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Sample records for acquired antibiotic resistance

  1. Acquired antibiotic resistance genes: an overview.

    OpenAIRE

    Hoek, Angela H.A.M. van; Dik eMevius; Beatriz eGuerra; Peter eMullany; Adam Paul Roberts; Aarts, Henk J. M.

    2011-01-01

    In this review an overview is given on antibiotic resistance mechanisms with special attentions to the antibiotic resistance 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 paid to mobile genetic elements such as plasmids, transposons and integrons, which are associated with antibiotic resistance genes, and involved in the dispersal of anti...

  2. Acquired antibiotic resistance genes:an overview

    NARCIS (Netherlands)

    Hoek, A.H. van; Mevius, D.; Guerra, B.; Mullany, P.; Robberts, A.P.

    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,

  3. Acquired antibiotic resistance genes: an overview

    NARCIS (Netherlands)

    Hoek, van A.H.; Mevius, D.J.; Guerra, B.; Mullany, P.; Roberts, A.P.; Aarts, H.J.

    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,

  4. Acquired Antibiotic Resistance Genes: An Overview

    OpenAIRE

    Hoek, Angela H.A.M. van; 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 betw...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Maria Cristina Thaller

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

  7. Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells

    DEFF Research Database (Denmark)

    Haaber, Jakob Krause; Leisner, Jørgen; Cohn, Marianne Thorup

    2016-01-01

    Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of S....... aureus cells enables the intact, prophage-containing population to acquire beneficial genes from competing, phage-susceptible strains present in the same environment. Phage infection kills competitor cells and bits of their DNA are occasionally captured in viral transducing particles. Return...... of such particles to the prophage-containing population can drive the transfer of genes encoding potentially useful traits such as antibiotic resistance. This process, which can be viewed as ‘auto-transduction’, allows S. aureus to efficiently acquire antibiotic resistance both in vitro and in an in vivo virulence...

  8. Antibiotic Resistance

    Science.gov (United States)

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

  9. Bacterial Etiology and Antibiotic Resistance Profile of Community-Acquired Urinary Tract Infections in a Cameroonian City

    OpenAIRE

    Rolf Nyah-tuku Nzalie; Hortense Kamga Gonsu; Sinata Koulla-Shiro

    2016-01-01

    Introduction. Community-acquired urinary tract infections (CAUTIs) are usually treated empirically. Geographical variations in etiologic agents and their antibiotic sensitivity patterns are common. Knowledge of antibiotic resistance trends is important for improving evidence-based recommendations for empirical treatment of UTIs. Our aim was to determine the major bacterial etiologies of CAUTIs and their antibiotic resistance patterns in a cosmopolitan area of Cameroon for comparison with pres...

  10. Analysis of the Clinical Characteristics and Antibiotics Resistance of Community-acquired Methicillin-resistant Staphylococcus aureus

    Institute of Scientific and Technical Information of China (English)

    章税锋; 徐志江; 王林峰

    2004-01-01

    The purpose of this investigation is to study the clinical characteristics of infections by community-acquired methicillin-resistant Staphylococcus aureus (MRSA) and the condition of antibiotics resistance of the clinical isolates in order to guide for the rational use of antibiotics. With the clinical isolates from cases of hospital-acquired MRSA at the same period as contro|s, the clinical characteristics of infections by community-acquired MRSA in Hangzhou area and the pattern of non-β-lactamase antibiotics resistance were determined in this study. It was found that the average age of patients with community-acquired MRSA infections was 30.89 + 13.3, in comparison with those of the hospital-acquired patients of 56.0 + 11.8, appearing to be younger than those of the latter, and the former showing no any basic illness. Both of the former and the latter were sensitive to vancomycin ( 100% vs 100% ), and they had the same degrees of sensitivity to rifampicin, fosfomycin, and STM/TMP (86.8%vs88.1%, P>0.05; 81.6% vs 82.9%, P>0.05; and 52.6% vs 61.9%, P>0.05, respectively). The former was more sensitive to netimycin, chndamycin, erythromycin and minocycline than those of the latter (73.7% vs50.5%, P<0.01; 60.5% vs45.7%, P<0.05; 28.9% vs 11.4%, P<0.01; and81.6% vs58.6%, P<0.01 respectively). Meanwhile, the incidence of multi-resistant strain of isolates in the former was significantly lowerthan that of the latter (31.6% vs 81.0%, P < 0.01). In conclusion, it appears that the strains of clinical isolates isolated from patients with the community-acquired MRSA infections show different clinical characteristics and antimicrobial susceptibility in comparison with those of the hospital-acquired cases of infection, and this necessitates an alteration in the chemotherapy of infections suspected to be caused by community-acquired MRSA.

  11. Antibiotic resistance in Chlamydiae.

    Science.gov (United States)

    Sandoz, Kelsi M; Rockey, Daniel D

    2010-09-01

    There are few documented reports of antibiotic resistance in Chlamydia and no examples of natural and stable antibiotic resistance in strains collected from humans. While there are several reports of clinical isolates exhibiting resistance to antibiotics, these strains either lost their resistance phenotype in vitro, or lost viability altogether. Differences in procedures for chlamydial culture in the laboratory, low recovery rates of clinical isolates and the unknown significance of heterotypic resistance observed in culture may interfere with the recognition and interpretation of antibiotic resistance. Although antibiotic resistance has not emerged in chlamydiae pathogenic to humans, several lines of evidence suggest they are capable of expressing significant resistant phenotypes. The adept ability of chlamydiae to evolve to antibiotic resistance in vitro is demonstrated by contemporary examples of mutagenesis, recombination and genetic transformation. The isolation of tetracycline-resistant Chlamydia suis strains from pigs also emphasizes their adaptive ability to acquire antibiotic resistance genes when exposed to significant selective pressure.

  12. Bacterial Etiology and Antibiotic Resistance Profile of Community-Acquired Urinary Tract Infections in a Cameroonian City

    Science.gov (United States)

    Gonsu, Hortense Kamga; Koulla-Shiro, Sinata

    2016-01-01

    Introduction. Community-acquired urinary tract infections (CAUTIs) are usually treated empirically. Geographical variations in etiologic agents and their antibiotic sensitivity patterns are common. Knowledge of antibiotic resistance trends is important for improving evidence-based recommendations for empirical treatment of UTIs. Our aim was to determine the major bacterial etiologies of CAUTIs and their antibiotic resistance patterns in a cosmopolitan area of Cameroon for comparison with prescription practices of local physicians. Methods. We performed a cross-sectional descriptive study at two main hospitals in Yaoundé, collecting a clean-catch mid-stream urine sample from 92 patients having a clinical diagnosis of UTI. The empirical antibiotherapy was noted, and identification of bacterial species was done on CLED agar; antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Results. A total of 55 patients had samples positive for a UTI. Ciprofloxacin and amoxicillin/clavulanic acid were the most empirically prescribed antibiotics (30.9% and 23.6%, resp.); bacterial isolates showed high prevalence of resistance to both compounds. Escherichia coli (50.9%) was the most common pathogen, followed by Klebsiella pneumoniae (16.4%). Prevalence of resistance for ciprofloxacin was higher compared to newer quinolones. Conclusions. E. coli and K. pneumoniae were the predominant bacterial etiologies; the prevalence of resistance to commonly prescribed antibiotics was high. PMID:27667998

  13. Risk of resistance related to antibiotic use before admission in patients with community-acquired bacteraemia

    DEFF Research Database (Denmark)

    Pedersen, Gitte; Schønheyder, Henrik Carl; Steffensen, Flemming Hald

    1999-01-01

    %), Streptococcus pneumoniae (23%) Staphylococcus aureus (10%). Of the 575 isolates of E. coli, 425 (74%), 432 (75%) and 518 (90%) were susceptible to ampicillin, sulphonamides and trimethoprim, respectively. Previous antibiotic prescriptions were strongly associated with resistance to ampicillin, sulphonamides...... admission and to 37% during the 6 months. The most frequently prescribed antibiotics within 30 days were ampicillin (28%), penicillin G (27%), sulphonamides and/or trimethoprim (16%) and macrolides (14%). The most frequent blood isolates were Escherichia coli (33%), other Enterobacteriaceae 8...

  14. Plasmid mediated multiple antibiotic resistance in Escherichia coli isolated from community acquired infection of urinary tract in Aligarh Hospital

    Institute of Scientific and Technical Information of China (English)

    Asad U Khan; Saeedut Zafar Ali; Mohammed S Zaman

    2008-01-01

    This study was to investigate the current trends of multiple drug resistance in bacteria against antibiotics for the proper empirical treatmen.Clinical isolates were collected from community-acquired infection of urinary tract patients in Aligarh India from March 1999 to August 1999.Antibiotic susceptibility test was performed,using the disc diffusion method followed by plasmid isolation by the method of Kado and Liu.Transfer experiments were performed by the method of Lederberg and Cohen.Clinical study revealed that this infection was more common in young women.Various strains of E.coli isolated during the course of study were found to show multiple antibiotic resistance which was further characterized as plasmid-borne drug resistance.This study shows that E.coli may be one of the important causative agents of urinary tract infection (UTI )in young women.

  15. Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells

    DEFF Research Database (Denmark)

    Haaber, Jakob; Leisner, Jørgen J; Cohn, Marianne T;

    2016-01-01

    Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of S...

  16. Bacterial viruses enable their host to acquire antibiotic resistance genes from neighbouring cells

    DEFF Research Database (Denmark)

    Haaber, Jakob Krause; Leisner, Jørgen; Cohn, Marianne Thorup;

    2016-01-01

    Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of...

  17. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...... of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I...... to rationally design drug combinations that limit the evolution of antibiotic resistance due to counteracting evolutionary trajectories. My results highlight that an in-depth knowledge about the genetic responses to the individual antimicrobial compounds enables the prediction of responses to drug combinations...

  18. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Hansen, Malene Plejdrup; Hoffmann, Tammy C; McCullough, Amanda R

    2015-01-01

    Numerous opportunities are available in primary care for alleviating the crisis of increasing antibiotic resistance. Preventing patients from developing an acute respiratory infection (ARI) will obviate any need for antibiotic use downstream. Hygiene measures such as physical barriers and hand...... wrong. Shared decision making might be a solution, as it enables clinician and patient to participate jointly in making a health decision, having discussed the options together with the evidence for their harms as well as benefits. Furthermore, GPs' diagnostic uncertainty - often leading...... will greatly improve the use of antibiotics for ARIs. However, used in concert, combinations are likely to enable clinicians and health care systems to implement the strategies that will reduce antimicrobial resistance in the future....

  19. Quinolone resistant Aeromonas spp. as carriers and potential tracers of acquired antibiotic resistance in hospital and municipal wastewater.

    Science.gov (United States)

    Varela, Ana Rita; Nunes, Olga C; Manaia, Célia M

    2016-01-15

    Members of the genus Aeromonas are recognized carriers of antibiotic resistance in aquatic environments. However, their importance on the spread of resistance from hospital effluents to the environment is poorly understood. Quinolone resistant Aeromonas spp. (n = 112) isolated from hospital effluent (HE) and from raw (RWW) and treated wastewater (TWW) of the receiving urban wastewater treatment plant (UWTP) were characterized. Species identification and genetic intraspecies diversity were assessed based on the 16S rRNA, cpn60 and gyrB genes sequence analysis. The antibiotic resistance phenotypes and genotypes (qnrA, qnrB, qnrC, qnrD, qnrS, qnrVC; qepA; oqxAB; aac(6′)-Ib-cr; blaOXA; incU) were analyzed in function of the origin and taxonomic group. Most isolates belonged to the species Aeromonas caviae and Aeromonas hydrophila (50% and 41%, respectively). The quinolone and the beta-lactamase resistance genes aac(6′)-Ib-cr and blaOXA, including gene blaOXA-101, identified for the first time in Aeromonas spp., were detected in 58% and 56% of the isolates, respectively, with identical prevalence in HE and UWTP wastewater. In contrast, the gene qnrS2 was observed mainly in isolates from the UWTP (51%) and rarely in HE isolates (3%), suggesting that its origin is not the clinical setting. Bacterial groups and genes that allow the identification of major routes of antibiotic resistance dissemination are valuable tools to control this problem. In this study, it was concluded that members of the genus Aeromonas harboring the genes aac(6′)-Ib-cr and blaOXA are relevant tracers of antibiotic resistance dissemination in wastewater habitats, while those yielding the gene qnrS2 allow the traceability from non-clinical sources.

  20. Resistance-resistant antibiotics.

    Science.gov (United States)

    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.

  1. Molecular mechanisms of antibiotic resistance.

    Science.gov (United States)

    Blair, Jessica M A; Webber, Mark A; Baylay, Alison J; Ogbolu, David O; Piddock, Laura J V

    2015-01-01

    Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  3. Facts about Antibiotic Resistance

    Science.gov (United States)

    ... Cost References Español: Datos breves Facts about Antibiotic Resistance Antibiotic resistance is one of the world’s most pressing public ... antibiotic use is a key strategy to control antibiotic resistance. Antibiotic resistance in children and older adults are ...

  4. The Antibiotic Resistance Profiles of Bacterial Strains Isolated from Patients with Hospital-Acquired Bloodstream and Urinary Tract Infections

    Directory of Open Access Journals (Sweden)

    Hamed Ghadiri

    2012-01-01

    Full Text Available Treatment of nosocomial infections is becoming difficult due to the increasing trend of antibiotics resistance. Current knowledge on antibiotic resistance pattern is essential for appropriate therapy. We aimed to evaluate antibiotic resistance profiles in nosocomial bloodstream and urinary tract pathogens. A total of 129 blood stream and 300 urinary tract positive samples were obtained from patients referring to Besat hospital over a two-year period (2009 and 2010. Antibiotic sensitivity was ascertained using the Kirby-Bauer disk diffusion technique according to CLSI guidelines. Patient's data such as gender and age were recorded. The ratio of gram-negative to gram-positive bacteria in BSIs was 1.6 : 1. The most prevalent BSI pathogen was Coagulase-Negative Staphylococci (CoNS. The highest resistance rate of CoNS was against penicillin (91.1% followed by ampicillin (75.6%, and the lowest rate was against vancomycin (4.4%. Escherichia coli was the most prevalent pathogen isolated from urinary tract infections (UTIs. Ratio of gram-negative to gram-positive bacteria was 3.2 : 1. The highest resistance rate of E. coli isolates was against nalidixic acid (57.7%. The present study showed that CoNS and E. coli are the most common causative agents of nosocomial BSIs and UTIs, and control of infection needs to be addressed in both antibiotic prescription and general hygiene.

  5. Antibiotic / Antimicrobial Resistance Glossary

    Science.gov (United States)

    ... Submit Search The CDC Get Smart: Know When Antibiotics Work Note: Javascript is disabled or is not ... What Everyone Should Know What You Can Do Antibiotic Resistance Q&As Fast Facts Antibiotics Quiz Glossary ...

  6. Resistance to antibiotics

    OpenAIRE

    1999-01-01

    The antibiotics represent the most important therapeutic arsenal in the fight against pathogen microorganisms. Even in the beginning of their use, there was registered bacterial resistance, phenomenon thatbecame an alarming subject in the last decades. There are some types of resistance to antibiotics that are influenced by many factors. The resistance term can be used as microbiological resistance and clinical resistance. The resistance to antibiotics can be a natural phenomenon or a gained ...

  7. Surveillance of Antibiotic Resistance among Hospital- and Community-Acquired Toxigenic Clostridium difficile Isolates over 5-Year Period in Kuwait

    Science.gov (United States)

    Jamal, Wafaa Y.; Rotimi, Vincent O.

    2016-01-01

    Clostridium difficile infection (CDI) is a leading and an important cause of diarrhea in a healthcare setting especially in industrialized countries. Community-associated CDI appears to add to the burden on healthcare setting problems. The aim of the study was to investigate the antimicrobial resistance of healthcare-associated and community-acquired C. difficile infection over 5 years (2008–2012) in Kuwait. A total of 111 hospital-acquired (HA-CD) and 35 community-acquired Clostridium difficile (CA-CD) clinical isolates from stool of patients with diarrhoea were studied. Antimicrobial susceptibility testing of 15 antimicrobial agents against these pathogens was performed using E test method. There was no evidence of resistance to amoxicillin-clavulanic acid, daptomycin, linezolid, piperacillin-tazobactam, teicoplanin and vancomycin by both HA-CD and CA-CD isolates. Metronidazole had excellent activity against CA-CD but there was a 2.9% resistance rate against HA-CD isolates. Ampicillin, clindamycin, levofloxacin and imipenem resistance rates among the HC-CD vs. CA-CD isolates were 100 vs. 47.4%; 43 vs. 47.4%; 100 vs. 100% and 100 vs. 89%, respectively. An unexpected high rifampicin resistance rate of 15.7% emerged amongst the HA-CD isolates. In conclusion, vancomycin resistance amongst the HA-CD and CA-CD isolates was not encountered in this series but few metronidazole resistant hospital isolates were isolated. High resistance rates of ampicillin, clindamycin, levofloxacin, and imipenem resistance were evident among both CA-CD and HA-CD isolates. Rifampicin resistance is emerging among the HA-CD isolates. PMID:27536994

  8. Spread of community-acquired meticillin-resistant Staphylococcus aureus skin and soft-tissue infection within a family: implications for antibiotic therapy and prevention.

    LENUS (Irish Health Repository)

    Amir, N H

    2010-04-01

    Outbreaks or clusters of community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) within families have been reported. We describe a family cluster of CA-MRSA skin and soft-tissue infection where CA-MRSA was suspected because of recurrent infections which failed to respond to flucloxacillin. While the prevalence of CA-MRSA is low worldwide, CA-MRSA should be considered in certain circumstances depending on clinical presentation and risk assessment. Surveillance cultures of family contacts of patients with MRSA should be considered to help establish the prevalence of CA-MRSA and to inform the optimal choice of empiric antibiotic treatment.

  9. Mechanisms of intrinsic resistance and acquired susceptibility of Pseudomonas aeruginosa isolated from cystic fibrosis patients to temocillin, a revived antibiotic

    Science.gov (United States)

    Chalhoub, Hussein; Pletzer, Daniel; Weingart, Helge; Braun, Yvonne; Tunney, Michael M.; Elborn, J. Stuart; Rodriguez-Villalobos, Hector; Plésiat, Patrick; Kahl, Barbara C.; Denis, Olivier; Winterhalter, Mathias; Tulkens, Paul M.; Van Bambeke, Françoise

    2017-01-01

    The β-lactam antibiotic temocillin (6-α-methoxy-ticarcillin) shows stability to most extended spectrum β-lactamases, but is considered inactive against Pseudomonas aeruginosa. Mutations in the MexAB-OprM efflux system, naturally occurring in cystic fibrosis (CF) isolates, have been previously shown to reverse this intrinsic resistance. In the present study, we measured temocillin activity in a large collection (n = 333) of P. aeruginosa CF isolates. 29% of the isolates had MICs ≤ 16 mg/L (proposed clinical breakpoint for temocillin). Mutations were observed in mexA or mexB in isolates for which temocillin MIC was ≤512 mg/L (nucleotide insertions or deletions, premature termination, tandem repeat, nonstop, and missense mutations). A correlation was observed between temocillin MICs and efflux rate of N-phenyl-1-naphthylamine (MexAB-OprM fluorescent substrate) and extracellular exopolysaccharide abundance (contributing to a mucoid phenotype). OpdK or OpdF anion-specific porins expression decreased temocillin MIC by ~1 two-fold dilution only. Contrarily to the common assumption that temocillin is inactive on P. aeruginosa, we show here clinically-exploitable MICs on a non-negligible proportion of CF isolates, explained by a wide diversity of mutations in mexA and/or mexB. In a broader context, this work contributes to increase our understanding of MexAB-OprM functionality and help delineating how antibiotics interact with MexA and MexB. PMID:28091521

  10. Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    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)

  11. Hospital-acquired Pneumonia due to Achromobacter spp. in a Geriatric Ward in China: Clinical Characteristics, Biofilm Production, Antibiotic Resistance and Integrons of Isolated Strains.

    Directory of Open Access Journals (Sweden)

    Xiangqun eFang

    2016-05-01

    Full Text Available Background: Hospital-acquired pneumonia (HAP due to Achromobacter has become a substantial concern in recent years. However, HAP due to Achromobacter in the elderly is rare.Methods: A retrospective analysis was performed on 15 elderly patients with HAP due to Achromobacter spp., in which the sequence types (STs, integrons, biofilm production and antibiotic resistance of the Achromobacter spp. were examined. Results: The mean age of the 15 elderly patients was 88.8±5.4 years. All patients had at least 3 underlying diseases and catheters. Clinical outcomes improved in 10 of the 15 patients after antibiotic and/or mechanical ventilation treatment, but three patients had chronic infections lasting more than 1 year. The mortality rate was 33.3% (5/15. All strains were resistant to aminoglycosides, aztreonam, nitrofurantoin, and third- and fourth-generation cephalosporins (except ceftazidime and cefoperazone. Six new STs were detected. The most frequent ST was ST306. ST5 was identified in two separate buildings of the hospital. ST313 showed higher MIC in cephalosporins, quinolones and carbapenems, which should be more closely considered in clinical practice. All strains produced biofilm and had integron I and blaOXA-114-like. The main type was blaOXA-114q. The variable region of integron I was different among strains, and the resistance gene of the aminoglycosides was most commonly inserted in integron I. Additionally, blaPSE-1 was first reported in this isolate. Conclusion: Achromobacter spp. infection often occurs in severely ill elders with underlying diseases. The variable region of integrons differs, suggesting that Achromobacter spp. is a reservoir of various resistance genes.

  12. Tetracycline Antibiotics and Resistance.

    Science.gov (United States)

    Grossman, Trudy H

    2016-04-01

    Tetracyclines possess many properties considered ideal for antibiotic drugs, including activity against Gram-positive and -negative pathogens, proven clinical safety, acceptable tolerability, and the availability of intravenous (IV) and oral formulations for most members of the class. As with all antibiotic classes, the antimicrobial activities of tetracyclines are subject to both class-specific and intrinsic antibiotic-resistance mechanisms. Since the discovery of the first tetracyclines more than 60 years ago, ongoing optimization of the core scaffold has produced tetracyclines in clinical use and development that are capable of thwarting many of these resistance mechanisms. New chemistry approaches have enabled the creation of synthetic derivatives with improved in vitro potency and in vivo efficacy, ensuring that the full potential of the class can be explored for use against current and emerging multidrug-resistant (MDR) pathogens, including carbapenem-resistant Enterobacteriaceae, MDR Acinetobacter species, and Pseudomonas aeruginosa.

  13. Antibiotic Resistance in Pediatric Urinary Tract Infections.

    Science.gov (United States)

    Stultz, Jeremy S; Doern, Christopher D; Godbout, Emily

    2016-12-01

    Urinary tract infections (UTIs) are a common problem in pediatric patients. Resistance to common antibiotic agents appears to be increasing over time, although resistance rates may vary based on geographic region or country. Prior antibiotic exposure is a pertinent risk factor for acquiring resistant organisms during a first UTI and recurrent UTI. Judicious prescribing of antibiotics for common pediatric conditions is needed to prevent additional resistance from occurring. Complex pediatric patients with histories of hospitalizations, prior antibiotic exposure, and recurrent UTIs are also at high risk for acquiring UTIs due to extended spectrum beta-lactamase-producing organisms. Data regarding the impact of in vitro antibiotic susceptibility testing interpretation on UTI treatment outcomes is lacking.

  14. Antibiotic Resistance Questions and Answers

    Science.gov (United States)

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

  15. Mutation Landscape of Acquired Cross-Resistance to Glycopeptide and β-Lactam Antibiotics in Enterococcus faecium

    Science.gov (United States)

    Sacco, Emmanuelle; Cortes, Mélanie; Josseaume, Nathalie; Bouchier, Christiane; Dubée, Vincent; Hugonnet, Jean-Emmanuel; Mainardi, Jean-Luc; Rice, Louis B.

    2015-01-01

    Bypass of the d,d-transpeptidase activity of penicillin-binding proteins by an l,d-transpeptidase (Ldtfm) results in resistance to ampicillin and glycopeptides in Enterococcus faecium M9, a mutant obtained by nine consecutive selection steps. Resistance requires activation of a cryptic locus for production of the essential tetrapeptide-containing substrate of Ldtfm and impaired activity of protein phosphatase StpA. Here, whole-genome sequencing revealed a high mutation rate for the entire selection procedure (79 mutations in 900 generations). Acquisition of a mutation in the mismatch repair gene mutL had little impact on the frequency of rifampin-resistant mutants although the mutation spectrum of M9 was typical of impaired MutL with high transversion to transition (40/11) and substitution to deletion (51/28) ratios. M9 did not mainly accumulate neutral mutations since base substitutions occurred more frequently in coding sequences than expected (χ2 = 5.0; P < 0.05) and silent mutations were underrepresented (χ2 = 5.72; P < 0.02). None of the mutations directly affected recognition of the tetrapeptide substrate of Ldtfm by peptidoglycan synthesis enzymes. Instead, mutations appear to remodel regulatory circuits involving two-component regulatory systems and sugar metabolism. The high number of mutations required for activation of the l,d-transpeptidase pathway may strongly limit emergence of cross-resistance to ampicillin and glycopeptides by this mechanism. PMID:26077262

  16. Mission Critical: Preventing Antibiotic Resistance

    Science.gov (United States)

    ... Button Past Emails CDC Features Mission Critical: Preventing Antibiotic Resistance Recommend on Facebook Tweet Share Compartir Can you ... spp. So, what can we do to prevent antibiotic resistance in healthcare settings? Patients, healthcare providers, healthcare facility ...

  17. Antibiotic-Resistant Gonorrhea (ARG)

    Science.gov (United States)

    ... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Basic Information Recommend on Facebook Tweet ... Page Surveillance Trends and Treatment Challenges Laboratory Issues Antibiotic resistance (AR) is the ability of bacteria to ...

  18. Investigating the Antibiotic Resistance Problem.

    Science.gov (United States)

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

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

  19. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

    Directory of Open Access Journals (Sweden)

    Suresh Jaiswal et al.

    2012-03-01

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

  20. Bacteriology of hospital-acquired infection and antibiotic resistance in a hospital university of Bushehr Port Fatemeh Zahra (s in 2002-2003

    Directory of Open Access Journals (Sweden)

    Katayoon Vahdat

    2005-02-01

    Full Text Available Nosocomial infection is an increasing problem. The global problem of antimicrobial resistance is particularly pressing in developing countries, where the infectious disease burden is high and cost constraints prevent the widespread application of newer, more expensive agents. In a prospective study, 203 consecutive cases with hospital-acquired infection in a university hospital in Bushehr port were evaluated. The most common hospital-acquired infection was urinary (76 cases, conjunctivitis (16 cases, bacteremia (8 cases, meningitis (5 cases, wound (3 cases, empyema (2 cases and peritonitis (1 case. The patients with hospital-acquired infection were from surgical and internal medicine I.C.Us (53.2% & 15.6%, respectively. The most frequent isolated organisms were Pseudomonas aeruginosa (25.6%, Acinetobacter baumannii (19.7%, E. coli (13.3%, Klebsiella pneumoniae (11.3%, Staphylococcus aureus (8.4%, Staphylococcus epidermidis (7.9%, Enterobacter species (7%, Streptococcus species (6.4%, and Proteus mirabilis (0.5%. The most resistant organisms to antimicrobial agents were Acinetobacter baumannii and Pseudomonas aeruginosa 97 & 93.3% of these bacteria were resistant to third generation cephalosporins. The isolated Staphylococcal species were resistant to amikacin (94%. In conclusion, gram negative bacteria were the most common etiologic agent of hospital-acquired infection and had a high level of resistance to amikacin and third generation cephalosporins. Therefore, new therapeutic strategies should be designed to combat these microorganisms.

  1. Mechanisms of polymyxin resistance: acquired and intrinsic resistance in bacteria

    Directory of Open Access Journals (Sweden)

    Abiola Olumuyiwa Olaitan

    2014-11-01

    Full Text Available Polymyxins are polycationic antimicrobial peptides that are currently the last-resort antibiotics for the treatment of multidrug-resistant, Gram-negative bacterial infections. The reintroduction of polymyxins for antimicrobial therapy has been followed by an increase in reports of resistance among Gram-negative bacteria. Some bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii, develop resistance to polymyxins in a process referred to as acquired resistance, whereas other bacteria, such as Proteus spp., Serratia spp. and Burkholderia spp., are naturally resistant to these drugs. Reports of polymyxin resistance in clinical isolates have recently increased, including acquired and intrinsically resistant pathogens. This increase is considered a serious issue, prompting concern due to the low number of currently available effective antibiotics. This review summarizes current knowledge concerning the different strategies bacteria employ to resist the activities of polymyxins.Gram-negative bacteria employ several strategies to protect themselves from polymyxin antibiotics (polymyxin B and colistin, including a variety of lipopolysaccharide (LPS modifications, such as modifications of lipid A with phosphoethanolamine and 4-amino-4-deoxy-L-arabinose, in addition to the use of efflux pumps, the formation of capsules and overexpression of the outer membrane protein OprH, which are all effectively regulated at the molecular level. The increased understanding of these mechanisms is extremely vital and timely to facilitate studies of antimicrobial peptides and find new potential drugs targeting clinically relevant Gram-negative bacteria.

  2. Selective decontamination and antibiotic resistance in ICUs

    NARCIS (Netherlands)

    Plantinga, Nienke L.; Bonten, Marc J. M.

    2015-01-01

    Selective digestive decontamination (SDD) and selective oropharyngeal decontamination (SOD) have been associated with reduced mortality and lower ICU-acquired bacteremia and ventilator-associated pneumonia rates in areas with low levels of antibiotic resistance. However, the effect of selective deco

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

    Science.gov (United States)

    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.

  4. Applying the ResFinder and VirulenceFinder web-services for easy identification of acquired antibiotic resistance and E. coli virulence genes in bacteriophage and prophage nucleotide sequences

    DEFF Research Database (Denmark)

    Kleinheinz, Kortine Annina; Joensen, Katrine Grimstrup; Larsen, Mette Voldby

    2014-01-01

    raised that this increased use and dissemination of phages could result in spread of deleterious genes, e.g., antibiotic resistance and virulence genes. Meanwhile, in the wake of the genomic era, several tools have been developed for characterization of bacterial genomes. Here we describe how two...... of these tools, ResFinder and VirulenceFinder, can be used to identify acquired antibiotic resistance and virulence genes in phage genomes of interest. The general applicability of the tools is demonstrated on data sets of 1,642 phage genomes and 1,442 predicted prophages.......Extensive research is currently being conducted on the use of bacteriophages for applications in human medicine, agriculture and food manufacturing. However, phages are important vehicles of horisontal gene transfer and play a significant role in bacterial evolution. As a result, concern has been...

  5. Handling Time-dependent Variables : Antibiotics and Antibiotic Resistance

    NARCIS (Netherlands)

    Munoz-Price, L. Silvia; Frencken, Jos F.; Tarima, Sergey; Bonten, Marc

    2016-01-01

    Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods, antibi

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

    Science.gov (United States)

    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.

  7. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    NARCIS (Netherlands)

    Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David

    2016-01-01

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This

  8. Epidemiology of antibiotic resistance in Burkina Faso

    Institute of Scientific and Technical Information of China (English)

    Simpore J; Zeba B; Karou D; Ilboudo D; Pignatelli S; Nacoulma OG; Musumeci S

    2008-01-01

    Burkina Faso (West Africa)is a tropical country with a high incidence of infectious diseases.The uncontrolled use of antibiotics against bacterial pathogens has given rise to the emergence of antibiotic resistance in this country.The aims of this study were.i)to determine the prevalences of the most important pathogenic bacteri-a,isolated in the town of Ouagadougou.ii)to identify the bacterial species which have acquired resistance as a result of antibiotic selection.iii)to compare antibiotic-resistances ofEscherichia coli isolated from stool cul-ture in the present study,with results obtained in 2002 from strains collected in the same structure in Burkina Faso.iv)to determine the trend of antibiotic resistance in Burkina Faso in order to give local advice on the most appropriate empiric antibiotic therapy.Six thousand two hundred and sixty four samples of blood,stools, urine,sputum,pus and vaginal secretion were collected and analyzed in Saint Camille Medical Center (SC-MC)laboratory from May 2001 to May 2006.Out of the 6264 samples tested no pathogen was identified in 1583 (25.31%),whilst 4681 (74.73%)were positive,with the incidence of the microrganisms isolated be-ing as follows:Escherichia coli 1291 (27.6%),Staphylococcus aureus 922 (19.7%),Salmonella spp 561 (12.0%),Streptococcus spp 499 (10.7%),Klebsiella spp 359 (7.7%),Shigella spp (6.3%),Acineto-bacter spp 266 (5.7%)and others 783 (16.7%).Among the isolated pathogens,the highest resistance was found to Amoxycillin:Proteus spp 95.6%,Escherichia coli 78.2%,Salmonella spp 62.2%,Shigella spp 73. 4% and Klebsiella spp 89.9%,followed by resistance to Ampicillin and cotrimoxazole.Comparing the preva-lence of antibiotic resistance of Escherichia coli from stool cultures isolated during 1999-2000 to that of 2001-2006,a significant reduction was found,which could be due to the improved use of antibiotics in recent years. The reduced antibiotic-resistance observed in pathogens isolated in Burkina Faso during this

  9. What Can Be Done about Antibiotic Resistance?

    Science.gov (United States)

    ... Us General Background: What can be done about Antibiotic Resistance? What can I do? Are antibacterial agents, such ... regulated? Is there any international action on the antibiotic resistance issue? Can the effectiveness of existing antibiotics be ...

  10. Antibiotics and the resistant microbiome

    DEFF Research Database (Denmark)

    Sommer, Morten; Dantas, Gautam

    2011-01-01

    . Less appreciated are the concomitant changes in the human microbiome in response to these assaults and their contribution to clinical resistance problems. Studies have shown that pervasive changes to the human microbiota result from antibiotic treatment and that resistant strains can persist for years....... Additionally, culture-independent functional characterization of the resistance genes from the microbiome has demonstrated a close evolutionary relationship between resistance genes in the microbiome and in pathogens. Application of these techniques and novel cultivation methods are expected to significantly...... expand our understanding of the interplay between antibiotics and the microbiome....

  11. Antibiotic resistance: An ethical challenge.

    Science.gov (United States)

    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.

  12. Bacterial vaccines and antibiotic resistance

    OpenAIRE

    Henriques-Normark, Birgitta; Normark, Staffan

    2014-01-01

    Spread of antibiotic resistance is mediated by clonal lineages of bacteria that besides being resistant also possess other properties promoting their success. Some vaccines already in use, such as the pneumococcal conjugate vaccines, have had an effect on these successful clones, but at the same time have allowed for the expansion and resistance evolution of previously minor clones not covered by the vaccine. Since resistance frequently is horizontally transferred it will be difficult to gene...

  13. Antibiotic resistance in Salmonella

    NARCIS (Netherlands)

    Vo, A.T.T.

    2007-01-01

    Immediately after their introduction in the beginning of the fourties of the previous century, the agents used to combat infectious diseases caused by bacteria were regarded with suspicion, but not long thereafter antibiotics had the status of miracle drugs. For decades mankind has lived under the i

  14. Antibiotic resistance in probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miguel eGueimonde

    2013-07-01

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

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

    Science.gov (United States)

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

    2016-03-17

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

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

    Directory of Open Access Journals (Sweden)

    Saswati eSengupta

    2013-03-01

    Full Text Available Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic-resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic-resistance in pathogens. In the natural milieu, antibiotics are often found to be present in subinhibitory concentrations acting as signalling molecules supporting quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell and so on. The evolutionary and ecological aspects of antibiotics and antibiotic-resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behaviour of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and genes that confer resistance to antibiotics in

  17. Antibiotic resistance of Acinetobacter baumannii causing hospital acquired pneumonia in patients with COPD%鲍氏不动杆菌致COPD患者继发医院获得性肺炎的耐药性分析

    Institute of Scientific and Technical Information of China (English)

    黄娥; 范文

    2012-01-01

    目的 了解医院慢性阻塞性肺疾病(COPD)患者肺部感染鲍氏不动杆菌(ABA)的耐药性,为临床医师合理用药提供试验依据.方法 鲍氏不动杆菌培养鉴定严格按照《全国临床检验操作规程》进行;药物敏感试验采用K-B法,结果判断按照CLSI折点评价;采用WHONET最新版本分析试验数据.结果 162株ABA对β-内酰胺类/β-内酰胺酶抑制剂复合制剂敏感率为66.0%~68.5%,对其他常用抗菌药物包括碳青霉烯类抗菌药物已产生了严重的耐药性;ABA泛耐药株检出率为23.5%.结论 临床医护人员应加强监控力度,遏制鲍氏不动杆菌医院感染的暴发流行.%OBJECTIVE To understand the antibiotic resistance of Acinetobacter baumannii (ABA) causing hospital-acquired pneumonia in patients with chronic obstructive pulmonary diseases (COPD) and provide the experimental evidence for rational use of antibiotics. METHODS Referring to national guide to clinical laboratory procedures, ABA were cultured and identified. The antibiotic susceptibility testing was performed by K-B methods. The susceptibility testing results were assessed according to CLSI breakpoints and analyzed statistically by new version WHONET software. RESULTS The susceptibility rates of bata-lactam antibiotic in combination with bata-lactamase inhibitors (cefoperazone/sulbactam, piperacillin/tazobactam) against 162 strains of ABA were high, varying from 66. 0% to 68. 5%. Serious antibiotic resistance occurred in other commonly used antibiotics including carbopenems. The detection rate of pan-resistant strains was 23. 5%. CONCLUSION Clinical staffs should strengthen the monitoring and controlling to restrain outbreak and prevalence of ABA causing nosocomial infections.

  18. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions

    DEFF Research Database (Denmark)

    Leibovici, Leonard; Paul, Mical; Garner, Paul

    2016-01-01

    be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized......Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies...

  19. Advances in pneumococcal antibiotic resistance.

    Science.gov (United States)

    Song, Jae-Hoon

    2013-10-01

    Antimicrobial resistance and serotypes in Streptococcus pneumoniae have been evolving with the widespread use of antibiotics and the introduction of pneumococcal conjugate vaccines (PCV). Particularly, among various types of antimicrobial resistance, macrolide resistance has most remarkably increased in many parts of the world, which has been reported to be >70% among clinical isolates from Asian countries. Penicillin resistance has dramatically decreased among nonmeningeal isolates due to the changes in resistance breakpoints, although resistance to other β-lactams such as cefuroxime has increased. Multidrug resistance became a serious concern in the treatment of invasive pneumococcal diseases, especially in Asian countries. After PCV7 vaccination, serotype 19A has emerged as an important cause of invasive pneumococcal diseases which was also associated with increasing prevalence of multidrug resistance in pneumococci. Widespread use of PCV13, which covers additional serotypes 3, 6A and 19A, may contribute to reduce the clonal spread of drug-resistant 19A pneumococci.

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

    Science.gov (United States)

    Sandegren, Linus

    2014-05-01

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

  1. Combination antibiotic therapy for community-acquired pneumonia

    OpenAIRE

    Caballero, Jesus; Rello, Jordi

    2011-01-01

    Community-acquired pneumonia (CAP) is a common and potentially serious illness that is associated with morbidity and mortality. Although medical care has improved during the past decades, it is still potentially lethal. Streptococcus pneumoniae is the most frequent microorganism isolated. Treatment includes mandatory antibiotic therapy and organ support as needed. There are several antibiotic therapy regimens that include β-lactams or macrolides or fluoroquinolones alone or in combination. Co...

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

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

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

    2013-01-01

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

  4. Antibiotics and Resistance: Glossary

    Science.gov (United States)

    ... chromosomes and plasmids. Transposons often carry genes specifying antimicrobial resistance. Virus An extremely small infective agent, visible only with an electron microscope. Viruses can cause disease in humans, animals and plants. Viruses consist of a protein coat ...

  5. Dielectrophoretic assay of bacterial resistance to antibiotics

    Energy Technology Data Exchange (ETDEWEB)

    Johari, Juliana [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Huebner, Yvonne [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hull, Judith C [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Dale, Jeremy W [School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom); Hughes, Michael P [School of Engineering, University of Surrey, Guildford, Surrey, GU2 7XH, UK (United Kingdom)

    2003-07-21

    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. (note)

  6. Antibiotic Resistance and Fungus

    Centers for Disease Control (CDC) Podcasts

    2017-02-28

    Dr. David Denning, President of the Global Action Fund for Fungal Infections and an infectious diseases clinician, discusses antimicrobial resistance and fungus.  Created: 2/28/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/28/2017.

  7. Addressing resistance to antibiotics in systematic reviews of antibiotic interventions.

    Science.gov (United States)

    Leibovici, Leonard; Paul, Mical; Garner, Paul; Sinclair, David J; Afshari, Arash; Pace, Nathan Leon; Cullum, Nicky; Williams, Hywel C; Smyth, Alan; Skoetz, Nicole; Del Mar, Chris; Schilder, Anne G M; Yahav, Dafna; Tovey, David

    2016-09-01

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies. This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should be reported and taken into account when interpreting results. Data on emergence of resistance (whether in the body reservoirs or in the bacteria causing infection) are important outcomes. Emergence of resistance should be taken into account when interpreting the evidence on antibiotic treatment in randomized controlled trials or systematic reviews.

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

    NARCIS (Netherlands)

    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 cl

  9. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

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

    2010-01-01

    and other components of the body's defence system. The persistence of, for example, staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infection in cystic fibrosis patients is caused by biofilm-growing mucoid strains...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...

  10. Priorities for antibiotic resistance surveillance in Europe

    DEFF Research Database (Denmark)

    Fluit, A. C.; van der Bruggen, J. T.; Aarestrup, Frank Møller

    2006-01-01

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

  11. Environmental pollution by antibiotics and by antibiotic resistance determinants

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jose Luis, E-mail: jlmtnez@cnb.csic.e [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)

    2009-11-15

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

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

    Science.gov (United States)

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

    2011-11-01

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

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

    KAUST Repository

    Hong, Pei-Ying

    2013-07-31

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

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

    Science.gov (United States)

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

    2013-07-31

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

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

    Directory of Open Access Journals (Sweden)

    Roderick I. Mackie

    2013-07-01

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

  16. The determinants of the antibiotic resistance process

    Directory of Open Access Journals (Sweden)

    Beatriz Espinosa Franco

    2009-04-01

    Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: 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.Keywords: antibiotic drug resistance

  17. Antibiotic resistance in cancer patients.

    Science.gov (United States)

    Gudiol, Carlota; Carratalà, Jordi

    2014-08-01

    Bacterial infection is one of the most frequent complications in cancer patients and hematopoietic stem cell transplant recipients. In recent years, the emergence of antimicrobial resistance has become a significant problem worldwide, and cancer patients are among those affected. Treatment of infections due to multidrug-resistant (MDR) bacteria represents a clinical challenge, especially in the case of Gram-negative bacilli, since the therapeutic options are often very limited. As the antibiotics active against MDR bacteria present several disadvantages (limited clinical experience, higher incidence of adverse effects, and less knowledge of the pharmacokinetics of the drug), a thorough acquaintance with the main characteristics of these drugs is mandatory in order to provide safe treatment to cancer patients with MDR bacterial infections. Nevertheless, the implementation of antibiotic stewardship programs and infection control measures is the cornerstone for controlling the development and spread of these MDR pathogens.

  18. Controlling antibiotic resistance in the ICU

    NARCIS (Netherlands)

    Derde, L.P.G.

    2013-01-01

    Patients admitted to intensive care units (ICUs) are frequently colonized with (antibiotic-resistant) bacteria, which may lead to healthcare associated infections. Antimicrobial-resistant bacteria (AMRB), such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (V

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

    Directory of Open Access Journals (Sweden)

    Jose Luis eBalcazar

    2015-10-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  1. Origins and evolution of antibiotic resistance.

    Science.gov (United States)

    Davies, Julian; Davies, Dorothy

    2010-09-01

    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.

  2. Probiotic approach to prevent antibiotic resistance.

    Science.gov (United States)

    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.

  3. Integron involvement in environmental spread of antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Thibault eStalder

    2012-04-01

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

  4. Antibiotic Resistance in Human Chronic Periodontitis Microbiota

    NARCIS (Netherlands)

    Rams, Thomas E.; Degener, John E.; van Winkelhoff, Arie J.

    2014-01-01

    Background: Patients with chronic periodontitis (CP) may yield multiple species of putative periodontal bacterial pathogens that vary in their antibiotic drug susceptibility. This study determines the occurrence of in vitro antibiotic resistance among selected subgingival periodontal pathogens in pa

  5. 儿童社区获得性肺炎323例病原菌分布与耐药性研究%Detection of pathogenic bacteria and antibiotic resistance in 323 children with community acquired pneumonia

    Institute of Scientific and Technical Information of China (English)

    王军; 郭丽萍; 汤进; 马维维

    2011-01-01

    目的 了解2008-2010年于本院住院的儿童社区获得性肺炎(community acquired pneumonia,CAP)病原菌分布及耐药情况 方法 采用法国梅里埃ATB expression鉴定及药敏仪,对儿童CAP患儿进行痰细菌培养、鉴定及药物敏感试验 结果 被检出的323株细菌结果中,G+球菌占38 4%,其中主要为肺炎链球菌(streptococcus pneumoniae,SP)(27 9%),金黄色葡萄球菌(staphylococcus aureus,SA)(10 5%);G-杆菌占61 6%,最常见的是大肠埃希菌(escherichia coli,E coli) (24 5%),肺炎克雷伯杆菌(klebsiella pneumoniae,K pn)(13 9%),流感嗜血杆菌(haemophilus influenzae,HI)(8%) SP感染率>6月患儿与<6月患儿有非常显著差异,且在>6月患儿各年龄组居首位 E coli和K pn感染率随着年龄增长下降,<6月与>6月患儿之间有显著差异 产ESBLs株的K pn和E coli检出率高达71 1%和77 2%;HI对氨苄西林的耐药率为66 7%;而SP对红霉素的耐药率高达98 9% 结论 本地区下呼吸道感染的细菌病原学的分布及变化,耐药情况,对合理选择抗生素,减缓耐药菌产生具有重要意义.%[Objective] To provide reference for the treatment for clinicians during the recent two years investigation of bacterial and antibiotic resistance analysis of hospitalized children with community acquired pneumonia(CAP)in some are-as of Hanzhong. [Method] The sputum bacterial culture, identification and drug sensitive test were made for children with CAP by rench Merieux ATB expression identification and susceptibility meter. [Results] Of the 323 strains of bacterial pathogens, 11 kinds of bacterial pathogens were isolated. Gram-positive cocci accounted for 38. 4%. Of them were streptococcus pneumoniae (SP) (27. 9%) and staphylococcus aureus (SA) (10. 5%). Gram-negative bacilli accounted for 61.6%, the predominant isolate was Escherichia coll (E. Coli) (24. 5%), followed by klebsiella pneumoniae (K. Pn) (13. 9%) and haemophilus influenzae (HI) (8

  6. Insights into antibiotic resistance through metagenomic approaches.

    Science.gov (United States)

    Schmieder, Robert; Edwards, Robert

    2012-01-01

    The consequences of bacterial infections have been curtailed by the introduction of a wide range of antibiotics. However, infections continue to be a leading cause of mortality, in part due to the evolution and acquisition of antibiotic-resistance genes. Antibiotic misuse and overprescription have created a driving force influencing the selection of resistance. Despite the problem of antibiotic resistance in infectious bacteria, little is known about the diversity, distribution and origins of resistance genes, especially for the unculturable majority of environmental bacteria. Functional and sequence-based metagenomics have been used for the discovery of novel resistance determinants and the improved understanding of antibiotic-resistance mechanisms in clinical and natural environments. This review discusses recent findings and future challenges in the study of antibiotic resistance through metagenomic approaches.

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

    Science.gov (United States)

    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.

  8. Determining of antibiotic resistance profile inStaphylococcus aureus isolates

    Institute of Scientific and Technical Information of China (English)

    Hossein Motamedi; Hadis Mirzabeigi; Tahere Shirali

    2010-01-01

    Objective:To determine the pattern of antibiotic resistance amongStaphylococcus aureus (S. aureus) isolates from clinical specimens and to identify community-acquired methicillin-resistantStaphylococcus aureus(CA-MRSA)in specimens that have been collected from patients referring to one of the hospitals of Ahvaz.Methods:S. aureus isolates from a hospital in Ahvaz were screened for resistance to various antibiotics including methicillin. The susceptibility of the isolates was determined by Kirby-Bauer disc diffusion method. TheMRSA was also treated with ethidium bromide to find the origin of resistance.Results: Among the bacterial isolates, all of 11S. aureus were resistant to methicillin and cefixime,2 were resistant to ciprofloxacine,6 were resistant to tetracycline and the reminder were sensitive or intermediate to other antibiotics. The treated isolates were reminded resistant to methicillin and this suggested that the plasmid was not the origin of resistance in these isolates.Conclusions: These results showed that infection due toMRSA is widespread in Ahvaz and with respect to the spread of vancomycin resistance among MRSA and appearance of overwhelming infections. It is necessary to identify continuously the profile of antibiotic resistance amongS. aureus isolates in other regions and finding appropriate antibiotic for infection control and eradication.

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

    Science.gov (United States)

    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.

  10. Antibiotic resistance pattern in uropathogens

    Directory of Open Access Journals (Sweden)

    Gupta V

    2002-01-01

    Full Text Available Uropathogenic strains from inpatient and outpatient departments were studied from April 1997 to March 1999 for their susceptibility profiles. The various isolates were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii and Enterococcus faecalis. Antibiotic susceptibility pattern of these isolates revealed that for outpatients, first generation cephalosporins, nitrofurantoin, norfloxacin/ciprofloxacin were effective for treatment of urinary tract infection but for inpatients, parenteral therapy with newer aminoglycosides and third generation cephalosporins need to be advocated as the organisms for nosocomial UTI exhibit a high degree of drug resistance. Trimethoprim and sulphamethoxazole combination was not found to be effective for the treatment of urinary tract infections as all the uropathogens from inpatients and outpatients showed high degree of resistance to co-trimoxazole. Culture and sensitivity of the isolates from urine samples should be done as a routine before advocating the therapy.

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

    Directory of Open Access Journals (Sweden)

    Editorial

    2017-03-01

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

  12. The Gut as Reservoir of Antibiotic Resistance: Microbial Diversity of Tetracycline Resistance in Mother and Infant

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Valles, Yvonne; Agersø, Yvonne;

    2011-01-01

    The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a ca...

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

    Science.gov (United States)

    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

  14. ANTIBIOTIC RESISTANCE IN THE OPPORTUNISTIC PATHOGEN STENOTROPHOMONAS MALTOPHILIA

    Directory of Open Access Journals (Sweden)

    María Blanca Sánchez

    2015-06-01

    Full Text Available Stenotrophomonas maltophilia is an environmental bacterium found in the soil, associated with plants and animals, and in aquatic environments. It is also an opportunistic pathogen now causing an increasing number of nosocomial infections. The treatment of S. maltophilia is quite difficult given its intrinsic resistance to a number of antibiotics, and because it is able to acquire new resistances via horizontal gene transfer and mutations. Certainly, strains resistant to quinolones, cotrimoxale and/or cephalosporins - antibiotics commonly used to treat S. maltophilia infections - have emerged. The increasing number of available S. maltophilia genomes has allowed the identification and annotation of a large number of antimicrobial and heavy metal resistance genes. Most encode inactivating enzymes and efflux pumps, but information on their role in intrinsic and acquired resistance is limited. Non-typical antibiotic resistance mechanisms that also form part of the intrinsic resistome have been identified via mutant library screening. These include non-typical antibiotic resistance genes, such as bacterial metabolism genes, and non-inheritable resistant phenotypes, such as biofilm formation and persistence. Their relationships with resistance are complex and require further study.

  15. Influence of population density on antibiotic resistance

    NARCIS (Netherlands)

    Bruinsma, N; Hutchinson, JM; van den Bogaard, AE; Giamarellou, H; Degener, J; Stobberingh, EE

    2003-01-01

    Antibiotic consumption and population density as a measure of crowding in the community were related to the prevalence of antibiotic resistance of three cities in three different countries: St Johns in Newfoundland (Canada), Athens in Greece and Groningen in The Netherlands. Antibiotic consumption w

  16. Inhibition of mutation and combating the evolution of antibiotic resistance.

    Directory of Open Access Journals (Sweden)

    Ryan T Cirz

    2005-06-01

    Full Text Available The emergence of drug-resistant bacteria poses a serious threat to human health. In the case of several antibiotics, including those of the quinolone and rifamycin classes, bacteria rapidly acquire resistance through mutation of chromosomal genes during therapy. In this work, we show that preventing induction of the SOS response by interfering with the activity of the protease LexA renders pathogenic Escherichia coli unable to evolve resistance in vivo to ciprofloxacin or rifampicin, important quinolone and rifamycin antibiotics. We show in vitro that LexA cleavage is induced during RecBC-mediated repair of ciprofloxacin-mediated DNA damage and that this results in the derepression of the SOS-regulated polymerases Pol II, Pol IV and Pol V, which collaborate to induce resistance-conferring mutations. Our findings indicate that the inhibition of mutation could serve as a novel therapeutic strategy to combat the evolution of antibiotic resistance.

  17. Nosocomial infection and its molecular mechanisms of antibiotic resistance.

    Science.gov (United States)

    Xia, Jufeng; Gao, Jianjun; Tang, Wei

    2016-02-01

    Nosocomial infection is a kind of infection, which is spread in various hospital environments, and leads to many serious diseases (e.g. pneumonia, urinary tract infection, gastroenteritis, and puerperal fever), and causes higher mortality than community-acquired infection. Bacteria are predominant among all the nosocomial infection-associated pathogens, thus a large number of antibiotics, such as aminoglycosides, penicillins, cephalosporins, and carbapenems, are adopted in clinical treatment. However, in recent years antibiotic resistance quickly spreads worldwide and causes a critical threat to public health. The predominant bacteria include Methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii. In these bacteria, resistance emerged from antibiotic resistant genes and many of those can be exchanged between bacteria. With technical advances, molecular mechanisms of resistance have been gradually unveiled. In this review, recent advances in knowledge about mechanisms by which (i) bacteria hydrolyze antibiotics (e.g. extended spectrum β-lactamases, (ii) AmpC β-lactamases, carbapenemases), (iii) avoid antibiotic targeting (e.g. mutated vanA and mecA genes), (iv) prevent antibiotic permeation (e.g. porin deficiency), or (v) excrete intracellular antibiotics (e.g. active efflux pump) are summarized.

  18. The antibiotics relo in bacteria resistance

    OpenAIRE

    Santana, Vinicius Canato; CESUMAR

    2007-01-01

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

  19. Antibiotic resistance: a physicist’s view

    Science.gov (United States)

    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.

  20. Helicobacter pylori Antibiotic Resistance: Trends Over Time

    Directory of Open Access Journals (Sweden)

    Raymond G Lahaie

    2000-01-01

    Full Text Available Resistance to antibiotics can be a major problem in the treatment of bacterial infections. As the use of antibiotics increases, bacterial resistance to these agents is rising and in many cases is responsible for the failure of treatment regimens. Although the treatment of Helicobacter pylori infection requires the use of more than one antibiotic to obtain adequate eradication rates, the efficacy of the currently used antibiotic combinations has been shown to be decreased by resistance to one of the antibiotics. The use of antibiotics in regimens for the treatment of H pylori is increasing in many countries, including Canada. This increase is both in the use of these antibiotics alone for the treatment of nongastrointestinal infections and in their use in association with proton pump inhibitors for the treatment of H pylori infection. In several European and Asian countries, where resistance to antibiotics is being monitored, it has been demonstrated that H pylori resistance to metronidazole and to clarithromycin increased throughout the 1990s. Thus far, the data available in Canada do not show increased resistance to either of these antibiotics. As for other antibiotics used in the treatment of H pylori infection, such as tetracycline and amoxicillin, the rate of resistance to these agents is still very low and does not constitute a significant problem. Because the efficacy of the regimens used in the treatment of H pylori infection is compromised by resistance to the antibiotics used, it is important that H pylori resistance rates in Canada and throughout the world continue to be monitored. Only with such reliable data can the most optimal regimens be recommended.

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

    Science.gov (United States)

    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...

  2. Persistence of antibiotic resistance in bacterial populations.

    Science.gov (United States)

    Andersson, Dan I; Hughes, Diarmaid

    2011-09-01

    Unfortunately for mankind, it is very likely that the antibiotic resistance problem we have generated during the last 60 years due to the extensive use and misuse of antibiotics is here to stay for the foreseeable future. This view is based on theoretical arguments, mathematical modeling, experiments and clinical interventions, suggesting that even if we could reduce antibiotic use, resistant clones would remain persistent and only slowly (if at all) be outcompeted by their susceptible relatives. In this review, we discuss the multitude of mechanisms and processes that are involved in causing the persistence of chromosomal and plasmid-borne resistance determinants and how we might use them to our advantage to increase the likelihood of reversing the problem. Of particular interest is the recent demonstration that a very low antibiotic concentration can be enriching for resistant bacteria and the implication that antibiotic release into the environment could contribute to the selection for resistance. Several mechanisms are contributing to the stability of antibiotic resistance in bacterial populations and even if antibiotic use is reduced it is likely that most resistance mechanisms will persist for considerable times.

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

    Science.gov (United States)

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

    2016-05-01

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

  4. Antibiotic resistance: are we all doomed?

    Science.gov (United States)

    Collignon, P

    2015-11-01

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

  5. Mechanisms of antibiotic resistance in enterococci.

    Science.gov (United States)

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

    2014-10-01

    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.

  6. Antibiotic resistance: an editorial review with recommendations.

    Science.gov (United States)

    Rosen, Ted

    2011-07-01

    Within a relatively short period of time after the first antimicrobial drugs were introduced, bacteria began exhibiting varying degrees of resistance. The excessive use (and abuse) of antibiotics in agriculture, and in both human and veterinary medicine, has played a critical causative role in the development of antibiotic resistance, which is now recognized as a global public health threat. Increasing concern over this issue should impact the practice of cutaneous medicine and surgery, as dermatologists can easily adopt new healthcare delivery patterns that might reduce the development of antibiotic resistance and still achieve acceptable treatment outcomes. Dermatologists should seriously consider any and all alternative therapies before committing to an extended course of antibiotic therapy for disease entities that are almost certainly not infectious. Conversely, dermatologists should carefully and closely adhere to dosage and duration recommendations when using antibiotics to treat a bona fide infectious disorder.

  7. Analysis of the Antibiotic Resistance of Streptococcus Pneumonia Isolated from Community Acquired Pneumonia in Children%儿童社区获得性肺炎病例肺炎链球菌分离株的耐药分析

    Institute of Scientific and Technical Information of China (English)

    何丽芸; 王应建; 李季美

    2012-01-01

    Objective To analyze the antibiotic resistance of Streptococcus pneumonia of community acquired pneumonia (CAP) in children. Methods From Jan 2007 to Dec. 2010, efforts were made to isolate S. pneumonia from throat swab and sputum samples in 4780 children with CAP, aged from 28 days to 8 years old, and to test the antimicrobial susceptibility of these clinical isolates by means of sputum culture and streptococcus bacteria identification plate identification. Results A total of 344 strains of S. pneumonia were isolated from throat swab and sputum. The prevalence of S. pneumonia non梥usceptible to penicillin was 45.6%. The resistance rates of S. pneumonia to the commonly used antibiotic were penicillin 38.5%, erythromycin 38.3%, clindamycin 4.8%, cefo?taxime 16.0% , ceftriaxone 16.4% and ofloxacin 3.6% during the period from 2007 to 2008, respectively. From 2009 to 2010, the resistance rates of S. pneumonia to the antibiotic were increased; it was 60.9% , 68.0% , 42.6%, 36.7%, 32.3% and 3.1%, respectively. No vancomycin resistance strain was found. The resistance rate of penicillin non-susceptible S. pneumonia (PNSSP) was higher than that of penicillin susceptible S. pneumonia ( PSSP). Conclusion The S. pneumonia isolated from children with CAP is susceptive to vancomycin and ofloxacin. There is an increasing tendency of the resistance rates of S. pneumonia to penicillin, erythromycin, clindamycin , cefotaxime and ceftriaxone in Kunming region.%目的 分析昆明地区社区获得性肺炎住院病例中肺炎链球菌感染的耐药状况.方法 对2007年1月至2010年12月间年龄28d~8岁的4 780例诊断为社区获得性肺炎(CAP)住院患儿进行痰培养,采用链球菌细菌鉴定板鉴定,并行药敏试验.结果 从所检测CAP患儿痰液中培养分离出344株肺炎链球菌,它们对青霉素不敏感率为45.6%; 2007年至2008年肺炎链球菌对青霉素、红霉素、克林霉素、头孢噻肟、头孢曲松、氧氟

  8. Antibiotic tolerance facilitates the evolution of resistance.

    Science.gov (United States)

    Levin-Reisman, Irit; Ronin, Irine; Gefen, Orit; Braniss, Ilan; Shoresh, Noam; Balaban, Nathalie Q

    2017-02-24

    Controlled experimental evolution during antibiotic treatment can help to explain the processes leading to antibiotic resistance in bacteria. Recently, intermittent antibiotic exposures have been shown to lead rapidly to the evolution of tolerance-that is, the ability to survive under treatment without developing resistance. However, whether tolerance delays or promotes the eventual emergence of resistance is unclear. Here we used in vitro evolution experiments to explore this question. We found that in all cases, tolerance preceded resistance. A mathematical population-genetics model showed how tolerance boosts the chances for resistance mutations to spread in the population. Thus, tolerance mutations pave the way for the rapid subsequent evolution of resistance. Preventing the evolution of tolerance may offer a new strategy for delaying the emergence of resistance.

  9. A new strategy to fight antimicrobial resistance: the revival of old antibiotics

    Directory of Open Access Journals (Sweden)

    Nadim eCassir

    2014-10-01

    Full Text Available The increasing prevalence of hospital- and community-acquired infections caused by multidrug-resistant bacterial pathogens is limiting the options for effective antibiotic therapy. Moreover, this alarming spread of antimicrobial resistance has not been paralleled by the development of novel antimicrobials. Resistance to the scarce new antibiotics is also emerging. In this context, the rational use of older antibiotics could represent an alternative for the treatment of multidrug-resistant bacterial pathogens. This strategy would help to optimize the armamentarium of antibiotics so as to preserve the effectiveness of new antibiotics and avoid the prescription of drugs known to favor the spread of resistance (i.e., quinolones. Furthermore, from a global economic perspective, this strategy could be useful in public health, given that several of these cheapest forgotten antibiotics are not available in many countries. We will review here the successful treatment of multidrug-resistant bacterial infections with old antibiotics and discuss their place in current practice.

  10. 儿童社区获得性肺炎病原体及细菌药敏结果分析%Pathogens and antibiotic resistance of community-acquired pneumonia in children

    Institute of Scientific and Technical Information of China (English)

    刘俊英

    2012-01-01

    Objective To investigate the pathogens and antibiotic resistance of community-acquired pneumonia (CAP) in children. Methods Pathogens were isolated from sputum specimens, drug sensitivity testing was done using the disc diffusion method (KB method) , and atypical pathogens and viruses were detected using immunofluorescence Results A total of 385 strains of pathogens were isolated from 651 children with CAP. These consisted of 142 strains of bacteria, 105 strains of viruses, and 138 strains of atypical pathogens. The pathogen most often detected was Mycoplasma pneumoniae (MP), with 108 strains delected. There were 54 strains of respiratory syncytial virus, 47 of hemophilus, 27 of parainfluenza virus, 23 of Chlamydiu pneumoniae , and 21 of Streptococcus pneumoniae. Eighty-nine children had a mixed infection. Hemophilus was resistant to ciprofloxacin and sensitive to azithromycin, vancomycin, and amoxicillin/clavu-lanate potassium. Conclusion MP was the predominant pathogen in children with community-acquired pneumonia. The isolates had little drug resistance.%目的 了解2011年医院儿童社区获得性肺炎(CAP)感染病原体类型及细菌的耐药情况. 方法 收集患儿痰液,进行菌种鉴定,KB纸片法进行药敏试验;非典型病原体、呼吸道合胞病毒等采用免疫荧光法检测鉴定. 结果 651例CAP患儿病原体感染385例,感染率为59.14%,其中检出细菌142株,病毒105株,非典型病原体138株.检出菌株数最多的是肺炎支原体,为108株(占28.05%),其次为呼吸道合胞病毒,为54株(占14.03%),其他病原体,如嗜血杆菌(47株),副流感病毒(27株),肺炎衣原体(23株)和肺炎链球菌(21株).患儿混合感染89例,以病毒和细菌混合感染为主.嗜血杆菌对环丙沙星耐药率最高,为55.32%;嗜血杆菌、肺炎链球菌和肺炎克雷伯菌对阿奇霉素、万古霉素、阿莫西林/克拉维酸敏感. 结论 CAP患儿以肺炎支原体感染为主,分离细菌对常见抗生素耐药性较低.

  11. Travel to Asia and traveller's diarrhoea with antibiotic treatment are independent risk factors for acquiring ciprofloxacin-resistant and extended spectrum β-lactamase-producing Enterobacteriaceae-a prospective cohort study.

    Science.gov (United States)

    Reuland, E A; Sonder, G J B; Stolte, I; Al Naiemi, N; Koek, A; Linde, G B; van de Laar, T J W; Vandenbroucke-Grauls, C M J E; van Dam, A P

    2016-08-01

    Travel to (sub)tropical countries is a well-known risk factor for acquiring resistant bacterial strains, which is especially of significance for travellers from countries with low resistance rates. In this study we investigated the rate of and risk factors for travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E), ciprofloxacin-resistant Enterobacteriaceae (CIPR-E) and carbapenem-resistant Enterobacteriaceae. Data before and after travel were collected from 445 participants. Swabs were cultured with an enrichment broth and sub-cultured on selective agar plates for ESBL detection, and on plates with a ciprofloxacin disc. ESBL production was confirmed with the double-disc synergy test. Species identification and susceptibility testing were performed with the Vitek-2 system. All isolates were subjected to ertapenem Etest. ESBL and carbapenemase genes were characterized by PCR and sequencing. Twenty-seven out of 445 travellers (6.1%) already had ESBL-producing strains and 45 of 445 (10.1%) travellers had strains resistant to ciprofloxacin before travel. Ninety-eight out of 418 (23.4%) travellers acquired ESBL-E and 130 of 400 (32.5%) travellers acquired a ciprofloxacin-resistant strain. Of the 98 ESBL-E, predominantly Escherichia coli and predominantly blaCTX-M-15, 56% (55/98) were resistant to gentamicin, ciprofloxacin and co-trimoxazole. Multivariate analysis showed that Asia was a high-risk area for ESBL-E as well as CIPR-E acquisition. Travellers with diarrhoea combined with antimicrobial use were significantly at higher risk for acquisition of resistant strains. Only one carbapenemase-producing isolate was acquired, isolated from a participant after visiting Egypt. In conclusion, travelling to Asia and diarrhoea combined with antimicrobial use are important risk factors for acquiring ESBL-E and CIPR-E.

  12. The Antibiotic Resistance Problem Revisited

    Science.gov (United States)

    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…

  13. Does chromatin remodeling mark systemic acquired resistance?

    NARCIS (Netherlands)

    Burg, van den H.A.; Takken, F.L.W.

    2009-01-01

    The recognition of plant pathogens activates local defense responses and triggers a long-lasting systemic acquired resistance (SAR) response. Activation of SAR requires the hormone salicylic acid (SA), which induces SA-responsive gene expression. Recent data link changes in gene expression to chroma

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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. Staphylococcus aureus phage types and their correlation to antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Mehndiratta P

    2010-10-01

    Full Text Available Context: Staphylococcus aureus is one of the most devastating human pathogen. The organism has a differential ability to spread and cause outbreak of infections. Characterization of these strains is important to control the spread of infection in the hospitals as well as in the community. Aim: To identify the currently existing phage groups of Staphylococcus aureus, their prevalence and resistance to antibiotics. Materials and Methods: Study was undertaken on 252 Staphylococcus aureus strains isolated from clinical samples. Strains were phage typed and their resistance to antibiotics was determined following standard microbiological procedures. Statistical Analysis: Chi square test was used to compare the antibiotic susceptibility between methicillin resistant Staph. aureus (MRSA and methicillin sensitive S. aureus (MSSA strains. Results: Prevalence of MRSA and MSSA strains was found to be 29.36% and 70.65% respectively. Of these 17.56% of MRSA and 40.44% of MSSA strains were community acquired. All the MSSA strains belonging to phage type 81 from the community were sensitive to all the antibiotics tested including clindamycin and were resistant to penicillin. Forty five percent strains of phage group III and 39% of non-typable MRSA strains from the hospital were resistant to multiple antibiotics. Conclusion: The study revealed that predominant phage group amongst MRSA strains was phage group III and amongst MSSA from the community was phage group NA (phage type 81. MSSA strains isolated from the community differed significantly from hospital strains in their phage type and antibiotic susceptibility. A good correlation was observed between community acquired strains of phage type 81 and sensitivity to gentamycin and clindamycin.

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

    Science.gov (United States)

    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.

  18. How to Fight Back Against Antibiotic Resistance

    DEFF Research Database (Denmark)

    Dantas, Gautam; Sommer, Morten

    2014-01-01

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

  19. The genomic enzymology of antibiotic resistance.

    Science.gov (United States)

    Morar, Mariya; Wright, Gerard D

    2010-01-01

    The need for new antibiotic therapies is acute and growing in large part because of the emergence of drug-resistant pathogens. A vast number of resistance determinants are, however, found in nonpathogenic micro-organisms. The resistance totality in the global microbiota is the antibiotic resistome and includes not only established resistance genes but also genes that have the potential to evolve into resistance elements. We term these proto-resistance genes and hypothesize that they share common ancestry with other functional units known as housekeeping genes. Genomic enzymology is the study of protein structure-function in light of genetic context and evolution of protein superfamilies. This concept is highly applicable to study of antibiotic resistance evolution from proto-resistance elements. In this review, we summarize some of the genomic enzymology evidence for resistance enzymes pointing to common ancestry with genes of other metabolic functions. Genomic enzymology plays a key role in understanding the origins of antibiotic resistance and aids in designing strategies for diagnosis and prevention thereof.

  20. Antibiotic resistance genes in the environment

    Directory of Open Access Journals (Sweden)

    Jianqiang Su

    2013-07-01

    Full Text Available Antibiotic resistance and its spread in bacteria are topics of great importance in global research. In this paper, we review recent progress in understanding sources, dissemination, distribution and discovery of novel antibiotics resistance genes (ARGs in the environment. Bacteria exhibiting intrinsic resistance and antibiotic resistant bacteria in feces from humans and animals are the major sources of ARGs occurring in the environment. A variety of novel ARGs have been discovered using functional metagenomics. Recently, the long-term overuse of antibotics in drug therapy and animal husbandry has led to an increase in diversity and abundance of ARGs, causing the environmental dissemination of ARGs in aquatic water, sewage treatmentplants, rivers, sediment and soil. Future research should focus on dissemination mechanisms of ARGs, the discovery of novel ARGs and their resistant mechanisms, and the establishment of environmental risk assessment systems for ARGs.

  1. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Claudia Vuotto

    2014-09-01

    Full Text Available 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.

  2. Drug resistance in community-acquired respiratory tract infections: role for an emerging antibacterial

    Directory of Open Access Journals (Sweden)

    Lorenzo Aguilar

    2010-06-01

    Full Text Available Lorenzo Aguilar1, María-José Giménez1, José Barberán21Microbiology Department, School of Medicine, University Complutense, Madrid; 2Infectious Diseases Department, Hospital Central de la Defensa Gomez Ulla, Madrid, SpainAbstract: The nasopharynx is the ecological niche where evolution towards resistance occurs in respiratory tract isolates. Dynamics of different bacterial populations in antibiotic-free multibacterial niches are the baseline that antibiotic treatments can alter by shifting the competitive balance in favor of resistant populations. For this reason, antibiotic resistance is increasingly being considered to be an ecological problem. Traditionally, resistance has implied the need for development of new antibiotics for which basic efficacy and safety data are required prior to licensing. Antibiotic development is mainly focused on demonstrating clinical efficacy and setting susceptibility breakpoints for efficacy prediction. However, additional information on pharmacodynamic data predicting absence of selection of resistance and of resistant subpopulations, and specific surveillance on resistance to core antibiotics (to detect emerging resistances and its link with antibiotic consumption in the community are valuable data in defining the role of a new antibiotic, not only from the perspective of its therapeutic potential but also from the ecologic perspective (countering resistances to core antibiotics in the community. The documented information on cefditoren gleaned from published studies in recent years is an example of the role for an emerging oral antibacterial facing current antibiotic resistance in community-acquired respiratory tract infections.Keywords: respiratory tract infection, antibiotic resistance, cefditoren, community

  3. Impact of guidelines on antibiotics prescription for community-acquired pneumonia

    Directory of Open Access Journals (Sweden)

    Lázaro A. Vélez

    2008-11-01

    Full Text Available PREVIOUS PRESENTATION: This study was presented in part at the 47th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC; September 17, 2007; Chicago, Ill. CONFLICT OF INTEREST STATEMENT: Lázaro Vélez has received research funding from Astra-Zeneca and Roche Colombia, and has been a consultant for Pfizer. Other authors did not declare conflicts of interest. BACKGROUND: Community Acquired Pneumonia (CAP is an important reason to prescribe antibiotics in hospitals. Since etiologic diagnosis is cumbersome, most clinicians use initial broad coverage as suggested by local/international guidelines. This approach may induce overprescription of antibiotics, increasing costs, resistance and adverse effects. Our aim was to quantify the impact that overprescription of antibiotic has on the implementation of IDSA/ATS 2007 guidelines. METHODS: A prospective cohort study conducted at 11 hospitals in Medellín, Colombia, 2005-06. We included 205 adult CAP patients with an identified pathogen. Four categories of appropriateness were established: appropriate, insufficient, excessive and useless. To quantify the magnitude of antibiotic prescription, we compared the Defined Daily Doses (DDD of antibiotics suggested for the empiric treatment by IDSA/ATS 2007 guidelines according to severity (mild, moderate and severe CAP with the DDD of the antibiotics that would be prescribed based on the identified respiratory pathogen. FINDINGS: Empiric coverage recommended by IDSA/ATS resulted appropriate in 24.9%, insufficient in 2.4%, excessive in 57.6% and useless in 15.1%. Total antibiotic consumption for the included patients, according to identified pathogens, would be 2.255 DDD. Predicted antibiotic use based on IDSA/ATS guidelines would increase to 4.440 (97% more. The DDD raise was higher in moderate and severe categories compared to mild CAP (130%, 129.4% and 53.9%, respectively. INTERPRETATION: Implementation of IDSA/ATS 2007 guidelines for the

  4. Collateral sensitivity of antibiotic-resistant microbes.

    Science.gov (United States)

    Pál, Csaba; Papp, Balázs; Lázár, Viktória

    2015-07-01

    Understanding how evolution of microbial resistance towards a given antibiotic influences susceptibility to other drugs is a challenge of profound importance. By combining laboratory evolution, genome sequencing, and functional analyses, recent works have charted the map of evolutionary trade-offs between antibiotics and have explored the underlying molecular mechanisms. Strikingly, mutations that caused multidrug resistance in bacteria simultaneously enhanced sensitivity to many other unrelated drugs (collateral sensitivity). Here, we explore how this emerging research sheds new light on resistance mechanisms and the way it could be exploited for the development of alternative antimicrobial strategies.

  5. Engineering antibiotic production and overcoming bacterial resistance.

    Science.gov (United States)

    Planson, Anne-Gaëlle; Carbonell, Pablo; Grigoras, Ioana; Faulon, Jean-Loup

    2011-07-01

    Progress in DNA technology, analytical methods and computational tools is leading to new developments in synthetic biology and metabolic engineering, enabling new ways to produce molecules of industrial and therapeutic interest. Here, we review recent progress in both antibiotic production and strategies to counteract bacterial resistance to antibiotics. Advances in sequencing and cloning are increasingly enabling the characterization of antibiotic biosynthesis pathways, and new systematic methods for de novo biosynthetic pathway prediction are allowing the exploration of the metabolic chemical space beyond metabolic engineering. Moreover, we survey the computer-assisted design of modular assembly lines in polyketide synthases and non-ribosomal peptide synthases for the development of tailor-made antibiotics. Nowadays, production of novel antibiotic can be tranferred into any chosen chassis by optimizing a host factory through specific strain modifications. These advances in metabolic engineering and synthetic biology are leading to novel strategies for engineering antimicrobial agents with desired specificities.

  6. Identification of acquired antimicrobial resistance genes

    DEFF Research Database (Denmark)

    Zankari, Ea; Hasman, Henrik; Cosentino, Salvatore;

    2012-01-01

    ObjectivesIdentification of antimicrobial resistance genes is important for understanding the underlying mechanisms and the epidemiology of antimicrobial resistance. As the costs of whole-genome sequencing (WGS) continue to decline, it becomes increasingly available in routine diagnostic laborato......ObjectivesIdentification of antimicrobial resistance genes is important for understanding the underlying mechanisms and the epidemiology of antimicrobial resistance. As the costs of whole-genome sequencing (WGS) continue to decline, it becomes increasingly available in routine diagnostic...... laboratories and is anticipated to substitute traditional methods for resistance gene identification. Thus, the current challenge is to extract the relevant information from the large amount of generated data.MethodsWe developed a web-based method, ResFinder that uses BLAST for identification of acquired...... antimicrobial resistance genes in whole-genome data. As input, the method can use both pre-assembled, complete or partial genomes, and short sequence reads from four different sequencing platforms. The method was evaluated on 1862 GenBank files containing 1411 different resistance genes, as well as on 23 de...

  7. Origin and evolution of antibiotic resistance: the common mechanisms of emergence and spread in water bodies

    Directory of Open Access Journals (Sweden)

    Agnese eLupo

    2012-01-01

    Full Text Available The environment, and especially fresh water, constitutes a reactor where the evolution and the rise of new resistances occur. In rivers or streams, bacteria from different sources such as urban, industrial and agricultural waste, probably selected by intensive antibiotic usage, are collected and mixed with environmental species. This may cause two effects on the development of antibiotic resistances: First, the contamination of water by antibiotics or other pollutants lead to the rise of resistance due to selection processes. For instance, of strains over-expressing broad range defensive mechanisms, such as efflux pumps. Second, since environmental species are provided with intrinsic antibiotic resistance mechanisms, the mixture with allochthonous species is likely to cause genetic exchange. In this context, the role of phages and integrons for the spread of resistance mechanisms appears significant. Allochthonous species could acquire new resistances from environmental donors and introduce the newly acquired resistance mechanisms into the clinics. This is illustrated by clinically relevant resistance mechanisms, such as the fluoroquinolones resistance genes qnr. Freshwater appears to play an important role in the emergence and in the spread of antibiotic resistances, highlighting the necessity for strategies of water quality improvement. Moreover, further knowledge is needed to better understand the role of the environment as reservoir of antibiotic resistances and to assess the risk of spread of antibiotic resistances via water bodies.

  8. The determinants of the antibiotic resistance process

    OpenAIRE

    Espinosa, Beatriz

    2009-01-01

    Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM), Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a se...

  9. Chemical Countermeasures for Antibiotic Resistance

    Science.gov (United States)

    2014-04-01

    SUPPLEMENTARY NOTES 14.ABSTRACT New approaches are required to control multi-drug resistant (MDR) bacterial infections in military medical facilities ...New approaches are required to control multi-drug resistant (MDR) bacterial infections in military medical facilities , as injured Warfighters...current position: postdoc in the Disney lab TSRI Florida 15 CONCLUSION: New approaches are desperately required to control multi-drug resistant

  10. Insertion sequence IS256 in canine pyoderma isolates of Staphylococcus pseudintermedius associated with antibiotic resistance.

    Science.gov (United States)

    Casagrande Proietti, P; Bietta, A; Coletti, M; Marenzoni, M L; Scorza, A V; Passamonti, F

    2012-06-15

    Staphylococcus pseudintermedius is the most frequent staphylococcal species isolated from canine pyoderma. The control of S. pseudintermedius infection is often difficult due to the expanded antimicrobial resistance phenotypes. Antibiotic resistance in staphylococcal pathogens is often associated to mobile genetic elements such as the insertion sequence IS256 that was first described as a part of the transposon Tn4001, which confers aminoglycoside resistance in Staphylococcus aureus and in Staphylococcus epidermidis. In this study a collection of 70 S. pseudintermedius isolates from canine pyoderma was used to investigate antimicrobial susceptibility to 15 antibiotics and the presence of IS256, not revealed in S. pseudintermedius yet. Antibiotic resistance profiling demonstrated that all S. pseudintermedius isolates had a multi-drug resistance phenotype, exhibiting simultaneous resistance to at least five antibiotics; indeed methicillin resistant S. pseudintermedius isolates were simultaneously resistant to at least nine antibiotics and all were also gentamicin resistant. PCR analyses revealed the presence of IS256 in 43/70 S. pseudintemedius isolates. The association between the presence of IS256 and the resistance was particularly significant for certain antibiotics: cefovecin, amikacin, gentamicin and oxacillin (χ(2)p-valuepseudintermedius isolates and its association with antibiotic resistance. Our findings suggest that S. pseudintermedius may acquire antibiotic resistance genes through mobile genetic elements which may play a predominant role in the dissemination of multi-drug resistance.

  11. Bacteriophage-mediated acquisition of antibiotic resistance by Staphylococcus aureus type 88.

    OpenAIRE

    Schaefler, S.

    1982-01-01

    Antibiotic-resistant Staphylococcus aureus strains of phage type 88, lysogenic for phage 188, when grown in mixed culture with a nonlysogenic novobiocin-resistant strain, acquired novobiocin resistance at a high rate from the nonlysogenic strain. With most strains of phage type 88, there was no detectable transfer of resistance from lysogenic to nonlysogenic cells. Lysogenization with phage 188 of phage-sensitive strains conferred on the lysogenized cells the ability to acquire chromosome and...

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

    OpenAIRE

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

    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 ...

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

    Science.gov (United States)

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

    2012-01-01

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

  14. Acquired genetic mechanisms of a multiresistant bacterium isolated from a treatment plant receiving wastewater from antibiotic production.

    Science.gov (United States)

    Johnning, Anna; Moore, Edward R B; Svensson-Stadler, Liselott; Shouche, Yogesh S; Larsson, D G Joakim; Kristiansson, Erik

    2013-12-01

    The external environment, particularly wastewater treatment plants (WWTPs), where environmental bacteria meet human commensals and pathogens in large numbers, has been highlighted as a potential breeding ground for antibiotic resistance. We have isolated the extensively drug-resistant Ochrobactrum intermedium CCUG 57381 from an Indian WWTP receiving industrial wastewater from pharmaceutical production contaminated with high levels of quinolones. Antibiotic susceptibility testing against 47 antibiotics showed that the strain was 4 to >500 times more resistant to sulfonamides, quinolones, tetracyclines, macrolides, and the aminoglycoside streptomycin than the type strain O. intermedium LMG 3301T. Whole-genome sequencing identified mutations in the Indian strain causing amino acid substitutions in the target enzymes of quinolones. We also characterized three acquired regions containing resistance genes to sulfonamides (sul1), tetracyclines [tet(G) and tetR], and chloramphenicol/florfenicol (floR). Furthermore, the Indian strain harbored acquired mechanisms for horizontal gene transfer, including a type I mating pair-forming system (MPFI), a MOBP relaxase, and insertion sequence transposons. Our results highlight that WWTPs serving antibiotic manufacturing may provide nearly ideal conditions for the recruitment of resistance genes into human commensal and pathogenic bacteria.

  15. Proteome studies of bacterial antibiotic resistance mechanisms.

    Science.gov (United States)

    Vranakis, Iosif; Goniotakis, Ioannis; Psaroulaki, Anna; Sandalakis, Vassilios; Tselentis, Yannis; Gevaert, Kris; Tsiotis, Georgios

    2014-01-31

    Ever since antibiotics were used to help humanity battle infectious diseases, microorganisms straight away fought back. Antibiotic resistance mechanisms indeed provide microbes with possibilities to by-pass and survive the action of antibiotic drugs. Several methods have been employed to identify these microbial resistance mechanisms in an ongoing effort to reduce the steadily increasing number of treatment failures due to multi-drug-resistant microbes. Proteomics has evolved to an important tool for this area of research. Following rapid advances in whole genome sequencing, proteomic technologies have been widely used to investigate microbial gene expression. This review highlights the contribution of proteomics in identifying microbial drug resistance mechanisms. It summarizes different proteomic studies on bacteria resistant to different antibiotic drugs. The review further includes an overview of the methodologies used, as well as lists key proteins identified, thus providing the reader not only a summary of research already done, but also directions for future research. This article is part of a Special Issue entitled: Trends in Microbial Proteomics.

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

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

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

  17. Predation and selection for antibiotic resistance in natural environments

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  18. Simulation Study for Transfer of Antibiotic Resistance via Mutator Subpopulation

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Aarestrup, Frank Møller

    Evolution of antibiotic resistance in bacterial populations is an increasing problem having fatal consequences for treatment of diseases. Therefore it is very important to understand this evolution. Traditionally evolution is considered to happen by single point mutations, where each mutant must...... have a growth advantage over the parent strain and grow to a sufficient number before a second mutation can occur. However, when multiple mutations are necessary for development of resistance, single mutations occurring with a normal mutation rate can not always explain the observed resistance. We...... introduce an alternative hypothesis by which a subpopulation of mutators drives the evolution process. Resistance is acquired by a subpoplution of mutators, for which the mutation rate is much higher than the wild-type. If the resistance is located on a transferable plasmid it can subsequently...

  19. Antibiotic use and resistance in long term care facilities.

    OpenAIRE

    Buul, L.W. van; Steen, J.T. van der; Veenhuizen, R.B.; Achterberg, W.P.; Schellevis, F G; Essink, R.T.G.M.; VAN BENTHEM, B. H B; Natsch, S. (Stefan); Hertogh, C. M. P. M.

    2012-01-01

    Introduction: The common occurrence of infectious diseases in nursing homes and residential care facilities may result in substantial antibiotic use, and consequently antibiotic resistance. Focusing on these settings, this article aims to provide a comprehensive overview of the literature available on antibiotic use, antibiotic resistance, and strategies to reduce antibiotic resistance. Methods: Relevant literature was identified by conducting a systematic search in the MEDLINE and EMBASE dat...

  20. The negative impact of antibiotic resistance.

    Science.gov (United States)

    Friedman, N D; Temkin, E; Carmeli, Y

    2016-05-01

    Antibacterial therapy is one of the most important medical developments of the twentieth century; however, the spread of resistance in healthcare settings and in the community threatens the enormous gains made by the availability of antibiotic therapy. Infections caused by resistant bacteria lead to up to two-fold higher rates of adverse outcomes compared with similar infections caused by susceptible strains. These adverse outcomes may be clinical or economic and reflect primarily the failure or delay of antibiotic treatment. The magnitude of these adverse outcomes will be more pronounced as disease severity, strain virulence, or host vulnerability increases. The negative impacts of antibacterial resistance can be measured at the patient level by increased morbidity and mortality, at the healthcare level by increased resource utilization, higher costs and reduced hospital activity and at the society level by antibiotic treatment guidelines favouring increasingly broad-spectrum empiric therapy. In this review we will discuss the negative impact of antibiotic resistance on patients, the healthcare system and society.

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

    Science.gov (United States)

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

  2. Helicobacter pylori antibiotic resistance in Iran

    Institute of Scientific and Technical Information of China (English)

    Marjan Mohammadi; Delaram Doroud; Nazanin Mohajerani; Sadegh Massarrat

    2005-01-01

    AIM: To examine the frequency of antibiotic resistance in Iranian Helicobacter pylori(H pylori) strains isolated from two major hospitals in Tehran.METHODS: Examination of antibiotic resistance was performed on 120 strains by modified disc diffusion test and PCR-RFLP methods. In addition, in order to identify the possible causes of the therapeutic failure in Iran, we also determined the resistance of these strains to the most commonly used antibiotics (metronidazole, amoxicillin,and tetracycline) by modified disc diffusion test.RESULTS: According to modified disc diffusion test, 1.6% of the studied strains were resistant to amoxicillin, 16.7% to clarithromycin, 57.5% to metronidazole, and there was no resistance to tetracycline. Of the clarithromycin resistant strains, 73.68% had the A2143G mutation in the 23S rRNA gene, 21.05% A2142C, and 5.26% A2142G.None of the sensitive strains were positive for any of the three point mutations. Of the metronidazole resistant strains, deletion in rdxA gene was studied and detected in only 6 (5%) of the antibiogram-based resistant strains.None of the metronidazole sensitive strains possessed rdxA gene deletion.CONCLUSION: These data show that despite the fact that clarithromycin has not yet been introduced to the Iranian drug market as a generic drug, nearly 20% rate of resistance alerts toward the frequency of macrolide resistance strains, which may be due to the widespread prescription of erythromycin in Iran. rdxA gene inactivation,if present in Iranian H pylori strains, may be due to other genetic defects rather than gene deletion.

  3. 'Superbug' Resistant to All Antibiotics Killed Nevada Woman

    Science.gov (United States)

    ... news/fullstory_163038.html 'Superbug' Resistant to All Antibiotics Killed Nevada Woman She died after possibly picking ... September from a "superbug" infection that resisted all antibiotics, according to a report released Friday. The case ...

  4. Antibiotic-Resistant Bacteria Detected in Sewage Spill

    Science.gov (United States)

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

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

    Science.gov (United States)

    Brown, David

    2015-12-01

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

  6. Chemical Countermeasures for Antibiotic Resistance

    Science.gov (United States)

    2015-01-01

    library for suppression of MRSA resistance to penicillin G and oxacillin. Synthetic methodologies to access seven scaffolds (Figure 2)3-8 based...Infective Agents, Accepted Bacterial biofilms are defined as a surface attached community of bacteria embedded in a matrix of extracellular polymeric ...a surface attached community of bacteria embedded in a matrix of extracellular polymeric substances that they have produced. When in the biofilm

  7. The role of aquatic ecosystems as reservoirs of antibiotic resistance.

    Science.gov (United States)

    Marti, Elisabet; Variatza, Eleni; Balcazar, Jose Luis

    2014-01-01

    Although antibiotic resistance has become a major threat to human health worldwide, this phenomenon has been largely overlooked in studies in environmental settings. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance, because they are frequently impacted by anthropogenic activities. This review focuses primarily on the emergence and dissemination of antibiotic resistance in the aquatic environment, with a special emphasis on the role of antibiotic resistance genes.

  8. Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance

    OpenAIRE

    Nishant A. Dafale; Uttam P. Semwal; Rupak K. Rajput; Singh, G. N.

    2016-01-01

    Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms. Resistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics. In order to overcome the resistance problem and to safely use antibiotics, the correct measurement of potency and bioactivity of antibiotics is essential. Microbiological assay and high performance liquid chromatography (HPLC) method are used to quantify the pote...

  9. Antibiotic-Resistant Vibrios in Farmed Shrimp

    Directory of Open Access Journals (Sweden)

    Renata Albuquerque Costa

    2015-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  11. Functional characterization of the antibiotic resistance reservoir in the human microflora

    OpenAIRE

    Sommer, Morten O. A.; Dantas, Gautam; Church, George M.

    2009-01-01

    To understand the process by which antibiotic resistance genes are acquired by human pathogens, we functionally characterized the resistance reservoir in the microbial flora of healthy individuals. Most of the resistance genes we identified using culture independent sampling have not been previously identified and are evolutionarily distant from known resistance genes. By contrast, nearly half of the resistance genes we identified in cultured aerobic gut isolates (a small subset of the gut mi...

  12. Empiric antibiotic choices for community-acquired biliary tract infections

    Directory of Open Access Journals (Sweden)

    Kuo-Kuan Chang

    2014-06-01

    Conclusion: The combination of ceftriaxone plus metronidazole appears to be the most appropriate empiric antibiotics for the treatment of CA-BTI at this hospital. Because different hospitals may encounter microorganisms of different antimicrobial susceptibilities, similar approaches may be followed by other hospitals where appropriate empiric therapy has not yet been established for the treatment of CA-BTI.

  13. Bacterial Multidrug Efflux Pumps: Much More Than Antibiotic Resistance Determinants

    Science.gov (United States)

    Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis

    2016-01-01

    Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics. PMID:27681908

  14. Antibiotic resistances of intestinal lactobacilli isolated from wild boars.

    Science.gov (United States)

    Klose, Viviana; Bayer, Katharina; Kern, Corinna; Goelß, Florian; Fibi, Silvia; Wegl, Gertrude

    2014-01-10

    Acquired antibiotic resistances have been reported in lactobacilli of various animal and food sources, but there are no data from wild boar. The objective was a preliminary examination of the antibiotic resistance prevalence of intrinsically vancomycin-resistant lactobacilli isolated from wild boar intestines and analysis of the genetic determinants implicated. Out of three wild boars, 121 lactobacilli were recovered and grouped according to their whole cell protein patterns. Initial phenotypic screening revealed that all were susceptible to erythromycin (2 μg/ml), but 30 were resistant to tetracycline (32 μg/ml). Based on Randomly Amplified Polymorphic DNA-PCR clustering, 64 strains were selected as representative genotypes for identification and minimum inhibitory concentration (MIC) determination. Partial 16S rRNA gene sequencing identified four species: (i) L. mucosae (n=57), (ii) L. reuteri (n=47), (iii) L. fermentum (n=12), and (iv) L. murinus (n=5). Most heterofermentative strains displayed low MICs for ampicillin (AMP), chloramphenicol (CHL), streptomycin (STR), kanamycin (KAN), gentamicin (GEN), erythromycin (ERY), quinupristin/dalfopristin (Q/D), and clindamycin (CLI). Atypical MICs were found mainly in L. mucosae and L. reuteri for TET, KAN, STR, AMP and CHL, but except the TET MICs of L. mucosae mostly at low level. L. murinus strains revealed atypical MICs for aminoglycosides, and/or CHL, AMP, CLI. PCR screening detected tet(W) in 12 and tet(M) in one of heterofermentative strains, as well as the aph(3')-III kanamycin gene in L. murinus. This is the first report showing acquired antibiotic resistance determinants in intestinal lactobacilli of wild boar origin.

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

    Science.gov (United States)

    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.

  16. Prescription of antibiotics in community-acquired pneumonia in children: are we following the recommendations?

    Science.gov (United States)

    da Fonseca Lima, Eduardo Jorge; Lima, Débora Ellen Pessoa; Serra, George Henrique Cordeiro; Abreu e Lima, Maria Anaide Zacche S; de Mello, Maria Júlia Gonçalves

    2016-01-01

    Objective To assess the adequacy of antibiotic prescription in children hospitalized for pneumonia in a reference pediatric hospital in Brazil. Methods This was a cross-sectional study involving children aged between 1 month and 5 years who were hospitalized between October 2010 and September 2013. The classification of community-acquired pneumonia (CAP) was based on the clinical and radiological criteria of the World Health Organization (WHO). The analysis of antibiotic adequacy was performed according to the main guidelines on CAP treatment, which include the WHO guidelines, Brazilian Society of Pediatrics guidelines, and international guidelines (Pediatrics Infectious Diseases Society, the Infectious Disease Society of America, British Thoracic Society, and Consenso de la Sociedad latinoamericana de Infectología). A multivariate analysis was performed including variables that have statistical significance of P≤0.25 in the bivariate analysis. Results The majority of the 452 hospitalized children were classified as having severe or very severe CAP (85.18%), and inadequate empiric antimicrobial therapy was started in 26.10% (118/452) of them. Ampicillin was the most used empiric antibiotic therapy (62.17%) for pneumonia, followed by a combination of ampicillin and associated with gentamicin. The initially proposed regimen was modified in 29.6% of the patients, and the most frequent change was the replacement of ampicillin by oxacillin combined with chloramphenicol. The median hospitalization time was 8.5 days, and the lethality rate was 1.55%. There was no statistical difference in adequacy in relation to the severity of pneumonia or degree of malnutrition. In the bivariate analysis, inadequacy of antibiotic therapy regimen was higher in patients undergoing oxygen therapy (P<0.05), which was given to 219 patients (48.45%). Pleural effusion was observed in 118 patients (26.11%) and was associated with higher prescription inadequacy, and it was the only factor

  17. Genetic analyses of the antibiotic resistance of Bifidobacterium bifidum strain Yakult YIT 4007.

    Science.gov (United States)

    Sato, Takashi; Iino, Tohru

    2010-02-28

    Bifidobacterium bifidum strain Yakult YIT 4007 (abbreviated as B. bifidum YIT 4007) is a commercial strain and resistant to erythromycin, neomycin, and streptomycin. Resistances to these antibiotics were endowed by sequential isolation of resistant mutants from its susceptible progenitor strain YIT 4001. Comparison of nucleotide sequences of various candidate genes of both strains led us to find that B. bifidum YIT 4007 had mutations on three copies of 23S ribosomal RNA genes, an 8 bp deletion of the rluD gene for pseudouridine synthase, and a mutation on the rpsL gene for ribosomal protein S12. The responsibility of these mutations to antibiotic resistances was supported by analyses of newly isolated mutants resistant to these antibiotics. The antibiotic resistances of B. bifidum YIT 4007 were evidently acquired by mutations of the structural genes on the chromosome and not associated with mobile genetic elements like insertion sequences, phages, and plasmids.

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

    Science.gov (United States)

    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.

  19. REDUCTION OF ANTIBIOTIC RESISTANCE IN BACTERIA: A REVIEW

    OpenAIRE

    Suresh Jaiswal et al.

    2012-01-01

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

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

    OpenAIRE

    Martínez, José Luis; 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 evol...

  1. Bacteriophage biosensors for antibiotic-resistant bacteria.

    Science.gov (United States)

    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.

  2. Biofilm-specific antibiotic tolerance and resistance.

    Science.gov (United States)

    Olsen, I

    2015-05-01

    Biofilms are heterogeneous structures composed of bacterial cells surrounded by a matrix and attached to solid surfaces. The bacteria here are 100 to 1,000 times more tolerant to antimicrobials than corresponding planktonic cells. Biofilms can be difficult to eradicate when they cause biofilm-related diseases, e.g., implant infections, cystic fibrosis, urinary tract infections, and periodontal diseases. A number of phenotypic features of the biofilm can be involved in biofilm-specific tolerance and resistance. Little is known about the molecular mechanisms involved. The current review deals with both phenotypic and molecular mechanisms of biofilm-specific antibiotic tolerance and resistance.

  3. Screening and deciphering antibiotic resistance in Acinetobacter baumannii: a state of the art.

    Science.gov (United States)

    Bonnin, Rémy A; Nordmann, Patrice; Poirel, Laurent

    2013-06-01

    Acinetobacter baumannii, recognized as a serious threat in healthcare facilities, has the ability to develop resistance to antibiotics quite easily. This resistance is related to either gene acquisition (horizontal gene transfer) or mutations in the genome, leading to gene disruption, over- or down-expression of genes. The clinically relevant antibiotic resistances in A. baumannii include resistance to aminoglycosides, broad-spectrum cephalosporins, carbapenems, tigecycline and colistin, which are the last resort antibiotics. The intrinsic and acquired resistance mechanisms of A. baumannii are presented here, with special focus on β-lactam resistance. The most up-to-date techniques for identification, including phenotypical and molecular tests, and screening of those emerging resistance traits are also highlighted. The implementation of early detection and identification of multidrug-resistant A. baumannii is crucial to control their spread.

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

    Science.gov (United States)

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

  5. Antibiotics and antibiotic resistance in agroecosystems: Cultural methods and gaps in knowledge

    Science.gov (United States)

    Varying cultural methodologies are used in assessment of antibiotic resistance in environmental samples. Culture based methods commonly involve isolation of target bacteria on general or selective media, and assessing growth in response to specific concentrations of antibiotics. Though time consumin...

  6. Antibiotic resistance--consequences for animal health, welfare, and food production.

    Science.gov (United States)

    Bengtsson, Björn; Greko, Christina

    2014-05-01

    Most of the literature on the consequences of emergence and spread of bacteria resistant to antibiotics among animals relate to the potential impact on public health. But antibiotics are used to treat sick animals, and resistance in animal pathogens may lead to therapy failure. This has received little scientific attention, and therefore, in this article, we discuss examples that illustrate the possible impact of resistance on animal health and consequences thereof. For all animals, there may be a negative effect on health and welfare when diseases cannot be treated. Other consequences will vary depending on why and how different animal species are kept. Animals kept as companions or for sports often receive advanced care, and antibiotic resistance can lead to negative social and economic consequences for the owners. Further, spread of hospital-acquired infections can have an economic impact on the affected premises. As to animals kept for food production, antibiotics are not needed to promote growth, but, if infectious diseases cannot be treated when they occur, this can have a negative effect on the productivity and economy of affected businesses. Antibiotic resistance in animal bacteria can also have positive consequences by creating incentives for adoption of alternative regimes for treatment and prevention. It is probable that new antibiotic classes placed on the market in the future will not reach veterinary medicine, which further emphasizes the need to preserve the efficacy of currently available antibiotics through antibiotic stewardship. A cornerstone in this work is prevention, as healthy animals do not need antibiotics.

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

    Science.gov (United States)

    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...

  8. Occurrence and reservoirs of antibiotic resistance genes in the environment

    NARCIS (Netherlands)

    Seveno, N.; Kallifidas, D.; Smalla, K.; Elsas, van J.D.; Collard, J.M.; Karagouni, A.; Wellington, E.M.H.

    2002-01-01

    Antibiotic resistance genes have become highly mobile since the development of antibiotic chemotherapy. A considerable body of evidence exists proving the link between antibiotic use and the significant increase in drug-resistant human bacterial pathogens. The application of molecular detection and

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

    OpenAIRE

    Parsons, Joshua B.; Yao, Jiangwei; Frank, Matthew W.; Rock, Charles O.

    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...

  10. Antibiotic resistance: current issues and future strategies

    Directory of Open Access Journals (Sweden)

    Giancarlo Scarafile

    2016-09-01

    Full Text Available The antibiotic resistance (antimicrobial resistance – AMR and the particular emergence of multi-resistant bacterial strains, is a problem of clinical relevance involving serious threats to public health worldwide. From early this decade, a lot of studies have demonstrated a significant increase in the rates of antibiotic resistance by bacterial pathogens responsible for nosocomial and community infections all over the world. The AMR leads to a reduced drug efficacy in the treatment options available and therefore, to an increase in mortality rates. The original causes of the phenomenon are: environmental factors which favor a mutation of the genetic bacterial inheritance, thereby inhibiting the active ingredient of the antibiotics; unsuitable administering of antibiotics in veterinary, incorrect taking both in hospitals and at home and, lately, lack of investments in the development of new drugs. The alarming epidemiological data prompted the World Health Organization (WHO in 2011 to coin the slogan "No action today, no cure tomorrow" in order to immediately implement a new strategy to improve the use of available drugs and to accelerate the introduction of new ones through a new phase of research involving private and public institutions. The European Union has stressed that the surveillance is considered an essential factor for an effective response to this problem but it has also highlighted that the results produced have been lower than expectations because of serious shortcomings such as lack of methodological standards, insufficient data sharing and no coordination among European countries. In Italy the situation is much more troubling; in fact, according to the Ministry of Health, 5000-7000 yearly deaths are deemed due to nosocomial infections, with an annual cost of more than 100 million €.These figures explain how the fight against infections is far from being won. The purpose of this review is to analyze the basic causes of the

  11. Pyrosequencing of antibiotic-contaminated river sediments reveals high levels of resistance and gene transfer elements.

    Directory of Open Access Journals (Sweden)

    Erik Kristiansson

    Full Text Available The high and sometimes inappropriate use of antibiotics has accelerated the development of antibiotic resistance, creating a major challenge for the sustainable treatment of infections world-wide. Bacterial communities often respond to antibiotic selection pressure by acquiring resistance genes, i.e. mobile genetic elements that can be shared horizontally between species. Environmental microbial communities maintain diverse collections of resistance genes, which can be mobilized into pathogenic bacteria. Recently, exceptional environmental releases of antibiotics have been documented, but the effects on the promotion of resistance genes and the potential for horizontal gene transfer have yet received limited attention. In this study, we have used culture-independent shotgun metagenomics to investigate microbial communities in river sediments exposed to waste water from the production of antibiotics in India. Our analysis identified very high levels of several classes of resistance genes as well as elements for horizontal gene transfer, including integrons, transposons and plasmids. In addition, two abundant previously uncharacterized resistance plasmids were identified. The results suggest that antibiotic contamination plays a role in the promotion of resistance genes and their mobilization from environmental microbes to other species and eventually to human pathogens. The entire life-cycle of antibiotic substances, both before, under and after usage, should therefore be considered to fully evaluate their role in the promotion of resistance.

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

    Science.gov (United States)

    Raghunath, D

    2008-11-01

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

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

    Indian Academy of Sciences (India)

    D Raghunath

    2008-11-01

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

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

    OpenAIRE

    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 w...

  15. Antibiotic Use, Its Resistance in Nepal and Recommendations for Action: A Situation Analysis.

    Science.gov (United States)

    Basnyat, B; Pokharel, P; Dixit, S; Giri, S

    2015-01-01

    Antibiotics are crucial, life-saving medicines in the fight against infectious disease, but resistance to these drugs is growing all over. This article presents key findings from a detailed situation analysis produced by the Global Antibiotic Resistance Partnership (GARP)-Nepal working group. In the absence of nationally-representative surveillance, it is not possible to fully describe antibiotic resistance in the country, but many important bacterial pathogens are highly resistant to most first-line and some second-line antibiotics, according to available reports. In credible studies, more than half of Escherichia coli, Klebsiella pneumoniae and Streptococcus pneumoniae isolates tested, and over 30 percent of some Shigella spp. and Vibrio cholerae isolates were resistant to first-line antibiotics. The findings for Neisseria gonorrheae and hospital-acquired Staphylococcus aureus are similar. Antibiotic use in animal food is poorly documented in Nepal, but it is commonly acknowledged to be widespread, contributing to the overall antibiotic resistance burden. The volume of veterinary antibiotic sales in Nepal rose over 50 percent from 2008 to 2012, most through retailers without veterinarian prescription. Antibiotics are necessary to treat infections in animals, but they are also used extensively for preventing disease, a use that can be restricted without jeopardizing animal or human health. They may also be used for promoting animal growth, which can be eliminated with no health consequences. Nepal has made important advances in reducing mortality and morbidity and increasing health coverage, but has not yet taken steps to address antibiotic resistance. The GARP-Nepal working group outlines the components of a national strategy on antibiotic resistance, consistent with the recent call by the World Health Organization for national action plans, to be developed collaboratively with stakeholders and partners from government and all relevant sectors.

  16. Antibiotic Resistance Threats in the U.S.

    Science.gov (United States)

    ... What's this? Submit Button Past Emails CDC Features Antibiotic Resistance Threats in the US Recommend on Facebook Tweet Share Compartir Antibiotics are powerful tools for fighting illness and disease, ...

  17. CURRENT ISSUES REGARDING ENDOCRINE DISRUPTING CHEMICALS AND ANTIBIOTIC RESISTANCE

    Science.gov (United States)

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

  18. Antibiotic use and resistance in long term care facilities

    NARCIS (Netherlands)

    Buul, L.W. van; Steen, J.T. van der; Veenhuizen, R.B.; Achterberg, W.P.; Schellevis, F.G.; Essink, R.T.G.M.; Benthem, B.H. van; Natsch, S.S.; Hertogh, C.M.P.M.

    2012-01-01

    INTRODUCTION: The common occurrence of infectious diseases in nursing homes and residential care facilities may result in substantial antibiotic use, and consequently antibiotic resistance. Focusing on these settings, this article aims to provide a comprehensive overview of the literature available

  19. Antibiotic use and resistance in long term care facilities.

    NARCIS (Netherlands)

    Buul, L.W. van; Steen, J.T. van der; Veenhuizen, R.B.; Achterberg, W.P.; Schellevis, F.G.; Essink, R.T.G.M.; Benthem, B.H.B. van; Natsch, S.; Hertogh, C.M.P.M.

    2012-01-01

    Introduction: The common occurrence of infectious diseases in nursing homes and residential care facilities may result in substantial antibiotic use, and consequently antibiotic resistance. Focusing on these settings, this article aims to provide a comprehensive overview of the literature available

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

    Science.gov (United States)

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

    2005-10-15

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

  1. Persistence and resistance as complementary bacterial adaptations to antibiotics

    OpenAIRE

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

    2016-01-01

    Abstract 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 res...

  2. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options

    Science.gov (United States)

    Lee, Chang-Ro; Lee, Jung Hun; Park, Moonhee; Park, Kwang Seung; Bae, Il Kwon; Kim, Young Bae; Cha, Chang-Jun; Jeong, Byeong Chul; Lee, Sang Hee

    2017-01-01

    Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized. PMID:28348979

  3. Analysis of Romanian Bacteroides isolates for antibiotic resistance levels and the corresponding antibiotic resistance genes.

    Science.gov (United States)

    Székely, Edit; Eitel, Zsuzsa; Molnár, Szabolcs; Szász, Izabella Éva; Bilca, Doina; Sóki, József

    2015-02-01

    As part of an ESCMID Study Group on Anaerobic Infections (ESGAI) project, a study was conducted to measure the antibiotic susceptibilities and corresponding gene contents of 53 Bacteroides fragilis group strains isolated in Romania. The antibiotic resistance data was comparable with the data found for other East-European countries. Here, no resistant isolate was found for imipenem, metronidazole and tigecycline. An increasing role of the cepA, cfxA and cfiA genes was observed in their corresponding antibiotic resistances. Moreover, no isolate was found that harbored the cfiA gene with a possible activating IS element. Clindamycin resistance was low, similarly to that the rate for the ermF gene. However, we did find some isolates with nimB, ermB, msrSA, linA, satG, tetX, tetM and bexA genes. This study was the first to provide antibiotic resistance data for clinical Bacteroides strains from Romania.

  4. BACTERIAL CAUSES OF LOWER RESPIRATORY TRACT INFECTIONS IN PATIENTS ATTENDING CENTRAL REFERRAL HOSPITAL, GANGTOK WITH REFERENCE TO ANTIBIOTIC RESISTANCE PATTERN

    OpenAIRE

    Priyanka Paul; Tukaram Prabhu

    2013-01-01

    ABSTRACT: BACKGROUND: There is inadequate information from India on various lower respiratory tract pathogens and their resistance pattern in hospital settings. The present study was undertaken to see the bacteriological profile an d the antibiotic resistance pattern of the isolates causing LRTI from this geographic region. OBJECTIVE: To identify and characterize bacterial pathogens causing community acquired and hospital acquired infections with reference to ant...

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

    Directory of Open Access Journals (Sweden)

    R Choudhury

    2012-01-01

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

  6. Helicobacter pylori resistance to antibiotics in Europe and its relationship to antibiotic consumption

    DEFF Research Database (Denmark)

    Megraud, Francis; Coenen, Samuel; Versporten, Ann

    2013-01-01

    OBJECTIVE: Resistance to antibiotics is the major cause of treatment failure of Helicobacter pylori infection. A study was conducted to assess prospectively the antibacterial resistance rates of H pylori in Europe and to study the link between outpatient antibiotic use and resistance levels in di...

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

    Science.gov (United States)

    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.

  8. Evidence of increased antibiotic resistance in phylogenetically-diverse Aeromonas isolates from semi-intensive fish ponds treated with antibiotics

    Directory of Open Access Journals (Sweden)

    Hemant J Patil

    2016-11-01

    Full Text Available The genus Aeromonas is ubiquitous in aquatic environments encompassing a broad range of fish and human pathogens. Aeromonas strains are known for their enhanced capacity to acquire and exchange antibiotic resistance genes and therefore, are frequently targeted as indicator bacteria for monitoring antimicrobial resistance in aquatic environments. This study evaluated temporal trends in Aeromonas diversity and antibiotic resistance in two adjacent semi-intensive aquaculture facilities to ascertain effects of antibiotic treatment on antimicrobial resistance. In the first facility, sulfadiazine-trimethoprim was added prophylactically upon fingerling stocking and water column-associated Aeromonas were monitored periodically over an eleven-month fish-fattening cycle to assess temporal dynamics in taxonomy and antibiotic resistance. In the second facility, Aeromonas were isolated from fish skin ulcers sampled over a three-year period and from pond water samples to assess associations between pathogenic strains to those in the water column. A total of 1200 Aeromonas spp. were isolated, initially screened for sulfadiazine resistance and further screened against five additional antibiotics. In both facilities, strong correlations were observed between sulfadiazine resistance and trimethoprim and tetracycline resistances, whereas correlations between sulfadiazine resistance and ceftriaxone, gentamycin and chloramphenicol resistances were low. Abundance of multi-drug resistant strains as well as sul1, tetA and intI1 gene-harboring strains was significantly higher in profiles sampled during the fish cycle than those isolated prior to stocking and these genes were extremely abundant in the pathogenic strains. Five phylogenetically-distinct Aeromonas clusters were revealed using partial rpoD gene sequence analysis. Interestingly, prior to fingerling stocking the diversity of water column strains was high, and representatives from all five clusters were

  9. Nosocomial urinary tract infections and resistance profile to antibiotics

    Directory of Open Access Journals (Sweden)

    Hasan Naz

    2009-06-01

    Full Text Available The aim of this study is to investigate the risk factors, laboratuary results, distrubition of pathogens and sensitivity to antibiotics in patients with hospital acquired urinary tract infections (HAUTI. 161 HAUTI patients were diagnosed. The most common predisposing factors were identified as long term hospitalization, urinary catheterization, hospitalization at intensive care unit and neurologic diseases. The most commom pathogens isolated were Escherichia coli 33 (29.5 %, Pseudomonas spp. 32 (28.6 % and Klebsiella spp. 12 (10.7 %. The lowest rates of resistance in E.coli, Pseudomonas spp. and Klebsiella spp. were observed to amikacin (respectively 3 %, 9 %, 8 %, to imipenem (9 %, 41 %, 8 %, to piperacilin/tazobactam (PIP/TAZ (24 %, 47 %, 17 % and to ciprofloxasin (52 %, 69 %, 25 %. Mortality was detected in 31(19% of 161 patients diagnosed with HAUTI. As a result, high rate resistance was found in bacterial microorganism, especially in Pseudomonas spp.

  10. Prescription of antibiotics in community-acquired pneumonia in children: are we following the recommendations?

    Directory of Open Access Journals (Sweden)

    Fonseca Lima EJ

    2016-06-01

    Full Text Available Eduardo Jorge da Fonseca Lima,1,2 Débora Ellen Pessoa Lima,3 George Henrique Cordeiro Serra,2 Maria Anaide Zacche S Abreu e Lima,2 Maria Júlia Gonçalves de Mello1,2 1Instituto de Medicina Integral Professor Fernando Figueira – IMIP, Recife, PE, Brazil; 2Faculdade Pernambucana de Saúde – FPS, Recife, PE, Brazil; 3Universidade de Pernambuco, Recife, PE, Brazil Objective: To assess the adequacy of antibiotic prescription in children hospitalized for pneumonia in a reference pediatric hospital in Brazil. Methods: This was a cross-sectional study involving children aged between 1 month and 5 years who were hospitalized between October 2010 and September 2013. The classification of community-acquired pneumonia (CAP was based on the clinical and radiological criteria of the World Health Organization (WHO. The analysis of antibiotic adequacy was performed according to the main guidelines on CAP treatment, which include the WHO guidelines, Brazilian Society of Pediatrics guidelines, and international guidelines (Pediatrics Infectious Diseases Society, the Infectious Disease Society of America, British Thoracic Society, and Consenso de la Sociedad latinoamericana de Infectología. A multivariate analysis was performed including variables that have statistical significance of P≤0.25 in the bivariate analysis. Results: The majority of the 452 hospitalized children were classified as having severe or very severe CAP (85.18%, and inadequate empiric antimicrobial therapy was started in 26.10% (118/452 of them. Ampicillin was the most used empiric antibiotic therapy (62.17% for pneumonia, followed by a combination of ampicillin and associated with gentamicin. The initially proposed regimen was modified in 29.6% of the patients, and the most frequent change was the replacement of ampicillin by oxacillin combined with chloramphenicol. The median hospitalization time was 8.5 days, and the lethality rate was 1.55%. There was no statistical difference in

  11. Bottlenecks in the Transferability of Antibiotic Resistance from Natural Ecosystems to Human Bacterial Pathogens

    OpenAIRE

    Martínez, José L.

    2012-01-01

    It is generally accepted that resistance genes acquired by human pathogens through horizontal gene transfer originated in environmental, non-pathogenic bacteria. As a consequence, there is increasing concern on the roles that natural, non-clinical ecosystems, may play in the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resistance on their expression in a heterologous host is much larger than what is actually found in human...

  12. Antibiotic resistance is prevalent in an isolated cave microbiome.

    Directory of Open Access Journals (Sweden)

    Kirandeep Bhullar

    Full Text Available 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.

  13. Functional metagenomics for the investigation of antibiotic resistance.

    Science.gov (United States)

    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.

  14. 脑性瘫痪儿童医院获得性肺炎的病原菌分布及耐药性分析%Pathological bacterial distribution and antibiotic resistance of hospital acquired pneumonia in children with cerebral palsy

    Institute of Scientific and Technical Information of China (English)

    刘常青; 左满凤; 钟新; 杨恩华; 朱木良; 高翠姣

    2016-01-01

    目的:了解脑性瘫痪(简称脑瘫)儿童医院获得性肺炎( HAP)的病原菌分布及耐药情况。方法收集2012年1月至2015年5月在本院儿童康复科住院期间感染肺炎的脑瘫患儿402例。结果402份痰标本中共分离到菌株291株,检出率72.4%,其中革兰阴性菌259株(89.0%),革兰阳性菌26株(8.9%),真菌6株(2.1%)。革兰阴性菌主要为大肠埃希菌(32.6%)、肺炎克雷伯菌(24.4%)和铜绿假单胞菌(14.4%),其中大肠埃希菌和肺炎克雷伯菌主要产超广谱β内酰胺酶( ESBLs,产酶率分别为58.9%、59.2%),产ESBLs菌的平均耐药率为55.5%,对碳青霉烯类抗生素的平均耐药率为5.0%。铜绿假单胞菌的平均耐药率34.9%,对碳青霉烯类抗生素均敏感。结论脑瘫儿童HAP的病原菌以革兰阴性菌“大肠埃希菌、肺炎克雷伯菌”为主,两者产ESBLs 菌检出率达58%以上,平均耐药率为55.5%,可指导临床首次经验性选药,以提高脑瘫儿童HAP的治疗有效率。%Objective To investigate the pathological bacterial distribution and their antibiotic resistance of hospital acquired pneumonia in children with cerebral palsy. Methods Induced sputum was extracted from 402 ca-ses of hospitalized children with cerebral palsy infected hospital acquired pneumonia in children rehabilitation depart-ment from January 2012 to May 2015. Results A total of 291 (72. 4%) strains of bacteria were isolated from in-duced sputum in the 402 children. The Gram-negative strains were detected in 259 strains (89. 0%), and the Gram-positive strains were found in 26 strains ( 8. 9%) in 291 strains. The others were fungal strains ( 6 strains, 2. 1%) . The Gram-negative bacteria included Escherichia coli ( 32. 6%) , Klebsiella pneumoniae ( 24. 4%) , and Pseudomonas aeruginosa (14. 4%). Escherichia coli and Klebsiella pneumoniae could produce extended-spectrumβ-lactamases ( ESBLs) ( The rates of enzyme production were 58. 9% and 59. 2%) . The

  15. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

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

  16. Can guidelines for the treatment of respiratory infections lead to reduced rates of antibiotic resistance?

    Science.gov (United States)

    Niederman, M S

    2001-09-01

    Guidelines have been developed for the therapy of both community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP), and, potentially, if applied appropriately, could lead to a containment or reduction in the frequency of antibiotic resistance. In the therapy of CAP, guidelines could minimize the use of excessive antibiotic therapy, and if they also improve the accuracy of therapy, they could minimize the emergence of resistant organisms in the community. However, the impact of such guidelines on resistance remains to be shown. In the near future, CAP guidelines could help contain the growing problem of quinolone-resistant pneumococci by advocating the use of the most effective of the new agents, administered at the optimal dosages. When managing HAP, the use of guidelines could improve outcome by leading to a greater percentage of patients receiving adequate empiric antibiotic therapy. It remains uncertain whether such an approach can minimize the emergence of antibiotic resistance, particularly in the intensive care unit (ICU), but it is clear that if guidelines are to be accurate, they must account for the resistance patterns that are unique to each individual hospital setting. To date, the use of computer-assisted guidelines for the therapy of nosocomial infections has been successful in minimizing the frequency of inadequate therapy, with no negative impact on antibiotic resistance. Antibiotic restriction policies have been proposed as a way to have an impact on resistance, with variable effects. In the future, antibiotic rotation is likely to be studied as a way to reduce resistance, particularly in the ICU, but a number of practical issues may limit the efficacy of such an approach.

  17. The relationship between pneumococcal serotypes and antibiotic resistance.

    Science.gov (United States)

    Song, Jae-Hoon; Dagan, Ron; Klugman, Keith P; Fritzell, Bernard

    2012-04-05

    Streptococcus pneumoniae (SP) causes significant burden of disease, including invasive pneumococcal disease and noninvasive diseases such as pneumonia and acute otitis media. SP has at least 93 different capsular serotypes, with the various serotypes having different propensities for producing disease or developing antibiotic resistance. An increase in the prevalence of antibiotic-resistant SP serotypes has been observed globally. The objective of this paper was to examine the relationship between antibiotic resistance and SP serotypes, with a primary focus on studies published in the past 10 years. Changing trends in antibiotic resistance and serotype distribution during this time, including those before and after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7), were analyzed. Factors that influence the prevalence of antibiotic-resistant serotypes include antibiotic selection pressure, the use of PCV7, and the emergence and spread of antibiotic-resistant clones. The emergence of multidrug resistant serotype 19A is of particular concern. Antibiotic-resistant SP is a global problem that must be addressed through multiple strategies, including national vaccination programs, antibiotic control programs, and ongoing surveillance.

  18. Direction of aminoacylated transfer RNAs into antibiotic synthesis and peptidoglycan-mediated antibiotic resistance.

    Science.gov (United States)

    Shepherd, Jennifer; Ibba, Michael

    2013-09-17

    Prokaryotic aminoacylated-transfer RNAs often need to be efficiently segregated between translation and other cellular biosynthetic pathways. Many clinically relevant bacteria, including Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa direct some aminoacylated-tRNA species into peptidoglycan biosynthesis and/or membrane phospholipid modification. Subsequent indirect peptidoglycan cross-linkage or change in membrane permeability is often a prerequisite for high-level antibiotic resistance. In Streptomycetes, aminoacylated-tRNA species are used for antibiotic synthesis as well as antibiotic resistance. The direction of coding aminoacylated-tRNA molecules away from translation and into antibiotic resistance and synthesis pathways are discussed in this review.

  19. Antibiotic misuse in the community--a contributor to resistance?

    LENUS (Irish Health Repository)

    Carey, B

    2012-02-03

    The problem of antibiotic resistance is associated with the indiscriminate usage of antibiotics. Efforts have been directed at encouraging the rational use of these drugs to reduce the volume of antibiotic consumption and decrease resistance rates. There is evidence to suggest that the misuse of antibiotics by patients may also contribute to the problem. We describe a survey of a random selection of patients attending a General Practitioners\\' surgery over a six week period in an effort to estimate the level of non-compliance to antibiotic therapy in the community. The results suggest that there may be a significant level of antibiotic misuse prevalent in the local community. We discuss these results and present evidence in the literature suggesting how antibiotic misuse may affect resistance in the community. The factors affecting patient compliance to therapy are outlined along with suggested measures to improve compliance among patients.

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

    NARCIS (Netherlands)

    Bell, B.G.; Schellevis, F.; Stobberingh, E.; Goossen, H.; Pringle, M.

    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 substant

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

    Science.gov (United States)

    Heß, Stefanie; Gallert, Claudia

    2015-12-01

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

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

    OpenAIRE

    Raghunath, D.

    2008-01-01

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

  3. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

    Martínez, José Luis; Baquero, Fernando

    2014-05-01

    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.

  5. Community-acquired methicillin-resistant Staphylococcus aureus in Central Australia.

    Science.gov (United States)

    Stevens, Claire L; Ralph, Anna; McLeod, James E T; McDonald, Malcolm I

    2006-01-01

    To date, there has been scant information about the burden of methicillin-resistant Staphylococcus aureus infections in Central Australia. Our aims were to determine the proportion of Staphylococcus aureus infections due to methicillin-resistant strains in Central Australia, to characterise resistance to non-beta lactam antibiotics and to correlate findings with available demographic information. We retrospectively reviewed S. aureus isolates identified by the Microbiology Laboratory of the Pathology Department, Alice Springs Hospital between September 2005 and February 2006. Multi-resistance was defined as resistance to three or more non-beta lactam antibiotics. We identified the recovery site and extended antibiotic resistance profile of each isolate. Demographic data included place of residence, discharge diagnosis and ethnicity. There were 524 S. aureus isolates: 417 (79.6%) methicillin-sensitive S. aureus, 104 (19.7%) non-multi-resistant MRSA (nmrMRSA) and 3 (0.7%) multi-resistant MRSA (mrMRSA). MRSA accounted for 7/22 (32%) invasive infections and 91/474 (19.2%) cases of staphylococcal skin infections. Aboriginal people comprised 89 per cent (93/104) of patients with nmrMRSA; 57 per cent lived in remote communities, 21 per cent in suburban Alice Springs, and 18 per cent in Alice Springs Town Camps. Six per cent (6/104) of nmrMRSA were hospital-acquired. Of the nmrMRSA isolates, 57 per cent (59/104) were resistant to erythromycin and 7 per cent (7/104) to fusidic acid. All MRSA isolates were susceptible to co-trimoxazole. In conclusion, Central Australia has high rates of community-acquired nmrMRSA and low rates of multi-resistant MRSA. Erythromycin resistance in S. aureus is also common. These findings should prompt the review of antimicrobial prescribing guidelines for the region, especially for treatment of skin and soft tissue infections.

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

    Science.gov (United States)

    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.

  7. Genomic insights into intrinsic and acquired drug resistance mechanisms in Achromobacter xylosoxidans.

    Science.gov (United States)

    Hu, Yongfei; Zhu, Yuying; Ma, Yanan; Liu, Fei; Lu, Na; Yang, Xi; Luan, Chunguang; Yi, Yong; Zhu, Baoli

    2015-02-01

    Achromobacter xylosoxidans is an opportunistic pathogen known to be resistant to a wide range of antibiotics; however, the knowledge about the drug resistance mechanisms is limited. We used a high-throughput sequencing approach to sequence the genomes of the A. xylosoxidans type strain ATCC 27061 and a clinical isolate, A. xylosoxidans X02736, and then we used different bioinformatics tools to analyze the drug resistance genes in these bacteria. We obtained the complete genome sequence for A. xylosoxidans ATCC 27061 and the draft sequence for X02736. We predicted a total of 50 drug resistance-associated genes in the type strain, including 5 genes for β-lactamases and 17 genes for efflux pump systems; these genes are also conserved among other A. xylosoxidans genomes. In the clinical isolate, except for the conserved resistance genes, we also identified several acquired resistance genes carried by a new transposon embedded in a novel integrative and conjugative element. Our study provides new insights into the intrinsic and acquired drug resistance mechanisms in A. xylosoxidans, which will be helpful for better understanding the physiology of A. xylosoxidans and the evolution of antibiotic resistance in this bacterium.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-05-01

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

  10. Effective Antibiotic Resistance Mitigation during Cheese Fermentation ▿

    OpenAIRE

    Li, Xinhui; Li, Yingli; Alvarez, Valente; Harper, Willis James; Wang, Hua H.

    2011-01-01

    Controlling antibiotic-resistant (ART) bacteria in cheese fermentation is important for food safety and public health. A plant-maintained culture was found to be a potential source for ART bacterial contamination in cheese fermentation. Antibiotics had a detectable effect on the ART population from contamination in the finished product. The decrease in the prevalence of antibiotic resistance (AR) in retail cheese samples from 2010 compared to data from 2006 suggested the effectiveness of targ...

  11. The Gut as Reservoir of Antibiotic Resistance: Microbial Diversity of Tetracycline Resistance in Mother and Infant

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Valles, Yvonne; Agersø, Yvonne;

    2011-01-01

    The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case...... study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc-r) in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc-r genes. Fecal fosmid...... libraries were functionally screened for Tc-r, and further PCR-screened for specific Tc-r genes. Tc-r fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tc-r, although encoded by different genes and organisms. Tc-r organisms in the mother...

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

    Science.gov (United States)

    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...

  13. Transmission of antibiotic resistance from animals to humans

    NARCIS (Netherlands)

    Huijbers, P.M.C.

    2016-01-01

    Huijbers, P.M.C. (2016). Transmission of antibiotic resistance from animals to humans: Broilers as a reservoir of ESBL-producing bacteria. PhD thesis, Wageningen University, Wageningen, the Netherlands. Antibiotic resistance in animals becomes a public health issue when there is transmission of anti

  14. Transfer of antibiotic resistant bacteria from animals to man

    DEFF Research Database (Denmark)

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

    1999-01-01

    ). Infections with these agents do not generally require antibiotic therapy, but in some cases antibiotics are essential to obtain a successful cure. The levels and types of resistance observed in zoonotic bacteria in some countries, especially the increasing levels of fluoroquinolone resistance in salmonella...

  15. Diversity and antibiotic resistance of uropathogenic bacteria from Abidjan

    Directory of Open Access Journals (Sweden)

    J.-L.A. Moroh

    2014-03-01

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

  16. Epidemiology of the Antibiotic Resistance of Helicobacter pylori in Canada

    Directory of Open Access Journals (Sweden)

    Carlo A Fallone

    2000-01-01

    Full Text Available BACKGROUND: The rate of Helicobacter pylori resistance to antibiotics determines the cure rate of treatment regimens containing such antibiotics. AIMS: To review the literature to determine the rates of H pylori resistance to metronidazole and clarithromycin in Canada, and whether these rates vary in different regions of Canada.

  17. Consolidating and Exploring Antibiotic Resistance Gene Data Resources

    DEFF Research Database (Denmark)

    Xavier, Basil Britto; Das, Anupam J.; Cochrane, Guy

    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...

  18. Antibiotic resistance in the wild: an eco-evolutionary perspective

    Science.gov (United States)

    Virta, Marko

    2017-01-01

    The legacy of the use and misuse of antibiotics in recent decades has left us with a global public health crisis: antibiotic-resistant bacteria are on the rise, making it harder to treat infections. At the same time, evolution of antibiotic resistance is probably the best-documented case of contemporary evolution. To date, research on antibiotic resistance has largely ignored the complexity of interactions that bacteria engage in. However, in natural populations, bacteria interact with other species; for example, competition and grazing are import interactions influencing bacterial population dynamics. Furthermore, antibiotic leakage to natural environments can radically alter bacterial communities. Overall, we argue that eco-evolutionary feedback loops in microbial communities can be modified by residual antibiotics and evolution of antibiotic resistance. The aim of this review is to connect some of the well-established key concepts in evolutionary biology and recent advances in the study of eco-evolutionary dynamics to research on antibiotic resistance. We also identify some key knowledge gaps related to eco-evolutionary dynamics of antibiotic resistance, and review some of the recent technical advantages in molecular microbiology that offer new opportunities for tackling these questions. Finally, we argue that using the full potential of evolutionary theory and active communication across the different fields is needed for solving this global crisis more efficiently. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences'. PMID:27920384

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

    Directory of Open Access Journals (Sweden)

    Tomson Göran

    2010-09-01

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

  20. Epidemiological Interpretation of Studies Examining the Effect of Antibiotic Usage on Resistance

    OpenAIRE

    Schechner, V.; Temkin, E.; Harbarth, S; Carmeli, Y; Schwaber, M. J.

    2013-01-01

    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 pre...

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

    Science.gov (United States)

    Nordmann, P; Poirel, L

    2014-04-23

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

  2. Prevalence and antibiotic resistance of commensal Streptococcus pneumoniae in nine European countries.

    Science.gov (United States)

    Yahiaoui, Rachid Y; den Heijer, Casper Dj; van Bijnen, Evelien Me; Paget, W John; Pringle, Mike; Goossens, Herman; Bruggeman, Cathrien A; Schellevis, François G; Stobberingh, Ellen E

    2016-06-01

    The human microbiota represents an important reservoir of antibiotic resistance. Moreover, the majority of antibiotics are prescribed in primary care. For this reason, we assessed the prevalence and antibiotic resistance of nasal carriage strains of Streptococcus pneumoniae, the most prevalent bacterial causative agent of community-acquired respiratory tract infections, in outpatients in nine European countries. Nasal swabs were collected between October 2010 and May 2011, from 32,770 patients, recruited by general practices in nine European countries. Overall prevalence of S. pneumoniae nasal carriage in the nine countries was 2.9%. The carriage was higher in men (3.7%) than in women (2.7%). Children (4-9 years) had a higher carriage prevalence (27.2%) compared with those older than 10 years (1.9%). The highest resistance observed was to cefaclor. The highest prevalence of multidrug resistance was found in Spain and the lowest prevalence was observed in Sweden.

  3. Detecting mechanisms of acquired BRAF inhibitor resistance in melanoma.

    Science.gov (United States)

    Lo, Roger S; Shi, Hubing

    2014-01-01

    (V600)BRAF mutation was identified as an ideal target for clinical therapy due to its indispensable roles in supporting melanoma initiation and progression. Despite the fact that BRAF inhibitors (BRAFi) can elicit anti-tumor responses in the majority of treated patients and confer overall survival benefits, acquired drug resistance is a formidable obstacle to long-term management of the disease. Several aberrant events including RTK upregulation, NRAS mutation, mutant BRAF amplification or alternative splicing, and MEK mutation have been reported as acquired BRAFi resistance mechanisms. Clinially, detection of these resistance mechanisms help understand drug response patterns and help guide combinatorial therapeutic strategies. Therefore, quick and accurate diagnosis of the resistant mechanisms in tumor biopsies has become an important starting point for personalized therapy. In this chapter, we review the major acquired BRAFi resistance mechanisms, highlight their therapeutic implications, and provide the diagnostic methods from clinical samples.

  4. Response to "Antibiotic Use and Resistance"

    DEFF Research Database (Denmark)

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

    2014-01-01

    As mentioned, antibiotic consumption in heavy users, especially in children, is really striking. Certainly, our results revealed an antibiotic use in this age group higher than published in previous studies, and in line with different reports repeatedly presenting the high antibiotic consumption ...

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

    Science.gov (United States)

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Filipić Brankica

    2015-01-01

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

  7. Ribosomal mutations promote the evolution of antibiotic resistance in a multidrug environment

    Science.gov (United States)

    Gomez, James E; Kaufmann-Malaga, Benjamin B; Wivagg, Carl N; Kim, Peter B; Silvis, Melanie R; Renedo, Nikolai; Ioerger, Thomas R; Ahmad, Rushdy; Livny, Jonathan; Fishbein, Skye; Sacchettini, James C; Carr, Steven A; Hung, Deborah T

    2017-01-01

    Antibiotic resistance arising via chromosomal mutations is typically specific to a particular antibiotic or class of antibiotics. We have identified mutations in genes encoding ribosomal components in Mycobacterium smegmatis that confer resistance to several structurally and mechanistically unrelated classes of antibiotics and enhance survival following heat shock and membrane stress. These mutations affect ribosome assembly and cause large-scale transcriptomic and proteomic changes, including the downregulation of the catalase KatG, an activating enzyme required for isoniazid sensitivity, and upregulation of WhiB7, a transcription factor involved in innate antibiotic resistance. Importantly, while these ribosomal mutations have a fitness cost in antibiotic-free medium, in a multidrug environment they promote the evolution of high-level, target-based resistance. Further, suppressor mutations can then be easily acquired to restore wild-type growth. Thus, ribosomal mutations can serve as stepping-stones in an evolutionary path leading to the emergence of high-level, multidrug resistance. DOI: http://dx.doi.org/10.7554/eLife.20420.001 PMID:28220755

  8. Ribosome-targeting antibiotics and mechanisms of bacterial resistance.

    Science.gov (United States)

    Wilson, Daniel N

    2014-01-01

    The ribosome is one of the main antibiotic targets in the bacterial cell. Crystal structures of naturally produced antibiotics and their semi-synthetic derivatives bound to ribosomal particles have provided unparalleled insight into their mechanisms of action, and they are also facilitating the design of more effective antibiotics for targeting multidrug-resistant bacteria. In this Review, I discuss the recent structural insights into the mechanism of action of ribosome-targeting antibiotics and the molecular mechanisms of bacterial resistance, in addition to the approaches that are being pursued for the production of improved drugs that inhibit bacterial protein synthesis.

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

    Science.gov (United States)

    Pamer, Eric G

    2016-04-29

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

  10. Antibiotic resistant urinary tract infections in an urology ward

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    A. Rădulescu

    2015-12-01

    Full Text Available Introduction: UTI (urinary tract infections represent a central pathology for a urological service. Antibiotic resistance is growing at a steady and alarming rate worldwide and especially in Romania. Method and materials: We have analyzed all the patients that were admitted to our clinic for continuous hospitalization between January 2015 and October 2015. All patients undergone urine culture and all cultures positive had an antibiogram worked up. We have selected all patients that had antibiotic resistance to at least an antibiotic. Results: From 1745 patients admitted for continuous hospitalization, we had 180 positive urine cultures at admission from which 125 had at least an antibiotic resistance. Conclusions: Antibiotic resistance is a serious phenomenon, with potential lethal complications, which we encounter daily in urological practice.

  11. Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing

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    Toshihiro eNishizawa

    2014-10-01

    Full Text Available Antibiotic resistance in Helicobacter pylori (H. pylori is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10 to 14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attractive alternative to the above-mentioned techniques. The technique of polymerase chain reaction (PCR is an accurate and rapid method for the detection of mutations that confer antibiotic resistance. This review highlights the mechanisms of antibiotic resistance in H. pylori and the molecular methods for antibiotic susceptibility testing.

  12. Emerging Community-Acquired Methicillin-Resistant Staphylococcus Aureus Pneumonia

    Directory of Open Access Journals (Sweden)

    Dragana Orlovic

    2009-04-01

    patient each. Sputum samples were collected at the time of admission and all grew MRSA. Two isolates were resistant only to oxacillin, while four were also resistant to levofloxacin (3 isolates, erythromycin (2 isolates, ciprofloxacin (1 isolate, and/or clindamycin (1 isolate. One patient had concurrent Pseudomonas bacteremia, and another had Pseudomonas isolated from sputum culture in addition to MRSA. All patients had abnormal chest radiographs; three had focal unilateral pneumonia, two had bilateral pneumonia, and one had a lung abscess. The latter patient also had evidence of metastatic infection with sternoclavicular osteomyelitis. Three patients required ventilatory support; two of these subjects died and one was discharged to hospice care. None of the six patients had any epidemiologic connection to one another. Conclusion: CA-MRSA is becoming an increasingly important cause of community-acquired pneumonia in many parts of the world, and in these regions empiric antibiotic treatment guidelines should be reconsidered.

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

    DEFF Research Database (Denmark)

    Singer, R.S.; Finch, R.; Wegener, Henrik Caspar

    2003-01-01

    levels in people has also come under scrutiny. Antimicrobials are used therapeutically and prophylactically in animals. More controversially, antimicrobials are also used as growth promoters to improve the ability of the animal to convert feed into body mass. Some argue that the impact of use...... meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance...... of antibiotics in animals-whether therapeutic or as growth promoters-pales by comparison with human use, and that efforts should be concentrated on the misuse of antibiotics in people. Others warn of the dangers of unregulated and unnecessary use of antibiotics, especially growth promoters in animal husbandry...

  14. Plasmid interference for curing antibiotic resistance plasmids in vivo

    Science.gov (United States)

    Kamruzzaman, Muhammad; Shoma, Shereen; Thomas, Christopher M.; Partridge, Sally R.

    2017-01-01

    Antibiotic resistance increases the likelihood of death from infection by common pathogens such as Escherichia coli and Klebsiella pneumoniae in developed and developing countries alike. Most important modern antibiotic resistance genes spread between such species on self-transmissible (conjugative) plasmids. These plasmids are traditionally grouped on the basis of replicon incompatibility (Inc), which prevents coexistence of related plasmids in the same cell. These plasmids also use post-segregational killing (‘addiction’) systems, which poison any bacterial cells that lose the addictive plasmid, to guarantee their own survival. This study demonstrates that plasmid incompatibilities and addiction systems can be exploited to achieve the safe and complete eradication of antibiotic resistance from bacteria in vitro and in the mouse gut. Conjugative ‘interference plasmids’ were constructed by specifically deleting toxin and antibiotic resistance genes from target plasmids. These interference plasmids efficiently cured the corresponding antibiotic resistant target plasmid from different Enterobacteriaceae in vitro and restored antibiotic susceptibility in vivo to all bacterial populations into which plasmid-mediated resistance had spread. This approach might allow eradication of emergent or established populations of resistance plasmids in individuals at risk of severe sepsis, enabling subsequent use of less toxic and/or more effective antibiotics than would otherwise be possible, if sepsis develops. The generalisability of this approach and its potential applications in bioremediation of animal and environmental microbiomes should now be systematically explored. PMID:28245276

  15. Detection of antibiotic resistance in probiotics of dietary supplements

    KAUST Repository

    Wong, Aloysius Tze

    2015-09-14

    Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

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

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    Golsha, R. (MD

    2014-06-01

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

  17. Antibiotic use in acne vulgaris and rosacea: clinical considerations and resistance issues of significance to dermatologists.

    Science.gov (United States)

    Del Rosso, James Q; Leyden, James J; Thiboutot, Diane; Webster, Guy F

    2008-08-01

    Antibiotics are commonly prescribed in dermatology practice for a variety of disorders, including acne vulgaris and rosacea. Importantly, they often are used long-term for these inflammatory dermatoses. Changes in bacterial ecology related to antibiotic prescribing have led to the decreased sensitivity of some bacterial organisms, such as Propionibacterium acnes, to antibiotics commonly prescribed by dermatologists. The potential clinical outcomes of altered bacterial sensitivities may vary among specific disease states and include decreased therapeutic response and the need to alter approaches in disease management. Additionally, changing patterns of antibiotic sensitivity and the emergence of more virulent pathogens, such as community-acquired methicillin-resistant Staphylococcus aureus, macrolide-resistant staphylococci and streptococci, and mupirocin-resistant S aureus, have led to marked changes in how clinicians use antibiotics in clinical practice. This article reviews antibiotic prescribing in dermatology practice and provides important clinical perspectives and recommendations to preserve the therapeutic value of antibiotics based on a thorough review of current literature and clinical experience.

  18. Selection of appropriate analytical tools to determine the potency and bioactivity of antibiotics and antibiotic resistance$

    Institute of Scientific and Technical Information of China (English)

    Nishant A. Dafale n; Uttam P. Semwal; Rupak K. Rajput; G.N. Singh

    2016-01-01

    Antibiotics are the chemotherapeutic agents that kill or inhibit the pathogenic microorganisms. Re-sistance of microorganism to antibiotics is a growing problem around the world due to indiscriminate and irrational use of antibiotics. In order to overcome the resistance problem and to safely use antibiotics, the correct measurement of potency and bioactivity of antibiotics is essential. Microbiological assay and high performance liquid chromatography (HPLC) method are used to quantify the potency of antibiotics. HPLC method is commonly used for the quantification of potency of antibiotics, but unable to determine the bioactivity; whereas microbiological assay estimates both potency and bioactivity of antibiotics. Additionally, bioassay is used to estimate the effective dose against antibiotic resistant microbes. Simultaneously, microbiological assay addresses the several parameters such as minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC), mutation prevention concentration (MPC) and critical concentration (Ccr) which are used to describe the potency in a more informative way. Microbiological assay is a simple, sensitive, precise and cost effective method which gives reproducible results similar to HPLC. However, the HPLC cannot be a complete substitute for microbiological assay and both methods have their own significance to obtain more realistic and precise results.

  19. Economic implications of antibiotic resistance in a global economy.

    Science.gov (United States)

    Rudholm, Niklas

    2002-11-01

    This paper concerns the economic implications of antibiotic resistance in a global economy. The global economy consists of several countries, where antibiotic consumption creates a stock of bacteria which is resistant to antibiotics. This stock affects the welfare in all countries because of the risk that resistant bacterial strains may be transmitted. The main purpose of the paper is to compare the socially optimal resource allocation with the allocation brought forward by the decentralized market economy. In addition, a dynamic Pigouvian tax designed to implement the globally optimal resource allocation is presented.

  20. Yeasts acquire resistance secondary to antifungal drug treatment by adaptive mutagenesis.

    Directory of Open Access Journals (Sweden)

    David Quinto-Alemany

    Full Text Available Acquisition of resistance secondary to treatment both by microorganisms and by tumor cells is a major public health concern. Several species of bacteria acquire resistance to various antibiotics through stress-induced responses that have an adaptive mutagenesis effect. So far, adaptive mutagenesis in yeast has only been described when the stress is nutrient deprivation. Here, we hypothesized that adaptive mutagenesis in yeast (Saccharomyces cerevisiae and Candida albicans as model organisms would also take place in response to antifungal agents (5-fluorocytosine or flucytosine, 5-FC, and caspofungin, CSP, giving rise to resistance secondary to treatment with these agents. We have developed a clinically relevant model where both yeasts acquire resistance when exposed to these agents. Stressful lifestyle associated mutation (SLAM experiments show that the adaptive mutation frequencies are 20 (S. cerevisiae -5-FC, 600 (C. albicans -5-FC or 1000 (S. cerevisiae--CSP fold higher than the spontaneous mutation frequency, the experimental data for C. albicans -5-FC being in agreement with the clinical data of acquisition of resistance secondary to treatment. The spectrum of mutations in the S. cerevisiae -5-FC model differs between spontaneous and acquired, indicating that the molecular mechanisms that generate them are different. Remarkably, in the acquired mutations, an ectopic intrachromosomal recombination with an 87% homologous gene takes place with a high frequency. In conclusion, we present here a clinically relevant adaptive mutation model that fulfils the conditions reported previously.

  1. Antibiotic resistance patterns of Pseudomonas spp. isolated from the River Danube

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    Clemens eKittinger

    2016-05-01

    Full Text Available Spread and persistence of antibiotic resistance pose a severe threat to human health, yet there is still lack of knowledge about reservoirs of antibiotic resistant bacteria in the environment. We took the opportunity of the Joint Danube Survey 3 (JDS3, the world's biggest river research expedition of its kind in 2013, to analyse samples originating from different sampling points along the whole length of the river. Due to its high clinical relevance, we concentrated on the characterization of Pseudomonas spp. and evaluated the resistance profiles of Pseudomonas spp. which were isolated from eight sampling points. In total, 520 Pseudomonas isolates were found, 344 (66.0% isolates were identified as Pseudomonas putida, and 141 (27.1% as Pseudomonas fluorescens, all other Pseudomonas species were represented by less than five isolates, among those two P. aeruginosa isolates. Thirty seven percent (37% of all isolated Pseudomonas species showed resistance to at least one out of eleven tested antibiotics. The most common resistance was against meropenem (30.4% / 158 isolates piperacillin/tazobactam (10.6% / 55 isolates and ceftazidime (4.2% / 22 isolates. 16 isolates (3.1% / 16 isolates were multi-resistant. For each tested antibiotic at least one resistant isolate could be detected. Sampling points from the upper stretch of the River Danube showed more resistant isolates than downriver. Our results suggest that antibiotic resistance can be acquired by and persists even in Pseudomonas species that are normally not in direct contact with humans. A possible scenario is that these bacteria provide a reservoir of antibiotic resistance genes that can spread to related human pathogens by horizontal gene transfer.

  2. Molecular Mechanisms of Antibiotic Resistance in Helicobacter pylori

    OpenAIRE

    Gerrits, Monique

    2004-01-01

    textabstractAn estimated 4 to 5 million individuals in the Netherlands are actively infected with Helicobacter pylori. Eradication of this bacterium becomes more difficult as the prevalence of antibiotic resistance is increasing worldwide. Most H. pylori infections are now diagnosed by non-invasive testing (i.e. urea breath test, serology, stool test), and thus data on antibiotic susceptibility are lacking. Furthermore, once the antibiotic susceptibility is assessed using conventional culture...

  3. The chemistry of peptidyltransferase center-targeted antibiotics: enzymatic resistance and approaches to countering resistance.

    Science.gov (United States)

    McCusker, Kevin P; Fujimori, Danica Galonić

    2012-01-20

    The continued ability to treat bacterial infections requires effective antibiotics. The development of new therapeutics is guided by knowledge of the mechanisms of action of and resistance to these antibiotics. Continued efforts to understand and counteract antibiotic resistance mechanisms at a molecular level have the potential to direct development of new therapeutic strategies in addition to providing insight into the underlying biochemical functions impacted by antibiotics. The interaction of antibiotics with the peptidyltransferase center and adjacent exit tunnel within the bacterial ribosome is the predominant mechanism by which antibiotics impede translation, thus stalling growth. Resistance enzymes catalyze the chemical modification of the RNA that composes these functional regions, leading to diminished binding of antibiotics. This review discusses recent advances in the elucidation of chemical mechanisms underlying resistance and driving the development of new antibiotics.

  4. Characterization of SCCmec types, antibiotic resistance, and toxin gene profiles of Staphylococcus aureus strains.

    Science.gov (United States)

    Szczuka, Ewa; Grabska, Katarzyna; Trawczyński, Krzysztof; Bosacka, Karolina; Kaznowski, Adam

    2013-09-01

    Methicillin-resistant Staphylococcus aureus (MRSA) causes serious nosocomial and community acquired infections. Resistance to methicillin is mediated by the mecA gene, which is inserted in a mobile genetic element called staphylococcal cassette chromosome mec (SCCmec). We determined the SCCmec types, the occurrence of genes encoding toxic shock syndrome toxin (tst), exfoliative toxin (eta, etb), Panton-Valentine leukocidin (pvl) as well as antibiotic susceptibility of these isolates. Among 65 hospital-acquired methicillin-resistant S. aureus (HA-MRSA) strains, SCCmec types II, III and IV were identified. Type III SCCmec was the most prevalent (62%), followed by mec types II (24%) and IV (14%). Four community acquired methicillin-resistant S. aureus (CA-MRSA) strains carried SCCmec type IV and were pvl-positive. The most prevalent gene among HA-MRSA was pvl. The toxic shock syndrome toxin and exfoliative toxin genes were found only in hospital-acquired methicillin-resistant S. aureus. The results of this study demonstrate that the SCCmec type III is predominant among strains recovered from hospitalized patients with infections and that these strains were resistant to many antibiotics used in the treatment of staphylococcal infections.

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

    Science.gov (United States)

    McKinney, Chad W; Pruden, Amy

    2012-12-18

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

  6. Impact of antibiotic restriction on resistance levels of Escherichia coli

    DEFF Research Database (Denmark)

    Boel, Jonas Bredtoft; Andreasen, Viggo; Jarløv, Jens Otto

    2016-01-01

    OBJECTIVES: We evaluated the effect of an antibiotic stewardship programme (ASP) on the use of antibiotics and resistance levels of Escherichia coli using a method that allowed direct comparison between an intervention hospital and a control hospital. METHODS: The study was conducted...

  7. Evaluating antibiotic resistance genes in soils with applied manures

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  9. [Antibiotic resistance: recommendations from the Advisory Council for Health Research

    NARCIS (Netherlands)

    Hoogkamp-Korstanje, J.A.A.

    2001-01-01

    The Advisory Council for Health Research (RGO) advised the Dutch Minister of Health on research into the epidemiology, prevention and research of antibiotic resistance in the Netherlands. Good antimicrobial practice, insight into antibiotic use, implementation of measures to prevent development of r

  10. A framework for global surveillance of antibiotic resistance

    NARCIS (Netherlands)

    Grundmann, Hajo; Klugman, Keith P.; Walsh, Timothy; Ramon-Pardo, Pilar; Sigauque, Betuel; Khan, Wasif; Laxminarayan, Ramanan; Heddini, Andreas; Stelling, John

    2011-01-01

    The foreseen decline in antibiotic effectiveness explains the needs for data to inform the global public health agenda about the magnitude and evolution of antibiotic resistance as a serious threat to human health and development. Opportunistic bacterial pathogens are the cause of the majority of co

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  12. Antibiotic-Resistant Bacteria: There is Hope.

    Science.gov (United States)

    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)

  13. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

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

    2008-03-11

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

  16. Recent Insights into Antibiotic Resistance in Helicobacter pylori Eradication

    Directory of Open Access Journals (Sweden)

    Wenming Wu

    2012-01-01

    Full Text Available Antibiotics have been useful in the treatment of H. pylori-related benign and malignant gastroduodenal diseases. However, emergence of antibiotic resistance often decreases the eradication rates of H. pylori infections. Many factors have been implicated as causes of treatment failure, but the main antibiotic resistance mechanisms described to date are due to point mutations on the bacterial chromosome, a consequence of a significantly phenotypic variation in H. pylori. The prevalence of antibiotic (e.g., clarithromycin, metronidazole, tetracycline, amoxicillin, and furazolidone resistance varies among different countries; it appears to be partly determined by geographical factors. Since the worldwide increase in the rate of antibiotic resistance represents a problem of relevance, some studies have been performed in order to identify highly active and well-tolerated anti-H. pylori therapies including sequential, concomitant quadruple, hybrid, and quadruple therapy. These represent a promising alternatives in the effort to overcome the problem of resistance. The aim of this paper is to review the current status of antibiotic resistance in H. pylori eradication, highlighting the evolutionary processes in detail at alternative approaches to treatment in the past decade. The underlying resistance mechanisms will be also followed.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Methicillin-resistant and methicillin-susceptible community-acquired Staphylococcus aureus infection among children

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    Renata Tavares Gomes

    2013-10-01

    Full Text Available Methicillin-resistant Staphylococcus aureus has emerged as a pathogen associated with community-acquired infections worldwide. We report the spectrum of community-acquired S. aureus infections and compare the patients infected with methicillin-susceptible or methicillin-resistant strains among patients aged <20 years. Overall, 90 cases of community acquired S. aureus were detected in an 11-year period. Clinical and microbiological data were registered. Fifty-nine (66% patients were male and the median age was two years. The majority (87% of the patients were hospitalized and chronic underlying illnesses were detected in 27 (30% cases. Overall, 34 (37.8% patients had skin/soft tissue infections and 56 (62.2% patients had deep-seated infection. Four (5.1% patients were transferred to the intensive care unit and two (2.6% died. Complications were detected in 17 (18.9% cases, such as pleural effusion (41.2%, osteomyelitis (23.5%, and sepsis (17.6%. Six (6.7% methicillin-resistant strains were detected. Patients infected with methicillin-susceptible or methicillin-resistant strains had similar baseline characteristics and treatment outcomes. Approximately 93% of the cases received systemic antibiotics, out of which 59 (65.5% used oxacillin or cefalotin. Both methicillin-susceptible and methicillin-resistant S. aureus strains resulted in morbidity and death among children in this setting where methicillin-resistant strains are infrequent.

  20. 急性重症脑卒中患者并发院内获得性肺炎的病原菌分布及耐药性分析%Distribution and Antibiotic Resistance of Pathogens Isolated from Patients with Acute Severe Stroke Accompanyied with Hospital Acquired Pneumonia

    Institute of Scientific and Technical Information of China (English)

    刘伦

    2013-01-01

    Objective investigate the distribution and antibiotic resistance of pathogens isolated from patients with acute severe stroke accompanyied with hospital acquired pneumonia.Methods The clinical data of 225 patients with acute severe stroke accompanied with hospital acquired pneumonia in NICU from Jan 2011 to May 2012 were analyzed retrospectively.Results 11 pathogenic microorganisms and 121 strains were cultivated among the 225 cases accompanied with nosocomial pneumonia.Gram negative bacilli,gram positive bacteria and fungi accounted for 68.60%,29.75% and 1.65%,respectively.Among gram negative bacilli,the most common pathogens were Pseudomonas aeruginosa,Escherichia coli and Acinetobacter baumannii.Staphylococcus aureus was the most prominent of gram positive bacteria.All strains of fungi were Candida albicans.The drug resistance rate of Acinetobacter baumannii and Pseudomonas aeruginosa strains to carbapenems antibiotics was 78.4%,83.3% respectively while Escherichia coli and klebsiella pneumoniae strains were 100% sensitive to carbapenems antibiotics.The drug resistance rate of Staphylococcus aureus to penicillins antibiotics was above 90%,but none of Staphylococcus aureus strains was resistant to vancomycin.Conclusion Gram negative bacilli and gram positive bacteria were the main pathogens for patients with acute severe stroke accompanyied with nosocomial pneumonia,but Gram negitive bacteria were the leading ones.Antibiotics should be rationally used according to the results of susceptibility testing.The NICU should enhance monitoring and control of antibiotics in order to help patients to recover quickly.%目的 了解医院急性重症脑卒中患者并发院内获得性肺炎(hospital acquived peneumonia,HAP)的病原菌分布及耐药性,以指导临床抗生素的合理使用.方法 回顾分析湖北省武汉市第一医院神经内科重症监护病房自2011年1月——2012年5月收治的225例急性重症脑卒中并

  1. Antimicrobial susceptibility and antibiotic resistance gene transfer analysis of foodborne, clinical, and environmental Listeria spp. isolates including Listeria monocytogenes.

    Science.gov (United States)

    Bertsch, David; Muelli, Mirjam; Weller, Monika; Uruty, Anaïs; Lacroix, Christophe; Meile, Leo

    2014-02-01

    The aims of this study were to assess antibiotic resistance pheno- and genotypes in foodborne, clinical, and environmental Listeria isolates, as well as to elucidate the horizontal gene transfer potential of detected resistance genes. A small fraction of in total 524 Listeria spp. isolates (3.1%) displayed acquired antibiotic resistance mainly to tetracycline (n = 11), but also to clindamycin (n = 4) and trimethoprim (n = 3), which was genotypically confirmed. In two cases, a tetracycline resistance phenotype was observed together with a trimethoprim resistance phenotype, namely in a clinical L. monocytogenes strain and in a foodborne L. innocua isolate. Depending on the applied guidelines, a differing number of isolates (n = 2 or n = 20) showed values for ampicillin that are on the edge between intermediate susceptibility and resistance. Transferability of the antibiotic resistance genes from the Listeria donors, elucidated in vitro by filter matings, was demonstrated for genes located on transposons of the Tn916 family and for an unknown clindamycin resistance determinant. Transfer rates of up to 10(-5) transconjugants per donor were obtained with a L. monocytogenes recipient and up to 10(-7) with an Enterococcus faecalis recipient, respectively. Although the prevalence of acquired antibiotic resistance in Listeria isolates from this study was rather low, the transferability of these resistances enables further spread in the future. This endorses the importance of surveillance of L. monocytogenes and other Listeria spp. in terms of antibiotic susceptibility.

  2. Causative agent distribution and antibiotic therapy assessment among adult patients with community acquired pneumonia in Chinese urban population

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    Liu Yong

    2009-03-01

    Full Text Available Abstract Background Knowledge of predominant microbial patterns in community-acquired pneumonia (CAP constitutes the basis for initial decisions about empirical antimicrobial treatment, so a prospective study was performed during 2003–2004 among CAP of adult Chinese urban populations. Methods Qualified patients were enrolled and screened for bacterial, atypical, and viral pathogens by sputum and/or blood culturing, and by antibody seroconversion test. Antibiotic treatment and patient outcome were also assessed. Results Non-viral pathogens were found in 324/610 (53.1% patients among whom M. pneumoniae was the most prevalent (126/610, 20.7%. Atypical pathogens were identified in 62/195 (31.8% patients carrying bacterial pathogens. Respiratory viruses were identified in 35 (19% of 184 randomly selected patients with adenovirus being the most common (16/184, 8.7%. The nonsusceptibility of S. pneumoniae to penicillin and azithromycin was 22.2% (Resistance (R: 3.2%, Intermediate (I: 19.0% and 79.4% (R: 79.4%, I: 0%, respectively. Of patients (312 from whom causative pathogens were identified and antibiotic treatments were recorded, clinical cure rate with β-lactam antibiotics alone and with combination of a β-lactam plus a macrolide or with fluoroquinolones was 63.7% (79/124 and 67%(126/188, respectively. For patients having mixed M. pneumoniae and/or C. pneumoniae infections, a better cure rate was observed with regimens that are active against atypical pathogens (e.g. a β-lactam plus a macrolide, or a fluoroquinolone than with β-lactam alone (75.8% vs. 42.9%, p = 0.045. Conclusion In Chinese adult CAP patients, M. pneumoniae was the most prevalent with mixed infections containing atypical pathogens being frequently observed. With S. pneumoniae, the prevalence of macrolide resistance was high and penicillin resistance low compared with data reported in other regions.

  3. Intravenous antibiotics infusion and bacterial resistence: nursing responsability

    OpenAIRE

    2006-01-01

    The success of antibiotics treatment and development of bacterial resistance depend on many factors. The preparation and management of these factors are associated with nursing care. The aim of this paper is review literature about preparation, management and knowledge of intravenous antibiotics errors analyzing possibilities of influence of bacterial resistance prevention by nurses. Methods: a systematic review was done from LiILACS and M...

  4. Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru

    Science.gov (United States)

    Boehnke, Kevin F; Valdivieso, Manuel; Bussalleu, Alejandro; Sexton, Rachael; Thompson, Kathryn C; Osorio, Soledad; Reyes, Italo Novoa; Crowley, John J; Baker, Laurence H; Xi, Chuanwu

    2017-01-01

    Objectives Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. Materials and methods H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. Results Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. Conclusion The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively. PMID:28331349

  5. Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing

    OpenAIRE

    Toshihiro eNishizawa; Hidekazu eSuzuki

    2014-01-01

    Antibiotic resistance in Helicobacter pylori (H. pylori) is the main factor affecting the efficacy of current treatment methods against infection caused by this organism. The traditional culture methods for testing bacterial susceptibility to antibiotics are expensive and require 10 to 14 days. Since resistance to clarithromycin, fluoroquinolone, and tetracycline seems to be exclusively caused by specific mutations in a small region of the responsible gene, molecular methods offer an attracti...

  6. Antibiotic resistance in Enterobacteriaceae: what impact on the efficacy of antibiotic prophylaxis in colorectal surgery?

    Science.gov (United States)

    Kirby, A; Santoni, N

    2015-04-01

    Antibiotic prophylaxis, introduced in the 1940s, brought in an era of relatively safe colorectal surgery. This was achieved in part due to the prevention of surgical site infections (SSIs) caused by Enterobacteriaceae. Since then, Enterobacteriaceae have become increasingly resistant to the antibiotics commonly used for prophylaxis. The impact of being colonized preoperatively with resistant Enterobacteriaceae on the efficacy of colorectal SSI prophylaxis, if any, is unknown. It is also difficult to predict the likely impact of resistance as the exposure‒response relationships have not been determined for antibiotic surgical prophylaxis. Neither is it known which test for resistance to use; the importance of the concentration of Enterobacteriaceae in the colon, the ability of different species of Enterobacteriaceae to cause SSIs, and the comparative ability of minimum inhibitory concentration or presence of a resistance mechanism in predicting SSI risk have yet to be established. Clinical research is urgently needed to answer these questions.

  7. THE OUTCOME OF ANTIBIOTIC THERAPY AMONG CHILDREN WITH SEVERE COMMUNITY ACQUIRED PNEUMONIA

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    M. R. Usman

    2015-08-01

    Full Text Available Background: The effect of human immunodeficiency virus (HIV status on the evolution of community acquired pneumonia (CAP is still controversial. There are controversies regarding antibiotic treatment outcome of CAP in HIV infected children. Objective: The aim of this study was to investigate possible differences in hospital outcomes, with compared the outcome of the treatment in severe CAP among HIV infected and HIV uninfected children which had an empiric antibiotic therapy. Methods: A case control study of 80 patients with severe CAP in Department of Child Health, Sanglah General Hospital, Bali-Indonesia. We evaluated clinical features for seeing the effectiveness of the antibiotic therapy according to Department of Child Health, Sanglah General Hospital’s clinical pathway for severe pneumonia between HIV infected and HIV uninfected patients. Results: 58% patients in failure treatment and 45% patients in favorable treatment were HIV infected. There were similar characteristics from both groups, except malnutrition condition was statistically significant contribute the outcome (OR 2.87 (95% CI 1.098 to 7.500, p= 0.031. There was no significantly statistic difference of the outcome in HIV infected as compared to HIV uninfected patients with severe CAP (OR 1.65 (95% CI 0.683 to 4.002, p= 0.263. Conclusion: HIV infection was not gave an effect on the outcome of severe CAP patients which had an antibiotic therapy based on Department of Child Health, Sanglah General Hospital’s clinical pathway for severe pneumonia.

  8. Antibiotics in animal feed and their role in resistance development

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar

    2003-01-01

    Animals and humans constitute overlapping reservoirs of resistance, and consequently use of antimicrobials in animals can impact on public health. For example, the occurrence of vancomycin-resistant enterococci in food-animals is associated with the use of avoparcin, a glycopeptide antibiotic used...... as a feed additive for the growth promotion of animals. Vancomycin-resistant enterococci and vancomycin resistance determinants can therefore spread from animals to humans. The bans on avoparcin and other antibiotics as growth promoters in the EU have provided scientists with a unique opportunity......, the effects on animal health and productivity have been very minor....

  9. Arabidopsis map kinase 4 negatively regulates systemic acquired resistance

    DEFF Research Database (Denmark)

    Brodersen, P; Johansen, Bo; Petersen, M;

    2000-01-01

    Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) levels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern...... of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression....

  10. Arabidopsis MAP kinase 4 negatively regulates systemic acquired resistance

    DEFF Research Database (Denmark)

    Petersen, M.; Brodersen, P.; Naested, H.

    2000-01-01

    Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) revels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern...... of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression....

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

    Science.gov (United States)

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

  12. Antibiotic tolerance and resistance in biofilms

    DEFF Research Database (Denmark)

    Ciofu, Oana; Tolker-Nielsen, Tim

    2010-01-01

    One of the most important features of microbial biofilms is their tolerance to antimicrobial agents and components of the host immune system. The difficulty of treating biofilm infections with antibiotics is a major clinical problem. Although antibiotics may decrease the number of bacteria...... in biofilms, they will not completely eradicate the bacteria in vivo which may have important clinical consequences in form of relapses of the infection....

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

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    Helen Madden

    2013-11-01

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

  14. Intravenous antibiotics infusion and bacterial resistence: nursing responsability

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    Heloisa Helena Karnas Hoefel

    2006-12-01

    Full Text Available The success of antibiotics treatment and development of bacterial resistance depend on many factors. The preparation and management of these factors are associated with nursing care. The aim of this paper is review literature about preparation, management and knowledge of intravenous antibiotics errors analyzing possibilities of influence of bacterial resistance prevention by nurses. Methods: a systematic review was done from LiILACS and Medline searching for the word nursing and bacterial resistance, antibiotics control, hospital infections, administration drugs, errors and adverse events. There were chose 58 papers about nursing and/or were basics for international and Brazilian studies. Results: It was described international classifications errors and consequences analyzing their possible influences on antibiotics effects. Based on these knowledge, interventions are recommended to implement safety practice and care.

  15. Investigating antibiotic resistance in non-clinical environments

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    Fiona eWalsh

    2013-02-01

    Full Text Available There have been many calls for more information about the natural resistome and these have also highlighted the importance of understanding the soil resistome in the preservation of antibiotics for the treatment of infections. However, to date there have been few studies which have investigated the culturable soil resistome, which highlights the difficulties faced by microbiologists in designing these experiments to produce meaningful data. The World Health Organization definition of resistance is the most fitting to non-clinical environmental studies: Antimicrobial resistance is resistance of a microorganism to an antimicrobial medicine to which it was previously sensitive. The ideal investigation of non-clinical environments for antibiotic resistance of clinical relevance would be using standardized guidelines and breakpoints. This review outlines different definitions and methodologies used to understand antibiotic resistance and suggests how this can be performed outside of the clinical environment.

  16. Antibiotic and Antimicrobial Resistance: Threat Report 2013

    Science.gov (United States)

    ... resistant Staphylococcus aureus (MRSA) [page 77] Drug-resistant Streptococcus pneumoniae [page 79] Drug-resistant tuberculosis [page 81] Microorganisms with a Threat Level of Concerning Vancomycin-resistant Staphylococcus aureus ... Streptococcus [page 87] Clindamycin-resistant Group B Streptococcus [page ...

  17. Antibiotic resistance amongst healthcare-associated pathogens in China.

    Science.gov (United States)

    Yezli, Saber; Li, Han

    2012-11-01

    The People's Republic of China, commonly known as China, comprises approximately one-fifth of the world's population. Because of the expanding size and density of its population and the frequent interaction of people with animals, China is a hotspot for the emergence and spread of new microbial threats and is a major contributor to the worldwide infectious disease burden. In recent years, the emergence and rapid spread of severe acute respiratory syndrome (SARS) generated considerable interest in the Chinese healthcare system and its infection control and prevention measures. This review examines antibiotic misuse and the status of antibiotic resistance in the Chinese healthcare system. China has high rates of antibiotic resistance driven by misuse of these agents in a healthcare system that provides strong incentives for overprescribing and in a country where self-medication is common. Tuberculosis remains a serious problem in China, with a high prevalence of multidrug-resistant and extensively drug-resistant strains. Drug resistance amongst nosocomial bacteria has been on a rapid upward trend with a strong inclination towards multidrug resistance. There is a need for effective infection prevention and control measures and strict use of antibiotics in China to control the rise and spread of antibiotic resistance in the country.

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

    Science.gov (United States)

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

    2015-04-01

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

  19. ABC-F Proteins Mediate Antibiotic Resistance through Ribosomal Protection.

    Science.gov (United States)

    Sharkey, Liam K R; Edwards, Thomas A; O'Neill, Alex J

    2016-03-22

    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 anin vitrotranslation assay prompts dose-dependent rescue of translation, and demonstrate that such proteins are capable of displacing antibiotic from the ribosomein vitro To our knowledge, these experiments constitute the first direct evidence that ABC-F proteins mediate antibiotic resistance through ribosomal protection.IMPORTANCEAntimicrobial resistance ranks among the greatest threats currently facing human health. Elucidation of the mechanisms by which microorganisms resist the effect of antibiotics is central to understanding the biology of this phenomenon and has the potential to inform the development of new drugs capable of blocking or circumventing resistance. Members of the ABC-F family, which includelsa(A),msr(A),optr(A), andvga(A), collectively yield resistance to a broader range of clinically significant antibiotic classes than any other family of resistance determinants, although their mechanism of action has been controversial since their discovery 25 years ago. Here we present the first direct evidence that proteins of the ABC-F family act to protect the bacterial ribosome from antibiotic-mediated inhibition.

  20. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

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    Ana Carolina Costa REIS

    2016-01-01

    Full Text Available SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014. All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy.

  1. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

    Science.gov (United States)

    REIS, Ana Carolina Costa; SANTOS, Susana Regia da Silva; de SOUZA, Siane Campos; SALDANHA, Milena Góes; PITANGA, Thassila Nogueira; OLIVEIRA, Ricardo Riccio

    2016-01-01

    SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy. PMID:27410913

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

    Science.gov (United States)

    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.

  3. SURVEILLANCE AND CONTROL OF ANTIBIOTIC RESISTANCE IN THE MEDITERRANEAN REGION

    Directory of Open Access Journals (Sweden)

    Walter Ricciardi

    2016-07-01

    Full Text Available Antibiotic resistance is one of the most relevant problems in the healthcare: the growth of resistant micro-organisms 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 on antibiotic resistance in 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 particularly worrying 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 amino glycosides. Is particularly relevant 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

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

    Directory of Open Access Journals (Sweden)

    Carlet Jean

    2012-02-01

    Full Text Available Abstract 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.

  5. Differential epigenetic compatibility of qnr antibiotic resistance determinants with the chromosome of Escherichia coli.

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    María B Sánchez

    Full Text Available Environmental bacteria harbor a plethora of genes that, upon their horizontal transfer to new hosts, may confer resistance to antibiotics, although the number of such determinants actually acquired by pathogenic bacteria is very low. The founder effect, fitness costs and ecological connectivity all influence the chances of resistance transfer being successful. We examined the importance of these bottlenecks using the family of quinolone resistance determinants Qnr. The results indicate the epigenetic compatibility of a determinant with the host genome to be of great importance in the acquisition and spread of resistance. A plasmid carrying the widely distributed QnrA determinant was stable in Escherichia coli, whereas the SmQnr determinant was unstable despite both proteins having very similar tertiary structures. This indicates that the fitness costs associated with the acquisition of antibiotic resistance may not derive from a non-specific metabolic burden, but from the acquired gene causing specific changes in bacterial metabolic and regulatory networks. The observed stabilization of the plasmid encoding SmQnr by chromosomal mutations, including a mutant lacking the global regulator H-NS, reinforces this idea. Since quinolones are synthetic antibiotics, and since the origin of QnrA is the environmental bacterium Shewanella algae, the role of QnrA in this organism is unlikely to be that of conferring resistance. Its evolution toward this may have occurred through mutations or because of an environmental change (exaptation. The present results indicate that the chromosomally encoded Qnr determinants of S. algae can confer quinolone resistance upon their transfer to E. coli without the need of any further mutation. These results suggest that exaptation is important in the evolution of antibiotic resistance.

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

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    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.

  7. Trends in antibiotic resistance of corneal pathogens: Part I. An analysis of commonly used ocular antibiotics

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    Sharma Savitri

    1999-01-01

    Full Text Available Purpose: To analyse commonly used ocular antibiotics and determine their in-vitro efficacies against bacterial keratitis pathogens. Methods: A retrospective review of microbiology records at the LV Prasad Eye Institute in Hyderabad, India identified 1,633 bacterial keratitis isolates. Antibiotic susceptibility of corneal isolates was determined for various ocular antibiotics using the Kirby-Bauer disc-diffusion method. Results: Cefazolin had coverage against 1,296 (83.0% of 1,562 isolates tested; chloramphenicol against 1,136 (71.7% of 1,585 isolates; ciprofloxacin against 1,080 (69.3% of 1,558 isolates; gentamicin against 1,106 (70.6% of 1,567 isolates; norfloxacin against 1,057 (67.7% of 1,561 isolates; vancomycin against 463 (84.3% of 549 isolates; and framycetin against 105 (36.2% of 290 isolates. Also included is a breakdown by species, and sensitivity profiles for resistant isolates.Conclusion: This study provides information on the efficacies of ocular antibiotics commonly used against bacterial keratitis pathogens. It also examines the antibiotic susceptibility profiles for corneal pathogens that are resistant to an ocular antibiotic but sensitive to other selected antibiotics. It is hoped that this information will aid in the decision-making of empiric initial treatment of bacterial keratitis.

  8. Nationwide survey of Helicobacter pylori antibiotic resistance in Thailand.

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    Vilaichone, Ratha-Korn; Gumnarai, Pornpen; Ratanachu-Ek, Thawee; Mahachai, Varocha

    2013-12-01

    The objectives of this study are to survey the antibiotic-resistant pattern of Helicobacter pylori infection in different geographical locations in Thailand and to determine factors associated with antibiotic resistance. Dyspeptic patients undergoing upper gastrointestinal endoscopy from the Northern, Northeastern, Central, and Southern regions of Thailand between January 2004 and December 2012 were enrolled in this study. Two antral gastric biopsies were obtained for culture; susceptibility tests were performed using E-test. A total of 3964 were enrolled, and 1350 patients (34.1%) were infected with H. pylori as identified by rapid urease test. Cultures were positive in 619 isolates. E-test for amoxicillin, clarithromycin, metronidazole, and tetracycline were successful in 400 isolates and for levofloxacin and ciprofloxacin in 208 isolates. Antibiotic resistance was present in 50.3% including amoxicillin 5.2%, tetracycline 1.7%, clarithromycin 3.7%, metronidazole 36%, ciprofloxacin 7.7%, levofloxacin 7.2%, and multi-drugs in 4.2%. Clarithromycin resistance was significantly more common in those older than 40 years (i.e., 100% versus 0%; P = 0.04). The prevalence of metronidazole resistant in Southern Thailand was significantly higher than in the Northeastern region (66.7% versus 33.3% P = 0.04). Metronidazole resistance remains the most common antibiotic resistant type of H. pylori in Thailand. The pattern of H. pylori antibiotic resistance over 9 years demonstrated a fall in clarithromycin resistance such that currently age >40 years is a predictor for clarithromycin resistance in Thailand. Quinolone resistance is a growing problem.

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

    Science.gov (United States)

    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.

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

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    Aimée M Moore

    Full Text Available 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

  11. Effects of combination of antibiotic-resistant bifidobacteria and corresponding antibiotics on survival of irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Korshunov, V.M.; Pinegin, B.V.; Ivanova, N.P.; Mal' tsev, V.N.

    1982-05-01

    Broad-spectrum antibiotics are used to treat intestinal dysbacteriosis of diverse etiology, including postradiation dysbacteriosis. Antibiotic therapy is instrumental in decontaminating the intestine. In addition to pathogenic microorganisms, there is disappearance of lactobacilli and bifidobacteria which perform several important and useful functions. For this reason, in addition to antibiotics, bifidobacterial preparations are used to restore the microbial cenosis and administration thereof is started after antibiotics are discontinued. There are some flaws to deferred administration of bifidobacteria, since the process of colonization of the intestine with commercial bifidobacterial preparations is rather lengthy, and there is slow elevation of bididobacterium level in the intestinal tract, whereas exogenous recontamination of the intestine by conditionally pathogenic bacteria is possible after antibiotic therapy is discontinued. On the other hand, use of antibiotics alone could, in turn, be the cause of intestinal dysbacteriosis. Our objective was to eliminate intestinal dysbacteriosis in irradiated animals by means of combining antibiotics and preparations of bifidobacteria resistant to these antibiotics, and thus prolong the life of these animals.

  12. Characterization of Antibiotics and Antibiotic Resistance Genes on an Ecological Farm System

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    Songhe Zhang

    2015-01-01

    Full Text Available There is a growing concern worldwide about the prevalence of antibiotics and antibiotic resistance genes (ARGs on the farm. In this study, we investigated the distribution of seven antibiotics and ten ARGs in fresh and dried pig feces, in biogas slurry, and in grape-planting soil from an ecological farm. Antibiotics including sulfamethazine, norfloxacin, ofloxacin, tetracycline, oxytetracycline, and chlortetracycline were detected in these samples (except for sulfamethoxazole in dried feces. In general, antibiotics levels in samples were in the sequence: biogas slurry > fresh feces > soil or dried feces. Results of ecological risk assessments revealed that among the seven antibiotics chlortetracycline showed the highest ecological risk. Among the ten ARGs, sulI and tetO were the most prevalent on this ecological farm. There were positive correlations between certain ARGs and the corresponding antibiotics on this ecological farm. Therefore, continuous monitoring of antibiotics and their corresponding ARGs should be conducted in the agroecosystem near the concentrated animal farming operation systems.

  13. Antibiotic resistance potential of the healthy preterm infant gut microbiome

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    Shaw, Alexander G.; Sim, Kathleen; Wooldridge, David J.; Li, Ming-Shi; Gharbia, Saheer; Misra, Raju; Kroll, John Simon

    2017-01-01

    Background Few studies have investigated the gut microbiome of infants, fewer still preterm infants. In this study we sought to quantify and interrogate the resistome within a cohort of premature infants using shotgun metagenomic sequencing. We describe the gut microbiomes from preterm but healthy infants, characterising the taxonomic diversity identified and frequency of antibiotic resistance genes detected. Results Dominant clinically important species identified within the microbiomes included C. perfringens, K. pneumoniae and members of the Staphylococci and Enterobacter genera. Screening at the gene level we identified an average of 13 antimicrobial resistance genes per preterm infant, ranging across eight different antibiotic classes, including aminoglycosides and fluoroquinolones. Some antibiotic resistance genes were associated with clinically relevant bacteria, including the identification of mecA and high levels of Staphylococci within some infants. We were able to demonstrate that in a third of the infants the S. aureus identified was unrelated using MLST or metagenome assembly, but low abundance prevented such analysis within the remaining samples. Conclusions We found that the healthy preterm infant gut microbiomes in this study harboured a significant diversity of antibiotic resistance genes. This broad picture of resistances and the wider taxonomic diversity identified raises further caution to the use of antibiotics without consideration of the resident microbial communities. PMID:28149696

  14. Antibiotic resistance potential of the healthy preterm infant gut microbiome

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    Graham Rose

    2017-01-01

    Full Text Available Background Few studies have investigated the gut microbiome of infants, fewer still preterm infants. In this study we sought to quantify and interrogate the resistome within a cohort of premature infants using shotgun metagenomic sequencing. We describe the gut microbiomes from preterm but healthy infants, characterising the taxonomic diversity identified and frequency of antibiotic resistance genes detected. Results Dominant clinically important species identified within the microbiomes included C. perfringens, K. pneumoniae and members of the Staphylococci and Enterobacter genera. Screening at the gene level we identified an average of 13 antimicrobial resistance genes per preterm infant, ranging across eight different antibiotic classes, including aminoglycosides and fluoroquinolones. Some antibiotic resistance genes were associated with clinically relevant bacteria, including the identification of mecA and high levels of Staphylococci within some infants. We were able to demonstrate that in a third of the infants the S. aureus identified was unrelated using MLST or metagenome assembly, but low abundance prevented such analysis within the remaining samples. Conclusions We found that the healthy preterm infant gut microbiomes in this study harboured a significant diversity of antibiotic resistance genes. This broad picture of resistances and the wider taxonomic diversity identified raises further caution to the use of antibiotics without consideration of the resident microbial communities.

  15. Simultaneous breakdown of multiple antibiotic resistance mechanisms in S. aureus.

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    Kaneti, Galoz; Sarig, Hadar; Marjieh, Ibrahim; Fadia, Zaknoon; Mor, Amram

    2013-12-01

    In previous studies, the oligo-acyl-lysyl (OAK) C12(ω7)K-β12 added to cultures of gram-positive bacteria exerted a bacteriostatic activity that was associated with membrane depolarization, even at high concentrations. Here, we report that multidrug-resistant Staphylococcus aureus strains, unlike other gram-positive species, have reverted to the sensitive phenotype when exposed to subminimal inhibitory concentrations (sub-MICs) of the OAK, thereby increasing antibiotics potency by up to 3 orders of magnitude. Such chemosensitization was achieved using either cytoplasm or cell-wall targeting antibiotics. Moreover, eventual emergence of resistance to antibiotics was significantly delayed. Using the mouse peritonitis-sepsis model, we show that on single-dose administration of oxacillin and OAK combinations, death induced by a lethal staphylococcal infection was prevented in a synergistic manner, thereby supporting the likelihood for synergism to persist under in vivo conditions. Toward illuminating the molecular basis for these observations, we present data arguing that sub-MIC OAK interactions with the plasma membrane can inhibit proton-dependent signal transduction responsible for expression and export of resistance factors, as demonstrated for β-lactamase and PBP2a. Collectively, the data reveal a potentially useful approach for overcoming antibiotic resistance and for preventing resistance from emerging as readily as when bacteria are exposed to an antibiotic alone.

  16. Community-acquired methicillin-resistant Staphylococcus aureus pyomyositis with myelitis: A rare occurrence with diverse presentation

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    Kulkarni Girish

    2009-12-01

    Full Text Available Staphylococcus aureus is the most common bacterial pathogen implicated in pyomyositis. There are increasing reports of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA infections. The present case report brings out the diverse clinical manifestations of MRSA infection in the form of paraspinal pyomyositis, myelitis, spinal osteomyelitis, and pneumonia. Molecular typing of the organism confirmed the diagnosis. Patient was successfully treated with vancomycin and surgical drainage. Consideration of the possibility of methicillin-resistance and appropriate antibiotic selection is vital in the treatment of serious community-acquired staphylococcal infections.

  17. Sponge microbiota are a reservoir of functional antibiotic resistance genes

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    Dennis Versluis

    2016-11-01

    Full Text Available Wide application of antibiotics has contributed to the evolution of multi-drug resistant human pathogens, resulting in poorer treatment outcomes for infections. In the marine environment, seawater samples have been investigated as a resistance reservoir; however, no studies have methodically examined sponges as a reservoir of antibiotic resistance. Sponges could be important in this respect because they often contain diverse microbial communities that have the capacity to produce bioactive metabolites. Here, we applied functional metagenomics to study the presence and diversity of functional resistance genes in the sponges Aplysina aerophoba, Petrosia ficiformis and Corticium candelabrum. We obtained 37 insert sequences facilitating resistance to D-cycloserine (n=6, gentamicin (n=1, amikacin (n=7, trimethoprim (n=17, chloramphenicol (n=1, rifampicin (n=2 and ampicillin (n=3. Fifteen of 37 inserts harboured resistance genes that shared <90% amino acid identity with known gene products, whereas on 13 inserts no resistance gene could be identified with high confidence, in which case we predicted resistance to be mainly mediated by antibiotic efflux. One marine-specific ampicillin-resistance-conferring β-lactamase was identified in the genus Pseudovibrio with 41% global amino acid identity to the closest β-lactamase with demonstrated functionality, and subsequently classified into a new family termed PSV. Taken together, our results show that sponge microbiota host diverse and novel resistance genes that may be harnessed by phylogenetically distinct bacteria.

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

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    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.

  19. [Epidemiological overview of antibiotic resistance in France and worldwide].

    Science.gov (United States)

    Arlet, Guillaume

    2012-09-01

    Antibiotic resistance appeared early after the introduction of these molecules in therapeutic. But, this resistance has long been confined to care facilities. Twenty years ago, resistance emerged in community with the methicillin resistance in Staphylococcus aureus and also with the reduced susceptibility to penicillin in pneumococci, which are good examples. Fortunately, for these two species, in France, the situation appears to be controlled. The most worrying now is the emergence of resistance to major antimicrobial agents in Escherichia coli both in community and in hospitals. The third-generation cephalosporins and the fluoroquinolones are concerned. This situation is currently not well controlled here and worldwide. The only recourse remaining carbapenems, antibiotics reserved for hospital use. Unfortunately, new mechanisms of resistance to these molecules are emerging.

  20. Resistencia antimicrobiana en la infección urinaria por Escherichia coli adquirida en la comunidad: ¿Cuál antibiótico voy a usar? Antibiotic resistance of Escherichia coli from community-acquired urinary tract infections: What antimicrobial to use?

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    Claudia Elena Guajardo-Lara

    2009-04-01

    Full Text Available OBJETIVO: Determinar la resistencia del uropatógeno comunitario más frecuente, Escherichia coli, a diversos antimicrobianos y deducir opciones de manejo empírico. MATERIAL Y MÉTODOS: Del 14 de julio de 2005 al 13 julio de 2006 se estudiaron cepas de Escherichia coli aisladas de urocultivos de pacientes que asistieron a la consulta externa de la Clínica Nova y del Hospital San José, en Monterrey, Nuevo León, México. Se identificó la bacteria y se determinó susceptibilidad a antibióticos mediante método automatizado. Se compararon los resultados entre las dos instituciones y la frecuencia de resistencia a antimicrobianos entre mujeres de entre 15 a 50 años de edad y > 50. RESULTADOS: Se analizaron 652 urocultivos: 303 (46.5% de Clínica Nova y 349 (53.5% del Hospital San José. Las cepas aisladas fueron resistentes a ampicilina, en 67.2%; a trimetoprim-sulfametoxazol, en 59.2%; a cefazolina, en 35.6%, y a ciprofloxacino, en 24.7%. CONCLUSIONES: La resistencia a trimetoprim-sulfametoxazol y ciprofloxacino, considerados de elección en el manejo empírico de las infecciones de vías urinarias adquiridas en la comunidad, es alta. Las opciones de manejo son pocas.OBJECTIVE: Determine antibiotic resistance of community-acquired uropathogen Escherichia coli and infer therapeutic options. MATERIAL AND METHODS: E. coli strains isolated from urine during a one-year period were studied. Identification and susceptibility tests were performed. RESULTS: A total of 652 isolates were included from patients in two institutions, a healthcare clinic 303 (46.5% and a hospital 349 ( 53.5%. The antimicrobials with higher resistance rates were ampicillin 67.2%, trimethoprim-sulfametoxazole 59.2%, cefazolin 35.6% and ciprofloxacin 24.7%. CONCLUSIONS: Resistance to trimethoprim-sulfamethoxazole and ciprofloxacin used for empiric treatment in community urinary infections is high, and there are few available treatment options.

  1. Strain-Specific Transfer of Antibiotic Resistance from an Environmental Plasmid to Foodborne Pathogens

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    Eva Van Meervenne

    2012-01-01

    Full Text Available Pathogens resistant to multiple antibiotics are rapidly emerging, entailing important consequences for human health. This study investigated if the broad-host-range multiresistance plasmid pB10, isolated from a wastewater treatment plant, harbouring amoxicillin, streptomycin, sulfonamide, and tetracycline resistance genes, was transferable to the foodborne pathogens Salmonella spp. or E. coli O157:H7 and how this transfer alters the phenotype of the recipients. The transfer ratio was determined by both plating and flow cytometry. Antibiotic resistance profiles were determined for both recipients and transconjugants using the disk diffusion method. For 14 of the 15 recipient strains, transconjugants were detected. Based on plating, transfer ratios were between 6.8×10−9 and 3.0×10−2 while using flow cytometry, transfer ratios were between <1.0×10−5 and 1.9×10−2. With a few exceptions, the transconjugants showed phenotypically increased resistance, indicating that most of the transferred resistance genes were expressed. In summary, we showed that an environmental plasmid can be transferred into foodborne pathogenic bacteria at high transfer ratios. However, the transfer ratio seemed to be recipient strain dependent. Moreover, the newly acquired resistance genes could turn antibiotic susceptible strains into resistant ones, paving the way to compromise human health.

  2. Acquired antibiotic resistance gene:an emerging contaminant posing a threat to food safety in the fermented vegetable food%获得性抗生素抗性基因:威胁发酵蔬菜食品安全的一种新型污染物

    Institute of Scientific and Technical Information of China (English)

    向文良; 张庆; 卢倩文; 赵婷婷; 曾林; 徐顾榕; 蔡婷

    2015-01-01

    The acquired antibiotic resistance genes (AARGs), as a kind of emerging diffused contaminants, are increasing global concern in the recent years, and their transfer is a new research topic in the food safety. The fermentation vegetable industry is an important part of Chinese food industries. Unfortunately, its fermentation processing mediated by the complex microflora provides a better ecological court for the AARGs transfer and dissemination among the microorganisms, and thus the AARGs could pose a new threat to food safety in the fermented vegetable food. This paper introduced recent progress in understanding sources, dissemination and transfer pathway of AARGs in the fermentation vegetable processing, and it is recommended that some research topics and effective strategies to control AARGs dissemination should be focused on in the vegetable fermentation process.%作为全球关注的新型面源污染之一,获得性抗生素抗性基因(AARGs)的水平转移成为食品安全领域近年来研究的新课题。发酵蔬菜是我国食品加工的重要组成部分,其发酵过程多样化的微生物参与为 AARGs的传播和扩散转移提供了高风险的生态场所。为此,本文提出将AARGs作为威胁发酵蔬菜食品安全的一种新型污染物,对该类污染物的来源、潜在的传播途径以及国内外相关研究进行综述,并提出了当前形势下我国开展发酵蔬菜中AARGs污染研究的方向和防控建议。

  3. Anthropogenic antibiotic resistance genes mobilization to the polar regions

    Science.gov (United States)

    Hernández, Jorge; González-Acuña, Daniel

    2016-01-01

    Anthropogenic influences in the southern polar region have been rare, but lately microorganisms associated with humans have reached Antarctica, possibly from military bases, fishing boats, scientific expeditions, and/or ship-borne tourism. Studies of seawater in areas of human intervention and proximal to fresh penguin feces revealed the presence of Escherichia coli strains least resistant to antibiotics in penguins, whereas E. coli from seawater elsewhere showed resistance to one or more of the following antibiotics: ampicillin, tetracycline, streptomycin, and trim-sulfa. In seawater samples, bacteria were found carrying extended-spectrum β-lactamase (ESBL)-type CTX-M genes in which multilocus sequencing typing (MLST) showed different sequence types (STs), previously reported in humans. In the Arctic, on the contrary, people have been present for a long time, and the presence of antibiotic resistance genes (ARGs) appears to be much more wide-spread than was previously reported. Studies of E coli from Arctic birds (Bering Strait) revealed reduced susceptibility to antibiotics, but one globally spreading clone of E. coli genotype O25b-ST131, carrying genes of ESBL-type CTX-M, was identified. In the few years between sample collections in the same area, differences in resistance pattern were observed, with E. coli from birds showing resistance to a maximum of five different antibiotics. Presence of resistance-type ESBLs (TEM, SHV, and CTX-M) in E. coli and Klebsiella pneumoniae was also confirmed by specified PCR methods. MLST revealed that those bacteria carried STs that connect them to previously described strains in humans. In conclusion, bacteria previously related to humans could be found in relatively pristine environments, and presently human-associated, antibiotic-resistant bacteria have reached a high global level of distribution that they are now found even in the polar regions. PMID:27938628

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

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    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.

  5. A new antibiotic kills pathogens without detectable resistance.

    Science.gov (United States)

    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.

  6. Antibiotic resistance of Neisseria gonorrhoeae isolated from gonorrhoeae patients

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    Mohammad Bokaeian

    2010-06-01

    Full Text Available Background: The objective of this study was to determine antibiotic susceptibility and penicillinase production by Neisseria gonorrhoeae strains isolated from gonorrhoeae patients in Zahedan.Materials and methods: In a descriptive study during 2005-2008 years, 400 suspected patients were studied by history review, medical examination, gram staining and culture in Thayer-Martin medium. Antibiotic susceptibility and penicillinase tests of isolated strains were done by disk diffusion method and aciodometric method, respectively.Results: Cultures were positive in 77(19.2% patients. The resistanat rate against antibiotics were as follow: penicillin (79.2%, ciprofloxacin (53.2%, ceftriaxone(3.8%, spectinomycin(2.5%, cefixime(12.9%, co-trimoxazole(93.5%, tetracycline(88.3% and gentamicin(29.8%. In the meanwhile, 83.1 percent of penicillin resistant isolates produced penicillinase enzyme. Discussion: Ceftriaxone, spectinomycin and cefixime are the sole antibiotics that could be considered as selective drugs. Quinolones which were regarded as an effective group of antibiotics recently have lost their importance. Resistance against other antibiotics is rapidly developing, thus, conducting experimental tests and determination of minimum inhibitory concentration and clinical trial studies at fixed intervals can contribute to diagnosis of resistance of gonococci and rapid and successful treatment of their infections in Zahedan region.

  7. Mechanisms of antibiotic resistance of Enterobacteriaceae family representatives

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    K. R. Kotsyuba

    2014-04-01

    Full Text Available The paper deals with the basic medical scheme of antibiotics use for treatment of lesions caused by enterobacteria and mechanisms of resistance of Enterobacteriaceae to different classes of antibiotics. It is known that the main mechanisms of resistance to antibiotics are enzymatic inactivation, modification of the target, efflux, violation of conduct through the membrane and formation of metabolic shunt. The most common cases of resistance to beta-lactams among Enterobacteriaceae relate to production of plasmid and chromosomal beta-lactamases, violation of the permeability of the outer membrane, and modification of target penicillin binding proteins. Active release of antibiotics from the cell, or efflux, in Enterobacteriaceae is used for maintaining resistance to tetracyclines, macrolides, carbapenems. Genes of efflux system are localized on plasmids and contribute to rapid spreading among Enterobacteriaceae. Mutations are the basis of resistance to novobiocinum and rifampicinum. Enzymatic inactivation by modifying is typical for resistance to aminoglycosides. Three groups of enzymes are engaged in the process, by adding the molecule of acetic acid, phosphate or adenine. Joining of these groups is irreversible and leads to complete loss of biological activity of the antibiotic. Resistance to aminoglycosides appears also due to inhibition of drug penetration, that is associated with genetically determined mechanisms of electron transport through the membrane. Resistance to quinolones and fluoroquinolones is associated with the modification of topoisomerase II and IV which are targets of these groups of antibiotics. Resistance is possible as a result of changes in the structure of the target, breaching of penetration into the cell, and active release from the cell. The highest level of resistance is develope in the case of two- or three-stage mutations in one or the other, or both, subunits in different genes. At the same time, for breaching of

  8. Antibiotic administration routes significantly influence the levels of antibiotic resistance in gut microbiota.

    Science.gov (United States)

    Zhang, Lu; Huang, Ying; Zhou, Yang; Buckley, Timothy; Wang, Hua H

    2013-08-01

    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.

  9. Antibiotic resistance in Aeromonas upstream and downstream of a water resource recovery facility.

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    Cisar, Cindy R; Henderson, Samantha K; Askew, Maegan L; Risenhoover, Hollie G; McAndrews, Chrystle R; Kennedy, S Dawn; Paine, C Sue

    2014-09-01

    Aeromonas strains isolated from sediments upstream and downstream of a water resource recovery facility (WRRF) over a two-year time period were tested for susceptibility to 13 antibiotics. Incidence of resistance to antibiotics, antibiotic resistance phenotypes, and diversity (based on resistance phenotypes) were compared in the two populations. At the beginning of the study, the upstream and downstream Aeromonas populations were different for incidence of antibiotic resistance (p resistance phenotypes (p antibiotic resistance in Aeromonas in stream sediments fluctuates considerably over time and (2) suggest that WRRF effluent does not, when examined over the long- term, affect antibiotic resistance in Aeromonas in downstream sediment.

  10. Inducible and Acquired Clarithromycin Resistance in the Mycobacterium abscessus Complex.

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    Marc Rubio

    Full Text Available Clarithromycin was considered the cornerstone for the treatment of Mycobacterium abscessus complex infections. Genetic resistance mechanisms have been described and many experts propose amikacin as an alternative. Nevertheless, clarithromycin has several advantages; therefore, it is necessary to identify the non-functional erm(41 allele to determine the most suitable treatment. The aims of this study were to characterize the molecular mechanisms of clarithromycin resistance in a collection of Mycobacterium abscessus complex isolates and to verify the relationship between these mechanisms and the antibiogram.Clinical isolates of M. abscessus complex (n = 22 from 16 patients were identified using four housekeeping genes (rpoB, secA1, sodA and hsp65, and their genetic resistance was characterized by studying erm(41 and rrl genes. Nine strains were recovered from the clinical isolates and subjected to E-test and microdilution clarithromycin susceptibility tests, with readings at 3, 7 and 14 days.We classified 11/16 (68.8% M. abscessus subsp. abscessus, 4/16 (25.0% M. abscessus subsp. bolletii, and 1/16 (6.3% M. abscessus subsp. massiliense. T28 erm(41 allele was observed in 8 Mycobacterium abscessus subps. abscessus and 3 Mycobacterium abscessus subsp. bolletii. One strain of M. abscessus subsp. bolletii had an erm(41 gene truncated and was susceptible to clarithromycin. No mutations were observed in rrl gene first isolates. In three patients, follow-up of initial rrl wild-type strains showed acquired resistance.Most clinical isolates of M. abscessus complex had inducible resistance to clarithromycin and total absence of constitutive resistance. Our findings showed that the acquisition of resistance mutations in rrl gene was associated with functional and non-functional erm(41 gene. Caution is needed when using erm(41 sequencing alone to identify M. abscessus subspecies. This study reports an acquired mutation at position 2057 of rrl gene

  11. Properties of Achromobacter xylosoxidans highly resistant to aminoglycoside antibiotics.

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    Nakamoto, Sachiko; Goda, Natsumi; Hayabuchi, Tatsuya; Tamaki, Hiroo; Ishida, Ayami; Suzuki, Ayaka; Nakano, Kaori; Yui, Shoko; Katsumata, Yuto; Yamagami, Yuki; Burioka, Naoto; Chikumi, Hiroki; Shimizu, Eiji

    2016-04-01

    We herein discovered a highly resistant clinical isolate of Pseudomonas aeruginosa with MICs to amikacin, gentamicin, and arbekacin of 128 μg/mL or higher in a drug sensitivity survey of 92 strains isolated from the specimens of Yoka hospital patients between January 2009 and October 2010, and Achromobacter xylosoxidans was separated from this P. aeruginosa isolate. The sensitivity of this bacterium to 29 antibiotics was investigated. The MICs of this A. xylosoxidans strain to 9 aminoglycoside antibiotics were: amikacin, gentamicin, arbekacin, streptomycin, kanamycin, neomycin, and spectinomycin, 1,024 μg/mL or ≥ 1,024 μg/mL; netilmicin, 512 μg/mL; and tobramycin, 256 μg/mL. This strain was also resistant to dibekacin. This aminoglycoside antibiotic resistant phenotype is very rare, and we are the first report the emergence of A. xylosoxidans with this characteristic.

  12. Antibiotic Resistant Salmonella and Vibrio Associated with Farmed Litopenaeus vannamei

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    Sanjoy Banerjee

    2012-01-01

    Full Text Available Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed individual and multiple antibiotic resistance patterns. Five Vibrio species having individual and multiple antibiotic resistance were also identified. They were Vibrio cholerae (18.3%, V. mimicus (16.7%, V. parahaemolyticus (10%, V. vulnificus (6.7%, and V. alginolyticus (1.7%. Farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of shrimp.

  13. Antibiotic resistant Salmonella and Vibrio associated with farmed Litopenaeus vannamei.

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    Banerjee, Sanjoy; Ooi, Mei Chen; Shariff, Mohamed; Khatoon, Helena

    2012-01-01

    Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed individual and multiple antibiotic resistance patterns. Five Vibrio species having individual and multiple antibiotic resistance were also identified. They were Vibrio cholerae (18.3%), V. mimicus (16.7%), V. parahaemolyticus (10%), V. vulnificus (6.7%), and V. alginolyticus (1.7%). Farm owners should be concerned about the presence of these pathogenic bacteria which also contributes to human health risk and should adopt best management practices for responsible aquaculture to ensure the quality of shrimp.

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

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    Allahverdiyev AM

    2013-09-01

    Full Text Available Adil M Allahverdiyev,1 Melahat Bagirova,1 Emrah Sefik Abamor,1 Sezen Canim Ates,1 Rabia Cakir Koc,2 Meral Miraloglu,3 Serhat Elcicek,4 Serkan Yaman,1 Gokce Unal1 1Department of Bioengineering, Yildiz Technical University, Istanbul, Turkey; 2Department of Biomedical Engineering, Yeni Yuzyil University, Istanbul, Turkey; 3Vocational School of Health Services, Cukurova University, Adana, Turkey; 4Department of Bioengineering, Firat University, Elazig, Turkey Abstract: 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

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

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

    2015-02-01

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

  16. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii.

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    Kröger, Carsten; Kary, Stefani C; Schauer, Kristina; Cameron, Andrew D S

    2016-12-28

    Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance.

  17. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii

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    Carsten Kröger

    2016-12-01

    Full Text Available Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance.

  18. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii

    Science.gov (United States)

    Kröger, Carsten; Kary, Stefani C.; Schauer, Kristina; Cameron, Andrew D. S.

    2016-01-01

    Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance. PMID:28036056

  19. Occurrence and prevalence of antibiotic resistance in landfill leachate.

    Science.gov (United States)

    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.

  20. Epidemiological interpretation of studies examining the effect of antibiotic usage on resistance.

    Science.gov (United States)

    Schechner, Vered; Temkin, Elizabeth; Harbarth, Stephan; Carmeli, Yehuda; Schwaber, Mitchell J

    2013-04-01

    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.

  1. Excretion of antibiotic resistance genes by dairy calves fed milk replacers with varying doses of antibiotics

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    Callie H. Thames

    2012-04-01

    Full Text Available Elevated levels of antibiotic resistance genes (ARGs in soil and water have been linked to livestock farms and in some cases feed antibiotics may select for antibiotic resistant gut microbiota. The purpose of this study was to examine the establishment of ARGs in the feces of calves receiving milk replacer containing no antibiotics versus subtherapeutic or therapeutic doses of tetracycline and neomycin. The effect of antibiotics on calf health was also of interest. Twenty-eight male and female dairy calves were assigned to one of the three antibiotic treatment groups at birth and fecal samples were collected at weeks 6, 7 (prior to weaning, and 12 (5 weeks after weaning. ARGs corresponding to the tetracycline (tetC, tetG, tetO, tetW, and tetX, macrolide (ermB, ermF, and sulfonamide (sul1, sul2 classes of antibiotics along with the class I integron gene, intI1, were monitored by quantitative polymerase chain reaction as potential indicators of direct selection, co-selection, or horizontal gene transfer of ARGs. Surprisingly, there was no significant effect of antibiotic treatment on the absolute abundance (gene copies/ g wet manure of any of the ARGs except ermF, which was lower in the antibiotic-treated calf manure, presumably because a significant portion of host bacterial cells carrying ermF were not resistant to tetracycline or neomycin. However, relative abundance (gene copies normalized to 16S rRNA genes of tetO was higher in calves fed the highest dose of antibiotic than in the other treatments. All genes, except tetC and intI1, were detectable in feces from 6 weeks onwards, and tetW and tetG significantly increased (P<0.10, even in control calves. Overall, the results provide new insight into the colonization of calf gut flora with ARGs in the early weeks. Although feed antibiotics exerted little effect on the ARGs monitored in this study, the fact that they also provided no health benefit suggests that the greater than conventional

  2. Removal of antibiotics and antibiotic resistance genes in rural wastewater by an integrated constructed wetland.

    Science.gov (United States)

    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.

  3. Characterization of in vivo-acquired resistance to macrolides of Mycoplasma gallisepticum strains isolated from poultry

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    Gerchman Irena

    2011-08-01

    Full Text Available Abstract The macrolide class of antibiotics, including tylosin and tilmicosin, is widely used in the veterinary field for prophylaxis and treatment of mycoplasmosis. In vitro susceptibility testing of 50 strains of M. gallisepticum isolated in Israel during the period 1997-2010 revealed that acquired resistance to tylosin as well as to tilmicosin was present in 50% of them. Moreover, 72% (13/18 of the strains isolated from clinical samples since 2006 showed acquired resistance to enrofloxacin, tylosin and tilmicosin. Molecular typing of the field isolates, performed by gene-target sequencing (GTS, detected 13 molecular types (I-XIII. Type II was the predominant type prior to 2006 whereas type X, first detected in 2008, is currently prevalent. All ten type X strains were resistant to both fluoroquinolones and macrolides, suggesting selective pressure leading to clonal dissemination of resistance. However, this was not a unique event since resistant strains with other GTS molecular types were also found. Concurrently, the molecular basis for macrolide resistance in M. gallisepticum was identified. Our results revealed a clear-cut correlation between single point mutations A2058G or A2059G in domain V of the gene encoding 23S rRNA (rrnA, MGA_01 and acquired macrolide resistance in M. gallisepticum. Indeed, all isolates with MIC ≥ 0.63 μg/mL to tylosin and with MIC ≥ 1.25 μg/mL to tilmicosin possess one of these mutations, suggesting an essential role in decreased susceptibility of M. gallisepticum to 16-membered macrolides.

  4. Molecular basis of NDM-1, a new antibiotic resistance determinant.

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    Zhongjie Liang

    Full Text Available The New Delhi Metallo-β-lactamase (NDM-1 was first reported in 2009 in a Swedish patient. A recent study reported that Klebsiella pneumonia NDM-1 positive strain or Escherichia coli NDM-1 positive strain was highly resistant to all antibiotics tested except tigecycline and colistin. These can no longer be relied on to treat infections and therefore, NDM-1 now becomes potentially a major global health threat.In this study, we performed modeling studies to obtain its 3D structure and NDM-1/antibiotics complex. It revealed that the hydrolytic mechanisms are highly conserved. In addition, the detailed analysis indicates that the more flexible and hydrophobic loop1, together with the evolution of more positive-charged loop2 leads to NDM-1 positive strain more potent and extensive in antibiotics resistance compared with other MBLs. Furthermore, through biological experiments, we revealed the molecular basis for antibiotics catalysis of NDM-1 on the enzymatic level. We found that NDM-1 enzyme was highly potent to degrade carbapenem antibiotics, while mostly susceptible to tigecycline, which had the ability to slow down the hydrolysis velocity of meropenem by NDM-1. Meanwhile, the mutagenesis experiments, including D124A, C208A, K211A and K211E, which displayed down-regulation on meropenem catalysis, proved the accuracy of our model.At present, there are no effective antibiotics against NDM-1 positive pathogen. Our study will provide clues to investigate the molecular basis of extended antibiotics resistance of NDM-1 and then accelerate the search for new antibiotics against NDM-1 positive strain in clinical studies.

  5. Molecular basis of NDM-1, a new antibiotic resistance determinant.

    Science.gov (United States)

    Liang, Zhongjie; Li, Lianchun; Wang, Yuanyuan; Chen, Limin; Kong, Xiangqian; Hong, Yao; Lan, Lefu; Zheng, Mingyue; Guang-Yang, Cai; Liu, Hong; Shen, Xu; Luo, Cheng; Li, Keqin Kathy; Chen, Kaixian; Jiang, Hualiang

    2011-01-01

    The New Delhi Metallo-β-lactamase (NDM-1) was first reported in 2009 in a Swedish patient. A recent study reported that Klebsiella pneumonia NDM-1 positive strain or Escherichia coli NDM-1 positive strain was highly resistant to all antibiotics tested except tigecycline and colistin. These can no longer be relied on to treat infections and therefore, NDM-1 now becomes potentially a major global health threat.In this study, we performed modeling studies to obtain its 3D structure and NDM-1/antibiotics complex. It revealed that the hydrolytic mechanisms are highly conserved. In addition, the detailed analysis indicates that the more flexible and hydrophobic loop1, together with the evolution of more positive-charged loop2 leads to NDM-1 positive strain more potent and extensive in antibiotics resistance compared with other MBLs. Furthermore, through biological experiments, we revealed the molecular basis for antibiotics catalysis of NDM-1 on the enzymatic level. We found that NDM-1 enzyme was highly potent to degrade carbapenem antibiotics, while mostly susceptible to tigecycline, which had the ability to slow down the hydrolysis velocity of meropenem by NDM-1. Meanwhile, the mutagenesis experiments, including D124A, C208A, K211A and K211E, which displayed down-regulation on meropenem catalysis, proved the accuracy of our model.At present, there are no effective antibiotics against NDM-1 positive pathogen. Our study will provide clues to investigate the molecular basis of extended antibiotics resistance of NDM-1 and then accelerate the search for new antibiotics against NDM-1 positive strain in clinical studies.

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

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    Ying eHuang

    2015-09-01

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

  7. Sensitivity and resistance of Legionella pneumophila to some antibiotics and combinations of antibiotics.

    Science.gov (United States)

    Moffie, B G; Mouton, R P

    1988-10-01

    For the treatment of Legionella pneumophila infections erythromycin and rifampicin are the antibiotics of choice. In view of reported therapy failures other antibiotics, e.g. the quinolones, are currently under investigation. The sensitivity of L. pneumophila to four antibiotics and to combinations of antibiotics was investigated and the rate of mutations was calculated. For 20 L. pneumophila strains we determined the MIC of rifampicin (0.002-0.004 mg/l), erythromycin (0.063-0.125 mg/l), norfloxacin (0.125 mg/l) and ciprofloxacin (0.016-0.032 mg/l). Mutation rates ranged from 1 x 10(-8) for ciprofloxacin to greater than 1 x 10(-7) for erythromycin, resulting in high-level resistance to rifampicin in most strains and erythromycin resistance in one strain, but not in resistance to the quinolones. The combination of erythromycin and rifampicin was synergistic (FIC index less than 0.5) against four of the L. pneumophila strains and showed indifference (FIC index 0.5-2.0) for the remainder (mean FIC index 0.79). Combinations of ciprofloxacin and erythromycin and of rifampicin and ciprofloxacin showed only indifference (mean FIC index respectively 1.05 and 1.21). Combining rifampicin with ciprofloxacin was not effective in reducing the number of mutants for either of these antibiotics, whereas the other combinations did prevent this.

  8. Determination of the Antibiotic Resistance Profile of Student Cell Phones

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    Lisa Ann Blankinship

    2012-08-01

    Full Text Available Sampling of common use items (e.g., student cell phones for bacterial presence, identification, and antibiotic resistance profiling helps students to recognize the need for routine cleaning of personal items and encourages thoughtful use of currently available medications. This multilab period project can be used to teach or reinforce several methods from general microbiology including aseptic technique, isolation streak, serial dilution, spread plating, Kirby Bauer testing, unknown identification, and media production. The data generated can be saved and added to each semester, thus providing a data set that reflects a local trend of antibiotic resistance.      

  9. Bacteriophage therapy: a potential solution for the antibiotic resistance crisis.

    Science.gov (United States)

    Golkar, Zhabiz; Bagasra, Omar; Pace, Donald Gene

    2014-02-13

    The emergence of multiple drug-resistant bacteria has prompted interest in alternatives to conventional antimicrobials. One of the possible replacement options for antibiotics is the use of bacteriophages as antimicrobial agents. Phage therapy is an important alternative to antibiotics in the current era of drug-resistant pathogens. Bacteriophages have played an important role in the expansion of molecular biology and have been used as antibacterial agents since 1966. In this review, we describe a brief history of bacteriophages and clinical studies on their use in bacterial disease prophylaxis and therapy. We discuss the advantages and disadvantages of bacteriophages as therapeutic agents in this regard.

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

    Science.gov (United States)

    Ji, Yinduo; Lei, Ting

    2013-01-01

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

  11. Prevalence and resistance pattern of Moraxella catarrhalis in community-acquired lower respiratory tract infections

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    Shaikh SBU

    2015-07-01

    Full Text Available Safia Bader Uddin Shaikh, Zafar Ahmed, Syed Ali Arsalan, Sana Shafiq Department of Pulmonology, Liaquat National Hospital, Karachi, Pakistan Introduction: Moraxella catarrhalis previously considered as commensal of upper respiratory tract has gained importance as a pathogen responsible for respiratory tract infections. Its beta-lactamase-producing ability draws even more attention toward its varying patterns of resistance. Methods: This was an observational study conducted to evaluate the prevalence and resistance pattern of M. catarrhalis. Patients aged 20–80 years admitted in the Department of Chest Medicine of Liaquat National Hospital from March 2012 to December 2012 were included in the study. Respiratory samples of sputum, tracheal secretions, and bronchoalveolar lavage were included, and their cultures were followed. Results: Out of 110 respiratory samples, 22 showed positive cultures for M. catarrhalis in which 14 were males and eight were females. Ten samples out of 22 showed resistance to clarithromycin, and 13 samples out of 22 displayed resistance to erythromycin, whereas 13 showed resistance to levofloxacin. Hence, 45% of the cultures showed resistance to macrolides so far and 59% showed resistance to quinolones. Conclusion: Our study shows that in our environment, M. catarrhalis may be resistant to macrolides and quinolones; hence, these should not be recommended as an alternative treatment in community-acquired lower respiratory tract infections caused by M. catarrhalis. However, a study of larger sample size should be conducted to determine if the recommendations are required to be changed. Keywords: community-acquired lower respiratory tract infections or pneumonia, M. catarrhalis, antibiotic resistance, gram-negative diplococcic, Pakistan

  12. Relationships between antibiotics and antibiotic resistance gene levels in municipal solid waste leachates in Shanghai, China.

    Science.gov (United States)

    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 antibiotics can prevail in MSW leachates and landfills may be an underappreciated as a source of antibiotics and ARGs to the environment.

  13. Effectiveness of Antipseudomonal Antibiotics and Mechanisms of Multidrug Resistance in Pseudomonas aeruginosa.

    Science.gov (United States)

    El ZOWALATYl, Mohamed E; Gyetvaii, Bpla

    2016-01-01

    Pseudomonas aeruginosa is a leading human pathogen that causes serious infections at various tissues and organs leading to life threatening health problems and possible deadly outcomes. Resistance patterns vary widely whether it is from hospitals or community acquired infections. Reporting resistance profiles to a certain antibiotics provide valuable information in a given setting, but may be extrapolated outside the sampling location. In the present study, P. aeruginosa isolates were screened to determine their susceptibilities against anti-pseudomonal antimicrobial agents and possible existing mechanisms of resistance were determined. Eighty-six isolates of P. aeruginosa were recovered. Isolates representing different resistance profiles were screened for the existence of three different resistance mechanisms including drug inactivation due to metallo-β-lactamases, drug impermeability by outer membrane proteins and drug efflux. All tested isolates showed uniform susceptibility (100%, n = 86/86) to piperacillin, meropenem, amikacin, and polymyxin B. A single isolate was found to be imipenem resistant (99%, n = 85/86). The possible mechanisms of resistance of P. aeruginosa to imipenem involve active drug efflux pumps, outer membrane impermeability as well as drug inactivating enzymes. These findings demonstrate the fundamental importance of the in vitro susceptibility testing of antibiotics prior to antipseudomonal therapy and highlight the need for a continuous antimicrobial resistance surveillance programs to monitor the changing resistance patterns so that clinicians and health care officials are updated as to the most effective therapeutic agents to combat the serious outcomes of P. aeruginosa infections.

  14. Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

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    Afzali H.MD,

    2016-03-01

    Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

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

    Science.gov (United States)

    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.

  16. Perturbation of iron homeostasis promotes the evolution of antibiotic resistance.

    Science.gov (United States)

    Méhi, Orsolya; Bogos, Balázs; Csörgő, Bálint; Pál, Ferenc; Nyerges, Akos; Papp, Balázs; Pál, Csaba

    2014-10-01

    Evolution of antibiotic resistance in microbes is frequently achieved by acquisition of spontaneous mutations during antimicrobial therapy. Here, we demonstrate that inactivation of a central transcriptional regulator of iron homeostasis (Fur) facilitates laboratory evolution of ciprofloxacin resistance in Escherichia coli. To decipher the underlying molecular mechanisms, we first performed a global transcriptome analysis and demonstrated that the set of genes regulated by Fur changes substantially in response to antibiotic treatment. We hypothesized that the impact of Fur on evolvability under antibiotic pressure is due to the elevated intracellular concentration of free iron and the consequent enhancement of oxidative damage-induced mutagenesis. In agreement with expectations, overexpression of iron storage proteins, inhibition of iron transport, or anaerobic conditions drastically suppressed the evolution of resistance, whereas inhibition of the SOS response-mediated mutagenesis had only a minor effect. Finally, we provide evidence that a cell permeable iron chelator inhibits the evolution of resistance. In sum, our work revealed the central role of iron metabolism in the de novo evolution of antibiotic resistance, a pattern that could influence the development of novel antimicrobial strategies.

  17. Alarmingly High Segregation Frequencies of Quinolone Resistance Alleles within Human and Animal Microbiomes Are Not Explained by Direct Clinical Antibiotic Exposure.

    Science.gov (United States)

    Field, Wesley; Hershberg, Ruth

    2015-05-26

    Antibiotic resistance poses a major threat to human health. It is therefore important to characterize the frequency of resistance within natural bacterial environments. Many studies have focused on characterizing the frequencies with which horizontally acquired resistance genes segregate within natural bacterial populations. Yet, very little is currently understood regarding the frequency of segregation of resistance alleles occurring within the housekeeping targets of antibiotics. We surveyed a large number of metagenomic datasets extracted from a large variety of host-associated and non host-associated environments for such alleles conferring resistance to three groups of broad spectrum antibiotics: streptomycin, rifamycins, and quinolones. We find notable segregation frequencies of resistance alleles occurring within the target genes of each of the three antibiotics, with quinolone resistance alleles being the most frequent and rifamycin resistance alleles being the least frequent. Resistance allele frequencies varied greatly between different phyla and as a function of environment. The frequency of quinolone resistance alleles was especially high within host-associated environments, where it averaged an alarming ∼ 40%. Within host-associated environments, resistance to quinolones was most often conferred by a specific resistance allele. High frequencies of quinolone resistance alleles were also found within hosts that were not directly treated with antibiotics. Therefore, the high segregation frequency of quinolone resistance alleles occurring within the housekeeping targets of antibiotics in host-associated environments does not seem to be the sole result of clinical antibiotic usage.

  18. Systemic Acquired Resistance and Signal Transduction in Plant

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shu-qing; GUO Jian-bo

    2003-01-01

    Systemic acquired resistance (SAR), known as the broad-spectrum, inducible plant immunity,is a defense response triggered by pathogen infection. The response starts from the recognition of plant resist-ance (R) with the corresponding avirulence (avr) gene from the pathogen. There are some genes for conver-gence of signals downstream of different R/avr interacting partners into a single signaling pathway. Salicylicacid (SA) is required for the induction of SAR and involved in transducing the signal in target tissues. The SAsignal is transduced through NPR1, a nuclear-localized protein that interacts with transcription factors thatare involved in regulating SA-mediated gene expression. Some chemicals that mimic natural signaling com-pounds can also activate SAR. The application of biochemical activators to agriculture for plant protection is anovel idea for developing green chemical pesticide.

  19. Monopoly pricing of an antibiotic subject to bacterial resistance.

    Science.gov (United States)

    Herrmann, Markus

    2010-01-01

    We develop a dynamic bio-economic model of bacterial resistance and disease transmission in which we characterize the pricing policy of a monopolist who is protected by a patent. After expiration, the monopolist behaves competitively in a generic industry having open access to the common pool of antibiotic efficacy and infection. The monopolist manages endogenously the levels of antibiotic efficacy as well as the infected population, which represent quality and market size respectively and achieves, at least temporarily, higher such levels than a hypothetically myopic monopolist who does not take into account the dynamic externalities. The pricing policy and the biological system is characterized by the turnpike property. Before the patent vanishes, the monopolist behaves more and more myopically, leading to a continuous decrease in the price of the antibiotic. Once the generic industry takes over, a discontinuous fall in price occurs. Whether a prolongation of the patent is socially desirable depends on the relative levels of antibiotic efficacy and infection.

  20. Characterization of antibiotic resistance determinants in oral biofilms.

    Science.gov (United States)

    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.

  1. Why is antibiotic resistance a deadly emerging disease?

    Science.gov (United States)

    Courvalin, P

    2016-05-01

    Evolution of bacteria towards resistance to antimicrobial agents, including multidrug resistance, is unavoidable because it represents a particular aspect of the general evolution of bacteria that is unstoppable. Therefore, the only means of dealing with this situation is to delay the emergence and subsequent dissemination of resistant bacteria or resistance genes. In this review, we will consider the biochemical mechanisms and the genetics that bacteria use to offset antibiotic selective pressure. The data provided are mainly, if not exclusively, taken from the work carried out in the laboratory, although there are numerous other examples in the literature.

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

    Science.gov (United States)

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

    2016-08-15

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

  3. Persistence of antibiotic resistance: evaluation of a probiotic approach using antibiotic-sensitive Megasphaera elsdenii strains to prevent colonization of swine by antibiotic-resistant strains.

    Science.gov (United States)

    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 (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.

  4. Label-free SRM-based relative quantification of antibiotic resistance mechanisms in Pseudomonas aeruginosa clinical isolates

    Directory of Open Access Journals (Sweden)

    Yannick eCharretier

    2015-02-01

    Full Text Available Both acquired and intrinsic mechanisms play a crucial role in Pseudomonas aeruginosa antibiotic resistance. Many clinically relevant resistance mechanisms result from changes in gene expression, namely multidrug efflux pump overproduction, AmpC beta-lactamase induction or derepression, and inactivation or repression of the carbapenem-specific porin OprD. Changes in gene expression are usually assessed using reverse-transcription quantitative real-time PCR (RT-qPCR assays. Here, we evaluated label-free Selected Reaction Monitoring (SRM-based mass spectrometry to directly quantify proteins involved in antibiotic resistance. We evaluated the label-free SRM using a defined set of P. aeruginosa isolates with known resistance mechanisms and compared it against RT-qPCR. Referring to efflux systems, we found a more robust relative quantification of antibiotic resistance mechanisms by SRM than RT-qPCR. The SRM-based approach was applied to a set of clinical P. aeruginosa isolates to detect antibiotic resistance proteins. This multiplexed SRM-based approach is a rapid and reliable method for the simultaneous detection and quantification of resistance mechanisms and we demonstrate its relevance for antibiotic resistance prediction.

  5. ANTIBIOTIC RESISTANT BACTERIA FROM HALIOTIS TUBERCULATA AND MYTILUS GALLOPROVINCIALIS

    Directory of Open Access Journals (Sweden)

    F. Conte

    2009-12-01

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

  6. The use of antibiotics and implications for antimicrobial resistance development

    NARCIS (Netherlands)

    Loon, Harald-Jan van

    2004-01-01

    Antibiotic resistance has reached pandemic proportions and the increasing incidences have alarmed medical healthcare associations world wide. Some thirty years ago it was almost all infectious diseases were conquered, but over the last decades we have witnessed the re-emergence of known contagious d

  7. Antibiotic Resistance in Urinary Tract Infections in College Students

    Science.gov (United States)

    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…

  8. Collective Resistance in Microbial Communities by Intracellular Antibiotic Deactivation

    Science.gov (United States)

    Sorg, Robin A.; Lin, Leo; van Doorn, G. Sander; Sorg, Moritz; Olson, Joshua; Nizet, Victor; Veening, Jan-Willem

    2016-01-01

    The structure and composition of bacterial communities can compromise antibiotic efficacy. For example, the secretion of β-lactamase by individual bacteria provides passive resistance for all residents within a polymicrobial environment. Here, we uncover that collective resistance can also develop via intracellular antibiotic deactivation. Real-time luminescence measurements and single-cell analysis demonstrate that the opportunistic human pathogen Streptococcus pneumoniae grows in medium supplemented with chloramphenicol (Cm) when resistant bacteria expressing Cm acetyltransferase (CAT) are present. We show that CAT processes Cm intracellularly but not extracellularly. In a mouse pneumonia model, more susceptible pneumococci survive Cm treatment when coinfected with a CAT-expressing strain. Mathematical modeling predicts that stable coexistence is only possible when antibiotic resistance comes at a fitness cost. Strikingly, CAT-expressing pneumococci in mouse lungs were outcompeted by susceptible cells even during Cm treatment. Our results highlight the importance of the microbial context during infectious disease as a potential complicating factor to antibiotic therapy. PMID:28027306

  9. Molecular Mechanisms of Antibiotic Resistance in Helicobacter pylori

    NARCIS (Netherlands)

    M.M. Gerrits (Monique)

    2004-01-01

    textabstractAn estimated 4 to 5 million individuals in the Netherlands are actively infected with Helicobacter pylori. Eradication of this bacterium becomes more difficult as the prevalence of antibiotic resistance is increasing worldwide. Most H. pylori infections are now diagnosed by non-invasi

  10. Stalking Antibiotic-Resistant Bacteria in Common Vegetables

    Science.gov (United States)

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

    2004-01-01

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

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

    Science.gov (United States)

    Pascoe, Neil; Felkner, Marilyn; Maldonado, Maria

    2003-01-01

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

  12. Antibiotic Resistant Salmonella and Vibrio Associated with Farmed Litopenaeus vannamei

    OpenAIRE

    Sanjoy Banerjee; Mei Chen Ooi; Mohamed Shariff; Helena Khatoon

    2012-01-01

    Salmonella and Vibrio species were isolated and identified from Litopenaeus vannamei cultured in shrimp farms. Shrimp samples showed occurrence of 3.3% of Salmonella and 48.3% of Vibrio. The isolates were also screened for antibiotic resistance to oxolinic acid, sulphonamides, tetracycline, sulfamethoxazole/trimethoprim, norfloxacin, ampicillin, doxycycline hydrochloride, erythromycin, chloramphenicol, and nitrofurantoin. Salmonella enterica serovar Corvallis isolated from shrimp showed indiv...

  13. Antibiotic resistance in human peri-implantitis microbiota

    NARCIS (Netherlands)

    Rams, Thomas E.; Degener, John E.; van Winkelhoff, Arie J.

    2014-01-01

    ObjectivesBecause antimicrobial therapy is often employed in the treatment of infectious dental implant complications, this study determined the occurrence of in vitro antibiotic resistance among putative peri-implantitis bacterial pathogens. MethodsSubmucosal biofilm specimens were cultured from 16

  14. Multidrug transporters and antibiotic resistance in Lactococcus lactis

    NARCIS (Netherlands)

    Poelarends, GJ; Mazurkiewicz, P; Konings, WN

    2002-01-01

    The Gram-positive bacterium Lactococcus lactis produces two distinct multidrug transporters, designated LmrA and LmrP, that both confer resistance to a wide variety of cationic lipophilic cytotoxic compounds as well as to many clinically relevant antibiotics. While LmrP is a proton/drug antiporter t

  15. Bacteriology and changes in antibiotic susceptibility in adults with community-acquired perforated appendicitis.

    Directory of Open Access Journals (Sweden)

    Hong Gil Jeon

    Full Text Available This study evaluated bacterial etiology and antibiotic susceptibility in patients diagnosed with community-acquired perforated appendicitis over a 12-year-period. We retrospectively reviewed records of adult patients diagnosed with perforated appendicitis at an 800-bed teaching hospital between January 2000 and December 2011. In total, 415 culture-positive perforated appendicitis cases were analyzed. Escherichia coli was the most common pathogen (277/415, 66.7%, followed by Streptococcus species (61/415, 14.7%. The susceptibility of E. coli to ampicillin, piperacillin/tazobactam, ceftriaxone, cefepime, amikacin, gentamicin, and imipenem was 35.1%, 97.1%, 97.0%, 98.2%, 98.9%, 81.8%, and 100%, respectively. The overall susceptibility of E. coli to quinolones (ciprofloxacin or levofloxacin was 78.7%. During the study period, univariate logistic regression analysis showed a significant decrease in E. coli susceptibility to quinolones (OR = 0.91, 95% CI 0.84-0.99, P = 0.040. We therefore do not recommend quinolones as empirical therapy for community-acquired perforated appendicitis.

  16. Augmented HR Repair Mediates Acquired Temozolomide Resistance in Glioblastoma.

    Science.gov (United States)

    Gil Del Alcazar, Carlos Rodrigo; Todorova, Pavlina Krasimirova; Habib, Amyn A; Mukherjee, Bipasha; Burma, Sandeep

    2016-10-01

    Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults and is universally fatal. The DNA alkylating agent temozolomide is part of the standard-of-care for GBM. However, these tumors eventually develop therapy-driven resistance and inevitably recur. While loss of mismatch repair (MMR) and re-expression of MGMT have been shown to underlie chemoresistance in a fraction of GBMs, resistance mechanisms operating in the remaining GBMs are not well understood. To better understand the molecular basis for therapy-driven temozolomide resistance, mice bearing orthotopic GBM xenografts were subjected to protracted temozolomide treatment, and cell lines were generated from the primary (untreated) and recurrent (temozolomide-treated) tumors. As expected, the cells derived from primary tumors were sensitive to temozolomide, whereas the cells from the recurrent tumors were significantly resistant to the drug. Importantly, the acquired resistance to temozolomide in the recurrent lines was not driven by re-expression of MGMT or loss of MMR but was due to accelerated repair of temozolomide-induced DNA double-strand breaks (DSB). Temozolomide induces DNA replication-associated DSBs that are primarily repaired by the homologous recombination (HR) pathway. Augmented HR appears to underpin temozolomide resistance in the recurrent lines, as these cells were cross-resistant to other agents that induced replication-associated DSBs, exhibited faster resolution of damage-induced Rad51 foci, and displayed higher levels of sister chromatid exchanges (SCE). Furthermore, in light of recent studies demonstrating that CDK1 and CDK2 promote HR, it was found that CDK1/2 inhibitors countered the heightened HR in recurrent tumors and sensitized these therapy-resistant tumor cells to temozolomide.

  17. Class 1 integron and Imipenem Resistance in Clinical Isolates of Pseudomonas aeruginosa: Prevalence and Antibiotic Susceptibility

    Directory of Open Access Journals (Sweden)

    M Milani

    2010-12-01

    Full Text Available Background and Objectives: Pseudomonas aeruginosa is one of the most important causative agents of nosocomial infections especially in ICU and burn units. P. aeruginosa infections are normally difficult to eradicate due to acquired resistance to many antibiotics. Recent appearance of carbapenem resistant P. aeruginosa isolates is considered a major healthcare problem. The present study was conducted to detect class 1 integron and antibiotic susceptibility profiles of imipenem-sensitive and resistant clinical isolates of P. aeruginosa."nMaterials and Methods: Antibiotic susceptibility profiles and minimum inhibitory concentration against imipenem was studied in 160 clinical isolates of P. aeruginosa by disk agar diffusion method and Etest, respectively. Detection of class 1 integron was performed by the PCR method. Demographic and microbiological data were compared between imipenem susceptible and non-susceptible isolates by the SPSS software."nResults: PCR results showed that 90 (56.3% of P. aeruginosa isolates carried class 1 integron. Antibiotic susceptibility results revealed that 93 (58.1% were susceptible and 67 (41.9% were non-susceptible to imipenem. Comparison of antibiotic susceptibility patterns showed high level of drug resistance among imipenem non-susceptible isolates. We found that MDR phenotype, presence of class 1 integron and hospitalization in ICU and burn units were significantly associated with imipenem non-susceptible isolates."nConclusion: The high frequency of imipenem resistance was seen among our P. aeruginosa isolates. Since carbapenems are considered as the last drugs used for treatment of P. aeruginosa infections, it is crucial to screen imipenem non-susceptible isolates in infection control and optimal therapy.

  18. Acquired resistance to auranofin in cultured human cells.

    Science.gov (United States)

    Glennås, A; Rugstad, H E

    1985-01-01

    A substrain (HEAF) of cultured human epithelial cells, grown as monolayers, was selected for resistance to auranofin (AF), a gold-containing anti-arthritic drug, by growing the parental HE cells with stepwise increased concentrations of AF in the medium. HEAF cells acquired resistance to 2 mumol AF/l, twice the concentration tolerated by the sensitive HE cells. Resistance to AF was also demonstrated in another substrain (HE100) originally selected for by its cadmium resistance, and characterized by a high cytosolic metallothionein (MT) content. Following continuous exposure to 2 mumol AF/l for 4 days, 58% of the HEAF cells, 67% of the HE100 cells, and 16% of the HE cells remained adherent to the flasks, compared with non-treated controls. Following 24 h AF exposure to living cells, HEAF cells had one-half and HE100 cells twice the cellular and cytosolic gold concentration per mg protein, as compared with HE cells. Gel filtration of cell cytosols revealed gold-binding proteins with a mol. wt. of about 10 000 apparently occurring on AF exposure in HEAF and HE cells. They bound 10-15% of cytosolic gold. MT in HE100 cells bound AF-gold to about the same extent. We suggest that the ability of cells to maintain the gold concentration at a low level (HEAF) and trapping of gold by MT (HE100) or low molecular weight proteins occurring on AF treatment (HEAF) may be mechanisms contributing to the observed cellular resistance to AF.

  19. Antibiotics, Antibiotic Resistance Genes, and Bacterial Community Composition in Fresh Water Aquaculture Environment in China.

    Science.gov (United States)

    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. Multidrug efflux pumps as main players in intrinsic and acquired resistance to antimicrobials.

    Science.gov (United States)

    Hernando-Amado, Sara; Blanco, Paula; Alcalde-Rico, Manuel; Corona, Fernando; Reales-Calderón, Jose A; Sánchez, María B; Martínez, José L

    2016-09-01

    Multidrug efflux pumps constitute a group of transporters that are ubiquitously found in any organism. In addition to other functions with relevance for the cell physiology, efflux pumps contribute to the resistance to compounds used for treating different diseases, including resistance to anticancer drugs, antibiotics or antifungal compounds. In the case of antimicrobials, efflux pumps are major players in both intrinsic and acquired resistance to drugs currently in use for the treatment of infectious diseases. One important aspect not fully explored of efflux pumps consists on the identification of effectors able to induce their expression. Indeed, whereas the analysis of clinical isolates have shown that mutants overexpressing these resistance elements are frequently found, less is known on the conditions that may trigger expression of efflux pumps, hence leading to transient induction of resistance in vivo, a situation that is barely detectable using classical susceptibility tests. In the current article we review the structure and mechanisms of regulation of the expression of bacterial and fungal efflux pumps, with a particular focus in those for which a role in clinically relevant resistance has been reported.

  1. The gut as reservoir of antibiotic resistance: microbial diversity of tetracycline resistance in mother and infant.

    Directory of Open Access Journals (Sweden)

    Lisbeth E de Vries

    Full Text Available The microbiota in the human gastrointestinal tract (GIT is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc(r in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc(r genes. Fecal fosmid libraries were functionally screened for Tc(r, and further PCR-screened for specific Tc(r genes. Tc(r fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tc(r, although encoded by different genes and organisms. Tc(r organisms in the mother consisted mainly of Firmicutes and Bacteroidetes, and the main gene detected was tet(O, although tet(W and tet(X were also found. Identical Tc(r gene sequences were present in different bacterial families and even phyla, which may indicate horizontal transfer within the maternal GIT. In the infant library, Tc(r was present exclusively in streptococci carrying tet(M, tet(L and erm(T within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within the infant's gut. In addition, although not found in the infant metagenomic library, tet(O and tet(W could be detected in the uncloned DNA purified from the infant fecal sample. This is the first study to reveal the diversity of Tc(r bacteria in the human gut, to detect a likely transmission of antibiotic resistance from mother to infant GITs and to indicate the possible occurrence of gene transfers among distantly related bacteria coinhabiting the GIT of the same

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

    Science.gov (United States)

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

  3. Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics

    DEFF Research Database (Denmark)

    Rathe, Mathias; Lise, Kristensen,; Ellermann-Eriksen, Svend;

    Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics......Vancomycin-resistant enterococci: validation of susceptibility testing and in vitro activity of novel antibiotics...

  4. Management options for reducing the release of antibiotics and antibiotic resistance genes to the environment

    DEFF Research Database (Denmark)

    Pruden, Amy; Larsson, D.G. Joakim; Amézquita, Alejandro

    2013-01-01

    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...

  5. Broad-spectrum acquired resistance in barley induced by the Pseudomonas pathosystem shares transcriptional components with Arabidopsis systemic acquired resistance.

    Science.gov (United States)

    Colebrook, E H; Creissen, G; McGrann, G R D; Dreos, R; Lamb, C; Boyd, L A

    2012-05-01

    Inducible resistance responses play a central role in the defense of plants against pathogen attack. Acquired resistance (AR) is induced alongside defense toward primary attack, providing broad-spectrum protection against subsequent pathogen challenge. The localization and molecular basis of AR in cereals is poorly understood, in contrast with the well-characterized systemic acquired resistance (SAR) response in Arabidopsis. Here, we use Pseudomonas syringae as a biological inducer of AR in barley, providing a clear frame of reference to the Arabidopsis-P. syringae pathosystem. Inoculation of barley leaf tissue with the nonadapted P. syringae pv. tomato avrRpm1 (PstavrRpm1) induced an active local defense response. Furthermore, inoculation of barley with PstavrRpm1 resulted in the induction of broad-spectrum AR at a distance from the local lesion, "adjacent" AR, effective against compatible isolates of P. syringae and Magnaporthe oryzae. Global transcriptional profiling of this adjacent AR revealed similarities with the transcriptional profile of SAR in Arabidopsis, as well as transcripts previously associated with chemically induced AR in cereals, suggesting that AR in barley and SAR in Arabidopsis may be mediated by analogous pathways.

  6. Cultures of resistance? A Bourdieusian analysis of doctors' antibiotic prescribing.

    Science.gov (United States)

    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.

  7. Antibiotic resistance-the need for global solutions.

    Science.gov (United States)

    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.

  8. Antibiotic resistance in prevalent bacterial and protozoan sexually transmitted infections

    Directory of Open Access Journals (Sweden)

    Karl Krupp

    2015-01-01

    Full Text Available 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.

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

    OpenAIRE

    2011-01-01

    International audience; , a major cause of potentially life-threatening hospital-acquired human infections, can be resistant to several antimicrobials, such that streptogramin quinupristin-dalfopristin (Q/D) is one of the few antibiotics still effective. Consequently use of the streptogramin virginiamycin as an animal growth promoter was banned in the EU in 1999 as some believed this contributed to the emergence of Q/D resistant E. . Virginiamycin is advocated for preventing equine pasture-as...

  10. Antibiotic-Resistant Enteric Bacteria in Environmental Waters

    Directory of Open Access Journals (Sweden)

    Lisa M. Casanova

    2016-11-01

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

  11. Cellular memory of acquired stress resistance in Saccharomyces cerevisiae.

    Science.gov (United States)

    Guan, Qiaoning; Haroon, Suraiya; Bravo, Diego González; Will, Jessica L; Gasch, Audrey P

    2012-10-01

    Cellular memory of past experiences has been observed in several organisms and across a variety of experiences, including bacteria "remembering" prior nutritional status and amoeba "learning" to anticipate future environmental conditions. Here, we show that Saccharomyces cerevisiae maintains a multifaceted memory of prior stress exposure. We previously demonstrated that yeast cells exposed to a mild dose of salt acquire subsequent tolerance to severe doses of H(2)O(2). We set out to characterize the retention of acquired tolerance and in the process uncovered two distinct aspects of cellular memory. First, we found that H(2)O(2) resistance persisted for four to five generations after cells were removed from the prior salt treatment and was transmitted to daughter cells that never directly experienced the pretreatment. Maintenance of this memory did not require nascent protein synthesis after the initial salt pretreatment, but rather required long-lived cytosolic catalase Ctt1p that was synthesized during salt exposure and then distributed to daughter cells during subsequent cell divisions. In addition to and separable from the memory of H(2)O(2) resistance, these cells also displayed a faster gene-expression response to subsequent stress at >1000 genes, representing transcriptional memory. The faster gene-expression response requires the nuclear pore component Nup42p and serves an important function by facilitating faster reacquisition of H(2)O(2) tolerance after a second cycle of salt exposure. Memory of prior stress exposure likely provides a significant advantage to microbial populations living in ever-changing environments.

  12. Why Finish Your Antibiotics? A Novel, Hands-On, Classroom Approach for Teaching the Dynamics of Antibiotic Resistance

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    Science.gov (United States)

    Sandoval-Motta, Santiago; Aldana, Maximino

    2016-05-01

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

  15. The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

    DEFF Research Database (Denmark)

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca;

    2015-01-01

    in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P....... aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P....... In conclusion, serotype switching in combination with acquisition of an antibiotic resistance determinant most likely contributed to the dissemination of the O12 serotype in clinical settings. Infection rates in hospital settings by multidrug-resistant (MDR) Pseudomonas aeruginosa clones have increased during...

  16. Use of commercial organic fertilizer increases the abundance of antibiotic resistance genes and antibiotics in soil.

    Science.gov (United States)

    Zhou, Xue; Qiao, Min; Wang, Feng-Hua; Zhu, Yong-Guan

    2017-01-01

    The application of manure-based commercial organic fertilizers (COFs) is becoming increasingly extensive because of the expanding market for organic food. The present study examined the effects of repeated applications of chicken or swine manure-based COFs on the fate of antibiotics and antibiotic resistance genes (ARGs) in soil by conducting a soil microcosm experiment. Application of COFs significantly increased antibiotics residues, as well as the relative abundance of ARGs and the integrase gene of class 1 integrons (intΙ1) in soil. Two months after each application, antibiotics and ARGs dissipated in amended soils, but they still remained at an elevated level, compared with the control. And, the accumulation of antibiotics was found due to repeated COF applications. However, the relative abundance of ARGs in most COF-amended soils did not differ significantly between the first application and the repeated application. The results imply that 2 months are not sufficient for ARGs to approach background levels, and that animal manure must be treated more effectively prior to using it in agriculture ecosystems.

  17. Antibiotic resistance in primary care in Austria - a systematic review of scientific and grey literature

    Directory of Open Access Journals (Sweden)

    Hoffmann Kathryn

    2011-11-01

    Full Text Available Abstract Background Antibiotic resistance is an increasing challenge for health care services worldwide. While up to 90% of antibiotics are being prescribed in the outpatient sector recommendations for the treatment of community-acquired infections are usually based on resistance findings from hospitalized patients. In context of the EU-project called "APRES - the appropriateness of prescribing antibiotic in primary health care in Europe with respect to antibiotic resistance" it was our aim to gain detailed information about the resistance data from Austria in both the scientific and the grey literature. Methods A systematic review was performed including scientific and grey literature published between 2000 and 2010. Inclusion and exclusion criteria were defined and the review process followed published recommendations. Results Seventeen scientific articles and 23 grey literature documents could be found. In contrast to the grey literature, the scientific publications describe only a small part of the resistance situation in the primary health care sector in Austria. Merely half of these publications contain data from the ambulatory sector exclusively but these data are older than ten years, are very heterogeneous concerning the observed time period, the number and origin of the isolates and the kind of bacteria analysed. The grey literature yields more comprehensive and up-to-date information of the content of interest. These sources are available in German only and are not easily accessible. The resistance situation described in the grey literature can be summarized as rather stable over the last two years. For Escherichia coli e.g. the highest antibiotic resistance rates can be seen with fluorochiniolones (19% and trimethoprim/sulfamethoxazole (27%. Conclusion Comprehensive and up-to-date antibiotic resistance data of different pathogens isolated from the community level in Austria are presented. They could be found mainly in the grey

  18. On the natural and laboratory evolution of an antibiotic resistance gene

    NARCIS (Netherlands)

    Salverda, M.L.M.

    2008-01-01

    TEM-1 ß-lactamase is one of the most notorious antibiotic resistance enzymes around. It exists at high frequencies in antibiotic-resistant bacteria around the world and confers resistance to ß-lactam antibiotics, including penicillins (e.g. ampicillin) and cephalosporins. The enzyme displays a remar

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

    Science.gov (United States)

    Longtin, Sarah; Guilfoile, Patrick; Asper, Andrea

    2004-01-01

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

  20. Bottlenecks in the transmission of antibiotic resistance from natural ecosystems to human bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Jose L Martinez

    2012-01-01

    Full Text Available It is generally accepted that resistance genes acquired by human pathogens trough horizontal gene transfer have been originated in environmental, non pathogenic bacteria. As the consequence, there exists an increasing concern on the role that natural, non-clinical ecosystems, may play on the evolution of resistance. Recent studies have shown that the variability of determinants that can provide antibiotic resistance upon their expression in a heterologous host is much larger than what is actually found in human pathogens. Along the review, the role that different processes as founder effect, ecological connectivity, fitness costs or second-order selection may have on the establishment of a specific resistance determinant in the population of bacterial pathogens is analysed.

  1. Development of quality indicators to evaluate antibiotic treatment of patients with community-acquired pneumonia in Indonesia

    NARCIS (Netherlands)

    Farida, H.; Rondags, A.; Gasem, M.H.; Leong, K.; Adityana, A.; Broek, P.J. van den; Keuter, M.; Natsch, S.S.

    2015-01-01

    OBJECTIVE: To develop an instrument for evaluating the quality of antibiotic management of patients with community-acquired pneumonia (CAP) applicable in a middle-income developing country. METHOD: A previous study and Indonesian guidelines were reviewed to derive potential quality of care indicator

  2. Insights into an evolutionary strategy leading to antibiotic resistance

    Science.gov (United States)

    Hou, Chun-Feng D.; Liu, Jian-Wei; Collyer, Charles; Mitić, Nataša; Pedroso, Marcelo Monteiro; Schenk, Gerhard; Ollis, David L.

    2017-01-01

    Metallo-β-lactamases (MBLs) with activity towards a broad-spectrum of β-lactam antibiotics have become a major threat to public health, not least due to their ability to rapidly adapt their substrate preference. In this study, the capability of the MBL AIM-1 to evade antibiotic pressure by introducing specific mutations was probed by two alternative methods, i.e. site-saturation mutagenesis (SSM) of active site residues and in vitro evolution. Both approaches demonstrated that a single mutation in AIM-1 can greatly enhance a pathogen’s resistance towards broad spectrum antibiotics without significantly compromising the catalytic efficiency of the enzyme. Importantly, the evolution experiments demonstrated that relevant amino acids are not necessarily in close proximity to the catalytic centre of the enzyme. This observation is a powerful demonstration that MBLs have a diverse array of possibilities to adapt to new selection pressures, avenues that cannot easily be predicted from a crystal structure alone.

  3. Natural solution to antibiotic resistance: bacteriophages 'The Living Drugs'.

    Science.gov (United States)

    Jassim, Sabah A A; Limoges, Richard G

    2014-08-01

    Antibiotics have been a panacea in animal husbandry as well as in human therapy for decades. The huge amount of antibiotics used to induce the growth and protect the health of farm animals has lead to the evolution of bacteria that are resistant to the drug's effects. Today, many researchers are working with bacteriophages (phages) as an alternative to antibiotics in the control of pathogens for human therapy as well as prevention, biocontrol, and therapy in animal agriculture. Phage therapy and biocontrol have yet to fulfill their promise or potential, largely due to several key obstacles to their performance. Several suggestions are shared in order to point a direction for overcoming common obstacles in applied phage technology. The key to successful use of phages in modern scientific, farm, food processing and clinical applications is to understand the common obstacles as well as best practices and to develop answers that work in harmony with nature.

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

    Science.gov (United States)

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

    2014-03-01

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

  5. Antibiotic Resistance in Escherichia Coli Strains Isolated from Urine of Inpatients and Outpatients

    Directory of Open Access Journals (Sweden)

    Abolfazl Davoodabadi

    2012-08-01

    Full Text Available The urinary tract infections regarded as a health problem around the world and not only as an agent of nosocomial infections but also infections in the community. Community acquired UTIs cause significant illness in the first 2 years of life [1]. Urinary tract infections in both inpatient and outpatient are common and widespread use of antibiotics is often the cause of emerging one or more antibiotic-resistant microorganisms [2]. Most studies have shown higher antibiotic resistance in bacterial strains isolated from hospitalized patients than outpatients. In this study, antibiogram was performed using disk diffusion susceptibility method according to NCCLS standards of the International Committee [3]. 8 different antibiotics, including ciprofloxacin (CP: 30 μg, ceftriaxone (CRO: 30 μg, cephalotin (CF: 30 μg, cefixime (CFM: 5 μg, cotrimoxazole (SXT, nalidixic acid (NA: 30 μg, nitrofurantoin (FM: 300 μg, gentamicin (GM: 10 μg were used for antibiogram. During 1388 the total number of urine samples sent to hospital microbiology laboratories valiasr (aj of Arak was 5156, of which 446 samples (65.8% were positive for E. coli culture.

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

    Science.gov (United States)

    Fraqueza, Maria João

    2015-11-06

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

  7. Multiple Antibiotic Resistances of Vibrio Isolates from Coastal and Brackish Water Areas

    Directory of Open Access Journals (Sweden)

    S. Manjusha

    2005-01-01

    Full Text Available An experiment was designed to assess the occurrence of multiple antibiotic resistances in Vibrio spp. from different (brackish and marine environments. Water samples from nine marine landing sites and two coastal inland aquaculture farms were screened for the Vibrio spp. and assessed their resistance to twenty-two different antibiotics, which are commonly encountered in the aquatic ecosystem. Tissue samples (shrimp, mussel and sepia were tested from the sampling site with highest antibiotic resistance. Of the total 119 Vibrio isolates, 16. 8% were susceptible to all antibiotics. Of the resistant (83.19% Vibrio strains, 30.3% were resistant against three antibiotics, 55.5% were resistant against 4-10 antibiotics, 14.14% were resistant against more than 10 antibiotics and 54% have shown multiple antibiotics resistance (MAR. Antibiotic resistance index was higher in Coastal 3, 6, Aqua farm 2 in isolates from water samples and all the tissues tested. Interestingly, incidence of antibiotic resistance in isolates from water samples was comparatively lower in aquaculture farms than that observed in coastal areas. Highest incidence of antibiotic resistance was evident against Amoxycillin, Ampicillin, Carbencillin and Cefuroxime followed by Rifampicin and Streptomycin and lowest against Chloramphenicol, Tetracycline, Chlortetracycline, Furazolidone, Nalidixic acid, Gentamycin Sulphafurazole, Trimethoprim, Neomycin and Amikacin irrespective of the sampling sites. Results from various tissue samples collected from the sites of highest antibiotic resistance indicated that antibiotic resistance Vibrio spp. collected from fish and tissue samples were higher than that of water samples. Overall results indicated that persistent use of antibiotics against diseases in human beings and other life forms may pollute the aquatic system and their impact on developing antibiotic resistant Vibrio spp. may be a serious threat in addition to the use of

  8. Study of Bacterial Resistance against Antibiotics in Patients Body Fluid Germs

    OpenAIRE

    2007-01-01

    Background: Increase of bacterial resistance against antibiotics makes some difficulties in patient’s treatment and it is essential to study of antibiotics situation and bacterial sensitivity pattern against antibiotics. Physicians often get soon start to treatment patients based on bacterial quantities and bacterial sensitivity against antibiotics that seem always is not an effective treatment and make to spread some resistant species against antibiotics and increase their quantities in popu...

  9. Comparison of Efflux Pump Involvement in Antibiotic Resistance Among Pseudomonas aeruginosa Isolates of Burn and Non-Burn Patients

    Directory of Open Access Journals (Sweden)

    Azimi

    2016-05-01

    Full Text Available Background Pseudomonas aeruginosa is an important cause of hospital-acquired infections that can create serious problem for patients and physicians. Many factors are associated with the antibiotic resistance of P. aeruginosa, such as efflux pumps. Objectives The aim of this study was the phenotypic and molecular detection of efflux pumps in our clinical P. aeruginosa isolates in a comparison between burn and non-burn specimens. Materials and Methods In this study, clinical strains of P. aeruginosa were collected from burn and non-burn specimens from April - July 2013. Antibiotic susceptibility testing of the isolates was performed after biochemical and molecular identification. The minimum inhibitory concentration (MIC of imipenem, cefepime, gentamycin, and ciprofloxacin, with and without carbonyl cyanide 3-chlorophenylhydrazone (CCCP, was determined for phenotypic detection of efflux pumps. Results Our results confirmed 203 and 60 P. aeruginosa isolates from burn and non-burn specimens, respectively. The most antibiotic resistance was observed against tobramycin in both group of specimens, and no resistance was seen to colistin. Phenotypic detection of efflux pumps was determined to correlate to a > 4-fold decrease in the MICs of the tested antibiotics with CCCP compared to without CCCP in 57 strains. Conclusions High-level antibiotic resistance can occur as a result of multidrug efflux pumps combined with other mechanisms of resistance. However, the association between over-expression of these genes and highly resistant clinical isolates cannot be ignored.

  10. Insights on Virulence and Antibiotic Resistance: A Review of the Accessory Genome of Staphylococcus aureus.

    Science.gov (United States)

    Shittu, Adebayo O; Udo, Edet E; Lin, Johnson

    2007-09-01

    Staphylococcus aureus continues to be a serious health problem worldwide due to its intrinsic nature of virulence, ability to cause a wide array of infection, and its capacity to develop resistance to a number of antibiotics. The S aureus genome has continually evolved through both mutation and acquisition of exogenous genes, leading to the emergence of antibiotic-resistant strains with the ability for clonal dissemination across nations and continents. Methicillin-resistant S aureus (MRSA) is one of the most commonly identified antibiotic-resistant pathogens in the hospital and community settings with substantial mortality and morbidity. This review examines the accessory genome of 8 sequenced S aureus strains regarding the variety of virulence factors and mechanisms of antibiotic resistance. The remarkable nature of this organism to acquire and disseminate an array of mobile genetic elements (MBEs) through horizontal gene transfer illustrates the mechanisms for evolution and its fitness level in the face of constant environmental challenges. The relative ease of transfer of genetic materials, especially antibiotic-resistant genes, across staphylococcal species indicates that there is a potential pandemic problem in the hospital and community environment.

  11. Isolation and identification of antibiotic resistance genes in Staphylococcus aureus isolates from respiratory system infections in shahrekord, Iran

    Directory of Open Access Journals (Sweden)

    Maryam Reisi

    2014-07-01

    Full Text Available   Introduction : Staphylococcus aureus is considered as one of pathogenic agents in humans, that engages different body parts including respiratory system and causes to spend lots of costs and extending patient’s treatment period. This study which is performed to separate and investigate the pattern of antibiotic resistance in Staphylococcus aureus isolates from upper respiratory system infections in Shahrekord.   Materials and methods: This study was done by sectional-descriptive method On 200 suspicious persons to the upper respiratory system infections who were referred to the Imam Ali clinic in Shahrekord in 2012. After isolation of Staphylococcus aureus from cultured nose discharges, antibiotic resistance genes were identified by polymerase chain reaction (PCR by using defined primer pairs .   Results : Among 200 investigated samples in 60 cases (30% Staphylococcus aureus infection (by culturing and PCR method was determined. Isolates showed the lowest amount of antibiotic resistance to vancomycin (0.5% and the highest amount of resistance to the penicillin G and cefotaxime (100%. mecA gene (encoding methicillin resistance with frequency of 85.18% and aacA-D gene (encoding resistance to aminoglycosides with frequency of 28.33% showed the highest and lowest frequency of antibiotic resistance genes coding in Staphylococcus aureus isolates respectively .   Discussion and conclusion : Notable prevalence of resistant Staphylococcus aureus isolates in community acquired respiratory infections, recommend continuous control necessity to impede the spreading of these bacteria and their infections.  

  12. A Hybrid Drug Limits Resistance by Evading the Action of the Multiple Antibiotic Resistance Pathway.

    Science.gov (United States)

    Wang, Kathy K; Stone, Laura K; Lieberman, Tami D; Shavit, Michal; Baasov, Timor; Kishony, Roy

    2016-02-01

    Hybrid drugs are a promising strategy to address the growing problem of drug resistance, but the mechanism by which they modulate the evolution of resistance is poorly understood. Integrating high-throughput resistance measurements and genomic sequencing, we compared Escherichia coli populations evolved in a hybrid antibiotic that links ciprofloxacin and neomycin B with populations evolved in combinations of the component drugs. We find that populations evolved in the hybrid gain less resistance than those evolved in an equimolar mixture of the hybrid's components, in part because the hybrid evades resistance mediated by the multiple antibiotic resistance (mar) operon. Furthermore, we find that the ciprofloxacin moiety of the hybrid inhibits bacterial growth whereas the neomycin B moiety diminishes the effectiveness of mar activation. More generally, comparing the phenotypic and genotypic paths to resistance across different drug treatments can pinpoint unique properties of new compounds that limit the emergence of resistance.

  13. Antibiotic resistance: what is the impact of agricultural uses of antibiotics on children's health?

    Science.gov (United States)

    Shea, Katherine M

    2003-07-01

    Antimicrobial resistance has reached crisis stage in human medicine. The rapid acceleration of multidrug-resistant bacteria in the past 2 decades has overtaken new drug development, and patients and clinicians are faced with the prospect of untreatable infections. Although much of the problem stems from overuse and misuse of antimicrobial agents in human medicine, large-scale use of antimicrobials in agriculture also contributes to the crisis. Agricultural uses of antibiotics produce environmental exposures in a variety of reservoirs, which select for resistant microbes and microbial genes. This article presents the major lines of evidence documenting the risks to human health of some of the agricultural uses of antimicrobials. A brief review of the microbiologic antecedents of resistance is followed by a discussion of agricultural uses of antimicrobials and a targeted review of the literature, which provides the background knowledge and evidence necessary for pediatricians and other clinicians to be informed and to advocate for judicious use of antimicrobials in all sectors.

  14. Quantifying the associations between antibiotic exposure and resistance - a step towards personalised antibiograms.

    Science.gov (United States)

    Sanden, L; Paul, M; Leibovici, L; Andreassen, S

    2016-12-01

    Empirical antibiotic treatment is selected to target causative bacteria with antibiotics to which they are not resistant. We analysed the increase in bacterial resistance among individual patients associated with antibiotic exposure in the month prior to infection onset, compared to unexposed patients. From a series of prospective cohort studies in the period 2002-2011 at Beilinson Hospital, Israel, 4232 consecutive patients suspected of infection were included. We analysed resistance to antibiotics in bacterial isolates from patients with clinically significant and microbiologically documented infections, starting antibiotics after obtaining cultures (n = 775). In Gram-negative bacteria, significantly higher rates of resistance was associated with exposure to antibiotics, while no significant associations were found for Gram-positive bacteria. Significant odds ratios (ORs) for increased resistance to classes of antibiotics ranged from 2.1 to 3.3 in Gram-negative bacteria from patients exposed to any antibiotic(s), with quinolones having the highest OR, followed by aminoglycosides, penicillins with β-lactamase inhibitor and cephalosporins. The majority of significant associations also had significant ORs after exposure to another class of antibiotics, indicating a substantial effect of cross-resistance. In conclusion, increased resistance was observed following exposure to antibiotics, both from the same class and from other classes. The results indicate a reason to adjust the expected coverage of empirical antibiotic treatments for patients recently exposed to antibiotics, with some antibiotics being more affected than others.

  15. Carriage of antibiotic-resistant pneumococci in a cohort of a daycare center

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    Gómez-Barreto Demóstenes

    2002-01-01

    Full Text Available Objective. To define epidemiologic relationships to determine the prevalence and potential risk factors for nasopharyngeal colonization by antibiotic-resistant pneumococci, their serotypes and their antibiotic susceptibility patterns in children attending a daycare center (DCC. Material and Methods. A prospective cohort study was conducted among children (n=53 attending the DCC at Hospital Infantil de México Federico Gómez, which is staffed by 20 employees. Patients were enrolled in the study during a two-year period from September 1997 to September 1999. All the participants were followed prospectively, swabbing them every four months. The strains recovered were typed and screened for susceptibility to several antibiotics. The daycare records were reviewed also. Odds ratios and fisher's exact test: or chi square test of significance were computed from contingency tables as appropriate. Exact 95% confidence intervals were computed for odds ratios. Data analysis was performed using Epi statistics program version 6.04 a. Results. Pneumococci were recovered from 45/53 of the infants at one or more visits. A total of 178 isolates were carried. The carriage rate was 47%. Only 7 adults acquired pneumococci during the study. Types 6,14,19 and 23 were prevalent and represented 77% of the total. Antibiotic-resistant strains were higher to penicillin and erythromycin. Conclusions. Children were frequent carriers of pneumococci, the rate of carriage was high in infancy and tended to decrease with age. The types commonly carried by children were the same as those causing invasive disease. There is a high proportion of carriers with antibiotic-resistant S. pneumoniae strains. Children who have had frequent antimicrobial courses are at particular risk.

  16. CHANGING BACTERIAL ORGANISMS AND ANTIMICROBIAL RESISTANCE PATTERN AMONG HOSPITALIZED COMMUNITY ACQUIRED PNEUMONIA PATIENTS IN A TERTIARY CARE CENTER

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    Raveendra Kodur

    2013-04-01

    Full Text Available ABSTRACT: BACKGROUND: Most of the times a Community Acquired Pneumonia (CAP patient is being treated with empirical antibiotics by best guess method by the clinician.MDR strains are being reported from c/s reports and Gram negative rods are fast increasing both in the etiolog y and mortality of CAP patients AIM OF STUDY: 1. To find out the profile of different bacteria causing CAP at a tertiary hospital. 2. To know the treatment outcome & drug resistance pattern among culture positive CAP patients. MATERIALS & METHODS: 450 CAP patients admitted & treated between Jan. to Dec.2012 at Victoria Hospital, Bangalore were included in this hospitalized cross sectional study. All relevant investigations including sputum c/s were done. RESULTS: Positive culture reports were obtained in 165(36.33% out of 450 patients Following are the isolates - Strept.pnemoniae 32.7%, Klebsiella 18.2%, Staph.aureas 10.9%, Psedomonas 10.9%, E.coli 5.4%, Acinetobacter 7.3%, H.influenza 5.4%, Mixed growth 10%. 76% of patients recovered from CAP, 6% went a gainst medical advice, 6.6% showed unresolved pneumonia & deaths in 5.33% of patients. High degree of resistance was noted to many antibiotics including to latest cephalosporins. CONCLUSION: This study highlights the importance of culture tests and selection of proper antibiotics and to avoid misuse & abuse of higher antibiotics to prevent the emergence of MDR strains. An antibiotic policy at every level may help.

  17. Antibiotic resistance in the environment, with particular reference to MRSA

    OpenAIRE

    Gaze, William H.; O'Neill, Colette; Wellington, E. M. H.; Hawkey, P M

    2008-01-01

    The introduction of β-lactam antibiotics (penicillins and cephalosporins) in the 1940s and 1950s probably represents the most dramatic event in the battle against infection in human medicine. Even before widespread global use of penicillin, resistance was already recorded. E. coli producing a penicillinase was reported in Nature in 1940 (Abraham, 1940) and soon after a similar penicillinase was discovered in Staphylococcus aureus (Kirby, 1944). The appearance of these genes, so quickly after ...

  18. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

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

    2008-01-01

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

  19. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

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

    2008-01-01

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

  20. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

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

    2008-01-01

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

  1. Detection of antibiotic resistance in probiotics of dietary supplements

    OpenAIRE

    Wong, Aloysius; Ngu, Davey Yueh Saint; Dan, Lydia Annabel; Ooi, Amanda; Lim, Renee Lay Hong

    2015-01-01

    Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplemen...

  2. Economic burden of antibiotic resistance: how much do we really know?

    Science.gov (United States)

    Gandra, S; Barter, D M; Laxminarayan, R

    2014-10-01

    The declining effectiveness of antibiotics imposes potentially large health and economic burdens on societies. Quantifying the economic outcomes of antibiotic resistance effectively can help policy-makers and healthcare professionals to set priorities, but determining the actual effect of antibiotic resistance on clinical outcomes is a necessary first step. In this article, we review and discuss the contributions and limitations of studies that estimate the disease burden attributable to antibiotic resistance and studies that estimate the economic burden of resistance. We also consider other factors that are important in a comprehensive approach to evaluating the economic burden of antibiotic resistance.

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

    Science.gov (United States)

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

    2012-01-01

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

  4. [Ecology and mechanisms of bacterial resistance to antibiotics in peritonitis].

    Science.gov (United States)

    Edern, Anita; Fines-Guyon, Marguerite; Castrale, Cindy; Ficheux, Maxence; Ryckelynck, Jean-Philippe; Lobbedez, Thierry

    2012-11-01

    Peritonitis remains a common complication of peritoneal dialysis. The aim of our study is to describe the mechanisms of antibiotic resistance in bacteria isolated during peritonitis in peritoneal dialysis, to determine whether antibiotic therapy proposed by the International Society for Peritoneal Dialysis (ISPD) is adapted to the mechanisms of resistance. All causative microorganisms of peritonitis, isolated in 106 dialysis patients and reported 170 episodes of peritonitis, during the study period (01/01/2005 to 31/12/2010) were reviewed. According to the usual classification, twelve groups of microorganism were created. An interpretive reading of antibiograms was performed in each group to identify resistance phenotypes. The species most frequently isolated are coagulase-negative staphylococci (n=73) of which 46 had PBP2a (penicillin-binding protein). Many Enterobacteriaceae were also isolated (n=45), they are susceptible to third generation cephalosporins with the exception of Enterobacteriaceae producing an extended spectrum β-lactamase (ESBL) or a cephalosporinase. Except for staphylococci, probabilistic antibiotic therapy recommended by the ISPD to treat peritonitis is effective. Indeed, many staphylococci producing a PBP2a, a first-generation cephalosporin cannot be administered in all cases. It is therefore necessary to identify patients with a strain of staphylococcus producing a PBP2a, it must be treated by vancomycin.

  5. Exploring the contribution of bacteriophages to antibiotic resistance.

    Science.gov (United States)

    Lekunberri, Itziar; Subirats, Jèssica; Borrego, Carles M; Balcázar, José Luis

    2017-01-01

    Bacteriophages (phages) are the most abundant and diverse biological entities in our planet. They infect susceptible bacterial hosts into which they either multiply or persist. In the latter case, phages can confer new functions to their hosts as a result of gene transfer, thus contributing to their adaptation (short-term) and evolution (long-term). In this regard, the role of phages on the dissemination of antibiotic resistance genes (ARGs) among bacterial hosts in natural environments has not yet been clearly resolved. Here, we carry out a comprehensive analysis of thirty-three viromes from different habitats to investigate whether phages harbor ARGs. Our results demonstrate that while human-associated viromes do not or rarely carry ARGs, viromes from non-human sources (e.g. pig feces, raw sewage, and freshwater and marine environments) contain a large reservoir of ARGs, thus pointing out that phages could play a part on the spread of antibiotic resistance. Given this, the role of phages should not be underestimated and it should be considered when designing strategies to tackle the global crisis of antibiotic resistance.

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

    Science.gov (United States)

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

    2008-07-01

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

  7. The Relationship Between Antibiotic Resistance and Agr Type in Methicillin-Resistant Staphylococcus aureus (MRSA Isolated From Burn Wound of Hospitalized Patient in Tehran

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Vaziri

    2015-12-01

    Full Text Available Introduction: Staphylococcus aureus is the major cause of hospital and community-acquired infections. This bacterium possesses an accessory gene regulator (agr that plays role in colonization, expression of virulence factors and antibiotic resistance. It’s four major polypeptide with variable sequences lead to at least four agr type in S. aureus.The aim of this study was to determine the relationship between the antibiogram patterns with agr type of clinical S. aureus.Methods: Detection of methicillin-resistant Staphylococcus aureus (MRSA from burn wounds was performed by phenotypic and genotypic profiles. The antibiotics resistance pattern was determined by disk agar diffusion (Tigecycline (TGC, Ciprofloxacin(CIP, Erythromycin(E, Cloxacillin(CX, Clindamycin(CD, Imipenem(IMI, Co-trimoxazole(SXT, Kanamycin(K, Teicoplanin(TEC, Gentamicin(GM, Mupirocin(MUP, Ceftriaxone (CTR. The agr typing by PCR-RFLP method using the Restriction endonuclease ScaI was performed and spss19 was used for data analysis.Results: The total of 76 MRSA isolates was studied. The agr type distribution was 75.6% Type I, 8.2% Type II, 5.4% Type III, 10.8% type IV. The most antibiotics resistant agr type belongs to the type I. There was no significance relationship between every agr type and antibiotics but only a statistically significant association exist between CX, E, CTR, SXT, GM, CIP antibiotics and all agr types (P<0.05.Conclusion: There was no significance relationship between every agr type and antibiotics but significant relationship observed between resistance to some antibiotics with all agr types could be related to the number and source of isolated bacteria or extra use of these antibiotics. By considering that agr locus belongs to upstream genes so it may use the Quorum Sensing (QS system to induce the most drug resistance.

  8. Increasing transmission of antibiotic resistance from animals to humans

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Frimodt-Møller, Niels

    2011-01-01

    usage of antibiotics which contributes most to resistance observed in humans, but also that the contribution from animals is large and larger than estimated just a few years ago. This indicates the need to implement restriction on antimicrobial usage for both humans and animals.......The importance of the animal reservoir for emergence of antimicrobial resistance in bacteria in humans is difficult to estimate. In this article we give our estimate of the importance and also highlight on which points we have become wiser during recent years. We conclude that it still is the human...

  9. Impact of Antibiotic Use on Carbapenem Resistance in Pseudomonas aeruginosa: Is There a Role for Antibiotic Diversity?

    Science.gov (United States)

    Pannatier, A.; Kronenberg, A.; Mühlemann, K.; Zanetti, G.

    2013-01-01

    In this study, we aimed to evaluate the relationship between the rates of resistance of Pseudomonas aeruginosa to carbapenems and the levels and diversity of antibiotic consumption. Data were retrospectively collected from 20 acute care hospitals across 3 regions of Switzerland between 2006 and 2010. The main outcome of the present study was the rate of resistance to carbapenems among P. aeruginosa. Putative predictors included the total antibiotic consumption and carbapenem consumption in defined daily doses per 100 bed days, the proportion of very broad-spectrum antibiotics used, and the Peterson index. The present study confirmed a correlation between carbapenem use and carbapenem resistance rates at the hospital and regional levels. The impact of diversifying the range of antibiotics used against P. aeruginosa resistance was suggested by (i) a positive correlation in multivariate analysis between the above-mentioned resistance and the proportion of consumed antibiotics having a very broad spectrum of activity (coefficient = 1.77; 95% confidence interval, 0.58 to 2.96; P < 0.01) and (ii) a negative correlation between the resistance and diversity of antibiotic use as measured by the Peterson homogeneity index (coefficient = −0.52; P < 0.05). We conclude that promoting heterogeneity plus parsimony in the use of antibiotics appears to be a valuable strategy for minimizing the spread of carbapenem resistance in P. aeruginosa in hospitals. PMID:23357763

  10. Chemical communication of antibiotic resistance by a highly resistant subpopulation of bacterial cells.

    Directory of Open Access Journals (Sweden)

    Omar M El-Halfawy

    Full Text Available The overall antibiotic resistance of a bacterial population results from the combination of a wide range of susceptibilities displayed by subsets of bacterial cells. Bacterial heteroresistance to antibiotics has been documented for several opportunistic Gram-negative bacteria, but the mechanism of heteroresistance is unclear. We use Burkholderia cenocepacia as a model opportunistic bacterium to investigate the implications of heterogeneity in the response to the antimicrobial peptide polymyxin B (PmB and also other bactericidal antibiotics. Here, we report that B. cenocepacia is heteroresistant to PmB. Population analysis profiling also identified B. cenocepacia subpopulations arising from a seemingly homogenous culture that are resistant to higher levels of polymyxin B than the rest of the cells in the culture, and can protect the more sensitive cells from killing, as well as sensitive bacteria from other species, such as Pseudomonas aeruginosa and Escherichia coli. Communication of resistance depended on upregulation of putrescine synthesis and YceI, a widely conserved low-molecular weight secreted protein. Deletion of genes for the synthesis of putrescine and YceI abrogate protection, while pharmacologic inhibition of putrescine synthesis reduced resistance to polymyxin B. Polyamines and YceI were also required for heteroresistance of B. cenocepacia to various bactericidal antibiotics. We propose that putrescine and YceI resemble "danger" infochemicals whose increased production by a bacterial subpopulation, becoming more resistant to bactericidal antibiotics, communicates higher level of resistance to more sensitive members of the population of the same or different species.

  11. The gut is the epicentre of antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Carlet Jean

    2012-11-01

    Full Text Available Abstract The gut contains very large numbers of bacteria. Changes in the composition of the gut flora, due in particular to antibiotics, can happen silently, leading to the selection of highly resistant bacteria and Candida species. These resistant organisms may remain for months in the gut of the carrier without causing any symptoms or translocate through the gut epithelium, induce healthcare-associated infections, undergo cross-transmission to other individuals, and cause limited outbreaks. Techniques are available to prevent, detect, and treat the carriage of resistant organisms in the gut. However, evidence on these techniques is scant, the only exception being selective digestive decontamination (SDD, which has been extensively studied in neutropenic and ICU patients. After the destruction of resistant colonizing bacteria, which has been successfully obtained in several studies, the gut could be re-colonized with normal faecal flora or probiotics. Studies are warranted to evaluate this concept.

  12. Bacterial infections in Lilongwe, Malawi: aetiology and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Makoka Mwai H

    2012-03-01

    Full Text Available Abstract Background Life-threatening infections present major challenges for health systems in Malawi and the developing world because routine microbiologic culture and sensitivity testing are not performed due to lack of capacity. Use of empirical antimicrobial therapy without regular microbiologic surveillance is unable to provide adequate treatment in the face of emerging antimicrobial resistance. This study was conducted to determine antimicrobial susceptibility patterns in order to inform treatment choices and generate hospital-wide baseline data. Methods Culture and susceptibility testing was performed on various specimens from patients presenting with possible infectious diseases at Kamuzu Central Hospital, Lilongwe, Malawi. Results Between July 2006 and December 2007 3104 specimens from 2458 patients were evaluated, with 60.1% from the adult medical service. Common presentations were sepsis, meningitis, pneumonia and abscess. An etiologic agent was detected in 13% of patients. The most common organisms detected from blood cultures were Staphylococcus aureus, Escherichia coli, Salmonella species and Streptococcus pneumoniae, whereas Streptococcus pneumoniae and Cryptococcus neoformans were most frequently detected from cerebrospinal fluid. Haemophilus influenzae was rarely isolated. Resistance to commonly used antibiotics was observed in up to 80% of the isolates while antibiotics that were not commonly in use maintained susceptibility. Conclusions There is widespread resistance to almost all of the antibiotics that are empirically used in Malawi. Antibiotics that have not been widely introduced in Malawi show better laboratory performance. Choices for empirical therapy in Malawi should be revised accordingly. A microbiologic surveillance system should be established and prudent use of antimicrobials promoted to improve patient care.

  13. Improved annotation of antibiotic resistance determinants reveals microbial resistomes cluster by ecology.

    Science.gov (United States)

    Gibson, Molly K; Forsberg, Kevin J; Dantas, Gautam

    2015-01-01

    Antibiotic resistance is a dire clinical problem with important ecological dimensions. While antibiotic resistance in human pathogens continues to rise at alarming rates, the impact of environmental resistance on human health is still unclear. To investigate the relationship between human-associated and environmental resistomes, we analyzed functional metagenomic selections for resistance against 18 clinically relevant antibiotics from soil and human gut microbiota as well as a set of multidrug-resistant cultured soil isolates. These analyses were enabled by Resfams, a new curated database of protein families and associated highly precise and accurate profile hidden Markov models, confirmed for antibiotic resistance function and organized by ontology. We demonstrate that the antibiotic resistance functions that give rise to the resistance profiles observed in environmental and human-associated microbial communities significantly differ between ecologies. Antibiotic resistance functions that most discriminate between ecologies provide resistance to β-lactams and tetracyclines, two of the most widely used classes of antibiotics in the clinic and agriculture. We also analyzed the antibiotic resistance gene composition of over 6000 sequenced microbial genomes, revealing significant enrichment of resistance functions by both ecology and phylogeny. Together, our results indicate that environmental and human-associated microbial communities harbor distinct resistance genes, suggesting that antibiotic resistance functions are largely constrained by ecology.

  14. 'The body gets used to them': patients' interpretations of antibiotic resistance and the implications for containment strategies.

    NARCIS (Netherlands)

    Brookes-Howell, L.; Elwyn, G.; Hood, K.; Wood, F.; Cooper, L.; Goossens, H.; Ieven, M.; Butler, C.C.

    2012-01-01

    BACKGROUND: Interventions promoting evidence based antibiotic prescribing and use frequently build on the concept of antibiotic resistance but patients and clinicians may not share the same assumptions about its meaning. OBJECTIVE: To explore patients' interpretations of 'antibiotic resistance' and

  15. Effects of therapeutical and reduced levels of antibiotics on the fraction of antibiotic-resistant strains of Escherichia coli in the chicken gut

    NARCIS (Netherlands)

    van der Horst, M.A.; Fabri, T.H.; Schuurmans, J.M.; Koenders, B.B.; Brul, S.; ter Kuile, B.H.

    2013-01-01

    Development of antibiotic resistance in the microbiota of farm animals and spread of antibiotic-resistant bacteria in the agricultural sector not only threaten veterinary use of antibiotics, but jeopardize human health care as well. The effects of exposure to antibiotics on spread and development of

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

    Directory of Open Access Journals (Sweden)

    Douglas Ruben Call

    2013-07-01

    Full Text Available When we consider factors that contribute to the emergence, amplification, and persistence of antibiotic resistant bacteria, the conventional assumption is that antibiotic use is the primary driver in these processes and that selection occurs primarily in the patient or animal. Evidence suggests that this may not always be the case. Experimental trials show that parenteral administration of a third-generation cephalosporin (ceftiofur in cattle has limited or short-term effects on the prevalence of ceftiofur-resistant bacteria in the gastrointestinal tract. While this response may be sufficient to explain a pattern of widespread resistance to cephalosporins, approximately two-thirds of ceftiofur metabolites are excreted in the urine raising the possibility that environmental selection plays an important additive role in the amplification and maintenance of antibiotic resistant E. coli on farms. Consequently, we present a rationale for an environmental selection hypothesis whereby excreted antibiotic residues such as ceftiofur are a significant contributor to the proliferation of antibiotic resistant bacteria in food animal systems. We also present a mathematical model of our hypothesized system as a guide for designing experiments to test this hypothesis. If supported for antibiotics such as ceftiofur, then there may be new approaches to combat the proliferation of antibiotic resistance beyond the prudent use mantra.

  17. Assessment of selected antibiotic resistances in ungrazed native Nebraska prairie soils

    Science.gov (United States)

    Measurements of antibiotic resistance from manure-impacted soils result in conflated data. It is difficult to sort out the features that are a result of human antibiotic use, from the features that are a result of the inherent spatial heterogeneity, complexity and dynamics of antibiotic resistant b...

  18. Prevalence of antibiotic-resistant S.aureus among general practice patients.

    NARCIS (Netherlands)

    Donker, G.A.; Nys, S.; Driessen, C.; Deurenberg, R.H.; Stobberingh, E.E.

    2006-01-01

    Background: Worldwide, the prevalence of antibiotic-resistant Staphylococcus aureus is an increasing problem both inside and outside the hospital. As antibiotic prescription by general practitioners is mainly an empiric therapy, actual data on antibiotic resistance of the microorganisms involved are

  19. First case of Helicobacter pylori infection resistant to seven antibiotics in Iran

    Directory of Open Access Journals (Sweden)

    Amin Talebi Bezmin Abadi

    2014-10-01

    Full Text Available Treatment of Helicobacter pylori infection with common antibiotics is typically recommended for several digestive conditions, including peptic ulcers. However, reports of resistant H. pylori isolates are increasing, and unfortunately, these do not respond to currently available therapeutic regimens. We report the case of a 31-year-old woman with two peptic ulcers in the duodenal antrum. An H. pylori strain was isolated, and tested for antibiotic resistance using agar dilution and disk diffusion. The isolated strain was found to be resistant to all seven antibiotics that were tested. Therefore, constant monitoring for antibiotic resistance should be performed prior to initiating antibiotic therapy.

  20. Apigenin as an anti-quinolone-resistance antibiotic.

    Science.gov (United States)

    Morimoto, Yuh; Baba, Tadashi; Sasaki, Takashi; Hiramatsu, Keiichi

    2015-12-01

    We previously reported the first 'reverse antibiotic' (RA), nybomycin (NYB), which showed a unique antimicrobial activity against Staphylococcus aureus strains. NYB specifically suppressed the growth of quinolone-resistant S. aureus strains but was not effective against quinolone-susceptible strains. Although NYB was first reported in 1955, little was known about its unique antimicrobial activity because it was before the synthesis of the first quinolone ('old quinolone'), nalidixic acid, in 1962. Following our re-discovery of NYB, we looked for other RAs among natural substances that act on quinolone-resistant bacteria. Commercially available flavones were screened against S. aureus, including quinolone-resistant strains, and their minimum inhibitory concentrations (MICs) were compared using the microbroth dilution method. Some of the flavones screened showed stronger antimicrobial activity against quinolone-resistant strains than against quinolone-susceptible ones. Amongst them, apigenin (API) was the most potent in its RA activity. DNA cleavage assay showed that API inhibited DNA gyrase harbouring the quinolone resistance mutation gyrA(Ser84Leu) but did not inhibit 'wild-type' DNA gyrase that is sensitive to levofloxacin. An API-susceptible S. aureus strain Mu50 was also selected using agar plates containing 20mg/L API. Whole-genome sequencing of selected mutant strains was performed and frequent back-mutations (reverse mutations) were found among API-resistant strains derived from the API-susceptible S. aureus strains. Here we report that API represents another molecular class of natural antibiotic having RA activity against quinolone-resistant bacteria.

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

    Science.gov (United States)

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

    2012-09-01

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

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

    Science.gov (United States)

    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.

  3. Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

    Directory of Open Access Journals (Sweden)

    Geisla Mary Silva Soares

    2012-06-01

    Full Text Available Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

  4. Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs.

    Science.gov (United States)

    Soares, Geisla Mary Silva; Figueiredo, Luciene Cristina; Faveri, Marcelo; Cortelli, Sheila Cavalca; Duarte, Poliana Mendes; Feres, Magda

    2012-01-01

    Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

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

    OpenAIRE

    MacLean, R. Craig; Vogwill, Tom

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Advanced treatment of urban wastewater by UV radiation: Effect on antibiotics and antibiotic-resistant E. coli strains.

    Science.gov (United States)

    Rizzo, Luigi; Fiorentino, Antonino; Anselmo, Antonella

    2013-06-01

    Urban wastewater treatment plant (UWWTP) effluents are among the possible sources of antibiotics and antibiotic-resistant bacteria (ARB) spread into the environment. In this work, the effect of UV radiation on antibiotic-resistant Escherichia coli (E. coli) strains was compared with that of chlorination process. Under the investigated conditions, UV disinfection process resulted in a total inactivation after 60min of irradiation (1.25×10(4)μWscm(-2)) compared to 120min chlorine contact time (initial chlorine dose of 2mgL(-1)). Moreover, no change in E. coli strains' resistance to amoxicillin (AMX) (minimum inhibiting concentration (MIC)>256mgL(-1)) and sulfamethoxazole (SMZ) (MIC>1024mgL(-1)) could be observed after UV treatment, while the treatment affected resistance of the lower resistance strain to ciprofloxacin (CPX) (MIC decreased by 33% and 50% after 60 and 120min, respectively). Contrarily, chlorination process did not affect antibiotic resistance of the investigated E. coli strains. Finally, the effect of UV radiation on the mixture of three antibiotics was also investigated and photodegradation data fit quite well pseudo first order kinetic models with t1/2 values of 14, 20 and 25min for CPX, AMX and SMZ, respectively. According to these results, conventional disinfection processes may not be effective in the inactivation of ARB, and the simultaneous release of ARB and antibiotics at sub-lethal concentrations into UWWTP effluent may promote the development of resistance among bacteria in receiving water.

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

    DEFF Research Database (Denmark)

    Lerbeck, Anne Mette; Tersbøl, Britt Pinkowski; 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 (Co......NS) 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 (n5246 and n...... 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...

  9. Molecular Mechanisms and Clinical Impact of Acquired and Intrinsic Fosfomycin Resistance

    Directory of Open Access Journals (Sweden)

    Alexandro Rodríguez-Rojas

    2013-04-01

    Full Text Available Bacterial infections caused by antibiotic-resistant isolates have become a major health problem in recent years, since they are very difficult to treat, leading to an increase in morbidity and mortality. Fosfomycin is a broad-spectrum bactericidal antibiotic that inhibits cell wall biosynthesis in both Gram-negative and Gram-positive bacteria. This antibiotic has a unique mechanism of action and inhibits the initial step in peptidoglycan biosynthesis by blocking the enzyme, MurA. Fosfomycin has been used successfully for the treatment of urinary tract infections for a long time, but the increased emergence of antibiotic resistance has made fosfomycin a suitable candidate for the treatment of infections caused by multidrug-resistant pathogens, especially in combination with other therapeutic partners. The acquisition of fosfomycin resistance could threaten the reintroduction of this antibiotic for the treatment of bacterial infection. Here, we analyse the mechanism of action and molecular mechanisms for the development of fosfomycin resistance, including the modification of the antibiotic target, reduced antibiotic uptake and antibiotic inactivation. In addition, we describe the role of each pathway in clinical isolates.

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Antibiotic Resistance Pattern in Pseudomonas Aeruginosa Species Isolated at a Tertiary Care Hospital, Ahmadabad

    Directory of Open Access Journals (Sweden)

    Rajat Rakesh M

    2012-04-01

    Full Text Available Introduction: Pseudomonas aeruginosa (Ps.aeruginosa is one of the important bacterial pathogens isolated from various samples. Despite advances in medical and surgical care and introduction of wide variety of antimicrobial agents against having anti-pseudomonal activities, life threatening infection caused by Ps. aeruginosa continues to cause complications in hospital acquired infections. Several different epidemiological studies indicate that antibiotic resistance is increasing in clinical isolates. Material and Method: This study was conducted during April 2009 to april 2010. During this period total of 630 samples were tested, in which 321 samples showed growth of bacteria. Out of 321 samples, 100 clinical isolates of Pseudomonas aeruginosa were isolated. The samples were selected on the basis of their growth on routine MacConkey medium which showed lactose Non-fermenting pale colonies which were oxidase test positive and on Nutrient agar pigmented and non-pigmented colonies with oxidase positive. Antimicrobial susceptibility of all the isolates was performed by the disc-diffusion (Modified-Kirby Baur disc diffusion method according to CLSIs guidelines. Result: In present study, maximum isolates of Ps. aeruginosa isolated from various samples are resistant to tobramycin (68% followed by gentamycin (63%, piperacillin (50%, ciprofloxacin (49% and ceftazidime (43%. Conclusion: To prevent the spread of the resistant bacteria, it is critically important to have strict antibiotic policies while surveillance programmes for multidrug resistant organisms and infection control procedures need to be implemented. [National J of Med Res 2012; 2(2.000: 156-159

  12. Resistance to antibiotics targeted to the bacterial cell wall.

    Science.gov (United States)

    Nikolaidis, I; Favini-Stabile, S; Dessen, A

    2014-03-01

    Peptidoglycan is the main component of the bacterial cell wall. It is a complex, three-dimensional mesh that surrounds the entire cell and is composed of strands of alternating glycan units crosslinked by short peptides. Its biosynthetic machinery has been, for the past five decades, a preferred target for the discovery of antibacterials. Synthesis of the peptidoglycan occurs sequentially within three cellular compartments (cytoplasm, membrane, and periplasm), and inhibitors of proteins that catalyze each stage have been identified, although not all are applicable for clinical use. A number of these antimicrobials, however, have been rendered inactive by resistance mechanisms. The employment of structural biology techniques has been instrumental in the understanding of such processes, as well as the development of strategies to overcome them. This review provides an overview of resistance mechanisms developed toward antibiotics that target bacterial cell wall precursors and its biosynthetic machinery. Strategies toward the development of novel inhibitors that could overcome resistance are also discussed.

  13. Glycopeptide antibiotics: evolving resistance, pharmacology and adverse event profile.

    Science.gov (United States)

    Henson, Karl Evans R; Levine, Miriam T; Wong, Eunice Ann H; Levine, Donald P

    2015-01-01

    The first glycopeptide antibiotic was vancomycin, isolated from the soil in the 1950s; since then, the class has expanded to include teicoplanin and the new semisynthetic glycopeptides dalbavancin, oritavancin and telavancin. They are bactericidal, active against most Gram-positive organisms, and in a concentration-dependent manner, inhibit cell wall synthesis. Resistance to vancomycin has emerged, especially among enterococci and Staphylococcus aureus through a variety of mechanisms. This emerging resistance to vancomycin makes proper dosing and monitoring of the area under the curve/MIC critically important. The chief adverse effect of vancomycin is nephrotoxicity, which is also intricately related to its dose. The efficacy of the semisynthetic glycopeptides has been demonstrated in skin and soft-tissue infections, but remains to be seen in serious methicillin-resistant Staphylococcus aureus infections.

  14. Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes.

    Science.gov (United States)

    Berglund, Björn; Khan, Ghazanfar Ali; Weisner, Stefan E B; Ehde, Per Magnus; Fick, Jerker; Lindgren, Per-Eric

    2014-04-01

    Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng×l(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes.

  15. Behavior of antibiotics and antibiotic resistance genes in eco-agricultural system: A case study.

    Science.gov (United States)

    Cheng, Weixiao; Li, Jianan; Wu, Ying; Xu, Like; Su, Chao; Qian, Yanyun; Zhu, Yong-Guan; Chen, Hong

    2016-03-01

    This study aims to determine abundance and persistence of antibiotics and antibiotic resistance genes (ARGs) in eco-agricultural system (EAS), which starts from swine feces to anaerobic digestion products, then application of anaerobic digestion solid residue (ADSR) and anaerobic digestion liquid residue (ADLR) to the soil to grow ryegrass, one of swine feed. Oxytetracycline had the highest concentration in manure reaching up to 138.7 mg/kg. Most of antibiotics could be effectively eliminated by anaerobic digestion and removal rates ranged from 11% to 86%. ARGs abundance fluctuated within EAS. TetQ had the highest relative abundance and the relative abundance of tetG had the least variation within the system, which indicates that tetG is persistent in the agricultural environment and requires more attention. Compared to the relative abundance in manure, tetC and tetM increased in biogas residue while three ribosomal protection proteins genes (tetO, tetQ, tetW) decreased (p0.05). Most ARGs in downstream components (soils and fishpond) of EAS showed significantly higher relative abundance than the control agricultural system (p<0.05), except for tetG and sulI.

  16. Abundance and dynamics of antibiotic resistance genes and integrons in lake sediment microcosms.

    Directory of Open Access Journals (Sweden)

    Björn Berglund

    Full Text Available Antibiotic resistance in bacteria causing disease is an ever growing threat to the world. Recently, environmental bacteria have become established as important both as sources of antibiotic resistance genes and in disseminating resistance genes. Low levels of antibiotics and other pharmaceuticals are regularly released into water environments via wastewater, and the concern is that such environmental contamination may serve to create hotspots for antibiotic resistance gene selection and dissemination. In this study, microcosms were created from water and sediments gathered from a lake in Sweden only lightly affected by human activities. The microcosms were exposed to a mixture of antibiotics of varying environmentally relevant concentrations (i.e., concentrations commonly encountered in wastewaters in order to investigate the effect of low levels of antibiotics on antibiotic resistance gene abundances and dynamics in a previously uncontaminated environment. Antibiotic concentrations were measured using liquid chromatography-tandem mass spectrometry. Abundances of seven antibiotic resistance genes and the class 1 integron integrase gene, intI1, were quantified using real-time PCR. Resistance genes sulI and ermB were quantified in the microcosm sediments with mean abundances 5 and 15 gene copies/10(6 16S rRNA gene copies, respectively. Class 1 integrons were determined in the sediments with a mean concentration of 3.8 × 10(4 copies/106 16S rRNA gene copies. The antibiotic treatment had no observable effect on antibiotic resistance gene or integron abundances.

  17. Antibiotic susceptibility in relation to genotype of Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae responsible for community-acquired pneumonia in children.

    Science.gov (United States)

    Morozumi, Miyuki; Chiba, Naoko; Okada, Takafumi; Sakata, Hiroshi; Matsubara, Keita; Iwata, Satoshi; Ubukata, Kimiko

    2013-06-01

    Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae are the main pathogens causing community-acquired pneumonia (CAP). We identified S. pneumoniae (n = 241), H. influenzae (n = 123), and M. pneumoniae (n = 54) as causative pathogens from clinical findings and blood tests from pediatric CAP patients (n = 903) between April 2008 and April 2009. Identification of genes mediating antimicrobial resistance by real-time PCR was performed for all isolates of these three pathogens, as was antibiotic susceptibility testing using an agar dilution method or broth microdilution method. The genotypic (g) resistance rate was 47.7 % for penicillin-resistant S. pneumoniae (gPRSP) possessing abnormal pbp1a, pbp2x, and pbp2b genes, 62.6 % for β-lactamase-nonproducing, ampicillin-resistant (gBLNAR) H. influenzae possessing the amino acid substitutions Ser385Thr and Asn526Lys, and 44.4 % for macrolide-resistant M. pneumoniae (gMRMP) possessing a mutation of A2063G, A2064G, or C2617A. Serotype 6B (20.3 %) predominated in S. pneumoniae, followed by 19F (15.4 %), 14 (14.5 %), 23F (12.0 %), 19A (6.2 %), and 6C (5.4 %). Coverage for the isolates by heptavalent pneumococcal conjugate vaccine (PCV7) and PCV13, respectively, was calculated as 68.5 and 80.9 %. A small number of H. influenzae were identified as type b (6.5 %), type e (0.8 %), or type f (0.8 %); all others were nontypeable. Proper use of antibiotics based on information about resistance in CAP pathogens is required to control rapid increases in resistance. Epidemiological surveillance of pediatric patients also is needed to assess the effectiveness of PCV7 and Hib vaccines after their introduction in Japan.

  18. Molecular Mechanisms and Clinical Impact of Acquired and Intrinsic Fosfomycin Resistance

    OpenAIRE

    Alexandro Rodríguez-Rojas; Jesús Blázquez; Alfredo Castañeda-García

    2013-01-01

    Bacterial infections caused by antibiotic-resistant isolates have become a major health problem in recent years, since they are very difficult to treat, leading to an increase in morbidity and mortality. Fosfomycin is a broad-spectrum bactericidal antibiotic that inhibits cell wall biosynthesis in both Gram-negative and Gram-positive bacteria. This antibiotic has a unique mechanism of action and inhibits the initial step in peptidoglycan biosynthesis by blocking the enzyme, MurA. Fosfomycin h...

  19. Status Report from the Scientific Panel on Antibiotic Use in Dermatology of the American Acne and Rosacea Society: Part 1: Antibiotic Prescribing Patterns, Sources of Antibiotic Exposure, Antibiotic Consumption and Emergence of Antibiotic Resistance, Impact of Alterations in Antibiotic Prescribing, and Clinical Sequelae of Antibiotic Use.

    Science.gov (United States)

    Del Rosso, James Q; Webster, Guy F; Rosen, Ted; Thiboutot, Diane; Leyden, James J; Gallo, Richard; Walker, Clay; Zhanel, George; Eichenfield, Lawrence

    2016-04-01

    Oral and topical antibiotics are commonly prescribed in dermatologie practice, often for noninfectious disorders, such as acne vulgaris and rosacea. Concerns related to antibiotic exposure from both medical and nonmedical sources require that clinicians consider in each case why and how antibiotics are being used and to make appropriate adjustments to limit antibiotic exposure whenever possible. This first article of a three-part series discusses prescribing patterns in dermatology, provides an overview of sources of antibiotic exposure, reviews the relative correlations between the magnitude of antibiotic consumption and emergence of antibiotic resistance patterns, evaluates the impact of alterations in antibiotic prescribing, and discusses the potential relevance and clinical sequelae of antibiotic use, with emphasis on how antibiotics are used in dermatology.

  20. Community acquired pneumonia due to gram negative bacilli and its antibiotic sensitivity pattern in a tertiary care centre

    Directory of Open Access Journals (Sweden)

    Ashish Jitendranath

    2016-08-01

    Results: During the study period in 120 cases of pneumonia, there was growth of pathogenic organism. Among the GNB isolated Klebsiella spp was the most common organism isolated at 33.9% followed by Pseudomonas aeruginosa and Escherichia coli at 22.1%. Out of the 53 gram negative samples isolated 4 (7% were Amp C positive, 10 (18.8% were ESBL positive and there was one single case of MBL. The antibiotic sensitivity showed that all the isolates were sensitive to colisitin (100%, while Klebsiella spp, Pseudomonas spp, and Escherichia coli were 100% sensitive to imipenem and meropenem. Resistance pattern of all the isolates showed that the isolates exhibited high resistance to amoxycillin-clavulunate, cefuroxime and cotrimoxazole. While resistance against ceftazidime and cefipime was >40%. On the other hand, isolates showed a low level of resistance against piperacillin tazobactam and cefoperazone-sulbactam. Extremely low level of resistance was observed against imipenem and meropenem, while colistin showed no resistance among the isolates obtained in this study. Conclusions: The study showed that gram-negative bacteria and P. aeruginosa form a relevant part of the microbial pattern of CAP in patients who require hospitalization, particularly those with severe CAP. Initiating antibiotics with gram negative coverage should be considered in this subgroup of patients since initiating the correct antibiotic plays a critical role in the outcome of pneumonia. [Int J Res Med Sci 2016; 4(8.000: 3121-3124

  1. Drug-resistance mechanisms and prevalence of Enterobacter cloacae resistant to multi-antibiotics

    Institute of Scientific and Technical Information of China (English)

    张杰; 顾怡明; 俞云松; 周志慧; 杜小玲

    2004-01-01

    @@The main drug-resistance mechanism of gram-negative bacteria is producing β-lactamases. Two kinds of enzymes cause drug resistance by hydrolyzing oxyimino-cephalosporins and aztreonam: one is chromosomally encoded AmpC β-lactamases, the other is plasmid-mediated extended-spectrum β-lactamases (ESBLs). Enterobacter cloacae can produce both of them, so that these strains are seriously resistance to many antibiotics. In order to study the main drug-resistant mechanism in Enterobacter cloacae, PCR and nucleotide sequencing were performed on 58 multidrug resistant strains.

  2. Putrescine reduces antibiotic-induced oxidative stress as a mechanism of modulation of antibiotic resistance in Burkholderia cenocepacia.

    Science.gov (United States)

    El-Halfawy, Omar M; Valvano, Miguel A

    2014-07-01

    Communication of antibiotic resistance among bacteria via small molecules is implicated in transient reduction of bacterial susceptibility to antibiotics, which could lead to therapeutic failures aggravating the problem of antibiotic resistance. Released putrescine from the extremely antibiotic-resistant bacterium Burkholderia cenocepacia protects less-resistant cells from different species against the antimicrobial peptide polymyxin B (PmB). Exposure of B. cenocepacia to sublethal concentrations of PmB and other bactericidal antibiotics induces reactive oxygen species (ROS) production and expression of the oxidative stress response regulator OxyR. We evaluated whether putrescine alleviates antibiotic-induced oxidative stress. The accumulation of intracellular ROS, such as superoxide ion and hydrogen peroxide, was assessed fluorometrically with dichlorofluorescein diacetate, while the expression of OxyR and putrescine synthesis enzymes was determined in luciferase assays using chromosomal promoter-lux reporter system fusions. We evaluated wild-type and isogenic deletion mutant strains with defects in putrescine biosynthesis after exposure to sublethal concentrations of PmB and other bactericidal antibiotics. Exogenous putrescine protected against oxidative stress induced by PmB and other antibiotics, whereas reduced putrescine synthesis resulted in increased ROS generation and a parallel increased sensitivity to PmB. Of the 3 B. cenocepacia putrescine-synthesizing enzymes, PmB induced only BCAL2641, an ornithine decarboxylase. This study reveals BCAL2641 as a critical component of the putrescine-mediated communication of antibiotic resistance and as a plausible target for designing inhibitors that would block the communication of such resistance among different bacteria, ultimately reducing the window of therapeutic failure in treating bacterial infections.

  3. Mobile antibiotic resistance encoding elements promote their own diversity.

    Directory of Open Access Journals (Sweden)

    Geneviève Garriss

    2009-12-01

    Full Text Available Integrating conjugative elements (ICEs are a class of bacterial mobile genetic elements that disseminate via conjugation and then integrate into the host cell genome. The SXT/R391 family of ICEs consists of more than 30 different elements that all share the same integration site in the host chromosome but often encode distinct properties. These elements contribute to the spread of antibiotic resistance genes in several gram-negative bacteria including Vibrio cholerae, the agent of cholera. Here, using comparative analyses of the genomes of several SXT/R391 ICEs, we found evidence that the genomes of these elements have been shaped by inter-ICE recombination. We developed a high throughput semi-quantitative method to explore the genetic determinants involved in hybrid ICE formation. Recombinant ICE formation proved to be relatively frequent, and to depend on host (recA and ICE (s065 and s066 loci, which can independently and potentially cooperatively mediate hybrid ICE formation. s065 and s066, which are found in all SXT/R391 ICEs, are orthologues of the bacteriophage lambda Red recombination genes bet and exo, and the s065/s066 recombination system is the first Red-like recombination pathway to be described in a conjugative element. Neither ICE excision nor conjugative transfer proved to be essential for generation of hybrid ICEs. Instead conjugation facilitates the segregation of hybrids and could provide a means to select for functional recombinant ICEs containing novel combinations of genes conferring resistance to antibiotics. Thus, ICEs promote their own diversity and can yield novel mobile elements capable of disseminating new combinations of antibiotic resistance genes.

  4. Low Temperature and Modified Atmosphere: Hurdles for Antibiotic Resistance Transfer?

    Science.gov (United States)

    Van Meervenne, Eva; Van Coillie, Els; Van Weyenberg, Stephanie; Boon, Nico; Herman, Lieve; Devlieghere, Frank

    2015-12-01

    Food is an important dissemination route for antibiotic-resistant bacteria. Factors used during food production and preservation may contribute to the transfer of antibiotic resistance genes, but research on this subject is scarce. In this study, the effect of temperature (7 to 37°C) and modified atmosphere packaging (air, 50% CO2-50% N2, and 100% N2) on antibiotic resistance transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes was evaluated. Filter mating was performed on nonselective agar plates with high-density inocula. A more realistic setup was created by performing modified atmosphere experiments on cooked ham using high-density and low-density inocula. Plasmid transfer was observed between 10 and 37°C, with plasmid transfer also observed at 7°C during a prolonged incubation period. When high-density inocula were used, transconjugants were detected, both on agar plates and cooked ham, under the three atmospheres (air, 50% CO2-50% N2, and 100% N2) at 7°C. This yielded a median transfer ratio (number of transconjugants/number of recipients) with an order of magnitude of 10(-4) to 10(-6). With low-density inocula, transfer was only detected under the 100% N2 atmosphere after 10-day incubation at 7°C, yielding a transfer ratio of 10(-5). Under this condition, the highest bacterial density was obtained. The results indicate that low temperature and modified atmosphere packaging, two important hurdles in the food industry, do not necessarily prevent plasmid transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes.

  5. Quantifying Attachment and Antibiotic Resistance of from Conventional and Organic Swine Manure.

    Science.gov (United States)

    Zwonitzer, Martha R; Soupir, Michelle L; Jarboe, Laura R; Smith, Douglas R

    2016-03-01

    Broad-spectrum antibiotics are often administered to swine, contributing to the occurrence of antibiotic-resistant bacteria in their manure. During land application, the bacteria in swine manure preferentially attach to particles in the soil, affecting their transport in overland flow. However, a quantitative understanding of these attachment mechanisms is lacking, and their relationship to antibiotic resistance is unknown. The objective of this study is to examine the relationships between antibiotic resistance and attachment to very fine silica sand in collected from swine manure. A total of 556 isolates were collected from six farms, two organic and four conventional (antibiotics fed prophylactically). Antibiotic resistance was quantified using 13 antibiotics at three minimum inhibitory concentrations: resistant, intermediate, and susceptible. Of the 556 isolates used in the antibiotic resistance assays, 491 were subjected to an attachment assay. Results show that isolates from conventional systems were significantly more resistant to amoxicillin, ampicillin, chlortetracycline, erythromycin, kanamycin, neomycin, streptomycin, tetracycline, and tylosin ( < 0.001). Results also indicate that isolated from conventional systems attached to very fine silica sand at significantly higher levels than those from organic systems ( < 0.001). Statistical analysis showed that a significant relationship did not exist between antibiotic resistance levels and attachment in from conventional systems but did for organic systems ( < 0.001). Better quantification of these relationships is critical to understanding the behavior of in the environment and preventing exposure of human populations to antibiotic-resistant bacteria.

  6. Antibiotics

    Science.gov (United States)

    Antibiotics are powerful medicines that fight bacterial infections. Used properly, antibiotics can save lives. They either kill bacteria or ... natural defenses can usually take it from there. Antibiotics do not fight infections caused by viruses, such ...

  7. Exploring Antibiotic Resistance Genes and Metal Resistance Genes in Plasmid Metagenomes from Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    An-Dong eLi

    2015-09-01

    Full Text Available Plasmids operate as independent genetic elements in microorganism communities. Through horizontal gene transfer, they can provide their host microorganisms with important functions such as antibiotic resistance and heavy metal resistance. In this study, six metagenomic libraries were constructed with plasmid DNA extracted from influent, activated sludge and digested sludge of two wastewater treatment plants. Compared with the metagenomes of the total DNA extracted from the same sectors of the wastewater treatment plant, the plasmid metagenomes had significantly higher annotation rates, indicating that the functional genes on plasmids are commonly shared by those studied microorganisms. Meanwhile, the plasmid metagenomes also encoded many more genes related to defense mechanisms, including ARGs. Searching against an antibiotic resistance genes (ARGs database and a metal resistance genes (MRGs database revealed a broad-spectrum of antibiotic (323 out of a total 618 subtypes and metal resistance genes (23 out of a total 23 types on these plasmid metagenomes. The influent plasmid metagenomes contained many more resistance genes (both ARGs and MRGs than the activated sludge and the digested sludge metagenomes. Sixteen novel plasmids with a complete circular structure that carried these resistance genes were assembled from the plasmid metagenomes. The results of this study demonstrated that the plasmids in wastewater treatment plants could be important reservoirs for resistance genes, and may play a significant role in the horizontal transfer of these genes.

  8. A modeling framework for the evolution and spread of antibiotic resistance: literature review and model categorization.

    Science.gov (United States)

    Spicknall, Ian H; Foxman, Betsy; Marrs, Carl F; Eisenberg, Joseph N S

    2013-08-15

    Antibiotic-resistant infections complicate treatment and increase morbidity and mortality. Mathematical modeling has played an integral role in improving our understanding of antibiotic resistance. In these models, parameter sensitivity is often assessed, while model structure sensitivity is not. To examine the implications of this, we first reviewed the literature on antibiotic-resistance modeling published between 1993 and 2011. We then classified each article's model structure into one or more of 6 categories based on the assumptions made in those articles regarding within-host and population-level competition between antibiotic-sensitive and antibiotic-resistant strains. Each model category has different dynamic implications with respect to how antibiotic use affects resistance prevalence, and therefore each may produce different conclusions about optimal treatment protocols that minimize resistance. Thus, even if all parameter values are correctly estimated, inferences may be incorrect because of the incorrect selection of model structure. Our framework provides insight into model selection.

  9. Applying the emergency risk management process to tackle the crisis of antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Dale eDominey-Howes

    2015-09-01

    Full Text Available We advocate that antibiotic resistance be reframed as a disaster risk management problem. Antibiotic resistant infections represent a risk to life every bit as significant as other commonly occurring natural disasters (e.g. earthquakes. Despite significant efforts by global health authorities, antibiotic resistance continues to escalate. Therefore, new approaches and expertise are needed to manage the issue. In this perspective we: (1 make a novel call for the emergency management community to recognise the antibiotic resistance risk and join in addressing this problem; (2 suggest using the risk management process to help tackle antibiotic resistance; (3 show why this approach has value and why it is different to existing approaches; and (4 identify public perception of antibiotic resistance as an important issue that warrants exploration.

  10. Applying the emergency risk management process to tackle the crisis of antibiotic resistance.

    Science.gov (United States)

    Dominey-Howes, Dale; Bajorek, Beata; Michael, Carolyn A; Betteridge, Brittany; Iredell, Jonathan; Labbate, Maurizio

    2015-01-01

    We advocate that antibiotic resistance be reframed as a disaster risk management problem. Antibiotic-resistant infections represent a risk to life as significant as other commonly occurring natural disasters (e.g., earthquakes). Despite efforts by global health authorities, antibiotic resistance continues to escalate. Therefore, new approaches and expertise are needed to manage the issue. In this perspective we: (1) make a call for the emergency management community to recognize the antibiotic resistance risk and join in addressing this problem; (2) suggest using the risk management process to help tackle antibiotic resistance; (3) show why this approach has value and why it is different to existing approaches; and (4) identify public perception of antibiotic resistance as an important issue that warrants exploration.

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

    DEFF Research Database (Denmark)

    Jitwasinkul, Tossawan; Suriyaphol, Prapat; Tangphatsornruang, Sithichoke

    2016-01-01

    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...... 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...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

    Greenspan, Neil S.

    2017-01-01

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

  15. Current perspectives on the dynamics of antibiotic resistance in different reservoirs

    OpenAIRE

    Eduarda Gomes-Neves

    2015-01-01

    Antibiotic resistance consists of a dynamic web. In this review, we describe the path by which different antibiotic residues and antibioticresistance genes disseminate among relevant reservoirs (human, animal, and environmental settings), evaluating how these events contribute tothe current scenario of antibiotic resistance. The relationship between the spread of resistance and the contribution of different genetic elementsand events is revisited, exploring examples of the processes by which ...

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

    OpenAIRE

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

    2008-01-01

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

  17. Exploring antibiotic resistance genes and metal resistance genes in plasmid metagenomes from wastewater treatment plants.

    Science.gov (United States)

    Li, An-Dong; Li, Li-Guan; Zhang, Tong

    2015-01-01

    Plasmids operate as independent genetic elements in microorganism communities. Through horizontal gene transfer (HGT), they can provide their host microorganisms with important functions such as antibiotic resistance and heavy metal resistance. In this study, six metagenomic libraries were constructed with plasmid DNA extracted from influent, activated sludge (AS) and digested sludge (DS) of two wastewater treatment plants (WWTPs). Compared with the metagenomes of the total DNA extracted from the same sectors of the wastewater treatment plant, the plasmid metagenomes had significantly higher annotation rates, indicating that the functional genes on plasmids are commonly shared by those studied microorganisms. Meanwhile, the plasmid metagenomes also encoded many more genes related to defense mechanisms, including ARGs. Searching against an antibiotic resistance genes (ARGs) database and a metal resistance genes (MRGs) database revealed a broad-spectrum of antibiotic (323 out of a total 618 subtypes) and MRGs (23 out of a total 23 types) on these plasmid metagenomes. The influent plasmid metagenomes contained many more resistance genes (both ARGs and MRGs) than the AS and the DS metagenomes. Sixteen novel plasmids with a complete circular structure that carried these resistance genes were assembled from the plasmid metagenomes. The results of this study demonstrated that the plasmids in WWTPs could be important reservoirs for resistance genes, and may play a significant role in the horizontal transfer of these genes.

  18. Disruption of the Gut Microbiome: Clostridium difficile Infection and the Threat of Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Priscilla A. Johanesen

    2015-12-01

    Full Text Available Clostridium difficile is well recognized as the leading cause of antibiotic-associated diarrhea, having a significant impact in both health-care and community settings. Central to predisposition to C. difficile infection is disruption of the gut microbiome by antibiotics. Being a Gram-positive anaerobe, C. difficile is intrinsically resistant to a number of antibiotics. Mobile elements encoding antibiotic resistance determinants have also been characterized in this pathogen. While resistance to antibiotics currently used to treat C. difficile infection has not yet been detected, it may be only a matter of time before this occurs, as has been seen with other bacterial pathogens. This review will discuss C. difficile disease pathogenesis, the impact of antibiotic use on inducing disease susceptibility, and the role of antibiotic resistance and mobile elements in C. difficile epidemiology.

  19. Antibiotic resistance and microecological balance%细菌耐药与微生态平衡

    Institute of Scientific and Technical Information of China (English)

    郑跃杰

    2016-01-01

    细菌耐药性增加是抗菌药物使用的结果,抗菌药物还可以引起正常菌群产生耐药性,成为耐药基因库,将会导致更多的耐药菌产生和扩散。控制使用抗菌药物是目前的首要措施。%The increasing levels of antibiotic resistance was due to the effects of antibiotics.Clinical application of antibiotics could induce the antibiotic resistance in the human microflora,which can become the reservoir of antibiotic resistance genes,subsequently contribute to more emergence and spread of antibiotic resistance in future.This highlights the importance of a controlled use of antibiotics.

  20. Prospects for circumventing aminoglycoside kinase mediated antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Kun eShi

    2013-06-01

    Full Text Available Aminoglycosides are a class of antibiotics with a broad spectrum of antimicrobial activity. Unfortunately, resistance in clinical isolates is pervasive, rendering many aminoglycosides ineffective. The most widely disseminated means of resistance to this class of antibiotics is inactivation of the drug by aminoglycoside-modifying enzymes (AMEs. There are two principal strategies to overcoming the effects of AMEs. The first approach involves the design of novel aminoglycosides that can evade modification. Although this strategy has yielded a number of superior aminoglycoside variants, their efficacy cannot be sustained in the long term. The second approach entails the development of molecules that interfere with the mechanism of AMEs such that the activity of aminoglycosides is preserved. Although such a molecule has yet to enter clinical development, the search for AME inhibitors has been greatly facilitated by the wealth of structural information amassed in recent years. In particular, aminoglycoside phosphotransferases or kinases (APHs have been studied extensively and crystal structures of a number of APHs with diverse regiospecificity and substrate specificity have been elucidated. In this review, we present a comprehensive overview of the available APH structures and recent progress in APH inhibitor development, with a focus on the structure-guided strategies.

  1. Rapid identification of antibiotic resistance using droplet microfluidics.

    Science.gov (United States)

    Keays, Marie C; O'Brien, Mark; Hussain, Anam; Kiely, Patrick A; Dalton, Tara

    2016-04-02

    Culturing bacteria and monitoring bacterial cell growth is a critical issue when dealing with patients who present with bacterial infections. One of the main challenges that arises is the time taken to identify the particular strain of bacteria and consequently, decide the correct treatment. In the majority of cases, broad spectrum antibiotics are used to target infections when a narrow spectrum drug would be more appropriate. The efficient monitoring of bacterial growth and potential antibiotic resistance is necessary to identify the best treatment options for patients. Minturising the reactions into microfluidic droplets offers a novel method to rapidy analyze bacteria. Microfluidics facilitates low volume reactions that provide a unique system where each droplet reaction acts as an individual bioreactor. Here, we designed and built a novel platform that allowed us to create and monitor E.coli microfluidic droplet cultures. Optical capacity was built in and measurements of bacterial cultures were captured facilitating the continuous monitoring of individual reactions. The capacity of the instrument was demonstrated by the application of treatments to both bacteria and drug resistant strains of bacteria. We were able to detect responses within one hour in the droplet cultures, demonstrating the capacity of this workflow to the culture and rapid characterization of bacterial strains.

  2. Molecular characterization and antibiotic resistance of Enterococcus species from gut microbiota of Chilean Altiplano camelids

    Directory of Open Access Journals (Sweden)

    Katheryne Guerrero-Olmos

    2014-10-01

    Full Text Available Background: Enterococcus is one of the major human pathogens able to acquire multiple antibiotic-resistant markers as well as virulence factors which also colonize remote ecosystems, including wild animals. In this work, we characterized the Enterococcus population colonizing the gut of Chilean Altiplano camelids without foreign human contact. Material and methods: Rectal swabs from 40 llamas and 10 alpacas were seeded in M-Enterococcus agar, and we selected a total of 57 isolates. Species identification was performed by biochemical classical tests, semi-automated WIDER system, mass spectrometry analysis by MALDI-TOF (matrix-assisted laser desorption/ionization with a time-of-flight mass spectrometer, and, finally, nucleotide sequence of internal fragments of the 16S rRNA, rpoB, pheS, and aac(6-I genes. Genetic diversity was measured by pulsed field gel electrophoresis (PFGE-SmaI, whereas the antibiotic susceptibility was determined by the WIDER system. Carriage of virulence factors was explored by polymerase chain reaction (PCR. Results: Our results demonstrated that the most prevalent specie was Enterococcus hirae (82%, followed by other non–Enterococcus faecalis and non–Enterococcus faecium species. Some discrepancies were detected among the identification methods used, and the most reliable were the rpoB, pheS, and aac(6-I nucleotide sequencing. Selected isolates exhibited susceptibility to almost all studied antibiotics, and virulence factors were not detected by PCR. Finally, some predominant clones were characterized by PFGE into a diverse genetic background. Conclusion: Enterococcus species from the Chilean camelids’ gut microbiota were different from those adapted to humans, and they remained free of antibiotic resistance mechanisms as well as virulence factors.

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

    Science.gov (United States)

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

    2015-05-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

  5. Mutations in mmpL and in the cell wall stress stimulon contribute to resistance to oxadiazole antibiotics in methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Xiao, Qiaobin; Vakulenko, Sergei; Chang, Mayland; Mobashery, Shahriar

    2014-10-01

    Staphylococcus aureus is a leading cause of hospital- and community-acquired infections, which exhibit broad resistance to various antibiotics. We recently disclosed the discovery of the oxadiazole class of antibiotics, which has in vitro and in vivo activities against methicillin-resistant S. aureus (MRSA). We report herein that MmpL, a putative member of the resistance, nodulation, and cell division (RND) family of proteins, contributes to oxadiazole resistance in the S. aureus strain COL. Through serial passages, we generated two S. aureus COL variants that showed diminished susceptibilities to an oxadiazole antibiotic. The MICs for the oxadiazole against one strain (designated S. aureus COL(I)) increased reproducibly 2-fold (to 4 μg/ml), while against the other strain (S. aureus COL(R)), they increased >4-fold (to >8 μg/ml, the limit of solubility). The COL(R) strain was derived from the COL(I) strain. Whole-genome sequencing revealed 31 mutations in S. aureus COL(R), of which 29 were shared with COL(I). Consistent with our previous finding that oxadiazole antibiotics inhibit cell wall biosynthesis, we found 13 mutations that occurred either in structural genes or in promoters of the genes of the cell wall stress stimulon. Two unique mutations in S. aureus COL(R) were substitutions in two genes that encode the putative thioredoxin (SACOL1794) and MmpL (SACOL2566). A role for mmpL in resistance to oxadiazoles was discerned from gene deletion and complementation experiments. To our knowledge, this is the first report that a cell wall-acting antibiotic selects for mutations in the cell wall stress stimulon and the first to implicate MmpL in resistance to antibiotics in S. aureus.

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

    Science.gov (United States)

    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

  7. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    Science.gov (United States)

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  8. Transfer of antibiotic-resistance genes via phage-related mobile elements.

    Science.gov (United States)

    Brown-Jaque, Maryury; Calero-Cáceres, William; Muniesa, Maite

    2015-05-01

    Antibiotic resistance is a major concern for society because it threatens the effective prevention of infectious diseases. While some bacterial strains display intrinsic resistance, others achieve antibiotic resistance by mutation, by the recombination of foreign DNA into the chromosome or by horizontal gene acquisition. In many cases, these three mechanisms operate together. Several mobile genetic elements (MGEs) have been reported to mobilize different types of resistance genes and despite sharing common features, they are often considered and studied separately. Bacteriophages and phage-related particles have recently been highlighted as MGEs that transfer antibiotic resistance. This review focuses on phages, phage-related elements and on composite MGEs (phages-MGEs) involved in antibiotic resistance mobility. We review common features of these elements, rather than differences, and provide a broad overview of the antibiotic resistance transfer mechanisms observed in nature, which is a necessary first step to controlling them.

  9. [Resistance acquisition via the bacterial SOS response: the inducive role of antibiotics].

    Science.gov (United States)

    Da Re, Sandra; Ploy, Marie-Cécile

    2012-02-01

    After the euphoria of the antibiotic discovery and their tremendous action on bacterial infections outcomes, arrives a period of fear with the continuous emergence of bacteria that are resistant to almost all antibiotic treatments. It is becoming essential to better understand antibiotic resistance mechanisms to find new approaches to prevent the worldwide problem of multiresistance. The role of antibiotics on the direct induction of resistance acquisition is known. Recent studies have shown that some antibiotics, by inducing the bacterial SOS response, global repair response after DNA damages, are involved on a broader level in the induction, acquisition and dissemination of resistances in bacteria. We discuss here the role of antibiotics in resistance acquisition via the SOS response through several examples and the interest of identifying the SOS response regulators as the future targets of new families of antimicrobial molecules.

  10. Community-acquired Methicillin-resistant Staphylococcus Aureus (CA-MRSA):A Public Health Concern in Athletic Settings

    Institute of Scientific and Technical Information of China (English)

    Lindsay K. Drewes

    2008-01-01

    @@ Background Methicillin-resistant Staphylococcus aureus (MRSA) is a type of bacteria, commonly manifesting itself in the form of skin infections, and resistant to beta-lactum antibiotics[2]. These infections were seen in hospital settings starting in the 1960s in patients that had recently been hospitalized or undergone a medical procedure[3]. In the 1980s reports were first published in the literature of MRSA acquired in otherwise healthy individuals from community settingsr[4,5]. An increased occurrence of community-associated Methicillin-resistant Staphylococcus aureus (CA-MRSA) has been on the rise since the late 1990s and manifests itself as a skin infection in populations without other previously known risk factors[6-8].

  11. Antibiotic resistance patterns of major zoonotic pathogens from all-natural, antibiotic-free, pasture-raised broiler flocks in the southeastern United States

    Science.gov (United States)

    The use of antibiotics in agroecosystems has been implicated in the rise in antibiotic resistance that can affect environmental, animal, and human health. In order to effectively determine the environmental impact of antibiotic use in agroecosystems, appropriate background levels of antibiotic resi...

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

    NARCIS (Netherlands)

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

    2002-01-01

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

  13. Cancer resistance as an acquired and inheritable trait

    DEFF Research Database (Denmark)

    Koch, Janne; Hau, Jann; Jensen, Henrik Elvang

    2014-01-01

    AIM: To induce cancer resistance in wild-type mice and detect if the resistance could be inherited to the progeny of the induced resistant mice. Furthermore to investigate the spectrum and immunology of this inherited cancer resistance. MATERIALS AND METHODS: Resistance to with live S180 cancer...... cells in BALB/c mice was induced by immunization with inactivated S180 cancer cells. The immunization was performed by either frozen/thawed or irradiated cancer cells or cell-free ascitic fluid (CFAF). RESULTS: In all instances the induced resistance was demonstrated to be inheritable. The phenotype...... was named HICR (heritable induced cancer resistance) and was defined as primary resistant progeny from mice immunized with frozen/thawed or irradiated S180 cells or CFAF obtained from mice with S180 induced ascites. Notably, this resistance was transferred from both male and female mice to the offspring...

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

    Science.gov (United States)

    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.

  15. Insects represent a link between food animal farms and the urban environment for antibiotic resistance traits.

    Science.gov (United States)

    Zurek, Ludek; Ghosh, Anuradha

    2014-06-01

    Antibiotic-resistant bacterial infections result in higher patient mortality rates, prolonged hospitalizations, and increased health care costs. Extensive use of antibiotics as growth promoters in the animal industry represents great pressure for evolution and selection of antibiotic-resistant bacteria on farms. Despite growing evidence showing that antibiotic use and bacterial resistance in food animals correlate with resistance in human pathogens, the proof for direct transmission of antibiotic resistance is difficult to provide. In this review, we make a case that insects commonly associated with food animals likely represent a direct and important link between animal farms and urban communities for antibiotic resistance traits. Houseflies and cockroaches have been shown to carry multidrug-resistant clonal lineages of bacteria identical to those found in animal manure. Furthermore, several studies have demonstrated proliferation of bacteria and horizontal transfer of resistance genes in the insect digestive tract as well as transmission of resistant bacteria by insects to new substrates. We propose that insect management should be an integral part of pre- and postharvest food safety strategies to minimize spread of zoonotic pathogens and antibiotic resistance traits from animal farms. Furthermore, the insect link between the agricultural and urban environment presents an additional argument for adopting prudent use of antibiotics in the food animal industry.

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

    Science.gov (United States)

    Tazzyman, Samuel J; Hall, Alex R

    2015-03-17

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under phage parasitism, the likelihood that antibiotic-resistant genetic backgrounds spread depends on their initial frequency, mutation rate and intrinsic growth rate relative to drug-susceptible genotypes, because these parameters determine relative rates of phage-resistance evolution on different genetic backgrounds. Moreover, the average cost of antibiotic resistance in terms of intrinsic growth in the antibiotic-free experimental environment was small relative to the benefits of an increased mutation rate in the presence of phages. This is consistent with our theoretical work indicating that, under phage selection, typical costs of antibiotic resistance can be outweighed by realistic increases in mutability if drug resistance and hypermutability are genetically linked, as is frequently observed in clinical isolates. This suggests the long-term distribution of antibiotic resistance depends on the relative rates at which different lineages adapt to other types of selection, which in the case of phage parasitism is probably extremely common, as well as costs of resistance inferred by classical in vitro methods.

  17. Effects of antibiotic resistance alleles on bacterial evolutionary responses to viral parasites.

    Science.gov (United States)

    Arias-Sánchez, Flor I; Hall, Alex R

    2016-05-01

    Antibiotic resistance has wide-ranging effects on bacterial phenotypes and evolution. However, the influence of antibiotic resistance on bacterial responses to parasitic viruses remains unclear, despite the ubiquity of such viruses in nature and current interest in therapeutic applications. We experimentally investigated this by exposing various Escherichia coli genotypes, including eight antibiotic-resistant genotypes and a mutator, to different viruses (lytic bacteriophages). Across 960 populations, we measured changes in population density and sensitivity to viruses, and tested whether variation among bacterial genotypes was explained by their relative growth in the absence of parasites, or mutation rate towards phage resistance measured by fluctuation tests for each phage. We found that antibiotic resistance had relatively weak effects on adaptation to phages, although some antibiotic-resistance alleles impeded the evolution of resistance to phages via growth costs. By contrast, a mutator allele, often found in antibiotic-resistant lineages in pathogenic populations, had a relatively large positive effect on phage-resistance evolution and population density under parasitism. This suggests costs of antibiotic resistance may modify the outcome of phage therapy against pathogenic populations previously exposed to antibiotics, but the effects of any co-occurring mutator alleles are likely to be stronger.

  18. Evaluating the mobility potential of antibiotic resistance genes in environmental resistomes without metagenomics

    Science.gov (United States)

    Pärnänen, Katariina; Karkman, Antti; Tamminen, Manu; Lyra, Christina; Hultman, Jenni; Paulin, Lars; Virta, Marko

    2016-01-01

    Antibiotic resistance genes are ubiquitous in the environment. However, only a fraction of them are mobile and able to spread to pathogenic bacteria. Until now, studying the mobility of antibiotic resistance genes in environmental resistomes has been challenging due to inadequate sensitivity and difficulties in contig assembly of metagenome based methods. We developed a new cost and labor efficient method based on Inverse PCR and long read sequencing for studying mobility potential of environmental resistance genes. We applied Inverse PCR on sediment samples and identified 79 different MGE clusters associated with the studied resistance genes, including novel mobile genetic elements, co-selected resistance genes and a new putative antibiotic resistance gene. The results show that the method can be used in antibiotic resistance early warning systems. In comparison to metagenomics, Inverse PCR was markedly more sensitive and provided more data on resistance gene mobility and co-selected resistances. PMID:27767072

  19. Evolution by Pervasive Gene Fusion in Antibiotic Resistance and Antibiotic Synthesizing Genes

    Directory of Open Access Journals (Sweden)

    Orla Coleman

    2015-03-01

    Full Text Available Phylogenetic (tree-based approaches to understanding evolutionary history are unable to incorporate convergent evolutionary events where two genes merge into one. In this study, as exemplars of what can be achieved when a tree is not assumed a priori, we have analysed the evolutionary histories of polyketide synthase genes and antibiotic resistance genes and have shown that their history is replete with convergent events as well as divergent events. We demonstrate that the overall histories of these genes more closely resembles the remodelling that might be seen with the children’s toy Lego, than the standard model of the phylogenetic tree. This work demonstrates further that genes can act as public goods, available for re-use and incorporation into other genetic goods.

  20. Occurrence of antibiotics and antibiotic resistance genes in hospital and urban wastewaters and their impact on the receiving river.

    Science.gov (United States)

    Rodriguez-Mozaz, Sara; Chamorro, Sara; Marti, Elisabet; Huerta, Belinda; Gros, Meritxell; Sànchez-Melsió, Alexandre; Borrego, Carles M; Barceló, Damià; Balcázar, Jose Luis

    2015-02-01

    Antibiotic resistance has become a major health concern; thus, there is a growing interest in exploring the occurrence of antibiotic resistance genes (ARGs) in the environment as well as the factors that contribute to their emergence. Aquatic ecosystems provide an ideal setting for the acquisition and spread of ARGs due to the continuous pollution by antimicrobial compounds derived from anthropogenic activities. We investigated, therefore, the pollution level of a broad range of antibiotics and ARGs released from hospital and urban wastewaters, their removal through a wastewater treatment plant (WWTP) and their presence in the receiving river. Several antimicrobial compounds were detected in all water samples collected. Among antibiotic families, fluoroquinolones were detected at the highest concentration, especially in hospital effluent samples. Although good removal efficiency by treatment processes was observed for several antimicrobial compounds, most antibiotics were still present in WWTP effluents. The results also revealed that copy numbers of ARGs, such as blaTEM (resistance to β-lactams), qnrS (reduced susceptibility to fluoroquinolones), ermB (resistance to macrolides), sulI (resistance to sulfonamides) and tetW (resistance to tetracyclines), were detected at the highest concentrations in hospital effluent and WWTP influent samples. Although there was a significant reduction in copy numbers of these ARGs in WWTP effluent samples, this reduction was not uniform across analyzed ARGs. Relative concentration of ermB and tetW genes decreased as a result of wastewater treatment, whereas increased in the case of blaTEM, sulI and qnrS genes. The incomplete removal of antibiotics and ARGs in WWTP severely affected the receiving river, where both types of emerging pollutants were found at higher concentration in downstream waters than in samples collected upstream from the discharge point. Taken together, our findings demonstrate a widespread occurrence of

  1. Occurrence and distribution of antibiotics, antibiotic resistance genes in the urban rivers in Beijing, China.

    Science.gov (United States)

    Xu, Yan; Guo, Changsheng; Luo, Yi; Lv, Jiapei; Zhang, Yuan; Lin, Haixia; Wang, Li; Xu, Jian

    2016-06-01

    The occurrence and distribution of sulfonamide and tetracycline, corresponding bacterial resistant rate and resistance genes (ARGs) and two integrase genes were investigated in seven urban rivers in Beijing, China. The total concentration of sulfonamide and tetracycline ranged from 1.3 × 10(1)-1.5 × 10(3) ng/L and 3.9 × 10(1)-5.4 × 10(4) ng/L for water, and 1.0 × 10(0)-2.7 × 10(2) and 3.1 × 10(1)-1.6 × 10(2) ng/g for sediment, respectively. The sul resistant rate was 2-3 times higher than tet resistant rate in both surface water and sediment. The average rate of sul resistance and tet resistance were up to 81.3% and 38.6% in surface water, 89.1% and 69.4% in the sediment, respectively. The sul1, tetA and tetE genes were predominant in term of the absolute abundance. The absolute abundance of ARGs in Wenyu River and Qinghe River, which were close to the direct discharging sites, were 5-50 times higher than those in the other investigated urban rivers, suggesting that the source release played an important role in the distribution of ARGs. The sul1 and sul2 genes had positive correlation (p resistance genes was significantly correlated with tetracyclines (p antibiotics in the urban rivers had identical sources of pollution. Considering principal component analysis, sampling sites (QH5, QH6, B1, B2, B3 and BX2) intimated that a complex interplay of processes govern fate and transport of ARGs in the junction of rivers. These results are significant to understand the fate, and the contribution of ARGs from the source release. In view of the large-scale investigation of urban rivers system in Beijing, it reflected the bacterial resistance in sewage drainage system. Such investigation highlights the management on controlling the pollutant release which was seemed as a major driving force for the maintenance and propagation of many ARGs during the development of urbanization in the future.

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

    Directory of Open Access Journals (Sweden)

    Fiona Walsh

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

  3. Role of Old Antibiotics in the Era of Antibiotic Resistance. Highlighted Nitrofurantoin for the Treatment of Lower Urinary Tract Infections

    OpenAIRE

    Maria Jose Munoz-Davila

    2014-01-01

    Bacterial infections caused by antibiotic-resistant isolates have become a major health problem in recent years, since they are very difficult to treat, leading to an increase in morbidity and mortality. Nitrofurantoin is a broad-spectrum bactericidal antibiotic that, through a complex mode of action which is not completely understood, affects both Gram-negative and Gram-positive bacteria. Nitrofurantoin has been used successfully for a long time for the prophylaxis and treatment of acute lo...

  4. Dispersal of antibiotic-resistant high-risk clones by hospital networks : changing the patient direction can make all the difference

    NARCIS (Netherlands)

    Donker, T.; Wallinga, J.; Grundmann, H.

    2014-01-01

    Background: Patients who seek treatment in hospitals can introduce high-risk clones of hospital-acquired, antibiotic-resistant pathogens from previous admissions. In this manner, different healthcare institutions become linked epidemiologically. All links combined form the national patient referral

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

    Directory of Open Access Journals (Sweden)

    Erika M C D'Agata

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

  6. Antibiotic resistance among cultured bacterial isolates from bioethanol fermentation facilities across the United States.

    Science.gov (United States)

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

    2014-09-01

    Bacterial contamination of fuel ethanol fermentations by lactic acid bacteria (LAB) can have crippling effects on bioethanol production. Producers have had success controlling bacterial growth through prophylactic addition of antibiotics to fermentors, yet concerns have arisen about antibiotic resistance among the LAB. Here, we report on mechanisms used by 32 LAB isolates from eight different US bioethanol facilities to persist under conditions of antibiotic stress. Minimum inhibitory concentration assays with penicillin, erythromycin, and virginiamycin revealed broad resistance to each of the antibiotics as well as high levels of resistance to individual antibiotics. Phenotypic assays revealed that antibiotic inactivation mechanisms contributed to the high levels of individual resistances among the isolates, especially to erythromycin and virginiamycin, yet none of the isolates appeared to use a β-lactamase. Biofilm formation was noted among the majority of the isolates and may contribute to persistence under low levels of antibiotics. Nearly all of the isolates carried at least one canonical antibiotic resistance gene and many carried more than one. The erythromycin ribosomal methyltransferase (erm) gene class was found in 19 of 32 isolates, yet a number of these isolates exhibit little to no resistance to erythromycin. The erm genes were present in 15 isolates that encoded more than one antibiotic resistance mechanism, suggestive of potential genetic linkages.

  7. Antibiotic susceptibility in benzalkonium chloride-resistant and -susceptible Listeria monocytogenes strains.

    Science.gov (United States)

    Ortiz, Sagrario; López, Pilar; López, Victoria; Martínez-Suárez, Joaquín V

    2014-07-01

    This study aimed to investigate whether Listeria monocytogenes strains with resistance to a commonly used biocide display any cross-resistance to antibiotics. Using pulsed-field gel electrophoresis (PFGE), 29 different PFGE types were previously identified in an Iberian pig abattoir and processing plant. Only three PFGE types were resistant to benzalkonium chloride (BAC), but they represented a significant proportion of the PFGE types surviving in the plant after 4 years. In the present study, a subset of 29 strains, representing the 29 different PFGE types, underwent antibiotic susceptibility testing. Antibiotic susceptibility was assessed by Etest, utilizing 12 commonly prescribed antibiotics. All of the 29 strains were susceptible to all of the antibiotics tested. The study revealed that this group of different PFGE types of L. monocytogenes, including those resistant to BAC, possesses uniform sensitivity to antibiotics.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Marinella Silva Laport

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

  10. MICROORGANISMS RESISTANCE OF THE CHERNOZEM POLLUTION BY ANTIBIOTICS IN THE CONDITIONS OF FIELD MODEL EXPERIMENT

    OpenAIRE

    2014-01-01

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