas, Tugba; Taskin, Bilgin; Gozen, Ayse G

    2012-12-01

    Freshwater fish, Alburnus alburnus (bleak), were captured from Lake Mogan, situated in Ankara, during spring. The surface mucus of the fish was collected and associated bacteria were cultured and isolated. By sequencing PCR-amplified 16S RNA encoding genes, the isolates were identified as members of 12 different genera: Acinetobacter, Aeromonas, Bacillus, Brevundimonas, Gordonia, Kocuria, Microbacterium, Mycobacterium, Pseudomonas, Rhodococcus, and Staphylococcus, in addition to one strain that was unidentified. The mucus-dwelling bacterial isolates were tested for resistance against ampicillin, kanamycin, streptomycin and chloramphenicol. About 95% of the isolates were found to be resistant to ampicillin, 93% to chloramphenicol, and 88% to kanamycin and streptomycin. A Microbacterium oxydans and the unidentified environmental isolate were resistant to all four antibiotics tested at very high levels (>1600 μg/ml ampicillin and streptomycin; >1120 μg/ml kanamycin; >960 μg/ml chloramphenicol). Only a Kocuria sp. was sensitive to all four antibiotics at the lowest concentrations tested (3.10 μg/ml ampicillin and streptomycin; 2.15 μg/ml kanamycin; 1.85 μg/ml chloramphenicol). The rest of the isolates showed different resistance levels. Plasmid isolations were carried out to determine if the multiple antibiotic resistance could be attributed to the presence of plasmids. However, no plasmid was detected in any of the isolates. The resistance appeared to be mediated by chromosome-associated functions. This study indicated that multiple antibiotic resistance at moderate to high levels is common among the current phenotypes of the fish mucus-dwelling bacterial populations in this temperate, shallow lake which has not been subjected to any aquaculturing so far but under anthropogenic effect being in a recreational area. PMID:23039919

  14. Genome Sequence of a Novel Multiple-Antibiotic-Resistant Member of the Erysipelotrichaceae Family Isolated from a Swine Manure Storage Pit.

    PubMed

    Haley, Bradd J; Kim, Seon Woo; Whitehead, Terence R

    2016-01-01

    The swine gastrointestinal tract and stored swine manure may serve as reservoirs of antibiotic resistance genes, as well as sources of novel bacteria. Here, we report the draft genome sequence of a novel taxon in the Erysipelotrichaceae family, isolated from a swine manure storage pit that is resistant to multiple antibiotics. PMID:27660777

  15. Genome Sequence of a Novel Multiple-Antibiotic-Resistant Member of the Erysipelotrichaceae Family Isolated from a Swine Manure Storage Pit

    PubMed Central

    Haley, Bradd J.; Kim, Seon Woo

    2016-01-01

    The swine gastrointestinal tract and stored swine manure may serve as reservoirs of antibiotic resistance genes, as well as sources of novel bacteria. Here, we report the draft genome sequence of a novel taxon in the Erysipelotrichaceae family, isolated from a swine manure storage pit that is resistant to multiple antibiotics. PMID:27660777

  16. Genome Sequence of a Novel Multiple-Antibiotic-Resistant Member of the Erysipelotrichaceae Family Isolated from a Swine Manure Storage Pit.

    PubMed

    Haley, Bradd J; Kim, Seon Woo; Whitehead, Terence R

    2016-09-22

    The swine gastrointestinal tract and stored swine manure may serve as reservoirs of antibiotic resistance genes, as well as sources of novel bacteria. Here, we report the draft genome sequence of a novel taxon in the Erysipelotrichaceae family, isolated from a swine manure storage pit that is resistant to multiple antibiotics.

  17. The Transmission and Antibiotic Resistance Variation in a Multiple Drug Resistance Clade of Vibrio cholerae Circulating in Multiple Countries in Asia.

    PubMed

    Pang, Bo; Du, Pengcheng; Zhou, Zhemin; Diao, Baowei; Cui, Zhigang; Zhou, Haijian; Kan, Biao

    2016-01-01

    Vibrio cholerae has caused massive outbreaks and even trans-continental epidemics. In 2008 and 2010, at least 3 remarkable cholera outbreaks occurred in Hainan, Anhui and Jiangsu provinces of China. To address the possible transmissions and the relationships to the 7th pandemic strains of those 3 outbreaks, we sequenced the whole genomes of the outbreak isolates and compared with the global isolates from the 7th pandemic. The three outbreaks in this study were caused by a cluster of V. cholerae in clade 3.B which is parallel to the clade 3.C that was transmitted from Nepal to Haiti and caused an outbreak in 2010. Pan-genome analysis provided additional evolution information on the mobile element and acquired multiple antibiotic resistance genes. We suggested that clade 3.B should be monitored because the multiple antibiotic resistant characteristics of this clade and the 'amplifier' function of China in the global transmission of current Cholera pandemic. We also show that dedicated whole genome sequencing analysis provided more information than the previous techniques and should be applied in the disease surveillance networks. PMID:26930352

  18. The Transmission and Antibiotic Resistance Variation in a Multiple Drug Resistance Clade of Vibrio cholerae Circulating in Multiple Countries in Asia

    PubMed Central

    Zhou, Zhemin; Diao, Baowei; Cui, Zhigang; Zhou, Haijian; Kan, Biao

    2016-01-01

    Vibrio cholerae has caused massive outbreaks and even trans-continental epidemics. In 2008 and 2010, at least 3 remarkable cholera outbreaks occurred in Hainan, Anhui and Jiangsu provinces of China. To address the possible transmissions and the relationships to the 7th pandemic strains of those 3 outbreaks, we sequenced the whole genomes of the outbreak isolates and compared with the global isolates from the 7th pandemic. The three outbreaks in this study were caused by a cluster of V. cholerae in clade 3.B which is parallel to the clade 3.C that was transmitted from Nepal to Haiti and caused an outbreak in 2010. Pan-genome analysis provided additional evolution information on the mobile element and acquired multiple antibiotic resistance genes. We suggested that clade 3.B should be monitored because the multiple antibiotic resistant characteristics of this clade and the ‘amplifier’ function of China in the global transmission of current Cholera pandemic. We also show that dedicated whole genome sequencing analysis provided more information than the previous techniques and should be applied in the disease surveillance networks. PMID:26930352

  19. The Transmission and Antibiotic Resistance Variation in a Multiple Drug Resistance Clade of Vibrio cholerae Circulating in Multiple Countries in Asia.

    PubMed

    Pang, Bo; Du, Pengcheng; Zhou, Zhemin; Diao, Baowei; Cui, Zhigang; Zhou, Haijian; Kan, Biao

    2016-01-01

    Vibrio cholerae has caused massive outbreaks and even trans-continental epidemics. In 2008 and 2010, at least 3 remarkable cholera outbreaks occurred in Hainan, Anhui and Jiangsu provinces of China. To address the possible transmissions and the relationships to the 7th pandemic strains of those 3 outbreaks, we sequenced the whole genomes of the outbreak isolates and compared with the global isolates from the 7th pandemic. The three outbreaks in this study were caused by a cluster of V. cholerae in clade 3.B which is parallel to the clade 3.C that was transmitted from Nepal to Haiti and caused an outbreak in 2010. Pan-genome analysis provided additional evolution information on the mobile element and acquired multiple antibiotic resistance genes. We suggested that clade 3.B should be monitored because the multiple antibiotic resistant characteristics of this clade and the 'amplifier' function of China in the global transmission of current Cholera pandemic. We also show that dedicated whole genome sequencing analysis provided more information than the previous techniques and should be applied in the disease surveillance networks.

  20. Natural hot spots for gain of multiple resistances: arsenic and antibiotic resistances in heterotrophic, aerobic bacteria from marine hydrothermal vent fields.

    PubMed

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

    2015-04-01

    Microorganisms are responsible for multiple antibiotic resistances that have been associated with resistance/tolerance to heavy metals, with consequences to public health. Many genes conferring these resistances are located on mobile genetic elements, easily exchanged among phylogenetically distant bacteria. The objective of the present work was to isolate arsenic-, antimonite-, and antibiotic-resistant strains and to determine the existence of plasmids harboring antibiotic/arsenic/antimonite resistance traits in phenotypically resistant strains, in a nonanthropogenically impacted environment. The hydrothermal Lucky Strike field in the Azores archipelago (North Atlantic, between 11°N and 38°N), at the Mid-Atlantic Ridge, protected under the OSPAR Convention, was sampled as a metal-rich pristine environment. A total of 35 strains from 8 different species were isolated in the presence of arsenate, arsenite, and antimonite. ACR3 and arsB genes were amplified from the sediment's total DNA, and 4 isolates also carried ACR3 genes. Phenotypic multiple resistances were found in all strains, and 7 strains had recoverable plasmids. Purified plasmids were sequenced by Illumina and assembled by EDENA V3, and contig annotation was performed using the "Rapid Annotation using the Subsystems Technology" server. Determinants of resistance to copper, zinc, cadmium, cobalt, and chromium as well as to the antibiotics β-lactams and fluoroquinolones were found in the 3 sequenced plasmids. Genes coding for heavy metal resistance and antibiotic resistance in the same mobile element were found, suggesting the possibility of horizontal gene transfer and distribution of theses resistances in the bacterial population. PMID:25636836

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

    PubMed Central

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

    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 resistance traits in phenotypically resistant strains, in a nonanthropogenically impacted environment. The hydrothermal Lucky Strike field in the Azores archipelago (North Atlantic, between 11°N and 38°N), at the Mid-Atlantic Ridge, protected under the OSPAR Convention, was sampled as a metal-rich pristine environment. A total of 35 strains from 8 different species were isolated in the presence of arsenate, arsenite, and antimonite. ACR3 and arsB genes were amplified from the sediment's total DNA, and 4 isolates also carried ACR3 genes. Phenotypic multiple resistances were found in all strains, and 7 strains had recoverable plasmids. Purified plasmids were sequenced by Illumina and assembled by EDENA V3, and contig annotation was performed using the “Rapid Annotation using the Subsystems Technology” server. Determinants of resistance to copper, zinc, cadmium, cobalt, and chromium as well as to the antibiotics β-lactams and fluoroquinolones were found in the 3 sequenced plasmids. Genes coding for heavy metal resistance and antibiotic resistance in the same mobile element were found, suggesting the possibility of horizontal gene transfer and distribution of theses resistances in the bacterial population. PMID:25636836

  2. Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of faecal contamination of water.

    PubMed

    Titilawo, Yinka; Sibanda, Timothy; Obi, Larry; Okoh, Anthony

    2015-07-01

    We evaluated the antibiogram profile of Escherichia coli (n = 300) isolated from selected rivers in Osun State, Nigeria. The identities of the E. coli isolates were confirmed by polymerase chain reaction (PCR) technique. Susceptibility of the isolates to 20 antibiotics conventionally used in clinical cases was assessed in vitro by the standardized agar disc-diffusion method. All the isolates were susceptible to imipenem, meropenem, amikacin and gatilofloxacin. The isolates were variously susceptible to the other antibiotics as follows: ciprofloxacin (96 %), kanamycin (95 %), neomycin (92 %), streptomycin (84 %), chloramphenicol (73 %), nalidixic acid (66 %), nitrofurantoin (64 %), gentamycin (63 %), doxycycline (58 %), cefepime (57 %), tetracycline (49 %) and cephalothin (42 %). The multiple antibiotic resistance indexing ranged from 0.50 to 0.80 for all the sampling locations and exceeded the threshold value of 0.2, suggesting the origin of the isolates to be of high antimicrobial usage. Our findings signify an increase in the incidence of antimicrobial resistance of E. coli towards conventionally used antibiotics necessitating proper surveillance programmes towards the monitoring of antimicrobial resistance determinants in water bodies. PMID:25779106

  3. Resistance to Antibiotics Mediated by Target Alterations

    NASA Astrophysics Data System (ADS)

    Spratt, Brian G.

    1994-04-01

    The development of resistance to antibiotics by reductions in the affinities of their enzymatic targets occurs most rapidly for antibiotics that inactivate a single target and that are not analogs of substrate. In these cases of resistance (for example, resistance to rifampicin), numerous single amino acid substitutions may provide large decreases in the affinity of the target for the antibiotic, leading to clinically significant levels of resistance. Resistance due to target alterations should occur much more slowly for those antibiotics (penicillin, for example) that inactivate multiple targets irreversibly by acting as close analogs of substrate. Resistance to penicillin because of target changes has emerged, by unexpected mechanisms, only in a limited number of species. However, inactivating enzymes commonly provide resistance to antibiotics that, like penicillin, are derived from natural products, although such enzymes have not been found for synthetic antibiotics. Thus, the ideal antibiotic would be produced by rational design, rather than by the modification of a natural product.

  4. Multiple Antibiotic-resistant Bacteria on Fluted Pumpkin Leaves, a Herb of Therapeutic Value

    PubMed Central

    Abdu, Abdulrasheed B.

    2014-01-01

    ABSTRACT 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

  5. Mechanisms of Antibiotic Resistance

    PubMed Central

    Munita, Jose M.; Arias, Cesar A.

    2015-01-01

    Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have emerged not only in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic “attack” is the prime example of bacterial adaptation and the pinnacle of evolution. “Survival of the fittest” is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice providing specific examples in relevant bacterial pathogens. PMID:27227291

  6. Mechanisms of Antibiotic Resistance.

    PubMed

    Munita, Jose M; Arias, Cesar A

    2016-04-01

    Emergence of resistance among the most important bacterial pathogens is recognized as a major public health threat affecting humans worldwide. Multidrug-resistant organisms have not only emerged in the hospital environment but are now often identified in community settings, suggesting that reservoirs of antibiotic-resistant bacteria are present outside the hospital. The bacterial response to the antibiotic "attack" is the prime example of bacterial adaptation and the pinnacle of evolution. "Survival of the fittest" is a consequence of an immense genetic plasticity of bacterial pathogens that trigger specific responses that result in mutational adaptations, acquisition of genetic material, or alteration of gene expression producing resistance to virtually all antibiotics currently available in clinical practice. Therefore, understanding the biochemical and genetic basis of resistance is of paramount importance to design strategies to curtail the emergence and spread of resistance and to devise innovative therapeutic approaches against multidrug-resistant organisms. In this chapter, we will describe in detail the major mechanisms of antibiotic resistance encountered in clinical practice, providing specific examples in relevant bacterial pathogens. PMID:27227291

  7. Origins and Evolution of Antibiotic Resistance

    PubMed Central

    Davies, Julian; Davies, Dorothy

    2010-01-01

    Summary: Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise. This review presents the salient aspects of antibiotic resistance development over the past half-century, with the oft-restated conclusion that it is time to act. To achieve complete restitution of therapeutic applications of antibiotics, there is a need for more information on the role of environmental microbiomes in the rise of antibiotic resistance. In particular, creative approaches to the discovery of novel antibiotics and their expedited and controlled introduction to therapy are obligatory. PMID:20805405

  8. Tn6026 and Tn6029 are found in complex resistance regions mobilised by diverse plasmids and chromosomal islands in multiple antibiotic resistant Enterobacteriaceae.

    PubMed

    Reid, Cameron J; Roy Chowdhury, Piklu; Djordjevic, Steven P

    2015-07-01

    Transposons flanked by direct copies of IS26 are important contributors to the evolution of multiple antibiotic resistance. Tn6029 and Tn6026 are examples of composite transposons that have become widely disseminated on small and large plasmids with different incompatibility markers in pathogenic and commensal Escherichia coli and various serovars of Salmonella enterica. Some of the plasmids that harbour these transposons also carry combinations of virulence genes. Recently, Tn6029 and Tn6026 and derivatives thereof have been found on chromosomal islands in both established and recently emerged pathogens. While Tn6029 and Tn6026 carry genes encoding resistance to older generation antibiotics, they also provide a scaffold for the introduction of genes encoding resistance to a wide variety of clinically relevant antibiotics that are mobilised by IS26. As a consequence, Tn6029 and Tn6026 or variants are likely to increasingly feature in complex resistance regions in multiple antibiotic resistant Enterobacteriaceae that threaten the health of humans and food production animals.

  9. Multiple strategies to activate gold nanoparticles as antibiotics.

    PubMed

    Zhao, Yuyun; Jiang, Xingyu

    2013-09-21

    Widespread antibiotic resistance calls for new strategies. Nanotechnology provides a chance to overcome antibiotic resistance by multiple antibiotic mechanisms. This paper reviews the progress in activating gold nanoparticles with nonantibiotic or antibiotic molecules to combat bacterial resistance, analyzes the gap between experimental achievements and real clinical application, and suggests some potential directions in developing antibacterial nanodrugs.

  10. Multiple strategies to activate gold nanoparticles as antibiotics

    NASA Astrophysics Data System (ADS)

    Zhao, Yuyun; Jiang, Xingyu

    2013-08-01

    Widespread antibiotic resistance calls for new strategies. Nanotechnology provides a chance to overcome antibiotic resistance by multiple antibiotic mechanisms. This paper reviews the progress in activating gold nanoparticles with nonantibiotic or antibiotic molecules to combat bacterial resistance, analyzes the gap between experimental achievements and real clinical application, and suggests some potential directions in developing antibacterial nanodrugs.

  11. Tackling antibiotic resistance.

    PubMed

    Bush, Karen; Courvalin, Patrice; Dantas, Gautam; Davies, Julian; Eisenstein, Barry; Huovinen, Pentti; Jacoby, George A; Kishony, Roy; Kreiswirth, Barry N; Kutter, Elizabeth; Lerner, Stephen A; Levy, Stuart; Lewis, Kim; Lomovskaya, Olga; Miller, Jeffrey H; Mobashery, Shahriar; Piddock, Laura J V; Projan, Steven; Thomas, Christopher M; Tomasz, Alexander; Tulkens, Paul M; Walsh, Timothy R; Watson, James D; Witkowski, Jan; Witte, Wolfgang; Wright, Gerry; Yeh, Pamela; Zgurskaya, Helen I

    2011-11-02

    The development and spread of antibiotic resistance in bacteria is a universal threat to both humans and animals that is generally not preventable but can nevertheless be controlled, and it must be tackled in the most effective ways possible. To explore how the problem of antibiotic resistance might best be addressed, a group of 30 scientists from academia and industry gathered at the Banbury Conference Centre in Cold Spring Harbor, New York, USA, from 16 to 18 May 2011. From these discussions there emerged a priority list of steps that need to be taken to resolve this global crisis.

  12. Tackling antibiotic resistance

    PubMed Central

    Bush, Karen; Courvalin, Patrice; Dantas, Gautam; Davies, Julian; Eisenstein, Barry; Huovinen, Pentti; Jacoby, George A.; Kishony, Roy; Kreiswirth, Barry N.; Kutter, Elizabeth; Lerner, Stephen A.; Levy, Stuart; Lewis, Kim; Lomovskaya, Olga; Miller, Jeffrey H.; Mobashery, Shahriar; Piddock, Laura J. V.; Projan, Steven; Thomas, Christopher M.; Tomasz, Alexander; Tulkens, Paul M.; Walsh, Timothy R.; Watson, James D.; Witkowski, Jan; Witte, Wolfgang; Wright, Gerry; Yeh, Pamela; Zgurskaya, Helen I.

    2014-01-01

    The development and spread of antibiotic resistance in bacteria is a universal threat to both humans and animals that is generally not preventable, but can nevertheless be controlled and must be tackled in the most effective ways possible. To explore how the problem of antibiotic resistance might best be addressed, a group of thirty scientists from academia and industry gathered at the Banbury Conference Centre in Cold Spring Harbor, New York, May 16-18, 2011. From these discussions emerged a priority list of steps that need to be taken to resolve this global crisis. PMID:22048738

  13. Swarming populations of Salmonella represent a unique physiological state coupled to multiple mechanisms of antibiotic resistance

    PubMed Central

    Kim, Wook

    2003-01-01

    Salmonella enterica serovar Typhimurium is capable of swarming over semi-solid surfaces. Although its swarming behavior shares many readily observable similarities with other swarming bacteria, the phenomenon remains somewhat of an enigma in this bacterium since some attributes skew away from the better characterized systems. Swarming is quite distinct from the classic swimming motility, as there is a prerequisite for cells to first undergo a morphological transformation into swarmer cells. In some organisms, swarming is controlled by quorum sensing, and in others, swarming has been shown to be coupled to increased expression of important virulence factors. Swarming in serovar Typhimurium is coupled to elevated resistance to a wide variety of structurally and functionally distinct classes of antimicrobial compounds. As serovar Typhimurium differentiates into swarm cells, the pmrHFIJKLM operon is up-regulated, resulting in a more positively charged LPS core. Furthermore, as swarm cells begin to de-differentiate, the pmr operon expression is down-regulated, rapidly reaching the levels observed in swim cells. This is one potential mechanism which confers swarm cells increased resistance to antibiotics such as the cationic antimicrobial peptides. However, additional mechanisms are likely associated with the cells in the swarm state that confer elevated resistance to such a broad spectrum of antimicrobial agents. PMID:14615815

  14. Genome sequence of a novel multiple antibiotic resistant member of Erysipelotrichaceae family isolated from a swine manure storage pit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The swine gastro intestinal (GI) tract and stored manure may serve as reservoirs of antibiotic resistance genes as well as sources of novel bacteria. We report the draft genome sequence of “Cottaibacterium suis” strain MTC7, a novel antibiotic resistant bacterium. The strain was isolated from a swin...

  15. Investigating the Antibiotic Resistance Problem.

    ERIC Educational Resources Information Center

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

    Seeks to give teachers useful information on the extent of the problem of antibiotic-resistant bacteria, mechanisms bacteria use to resist antibiotics, the causes of the emergence of antibiotic-resistant organisms, and practices that can prevent or reverse this trend. Contains 19 references. (DDR)

  16. Strategies to Minimize Antibiotic Resistance

    PubMed Central

    Lee, Chang-Ro; Cho, Ill Hwan; Jeong, Byeong Chul; Lee, Sang Hee

    2013-01-01

    Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs) and various data such as pharmacokinetic (PK) and pharmacodynamic (PD) properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST), clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care), the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students) regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing). The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics. PMID:24036486

  17. Surveillance of antibiotic resistance

    PubMed Central

    Johnson, Alan P.

    2015-01-01

    Surveillance involves the collection and analysis of data for the detection and monitoring of threats to public health. Surveillance should also inform as to the epidemiology of the threat and its burden in the population. A further key component of surveillance is the timely feedback of data to stakeholders with a view to generating action aimed at reducing or preventing the public health threat being monitored. Surveillance of antibiotic resistance involves the collection of antibiotic susceptibility test results undertaken by microbiology laboratories on bacteria isolated from clinical samples sent for investigation. Correlation of these data with demographic and clinical data for the patient populations from whom the pathogens were isolated gives insight into the underlying epidemiology and facilitates the formulation of rational interventions aimed at reducing the burden of resistance. This article describes a range of surveillance activities that have been undertaken in the UK over a number of years, together with current interventions being implemented. These activities are not only of national importance but form part of the international response to the global threat posed by antibiotic resistance. PMID:25918439

  18. Antibiotic resistance: an ecological imbalance.

    PubMed

    Levy, S B

    1997-01-01

    Antibiotic resistance thwarts the treatment of infectious diseases worldwide. Although a number of factors can be identified which contribute to the problem, clearly the antibiotic as a selective agent and the resistance gene as the vehicle of resistance are the two most important, making up a 'drug resistance equation'. Both are needed in order for a clinical problem to arise. Given sufficient time and quantity of antibiotic, drug resistance will eventually appear. But a public health problem is not inevitable if the two components of the drug resistance equation are kept in check. Enhancing the emergence of resistance is the case by which resistance determinants and resistant bacteria can spread locally and globally, selected by widespread use of the same antibiotics in people, animal husbandry and agriculture. Antibiotics are societal drugs. Each individual use contributes to the sum total of society's antibiotic exposure. In a broader sense, the resistance problem is ecological. In the framework of natural competition between susceptible and resistant bacteria, antibiotic use has encouraged growth of the resistant strains, leading to an imbalance in prior relationships between susceptible and resistant bacteria. To restore efficacy to earlier antibiotics and to maintain the success of new antibiotics that are introduced, we need to use antibiotics in a way which assures an ecological balance that favours the predominance of susceptible bacterial flora.

  19. Nanoparticles functionalized with ampicillin destroy multiple-antibiotic-resistant isolates of Pseudomonas aeruginosa and Enterobacter aerogenes and methicillin-resistant Staphylococcus aureus.

    PubMed

    Brown, Ashley N; Smith, Kathryn; Samuels, Tova A; Lu, Jiangrui; Obare, Sherine O; Scott, Maria E

    2012-04-01

    We show here that silver nanoparticles (AgNP) were intrinsically antibacterial, whereas gold nanoparticles (AuNP) were antimicrobial only when ampicillin was bound to their surfaces. Both AuNP and AgNP functionalized with ampicillin were effective broad-spectrum bactericides against Gram-negative and Gram-positive bacteria. Most importantly, when AuNP and AgNP were functionalized with ampicillin they became potent bactericidal agents with unique properties that subverted antibiotic resistance mechanisms of multiple-drug-resistant bacteria.

  20. Genome Sequence of the Multiple-β-Lactam-Antibiotic-Resistant Bacterium Acidovorax sp. Strain MR-S7.

    PubMed

    Miura, Takamasa; Kusada, Hiroyuki; Kamagata, Yoichi; Hanada, Satoshi; Kimura, Nobutada

    2013-06-27

    Acidovorax sp. strain MR-S7 was isolated from activated sludge in a treatment system for wastewater containing β-lactam antibiotic pollutants. Strain MR-S7 demonstrates multidrug resistance for various types of β-lactam antibiotics at high levels of MIC. The draft genome sequence clarified that strain MR-S7 harbors unique β-lactamase genes.

  1. Bacterial cheating limits antibiotic resistance

    NASA Astrophysics Data System (ADS)

    Xiao Chao, Hui; Yurtsev, Eugene; Datta, Manoshi; Artemova, Tanya; Gore, Jeff

    2012-02-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain---which does not contribute to breaking down the antibiotic---may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors.

  2. The Comprehensive Antibiotic Resistance Database

    PubMed Central

    McArthur, Andrew G.; Waglechner, Nicholas; Nizam, Fazmin; Yan, Austin; Azad, Marisa A.; Baylay, Alison J.; Bhullar, Kirandeep; Canova, Marc J.; De Pascale, Gianfranco; Ejim, Linda; Kalan, Lindsay; King, Andrew M.; Koteva, Kalinka; Morar, Mariya; Mulvey, Michael R.; O'Brien, Jonathan S.; Pawlowski, Andrew C.; Piddock, Laura J. V.; Spanogiannopoulos, Peter; Sutherland, Arlene D.; Tang, Irene; Taylor, Patricia L.; Thaker, Maulik; Wang, Wenliang; Yan, Marie; Yu, Tennison

    2013-01-01

    The field of antibiotic drug discovery and the monitoring of new antibiotic resistance elements have yet to fully exploit the power of the genome revolution. Despite the fact that the first genomes sequenced of free living organisms were those of bacteria, there have been few specialized bioinformatic tools developed to mine the growing amount of genomic data associated with pathogens. In particular, there are few tools to study the genetics and genomics of antibiotic resistance and how it impacts bacterial populations, ecology, and the clinic. We have initiated development of such tools in the form of the Comprehensive Antibiotic Research Database (CARD; http://arpcard.mcmaster.ca). The CARD integrates disparate molecular and sequence data, provides a unique organizing principle in the form of the Antibiotic Resistance Ontology (ARO), and can quickly identify putative antibiotic resistance genes in new unannotated genome sequences. This unique platform provides an informatic tool that bridges antibiotic resistance concerns in health care, agriculture, and the environment. PMID:23650175

  3. Antibiotic resistance in wild birds

    PubMed Central

    Bonnedahl, Jonas

    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 studies of the spatial and temporal distribution of resistant bacteria in wild birds, we can better assess their role and thereby help to mitigate the increasing global problem of antibiotic resistance. PMID:24697355

  4. Antibiotic resistance in wild birds.

    PubMed

    Bonnedahl, Jonas; Järhult, Josef D

    2014-05-01

    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 studies of the spatial and temporal distribution of resistant bacteria in wild birds, we can better assess their role and thereby help to mitigate the increasing global problem of antibiotic resistance. PMID:24697355

  5. The Prehistory of Antibiotic Resistance.

    PubMed

    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

  6. Antibiotic resistance in pediatric urology

    PubMed Central

    Copp, Hillary L.

    2014-01-01

    Antibiotics are a mainstay in the treatment of bacterial infections, though their use is a primary risk factor for the development of antibiotic resistance. Antibiotic resistance is a growing problem in pediatric urology as demonstrated by increased uropathogen resistance. Lack of urine testing, nonselective use of prophylaxis, and poor empiric prescribing practices exacerbate this problem. This article reviews antibiotic utilization in pediatric urology with emphasis on modifiable practice patterns to potentially help mitigate the growing rates of antibiotic resistance. This includes urine testing to only treat when indicated and tailor broad-spectrum therapy as able; selective application of antibiotic prophylaxis to patients with high-grade vesicoureteral reflux and hydronephrosis with counseling regarding the importance of compliance; and using local antiobiograms, particularly pediatric-specific antiobiograms, with inpatient versus outpatient data. PMID:24688601

  7. Epidemic Typhoid in Vietnam: Molecular Typing of Multiple-Antibiotic-Resistant Salmonella enterica Serotype Typhi from Four Outbreaks

    PubMed Central

    Connerton, Phillippa; Wain, John; Hien, Tran T.; Ali, Tahir; Parry, Christopher; Chinh, Nguyen T.; Vinh, Ha; Ho, Vo A.; Diep, To S.; Day, Nicholas P. J.; White, Nicholas J.; Dougan, Gordon; Farrar, Jeremy J.

    2000-01-01

    Multidrug-resistant Salmonella enterica serotype Typhi isolates from four outbreaks of typhoid fever in southern Vietnam between 1993 and 1997 were compared. Pulsed-field gel electrophoresis, bacteriophage and plasmid typing, and antibiotic susceptibilities showed that independent outbreaks of multidrug-resistant typhoid fever in southern Vietnam are caused by single bacterial strains. However, different outbreaks do not derive from the clonal expansion of a single multidrug-resistant serotype Typhi strain. PMID:10655411

  8. Emergence of antibiotic-resistant extremophiles (AREs).

    PubMed

    Gabani, Prashant; Prakash, Dhan; Singh, Om V

    2012-09-01

    Excessive use of antibiotics in recent years has produced bacteria that are resistant to a wide array of antibiotics. Several genetic and non-genetic elements allow microorganisms to adapt and thrive under harsh environmental conditions such as lethal doses of antibiotics. We attempt to classify these microorganisms as antibiotic-resistant extremophiles (AREs). AREs develop strategies to gain greater resistance to antibiotics via accumulation of multiple genes or plasmids that harbor genes for multiple drug resistance (MDR). In addition to their altered expression of multiple genes, AREs also survive by producing enzymes such as penicillinase that inactivate antibiotics. It is of interest to identify the underlying molecular mechanisms by which the AREs are able to survive in the presence of wide arrays of high-dosage antibiotics. Technologically, "omics"-based approaches such as genomics have revealed a wide array of genes differentially expressed in AREs. Proteomics studies with 2DE, MALDI-TOF, and MS/MS have identified specific proteins, enzymes, and pumps that function in the adaptation mechanisms of AREs. This article discusses the molecular mechanisms by which microorganisms develop into AREs and how "omics" approaches can identify the genetic elements of these adaptation mechanisms. These objectives will assist the development of strategies and potential therapeutics to treat outbreaks of pathogenic microorganisms in the future.

  9. Combating Antibiotic Resistance

    MedlinePlus

    ... for infectious diseases. back to top Antibiotics Fight Bacteria, Not Viruses Antibiotics are meant to be used ... treat strep throat, which is caused by streptococcal bacteria, and skin infections caused by staphylococcal bacteria. Although ...

  10. Fighting antibiotic resistance in the intensive care unit using antibiotics.

    PubMed

    Plantinga, Nienke L; Wittekamp, Bastiaan H J; van Duijn, Pleun J; Bonten, Marc J M

    2015-01-01

    Antibiotic resistance is a global and increasing problem that is not counterbalanced by the development of new therapeutic agents. The prevalence of antibiotic resistance is especially high in intensive care units with frequently reported outbreaks of multidrug-resistant organisms. In addition to classical infection prevention protocols and surveillance programs, counterintuitive interventions, such as selective decontamination with antibiotics and antibiotic rotation have been applied and investigated to control the emergence of antibiotic resistance. This review provides an overview of selective oropharyngeal and digestive tract decontamination, decolonization of methicillin-resistant Staphylococcus aureus and antibiotic rotation as strategies to modulate antibiotic resistance in the intensive care unit.

  11. Antibiotic resistant in microorganisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Therapeutic strategies to combat antibiotic resistance.

    PubMed

    Brooks, Benjamin D; Brooks, Amanda E

    2014-11-30

    With multidrug resistant bacteria on the rise, new antibiotic approaches are required. Although a number of new small molecule antibiotics are currently in the development pipeline with many more in preclinical development, the clinical options and practices for infection control must be expanded. Biologics and non-antibiotic adjuvants offer this opportunity for expansion. Nevertheless, to avoid known mechanisms of resistance, intelligent combination approaches for multiple simultaneous and complimentary therapies must be designed. Combination approaches should extend beyond biologically active molecules to include smart controlled delivery strategies. Infection control must integrate antimicrobial stewardship, new antibiotic molecules, biologics, and delivery strategies into effective combination therapies designed to 1) fight the infection, 2) avoid resistance, and 3) protect the natural microbiome. This review explores these developing strategies in the context of circumventing current mechanisms of resistance. PMID:25450262

  13. Therapeutic strategies to combat antibiotic resistance.

    PubMed

    Brooks, Benjamin D; Brooks, Amanda E

    2014-11-30

    With multidrug resistant bacteria on the rise, new antibiotic approaches are required. Although a number of new small molecule antibiotics are currently in the development pipeline with many more in preclinical development, the clinical options and practices for infection control must be expanded. Biologics and non-antibiotic adjuvants offer this opportunity for expansion. Nevertheless, to avoid known mechanisms of resistance, intelligent combination approaches for multiple simultaneous and complimentary therapies must be designed. Combination approaches should extend beyond biologically active molecules to include smart controlled delivery strategies. Infection control must integrate antimicrobial stewardship, new antibiotic molecules, biologics, and delivery strategies into effective combination therapies designed to 1) fight the infection, 2) avoid resistance, and 3) protect the natural microbiome. This review explores these developing strategies in the context of circumventing current mechanisms of resistance.

  14. Efflux Pump Overexpression in Multiple-Antibiotic-Resistant Mutants of Bacteroides fragilis

    PubMed Central

    Pumbwe, Lilian; Glass, Daniel; Wexler, Hannah M.

    2006-01-01

    Multidrug-resistant mutants of a wild-type Bacteroides fragilis strain (strain ADB77) and a quadruple resistance nodulation division family efflux pump deletion mutant (ADB77 ΔbmeB1 ΔbmeB3 ΔbmeB12 ΔbmeB15) were selected with antimicrobials. Ampicillin, doripenem, imipenem, levofloxacin, and metronidazole selected for mutants from both strains; cefoxitin selected for mutants from strain ADB77 only; and sodium dodecyl sulfate selected mutants from ADB77ΔbmeB1 ΔbmeB3 ΔbmeB12 ΔbmeB15 only. The mutants overexpressed one or more efflux pumps. PMID:16940115

  15. Reservoirs of antibiotic resistance genes.

    PubMed

    Salyers, Abigail; Shoemaker, Nadja B

    2006-01-01

    A potential concern about the use of antibiotics in animal husbundary is that, as antibiotic resistant bacteria move from the farm into the human diet, they may pass antibiotic resistance genes to bacteria that normally reside in a the human intestinal tract and from there to bacteria that cause human disease (reservoir hypothesis). In this article various approaches to evaluating the risk of agricultural use of antibiotics are assessed critically. In addition, the potential benefits of applying new technology and using new insights from the field of microbial ecology are explained.

  16. Antibiotic preparations contain DNA: a source of drug resistance genes?

    PubMed Central

    Webb, V; Davies, J

    1993-01-01

    Fluorescence measurements and polymerase chain reaction amplification of streptomycete 16S ribosomal DNA sequences were used to show that a number of antibiotic preparations employed for human and animal use are contaminated with chromosomal DNA of the antibiotic-producing organism. The DNA contains identifiable antibiotic resistance gene sequences; the uptake of this DNA by bacteria and its functional incorporation into bacterial replicons would lead to the generation of antibiotic resistance determinants. We propose that the presence of DNA encoding drug resistance in antibiotic preparations has been a factor in the rapid development of multiple antibiotic resistance in bacteria. Images PMID:8285621

  17. Cloning, expression, crystallization and preliminary X-ray analysis of a putative multiple antibiotic resistance repressor protein (MarR) from Xanthomonas campestris

    SciTech Connect

    Tu, Zhi-Le; Li, Juo-Ning; Chin, Ko-Hsin; Chou, Chia-Cheng; Lee, Cheng-Chung; Shr, Hui-Lin; Lyu, Ping-Chiang; Gao, Fei Philip; Wang, Andrew H.-J.; Chou, Shan-Ho

    2005-07-01

    A putative repressor for the multiple antibiotic resistance operon from a plant pathogen X. campestris pv. campestris has been overexpressed in E. coli, purified and crystallized. The crystals diffracted to 2.3 Å with good quality. The multiple antibiotic resistance operon (marRAB) is a member of the multidrug-resistance system. When induced, this operon enhances resistance of bacteria to a variety of medically important antibiotics, causing a serious global health problem. MarR is a marR-encoded protein that represses the transcription of the marRAB operon. Through binding with salicylate and certain antibiotics, however, MarR can derepress and activate the marRAB operon. In this report, the cloning, expression, crystallization and preliminary X-ray analysis of XC1739, a putative MarR repressor protein present in the Xanthomonas campestris pv. campestris, a Gram-negative bacterium causing major worldwide disease of cruciferous crops, are described. The XC1739 crystals diffracted to a resolution of at least 1.8 Å. They are orthorhombic and belong to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 39.5, b = 54.2 and c = 139.5 Å, respectively. They contain two molecules in the asymmetric unit from calculation of the self-rotation function.

  18. [Antibiotic resistance: A global crisis].

    PubMed

    Alós, Juan-Ignacio

    2015-12-01

    The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics.

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

    PubMed

    Ogan, M T; Nwiika, D E

    1993-05-01

    The ecology of multiple antibiotic resistant (MAR) bacteria in the fresh-waters of the lower Niger Delta was studied in the Port Harcourt area, Rivers State. On the basis of decreasing pollution levels three zones, A, B, C, were recognized. Cell recovery by two viable count media, casein-peptone-starch (CPS) and plate count (PC) agar containing chloramphenicol, tetracycline, penicillin, streptomycin or ampicillin were compared in an initial study. Higher numbers of antibiotic resistant (AR) bacteria were recovered on CPS containing tetracycline, penicillin, streptomycin and ampicillin from the faecally-polluted New Calabar River (zone A) than on SPC agar containing similar antibiotics but the reverse was observed for forest stream (zone B) samples. Differences between the two media were also observed at individual sample sites. The proportions of strains of AR bacteria resistant to their primary isolation antibiotic varied from 55% (zone B) to 72% in the least polluted Isiokpo and Elele-Alimini streams (zone C), for ampicillin, and mostly < 50% for the other drugs in each zone. Thirty bacterial strains purified from the prevent colonial types on the count media without antibiotics included mainly species of Bacillus (12) and enterobacteria (18). Between five and 10 strains were resistant to > or = three antibiotics; seven were resistant to all five. The antibiograms of most strains were variable and depended on the method of drug application (discs or incorporation into agar), media and temperature of incubation (25 degrees, 37 degrees or 44.5 degrees C). Twenty-one strains were consistently resistant to ampicillin by the two methods; 10 to 19 were consistent for chloramphenicol, tetracycline and penicillin.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Suppression of antibiotic resistance acquisition by combined use of antibiotics.

    PubMed

    Suzuki, Shingo; Horinouchi, Takaaki; Furusawa, Chikara

    2015-10-01

    We analyzed the effect of combinatorial use of antibiotics with a trade-off relationship of resistance, i.e., resistance acquisition to one drug causes susceptibility to the other drug, and vice versa, on the evolution of antibiotic resistance. We demonstrated that this combinatorial use of antibiotics significantly suppressed the acquisition of resistance.

  1. Antibiotic-Resistant Vibrios in Farmed Shrimp

    PubMed Central

    Albuquerque Costa, Renata; Araújo, Rayza Lima; Souza, Oscarina Viana; Vieira, Regine Helena Silva dos Fernandes

    2015-01-01

    Antimicrobial susceptibility pattern was determined in 100 strains of Vibrio isolated from the Litopenaeus vannamei shrimp and identified phenotypically. A high antibiotic-resistance index (75%) was observed, with the following phenotypic profiles: monoresistance (n = 42), cross-resistance to β-lactams (n = 20) and multiple resistance (n = 13). Plasmid resistance was characterized for penicillin (n = 11), penicillin + ampicillin (n = 1), penicillin + aztreonam (n = 1), and ampicillin (n = 1). Resistance to antimicrobial drugs by the other strains (n = 86) was possibly mediated by chromosomal genes. The findings of this study support the conclusion that the cultured shrimps can be vehicles of vibrios resistant to β-lactam and tetracycline. PMID:25918714

  2. Antibiotic-resistant vibrios in farmed shrimp.

    PubMed

    Albuquerque Costa, Renata; Araújo, Rayza Lima; Souza, Oscarina Viana; Vieira, Regine Helena Silva dos Fernandes

    2015-01-01

    Antimicrobial susceptibility pattern was determined in 100 strains of Vibrio isolated from the Litopenaeus vannamei shrimp and identified phenotypically. A high antibiotic-resistance index (75%) was observed, with the following phenotypic profiles: monoresistance (n = 42), cross-resistance to β-lactams (n = 20) and multiple resistance (n = 13). Plasmid resistance was characterized for penicillin (n = 11), penicillin + ampicillin (n = 1), penicillin + aztreonam (n = 1), and ampicillin (n = 1). Resistance to antimicrobial drugs by the other strains (n = 86) was possibly mediated by chromosomal genes. The findings of this study support the conclusion that the cultured shrimps can be vehicles of vibrios resistant to β-lactam and tetracycline.

  3. Expanding multiple antibiotic resistance among clinical strains of Vibrio cholerae isolated from 1992-7 in Calcutta, India.

    PubMed Central

    Garg, P.; Chakraborty, S.; Basu, I.; Datta, S.; Rajendran, K.; Bhattacharya, T.; Yamasaki, S.; Bhattacharya, S. K.; Takeda, Y.; Nair, G. B.; Ramamurthy, T.

    2000-01-01

    Antimicrobial susceptibilities of Vibrio cholerae strains isolated from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India for 6 years were analysed to determine the changing trends; 840 V. cholerae strains isolated in 1992-1997 were included in this study. Among V. cholerae serogoup O1 and O139, ampicillin resistance increased from 1992 (35 and 70%, respectively) to 1997 (both serogroups 100%). Resistance to furazolidone and streptomycin was constantly high among V. cholerae O1 strains with gradual increase in resistance to other drugs such as ciprofloxacin, co-trimoxazole, neomycin and nalidixic acid. V. cholerae O139 strains exhibited susceptibilities to furazolidone and streptomycin comparable with those of O1 strains. However, after initial increase in resistance to chloramphenicol and co-trimoxazole, all the V. cholerae O139 strains became susceptible to these two drugs from 1995 onwards. Both V. cholerae O1 and O139 remained largely susceptible to gentamicin and tetracycline. V. cholerae non-O1, non-O139 strains, in contrast, exhibited high levels of resistance to virtually every class of antimicrobial agents tested in this study especially from 1995. Kruskal-Wallis one-way analysis showed that V. cholerae O1 Ogawa serogroup exhibited significant yearly increase in resistance to nine antibiotics followed by non-O1 non-O139 and O139 strains to six antibiotics and two antibiotics respectively. Interesting observation encountered in this study was the dissipation of some of the resistant patterns commonly found among V. cholerae non-O1 non-O139 or O1 serogroups to the O139 serogroup and vice versa during the succeeding years. PMID:10982062

  4. Antibiotic / Antimicrobial Resistance Glossary

    MedlinePlus

    ... on the Farm Get Smart About Antibiotics Week File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel ...

  5. RAC: Repository of Antibiotic resistance Cassettes

    PubMed Central

    Tsafnat, Guy; Copty, Joseph; Partridge, Sally R.

    2011-01-01

    Antibiotic resistance in bacteria is often due to acquisition of resistance genes associated with different mobile genetic elements. In Gram-negative bacteria, many resistance genes are found as part of small mobile genetic elements called gene cassettes, generally found integrated into larger elements called integrons. Integrons carrying antibiotic resistance gene cassettes are often associated with mobile elements and here are designated ‘mobile resistance integrons’ (MRIs). More than one cassette can be inserted in the same integron to create arrays that contribute to the spread of multi-resistance. In many sequences in databases such as GenBank, only the genes within cassettes, rather than whole cassettes, are annotated and the same gene/cassette may be given different names in different entries, hampering analysis. We have developed the Repository of Antibiotic resistance Cassettes (RAC) website to provide an archive of gene cassettes that includes alternative gene names from multiple nomenclature systems and allows the community to contribute new cassettes. RAC also offers an additional function that allows users to submit sequences containing cassettes or arrays for annotation using the automatic annotation system Attacca. Attacca recognizes features (gene cassettes, integron regions) and identifies cassette arrays as patterns of features and can also distinguish minor cassette variants that may encode different resistance phenotypes (aacA4 cassettes and bla cassettes-encoding β-lactamases). Gaps in annotations are manually reviewed and those found to correspond to novel cassettes are assigned unique names. While there are other websites dedicated to integrons or antibiotic resistance genes, none includes a complete list of antibiotic resistance gene cassettes in MRI or offers consistent annotation and appropriate naming of all of these cassettes in submitted sequences. RAC thus provides a unique resource for researchers, which should reduce confusion

  6. Antibiotic resistance: An ethical challenge.

    PubMed

    Littmann, Jasper; Buyx, Alena; Cars, Otto

    2015-10-01

    In this paper, we argue that antibiotic resistance (ABR) raises a number of ethical problems that have not yet been sufficiently addressed. We outline four areas in which ethical issues that arise in relation to ABR are particularly pressing. First, the emergence of multidrug-resistant and extensively drug-resistant infections exacerbates traditional ethical challenges of infectious disease control, such as the restriction of individual liberty for the protection of the public's health. Second, ABR raises issues of global distributive justice, both with regard to the overuse and lack of access to antibiotics. Third, the use of antibiotics in veterinary medicine raises serious concerns for animal welfare and sustainable farming practices. Finally, the diminishing effectiveness of antibiotics leads to questions about intergenerational justice and our responsibility for the wellbeing of future generations. We suggest that current policy discussions should take ethical conflicts into account and engage openly with the challenges that we outline in this paper.

  7. Antibiotic resistance in soil and water environments.

    PubMed

    Esiobu, Nwadiuto; Armenta, Lisa; Ike, Joseph

    2002-06-01

    Seven locations were screened for antibiotic-resistant bacteria using a modified agar dilution technique. Isolates resistant to high levels of antibiotics were screened for r plasmids. Low-level resistance (25 micro g x ml(-1)) was widespread for ampicillin, penicillin, tetracycline, vancomycin and streptomycin but not for kanamycin. Resistant populations dropped sharply at high antibiotic levels, suggesting that intrinsic non-emergent mechanisms were responsible for the multiple drug resistance exhibited at low doses. Dairy farm manure contained significantly (P < 0.01) more (%) resistant bacteria than the other sites. Bacteria isolated from a dairy water canal, a lake by a hospital and a residential garden (fertilized by farm manure) displayed resistance frequencies of 77, 75 and 70%, respectively. Incidence of tetracycline resistance was most prevalent at 47-89% of total bacteria. Out of 200 representative isolates analyzed, Pseudomonas, Enterococcus-like bacteria, Enterobacter and Burkholderia species constituted the dominant reservoirs of resistance at high drug levels (50-170 micro g x ml(-1)). Plasmids were detected in only 29% (58) of these bacteria with tetracycline resistance accounting for 65% of the plasmid pool. Overall, resistance trends correlated to the abundance and type of bacterial species present in the habitat. Environmental reservoirs of resistance include opportunistic pathogens and constitute some public health concern. PMID:12396530

  8. Antibiotic resistance in probiotic bacteria

    PubMed Central

    Gueimonde, Miguel; Sánchez, Borja; G. de los Reyes-Gavilán, Clara; Margolles, Abelardo

    2013-01-01

    Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue. PMID:23882264

  9. The multifaceted roles of antibiotics and antibiotic resistance in nature

    PubMed Central

    Sengupta, Saswati; Chattopadhyay, Madhab K.; Grossart, Hans-Peter

    2013-01-01

    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 sub-inhibitory concentrations acting as signaling molecules supporting the process of 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 behavior 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 the genes that confer resistance to antibiotics

  10. Multiple Genetic Analysis System-Based Antibiotic Susceptibility Testing in Helicobacter pylori and High Eradication Rate With Phenotypic Resistance-Guided Quadruple Therapy.

    PubMed

    Dong, Fangyuan; Ji, Danian; Huang, Renxiang; Zhang, Fan; Huang, Yiqin; Xiang, Ping; Kong, Mimi; Nan, Li; Zeng, Xianping; Wu, Yong; Bao, Zhijun

    2015-11-01

    Antibiotics resistance in Helicobacter pylori (H. pylori) is the major factor for eradication failure. Molecular tests including fluorescence in situ hybridization, PCR-restriction fragment length polymorphism, and dual priming oligonucleotide-PCR (DPO-PCR) play critical roles in the detection of antibiotic susceptibility; however, limited knowledge is known about application of multiple genetic analysis system (MGAS) in the area of H. pylori identification and antibiotics resistance detection.The aim of this study is to determine the antibiotics resistance using different molecular tests and evaluate the treatment outcomes of E-test-based genotypic resistance.A total of 297 patients with dyspepsia complaint were recruited for gastroscopies. Ninety patients with H. pylori culture positive were randomly divided into 2 groups (test group and control group). E-test, general PCR, and MGAS assay were performed in test group. Patients in control group were treated with empirical therapy (rabeprazole + bismuth potassium citrate + amoxicillin [AMX] + clarithromycin [CLR]), whereas patients in test group received quadruple therapy based on E-test results twice daily for 14 consecutive days. The eradication effect of H. pylori was confirmed by C-urea breath test after at least 4 weeks when treatment was finished.Rapid urease test showed 46.5% (128/297) patients with H. pylori infection, whereas 30.3% (90/297) patients were H. pylori culture positive. E-test showed that H. pylori primary resistance rate to CLR, AMX, metronidazole, tetracycline, and levofloxacin (LVX) was 40.0% (18/45), 4.4% (2/45), 53.3% (24/45), 0% (0/45), and 55.6% (25/45), respectively. In addition, there are many multidrug resistant (MDR) phenotypes, and the MDR strains have higher minimum inhibitory concentration than their single-drug resistant counterparts. Considering E-test as the reference test, the sensitivities of general PCR and MGAS in detecting CLR resistance were 83.3% (15/18) and 94.4% (17

  11. Multiple Genetic Analysis System-Based Antibiotic Susceptibility Testing in Helicobacter pylori and High Eradication Rate With Phenotypic Resistance-Guided Quadruple Therapy

    PubMed Central

    Dong, Fangyuan; Ji, Danian; Huang, Renxiang; Zhang, Fan; Huang, Yiqin; Xiang, Ping; Kong, Mimi; Nan, Li; Zeng, Xianping; Wu, Yong; Bao, Zhijun

    2015-01-01

    Abstract Antibiotics resistance in Helicobacter pylori (H. pylori) is the major factor for eradication failure. Molecular tests including fluorescence in situ hybridization, PCR-restriction fragment length polymorphism, and dual priming oligonucleotide-PCR (DPO-PCR) play critical roles in the detection of antibiotic susceptibility; however, limited knowledge is known about application of multiple genetic analysis system (MGAS) in the area of H. pylori identification and antibiotics resistance detection. The aim of this study is to determine the antibiotics resistance using different molecular tests and evaluate the treatment outcomes of E-test-based genotypic resistance. A total of 297 patients with dyspepsia complaint were recruited for gastroscopies. Ninety patients with H. pylori culture positive were randomly divided into 2 groups (test group and control group). E-test, general PCR, and MGAS assay were performed in test group. Patients in control group were treated with empirical therapy (rabeprazole + bismuth potassium citrate + amoxicillin [AMX] + clarithromycin [CLR]), whereas patients in test group received quadruple therapy based on E-test results twice daily for 14 consecutive days. The eradication effect of H. pylori was confirmed by 13C-urea breath test after at least 4 weeks when treatment was finished. Rapid urease test showed 46.5% (128/297) patients with H. pylori infection, whereas 30.3% (90/297) patients were H. pylori culture positive. E-test showed that H. pylori primary resistance rate to CLR, AMX, metronidazole, tetracycline, and levofloxacin (LVX) was 40.0% (18/45), 4.4% (2/45), 53.3% (24/45), 0% (0/45), and 55.6% (25/45), respectively. In addition, there are many multidrug resistant (MDR) phenotypes, and the MDR strains have higher minimum inhibitory concentration than their single-drug resistant counterparts. Considering E-test as the reference test, the sensitivities of general PCR and MGAS in detecting CLR resistance were 83.3% (15

  12. The determinants of the antibiotic resistance process

    PubMed Central

    Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I

    2009-01-01

    Background: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals. PMID:21694883

  13. Characterization of multiple-antibiotic-resistant Salmonella typhimurium stains: molecular epidemiology of PER-1-producing isolates and evidence for nosocomial plasmid exchange by a clone.

    PubMed Central

    Vahaboglu, H; Dodanli, S; Eroglu, C; Oztürk, R; Soyletir, G; Yildirim, I; Avkan, V

    1996-01-01

    We characterized epidemiologic and genetic features of nosocomially originated multiple-antibiotic-resistant Salmonella typhimurium isolates from two hospitals. A total of 32 multiply resistant strains, isolated during a 28-month period, were studied. Four resistance phenotypes were distinguished on the basis of the results of disc diffusion tests. Group 1 was resistant to chloramphenicol, gentamicin, tobramycin, amikacin, and the newer cephalosporins because of the production of an extended-spectrum beta-lactamase (PER-1). Group 2 exhibited the same pattern plus resistance to sulfamethoxazole-trimethoprim (Sxt). Except for Sxt resistance, dominant phenotypes of both groups were transferred on an identical plasmid, pSTI1 (81 MDa). Group 3 was resistant to ampicillin, chloramphenicol, gentamicin, tobramycin, and Sxt. This pattern was also transferred on an 81-MDa plasmid (pSTI2) which differed from pSTI1 on the basis of EcoRI and HindIII restriction fragments. Group 4 was resistant to ampicillin, chloramphenicol, and tetracycline, and a 74-MDa nonconjugative plasmid was detected. Restriction fragment length polymorphism of RNA-encoding DNA and arbitrarily primed PCR tests revealed that bacteria from groups 1, 2, and 3 were clonally related. Epidemiologic data also supported the clonal-dissemination hypothesis. We concluded that S. typhimurium isolates acquire and exchange multiple-resistance plasmids in hospital microflora. PMID:8940427

  14. Selection of antibiotic resistance at very low antibiotic concentrations.

    PubMed

    Sandegren, Linus

    2014-05-01

    Human use of antibiotics has driven the selective enrichment of pathogenic bacteria resistant to clinically used drugs. Traditionally, the selection of resistance has been considered to occur mainly at high, therapeutic levels of antibiotics, but we are now beginning to understand better the importance of selection of resistance at low levels of antibiotics. The concentration of an antibiotic varies in different body compartments during treatment, and low concentrations of antibiotics are found in sewage water, soils, and many water environments due to natural production and contamination from human activities. Selection of resistance at non-lethal antibiotic concentrations (below the wild-type minimum inhibitory concentration) occurs due to differences in growth rate at the particular antibiotic concentration between cells with different tolerance levels to the antibiotic. The minimum selective concentration for a particular antibiotic is reached when its reducing effect on growth of the susceptible strain balances the reducing effect (fitness cost) of the resistance determinant in the resistant strain. Recent studies have shown that resistant bacteria can be selected at concentrations several hundred-fold below the lethal concentrations for susceptible cells. Resistant mutants selected at low antibiotic concentrations are generally more fit than those selected at high concentrations but can still be highly resistant. The characteristics of selection at low antibiotic concentrations, the potential clinical problems of this mode of selection, and potential solutions will be discussed.

  15. Antibiotic Resistance, RAPD- PCR Typing of Multiple Drug Resistant Strains of Escherichia Coli From Urinary Tract Infection (UTI)

    PubMed Central

    Marialouis, Xavier Alexander

    2016-01-01

    Introduction Global spreading of multidrug resistant strains of Escherichia coli is responsible for Urinary Tract Infection (UTI) which is a major health problem in of concern. Among the gram negative bacteria, the major contributors for UTI belongs to the family Enterobacteriaceae, which includes E. coli, Klebsiella, Citrobacter and Proteus. However, E. coli accounts for the major cause of Urinary tract infections (UTIs) and accounts for 75% to 90% of UTI isolates. Aim The main aim of this study is to analyse the phylogenetic grouping of clinical isolates of UTI E. coli. Materials and Methods In this study nearly 58 E. coli strains were isolated and confirmed through microbiological, biochemical characterization. The urine samples were collected from outpatients having symptoms of UTI, irrespective of age and sex in Tamil Nadu, India. The isolates were subjected to analyse for ESBL and AmpC β-lactamase production. To understand its genetic correlation, molecular typing was carried out using RAPD-PCR method. Results Here we noted phenotypically twenty seven isolates were positive for ESBL and seven for AmpC β-lactamase production. However, among the ESBL isolates higher sensitivity was noted for Nitrofurantoin and Cefoxitin. It is worth to note that the prevalence of UTIs was more common among female and elderly male. Phylogenetic grouping revealed the presence of 24 isolates belonged to B2 group followed by 19 isolates to group A, eight isolates to group B1 and Seven isolates to group D. Conclusion Phenotypically most of the strains were positive for ESBL and showed high sensitivity for Nitrofurantoin and cefoxitin. PMID:27134870

  16. Antibiotics and antibiotic resistance in agroecosystems: State of the science

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This review article proposes a simple causal model depicting relationships involved in dissemination of antibiotics and antibiotic resistance in agroecosystems and potential effects on human health, functioning of natural ecosystems, and agricultural productivity. Available evidence for each causal ...

  17. Antibiotic resistance in Burkholderia species.

    PubMed

    Rhodes, Katherine A; Schweizer, Herbert P

    2016-09-01

    The genus Burkholderia comprises metabolically diverse and adaptable Gram-negative bacteria, which thrive in often adversarial environments. A few members of the genus are prominent opportunistic pathogens. These include Burkholderia mallei and Burkholderia pseudomallei of the B. pseudomallei complex, which cause glanders and melioidosis, respectively. Burkholderia cenocepacia, Burkholderia multivorans, and Burkholderia vietnamiensis belong to the Burkholderia cepacia complex and affect mostly cystic fibrosis patients. Infections caused by these bacteria are difficult to treat because of significant antibiotic resistance. The first line of defense against antimicrobials in Burkholderia species is the outer membrane penetration barrier. Most Burkholderia contain a modified lipopolysaccharide that causes intrinsic polymyxin resistance. Contributing to reduced drug penetration are restrictive porin proteins. Efflux pumps of the resistance nodulation cell division family are major players in Burkholderia multidrug resistance. Third and fourth generation β-lactam antibiotics are seminal for treatment of Burkholderia infections, but therapeutic efficacy is compromised by expression of several β-lactamases and ceftazidime target mutations. Altered DNA gyrase and dihydrofolate reductase targets cause fluoroquinolone and trimethoprim resistance, respectively. Although antibiotic resistance hampers therapy of Burkholderia infections, the characterization of resistance mechanisms lags behind other non-enteric Gram-negative pathogens, especially ESKAPE bacteria such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. PMID:27620956

  18. Spatial mapping of antibiotic resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A serious concern for modern animal production is the fear that feed antimicrobials, such as monensin, increase the potential for high levels of antibiotic resistant (AR) gene prevalence in the manure, which may subsequently be shared with soil communities and eventually be taken up by human pathoge...

  19. Antibiotic resistance of bacterial litter isolates.

    PubMed

    Kelley, T R; Pancorbo, O C; Merka, W C; Barnhart, H M

    1998-02-01

    Use of antibiotics in subtherapeutic doses as growth-promoting feed additives for animal production is widespread in the U.S. and throughout the world. Previous studies by our research group concluded that size fractionation of poultry (broiler) litter followed by storage facilitated reutilization of litter as a soil amendment or bedding supplement. However, litter microbial contamination, including antibiotic-resistant populations, and accumulation of metals and other elements may limit litter reutilization. Litter from four broiler houses was separated into a fine fraction for use as a soil amendment, and a coarse fraction for reutilization as a bedding supplement in growing subsequent flocks of broilers. Fractions and whole litter were stored in indoor piles simulating farm storage conditions for 4 mo with periodic analysis for metals, other elements, and culturable bacteria (including total and fecal coliform, Aeromonas hydrophila, Pseudomonas aeruginosa, Yersinia enterocolitica, and Campylobacter jejuni). Representative bacterial isolates were tested for their sensitivity to 12 common antibiotics (ampicillin, bacitracin, cephalothin, erythromycin, gentamicin, kanamycin, nalidixic acid, neomycin, penicillin, streptomycin, sulfisoxazole, and tetracycline) using the Kirby-Bauer technique. Pathogens and indicator bacteria tested were found to be resistant to multiple antibiotics. Data suggest that microbial contamination of litter should be reduced or eliminated prior to reutilization to minimize environmental health risks related to transfer of antibiotic-resistant bacteria to humans or other animals. PMID:9495488

  20. Development of Multiple Antibiotic Resistance in Bacillus subtilis Cells Exposed to Microgravity: the BRIC-18 Experiment to the International Space Station

    NASA Astrophysics Data System (ADS)

    Fajardo-Cavazos, Patricia; Moeller, Ralf; Nicholson, Wayne; Narvel, Raed

    Increased pathogenicity of opportunistic bacteria during long-term spaceflight is considered an astronaut risk. Because only a limited pharmacy can be carried on long-duration missions, the development of resistance to multiple antibiotics is a concern for mission planning. In support of the BRIC-18 experiment to the ISS, we have performed ground-based experiments to address the question whether simulated microgravity affects the frequency of resistance to the model antibiotics rifampicin (RFM) and trimethoprim (TMP). In these experiments, the model bacteria Bacillus subtilis and Staphylococcus epidermidis were cultivated for 6 days at ISS ambient temperature in 10-ml High Aspect Ratio Vessels (HARVs) on two 4-place clinostats (Synthecon) oriented either vertically (V) or horizontally (H). Cells were harvested, enumerated and plated onto medium containing RFM (5 micrograms/ml). The frequency of mutation to RFM resistance was calculated, and RFM-resistant mutants were plated onto medium containing the second antibiotic, TMP (5 micrograms/ml) to determine the frequency of mutation to double (RFM+TMP) resistance. After 6 days of cultivation, V-cultures showed higher cell densities and than H-cultures for both bacteria. However, only in B. subtilis did V-cultures show higher frequencies of mutation to RFM resistance than H-cultures. Launch of BRIC-18 to the ISS is currently scheduled for March 16, 2014 and return 30 days later. Results from both the spaceflight and ground control experiments will be presented. Supported by NASA-SAIP fellowship to R.N. and NASA grant (NNX12AN70G) to P.F.-C., R.M., and W.L.N.

  1. The food safety perspective of antibiotic resistance.

    PubMed

    McDermott, P F; Zhao, S; Wagner, D D; Simjee, S; Walker, R D; White, D G

    2002-05-01

    Bacterial antimicrobial resistance in both the medical and agricultural fields has become a serious problem worldwide. Antibiotic resistant strains of bacteria are an increasing threat to animal and human health, with resistance mechanisms having been identified and described for all known antimicrobials currently available for clinical use. There is currently increased public and scientific interest regarding the administration of therapeutic and sub-therapeutic antimicrobials to animals, due primarily to the emergence and dissemination of multiple antibiotic resistant zoonotic bacterial pathogens. This issue has been the subject of heated debates for many years, however, there is still no complete consensus on the significance of antimicrobial use in animals, or resistance in bacterial isolates from animals, on the development and dissemination of antibiotic resistance among human bacterial pathogens. In fact, the debate regarding antimicrobial use in animals and subsequent human health implications has been going on for over 30 years, beginning with the release of the Swann report in the United Kingdom. The latest report released by the National Research Council (1998) confirmed that there were substantial information gaps that contribute to the difficulty of assessing potential detrimental effects of antimicrobials in food animals on human health. Regardless of the controversy, bacterial pathogens of animal and human origin are becoming increasingly resistant to most frontline antimicrobials, including expanded-spectrum cephalosporins, aminoglycosides, and even fluoroquinolones. The lion's share of these antimicrobial resistant phenotypes is gained from extra-chromosomal genes that may impart resistance to an entire antimicrobial class. In recent years, a number of these resistance genes have been associated with large, transferable, extra-chromosomal DNA elements, called plasmids, on which may be other DNA mobile elements, such as transposons and integrons

  2. Chromosomal mutations involved in antibiotic resistance in Staphylococcus aureus.

    PubMed

    Espedido, Bjorn A; Gosbell, Iain B

    2012-01-01

    Staphylococcus aureus is an important pathogen involved in infections in both the community and hospital setting. Strains that are resistant to multiple classes of antibiotics, particularly methicillin-resistant strains (MRSA), are prevalent in nosocomial infections and are associated with high morbidity and mortality rates. Such antibiotic-resistant strains limit the therapeutic options and place a burden on the health care system. In the hospital setting, horizontal gene transfer plays an important role in disseminating antibiotic resistant determinants among S. aureus. However, resistance to all known classes of antibiotics have been attributed to genes found within the S. aureus chromosome or to due to mutation as a result of selection pressure. Spontaneous mutations, in particular, are pivotal in the emergence of novel resistances. Consequently, newer drugs with better activity and/or antibacterial agents with novel targets need to be developed to combat and control the further spread of antibiotic resistance.

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

    PubMed

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

    2013-01-01

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the "perfect microbial storm". Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

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

    PubMed Central

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

    2013-01-01

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water. PMID:27029309

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

    PubMed

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

    2015-05-01

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

  6. Distribution of antibiotic resistance in urban watershed in Japan.

    PubMed

    Ham, Young-Sik; Kobori, Hiromi; Kang, Joo-Hyon; Matsuzaki, Takayuki; Iino, Michiyo; Nomura, Hayashi

    2012-03-01

    Antibiotic-resistant E. coli concentrations showed large spatial and temporal variations, with greater concentrations observed in tributaries and downstream than in the upstream and midstream. Twenty percent of the geometric mean concentrations of antibiotic-resistant E. coli in the Tama River basin (Japan) exceeded the maximum acceptable concentration of indicator E. coli established by the USEPA. The indicator E. coli concentrations were positively correlated with those of antibiotic-resistant E. coli and multiple-antibiotic-resistant E. coli (resistance to more than two kinds of antibiotics), respectively, but not the detection rate of antibiotic-resistant E. coli, implying that use of antibiotic-resistant E. coli concentration rather than the detection rate can be a better approach for water quality assessment. Multiple-antibiotic-resistant E. coli is a useful indicator for estimating the resistance diffusion, water quality degradation and public health risk potential. This assessment provides beneficial information for setting national regulatory or environmental standards and managing integrated watershed areas.

  7. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    PubMed Central

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

    2016-01-01

    The administration of antimicrobials in aquaculture provides a selective pressure creating a reservoir of multiple resistant bacteria in the cultured fish and shrimps as well as the aquaculture environment. The objective of this study was to determine the extent of antibiotic resistance in aquaculture products and aquaculture's surrounding environment in Sarawak, Malaysian Borneo. Ninety-four identified bacterial isolates constituted of 17 genera were isolated from sediment, water, and cultured organisms (fish and shrimp) in selected aquaculture farms. These isolates were tested for their antibiotic resistance against 22 antibiotics from several groups using the disk diffusion method. The results show that the highest resistance was observed towards streptomycin (85%, n = 20), while the lowest resistance was towards gentamicin (1.1%, n = 90). The multiple antibiotic resistant (MAR) index of the isolates tested ranged between 0 and 0.63. It was suggested that isolates with MAR index > 0.2 were recovered from sources with high risk of antibiotic resistant contamination. This study revealed low level of antibiotic resistance in the aquaculture bacterial isolates except for streptomycin and ampicillin (>50% resistance, n = 94) which have been used in the aquaculture industry for several decades. Antibiotic resistant patterns should be continuously monitored to predict the emergence and widespread of MAR. Effective action is needed to keep the new resistance from further developing and spreading. PMID:27746817

  8. Rationalizing antibiotic use to limit antibiotic resistance in India+

    PubMed Central

    2011-01-01

    Antibiotic resistance, a global concern, is particularly pressing in developing nations, including India, where the burden of infectious disease is high and healthcare spending is low. The Global Antibiotic Resistance Partnership (GARP) was established to develop actionable policy recommendations specifically relevant to low- and middle-income countries where suboptimal access to antibiotics - not a major concern in high-income countries - is possibly as severe a problem as is the spread of resistant organisms. This report summarizes the situation as it is known regarding antibiotic use and growing resistance in India and recommends short and long term actions. Recommendations aim at (i) reducing the need for antibiotics; (ii) lowering resistance-enhancing drug pressure through improved antibiotic targeting, and (iii) eliminating antibiotic use for growth promotion in agriculture. The highest priority needs to be given to (i) national surveillance of antibiotic resistance and antibiotic use - better information to underpin decisions on standard treatment guidelines, education and other actions, as well as to monitor changes over time; (ii) increasing the use of diagnostic tests, which necessitates behavioural changes and improvements in microbiology laboratory capacity; (iii) setting up and/or strengthening infection control committees in hospitals; and (iv) restricting the use of antibiotics for non-therapeutic uses in agriculture. These interventions should help to reduce the spread of antibiotic resistance, improve public health directly, benefit the populace and reduce pressure on the healthcare system. Finally, increasing the types and coverage of childhood vaccines offered by the government would reduce the disease burden enormously and spare antibiotics. PMID:21985810

  9. Probiotic approach to prevent antibiotic resistance.

    PubMed

    Ouwehand, Arthur C; Forssten, Sofia; Hibberd, Ashley A; Lyra, Anna; Stahl, Buffy

    2016-01-01

    Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it.

  10. Antibiotic resistance: a growing and multifaceted problem.

    PubMed

    Clark, L

    Antibiotic resistance is an increasing problem worldwide that is exacerbated by the overuse and misuse of antibiotics. Patients, pharmaceutical marketing, and the use of antibiotics in veterinary medicine and animal husbandry are important factors to consider in the emergence of resistance. Infection control measures to prevent the spread of antibiotic-resistant bacteria are compromised by poor compliance to basic measures such as handwashing and standards of environmental cleanliness. Wider epidemiological factors such as global travel and complacency towards public health must also be considered. This article aims to improve understanding of antibiotic resistance and suggests ways in which nurses can contribute towards the strategy to address the problem.

  11. Overcoming Resistance to β-Lactam Antibiotics

    PubMed Central

    Worthington, Roberta J.; Melander, Christian

    2013-01-01

    β-Lactam antibiotics are one of the most important antibiotic classes but are plagued by problems of resistance and the development of new β-lactam antibiotics through side chain modification of existing β-lactam classes is not keeping pace with resistance development. In this perspective we summarize small molecule strategies to overcome resistance to β-lactam antibiotics. These approaches include the development of β-lactamase inhibitors and compounds that interfere with the ability of the bacteria to sense an antibiotic threat and activate their resistance mechanisms. PMID:23530949

  12. Bactericidal effect of polyethyleneimine capped ZnO nanoparticles on multiple antibiotic resistant bacteria harboring genes of high-pathogenicity island.

    PubMed

    Chakraborti, Soumyananda; Mandal, Amit Kumar; Sarwar, Shamila; Singh, Prashantee; Chakraborty, Ranadhir; Chakrabarti, Pinak

    2014-09-01

    Zinc oxide nanoparticles (ZnO-NP) were synthesized by alcoholic route using zinc acetate as the precursor material and lithium hydroxide as hydrolyzing agent. Further ZnO-PEI NP (derivative of ZnO-NP) was made in aqueous medium using the capping agent polyethyleneimine (PEI). The nanoparticles were characterized by XRD measurements, TEM and other techniques; the weight % of coating shell in the polymer-capped particles was determined by TGA. ZnO-PEI NP is more soluble in water than the uncapped ZnO-NP, and forms a colloidal suspension in water. PEI-capped ZnO-NP exhibited better antibacterial activity when compared with that of uncapped ZnO-NP against a range of multiple-antibiotic-resistant (MAR) Gram-negative bacterial strains harboring genes of high-pathogenicity island. ZnO-NP effectively killed these microorganisms by generating reactive oxygen species (ROS) and damaging bacterial membrane. ZnO-PEI NP at LD50 dose in combination with tetracycline showed synergistic effect to inhibit tetracycline-resistant Escherichia coli MREC33 growth by 80%. These results open up a new vista in therapeutics to use antibiotics (which have otherwise been rendered useless against MAR bacteria) in combination with minimized dosage of nanoparticles for the more effective control of MAR pathogenic bacteria.

  13. The global problem of antibiotic resistance.

    PubMed

    Gootz, Thomas D

    2010-01-01

    Amid the recent attention justly focused on the potential problem of microbial sources for weapons of bioterrorism, it is also apparent that human pathogens frequently isolated from infections in patients from community and hospital sources have been growing more resistant to commonly used antibiotics. Much of the growth of multiple-drug-resistant (MDR) bacterial pathogens can be contributed to the overuse of broad-spectrum antimicrobial products. However, an equally troubling and often overlooked component of the problem involves the elegant ways in which pathogenic bacteria continually evolve complex genetic systems for acquiring and regulating an endless array of antibiotic-resistance mechanisms. Efforts to develop new antimicrobials have over the past two decades been woefully behind the rapid evolution of resistance genes developing among both gram-positive and gram-negative pathogens. Several new agents that are best suited for use in the hospital environment have been developed to combat staphylococci resistant to beta-lactam antimicrobials following acquisition of the mecA gene. However, the dramatic spread in the US of the now common community strain of Staphylococcus aureus USA300 has shifted the therapeutic need for new antibiotics useful against MRSA to the community. As the pharmaceutical industry focused on discovering new agents for use against MRSA, hospitals in many parts of the world have seen the emergence of gram-negative pathogens such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae that are clinically resistant to almost all available antimicrobials. Such MDR isolates usually contain multiple-resistance determinants, including loss of outer membrane porins via gene inactivation by chromosomally encoded insertion sequences, up-regulation of inate efflux pumps, as well as acquisition of drug-inactivating enzymes whose genes are encoded on self-transmissible plasmids, integrons, and complex transposable elements

  14. Antibiotic overuse and resistance in dermatology.

    PubMed

    Chon, Susan Y; Doan, Hung Q; Mays, Rana Majd; Singh, Selina M; Gordon, Rachel A; Tyring, Stephen K

    2012-01-01

    Antibiotics have a significant role in dermatology, treating a wide range of diseases, including acne, rosacea, inflammatory skin conditions and skin structure infections, such as cellulitis, folliculitis, carbuncles, and furuncles. Because of their consistent use, utility, and availability, antibiotics are susceptible to overuse within the medical practice, and, specific to this discussion, in the dermatologic setting. The issue of continuously increasing risk of antibiotic resistance remains an important concern to the dermatologist. The scope of this review will be to provide an overview of the common antibiotics used in the dermatologic setting with an emphasis on identifying areas of overuse, reported bacterial resistance, and discussion of clinical management aimed at decreasing antibiotic resistance.

  15. Antibiotics and antibiotic resistance: a bitter fight against evolution.

    PubMed

    Rodríguez-Rojas, Alexandro; Rodríguez-Beltrán, Jerónimo; Couce, Alejandro; Blázquez, Jesús

    2013-08-01

    One of the most terrible consequences of Darwinian evolution is arguably the emergence and spread of antibiotic resistance, which is becoming a serious menace to modern societies. While spontaneous mutation, recombination and horizontal gene transfer are recognized as the main causes of this notorious phenomenon; recent research has raised awareness that sub-lethal concentrations of antibiotics can also foster resistance as an undesirable side-effect. They can produce genetic changes by different ways, including a raise of free radicals within the cell, induction of error-prone DNA-polymerases mediated by SOS response, imbalanced nucleotide metabolism or affect directly DNA. In addition to certain environmental conditions, subinhibitory concentrations of antimicrobials may increase, even more, the mutagenic effect of antibiotics. Here, we review the state of knowledge on antibiotics as promoters of antibiotic resistance.

  16. Diversity among strains of Pseudomonas aeruginosa from manure and soil, evaluated by multiple locus variable number tandem repeat analysis and antibiotic resistance profiles.

    PubMed

    Youenou, Benjamin; Brothier, Elisabeth; Nazaret, Sylvie

    2014-01-01

    The results of a multiple locus variable number of tandem repeat (VNTR) analysis (MLVA)-based study designed to understand the genetic diversity of soil and manure-borne Pseudomonas aeruginosa isolates, and the relationship between these isolates and a set of clinical and environmental isolates, are hereby reported. Fifteen described VNTR markers were first selected, and 62 isolates recovered from agricultural and industrial soils in France and Burkina Faso, and from cattle and horse manure, along with 26 snake-related isolates and 17 environmental and clinical isolates from international collections, were genotyped. Following a comparison with previously published 9-marker MLVA schemes, an optimal 13-marker MLVA scheme (MLVA13-Lyon) was identified that was found to be the most efficient, as it showed high typability (90%) and high discriminatory power (0.987). A comparison of MLVA with PFGE for typing of the snake-related isolates confirmed the MLVA13-Lyon scheme to be a robust method for quickly discriminating and inferring genetic relatedness among environmental isolates. The 62 isolates displayed wide diversity, since 41 MLVA types (i.e. MTs) were observed, with 26 MTs clustered in 10 MLVA clonal complexes (MCs). Three and eight MCs were found among soil and manure isolates, respectively. Only one MC contained both soil and manure-borne isolates. No common MC was observed between soil and manure-borne isolates and the snake-related or environmental and clinical isolates. Antibiotic resistance profiles were performed to determine a potential link between resistance properties and the selective pressure that might be present in the various habitats. Except for four soil and manure isolates resistant to ticarcillin and ticarcillin/clavulanic acid and one isolate from a hydrocarbon-contaminated soil resistant to imipenem, all environmental isolates showed wild-type antibiotic profiles.

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

    PubMed

    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.

  18. Tackling antibiotic resistance: the environmental framework.

    PubMed

    Berendonk, Thomas U; Manaia, Célia M; Merlin, Christophe; Fatta-Kassinos, Despo; Cytryn, Eddie; Walsh, Fiona; Bürgmann, Helmut; Sørum, Henning; Norström, Madelaine; Pons, Marie-Noëlle; Kreuzinger, Norbert; Huovinen, Pentti; Stefani, Stefania; Schwartz, Thomas; Kisand, Veljo; Baquero, Fernando; Martinez, José Luis

    2015-05-01

    Antibiotic resistance is a threat to human and animal health worldwide, and key measures are required to reduce the risks posed by antibiotic resistance genes that occur in the environment. These measures include the identification of critical points of control, the development of reliable surveillance and risk assessment procedures, and the implementation of technological solutions that can prevent environmental contamination with antibiotic resistant bacteria and genes. In this Opinion article, we discuss the main knowledge gaps, the future research needs and the policy and management options that should be prioritized to tackle antibiotic resistance in the environment.

  19. Tackling antibiotic resistance: the environmental framework.

    PubMed

    Berendonk, Thomas U; Manaia, Célia M; Merlin, Christophe; Fatta-Kassinos, Despo; Cytryn, Eddie; Walsh, Fiona; Bürgmann, Helmut; Sørum, Henning; Norström, Madelaine; Pons, Marie-Noëlle; Kreuzinger, Norbert; Huovinen, Pentti; Stefani, Stefania; Schwartz, Thomas; Kisand, Veljo; Baquero, Fernando; Martinez, José Luis

    2015-05-01

    Antibiotic resistance is a threat to human and animal health worldwide, and key measures are required to reduce the risks posed by antibiotic resistance genes that occur in the environment. These measures include the identification of critical points of control, the development of reliable surveillance and risk assessment procedures, and the implementation of technological solutions that can prevent environmental contamination with antibiotic resistant bacteria and genes. In this Opinion article, we discuss the main knowledge gaps, the future research needs and the policy and management options that should be prioritized to tackle antibiotic resistance in the environment. PMID:25817583

  20. General principles of antibiotic resistance in bacteria.

    PubMed

    Martinez, Jose L

    2014-03-01

    Given the impact of antibiotic resistance on human health, its study is of great interest from a clinical view- point. In addition, antibiotic resistance is one of the few examples of evolution that can be studied in real time. Knowing the general principles involved in the acquisition of antibiotic resistance is therefore of interest to clinicians, evolutionary biologists and ecologists. The origin of antibiotic resistance genes now possessed by human pathogens can be traced back to environmental microorganisms. Consequently, a full understanding of the evolution of antibiotic resistance requires the study of natural environments as well as clinical ecosystems. Updated information on the evolutionary mechanisms behind resistance, indicates that ecological connectivity, founder effect and fitness costs are important bottle- necks that modulate the transfer of resistance from environmental microorganisms to pathogens. PMID:24847651

  1. Engineering multiple genomic deletions in Gram-negative bacteria: analysis of the multi-resistant antibiotic profile of Pseudomonas putida KT2440.

    PubMed

    Martínez-García, Esteban; de Lorenzo, Víctor

    2011-10-01

    The genome of the soil bacterium Pseudomonas putida strain KT2440 has been erased of various determinants of resistance to antibiotics encoded in its extant chromosome. To this end, we employed a coherent genetic platform that allowed the precise deletion of multiple genomic segments in a large variety of Gram-negative bacteria including (but not limited to) P. putida. The method is based on the obligatory recombination between free-ended homologous DNA sequences that are released as linear fragments generated upon the cleavage of the chromosome with unique I-SceI sites, added to the segment of interest by the vector system. Despite the potential for a SOS response brought about by the appearance of double stranded DNA breaks during the process, fluctuation experiments revealed that the procedure did not increase mutation rates - perhaps due to the protection exerted by I-SceI bound to the otherwise naked DNA termini. With this tool in hand we made sequential deletions of genes mexC, mexE, ttgA and ampC in the genome of the target bacterium, orthologues of which are known to determine various degrees of antibiotic resistance in diverse microorganisms. Inspection of the corresponding phenotypes demonstrated that the efflux pump encoded by ttgA sufficed to endow P. putida with a high-level of tolerance to β-lactams, chloramphenicol and quinolones, but had little effect on, e.g. aminoglycosides. Analysis of the mutants revealed also a considerable diversity in the manifestation of the resistance phenotype within the population and suggested a degree of synergism between different pumps. The directed edition of the P. putida chromosome shown here not only enhances the amenability of this bacterium to deep genomic engineering, but also validates the corresponding approach for similar handlings of a large variety of Gram-negative microorganisms.

  2. Occurrence and antibiotic resistance of multiple Salmonella serotypes recovered from water, sediment and soil on mid-Atlantic tomato farms.

    PubMed

    Micallef, Shirley A; Rosenberg Goldstein, Rachel E; George, Ashish; Kleinfelter, Lara; Boyer, Marc S; McLaughlin, Cristina R; Estrin, Andrew; Ewing, Laura; Jean-Gilles Beaubrun, Junia; Hanes, Darcy E; Kothary, Mahendra H; Tall, Ben D; Razeq, Jafar H; Joseph, Sam W; Sapkota, Amy R

    2012-04-01

    Salmonella outbreaks associated with the consumption of raw tomatoes have been prevalent in recent years. However, sources of Salmonella contamination of tomatoes remain poorly understood. The objectives of this study were to identify ecological reservoirs of Salmonella on tomato farms, and to test antimicrobial susceptibilities of recovered Salmonella isolates. Fourteen Mid-Atlantic tomato farms in the U.S. were sampled in 2009 and 2010. Groundwater, irrigation pond water, pond sediment, irrigation ditch water, rhizosphere and irrigation ditch soil, leaves, tomatoes, and swabs of harvest bins and worker sanitary facilities were analyzed for Salmonella using standard culture methods and/or a flow-through immunocapture method. All presumptive Salmonella isolates (n=63) were confirmed using PCR and the Vitek(®) 2 Compact System, and serotyped using the Premi(®)Test Salmonella and a conventional serotyping method. Antimicrobial susceptibility testing was carried out using the Sensititre™ microbroth dilution system. Four of the 14 farms (29%) and 12 out of 1,091 samples (1.1%) were found to harbor Salmonella enterica subsp. enterica. Salmonella was isolated by the immunocapture method from soil, while the culture method recovered isolates from irrigation pond water and sediment, and irrigation ditch water. No Salmonella was detected on leaves or tomatoes. Multiple serotypes were identified from soil and water, four of which-S. Braenderup, S. Javiana, S. Newport and S. Typhimurium-have been previously implicated in Salmonella outbreaks associated with tomato consumption. Resistance to sulfisoxazole was prevalent and some resistance to ampicillin, cefoxitin, amoxicillin/clavulanic acid, and tetracycline was also observed. This study implicates irrigation water and soil as possible reservoirs of Salmonella on tomato farms and irrigation ditches as ephemeral habitats for Salmonella. The findings point to the potential for pre-harvest contamination of tomatoes from

  3. Molecular Typing of Multiple-Antibiotic-Resistant Salmonella enterica Serovar Typhi from Vietnam: Application to Acute and Relapse Cases of Typhoid Fever

    PubMed Central

    Wain, John; Hien, Tran T.; Connerton, Phillippa; Ali, Tahir; M. Parry, Christopher; Chinh, Nguyen T. T.; Vinh, Ha; Phuong, Cao X. T.; Ho, Vo A.; Diep, To S.; Farrar, Jeremy J.; White, Nicholas J.; Dougan, Gordon

    1999-01-01

    The rate of multiple-antibiotic resistance is increasing among Salmonella enterica serovar Typhi strains in Southeast Asia. Pulsed-field gel electrophoresis (PFGE) and other typing methods were used to analyze drug-resistant and -susceptible organisms isolated from patients with typhoid fever in several districts in southern Vietnam. Multiple PFGE and phage typing patterns were detected, although individual patients were infected with strains of a single type. The PFGE patterns were stable when the S. enterica serovar Typhi strains were passaged many times in vitro on laboratory medium. Paired S. enterica serovar Typhi isolates recovered from the blood and bone marrow of individual patients exhibited similar PFGE patterns. Typing of S. enterica serovar Typhi isolates from patients with relapses of typhoid indicated that the majority of relapses were caused by the same S. enterica serovar Typhi strain that was isolated during the initial infection. However, some individuals were infected with distinct and presumably newly acquired S. enterica serovar Typhi isolates. PMID:10405386

  4. Sequences of Two Related Multiple Antibiotic Resistance Virulence Plasmids Sharing a Unique IS26-Related Molecular Signature Isolated from Different Escherichia coli Pathotypes from Different Hosts

    PubMed Central

    Venturini, Carola; Hassan, Karl A.; Roy Chowdhury, Piklu; Paulsen, Ian T.; Walker, Mark J.; Djordjevic, Steven P.

    2013-01-01

    Enterohemorrhagic Escherichia coli (EHEC) and atypical enteropathogenic E. coli (aEPEC) are important zoonotic pathogens that increasingly are becoming resistant to multiple antibiotics. Here we describe two plasmids, pO26-CRL125 (125 kb) from a human O26:H- EHEC, and pO111-CRL115 (115kb) from a bovine O111 aEPEC, that impart resistance to ampicillin, kanamycin, neomycin, streptomycin, sulfathiazole, trimethoprim and tetracycline and both contain atypical class 1 integrons with an identical IS26-mediated deletion in their 3´-conserved segment. Complete sequence analysis showed that pO26-CRL125 and pO111-CRL115 are essentially identical except for a 9.7 kb fragment, present in the backbone of pO26-CRL125 but absent in pO111-CRL115, and several indels. The 9.7 kb fragment encodes IncI-associated genes involved in plasmid stability during conjugation, a putative transposase gene and three imperfect repeats. Contiguous sequence identical to regions within these pO26-CRL125 imperfect repeats was identified in pO111-CRL115 precisely where the 9.7 kb fragment is missing, suggesting it may be mobile. Sequences shared between the plasmids include a complete IncZ replicon, a unique toxin/antitoxin system, IncI stability and maintenance genes, a novel putative serine protease autotransporter, and an IncI1 transfer system including a unique shufflon. Both plasmids carry a derivate Tn21 transposon with an atypical class 1 integron comprising a dfrA5 gene cassette encoding resistance to trimethoprim, and 24 bp of the 3´-conserved segment followed by Tn6026, which encodes resistance to ampicillin, kanymycin, neomycin, streptomycin and sulfathiazole. The Tn21-derivative transposon is linked to a truncated Tn1721, encoding resistance to tetracycline, via a region containing the IncP-1α oriV. Absence of the 5 bp direct repeats flanking Tn3-family transposons, indicates that homologous recombination events played a key role in the formation of this complex antibiotic resistance

  5. Antibiotic resistance: a physicist’s view

    PubMed Central

    Allen, Rosalind; Waclaw, Bartłomiej

    2016-01-01

    The problem of antibiotic resistance poses challenges across many disciplines. One such challenge is to understand the fundamental science of how antibiotics work, and how resistance to them can emerge. This is an area where physicists can make important contributions. Here, we highlight cases where this is already happening, and suggest directions for further physics involvement in antimicrobial research. PMID:27510596

  6. Antibiotic resistance: a physicist’s view

    NASA Astrophysics Data System (ADS)

    Allen, Rosalind; Waclaw, Bartłomiej

    2016-08-01

    The problem of antibiotic resistance poses challenges across many disciplines. One such challenge is to understand the fundamental science of how antibiotics work, and how resistance to them can emerge. This is an area where physicists can make important contributions. Here, we highlight cases where this is already happening, and suggest directions for further physics involvement in antimicrobial research.

  7. Background antibiotic resistance patterns in antibiotic-free pastured poultry production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in th...

  8. Outer Membrane Permeability and Antibiotic Resistance

    PubMed Central

    Delcour, Anne H.

    2009-01-01

    Summary To date most antibiotics are targeted at intracellular processes, and must be able to penetrate the bacterial cell envelope. In particular, the outer membrane of Gram-negative bacteria provides a formidable barrier that must be overcome. There are essentially two pathways that antibiotics can take through the outer membrane: a lipid-mediated pathway for hydrophobic antibiotics, and general diffusion porins for hydrophilic antibiotics. The lipid and protein compositions of the outer membrane have a strong impact on the sensitivity of bacteria to many types of antibiotics, and drug resistance involving modifications of these macromolecules is common. This review will describe the molecular mechanisms for permeation of antibiotics through the outer membrane, and the strategies that bacteria have deployed to resist antibiotics by modifications of these pathways. PMID:19100346

  9. Syphilis: antibiotic treatment and resistance.

    PubMed

    Stamm, L V

    2015-06-01

    Syphilis is a chronic, multi-stage infectious disease that is usually transmitted sexually by contact with an active lesion of a partner or congenitally from an infected pregnant woman to her fetus. Although syphilis is still endemic in many developing countries, it has re-emerged in several developed countries. The resurgence of syphilis is a major concern to global public health, particularly since the lesions of early syphilis increase the risk of acquisition and transmission of infection with human immunodeficiency virus (HIV). Because there is no vaccine to prevent syphilis, control is mainly dependent on the identification and treatment of infected individuals and their contacts with penicillin G, the first-line drug for all stages of syphilis. The emergence of clinically significant azithromycin resistance in Treponema pallidum subsp. pallidum, the syphilis agent, has resulted in treatment failures, thus precluding the routine use of this second-line drug. Information is presented here on the diagnosis and recommended antibiotic treatment of syphilis and the challenge of macrolide-resistant T. pallidum.

  10. [Antibiotic resistance--bacteria fight back].

    PubMed

    Tambić Andrasević, Arjana

    2004-01-01

    Antibiotic resistance has become one of the leading problems in modern medicine. Resistance to antibiotics emerges in bacteria due to genetic mutations and consecutive selection of resistant mutants through selective pressure of antibiotics present in large amounts in soil, plants, animals and humans. Exchange of genetic material coding for resistance is possible even between unrelated organisms and further promotes the spread of resistance. Constantly evolving resistance mechanisms force experts to redefine breakpoint concentrations and interpretation of in vitro antibiotic sensitivity testing. Developing new antimicrobial agents does not seem to be enough to keep up pace with ever changing bacteria. Using antibiotics prudently and developing new approaches to the treatment of infections is vital for the future. The European Antimicrobial Resistance Surveillance System (EARSS) data clearly show that Scandinavian countries and The Netherlands have the lowest rates of resistance, while Southern and Eastern European countries have the highest prevalence of resistance. This is linked to the European Surveillance of Antimicrobial Consumption (ESAC) data that show very low consumption of antibiotics in Scandinavian countries and The Netherlands. Compliance with strict infection control policies related to multidrug resistant organisms is also high in these countries. Although it is important to be aware of the resistance problems worldwide, rational use of antibiotics should be based on the knowledge of local resistance patterns in common pathogens. Since 1996 there is a continuous surveillance of resistance in Croatia through the Croatian Committee for Antibiotic Resistance Surveillance. There is a particular concern about the rising penicillin and macrolide resistance in pneumococci. In Croatia, data for 2002 suggest that resistance to penicillin in pneumococci was 30% (low level) and 2% (high level). Among invasive isolates, 19% had reduced susceptibility to

  11. Antibiotic-Resistant Bacteria Detected in Sewage Spill

    MedlinePlus

    ... animals -- the more the antibiotic resistant organisms and antibiotic resistance genes can enter the environment and contribute to the spread of antibiotic resistance, especially for those drugs considered the 'last resort' ...

  12. Water Disinfection Byproducts Induce Antibiotic Resistance-Role of Environmental Pollutants in Resistance Phenomena.

    PubMed

    Li, Dan; Zeng, Siyu; He, Miao; Gu, April Z

    2016-03-15

    The spread of antibiotic resistance represents a global threat to public health, and has been traditionally attributed to extensive antibiotic uses in clinical and agricultural applications. As a result, researchers have mostly focused on clinically relevant high-level resistance enriched by antibiotics above the minimal inhibitory concentrations (MICs). Here, we report that two common water disinfection byproducts (chlorite and iodoacetic acid) had antibiotic-like effects that led to the evolution of resistant E. coli strains under both high (near MICs) and low (sub-MIC) exposure concentrations. The subinhibitory concentrations of DBPs selected strains with resistance higher than those evolved under above-MIC exposure concentrations. In addition, whole-genome analysis revealed distinct mutations in small sets of genes known to be involved in multiple drug and drug-specific resistance, as well as in genes not yet identified to play role in antibiotic resistance. The number and identities of genetic mutations were distinct for either the high versus low sub-MIC concentrations exposure scenarios. This study provides evidence and mechanistic insight into the sub-MIC selection of antibiotic resistance by antibiotic-like environmental pollutants such as disinfection byproducts in water, which may be important contributors to the spread of global antibiotic resistance. The results from this study open an intriguing and profound question on the roles of large amount and various environmental contaminants play in selecting and spreading the antibiotics resistance in the environment. PMID:26928861

  13. Water Disinfection Byproducts Induce Antibiotic Resistance-Role of Environmental Pollutants in Resistance Phenomena.

    PubMed

    Li, Dan; Zeng, Siyu; He, Miao; Gu, April Z

    2016-03-15

    The spread of antibiotic resistance represents a global threat to public health, and has been traditionally attributed to extensive antibiotic uses in clinical and agricultural applications. As a result, researchers have mostly focused on clinically relevant high-level resistance enriched by antibiotics above the minimal inhibitory concentrations (MICs). Here, we report that two common water disinfection byproducts (chlorite and iodoacetic acid) had antibiotic-like effects that led to the evolution of resistant E. coli strains under both high (near MICs) and low (sub-MIC) exposure concentrations. The subinhibitory concentrations of DBPs selected strains with resistance higher than those evolved under above-MIC exposure concentrations. In addition, whole-genome analysis revealed distinct mutations in small sets of genes known to be involved in multiple drug and drug-specific resistance, as well as in genes not yet identified to play role in antibiotic resistance. The number and identities of genetic mutations were distinct for either the high versus low sub-MIC concentrations exposure scenarios. This study provides evidence and mechanistic insight into the sub-MIC selection of antibiotic resistance by antibiotic-like environmental pollutants such as disinfection byproducts in water, which may be important contributors to the spread of global antibiotic resistance. The results from this study open an intriguing and profound question on the roles of large amount and various environmental contaminants play in selecting and spreading the antibiotics resistance in the environment.

  14. Multiple Discharges of Treated Municipal Wastewater Have a Small Effect on the Quantities of Numerous Antibiotic Resistance Determinants in the Upper Mississippi River.

    PubMed

    LaPara, Timothy M; Madson, Matthew; Borchardt, Spencer; Lang, Kevin S; Johnson, Timothy J

    2015-10-01

    This study evaluated multiple discharges of treated wastewater on the quantities of antibiotic resistance genes (ARGs) in the Upper Mississippi River. Surface water and treated wastewater samples were collected along the Mississippi River during three different periods of 4 days during the summer of 2012, and quantitative real-time PCR (qPCR) was used to enumerate several ARGs and related targets. Even though the wastewater effluents contained 75- to 831-fold higher levels of ARGs than the river water, the quantities of ARGs in the Mississippi River did not increase with downstream distance. Plasmids from the incompatibility group A/C were detected at low levels in the wastewater effluents but not in the river water; synthetic DNA containing an ampicillin resistance gene (bla) from cloning vectors was not detected in either the wastewater effluent or river samples. A simple 1D model suggested that the primary reason for the small impact of the wastewater discharges on ARG levels was the large flow rate of the Mississippi River compared to that of the wastewater discharges. Furthermore, this model generally overpredicted the ARG levels in the Mississippi River, suggesting that substantial loss mechanisms (e.g., decay or deposition) were occurring in the river.

  15. Multiple Discharges of Treated Municipal Wastewater Have a Small Effect on the Quantities of Numerous Antibiotic Resistance Determinants in the Upper Mississippi River.

    PubMed

    LaPara, Timothy M; Madson, Matthew; Borchardt, Spencer; Lang, Kevin S; Johnson, Timothy J

    2015-10-01

    This study evaluated multiple discharges of treated wastewater on the quantities of antibiotic resistance genes (ARGs) in the Upper Mississippi River. Surface water and treated wastewater samples were collected along the Mississippi River during three different periods of 4 days during the summer of 2012, and quantitative real-time PCR (qPCR) was used to enumerate several ARGs and related targets. Even though the wastewater effluents contained 75- to 831-fold higher levels of ARGs than the river water, the quantities of ARGs in the Mississippi River did not increase with downstream distance. Plasmids from the incompatibility group A/C were detected at low levels in the wastewater effluents but not in the river water; synthetic DNA containing an ampicillin resistance gene (bla) from cloning vectors was not detected in either the wastewater effluent or river samples. A simple 1D model suggested that the primary reason for the small impact of the wastewater discharges on ARG levels was the large flow rate of the Mississippi River compared to that of the wastewater discharges. Furthermore, this model generally overpredicted the ARG levels in the Mississippi River, suggesting that substantial loss mechanisms (e.g., decay or deposition) were occurring in the river. PMID:26325533

  16. Prevalence of Multiple Antibiotics Resistant (MAR) Pseudomonas Species in the Final Effluents of Three Municipal Wastewater Treatment Facilities in South Africa

    PubMed Central

    Odjadjare, Emmanuel E.; Igbinosa, Etinosa O.; Mordi, Raphael; Igere, Bright; Igeleke, Clara L.; Okoh, Anthony I.

    2012-01-01

    The final effluents of three (Alice, Dimbaza, and East London) wastewater treatment plants (WWTPs) were evaluated to determine their physicochemical quality and prevalence of multiple antibiotics resistant (MAR) Pseudomonas species, between August 2007 and July 2008. The annual mean total Pseudomonas count (TPC) was 1.20 × 104 (cfu/100 mL), 1.08 × 104 (cfu/100 mL), and 2.66 × 104 (cfu/100 mL), for the Alice, Dimbaza, and East London WWTPs respectively. The effluents were generally compliant with recommended limits for pH, temperature, TDS, DO, nitrite and nitrate; but fell short of target standards for turbidity, COD, and phosphate. The tested isolates were highly sensitive to gentamicin (100%), ofloxacin (100%), clindamycin (90%), erythromycin (90%) and nitrofurantoin (80%); whereas high resistance was observed against the penicillins (90–100%), rifampin (90%), sulphamethoxazole (90%) and the cephems (70%). MAR index ranged between 0.26 and 0.58. The study demonstrated that MAR Pseudomonas species were quite prevalent in the final effluents of WWTPs in South Africa; and this can lead to serious health risk for communities that depend on the effluent-receiving waters for sundry purposes. PMID:22829792

  17. Targets for Combating the Evolution of Acquired Antibiotic Resistance.

    PubMed

    Culyba, Matthew J; Mo, Charlie Y; Kohli, Rahul M

    2015-06-16

    Bacteria possess a remarkable ability to rapidly adapt and evolve in response to antibiotics. Acquired antibiotic resistance can arise by multiple mechanisms but commonly involves altering the target site of the drug, enzymatically inactivating the drug, or preventing the drug from accessing its target. These mechanisms involve new genetic changes in the pathogen leading to heritable resistance. This recognition underscores the importance of understanding how such genetic changes can arise. Here, we review recent advances in our understanding of the processes that contribute to the evolution of antibiotic resistance, with a particular focus on hypermutation mediated by the SOS pathway and horizontal gene transfer. We explore the molecular mechanisms involved in acquired resistance and discuss their viability as potential targets. We propose that additional studies into these adaptive mechanisms not only can provide insights into evolution but also can offer a strategy for potentiating our current antibiotic arsenal.

  18. Targets for Combating the Evolution of Acquired Antibiotic Resistance

    PubMed Central

    2015-01-01

    Bacteria possess a remarkable ability to rapidly adapt and evolve in response to antibiotics. Acquired antibiotic resistance can arise by multiple mechanisms but commonly involves altering the target site of the drug, enzymatically inactivating the drug, or preventing the drug from accessing its target. These mechanisms involve new genetic changes in the pathogen leading to heritable resistance. This recognition underscores the importance of understanding how such genetic changes can arise. Here, we review recent advances in our understanding of the processes that contribute to the evolution of antibiotic resistance, with a particular focus on hypermutation mediated by the SOS pathway and horizontal gene transfer. We explore the molecular mechanisms involved in acquired resistance and discuss their viability as potential targets. We propose that additional studies into these adaptive mechanisms not only can provide insights into evolution but also can offer a strategy for potentiating our current antibiotic arsenal. PMID:26016604

  19. [Modification of antibiotic resistance in microbial symbiosis].

    PubMed

    Aznabaeva, L M; Usviatsov, B Ia; Bukharin, O V

    2010-01-01

    In antibiotic therapy it is necessary to use drugs active against the pathogen in its association with the host normal microflora. The aim of the study was to investigate modification of antibiotic resistance under conditions of the pathogen association with the representatives of the host normal microflora and to develop the microbiological criteria for determining effectiveness of antibacterials. Modification of microbial antibiotic resistance was investigated in 408 associations. Various changes in the antibiotic resistance of the strains were revealed: synergism, antagonism and indifference. On the basis of the results it was concluded that in the choice of the antibiotic active against Staphylococcus aureus and Streptococcus pyogenes the preference should be given to oxacillin, gentamicin and levomycetin, since the resistance of the pathogens to these antibiotics under the association conditions did not increase, which could contribute to their destruction, whereas the resistance of the normoflora increased or did not change, which was important for its retention in the biocenosis. The data on changeability of the antibiotic resistance of the microbial strains under the association conditions made it possible to develop microbiological criteria for determining effectiveness of antibiotics in the treatment of inflammatory diseases of microbial etiology (RF Patent No. 2231554). PMID:21033469

  20. The isolation of antibiotic resistant coliforms from meat and sewage.

    PubMed

    Bensink, J C; Frost, A J; Mathers, W; Mutimer, M D; Rankin, G; Woolcock, J B

    1981-01-01

    Beef and pig carcases, meat products, frozen chickens, and sewage were examined in 3 separate surveys for antibiotic resistant coliforms. Escherichia coli was isolated from 18 of 50 beef carcases; the numbers were low and resistance was found only to tetracycline. E. coli was isolated from 45 to 50 pig carcases; the numbers were high and showed a range of patterns of multiple antibiotic resistance. In meat products, the proportion of E. coli in contaminating organisms was low, and most resistance found was to tetracycline and streptomycin. E. coli was isolated from 66 of 75 chickens and these gave 23 patterns of antibiotic resistance, often multiple. Sewage from hospital or domestic origin and abattoir effluent yielded approximately 10(6) coliforms/ml, most of which were resistant to one or more antibiotics; few of those from hospital or domestic origin however, were classified as E. coli of faecal origin. Twenty-four patterns of resistance were found in coliforms from domestic sewage, 19 from hospital sewage and 11 from abattoir effluent. Transfer of resistance, often multiple, was achieved from 55% of 447 resistant strains to an E. coli K12 recipient. Much more information is required on the prevalence of R-factors in bacteria associated with food producing animals and their products. PMID:7016108

  1. Complex Multiple Antibiotic and Mercury Resistance Region Derived from the r-det of NR1 (R100)

    PubMed Central

    Partridge, Sally R.; Hall, Ruth M.

    2004-01-01

    The sequence of the 45.2-kb multidrug and mercury resistance region of pRMH760, a large plasmid from a clinical isolate of Klebsiella pneumoniae collected in 1997 in Australia, was completed. Most of the modules found in the resistance determinant (r-det), or Tn2670, region of NR1 (also known as R100), isolated from a Shigella flexneri strain in Japan in the late 1950s, were present in pRMH760 but in a different configuration. The location was also different, with the Tn2670-derived region flanked by the transposition module of Tn1696 and a mercury resistance module almost identical to one found in the plasmid pDU1358. This arrangement is consistent with a three-step process. First, the r-det was circularized via homologous recombination between the IS1 elements and reincorporated at a new location, possibly in a different plasmid, via homologous recombination between the 5′-conserved (5′-CS) or 3′-CS of the In34 integron in the r-det and the same region of a second class 1 integron in a Tn1696 relative. Subsequently, resolvase-mediated recombination between the res sites in the r-det and a second mercury resistance transposon removed one end of the Tn1696-like transposon and part of the second transposon. Other events occurring within the r-det-derived portion have also contributed to the formation of the pRMH760 resistance region. Tn2 or a close relative that includes the blaTEM-1b gene had moved into the Tn21 mercury resistance module with subsequent deletion of the adjacent sequence, and all four 38-bp inverted repeats corresponding to Tn21 family transposon termini have been interrupted by an IS4321-like element. PMID:15504849

  2. Antibiotic resistance: are we all doomed?

    PubMed

    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.

  3. Antibiotic resistance: are we all doomed?

    PubMed

    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

  4. Coping with antibiotic resistance: contributions from genomics

    PubMed Central

    2010-01-01

    Antibiotic resistance is a public health issue of global dimensions with a significant impact on morbidity, mortality and healthcare-associated costs. The problem has recently been worsened by the steady increase in multiresistant strains and by the restriction of antibiotic discovery and development programs. Recent advances in the field of bacterial genomics will further current knowledge on antibiotic resistance and help to tackle the problem. Bacterial genomics and transcriptomics can inform our understanding of resistance mechanisms, and comparative genomic analysis can provide relevant information on the evolution of resistant strains and on resistance genes and cognate genetic elements. Moreover, bacterial genomics, including functional and structural genomics, is also proving to be instrumental in the identification of new targets, which is a crucial step in new antibiotic discovery programs. PMID:20236502

  5. Mechanisms of antibiotic resistance in enterococci

    PubMed Central

    Miller, William R; Munita, Jose M; Arias, Cesar A

    2015-01-01

    Multidrug-resistant (MDR) enterococci are important nosocomial pathogens and a growing clinical challenge. These organisms have developed resistance to virtually all antimicrobials currently used in clinical practice using a diverse number of genetic strategies. Due to this ability to recruit antibiotic resistance determinants, MDR enterococci display a wide repertoire of antibiotic resistance mechanisms including modification of drug targets, inactivation of therapeutic agents, overexpression of efflux pumps and a sophisticated cell envelope adaptive response that promotes survival in the human host and the nosocomial environment. MDR enterococci are well adapted to survive in the gastrointestinal tract and can become the dominant flora under antibiotic pressure, predisposing the severely ill and immunocompromised patient to invasive infections. A thorough understanding of the mechanisms underlying antibiotic resistance in enterococci is the first step for devising strategies to control the spread of these organisms and potentially establish novel therapeutic approaches. PMID:25199988

  6. A locked nucleic acid (LNA)-based real-time PCR assay for the rapid detection of multiple bacterial antibiotic resistance genes directly from positive blood culture.

    PubMed

    Zhu, Lingxiang; Shen, Dingxia; Zhou, Qiming; Li, Zexia; Fang, Xiangdong; Li, Quan-Zhen

    2015-01-01

    Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA)-based quantitative real-time PCR (LNA-qPCR) method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1-10 colony forming units (CFU) per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4%) were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.

  7. Overview: Global and Local Impact of Antibiotic Resistance.

    PubMed

    Watkins, Richard R; Bonomo, Robert A

    2016-06-01

    The rapid and ongoing spread of antibiotic resistance poses a serious threat to global public health. The indiscriminant use of antibiotics in agriculture and human medicine along with increasingly connected societies has fueled the distribution of antibiotic-resistant bacteria. These factors together have led to rising numbers of infections caused by multidrug-resistant and pan-resistant bacteria, with increases in morbidity and mortality. This article summarizes the trends in antibiotic resistance, discusses the impact of antibiotic resistance on society, and reviews the use of antibiotics in agriculture. Feasible ways to tackle antibiotic resistance to avert a post-antibiotic era are suggested.

  8. The Antibiotic Resistance Problem Revisited

    ERIC Educational Resources Information Center

    Lawson, Michael A.

    2008-01-01

    The term "antibiotic" was first proposed by Vuillemin in 1889 but was first used in the current sense by Walksman in 1941. An antibiotic is defined as a "derivative produced by the metabolism of microorganisms that possess antibacterial activity at low concentrations and is not toxic to the host." In this article, the author describes how…

  9. Management Options For Reducing The Release Of Antibiotics And Antibiotic Resistance Genes To The Environment

    EPA Science Inventory

    Background: There is growing concern worldwide about the role of polluted soil and water - 77 environments in the development and dissemination of antibiotic resistance. 78 Objective: To identify management options for reducing the spread of antibiotics and 79 antibiotic resist...

  10. A systematic review and meta-analysis of the effects of antibiotic consumption on antibiotic resistance

    PubMed Central

    2014-01-01

    Background Greater use of antibiotics during the past 50 years has exerted selective pressure on susceptible bacteria and may have favoured the survival of resistant strains. Existing information on antibiotic resistance patterns from pathogens circulating among community-based patients is substantially less than from hospitalized patients on whom guidelines are often based. We therefore chose to assess the relationship between the antibiotic resistance pattern of bacteria circulating in the community and the consumption of antibiotics in the community. Methods Both gray literature and published scientific literature in English and other European languages was examined. Multiple regression analysis was used to analyse whether studies found a positive relationship between antibiotic consumption and resistance. A subsequent meta-analysis and meta-regression was conducted for studies for which a common effect size measure (odds ratio) could be calculated. Results Electronic searches identified 974 studies but only 243 studies were considered eligible for inclusion by the two independent reviewers who extracted the data. A binomial test revealed a positive relationship between antibiotic consumption and resistance (p < .001) but multiple regression modelling did not produce any significant predictors of study outcome. The meta-analysis generated a significant pooled odds ratio of 2.3 (95% confidence interval 2.2 to 2.5) with a meta-regression producing several significant predictors (F(10,77) = 5.82, p < .01). Countries in southern Europe produced a stronger link between consumption and resistance than other regions. Conclusions Using a large set of studies we found that antibiotic consumption is associated with the development of antibiotic resistance. A subsequent meta-analysis, with a subsample of the studies, generated several significant predictors. Countries in southern Europe produced a stronger link between consumption and resistance than other

  11. Antibacterial activity of Lactobacillus acidophilus strains isolated from honey marketed in Malaysia against selected multiple antibiotic resistant (MAR) Gram-positive bacteria.

    PubMed

    Aween, Mohamed Mustafa; Hassan, Zaiton; Muhialdin, Belal J; Eljamel, Yossra A; Al-Mabrok, Asma Saleh W; Lani, Mohd Nizam

    2012-07-01

    A total of 32 lactic acid bacteria (LAB) were isolated from 13 honey samples commercially marketed in Malaysia, 6 strains identified as Lactobacillus acidophilus by API CHL50. The isolates had antibacterial activities against multiple antibiotic resistant's Staphylococcus aureus (25 to 32 mm), Staphylococcus epidermis (14 to 22 mm) and Bacillus subtilis (12 to 19 mm) in the agar overlay method after 24 h incubation at 30 °C. The crude supernatant was heat stable at 90 °C and 121 °C for 1 h. Treatment with proteinase K and RNase II maintained the antimicrobial activity of all the supernatants except sample H006-A and H010-G. All the supernatants showed antimicrobial activities against target bacteria at pH 3 and pH 5 but not at pH 6 within 72 h incubation at 30 °C. S. aureus was not inhibited by sample H006-A isolated from Libyan honey and sample H008-D isolated from Malaysian honey at pH 5, compared to supernatants from other L. acidophilus isolates. The presence of different strains of L. acidophilus in honey obtained from different sources may contribute to the differences in the antimicrobial properties of honey. PMID:22757710

  12. Methicillin-resistant Staphylococcus aureus antibiotic resistance and virulence.

    PubMed

    Xia, Jufeng; Gao, Jianjun; Kokudo, Norihiro; Hasegawa, Kiyoshi; Tang, Wei

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most critical causes of healthcare-related or community-related infections. Resistance to most β-lactam antibiotics makes MRSA a big threat to clinical treatment. Utilization of low efficiency antibiotics such as vancomycin and teicoplanin makes new choices for therapies. Recently, much researchhas shed light on relevance between genetic mutations of MRSA and clinical characteristics such as antibiotic resistance, and virulence. These findings could contribute to development of novel antibiotics and vaccines.

  13. Acquired Antibiotic Resistance Genes: An Overview

    PubMed Central

    van Hoek, Angela H. A. M.; Mevius, Dik; Guerra, Beatriz; Mullany, Peter; Roberts, Adam Paul; Aarts, Henk J. M.

    2011-01-01

    In this review an overview is given on antibiotic resistance (AR) mechanisms with special attentions to the AR genes described so far preceded by a short introduction on the discovery and mode of action of the different classes of antibiotics. As this review is only dealing with acquired resistance, attention is also paid to mobile genetic elements such as plasmids, transposons, and integrons, which are associated with AR genes, and involved in the dispersal of antimicrobial determinants between different bacteria. PMID:22046172

  14. Curing bacteria of antibiotic resistance: reverse antibiotics, a novel class of antibiotics in nature.

    PubMed

    Hiramatsu, Keiichi; Igarashi, Masayuki; Morimoto, Yuh; Baba, Tadashi; Umekita, Maya; Akamatsu, Yuzuru

    2012-06-01

    By screening cultures of soil bacteria, we re-discovered an old antibiotic (nybomycin) as an antibiotic with a novel feature. Nybomycin is active against quinolone-resistant Staphylococcus aureus strains with mutated gyrA genes but not against those with intact gyrA genes against which quinolone antibiotics are effective. Nybomycin-resistant mutant strains were generated from a quinolone-resistant, nybomycin-susceptible, vancomycin-intermediate S. aureus (VISA) strain Mu 50. The mutants, occurring at an extremely low rate (<1 × 10(-11)/generation), were found to have their gyrA genes back-mutated and to have lost quinolone resistance. Here we describe nybomycin as the first member of a novel class of antibiotics designated 'reverse antibiotics'. PMID:22534508

  15. Assessing Antibiotic Resistance of Staphyloccocus: Students Use Their Own Microbial Flora To Explore Antibiotic Resistance.

    ERIC Educational Resources Information Center

    Omoto, Charlotte K.; Malm, Kirstin

    2003-01-01

    Describes a microbiology laboratory experiment in which students test their own microbial flora of Staphylococcus for antibiotic resistance. Provides directions on how to conduct the experiment. (YDS)

  16. Chlorinated phenol-induced physiological antibiotic resistance in Pseudomonas aeruginosa.

    PubMed

    Muller, Jocelyn Fraga; Ghosh, Sudeshna; Ikuma, Kaoru; Stevens, Ann M; Love, Nancy G

    2015-11-01

    Pseudomonas aeruginosa is a ubiquitous environmental bacterium and an opportunistic pathogen with the ability to rapidly develop multidrug resistance under selective pressure. Previous work demonstrated that upon exposure to the environmental contaminant pentachlorophenol (PCP), P. aeruginosa PAO1 increases expression of multiple multidrug efflux pumps, including the MexAB-OprM pump. The current study describes increases in the antibiotic resistance of PAO1 upon exposure to PCP and other chlorinated organics, including triclosan. Only exposure to chlorinated phenols induced the mexAB-oprM-mediated antibiotic-resistant phenotype. Thus, chlorinated phenols have the potential to contribute to transient phenotypic increases of antibiotic resistance that are relevant when both compounds are present in the environment.

  17. The fitness costs of antibiotic resistance mutations

    PubMed Central

    Melnyk, Anita H; Wong, Alex; Kassen, Rees

    2015-01-01

    Antibiotic resistance is increasing in pathogenic microbial populations and is thus a major threat to public health. The fate of a resistance mutation in pathogen populations is determined in part by its fitness. Mutations that suffer little or no fitness cost are more likely to persist in the absence of antibiotic treatment. In this review, we performed a meta-analysis to investigate the fitness costs associated with single mutational events that confer resistance. Generally, these mutations were costly, although several drug classes and species of bacteria on average did not show a cost. Further investigations into the rate and fitness values of compensatory mutations that alleviate the costs of resistance will help us to better understand both the emergence and management of antibiotic resistance in clinical settings. PMID:25861385

  18. Antibiotic resistance mechanisms of Myroides sp.

    PubMed

    Hu, Shao-hua; Yuan, Shu-xing; Qu, Hai; Jiang, Tao; Zhou, Ya-jun; Wang, Ming-xi; Ming, De-song

    2016-03-01

    Bacteria of the genus Myroides (Myroides spp.) are rare opportunistic pathogens. Myroides sp. infections have been reported mainly in China. Myroides sp. is highly resistant to most available antibiotics, but the resistance mechanisms are not fully elucidated. Current strain identification methods based on biochemical traits are unable to identify strains accurately at the species level. While 16S ribosomal RNA (rRNA) gene sequencing can accurately achieve this, it fails to give information on the status and mechanisms of antibiotic resistance, because the 16S rRNA sequence contains no information on resistance genes, resistance islands or enzymes. We hypothesized that obtaining the whole genome sequence of Myroides sp., using next generation sequencing methods, would help to clarify the mechanisms of pathogenesis and antibiotic resistance, and guide antibiotic selection to treat Myroides sp. infections. As Myroides sp. can survive in hospitals and the environment, there is a risk of nosocomial infections and pandemics. For better management of Myroides sp. infections, it is imperative to apply next generation sequencing technologies to clarify the antibiotic resistance mechanisms in these bacteria.

  19. Antibiotic resistance mechanisms of Myroides sp.*

    PubMed Central

    Hu, Shao-hua; Yuan, Shu-xing; Qu, Hai; Jiang, Tao; Zhou, Ya-jun; Wang, Ming-xi; Ming, De-song

    2016-01-01

    Bacteria of the genus Myroides (Myroides spp.) are rare opportunistic pathogens. Myroides sp. infections have been reported mainly in China. Myroides sp. is highly resistant to most available antibiotics, but the resistance mechanisms are not fully elucidated. Current strain identification methods based on biochemical traits are unable to identify strains accurately at the species level. While 16S ribosomal RNA (rRNA) gene sequencing can accurately achieve this, it fails to give information on the status and mechanisms of antibiotic resistance, because the 16S rRNA sequence contains no information on resistance genes, resistance islands or enzymes. We hypothesized that obtaining the whole genome sequence of Myroides sp., using next generation sequencing methods, would help to clarify the mechanisms of pathogenesis and antibiotic resistance, and guide antibiotic selection to treat Myroides sp. infections. As Myroides sp. can survive in hospitals and the environment, there is a risk of nosocomial infections and pandemics. For better management of Myroides sp. infections, it is imperative to apply next generation sequencing technologies to clarify the antibiotic resistance mechanisms in these bacteria. PMID:26984839

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

    PubMed Central

    Bennett, P M

    2008-01-01

    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

  1. [Antibiotic resistance of bacteria Campylobacter sp].

    PubMed

    Rzewuska, Katarzyna; Korsak, Dorota; Maćkiw, Elzbieta

    2010-01-01

    Campylobacter is recognized as a major cause of human acute bacterial enteritis. The incidence of human Campylobacter infection has increased markedly in both developed and developing countries and, more significantly, so has rapid emergence of antibiotic-resistant Campylobacter strains. It is caused by improper applying antibiotics in treating people and too frequent applying these substances in the animal husbandry. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter spp. are discussed.

  2. Rapid Antibiotic Resistance Evolution of GASP Mutants

    NASA Astrophysics Data System (ADS)

    Zhang, Qiucen; Kim, Hyunsung; Pourmand, Nader; Austin, Robert

    2012-02-01

    The GASP phenotype in bacteria is due to a mutation which enables the bacteria to grow under high stress conditions where other bacteria stop growing. We probe using our Death Galaxy microenvironment how rapidly the GASP mutant can evolve resistance to mutagenic antibiotics compared to wild-type bacteria, and explore the genomic landscape changes due to the evolution of resistance.

  3. [Evolution in the antibiotic susceptibility and resistance].

    PubMed

    Stefani, S

    2009-07-01

    Over the last decade the proliferation of antibiotic-resistant pathogens has been a growing problem, especially in some geographic areas, making useless most of the classical antibiotic therapies. The rapid emergence of resistant bacteria is the result of different factors as the intrinsic microbial complexity, the growing attitude to travel of humans, animals and goods, the use of antibiotics outside hospitals, and the lack of precise therapeutic chooses for high risk group of patients. The antibiotic-resistance becomes certainly a serious problem when a resistant pathogen, and often multi-resistant today, is present in an infective site. In fact in a recent estimate of the Centre for Disease Control and Prevention (CDC) about 90.000 deaths per year in the USA are attributable to bacterial infections and in particular to resistant pathogens. It appears clear that the clinic relevance of this problem is the decimation of the sensible germs of the normal flora that leads to the upper hand of the only resistant bacteria. The antibiotic therapy, in fact, select the resistance and each bacteria has developed a particular strategy to survive: mutations of the genetic content or acquisition of resistance genes from the external. Among the Gram positive bacteria, besides methicillin resistant Staphyloccocus aureus, there are other pathogens such as coagulase-negative staphylococci (CoNS), Enterococcus faecium and Enterococcus faecalis, some species of streptococci and multiresistant Corynebacterium. The CoNS, eg. S. epidermidis, S. hominis and S. haemolyticus, are recognized as new important nosocomial pathogens and are not only responsible of invasive infections but have become in few years resistant to oxacillin (more than 60%) and multiresistant. The unsuspected fragility of glycopeptides, which for 40 years have been the most important treatment against infections due to Gram-positive bacteria, has posed the need for new antimicrobial molecules. Among the therapeutic

  4. [New aspects of antibiotic resistance and possibilities of its prevention].

    PubMed

    Blahová, J; Králiková, K; Krcméry, V

    2001-08-01

    New phenomena of the antibiotic resistance in bacteria have recently appeared. The may hold present explosive development of resistance and prevent its transferability from multiple drug resistant bacteria to still sensitive ones. They may prevent the production of so-called extended-spectrum beta-lactamases (ESBLs) among Enterobacteriaceae producing resistance virtually to all penicillins and cephalosporins with exception of those antibiotics potentiated by clavulanic acid or sulbactam, the resistance to vancomycin in enterococci and staphylococce, and the resistance of Stenotrophomonas maltophilia. Factors participating on the development of resistance include: a) transferability of resistance genes among bacteria which explosively change susceptible strains to resistant ones, b) dosage and types of antibiotics which cause the selection pressure to certain species of bacteria, c) level of organization and strict adherence to hygienic and anti-epidemic regimen starting with the entry of patients into the hospital. Analyses are necessary to check whether the patient brings resistant bacteria with a transferable resistance (with ESBLs) into the hospital. Preventive measures would be strictly applied to stop the clonal spread of resistant strains among the patients and/or hospital environment, which occurs if these strains have such opportunity. Last, but not least to be considered is the dosage, composition and rationality of administration of antibacterials, mainly in post-operative prophylaxis in intensive care units, in so-called empirical usage, etc. At the same time, it would be highly unethical to hesitate with application of antibacterials to patients when it is justified, necessary and rational. Hospital antibiotics policy should rationally decide between these alternatives in each application of antibiotics or their combinations.

  5. IncM Plasmid R1215 Is the Source of Chromosomally Located Regions Containing Multiple Antibiotic Resistance Genes in the Globally Disseminated Acinetobacter baumannii GC1 and GC2 Clones

    PubMed Central

    Blackwell, Grace A.

    2016-01-01

    ABSTRACT Clear similarities between antibiotic resistance islands in the chromosomes of extensively antibiotic-resistant isolates from the two dominant, globally distributed Acinetobacter baumannii clones, GC1 and GC2, suggest a common origin. A close relative of the likely progenitor of both of these regions was found in R1215, a conjugative IncM plasmid from a Serratia marcescens strain isolated prior to 1980. The 37.8-kb resistance region in R1215 lies within the mucB gene and includes aacC1, aadA1, aphA1b, blaTEM, catA1, sul1, and tetA(A), genes that confer resistance to gentamicin, streptomycin and spectinomycin, kanamycin and neomycin, ampicillin, chloramphenicol, sulfamethoxazole, and tetracycline, respectively. The backbone of this region is derived from Tn1721 and is interrupted by a hybrid Tn2670 (Tn21)-Tn1696-type transposon, Tn6020, and an incomplete Tn1. After minor rearrangements, this R1215 resistance island can generate AbGRI2-0*, the predicted earliest form of the IS26-bounded AbGRI2-type resistance island of GC2 isolates, and to the multiple antibiotic resistance region (MARR) of AbaR0, the precursor of this region in AbaR-type resistance islands in the GC1 group. A 29.9-kb circle excised by IS26 has been inserted into the A. baumannii chromosome to generate AbGRI2-0*. To create the MARR of AbaR0, a different circular form, again generated by IS26 from an R1215 resistance region variant, has been opened at a different point by recombination with a copy of the sul1 gene already present in the AbaR precursor. Recent IncM plasmids related to R1215 have a variant resistance island containing a blaSHV gene in the same location. IMPORTANCE Two lineages of extensively antibiotic-resistant A. baumannii currently plaguing modern medicine each acquired resistance to all of the original antibiotics (ampicillin, tetracycline, kanamycin, and sulfonamides) by the end of the 1970s and then became resistant to antibiotics from newer families after they were

  6. Antibiotic resistance mechanisms in M. tuberculosis: an update.

    PubMed

    Nguyen, Liem

    2016-07-01

    Treatment of tuberculosis (TB) has been a therapeutic challenge because of not only the naturally high resistance level of Mycobacterium tuberculosis to antibiotics but also the newly acquired mutations that confer further resistance. Currently standardized regimens require patients to daily ingest up to four drugs under direct observation of a healthcare worker for a period of 6-9 months. Although they are quite effective in treating drug susceptible TB, these lengthy treatments often lead to patient non-adherence, which catalyzes for the emergence of M. tuberculosis strains that are increasingly resistant to the few available anti-TB drugs. The rapid evolution of M. tuberculosis, from mono-drug-resistant to multiple drug-resistant, extensively drug-resistant and most recently totally drug-resistant strains, is threatening to make TB once again an untreatable disease if new therapeutic options do not soon become available. Here, I discuss the molecular mechanisms by which M. tuberculosis confers its profound resistance to antibiotics. This knowledge may help in developing novel strategies for weakening drug resistance, thus enhancing the potency of available antibiotics against both drug susceptible and resistant M. tuberculosis strains. PMID:27161440

  7. Characterization of antibiotic-resistance genes in antibiotic resistance Escherichia coli isolates from a lake.

    PubMed

    Wang, Chao; Gu, Xiucong; Zhang, Songhe; Wang, Peifang; Guo, Chuan; Gu, Ju; Hou, Jun

    2013-11-01

    The spread of antibiotic-resistance bacteria and antibiotic-resistance genes (ARGs) has been of concern worldwide. In this study, 114 Escherichia coli isolates were isolated from surface water samples of a lake to identify their susceptibility to antibiotics, including tetracycline (TC), gentamicin (GN), ampicillin (AMP), streptomycin (ST), oxytetracycline (OC), levofloxacin (LEV), nalidixic acid (NA), and sulfamethoxazole/trimethoprim (SFT). Isolates showing resistance to TC, GN, AMP, ST, OC, LEV, NA, and SFT occurred in 50, 76, 68, 71, 55, 32, 82, and 85 % of the total isolates, respectively. Thirty-seven different resistance patterns were identified, and the most abundant resistance profile (28 of 104) was TC/GN/AMP/ST/OC/LEV/NA/SFT. The occurrence of 29 ARGs were detected in their corresponding resistance clones, and 88 % of TC-resistance, 94 % of SFT-resistance, 90 % of AMP-resistance, 78 % of ST-resistance, and 72 % of quinolone-resistance clones can be described by their corresponding ARGs. It should be noted that most of these antibiotic-resistance clones harbored at least two corresponding ARGs, indicating that high frequencies of combined ARGs occurred in these isolates. In addition, 9 new types of DNA sequence of qnr(B) gene were obtained and were clustered into the same group as showed by phylogenetic trees analysis. These results suggest that the development of antibiotic resistance can be ascribed to the high frequency in the recombination of ARGs through horizontal gene transfer.

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

    PubMed

    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

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

    PubMed

    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.

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

    PubMed

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

    2016-01-01

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

  11. Antibiotic resistance of bacteria in raw and biologically treated sewage and in groundwater below leaking sewers.

    PubMed

    Gallert, C; Fund, K; Winter, J

    2005-11-01

    More than 750 isolates of faecal coliforms (>200 strains), enterococci (>200 strains) and pseudomonads (>340 strains) from three wastewater treatment plants (WTPs) and from four groundwater wells in the vicinity of leaking sewers were tested for resistance against 14 antibiotics. Most, or at least some, strains of the three bacterial groups, isolated from raw or treated sewage of the three WTPs, were resistant against penicillin G, ampicillin, vancomycin, erythromycin, triple sulfa and trimethoprim/sulfamethoxazole (SXT). Only a few strains of pseudomonads or faecal coliforms were resistant against some of the other tested antibiotics. The antibiotic resistances of pseudomonads, faecal coliforms and enterococci from groundwater varied to a higher extent. In contrast to the faecal coliforms and enterococci, most pseudomonads from all groundwater samples, including those from non-polluted groundwater, were additionally resistant against chloramphenicol and SXT. Pseudomonads from sewage and groundwater had more multiple antibiotic resistances than the faecal coliforms or the enterococci, and many pseudomonads from groundwater were resistant to more antibiotics than those from sewage. The pseudomonads from non-polluted groundwater were the most resistant isolates of all. The few surviving faecal coliforms in groundwater seemed to gain multiple antibiotic resistances, whereas the enterococci lost antibiotic resistances. Pseudomonads, and presumably, other autochthonous soil or groundwater bacteria, such as antibiotic-producing Actinomyces sp., seem to contribute significantly to the gene pool for acquisition of resistances against antibiotics in these environments. PMID:16001254

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

    PubMed

    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

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

    PubMed

    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.

  14. The drinking water treatment process as a potential source of affecting the bacterial antibiotic resistance.

    PubMed

    Bai, Xiaohui; Ma, Xiaolin; Xu, Fengming; Li, Jing; Zhang, Hang; Xiao, Xiang

    2015-11-15

    Two waterworks, with source water derived from the Huangpu or Yangtze River in Shanghai, were investigated, and the effluents were plate-screened for antibiotic-resistant bacteria (ARB) using five antibiotics: ampicillin (AMP), kanamycin (KAN), rifampicin (RFP), chloramphenicol (CM) and streptomycin (STR). The influence of water treatment procedures on the bacterial antibiotic resistance rate and the changes that bacteria underwent when exposed to the five antibiotics at concentration levels ranging from 1 to 100 μg/mL were studied. Multi-drug resistance was also analyzed using drug sensitivity tests. The results indicated that bacteria derived from water treatment plant effluent that used the Huangpu River rather than the Yangtze River as source water exhibited higher antibiotic resistance rates against AMP, STR, RFP and CM but lower antibiotic resistance rates against KAN. When the antibiotic concentration levels ranged from 1 to 10 μg/mL, the antibiotic resistance rates of the bacteria in the water increased as water treatment progressed. Biological activated carbon (BAC) filtration played a key role in increasing the antibiotic resistance rate of bacteria. Chloramine disinfection can enhance antibiotic resistance. Among the isolated ARB, 75% were resistant to multiple antibiotics. Ozone oxidation, BAC filtration and chloramine disinfection can greatly affect the relative abundance of bacteria in the community.

  15. The expression of antibiotic resistance genes in antibiotic-producing bacteria.

    PubMed

    Mak, Stefanie; Xu, Ye; Nodwell, Justin R

    2014-08-01

    Antibiotic-producing bacteria encode antibiotic resistance genes that protect them from the biologically active molecules that they produce. The expression of these genes needs to occur in a timely manner: either in advance of or concomitantly with biosynthesis. It appears that there have been at least two general solutions to this problem. In many cases, the expression of resistance genes is tightly linked to that of antibiotic biosynthetic genes. In others, the resistance genes can be induced by their cognate antibiotics or by intermediate molecules from their biosynthetic pathways. The regulatory mechanisms that couple resistance to antibiotic biosynthesis are mechanistically diverse and potentially relevant to the origins of clinical antibiotic resistance.

  16. Antibiotic resistance genes in water environment.

    PubMed

    Zhang, Xu-Xiang; Zhang, Tong; Fang, Herbert H P

    2009-03-01

    The use of antibiotics may accelerate the development of antibiotic resistance genes (ARGs) and bacteria which shade health risks to humans and animals. The emerging of ARGs in the water environment is becoming an increasing worldwide concern. Hundreds of various ARGs encoding resistance to a broad range of antibiotics have been found in microorganisms distributed not only in hospital wastewaters and animal production wastewaters, but also in sewage, wastewater treatment plants, surface water, groundwater, and even in drinking water. This review summarizes recently published information on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs, including specific and multiplex PCR (polymerase chain reaction), real-time PCR, DNA sequencing, and hybridization based techniques. PMID:19130050

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

    PubMed

    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.

  18. NOTE: Dielectrophoretic assay of bacterial resistance to antibiotics

    NASA Astrophysics Data System (ADS)

    Johari, Juliana; Hübner, Yvonne; Hull, Judith C.; Dale, Jeremy W.; Hughes, Michael P.

    2003-07-01

    The dielectrophoretic collection spectra of antibiotic-sensitive and antibiotic-resistant strains of Staphylococcus epidermidis have been determined. These indicate that in the absence of antibiotic treatment there is a strong similarity between the dielectric properties of sensitive and resistant strains, and that there is a significant difference between the sensitive strains before and after treatment with the antibiotic streptomycin after 24 h exposure. This method offers possibilities for the assessment of bacterial resistance to antibiotics.

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

    PubMed Central

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

    2016-01-01

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  1. Helicobacter pylori and Antibiotic Resistance, A Continuing and Intractable Problem.

    PubMed

    Hu, Yue; Zhang, Meng; Lu, Bin; Dai, Jinfeng

    2016-10-01

    Helicobacter pylori, a human pathogen with a high global prevalence, is the causative pathogen for multiple gastrointestinal diseases, especially chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric malignancies. Antibiotic therapies remain the mainstay for H. pylori eradication; however, this strategy is hampered by the emergence and spread of H. pylori antibiotic resistance. Exploring the mechanistic basis of this resistance is becoming one of the major research questions in contemporary biomedical research, as such knowledge could be exploited to devise novel rational avenues for counteracting the existing resistance and devising strategies to avoid the development of a novel anti-H. pylori medication. Encouragingly, important progress in this field has been made recently. Here, we attempt to review the current state and progress with respect to the molecular mechanism of antibiotic resistance for H. pylori. A picture is emerging in which mutations of various genes in H. pylori, resulting in decreased membrane permeability, altered oxidation-reduction potential, and a more efficient efflux pump system. The increased knowledge on these mechanisms produces hope that antibiotic resistance in H. pylori can ultimately be countered.

  2. Antibiotic profiling of Clostridium difficile ribotype 176--A multidrug resistant relative to C. difficile ribotype 027.

    PubMed

    Krutova, Marcela; Matejkova, Jana; Tkadlec, Jan; Nyc, Otakar

    2015-12-01

    Antibiotic profiling of twenty Czech Clostridium difficile PCR-ribotype 176 isolates revealed a high level of resistance to erythromycin, ciprofloxacin and moxifloxacin (n = 20) and to rifampicin (n = 13). Accumulation of resistance mechanisms to multiple antibiotics highlight that PCR-ribotype 176 belong to problematic epidemic strains.

  3. Antibiotic resistance gene discovery in food-producing animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous environmental reservoirs contribute to the widespread antibiotic resistance problem in human pathogens. One environmental reservoir of particular importance is the intestinal bacteria of food-producing animals. In this review I examine recent discoveries of antibiotic resistance genes in ...

  4. Antibiotic resistance breakers: can repurposed drugs fill the antibiotic discovery void?

    PubMed

    Brown, David

    2015-12-01

    Concern over antibiotic resistance is growing, and new classes of antibiotics, particularly against Gram-negative bacteria, are needed. However, even if the scientific hurdles can be overcome, it could take decades for sufficient numbers of such antibiotics to become available. As an interim solution, antibiotic resistance could be 'broken' by co-administering appropriate non-antibiotic drugs with failing antibiotics. Several marketed drugs that do not currently have antibacterial indications can either directly kill bacteria, reduce the antibiotic minimum inhibitory concentration when used in combination with existing antibiotics and/or modulate host defence through effects on host innate immunity, in particular by altering inflammation and autophagy. This article discusses how such 'antibiotic resistance breakers' could contribute to reducing the antibiotic resistance problem, and analyses a priority list of candidates for further investigation.

  5. Antibiotic resistance breakers: can repurposed drugs fill the antibiotic discovery void?

    PubMed

    Brown, David

    2015-12-01

    Concern over antibiotic resistance is growing, and new classes of antibiotics, particularly against Gram-negative bacteria, are needed. However, even if the scientific hurdles can be overcome, it could take decades for sufficient numbers of such antibiotics to become available. As an interim solution, antibiotic resistance could be 'broken' by co-administering appropriate non-antibiotic drugs with failing antibiotics. Several marketed drugs that do not currently have antibacterial indications can either directly kill bacteria, reduce the antibiotic minimum inhibitory concentration when used in combination with existing antibiotics and/or modulate host defence through effects on host innate immunity, in particular by altering inflammation and autophagy. This article discusses how such 'antibiotic resistance breakers' could contribute to reducing the antibiotic resistance problem, and analyses a priority list of candidates for further investigation. PMID:26493767

  6. Ecology and evolution of antibiotic resistance.

    PubMed

    Baquero, F; Alvarez-Ortega, C; Martinez, J L

    2009-12-01

    The evolution of bacterial pathogens towards antibiotic resistance is not just a relevant problem for human health, but a fascinating example of evolution that can be studied in real time as well. Although most antibiotics are natural compounds produced by environmental microbiota, exposure of bacterial populations to high concentrations of these compounds as the consequence of their introduction for human therapy (and later on for farming) a few decades ago is a very recent situation in evolutionary terms. Resistance genes are originated in environmental bacteria, where they have evolved for millions of years to play different functions that include detoxification, signal trafficking or metabolic functions among others. However, as the consequence of the strong selective pressure exerted by antimicrobials at clinical settings, farms and antibiotic-contaminated natural ecosystems, the selective forces driving the evolution of these potential resistance determinants have changed in the last few decades. Natural ecosystems contain a large number of potential resistance genes; nevertheless, just a few of them are currently present in gene-transfer units and disseminated among pathogens. Along the review, the processes implied in this situation and the consequences for the future evolution of resistance and the environmental microbiota are discussed.

  7. Study of Antibiotic Resistance Pattern in Methicillin Resistant Staphylococcus Aureus with Special Reference to Newer Antibiotic

    PubMed Central

    Kaur, Dardi Charan; Chate, Sadhana Sanjay

    2015-01-01

    The worldwide epidemic of antibiotic resistance is in danger of ending the golden age of antibiotic therapy. Resistance impacts on all areas of medicine, and is making successful empirical therapy much more difficult to achieve. Staphylococcus aureus demonstrates a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin, until the most recent, linezolid and daptomycin. Methicillin resistant S. aureus (MRSA) has become endemic today in hospitals worldwide. Resistance to the newer antimicrobial-agents — linezolid, vancomycin, teicoplanin, and daptomycin are been reported and also the fear of pandrug-resistance. This study was carried out to know the antimicrobial resistant pattern of MRSA to newer antibiotic, to know any isolates are extensively-drug resistant (XDR)/pandrug resistant (PDR), inducible macrolide-lincosamide streptogramin B (iMLSB), and mupirocin resistance. Thirty-six MRSA isolates resistant to the routinely tested antibiotic were further tested for list of antibiotic by a group of international experts. Isolates were tested for iMLSB and mupirocin resistance by the disk diffusion method. Of 385 MRSA, 36 (9.35%) isolates of MRSA were resistant to the routinely tested antibiotic. Among these 36 MRSA isolates, none of our isolates were XDR/PDR or showed resistant to anti-MRSA cephalosporins (ceftaroline), phosphonic acids, glycopeptides, glycylcyclines, and fucidanes. Lower resistance was seen in oxazolidinones (2.78%), streptogramins (5.56%), lipopeptide (5.56%). Thirty-four (94.44%) isolates showed constitutive MLSB (cMLSB) resistance and two (5.56%) iMLSB phenotypes. High- and low-level mupirocin resistance were seen in 13 (36.11%) and six (16.67%), respectively. In our study, none of our isolates were XDR or PDR. No resistance was observed to ceftaroline, telavancin, teicoplanin, and vancomycin; but the presence of linezolid resistance (1, 2.28%) and daptomycin resistance (2

  8. Occurrence of antibiotic resistance and characterization of resistant genes and integrons in Enterobacteriaceae isolated from integrated fish farms south China

    USGS Publications Warehouse

    Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.

    2011-01-01

    Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

  9. Molecular Analysis of Antibiotic Resistance Determinants and Plasmids in Malaysian Isolates of Multidrug Resistant Klebsiella pneumoniae

    PubMed Central

    Al-Marzooq, Farah; Mohd Yusof, Mohd Yasim; Tay, Sun Tee

    2015-01-01

    Infections caused by multidrug resistant Klebsiella pneumoniae have been increasingly reported in many parts of the world. A total of 93 Malaysian multidrug resistant K. pneumoniae isolated from patients attending to University of Malaya Medical Center, Kuala Lumpur, Malaysia from 2010-2012 were investigated for antibiotic resistance determinants including extended-spectrum beta-lactamases (ESBLs), aminoglycoside and trimethoprim/sulfamethoxazole resistance genes and plasmid replicons. CTX-M-15 (91.3%) was the predominant ESBL gene detected in this study. aacC2 gene (67.7%) was the most common gene detected in aminoglycoside-resistant isolates. Trimethoprim/sulfamethoxazole resistance (90.3%) was attributed to the presence of sul1 (53.8%) and dfrA (59.1%) genes in the isolates. Multiple plasmid replicons (1-4) were detected in 95.7% of the isolates. FIIK was the dominant replicon detected together with 13 other types of plasmid replicons. Conjugative plasmids (1-3 plasmids of ~3-100 kb) were obtained from 27 of 43 K. pneumoniae isolates. An ESBL gene (either CTX-M-15, CTX-M-3 or SHV-12) was detected from each transconjugant. Co-detection with at least one of other antibiotic resistance determinants [sul1, dfrA, aacC2, aac(6ˊ)-Ib, aac(6ˊ)-Ib-cr and qnrB] was noted in most conjugative plasmids. The transconjugants were resistant to multiple antibiotics including β-lactams, gentamicin and cotrimoxazole, but not ciprofloxacin. This is the first study describing the characterization of plasmids circulating in Malaysian multidrug resistant K. pneumoniae isolates. The results of this study suggest the diffusion of highly diverse plasmids with multiple antibiotic resistance determinants among the Malaysian isolates. Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of the multidrug resistant bacteria in healthcare settings. PMID:26203651

  10. Molecular Analysis of Antibiotic Resistance Determinants and Plasmids in Malaysian Isolates of Multidrug Resistant Klebsiella pneumoniae.

    PubMed

    Al-Marzooq, Farah; Mohd Yusof, Mohd Yasim; Tay, Sun Tee

    2015-01-01

    Infections caused by multidrug resistant Klebsiella pneumoniae have been increasingly reported in many parts of the world. A total of 93 Malaysian multidrug resistant K. pneumoniae isolated from patients attending to University of Malaya Medical Center, Kuala Lumpur, Malaysia from 2010-2012 were investigated for antibiotic resistance determinants including extended-spectrum beta-lactamases (ESBLs), aminoglycoside and trimethoprim/sulfamethoxazole resistance genes and plasmid replicons. CTX-M-15 (91.3%) was the predominant ESBL gene detected in this study. aacC2 gene (67.7%) was the most common gene detected in aminoglycoside-resistant isolates. Trimethoprim/sulfamethoxazole resistance (90.3%) was attributed to the presence of sul1 (53.8%) and dfrA (59.1%) genes in the isolates. Multiple plasmid replicons (1-4) were detected in 95.7% of the isolates. FIIK was the dominant replicon detected together with 13 other types of plasmid replicons. Conjugative plasmids (1-3 plasmids of ~3-100 kb) were obtained from 27 of 43 K. pneumoniae isolates. An ESBL gene (either CTX-M-15, CTX-M-3 or SHV-12) was detected from each transconjugant. Co-detection with at least one of other antibiotic resistance determinants [sul1, dfrA, aacC2, aac(6')-Ib, aac(6')-Ib-cr and qnrB] was noted in most conjugative plasmids. The transconjugants were resistant to multiple antibiotics including β-lactams, gentamicin and cotrimoxazole, but not ciprofloxacin. This is the first study describing the characterization of plasmids circulating in Malaysian multidrug resistant K. pneumoniae isolates. The results of this study suggest the diffusion of highly diverse plasmids with multiple antibiotic resistance determinants among the Malaysian isolates. Effective infection control measures and antibiotic stewardship programs should be adopted to limit the spread of the multidrug resistant bacteria in healthcare settings.

  11. [The international surveillance of antibiotics resistance].

    PubMed

    Frimodt-Møller, Niels

    2011-11-01

    The growth promoter story in the 1990 s increased the focus on antibiotic misuse and related resistance. A Danish EU conference, The Microbial Threat, in 1998 resulted in The Copenhagen Recommendations, on the basic principles for a policy to contain resistance, which was transformed into EU recommendations in 2001. Following this a range of programs on monitoring of resistance and consumption, research, national campaigns etc. has been accomplished. The US, Canada and Australia have also upgraded their efforts in this area, while the WHO lacks resources to approach the countries in the rest of the world, in which these problems are the worst. PMID:22053806

  12. Antibiotic resistance: from Darwin to Lederberg to Keynes.

    PubMed

    Amábile-Cuevas, Carlos F

    2013-04-01

    The emergence and spread of antibiotic-resistant bacteria reflects both, a gradual, completely Darwinian evolution, which mostly yields slight decreases in antibiotic susceptibility, along with phenotypes that are not precisely characterized as "resistance"; and sudden changes, from full susceptibility to full resistance, which are driven by a vast array of horizontal gene transfer mechanisms. Antibiotics select for more than just antibiotic resistance (i.e., increased virulence and enhanced gene exchange abilities); and many non-antibiotic agents or conditions select for or maintain antibiotic resistance traits as a result of a complex network of underlying and often overlapping mechanisms. Thus, the development of new antibiotics and thoughtful, integrated anti-infective strategies is needed to address the immediate and long-term threat of antibiotic resistance. Since the biology of resistance is complex, these new drugs and strategies will not come from free-market forces, or from "incentives" for pharmaceutical companies.

  13. Fate of antibiotic resistant bacteria and genes during wastewater chlorination: implication for antibiotic resistance control.

    PubMed

    Yuan, Qing-Bin; Guo, Mei-Ting; Yang, Jian

    2015-01-01

    This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L). The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L). By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L). However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.

  14. Fate of Antibiotic Resistant Bacteria and Genes during Wastewater Chlorination: Implication for Antibiotic Resistance Control

    PubMed Central

    Yuan, Qing-Bin; Guo, Mei-Ting; Yang, Jian

    2015-01-01

    This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L). The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L). By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L). However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination. PMID:25738838

  15. Antibiotic resistance genes & susceptibility patterns in staphylococci

    PubMed Central

    Duran, Nizami; Ozer, Burcin; Duran, Gulay Gulbol; Onlen, Yusuf; Demir, Cemil

    2012-01-01

    Background & objectives: This study was carried out to evaluate the association between the antibiotic susceptibility patterns and the antibiotic resistance genes in staphylococcal isolates obtained from various clinical samples of patients attending a teaching hospital in Hatay, Turkey. Methods: A total of 298 staphylococci clinical isolates were subjected to antimicrobial susceptibility testing. The genes implicated in resistance to oxacillin (mecA), gentamicin (aac(6’)/aph(2”), aph(3’-IIIa, ant(4’)-Ia), erythromycin (ermA, ermB, ermC, and msrA), tetracyclin (tetK, tetM), and penicillin (blaZ) were amplified using multiplex PCR method. Results: Methicillin resistance rate among 139 Staphlococcus aureus isolates was 16.5 and 25.9 per cent of S. aureus carried mecA gene. Of the 159 CoNS isolates, methicillin resistance rate was 18.9 and 29.6 per cent carried mecA gene. Ninety four isolates identified as gentamicin resistant phenotypically, contained at least one of the gentamicin resistance genes [aac(6’)/aph(2”), aph(3’)-IIIa, ant(4’)-Ia], 17 gentamicin-susceptible isolates were found as positive in terms of one or more resistance genes [aac(6’)/aph(2”), aph(3’)-IIIa, ant(4’)-Ia] by multiplex PCR. A total of 165 isolates were resistant to erythromycin, and contained at least one of the erythromycin resistance genes (ermA, ermB, ermC and msrA). Phenotypically, 106 staphylococcal isolates were resistant to tetracycline, 121 isolates carried either tetK or tetM or both resistance genes. The majority of staphylococci tested possessed the blaZ gene (89.9%). Interpretation & conclusions: The present results showed that the phenotypic antibiotic susceptibility patterns were not similar to those obtained by genotyping done by multiplex PCR. Rapid and reliable methods for antibiotic susceptibility are important to determine the appropriate therapy decisions. Multiplex PCR can be used for confirmation of the results obtained by conventional

  16. Prevalence and characterization of antibiotic resistant Enterococcus faecalis in French cheeses.

    PubMed

    Jamet, Emmanuel; Akary, Elodie; Poisson, Marie-Ange; Chamba, Jean-François; Bertrand, Xavier; Serror, Pascale

    2012-09-01

    Prevalence of enterococci and antibiotic resistance profiles of Enterococcus faecalis was analyzed in 126 French cheeses from retail stores. Forty-four percent of pasteurized or thermised-milk cheeses, and up to 92% of raw-milk cheeses contained detectable enterococci. A total of 337 antibiotic resistant enterococci were isolated in 29% and 60% of pasteurized-milk and raw-milk cheeses, respectively. E. faecalis was the predominant antibiotic resistant species recovered (81%), followed by Enterococcus faecium (13%), and Enterococcus durans (6%). The most prevalent antibiotic resistances were tetracycline (Tet) and minocycline (Min), followed by erythromycin (Ery), kanamycin (Kan) and chloramphenicol (Cm). The most common multiple antibiotic resistance phenotype was Cm Ery Kan Min Tet. The occurrence of antibiotic genes, as searched by PCR, was 100 % for aph3'IIIa, 96 % for ermB, 90 % for tetM and 80 % for catA in isolates resistant to Kan, Ery, Tet or Cm, respectively. MLST analysis of 30 multidrug resistant E. faecalis revealed that ST19, CC21, CC25 and CC55 isolates were the most common in cheeses. In conclusion, as in many other European countries, French cheeses do contain enterococci with multiple antibiotics resistances. However, low occurrence of high-level gentamicin resistant or sulfamethoxazole/trimethoprim-resistant enterococci and absence of vancomycin- or ampicillin- resistant enterococci indicate that cheeses cannot be considered as a major reservoir for nosocomial multi-drug resistant enterococci.

  17. Isolated cell behavior drives the evolution of antibiotic resistance.

    PubMed

    Artemova, Tatiana; Gerardin, Ylaine; Dudley, Carmel; Vega, Nicole M; Gore, Jeff

    2015-07-29

    Bacterial antibiotic resistance is typically quantified by the minimum inhibitory concentration (MIC), which is defined as the minimal concentration of antibiotic that inhibits bacterial growth starting from a standard cell density. However, when antibiotic resistance is mediated by degradation, the collective inactivation of antibiotic by the bacterial population can cause the measured MIC to depend strongly on the initial cell density. In cases where this inoculum effect is strong, the relationship between MIC and bacterial fitness in the antibiotic is not well defined. Here, we demonstrate that the resistance of a single, isolated cell-which we call the single-cell MIC (scMIC)-provides a superior metric for quantifying antibiotic resistance. Unlike the MIC, we find that the scMIC predicts the direction of selection and also specifies the antibiotic concentration at which selection begins to favor new mutants. Understanding the cooperative nature of bacterial growth in antibiotics is therefore essential in predicting the evolution of antibiotic resistance.

  18. [The roles of epigenetics and protein post-translational modifications in bacterial antibiotic resistance].

    PubMed

    Xie, Longxiang; Yu, Zhaoxiao; Guo, Siyao; Li, Ping; Abdalla, Abualgasim Elgaili; Xie, Jianping

    2015-08-01

    The increasing antibiotic resistance is now threatening to take us back to a pre-antibiotic era. Bacteria have evolved diverse resistance mechanisms, on which in-depth research could help the development of new strategies to control antibiotic-resistant infections. Epigenetic alterations and protein post-translational modifications (PTMs) play important roles in multiple cellular processes such as metabolism, signal transduction, protein degradation, DNA replication regulation and stress response. Recent studies demonstrated that epigenetics and PTMs also play vital roles in bacterial antibiotic resistance. In this review, we summarize the regulatory roles of epigenetic factors including DNA methylation and regulatory RNAs as well as PTMs such as phosphorylation and succinylation in bacterial antibiotic resistance, which may provide innovative perspectives on selecting antibacterial targets and developing antibiotics. PMID:26266782

  19. 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.

    PubMed

    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

  20. Impact of urban contamination of the La Paz River basin on thermotolerant coliform density and occurrence of multiple antibiotic resistant enteric pathogens in river water, irrigated soil and fresh vegetables.

    PubMed

    Poma, Violeta; Mamani, Nataniel; Iñiguez, Volga

    2016-01-01

    La Paz River in Andean highlands is heavily polluted with urban run-off and further contaminates agricultural lowlands and downstream waters at the Amazon watershed. Agricultural produce at this region is the main source of vegetables for the major Andean cities of La Paz and El Alto. We conducted a 1 year study, to evaluate microbial quality parameters and occurrence of multiple enteropathogenic bacteria (Enterohemorrhagic E. coli-EHEC, Enteroinvasive E. coli or Shigella-EIEC/Shigella, Enteroaggregative E. coli-EAEC, Enteropathogenic E. coli-EPEC Enterotoxigenic E. coli-ETEC and Salmonella) and its resistance to 11 antibiotics. Four sampling locations were selected: a fresh mountain water reservoir (un-impacted, site 1) and downstream sites receiving wastewater discharges (impacted, sites 2-4). River water (sites 1-4, N = 48), and soil and vegetable samples (site 3, N = 24) were collected during dry (April-September) and rainy seasons (October-March). Throughout the study, thermotolerant coliform density values at impacted sites greatly exceeded the guidelines for recreational and agricultural water uses. Seasonal differences were found for thermotolerant coliform density during dry season in water samples nearby a populated and hospital compound area. In contrast to the un-impacted site, where none of the tested enteropathogens were found, 100 % of surface water, 83 % of soil and 67 % of vegetable samples at impacted sites, were contaminated with at least one enteropathogen, being ETEC and Salmonella the most frequently found. ETEC isolates displayed different patterns of toxin genes among sites. The occurrence of enteropathogens was associated with the thermotolerant coliform density. At impacted sites, multiple enteropathogens were frequently found during rainy season. Among isolated enteropathogens, 50 % were resistant to at least two antibiotics, with resistance to ampicillin, nalidixic acid, trimethoprim-sulfamethoxazole and tetracycline commonly

  1. Assessment of bacterial antibiotic resistance transfer in the gut.

    PubMed

    Schjørring, Susanne; 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 resistant bacteria. The human gastrointestinal tract is a massive reservoir of bacteria with a potential for both receiving and transferring antibiotic resistance genes. The increased use of fermented food products and probiotics, as food supplements and health promoting products containing massive amounts of bacteria acting as either donors and/or recipients of antibiotic resistance genes in the human GI tract, also contributes to the emergence of antibiotic resistant strains. This paper deals with the assessment of antibiotic resistance gene transfer occurring in the gut. PMID:21318188

  2. Parallel Mapping of Antibiotic Resistance Alleles in Escherichia coli

    PubMed Central

    Mortazavi, Pooneh; Knight, Rob; Gill, Ryan T.

    2016-01-01

    Chemical genomics expands our understanding of microbial tolerance to inhibitory chemicals, but its scope is often limited by the throughput of genome-scale library construction and genotype-phenotype mapping. Here we report a method for rapid, parallel, and deep characterization of the response to antibiotics in Escherichia coli using a barcoded genome-scale library, next-generation sequencing, and streamlined bioinformatics software. The method provides quantitative growth data (over 200,000 measurements) and identifies contributing antimicrobial resistance and susceptibility alleles. Using multivariate analysis, we also find that subtle differences in the population responses resonate across multiple levels of functional hierarchy. Finally, we use machine learning to identify a unique allelic and proteomic fingerprint for each antibiotic. The method can be broadly applied to tolerance for any chemical from toxic metabolites to next-generation biofuels and antibiotics. PMID:26771672

  3. The world alliance against antibiotic resistance: consensus for a declaration.

    PubMed

    Carlet, Jean

    2015-06-15

    Antibiotic resistance is increasing worldwide and has become a very important threat to public health. The overconsumption of antibiotics is the most important cause of this problem. We created a World Alliance Against Antibiotic Resistance (WAAAR), which now includes 720 people from 55 different countries and is supported by 145 medical societies or various groups. In June 2014, WAAAR launched a declaration against antibiotic resistance. This article describes the process and the content of this declaration.

  4. Bacteriophage biosensors for antibiotic-resistant bacteria.

    PubMed

    Sorokulova, Irina; Olsen, Eric; Vodyanoy, Vitaly

    2014-03-01

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

  5. Antibiotic treatment and resistance in chronic wounds of vascular origin

    PubMed Central

    TZANEVA, VALENTINA; MLADENOVA, IRENA; TODOROVA, GALINA; PETKOV, DIMITAR

    2016-01-01

    Background and aim The problem of antibiotic resistance is worldwide and affects many types of pathogens. This phenomenon has been growing for decades and nowadays we are faced with a wide range of worrisome pathogens that are becoming resistant and many pathogens that may soon be untreatable. The aim of this study was to determine the resistance and antibiotic treatment in chronic wounds of vascular origin. Methods We performed a cross sectional study on a sample of patients with chronic vascular wounds, hospitalized between October 2014 and August 2015, in the Clinic of Vascular Surgery in Trakia Hospital Stara Zagora. The statistical analysis of data was descriptive, considering the p value of ≤0.05, the threshold of statistical significance. Results In the group of 110 patients, the significantly most frequent chronic wound (p<0.001) was peripheral arteriopathy (47.3%, CI95%: 38.19–56.54). Among 159 strains, 30% of patients having multiple etiology, the species most frequently isolated were Staphylococcus aureus, E.coli, Enterococcus faecalis, Pseudomonas aeruginosa and Proteus mirabilis with a significant predominance (p<0.05) of the Gram negative (55.1%). The spectrum of strains resistance included the Beta-lactams (36.4%, p<0.001), Macrolides (20%), Tetracyclines (9.1%), Aminoglycosides (8.2%) and Fluoroquinolones (4.5%). Conclusions Gram negative microorganisms were the main isolates in patients with vascular chronic wound. Significantly predominant was the resistance to the beta-lactam antibiotics. PMID:27547055

  6. Will tuberculosis become resistant to all antibiotics?

    PubMed Central

    Dye, C; Espinal, M A

    2001-01-01

    The discovery of high prevalences of antibiotic resistance in some pathogens, in some parts of the world, has provoked fears of a widespread loss of drug efficacy. Here, we use a mathematical model to investigate the evolution of resistance to four major anti-tuberculosis drugs (isoniazid, rifampicin, ethambutol and streptomycin) in 47 sites around the world. The model provides a new method of estimating the relative risk of treatment failure for patients carrying drug-resistant strains and the proportion of patients who develop resistance after failing treatment. Using estimates of these two quantities together with other published data, we reconstructed the epidemic spread of isoniazid resistance over the past 50 years. The predicted median prevalence of resistance among new cases today was 7.0% (range 0.9-64.3%), close to the 6.3% (range 0-28.1%) observed. Predicted and observed prevalences of resistance to isoniazid plus rifampicin (multidrug-resistant or MDR-TB) after 30 years of combined drug use were also similar, 0.9% (0.1-5.9%) and 1.0% (range 0-14.1%), respectively. With current data, and under prevailing treatment practices, it appears that MDR-TB will remain a localized problem, rather than becoming a global obstacle to tuberculosis control. To substantiate this result, further measurements are needed of the relative fitness of drug-resistant strains. PMID:12123297

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Cooperative Antibiotic Resistance in a Multi-Drug Environment

    NASA Astrophysics Data System (ADS)

    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.

  9. Association between clinical antibiotic resistance and susceptibility of Pseudomonas in the cystic fibrosis lung

    PubMed Central

    Jansen, Gunther; Mahrt, Niels; Tueffers, Leif; Barbosa, Camilo; Harjes, Malte; Adolph, Gernot; Friedrichs, Anette; Krenz-Weinreich, Annegret; Rosenstiel, Philip; Schulenburg, Hinrich

    2016-01-01

    Background and objectives: Cystic fibrosis patients suffer from chronic lung infections that require long-term antibiotic therapy. Pseudomonas readily evolve resistance, rendering antibiotics ineffective. In vitro experiments suggest that resistant bacteria may be treated by exploiting their collateral sensitivity to other antibiotics. Here, we investigate correlations of sensitivity and resistance profiles of Pseudomonas aeruginosa that naturally adapted to antibiotics in the cystic fibrosis lung. Methodology: Resistance profiles for 13 antibiotics were obtained using broth dilution, E-test and VITEK mass spectroscopy. Genetic variants were determined from whole-genome sequences and interrelationships among isolates were analyzed using 13 MLST loci. Result: Our study focused on 45 isolates from 13 patients under documented treatment with antibiotics. Forty percent of these were clinically resistant and 15% multi-drug resistant. Colistin resistance was found once, despite continuous colistin treatment and even though colistin resistance can readily evolve experimentally in the laboratory. Patients typically harbored multiple genetically and phenotypically distinct clones. However, genetically similar clones often had dissimilar resistance profiles. Isolates showed mutations in genes encoding cell wall synthesis, alginate production, efflux pumps and antibiotic modifying enzymes. Cross-resistance was commonly observed within antibiotic classes and between aminoglycosides and β-lactam antibiotics. No evidence was found for consistent phenotypic resistance to one antibiotic and sensitivity to another within one genotype. Conclusions and implications: Evidence supporting potential collateral sensitivity in clinical P. aeruginosa isolates remains equivocal. However, cross-resistance within antibiotic classes is common. Colistin therapy is promising since resistance to it was rare despite its intensive use in the studied patients. PMID:27193199

  10. Antibiotic Restriction Might Facilitate the Emergence of Multi-drug Resistance.

    PubMed

    Obolski, Uri; Stein, Gideon Y; Hadany, Lilach

    2015-06-01

    High antibiotic resistance frequencies have become a major public health issue. The decrease in new antibiotics' production, combined with increasing frequencies of multi-drug resistant (MDR) bacteria, cause substantial limitations in treatment options for some bacterial infections. To diminish overall resistance, and especially the occurrence of bacteria that are resistant to all antibiotics, certain drugs are deliberately scarcely used--mainly when other options are exhausted. We use a mathematical model to explore the efficiency of such antibiotic restrictions. We assume two commonly used drugs and one restricted drug. The model is examined for the mixing strategy of antibiotic prescription, in which one of the drugs is randomly assigned to each incoming patient. Data obtained from Rabin medical center, Israel, is used to estimate realistic single and double antibiotic resistance frequencies in incoming patients. We find that broad usage of the hitherto restricted drug can reduce the number of incorrectly treated patients, and reduce the spread of bacteria resistant to both common antibiotics. Such double resistant infections are often eventually treated with the restricted drug, and therefore are prone to become resistant to all three antibiotics. Thus, counterintuitively, a broader usage of a formerly restricted drug can sometimes lead to a decrease in the emergence of bacteria resistant to all drugs. We recommend re-examining restriction of specific drugs, when multiple resistance to the relevant alternative drugs already exists.

  11. Clusters of antibiotic resistance genes enriched together stay together in swine agriculture

    DOE PAGES

    Johnson, Timothy A.; Stedtfeld, Robert D.; Wang, Qiong; Cole, James R.; Hashsham, Syed A.; Looft, Torey; Zhu, Yong -Guan; Tiedje, James M.

    2016-04-12

    Antibiotic resistance is a worldwide health risk, but the influence of animal agriculture on the genetic context and enrichment of individual antibiotic resistance alleles remains unclear. Using quantitative PCR followed by amplicon sequencing, we quantified and sequenced 44 genes related to antibiotic resistance, mobile genetic elements, and bacterial phylogeny in microbiomes from U.S. laboratory swine and from swine farms from three Chinese regions. We identified highly abundant resistance clusters: groups of resistance and mobile genetic element alleles that cooccur. For example, the abundance of genes conferring resistance to six classes of antibiotics together with class 1 integrase and the abundancemore » of IS6100-type transposons in three Chinese regions are directly correlated. These resistance cluster genes likely colocalize in microbial genomes in the farms. Resistance cluster alleles were dramatically enriched (up to 1 to 10% as abundant as 16S rRNA) and indicate that multidrug-resistant bacteria are likely the norm rather than an exception in these communities. This enrichment largely occurred independently of phylogenetic composition; thus, resistance clusters are likely present in many bacterial taxa. Furthermore, resistance clusters contain resistance genes that confer resistance to antibiotics independently of their particular use on the farms. Selection for these clusters is likely due to the use of only a subset of the broad range of chemicals to which the clusters confer resistance. The scale of animal agriculture and its wastes, the enrichment and horizontal gene transfer potential of the clusters, and the vicinity of large human populations suggest that managing this resistance reservoir is important for minimizing human risk.Agricultural antibiotic use results in clusters of cooccurring resistance genes that together confer resistance to multiple antibiotics. The use of a single antibiotic could select for an entire suite of resistance

  12. What Can Be Done about Antibiotic Resistance?

    MedlinePlus

    ... antibiotics for treating human disease. (See Antibiotics in agriculture .) Is there any international action on the antibiotic ... and reducing antibiotic use in animal farming and agriculture. Experts agree that a global system for tracking ...

  13. Addressing the Natural Antibiotic Resistome in Studies of Soil Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The environment is recognized as a source and a reservoir of antibiotic resistance (AR). Many antibiotic compounds are derived from bacteria and fungi that are naturally present in the environment. These microbes carry genes encoding resistance to the antibiotic that they produce and their resistanc...

  14. The problems of antibiotic resistance in cystic fibrosis and solutions.

    PubMed

    López-Causapé, Carla; Rojo-Molinero, Estrella; Macià, María D; Oliver, Antonio

    2015-02-01

    Chronic respiratory infection is the main cause of morbidity and mortality in cystic fibrosis (CF) patients. One of the hallmarks of these infections, led by the opportunistic pathogen Pseudomonas aeruginosa, is their long-term (lifelong) persistence despite intensive antimicrobial therapy. Antimicrobial resistance in CF is indeed a multifactorial problem, which includes physiological changes, represented by the transition from the planktonic to the biofilm mode of growth and the acquisition of multiple (antibiotic resistance) adaptive mutations catalyzed by frequent mutator phenotypes. Emerging multidrug-resistant CF pathogens, transmissible epidemic strains and transferable genetic elements (such as those encoding class B carbapenemases) also significantly contribute to this concerning scenario. Strategies directed to combat biofilm growth, prevent the emergence of mutational resistance, promote the development of novel antimicrobial agents against multidrug-resistant strains and implement strict infection control measures are thus needed. PMID:25541089

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

    PubMed Central

    Berglund, Björn

    2015-01-01

    Antibiotic resistance is a growing problem which threatens modern healthcare globally. Resistance has traditionally been viewed as a clinical problem, but recently non-clinical environments have been highlighted as an important factor in the dissemination of antibiotic resistance genes (ARGs). Horizontal gene transfer (HGT) events are likely to be common in aquatic environments; integrons in particular are well suited for mediating environmental dissemination of ARGs. A growing body of evidence suggests that ARGs are ubiquitous in natural environments. Particularly, elevated levels of ARGs and integrons in aquatic environments are correlated to proximity to anthropogenic activities. The source of this increase is likely to be routine discharge of antibiotics and resistance genes, for example, via wastewater or run-off from livestock facilities and agriculture. While very high levels of antibiotic contamination are likely to select for resistant bacteria directly, the role of sub-inhibitory concentrations of antibiotics in environmental antibiotic resistance dissemination remains unclear. In vitro studies have shown that low levels of antibiotics can select for resistant mutants and also facilitate HGT, indicating the need for caution. Overall, it is becoming increasingly clear that the environment plays an important role in dissemination of antibiotic resistance; further studies are needed to elucidate key aspects of this process. Importantly, the levels of environmental antibiotic contamination at which resistant bacteria are selected for and HGT is facilitated at should be determined. This would enable better risk analyses and facilitate measures for preventing dissemination and development of antibiotic resistance in the environment. PMID:26356096

  16. Long-Term Shifts in Patterns of Antibiotic Resistance in Enteric Bacteria

    PubMed Central

    Houndt, Tara; Ochman, Howard

    2000-01-01

    Several mechanisms are responsible for the ability of microorganisms to tolerate antibiotics, and the incidence of resistance to these compounds within bacterial species has increased since the commercial use of antibiotics became widespread. To establish the extent of and changes in the diversity of antibiotic resistance patterns in natural populations, we determined the MICs of five antibiotics for collections of enteric bacteria isolated from diverse hosts and geographic locations and during periods before and after commercial application of antibiotics began. All of the pre-antibiotic era strains were susceptible to high levels of these antibiotics, whereas 20% of strains from contemporary populations of Escherichia coli and Salmonella enterica displayed high-level resistance to at least one of the antibiotics. In addition to the increase in the frequency of high-level resistance, background levels, conferred by genes providing nonspecific low-level resistance to multiple antibiotics, were significantly higher among contemporary strains. Changes in the incidence and levels of antibiotic resistance are not confined to particular segments of the bacterial population and reflect responses to the increased exposure of bacteria to antimicrobial compounds over the past several decades. PMID:11097921

  17. Bacterial Cheating Limits the Evolution of Antibiotic Resistance

    NASA Astrophysics Data System (ADS)

    Yurtsev, Eugene; Xiao Chao, Hui; Datta, Manoshi; Artemova, Tatiana; Gore, Jeff

    2012-02-01

    The emergence of antibiotic resistance in bacteria is a significant health concern. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removal of the antibiotic. The presence of a cooperative mechanism of resistance suggests that a cheater strain - which does not contribute to breaking down the antibiotic - may be able to take advantage of resistant cells. We find experimentally that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We use a simple model in conjunction with difference equations to explain the observed population dynamics as a function of cell density and antibiotic concentration. Our experimental difference equations resemble the logistic map, raising the possibility of oscillations or even chaotic dynamics.

  18. New and alternative approaches to tackling antibiotic resistance

    PubMed Central

    Theriault, Nicolette

    2013-01-01

    Multidrug-resistant bacteria are becoming more common and due to their multiplicity of mechanisms, they are frequently resistant to many if not all of the current antibiotics. This daunting spectre has been the target of many research efforts into conventional antibiotics and alternative approaches. This review focuses on the more recent advances in these fields with an overview on peptidomimetics, nanoparticles and their derivatives, FimH inhibitors, quorum sensing inhibition molecules, neoglycosides and phage therapies. These various approaches are at different stages of development, some are closer to the clinic than others, but recent regulatory guidance and re-awakened interest from the pharmaceutical companies gives us some optimism for the future. PMID:24381727

  19. Development of antibiotics and the future of marine microorganisms to stem the tide of antibiotic resistance

    PubMed Central

    Kasanah, Noer; Hamann, Mark T

    2016-01-01

    Antibiotics remain essential tools in the control of infectious diseases. With the emergence of new diseases, resistant forms of diseases such as tuberculosis and malaria, as well as the emergence of multidrug-resistant bacteria, it has become essential to develop novel antibiotics. Development of the existing antibiotics involved three strategies, including discovery of new target sites, modification of existing antibiotic structures, and the identification of new resources for novel antibiotics. Marine microorganisms have clearly become an essential new resource in the discovery of new antibiotic leads. PMID:15600239

  20. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7

    PubMed Central

    Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun

    2015-01-01

    Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments. PMID:26426011

  1. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    PubMed

    Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun

    2015-01-01

    Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments. PMID:26426011

  2. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    PubMed

    Chen, Songcan; Li, Xiaomin; Sun, Guoxin; Zhang, Yingjiao; Su, Jianqiang; Ye, Jun

    2015-09-29

    Co-contamination of antibiotics and heavy metals prevails in the environment, and may play an important role in disseminating bacterial antibiotic resistance, but the selective effects of heavy metals on bacterial antibiotic resistance is largely unclear. To investigate this, the effects of heavy metals on antibiotic resistance were studied in a genome-sequenced bacterium, LSJC7. The results showed that the presence of arsenate, copper, and zinc were implicated in fortifying the resistance of LSJC7 towards tetracycline. The concentrations of heavy metals required to induce antibiotic resistance, i.e., the minimum heavy metal concentrations (MHCs), were far below (up to 64-fold) the minimum inhibition concentrations (MIC) of LSJC7. This finding indicates that the relatively low heavy metal levels in polluted environments and in treated humans and animals might be sufficient to induce bacterial antibiotic resistance. In addition, heavy metal induced antibiotic resistance was also observed for a combination of arsenate and chloramphenicol in LSJC7, and copper/zinc and tetracycline in antibiotic susceptible strain Escherichia coli DH5α. Overall, this study implies that heavy metal induced antibiotic resistance might be ubiquitous among various microbial species and suggests that it might play a role in the emergence and spread of antibiotic resistance in metal and antibiotic co-contaminated environments.

  3. Predation and selection for antibiotic resistance in natural environments.

    PubMed

    Leisner, Jørgen J; Jørgensen, Niels O G; Middelboe, Mathias

    2016-03-01

    Genes encoding resistance to antibiotics appear, like the antibiotics themselves, to be ancient, originating long before the rise of the era of anthropogenic antibiotics. However, detailed understanding of the specific biological advantages of antibiotic resistance in natural environments is still lacking, thus limiting our efforts to prevent environmental influx of resistance genes. Here, we propose that antibiotic-resistant cells not only evade predation from antibiotic producers but also take advantage of nutrients released from cells that are killed by the antibiotic-producing bacteria. Thus, predation is potentially an important mechanism for driving antibiotic resistance during slow or stationary phase of growth when nutrients are deprived. This adds to explain the ancient nature and widespread occurrence of antibiotic resistance in natural environments unaffected by anthropogenic antibiotics. In particular, we suggest that nutrient-poor environments including indoor environments, for example, clean rooms and intensive care units may serve as a reservoir and source for antibiotic-producing as well as antibiotic-resistant bacteria.

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

    USGS Publications Warehouse

    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-resistance

  5. CURRENT ISSUES REGARDING ENDOCRINE DISRUPTING CHEMICALS AND ANTIBIOTIC RESISTANCE

    EPA Science Inventory

    Recently public concern has increased regarding industrial and environmental substances that may have adverse hormonal effects in human and wildlife populations. This concern has also been expanded to include antibiotic-resistant bacteria and the presence of various antibiotics a...

  6. U.K. Case of Throat Gonorrhea Resists Antibiotics

    MedlinePlus

    ... html U.K. Case of Throat Gonorrhea Resists Antibiotics U.S. officials concerned about potential danger of untreatable ... throat gonorrhea that proved untreatable with the standard antibiotic regimen. The patient, a heterosexual man who had ...

  7. Agricultural use of antibiotics and the evolution and transfer of antibiotic-resistant bacteria.

    PubMed

    Khachatourians, G G

    1998-11-01

    Microbial Resistance to antibiotics is on the rise, in part because of inappropriate use of antibiotics in human medicine but also because of practices in the agricultural industry. Intensive animal production involves giving livestock animals large quantities of antibiotics to promote growth and prevent infection. These uses promote the selection of antibiotic resistance in bacterial populations. The resistant bacteria from agricultural environments may be transmitted to humans, in whom they cause disease that cannot be treated by conventional antibiotics. The author reviews trends in antibiotic use in animal husbandry and agriculture in general. The development of resistance is described, along with the genetic mechanisms that create resistance and facilitate its spread among bacterial species. Particular aspects of resistance in bacterial species common to both the human population and the agrifood industry are emphasized. Control measures that might reverse the current trends are highlighted.

  8. Antibiotic resistance monitoring in Vibrio spp. isolated from rearing environment and intestines of abalone Haliotis diversicolor.

    PubMed

    Wang, R X; Wang, J Y; Sun, Y C; B L Yang; A L Wang

    2015-12-30

    546 Vibrio isolates from rearing seawater (292 strains) and intestines of abalone (254 strains) were tested to ten antibiotics using Kirby-Bauer diffusion method. Resistant rates of abalone-derived Vibrio isolates to chloramphenicol (C), enrofloxacin (ENX) and norfloxacin (NOR) were <28%, whereas those from seawater showed large fluctuations in resistance to each of the tested antibiotics. Many strains showed higher resistant rates (>40%) to kanamycin (KNA), furazolidone (F), tetracycline (TE), gentamicin (GM) and rifampin (RA). 332 isolates from seawater (n=258) and abalone (n=74) were resistant to more than three antibiotics. Peaked resistant rates of seawater-derived isolates to multiple antibiotics were overlapped in May and August. Statistical analysis showed that pH had an important effect on resistant rates of abalone-derived Vibrio isolates to RA, NOR, and ENX. Salinity and dissolved oxygen were negatively correlated with resistant rates of seawater-derived Vibrio isolates to KNA, RA, and PG. PMID:26494250

  9. Antibiotic resistance monitoring in Vibrio spp. isolated from rearing environment and intestines of abalone Haliotis diversicolor.

    PubMed

    Wang, R X; Wang, J Y; Sun, Y C; B L Yang; A L Wang

    2015-12-30

    546 Vibrio isolates from rearing seawater (292 strains) and intestines of abalone (254 strains) were tested to ten antibiotics using Kirby-Bauer diffusion method. Resistant rates of abalone-derived Vibrio isolates to chloramphenicol (C), enrofloxacin (ENX) and norfloxacin (NOR) were <28%, whereas those from seawater showed large fluctuations in resistance to each of the tested antibiotics. Many strains showed higher resistant rates (>40%) to kanamycin (KNA), furazolidone (F), tetracycline (TE), gentamicin (GM) and rifampin (RA). 332 isolates from seawater (n=258) and abalone (n=74) were resistant to more than three antibiotics. Peaked resistant rates of seawater-derived isolates to multiple antibiotics were overlapped in May and August. Statistical analysis showed that pH had an important effect on resistant rates of abalone-derived Vibrio isolates to RA, NOR, and ENX. Salinity and dissolved oxygen were negatively correlated with resistant rates of seawater-derived Vibrio isolates to KNA, RA, and PG.

  10. Antibiotic Resistance Threats in the U.S.

    MedlinePlus

    ... and drug-resistant infections can be prevented. How Bacteria Become Resistant When bacteria are exposed to antibiotics, they start learning how to outsmart the drugs. This process occurs in bacteria found in humans, animals, and the environment. Resistant ...

  11. Fungal treatment for the removal of antibiotics and antibiotic resistance genes in veterinary hospital wastewater.

    PubMed

    Lucas, D; Badia-Fabregat, M; Vicent, T; Caminal, G; Rodríguez-Mozaz, S; Balcázar, J L; Barceló, D

    2016-06-01

    The emergence and spread of antibiotic resistance represents one of the most important public health concerns and has been linked to the widespread use of antibiotics in veterinary and human medicine. The overall elimination of antibiotics in conventional wastewater treatment plants is quite low; therefore, residual amounts of these compounds are continuously discharged to receiving surface waters, which may promote the emergence of antibiotic resistance. In this study, the ability of a fungal treatment as an alternative wastewater treatment for the elimination of forty-seven antibiotics belonging to seven different groups (β-lactams, fluoroquinolones, macrolides, metronidazoles, sulfonamides, tetracyclines, and trimethoprim) was evaluated. 77% of antibiotics were removed after the fungal treatment, which is higher than removal obtained in conventional treatment plants. Moreover, the effect of fungal treatment on the removal of some antibiotic resistance genes (ARGs) was evaluated. The fungal treatment was also efficient in removing ARGs, such as ermB (resistance to macrolides), tetW (resistance to tetracyclines), blaTEM (resistance to β-lactams), sulI (resistance to sulfonamides) and qnrS (reduced susceptibility to fluoroquinolones). However, it was not possible to establish a clear link between concentrations of antibiotics and corresponding ARGs in wastewater, which leads to the conclusion that there are other factors that should be taken into consideration besides the antibiotic concentrations that reach aquatic ecosystems in order to explain the emergence and spread of antibiotic resistance. PMID:26991378

  12. Fungal treatment for the removal of antibiotics and antibiotic resistance genes in veterinary hospital wastewater.

    PubMed

    Lucas, D; Badia-Fabregat, M; Vicent, T; Caminal, G; Rodríguez-Mozaz, S; Balcázar, J L; Barceló, D

    2016-06-01

    The emergence and spread of antibiotic resistance represents one of the most important public health concerns and has been linked to the widespread use of antibiotics in veterinary and human medicine. The overall elimination of antibiotics in conventional wastewater treatment plants is quite low; therefore, residual amounts of these compounds are continuously discharged to receiving surface waters, which may promote the emergence of antibiotic resistance. In this study, the ability of a fungal treatment as an alternative wastewater treatment for the elimination of forty-seven antibiotics belonging to seven different groups (β-lactams, fluoroquinolones, macrolides, metronidazoles, sulfonamides, tetracyclines, and trimethoprim) was evaluated. 77% of antibiotics were removed after the fungal treatment, which is higher than removal obtained in conventional treatment plants. Moreover, the effect of fungal treatment on the removal of some antibiotic resistance genes (ARGs) was evaluated. The fungal treatment was also efficient in removing ARGs, such as ermB (resistance to macrolides), tetW (resistance to tetracyclines), blaTEM (resistance to β-lactams), sulI (resistance to sulfonamides) and qnrS (reduced susceptibility to fluoroquinolones). However, it was not possible to establish a clear link between concentrations of antibiotics and corresponding ARGs in wastewater, which leads to the conclusion that there are other factors that should be taken into consideration besides the antibiotic concentrations that reach aquatic ecosystems in order to explain the emergence and spread of antibiotic resistance.

  13. [Resistance of Haemophilus sp. to antibiotics].

    PubMed

    Janicka, G; Gospodarek, E; Mikucka, A; Białek, M; Wojak, I; Krawiecka, D

    1998-02-01

    The present study was undertaken to determine the in vitro drug resistance of Haemophilus influenzae (68 isolates) and H. parainfluenzae (17 isolates). The tests susceptibility to Ampicillin, Amoxicilin/Clavulanic Acid, Cefaclor, Cefuroxime, Cotrimoxazole, Aztreonam, Ceftriaxone, Tetracycline, Ciprofloxacin, Rifampicin and Chloramphenicol were performed with a standard disk-diffusion method. The NCCLS methodology and susceptibility interpretative criteria were applied as described by the disk manufacturer. Beta-lactamase production was detected with nitrocefin impregnated disk (Cefinase, BBL Microbiology System). Resistance in nosocomially acquired Haemophilus isolates to several antibiotics was observed. Of the Haemophilus isolates 28.2% were Ampicillin in resistant, all were susceptible to the combination of Amoxicillin/Clavulanic acid. The Ampicillin-resistant strains were beta-lactamase producers. We observed the high resistance (70.1%) to Tetracycline and (28.2%) to SXT (Cotrimoxazole). All isolates of Haemophilus were susceptible to Ciprofloxacin. The low resistance percentages to Rifampin (1.2%), Aztreonam (3.5%) and Chloramphenicol (3.5%) was observed.

  14. Results of a pilot antibiotic resistance survey of Albanian poultry farms.

    PubMed

    Alcaine, S D; Molla, L; Nugen, S R; Kruse, H

    2016-03-01

    Global dissemination of antibiotic-resistant bacteria in food animals is a major public health concern. Whilst many countries have implemented prudent antibiotic use policies and surveillance systems both in clinical and veterinary settings, there are no such systems in place in Albania and little is known about the levels of antibiotic-resistant bacteria in food animals within the country. A total of 172 poultry samples were taken from six Albanian farms over a 3-month period and were tested for the presence of Enterobacteriaceae. In total, 91 bacterial isolates were obtained and were characterised by species (Escherichia coli, Salmonella spp. or other Enterobacteriaceae) and by susceptibility to 11 antibiotics. Resistance rates of E. coli and Salmonella isolates were, respectively: amoxicillin (86%, 64%); chloramphenicol (77%, 82%); ciprofloxacin (93%, 73%); cefotaxime (14%, 0%); gentamicin (12%, 0%); kanamycin (30%, 18%); nalidixic acid (91%, 73%); streptomycin (70%, 55%); sulphonamides (91%, 73%); tetracycline (95%, 73%); and trimethoprim (79%, 64%). Multidrug resistance to at least four antibiotics was observed in 95% of E. coli isolates and 82% of Salmonella. In conclusion, these data indicate that: (i) Salmonella and E. coli isolates from Albanian poultry farms exhibit high to extremely high levels of antibiotic resistance; (ii) Salmonella and E. coli isolates exhibit resistance to multiple antibiotics; and (iii) multidrug resistance profiles among Enterobacteriaceae are geographically widespread. Implementation of prudent antibiotic use policies in food animals and related surveillance will be necessary to reduce the emergence, spread and establishment of highly resistant strains across poultry farms in Albania. PMID:27436396

  15. Exposure to mutagenic disinfection byproducts leads to increase of antibiotic resistance in Pseudomonas aeruginosa.

    PubMed

    Lv, Lu; Jiang, Tao; Zhang, Shenghua; Yu, Xin

    2014-07-15

    Bacterial antibiotic resistance (BAR) in drinking water has become a global issue because of its risks on the public health. Usually, the antibiotic concentrations in drinking water are too low to select antibiotic resistant strains effectively, suggesting that factors other than antibiotics would contribute to the emergence of BAR. In the current study, the impacts of mutagenic disinfection byproducts (DBPs) on BAR were explored, using four typical DBPs: dibromoacetic acid, dichloroacetonitrile, potassium bromate, and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). After exposure to DBPs, resistances to 10 individual antibiotics and multiple antibiotics were both raised by various levels, norfloxacin and polymycin B resistances were enhanced even greater than 10-fold compared with control. MX increased the resistance most observably in the selected DBPs, which was consistent with its mutagenic activity. The resistant mutants showed hereditary stability during 5-day culturing. The increase of BAR was caused by the mutagenic activities of DBPs, since mutation frequency declined by adding ROS scavenger. Mutagenesis was further confirmed by sequencing of the related genes. Our study indicated that mutagenic activities of the selected DBPs could induce antibiotic resistance, even multidrug resistance, which may partially explain the lack of agreement between BAR and antibiotic levels in drinking water.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    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.

  18. Antibiotic Resistance in the Environment: Not the Usual Suspects.

    PubMed

    Graham, David W

    2015-07-23

    In this issue of Chemistry & Biology, Forsberg et al. (2015) show how metagenomics and biological chemistry can be combined to discover new classes of antibiotic resistance from soil metagenomes. The authors specifically reveal previously unseen resistance mechanisms and genes evident in soils, which will better inform both environmental and clinical studies on antibiotic resistance.

  19. Occurrence and spread of antibiotic resistances in Enterococcus faecium.

    PubMed

    Klare, Ingo; Konstabel, Carola; Badstübner, Dietlinde; Werner, Guido; Witte, Wolfgang

    2003-12-01

    Enterococci are the second to third most important bacterial genus in hospital infections. Especially Enterococcus (E.) faecium possesses a broad spectrum of natural and acquired antibiotic resistances which are presented in detail in this paper. From medical point of view, the transferable resistances to glycopeptides (e.g., vancomycin, VAN, or teicoplanin, TPL) and streptogramins (e.g., quinupristin/dalfopristin, Q/D) in enterococci are of special interest. The VanA type of enterococcal glycopeptide resistance is the most important one (VAN-r, TPL-r); its main reservoir is E. faecium. Glycopeptide-resistant E. faecium (GREF) can be found in hospitals and outside of them, namely in European commercial animal husbandry in which the glycopeptide avoparcin (AVO) was used as growth promoter in the past. There are identical types of the vanA gene clusters in enterococci from different ecological origins (faecal samples of animals, animal feed, patients in hospitals, persons in the community, waste water samples). Obviously, across the food chain (by GREF-contaminated meat products), these multiple-resistant bacteria or their vanA gene clusters can reach humans. In hospital infections, widespread epidemic-virulent E. faecium isolates of the same clone with or without glycopeptide resistance can occur; these strains often harbour different plasmids and the esp gene. This indicates that hospital-adapted epidemic-virulent E. faecium strains have picked up the vanA gene cluster after they were already widely spread. The streptogramin virginiamycin was also used as feed additive in commercial animal husbandry in Europe for more than 20 years, and it created reservoirs for streptogramin-resistant E. faecium (SREF). In 1998/1999, SREF could be isolated in Germany from waste water of sewage treatment plants, from faecal samples and meat products of animals that were fed virginiamycin (cross resistance to Q/D), from stools of humans in the community, and from clinical samples

  20. Antibiotic resistance of Streptococcus agalactiae from cows with mastitis.

    PubMed

    Gao, Jian; Yu, Fu-Qing; Luo, Li-Ping; He, Jian-Zhong; Hou, Rong-Guang; Zhang, Han-Qi; Li, Shu-Mei; Su, Jing-Liang; Han, Bo

    2012-12-01

    The aim of this study was to characterise the phenotypic and genotypic antibiotic resistance patterns of Streptococcus agalactiae isolated from cows with mastitis in China. Antibiotic resistance was based on minimum inhibitory concentrations and detection of resistance genes by PCR. S. agalactiae isolates most frequently exhibited phenotypic resistance to tetracycline, while the resistance genes most frequently detected were ermB, tetL and tetM. Resistance genes were detected in some susceptible isolates, whereas no resistance genes could be detected in some resistant isolates, indicating that the resistance genotype does not accurately predict phenotypic resistance. PMID:22627045

  1. Thermosensitive antibiotic resistance plasmids in enterobacteria.

    PubMed

    Smith, H W; Parsell, Z; Green, P

    1978-11-01

    Of 775 conjugative plasmids found in enterobacteria mediating antibiotic resistance, 24 (3.1%) were thermosensitive (ts); they were most common in Klebsiella pneumoniae. Ts plasmids were also found in all the samples of sewage and river water examined. Over half of 73 ts plasmids from unrelated sources mediated resistance to chloramphenicol in addition to several other antibiotics. Many of them mediated resistance to mercury (53.4%), arsenite (38.4%) and tellurite (79.5%) but not to copper, cobalt and silver. Fifty-eight belonged to incompatibility group H2 and 12 belonged to the H1 group. Resistance to mercury, arsenite and tellurite was common in strains containing H2 plasmids but not in H1 plasmids. The 73 plasmids transferred at high rates at 22 and 28 degrees C and at lower rates at 15 degrees C; they transferred at very low rates or not at all at 37 degrees C. They could be divided into two sets according to whether they transferred at a high or at a low rate at 33 degrees C. Unlike the prototype plasmid, Rts 1, they were solely or mainly ts for transfer and not for replication and only one of them brought about a marked reduction in growth rate of its host organism at 42 degrees C. None of the 73 plasmids mediated colicin or haemolysin production. Three plasmids, all from K. pneumoniae, mediated utilization of lactose, two of sucrose and raffinose and three, all belonging to group H1, of citrate. None of the plasmids increased the pathogenicity of Salmonella typhimurium for chicks or Escherichia coli K12 for mice.

  2. Host-dependent Induction of Transient Antibiotic Resistance: A Prelude to Treatment Failure.

    PubMed

    Kubicek-Sutherland, Jessica Z; Heithoff, Douglas M; Ersoy, Selvi C; Shimp, William R; House, John K; Marth, Jamey D; Smith, Jeffrey W; Mahan, Michael J

    2015-09-01

    Current antibiotic testing does not include the potential influence of host cell environment on microbial susceptibility and antibiotic resistance, hindering appropriate therapeutic intervention. We devised a strategy to identify the presence of host-pathogen interactions that alter antibiotic efficacy in vivo. Our findings revealed a bacterial mechanism that promotes antibiotic resistance in vivo at concentrations of drug that far exceed dosages determined by standardized antimicrobial testing. This mechanism has escaped prior detection because it is reversible and operates within a subset of host tissues and cells. Bacterial pathogens are thereby protected while their survival promotes the emergence of permanent drug resistance. This host-dependent mechanism of transient antibiotic resistance is applicable to multiple pathogens and has implications for the development of more effective antimicrobial therapies.

  3. Antibiotic Resistance Is Prevalent in an Isolated Cave Microbiome

    PubMed Central

    Bhullar, Kirandeep; Waglechner, Nicholas; Pawlowski, Andrew; Koteva, Kalinka; Banks, Eric D.; Johnston, Michael D.; Barton, Hazel A.; Wright, Gerard D.

    2012-01-01

    Antibiotic resistance is a global challenge that impacts all pharmaceutically used antibiotics. The origin of the genes associated with this resistance is of significant importance to our understanding of the evolution and dissemination of antibiotic resistance in pathogens. A growing body of evidence implicates environmental organisms as reservoirs of these resistance genes; however, the role of anthropogenic use of antibiotics in the emergence of these genes is controversial. We report a screen of a sample of the culturable microbiome of Lechuguilla Cave, New Mexico, in a region of the cave that has been isolated for over 4 million years. We report that, like surface microbes, these bacteria were highly resistant to antibiotics; some strains were resistant to 14 different commercially available antibiotics. Resistance was detected to a wide range of structurally different antibiotics including daptomycin, an antibiotic of last resort in the treatment of drug resistant Gram-positive pathogens. Enzyme-mediated mechanisms of resistance were also discovered for natural and semi-synthetic macrolide antibiotics via glycosylation and through a kinase-mediated phosphorylation mechanism. Sequencing of the genome of one of the resistant bacteria identified a macrolide kinase encoding gene and characterization of its product revealed it to be related to a known family of kinases circulating in modern drug resistant pathogens. The implications of this study are significant to our understanding of the prevalence of resistance, even in microbiomes isolated from human use of antibiotics. This supports a growing understanding that antibiotic resistance is natural, ancient, and hard wired in the microbial pangenome. PMID:22509370

  4. Functional metagenomics for the investigation of antibiotic resistance.

    PubMed

    Mullany, Peter

    2014-04-01

    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 these organisms is to use metagenomic approaches. Furthermore, the only method that does not require any prior knowledge about the resistance genes is functional metagenomics, which involves expressing genes from metagenomic clones in surrogate hosts. In this review the methods and limitations of functional metagenomics to isolate new antibiotic resistance genes and the mobile genetic elements that mediate their spread are explored.

  5. Concomitant Antibiotic and Mercury Resistance Among Gastrointestinal Microflora of Feral Brook Trout, Salvelinus fontinalis

    PubMed Central

    Meredith, Matthew M.; Parry, Erin M.; Guay, Justin A.; Markham, Nicholas O.; Danner, G. Russell; Johnson, Keith A.; Barkay, Tamar; Fekete, Frank A.

    2013-01-01

    Twenty-nine bacterial isolates representing eight genera from the gastrointestinal tracts of feral brook trout Salvelinus fontinalis (Mitchell) demonstrated multiple maximal antibiotic resistances and concomitant broad-spectrum mercury (Hg) resistance. Equivalent viable plate counts on tryptic soy agar supplemented with either 0 or 25 μM HgCl2 verified the ubiquity of mercury resistance in this microbial environment. Mercury levels in lake water samples measured 1.5 ng L−1; mercury concentrations in fish filets ranged from 81.8 to 1,080 ng g−1 and correlated with fish length. The presence of similar antibiotic and Hg resistance patterns in multiple genera of gastrointestinal microflora supports a growing body of research that multiple selective genes can be transferred horizontally in the presence of an unrelated individual selective pressure. We present data that bioaccumulation of non-point source Hg pollution could be a selective pressure to accumulate both antibiotic and Hg resistant bacteria. PMID:22850694

  6. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    SciTech Connect

    Maltz, Lauren

    2015-08-25

    By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β-lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes.

  7. Antibiotic resistant bacterial profiles of anaerobic swine lagoon effluent.

    PubMed

    Brooks, J P; McLaughlin, M R

    2009-01-01

    Although land application of swine (Sus scrofa) manure lagoon effluent is a common and effective method of disposal, the presence of antibiotic-resistant bacteria, both pathogenic and commensal can complicate already understood issues associated with its safe disposal. The aim of this study was to assess antibiotic resistance in swine lagoon bacteria from sow, nursery, and finisher farms in the southeastern United States. Effluents from 37 lagoons were assayed for the presence of Escherichia coli, Campylobacter, Listeria, and Salmonella. Antibiotic resistance profiles were determined by the Kirby-Bauer swab method for 12 antibiotics comprising eight classes. Statistical analyses indicated that farm type influenced the amount and type of resistance, with nurseries and sow farms ranking as most influential, perhaps due to use of more antibiotic treatments. Finisher farms tended to have the least amount of antibiotic class resistance, signaling an overall healthier market pig, and less therapeutic or prophylactic antibiotic use. Many bacterial isolates were resistant to penicillin, cephalosporin, and tetracycline class antibiotics, while nearly all were susceptible to quinolone antibiotics. It appeared that swine farm type had a significant association with the amount of resistance associated with bacterial genera sampled from the lagoons; nurseries contributed the largest amount of bacterial resistance.

  8. Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

    SciTech Connect

    Meckes, M.C.

    1982-02-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli.

  9. Effect of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents.

    PubMed Central

    Meckes, M C

    1982-01-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor-mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistance patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli. PMID:7059170

  10. Cooperative Bacterial Growth Dynamics Predict the Evolution of Antibiotic Resistance

    NASA Astrophysics Data System (ADS)

    Artemova, Tatiana; Gerardin, Ylaine; Hsin-Jung Li, Sophia; Gore, Jeff

    2011-03-01

    Since the discovery of penicillin, antibiotics have been our primary weapon against bacterial infections. Unfortunately, bacteria can gain resistance to penicillin by acquiring the gene that encodes beta-lactamase, which inactivates the antibiotic. However, mutations in this gene are necessary to degrade the modern antibiotic cefotaxime. Understanding the conditions that favor the spread of these mutations is a challenge. Here we show that bacterial growth in beta-lactam antibiotics is cooperative and that the nature of this growth determines the conditions in which resistance evolves. Quantitative analysis of the growth dynamics predicts a peak in selection at very low antibiotic concentrations; competition between strains confirms this prediction. We also find significant selection at higher antibiotic concentrations, close to the minimum inhibitory concentrations of the strains. Our results argue that an understanding of the evolutionary forces that lead to antibiotic resistance requires a quantitative understanding of the evolution of cooperation in bacteria.

  11. Antibiotic resistance pattern and gene expression of non-typhoid Salmonella in riversheds.

    PubMed

    Hsu, Chao-Yu; Hsu, Bing-Mu; Ji, Wen-Tsai; Chen, Jung-Sheng; Hsu, Tsui-Kang; Ji, Dar-Der; Tseng, Shao-Feng; Chiu, Yi-Chou; Kao, Po-Min; Huang, Yu-Li

    2015-05-01

    In this study, antibiotic resistance and major phenol and genotypes of non-typhoid Salmonella spp. from riversheds in Taiwan were examined. In 236 water samples tested, 54 (22.9%) contained Salmonella spp. Fifteen Salmonella serovars were identified from the Salmonella isolates, and some common serovars are associated with infections of human and livestock, including Albany (27.8%), Newport (14.8%), Bareilly (13.0%), Derby (11.1%), and Typhimurium (7.4%). Various environmental factors may also affect the presence and proportion of different serovars in the receiving waters. In contrast, serovars with narrower range of hosts, e.g., Dublin, were rarely detected. The Salmonella isolates were subjected to eight antibiotics for drug resistance, and 51.9% of the samples were resistant to at least one tested antibiotics. Tetracycline and sulfadiazine were the two most ineffective antibiotics against the Salmonella isolates, and the results were indicative of long-term antibiotics abuse as fodder supplements in animal husbandry. The more commonly detected serovars such as Albany, Derby, and Typhimurium were also more likely to be resistant to multiple antibiotics. Finally, a significant correlation was observed between resistance to chloramphenicol and the resistance gene cmlA, suggesting that the resistance genotypes could persist in the environment even long after prohibition of the drug use. The high prevalence of antibiotic-resistant Salmonella spp. infers elevated infection risks that must be further examined.

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

    PubMed

    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.

  13. Antibiotic resistance genes in freshwater biofilms along a whole river.

    PubMed

    Winkworth, Cynthia L

    2013-06-01

    A key problem challenging public health officials' efforts to stem the spread of antibiotic resistance is the potential increase of resistance in the environment. Yet, despite recent and significant changes to agricultural land in New Zealand, as well as the sector's high antibiotic use, the influence on antibiotic resistance in the environment remained uncharacterised. Spatial and temporal dynamics of antibiotic resistance genes in freshwater biofilms from NZ's fourth longest river as it transitioned between low and high intensity farming were examined for 1 year. Polymerase chain reaction was employed to gauge the level of resistance present. Biofilms were screened for 10 genes conferring resistance to antibiotics used in humans only and both humans and agricultural animals. Three genes were detected, one which conferred resistance to the important human-only use antibiotic vancomycin. Detected at the two downstream sites only, and those subject to the highest combined land-use stressors, the three genes indicated an elevated presence of antibiotic resistance in relation to surrounding land use; 7.7% versus 2% across the whole river system. The detection of a gene conferring resistance to an important human-only use antibiotic was particularly concerning and highlighted human-based contamination sources along the river, in addition to those of agricultural origin.

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

    PubMed

    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.

  15. Emergence and spread of antibiotic resistance: setting a parameter space

    PubMed Central

    Baquero, Fernando

    2014-01-01

    The emergence and spread of antibiotic resistance among human pathogens is a relevant problem for human health and one of the few evolution processes amenable to experimental studies. In the present review, we discuss some basic aspects of antibiotic resistance, including mechanisms of resistance, origin of resistance genes, and bottlenecks that modulate the acquisition and spread of antibiotic resistance among human pathogens. In addition, we analyse several parameters that modulate the evolution landscape of antibiotic resistance. Learning why some resistance mechanisms emerge but do not evolve after a first burst, whereas others can spread over the entire world very rapidly, mimicking a chain reaction, is important for predicting the evolution, and relevance for human health, of a given mechanism of resistance. Because of this, we propose that the emergence and spread of antibiotic resistance can only be understood in a multi-parameter space. Measuring the effect on antibiotic resistance of parameters such as contact rates, transfer rates, integration rates, replication rates, diversification rates, and selection rates, for different genes and organisms, growing under different conditions in distinct ecosystems, will allow for a better prediction of antibiotic resistance and possibilities of focused interventions. PMID:24678768

  16. Antibiotic resistance: a primer and call to action.

    PubMed

    Smith, Rachel A; M'ikanatha, Nkuchia M; Read, Andrew F

    2015-01-01

    During the past century, discoveries of microorganisms as causes of infections and antibiotics as effective therapeutic agents have contributed to significant gains in public health in many parts of the world. Health agencies worldwide are galvanizing attention toward antibiotic resistance, which is a major threat to public health (Centers for Disease Control and Prevention, 2013; World Health Organization, 2014). Some life scientists believe that we are approaching the post-antibiotic age (Davies & Davies, 2010). The growing threat of antimicrobial resistance is fueled by complex factors with biological, behavioral, and societal aspects. This primer provides an overview of antibiotic resistance and its growing burden on public health, the biological and behavioral mechanisms that increase antibiotic resistance, and examples of where health communication scholars can contribute to efforts to make our current antibiotic drugs last as long as possible. In addition, we identify compelling challenges for current communication theories and practices.

  17. [Old and new antibiotics for therapy of multidrug resistant bacteria].

    PubMed

    Pintado, V

    2016-09-01

    The lack of new antibiotics for multidrug-resistant bacteria is a matter of concern in microorganisms such as Pseudomonas aeruginosa, ESBL- and carbapenemase-producing Enterobacteriaceae, Acinetobacter baumannii, methicillin-resistant Staphylococcous aureus and vancomycin-resistant Enterococcus faecium. This situation has conditioned the reuse of "old" antibiotics (colistin, fosfomycin), the use of more recent antibiotics with new indications or dosage regimens (tigecycline, meropenem) and the introduction of "new" antibiotics (β-lactams, lipoglycopeptides, oxazolidinones) that are the subject of this review. PMID:27608312

  18. Antibiotic resistance gene discovery in food-producing animals.

    PubMed

    Allen, Heather K

    2014-06-01

    Numerous environmental reservoirs contribute to the widespread antibiotic resistance problem in human pathogens. One environmental reservoir of particular importance is the intestinal bacteria of food-producing animals. In this review I examine recent discoveries of antibiotic resistance genes in agricultural animals. Two types of antibiotic resistance gene discoveries will be discussed: the use of classic microbiological and molecular techniques, such as culturing and PCR, to identify known genes not previously reported in animals; and the application of high-throughput technologies, such as metagenomics, to identify novel genes and gene transfer mechanisms. These discoveries confirm that antibiotics should be limited to prudent uses.

  19. Tracking Change: A Look at the Ecological Footprint of Antibiotics and Antimicrobial Resistance

    PubMed Central

    Keen, Patricia L.; Patrick, David M.

    2013-01-01

    Among the class of pollutants considered as ‘emerging contaminants’, antibiotic compounds including drugs used in medical therapy, biocides and disinfectants merit special consideration because their bioactivity in the environment is the result of their functional design. Antibiotics can alter the structure and function of microbial communities in the receiving environment and facilitate the development and spread of resistance in critical species of bacteria including pathogens. Methanogenesis, nitrogen transformation and sulphate reduction are among the key ecosystem processes performed by bacteria in nature that can also be affected by the impacts of environmental contamination by antibiotics. Together, the effects of the development of resistance in bacteria involved in maintaining overall ecosystem health and the development of resistance in human, animal and fish pathogens, make serious contributions to the risks associated with environmental pollution by antibiotics. In this brief review, we discuss the multiple impacts on human and ecosystem health of environmental contamination by antibiotic compounds. PMID:27029298

  20. Persistence and resistance as complementary bacterial adaptations to antibiotics.

    PubMed

    Vogwill, T; Comfort, A C; Furió, V; MacLean, R C

    2016-06-01

    Bacterial persistence represents a simple of phenotypic heterogeneity, whereby a proportion of cells in an isogenic bacterial population can survive exposure to lethal stresses such as antibiotics. In contrast, genetically based antibiotic resistance allows for continued growth in the presence of antibiotics. It is unclear, however, whether resistance and persistence are complementary or alternative evolutionary adaptations to antibiotics. Here, we investigate the co-evolution of resistance and persistence across the genus Pseudomonas using comparative methods that correct for phylogenetic nonindependence. We find that strains of Pseudomonas vary extensively in both their intrinsic resistance to antibiotics (ciprofloxacin and rifampicin) and persistence following exposure to these antibiotics. Crucially, we find that persistence correlates positively to antibiotic resistance across strains. However, we find that different genes control resistance and persistence implying that they are independent traits. Specifically, we find that the number of type II toxin-antitoxin systems (TAs) in the genome of a strain is correlated to persistence, but not resistance. Our study shows that persistence and antibiotic resistance are complementary, but independent, evolutionary adaptations to stress and it highlights the key role played by TAs in the evolution of persistence.

  1. Persistence and resistance as complementary bacterial adaptations to antibiotics.

    PubMed

    Vogwill, T; Comfort, A C; Furió, V; MacLean, R C

    2016-06-01

    Bacterial persistence represents a simple of phenotypic heterogeneity, whereby a proportion of cells in an isogenic bacterial population can survive exposure to lethal stresses such as antibiotics. In contrast, genetically based antibiotic resistance allows for continued growth in the presence of antibiotics. It is unclear, however, whether resistance and persistence are complementary or alternative evolutionary adaptations to antibiotics. Here, we investigate the co-evolution of resistance and persistence across the genus Pseudomonas using comparative methods that correct for phylogenetic nonindependence. We find that strains of Pseudomonas vary extensively in both their intrinsic resistance to antibiotics (ciprofloxacin and rifampicin) and persistence following exposure to these antibiotics. Crucially, we find that persistence correlates positively to antibiotic resistance across strains. However, we find that different genes control resistance and persistence implying that they are independent traits. Specifically, we find that the number of type II toxin-antitoxin systems (TAs) in the genome of a strain is correlated to persistence, but not resistance. Our study shows that persistence and antibiotic resistance are complementary, but independent, evolutionary adaptations to stress and it highlights the key role played by TAs in the evolution of persistence. PMID:26999656

  2. Metagenomics and other Methods for Measuring Antibiotic Resistance in Agroecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: There is broad concern regarding antibiotic resistance on farms and in fields, however there is no standard method for defining or measuring antibiotic resistance in environmental samples. Methods: We used metagenomic, culture-based, and molecular methods to characterize the amount, t...

  3. Antibiotic resistance differentiates Echinacea purpurea endophytic bacterial communities with respect to plant organs.

    PubMed

    Mengoni, Alessio; Maida, Isabel; Chiellini, Carolina; Emiliani, Giovanni; Mocali, Stefano; Fabiani, Arturo; Fondi, Marco; Firenzuoli, Fabio; Fani, Renato

    2014-10-01

    Recent findings have shown that antibiotic resistance is widespread in multiple environments and multicellular organisms, as plants, harboring rich and complex bacterial communities, could be hot spot for emergence of antibiotic resistances as a response to bioactive molecules production by members of the same community. Here, we investigated a panel of 137 bacterial isolates present in different organs of the medicinal plant Echinacea purpurea, aiming to evaluate if different plant organs harbor strains with different antibiotic resistance profiles, implying then the presence of different biological interactions in the communities inhabiting different plant organs. Data obtained showed a large antibiotic resistance variability among strains, which was strongly related to the different plant organs (26% of total variance, P < 0.0001). Interestingly this uneven antibiotic resistance pattern was present also when a single genus (Pseudomonas), ubiquitous in all organs, was analyzed and no correlation of antibiotic resistance pattern with genomic relatedness among strains was found. In conclusion, we speculate that antibiotic resistance patterns are tightly linked to the type of plant organ under investigation, suggesting the presence of differential forms of biological interaction in stem/leaves, roots and rhizosphere. PMID:25283726

  4. Antibiotic Resistance Determinants in a Pseudomonas putida Strain Isolated from a Hospital

    PubMed Central

    Duque, Estrella; Fernández, Matilde; Molina-Santiago, Carlos; Roca, Amalia; Porcel, Mario; de la Torre, Jesús; Segura, Ana; Plesiat, Patrick; Jeannot, Katy; Ramos, Juan-Luis

    2014-01-01

    Environmental microbes harbor an enormous pool of antibiotic and biocide resistance genes that can impact the resistance profiles of animal and human pathogens via horizontal gene transfer. Pseudomonas putida strains are ubiquitous in soil and water but have been seldom isolated from humans. We have established a collection of P. putida strains isolated from in-patients in different hospitals in France. One of the isolated strains (HB3267) kills insects and is resistant to the majority of the antibiotics used in laboratories and hospitals, including aminoglycosides, ß-lactams, cationic peptides, chromoprotein enediyne antibiotics, dihydrofolate reductase inhibitors, fluoroquinolones and quinolones, glycopeptide antibiotics, macrolides, polyketides and sulfonamides. Similar to other P. putida clinical isolates the strain was sensitive to amikacin. To shed light on the broad pattern of antibiotic resistance, which is rarely found in clinical isolates of this species, the genome of this strain was sequenced and analysed. The study revealed that the determinants of multiple resistance are both chromosomally-borne as well as located on the pPC9 plasmid. Further analysis indicated that pPC9 has recruited antibiotic and biocide resistance genes from environmental microorganisms as well as from opportunistic and true human pathogens. The pPC9 plasmid is not self-transmissible, but can be mobilized by other bacterial plasmids making it capable of spreading antibiotic resistant determinants to new hosts. PMID:24465371

  5. Antibiotic resistance differentiates Echinacea purpurea endophytic bacterial communities with respect to plant organs.

    PubMed

    Mengoni, Alessio; Maida, Isabel; Chiellini, Carolina; Emiliani, Giovanni; Mocali, Stefano; Fabiani, Arturo; Fondi, Marco; Firenzuoli, Fabio; Fani, Renato

    2014-10-01

    Recent findings have shown that antibiotic resistance is widespread in multiple environments and multicellular organisms, as plants, harboring rich and complex bacterial communities, could be hot spot for emergence of antibiotic resistances as a response to bioactive molecules production by members of the same community. Here, we investigated a panel of 137 bacterial isolates present in different organs of the medicinal plant Echinacea purpurea, aiming to evaluate if different plant organs harbor strains with different antibiotic resistance profiles, implying then the presence of different biological interactions in the communities inhabiting different plant organs. Data obtained showed a large antibiotic resistance variability among strains, which was strongly related to the different plant organs (26% of total variance, P < 0.0001). Interestingly this uneven antibiotic resistance pattern was present also when a single genus (Pseudomonas), ubiquitous in all organs, was analyzed and no correlation of antibiotic resistance pattern with genomic relatedness among strains was found. In conclusion, we speculate that antibiotic resistance patterns are tightly linked to the type of plant organ under investigation, suggesting the presence of differential forms of biological interaction in stem/leaves, roots and rhizosphere.

  6. [Micromonospora resistence to definite antibiotics and their ability to produce structurally analogous antibiotics].

    PubMed

    Bibikova, M V; Ivanitskaia, L P; Tikhonova, A S

    1980-01-01

    Thirty six cultures of Micromonospora freshly isolated from soil samples were studied with respect to their sensitivity to a number of antibiotics of various structures and modes of action. It was found that all of them were highly sensitive to penicillin, ristomycin, tetracycline, rifampicin, streptomycin, olivomycin, carminomycin and dactinomycin. Significant differences in sensitivity of the Micromonospora cultures were revealed only with respect to gentamicin, tobramicin, erythromycin and lincomycin. Seven cultures were resistant to gentamicin and tobramicin and sensitive to all of the other antibiotics. Broad spectrum antibiotics were isolated from these cultures. The study of the antibiotic chemistry showed that they were 2-desoxystreptamine-containing aminoglycosides. Two cultures proved to be resistant to erythromycin and lincomycin. When identified with the use of antibiotic resistant staphylococcal strains, the crude antibiotic substances isolated from these cultures appeared to be not active against staphylococci resistant to erythromycin and lincomycin. By their chromatograpi- behaviour the antibiotics were close to macrolides. Therefore, it was found that production of aminoglycoside and macrolide antibiotics was most characteristic of Micromonospora. A certain correlation between resistance of Micromonospora to these 2 antibiotic groups and capacity for their production was shown. PMID:7356302

  7. Monitoring and identifying antibiotic resistance mechanisms in bacteria.

    PubMed

    Roe, M T; Pillai, S D

    2003-04-01

    Sub-therapeutic administration of antibiotics to animals is under intense scrutiny because they contribute to the dissemination of antibiotic-resistant bacteria into the food chain. Studies suggest that there is a link between the agricultural use of antibiotics and antibiotic-resistant human infections. Antibiotic-resistant organisms from animal and human wastes reenter the human and animal populations through a number of pathways including natural waters, irrigation water, drinking water, and vegetables and foods. Antibiotic usage in the United States for animal production (disease prevention and growth promotion) is estimated to be 18 million pounds annually. As much as 25 to 75% of the antibiotics administered to feedlot animals are excreted unaltered in feces. Because about 180 million dry tons of livestock and poultry waste is generated annually in the United States, it is not surprising that animal-derived antibiotic-resistant organisms are found contaminating groundwater, surface water, and food crops. It is extremely important to clearly understand the molecular mechanisms that could potentially cause lateral or horizontal gene transfer of antibiotic resistance genes among bacteria. Once the mechanisms and magnitude of resistance gene transfer are clearly understood and quantified, strategies can be instituted to reduce the potential for dissemination of these genes.

  8. Antibiotic-Resistant Neisseria gonorrhoeae Spread Faster with More Treatment, Not More Sexual Partners

    PubMed Central

    Bonhoeffer, Sebastian; Low, Nicola; Althaus, Christian L.

    2016-01-01

    The sexually transmitted bacterium Neisseria gonorrhoeae has developed resistance to all antibiotic classes that have been used for treatment and strains resistant to multiple antibiotic classes have evolved. In many countries, there is only one antibiotic remaining for empirical N. gonorrhoeae treatment, and antibiotic management to counteract resistance spread is urgently needed. Understanding dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management. In our study, we first used antibiotic resistance surveillance data to estimate the rates at which antibiotic-resistant N. gonorrhoeae spread in two host populations, heterosexual men (HetM) and men who have sex with men (MSM). We found higher rates of spread for MSM (0.86 to 2.38 y−1, mean doubling time: 6 months) compared to HetM (0.24 to 0.86 y−1, mean doubling time: 16 months). We then developed a dynamic transmission model to reproduce the observed dynamics of N. gonorrhoeae transmission in populations of heterosexual men and women (HMW) and MSM. We parameterized the model using sexual behavior data and calibrated it to N. gonorrhoeae prevalence and incidence data. In the model, antibiotic-resistant N. gonorrhoeae spread with a median rate of 0.88 y−1 in HMW and 3.12 y−1 in MSM. These rates correspond to median doubling times of 9 (HMW) and 3 (MSM) months. Assuming no fitness costs, the model shows the difference in the host population’s treatment rate rather than the difference in the number of sexual partners explains the differential spread of resistance. As higher treatment rates result in faster spread of antibiotic resistance, treatment recommendations for N. gonorrhoeae should carefully balance prevention of infection and avoidance of resistance spread. PMID:27196299

  9. Antibiotic-Resistant Neisseria gonorrhoeae Spread Faster with More Treatment, Not More Sexual Partners.

    PubMed

    Fingerhuth, Stephanie M; Bonhoeffer, Sebastian; Low, Nicola; Althaus, Christian L

    2016-05-01

    The sexually transmitted bacterium Neisseria gonorrhoeae has developed resistance to all antibiotic classes that have been used for treatment and strains resistant to multiple antibiotic classes have evolved. In many countries, there is only one antibiotic remaining for empirical N. gonorrhoeae treatment, and antibiotic management to counteract resistance spread is urgently needed. Understanding dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management. In our study, we first used antibiotic resistance surveillance data to estimate the rates at which antibiotic-resistant N. gonorrhoeae spread in two host populations, heterosexual men (HetM) and men who have sex with men (MSM). We found higher rates of spread for MSM (0.86 to 2.38 y-1, mean doubling time: 6 months) compared to HetM (0.24 to 0.86 y-1, mean doubling time: 16 months). We then developed a dynamic transmission model to reproduce the observed dynamics of N. gonorrhoeae transmission in populations of heterosexual men and women (HMW) and MSM. We parameterized the model using sexual behavior data and calibrated it to N. gonorrhoeae prevalence and incidence data. In the model, antibiotic-resistant N. gonorrhoeae spread with a median rate of 0.88 y-1 in HMW and 3.12 y-1 in MSM. These rates correspond to median doubling times of 9 (HMW) and 3 (MSM) months. Assuming no fitness costs, the model shows the difference in the host population's treatment rate rather than the difference in the number of sexual partners explains the differential spread of resistance. As higher treatment rates result in faster spread of antibiotic resistance, treatment recommendations for N. gonorrhoeae should carefully balance prevention of infection and avoidance of resistance spread.

  10. Antibiotic-Resistant Neisseria gonorrhoeae Spread Faster with More Treatment, Not More Sexual Partners.

    PubMed

    Fingerhuth, Stephanie M; Bonhoeffer, Sebastian; Low, Nicola; Althaus, Christian L

    2016-05-01

    The sexually transmitted bacterium Neisseria gonorrhoeae has developed resistance to all antibiotic classes that have been used for treatment and strains resistant to multiple antibiotic classes have evolved. In many countries, there is only one antibiotic remaining for empirical N. gonorrhoeae treatment, and antibiotic management to counteract resistance spread is urgently needed. Understanding dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management. In our study, we first used antibiotic resistance surveillance data to estimate the rates at which antibiotic-resistant N. gonorrhoeae spread in two host populations, heterosexual men (HetM) and men who have sex with men (MSM). We found higher rates of spread for MSM (0.86 to 2.38 y-1, mean doubling time: 6 months) compared to HetM (0.24 to 0.86 y-1, mean doubling time: 16 months). We then developed a dynamic transmission model to reproduce the observed dynamics of N. gonorrhoeae transmission in populations of heterosexual men and women (HMW) and MSM. We parameterized the model using sexual behavior data and calibrated it to N. gonorrhoeae prevalence and incidence data. In the model, antibiotic-resistant N. gonorrhoeae spread with a median rate of 0.88 y-1 in HMW and 3.12 y-1 in MSM. These rates correspond to median doubling times of 9 (HMW) and 3 (MSM) months. Assuming no fitness costs, the model shows the difference in the host population's treatment rate rather than the difference in the number of sexual partners explains the differential spread of resistance. As higher treatment rates result in faster spread of antibiotic resistance, treatment recommendations for N. gonorrhoeae should carefully balance prevention of infection and avoidance of resistance spread. PMID:27196299

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

    PubMed Central

    2010-01-01

    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 resistance based on

  12. [The threat of antibiotic resistance to nursing homes].

    PubMed

    Bonten, M J M

    2016-01-01

    Antibiotic resistance is considered a major threat to healthcare. The Dutch government recently announced additional measures to contain this threat, one of these being the creation of regional care networks dedicated to control antibiotic resistance. Among the anticipated activities of these networks is quantifying the prevalence of antibiotic resistance in nursing homes, through regular point-prevalence surveillance studies. There is a broadly felt belief that nursing homes might be a 'mer à boire' of antibiotic resistance. Although scientific data do not support that claim, it is nevertheless likely that the planned investigations will identify yet unknown clusters of ESBL-carriers, necessitating infection control measures. Given the absence of an acute problem and the consequences for nursing home management, staff and clients of point-prevalence surveillance studies, a staged approach for investigating antibiotic resistance in nursing homes should be considered. PMID:27650029

  13. Antibiotic failure mediated by a resistant subpopulation in Enterobacter cloacae.

    PubMed

    Band, Victor I; Crispell, Emily K; Napier, Brooke A; Herrera, Carmen M; Tharp, Greg K; Vavikolanu, Kranthi; Pohl, Jan; Read, Timothy D; Bosinger, Steven E; Trent, M Stephen; Burd, Eileen M; Weiss, David S

    2016-01-01

    Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infection, but in the absence of colistin, innate immune defences led to an increased frequency of the resistant subpopulation, leading to inefficacy of subsequent colistin therapy. An isolate with a lower-frequency colistin-resistant subpopulation similarly caused treatment failure but was misclassified as susceptible by current diagnostics once cultured outside the host. These data demonstrate the ability of low-frequency bacterial subpopulations to contribute to clinically relevant antibiotic resistance, elucidating an enigmatic cause of antibiotic treatment failure and highlighting the critical need for more sensitive diagnostics. PMID:27572838

  14. [The threat of antibiotic resistance to nursing homes].

    PubMed

    Bonten, M J M

    2016-01-01

    Antibiotic resistance is considered a major threat to healthcare. The Dutch government recently announced additional measures to contain this threat, one of these being the creation of regional care networks dedicated to control antibiotic resistance. Among the anticipated activities of these networks is quantifying the prevalence of antibiotic resistance in nursing homes, through regular point-prevalence surveillance studies. There is a broadly felt belief that nursing homes might be a 'mer à boire' of antibiotic resistance. Although scientific data do not support that claim, it is nevertheless likely that the planned investigations will identify yet unknown clusters of ESBL-carriers, necessitating infection control measures. Given the absence of an acute problem and the consequences for nursing home management, staff and clients of point-prevalence surveillance studies, a staged approach for investigating antibiotic resistance in nursing homes should be considered.

  15. Probing minority population of antibiotic-resistant bacteria.

    PubMed

    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

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

    PubMed

    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.

  17. The role of biofilms as environmental reservoirs of antibiotic resistance.

    PubMed

    Balcázar, José L; Subirats, Jéssica; Borrego, Carles M

    2015-01-01

    Antibiotic resistance has become a significant and growing threat to public and environmental health. To face this problem both at local and global scales, a better understanding of the sources and mechanisms that contribute to the emergence and spread of antibiotic resistance is required. Recent studies demonstrate that aquatic ecosystems are reservoirs of resistant bacteria and antibiotic resistance genes as well as potential conduits for their transmission to human pathogens. Despite the wealth of information about antibiotic pollution and its effect on the aquatic microbial resistome, the contribution of environmental biofilms to the acquisition and spread of antibiotic resistance has not been fully explored in aquatic systems. Biofilms are structured multicellular communities embedded in a self-produced extracellular matrix that acts as a barrier to antibiotic diffusion. High population densities and proximity of cells in biofilms also increases the chances for genetic exchange among bacterial species converting biofilms in hot spots of antibiotic resistance. This review focuses on the potential effect of antibiotic pollution on biofilm microbial communities, with special emphasis on ecological and evolutionary processes underlying acquired resistance to these compounds.

  18. The role of biofilms as environmental reservoirs of antibiotic resistance

    PubMed Central

    Balcázar, José L.; Subirats, Jéssica; Borrego, Carles M.

    2015-01-01

    Antibiotic resistance has become a significant and growing threat to public and environmental health. To face this problem both at local and global scales, a better understanding of the sources and mechanisms that contribute to the emergence and spread of antibiotic resistance is required. Recent studies demonstrate that aquatic ecosystems are reservoirs of resistant bacteria and antibiotic resistance genes as well as potential conduits for their transmission to human pathogens. Despite the wealth of information about antibiotic pollution and its effect on the aquatic microbial resistome, the contribution of environmental biofilms to the acquisition and spread of antibiotic resistance has not been fully explored in aquatic systems. Biofilms are structured multicellular communities embedded in a self-produced extracellular matrix that acts as a barrier to antibiotic diffusion. High population densities and proximity of cells in biofilms also increases the chances for genetic exchange among bacterial species converting biofilms in hot spots of antibiotic resistance. This review focuses on the potential effect of antibiotic pollution on biofilm microbial communities, with special emphasis on ecological and evolutionary processes underlying acquired resistance to these compounds. PMID:26583011

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

    PubMed

    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.

  20. Bypass of genetic constraints during mutator evolution to antibiotic resistance

    PubMed Central

    Couce, Alejandro; Rodríguez-Rojas, Alexandro; Blázquez, Jesús

    2015-01-01

    Genetic constraints can block many mutational pathways to optimal genotypes in real fitness landscapes, yet the extent to which this can limit evolution remains to be determined. Interestingly, mutator bacteria elevate only specific types of mutations, and therefore could be very sensitive to genetic constraints. Testing this possibility is not only clinically relevant, but can also inform about the general impact of genetic constraints in adaptation. Here, we evolved 576 populations of two mutator and one wild-type Escherichia coli to doubling concentrations of the antibiotic cefotaxime. All strains carried TEM-1, a β-lactamase enzyme well known by its low availability of mutational pathways. Crucially, one of the mutators does not elevate any of the relevant first-step mutations known to improve cefatoximase activity. Despite this, both mutators displayed a similar ability to evolve more than 1000-fold resistance. Initial adaptation proceeded in parallel through general multi-drug resistance mechanisms. High-level resistance, in contrast, was achieved through divergent paths; with the a priori inferior mutator exploiting alternative mutational pathways in PBP3, the target of the antibiotic. These results have implications for mutator management in clinical infections and, more generally, illustrate that limits to natural selection in real organisms are alleviated by the existence of multiple loci contributing to fitness. PMID:25716795

  1. Bypass of genetic constraints during mutator evolution to antibiotic resistance.

    PubMed

    Couce, Alejandro; Rodríguez-Rojas, Alexandro; Blázquez, Jesús

    2015-04-01

    Genetic constraints can block many mutational pathways to optimal genotypes in real fitness landscapes, yet the extent to which this can limit evolution remains to be determined. Interestingly, mutator bacteria elevate only specific types of mutations, and therefore could be very sensitive to genetic constraints. Testing this possibility is not only clinically relevant, but can also inform about the general impact of genetic constraints in adaptation. Here, we evolved 576 populations of two mutator and one wild-type Escherichia coli to doubling concentrations of the antibiotic cefotaxime. All strains carried TEM-1, a β-lactamase enzyme well known by its low availability of mutational pathways. Crucially, one of the mutators does not elevate any of the relevant first-step mutations known to improve cefatoximase activity. Despite this, both mutators displayed a similar ability to evolve more than 1000-fold resistance. Initial adaptation proceeded in parallel through general multi-drug resistance mechanisms. High-level resistance, in contrast, was achieved through divergent paths; with the a priori inferior mutator exploiting alternative mutational pathways in PBP3, the target of the antibiotic. These results have implications for mutator management in clinical infections and, more generally, illustrate that limits to natural selection in real organisms are alleviated by the existence of multiple loci contributing to fitness.

  2. Isolated cell behavior drives the evolution of antibiotic resistance

    PubMed Central

    Artemova, Tatiana; Gerardin, Ylaine; Dudley, Carmel; Vega, Nicole M; Gore, Jeff

    2015-01-01

    Bacterial antibiotic resistance is typically quantified by the minimum inhibitory concentration (MIC), which is defined as the minimal concentration of antibiotic that inhibits bacterial growth starting from a standard cell density. However, when antibiotic resistance is mediated by degradation, the collective inactivation of antibiotic by the bacterial population can cause the measured MIC to depend strongly on the initial cell density. In cases where this inoculum effect is strong, the relationship between MIC and bacterial fitness in the antibiotic is not well defined. Here, we demonstrate that the resistance of a single, isolated cell—which we call the single-cell MIC (scMIC)—provides a superior metric for quantifying antibiotic resistance. Unlike the MIC, we find that the scMIC predicts the direction of selection and also specifies the antibiotic concentration at which selection begins to favor new mutants. Understanding the cooperative nature of bacterial growth in antibiotics is therefore essential in predicting the evolution of antibiotic resistance. PMID:26227664

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

    PubMed

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

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

  4. Effect of Surfactants on Antibiotic Resistance

    PubMed Central

    Suling, William J.; O'Leary, William M.

    1975-01-01

    The effectiveness of surfactants as potentiators of antibiotic activity on several resistant strains of bacteria, selected from clinical sources and laboratory collections, was studied using a tube dilution assay. Bacterial strains included members of the Enterobacteriaceae and staphylococci. Cetyltrimethylammonium bromide (CTAB), Tween 80 (Tw80), a mixture of n-alkyldimethyl betaines (L14), and alpha-(2,4,5-trichlorophenoxy) propionic acid (TCP) were tested in combination with pencillin G (PenG), methicillin (Met), streptomycin (Sm), polymyxin B (PmB), and chlortetracycline (CTC). Growth response to the drug combinations was compared with the response to each drug alone. CTAB and L14 but not Tw80 or TCP were found to potentiate the activity of CTC on strains of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae. Studies on the inhibition of protein synthesis by CTC in cells of a strain of E. coli suggested that the surfactants increased the uptake of antibiotic into the cells. CTAB and L14 almost completely sensitized strains of P. mirabilis, Serratia marcescens, K. pneumoniae, and E. coli to PmB. With the exception of K. pneumoniae, TCP was also effective in potentiating the activity of PmB on the above strains whereas Tw80 showed potentiation only with a strain of E. coli. CTAB and L14 but not TCP or Tw80 potentiated the activity of PenG but not Met on strains of staphylococci. Studies of penicillinase in the cells suggested that the surfactants inhibited the formation of this enzyme possibly at the level of induction. None of the surfactants were found to potentiate the activity of Sm. PMID:1101823

  5. Antibiotic resistance of Vibrio parahaemolyticus and Vibrio vulnificus in various countries: A review.

    PubMed

    Elmahdi, Sara; DaSilva, Ligia V; Parveen, Salina

    2016-08-01

    Vibrio parahaemolyticus and Vibrio vulnificus are the leading causes of seafood associated infections and mortality in the United States. The main syndromes caused by these pathogens are gastroenteritis, wound infections, and septicemia. This article reviewed the antibiotic resistance profile of V. parahaemolyticus and V. vulnificus in the United States and other countries including Italy, Brazil, Philippines, Malaysia, Thailand, China, India, Iran, South Africa and Australia. The awareness of antimicrobial resistance of these two pathogens is not as well documented as other foodborne bacterial pathogens. Vibrio spp. are usually susceptible to most antimicrobials of veterinary and human significance. However, many studies reported that V. vulnificus and V. parahaemolyticus showed multiple-antibiotic resistance due to misuse of antibiotics to control infections in aquaculture production. In addition, both environmental and clinical isolates showed similar antibiotic resistance profiles. Most frequently observed antibiotic resistance profiles involved ampicillin, penicillin and tetracycline regardless of the countries. The presence of multiple-antibiotic resistant bacteria in seafood and aquatic environments is a major concern in fish and shellfish farming and human health.

  6. Antibiotic use and resistance in animals: Belgian initiatives.

    PubMed

    Daeseleire, Els; De Graef, Evelyne; Rasschaert, Geertrui; De Mulder, Thijs; Van den Meersche, Tina; Van Coillie, Els; Dewulf, Jeroen; Heyndrickx, Marc

    2016-05-01

    The widespread use of antibiotics in animals is causing concerns about the growing risk for development and the spread of antibiotic-resistant bacteria. Antibiotic consumption is higher in animals than in humans as reported in a joint publication of EFSA (European Food Safety Agency), ECDC (European Centre for Disease Prevention and Control), and EMA (European Medicines Agency) using data from 2011 and 2012. Both in humans and animals, positive associations between the consumption of antibiotics and resistant bacteria are observed. Responsible use of antibiotics in humans and animals should therefore be promoted. In this paper some general aspects of antibiotic resistance such as microbiological versus clinical resistance, intrinsic versus acquired resistance, resistance mechanisms, and transfer of resistance are briefly introduced. In 2012, the Belgian Center of Expertise on Antimicrobial Consumption and Resistance in Animals (AMCRA) was founded. Its mission is to collect and analyze all data related to antibiotic use and resistance in animals in Belgium and to communicate these findings in a neutral and objective manner. One of AMCRA's 10 objectives is a 50% reduction in antibiotic consumption in veterinary medicine in Belgium by 2020. The aim of this paper is to report on the achievements of this national project. The Institute for Agricultural and Fisheries Research (ILVO, Merelbeke-Melle), in collaboration with Ghent University, is currently working on three nationally funded projects on antibiotic resistance in animal husbandry. In the first project, an in vitro model is used to study the influence of low antibiotic concentrations due to carry-over after production and usage of medicated feed on the development of resistance in the pig gut. Part of that project is to develop a quantitative risk assessment model. A second project focuses on tracking excreted antibiotics used in pig rearing and their influence on the development of antibiotic resistance in pig

  7. Antibiotic use and resistance in animals: Belgian initiatives.

    PubMed

    Daeseleire, Els; De Graef, Evelyne; Rasschaert, Geertrui; De Mulder, Thijs; Van den Meersche, Tina; Van Coillie, Els; Dewulf, Jeroen; Heyndrickx, Marc

    2016-05-01

    The widespread use of antibiotics in animals is causing concerns about the growing risk for development and the spread of antibiotic-resistant bacteria. Antibiotic consumption is higher in animals than in humans as reported in a joint publication of EFSA (European Food Safety Agency), ECDC (European Centre for Disease Prevention and Control), and EMA (European Medicines Agency) using data from 2011 and 2012. Both in humans and animals, positive associations between the consumption of antibiotics and resistant bacteria are observed. Responsible use of antibiotics in humans and animals should therefore be promoted. In this paper some general aspects of antibiotic resistance such as microbiological versus clinical resistance, intrinsic versus acquired resistance, resistance mechanisms, and transfer of resistance are briefly introduced. In 2012, the Belgian Center of Expertise on Antimicrobial Consumption and Resistance in Animals (AMCRA) was founded. Its mission is to collect and analyze all data related to antibiotic use and resistance in animals in Belgium and to communicate these findings in a neutral and objective manner. One of AMCRA's 10 objectives is a 50% reduction in antibiotic consumption in veterinary medicine in Belgium by 2020. The aim of this paper is to report on the achievements of this national project. The Institute for Agricultural and Fisheries Research (ILVO, Merelbeke-Melle), in collaboration with Ghent University, is currently working on three nationally funded projects on antibiotic resistance in animal husbandry. In the first project, an in vitro model is used to study the influence of low antibiotic concentrations due to carry-over after production and usage of medicated feed on the development of resistance in the pig gut. Part of that project is to develop a quantitative risk assessment model. A second project focuses on tracking excreted antibiotics used in pig rearing and their influence on the development of antibiotic resistance in pig

  8. Eight More Ways To Deal with Antibiotic Resistance

    PubMed Central

    Shlaes, David M.

    2014-01-01

    The fight against antibiotic resistance must be strengthened. We propose actions that U.S. government agencies and private sector entities can take to build a more comprehensive effort. These actions can increase the viability of investing in new antibiotics, ensure the quality and stewardship of all antibiotics, and make responses to emerging resistance more informed. Success requires the thoughtful exercise of federal authority and a firm commitment to share data and reward developers for the value generated with new, life-saving antibiotics. PMID:24867992

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

    PubMed Central

    Pamer, Eric G.

    2016-01-01

    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

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

    PubMed

    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

  11. Microbial selectivity of UV treatment on antibiotic-resistant heterotrophic bacteria in secondary effluents of a municipal wastewater treatment plant.

    PubMed

    Guo, Mei-Ting; Yuan, Qing-Bin; Yang, Jian

    2013-10-15

    Little is known about the microbial selectivity of UV treatment for antibiotic resistant bacteria, and the results of limited studies are conflicting. To understand the effect of UV disinfection on antibiotic resistant bacteria, both total heterotrophic bacteria and antibiotic resistant bacteria (including cephalexin-, ciprofloxacin-, erythromycin-, gentamicin-, vancomycin-, sulfadiazine-, rifampicin-, tetracycline- and chloramphenicol-resistant bacteria) were examined in secondary effluent samples from a municipal wastewater treatment plant. Bacteria resistant to both erythromycin and tetracycline were chosen as the representative of multiple-antibiotic-resistant bacteria and their characteristics after UV treatment were also investigated. UV disinfection results in effective inactivation for total heterotrophic bacteria, as well as all antibiotic resistant bacteria. After UV treatment at a fluence of 5 mJ/cm(2), the log reductions of nine types of antibiotic resistant bacteria varied from 1.0 ± 0.1 to 2.4 ± 0.1. Bacteria resistant to both erythromycin and tetracycline had a similar fluence response as did total heterotrophic bacteria. The findings suggest that UV disinfection could eliminate antibiotic resistance in wastewater treatment effluents and thus ensure public health security. Our experimental results indicated that UV disinfection led to enrichment of bacteria with resistance to sulfadiazine, vancomycin, rifampicin, tetracycline and chloramphenicol, while the proportions of cephalexin-, erythromycin-, gentamicin- and ciprofloxacin-resistant bacteria in the wastewater decreased. This reveals the microbial selectivity of UV disinfection for antibiotic resistant bacteria. PMID:24001605

  12. Antibiotics, Bacteria, and Antibiotic Resistance Genes: Aerial Transport from Cattle Feed Yards via Particulate Matter

    PubMed Central

    McEachran, Andrew D.; Blackwell, Brett R.; Hanson, J. Delton; Wooten, Kimberly J.; Mayer, Gregory D.; Cox, Stephen B.

    2015-01-01

    Background: Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized. Objectives: The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards. Methods: PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing. Results: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind. Conclusions: Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs. Citation: McEachran AD, Blackwell BR, Hanson JD, Wooten KJ, Mayer GD, Cox SB, Smith PN. 2015. Antibiotics, bacteria, and antibiotic

  13. Recent advances in the understanding of antibiotic resistance in Clostridium difficile infection

    PubMed Central

    2016-01-01

    Clostridium difficile epidemiology has changed in recent years, with the emergence of highly virulent types associated with severe infections, high rates of recurrences and mortality. Antibiotic resistance plays an important role in driving these epidemiological changes and the emergence of new types. While clindamycin resistance was driving historical endemic types, new types are associated with resistance to fluoroquinolones. Furthermore, resistance to multiple antibiotics is a common feature of the newly emergent strains and, in general, of many epidemic isolates. A reduced susceptibility to antibiotics used for C. difficile infection (CDI) treatment, in particular to metronidazole, has recently been described in several studies. Furthermore, an increased number of strains show resistance to rifamycins, used for the treatment of relapsing CDI. Several mechanisms of resistance have been identified in C. difficile, including acquisition of genetic elements and alterations of the antibiotic target sites. The C. difficile genome contains a plethora of mobile genetic elements, many of them involved in antibiotic resistance. Transfer of genetic elements among C. difficile strains or between C. difficile and other bacterial species can occur through different mechanisms that facilitate their spread. Investigations of the fitness cost in C. difficile indicate that both genetic elements and mutations in the molecular targets of antibiotics can be maintained regardless of the burden imposed on fitness, suggesting that resistances may persist in the C. difficile population also in absence of antibiotic selective pressure. The rapid evolution of antibiotic resistance and its composite nature complicate strategies in the treatment and prevention of CDI. The rapid identification of new phenotypic and genotypic traits, the implementation of effective antimicrobial stewardship and infection control programs, and the development of alternative therapies are needed to prevent and

  14. Recent advances in the understanding of antibiotic resistance in Clostridium difficile infection.

    PubMed

    Spigaglia, Patrizia

    2016-02-01

    Clostridium difficile epidemiology has changed in recent years, with the emergence of highly virulent types associated with severe infections, high rates of recurrences and mortality. Antibiotic resistance plays an important role in driving these epidemiological changes and the emergence of new types. While clindamycin resistance was driving historical endemic types, new types are associated with resistance to fluoroquinolones. Furthermore, resistance to multiple antibiotics is a common feature of the newly emergent strains and, in general, of many epidemic isolates. A reduced susceptibility to antibiotics used for C. difficile infection (CDI) treatment, in particular to metronidazole, has recently been described in several studies. Furthermore, an increased number of strains show resistance to rifamycins, used for the treatment of relapsing CDI. Several mechanisms of resistance have been identified in C. difficile, including acquisition of genetic elements and alterations of the antibiotic target sites. The C. difficile genome contains a plethora of mobile genetic elements, many of them involved in antibiotic resistance. Transfer of genetic elements among C. difficile strains or between C. difficile and other bacterial species can occur through different mechanisms that facilitate their spread. Investigations of the fitness cost in C. difficile indicate that both genetic elements and mutations in the molecular targets of antibiotics can be maintained regardless of the burden imposed on fitness, suggesting that resistances may persist in the C. difficile population also in absence of antibiotic selective pressure. The rapid evolution of antibiotic resistance and its composite nature complicate strategies in the treatment and prevention of CDI. The rapid identification of new phenotypic and genotypic traits, the implementation of effective antimicrobial stewardship and infection control programs, and the development of alternative therapies are needed to prevent and

  15. Antibiotic surgical prophylaxis increases nasal carriage of antibiotic-resistant staphylococci.

    PubMed

    McMurray, Claire L; Hardy, Katherine J; Verlander, Neville Q; Hawkey, Peter M

    2015-12-01

    Staphylococci are a significant cause of hospital-acquired infection. Nasal carriage of Staphylococcus aureus is an important risk factor for infection in surgical patients and coagulase-negative staphylococci (CNS) are a major cause of prosthetic joint infections. The impact that antibiotic surgical prophylaxis has on the nasal carriage of staphylococci has not been studied. Daily nasal swabs were taken from 63 patients who received antibiotic surgical prophylaxis and 16 patients who received no antibiotics. Total aerobic bacterial count, S. aureus and CNS were enumerated by culture from nasal swabs. Representative isolates were typed by staphylococcal interspersed repeat units (SIRU) typing and PFGE, and MICs to nine antibiotics were determined. After antibiotic administration, there was a reduction in S. aureus counts (median - 2.3 log(10)c.f.u. ml(- 1)) in 64.0 % of S. aureus carriers, compared with only a 0.89 log(10)c.f.u. ml(- 1) reduction in 75.0 % of S. aureus carriers who did not receive antibiotics. A greater increase in the nasal carriage rate of meticillin-resistant CNS was observed after antibiotic surgical prophylaxis compared with hospitalization alone, with increases of 16.4 and 4.6 %, respectively. Antibiotic-resistant S. epidermidis carriage rate increased by 16.6 % after antibiotic administration compared with 7.5 % with hospitalization alone. Antibiotic surgical prophylaxis impacts the nasal carriage of both S. aureus and CNS.

  16. Antibiotic resistance to Propionobacterium acnes: worldwide scenario, diagnosis and management.

    PubMed

    Sardana, Kabir; Gupta, Tanvi; Garg, Vijay K; Ghunawat, Sneha

    2015-07-01

    Antibiotic resistance in cutaneous Propionobacterium is a global problem. As a general rule, resistance levels are high to macrolides, trimethoprim/sulfamethoxazole and clindamycin, while tetracyclines and levofloxacin have low resistance potential. Newer preparations like doxycycline MR and doxycycline 20 mg are subantimicrobial and may not lead to resistance. Sampling techniques are crucial to determine resistance. Genomic evaluation using 16S ribosomal RNA gene sequencing can be useful in diagnosing mutations and mapping phylotypes of Propionobacterium acnes. Resistance may lead to slow response and relapses. Apart from benzoyl peroxide, azelaic acid, topical dapsone, oral zinc and retinoids, novel molecules with little resistance potential include octadecenedioic acid, phytosphingosine, lauric acid, retapamulin, resveratrol, T-3912 and NB-003. The use of oral retinoids and non-antibiotics like zinc can prevent resistance and help reduce the dependence on antibiotics.

  17. Antibiotic resistance to Propionobacterium acnes: worldwide scenario, diagnosis and management.

    PubMed

    Sardana, Kabir; Gupta, Tanvi; Garg, Vijay K; Ghunawat, Sneha

    2015-07-01

    Antibiotic resistance in cutaneous Propionobacterium is a global problem. As a general rule, resistance levels are high to macrolides, trimethoprim/sulfamethoxazole and clindamycin, while tetracyclines and levofloxacin have low resistance potential. Newer preparations like doxycycline MR and doxycycline 20 mg are subantimicrobial and may not lead to resistance. Sampling techniques are crucial to determine resistance. Genomic evaluation using 16S ribosomal RNA gene sequencing can be useful in diagnosing mutations and mapping phylotypes of Propionobacterium acnes. Resistance may lead to slow response and relapses. Apart from benzoyl peroxide, azelaic acid, topical dapsone, oral zinc and retinoids, novel molecules with little resistance potential include octadecenedioic acid, phytosphingosine, lauric acid, retapamulin, resveratrol, T-3912 and NB-003. The use of oral retinoids and non-antibiotics like zinc can prevent resistance and help reduce the dependence on antibiotics. PMID:26025191

  18. Occurrence and Antibiotic Resistance of Vibrio parahaemolyticus from Shellfish in Selangor, Malaysia

    PubMed Central

    Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

    2015-01-01

    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid

  19. Occurrence and Antibiotic Resistance of Vibrio parahaemolyticus from Shellfish in Selangor, Malaysia.

    PubMed

    Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

    2015-01-01

    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid

  20. Occurrence and Antibiotic Resistance of Vibrio parahaemolyticus from Shellfish in Selangor, Malaysia.

    PubMed

    Letchumanan, Vengadesh; Pusparajah, Priyia; Tan, Loh Teng-Hern; Yin, Wai-Fong; Lee, Learn-Han; Chan, Kok-Gan

    2015-01-01

    High consumer demand for shellfish has led to the need for large-scale, reliable shellfish supply through aquaculture or shellfish farming. However, bacterial infections which can spread rapidly among shellfish poses a major threat to this industry. Shellfish farmers therefore often resort to extensive use of antibiotics, both prophylactically and therapeutically, in order to protect their stocks. The extensive use of antibiotics in aquaculture has been postulated to represent a major contributing factor in the rising incidence of antimicrobial resistant pathogenic bacteria in shellfish. This study aimed to investigate the incidence of pathogenic Vibrio parahaemolyticus and determine the antibiotic resistance profile as well as to perform plasmid curing in order to determine the antibiotic resistance mediation. Based on colony morphology, all 450 samples tested were positive for Vibrio sp; however, tox-R assay showed that only 44.4% (200/450) of these were V. parahaemolyticus. Out of these 200 samples, 6.5% (13/200) were trh-positive while none were tdh-positive. Antibiotic resistance was determined for all V. parahaemolyticus identified against 14 commonly used antibiotics and the multiple antibiotic resistance index (MAR) was calculated. The isolates demonstrated high resistance to several antibiotics tested- including second and third-line antibiotics- with 88% resistant to ampicillin, 81% to amikacin,70.5% to kanamycin, 73% to cefotaxime, and 51.5% to ceftazidime. The MAR index ranged from 0.00 to 0.79 with the majority of samples having an index of 0.36 (resistant to five antibiotics). Among the 13 trh-positive strains, almost 70% (9/13) demonstrated resistance to 4 or more antibiotics. Plasmid profiling for all V. parahaemolyticus isolates revealed that 86.5% (173/200) contained plasmids - ranging from 1 to 7 plasmids with DNA band sizes ranging from 1.2 kb to greater than 10 kb. 6/13 of the pathogenic V. pathogenic strains contained plasmid. After plasmid

  1. Evolution of antibiotic resistance by human and bacterial niche construction.

    PubMed

    Boni, Maciej F; Feldman, Marcus W

    2005-03-01

    Antibiotic treatment by humans generates strong viability selection for antibiotic-resistant bacterial strains. The frequency of host antibiotic use often determines the strength of this selection, and changing patterns of antibiotic use can generate many types of behaviors in the population dynamics of resistant and sensitive bacterial populations. In this paper, we present a simple model of hosts dimorphic for their tendency to use/avoid antibiotics and bacterial pathogens dimorphic in their resistance/sensitivity to antibiotic treatment. When a constant fraction of hosts uses antibiotics, the two bacterial strain populations can coexist unless host use-frequency is above a critical value; this critical value is derived as the ratio of the fitness cost of resistance to the fitness cost of undergoing treatment. When strain frequencies can affect host behavior, the dynamics may be analyzed in the light of niche construction. We consider three models underlying changing host behavior: conformism, the avoidance of long infections, and adherence to the advice of public health officials. In the latter two, we find that the pathogen can have quite a strong effect on host behavior. In particular, if antibiotic use is discouraged when resistance levels are high, we observe a classic niche-construction phenomenon of maintaining strain polymorphism even in parameter regions where it would not be expected.

  2. Management Options for Reducing the Release of Antibiotics and Antibiotic Resistance Genes to the Environment

    PubMed Central

    Pruden, Amy; Amézquita, Alejandro; Collignon, Peter; Brandt, Kristian K.; Graham, David W.; Lazorchak, James M.; Suzuki, Satoru; Silley, Peter; Snape, Jason R.; Topp, Edward; Zhang, Tong; Zhu, Yong-Guan

    2013-01-01

    Background: There is growing concern worldwide about the role of polluted soil and water environments in the development and dissemination of antibiotic resistance. Objective: Our aim in this study was to identify management options for reducing the spread of antibiotics and antibiotic-resistance determinants via environmental pathways, with the ultimate goal of extending the useful life span of antibiotics. We also examined incentives and disincentives for action. Methods: We focused on management options with respect to limiting agricultural sources; treatment of domestic, hospital, and industrial wastewater; and aquaculture. Discussion: We identified several options, such as nutrient management, runoff control, and infrastructure upgrades. Where appropriate, a cross-section of examples from various regions of the world is provided. The importance of monitoring and validating effectiveness of management strategies is also highlighted. Finally, we describe a case study in Sweden that illustrates the critical role of communication to engage stakeholders and promote action. Conclusions: Environmental releases of antibiotics and antibiotic-resistant bacteria can in many cases be reduced at little or no cost. Some management options are synergistic with existing policies and goals. The anticipated benefit is an extended useful life span for current and future antibiotics. Although risk reductions are often difficult to quantify, the severity of accelerating worldwide morbidity and mortality rates associated with antibiotic resistance strongly indicate the need for action. PMID:23735422

  3. FabH Mutations Confer Resistance to FabF-Directed Antibiotics in Staphylococcus aureus

    PubMed Central

    Parsons, Joshua B.; Yao, Jiangwei; Frank, Matthew W.

    2014-01-01

    Delineating the mechanisms for genetically acquired antibiotic resistance is a robust approach to target validation and anticipates the evolution of clinical drug resistance. This study defines a spectrum of mutations in fabH that render Staphylococcus aureus resistant to multiple natural products known to inhibit the elongation condensing enzyme (FabF) of bacterial type II fatty acid synthesis. Twenty independently isolated clones resistant to platensimycin, platencin, or thiolactomycin were isolated. All mutants selected against one antibiotic were cross-resistant to the other two antibiotics. Mutations were not detected in fabF, but the resistant strains harbored missense mutations in fabH. The altered amino acids clustered in and around the FabH active-site tunnel. The mutant FabH proteins were catalytically compromised based on the low activities of the purified enzymes, a fatty acid-dependent growth phenotype, and elevated expression of the fabHF operon in the mutant strains. Independent manipulation of fabF and fabH expression levels showed that the FabH/FabF activity ratio was a major determinant of antibiotic sensitivity. Missense mutations that reduce FabH activity are sufficient to confer resistance to multiple antibiotics that bind to the FabF acyl-enzyme intermediate in S. aureus. PMID:25403676

  4. Environmental waters as a source of antibiotic-resistant Enterococcus species in Belgrade, Serbia.

    PubMed

    Veljović, Katarina; Popović, Nikola; Vidojević, Amarela Terzić; Tolinački, Maja; Mihajlović, Sanja; Jovčić, Branko; Kojić, Milan

    2015-09-01

    Despite the number of studies on antibiotic-resistant enterococci from Serbian clinical settings, there are no data about environmental contamination with these bacteria. Thus, this study investigated the prevalence of antibiotic-resistant enterococci in Belgrade, Serbia. Enterococcus species collected from ten surface water sites, including a lake, two major river systems, and springs, were tested. Among enterococci, we found single (21.7 %), double (17.4 %), and multiple antibiotic resistance patterns (56.3 %). Vancomycin-resistant strains were not found, indicating that their abundance in Belgrade is tightly linked to clinical settings. The multiple drug-resistant strains Enterococcus faecalis, Enterococcus faecium, and Enterococcus mundtii were frequently detected in the lake during the swimming season and in the rivers near industrial zones. We confirmed the presence of ermB, ermC, ant(6)-Ia, tetM, and tetL and mutations in gyrA genes. The phylogenetic analysis of 16S rRNA gene of E. faecium isolates that harbor esp gene classified them into two groups based on high-bootstraps scores in the tree analysis. Pulsed-field gel electrophoresis analysis of antibiotic-resistant enterococci revealed genomic similarity ranging from 75 to 100 %. This study indicates the importance of anthropogenic impact to the spread of antibiotic-resistant enterococci in environmental waters of Belgrade, Serbia.

  5. Resistance to antibiotics: are we in the post-antibiotic era?

    PubMed

    Alanis, Alfonso J

    2005-01-01

    Serious infections caused by bacteria that have become resistant to commonly used antibiotics have become a major global healthcare problem in the 21st century. They not only are more severe and require longer and more complex treatments, but they are also significantly more expensive to diagnose and to treat. Antibiotic resistance, initially a problem of the hospital setting associated with an increased number of hospital-acquired infections usually in critically ill and immunosuppressed patients, has now extended into the community causing severe infections difficult to diagnose and treat. The molecular mechanisms by which bacteria have become resistant to antibiotics are diverse and complex. Bacteria have developed resistance to all different classes of antibiotics discovered to date. The most frequent type of resistance is acquired and transmitted horizontally via the conjugation of a plasmid. In recent times new mechanisms of resistance have resulted in the simultaneous development of resistance to several antibiotic classes creating very dangerous multidrug-resistant (MDR) bacterial strains, some also known as "superbugs". The indiscriminate and inappropriate use of antibiotics in outpatient clinics, hospitalized patients and in the food industry is the single largest factor leading to antibiotic resistance. In recent years, the number of new antibiotics licensed for human use in different parts of the world has been lower than in the recent past. In addition, there has been less innovation in the field of antimicrobial discovery research and development. The pharmaceutical industry, large academic institutions or the government are not investing the necessary resources to produce the next generation of newer safe and effective antimicrobial drugs. In many cases, large pharmaceutical companies have terminated their anti-infective research programs altogether due to economic reasons. The potential negative consequences of all these events are relevant because

  6. Integron Involvement in Environmental Spread of Antibiotic Resistance

    PubMed Central

    Stalder, Thibault; Barraud, Olivier; Casellas, Magali; Dagot, Christophe; Ploy, Marie-Cécile

    2012-01-01

    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.). PMID:22509175

  7. Essential Oils, A New Horizon in Combating Bacterial Antibiotic Resistance

    PubMed Central

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

    2014-01-01

    For many years, the battle between humans and the multitudes of infection and disease causing pathogens continues. Emerging at the battlefield as some of the most significant challenges to human health are bacterial resistance and its rapid rise. These have become a major concern in global public health invigorating the need for new antimicrobial compounds. A rational approach to deal with antibiotic resistance problems requires detailed knowledge of the different biological and non-biological factors that affect the rate and extent of resistance development. Combination therapy combining conventional antibiotics and essential oils is currently blooming and represents a potential area for future investigations. This new generation of phytopharmaceuticals may shed light on the development of new pharmacological regimes in combating antibiotic resistance. This review consolidated and described the observed synergistic outcome between essential oils and antibiotics, and highlighted the possibilities of essential oils as the potential resistance modifying agent. PMID:24627729

  8. Antibiotic-Resistant Fecal Bacteria, Antibiotics, and Mercury in Surface Waters of Oakland County, Michigan, 2005-2006

    USGS Publications Warehouse

    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-resistance

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

    PubMed

    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.

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

    PubMed

    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

  11. Staphylococcus hominis subsp. novobiosepticus subsp. nov., a novel trehalose- and N-acetyl-D-glucosamine-negative, novobiocin- and multiple-antibiotic-resistant subspecies isolated from human blood cultures.

    PubMed

    Kloos, W E; George, C G; Olgiate, J S; Van Pelt, L; McKinnon, M L; Zimmer, B L; Muller, E; Weinstein, M P; Mirrett, S

    1998-07-01

    A new subspecies, Staphylococcus hominis subsp. novobiosepticus, isolated from human blood cultures, a wound, a breast abscess and a catheter tip, is described on the basis of a study of 26 strains isolated between 1989 and 1996. DNA-DNA reassociation reactions, conducted under stringent conditions, and macrorestriction pattern analysis demonstrated that these strains are closely related to previously characterized S. hominis strains isolated from human skin and clinical specimens, but are significantly divergent. S. hominis subsp. novobiosepticus can be distinguished from S. hominis (now named S. hominis subsp. hominis) by its combined characteristics of novobiocin resistance and failure to produce acid aerobically from D-trehalose and N-acetyl-D-glucosamine. Furthermore, all 26 strains of the new subspecies are resistant to nalidixic acid, penicillin G, oxacillin, kanamycin and streptomycin, and were either resistant or had intermediate resistance to methicillin and gentamicin. Most strains were also resistant to erythromycin, clindamycin, chloramphenicol, trimethoprim/sulfamethoxazole and ciprofloxacin. Based on a comparison of the sequences of a 1001 bp mecA amplification product from reference methicillin-resistant staphylococci, the mecA gene present in S. hominis subsp. novobiosepticus was identified as homologue A, commonly found in S. aureus and many coagulase-negative staphylococcal species. The type strain of S. hominis subsp. novobiosepticus is ATCC 700236T. Descriptions of S. hominis subsp. novobiosepticus subsp. nov and S. hominis subsp. hominis are given and the description of S. hominis is emended.

  12. Occurrence of antibiotic resistance and characterization of resistance genes and integrons in Enterobacteriaceae isolated from integrated fish farms in South China.

    PubMed

    Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa Reynolds; Kolpin, Dana W

    2011-11-01

    Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

  13. Current status of antibiotic resistance in animal production.

    PubMed

    Franklin, A

    1999-01-01

    It is generally accepted that the more antibiotics we use, the faster bacteria will develop resistance. Further it has been more or less accepted that once an antibiotic is withdrawn from the clinic, the resistance genes will eventually disappear, [table: see text] since they will no more be of any survival value for the bacterial cell. However, recent research has shown that after a long time period of exposure to antibiotics, certain bacterial species may adapt to this environment in such a way that they keep their resistance genes stably also after the removal of antibiotics. Thus, there is reason to believe that once resistance has developed it will not even in the long term be eradicated. What then can we do not to increase further the already high level of antibiotic-resistant bacteria in animals? We should of course encourage a prudent use of these valuable drugs. In Sweden antibiotics are not used for growth promoting purposes and are available only after veterinary prescription on strict indications. Generally, antimicrobial treatment of animals on individual or on herd basis should not be considered unless in connection with relevant diagnostics. The amounts of antibiotics used and the development of resistance in important pathogens should be closely monitored. Furthermore, resistance monitoring in certain non-pathogenic intestinal bacteria, which may serve as a reservoir for resistance genes is probably more important than hitherto anticipated. Once the usage of or resistance to a certain antibiotic seems to increase in an alarming way, steps should be taken to limit the usage of the drug in order to prevent further spread of resistance genes in animals, humans and the environment. Better methods for detecting and quantifying antibiotic resistance have to be developed. Screening methods must be standardized and evaluated in order to obtain comparable and reliable results from different countries. The genetic mechanisms for development of resistance and

  14. Evaluating antibiotic resistance genes in soils with applied manures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antibiotics are commonly used in livestock production to promote growth and combat disease. Recent studies have shown the potential for spread of antibiotic resistance genes (ARG) to the environment following application of livestock manures. In this study, concentrations of bacteria with ARG in soi...

  15. Composting swine slurry to reduce indicators and antibiotic resistance genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the last twenty years there have been considerable increases in the incidence of human infections with bacteria that are resistant to commonly used antibiotics. This has precipitated concerns about the use of antibiotics in livestock production. Composting of swine manure has several advantages...

  16. Assessment of antibiotic resistance in runoff from cattle feedlots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of antibiotics in veterinary medicine, especially at sub-therapeutic doses, is an important issue that has captured national attention, and there is considerable concern about the potential to transmit antibiotic resistance from animals to humans via fecal contamination of surface and ground...

  17. Bacterial cheating limits the evolution of antibiotic resistance

    NASA Astrophysics Data System (ADS)

    Chao, Hui Xiao; Datta, Manoshi; Yurtsev, Eugene; Gore, Jeff

    2011-03-01

    The widespread use of antibiotics has led to the evolution of resistance in bacteria. Bacteria can gain resistance to the antibiotic ampicillin by acquiring a plasmid carrying the gene beta-lactamase, which inactivates the antibiotic. This inactivation may represent a cooperative behavior, as the entire bacterial population benefits from removing the antibiotic. The cooperative nature of this growth suggests that a cheater strain--which does not contribute to breaking down the antibiotic--may be able to take advantage of cells cooperatively inactivating the antibiotic. Here we experimentally find that a ``sensitive'' bacterial strain lacking the plasmid conferring resistance can invade a population of resistant bacteria, even in antibiotic concentrations that should kill the sensitive strain. We observe stable coexistence between the two strains and find that a simple model successfully explains the behavior as a function of antibiotic concentration and cell density. We anticipate that our results will provide insight into the evolutionary origin of phenotypic diversity and cooperative behaviors found in nature.

  18. Antibiotic-Resistant Bacteria: There is Hope.

    ERIC Educational Resources Information Center

    Offner, Susan

    1998-01-01

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

  19. Antibiotic-resistant soil bacteria in transgenic plant fields

    PubMed Central

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

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-year culture of the transgenic Bt176 corn, which has a blaTEM marker gene, could have had on the soil bacterial community. The bla gene encoding resistance to ampicillin belongs to the beta-lactam antibiotic family, which is widely used in medicine but is readily compromised by bacterial antibiotic resistance. Our results indicate that soil bacteria are naturally resistant to a broad spectrum of beta-lactam antibiotics, including the third cephalosporin generation, which has a slightly stronger discriminating effect on soil isolates than other cephalosporins. These high resistance levels for a wide range of antibiotics are partly due to the polymorphism of bla genes, which occur frequently among soil bacteria. The blaTEM116 gene of the transgenic corn Bt176 investigated here is among those frequently found, thus reducing any risk of introducing a new bacterial resistance trait from the transgenic material. In addition, no significant differences were observed in bacterial antibiotic-resistance levels between transgenic and nontransgenic corn fields, although the bacterial populations were different. PMID:18292221

  20. [Effect of Three Typical Disinfection Byproducts on Bacterial Antibiotic Resistance].

    PubMed

    Lü, Lu; Zhang, Meng-lu; Wang, Chun-ming; Lin, Hui-rong; Yu, Xin

    2015-07-01

    The effect of typical disinfection byproducts (DBPs) on bacterial antibiotic resistance was investigated in this study. chlorodibromomethane (CDBM), iodoacetic acid (IAA) and chloral hydrate (CH) were selected, which belong to trihalomethanes (THMs), haloacetic acids (HAAs) and aldehydes, respectively. After exposure to the selected DBPs, the resistance change of the tested strains to antibiotics was determined. As a result, all of the three DBPs induced Pseudomonas aeruginosa PAO1 to gain increased resistance to the five antibiotics tested, and the DBPs ranked as IAA > CH > CDBM according to their enhancement effects. Multidrug resistance could also be enhanced by treatment with IAA. The same result was observed in Escherichia coli K12, suggesting that the effect of DBPs on antibiotic resistance was a common phenomenon. The mechanism was probably that DBPs stimulated oxidative stress, which induced mutagenesis. And the antibiotic resistance mutation frequency could be increased along with mutagenesis. This study revealed that the acquisition of bacterial antibiotic resistance might be related to DBPs in drinking water systems. Besides the genotoxicological risks, the epidemiological risks of DBPs should not be overlooked.

  1. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    EPA Science Inventory

    1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...

  2. Antibiotic resistance of Vibrio species isolated from Sparus aurata reared in Italian mariculture.

    PubMed

    Scarano, Christian; Spanu, Carlo; Ziino, Graziella; Pedonese, Francesca; Dalmasso, Alessandra; Spanu, Vincenzo; Virdis, Salvatore; De Santis, Enrico P L

    2014-07-01

    Extensive use of antimicrobial agents in finfish farming and the consequent selective pressure lead to the acquisition of antibiotic resistance in aquaculture environment bacteria. Vibrio genus represents one of the main pathogens affecting gilthead sea bream. The development of antibiotic resistance by Vibrio represents a potential threat to human health by exchange of resistant genes to human pathogens through food chain. The objective of the present study was to conduct a multisite survey on the antibiotic resistance of Vibrio spp. isolated from gilthead sea bream reared in Italian mariculture. Vibrio spp. strains were isolated from skin, gills, muscles and intestinal content of 240 gilthead sea bream. A random selection of 150 strains was sequenced for species identification. Resistance against 15 antimicrobial agents was tested by the broth microdilution method. Vibrio harveyi and Vibrio alginolyticus accounted for 36.7% and 33.3% of the isolates respectively. 96% of the strains showed multiple resistance to the tested drugs, with two strains, Vibrio aestuarianus and Vibrio harveyi resistant to 10 and 9 antibiotics, respectively. Ampicillin, amoxicillin, erythromycin and sulfadiazine showed low efficacy against Vibrio spp. Rational use of antimicrobial agents and surveillance on antibiotic administration may reduce the acquisition of resistance by microorganisms of aquatic ecosystems.

  3. Assessing antibiotic resistance of microorganisms in sanitary sewage.

    PubMed

    Kaeseberg, Thomas; Blumensaat, Frank; Zhang, Jin; Krebs, Peter

    2015-01-01

    The release of antimicrobial substances into surface waters is of growing concern due to direct toxic effects on all trophic levels and the promotion of antibiotic resistance through sub-inhibitory concentration levels. This study showcases (1) the variation of antibiotics in sanitary sewage depending on different timescales and (2) a method to assess the antibiotic resistance based on an inhibition test. The test is based on the measurement of the oxygen uptake rate (OUR) in wastewater samples with increasing concentrations of the selected antibiotic agents. The following antibiotics were analysed in the present study: clarithromycin (CLA) was selected due to its high toxicity to many microorganisms (low EC50), ciprofloxacin (CIP) which is used to generally fight all bacteria concerning interstitial infections and doxycyclin (DOX) having a broad spectrum efficacy. Results show that CLA inhibited the OUR by approximately 50% at a concentration of about 10 mg L⁻¹, because Gram-negative bacteria such as Escherichia coli are resistant, whereas CIP inhibited about 90% of the OUR at a concentration equal to or greater than 10 mg L⁻¹. In the case of DOX, a moderate inhibition of about 38% at a concentration of 10 mg L⁻¹ was identified, indicating a significant antibiotic resistance. The results are consistent with the corresponding findings from the Clinical and Laboratory Standards Institute. Thus, the presented inhibition test provides a simple but robust alternative method to assess antibiotic resistance in biofilms instead of more complex clinical tests.

  4. Assessing antibiotic resistance of microorganisms in sanitary sewage.

    PubMed

    Kaeseberg, Thomas; Blumensaat, Frank; Zhang, Jin; Krebs, Peter

    2015-01-01

    The release of antimicrobial substances into surface waters is of growing concern due to direct toxic effects on all trophic levels and the promotion of antibiotic resistance through sub-inhibitory concentration levels. This study showcases (1) the variation of antibiotics in sanitary sewage depending on different timescales and (2) a method to assess the antibiotic resistance based on an inhibition test. The test is based on the measurement of the oxygen uptake rate (OUR) in wastewater samples with increasing concentrations of the selected antibiotic agents. The following antibiotics were analysed in the present study: clarithromycin (CLA) was selected due to its high toxicity to many microorganisms (low EC50), ciprofloxacin (CIP) which is used to generally fight all bacteria concerning interstitial infections and doxycyclin (DOX) having a broad spectrum efficacy. Results show that CLA inhibited the OUR by approximately 50% at a concentration of about 10 mg L⁻¹, because Gram-negative bacteria such as Escherichia coli are resistant, whereas CIP inhibited about 90% of the OUR at a concentration equal to or greater than 10 mg L⁻¹. In the case of DOX, a moderate inhibition of about 38% at a concentration of 10 mg L⁻¹ was identified, indicating a significant antibiotic resistance. The results are consistent with the corresponding findings from the Clinical and Laboratory Standards Institute. Thus, the presented inhibition test provides a simple but robust alternative method to assess antibiotic resistance in biofilms instead of more complex clinical tests. PMID:25633938

  5. Antibiotics and bioactive natural products in treatment of methicillin resistant Staphylococcus aureus: A brief review

    PubMed Central

    Kali, Arunava

    2015-01-01

    Infections caused by Staphylococcus aureus strains with Methicillin resistance are associated with increased mortality and morbidity, aggressive course, multiple drug resistance and hospital outbreaks. Several first and second line antibiotics are rapidly becoming ineffective for treatment due to emergence of resistance. Extracts of medicinal plants are rich source of unique phytochemicals. Plants used in traditional medicine have been reported to have significant anti-MRSA activity. The objective of this review is to provide a brief overview of antibiotics as well as anti-MRSA natural products and their future prospect. PMID:26009690

  6. Antibiotic Methylation: A New Mechanism of Antimicrobial Resistance.

    PubMed

    Malone, Kerri M; Gordon, Stephen V

    2016-10-01

    In new research on Mycobacterium tuberculosis, the causative agent of tuberculosis, Warrier and colleagues have discovered a novel mode of bacterial drug resistance, namely antibiotic inactivation via N-methylation.

  7. Antibiotic Resistance in India: Drivers and Opportunities for Action.

    PubMed

    Laxminarayan, Ramanan; Chaudhury, Ranjit Roy

    2016-03-01

    Ramanan Laxminarayan and Ranjit Roy Chaudhury examine the factors encouraging the emergence of antibiotic resistance in India, the implications nationally and internationally, and what might be done to help. PMID:26934098

  8. Bacterial antibiotic resistance in soils irrigated with reclaimed municipal wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wastewater reclamation for municipal irrigation and groundwater recharge is an increasingly attractive option for extending water supplies. However, public health concerns include the potential for development of antibiotic resistance (AR) in soil bacteria after exposure to residual chemicals in rec...

  9. Antibiotic Resistance in India: Drivers and Opportunities for Action.

    PubMed

    Laxminarayan, Ramanan; Chaudhury, Ranjit Roy

    2016-03-01

    Ramanan Laxminarayan and Ranjit Roy Chaudhury examine the factors encouraging the emergence of antibiotic resistance in India, the implications nationally and internationally, and what might be done to help.

  10. Antibiotic Methylation: A New Mechanism of Antimicrobial Resistance.

    PubMed

    Malone, Kerri M; Gordon, Stephen V

    2016-10-01

    In new research on Mycobacterium tuberculosis, the causative agent of tuberculosis, Warrier and colleagues have discovered a novel mode of bacterial drug resistance, namely antibiotic inactivation via N-methylation. PMID:27593675

  11. Antibiotic Resistance: The Need For a Global Strategy.

    PubMed

    Elder, David P; Kuentz, Martin; Holm, René

    2016-08-01

    The development of antibiotic resistance is a major problem for mankind and results in fatal consequences on a daily basis across the globe. There are a number of reasons for this situation including increasing globalization with worldwide travel, health tourism, over use and ineffective use (both in man and animals), and counterfeiting of the antimicrobial drug products we have available currently. Although there are huge economical, demographic, legal and logistic differences among the global communities, there are also differences regarding the best approach to dealing with antibiotic resistance. However, as resistant bacteria do not respect international borders, there is clearly a need for a global strategy to minimize the spread of antibiotic resistance, to optimize the use of antibiotics, and to facilitate the development of new and effective medications. This commentary provides an insight into the issues and some of the ongoing programs to ensure an effective treatment for the future. PMID:27397433

  12. Antibiotics Resistance in Rhizobium: Type, Process, Mechanism and Benefit for Agriculture.

    PubMed

    Naamala, Judith; Jaiswal, Sanjay K; Dakora, Felix D

    2016-06-01

    The use of high-quality rhizobial inoculants on agricultural legumes has contributed substantially to the N economy of farming systems through inputs from biological nitrogen fixation (BNF). Large populations of symbiotically effective rhizobia should be available in the rhizosphere for symbiotic BNF with host plants. The rhizobial populations should also be able to compete and infect host plants. However, the rhizosphere comprises large populations of different microorganisms. Some of these microorganisms naturally produce antibiotics which are lethal to susceptible rhizobial populations in the soil. Therefore, intrinsic resistance to antibiotics is a desirable trait for the rhizobial population. It increases the rhizobia's chances of growth, multiplication and persistence in the soil. With a large population of rhizobia in the soil, infectivity of host plants and the subsequent BNF efficiency can be guaranteed. This review, therefore, puts together findings by various researchers on antibiotic resistance in bacteria with the main emphasis on rhizobia. It describes the different modes of action of different antibiotics, the types of antibiotic resistance exhibited by rhizobia, the mechanisms of acquisition of antibiotic resistance in rhizobia and the levels of tolerance of different rhizobial species to different antibiotics. PMID:26897128

  13. Membrane Proteases and Aminoglycoside Antibiotic Resistance ▿ †

    PubMed Central

    Hinz, Aaron; Lee, Samuel; Jacoby, Kyle; Manoil, Colin

    2011-01-01

    We present genetic studies that help define the functional network underlying intrinsic aminoglycoside resistance in Pseudomonas aeruginosa. Our analysis shows that proteolysis, particularly that controlled by the membrane protease FtsH, is a major determinant of resistance. First, we examined the consequences of inactivating genes controlled by AmgRS, a two-component regulator required for intrinsic tobramycin resistance. Three of the gene products account for resistance: a modulator of FtsH protease (YccA), a membrane protease (HtpX), and a membrane protein of unknown function (PA5528). Second, we screened mutations inactivating 66 predicted proteases and related functions. Insertions inactivating two FtsH protease accessory factors (HflK and HflC) and a cytoplasmic protease (HslUV) increased tobramycin sensitivity. Finally, we generated an ftsH deletion mutation. The mutation dramatically increased aminoglycoside sensitivity. Many of the functions whose inactivation increased sensitivity appeared to act independently, since multiple mutations led to additive or synergistic effects. Up to 500-fold increases in tobramycin sensitivity were observed. Most of the mutations also were highly pleiotropic, increasing sensitivity to a membrane protein hybrid, several classes of antibiotics, alkaline pH, NaCl, and other compounds. We propose that the network of proteases provides robust protection from aminoglycosides and other substances through the elimination of membrane-disruptive mistranslation products. PMID:21764915

  14. Antibiotic resistance monitoring in heterotrophic bacteria from anthropogenic-polluted seawater and the intestines of oyster Crassostrea hongkongensis.

    PubMed

    Wang, Rui Xuan; Wang, AnLi; Wang, Jiang Yong

    2014-11-01

    A total of 1,050 strains of heterotrophic bacteria isolated from farming seawater and the intestines of oyster species Crassostrea hongkongensis were tested for resistance to 10 antibiotics by the Kirby-Bauer diffusion method. The resistant rates of seawater-derived bacteria to chloramphenicol, enrofloxacin, and ciprofloxacin were low (less than 20%), whereas the bacteria obtained from oysters showed low resistance to chloramphenicol and enrofloxacin. Many strains showed high resistant rates (more than 40%) to furazolidone, penicillin G, and rifampin. A total of 285 strains from farming seawater and oysters were resistant to more than three antibiotics. Several strains showed resistance to more than nine antibiotics. Furthermore, the peak resistant rates of the seawater-derived strains to multiple antibiotics overlapped in April, June, September, and November, and those of oyster-derived strains overlapped during April, July, and September. The multi-resistant rate patterns of strains from farming seawater and oyster intestines were similar.

  15. Antibiotic resistance monitoring in heterotrophic bacteria from anthropogenic-polluted seawater and the intestines of oyster Crassostrea hongkongensis.

    PubMed

    Wang, Rui Xuan; Wang, AnLi; Wang, Jiang Yong

    2014-11-01

    A total of 1,050 strains of heterotrophic bacteria isolated from farming seawater and the intestines of oyster species Crassostrea hongkongensis were tested for resistance to 10 antibiotics by the Kirby-Bauer diffusion method. The resistant rates of seawater-derived bacteria to chloramphenicol, enrofloxacin, and ciprofloxacin were low (less than 20%), whereas the bacteria obtained from oysters showed low resistance to chloramphenicol and enrofloxacin. Many strains showed high resistant rates (more than 40%) to furazolidone, penicillin G, and rifampin. A total of 285 strains from farming seawater and oysters were resistant to more than three antibiotics. Several strains showed resistance to more than nine antibiotics. Furthermore, the peak resistant rates of the seawater-derived strains to multiple antibiotics overlapped in April, June, September, and November, and those of oyster-derived strains overlapped during April, July, and September. The multi-resistant rate patterns of strains from farming seawater and oyster intestines were similar. PMID:25133348

  16. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae.

    PubMed

    Vuotto, Claudia; Longo, Francesca; Balice, Maria Pia; Donelli, Gianfranco; Varaldo, Pietro E

    2014-01-01

    The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae.

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

    PubMed Central

    Norris, Pauline; Chamberlain, Kerry; Dew, Kevin; Gabe, Jonathan; Hodgetts, Darrin; Madden, Helen

    2013-01-01

    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. PMID:27029314

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Selection of a multidrug resistance plasmid by sublethal levels of antibiotics and heavy metals.

    PubMed

    Gullberg, Erik; Albrecht, Lisa M; Karlsson, Christoffer; Sandegren, Linus; Andersson, Dan I

    2014-01-01

    How sublethal levels of antibiotics and heavy metals select for clinically important multidrug resistance plasmids is largely unknown. Carriage of plasmids generally confers substantial fitness costs, implying that for the plasmid-carrying bacteria to be maintained in the population, the plasmid cost needs to be balanced by a selective pressure conferred by, for example, antibiotics or heavy metals. We studied the effects of low levels of antibiotics and heavy metals on the selective maintenance of a 220-kbp extended-spectrum β-lactamase (ESBL) plasmid identified in a hospital outbreak of Klebsiella pneumoniae and Escherichia coli. The concentrations of antibiotics and heavy metals required to maintain plasmid-carrying bacteria, the minimal selective concentrations (MSCs), were in all cases below (almost up to 140-fold) the MIC of the plasmid-free susceptible bacteria. This finding indicates that the very low antibiotic and heavy metal levels found in polluted environments and in treated humans and animals might be sufficiently high to maintain multiresistance plasmids. When resistance genes were moved from the plasmid to the chromosome, the MSC decreased, showing that MSC for a specific resistance conditionally depends on genetic context. This finding suggests that a cost-free resistance could be maintained in a population by an infinitesimally low concentration of antibiotic. By studying the effect of combinations of several compounds, it was observed that for certain combinations of drugs each new compound added lowered the minimal selective concentration of the others. This combination effect could be a significant factor in the selection of multidrug resistance plasmids/bacterial clones in complex multidrug environments. Importance: Antibiotic resistance is in many pathogenic bacteria caused by genes that are carried on large conjugative plasmids. These plasmids typically contain multiple antibiotic resistance genes as well as genes that confer resistance to

  20. Inactivation of antibiotics and the dissemination of resistance genes.

    PubMed

    Davies, J

    1994-04-15

    The emergence of multidrug-resistant bacteria is a phenomenon of concern to the clinician and the pharmaceutical industry, as it is the major cause of failure in the treatment of infectious diseases. The most common mechanism of resistance in pathogenic bacteria to antibiotics of the aminoglycoside, beta-lactam (penicillins and cephalosporins), and chloramphenicol types involves the enzymic inactivation of the antibiotic by hydrolysis or by formation of inactive derivatives. Such resistance determinants most probably were acquired by pathogenic bacteria from a pool of resistance genes in other microbial genera, including antibiotic-producing organisms. The resistance gene sequences were subsequently integrated by site-specific recombination into several classes of naturally occurring gene expression cassettes (typically "integrons") and disseminated within the microbial population by a variety of gene transfer mechanisms. Although bacterial conjugation once was believed to be restricted in host range, it now appears that this mechanism of transfer permits genetic exchange between many different bacterial genera in nature.

  1. Formation and transmission of Staphylococcus aureus (including MRSA) aerosols carrying antibiotic-resistant genes in a poultry farming environment.

    PubMed

    Liu, Dunjiang; Chai, Tongjie; Xia, Xianzhu; Gao, Yuwei; Cai, Yumei; Li, Xiaoxia; Miao, Zengming; Sun, Lingyu; Hao, Haiyu; Roesler, Uwe; Wang, Jian

    2012-06-01

    There is a rather limited understanding concerning the antibiotic-resistance of the airborne S. aureus and the transmission of the antibiotic-resistant genes it carries Therefore, we isolated 149 S. aureus strains from the samples collected from the feces, the indoor air and the outdoor air of 6 chicken farms, and performed the research on them with 15 types of antibiotics and the REP-PCR trace identification. The 100% homologous strains were selected to conduct the research on the carrying and transmission status of the antibiotic-resistant genes. The results revealed that 5.37% strains (8/149) were resistant to methicillins (MRSA), and 94% strains (140/149) were resistant to compound sulfamethoxazole, etc. In addition, these strains displayed a resistance to multiple antibiotics (4, 5 or 6 types) and there were also 3 strains resistant to 9 antibiotics. It should be noted that the antibiotic-resistance of some strains isolated from the feces, the indoor and outdoor air was basically the same, and the strains with the same REP-PCR trace identification result carried the same type of antibiotic-resistant genes. The results showed that airborne transmission not only causes the spread of epidemic diseases but also exerts threats to the public health of a community.

  2. The ABC of Ribosome-Related Antibiotic Resistance.

    PubMed

    Wilson, Daniel N

    2016-01-01

    The increase in multidrug-resistant pathogenic bacteria is limiting the utility of our current arsenal of antimicrobial agents. Mechanistically understanding how bacteria obtain antibiotic resistance is a critical first step to the development of improved inhibitors. One common mechanism for bacteria to obtain antibiotic resistance is by employing ATP-binding cassette (ABC) transporters to actively pump the drug from the cell. The ABC-F family includes proteins conferring resistance to a variety of clinically important ribosome-targeting antibiotics; however, controversy remains as to whether resistance is conferred via efflux like other ABC transporters or whether another mechanism, such as ribosome protection, is at play. A recent study by Sharkey and coworkers (L. K. Sharkey, T. A. Edwards, and A. J. O'Neill, mBio 7:e01975-15, 2016, http://dx.doi.org/10.1128/mBio.01975-15) provides strong evidence that ABC-F proteins conferring antibiotic resistance utilize ribosome protection mechanisms, namely, by interacting with the ribosome and displacing the drug from its binding site, thus revealing a novel role for ABC-F proteins in antibiotic resistance. PMID:27143393

  3. The ABC of Ribosome-Related Antibiotic Resistance.

    PubMed

    Wilson, Daniel N

    2016-05-03

    The increase in multidrug-resistant pathogenic bacteria is limiting the utility of our current arsenal of antimicrobial agents. Mechanistically understanding how bacteria obtain antibiotic resistance is a critical first step to the development of improved inhibitors. One common mechanism for bacteria to obtain antibiotic resistance is by employing ATP-binding cassette (ABC) transporters to actively pump the drug from the cell. The ABC-F family includes proteins conferring resistance to a variety of clinically important ribosome-targeting antibiotics; however, controversy remains as to whether resistance is conferred via efflux like other ABC transporters or whether another mechanism, such as ribosome protection, is at play. A recent study by Sharkey and coworkers (L. K. Sharkey, T. A. Edwards, and A. J. O'Neill, mBio 7:e01975-15, 2016, http://dx.doi.org/10.1128/mBio.01975-15) provides strong evidence that ABC-F proteins conferring antibiotic resistance utilize ribosome protection mechanisms, namely, by interacting with the ribosome and displacing the drug from its binding site, thus revealing a novel role for ABC-F proteins in antibiotic resistance.

  4. The use of platensimycin and platencin to fight antibiotic resistance

    PubMed Central

    Allahverdiyev, Adil M; Bagirova, Melahat; Abamor, Emrah Sefik; Ates, Sezen Canim; Koc, Rabia Cakir; Miraloglu, Meral; Elcicek, Serhat; Yaman, Serkan; Unal, Gokce

    2013-01-01

    Infectious diseases are known as one of the most life-threatening disabilities worldwide. Approximately 13 million deaths related to infectious diseases are reported each year. The only way to combat infectious diseases is by chemotherapy using antimicrobial agents and antibiotics. However, due to uncontrolled and unnecessary use of antibiotics in particular, surviving bacteria have evolved resistance against several antibiotics. Emergence of multidrug resistance in bacteria over the past several decades has resulted in one of the most important clinical health problems in modern medicine. For instance, approximately 440,000 new cases of multidrug-resistant tuberculosis are reported every year leading to the deaths of 150,000 people worldwide. Management of multidrug resistance requires understanding its molecular basis and the evolution and dissemination of resistance; development of new antibiotic compounds in place of traditional antibiotics; and innovative strategies for extending the life of antibiotic molecules. Researchers have begun to develop new antimicrobials for overcoming this important problem. Recently, platensimycin – isolated from extracts of Streptomyces platensis – and its analog platencin have been defined as promising agents for fighting multidrug resistance. In vitro and in vivo studies have shown that these new antimicrobials have great potential to inhibit methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae by targeting type II fatty acid synthesis in bacteria. Showing strong efficacy without any observed in vivo toxicity increases the significance of these antimicrobial agents for their use in humans. However, at the present time, clinical trials are insufficient and require more research. The strong antibacterial efficacies of platensimycin and platencin may be established in clinical trials and their use in humans for coping with multidrug resistance may be

  5. Selective Conditions for a Multidrug Resistance Plasmid Depend on the Sociality of Antibiotic Resistance.

    PubMed

    Bottery, Michael J; Wood, A Jamie; Brockhurst, Michael A

    2016-04-01

    Multidrug resistance (MDR) plasmids frequently carry antibiotic resistance genes conferring qualitatively different mechanisms of resistance. We show here that the antibiotic concentrations selecting for the RK2 plasmid inEscherichia colidepend upon the sociality of the drug resistance: the selection for selfish drug resistance (efflux pump) occurred at very low drug concentrations, just 1.3% of the MIC of the plasmid-free antibiotic-sensitive strain, whereas selection for cooperative drug resistance (modifying enzyme) occurred at drug concentrations exceeding the MIC of the plasmid-free strain. PMID:26787694

  6. Selective Conditions for a Multidrug Resistance Plasmid Depend on the Sociality of Antibiotic Resistance

    PubMed Central

    Wood, A. Jamie; Brockhurst, Michael A.

    2016-01-01

    Multidrug resistance (MDR) plasmids frequently carry antibiotic resistance genes conferring qualitatively different mechanisms of resistance. We show here that the antibiotic concentrations selecting for the RK2 plasmid in Escherichia coli depend upon the sociality of the drug resistance: the selection for selfish drug resistance (efflux pump) occurred at very low drug concentrations, just 1.3% of the MIC of the plasmid-free antibiotic-sensitive strain, whereas selection for cooperative drug resistance (modifying enzyme) occurred at drug concentrations exceeding the MIC of the plasmid-free strain. PMID:26787694

  7. Antibiotic Exposure in a Low-Income Country: Screening Urine Samples for Presence of Antibiotics and Antibiotic Resistance in Coagulase Negative Staphylococcal Contaminants

    PubMed Central

    Lerbech, Anne Mette; Opintan, Japheth A.; Bekoe, Samuel Oppong; Ahiabu, Mary-Anne; Tersbøl, Britt Pinkowski; Hansen, Martin; Brightson, Kennedy T. C.; Ametepeh, Samuel; Frimodt-Møller, Niels; Styrishave, Bjarne

    2014-01-01

    Development of antimicrobial resistance has been assigned to excess and misuse of antimicrobial agents. Staphylococci are part of the normal flora but are also potential pathogens that have become essentially resistant to many known antibiotics. Resistances in coagulase negative staphylococci (CoNS) are suggested to evolve due to positive selective pressure following antibiotic treatment. This study investigated the presence of the nine most commonly used antimicrobial agents in human urine from outpatients in two hospitals in Ghana in relation to CoNS resistance. Urine and CoNS were sampled (n = 246 and n = 96 respectively) from patients in two hospitals in Ghana. CoNS were identified using Gram staining, coagulase test, and MALDI-TOF/MS, and the antimicrobial susceptibility to 12 commonly used antimicrobials was determined by disk diffusion. Moreover an analytical method was developed for the determination of the nine most commonly used antimicrobial agents in Ghana by using solid-phase extraction in combination with HPLC-MS/MS using electron spray ionization. The highest frequency of resistance to CoNS was observed for penicillin V (98%), trimethoprim (67%), and tetracycline (63%). S. haemolyticus was the most common isolate (75%), followed by S. epidermidis (13%) and S. hominis (6%). S. haemolyticus was also the species displaying the highest resistance prevalence (82%). 69% of the isolated CoNS were multiple drug resistant (≧4 antibiotics) and 45% of the CoNS were methicillin resistant. Antimicrobial agents were detected in 64% of the analysed urine samples (n = 121) where the most frequently detected antimicrobials were ciprofloxacin (30%), trimethoprim (27%), and metronidazole (17%). The major findings of this study was that the prevalence of detected antimicrobials in urine was more frequent than the use reported by the patients and the prevalence of resistant S. haemolyticus was more frequent than other resistant CoNS species when

  8. Ready for a world without antibiotics? The Pensières Antibiotic Resistance Call to Action

    PubMed Central

    2012-01-01

    Resistance to antibiotics has increased dramatically over the past few years and has now reached a level that places future patients in real danger. Microorganisms such as Escherichia coli and Klebsiella pneumoniae, which are commensals and pathogens for humans and animals, have become increasingly resistant to third-generation cephalosporins. Moreover, in certain countries, they are also resistant to carbapenems and therefore susceptible only to tigecycline and colistin. Resistance is primarily attributed to the production of beta-lactamase genes located on mobile genetic elements, which facilitate their transfer between different species. In some rare cases, Gram-negative rods are resistant to virtually all known antibiotics. The causes are numerous, but the role of the overuse of antibiotics in both humans and animals is essential, as well as the transmission of these bacteria in both the hospital and the community, notably via the food chain, contaminated hands, and between animals and humans. In addition, there are very few new antibiotics in the pipeline, particularly for Gram-negative bacilli. The situation is slightly better for Gram-positive cocci as some potent and novel antibiotics have been made available in recent years. A strong and coordinated international programme is urgently needed. To meet this challenge, 70 internationally recognized experts met for a two-day meeting in June 2011 in Annecy (France) and endorsed a global call to action ("The Pensières Antibiotic Resistance Call to Action"). Bundles of measures that must be implemented simultaneously and worldwide are presented in this document. In particular, antibiotics, which represent a treasure for humanity, must be protected and considered as a special class of drugs. PMID:22958833

  9. Antibiotic and antimicrobial peptide combinations: synergistic inhibition of Pseudomonas fluorescens and antibiotic-resistant variants.

    PubMed

    Naghmouchi, Karim; Le Lay, Christophe; Baah, John; Drider, Djamel

    2012-02-01

    Variants resistant to penicillin G (RvP), streptomycin (RvS), lincomycin (RvL) and rifampicin (RvR) were developed from a colistin-sensitive isolate of Pseudomonas fluorescens LRC-R73 (P. fluorescens). Cell fatty acid composition, K(+) efflux and sensitivity to antimicrobial peptides (nisin Z, pediocin PA-1/AcH and colistin) alone or combined with antibiotics were determined. P. fluorescens was highly sensitive to kanamycin, tetracycline and chloramphenicol at minimal inhibitory concentrations of 0.366, 0.305 and 0.732 μg/ml respectively. P. fluorescens, RvP, RvS, RvL and RvR were resistant to nisin Z and pediocin PA-1/AcH at concentrations ≥100 μg/ml but sensitive to colistin at 0.076, 0.043, 0.344, 0.344 and 0.258 μg/ml respectively. A synergistic inhibitory effect (FICI ≤0.5) was observed when resistant variants were treated with peptide/antibiotic combinations. No significant effect on K(+) efflux from the resistant variants in the presence of antibiotics or peptides alone or combined was observed. The proportion of C16:0 was significantly higher in antibiotic-resistant variants than in the parent strain, accounting for 32.3%, 46.49%, 43.3%, 40.1% and 44.1% of the total fatty acids in P. fluorescens, RvP, RvS, RvL and RvR respectively. Combination of antibiotics with antimicrobial peptides could allow reduced use of antibiotics in medical applications and could help slow the emergence of bacteria resistant to antibiotics. PMID:22172555

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

    PubMed

    McKinney, Chad W; Pruden, Amy

    2012-12-18

    Disinfection of wastewater treatment plant effluent may be an important barrier for limiting the spread of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). While ideally disinfection should destroy ARGs, to prevent horizontal gene transfer to downstream bacteria, little is known about the effect of conventional water disinfection technologies on ARGs. This study examined the potential of UV disinfection to damage four ARGs, mec(A), van(A), tet(A), and amp(C), both in extracellular form and present within a host ARBs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Escherichia coli SMS-3-5, and Pseudomonas aeruginosa 01, respectively. An extended amplicon-length quantitative polymerase chain reaction assay was developed to enhance capture of ARG damage events and also to normalize to an equivalent length of target DNA (∼1000 bp) for comparison. It was found that the two Gram-positive ARBs (MRSA and VRE) were more resistant to UV disinfection than the two Gram-negative ARBs (E. coli and P. aeruginosa). The two Gram-positive organisms also possessed smaller total genome sizes, which could also have reduced their susceptibility to UV because of fewer potential pyrimidine dimer targets. An effect of cell type on damage to ARGs was only observed in VRE and P. aeruginosa, the latter potentially because of extracellular polymeric substances. In general, damage of ARGs required much greater UV doses (200-400 mJ/cm² for 3- to 4-log reduction) than ARB inactivation (10-20 mJ/cm² for 4- to 5-log reduction). The proportion of amplifiable ARGs following UV treatment exhibited a strong negative correlation with the number of adjacent thymines (Pearson r < -0.9; p < 0.0001). ARBs surviving UV treatment were negatively correlated with total genome size (Pearson r < -0.9; p < 0.0001) and adjacent cytosines (Pearson r < -0.88; p < 0.0001) but positively correlated with adjacent thymines (Pearson r

  11. Surveillance and Control of Antibiotic Resistance in the Mediterranean Region.

    PubMed

    Ricciardi, Walter; Giubbini, Gabriele; Laurenti, Patrizia

    2016-01-01

    Antibiotic resistance is one of the most relevant problems in the healthcare: the growth of resistant microorganisms in healthcare settings is a worrisome threat, raising length to stay (LOS), morbidity and mortality in those patients. The importance of the antibiotic resistance and its spread around the world, gave rise to the activation of several surveillance systems, based especially on the collection of laboratory data to local or national level. The objective of this work is to carry out a review of the scientific literature existing on the topic and scientific activities related to surveillance of antibiotic resistance in the countries bordering the Mediterranean Sea. Recent Data from European Centre for Disease Prevention and Control (November 2015) show, for different combinations bacterium-drug, an increase of resistance from North to South and from West to East of Europe. It is of particular concern the phenomenon of resistance carried out by some gram-negative, specifically Klebsiella pneumoniae and Escherichia coli to third-generation cephalosporin, often combined in opposition to fluoroquinolones and aminoglycosides. Is particularly high the incidence of resistance to carbapenems by strains of Enterobacteriaceae (Klebsiella included). The resistance exerted by MRSA (Methicillin-resistant Staphylococcus aureus) continues to be relevant, albeit showing some decline in recent years. The incidence of resistance carried on by Streptococcus pneumoniae is stable and is mainly relevant to macrolides. Finally, a significant increase in recording relatively exercised by Enterococcus faecium to Vancomycin. Detecting, preventing, and controlling antibiotic resistance requires strategic, coordinated, and sustained efforts. It also depends on the engagement of governments, academia, industry, healthcare providers, the general public, and the agricultural community, as well as international partners. Committing to combating antibiotic-resistant microbes does support

  12. Surveillance and Control of Antibiotic Resistance in the Mediterranean Region

    PubMed Central

    Ricciardi, Walter; Giubbini, Gabriele; Laurenti, Patrizia

    2016-01-01

    Antibiotic resistance is one of the most relevant problems in the healthcare: the growth of resistant microorganisms in healthcare settings is a worrisome threat, raising length to stay (LOS), morbidity and mortality in those patients. The importance of the antibiotic resistance and its spread around the world, gave rise to the activation of several surveillance systems, based especially on the collection of laboratory data to local or national level. The objective of this work is to carry out a review of the scientific literature existing on the topic and scientific activities related to surveillance of antibiotic resistance in the countries bordering the Mediterranean Sea. Recent Data from European Centre for Disease Prevention and Control (November 2015) show, for different combinations bacterium-drug, an increase of resistance from North to South and from West to East of Europe. It is of particular concern the phenomenon of resistance carried out by some gram-negative, specifically Klebsiella pneumoniae and Escherichia coli to third-generation cephalosporin, often combined in opposition to fluoroquinolones and aminoglycosides. Is particularly high the incidence of resistance to carbapenems by strains of Enterobacteriaceae (Klebsiella included). The resistance exerted by MRSA (Methicillin-resistant Staphylococcus aureus) continues to be relevant, albeit showing some decline in recent years. The incidence of resistance carried on by Streptococcus pneumoniae is stable and is mainly relevant to macrolides. Finally, a significant increase in recording relatively exercised by Enterococcus faecium to Vancomycin. Detecting, preventing, and controlling antibiotic resistance requires strategic, coordinated, and sustained efforts. It also depends on the engagement of governments, academia, industry, healthcare providers, the general public, and the agricultural community, as well as international partners. Committing to combating antibiotic-resistant microbes does support

  13. Antibiotic surgical prophylaxis increases nasal carriage of antibiotic-resistant staphylococci.

    PubMed

    McMurray, Claire L; Hardy, Katherine J; Verlander, Neville Q; Hawkey, Peter M

    2015-12-01

    Staphylococci are a significant cause of hospital-acquired infection. Nasal carriage of Staphylococcus aureus is an important risk factor for infection in surgical patients and coagulase-negative staphylococci (CNS) are a major cause of prosthetic joint infections. The impact that antibiotic surgical prophylaxis has on the nasal carriage of staphylococci has not been studied. Daily nasal swabs were taken from 63 patients who received antibiotic surgical prophylaxis and 16 patients who received no antibiotics. Total aerobic bacterial count, S. aureus and CNS were enumerated by culture from nasal swabs. Representative isolates were typed by staphylococcal interspersed repeat units (SIRU) typing and PFGE, and MICs to nine antibiotics were determined. After antibiotic administration, there was a reduction in S. aureus counts (median - 2.3 log(10)c.f.u. ml(- 1)) in 64.0 % of S. aureus carriers, compared with only a 0.89 log(10)c.f.u. ml(- 1) reduction in 75.0 % of S. aureus carriers who did not receive antibiotics. A greater increase in the nasal carriage rate of meticillin-resistant CNS was observed after antibiotic surgical prophylaxis compared with hospitalization alone, with increases of 16.4 and 4.6 %, respectively. Antibiotic-resistant S. epidermidis carriage rate increased by 16.6 % after antibiotic administration compared with 7.5 % with hospitalization alone. Antibiotic surgical prophylaxis impacts the nasal carriage of both S. aureus and CNS. PMID:26445858

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

    PubMed

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

    2016-01-01

    In recent years, more and more antibiotics have become ineffective in the treatment of bacterial nfections. The acquisition of antibiotic resistance by bacteria is associated with circulation of genes in the environment. Determinants of antibiotic resistance may be transferred to pathogenic bacteria. It has been shown that conjugation is one of the key mechanisms responsible for spread of antibiotic resistance genes, which is highly efficient and allows the barrier to restrictions and modifications to be avoided. Some conjugative modules enable the transfer of plasmids even between phylogenetically distant bacterial species. Many scientific reports indicate that food is one of the main reservoirs of these genes. Antibiotic resistance genes have been identified in meat products, milk, fruits and vegetables. The reason for such a wide spread of antibiotic resistance genes is the overuse of antibiotics by breeders of plants and animals, as well as by horizontal gene transfer. It was shown, that resistance determinants located on mobile genetic elements, which are isolated from food products, can easily be transferred to another niche. The antibiotic resistance genes have been in the environment for 30 000 years. Their removal from food products is not possible, but the risks associated with the emergence of multiresistant pathogenic strains are very large. The only option is to control the emergence, selection and spread of these genes. Therefore measures are sought to prevent horizontal transfer of genes. Promising concepts involve the combination of developmental biology, evolution and ecology in the fight against the spread of antibiotic resistance. PMID:27383577

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

    PubMed

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

    2016-07-07

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

  16. Network-assisted investigation of virulence and antibiotic-resistance systems in Pseudomonas aeruginosa

    PubMed Central

    Hwang, Sohyun; Kim, Chan Yeong; Ji, Sun-Gou; Go, Junhyeok; Kim, Hanhae; Yang, Sunmo; Kim, Hye Jin; Cho, Ara; Yoon, Sang Sun; Lee, Insuk

    2016-01-01

    Pseudomonas aeruginosa is a Gram-negative bacterium of clinical significance. Although the genome of PAO1, a prototype strain of P. aeruginosa, has been extensively studied, approximately one-third of the functional genome remains unknown. With the emergence of antibiotic-resistant strains of P. aeruginosa, there is an urgent need to develop novel antibiotic and anti-virulence strategies, which may be facilitated by an approach that explores P. aeruginosa gene function in systems-level models. Here, we present a genome-wide functional network of P. aeruginosa genes, PseudomonasNet, which covers 98% of the coding genome, and a companion web server to generate functional hypotheses using various network-search algorithms. We demonstrate that PseudomonasNet-assisted predictions can effectively identify novel genes involved in virulence and antibiotic resistance. Moreover, an antibiotic-resistance network based on PseudomonasNet reveals that P. aeruginosa has common modular genetic organisations that confer increased or decreased resistance to diverse antibiotics, which accounts for the pervasiveness of cross-resistance across multiple drugs. The same network also suggests that P. aeruginosa has developed mechanism of trade-off in resistance across drugs by altering genetic interactions. Taken together, these results clearly demonstrate the usefulness of a genome-scale functional network to investigate pathogenic systems in P. aeruginosa. PMID:27194047

  17. Network-assisted investigation of virulence and antibiotic-resistance systems in Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Hwang, Sohyun; Kim, Chan Yeong; Ji, Sun-Gou; Go, Junhyeok; Kim, Hanhae; Yang, Sunmo; Kim, Hye Jin; Cho, Ara; Yoon, Sang Sun; Lee, Insuk

    2016-05-01

    Pseudomonas aeruginosa is a Gram-negative bacterium of clinical significance. Although the genome of PAO1, a prototype strain of P. aeruginosa, has been extensively studied, approximately one-third of the functional genome remains unknown. With the emergence of antibiotic-resistant strains of P. aeruginosa, there is an urgent need to develop novel antibiotic and anti-virulence strategies, which may be facilitated by an approach that explores P. aeruginosa gene function in systems-level models. Here, we present a genome-wide functional network of P. aeruginosa genes, PseudomonasNet, which covers 98% of the coding genome, and a companion web server to generate functional hypotheses using various network-search algorithms. We demonstrate that PseudomonasNet-assisted predictions can effectively identify novel genes involved in virulence and antibiotic resistance. Moreover, an antibiotic-resistance network based on PseudomonasNet reveals that P. aeruginosa has common modular genetic organisations that confer increased or decreased resistance to diverse antibiotics, which accounts for the pervasiveness of cross-resistance across multiple drugs. The same network also suggests that P. aeruginosa has developed mechanism of trade-off in resistance across drugs by altering genetic interactions. Taken together, these results clearly demonstrate the usefulness of a genome-scale functional network to investigate pathogenic systems in P. aeruginosa.

  18. Network-assisted investigation of virulence and antibiotic-resistance systems in Pseudomonas aeruginosa.

    PubMed

    Hwang, Sohyun; Kim, Chan Yeong; Ji, Sun-Gou; Go, Junhyeok; Kim, Hanhae; Yang, Sunmo; Kim, Hye Jin; Cho, Ara; Yoon, Sang Sun; Lee, Insuk

    2016-05-19

    Pseudomonas aeruginosa is a Gram-negative bacterium of clinical significance. Although the genome of PAO1, a prototype strain of P. aeruginosa, has been extensively studied, approximately one-third of the functional genome remains unknown. With the emergence of antibiotic-resistant strains of P. aeruginosa, there is an urgent need to develop novel antibiotic and anti-virulence strategies, which may be facilitated by an approach that explores P. aeruginosa gene function in systems-level models. Here, we present a genome-wide functional network of P. aeruginosa genes, PseudomonasNet, which covers 98% of the coding genome, and a companion web server to generate functional hypotheses using various network-search algorithms. We demonstrate that PseudomonasNet-assisted predictions can effectively identify novel genes involved in virulence and antibiotic resistance. Moreover, an antibiotic-resistance network based on PseudomonasNet reveals that P. aeruginosa has common modular genetic organisations that confer increased or decreased resistance to diverse antibiotics, which accounts for the pervasiveness of cross-resistance across multiple drugs. The same network also suggests that P. aeruginosa has developed mechanism of trade-off in resistance across drugs by altering genetic interactions. Taken together, these results clearly demonstrate the usefulness of a genome-scale functional network to investigate pathogenic systems in P. aeruginosa.

  19. Practical survey on antibiotic-resistant bacterial communities in livestock manure and manure-amended soil.

    PubMed

    Yang, Qingxiang; Wang, Ruifei; Ren, Siwei; Szoboszlay, Marton; Moe, Luke A

    2016-01-01

    Through livestock manure fertilization, antibiotics, antibiotic-resistant bacteria and genes are transferred to agricultural soils, resulting in a high prevalence of antibiotic-resistant bacteria in the soil. It is not clear, however, whether a correlation exists between resistant bacterial populations in manure and manure-amended soil. In this work, we demonstrate that the prevalence of cephalexin-, amoxicillin-, kanamycin- and gentamicin-resistant bacteria as well as bacteria simultaneously resistant to all four antibiotics was much higher in manure-amended soils than in manure-free soil. 454-pyrosequencing indicated that the ARB and multiple antibiotic-resistant bacteria (MARB) in swine or chicken manure and manure-amended soil were mainly distributed among Sphingobacterium, Myroides, Enterococcus, Comamonas and unclassified Flavobacteriaceae. The genus Sphingobacterium was highly prevalent among ARB from swine manure and manure-amended soil, and was also the most dominant genus among MARB from chicken manure and manure-amended soil. Other dominant genera among ARB or MARB populations in manure samples, including Myroides, Enterococcus and Comamonas, could not be detected or were detected at very low relative abundance in manure-amended soil. The present study suggests the possibility of transfer of ARBs from livestock manures to soils and persistence of ARB in these environments. PMID:26513264

  20. Parallel evolutionary pathways to antibiotic resistance selected by biocide exposure

    PubMed Central

    Webber, Mark A.; Whitehead, Rebekah N.; Mount, Manuella; Loman, Nick J.; Pallen, Mark J.; Piddock, Laura J. V.

    2015-01-01

    Objectives Biocides are widely used to prevent infection. We aimed to determine whether exposure of Salmonella to various biocides could act as a driver of antibiotic resistance. Methods Salmonella enterica serovar Typhimurium was exposed to four biocides with differing modes of action. Antibiotic-resistant mutants were selected during exposure to all biocides and characterized phenotypically and genotypically to identify mechanisms of resistance. Results All biocides tested selected MDR mutants with decreased antibiotic susceptibility; these occurred randomly throughout the experiments. Mutations that resulted in de-repression of the multidrug efflux pump AcrAB-TolC were seen in MDR mutants. A novel mutation in rpoA was also selected and contributed to the MDR phenotype. Other mutants were highly resistant to both quinolone antibiotics and the biocide triclosan. Conclusions This study shows that exposure of bacteria to biocides can select for antibiotic-resistant mutants and this is mediated by clinically relevant mechanisms of resistance prevalent in human pathogens. PMID:25953808

  1. Mechanisms of Resistance to Aminoglycoside Antibiotics: Overview and Perspectives

    PubMed Central

    Garneau-Tsodikova, Sylvie

    2015-01-01

    Aminoglycoside (AG) antibiotics are used to treat many Gram-negative and some Gram-positive infections and, importantly, multidrug-resistant tuberculosis. Among various bacterial species, resistance to AGs arises through a variety of intrinsic and acquired mechanisms. The bacterial cell wall serves as a natural barrier for small molecules such as AGs and may be further fortified via acquired mutations. Efflux pumps work to expel AGs from bacterial cells, and modifications here too may cause further resistance to AGs. Mutations in the ribosomal target of AGs, while rare, also contribute to resistance. Of growing clinical prominence is resistance caused by ribosome methyltransferases. By far the most widespread mechanism of resistance to AGs is the inactivation of these antibiotics by AG-modifying enzymes. We provide here an overview of these mechanisms by which bacteria become resistant to AGs and discuss their prevalence and potential for clinical relevance. PMID:26877861

  2. Prediction of antibiotic resistance by gene expression profiles

    PubMed Central

    Suzuki, Shingo; Horinouchi, Takaaki; Furusawa, Chikara

    2014-01-01

    Although many mutations contributing to antibiotic resistance have been identified, the relationship between the mutations and the related phenotypic changes responsible for the resistance has yet to be fully elucidated. To better characterize phenotype–genotype mapping for drug resistance, here we analyse phenotypic and genotypic changes of antibiotic-resistant Escherichia coli strains obtained by laboratory evolution. We demonstrate that the resistances can be quantitatively predicted by the expression changes of a small number of genes. Several candidate mutations contributing to the resistances are identified, while phenotype–genotype mapping is suggested to be complex and includes various mutations that cause similar phenotypic changes. The integration of transcriptome and genome data enables us to extract essential phenotypic changes for drug resistances. PMID:25517437

  3. Plant derived compounds inactivate antibiotic resistant Campylobacter jejuni strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixty-three Campylobacter isolates were screened for their resistance to the antibiotics ampicillin, cefaclor, ciprofloxacin, erythromycin, gentamycin, tetracycline, and trimethroprim/sulfamethoxazole. Based on this screen, the resistant strains D28a and H2a and the nonresistant strain A24a were se...

  4. Antibiotic Resistant Microbiota in the Swine Intestinal Tract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The healthy swine intestine is populated by upwards of 500 bacterial species, mainly obligate anaerobes. Our research focuses on the roles of these commensal bacteria in antimicrobial resistance and on interventions to reduce the prevalence of antibiotic resistant bacteria. In comparisons of intes...

  5. Antibiotics and Bacterial Resistance in the 21st Century

    PubMed Central

    Fair, Richard J; Tor, Yitzhak

    2014-01-01

    Dangerous, antibiotic resistant bacteria have been observed with increasing frequency over the past several decades. In this review the factors that have been linked to this phenomenon are addressed. Profiles of bacterial species that are deemed to be particularly concerning at the present time are illustrated. Factors including economic impact, intrinsic and acquired drug resistance, morbidity and mortality rates, and means of infection are taken into account. Synchronously with the waxing of bacterial resistance there has been waning antibiotic development. The approaches that scientists are employing in the pursuit of new antibacterial agents are briefly described. The standings of established antibiotic classes as well as potentially emerging classes are assessed with an emphasis on molecules that have been clinically approved or are in advanced stages of development. Historical perspectives, mechanisms of action and resistance, spectrum of activity, and preeminent members of each class are discussed. PMID:25232278

  6. [Antimicrobial resistance forever? Judicious and appropriate use of antibiotics].

    PubMed

    Cagliano, Stefano

    2015-06-01

    This article takes its cue from the original work of sir Alexander Fleming on penicillin, published in the first issue of Recenti Progressi in Medicina in 1946 and reproduced here on the occasion of the approaching 70-year anniversary of the journal. In 1928, at the time when penicillin was discovered, it could not be imagined that bacterial resistance to antibiotics would develop so rapidly: the introduction of every new class of antibiotics has been shortly followed by the emergence of new strains of bacteria resistant to that class. Bacterial resistance to antibiotic treatment is a huge concern. In this respect, an action plan against antimicrobial resistance has been devised in the United States that is targeted for a 50% reduction over the next five years.

  7. [Antimicrobial resistance forever? Judicious and appropriate use of antibiotics].

    PubMed

    Cagliano, Stefano

    2015-06-01

    This article takes its cue from the original work of sir Alexander Fleming on penicillin, published in the first issue of Recenti Progressi in Medicina in 1946 and reproduced here on the occasion of the approaching 70-year anniversary of the journal. In 1928, at the time when penicillin was discovered, it could not be imagined that bacterial resistance to antibiotics would develop so rapidly: the introduction of every new class of antibiotics has been shortly followed by the emergence of new strains of bacteria resistant to that class. Bacterial resistance to antibiotic treatment is a huge concern. In this respect, an action plan against antimicrobial resistance has been devised in the United States that is targeted for a 50% reduction over the next five years. PMID:26076416

  8. Prevalence of antibiotic resistance genes in staphylococci isolated from ready-to-eat meat products.

    PubMed

    Podkowik, M; Bystroń, J; Bania, J

    2012-01-01

    Prevalence of mecA, blaZ, tetO/K/M, ermA/B/C, aph, and vanA/B/C/D genes conferring resistance to oxacillin, penicillin, tetracycline, erythromycin, gentamicin, and vancomycin was investigated in 65 staphylococcal isolates belonging to twelve species obtained from ready-to-eat porcine, bovine, and chicken products. All coagulase negative staphylococci (CNS) and S. aureus isolates harbored at least one antibiotic resistance gene. None of the S. aureus possessed more than three genes, while 25% of the CNS isolates harbored at least four genes encoding resistance to clinically used antibiotics. In 15 CNS isolates the mecA gene was detected, while all S. aureus isolates were mecA-negative. We demonstrate that in ready-to-eat food the frequency of CNS harboring multiple antibiotic resistance genes is higher than that of multiple resistant S. aureus, meaning that food can be considered a reservoir of bacteria containing genes potentially contributing to the evolution of antibiotic resistance in staphylococci.

  9. Pediatric fecal microbiota harbor diverse and novel antibiotic resistance genes.

    PubMed

    Moore, Aimée M; Patel, Sanket; Forsberg, Kevin J; Wang, Bin; Bentley, Gayle; Razia, Yasmin; Qin, Xuan; Tarr, Phillip I; Dantas, Gautam

    2013-01-01

    Emerging antibiotic resistance threatens human health. Gut microbes are an epidemiologically important reservoir of resistance genes (resistome), yet prior studies indicate that the true diversity of gut-associated resistomes has been underestimated. To deeply characterize the pediatric gut-associated resistome, we created metagenomic recombinant libraries in an Escherichia coli host using fecal DNA from 22 healthy infants and children (most without recent antibiotic exposure), and performed functional selections for resistance to 18 antibiotics from eight drug classes. Resistance-conferring DNA fragments were sequenced (Illumina HiSeq 2000), and reads assembled and annotated with the PARFuMS computational pipeline. Resistance to 14 of the 18 antibiotics was found in stools of infants and children. Recovered genes included chloramphenicol acetyltransferases, drug-resistant dihydrofolate reductases, rRNA methyltransferases, transcriptional regulators, multidrug efflux pumps, and every major class of beta-lactamase, aminoglycoside-modifying enzyme, and tetracycline resistance protein. Many resistance-conferring sequences were mobilizable; some had low identity to any known organism, emphasizing cryptic organisms as potentially important resistance reservoirs. We functionally confirmed three novel resistance genes, including a 16S rRNA methylase conferring aminoglycoside resistance, and two tetracycline-resistance proteins nearly identical to a bifidobacterial MFS transporter (B. longum s. longum JDM301). We provide the first report to our knowledge of resistance to folate-synthesis inhibitors conferred by a predicted Nudix hydrolase (part of the folate synthesis pathway). This functional metagenomic survey of gut-associated resistomes, the largest of its kind to date, demonstrates that fecal resistomes of healthy children are far more diverse than previously suspected, that clinically relevant resistance genes are present even without recent selective antibiotic

  10. Diversity and antibiotic resistance in Pseudomonas spp. from drinking water.

    PubMed

    Vaz-Moreira, Ivone; Nunes, Olga C; Manaia, Célia M

    2012-06-01

    Pseudomonas spp. are common inhabitants of aquatic environments, including drinking water. Multi-antibiotic resistance in clinical isolates of P. aeruginosa is widely reported and deeply characterized. However, the information regarding other species and environmental isolates of this genus is scant. This study was designed based on the hypothesis that members of the genus Pseudomonas given their high prevalence, wide distribution in waters and genetic plasticity can be important reservoirs of antibiotic resistance in drinking water. With this aim, the diversity and antibiotic resistance phenotypes of Pseudomonas isolated from different drinking water sources were evaluated. The genotypic diversity analyses were based on six housekeeping genes (16S rRNA, rpoD, rpoB, gyrB, recA and ITS) and on pulsed field gel electrophoresis. Susceptibility to 21 antibiotics of eight classes was tested using the ATB PSE EU (08) and disk diffusion methods. Pseudomonas spp. were isolated from 14 of the 32 sampled sites. A total of 55 non-repetitive isolates were affiliated to twenty species. Although the same species were isolated from different sampling sites, identical genotypes were never observed in distinct types of water (water treatment plant/distribution system, tap water, cup fillers, biofilm, and mineral water). In general, the prevalence of antibiotic resistance was low and often the resistance patterns were related with the species and/or the strain genotype. Resistance to ticarcillin, ticarcillin with clavulanic acid, fosfomycin and cotrimoxazol were the most prevalent (69-84%). No resistance to piperacillin, levofloxacin, ciprofloxacin, tetracycline, gentamicin, tobramycin, amikacin, imipenem or meropenem was observed. This study demonstrates that Pseudomonas spp. are not so widespread in drinking water as commonly assumed. Nevertheless, it suggests that water Pseudomonas can spread acquired antibiotic resistance, preferentially via vertical transmission.

  11. Resistance mutations generate divergent antibiotic susceptibility profiles against translation inhibitors

    PubMed Central

    Cocozaki, Alexis I.; Altman, Roger B.; Huang, Jian; Buurman, Ed T.; Kazmirski, Steven L.; Doig, Peter; Prince, D. Bryan; Blanchard, Scott C.; Cate, Jamie H. D.; Ferguson, Andrew D.

    2016-01-01

    Mutations conferring resistance to translation inhibitors often alter the structure of rRNA. Reduced susceptibility to distinct structural antibiotic classes may, therefore, emerge when a common ribosomal binding site is perturbed, which significantly reduces the clinical utility of these agents. The translation inhibitors negamycin and tetracycline interfere with tRNA binding to the aminoacyl-tRNA site on the small 30S ribosomal subunit. However, two negamycin resistance mutations display unexpected differential antibiotic susceptibility profiles. Mutant U1060A in 16S Escherichia coli rRNA is resistant to both antibiotics, whereas mutant U1052G is simultaneously resistant to negamycin and hypersusceptible to tetracycline. Using a combination of microbiological, biochemical, single-molecule fluorescence transfer experiments, and X-ray crystallography, we define the specific structural defects in the U1052G mutant 70S E. coli ribosome that explain its divergent negamycin and tetracycline susceptibility profiles. Unexpectedly, the U1052G mutant ribosome possesses a second tetracycline binding site that correlates with its hypersusceptibility. The creation of a previously unidentified antibiotic binding site raises the prospect of identifying similar phenomena in antibiotic-resistant pathogens in the future. PMID:27382179

  12. Clinical, economic and societal impact of antibiotic resistance.

    PubMed

    Barriere, Steven L

    2015-02-01

    The concern over antibiotic resistance has been voiced since the discovery of modern antibiotics > 75 years ago. The concerns have only increased with time, with efforts to control resistance caused by widespread overuse of antibiotics in human medicine and far more than appreciated use in the feeding of animals for human consumption to promote growth. The problem is worldwide, but certain regions and selected health care institutions report far more resistance, including strains of Gram-negative bacteria that are susceptible only to the once discarded drugs polymyxin B or colistin, and pan-resistant strains are on the rise. One of the central efforts to control resistance, apart from antimicrobial stewardship, is the development of new antimicrobial agents. This has lagged significantly over the past 10 - 15 years, for a variety of reasons; but promising new agents are being developed, unfortunately none thus far addressing all potentially resistant strains. There is the unlikely, but not unreal, possibility that we could return to a pre-antibiotic era, where morbidity and mortality rates have risen dramatically and routine surgical procedures are not performed for fear of post-operative infections. The onus of control of resistance is a moral imperative that falls on the shoulders of all.

  13. Plasmids Carried by Antibiotic-Resistant Marine Bacteria

    PubMed Central

    Sizemore, Ronald K.; Colwell, R. R.

    1977-01-01

    Antibiotic-resistant bacteria were isolated from seawater samples collected in the Atlantic Ocean off the southeastern coast of the United States. Large numbers of antibiotic-resistant bacterial strains were found to be present in harbor and inshore waters; however, the percentage of resistant strains was higher for several seawater samples collected offshore than for those collected near shore. Bacteria resistant to tetracycline, chloramphenicol, and streptomycin were found in nearly all samples collected, including samples from 200 miles (about 522 km) offshore and at depths to 8,200 m. Sediment samples, in general, were found to contain smaller populations of resistant strains as compared with the seawater samples examined. Antibiotic-resistant bacteria exhibiting phenetic characteristics common to autochthonous marine bacterial species were examined in detail, and several of the isolates exhibited unstable antibiotic resistance, which was transferable to recipient Escherichia coli cells. Deoxyribonucleic acid preparations from 10 strains examined by ethidium bromide-cesium chloride density sedimentation revealed that 6 of the strains contained covalently closed circular plasmid deoxyribonucleic acid. PMID:334064

  14. Oral antibiotics are effective for highly resistant hip arthroplasty infections.

    PubMed

    Cordero-Ampuero, José; Esteban, Jaime; García-Cimbrelo, Eduardo

    2009-09-01

    Infected arthroplasties reportedly have a lower eradication rate when caused by highly resistant and/or polymicrobial isolates and in these patients most authors recommend intravenous antibiotics. We asked whether two-stage revision with interim oral antibiotics could eradicate these infections. We prospectively followed 36 patients (mean age, 71.8 years) with late hip arthroplasty infections. Combinations of oral antibiotics were prescribed according to cultures, biofilm, and intracellular effectiveness. The minimum followup was 1 year (mean, 4.4 years; range, 1-12 years). We presumed eradication in the absence of clinical, serologic, and radiographic signs of infection. Infection was eradicated in all 13 patients with highly resistant bacteria who completed a two-stage protocol (10 with methicillin-resistant Staphylococci) and in eight of 11 patients treated with only the first stage (and six of nine with methicillin-resistant Staphylococci). Infection was eradicated in six of six patients with polymicrobial isolates (of sensitive and/or resistant bacteria) who completed a two-stage protocol and in five of seven with polymicrobial isolates treated with only the first surgery. The Harris hip score averaged 88.1 (range, 70-98) in patients who underwent reimplantation and 56.8 (range, 32-76) in patients who underwent resection arthroplasty. Long cycles of combined oral antibiotics plus a two-stage surgical exchange appear a promising alternative for infections by highly resistant bacteria, methicillin-resistant Staphylococci, and polymicrobial infections.

  15. In tepid defense of population health: physicians and antibiotic resistance.

    PubMed

    Saver, Richard S

    2008-01-01

    Antibiotic resistance menaces the population as a dire public health threat and costly social problem. Recent proposals to combat antibiotic resistance focus to a large degree on supply side approaches. Suggestions include tinkering with patent rights so that pharmaceutical companies have greater incentives to discover novel antibiotics as well as to resist overselling their newer drugs already on market. This Article argues that a primarily supply side emphasis unfortunately detracts attention from physicians' important demand side influences. Physicians have a vital and unavoidably necessary role to play in ensuring socially optimal access to antibiotics. Dismayingly, physicians' management of the antibiotic supply has been poor and their defense of population health tepid at best. Acting as a prudent steward of the antibiotic supply often seems to be at odds with a physician's commonly understood fiduciary duties, ethical obligations, and professional norms, all of which traditionally emphasize the individual health paradigm as opposed to population health responsibilities. Meanwhile, physicians face limited incentives for antibiotic conservation from other sources, such as malpractice liability, regulatory standards, and reimbursement systems. While multifaceted efforts are needed to combat antibiotic resistance effectively, physician gatekeeping behavior should become a priority area of focus. This Article considers how health law and policy tools could favorably change the incentives physicians face for antibiotic conservation. A clear lesson from the managed care reform battles of the recent past is that interventions, to have the best chance of success, need to respect physician interest in clinical autonomy and individualized medicine even if, somewhat paradoxically, vigorously promoting population health perspectives. Also, physicians' legal and ethical obligations need to be reconceptualized in the antibiotic context in order to better support

  16. Induction of bacterial antibiotic resistance by mutagenic halogenated nitrogenous disinfection byproducts.

    PubMed

    Lv, Lu; Yu, Xin; Xu, Qian; Ye, Chengsong

    2015-10-01

    Halogenated nitrogenous disinfection byproducts (N-DBPs) raise concerns regarding their mutagenicity and carcinogenicity threatening public health. However, environmental consequence of their mutagenicity has received less attention. In this study, the effect of halogenated N-DBPs on bacterial antibiotic resistance (BAR) was investigated. After exposure to bromoacetamide (BAcAm), trichloroacetonitrile (TCAN) or tribromonitromethane (TBNM), the resistance of Pseudomonas aeruginosa PAO1 to both individual and multiple antibiotics (ciprofloxacin, gentamicin, polymyxin B, rifampin, tetracycline, ciprofloxacin + gentamicin and ciprofloxacin + tetracycline) was increased, which was predominantly ascribed to the overexpression of efflux pumps. The mechanism of this effect was demonstrated to be mutagenesis through sequencing and analyzing antibiotic resistance genes. The same induction phenomena also appeared in Escherichia coli, suggesting this effect may be universal to waterborne pathogens. Therefore, more attention should be given to halogenated N-DBPs, as they could increase not only genotoxicological risks but also epidemiological risks of drinking water.

  17. Occurrence of antibiotics and antibiotic resistances in soils from wastewater irrigation areas in Beijing and Tianjin, China.

    PubMed

    Chen, Chaoqi; Li, Jing; Chen, Peipei; Ding, Rui; Zhang, Pengfei; Li, Xiqing

    2014-10-01

    Non-irrigated and wastewater-irrigated soils were collected from five wastewater irrigation areas in Beijing and Tianjin, China. The concentrations of sulfadiazine, sulfamethoxazole, oxytetracycline and chlortetracycline in the soils were determined. Abundances of antibiotic resistant bacteria and corresponding resistance genes were also measured to examine the impact of wastewater irrigation. No significant difference in antibiotic resistance bacteria was observed between irrigated and non-irrigated soils. However, the concentrations of antibiotics and abundances of resistance genes were significantly greater in irrigated soils, indicating that agricultural activities enhanced the occurrence of antibiotics and resistance genes in the soils. In addition, no significant difference was observed between previously and currently wastewater-irrigated soils. Therefore, cessation of wastewater irrigation did not significantly reduce the levels of antibiotic concentrations and resistance gene abundances. Other factors, e.g., manure application, may explain the lack of significant difference in the occurrence of antibiotics and resistance genes between previously and currently wastewater-irrigated soils.

  18. Pervasive selection for and against antibiotic resistance in inhomogeneous multistress environments.

    PubMed

    Chait, Remy; Palmer, Adam C; Yelin, Idan; Kishony, Roy

    2016-01-20

    Antibiotic-sensitive and -resistant bacteria coexist in natural environments with low, if detectable, antibiotic concentrations. Except possibly around localized antibiotic sources, where resistance can provide a strong advantage, bacterial fitness is dominated by stresses unaffected by resistance to the antibiotic. How do such mixed and heterogeneous conditions influence the selective advantage or disadvantage of antibiotic resistance? Here we find that sub-inhibitory levels of tetracyclines potentiate selection for or against tetracycline resistance around localized sources of almost any toxin or stress. Furthermore, certain stresses generate alternating rings of selection for and against resistance around a localized source of the antibiotic. In these conditions, localized antibiotic sources, even at high strengths, can actually produce a net selection against resistance to the antibiotic. Our results show that interactions between the effects of an antibiotic and other stresses in inhomogeneous environments can generate pervasive, complex patterns of selection both for and against antibiotic resistance.

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

    PubMed

    Alam, Mohammad Zubair; Aqil, Farrukh; Ahmad, Iqbal; Ahmad, Shamim

    2013-01-01

    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 × 10(-3) to 8.8 × 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.

  20. A new antibiotic kills pathogens without detectable resistance.

    PubMed

    Ling, Losee L; Schneider, Tanja; Peoples, Aaron J; Spoering, Amy L; Engels, Ina; Conlon, Brian P; Mueller, Anna; Schäberle, Till F; Hughes, Dallas E; Epstein, Slava; Jones, Michael; Lazarides, Linos; Steadman, Victoria A; Cohen, Douglas R; Felix, Cintia R; Fetterman, K Ashley; Millett, William P; Nitti, Anthony G; Zullo, Ashley M; Chen, Chao; Lewis, Kim

    2015-01-22

    Antibiotic resistance is spreading faster than the introduction of new compounds into clinical practice, causing a public health crisis. Most antibiotics were produced by screening soil microorganisms, but this limited resource of cultivable bacteria was overmined by the 1960s. Synthetic approaches to produce antibiotics have been unable to replace this platform. Uncultured bacteria make up approximately 99% of all species in external environments, and are an untapped source of new antibiotics. We developed several methods to grow uncultured organisms by cultivation in situ or by using specific growth factors. Here we report a new antibiotic that we term teixobactin, discovered in a screen of uncultured bacteria. Teixobactin inhibits cell wall synthesis by binding to a highly conserved motif of lipid II (precursor of peptidoglycan) and lipid III (precursor of cell wall teichoic acid). We did not obtain any mutants of Staphylococcus aureus or Mycobacterium tuberculosis resistant to teixobactin. The properties of this compound suggest a path towards developing antibiotics that are likely to avoid development of resistance. PMID:25561178

  1. Rapid determination of antibiotic resistance in E. coli using dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Hoettges, Kai F.; Dale, Jeremy W.; Hughes, Michael P.

    2007-09-01

    In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which take approximately 24 h to complete and potentially place the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 h passes after isolating a culture from nutrient broth.

  2. Genomic transition of enterococci from gut commensals to leading causes of multidrug-resistant hospital infection in the antibiotic era.

    PubMed

    Gilmore, Michael S; Lebreton, Francois; van Schaik, Willem

    2013-02-01

    The enterococci evolved over eons as highly adapted members of gastrointestinal consortia of a wide variety of hosts, but for reasons that are not entirely clear, emerged in the 1970s as leading causes of multidrug resistant hospital infection. Hospital-adapted pathogenic isolates are characterized by the presence of multiple mobile elements conferring antibiotic resistance, as well as pathogenicity islands, capsule loci and other variable traits. Enterococci may have been primed to emerge among the vanguard of antibiotic resistant strains because of their occurrence in the GI tracts of insects and simple organisms living and feeding on organic matter that is colonized by antibiotic resistant, antibiotic producing micro-organisms. In response to the opportunity to inhabit a new niche--the antibiotic treated hospital patient--the enterococcal genome is evolving in a pattern characteristic of other bacteria that have emerged as pathogens because of opportunities stemming from anthropogenic change.

  3. Effects of selection pressure and genetic association on the relationship between antibiotic resistance and virulence in Escherichia coli.

    PubMed

    Zhang, Lixin; Levy, Karen; Trueba, Gabriel; Cevallos, William; Trostle, James; Foxman, Betsy; Marrs, Carl F; Eisenberg, Joseph N S

    2015-11-01

    Antibiotic selection pressure and genetic associations may lead to the cooccurrence of resistance and virulence in individual pathogens. However, there is a lack of rigorous epidemiological evidence that demonstrates the cooccurrence of resistance and virulence at the population level. Using samples from a population-based case-control study in 25 villages in rural Ecuador, we characterized resistance to 12 antibiotics among pathogenic (n = 86) and commensal (n = 761) Escherichia coli isolates, classified by the presence or absence of known diarrheagenic virulence factor genes. The prevalences of resistance to single and multiple antibiotics were significantly higher for pathogenic isolates than for commensal isolates. Using a generalized estimating equation, antibiotic resistance was independently associated with virulence factor carriage, case status, and antibiotic use (for these respective factors: odds ratio [OR] = 3.0, with a 95% confidence interval [CI] of 1.7 to 5.1; OR = 2.0, with a 95% CI of 1.3 to 3.0; and OR = 1.5, with a 95% CI of 0.9 to 2.5). Virulence factor carriage was more strongly related to antibiotic resistance than antibiotic use for all antibiotics examined, with the exception of fluoroquinolones, gentamicin, and cefotaxime. This study provides epidemiological evidence that antibiotic resistance and virulence factor carriage are linked in E. coli populations in a community setting. Further, these data suggest that while the cooccurrence of resistance and virulence in E. coli is partially due to antibiotic selection pressure, it is also genetically determined. These findings should be considered in developing strategies for treating infections and controlling for antibiotic resistance.

  4. Effects of Selection Pressure and Genetic Association on the Relationship between Antibiotic Resistance and Virulence in Escherichia coli

    PubMed Central

    Trueba, Gabriel; Cevallos, William; Trostle, James; Marrs, Carl F.; Eisenberg, Joseph N. S.

    2015-01-01

    Antibiotic selection pressure and genetic associations may lead to the cooccurrence of resistance and virulence in individual pathogens. However, there is a lack of rigorous epidemiological evidence that demonstrates the cooccurrence of resistance and virulence at the population level. Using samples from a population-based case-control study in 25 villages in rural Ecuador, we characterized resistance to 12 antibiotics among pathogenic (n = 86) and commensal (n = 761) Escherichia coli isolates, classified by the presence or absence of known diarrheagenic virulence factor genes. The prevalences of resistance to single and multiple antibiotics were significantly higher for pathogenic isolates than for commensal isolates. Using a generalized estimating equation, antibiotic resistance was independently associated with virulence factor carriage, case status, and antibiotic use (for these respective factors: odds ratio [OR] = 3.0, with a 95% confidence interval [CI] of 1.7 to 5.1; OR = 2.0, with a 95% CI of 1.3 to 3.0; and OR = 1.5, with a 95% CI of 0.9 to 2.5). Virulence factor carriage was more strongly related to antibiotic resistance than antibiotic use for all antibiotics examined, with the exception of fluoroquinolones, gentamicin, and cefotaxime. This study provides epidemiological evidence that antibiotic resistance and virulence factor carriage are linked in E. coli populations in a community setting. Further, these data suggest that while the cooccurrence of resistance and virulence in E. coli is partially due to antibiotic selection pressure, it is also genetically determined. These findings should be considered in developing strategies for treating infections and controlling for antibiotic resistance. PMID:26282415

  5. Antibiotic Administration Routes Significantly Influence the Levels of Antibiotic Resistance in Gut Microbiota

    PubMed Central

    Zhang, Lu; Huang, Ying; Zhou, Yang; Buckley, Timothy

    2013-01-01

    This study examined the impact of oral exposure to antibiotic-resistant bacteria and antibiotic administration methods on antibiotic resistance (AR) gene pools and the profile of resistant bacteria in host gastrointestinal (GI) tracts using C57BL/6J mice with natural gut microbiota. Mice inoculated with a mixture of tet(M)-carrying Enterococcus spp. or blaCMY-2-carrying Escherichia coli were treated with different doses of tetracycline hydrochloride (Tet) or ampicillin sodium (Amp) and delivered via either feed or intravenous (i.v.) injection. Quantitative PCR assessment of mouse fecal samples revealed that (i) AR gene pools were below the detection limit in mice without prior inoculation of AR gene carriers regardless of subsequent exposure to corresponding antibiotics; (ii) oral exposure to high doses of Tet and Amp in mice inoculated with AR gene carriers led to rapid enrichment of corresponding AR gene pools in feces; (iii) significantly less or delayed development of AR in the GI tract of the AR carrier-inoculated mice was observed when the same doses of antibiotics were administered via i.v. injection rather than oral administration; and (iv) antibiotic dosage, and maybe the excretion route, affected AR in the GI tract. The shift of dominant AR bacterial populations in the gut microbiota was consistent with the dynamics of AR gene pools. The emergence of endogenous resistant bacteria in the gut microbiota corresponding to drug exposure was also observed. Together, these data suggest that oral administration of antibiotics has a prominent effect on AR amplification and development in gut microbiota, which may be minimized by alternative drug administration approaches, as illustrated by i.v. injection in this study and proper drug selection. PMID:23689712

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

    PubMed Central

    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 samples were isolated and the Gram-negative bacteria were identified using phenotypic method and API 20E System. Antibiotic susceptibility and plasmid profile were determined by standard Agar disc diffusion and plasmid spin column extraction methods. Results: Totally 117 Gram-negative bacteria were isolated, the most common were Pseudomonas aerugionsa (37.6%), P. fluorescens (25.6%), Acinetobacter baumanii (20/5%) and Klebsiella pneumoniae (7.6%), respectively. The isolates showed high frequency of antibiotic resistance against ceftazidime and co-amoxiclave (100%) and low frequency of antibiotic resistance against amikacin with (70%).The results indicated that 60% of the isolates harboured plasmid. On the other hand, the patients infected with A. baumanii and P. aeruginosa were cured (with 60% frequency) whereas, those infected with P. fluorescens were not cured. Hence, probably antibiotic resistance markers of A. baumanii and P. aeruginosa are plasmid mediated; however, P. fluorescens is chromosomally mediated. Conclusions: Based on our findings, P. aerugionsa is a major causative agent of wound infections and amikacin could be considered as a more effective antibiotic for treatment of the burned patients. PMID:25789121

  7. Piggery manure used for soil fertilization is a reservoir for transferable antibiotic resistance plasmids.

    PubMed

    Binh, Chu Thi Thanh; Heuer, Holger; Kaupenjohann, Martin; Smalla, Kornelia

    2008-10-01

    In this study, the prevalence and types of transferable antibiotic resistance plasmids in piggery manure were investigated. Samples from manure storage tanks of 15 farms in Germany were analysed, representing diverse sizes of herds, meat or piglet production. Antibiotic resistance plasmids from manure bacteria were captured in gfp-tagged rifampicin-resistant Escherichia coli and characterized. The occurrence of plasmid types was also detected in total community DNA by PCR and hybridization. A total of 228 transconjugants were captured from 15 manures using selective media supplemented with amoxicillin, sulfadiazine or tetracycline. The restriction patterns of 81 plasmids representing different antibiotic resistance patterns or different samples clustered into seven groups. Replicon probing revealed that 28 of the plasmids belonged to IncN, one to IncW, 13 to IncP-1 and 19 to the recently discovered pHHV216-like plasmids. The amoxicillin resistance gene bla-TEM was detected on 44 plasmids, and sulphonamide resistance genes sul1, sul2 and/or sul3 on 68 plasmids. Hybridization of replicon-specific sequences amplified from community DNA revealed that IncP-1 and pHHV216-like plasmids were detected in all manures, while IncN and IncW ones were less frequent. This study showed that 'field-scale' piggery manure is a reservoir of broad-host range plasmids conferring multiple antibiotic resistance genes. PMID:18557938

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

    PubMed Central

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

    2016-01-01

    Animal manure is commonly used as fertilizer for agricultural crops worldwide, even though it is believed to contribute to the spread of antibiotic resistance from animal intestines to the soil environment. However, it is unclear whether and how there is any impact of manure fertilization on populations and community structure of antibiotic-resistant endophytic bacteria (AREB) in plant tissues. To investigate the effect of manure and organic fertilizer on endophytic bacterial communities, pot experiments were performed with pakchoi grown with the following treatments: (1) non-treated; (2) chicken manure-treated and (3) organic fertilizer-treated. Manure or organic fertilizer significantly increased the abundances of total cultivable endophytic bacteria (TCEB) and AREB in pakchoi, and the effect of chicken manure was greater than that of organic fertilizer. Further, 16S rDNA sequencing and the phylogenetic analysis indicated that chicken manure or organic fertilizer application increased the populations of multiple antibiotic-resistant bacteria (MARB) in soil and multiple antibiotic-resistant endophytic bacteria (MAREB) in pakchoi. The identical multiple antibiotic-resistant bacterial populations detected in chicken manure, manure- or organic fertilizer-amended soil and the vegetable endophytic system were Brevundimonas diminuta, Brachybacterium sp. and Bordetella sp., suggesting that MARB from manure could enter and colonize the vegetable tissues through manure fertilization. The fact that some human pathogens with multiple antibiotic resistance were detected in harvested vegetables after growing in manure-amended soil demonstrated a potential threat to human health. PMID:27376311

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

    Animal manure is commonly used as fertilizer for agricultural crops worldwide, even though it is believed to contribute to the spread of antibiotic resistance from animal intestines to the soil environment. However, it is unclear whether and how there is any impact of manure fertilization on populations and community structure of antibiotic-resistant endophytic bacteria (AREB) in plant tissues. To investigate the effect of manure and organic fertilizer on endophytic bacterial communities, pot experiments were performed with pakchoi grown with the following treatments: (1) non-treated; (2) chicken manure-treated and (3) organic fertilizer-treated. Manure or organic fertilizer significantly increased the abundances of total cultivable endophytic bacteria (TCEB) and AREB in pakchoi, and the effect of chicken manure was greater than that of organic fertilizer. Further, 16S rDNA sequencing and the phylogenetic analysis indicated that chicken manure or organic fertilizer application increased the populations of multiple antibiotic-resistant bacteria (MARB) in soil and multiple antibiotic-resistant endophytic bacteria (MAREB) in pakchoi. The identical multiple antibiotic-resistant bacterial populations detected in chicken manure, manure- or organic fertilizer-amended soil and the vegetable endophytic system were Brevundimonas diminuta, Brachybacterium sp. and Bordetella sp., suggesting that MARB from manure could enter and colonize the vegetable tissues through manure fertilization. The fact that some human pathogens with multiple antibiotic resistance were detected in harvested vegetables after growing in manure-amended soil demonstrated a potential threat to human health. PMID:27376311

  11. Antibiotic resistance and antibiotic sensitivity based treatment in Helicobacter pylori infection: advantages and outcome

    PubMed Central

    Street, M; Caruana, P; Caffarelli, C; Magliani, W; Manfredi, M; Fornaroli, F; de'Angelis, G

    2001-01-01

    AIMS—To compare two strategies for the eradication of Helicobacter pylori infection.
METHODS—Groups 1 and 2 each consisted of 75 consecutive patients. Patients in group 1 were treated with two antibiotics based on antibiotic susceptibility testing; those in group 2 received amoxycillin and clarithromycin for eight days, together with either ranitidine or omeprazole. Eradication rate was assessed in both groups six months after treatment.
RESULTS—In group 1, H pylori grew in culture in 63/75 cases. Susceptibility testing showed that 35/63 isolates were resistant to metronidazole, 10/63 to clarithromycin, 2/63 to ampicillin, 1/63 to tetracycline, and 5/63 to both clarithromycin and metronidazole. In group 1the infection was eradicated in 96% of the initial 75 subjects, and in 98% of the subjects treated according to the antibiotic assay (62/63). As two patients were lost at follow up the overall eradication rate was 99%. In group 2, eradication was achieved in 61/75 subjects (81%). This was significantly lower than the percentage of eradication observed in group 1 (81% versus 99%).
CONCLUSIONS—Antibiotic susceptibility tests are useful in childhood as a very high percentage of subjects are cured. This approach is costly, but selective antibiotic treatment contributes to limit further development of antibiotic resistance, and money is saved in terms of reinvestigation and further repeated treatments.

 PMID:11316688

  12. Antibiotic resistance: challenges and successes in respiratory infection.

    PubMed

    Sethi, Sanjay; Bryan, Jenny

    2016-01-01

    European Respiratory Society Congress, Amsterdam, 26-30 September 2015, and CHEST 2015, Montréal, Canada, 24-28 October 2015 With approximately 50,000 deaths in the US and EU attributed to antibacterial resistance each year, together with several million days of hospital care [1], the need to address resistance mechanisms and find new targets for novel antibiotics has never been greater. At the annual congresses of the European Respiratory Society and the American College of Chest Physicians, presenters reported advances in understanding of the mechanisms of antibiotic resistance and how these may be overcome. The latest clinical trial data on antibiotic treatment for hospital- and community-acquired pneumonia, including the potential for novel nebulized forms of therapy, were also discussed. PMID:27081910

  13. Urinary tract infections: bacteriology and antibiotic resistance patterns.

    PubMed

    Mashouf, Rasoul Yousefi; Babalhavaeji, Hooshang; Yousef, Javad

    2009-07-01

    The aim of this study was to identify the bacteria causing community acquired urinary tract infections (UTI) and detection of antibiotics resistance of isolates in 912 children below 18 years in the west of Iran. Data were analyzed for 4 age groups: infants, toddlers, preteens and teens. Fourteen antibiotics were tested by gel-diffusion method. Of 912 patients, 34.2% had positive bacterial cultures. The most common isolates were E. coli (57.4 %), K. pneumoniae (9.7 %), S. aureus (5.8%) and A. baumannii (2.2%). Most isolates showed high resistance against ampicillin, cotrimoxazole, nalidixic acid, tobramycin and nitrofurantoin. Klebsiella isolates showed more resistance against tested antibiotics than E. coli isolates.

  14. Urinary tract infections: bacteriology and antibiotic resistance patterns.

    PubMed

    Mashouf, Rasoul Yousefi; Babalhavaeji, Hooshang; Yousef, Javad

    2009-07-01

    The aim of this study was to identify the bacteria causing community acquired urinary tract infections (UTI) and detection of antibiotics resistance of isolates in 912 children below 18 years in the west of Iran. Data were analyzed for 4 age groups: infants, toddlers, preteens and teens. Fourteen antibiotics were tested by gel-diffusion method. Of 912 patients, 34.2% had positive bacterial cultures. The most common isolates were E. coli (57.4 %), K. pneumoniae (9.7 %), S. aureus (5.8%) and A. baumannii (2.2%). Most isolates showed high resistance against ampicillin, cotrimoxazole, nalidixic acid, tobramycin and nitrofurantoin. Klebsiella isolates showed more resistance against tested antibiotics than E. coli isolates. PMID:19430071

  15. Removal of antibiotics and antibiotic resistance genes in rural wastewater by an integrated constructed wetland.

    PubMed

    Chen, Jun; Liu, You-Sheng; Su, Hao-Chang; Ying, Guang-Guo; Liu, Feng; Liu, Shuang-Shuang; He, Liang-Ying; Chen, Zhi-Feng; Yang, Yong-Qiang; Chen, Fan-Rong

    2015-02-01

    Integrated constructed wetlands (ICWs) are regarded as one of the most important removal technology for pollutants in rural domestic wastewaters. This study investigated the efficiency of an ICW consisting of a regulating pool, four surface and subsurface flow-constructed wetlands, and a stabilization unit for removing antibiotics and antibiotic resistance genes (ARGs) from rural domestic wastewaters. The results showed that antibiotics leucomycin, ofloxacin, lincomycin, and sulfamethazine, and ARGs sul1, sul2, tetM, and tetO were the predominant antibiotics and ARGs in the influent, respectively. The ICW system could significantly reduce most of the detected antibiotics and ARGs with their aqueous removal rates of 78 to 100 % and >99 %, respectively. Based on the measured concentrations, the total pollution loadings of antibiotics were 3,479 μg/day in the influent and 199 μg/day in the final effluent. Therefore, constructed wetlands could be a promising technology for rural wastewater in removing contaminants such as antibiotics and ARGs.

  16. Occurrence and prevalence of antibiotic resistance in landfill leachate.

    PubMed

    Wang, Yangqing; Tang, Wei; Qiao, Jing; Song, Liyan

    2015-08-01

    Antibiotic resistance (AR) is extensively present in various environments, posing emerging threat to public and environmental health. Landfill receives unused and unwanted antibiotics through household waste and AR within waste (e.g., activated sludge and illegal clinical waste) and is supposed to serve as an important AR reservoir. In this study, we used culture-dependent methods and quantitative molecular techniques to detect and quantify antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in 12 landfill leachate samples from six geographic different landfills, China. Five tested ARGs (tetO, tetW, bla(TEM), sulI, and sulII) and seven kinds of antibiotic-resistant heterotrophic ARB were extensively detected in all samples, demonstrating their occurrence in landfill. The detected high ratio (10(-2) to 10(-5)) of ARGs to 16S ribosomal RNA (rRNA) gene copies implied that ARGs are prevalent in landfill. Correlation analysis showed that ARGs (tetO, tetW, sulI, and sulII) significantly correlated to ambient bacterial 16S rRNA gene copies, suggesting that the abundance of bacteria in landfill leachate may play an important role in the horizontal spread of ARGs.

  17. Antibiotic Resistance in Enterococcus faecalis Isolated from Hospitalized Patients

    PubMed Central

    Balaei Gajan, Esrafil; Shirmohammadi, Adileh; Aghazadeh, Mohammad; Alizadeh, Mohammad; Sighari Deljavan, Alireza; Ahmadpour, Farzin

    2013-01-01

    Background and aims Enterococci are Gram-positive cocci that often occur in pairs (diplococci) or short chains. Be-side developing high level of antibiotic resistance, these bacteria can cause wide range of disease in human, thus to help provide an effective treatment for infections caused by this genus, this study was conceived to provide information on Enterococcus faecalis Antibiotic resistance to widely used antibiotics in hospitalized patients. Materials and methods Disk diffusion agar and Broth dilution methods were used to perform Antibiogram test on isolated Enterococcus faecalis. Culture medium used for Disk diffusion agar test was Muller Hinton agar, and for Broth dilution methods, Muller Hinton broth culture medium was utilized. In disk diffusion agar method, different commercial antibiotics disks produced by Pharmaceutical companies were used. Microsoft Excel software was used to perform statistical analysis. Results Based on antibiograms of 105 cases, a high resistance to Synercid, Nalidixic acid, Oxacillin and Teofilin was de-tected whereas the lowest resistance observed in Nitrofurantoin, Vancomycin, Linezolid and Teicoplanin antibiotics. Conclusion According to the results, Teicoplanin, Vancomycin, Linezolid and Nitrofurantoin are recommended against E. faecalis species. PMID:23875089

  18. Epidemiological Interpretation of Studies Examining the Effect of Antibiotic Usage on Resistance

    PubMed Central

    Schechner, Vered; Temkin, Elizabeth; Harbarth, Stephan; Carmeli, Yehuda

    2013-01-01

    SUMMARY Bacterial resistance to antibiotics is a growing clinical problem and public health threat. Antibiotic use is a known risk factor for the emergence of antibiotic resistance, but demonstrating the causal link between antibiotic use and resistance is challenging. This review describes different study designs for assessing the association between antibiotic use and resistance and discusses strengths and limitations of each. Approaches to measuring antibiotic use and antibiotic resistance are presented. Important methodological issues such as confounding, establishing temporality, and control group selection are examined. PMID:23554418

  19. Assessment of Selected Antibiotic Resistances in Ungrazed Native Nebraska Prairie Soils.

    PubMed

    Durso, Lisa M; Wedin, David A; Gilley, John E; Miller, Daniel N; Marx, David B

    2016-03-01

    The inherent spatial heterogeneity and complexity of antibiotic-resistant bacteria and antibiotic resistance (AR) genes in manure-affected soils makes it difficult to sort out resistance that can be attributed to human antibiotic use from resistance that occurs naturally in the soil. This study characterizes native Nebraska prairie soils that have not been affected by human or food-animal waste products to provide data on background levels of resistance in southeastern Nebraskan soils. Soil samples were collected from 20 sites enumerated on tetracycline and cefotaxime media; screened for tetracycline-, sulfonamide-, β-lactamase-, and macrolide-resistance genes; and characterized for soil physical and chemical parameters. All prairies contained tetracycline- and cefotaxime-resistant bacteria, and 48% of isolates collected were resistant to two or more antibiotics. Most (98%) of the soil samples and all 20 prairies had at least one tetracycline gene. Most frequently detected were (D), (A) (O), (L), and (B). Sulfonamide genes, which are considered a marker of human or animal activity, were detected in 91% of the samples, despite the lack of human inputs at these sites. No correlations were found between either phenotypic or genotypic resistance and soil physical or chemical parameters. Heterogeneity was observed in AR within and between prairies. Therefore, multiple samples are necessary to overcome heterogeneity and to accurately assess AR. Conclusions regarding AR depend on the gene target measured. To determine the impacts of food-animal antibiotic use on resistance, it is essential that background and/or baseline levels be considered, and where appropriate subtracted out, when evaluating AR in agroecosystems. PMID:27065391

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

    PubMed

    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

  1. Consolidating and Exploring Antibiotic Resistance Gene Data Resources.

    PubMed

    Xavier, Basil Britto; Das, Anupam J; Cochrane, Guy; De Ganck, Sandra; Kumar-Singh, Samir; Aarestrup, Frank Møller; Goossens, Herman; Malhotra-Kumar, Surbhi

    2016-04-01

    The unrestricted use of antibiotics has resulted in rapid acquisition of antibiotic resistance (AR) and spread of multidrug-resistant (MDR) bacterial pathogens. With the advent of next-generation sequencing technologies and their application in understanding MDR pathogen dynamics, it has become imperative to unify AR gene data resources for easy accessibility for researchers. However, due to the absence of a centralized platform for AR gene resources, availability, consistency, and accuracy of information vary considerably across different databases. In this article, we explore existing AR gene data resources in order to make them more visible to the clinical microbiology community, to identify their limitations, and to propose potential solutions.

  2. Consolidating and Exploring Antibiotic Resistance Gene Data Resources

    PubMed Central

    Xavier, Basil Britto; Das, Anupam J.; Cochrane, Guy; De Ganck, Sandra; Kumar-Singh, Samir; Aarestrup, Frank Møller; Goossens, Herman

    2016-01-01

    The unrestricted use of antibiotics has resulted in rapid acquisition of antibiotic resistance (AR) and spread of multidrug-resistant (MDR) bacterial pathogens. With the advent of next-generation sequencing technologies and their application in understanding MDR pathogen dynamics, it has become imperative to unify AR gene data resources for easy accessibility for researchers. However, due to the absence of a centralized platform for AR gene resources, availability, consistency, and accuracy of information vary considerably across different databases. In this article, we explore existing AR gene data resources in order to make them more visible to the clinical microbiology community, to identify their limitations, and to propose potential solutions. PMID:26818666

  3. IncHI2 Plasmids Are Predominant in Antibiotic-Resistant Salmonella Isolates

    PubMed Central

    Chen, Wenyao; Fang, Tingzi; Zhou, Xiujuan; Zhang, Daofeng; Shi, Xianming; Shi, Chunlei

    2016-01-01

    The wide usage of antibiotics contributes to the increase in the prevalence of antibiotic-resistant Salmonella. Plasmids play a critical role in horizontal transfer of antibiotic resistance markers in Salmonella. This study aimed to screen and characterize plasmid profiles responsible for antibiotic resistance in Salmonella and ultimately to clarify the molecular mechanism of transferable plasmid-mediated antibiotic resistance. A total of 226 Salmonella isolates were examined for antimicrobial susceptibility by a disk diffusion method. Thirty-two isolates (14.2%) were resistant to at least one antibiotic. The presence of plasmid-mediated quinolone resistance (PMQR) genes and β-lactamase genes were established by PCR amplification. PCR-based replicon typing revealed that these 32 isolates represented seven plasmid incompatibility groups (IncP, HI2, A/C, FIIs, FIA, FIB, and I1), and the IncHI2 (59.4%) was predominant. Antibiotic resistance markers located on plasmids were identified through plasmid curing. Fifteen phenotypic variants were obtained with the curing efficiency of 46.9% (15/32). The cured plasmids mainly belong to the HI2 incompatibility group. The elimination of IncHI2 plasmids correlated with the loss of β-lactamase genes (blaOXA-1 and blaTEM-1) and PMQR genes (qnrA and aac(6′)-Ib-cr). Both IncHI2 and IncI1 plasmids in a S. enterica serovar Indiana isolate SJTUF 10584 were lost by curing. The blaCMY -2-carrying plasmid pS10584 from SJTUF 10584 was fully sequenced. Sequence analysis revealed that it possessed a plasmid scaffold typical for IncI1 plasmids with the unique genetic arrangement of IS1294-ΔISEcp1-blaCMY -2-blc-sugE-ΔecnR inserted into the colicin gene cia. These data suggested that IncHI2 was the major plasmid lineage contributing to the dissemination of antibiotic resistance in Salmonella and the activity of multiple mobile genetic elements may contribute to antibiotic resistance evolution and dissemination between different plasmid

  4. Prevalence of antibiotic-resistant E. coli in retail chicken: comparing conventional, organic, kosher, and raised without antibiotics

    PubMed Central

    Price, Lance B; Hungate, Bruce A

    2013-01-01

    Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April – June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen. PMID:24555073

  5. Impact of antibiotic resistance on the treatment of sepsis.

    PubMed

    Turnidge, John

    2003-01-01

    Antibiotics are essential to the treatment of bacterial sepsis as they reduce the bacterial burden. The impact of bacterial resistance has recently been studied and found to be important in a range of conditions. Resistance to antibiotics can be defined genotypically, phenotypically and clinically through pharmacokinetic/pharmacodynamic studies and their correlations with clinical outcomes. Although the kinetics of antibiotics has been shown to be favourably altered in sepsis, a range of studies in sepsis has revealed that for most pathogens resistance contributes to significant increases in mortality. This has been clearly demonstrated in bacteraemia, including community- and hospital-acquired infection, and with bacteraemia caused by vancomycin-resistant enterococci, methicillin-resistant staphylococci and extended-spectrum producing Gram-negative bacteria. Significant mortality increases have also been seen with ventilator-associated pneumonia and serious infections requiring admission to intensive care. Gentotypic and phenotypic resistance in coagulase-negative staphylococci causing bacteraemia, and in invasive pneumococcal disease has not shown differences in mortality. In the latter case, dosage regimens have to date been adequate to overcome laboratory-defined resistance. Early indications are that de-escalating therapy from broad-spectrum initial coverage after results of cultures and susceptibility tests become available does not jeopardize outcomes, and further prospective studies are warranted. There is now convincing evidence that broad-spectrum initial therapy to cover the likely pathogens and their resistances pending culture results is mandatory in sepsis to minimize adverse outcomes.

  6. Is household antibiotic use a risk factor for antibiotic-resistant pneumococcal infection?

    PubMed Central

    Kwan-Gett, T. S.; Davis, R. L.; Shay, D. K.; Black, S.; Shinefield, H.; Koepsell, T.

    2002-01-01

    We used microbiology and pharmacy data from health-maintenance organizations to determine whether antibiotic use by a household member increases the risk of penicillin-non-susceptible pneumococcal disease. Though it has been well established that an individual's antibiotic use increases one's risk of antibiotic-resistant infection, it is unclear whether the risk is increased if a member of one's household is exposed to antibiotics. We therefore conducted a case-control study of patients enrolled in health maintenance organizations in Western Washington and Northern California. Cases were defined as individuals with penicillin-non-susceptible pneumococcal infection; controls were individuals with penicillin-susceptible pneumococcal infection. Socioeconomic variables were obtained by linking addresses with 1997 census block group data. One-hundred and thirty-four cases were compared with 798 controls. Individual antibiotic use prior to diagnosis increased the odds of penicillin non-susceptibility, with the strongest effect seen for beta-lactam use within 2 months (OR 1.8, 95% CI 1.2, 2.8). When household antibiotic use by persons other than the patient were considered, at 4 months prior to diagnosis there was a trend towards an association between penicillin non-susceptibility and beta-lactam antibiotic use, and a possible association in a small subgroup of patients with eye and ear isolates. However, no significant overall pattern of association was seen. We conclude that though antibiotic use of any kind within 2 months prior to diagnosis is associated with an increased risk of penicillin-non-susceptible pneumococcal disease, there is no significant overall pattern of association between household antibiotic use and penicillin-non-susceptible pneumococcal infection. PMID:12558332

  7. Relationships between antibiotics and antibiotic resistance gene levels in municipal solid waste leachates in Shanghai, China.

    PubMed

    Wu, Dong; Huang, Zhiting; Yang, Kai; Graham, David; Xie, Bing

    2015-04-01

    Many studies have quantified antibiotics and antibiotic resistance gene (ARG) levels in soils, surface waters, and waste treatment plants (WTPs). However, similar work on municipal solid waste (MSW) landfill leachates is limited, which is concerning because antibiotics disposal is often in the MSW stream. Here we quantified 20 sulfonamide (SA), quinolone (FQ), tetracycline (TC), macrolide (ML), and chloramphenicol (CP) antibiotics, and six ARGs (sul1, sul2, tetQ, tetM, ermB, and mefA) in MSW leachates from two Shanghai transfer stations (TS; sites Hulin (HL) and Xupu (XP)) and one landfill reservoir (LR) in April and July 2014. Antibiotic levels were higher in TS than LR leachates (985 ± 1965 ng/L vs 345 ± 932 ng/L, n = 40), which was because of very high levels in the HL leachates (averaging at 1676 ± 5175 ng/L, n = 40). The mean MLs (3561 ± 8377 ng/L, n = 12), FQs (975 ± 1608 ng/L, n = 24), and SAs (402 ± 704 ng/L, n = 42) classes of antibiotics were highest across all samples. ARGs were detected in all leachate samples with normalized sul2 and ermB levels being especially elevated (-1.37 ± 1.2 and -1.76 ± 1.6 log (copies/16S-rDNA), respectively). However, ARG abundances did not correlate with detected antibiotic levels, except for tetW and tetQ with TC levels (r = 0.88 and 0.81, respectively). In contrast, most measured ARGs did significantly correlate with heavy metal levels (p < 0.05), especially with Cd and Cr. This study shows high levels of ARGs and antibiotics can prevail in MSW leachates and landfills may be an underappreciated as a source of antibiotics and ARGs to the environment.

  8. Development and characterisation of highly antibiotic resistant Bartonella bacilliformis mutants

    PubMed Central

    Gomes, Cláudia; Martínez-Puchol, Sandra; Ruiz-Roldán, Lidia; Pons, Maria J.; del Valle Mendoza, Juana; Ruiz, Joaquim

    2016-01-01

    The objective was to develop and characterise in vitro Bartonella bacilliformis antibiotic resistant mutants. Three B. bacilliformis strains were plated 35 or 40 times with azithromycin, chloramphenicol, ciprofloxacin or rifampicin discs. Resistance-stability was assessed performing 5 serial passages without antibiotic pressure. MICs were determined with/without Phe-Arg-β-Napthylamide and artesunate. Target alterations were screened in the 23S rRNA, rplD, rplV, gyrA, gyrB, parC, parE and rpoB genes. Chloramphenicol and ciprofloxacin resistance were the most difficult and easiest (>37.3 and 10.6 passages) to be selected, respectively. All mutants but one selected with chloramphenicol achieved high resistance levels. All rifampicin, one azithromycin and one ciprofloxacin mutants did not totally revert when cultured without antibiotic pressure. Azithromycin resistance was related to L4 substitutions Gln-66 → Lys or Gly-70 → Arg; L4 deletion Δ62–65 (Lys-Met-Tyr-Lys) or L22 insertion 83::Val-Ser-Glu-Ala-His-Val-Gly-Lys-Ser; in two chloramphenicol-resistant mutants the 23S rRNA mutation G2372A was detected. GyrA Ala-91 → Val and Asp-95 → Gly and GyrB Glu474 → Lys were detected in ciprofloxacin-resistant mutants. RpoB substitutions Gln-527 → Arg, His-540 → Tyr and Ser-545 → Phe plus Ser-588 → Tyr were detected in rifampicin-resistant mutants. In 5 mutants the effect of efflux pumps on resistance was observed. Antibiotic resistance was mainly related to target mutations and overexpression of efflux pumps, which might underlie microbiological failures during treatments. PMID:27667026

  9. The Association of Age and Antibiotic Resistance of Helicobacter Pylori

    PubMed Central

    Ji, Zizhong; Han, Feng; Meng, Fei; Tu, Miaoying; Yang, Ningmin; Zhang, Jianzhong

    2016-01-01

    Abstract The antibiotic resistance of Helicobacter pylori (H pylori) is steadily increasing worldwide, resulting in the low efficiency of the current therapeutic approaches for eradication. In this study, we investigated the relationship between antibiotic resistances, the year of sample collection, and the ages of the infected individuals. A total of 29,034 gastric mucosa biopsy samples were randomly collected from January 1, 2009 to December 9, 2014 in Jiaxing City, Zhejiang Province, China. An antibiotic susceptibility testing was determined using an agar-dilution method. The statistical significance was tested using the chi-squared (χ2) test. A total of 9687 strains were isolated. The resistance rate to clarithromycin, levofloxacin, and metronidazole were 17.76%, 19.66%, and 95.5%, respectively. Resistance was rare against amoxicillin, gentamicin, and furazolidone. The metronidazole resistance rate stayed at a consistently high level. In contrast, the resistance rates of clarithromycin and levofloxacin increased rapidly from 2009 to 2011, gradually decreased from 2012 to 2013, and then increased again in 2014. Although patients ages 31 to 50 and 71 to 80 years had lower infection rates of H pylori, they also had higher resistance rates to clarithromycin and levofloxacin. The highest antibiotic resistance rate was observed in patients’ ages 71 to 80 years old. Younger patients (below 30 years old) had a lower resistance to levofloxacin. Patients’ ages 51 to 60 years old may thus represent an important category for the future study of H pylori infection. Age plays a key element in H pylori resistance to clarithromycin and levofloxacin. It is therefore necessary to consider individualized therapy for the optimized treatment of H pylori-infected patients. PMID:26937912

  10. Inappropriate use of antibiotics in hospitals: the complex relationship between antibiotic use and antimicrobial resistance.

    PubMed

    Cantón, Rafael; Horcajada, Juan Pablo; Oliver, Antonio; Garbajosa, Patricia Ruiz; Vila, Jordi

    2013-09-01

    Hospitals are considered an excellent compartment for the selection of resistant and multi-drug resistant (MDR) bacteria. The overuse and misuse of antimicrobial agents are considered key points fuelling this situation. Antimicrobial stewardship programs have been designed for better use of these compounds to prevent the emergence of resistant microorganisms and to diminish the upward trend in resistance. Nevertheless, the relationship between antibiotic use and antimicrobial resistance is complex, and the desired objectives are difficult to reach. Various factors affecting this relationship have been advocated including, among others, antibiotic exposure and mutant selection windows, antimicrobial pharmacodynamics, the nature of the resistance (natural or acquired, including mutational and that associated with horizontal gene transfer) and the definition of resistance. Moreover, antimicrobial policies to promote better use of these drugs should be implemented not only in the hospital setting coupled with infection control programs, but also in the community, which should also include animal and environmental compartments. Within hospitals, the restriction of antimicrobials, cycling and mixing strategies and the use of combination therapies have been used to avoid resistance. Nevertheless, the results have not always been favorable and resistant bacteria have persisted despite the theoretical benefits of these strategies. Mathematical models as well as microbiological knowledge can explain this failure, which is mainly related to the current scenario involving MDR bacteria and overcoming the fitness associated with resistance. New antimicrobials, rapid diagnostic and antimicrobial susceptibility testing and biomarkers will be useful for future antimicrobial stewardship interventions.

  11. Inappropriate use of antibiotics in hospitals: the complex relationship between antibiotic use and antimicrobial resistance.

    PubMed

    Cantón, Rafael; Horcajada, Juan Pablo; Oliver, Antonio; Garbajosa, Patricia Ruiz; Vila, Jordi

    2013-09-01

    Hospitals are considered an excellent compartment for the selection of resistant and multi-drug resistant (MDR) bacteria. The overuse and misuse of antimicrobial agents are considered key points fuelling this situation. Antimicrobial stewardship programs have been designed for better use of these compounds to prevent the emergence of resistant microorganisms and to diminish the upward trend in resistance. Nevertheless, the relationship between antibiotic use and antimicrobial resistance is complex, and the desired objectives are difficult to reach. Various factors affecting this relationship have been advocated including, among others, antibiotic exposure and mutant selection windows, antimicrobial pharmacodynamics, the nature of the resistance (natural or acquired, including mutational and that associated with horizontal gene transfer) and the definition of resistance. Moreover, antimicrobial policies to promote better use of these drugs should be implemented not only in the hospital setting coupled with infection control programs, but also in the community, which should also include animal and environmental compartments. Within hospitals, the restriction of antimicrobials, cycling and mixing strategies and the use of combination therapies have been used to avoid resistance. Nevertheless, the results have not always been favorable and resistant bacteria have persisted despite the theoretical benefits of these strategies. Mathematical models as well as microbiological knowledge can explain this failure, which is mainly related to the current scenario involving MDR bacteria and overcoming the fitness associated with resistance. New antimicrobials, rapid diagnostic and antimicrobial susceptibility testing and biomarkers will be useful for future antimicrobial stewardship interventions. PMID:24129283

  12. Association of mercury resistance with antibiotic resistance in the gram-negative fecal bacteria of primates.

    PubMed Central

    Wireman, J; Liebert, C A; Smith, T; Summers, A O

    1997-01-01

    Gram-negative fecal bacterial from three longitudinal Hg exposure experiments and from two independent survey collections were examined for their carriage of the mercury resistance (mer) locus. The occurrence of antibiotic resistance was also assessed in both mercury-resistant (Hgr) and mercury-susceptible (Hgs) isolates from the same collections. The longitudinal studies involved exposure of the intestinal flora to Hg released from amalgam "silver" dental restorations in six monkeys. Hgr strains were recovered before the installation of amalgams, and frequently these became the dominant strains while amalgams were installed. Such persistent Hgr strains always carried the same mer locus throughout the experiments. In both the longitudinal and survey collections, certain mer loci were preferentially associated with one genus, whereas other mer loci were recovered from many genera. In general, strains with any mer locus were more likely to be multiresistant than were strains without mer loci; this clustering tendency was also seen for antibiotic resistance genes. However, the association of antibiotic multiresistance with mer loci was not random; regardless of source, certain mer loci occurred in highly multiresistant strains (with as many as seven antibiotic resistances), whereas other mer loci were found in strains without any antibiotic resistance. The majority of highly multiresistant Hgr strains also carried genes characteristic of an integron, a novel genetic element which enables the formation of tandem arrays of antibiotic resistance genes. Hgr strains lacking antibiotic resistance showed no evidence of integron components. PMID:9361435

  13. Enhanced killing of antibiotic-resistant bacteria enabled by massively parallel combinatorial genetics.

    PubMed

    Cheng, Allen A; Ding, Huiming; Lu, Timothy K

    2014-08-26

    New therapeutic strategies are needed to treat infections caused by drug-resistant bacteria, which constitute a major growing threat to human health. Here, we use a high-throughput technology to identify combinatorial genetic perturbations that can enhance the killing of drug-resistant bacteria with antibiotic treatment. This strategy, Combinatorial Genetics En Masse (CombiGEM), enables the rapid generation of high-order barcoded combinations of genetic elements for high-throughput multiplexed characterization based on next-generation sequencing. We created ∼ 34,000 pairwise combinations of Escherichia coli transcription factor (TF) overexpression constructs. Using Illumina sequencing, we identified diverse perturbations in antibiotic-resistance phenotypes against carbapenem-resistant Enterobacteriaceae. Specifically, we found multiple TF combinations that potentiated antibiotic killing by up to 10(6)-fold and delivered these combinations via phagemids to increase the killing of highly drug-resistant E. coli harboring New Delhi metallo-beta-lactamase-1. Moreover, we constructed libraries of three-wise combinations of transcription factors with >4 million unique members and demonstrated that these could be tracked via next-generation sequencing. We envision that CombiGEM could be extended to other model organisms, disease models, and phenotypes, where it could accelerate massively parallel combinatorial genetics studies for a broad range of biomedical and biotechnology applications, including the treatment of antibiotic-resistant infections.

  14. Effect of river landscape on the sediment concentrations of antibiotics and corresponding antibiotic resistance genes (ARG).

    PubMed

    Pei, Ruoting; Kim, Sung-Chul; Carlson, Kenneth H; Pruden, Amy

    2006-07-01

    The purpose of this study was to quantify antibiotic resistance genes (ARG) in the sediments of the mixed-landscape Cache La Poudre River, which has previously been studied and shown to have high concentrations of antibiotics related to urban and agricultural activities. River sediments were sampled during two events (high-flow and low-flow) from five sites with varying urban and agricultural impact levels. Polymerase-chain-reaction (PCR) detection assays were conducted for four sulfonamide resistance gene families, using newly designed primers, and five tetracycline resistance gene families, using previously published primers. Sul(I), sul(II), tet(W), and tet(O) gene families were further quantified by real-time quantitative polymerase chain reaction (Q-PCR). Resistance to four classes of antibiotics (tetracyclines, sulfonamides, ionophores, and macrolides) was also investigated using a culture-based approach. The quantities of resistance genes normalized to the 16S gene copy number were significantly different between the sites, with higher resistance gene concentrations at the impacted sites than at the pristine site. Total resistant CFUs were over an order of magnitude lower at the pristine site, but differences were less apparent when normalized to the total CFUs. Six tetracyclines and six sulfonamides were also quantified in the sediments and were found to be highest at sites impacted by urban and agricultural activity, with no antibiotics detected at the pristine sit. To the knowledge of the authors, this study is the first to demonstrate a relationship between urban and agricultural activity and microbial resistance in river sediments using quantitative molecular tools. PMID:16753197

  15. Enumeration and antibiotic resistance patterns of fecal indicator organisms isolated from migratory Canada geese (Branta canadensis).

    PubMed

    Middleton, J H; Ambrose, A

    2005-04-01

    Thermotolerant fecal indicator organisms carried by migratory waterfowl may serve as reservoirs of antibiotic resistance. To determine the extent to which such antibiotic resistance markers were present in migratory Canada geese (Branta canadensis) on the Maryland Eastern Shore, we isolated Enterococcus spp. and Escherichia coli from fresh feces and examined the antibiotic resistance profiles of these bacteria. Samples were obtained in October 2002, January 2003, and March 2003. Thermotolerant E. coli counts ranged from 0 to 1.0x10(7) colony forming units (CFU)/0.1g (g-1) wet weight of feces, whereas Enterococcus spp. counts ranged from 1.0x10(2)-1.0x10(7) CFU g-1 wet weight of feces. Primary isolates of each indicator organism were tested against a panel of 10 antibiotics. Greater than 95% of E. coli isolates were resistant to penicillin G, ampicillin, cephalothin, and sulfathiazole; no E. coli were resistant to ciprofloxacin. Enterococcal isolates showed highest resistance to cephalothin, streptomycin, and sulfathiazole; no enterococci were resistant to chloramphenicol. The tetracyclines, streptomycin, and gentamycin provided the greatest discrimination among E. coli isolates; chlortetracycline, cephalothin, and gentamycin resistance patterns provided the greatest discrimination between enterococcal strains. Multiple antibiotic resistance (MAR) profiles were calculated: fall (E. coli=0.499; enterococci=0.234), winter (E. coli=0.487; enterococci=0.389), and spring (E. coli=0.489; enterococci=0.348). E. faecalis and E. faecium, which are recognized human nosocomial pathogens, were cultured from winter (44 and 56%, respectively) and spring (13 and 31%, respectively) fecal samples.

  16. Antibiotic-resistant acne: getting under the skin.

    PubMed

    Sinha, Mau; Sadhasivam, Suresh; Bhattacharyya, Anamika; Jain, Shilpi; Ghosh, Shamik; Arndt, Kenneth A; Dover, Jeffrey S; Sengupta, Shiladitya

    2016-06-01

    Propionibacterium acnes is a key pathogenic factor in the development of acne. Antibiotics are the first choice of treatment for mild-to-moderate, mixed, papular/pustular, and moderate nodular acne, and an alternative choice in severe, nodular/conglobate acne. The emergence of resistance to the currently available antibiotics poses a serious set-back to this algorithm, and the reduced arsenal can diminish efficacy of treatment. This emerging situation should catalyze innovations in dermatology; for example, newer drugs and technologies such as next-generation antibiotics with excellent potency and low propensity to develop resistance, rapid diagnostic platforms to select responders and nonresponders, and delivery technologies that target the bacteria. Such innovations can dramatically expand the arsenal for dermatologists in the management of acne. PMID:27416310

  17. Beta-lactam Antibiotics: From Antibiosis to Resistance and Bacteriology

    PubMed Central

    Kong, Kok-Fai; Schneper, Lisa; Mathee, Kalai

    2010-01-01

    SUMMARY This review focuses on the era of antibiosis that led to a better understanding of bacterial morphology, in particlar the cell wall component peptidoglycan. This is an effort to take readers on a tour de force from the concept of antibiosis, to the serepidity of antibiotics, evolution of beta-lactam development, and the molecular biology of antibiotic resistance. These areas of research have culminated in a deeper understanding of microbiology, particularly in the area of bacterial cell wall synthesis and recycling. In spite of this knowledge, which has enabled design of new even more effective therapeutics to combat bacterial infection and has provided new research tools, antibiotic resistance remains a worldwide health care problem. PMID:20041868

  18. Antibiotic-resistant acne: getting under the skin.

    PubMed

    Sinha, Mau; Sadhasivam, Suresh; Bhattacharyya, Anamika; Jain, Shilpi; Ghosh, Shamik; Arndt, Kenneth A; Dover, Jeffrey S; Sengupta, Shiladitya

    2016-06-01

    Propionibacterium acnes is a key pathogenic factor in the development of acne. Antibiotics are the first choice of treatment for mild-to-moderate, mixed, papular/pustular, and moderate nodular acne, and an alternative choice in severe, nodular/conglobate acne. The emergence of resistance to the currently available antibiotics poses a serious set-back to this algorithm, and the reduced arsenal can diminish efficacy of treatment. This emerging situation should catalyze innovations in dermatology; for example, newer drugs and technologies such as next-generation antibiotics with excellent potency and low propensity to develop resistance, rapid diagnostic platforms to select responders and nonresponders, and delivery technologies that target the bacteria. Such innovations can dramatically expand the arsenal for dermatologists in the management of acne.

  19. Characterization of antibiotic resistance determinants in oral biofilms.

    PubMed

    Kim, Seon-Mi; Kim, Hyeong C; Lee, Seok-Woo S

    2011-08-01

    Oral biofilms contain numerous antibiotic resistance determinants that can be transferred within or outside of the oral cavity. The aim of this study was to evaluate the prevalence and the relative level of antibiotic resistance determinants from oral biofilms. Oral biofilm samples that were collected from healthy subjects and periodontitis patients were subjected to qualitative and quantitative analyses for selected antibiotic resistance determinants using PCR. The prevalence of tet(Q), tet(M), cfxA, and bla ( TEM ) was very high both in the patient and the healthy subject group, with a tendency toward higher values in the patient group, with the exception of erm(F), which was more prevalent in the healthy group. The two extended spectrum β-lactam (ESBL) resistance determinants bla ( SHV ) and bla ( TEM ) showed a dramatic difference, as bla ( TEM ) was present in all of the samples and bla ( SHV ) was not found at all. The aacA-aphD, vanA, and mecA genes were rarely detected, suggesting that they are not common in oral bacteria. A quantitative PCR analysis showed that the relative amount of resistance determinants present in oral biofilms of the patient group was much greater than that of the healthy group, exhibiting 17-, 13-, 145-, and 3-fold increases for tet(Q), tet(M), erm(F), and cfxA, respectively. The results of this study suggest that the oral antibiotic resistome is more diverse and abundant in periodontitis patients than in healthy subjects, suggesting that there is a difference in the diversity and distribution of antibiotic resistance in oral biofilms associated with health and disease.

  20. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae

    PubMed Central

    Vuotto, Claudia; Longo, Francesca; Balice, Maria Pia; Donelli, Gianfranco; Varaldo, Pietro E.

    2014-01-01

    The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae. PMID:25438022

  1. Antibiotic Resistance in Staphylococcus aureus and Coagulase Negative Staphylococci Isolated from Goats with Subclinical Mastitis

    PubMed Central

    Virdis, Salvatore; Scarano, Christian; Cossu, Francesca; Spanu, Vincenzo; Spanu, Carlo; De Santis, Enrico Pietro Luigi

    2010-01-01

    Antimicrobial resistance patterns and gene coding for methicillin resistance (mecA) were determined in 25 S. aureus and 75 Coagulase Negative Staphylococci (CNS) strains isolates from half-udder milk samples collected from goats with subclinical mastitis. Fourteen (56.0%) S. aureus and thirty-one (41.3%) CNS isolates were resistant to one or more antimicrobial agents. S. aureus showed the highest resistance rate against kanamycin (28.0%), oxytetracycline (16.0%), and ampicillin (12.0%). The CNS tested were more frequently resistant to ampicillin (36.0%) and kanamycin (6.7%). Multiple antimicrobial resistance was observed in eight isolates, and one Staphylococcus epidermidis was found to be resistant to six antibiotics. The mecA gene was not found in any of the tested isolates. Single resistance against β-lactamics or aminoglicosides is the most common trait observed while multiresistance is less frequent. PMID:20445785

  2. Persistence of antibiotic resistance: evaluation of a probiotic approach using antibiotic-sensitive Megasphaera elsdenii strains to prevent colonization of swine by antibiotic-resistant strains.

    PubMed

    Stanton, Thad B; Humphrey, Samuel B

    2011-10-01

    Megasphaera elsdenii is a lactate-fermenting, obligately anaerobic bacterium commonly present in the gastrointestinal tracts of mammals, including humans. Swine M. elsdenii strains were previously shown to have high levels of tetracycline resistance (MIC=64 to >256 μg/ml) and to carry mosaic (recombinant) tetracycline resistance genes. Baby pigs inherit intestinal microbiota from the mother sow. In these investigations we addressed two questions. When do M. elsdenii strains from the sow colonize baby pigs? Can five antibiotic-sensitive M. elsdenii strains administered intragastrically to newborn pigs affect natural colonization of the piglets by antibiotic-resistant (AR) M. elsdenii strains from the mother? M. elsdenii natural colonization of newborn pigs was undetectable (<10(4) CFU/g [wet weight] of feces) prior to weaning (20 days after birth). After weaning, all pigs became colonized (4 × 10(5) to 2 × 10(8) CFU/g feces). In a separate study, 61% (76/125) of M. elsdenii isolates from a gravid sow never exposed to antibiotics were resistant to chlortetracycline, ampicillin, or tylosin. The inoculation of the sow's offspring with mixtures of M. elsdenii antibiotic-sensitive strains prevented colonization of the offspring by maternal AR strains until at least 11 days postweaning. At 25 and 53 days postweaning, however, AR strains predominated. Antibiotic susceptibility phenotypes and single nucleotide polymorphism (SNP)-based identities of M. elsdenii isolated from sow and offspring were unexpectedly diverse. These results suggest that dosing newborn piglets with M. elsdenii antibiotic-sensitive strains delays but does not prevent colonization by maternal resistant strains. M. elsdenii subspecies diversity offers an explanation for the persistence of resistant strains in the absence of antibiotic selection. PMID:21821757

  3. The antibiotic resistance crisis: part 1: causes and threats.

    PubMed

    Ventola, C Lee

    2015-04-01

    Decades after the first patients were treated with antibiotics, bacterial infections have again become a threat because of the rapid emergence of resistant bacteria-a crisis attributed to abuse of these medications and a lack of new drug development. PMID:25859123

  4. Antibiotic Resistance in Urinary Tract Infections in College Students

    ERIC Educational Resources Information Center

    Olson, Ronald P.; Haith, Karen

    2012-01-01

    Objective: To determine resistance to antibiotics of "Escherichia coli" in uncomplicated urinary tract infections (uUTIs) in female college students. Participants: Symptomatic patients presenting to a student health service from September 2008 to December 2009. Methods: Clean catch midstream urine samples were tested for urinalysis (UA) and…

  5. Risk of antibiotic resistance from metal contaminated soils

    NASA Astrophysics Data System (ADS)

    Knapp, Charles

    2013-04-01

    It is known that contaminated soils can lead to increased incidence of illness and disease, but it may also prevent our ability to fight disease. Many antibiotic resistant genes (ARG) acquired by bacteria originate from the environment. It is important to understand factors that influence levels of ARG in the environment, which could affect us clinically and agriculturally. The presence of elevated metal content in soils often promotes antibiotic resistance in exposed microorganisms. Using qPCR, the abundances of ARG to compare levels with geochemical conditions in randomly selected soils from several countries. Many ARG positively correlated with soil metal content, especially copper, chromium, nickel, lead, and iron. Results suggest that geochemical metal conditions influence the potential for antibiotic resistance in soil, which might be used to estimate baseline gene presence on various landscape scales and may translate to epidemiological risk of antibiotic-resistance transmission from the environment. This suggests that we may have to reconsider tolerances of metal pollution in the environment.

  6. Evaluation of antimicrobial resistance of bovine bacteria to antibiotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance (AMR) is one of the most formidable threats to human medicine today. Therefore, the research objective is to evaluate the susceptibility of Staphylococcus species isolated from beef cows to 12 antibiotics commonly used in treating human and animal infections. This research w...

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

    ERIC Educational Resources Information Center

    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…

  8. Stalking Antibiotic-Resistant Bacteria in Common Vegetables

    ERIC Educational Resources Information Center

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

    2004-01-01

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

  9. Presence of antibiotic resistance genes in a sewage treatment plant in Thibodaux, Louisiana, USA.

    PubMed

    Naquin, Anthony; Shrestha, Arsen; Sherpa, Mingma; Nathaniel, Rajkumar; Boopathy, Raj

    2015-01-01

    Increasing uses and disposals of antibiotics to the environment have increased emergence of various antibiotic resistance. One of the sources for the spread of antibiotic resistance is wastewater treatment plant, where bacteria and antibiotics can come in contact and can acquire antibiotics resistance. There are very few studies on this subject from a small town sewage treatment plant. Therefore, this study was conducted using raw sewage as well as treated sewage from a sewage treatment plant in Thibodaux in rural southeast Louisiana in USA. Samples were collected monthly from the Thibodaux sewage treatment plant and the presence of antibiotic resistance genes was monitored. The study showed the presence of antibiotic resistance genes in both raw and treated sewage in every month of the study period. The genetic transformation assay showed the successful transformation of methicillin resistant gene, mecA to an antibiotic sensitive Staphylococcus aureus, which became antibiotic resistant within 24h. PMID:25662190

  10. Monitoring roadside ditches for antibiotic resistant E. coli in forest and agricultural landscapes

    NASA Astrophysics Data System (ADS)

    Storrer, S.; Archibald, J. A.

    2009-12-01

    There is growing concern over the threat of antibiotic resistant bacteria and how they travel through natural environments. This study was developed to: (1) measure the quantities of antibiotic resistant Escherichia coli present in stormwater collected from roadside ditches, (2) examine the spatial and temporal distribution of antibiotic resistance and (3) explore the difference in antibiotic resistance between different land uses. Autosamplers were used to collect composite samples of stormwater flowing in roadside ditches located near manure fertilized fields or forested areas. Samples were filtered using standard membrane filtration methods and grown with and without antibiotics on EC medium containing MUG. Three antibiotics commonly used to treat infection in humans and dairy cows were used to measure antibiotic resistance: penicillin, ampicillin and tetracycline. Though antibiotic resistance was found at forested and farm sites, preliminary data suggest higher counts of antibiotic resistant E. coli near agricultural areas.

  11. Presence of antibiotic resistance genes in a sewage treatment plant in Thibodaux, Louisiana, USA.

    PubMed

    Naquin, Anthony; Shrestha, Arsen; Sherpa, Mingma; Nathaniel, Rajkumar; Boopathy, Raj

    2015-01-01

    Increasing uses and disposals of antibiotics to the environment have increased emergence of various antibiotic resistance. One of the sources for the spread of antibiotic resistance is wastewater treatment plant, where bacteria and antibiotics can come in contact and can acquire antibiotics resistance. There are very few studies on this subject from a small town sewage treatment plant. Therefore, this study was conducted using raw sewage as well as treated sewage from a sewage treatment plant in Thibodaux in rural southeast Louisiana in USA. Samples were collected monthly from the Thibodaux sewage treatment plant and the presence of antibiotic resistance genes was monitored. The study showed the presence of antibiotic resistance genes in both raw and treated sewage in every month of the study period. The genetic transformation assay showed the successful transformation of methicillin resistant gene, mecA to an antibiotic sensitive Staphylococcus aureus, which became antibiotic resistant within 24h.

  12. Nonchromosomal Antibiotic Resistance in Bacteria: Genetic Transformation of Escherichia coli by R-Factor DNA*

    PubMed Central

    Cohen, Stanley N.; Chang, Annie C. Y.; Hsu, Leslie

    1972-01-01

    Transformation of E. coli cells treated with CaCl2 to multiple antibiotic resistance by purified R-factor DNA is reported. Drug resistance is expressed in a small fraction of the recipient bacterial population almost immediately after uptake of DNA, but full genetic expression of resistance requires subsequent incubation in drugfree medium before antibiotic challenge. Transformed bacteria acquire a closed circular, transferable DNA species having the resistance, fertility, and sedimentation characteristics of the parent R factor. Covalently-closed, catenated, and open (nicked) circular forms of R-factor DNA are all effective in transformation, but denaturation and sonication abolish the transforming ability of R-factor DNA in this system. PMID:4559594

  13. Multiple Disease Resistance in Plants.

    PubMed

    Wiesner-Hanks, Tyr; Nelson, Rebecca

    2016-08-01

    Many plants, both in nature and in agriculture, are resistant to multiple diseases. Although much of the plant innate immunity system provides highly specific resistance, there is emerging evidence to support the hypothesis that some components of plant defense are relatively nonspecific, providing multiple disease resistance (MDR). Understanding MDR is of fundamental and practical interest to plant biologists, pathologists, and breeders. This review takes stock of the available evidence related to the MDR hypothesis. Questions about MDR are considered primarily through the lens of forward genetics, starting at the organismal level and proceeding to the locus level and, finally, to the gene level. At the organismal level, MDR may be controlled by clusters of R genes that evolve under diversifying selection, by dispersed, pathogen-specific genes, and/or by individual genes providing MDR. Based on the few MDR loci that are well-understood, MDR is conditioned by diverse mechanisms at the locus and gene levels. PMID:27296142

  14. Antibiotic resistance in Enterobacteriaceae: mechanisms and clinical implications.

    PubMed

    Iredell, Jon; Brown, Jeremy; Tagg, Kaitlin

    2016-02-08

    Resistance of the Enterobacteriaceae to antibiotics, especially of the β lactam type, is increasingly dominated by the mobilization of continuously expressed single genes that encode efficient drug modifying enzymes. Strong and ubiquitous selection pressure has seemingly been accompanied by a shift from "natural" resistance, such as inducible chromosomal enzymes, membrane impermeability, and drug efflux, to the modern paradigm of mobile gene pools that largely determine the epidemiology of modern antibiotic resistance. In this way, antibiotic resistance is more available than ever before to organisms such as Escherichia coli and Klebsiella pneumoniae that are important causes of major sepsis. Modulation of the phenotype by host bacteria makes gene transmission less obvious and may in part explain why tracking and control of carbapenem resistance has been particularly problematic in the Enterobacteriaceae. This review discusses the underlying principles and clinical implications of the mobility and fixation of resistance genes and the exploitable opportunities and potential threats arising from apparent limitations on diversity in these mobile gene pools. It also provides some illustrative paradoxes and clinical corollaries, as well as a summary of future options.

  15. [Resistance to antibiotics in Pseudomonas aeruginosa in Colombian hospitals].

    PubMed

    Villa, Lina M; Cortés, Jorge A; Leal, Aura L; Meneses, Andrés; Meléndez, Martha P

    2013-12-01

    Pseudomonas aeruginosa infections cause high morbidity and mortality. We performed a descriptive analysis of the rates of antibiotic resistance in isolates of P. aeruginosa in 33 hospitals enrolled in a surveillance network in Colombia. The study was conducted between January 2005 and December 2009 .9905 isolates of P. aeruginosa were identified, (4.9% of all strains). In intensive care units (ICU) P. aeruginosa showed an overall resistance to aztreonam, cefepime , ceftazidime, imipenem, meropenem , and piperacillin / tazobactam of 31.8% , 23.9% , 24.8%, 22.5%, 20.3% and 22.3%, respectively. Resistance rates increased for piperacillin/tazobactam, cefepime, and imipenem; remained unchanged for meropenem; and decreased for aminoglycosides, quinolones and ceftazidime. Resistance to one, two and three or more families of antibiotics was found in 17%, 12.5%, and 32.1%, respectively. In samples collected from the wards, the resistance rate was lower but usually over 10%. Antibiotic resistance in P. aeruginosa isolates in hospitalized patients and particularly in those admitted to ICUs in Colombia is high.

  16. Joint Transcriptional Control of Virulence and Resistance to Antibiotic and Environmental Stress in Acinetobacter baumannii

    PubMed Central

    Gallagher, Larry A.; Jacobson, Rachael K.; Usacheva, Elena A.; Peterson, Lance R.; Zurawski, Daniel V.; Shuman, Howard A.

    2015-01-01

    ABSTRACT The increasing emergence of antibiotic-resistant bacterial pathogens represents a serious risk to human health and the entire health care system. Many currently circulating strains of Acinetobacter baumannii exhibit resistance to multiple antibiotics. A key limitation in combating A. baumannii is that our understanding of the molecular mechanisms underlying the pathogenesis of A. baumannii is lacking. To identify potential virulence determinants of a contemporary multidrug-resistant isolate of A. baumannii, we used transposon insertion sequencing (TnSeq) of strain AB5075. A collection of 250,000 A. baumannii transposon mutants was analyzed for growth within Galleria mellonella larvae, an insect-based infection model. The screen identified 300 genes that were specifically required for survival and/or growth of A. baumannii inside G. mellonella larvae. These genes encompass both known, established virulence factors and several novel genes. Among these were more than 30 transcription factors required for growth in G. mellonella. A subset of the transcription factors was also found to be required for resistance to antibiotics and environmental stress. This work thus establishes a novel connection between virulence and resistance to both antibiotics and environmental stress in A. baumannii. PMID:26556274

  17. Trends in antibiotic resistance in coagulase-negative staphylococci in the United States, 1999 to 2012.

    PubMed

    May, Larissa; Klein, Eili Y; Rothman, Richard E; Laxminarayan, Ramanan

    2014-01-01

    Coagulase-negative staphylococci (CoNS) are important bloodstream pathogens that are typically resistant to multiple antibiotics. Despite the concern about increasing resistance, there have been no recent studies describing the national prevalence of CoNS pathogens. We used national resistance data over a period of 13 years (1999 to 2012) from The Surveillance Network (TSN) to determine the prevalence of and assess the trends in resistance for Staphylococcus epidermidis, the most common CoNS pathogen, and all other CoNS pathogens. Over the course of the study period, S. epidermidis resistance to ciprofloxacin and clindamycin increased steadily from 58.3% to 68.4% and from 43.4% to 48.5%, respectively. Resistance to levofloxacin increased rapidly from 57.1% in 1999 to a high of 78.6% in 2005, followed by a decrease to 68.1% in 2012. Multidrug resistance for CoNS followed a similar pattern, and this rise and small decline in resistance were found to be strongly correlated with levofloxacin prescribing patterns. The resistance patterns were similar for the aggregate of CoNS pathogens. The results from our study demonstrate that the antibiotic resistance in CoNS pathogens has increased significantly over the past 13 years. These results are important, as CoNS can serve as sentinels for monitoring resistance, and they play a role as reservoirs of resistance genes that can be transmitted to other pathogens. The link between the levofloxacin prescription rate and resistance levels suggests a critical role for reducing the inappropriate use of fluoroquinolones and other broad-spectrum antibiotics in health care settings and in the community to help curb the reservoir of resistance in these colonizing pathogens.

  18. Infections and antibiotic resistance in nursing homes.

    PubMed Central

    Nicolle, L E; Strausbaugh, L J; Garibaldi, R A

    1996-01-01

    Infections occur frequently in nursing home residents. The most common infections are pneumonia, urinary tract infection, and skin and soft tissue infection. Aging-associated physiologic and pathologic changes, functional disability, institutionalization, and invasive devices all contribute to the high occurrence of infection. Antimicrobial agent use in nursing homes is intense and usually empiric. All of these factors contribute to the increasing frequency of antimicrobial agent-resistant organisms in nursing homes. Programs that will limit the emergence and impact of antimicrobial resistance and infections in nursing homes need to be developed. PMID:8665472

  19. Antibiotics, Antibiotic Resistance Genes, and Bacterial Community Composition in Fresh Water Aquaculture Environment in China.

    PubMed

    Xiong, Wenguang; Sun, Yongxue; Zhang, Tong; Ding, Xueyao; Li, Yafei; Wang, Mianzhi; Zeng, Zhenling

    2015-08-01

    Environmental antibiotic resistance has drawn increasing attention due to its great threat to human health. In this study, we investigated concentrations of antibiotics (tetracyclines, sulfonamides and (fluoro)quinolones) and abundances of antibiotic resistance genes (ARGs), including tetracycline resistance genes, sulfonamide resistance genes, and plasmid-mediated quinolone resistance genes, and analyzed bacterial community composition in aquaculture environment in Guangdong, China. The concentrations of sulfametoxydiazine, sulfamethazine, sulfamethoxazole, oxytetracycline, chlorotetracycline, doxycycline, ciprofloxacin, norfloxacin, and enrofloxacin were as high as 446 μg kg(-1) and 98.6 ng L(-1) in sediment and water samples, respectively. The relative abundances (ARG copies/16S ribosomal RNA (rRNA) gene copies) of ARGs (sul1, sul2, sul3, tetM, tetO, tetW, tetS, tetQ, tetX, tetB/P, qepA, oqxA, oqxB, aac(6')-Ib, and qnrS) were as high as 2.8 × 10(-2). The dominant phyla were Proteobacteria, Bacteroidetes, and Firmicutes in sediment samples and Proteobacteria, Actinobacteria and Bacteroidetes in water samples. The genera associated with pathogens were also observed, such as Acinetobacter, Arcobacter, and Clostridium. This study comprehensively investigated antibiotics, ARGs, and bacterial community composition in aquaculture environment in China. The results indicated that fish ponds are reservoirs of ARGs and the presence of potential resistant and pathogen-associated taxonomic groups in fish ponds might imply the potential risk to human health.

  20. Which antibiotic for resistant Gram-positives, and why?

    PubMed

    Bradley, John S

    2014-01-01

    Increasing resistance in Gram-positive pathogens, particularly Staphylococcus aureus, and enterococcus, has become a major clinical problem, particularly in the hospital environment, causing significant morbidity and mortality in both healthy hosts and in those with underlying comorbidities. Increased resistance drives the use of empiric therapy with less well-studied and potentially more toxic agents. Resistance mechanisms for currently recommended agents are discussed, with options for therapy of resistant pathogens. For any new agent used, resistance is likely to develop, which underscores the concept that both antibiotics and antimicrobial resistance are ancient, and only by prudent use of antimicrobial agents and effective infection control measures when resistance arises, will effective agents be available to treat Gram-positive pathogens in the future.

  1. The abundance of antibiotic resistance genes in human guts has correlation to the consumption of antibiotics in animal.

    PubMed

    Hu, Yongfei; Yang, Xi; Lu, Na; Zhu, Baoli

    2014-01-01

    Increasing evidence has accumulated to support that the human gut is a reservoir for antibiotic resistance genes. We previously identified more than 1000 genes displaying high similarity with known antibiotic resistance genes in the human gut gene set generated from the Chinese, Danish, and Spanish populations. Here, first, we add our new understanding of antibiotic resistance genes in the US and the Japanese populations; next, we describe the structure of a vancomycin-resistant operon in a Danish sample; and finally, we provide discussions on the correlation of the abundance of resistance genes in human gut with the antibiotic consumption in human medicine and in animal husbandry. These results, combined with those we published previously, provide comprehensive insights into the antibiotic resistance genes in the human gut microbiota at a population level.

  2. Oral Antibiotics are Effective for Highly Resistant Hip Arthroplasty Infections

    PubMed Central

    Esteban, Jaime; García-Cimbrelo, Eduardo

    2009-01-01

    Infected arthroplasties reportedly have a lower eradication rate when caused by highly resistant and/or polymicrobial isolates and in these patients most authors recommend intravenous antibiotics. We asked whether two-stage revision with interim oral antibiotics could eradicate these infections. We prospectively followed 36 patients (mean age, 71.8 years) with late hip arthroplasty infections. Combinations of oral antibiotics were prescribed according to cultures, biofilm, and intracellular effectiveness. The minimum followup was 1 year (mean, 4.4 years; range, 1–12 years). We presumed eradication in the absence of clinical, serologic, and radiographic signs of infection. Infection was eradicated in all 13 patients with highly resistant bacteria who completed a two-stage protocol (10 with methicillin-resistant Staphylococci) and in eight of 11 patients treated with only the first stage (and six of nine with methicillin-resistant Staphylococci). Infection was eradicated in six of six patients with polymicrobial isolates (of sensitive and/or resistant bacteria) who completed a two-stage protocol and in five of seven with polymicrobial isolates treated with only the first surgery. The Harris hip score averaged 88.1 (range, 70–98) in patients who underwent reimplantation and 56.8 (range, 32–76) in patients who underwent resection arthroplasty. Long cycles of combined oral antibiotics plus a two-stage surgical exchange appear a promising alternative for infections by highly resistant bacteria, methicillin-resistant Staphylococci, and polymicrobial infections. Level of Evidence: Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence. PMID:19333670

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 2nd U.S. Case of Bacteria Resistant to Last-Resort Antibiotic

    MedlinePlus

    ... 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 ...

  5. Antimicrobial Peptide Novicidin Synergizes with Rifampin, Ceftriaxone, and Ceftazidime against Antibiotic-Resistant Enterobacteriaceae In Vitro

    PubMed Central

    Soren, Odel; Brinch, Karoline Sidelmann; Patel, Dipesh; Liu, Yingjun; Liu, Alexander; Coates, Anthony

    2015-01-01

    The spread of antibiotic resistance among Gram-negative bacteria is a serious clinical threat, and infections with these organisms are a leading cause of mortality worldwide. Traditional novel drug development inevitably leads to the emergence of new resistant strains, rendering the new drugs ineffective. Therefore, reviving the therapeutic potentials of existing antibiotics represents an attractive novel strategy. Novicidin, a novel cationic antimicrobial peptide, is effective against Gram-negative bacteria. Here, we investigated novicidin as a possible antibiotic enhancer. The actions of novicidin in combination with rifampin, ceftriaxone, or ceftazidime were investigated against 94 antibiotic-resistant clinical Gram-negative isolates and 7 strains expressing New Delhi metallo-β-lactamase-1. Using the checkerboard method, novicidin combined with rifampin showed synergy with >70% of the strains, reducing the MICs significantly. The combination of novicidin with ceftriaxone or ceftazidime was synergistic against 89.7% of the ceftriaxone-resistant strains and 94.1% of the ceftazidime-resistant strains. Synergistic interactions were confirmed using time-kill studies with multiple strains. Furthermore, novicidin increased the postantibiotic effect when combined with rifampin or ceftriaxone. Membrane depolarization assays revealed that novicidin alters the cytoplasmic membrane potential of Gram-negative bacteria. In vitro toxicology tests showed novicidin to have low hemolytic activity and no detrimental effect on cell cultures. We demonstrated that novicidin strongly rejuvenates the therapeutic potencies of ceftriaxone or ceftazidime against resistant Gram-negative bacteria in vitro. In addition, novicidin boosted the activity of rifampin. This strategy can have major clinical implications in our fight against antibiotic-resistant bacterial infections. PMID:26248380

  6. Antibiotic resistance among bacteria isolated from seawater and penguin fecal samples collected near Palmer Station, Antarctica.

    PubMed

    Miller, Robert V; Gammon, Katharine; Day, Martin J

    2009-01-01

    Antibiotic resistance in aquatic bacteria has increased steadily as a consequence of the widespread use of antibiotics, but practice and international treaty should have limited antibiotic contamination in Antarctica. We estimated antibiotic resistance in microorganisms isolated from the Antarctic marine waters and a penguin rookery, for 2 reasons: (i) as a measure of human impact and (ii) as a potential "snapshot" of the preantibiotic world. Samples were taken at 4 established sampling sites near Palmer Station, which is situated at the southern end of the Palmer Archipelago (64 degrees 10'S, 61 degrees 50'W). Sites were chosen to provide different potentials for human contamination. Forty 50 mL samples of seawater were collected and colony-forming units (CFU)/mL were determined at 6 and 20 degrees C. For this study, presumed psychrophiles (growth at 6 degrees C) were assumed to be native to Antarctic waters, whereas presumed mesophiles (growth at 20 degrees C but not at 6 degrees C) were taken to represent introduced organisms. The 20-6 degrees C CFU/mL ratio was used as a measure of the relative impact to the ecosystem of presumably introduced organisms. This ratio was highest at the site nearest to Palmer Station and decreased with distance from it, suggesting that human presence has impacted the natural microbial flora of the site. The frequency of resistance to 5 common antibiotics was determined in each group of isolates. Overall drug resistance was higher among the presumed mesophiles than the presumed psychrophiles and increased with proximity to Palmer Station, with the presumed mesophiles showing higher frequencies of single and multiple drug resistance than the psychrophile population. The frequency of multidrug resistance followed the same pattern. It appears that multidrug resistance is low among native Antarctic bacteria but is increased by human habitation.

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

    PubMed

    Mohanta, Tandra; Goel, Sudha

    2014-08-01

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

  8. Temperate and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria.

    PubMed

    Yosef, Ido; Manor, Miriam; Kiro, Ruth; Qimron, Udi

    2015-06-01

    The increasing threat of pathogen resistance to antibiotics requires the development of novel antimicrobial strategies. Here we present a proof of concept for a genetic strategy that aims to sensitize bacteria to antibiotics and selectively kill antibiotic-resistant bacteria. We use temperate phages to deliver a functional clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) system into the genome of antibiotic-resistant bacteria. The delivered CRISPR-Cas system destroys both antibiotic resistance-conferring plasmids and genetically modified lytic phages. This linkage between antibiotic sensitization and protection from lytic phages is a key feature of the strategy. It allows programming of lytic phages to kill only antibiotic-resistant bacteria while protecting antibiotic-sensitized bacteria. Phages designed according to this strategy may be used on hospital surfaces and hand sanitizers to facilitate replacement of antibiotic-resistant pathogens with sensitive ones. PMID:26060300

  9. Temperate and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria.

    PubMed

    Yosef, Ido; Manor, Miriam; Kiro, Ruth; Qimron, Udi

    2015-06-01

    The increasing threat of pathogen resistance to antibiotics requires the development of novel antimicrobial strategies. Here we present a proof of concept for a genetic strategy that aims to sensitize bacteria to antibiotics and selectively kill antibiotic-resistant bacteria. We use temperate phages to deliver a functional clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) system into the genome of antibiotic-resistant bacteria. The delivered CRISPR-Cas system destroys both antibiotic resistance-conferring plasmids and genetically modified lytic phages. This linkage between antibiotic sensitization and protection from lytic phages is a key feature of the strategy. It allows programming of lytic phages to kill only antibiotic-resistant bacteria while protecting antibiotic-sensitized bacteria. Phages designed according to this strategy may be used on hospital surfaces and hand sanitizers to facilitate replacement of antibiotic-resistant pathogens with sensitive ones.

  10. Temperate and lytic bacteriophages programmed to sensitize and kill antibiotic-resistant bacteria

    PubMed Central

    Yosef, Ido; Manor, Miriam; Kiro, Ruth

    2015-01-01

    The increasing threat of pathogen resistance to antibiotics requires the development of novel antimicrobial strategies. Here we present a proof of concept for a genetic strategy that aims to sensitize bacteria to antibiotics and selectively kill antibiotic-resistant bacteria. We use temperate phages to deliver a functional clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated (Cas) system into the genome of antibiotic-resistant bacteria. The delivered CRISPR-Cas system destroys both antibiotic resistance-conferring plasmids and genetically modified lytic phages. This linkage between antibiotic sensitization and protection from lytic phages is a key feature of the strategy. It allows programming of lytic phages to kill only antibiotic-resistant bacteria while protecting antibiotic-sensitized bacteria. Phages designed according to this strategy may be used on hospital surfaces and hand sanitizers to facilitate replacement of antibiotic-resistant pathogens with sensitive ones. PMID:26060300

  11. ABC-F Proteins Mediate Antibiotic Resistance through Ribosomal Protection

    PubMed Central

    Sharkey, Liam K. R.; Edwards, Thomas A.

    2016-01-01

    ABSTRACT Members of the ABC-F subfamily of ATP-binding cassette proteins mediate resistance to a broad array of clinically important antibiotic classes that target the ribosome of Gram-positive pathogens. The mechanism by which these proteins act has been a subject of long-standing controversy, with two competing hypotheses each having gained considerable support: antibiotic efflux versus ribosomal protection. Here, we report on studies employing a combination of bacteriological and biochemical techniques to unravel the mechanism of resistance of these proteins, and provide several lines of evidence that together offer clear support to the ribosomal protection hypothesis. Of particular note, we show that addition of purified ABC-F proteins to an in vitro translation assay prompts dose-dependent rescue of translation, and demonstrate that such proteins are capable of displacing antibiotic from the ribosome in vitro. To our knowledge, these experiments constitute the first direct evidence that ABC-F proteins mediate antibiotic resistance through ribosomal protection. PMID:27006457

  12. Cultures of resistance? A Bourdieusian analysis of doctors' antibiotic prescribing.

    PubMed

    Broom, Alex; Broom, Jennifer; Kirby, Emma

    2014-06-01

    The prospect of an 'antimicrobial perfect storm' in the coming decades through the emergence and proliferation of multi-resistant organisms has become an urgent public health concern. With limited drug discovery solutions foreseeable in the immediate future, and with evidence that resistance can be ameliorated by optimisation of prescribing, focus currently centres on antibiotic use. In hospitals, this is manifest in the development of stewardship programs that aim to alter doctors' prescribing behaviour. Yet, in many clinical contexts, doctors' antibiotic prescribing continues to elude best practice. In this paper, drawing on qualitative interviews with 30 Australian hospital-based doctors in mid-2013, we draw on Bourdieu's theory of practice to illustrate that 'sub-optimal' antibiotic prescribing is a logical choice within the habitus of the social world of the hospital. That is, the rules of the game within the field are heavily weighted in favour of the management of immediate clinical risks, reputation and concordance with peer practice vis-à-vis longer-term population consequences. Antimicrobial resistance is thus a principal of limited significance in the hospital. We conclude that understanding the habitus of the hospital and the logics underpinning practice is a critical step toward developing governance practices that can respond to clinically 'sub-optimal' antibiotic use.

  13. Antibiotic resistance-the need for global solutions.

    PubMed

    Laxminarayan, Ramanan; Duse, Adriano; Wattal, Chand; Zaidi, Anita K M; Wertheim, Heiman F L; Sumpradit, Nithima; Vlieghe, Erika; Hara, Gabriel Levy; Gould, Ian M; Goossens, Herman; Greko, Christina; So, Anthony D; Bigdeli, Maryam; Tomson, Göran; Woodhouse, Will; Ombaka, Eva; Peralta, Arturo Quizhpe; Qamar, Farah Naz; Mir, Fatima; Kariuki, Sam; Bhutta, Zulfiqar A; Coates, Anthony; Bergstrom, Richard; Wright, Gerard D; Brown, Eric D; Cars, Otto

    2013-12-01

    The causes of antibiotic resistance are complex and include human behaviour at many levels of society; the consequences affect everybody in the world. Similarities with climate change are evident. Many efforts have been made to describe the many different facets of antibiotic resistance and the interventions needed to meet the challenge. However, coordinated action is largely absent, especially at the political level, both nationally and internationally. Antibiotics paved the way for unprecedented medical and societal developments, and are today indispensible in all health systems. Achievements in modern medicine, such as major surgery, organ transplantation, treatment of preterm babies, and cancer chemotherapy, which we today take for granted, would not be possible without access to effective treatment for bacterial infections. Within just a few years, we might be faced with dire setbacks, medically, socially, and economically, unless real and unprecedented global coordinated actions are immediately taken. Here, we describe the global situation of antibiotic resistance, its major causes and consequences, and identify key areas in which action is urgently needed.

  14. Antibiotic resistance in prevalent bacterial and protozoan sexually transmitted infections.

    PubMed

    Krupp, Karl; Madhivanan, Purnima

    2015-01-01

    The emergence of multi-drug resistant sexually transmitted infections (STIs) is causing a treatment crisis across the globe. While cephalosporin-resistant gonorrhea is one of the most pressing issues, extensively antibiotic resistant Chlamydia trachomatis and Mycoplasma hominis are also becoming commonplace. Experts have suggested that the failure of current treatment regimens are "largely inevitable" and have called for entirely new classes of antimicrobial agents. With the exception of several new classes of drugs primarily targeting nosocomial infections, progress has been slow. While pharmaceutical companies continue to introduce new drugs, they are based on decade-old discoveries. While there is disagreement about what constitutes new classes of antibiotics, many experts suggest that the last truly new family of antimicrobials was discovered in 1987. This review summarizes the existing literature on antibiotic resistance in common bacterial and protozoal STIs. It also briefly discusses several of the most promising alternatives to current therapies, and further examines how advances in drug delivery, formulation, concentration, and timing are improving the efficacy of existing treatments. Finally, the paper discusses the current state of pharmaceutical development for multidrug-resistant STI. PMID:26392647

  15. The Ocean as a Global Reservoir of Antibiotic Resistance Genes

    PubMed Central

    Hatosy, Stephen M.

    2015-01-01

    Recent studies of natural environments have revealed vast genetic reservoirs of antibiotic resistance (AR) genes. Soil bacteria and human pathogens share AR genes, and AR genes have been discovered in a variety of habitats. However, there is little knowledge about the presence and diversity of AR genes in marine environments and which organisms host AR genes. To address this, we identified the diversity of genes conferring resistance to ampicillin, tetracycline, nitrofurantoin, and sulfadimethoxine in diverse marine environments using functional metagenomics (the cloning and screening of random DNA fragments). Marine environments were host to a diversity of AR-conferring genes. Antibiotic-resistant clones were found at all sites, with 28% of the genes identified as known AR genes (encoding beta-lactamases, bicyclomycin resistance pumps, etc.). However, the majority of AR genes were not previously classified as such but had products similar to proteins such as transport pumps, oxidoreductases, and hydrolases. Furthermore, 44% of the genes conferring antibiotic resistance were found in abundant marine taxa (e.g., Pelagibacter, Prochlorococcus, and Vibrio). Therefore, we uncovered a previously unknown diversity of genes that conferred an AR phenotype among marine environments, which makes the ocean a global reservoir of both clinically relevant and potentially novel AR genes. PMID:26296734

  16. Antibiotic resistance in prevalent bacterial and protozoan sexually transmitted infections

    PubMed Central

    Krupp, Karl; Madhivanan, Purnima

    2015-01-01

    The emergence of multi-drug resistant sexually transmitted infections (STIs) is causing a treatment crisis across the globe. While cephalosporin-resistant gonorrhea is one of the most pressing issues, extensively antibiotic resistant Chlamydia trachomatis and Mycoplasma hominis are also becoming commonplace. Experts have suggested that the failure of current treatment regimens are “largely inevitable” and have called for entirely new classes of antimicrobial agents. With the exception of several new classes of drugs primarily targeting nosocomial infections, progress has been slow. While pharmaceutical companies continue to introduce new drugs, they are based on decade-old discoveries. While there is disagreement about what constitutes new classes of antibiotics, many experts suggest that the last truly new family of antimicrobials was discovered in 1987. This review summarizes the existing literature on antibiotic resistance in common bacterial and protozoal STIs. It also briefly discusses several of the most promising alternatives to current therapies, and further examines how advances in drug delivery, formulation, concentration, and timing are improving the efficacy of existing treatments. Finally, the paper discusses the current state of pharmaceutical development for multidrug-resistant STI. PMID:26392647

  17. Antibiotic resistance in prevalent bacterial and protozoan sexually transmitted infections.

    PubMed

    Krupp, Karl; Madhivanan, Purnima

    2015-01-01

    The emergence of multi-drug resistant sexually transmitted infections (STIs) is causing a treatment crisis across the globe. While cephalosporin-resistant gonorrhea is one of the most pressing issues, extensively antibiotic resistant Chlamydia trachomatis and Mycoplasma hominis are also becoming commonplace. Experts have suggested that the failure of current treatment regimens are "largely inevitable" and have called for entirely new classes of antimicrobial agents. With the exception of several new classes of drugs primarily targeting nosocomial infections, progress has been slow. While pharmaceutical companies continue to introduce new drugs, they are based on decade-old discoveries. While there is disagreement about what constitutes new classes of antibiotics, many experts suggest that the last truly new family of antimicrobials was discovered in 1987. This review summarizes the existing literature on antibiotic resistance in common bacterial and protozoal STIs. It also briefly discusses several of the most promising alternatives to current therapies, and further examines how advances in drug delivery, formulation, concentration, and timing are improving the efficacy of existing treatments. Finally, the paper discusses the current state of pharmaceutical development for multidrug-resistant STI.

  18. Antibiotic resistance in an in vitro subgingival biofilm model

    PubMed Central

    Sedlacek, M. J.; Walker, C.

    2007-01-01

    Introduction: The purpose of this study was to utilize an in vitro biofilm model of subgingival plaque to investigate resistances in subgingival biofilm communities to antibiotics commonly used as adjuncts to periodontal therapy. Methods: Biofilms were grown on saliva-coated hydroxyapatite supports in trypticasesoy broth for 4 h–10 days and then exposed for 48 h to either increasing twofold concentrations of tetracycline, amoxicillin, clindamycin, and erythromycin or therapeutically achievable concentrations of tetracycline, doxycycline, minocycline, amoxicillin, metronidazole, amoxicillin/clavulanate, and amoxicillin/metronidazole. Results: Concentrations necessary to inhibit bacterial strains in steady-state biofilms were up to 250 times greater than the concentrations needed to inhibit the same strains grown planktonically. In the presence of therapeutically available antibiotic concentrations, significantly higher proportions of the biofilms remained viable as the biofilms reached steady-state growth. The combinations of amoxicillin/clavulanate and amoxicillin/metronidazole were the most effective in suppressing growth. These combinations were particularly effective against biofilms up to and including 7 days of age and inhibited 90% or more of the bacteria present relative to untreated controls. As the biofilms approached steady state, these combinations were less effective with 50−60% of the bacteria retaining viability. Conclusion: Most, but not all, species of subgingival bacteria are considerably more resistant in biofilms than in planktonic cultures. Resistance appeared to be age-related because biofilms demonstrated progressive antibiotic resistance as they matured with maximum resistance coinciding with the steady-state phase of biofilm growth. PMID:17803631

  19. Rapid electrochemical phenotypic profiling of antibiotic-resistant bacteria.

    PubMed

    Besant, Justin D; Sargent, Edward H; Kelley, Shana O

    2015-07-01

    Rapid phenotyping of bacteria to identify drug-resistant strains is an important capability for the treatment and management of infectious disease. At present, the rapid determination of antibiotic susceptibility is hindered by the requirement that, in existing devices, bacteria must be pre-cultured for 2-3 days to reach detectable levels. Here we report a novel electrochemical approach that achieves rapid readout of the antibiotic susceptibility profile of a bacterial infection within one hour. The electrochemical reduction of a redox-active molecule is monitored that reports on levels of metabolically-active bacteria. Bacteria are captured in miniaturized wells, incubated with antimicrobials and monitored for resistance. This electrochemical phenotyping approach is effective with clinically-relevant levels of bacteria, and provides results comparable to culture-based analysis. Results, however, are delivered on a much faster timescale, with resistance profiles available after a one hour incubation period.

  20. Costs of antibiotic resistance - separating trait effects and selective effects.

    PubMed

    Hall, Alex R; Angst, Daniel C; Schiessl, Konstanze T; Ackermann, Martin

    2015-03-01

    Antibiotic resistance can impair bacterial growth or competitive ability in the absence of antibiotics, frequently referred to as a 'cost' of resistance. Theory and experiments emphasize the importance of such effects for the distribution of resistance in pathogenic populations. However, recent work shows that costs of resistance are highly variable depending on environmental factors such as nutrient supply and population structure, as well as genetic factors including the mechanism of resistance and genetic background. Here, we suggest that such variation can be better understood by distinguishing between the effects of resistance mechanisms on individual traits such as growth rate or yield ('trait effects') and effects on genotype frequencies over time ('selective effects'). We first give a brief overview of the biological basis of costs of resistance and how trait effects may translate to selective effects in different environmental conditions. We then review empirical evidence of genetic and environmental variation of both types of effects and how such variation may be understood by combining molecular microbiological information with concepts from evolution and ecology. Ultimately, disentangling different types of costs may permit the identification of interventions that maximize the cost of resistance and therefore accelerate its decline.

  1. Antibiotic resistance in triclosan tolerant fecal coliforms isolated from surface waters near wastewater treatment plant outflows (Morris County, NJ, USA).

    PubMed

    Middleton, June H; Salierno, James D

    2013-02-01

    Triclosan (TCS) is a common antimicrobial agent that has been detected in wastewater treatment plant (WWTP) effluent outflows. A link between TCS exposure and increased antibiotic resistance in microbes has been postulated. The purpose of this study was to evaluate whether fecal coliforms (FC) isolated from surface waters located near (WWTP) outflows display TCS resistance and, if so, whether such organisms exhibit increased resistance to antibiotics. Water samples were collected at two streams in Morris County, NJ that receive WWTP effluent: Loantaka Brook and the Whippany River. Water samples were collected at three sites within each location near the WWTP effluent outflow. Abiotic river parameters were measured and FCs were enumerated for each sample. River parameters were analyzed to determine if TCS or antibiotic resistance was correlated to water quality. Triclosan resistance levels were determined for individual isolates, and isolates were screened against seven classes of antibiotics at clinically relevant levels to assess cross-resistance. At Loantaka Brook, 78.8% of FC isolates were resistant to TCS with an average minimum inhibitory concentration (MIC) of 43.2 μg ml(-1). In addition, 89.6% of isolates were resistant to four classes of antibiotics and all were identified as Citrobacter freundii. There was a significant effect of stream location on mean TCS MIC values in the Loantaka Brook, with effluent isolates maintaining significantly higher MIC values compared to upstream isolates. At Whippany River sites, TCS resistant isolates were detected on 94% of sampling dates with a significant relationship between TCS resistance and multiple antibiotic resistances (≥ three antibiotic classes, p<0.001). TCS resistant isolates were significantly more resistant to chloramphenicol (p=0.007) and to nitrofurantoin (p=0.037) when compared to TCS sensitive isolates. Environmental FC isolates resistant to high level TCS included species of Escherichia, Enterobacter

  2. Antibiotic resistance in triclosan tolerant fecal coliforms isolated from surface waters near wastewater treatment plant outflows (Morris County, NJ, USA).

    PubMed

    Middleton, June H; Salierno, James D

    2013-02-01

    Triclosan (TCS) is a common antimicrobial agent that has been detected in wastewater treatment plant (WWTP) effluent outflows. A link between TCS exposure and increased antibiotic resistance in microbes has been postulated. The purpose of this study was to evaluate whether fecal coliforms (FC) isolated from surface waters located near (WWTP) outflows display TCS resistance and, if so, whether such organisms exhibit increased resistance to antibiotics. Water samples were collected at two streams in Morris County, NJ that receive WWTP effluent: Loantaka Brook and the Whippany River. Water samples were collected at three sites within each location near the WWTP effluent outflow. Abiotic river parameters were measured and FCs were enumerated for each sample. River parameters were analyzed to determine if TCS or antibiotic resistance was correlated to water quality. Triclosan resistance levels were determined for individual isolates, and isolates were screened against seven classes of antibiotics at clinically relevant levels to assess cross-resistance. At Loantaka Brook, 78.8% of FC isolates were resistant to TCS with an average minimum inhibitory concentration (MIC) of 43.2 μg ml(-1). In addition, 89.6% of isolates were resistant to four classes of antibiotics and all were identified as Citrobacter freundii. There was a significant effect of stream location on mean TCS MIC values in the Loantaka Brook, with effluent isolates maintaining significantly higher MIC values compared to upstream isolates. At Whippany River sites, TCS resistant isolates were detected on 94% of sampling dates with a significant relationship between TCS resistance and multiple antibiotic resistances (≥ three antibiotic classes, p<0.001). TCS resistant isolates were significantly more resistant to chloramphenicol (p=0.007) and to nitrofurantoin (p=0.037) when compared to TCS sensitive isolates. Environmental FC isolates resistant to high level TCS included species of Escherichia, Enterobacter

  3. Why Finish Your Antibiotics? A Novel, Hands-On, Classroom Approach for Teaching the Dynamics of Antibiotic Resistance

    ERIC Educational Resources Information Center

    Wassmer, Gary T.; Kipe-Nolt, Judith A.; Chayko, Catherine A.

    2006-01-01

    We present an effective, engaging, and fun method for teaching how the use or misuse of antibiotics can select for resistant strains of bacteria. This method uses candy as a substitute for strains of bacteria varying in resistance to a given antibiotic. Results and discussion are presented in the context of this emerging healthcare crisis.

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

    PubMed

    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

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

    PubMed

    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.

  6. Occurrence of antibiotic resistance genes in culturable bacteria isolated from Turkish trout farms and their local aquatic environment.

    PubMed

    Capkin, Erol; Terzi, Ertugrul; Altinok, Ilhan

    2015-05-21

    Antibiotic resistance and presence of the resistance genes were investigated in the bacteria isolated from water, sediment, and fish in trout farms. A total of 9 bacterial species, particularly Escherichia coli, were isolated from the water and sediment samples, and 12 species were isolated from fish. The antimicrobial test indicated the highest resistance against sulfamethoxazole and ampicillin in coliform bacteria, and against sulfamethoxazole, imipenem, and aztreonam in known pathogenic bacteria isolated from fish. The most effective antibiotics were rifampicin, chloramphenicol, and tetracycline. The multiple antibiotic resistance index was above the critical limit for almost all of the bacteria isolated. The most common antibiotic resistance gene was ampC, followed by tetA, sul2, blaCTX-M1, and blaTEM in the coliform bacteria. At least one resistance gene was found in 70.8% of the bacteria, and 66.6% of the bacteria had 2 or more resistance genes. Approximately 36.54% of the bacteria that contain plasmids were able to transfer them to other bacteria. The plasmid-mediated transferable resistance genes were ampC, blaCTX-M1, tetA, sul2, and blaTEM. These results indicate that the aquatic environment could play an important role in the development of antibiotic resistance and the dissemination of resistance genes among bacteria.

  7. Evidence of antibiotic resistance in free-swimming, top-level marine predatory fishes.

    PubMed

    Blackburn, Jason K; Mitchell, Mark A; Blackburn, Mary-Claire Holley; Curtis, Andrew; Thompson, Bruce A

    2010-03-01

    Antibiotic resistance in bacteria is a growing problem in both human and veterinary medicine. Several studies documented the presence of resistant bacteria in humans, livestock, and domestic animals; however, limited research is available on the presence of antibiotic drug resistance in wildlife species. A cross-sectional study was conducted to estimate the prevalence of resistant bacteria collected from wild-caught, marine predatory fishes. Seven species of sharks and a single teleost species were opportunistically sampled from six different study sites in coastal Belize, coastal and nearshore waters of Louisiana, the Florida Keys, and Martha's Vineyard, Massachusetts. A total of 134 viable bacteria samples were isolated from the cloacal swabs of predatory fishes. Isolates were characterized by Gram-stain morphology and tested for resistance by using the Kirby-Bauer disc diffusion method. Thirteen drugs (penicillin G, piperacillin, ticarcillin, cefotaxime, ceftazidime, ceftiofur, amikacin, gentamicin, ciprofloxacin, enrofloxacin, doxycycline, chloramphenicol, and sulfamethoxazole) were selected for this study. Prevalence was calculated as the total number of isolates resistant to one or more drugs against the total number of samples in that study area or fish population. Sharks sampled in the Florida Keys exhibited the greatest resistance to a wide selection of drugs. Resistance to at least one drug was found in each of the six study sites and in all of the fish species sampled. Multidrug resistance was also documented in most of the study sites. Interspecific comparisons between redfish, Sciaenops ocellata, and sharks from Louisiana offshore waters (which represent species of the Carcharhinus genus) demonstrated a significantly higher prevalence in redfish, which may be because of the older age of the population. The findings of this study confirmed the presence of antibiotic-resistant bacteria in marine predatory fishes from multiple taxa and multiple geographic

  8. Evidence of antibiotic resistance in free-swimming, top-level marine predatory fishes.

    PubMed

    Blackburn, Jason K; Mitchell, Mark A; Blackburn, Mary-Claire Holley; Curtis, Andrew; Thompson, Bruce A

    2010-03-01

    Antibiotic resistance in bacteria is a growing problem in both human and veterinary medicine. Several studies documented the presence of resistant bacteria in humans, livestock, and domestic animals; however, limited research is available on the presence of antibiotic drug resistance in wildlife species. A cross-sectional study was conducted to estimate the prevalence of resistant bacteria collected from wild-caught, marine predatory fishes. Seven species of sharks and a single teleost species were opportunistically sampled from six different study sites in coastal Belize, coastal and nearshore waters of Louisiana, the Florida Keys, and Martha's Vineyard, Massachusetts. A total of 134 viable bacteria samples were isolated from the cloacal swabs of predatory fishes. Isolates were characterized by Gram-stain morphology and tested for resistance by using the Kirby-Bauer disc diffusion method. Thirteen drugs (penicillin G, piperacillin, ticarcillin, cefotaxime, ceftazidime, ceftiofur, amikacin, gentamicin, ciprofloxacin, enrofloxacin, doxycycline, chloramphenicol, and sulfamethoxazole) were selected for this study. Prevalence was calculated as the total number of isolates resistant to one or more drugs against the total number of samples in that study area or fish population. Sharks sampled in the Florida Keys exhibited the greatest resistance to a wide selection of drugs. Resistance to at least one drug was found in each of the six study sites and in all of the fish species sampled. Multidrug resistance was also documented in most of the study sites. Interspecific comparisons between redfish, Sciaenops ocellata, and sharks from Louisiana offshore waters (which represent species of the Carcharhinus genus) demonstrated a significantly higher prevalence in redfish, which may be because of the older age of the population. The findings of this study confirmed the presence of antibiotic-resistant bacteria in marine predatory fishes from multiple taxa and multiple geographic

  9. Plasmids in antibiotic susceptible and antibiotic resistant commensal Escherichia coli from healthy Australian adults.

    PubMed

    Moran, Robert A; Anantham, Sashindran; Pinyon, Jeremy L; Hall, Ruth M

    2015-07-01

    A collection of 111 commensal Escherichia coli isolated from 84 faecal samples from healthy Australian adults were screened using PCR-based replicon typing. Each isolate represented a distinct strain found in a particular faecal sample. Fifty-one isolates were resistant to one or more of 12 antibiotics tested. FII and FIB replicons were most common and usually found together. The FII replicon was detected in 63 isolates (35 susceptible, 28 resistant), the FIB replicon was present in 65 (32 susceptible, 33 resistant) and 54 (30 susceptible, 24 resistant) included both. Other replicon types were found infrequently (A/C, I1, K, L/M, P, R, Y, FIA and FIC) or not at all (HI1, HI2, N, T, U, W, X). Only the B/O amplicon, found in 21 resistant but only 4 susceptible isolates, was associated with antibiotic resistance. Detailed analysis of this group revealed that the B/O PCR also detected Z plasmids of several distinguishable types. PCR assays were developed to detect the two repA genes (repABKI and repAZ) found in members of the I-complex