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Sample records for intrinsic antibiotic resistance

  1. Antibiotic Capture by Bacterial Lipocalins Uncovers an Extracellular Mechanism of Intrinsic Antibiotic Resistance.

    Science.gov (United States)

    El-Halfawy, Omar M; Klett, Javier; Ingram, Rebecca J; Loutet, Slade A; Murphy, Michael E P; Martín-Santamaría, Sonsoles; Valvano, Miguel A

    2017-03-14

    The potential for microbes to overcome antibiotics of different classes before they reach bacterial cells is largely unexplored. Here we show that a soluble bacterial lipocalin produced by Burkholderia cenocepacia upon exposure to sublethal antibiotic concentrations increases resistance to diverse antibiotics in vitro and in vivo These phenotypes were recapitulated by heterologous expression in B. cenocepacia of lipocalin genes from Pseudomonas aeruginosa , Mycobacterium tuberculosis , and methicillin-resistant Staphylococcus aureus Purified lipocalin bound different classes of bactericidal antibiotics and contributed to bacterial survival in vivo Experimental and X-ray crystal structure-guided computational studies revealed that lipocalins counteract antibiotic action by capturing antibiotics in the extracellular space. We also demonstrated that fat-soluble vitamins prevent antibiotic capture by binding bacterial lipocalin with higher affinity than antibiotics. Therefore, bacterial lipocalins contribute to antimicrobial resistance by capturing diverse antibiotics in the extracellular space at the site of infection, which can be counteracted by known vitamins. IMPORTANCE Current research on antibiotic action and resistance focuses on targeting essential functions within bacterial cells. We discovered a previously unrecognized mode of general bacterial antibiotic resistance operating in the extracellular space, which depends on bacterial protein molecules called lipocalins. These molecules are highly conserved in most bacteria and have the ability to capture different classes of antibiotics outside bacterial cells. We also discovered that liposoluble vitamins, such as vitamin E, overcome in vitro and in vivo antibiotic resistance mediated by bacterial lipocalins, providing an unexpected new alternative to combat resistance by using this vitamin or its derivatives as antibiotic adjuvants. Copyright © 2017 El-Halfawy et al.

  2. The Mycobacterial Transcriptional Regulator whiB7 Gene Links Redox Homeostasis and Intrinsic Antibiotic Resistance*

    Science.gov (United States)

    Burian, Ján; Ramón-García, Santiago; Sweet, Gaye; Gómez-Velasco, Anaximandro; Av-Gay, Yossef; Thompson, Charles J.

    2012-01-01

    Intrinsic drug resistance in Mycobacterium tuberculosis limits therapeutic options for treating tuberculosis. The mycobacterial transcriptional regulator whiB7 contributes to intrinsic resistance by activating its own expression and many drug resistance genes in response to antibiotics. To investigate whiB7 activation, we constructed a GFP reporter to monitor its expression, and we used it to investigate the whiB7 promoter and to screen our custom library of almost 600 bioactive compounds, including the majority of clinical antibiotics. Results showed whiB7 was transcribed from a promoter that was conserved across mycobacteria and other actinomycetes, including an AT-rich sequence that was likely targeted by WhiB7. Expression was induced by compounds having diverse structures and targets, independent of the ability of whiB7 to mediate resistance, and was dependent on media composition. Pretreatment with whiB7 activators resulted in clinically relevant increases in intrinsic drug resistance. Antibiotic-induced transcription was synergistically increased by the reductant dithiothreitol, an effect mirrored by a whiB7-dependent shift to a highly reduced cytoplasm reflected by the ratio of reduced/oxidized mycothiol. These data provided evidence that intrinsic resistance resulting from whiB7 activation is linked to fundamental changes in cell metabolism. PMID:22069311

  3. Assessment of three Resistance-Nodulation-Cell Division drug efflux transporters of Burkholderia cenocepacia in intrinsic antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Venturi Vittorio

    2009-09-01

    Full Text Available Abstract Background Burkholderia cenocepacia are opportunistic Gram-negative bacteria that can cause chronic pulmonary infections in patients with cystic fibrosis. These bacteria demonstrate a high-level of intrinsic antibiotic resistance to most clinically useful antibiotics complicating treatment. We previously identified 14 genes encoding putative Resistance-Nodulation-Cell Division (RND efflux pumps in the genome of B. cenocepacia J2315, but the contribution of these pumps to the intrinsic drug resistance of this bacterium remains unclear. Results To investigate the contribution of efflux pumps to intrinsic drug resistance of B. cenocepacia J2315, we deleted 3 operons encoding the putative RND transporters RND-1, RND-3, and RND-4 containing the genes BCAS0591-BCAS0593, BCAL1674-BCAL1676, and BCAL2822-BCAL2820. Each deletion included the genes encoding the RND transporter itself and those encoding predicted periplasmic proteins and outer membrane pores. In addition, the deletion of rnd-3 also included BCAL1672, encoding a putative TetR regulator. The B. cenocepacia rnd-3 and rnd-4 mutants demonstrated increased sensitivity to inhibitory compounds, suggesting an involvement of these proteins in drug resistance. Moreover, the rnd-3 and rnd-4 mutants demonstrated reduced accumulation of N-acyl homoserine lactones in the growth medium. In contrast, deletion of the rnd-1 operon had no detectable phenotypes under the conditions assayed. Conclusion Two of the three inactivated RND efflux pumps in B. cenocepacia J2315 contribute to the high level of intrinsic resistance of this strain to some antibiotics and other inhibitory compounds. Furthermore, these efflux systems also mediate accumulation in the growth medium of quorum sensing molecules that have been shown to contribute to infection. A systematic study of RND efflux systems in B. cenocepacia is required to provide a full picture of intrinsic antibiotic resistance in this opportunistic

  4. Unusual acylation of chloramphenicol in Lysobacter enzymogenes, a biocontrol agent with intrinsic resistance to multiple antibiotics.

    Science.gov (United States)

    Zhang, Wei; Huffman, Justin; Li, Shengying; Shen, Yuemao; Du, Liangcheng

    2017-07-04

    The environmental gliding bacteria Lysobacter are emerging as a new group of biocontrol agents due to their prolific production of lytic enzymes and potent antibiotic natural products. These bacteria are intrinsically resistant to many antibiotics, but the mechanisms behind the antibiotic resistance have not been investigated. Previously, we have used chloramphenicol acetyltransferase gene (cat) as a selection marker in genetic manipulation of natural product biosynthetic genes in Lysobacter, because chloramphenicol is one of the two common antibiotics that Lysobacter are susceptible to. Here, we found L. enzymogenes, the most studied species of this genus, could still grow in the presence of a low concentration of chloramphenicol. Three chloramphenicol derivatives (1-3) with an unusual acylation pattern were identified in a cat-containing mutant of L. enzymogenes and in the wild type. The compounds included chloramphenicol 3'-isobutyrate (1), a new compound chloramphenicol 1'-isobutyrate (2), and a rare chloramphenicol 3'-isovalerate (3). Furthermore, a mutation of a global regulator gene (clp) or a Gcn5-related N-acetyltransferase (GNAT) gene in L. enzymogenes led to nearly no growth in media containing chloramphenicol, whereas a complementation of clp restored the chloramphenicol acylation as well as antibiotic HSAF production in the clp mutant. The results indicated that L. enzymogenes contains a pool of unusual acyl donors for enzymatic modification of chloramphenicol that confers the resistance, which may involve the Clp-GNAT regulatory system. Because Lysobacter are ubiquitous inhabitants of soil and water, the finding may have important implications in understanding microbial competitions and bioactive natural product regulation.

  5. Antibiotics and Antibiotic Resistance

    Science.gov (United States)

    ... Drugs Resources for You Information for Consumers (Drugs) Buying & Using Medicine Safely Antibiotics and Antibiotic Resistance Antibiotics ... Antibiotic Resistance and Protect Public Health The White House Blog FDA’s Take on the Executive Order and ...

  6. An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria

    Science.gov (United States)

    Cox, Georgina; Koteva, Kalinka; Wright, Gerard D.

    2014-01-01

    Objectives An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. Methods E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. Results The anthracycline Antibiotic 301A1 was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure–activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A1 abolishes activity. Conclusions Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. PMID:24627312

  7. Intrinsic and acquired resistance mechanisms in enterococcus

    Science.gov (United States)

    Hollenbeck, Brian L.; Rice, Louis B.

    2012-01-01

    Enterococci have the potential for resistance to virtually all clinically useful antibiotics. Their emergence as important nosocomial pathogens has coincided with increased expression of antimicrobial resistance by members of the genus. The mechanisms underlying antibiotic resistance in enterococci may be intrinsic to the species or acquired through mutation of intrinsic genes or horizontal exchange of genetic material encoding resistance determinants. This paper reviews the antibiotic resistance mechanisms in Enterococcus faecium and Enterococcus faecalis and discusses treatment options. PMID:23076243

  8. The role of outer membrane in Serratia marcescens intrinsic resistance to antibiotics.

    Science.gov (United States)

    Sánchez, L; Ruiz, N; Leranoz, S; Viñas, M; Puig, M

    1997-09-01

    Three different porins from Serratia marcescens were described. They were named Omp1, Omp2 and Omp3 and their molecular weights were 42, 40 and 39 kDa respectively. Omp2 and Omp3 showed osmoregulation and thermoregulation in a similar way to OmpC and OmpF of Escherichia coli. Permeability coefficients of the outer membrane of this species were calculated following the Zimmermann and Rosselet method. P values were similar to those obtained in Escherichia coli, which suggests that the chromosomal beta-lactamase would play a major role in the resistance of Serratia marcescens to beta-lactam antibiotics. Both MIC values and permeabilities were modified by salycilates and acetylsalycilate. Synergism between the outer membrane and the beta-lactamase was also evaluated. When bacteria grew in the presence of a beta-lactam in the medium, the beta-lactamase accounted for most of the resistance.

  9. 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...... 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....... antibiotic prescribing are a major factor in the prescribing for ARIs. Professional interventions with educational components are effective, although they have modest effects, and are expensive. GPs' perceptions - that mistakenly assume as a default that patients want antibiotics for their ARIs - are often...

  10. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    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......Bacteria can avoid extinction during antimicrobial exposure by becoming resistant. They achieve this either via adaptive mutations or horizontally acquired resistance genes. If resistance emerges in clinical relevant species, it can lead to treatment failure and ultimately result in increasing...... 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...

  11. 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

  12. Combating Antibiotic Resistance

    Science.gov (United States)

    ... in Farm Animals FDA: Cutting-Edge Technology Sheds Light on Antibiotic Resistance For More Information Antibiotics and Antibiotic Resistance Antimicrobial Resistance Information for Consumers and Health Professionals CDC: Get Smart: Know When Antibiotics Work More in Consumer Updates ...

  13. 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. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

  14. Resistance-resistant antibiotics.

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    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Antibiotics and Resistance: Glossary

    Science.gov (United States)

    ... Work Contact Us ABOUT THE ISSUE What is Antibiotic Resistance? General Background Science of Resistance Glossary References ... for Adaptation Genetics and Drug Resistance Reservoirs of Antibiotic Resistance Project (ROAR) INTERNATIONAL CHAPTERS APUA Chapter Network ...

  16. Antibiotic-Resistant Gonorrhea

    Science.gov (United States)

    ... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Antibiotic-Resistant Gonorrhea Recommend on Facebook Tweet Share Compartir ... Threat Gonorrhea has progressively developed resistance to the antibiotic drugs prescribed to treat it. Following the spread ...

  17. 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.

  18. 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 Share Compartir Antibiotic-Resistant Gonorrhea: An Overview Antibiotic resistance is the ...

  19. Antibiotic-Resistant Bacteria.

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    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

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

  20. Antibiotic resistance reservoirs

    NARCIS (Netherlands)

    Versluis, Dennis

    2016-01-01

    One of the major threats to human health in the 21st century is the emergence of pathogenic bacteria that are resistant to multiple antibiotics, thereby limiting treatment options. An important route through which pathogens become resistant is via acquisition of resistance genes from environmental

  1. Antibiotic resistance reservoirs

    NARCIS (Netherlands)

    Versluis, Dennis

    2016-01-01

    One of the major threats to human health in the 21st century is the emergence of pathogenic bacteria that are resistant to multiple antibiotics, thereby limiting treatment options. An important route through which pathogens become resistant is via acquisition of resistance genes from

  2. Antibiotic Adjuvants: Rescuing Antibiotics from Resistance.

    Science.gov (United States)

    Wright, Gerard D

    2016-11-01

    Rooted in the mechanism of action of antibiotics and subject to bacterial evolution, antibiotic resistance is difficult and perhaps impossible to overcome. Nevertheless, strategies can be used to minimize the emergence and impact of resistance. Antibiotic adjuvants offer one such approach. These are compounds that have little or no antibiotic activity themselves but act to block resistance or otherwise enhance antibiotic action. Antibiotic adjuvants are therefore delivered in combination with antibiotics and can be divided into two groups: Class I agents that act on the pathogen, and Class II agents that act on the host. Adjuvants offer a means to both suppress the emergence of resistance and rescue the activity of existing drugs, offering an orthogonal strategy complimentary to new antibiotic discovery VIDEO ABSTRACT. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Mechanisms of Antibiotic Resistance

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    Munita, Jose M.; Arias, Cesar A.

    2015-01-01

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

  4. Antibiotic Resistance in Foodborne Pathogens

    OpenAIRE

    Walsh, Ciara; Duffy, Geraldine

    2013-01-01

    Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...

  5. 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.

  6. Antibiotic resistance in animals.

    Science.gov (United States)

    Barton, Mary D; Pratt, Rachael; Hart, Wendy S

    2003-01-01

    There is currently no systematic surveillance or monitoring of antibiotic resistance in Australian animals. Registration of antibiotics for use in animals is tightly controlled and has been very conservative. Fluoroquinolones have not been registered for use in food producing animals and other products have been removed from the market because of human health concerns. In the late 1970s, the Animal Health Committee coordinated a survey of resistance in Salmonella and Escherichia coli isolates from cattle, pigs and poultry and in bovine Staphylococcus aureus. Some additional information is available from published case reports. In samples collected prior to the withdrawal of avoparcin from the market, no vancomycin resistant Enterococcus faecium or Enterococcus faecalis were detected in samples collected from pigs, whereas some vanA enterococci, including E. faecium and E. faecalis, were found in chickens. No vanB enterococci were detected in either species. Virginiamycin resistance was common in both pig and poultry isolates. Multiple resistance was common in E. coli and salmonellae isolates. No fluoroquinolone resistance was found in salmonellae, E. coli or Campylobacter. Beta-lactamase production is common in isolates from bovine mastitis, but no methicillin resistance has been detected. However, methicillin resistance has been reported in canine isolates of Staphylococcus intermedius and extended spectrum beta-lactamase producing E. coli has been found in dogs.

  7. Strategies to Minimize Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Sang Hee Lee

    2013-09-01

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

  8. Surveillance of antibiotic resistance

    Science.gov (United States)

    Johnson, Alan P.

    2015-01-01

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

  9. Bacterial cheating limits antibiotic resistance

    Science.gov (United States)

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

    2012-02-01

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

  10. The Comprehensive Antibiotic Resistance Database

    Science.gov (United States)

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

    2013-01-01

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

  11. The Prehistory of Antibiotic Resistance.

    Science.gov (United States)

    Perry, Julie; Waglechner, Nicholas; Wright, Gerard

    2016-06-01

    Antibiotic resistance is a global problem that is reaching crisis levels. The global collection of resistance genes in clinical and environmental samples is the antibiotic "resistome," and is subject to the selective pressure of human activity. The origin of many modern resistance genes in pathogens is likely environmental bacteria, including antibiotic producing organisms that have existed for millennia. Recent work has uncovered resistance in ancient permafrost, isolated caves, and in human specimens preserved for hundreds of years. Together with bioinformatic analyses on modern-day sequences, these studies predict an ancient origin of resistance that long precedes the use of antibiotics in the clinic. Understanding the history of antibiotic resistance is important in predicting its future evolution. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

  12. Antibiotic Resistance in Nephrological Practice

    Directory of Open Access Journals (Sweden)

    O.I. Taran

    2017-02-01

    Full Text Available The problem of antibiotic resistance is a serious threat to the global public health and requires action by both the state and the public. The World Health Organization identified 15 most dangerous and prevalent superbugs, which it ranked based on three levels of threat they present to the public health. At the heart of the fight against antibiotic resistance lies the increased awareness of the health professionals and general public that incorrect and excessive use of antibiotics amid poor practices in infection prevention and control contributes to the acceleration of antibiotic resistance.

  13. 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.

  14. Antibiotics and the resistant microbiome

    DEFF Research Database (Denmark)

    Sommer, Morten; Dantas, Gautam

    2011-01-01

    Since the discovery and clinical application of antibiotics, pathogens and the human microbiota have faced a near continuous exposure to these selective agents. A well-established consequence of this exposure is the evolution of multidrug-resistant pathogens, which can become virtually untreatable....... 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...... expand our understanding of the interplay between antibiotics and the microbiome....

  15. 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,

  16. 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

    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

  17. PREVALENCE AND ANTIBIOTIC RESISTANCE OF ...

    African Journals Online (AJOL)

    9 mars 2015 ... strategy to prevent the spread of this resistance. Keywords: Staphylococci; Staphylococcus aureus; Oxacillin; Antibiotic resistance; Disc diffusion. Author Correspondence, e-mail: mn.boukhatem@yahoo.fr. ICID: 1142924. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at.

  18. The determinants of the antibiotic resistance process.

    Science.gov (United States)

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

    2009-01-01

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

  19. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  20. Antibiotic resistance: the Iowa experience.

    Science.gov (United States)

    Bell, Nancy

    2002-11-01

    In the past 10 years, the number of strains of Streptococcus pneumoniae and other common respiratory pathogens that are resistant to penicillin has increased. The Iowa Department of Public Health convened a multidisciplinary task force in January 1998 to develop strategies to combat antibiotic resistance in the state because they were alarmed by these reports. Within 18 months, the task force implemented statewide surveillance of resistant organisms and posted information about the surveillance on the Internet, distributed a public health guide on judicious antibiotic use and infection control measures to 7500 healthcare providers, and held a press conference to inform the public about antibiotic resistance. The task force collaborated with several major insurers in the state to profile the top prescribers of antibiotic agents in their plan. The profiling and educational interventions led to a substantial decrease in both overall antibiotic prescribing and drug costs. Other states may want to undertake similar programs to help protect their citizens from infections caused by resistant pathogens.

  1. 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

  2. Development of botanicals to combat antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Pooja D. Gupta

    2017-10-01

    Full Text Available The discovery of antibiotics in the previous century lead to reduction in mortality and morbidity due to infectious diseases but their inappropriate and irrational use has resulted in emergence of resistant microbial populations. Alteration of target sites, active efflux of drugs and enzymatic degradations are the strategies employed by the pathogenic bacteria to develop intrinsic resistance to antibiotics. This has led to an increased interest in medicinal plants since 25–50% of current pharmaceuticals are plant derived. Crude extracts of medicinal plants could serve as an alternate source of resistance modifying agents owing to the wide variety of secondary metabolites. These metabolites (alkaloids, tannins, polyphenols etc. could act as potentials for antimicrobials and resistance modifiers. Plant extracts have the ability to bind to protein domains leading to modification or inhibition protein–protein interactions. This enables the herbals to also present themselves as effective modulators of host related cellular processes viz immune response, mitosis, apoptosis and signal transduction. Thus they may exert their activity not only by killing the microorganism but by affecting key events in the pathogenic process, thereby, the bacteria, fungi and viruses may have a reduced ability to develop resistance to botanicals. The article is meant to stimulate research wherein the cidal activity of the extract is not the only parameter considered but other mechanism of action by which plants can combat drug resistant microbes are investigated. The present article emphasizes on mechanisms involved in countering multi drug resistance.

  3. 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

  4. Intrinsic nanofilamentation in resistive switching

    KAUST Repository

    Wu, Xing

    2013-03-15

    Resistive switching materials are promising candidates for nonvolatile data storage and reconfiguration of electronic applications. Intensive studies have been carried out on sandwiched metal-insulator-metal structures to achieve high density on-chip circuitry and non-volatile memory storage. Here, we provide insight into the mechanisms that govern highly reproducible controlled resistive switching via a nanofilament by using an asymmetric metal-insulator-semiconductor structure. In-situ transmission electron microscopy is used to study in real-time the physical structure and analyze the chemical composition of the nanofilament dynamically during resistive switching. Electrical stressing using an external voltage was applied by a tungsten tip to the nanosized devices having hafnium oxide (HfO2) as the insulator layer. The formation and rupture of the nanofilaments result in up to three orders of magnitude change in the current flowing through the dielectric during the switching event. Oxygen vacancies and metal atoms from the anode constitute the chemistry of the nanofilament.

  5. 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.

  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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. [Antibiotic resistance: A global crisis].

    Science.gov (United States)

    Alós, Juan-Ignacio

    2015-12-01

    The introduction of antibiotics into clinical practice represented one of the most important interventions for the control of infectious diseases. Antibiotics have saved millions of lives and have also brought a revolution in medicine. However, an increasing threat has deteriorated the effectiveness of these drugs, that of bacterial resistance to antibiotics, which is defined here as the ability of bacteria to survive in antibiotic concentrations that inhibit/kill others of the same species. In this review some recent and important examples of resistance in pathogens of concern for mankind are mentioned. It is explained, according to present knowledge, the process that led to the current situation in a short time, evolutionarily speaking. It begins with the resistance genes, continues with clones and genetic elements involved in the maintenance and dissemination, and ends with other factors that contribute to its spread. Possible responses to the problem are also reviewed, with special reference to the development of new antibiotics. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  8. 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.

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

    Science.gov (United States)

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

    2016-06-01

    Bacterial persistence represents a simple of phenotypic heterogeneity, whereby a proportion of cells in an isogenic bacterial population can survive exposure to lethal stresses such as antibiotics. In contrast, genetically based antibiotic resistance allows for continued growth in the presence of antibiotics. It is unclear, however, whether resistance and persistence are complementary or alternative evolutionary adaptations to antibiotics. Here, we investigate the co-evolution of resistance and persistence across the genus Pseudomonas using comparative methods that correct for phylogenetic nonindependence. We find that strains of Pseudomonas vary extensively in both their intrinsic resistance to antibiotics (ciprofloxacin and rifampicin) and persistence following exposure to these antibiotics. Crucially, we find that persistence correlates positively to antibiotic resistance across strains. However, we find that different genes control resistance and persistence implying that they are independent traits. Specifically, we find that the number of type II toxin-antitoxin systems (TAs) in the genome of a strain is correlated to persistence, but not resistance. Our study shows that persistence and antibiotic resistance are complementary, but independent, evolutionary adaptations to stress and it highlights the key role played by TAs in the evolution of persistence. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

  10. Dielectrophoretic assay of bacterial resistance to antibiotics

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  11. An Evolutionarily Conserved Mechanism for Intrinsic and Transferable Polymyxin Resistance.

    Science.gov (United States)

    Xu, Yongchang; Wei, Wenhui; Lei, Sheng; Lin, Jingxia; Srinivas, Swaminath; Feng, Youjun

    2018-04-10

    Polymyxins, a family of cationic antimicrobial cyclic peptides, act as a last line of defense against severe infections by Gram-negative pathogens with carbapenem resistance. In addition to the intrinsic resistance to polymyxin E (colistin) conferred by Neisseria eptA , the plasmid-borne mobilized colistin resistance gene mcr-1 has been disseminated globally since the first discovery in Southern China, in late 2015. However, the molecular mechanisms for both intrinsic and transferable resistance to colistin remain largely unknown. Here, we aim to address this gap in the knowledge of these proteins. Structural and functional analyses of EptA and MCR-1 and -2 have defined a conserved 12-residue cavity that is required for the entry of the lipid substrate, phosphatidylethanolamine (PE). The in vitro and in vivo data together have allowed us to visualize the similarities in catalytic activity shared by EptA and MCR-1 and -2. The expression of either EptA or MCR-1 or -2 is shown to remodel the surface of enteric bacteria (e.g., Escherichia coli , Salmonella enterica , Klebsiella pneumoniae , etc.), rendering them resistant to colistin. The parallels in the PE substrate-binding cavities among EptA, MCR-1, and MCR-2 provide a comprehensive understanding of both intrinsic and transferable colistin resistance. Domain swapping between EptA and MCR-1 and -2 reveals that the two domains (transmembrane [TM] region and p hospho e thanol a mine [PEA] transferase) are not functionally exchangeable. Taken together, the results represent a common mechanism for intrinsic and transferable PEA resistance to polymyxin, a last-resort antibiotic against multidrug-resistant pathogens. IMPORTANCE EptA and MCR-1 and -2 remodel the outer membrane, rendering bacteria resistant to colistin, a final resort against carbapenem-resistant pathogens. Structural and functional analyses of EptA and MCR-1 and -2 reveal parallel PE lipid substrate-recognizing cavities, which explains intrinsic and

  12. Antibiotic and Antimicrobial Resistance: Threat Report 2013

    Science.gov (United States)

    ... Role What CDC is Doing: AR Solutions Initiative Investing in States: Map Antibiotic Resistance Lab Network Antibiotic ... CDC and Partners Tackle Drug-Resistant TB in India Newly Reported Gene, mcr -1, Threatens Last-Resort ...

  13. Antibiotic Resistance in Modern World

    Directory of Open Access Journals (Sweden)

    Leyla S. Namazova-Baranova

    2017-01-01

    Full Text Available The article brings up the topic not only vital and urgent for further development of modern medical science, but also affecting the interests of mankind as a whole and of every inhabitant of the Earth in particular: that is the irrational use of antibiotics and antibiotic resistance which rate is growing rapidly. We investigate the reasons for the epidemic of antibiotic resistance and discuss in detail all the necessary measures in order to cope with this problem. The shocking data on the almost universal irrational use of antibiotics by both medical workers and parents is provided. We demonstrate the microbiome changes that follow antibacterial drugs application resulting in the development of severe chronic pediatric diseases which cause severe disability or life-threatening conditions in children with long-term results in adult age. In conclusion, we summarize the evidence-based research in phytomedicine that present the phytopreparations as a serious alternative to antibiotics in a number of clinical settings. 

  14. 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.

  15. Effects of ultraviolet disinfection on antibiotic-resistant Escherichia coli from wastewater: inactivation, antibiotic resistance profiles and antibiotic resistance genes.

    Science.gov (United States)

    Zhang, Chong-Miao; Xu, Li-Mei; Wang, Xiaochang C; Zhuang, Kai; Liu, Qiang-Qiang

    2017-04-29

    To evaluate the effect of ultraviolet (UV) disinfection on antibiotic-resistant Escherichia coli (E. coli). Antibiotic-resistant E. coli strains were isolated from a wastewater treatment plant and subjected to UV disinfection. The effect of UV disinfection on the antibiotic resistance profiles and the antibiotic resistance genes (ARGs) of antibiotic-resistant E. coli was evaluated by a combination of antibiotic susceptibility analysis and molecular methods. Results indicated that multiple-antibiotic-resistant (MAR) E. coli were more resistant at low UV doses and required a higher UV dose (20 mJ cm -2 ) to enter the tailing phase compared with those of antibiotic-sensitive E. coli (8 mJ cm -2 ). UV disinfection caused a selective change in the inhibition zone diameters of surviving antibiotic-resistant E. coli and a slight damage to ARGs. The inhibition zone diameters of the strains resistant to antibiotics were more difficult to alter than those susceptible to antibiotics because of the existence and persistence of corresponding ARGs. The resistance of MAR bacteria to UV disinfection at low UV doses and the changes in inhibition zone diameters could potentially contribute to the selection of ARB in wastewater treatment after UV disinfection. The risk of spread of antibiotic resistance still exists owing to the persistence of ARGs. Our study highlights the acquisition of other methods to control the spread of ARGs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

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

    DEFF Research Database (Denmark)

    Leibovici, Leonard; Paul, Mical; Garner, Paul

    2016-01-01

    Antibiotics are among the most important interventions in healthcare. Resistance of bacteria to antibiotics threatens the effectiveness of treatment. Systematic reviews of antibiotic treatments often do not address resistance to antibiotics even when data are available in the original studies....... This omission creates a skewed view, which emphasizes short-term efficacy and ignores the long-term consequences to the patient and other people. We offer a framework for addressing antibiotic resistance in systematic reviews. We suggest that the data on background resistance in the original trials should...... 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...

  17. 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

  18. Mathematical analysis of multi-antibiotic resistance.

    Science.gov (United States)

    Zhao, Bin; Zhang, Xiaoying

    2016-09-15

    Multi-antibiotic resistance in bacterial infections is a growing threat to public health. Some experiments were carried out to study the multi-antibiotic resistance. The changes of the multi-antibiotic resistance with time were achieved by numerical simulations and the mathematical models, with the calculated temperature field, velocity field, and the antibiotic concentration field. The computed results and experimental results are compared. Both numerical simulations and the analytic models suggest that minor low concentrations of antibiotics could induce antibiotic resistance in bacteria. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Environmental pollution by antibiotics and by antibiotic resistance determinants

    International Nuclear Information System (INIS)

    Martinez, Jose Luis

    2009-01-01

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

  20. 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.

  1. 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

  2. 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.

  3. Bacterial biofilms and antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Liliana Caldas-Arias

    2015-04-01

    Full Text Available Biofilms give to bacteria micro-environmental benefits; confers protection against antimicrobials. Bacteria have antibiotic resistance by conventional and unusual mechanisms leading to delayed wound healing, to increase recurrent chronic infections and nosocomial contamination of medical devices. Objective: This narrative review aims to introduce the characteristics of Bacteria-biofilms, antimicrobial resistance mechanisms and potential alternatives for prevention and control of its formation. Methods: Search strategy was performed on records: PubMed / Medline, Lilacs, Redalyc; with suppliers such as EBSCO and thesaurus MeSH and DeCS. Conclusions: Knowledge and research performance of biofilm bacteria are relevant in the search of technology for detection and measuring sensitivity to antibiotics. The identification of Bacterial-biofilms needs no-traditional microbiological diagnosis.

  4. Antibiotic resistance of lactic acid bacteria

    OpenAIRE

    Bulajić Snežana; Mijačević Zora; Savić-Radovanović Radoslava

    2008-01-01

    Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolat...

  5. 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.

  6. Overcoming resistance to β-lactam antibiotics.

    Science.gov (United States)

    Worthington, Roberta J; Melander, Christian

    2013-05-03

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

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

    Science.gov (United States)

    2011-01-01

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

  8. 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

  9. Antibiotic Resistance in Human Chronic Periodontitis Microbiota

    NARCIS (Netherlands)

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

    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

  10. Dissemination of antibiotic resistance genes from antibiotic producers to pathogens

    DEFF Research Database (Denmark)

    Jiang, Xinglin; Ellabaan, Mostafa M Hashim; Charusanti, Pep

    2017-01-01

    It has been hypothesized that some antibiotic resistance genes (ARGs) found in pathogenic bacteria derive from antibiotic-producing actinobacteria. Here we provide bioinformatic and experimental evidence supporting this hypothesis. We identify genes in proteobacteria, including some pathogens......, that appear to be closely related to actinobacterial ARGs known to confer resistance against clinically important antibiotics. Furthermore, we identify two potential examples of recent horizontal transfer of actinobacterial ARGs to proteobacterial pathogens. Based on this bioinformatic evidence, we propose...... results support the existence of ancient and, possibly, recent transfers of ARGs from antibiotic-producing actinobacteria to proteobacteria, and provide evidence for a defined mechanism....

  11. Resistance diagnosis and the changing epidemiology of antibiotic resistance.

    Science.gov (United States)

    McAdams, David

    2017-01-01

    Widespread adoption of point-of-care resistance diagnostics (POCRD) reduces ineffective antibiotic use but could increase overall antibiotic use. Indeed, in the context of a standard susceptible-infected epidemiological model with a single antibiotic, POCRD accelerates the rise of resistance in the disease-causing bacterial population. When multiple antibiotics are available, however, POCRD may slow the rise of resistance even as more patients receive antibiotic treatment, belying the conventional wisdom that antibiotics are "exhaustible resources" whose increased use necessarily promotes the rise of resistance. © 2017 New York Academy of Sciences.

  12. Antibiotic and disinfectant resistance of Salmonella serovars ...

    African Journals Online (AJOL)

    The Salmonella isolates tested displayed multiple antibiotic resistance to a number of antibiotics used to treat both humans and animals. No resistance was seen to disinfectants used at the manufacturer\\'s recommended rate of dilution. The bacteria were resistant, though, at lower dilutions, highlighting the necessity of ...

  13. Antibiotics and Bacterial Resistance in the 21st Century

    Science.gov (United States)

    Fair, Richard J; Tor, Yitzhak

    2014-01-01

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

  14. How Economic Development Affects Antibiotic Resistance

    OpenAIRE

    John B. Horowitz; H. Brian Moehring

    2014-01-01

    Initially, economic development increases resistance because migration of people to urban areas in developing countries increases incomes, crowding and the use of antibiotics. Also, developing countries often don't require prescriptions or distribute high quality antibiotics. In developed countries, antibiotic resistance often falls or there is a decline in the rate of growth of resistance because infections decline with improvements in water quality, sanitation, housing and nutrition. Howeve...

  15. 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.

  16. 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. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. 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.

  18. Non-genetic mechanisms communicating antibiotic resistance: rethinking strategies for antimicrobial drug design.

    Science.gov (United States)

    El-Halfawy, Omar M; Valvano, Miguel A

    2012-10-01

    Infections by multidrug-resistant bacteria are of great concern worldwide. In many cases, resistance is not due to the presence of specific antibiotic-modifying enzymes, but rather associated with a general impermeability of the bacterial cell envelope. The molecular bases of this intrinsic resistance are not completely understood. Moreover, horizontal gene transfers cannot solely explain the spread of intrinsic resistance among bacterial strains. This review focuses on the increased intrinsic antibiotic resistance mediated by small molecules. These small molecules can either be secreted from bacterial cells of the same or different species (e.g., indole, polyamines, ammonia, and the Pseudomonas quinolone signal) or be present in the bacterial cell milieu, whether in the environment, such as indole acetic acid and other plant hormones, or in human tissues and body fluids, such as polyamines. These molecules are metabolic byproducts that act as infochemicals and modulate bacterial responses toward antibiotics leading to increasing or decreasing resistance levels. The non-genetic mechanisms of antibiotic response modulation and communication discussed in this review should reorient our thinking of the mechanisms of intrinsic resistance to antibiotics and its spread across bacterial cell populations. The identification of chemical signals mediating increased intrinsic antibiotic resistance will expose novel critical targets for the development of new antimicrobial strategies.

  19. Antibiotic adjuvants - A strategy to unlock bacterial resistance to antibiotics.

    Science.gov (United States)

    González-Bello, Concepción

    2017-09-15

    Resistance to available antibiotics in pathogenic bacteria is currently a global challenge since the number of strains that are resistant to multiple types of antibiotics has increased dramatically each year and has spread worldwide. To unlock this problem, the use of an 'antibiotic adjuvant' in combination with an antibiotic is now being exploited. This approach enables us to prolong the lifespan of these life-saving drugs. This digests review provides an overview of the main types of antibiotic adjuvants, the basis of their operation and the remaining issues to be tackled in this field. Particular emphasis is placed on those compounds that are already in clinical development, namely β-lactamase inhibitors. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  20. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Antibiotic resistance mechanisms of Vibrio cholerae.

    Science.gov (United States)

    Kitaoka, Maya; Miyata, Sarah T; Unterweger, Daniel; Pukatzki, Stefan

    2011-04-01

    As the causative agent of cholera, the bacterium Vibrio cholerae represents an enormous public health burden, especially in developing countries around the world. Cholera is a self-limiting illness; however, antibiotics are commonly administered as part of the treatment regimen. Here we review the initial identification and subsequent evolution of antibiotic-resistant strains of V. cholerae. Antibiotic resistance mechanisms, including efflux pumps, spontaneous chromosomal mutation, conjugative plasmids, SXT elements and integrons, are also discussed. Numerous multidrug-resistant strains of V. cholerae have been isolated from both clinical and environmental settings, indicating that antibiotic use has to be restricted and alternative methods for treating cholera have to be implemented.

  2. An underappreciated hotspot of antibiotic resistance

    DEFF Research Database (Denmark)

    Chen, Qing-Lin; Li, Hu; Zhou, Xin-Yuan

    2017-01-01

    Landfills are so far the most common practice for the disposals of municipal solid waste (MSW) worldwide. Since MSW landfill receives miscellaneous wastes, including unused/expired antibiotics and bioactive wastes, it gradually becomes a huge potential bioreactor for breeding antibiotic resistance...... be the potential hosts of ARGs. These findings provide evidence that groundwater near MSW landfill is an underappreciated hotspot of antibiotic resistance and contribute to the spread of ARGs via the flowing contaminated groundwater....

  3. 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.

  4. Klebsiella pneumoniae antibiotic resistance identified by atomic ...

    Indian Academy of Sciences (India)

    Vincenzo Ierardi

    2017-10-03

    Oct 3, 2017 ... In the last decade the detection of the resistance of bacteria to antibiotics treatment, developed by different kind of bacteria, is becoming a huge problem. We hereby present a different approach to the current problem of detection of bacteria resistance to antibiotics. Our aims were to use the atomic force ...

  5. 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.

  6. 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...

  7. [Biorhythms of antibiotic resistance of microorganisms].

    Science.gov (United States)

    Bukharin, O V; Perunova, N B; Fadeev, S B; Timokhina, T Kh; Iavnova, S V

    2008-01-01

    To study of circadian dynamics of antibiotic susceptibility and resistance of Gram-positive and Gram-negative microorganisms. Circadian dynamics of antibiotic susceptibility was studied on clinical strains of enterobacteria, non-fermenting Gram-negative bacteria, and staphylococci which were isolated and identified by common methods. During a day, with 3-hours intervals, studied strains were tested on susceptibility to ampicillin, oxacillin, ceftriaxone, meropenem, gentamycin, and ciprofloxacin using method of serial dilutions in agar. Circadian biorhythms of resistance to antibiotics in studied microorganisms were revealed. Along with common patterns, differences in temporal changes of microrganisms' susceptibility to antibacterial drugs were noted. Chronobiologic approach allowed to reveal significant amplitude of changes of minimal inhibitoryconcentration (MIC) of antibiotics versus resistant Gram-positive cocci reflecting presence of susceptibility periods, whereas in susceptible Gram-negative bacteria peaks of resistance were observed. Circadian dynamics of MIC of majority of antibiotics versus resistant Gram-negative bacteria and susceptible Gram-positive cocci was characterized by lower amplitude of changes without shifts from antibiotic resistance to susceptibility and vice versa. Obtained data open perspective of using biorhythmological approach in study of susceptibility of microorganisms to antibiotics during the elucidation of mechanisms of pathogens adaptation to environmental conditions and creation of new strategies of control for antibiotic resistance strains.

  8. Antibiotic combinations for controlling colistin-resistant Enterobacter cloacae.

    Science.gov (United States)

    Lima, Thais Bergamin; Silva, Osmar Nascimento; de Almeida, Keyla Caroline; Ribeiro, Suzana Meira; Motta, Dielle de Oliveira; Maria-Neto, Simone; Lara, Michelle Brizolla; Filho, Carlos Roberto Souza; Ombredane, Alicia Simalie; de Faria Junior, Celio; Parachin, Nadia Skorupa; Magalhães, Beatriz Simas; Franco, Octávio Luiz

    2017-02-01

    Enterobacter cloacae is a Gram-negative bacterium associated with high morbidity and mortality in intensive care patients due to its resistance to multiple antibiotics. Currently, therapy against multi-resistant bacteria consists of using colistin, in spite of its toxic effects at higher concentrations. In this context, colistin-resistant E. cloacae strains were challenged with lower levels of colistin combined with other antibiotics to reduce colistin-associated side effects. Colistin-resistant E. cloacae (ATCC 49141) strains were generated by serial propagation in subinhibitory colistin concentrations. After this, three colistin-resistant and three nonresistant replicates were isolated. The identity of all the strains was confirmed by MALDI-TOF MS, VITEK 2 and MicroScan analysis. Furthermore, cross-resistance to other antibiotics was checked by disk diffusion and automated systems. The synergistic effects of the combined use of colistin and chloramphenicol were observed via the broth microdilution checkerboard method. First, data here reported showed that all strains presented intrinsic resistance to penicillin, cephalosporin (except fourth generation), monobactam, and some associations of penicillin and β-lactamase inhibitors. Moreover, a chloramphenicol and colistin combination was capable of inhibiting the induced colistin-resistant strains as well as two colistin-resistant clinical strains. Furthermore, no cytotoxic effect was observed by using such concentrations. In summary, the data reported here showed for the first time the possible therapeutic use of colistin-chloramphenicol for infections caused by colistin-resistant E. cloacae.

  9. Antibiotic Resistance in Severe Orofacial Infections.

    Science.gov (United States)

    Kim, Min Kyoung; Chuang, Sung-Kiang; August, Meredith

    2017-05-01

    This study assessed the antibiotic resistance profile in patients with severe orofacial infections treated at a single institution from 2009 through 2014. Factors contributing to resistance were studied. The resistance profile was compared with that of a cohort of similar patients treated a decade previously to identify changes in antibiotic resistance. In addition, the effect of antibiotic resistance on in-hospital course was studied. This was a 5-year retrospective cohort study. Patients were identified through the oral and maxillofacial surgery data registry. Inclusion criteria were patients treated for orofacial infection requiring hospital admission, surgical drainage, and availability of complete medical, surgical, and microbiological data. Patients with incomplete data or treated as outpatients or nonsurgically were excluded. Sixty patient charts were identified for review. Demographic data; medical, dental, and surgical histories; and hospital course and treatment specifics were obtained for each patient. Linear regression and logistic analyses were used to analyze the data. Men composed 60% of the cohort (mean age, 45 yr). Average hospital stay was 5.5 days. Penicillin resistance was found in 32.5% of aerobic isolates and clindamycin resistance was found in 29.3%. Streptococcus viridans and Staphylococcus species showed increased resistance to clindamycin and erythromycin compared with historic controls. Younger patient age, surgical history, and number of cultured aerobes showed a relevant correlation to antibiotic resistance. The need for changes in antibiotics, repeat surgical drainage, and increased serum urea nitrogen levels correlated with longer hospital stay. A serious increase in clindamycin and erythromycin resistance was found for S viridans and Staphylococcus species. Age, surgical history, and number of cultured aerobes showed a statistically meaningful correlation to antibiotic resistance. Presence of antibiotic resistance failed to show

  10. Linking microbial community structure and function to characterize antibiotic resistant bacteria and antibiotic resistant genes from cattle feces

    Science.gov (United States)

    There is widespread interest in monitoring the development of antibiotic resistant bacteria and antibiotic resistance genes in agriculturally impacted environments, however little is known about the relationships between bacterial community structure, and antibiotic resistance gene profiles. Cattl...

  11. Metal Resistance and Its Association With Antibiotic Resistance.

    Science.gov (United States)

    Pal, Chandan; Asiani, Karishma; Arya, Sankalp; Rensing, Christopher; Stekel, Dov J; Larsson, D G Joakim; Hobman, Jon L

    2017-01-01

    Antibiotic resistance is recognised as a major global threat to public health by the World Health Organization. Currently, several hundred thousand deaths yearly can be attributed to infections with antibiotic-resistant bacteria. The major driver for the development of antibiotic resistance is considered to be the use, misuse and overuse of antibiotics in humans and animals. Nonantibiotic compounds, such as antibacterial biocides and metals, may also contribute to the promotion of antibiotic resistance through co-selection. This may occur when resistance genes to both antibiotics and metals/biocides are co-located together in the same cell (co-resistance), or a single resistance mechanism (e.g. an efflux pump) confers resistance to both antibiotics and biocides/metals (cross-resistance), leading to co-selection of bacterial strains, or mobile genetic elements that they carry. Here, we review antimicrobial metal resistance in the context of the antibiotic resistance problem, discuss co-selection, and highlight critical knowledge gaps in our understanding. © 2017 Elsevier Ltd. All rights reserved.

  12. 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......, 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...

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

    Science.gov (United States)

    Tazzyman, Samuel J; Hall, Alex R

    2015-01-01

    The long-term persistence of antibiotic-resistant bacteria depends on their fitness relative to other genotypes in the absence of drugs. Outside the laboratory, viruses that parasitize bacteria (phages) are ubiquitous, but costs of antibiotic resistance are typically studied in phage-free experimental conditions. We used a mathematical model and experiments with Escherichia coli to show that lytic phages strongly affect the incidence of antibiotic resistance in drug-free conditions. Under 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. PMID:25268496

  14. Antibiotic resistance: are we all doomed?

    Science.gov (United States)

    Collignon, P

    2015-11-01

    Antibiotic resistance is a growing and worrying problem associated with increased deaths and suffering for people. Overall, there are only two factors that drive antimicrobial resistance, and both can be controlled. These factors are the volumes of antimicrobials used and the spread of resistant micro-organisms and/or the genes encoding for resistance. The One Health concept is important if we want to understand better and control antimicrobial resistance. There are many things we can do to better control antimicrobial resistance. We need to prevent infections. We need to have better surveillance with good data on usage patterns and resistance patterns available across all sectors, both human and agriculture, locally and internationally. We need to act on these results when we see either inappropriate usage or resistance levels rising in bacteria that are of concern for people. We need to ensure that food and water sources do not spread multi-resistant micro-organisms or resistance genes. We need better approaches to restrict successfully what and how antibiotics are used in people. We need to restrict the use of 'critically important' antibiotics in food animals and the entry of these drugs into the environment. We need to ensure that 'One Health' concept is not just a buzz word but implemented. We need to look at all sectors and control not only antibiotic use but also the spread and development of antibiotic resistant bacteria - both locally and internationally. © 2015 Royal Australasian College of Physicians.

  15. Mechanisms of antibiotic resistance in enterococci

    Science.gov (United States)

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

    2015-01-01

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

  16. 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.

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

    Science.gov (United States)

    Watkins, Richard R; Bonomo, Robert A

    2016-06-01

    The rapid and ongoing spread of antibiotic resistance poses a serious threat to global public health. The indiscriminant use of antibiotics in agriculture and human medicine along with increasingly connected societies has fueled the distribution of antibiotic-resistant bacteria. These factors together have led to rising numbers of infections caused by multidrug-resistant and pan-resistant bacteria, with increases in morbidity and mortality. This article summarizes the trends in antibiotic resistance, discusses the impact of antibiotic resistance on society, and reviews the use of antibiotics in agriculture. Feasible ways to tackle antibiotic resistance to avert a post-antibiotic era are suggested. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Antibiotic residues and resistance in the environment

    NARCIS (Netherlands)

    Pikkemaat, M.G.; Yassin, H.; Fels-Klerkx, H.J.; Berendsen, B.J.A.

    2016-01-01

    Antibiotic usage has benefited the animal industry and helped providing affordable animal proteins to the growing human population. However, since extensive use of antibiotics results in the inhibition of susceptible organisms while selecting for the resistant ones, agricultural use is contributing

  19. Klebsiella pneumoniae antibiotic resistance identified by atomic ...

    Indian Academy of Sciences (India)

    In particular, we studied Klebsiella pneumoniae bacteria provided by the Lavagna Hospital ASL4Liguria (Italy), where there are cases linked with antibiotics resistance of the Klebsiella pneumoniae. By comparing AFMimages of bacteria strains treated with different antibiotics is possible to identify unambiguously the ...

  20. Klebsiella pneumoniae antibiotic resistance identified by atomic ...

    Indian Academy of Sciences (India)

    In the last decade the detection of the resistance of bacteria to antibiotics treatment, developed by different kind of bacteria,is becoming a huge problem. We hereby present a different approach to the current problem of detection of bacteriaresistance to antibiotics. Our aims were to use the atomic force microscopy (AFM) to ...

  1. 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...

  2. Antibiotic Resistance: MedlinePlus Health Topic

    Science.gov (United States)

    ... GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Health Topics → Antibiotic Resistance URL of this page: https://medlineplus.gov/antibioticresistance. ...

  3. Molecular analysis and antibiotic resistance investigation of ...

    African Journals Online (AJOL)

    Molecular analysis and antibiotic resistance investigation of Staphylococcus aureus isolates associated with staphylococcal food poisoning and nosocomial infections. Y Zhang, S Cheng, G Ding, M Zhu, X Pan, L Zhang ...

  4. minimising antibiotic resistance to staphylococcus aureus

    African Journals Online (AJOL)

    2002-11-02

    (26). Prevention of emergence of antibiotic resistance during treatment is therefore an important goal when prescribing antimicrobials. Problems affecting the operation of laboratories at the peripheral level are widespread.

  5. Transfer of Antibiotic Resistance in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Haaber, Jakob; Penadés, José R; Ingmer, Hanne

    2017-01-01

    Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic...... of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen. Staphylococcus aureus cells...... are effective in exchanging mobile genetic elements, including antibiotic-resistance genes.During colonization or infection of host organisms, the exchange appears to be particularly effective.Bacteriophage-mediated transfer involves both transduction and autotransduction, which may enable lysogenic S. aureus...

  6. 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

  7. 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…

  8. 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...

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

    Science.gov (United States)

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

    2012-06-01

    By screening cultures of soil bacteria, we re-discovered an old antibiotic (nybomycin) as an antibiotic with a novel feature. Nybomycin is active against quinolone-resistant Staphylococcus aureus strains with mutated gyrA genes but not against those with intact gyrA genes against which quinolone antibiotics are effective. Nybomycin-resistant mutant strains were generated from a quinolone-resistant, nybomycin-susceptible, vancomycin-intermediate S. aureus (VISA) strain Mu 50. The mutants, occurring at an extremely low rate (generation), were found to have their gyrA genes back-mutated and to have lost quinolone resistance. Here we describe nybomycin as the first member of a novel class of antibiotics designated 'reverse antibiotics'. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  10. Antibiotic-Resistance Genes in Waste Water.

    Science.gov (United States)

    Karkman, Antti; Do, Thi Thuy; Walsh, Fiona; Virta, Marko P J

    2018-03-01

    Waste water and waste water treatment plants can act as reservoirs and environmental suppliers of antibiotic resistance. They have also been proposed to be hotspots for horizontal gene transfer, enabling the spread of antibiotic resistance genes between different bacterial species. Waste water contains antibiotics, disinfectants, and metals which can form a selection pressure for antibiotic resistance, even in low concentrations. Our knowledge of antibiotic resistance in waste water has increased tremendously in the past few years with advances in the molecular methods available. However, there are still some gaps in our knowledge on the subject, such as how active is horizontal gene transfer in waste water and what is the role of the waste water treatment plant in the environmental resistome? The purpose of this review is to briefly describe some of the main methods for studying antibiotic resistance in waste waters and the latest research and main knowledge gaps on the issue. In addition, some future research directions are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Convergent acquisition of antibiotic resistance determinants ...

    African Journals Online (AJOL)

    Convergent acquisition of antibiotic resistance determinants amongst the Enterobacteriaceae isolates of the Mhlathuze River, KwaZulu-Natal (RSA) ... The possibility of transmission of resistant genes between bacteria (especially pathogenic) which invade human and animal populations within this river poses a health risk ...

  12. Antibiotic resistance profiles of environmental isolates from ...

    African Journals Online (AJOL)

    ... resistance in the environment. The strong correlation (r=0.97) between the ARPs of the clinical and the environmental isolates may suggest a link between diarrhoeal incidence and the water quality in the region. It is thus imperative that the determination of antibiotic susceptibility/resistance patterns of isolated microbes is ...

  13. Antibiotic Resistance of Bacteria: A Global Challenge

    Indian Academy of Sciences (India)

    vealed several aminoglycoside resistances in nonculturable bac- teria. Notwithstanding the availability of so many antimicrobial agents, infectious diseases still remain the second leading cause of death worldwide. Eventually, the widespread occurrence of antibiotic-resistant bacteria has added a new dimension to the.

  14. Antibiotic Resistance of Bacteria: A Global Challenge

    Indian Academy of Sciences (India)

    provided a distinct advantage to the physicians in controlling bacterial infections. Discovery of streptomycin, the ... resistance to virtually all the therapeutically useful antibiotics had been evidenced. Emergence of ..... Genomic tools are helping us to select for antibacterial targets and understand bacterial resistance. On the ...

  15. Antibiotic resistance and pathogenicity factors in Staphylococcus ...

    Indian Academy of Sciences (India)

    Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of. S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic ...

  16. Prevalence of nasopharyngeal antibiotic-Resistant pneumococcal ...

    African Journals Online (AJOL)

    Conclusion: Pneumococcal resistance was significant in this group of children with easy access to paediatric services and antibiotic use. The implication of such high resistance for the treatment of pneumococcal diseases is that high-dose amoxicillin is the preferred empirical oral therapy for treatment of otitis media.

  17. Antibiotic resistance and pathogenicity factors in Staphylococcus ...

    Indian Academy of Sciences (India)

    Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic ...

  18. Antibiotic Resistance and the Biology of History.

    Science.gov (United States)

    Landecker, Hannah

    2016-12-01

    Beginning in the 1940s, mass production of antibiotics involved the industrial-scale growth of microorganisms to harvest their metabolic products. Unfortunately, the use of antibiotics selects for resistance at answering scale. The turn to the study of antibiotic resistance in microbiology and medicine is examined, focusing on the realization that individual therapies targeted at single pathogens in individual bodies are environmental events affecting bacterial evolution far beyond bodies. In turning to biological manifestations of antibiotic use, sciences fathom material outcomes of their own previous concepts. Archival work with stored soil and clinical samples produces a record described here as 'the biology of history': the physical registration of human history in bacterial life. This account thus foregrounds the importance of understanding both the materiality of history and the historicity of matter in theories and concepts of life today.

  19. Microbial resistance to antibiotics | Chinedum | African Journal of ...

    African Journals Online (AJOL)

    Microbial resistance to antibiotics. ... African Journal of Biotechnology ... Microorganisms develop resistance to antibiotics by any of the following mechanisms: selection, mutation, phage transduction, and transference while microbial resistance can either be inherent in the organism or acquired through the environment.

  20. Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam

    Science.gov (United States)

    Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J.; Stålsby Lundborg, Cecilia

    2017-01-01

    The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the blaTEM gene being more common than blaCTX-M. Co-harbouring of the blaCTX-M, blaTEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs. PMID:28661465

  1. Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam.

    Science.gov (United States)

    Lien, La Thi Quynh; Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia

    2017-06-29

    The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla TEM gene being more common than bla CTX-M . Co-harbouring of the bla CTX-M , bla TEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.

  2. Genomic and metagenomic diversity of antibiotic resistance in dairy animals

    Science.gov (United States)

    Antibiotic resistance in food animals has received increased scrutiny in recent years due to the increased prevalence of antibiotic resistant infections in the human clinical setting. The extent to which antibiotic usage in food animals is responsible for the burden of antibiotic resistance in human...

  3. The determinants of the antibiotic resistance process

    OpenAIRE

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

    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...

  4. 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.

  5. 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.

  6. Does antifouling paint select for antibiotic resistance?

    Science.gov (United States)

    Flach, Carl-Fredrik; Pal, Chandan; Svensson, Carl Johan; Kristiansson, Erik; Östman, Marcus; Bengtsson-Palme, Johan; Tysklind, Mats; Larsson, D G Joakim

    2017-07-15

    There is concern that heavy metals and biocides contribute to the development of antibiotic resistance via co-selection. Most antifouling paints contain high amounts of such substances, which risks turning painted ship hulls into highly mobile refuges and breeding grounds for antibiotic-resistant bacteria. The objectives of this study were to start investigate if heavy-metal based antifouling paints can pose a risk for co-selection of antibiotic-resistant bacteria and, if so, identify the underlying genetic basis. Plastic panels with one side painted with copper and zinc-containing antifouling paint were submerged in a Swedish marina and biofilms from both sides of the panels were harvested after 2.5-4weeks. DNA was isolated from the biofilms and subjected to metagenomic sequencing. Biofilm bacteria were cultured on marine agar supplemented with tetracycline, gentamicin, copper sulfate or zinc sulfate. Biofilm communities from painted surfaces displayed lower taxonomic diversity and enrichment of Gammaproteobacteria. Bacteria from these communities showed increased resistance to both heavy metals and tetracycline but not to gentamicin. Significantly higher abundance of metal and biocide resistance genes was observed, whereas mobile antibiotic resistance genes were not enriched in these communities. In contrast, we found an enrichment of chromosomal RND efflux system genes, including such with documented ability to confer decreased susceptibility to both antibiotics and biocides/heavy metals. This was paralleled by increased abundances of integron-associated integrase and ISCR transposase genes. The results show that the heavy metal-based antifouling paint exerts a strong selection pressure on marine bacterial communities and can co-select for certain antibiotic-resistant bacteria, likely by favoring species and strains carrying genes that provide cross-resistance. Although this does not indicate an immediate risk for promotion of mobile antibiotic resistance, the

  7. Distribution of antibiotic resistance in urban watershed in Japan

    International Nuclear Information System (INIS)

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

    2012-01-01

    Antibiotic-resistant E. coli concentrations showed large spatial and temporal variations, with greater concentrations observed in tributaries and downstream than in the upstream and midstream. Twenty percent of the geometric mean concentrations of antibiotic-resistant E. coli in the Tama River basin (Japan) exceeded the maximum acceptable concentration of indicator E. coli established by the USEPA. The indicator E. coli concentrations were positively correlated with those of antibiotic-resistant E. coli and multiple-antibiotic-resistant E. coli (resistance to more than two kinds of antibiotics), respectively, but not the detection rate of antibiotic-resistant E. coli, implying that use of antibiotic-resistant E. coli concentration rather than the detection rate can be a better approach for water quality assessment. Multiple-antibiotic-resistant E. coli is a useful indicator for estimating the resistance diffusion, water quality degradation and public health risk potential. This assessment provides beneficial information for setting national regulatory or environmental standards and managing integrated watershed areas. - Highlights: ► We extensively observed antibiotic-resistant E. coli (AREc) in Tama River (Japan). ► AREc count rather than the detection rate is better approach for water quality test. ► Multiple-AREc is resistant to the antibiotic to which single-AREc has no resistance. ► Multiple-AREc increase will accelerate the diffusion of antibiotic resistance. - Multiple-antibiotic-resistant E. coli in the watershed can cause the diffusion of conventionally rare antibiotic resistance.

  8. Low Prevalence of Carbapenem-Resistant Bacteria in River Water: Resistance Is Mostly Related to Intrinsic Mechanisms.

    Science.gov (United States)

    Tacão, Marta; Correia, António; Henriques, Isabel S

    2015-10-01

    Carbapenems are last-resort antibiotics to handle serious infections caused by multiresistant bacteria. The incidence of resistance to these antibiotics has been increasing and new resistance mechanisms have emerged. The dissemination of carbapenem resistance in the environment has been overlooked. The main goal of this research was to assess the prevalence and diversity of carbapenem-resistant bacteria in riverine ecosystems. The presence of frequently reported carbapenemase-encoding genes was inspected. The proportion of imipenem-resistant bacteria was on average 2.24 CFU/ml. Imipenem-resistant strains (n=110) were identified as Pseudomonas spp., Stenotrophomonas maltophilia, Aeromonas spp., Chromobacterium haemolyticum, Shewanella xiamenensis, and members of Enterobacteriaceae. Carbapenem-resistant bacteria were highly resistant to other beta-lactams such as quinolones, aminoglycosides, chloramphenicol, tetracyclines, and sulfamethoxazole/trimethoprim. Carbapenem resistance was mostly associated with intrinsically resistant bacteria. As intrinsic resistance mechanisms, we have identified the blaCphA gene in 77.3% of Aeromonas spp., blaL1 in all S. maltophilia, and blaOXA-48-like in all S. xiamenensis. As acquired resistance mechanisms, we have detected the blaVIM-2 gene in six Pseudomonas spp. (5.45%). Integrons with gene cassettes encoding resistance to aminoglycosides (aacA and aacC genes), trimethoprim (dfrB1b), and carbapenems (blaVIM-2) were found in Pseudomonas spp. Results suggest that carbapenem resistance dissemination in riverine ecosystems is still at an early stage. Nevertheless, monitoring these aquatic compartments for the presence of resistance genes and its host organisms is essential to outline strategies to minimize resistance dissemination.

  9. Antibiotic policies and control of resistance.

    Science.gov (United States)

    Gould, Ian M

    2002-08-01

    The current worldwide pandemic of antibiotic resistance shows no signs of abating. It is clear that it is driven mainly by heavy and often inappropriate antibiotic use. Although control measures are widely practised, it is important that we assess their efficacy critically in order to concentrate expensive control efforts where they will be most effective. The past year has seen much activity in this area, with evidence-based assessments of the literature according to strict guidelines, as well as progress in basic science studies of mechanisms of resistance, and their causes and relations to pathogenicity and adaptability. The present review summarizes current developments in the causes of antibiotic resistance, the classification of antibiotic stewardship and control measures, the evidence base for their efficacy, current problems in hospital practice, the adaptability of bacteria, the content of antibiotic policies and anticipated activities. The conclusions from the published literature are that much of it that pertains to changing prescribing practices does not stand up to modern evidence-based analysis concepts. Nevertheless, we can learn from experience in changing other areas of medical practice. We must be pragmatic and must not expect to change the world, but rather take it step by step, recognizing barriers and measuring outcomes and quality indicators. Studies into the molecular basis of resistance confirm the superb genetic adaptability of micro-organisms. They will always be several steps ahead of us. Nevertheless, we are learning how to modify our prescribing habits to minimize resistance, not only by using antibiotics less frequently but also by altering dosing schedules in various ways.

  10. Plasmid profile of multi antibiotic resistant staphylococcus aureus ...

    African Journals Online (AJOL)

    Multi-drug resistant bacterial strains evolving worldwide has created a great public health problem that needs urgent attention; as such bacteria show resistance to the drug of choice for treatment as well as being resistant to newer and last line antibiotics. In this study, the antibiotic susceptibility, multi antibiotic resistance ...

  11. Antibiotic resistance patterns and beta-lactamase identification in ...

    African Journals Online (AJOL)

    Background. Antibiotic resistance is a growing problem worldwide. Mechanisms of resistance vary, and some can confer resistance to multiple classes of antibiotics. Objective. To characterise the antibiotic resistance profiles of Escherichia coli isolates obtained from stool samples of young rural children exposed or ...

  12. 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

  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

    2016-02-16

    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.

  14. [Staphylococcus aureus and antibiotic resistance].

    Science.gov (United States)

    Sancak, Banu

    2011-07-01

    After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed.

  15. Resensitizing Resistant Bacteria to Antibiotics

    Science.gov (United States)

    2011-04-01

    Next, we added the phage displaying #39 or a randomized version of #39 to growing staphylococci and showed that #39, but not the randomized...synergy with oxacillin against methicillin-resistant staphylococci as well as synergy with vancomycin against vancomycin-resistant staphylococci . We...below in Task 3).   2 Task 3. Test top binding display phage against whole staphylococci . (months 7-9) Despite being covalently attached to a

  16. Antibiotic Cycling and Antibiotic Mixing: Which One Best Mitigates Antibiotic Resistance?

    Science.gov (United States)

    Peña-Miller, Rafael; Gori, Fabio; Iredell, Jonathan

    2017-01-01

    Abstract Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as “antibiotic cycling” and “antibiotic mixing.” However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to “cycle” between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic. Key words: antibiotic cycling, antibiotic mixing, optimal control, stochastic models. PMID:28096304

  17. Antibiotic Cycling and Antibiotic Mixing: Which One Best Mitigates Antibiotic Resistance?

    Science.gov (United States)

    Beardmore, Robert Eric; Peña-Miller, Rafael; Gori, Fabio; Iredell, Jonathan

    2017-04-01

    Can we exploit our burgeoning understanding of molecular evolution to slow the progress of drug resistance? One role of an infection clinician is exactly that: to foresee trajectories to resistance during antibiotic treatment and to hinder that evolutionary course. But can this be done at a hospital-wide scale? Clinicians and theoreticians tried to when they proposed two conflicting behavioral strategies that are expected to curb resistance evolution in the clinic, these are known as "antibiotic cycling" and "antibiotic mixing." However, the accumulated data from clinical trials, now approaching 4 million patient days of treatment, is too variable for cycling or mixing to be deemed successful. The former implements the restriction and prioritization of different antibiotics at different times in hospitals in a manner said to "cycle" between them. In antibiotic mixing, appropriate antibiotics are allocated to patients but randomly. Mixing results in no correlation, in time or across patients, in the drugs used for treatment which is why theorists saw this as an optimal behavioral strategy. So while cycling and mixing were proposed as ways of controlling evolution, we show there is good reason why clinical datasets cannot choose between them: by re-examining the theoretical literature we show prior support for the theoretical optimality of mixing was misplaced. Our analysis is consistent with a pattern emerging in data: neither cycling or mixing is a priori better than the other at mitigating selection for antibiotic resistance in the clinic. : antibiotic cycling, antibiotic mixing, optimal control, stochastic models. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Photodynamic inactivation of antibiotic-resistant pathogens

    International Nuclear Information System (INIS)

    Paronyan, M.H.

    2015-01-01

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

  19. Antibiotic resistance in Candida albicans and Staphylococcus ...

    African Journals Online (AJOL)

    Nowadays, vaginal candidiasis and bacterial vaginosis are frequently encountered in medical practice and antibiotic resistance in implicated pathogens has not been reported in Dschang. This study sought to determine the antimicrobial susceptibility patterns of 198 isolates of Candida albicans and 300 strains of ...

  20. Antibiotic resistance properties of uropathogenic Escherichia coli ...

    African Journals Online (AJOL)

    Purpose: To investigate the antibiotic resistance pattern of uropathogenic Escherichia coli (UPEC) strains isolated from pregnant women with history of recurrent urinary tract infections (RUTIs) and healthy pregnant women. Methods: A total of 485 high vaginal swab specimens were collected from pregnant women with ...

  1. Antibiotic resistance properties of uropathogenic Escherichia coli ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch), Scopus, ..... and Argentina [28]. CONCLUSION. As far as we know, the present study is the first prevalence report on antibiotic resistance pattern of UPEC strains in ... serogroups profiles of uropathogenic Escherichia coli isolated ...

  2. Antibiotics resistance of Stenotrophomonas maltophilia strains ...

    African Journals Online (AJOL)

    Introduction. Stenotrophomonas maltophilia is a resistant pathogen that can cause bacteremia, endocarditis, respiratory system, central nervous system and urinary tract infections in patients with risk factors like malignancy or neutrope- nia, use of broad-spectrum antibiotics like carbapenem or long-term hospitalization1,2.

  3. [Resistance of Pseudomonas aeruginosa to antibiotics].

    Science.gov (United States)

    Wolska, Katarzyna; Kot, Barbara; Piechota, Małgorzata; Frankowska, Aneta

    2013-12-16

    The main problem in the treatment of nosocomial infections is the increasing drug resistance of microorganisms that cause them, limiting the number of effective antibiotics. Pseudomonas aeruginosa bacilli are the cause of many serious hospital-acquired infections occurring primarily in patients within high-risk groups. The most vulnerable are those with weakened immune systems, as well as those with extensive surgical wounds and burn wounds. Infections are usually of the nature of secondary infections, caused by multidrug strains. Due to the high antimicrobial activity, beta-lactams, aminoglycosides and quinolones are drugs commonly used in hospitals, both in prevention and treatment of infections with P. aeruginosa. However, their irrational use is associated with selection and spread of strains resistant to these antibiotics. Resistance of P. aeruginosa to antibiotics is the result of a number of independent co-occurring mechanisms. These are: reducing the membrane permeability, the efflux system, and production of enzymes inactivating and degrading antibiotics. The paper devotes special attention to the determination of resistance mechanisms responsible for this phenomenon.

  4. Carriage rates, circulating serotypes and antibiotic resistance ...

    African Journals Online (AJOL)

    The carriage of Streptococcus pneumoniae, serotypes, antimicrobial susceptibility patterns and disease development are poorly understood in Yei. Availability of affordable antibiotics over the counter, lack of laboratory infrastructure and high rates of penicillin resistance have the potential to aggravate rates of childhood ...

  5. 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

  6. Prevalence and antibiotic resistance patterns of methicillin-resistant ...

    African Journals Online (AJOL)

    Prevalence and antibiotic resistance patterns of methicillin-resistant Staphylococcus aureus in raw milk and soft cheese (wara) sold in Abeokuta, Nigeria. ... (100%), ampicillin 16 (94.1%), doxycycline 11 (64.7%), tetracycline 17 (100%), oxacillin 15 (88.2%), augmentin 17 (100%), gentamycin 15 (88.2%), colistin 15 (88.2%), ...

  7. Nanotransformation of Vancomycin Overcomes the Intrinsic Resistance of Gram-Negative Bacteria.

    Science.gov (United States)

    Fernandes, Margarida M; Ivanova, Kristina; Hoyo, Javier; Pérez-Rafael, Sílvia; Francesko, Antonio; Tzanov, Tzanko

    2017-05-03

    The increased emergence of antibiotic-resistant bacteria is a growing public health concern, and although new drugs are constantly being sought, the pace of development is slow compared with the evolution and spread of multidrug-resistant species. In this study, we developed a novel broad-spectrum antimicrobial agent by simply transforming vancomycin into nanoform using sonochemistry. Vancomycin is a glycopeptide antibiotic largely used for the treatment of infections caused by Gram-positive bacteria but inefficient against Gram-negative species. The nanospherization extended its effect toward Gram-negative Escherichia coli and Pseudomonas aeruginosa, making these bacteria up to 10 and 100 times more sensitive to the antibiotic, respectively. The spheres were able to disrupt the outer membranes of these bacteria, overcoming their intrinsic resistance toward glycopeptides. The penetration of nanospheres into a Langmuir monolayer of bacterial membrane phospholipids confirmed the interaction of the nanoantibiotic with the membrane of E. coli cells, affecting their physical integrity, as further visualized by scanning electron microscopy. Such mechanism of antibacterial action is unlikely to induce mutations in the evolutionary conserved bacterial membrane, therefore reducing the possibility of acquiring resistance. Our results indicated that the nanotransformation of vancomycin could overcome the inherent resistance of Gram-negative bacteria toward this antibiotic and disrupt mature biofilms at antibacterial-effective concentrations.

  8. Antibiotic Resistance in Children with Bloody Diarrhea

    Directory of Open Access Journals (Sweden)

    Hamedi Abdolkarim

    2009-05-01

    Full Text Available Shigellosis is an important public health problem, especially in developing countries. Antibiotic treatment of bacterial dysentery, aimed at resolving diarrhea or reducing its duration is especially indicated whenever malnutrition is present. First-line drugs include ampicillin and trimethoprim sulfamethoxazole(TMP-SMX; however multidrug-resistance has occurred and careful antibiotic selection must be considered in prescribing .When epidemiologic data indicate a rise in resistancy, fluoroquinolones may be used in adults and oral third-generation cephalosporins and nalidixic acid in children. All children (n=2400 with acute diarrhea who were admitted to the Pediatric department of Dr.sheykh Hospital Mashhad, Iran from March 2004 to March 2005 were selected and their stool culture were obtained, then positive cultures (312 cases,13% were evaluated by antibiogram. This study showed that in heavily populated areas of IRAN like Mashhad, 97% shigella strain isolated from children with bloody diarrhea were sensitive to nalidixic acid, ciprofloxacin and cefixime and rarely susceptible to ampicillin and cotrimoxazole. There is increasing resistance of Shigella to most of the antibiotics in use, and for this reason, careful selection of antibiotics must use considered in each area. Development and use of new drugs are expensive and have severe limitations in the third world. Simple prophylactic alternatives are therefore, required, such as awareness of hygienic child care practices and early promotion of breast feeding. For treatment of shigellosis in infants Ceftriaxon, and in children Nalidixic Acid is recommended.

  9. 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

    Background: There is growing concern worldwide about the role of polluted soil and water environments in the development and dissemination of antibiotic resistance. Objective: Our aim in this study was to identify management options for reducing the spread of antibiotics and antibiotic resistance...... 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...... associated with antibiotic resistance strongly indicate the need for action....

  10. Comparative Analysis Of Antibiotic Resistance And R-Plasmids Of ...

    African Journals Online (AJOL)

    Bacterial resistance to antibiotics constitutes a major cause of failure in the treatment of bacterial infections. The genetic exchange of plasmids containing antibiotic resistant determinants between bacteria is believed to play a critical role in the evolution of antibiotics resistant bacteria and this has been shown in S. aureus.

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

    Directory of Open Access Journals (Sweden)

    Qing-Bin Yuan

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

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

    Science.gov (United States)

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

    2015-01-01

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

  13. A Review on Antibiotic Resistance: Alarm Bells are Ringing.

    Science.gov (United States)

    Zaman, Sojib Bin; Hussain, Muhammed Awlad; Nye, Rachel; Mehta, Varshil; Mamun, Kazi Taib; Hossain, Naznin

    2017-06-28

    Antibiotics are the 'wonder drugs' to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged. The aim of this review is to explore the origin, development, and the current state of antibiotic resistance, regulation, and challenges by examining available literature. We found that antibiotic resistance is increasing at an alarming rate. A growing list of infections i.e., pneumonia, tuberculosis, and gonorrhea are becoming harder and at times impossible to treat while antibiotics are becoming less effective. Antibiotic-resistant infections correlate with the level of antibiotic consumption. Non-judicial use of antibiotics is mostly responsible for making the microbes resistant. The antibiotic treatment repertoire for existing or emerging hard-to-treat multidrug-resistant bacterial infections is limited, resulting in high morbidity and mortality report. This review article reiterates the optimal use of antimicrobial medicines in human and animal health to reduce antibiotic resistance. Evidence from the literature suggests that the knowledge regarding antibiotic resistance in the population is still scarce. Therefore, the need of educating patients and the public is essential to fight against the antimicrobial resistance battle.

  14. Assessment of Antibiotic Resistant Commensal Bacteria in Food

    National Research Council Canada - National Science Library

    Lehman, Mark

    2006-01-01

    .... Although antibiotic resistance (AR) in foodborne pathogens has been studied extensively, the contribution of foodborne commensals in disseminating the resistance genes has been neglected in the past...

  15. Optimal use of antibiotic resistance surveillance systems.

    Science.gov (United States)

    Critchley, I A; Karlowsky, J A

    2004-06-01

    Increasing concern about the emergence of resistance in clinically important pathogens has led to the establishment of a number of surveillance programmes to monitor the true extent of resistance at the local, regional and national levels. Although some programmes have been operating for several years, their true usefulness is only now being realised. This review describes some of the major surveillance initiatives and the way in which the data have been used in a number of different settings. In the hospital, surveillance data have been used to monitor local antibiograms and determine infection control strategies and antibiotic usage policies. In the community, surveillance data have been used to monitor public health threats, such as infectious disease outbreaks involving resistant pathogens and the effects of bioterrorism countermeasures, by following the effects of prophylactic use of different antibiotics on resistance. Initially, the pharmaceutical industry sponsored surveillance programmes to monitor the susceptibility of clinical isolates to marketed products. However, in the era of burgeoning resistance, many developers of antimicrobial agents find surveillance data useful for defining new drug discovery and development strategies, in that they assist with the identification of new medical needs, allow modelling of future resistance trends, and identify high-profile isolates for screening the activity of new agents. Many companies now conduct pre-launch surveillance of new products to benchmark activity so that changes in resistance can be monitored following clinical use. Surveillance data also represent an integral component of regulatory submissions for new agents and, together with clinical trial data, are used to determine breakpoints. It is clear that antibiotic resistance surveillance systems will continue to provide valuable data to health care providers, university researchers, pharmaceutical companies, and government and regulatory agencies.

  16. [State-of-the-art status on airborne antibiotic resistant bacteria and antibiotic resistance genes].

    Science.gov (United States)

    Li, J; Yao, M S

    2018-04-06

    The world is facing more deaths due to increasing antibiotic-resistant bacterial infections and the shortage of new highly effective antibiotics, however the air media as its important transmission route has not been adequately studied. Based on the latest literature acquired in this work, we have discussed the state-of-the-art research progress of the concentration, distribution and spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in different environmental air media, and also analyzed some future prevention and control measures. The large use of antibiotics in the medical settings and animal husbandry places has resulted in higher abundances of ARB and ARGs in the relevant and surrounding atmosphere than in urban and general indoor air environments. ARGs can be spread by adhering to airborne particles, and researchers have also found that air media contain more abundant ARGs than other environmental media such as soil, water and sediment. It was suggested in this review that strengthening the monitoring, study on spreading factors and biological toxicity, and also research and development on pathogen accurate diagnosis and new green antibiotic are expected to help effectively monitor, prevent and control of the impacts of airborne resistant bacteria and resistance genes on both human and ecologies.

  17. A Review on Antibiotic Resistance: Alarm Bells are Ringing

    OpenAIRE

    Zaman, Sojib Bin; Hussain, Muhammed Awlad; Nye, Rachel; Mehta, Varshil; Mamun, Kazi Taib; Hossain, Naznin

    2017-01-01

    Antibiotics are the ?wonder drugs? to combat microbes. For decades, multiple varieties of antibiotics have not only been used for therapeutic purposes but practiced prophylactically across other industries such as agriculture and animal husbandry. Uncertainty has arisen, as microbes have become resistant to common antibiotics while the host remains unaware that antibiotic resistance has emerged. The aim of this review is to explore the origin, development, and the current state of antibiotic ...

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

    Science.gov (United States)

    Lupo, Agnese; Coyne, Sébastien; Berendonk, Thomas Ulrich

    2012-01-01

    The environment, and especially freshwater, constitutes a reactor where the evolution and the rise of new resistances occur. In water bodies such as waste water effluents, lakes, and rivers or streams, bacteria from different sources, e.g., 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 resistances 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. We assume that further knowledge is needed to better understand the role of the environment as reservoir of antibiotic resistances and to elucidate the link between environmental pollution by anthropogenic pressures and emergence of antibiotic resistances. Only an integrated vision of these two aspects can provide elements to assess the risk of spread of antibiotic resistances via water bodies and suggest, in this context, solutions for this urgent health issue.

  19. Banning antibiotics, reducing resistance, preventing and fighting infections : White paper on research enabling an 'antibiotic-free' animal husbandry

    OpenAIRE

    Kimman, T.G.; Smits, M.A.; Kemp, B.; Wever, P.; Verheijden, J.

    2010-01-01

    Resistance of bacteria to antibiotics in animal husbandry is increasing and a point of growing concern. The large use of antibiotics in agriculture undoubtedly leads to the development of antibiotic resistance. This has resulted in a growing public concern on the rise of antibiotic resistance, and in particular on the transmission of resistant bacteria and resistance markers from animals to humans. Large antibiotic use in animal husbandry and antibiotic resistance threatens the health and wel...

  20. Cooperative Antibiotic Resistance in a Multi-Drug Environment

    Science.gov (United States)

    Yurtsev, Eugene; Dai, Lei; Gore, Jeff

    2013-03-01

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

  1. Diversity and Antibiotic Resistance Patterns of Sphingomonadaceae Isolates from Drinking Water▿

    Science.gov (United States)

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

    2011-01-01

    Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water. PMID:21705522

  2. Diversity and antibiotic resistance patterns of Sphingomonadaceae isolates from drinking water.

    Science.gov (United States)

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

    2011-08-15

    Sphingomonadaceae (n = 86) were isolated from a drinking water treatment plant (n = 6), tap water (n = 55), cup fillers for dental chairs (n = 21), and a water demineralization filter (n = 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis of atpD gene sequence analysis. The isolates were identified as members of the genera Sphingomonas (n = 27), Sphingobium (n = 28), Novosphingobium (n = 12), Sphingopyxis (n = 7), and Blastomonas (n = 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the genera Sphingomonas and Sphingobium and for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the genera Sphingomonas and Sphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the family Sphingomonadaceae are potential reservoirs of antibiotic resistance in drinking water.

  3. 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

  4. Antibiotic resistance status of Escherichia coli isolated from healthy ...

    African Journals Online (AJOL)

    The research revealed a high level of antibiotic resistance among E. coli. The percentage of resistance observed for the antibiotics included in this study reflected the degree of their respective uses in pig production in the study area. This work further supports the need for prudent use of each of the antibiotics in animal ...

  5. Action and resistance mechanisms of antibiotics: A guide for clinicians

    Directory of Open Access Journals (Sweden)

    Garima Kapoor

    2017-01-01

    Full Text Available Infections account for a major cause of death throughout the developing world. This is mainly due to the emergence of newer infectious agents and more specifically due to the appearance of antimicrobial resistance. With time, the bacteria have become smarter and along with it, massive imprudent usage of antibiotics in clinical practice has resulted in resistance of bacteria to antimicrobial agents. The antimicrobial resistance is recognized as a major problem in the treatment of microbial infections. The biochemical resistance mechanisms used by bacteria include the following: antibiotic inactivation, target modification, altered permeability, and “bypass” of metabolic pathway. Determination of bacterial resistance to antibiotics of all classes (phenotypes and mutations that are responsible for bacterial resistance to antibiotics (genetic analysis are helpful. Better understanding of the mechanisms of antibiotic resistance will help clinicians regarding usage of antibiotics in different situations. This review discusses the mechanism of action and resistance development in commonly used antimicrobials.

  6. Bacterial Cheating Limits the Evolution of Antibiotic Resistance

    Science.gov (United States)

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

    2012-02-01

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

  7. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    Science.gov (United States)

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

    2015-09-29

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

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

    Science.gov (United States)

    Berglund, Björn

    2015-01-01

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

  9. ENTEROCOCCI AND THEIR RESISTANCE TO ANTIBIOTICS AND THYME ESSENTIAL OIL

    OpenAIRE

    Viera Ducková; Margita Čanigová; Miroslav Kročko

    2014-01-01

    Enterococci are important part of microflora of food animal origin. They have positive (probiotic effect, production flavor compounds during food ripening) and also negative (production biogenic amine, antibiotic resistance, biofilm production) properties. The aim of this work was to determine resistance to different concentrations of thyme essential oil and antibiotic resistance of enterococci isolated from pork (n=3) and poultry (n=17). The antibiotic resistance of isolates was determined b...

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

    DEFF Research Database (Denmark)

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

    2003-01-01

    Antibiotic-resistant bacteria were first identified in the 1940s, but while new antibiotics were being discovered at a steady rate, the consequences of this phenomenon were slow to be appreciated. Today, the excessive use of antibiotics compounded by the paucity of new agents on the market has...... meant the problem of antibiotic resistance is fast escalating into a global health crisis. There is no doubt that misuse of these drugs in human beings has contributed to the increasing rates of resistance, but recently the use of antibiotics in food animals and its consequent effect on resistance....... There is a growing concern over the transmission of resistant bacteria via the food chain. Many questions will be difficult to resolve, such as how do you distinguish the fraction of resistance in human beings that originated from animals? If we wait to see evidence that a significant amount of antibiotic resistance...

  11. Assessment of antibiotic resistance in Klebsiella pneumoniae exposed to sequential in vitro antibiotic treatments

    OpenAIRE

    Kim, Jeongjin; Jo, Ara; Chukeatirote, Ekachai; Ahn, Juhee

    2016-01-01

    Background Bacteria treated with different classes of antibiotics exhibit changes in susceptibility to successive antibiotic treatments. This study was designed to evaluate the influence of sequential antibiotic treatments on the development of antibiotic resistance in Klebsiella pneumoniae associated with ?-lactamase and efflux pump activities. Methods The antibiotic susceptibility, ?-lactamase activity, and efflux activity were determined in K. pneumoniae grown at 37??C by adding initial (0...

  12. 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...

  13. 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

  14. Surgical Antibiotic Prophylaxis and Risk for Postoperative Antibiotic-Resistant Infections.

    Science.gov (United States)

    Cohen, Margot E; Salmasian, Hojjat; Li, Jianhua; Liu, Jianfang; Zachariah, Philip; Wright, Jason D; Freedberg, Daniel E

    2017-11-01

    Antibiotic-resistant infections have high rates of morbidity and mortality, and exposure to antibiotics is the crucial risk factor for development of antibiotic resistance. If surgical antibiotic prophylaxis (SAP) increases risk for antibiotic-resistant infections, prophylaxis may cause net harm, even if it decreases overall infection rates. This retrospective cohort study included adults who underwent elective surgical procedures and developed infections within 30 postoperative days. Procedures from multiple disciplines were included if SAP was considered discretionary by current guidelines. Postoperative antibiotic-resistant infections were defined as positive culture results from any site within 30 postoperative days, showing intermediate or nonsusceptibility across 1 or more antibiotic classes. Surgical antibiotic prophylaxis included use of antibiotics within any class and at any dose from 1 hour before first incision until the end of the operation. Among 689 adults with postoperative infections, 338 (49%) had postoperative resistant infections. Use of SAP was not associated with postoperative antibiotic-resistant infections (odds ratio [OR] 0.99; 95% CI 0.67 to 1.46). This result remained robust when the SAP definition was extended to antibiotics given within 4 hours before first incision (OR 0.94; 95% CI 0.63 to 1.40) and when the follow-up window was narrowed to 14 days (OR 0.82; 95% CI 0.50 to 1.34). Previous antibiotic-resistant infections were associated with risk for postoperative antibiotic-resistant infections (OR 1.81; 95% CI 1.16 to 2.83). Use of SAP was not associated with risk for postoperative antibiotic-resistant infections in a large cohort of patients with postoperative infections. This provides important reassurance regarding use of surgical antibiotic prophylaxis. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Comparative Genomics of Environmental and Clinical Stenotrophomonas maltophilia Strains with Different Antibiotic Resistance Profiles.

    Science.gov (United States)

    Youenou, Benjamin; Favre-Bonté, Sabine; Bodilis, Josselin; Brothier, Elisabeth; Dubost, Audrey; Muller, Daniel; Nazaret, Sylvie

    2015-08-14

    Stenotrophomonas maltophilia, a ubiquitous Gram-negative γ-proteobacterium, has emerged as an important opportunistic pathogen responsible for nosocomial infections. A major characteristic of clinical isolates is their high intrinsic or acquired antibiotic resistance level. The aim of this study was to decipher the genetic determinism of antibiotic resistance among strains from different origins (i.e., natural environment and clinical origin) showing various antibiotic resistance profiles. To this purpose, we selected three strains isolated from soil collected in France or Burkina Faso that showed contrasting antibiotic resistance profiles. After whole-genome sequencing, the phylogenetic relationships of these 3 strains and 11 strains with available genome sequences were determined. Results showed that a strain's phylogeny did not match their origin or antibiotic resistance profiles. Numerous antibiotic resistance coding genes and efflux pump operons were revealed by the genome analysis, with 57% of the identified genes not previously described. No major variation in the antibiotic resistance gene content was observed between strains irrespective of their origin and antibiotic resistance profiles. Although environmental strains generally carry as many multidrug resistant (MDR) efflux pumps as clinical strains, the absence of resistance-nodulation-division (RND) pumps (i.e., SmeABC) previously described to be specific to S. maltophilia was revealed in two environmental strains (BurA1 and PierC1). Furthermore the genome analysis of the environmental MDR strain BurA1 showed the absence of SmeABC but the presence of another putative MDR RND efflux pump, named EbyCAB on a genomic island probably acquired through horizontal gene transfer. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Characterization of Antibiotic Resistance Genes from Lactobacillus Isolated from Traditional Dairy Products.

    Science.gov (United States)

    Guo, Huiling; Pan, Lin; Li, Lina; Lu, Jie; Kwok, Laiyu; Menghe, Bilige; Zhang, Heping; Zhang, Wenyi

    2017-03-01

    Lactobacilli are widely used as starter cultures or probiotics in yoghurt, cheese, beer, wine, pickles, preserved food, and silage. They are generally recognized as safe (GRAS). However, recent studies have shown that some lactic acid bacteria (LAB) strains carry antibiotic resistance genes and are resistant to antibiotics. Some of them may even transfer their intrinsic antibiotic resistance genes to other LAB or pathogens via horizontal gene transfer, thus threatening human health. A total of 33 Lactobacillus strains was isolated from fermented milk collected from different areas of China. We analyzed (1) their levels of antibiotic resistance using a standardized dilution method, (2) their antibiotic resistance gene profiles by polymerase chain reaction (PCR) using gene-specific primers, and (3) the transferability of some of the detected resistance markers by a filter mating assay. All Lactobacillus strains were found to be resistant to vancomycin, but susceptible to gentamicin, linezolid, neomycin, erythromycin, and clindamycin. Their susceptibilities to tetracycline, kanamycin, ciprofloxacin, streptomycin, quinupristin/dalfopristin, trimethoprim, ampicillin, rifampicin, and chloramphenicol was different. Results from our PCR analysis revealed 19 vancomycin, 10 ciprofloxacin, and 1 tetracycline-resistant bacteria that carried the van(X), van(E), gyr(A), and tet(M) genes, respectively. Finally, no transferal of the monitored antibiotic resistance genes was observed in the filter mating assay. Taken together, our study generated the antibiotic resistance profiles of some milk-originated lactobacilli isolates and preliminarily assessed their risk of transferring antibiotic gene to other bacteria. The study may provide important data concerning the safe use of LAB. © 2017 Institute of Food Technologists®.

  17. 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

    Antibiotic resistance develops in zoonotic bacteria in response to antibiotics used in food animals. A close association exists between the amounts of antibiotics used and the levels of resistance observed. The classes of antibiotics routinely used for treatment of human infections are also used...... for animals either for therapy or for growth promotion. Antibiotic resistance in zoonotic bacteria constitute a public health hazard, primarily through the increased risk of treatment failures. This paper describes the zoonotic bacteria, salmonella, campylobacter, yersinia and enterohaemorrhagic E. coli (EHEC......). 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...

  18. 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.

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

    OpenAIRE

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

    2016-01-01

    Understanding fate of antibiotic resistant bacteria (ARB) versus their antibiotic resistance genes (ARGs) during wastewater sludge treatment is critical in order to reduce the spread of antibiotic resistance through process optimization. Here, we spiked high concentrations of tetracycline-resistant bacteria, isolated from mesophilic (Iso M1-1- a Pseudomonas sp.) and thermophilic (Iso T10- a Bacillus sp.) anaerobic digested sludge, into batch digesters and monitored their fate by plate counts ...

  20. Genetic Mechanisms of Antibiotic Resistance and the Role of Antibiotic Adjuvants.

    Science.gov (United States)

    Pontes, Daniela Santos; de Araujo, Rodrigo Santos Aquino; Dantas, Natalina; Scotti, Luciana; Scotti, Marcus Tullius; de Moura, Ricardo Olimpio; Mendonca-Junior, Francisco Jaime Bezerra

    2018-01-01

    The ever increasing number of multidrug-resistant microorganism pathogens has become a great and global public health threat. Antibiotic mechanisms of action and the opposing mechanisms of resistance are intimately associated, but comprehension of the biochemical and molecular functions of such drugs is not a simple exercise. Both the environment, and genetic settings contribute to alterations in phenotypic resistance (natural bacterial evolution), and make it difficult to control the emergence and impacts of antibiotic resistance. Under such circumstances, comprehension of how bacteria develop and/or acquire antibiotic resistance genes (ARG) has a critical role in developing propositions to fight against these superbugs, and to search for new drugs. In this review, we present and discuss both general information and examples of common genetic and molecular mechanisms related to antibiotic resistance, as well as how the expression and interactions of ARGs are important to drug resistance. At the same time, we focus on the recent achievements in the search for antibiotic adjuvants, which help combat antibiotic resistance through deactivation of bacterial mechanisms of action such as β-lactamases. Recent advances involving the use of anti-resistance drugs such as: efflux pump inhibitors; anti-virulence drugs; drugs against quorum sensing; and against type II/III secretion systems are revealed. Such antibiotic adjuvants (as explored herein) collaborate against the problems of antibiotic resistance, and may restore or prolong the therapeutic activity of known antibiotics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. 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

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

    Science.gov (United States)

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

    2015-09-01

    Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are emerging contaminants of environmental concern. Heterotrophic bacteria in activated sludge have an important role in wastewater treatment plants (WWTPs). However, the fate of cultivable heterotrophic ARB and ARGs in WWPTs process remains unclear. In the present study, we investigated the antibiotic-resistant phenotypes of cultivable heterotrophic bacteria from influent and effluent water of three WWTPs and analysed thirteen ARGs in ARB and in activated sludge from anoxic, anaerobic and aerobic compartments. From each influent or effluent sample of the three plants, 200 isolates were randomly tested for susceptibility to 12 antibiotics. In these samples, between 5% and 64% isolates showed resistance to >9 antibiotics and the proportion of >9-drug-resistant bacteria was lower in isolates from effluent than from influent. Eighteen genera were identified in 188 isolates from influent (n=94) and effluent (n=94) of one WWTP. Six genera (Aeromonas, Bacillus, Lysinibacillus, Microbacterium, Providencia, and Staphylococcus) were detected in both influent and effluent samples. Gram-negative and -positive isolates dominated in influent and effluent, respectively. The 13 tetracycline-, sulphonamide-, streptomycin- and β-lactam-resistance genes were detected at a higher frequency in ARB from influent than from effluent, except for sulA and CTX-M, while in general, the abundances of ARGs in activated sludge from two of the three plants were higher in aerobic compartments than in anoxic ones, indicating abundant ARGs exit in the excess sledges and/or in uncultivable bacteria. These findings may be useful for elucidating the effect of WWTP on ARB and ARGs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Antibiotic resistance in community-acquired urinary tract infections

    African Journals Online (AJOL)

    the treatment of other infections would inevitably lead to the development of resistance. S Afr Med J 1994; 84: 600-602. Antibiotic resistance is a major problem in developing countries.' There are many reasons for this, including antibiotic use in animal feeds, inappropriate prescribing and poor sanitation. Resistance rates in ...

  5. Genomic and metagenomic analysis of antibiotic resistance in dairy animals

    Science.gov (United States)

    The extent to which carriage of antibiotic resistant bacteria in food animals is responsible for the burden of antibiotic resistance in human infections is currently not well known. Thus, there is a need to further evaluate the genomic diversity of multidrug resistant (MDR) bacteria and the microbi...

  6. Antibiotic resistance trends and mechanisms in the foodborne pathogen, Campylobacter.

    Science.gov (United States)

    Tang, Yizhi; Fang, Liangxing; Xu, Changyun; Zhang, Qijing

    2017-11-23

    Campylobacter is a major foodborne pathogen and is commonly present in food producing animals. This pathogenic organism is highly adaptable and has become increasingly resistant to various antibiotics. Recently, both the Centers for Disease Control and Prevention and the World Health Organization have designated antibiotic-resistant Campylobacter as a serious threat to public health. For the past decade, multiple mechanisms conferring resistance to clinically important antibiotics have been described in Campylobacter, and new resistance mechanisms constantly emerge in the pathogen. Some of the recent examples include the erm(B) gene conferring macrolide resistance, the cfr(C) genes mediating resistance to florfenicol and other antimicrobials, and a functionally enhanced variant of the multidrug resistance efflux pump, CmeABC. The continued emergence of new resistance mechanisms illustrates the extraordinary adaptability of Campylobacter to antibiotic selection pressure and demonstrate the need for innovative strategies to control antibiotic-resistant Campylobacter. In this review, we will briefly summarize the trends of antibiotic resistance in Campylobacter and discuss the mechanisms of resistance to antibiotics used for animal production and important for clinical therapy in humans. A special emphasis will be given to the newly discovered antibiotic resistance.

  7. Antibiotic Resistance Patterns of Common Gram-negative ...

    African Journals Online (AJOL)

    Background: The resistance of bacteria causing urinary tract infection (UTI) to commonly prescribed antibiotics is increasing both in developing and developed countries. Resistance has emerged even to more potent antimicrobial agents. This study was undertaken to determine the current antibiotic resistance pattern ...

  8. Sequence-Specific Targeting of Bacterial Resistance Genes Increases Antibiotic Efficacy.

    Science.gov (United States)

    Ayhan, Dilay Hazal; Tamer, Yusuf Talha; Akbar, Mohammed; Bailey, Stacey M; Wong, Michael; Daly, Seth M; Greenberg, David E; Toprak, Erdal

    2016-09-01

    The lack of effective and well-tolerated therapies against antibiotic-resistant bacteria is a global public health problem leading to prolonged treatment and increased mortality. To improve the efficacy of existing antibiotic compounds, we introduce a new method for strategically inducing antibiotic hypersensitivity in pathogenic bacteria. Following the systematic verification that the AcrAB-TolC efflux system is one of the major determinants of the intrinsic antibiotic resistance levels in Escherichia coli, we have developed a short antisense oligomer designed to inhibit the expression of acrA and increase antibiotic susceptibility in E. coli. By employing this strategy, we can inhibit E. coli growth using 2- to 40-fold lower antibiotic doses, depending on the antibiotic compound utilized. The sensitizing effect of the antisense oligomer is highly specific to the targeted gene's sequence, which is conserved in several bacterial genera, and the oligomer does not have any detectable toxicity against human cells. Finally, we demonstrate that antisense oligomers improve the efficacy of antibiotic combinations, allowing the combined use of even antagonistic antibiotic pairs that are typically not favored due to their reduced activities.

  9. Sequence-Specific Targeting of Bacterial Resistance Genes Increases Antibiotic Efficacy

    Science.gov (United States)

    Wong, Michael; Daly, Seth M.; Greenberg, David E.; Toprak, Erdal

    2016-01-01

    The lack of effective and well-tolerated therapies against antibiotic-resistant bacteria is a global public health problem leading to prolonged treatment and increased mortality. To improve the efficacy of existing antibiotic compounds, we introduce a new method for strategically inducing antibiotic hypersensitivity in pathogenic bacteria. Following the systematic verification that the AcrAB-TolC efflux system is one of the major determinants of the intrinsic antibiotic resistance levels in Escherichia coli, we have developed a short antisense oligomer designed to inhibit the expression of acrA and increase antibiotic susceptibility in E. coli. By employing this strategy, we can inhibit E. coli growth using 2- to 40-fold lower antibiotic doses, depending on the antibiotic compound utilized. The sensitizing effect of the antisense oligomer is highly specific to the targeted gene’s sequence, which is conserved in several bacterial genera, and the oligomer does not have any detectable toxicity against human cells. Finally, we demonstrate that antisense oligomers improve the efficacy of antibiotic combinations, allowing the combined use of even antagonistic antibiotic pairs that are typically not favored due to their reduced activities. PMID:27631336

  10. Empirical mode decomposition and k-nearest embedding vectors for timely analyses of antibiotic resistance trends.

    Directory of Open Access Journals (Sweden)

    Douglas Teodoro

    Full Text Available BACKGROUND: Antibiotic resistance is a major worldwide public health concern. In clinical settings, timely antibiotic resistance information is key for care providers as it allows appropriate targeted treatment or improved empirical treatment when the specific results of the patient are not yet available. OBJECTIVE: To improve antibiotic resistance trend analysis algorithms by building a novel, fully data-driven forecasting method from the combination of trend extraction and machine learning models for enhanced biosurveillance systems. METHODS: We investigate a robust model for extraction and forecasting of antibiotic resistance trends using a decade of microbiology data. Our method consists of breaking down the resistance time series into independent oscillatory components via the empirical mode decomposition technique. The resulting waveforms describing intrinsic resistance trends serve as the input for the forecasting algorithm. The algorithm applies the delay coordinate embedding theorem together with the k-nearest neighbor framework to project mappings from past events into the future dimension and estimate the resistance levels. RESULTS: The algorithms that decompose the resistance time series and filter out high frequency components showed statistically significant performance improvements in comparison with a benchmark random walk model. We present further qualitative use-cases of antibiotic resistance trend extraction, where empirical mode decomposition was applied to highlight the specificities of the resistance trends. CONCLUSION: The decomposition of the raw signal was found not only to yield valuable insight into the resistance evolution, but also to produce novel models of resistance forecasters with boosted prediction performance, which could be utilized as a complementary method in the analysis of antibiotic resistance trends.

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

    Science.gov (United States)

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

    2016-06-01

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

  12. Antibiotics involved in the occurrence of antibiotic-resistant bacteria: a nationwide multilevel study suggests differences within antibiotic classes.

    Science.gov (United States)

    Gbaguidi-Haore, Houssein; Dumartin, Catherine; L'Hériteau, François; Péfau, Muriel; Hocquet, Didier; Rogues, Anne-Marie; Bertrand, Xavier

    2013-02-01

    To identify the antibiotics potentially the most involved in the occurrence of antibiotic-resistant bacteria from an ecological perspective in French healthcare facilities (HCFs). This study was based on data from the French antimicrobial surveillance network (ATB-RAISIN, 2007-09). Antibiotics were expressed in defined daily doses per 1000 patient-days. Antibiotic-resistant bacteria were considered as count data adjusted for patient-days. These were third-generation cephalosporin (3GC)- and ciprofloxacin-resistant Escherichia coli, cefotaxime-resistant Enterobacter cloacae, methicillin-resistant Staphylococcus aureus and ceftazidime-, imipenem- and ciprofloxacin-resistant Pseudomonas aeruginosa. Three-level negative binomial regression models were built to take into account the hierarchical structure of data: level 1, repeated measures each year (count outcome, time, antibiotics); level 2, HCFs (type and size); and level 3, regions (geographical area). A total of 701 HCFs from 20 French regions and up to 1339 HCF-years were analysed. The use of ceftriaxone, but not of cefotaxime, was positively correlated with incidence rates of 3GC- and ciprofloxacin-resistant E. coli. In contrast, both 3GCs were positively correlated with the incidence rate of cefotaxime-resistant E. cloacae. Higher levels of use of ciprofloxacin and/or ofloxacin, but not of levofloxacin, were associated with higher incidence rates of 3GC- and ciprofloxacin-resistant E. coli, cefotaxime-resistant E. cloacae, methicillin-resistant S. aureus and ceftazidime- and ciprofloxacin-resistant P. aeruginosa. Our study suggests differences within antibiotic classes in promoting antibiotic resistance. We identified ceftriaxone, ciprofloxacin and ofloxacin as priority targets in public health strategies designed to reduce antibiotic use and antibiotic-resistant bacteria in French HCFs.

  13. 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.

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Antibiotic Consumption and Antibiotic Resistance Across Organisms, Drugs, and Consumer Groups

    Science.gov (United States)

    Olesen, Scott; Barnett, Michael; MacFadden, Derek; Lipsitch, Marc; Grad, Yonatan H

    2017-01-01

    Abstract Background Antibiotic consumption is considered a major driver of antibiotic resistance, but it remains unclear whether the consumption–resistance relationship is apparent for many organisms and drugs, and whether aggregate consumption is the best predictor of resistance. Methods We conducted a landscape assessment of the consumption-resistance relationship by comparing a 20% sample of Medicare Part D outpatient antibiotic pharmacy claims with a nationwide survey of hospital antibiotic susceptibility reports. Antibiotic consumption was summarized in individual states and hospital-referral regions (HRRs) using traditional, aggregate consumption or by metrics that account for the concentration of consumption in a few individuals (Gini coefficient). The consumption–resistance relationships for 17 organism–drug combinations were simultaneously evaluated (Spearman’s rho; linear models predicting resistance from aggregate consumption and Gini coefficient) and corrected for multiple-hypothesis testing (Benjamini–Hochberg). Results We identified a significant correlation between aggregate consumption of an antibiotic and an organism’s reported resistance to that antibiotic in only a few cases: quinolones and E. coli (Spearman’s rho = 0.65, adjusted P < 10−4) and E. cloacae (rho = 0.50, adjusted P = 0.006). In other cases, notably E. coli with trimethoprim–sulfamethoxazole, the distribution of antibiotic consumption among consumers has a marginal relationship with antibiotic resistance (−1.0 p.p. resistance per p.p. Gini coefficient of consumption among consumers, unadjusted P < 0.001). Conclusion There is a clear correlation between aggregate consumption of an antibiotic and resistance of an organism to that antibiotic in only a few cases, suggesting that antibiotic steward efforts might maximize their effectiveness by focusing on particular organisms, drugs, and consumer groups rather than overall, aggregate consumption

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

    Directory of Open Access Journals (Sweden)

    Gamze Başbülbül

    2015-06-01

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

  17. Diversity and antibiotic resistance of uropathogenic bacteria from ...

    African Journals Online (AJOL)

    J.-L.A. Moroh

    Abstract. Background: Urinary tract infections (UTI) are one of the major causes of prescribing and antibiotic con- sumption. In order to use the best antibiotic treatment for their patients, reliable and recent data about epidemiology and antibiotic resistance profile of uropathogenic bacteria must be available for clinicians.

  18. Diversity and antibiotic resistance of uropathogenic bacteria from ...

    African Journals Online (AJOL)

    Background: Urinary tract infections (UTI) are one of the major causes of prescribing and antibiotic consumption. In order to use the best antibiotic treatment for their patients, reliable and recent data about epidemiology and antibiotic resistance profile of uropathogenic bacteria must be available for clinicians. Therefore ...

  19. Combating antibiotic resistance - A Policy Roadmap to Reduce Use of Medically Important Antibiotics in Livestock

    DEFF Research Database (Denmark)

    Price, Lance B.; Newland, Jason; Bole, Aparna

    edical and public health organizations around the world agree that more prudent use of antibiotics in human medicine and in livestock production is paramount to slow the spread of antibiotic resistance. Of particular concern is the widespread use of antibiotics important to human medicine in food...... animals. In the U.S., such use accounts for 70% of all sales of medically important antibiotics. It is against this backdrop that 12 antibiotic resistance experts from the fields of infectious disease medicine, veterinary medicine, microbiology, epidemiology and public health joined to craft a policy...... roadmap to help move the U.S. forward in addressing the contribution of livestock antibiotic use to the growing global threat of antibiotic resistance. The policy roadmap consists of 11 core policy recommendations that are aimed at a broad set of stakeholders: federal, state and local policymakers, food...

  20. 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.

  1. 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.

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

    Science.gov (United States)

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

    2011-03-01

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

  3. The evolution of substrate discrimination in macrolide antibiotic resistance enzymes.

    Science.gov (United States)

    Pawlowski, Andrew C; Stogios, Peter J; Koteva, Kalinka; Skarina, Tatiana; Evdokimova, Elena; Savchenko, Alexei; Wright, Gerard D

    2018-01-09

    The production of antibiotics by microbes in the environment and their use in medicine and agriculture select for existing and emerging resistance. To address this inevitability, prudent development of antibiotic drugs requires careful consideration of resistance evolution. Here, we identify the molecular basis for expanded substrate specificity in MphI, a macrolide kinase (Mph) that does not confer resistance to erythromycin, in contrast to other known Mphs. Using a combination of phylogenetics, drug-resistance phenotypes, and in vitro enzyme assays, we find that MphI and MphK phosphorylate erythromycin poorly resulting in an antibiotic-sensitive phenotype. Using likelihood reconstruction of ancestral sequences and site-saturation combinatorial mutagenesis, supported by Mph crystal structures, we determine that two non-obvious mutations in combination expand the substrate range. This approach should be applicable for studying the functional evolution of any antibiotic resistance enzyme and for evaluating the evolvability of resistance enzymes to new generations of antibiotic scaffolds.

  4. Marine bacteria: potential sources for compounds to overcome antibiotic resistance.

    Science.gov (United States)

    Eom, Sung-Hwan; Kim, Young-Mog; Kim, Se-Kwon

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is the most problematic Gram-positive bacterium in the context of public health due to its resistance against almost all available antibiotics except vancomycin and teicoplanin. Moreover, glycopeptide-resistant S. aureus have been emerging with the increasing use of glycopeptides. Recently, resistant strains against linezolid and daptomycin, which are alternative drugs to treat MRSA infection, have also been reported. Thus, the development of new drugs or alternative therapies is clearly a matter of urgency. In response to the antibiotic resistance, many researchers have studied for alternative antibiotics and therapies. In this review, anti-MRSA substances isolated from marine bacteria, with their potential antibacterial effect against MRSA as potential anti-MRSA agents, are discussed and several strategies for overcoming the antibiotic resistance are also introduced. Our objective was to highlight marine bacteria that have potential to lead in developing novel antibiotics or clinically useful alternative therapeutic treatments.

  5. Newly approved antibiotics and antibiotics reserved for resistant infections: Implications for emergency medicine.

    Science.gov (United States)

    Mazer-Amirshahi, Maryann; Pourmand, Ali; May, Larissa

    2017-01-01

    Millions of patients are evaluated every year in the emergency department (ED) for bacterial infections. Emergency physicians often diagnose and prescribe initial antibiotic therapy for a variety of bacterial infections, ranging from simple urinary tract infections to severe sepsis. In life-threatening infections, inappropriate choice of initial antibiotic has been shown to increase morbidity and mortality. As such, initiation of appropriate antibiotic therapy on the part of the emergency physician is critical. Increasing rates of antibiotic resistance, drug allergies, and antibiotic shortages further complicates the choice of antibiotics. Patients may have a history of prior resistant infections or culture data indicating that common first-line antibiotics used in the ED may be ineffective. In recent years, there have been several new antibiotic approvals as well as renewed interest in second and third line antibiotics because of the aforementioned concerns. In addition, several newly approved antibiotics have the advantage of being administered once weekly or even as a single infusion, which has the potential to decrease hospitalizations and healthcare costs. This article reviews newly approved antibiotics and antibiotics used to treat resistant infections with a focus on implications for emergency medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. 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.

  7. Counteracting antibiotic resistance: breaking barriers among antibacterial strategies.

    Science.gov (United States)

    Baquero, Fernando; Coque, Teresa M; Cantón, Rafael

    2014-08-01

    To fight against antibiotic resistance, prevention-only is no longer an acceptable strategy. The old concept 'one-infection, one-bug, one-drug', genocentrism in antibiotic discovery, and lack of integration between different antimicrobial strategies have probably contributed to current weaknesses in confronting antibiotic resistance. Resistance should be combatted in all fronts simultaneously, in the patient (complex therapy), the group (where resistance is maintained), and the significant environment (polluted by resistance). This paper is reviewing why specific 'therapeutic' approaches are needed in each of these fronts, using different types of 'drugs' directed to a variety of targets, in the goal of inhibiting antibiotic resistant bacteria. Multi-target integrated combination strategies and therapies should be more extensively evaluated, not only in the infected patient (using novel formats for clinical trials), but as associations of 'therapeutic strategies' in the different compartments where antibiotic resistance emerges and flows (measuring global effects in resistance). Multi-targeted therapeutic approaches require a relaxation of barriers among the various compounds, including systemic and topic antibiotics, antiseptics, biocides, anti-resistant clones vaccination, phages, decontamination products, and in general eco-evo drugs acting on factors influencing ecology and evolution of resistant bacteria. The application of methods of systems biology will facilitate such a multi-lateral attack to antibiotic resistance. Such advances should be paralleled by a simultaneous progress in regulatory sciences and close coordination among all stakeholders.

  8. Antibiotic resistance of Staphylococcus aureus isolated from fresh ...

    African Journals Online (AJOL)

    The resistance pattern of the 55 S. aureus isolates showed that all the isolates were resistant to two or more antibiotics. Multidrug resistance was detected in 96.4% of the isolates. All the S. aureus were resistant to penicillin 55 (100.0%) rates of resistance to ampicillin (90.9%; n=50), tetracycline (81.8%; n=45) and ...

  9. Assessment of Bacterial Antibiotic Resistance Transfer in the Gut

    OpenAIRE

    Susanne Schjørring; Karen A. Krogfelt

    2011-01-01

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

  10. 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.

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

    NARCIS (Netherlands)

    Bell, B.G.; Schellevis, F.; Stobberingh, E.; Goossens, 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

  12. 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

  13. A New Product Development Partnership Model for Antibiotic Resistance.

    Science.gov (United States)

    Billington, John K

    2016-05-01

    Antibiotics have prevented countless deaths from common infections and have made possible many modern medical procedures. Over the past few decades, antibiotic-resistant bacteria have become a global threat, spreading between healthcare facilities and throughout communities worldwide at an alarming pace. Antibiotic overuse and misuse in humans, animals, and the environment accelerate resistance by selecting for bacteria with antibiotic-resistant traits, which then become predominant and infect others. Meanwhile, few antibiotics remain active against the most resistant bacteria. There is an urgent need for new antibiotics and other antibacterial products to replace second-line and last resort therapies when they no longer work. This Article proposes a new U.S.-based, non-governmental, not-for-profit product development partnership (PDP) model specifically designed for antibacterial development. This new model should both supplement and complement existing government-led efforts and should be built with mechanisms in place to balance the values of innovation, access, and conservation.

  14. Overcoming Aminoglycoside Enzymatic Resistance: Design of Novel Antibiotics and Inhibitors

    Directory of Open Access Journals (Sweden)

    Sandra G. Zárate

    2018-01-01

    Full Text Available Resistance to aminoglycoside antibiotics has had a profound impact on clinical practice. Despite their powerful bactericidal activity, aminoglycosides were one of the first groups of antibiotics to meet the challenge of resistance. The most prevalent source of clinically relevant resistance against these therapeutics is conferred by the enzymatic modification of the antibiotic. Therefore, a deeper knowledge of the aminoglycoside-modifying enzymes and their interactions with the antibiotics and solvent is of paramount importance in order to facilitate the design of more effective and potent inhibitors and/or novel semisynthetic aminoglycosides that are not susceptible to modifying enzymes.

  15. Banning antibiotics, reducing resistance, preventing and fighting infections : White paper on research enabling an 'antibiotic-free' animal husbandry

    NARCIS (Netherlands)

    Kimman, T.G.; Smits, M.A.; Kemp, B.; Wever, P.; Verheijden, J.

    2010-01-01

    Resistance of bacteria to antibiotics in animal husbandry is increasing and a point of growing concern. The large use of antibiotics in agriculture undoubtedly leads to the development of antibiotic resistance. This has resulted in a growing public concern on the rise of antibiotic resistance, and

  16. Knowledge of antibiotics and antibiotic resistance in patients followed by family physicians.

    Science.gov (United States)

    Robert, A; Nguyen, Y; Bajolet, O; Vuillemin, B; Defoin, B; Vernet-Garnier, V; Drame, M; Bani-Sadr, F

    2017-03-01

    We aimed to evaluate factors associated with knowledge of antibiotics and drug resistance. A questionnaire was handed out by 14 family physicians to their patients between December 20, 2014 and April 20, 2015 in Rethel (North-East of France). We conducted a cross-sectional study using a logistical regression model to assess factors associated with antibiotic knowledge. Three criteria were used to assess that knowledge. Overall, 293 questionnaires were analysed; 48% of patients had received antibiotics in the previous 12 months. Only 44% and 26% gave a correct answer for the statements "Antibiotics are effective against bacteria and ineffective against viruses" and "Antibiotic resistance decreases if the antibiotic use decreases", respectively. Characteristics such as female sex, age>30 years, high level of education, high professional categories, and having received antibiotic information by the media were associated with high level of knowledge about antibiotics and/or antibiotic resistance. In contrast, having received antibiotic information from family physicians was not associated with good knowledge. Although media awareness campaigns had an independent impact on a higher public knowledge of antibiotics, the overall public knowledge remains low. It would be necessary to strengthen antibiotic campaigns with clearer information on the relation between the excessive use of antibiotics and the increased risk of antibiotic resistance. Family physicians should be more involved to improve antibiotic knowledge among target groups such as men, young patients, and people from a poor social and cultural background. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. 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.

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

    OpenAIRE

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

    2016-01-01

    Antibiotic resistance is a major public health threat, further complicated by unexplained treatment failures caused by bacteria that appear antibiotic susceptible. We describe an Enterobacter cloacae isolate harbouring a minor subpopulation that is highly resistant to the last-line antibiotic colistin. This subpopulation was distinct from persisters, became predominant in colistin, returned to baseline after colistin removal and was dependent on the histidine kinase PhoQ. During murine infect...

  19. 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...

  20. Antibiotic resistance profiles and relatedness of enteric bacterial ...

    African Journals Online (AJOL)

    GREGO

    2007-04-16

    Apr 16, 2007 ... Antibiotic resistance profiles and the correlation of enteric bacterial pathogens from HIV positive indivi- duals with and ... from the various study cohorts showed multiple antibiotic resistance to penicillin, amoxicillin, ampicillin, erythromycin .... chose to work closely with support groups, NGOs and HIV care-.

  1. Comparison of antibiotic resistance patterns between laboratories in ...

    African Journals Online (AJOL)

    Antibiotic resistance is increasing rapidly and developing countries are the worse affected since they provide conditions and practices that support the development and spread of resistant microbes. For better health policy on antibiotic use a national surveillance program is needed to provide baseline data from different ...

  2. 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

  3. The challenges of overcoming antibiotic resistance: Plant extracts as ...

    African Journals Online (AJOL)

    The problem of antibiotic resistance, which has limited the use of cheap and old antibiotics, has necessitated the need for a continued search for new antimicrobial compounds. Understanding the mechanisms of resistance is important in the development of strategies to solving the problem. Active efflux of drugs, alteration of ...

  4. Antibiotic resistance plasmids in wastewater treatment plants and ...

    African Journals Online (AJOL)

    Antibiotic resistance plasmids found in wastewater treatment plants (WWTPs) may represent a threat to public health if they are readily disseminated into the environment and ultimately into pathogenic bacteria. The wastewater environments provide an ideal ecosystem for development and evolution of antibiotic resistance ...

  5. Antibiotic resistance development and identification of response measures

    NARCIS (Netherlands)

    ter Kuile, B.; Brul, S.; Sofos, J.

    2013-01-01

    Antibiotic resistance in human pathogens is becoming a major threat to human health. This is partly due to agriculture, because large amounts of antibiotics are used to treat animals, which encourages resistant genes to appear and transfer to humans through foodstuffs. This is a food safety issue.

  6. Microarray-based Detection of Antibiotic Resisteance Genes in Salmonella

    NARCIS (Netherlands)

    Hoek, van A.H.A.M.; Aarts, H.J.M.

    2008-01-01

    In the presented study, 143 Salmonella isolates belonging to 26 different serovars were screened for the presence of antibiotic resistance genes by microarray analysis. The microarray contained a total of 223 oligonucleotides representing genes encoding for resistance to the following antibiotic

  7. Antibiotic resistance among heterotrophic bacteria in Lagos Lagoon ...

    African Journals Online (AJOL)

    Antibiotic-resistant bacteria in the aquatic environment are considered reservoirs for drug-resistant genes. Therefore, culturable heterotrophic bacteria isolated from Lagos Lagoon surface waters between 2011 and 2012 were screened for their susceptibility to 14 commonly used antibiotics belonging to six major classes.

  8. correlations between antibiotic intake and resistance of some enteric ...

    African Journals Online (AJOL)

    DJFLEX

    2010-06-25

    Jun 25, 2010 ... Bacterial resistance to antibiotics has been attributed to many different factors with emphasis on the widespread use, misuse or overuse of antibiotics. Current thinking has referenced these as providing the selective pressure favouring propagation of resistant organisms (Livermore, 2003). This, however ...

  9. 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...

  10. Antibiotic resistant Staphylococcus aureus in Abia State of Nigeria ...

    African Journals Online (AJOL)

    The S. aureus. isolates varied in their antibiotic susceptibility pattern when tested for their sensitivity to 16 antibiotics. Eighty percent of the isolates were resistant to more than one antimicrobial agent. All the isolates showed resistance to nalidixic acid and 100% sensitivity to rifampicin. Key words: Staphylococcus aureus, ...

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

    Science.gov (United States)

    2014-01-01

    Background Greater use of antibiotics during the past 50 years has exerted selective pressure on susceptible bacteria and may have favoured the survival of resistant strains. Existing information on antibiotic resistance patterns from pathogens circulating among community-based patients is substantially less than from hospitalized patients on whom guidelines are often based. We therefore chose to assess the relationship between the antibiotic resistance pattern of bacteria circulating in the community and the consumption of antibiotics in the community. Methods Both gray literature and published scientific literature in English and other European languages was examined. Multiple regression analysis was used to analyse whether studies found a positive relationship between antibiotic consumption and resistance. A subsequent meta-analysis and meta-regression was conducted for studies for which a common effect size measure (odds ratio) could be calculated. Results Electronic searches identified 974 studies but only 243 studies were considered eligible for inclusion by the two independent reviewers who extracted the data. A binomial test revealed a positive relationship between antibiotic consumption and resistance (p resistance than other regions. Conclusions Using a large set of studies we found that antibiotic consumption is associated with the development of antibiotic resistance. A subsequent meta-analysis, with a subsample of the studies, generated several significant predictors. Countries in southern Europe produced a stronger link between consumption and resistance than other regions so efforts at reducing antibiotic consumption may need to be strengthened in this area. Increased consumption of antibiotics may not only produce greater resistance at the individual patient level but may also produce greater resistance at the community, country, and regional levels, which can harm individual patients. PMID:24405683

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

    Science.gov (United States)

    Hiltunen, Teppo; Virta, Marko; Laine, Anna-Liisa

    2017-01-19

    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'. © 2016 The Authors.

  13. Overexpression of antibiotic resistance genes in hospital effluents over time.

    Science.gov (United States)

    Rowe, Will P M; Baker-Austin, Craig; Verner-Jeffreys, David W; Ryan, Jim J; Micallef, Christianne; Maskell, Duncan J; Pearce, Gareth P

    2017-06-01

    Effluents contain a diverse abundance of antibiotic resistance genes that augment the resistome of receiving aquatic environments. However, uncertainty remains regarding their temporal persistence, transcription and response to anthropogenic factors, such as antibiotic usage. We present a spatiotemporal study within a river catchment (River Cam, UK) that aims to determine the contribution of antibiotic resistance gene-containing effluents originating from sites of varying antibiotic usage to the receiving environment. Gene abundance in effluents (municipal hospital and dairy farm) was compared against background samples of the receiving aquatic environment (i.e. the catchment source) to determine the resistome contribution of effluents. We used metagenomics and metatranscriptomics to correlate DNA and RNA abundance and identified differentially regulated gene transcripts. We found that mean antibiotic resistance gene and transcript abundances were correlated for both hospital ( ρ  = 0.9, two-tailed P  resistance genes ( bla GES and bla OXA ) were overexpressed in all hospital effluent samples. High β-lactam resistance gene transcript abundance was related to hospital antibiotic usage over time and hospital effluents contained antibiotic residues. We conclude that effluents contribute high levels of antibiotic resistance genes to the aquatic environment; these genes are expressed at significant levels and are possibly related to the level of antibiotic usage at the effluent source. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.

  14. 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

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

    Science.gov (United States)

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

    2016-05-09

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

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Combating antibiotic resistance, mitigating future threats and ongoing initiatives.

    Science.gov (United States)

    Velez, Roseann; Sloand, Elizabeth

    2016-07-01

    To emphasise the impact of antibiotic resistance as a persistent, global health threat and highlight efforts to improve this complex problem. Political agendas, legislation, development of therapies and educational initiatives are essential to mitigate the increasing rate of antibiotic resistance. Original manuscript. Prescribers, policymakers and researchers are charged with the complex task of mitigating antibiotic resistance in an era when new treatments for bacterial infections are limited. Monitoring, surveillance and incentivising of practice, policy and new treatments provide solutions to antibiotic resistance in both the human and agricultural sectors. This article emphasises the complexity of antibiotic resistance and highlights the need for a multifaceted approach to improve health care outcomes. © 2016 John Wiley & Sons Ltd.

  18. Community factors in the development of antibiotic resistance.

    Science.gov (United States)

    Larson, Elaine

    2007-01-01

    The global impact of antibiotic resistance is potentially devastating, threatening to set back progress against certain infectious diseases to the pre-antibiotic era. Although most antibiotic-resistant bacteria originally emerged in hospitals, drug-resistant strains are becoming more common in the community. Factors that facilitate the development of resistance within the community can be categorized as behavioral or environmental/policy. Behavioral factors include inappropriate use of antibiotics and ineffective infection control and hygiene practices. Environmental/policy factors include the continued use of antibiotics in agriculture and the lack of new drug development. A multifaceted approach that includes behavioral strategies in the community and the political will to make difficult regulatory decisions will help to minimize the problem of antimicrobial resistance globally.

  19. Probing minority population of antibiotic-resistant bacteria.

    Science.gov (United States)

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

    2016-06-15

    The evolution and spread of antibiotic-resistant pathogens has become a major threat to public health. Advanced tools are urgently needed to quickly diagnose antibiotic-resistant infections to initiate appropriate treatment. Here we report the development of a highly sensitive flow cytometric method to probe minority population of antibiotic-resistant bacteria via single cell detection. Monoclonal antibody against TEM-1 β-lactamase and Alexa Fluor 488-conjugated secondary antibody were used to selectively label resistant bacteria green, and nucleic acid dye SYTO 62 was used to stain all the bacteria red. A laboratory-built high sensitivity flow cytometer (HSFCM) was applied to simultaneously detect the side scatter and dual-color fluorescence signals of single bacteria. By using E. coli JM109/pUC19 and E. coli JM109 as the model systems for antibiotic-resistant and antibiotic-susceptible bacteria, respectively, as low as 0.1% of antibiotic-resistant bacteria were accurately quantified. By monitoring the dynamic population change of a bacterial culture with the administration of antibiotics, we confirmed that under the antimicrobial pressure, the original low population of antibiotic-resistant bacteria outcompeted susceptible strains and became the dominant population after 5hours of growth. Detection of antibiotic-resistant infection in clinical urine samples was achieved without cultivation, and the bacterial load of susceptible and resistant strains can be faithfully quantified. Overall, the HSFCM-based quantitative method provides a powerful tool for the fundamental studies of antibiotic resistance and holds the potential to provide rapid and precise guidance in clinical therapies. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Selective conditions for a multidrug resistance plasmid depend on the sociality of antibiotic resistance"

    OpenAIRE

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

    2016-01-01

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

  1. "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

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

    Directory of Open Access Journals (Sweden)

    Marothi Yogyata

    2010-07-01

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

  3. 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 different countries. DESIGN: Primary antibiotic resistance rates of H pylori were determined from April 2008 to June 2009 in 18 European countries. Data on yearly and cumulative use over several years of systemic antibacterial agents in ambulatory care for the period 2001-8 were expressed in Defined Daily...... Doses (DDD) per 1000 inhabitants per day. The fit of models and the degree of ecological association between antibiotic use and resistance data were assessed using generalised linear mixed models. RESULTS: Of 2204 patients included, H pylori resistance rates for adults were 17.5% for clarithromycin, 14...

  4. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Characterization of antibiotic resistance in Listeria spp. isolated from slaughterhouse environments, pork and human infections.

    Science.gov (United States)

    Moreno, Luisa Z; Paixão, Renata; Gobbi, Débora D S; Raimundo, Daniele C; Ferreira, Thais P; Moreno, Andrea M; Hofer, Ernesto; Reis, Cristhiane M F; Matté, Glavur R; Matté, Maria H

    2014-04-15

    Listeria species are susceptible to most antibiotics. However, over the last decade, increasing reports of multidrug-resistant Listeria spp. from various sources have prompted public health concerns. The objective of this study was to characterize the antibiotic susceptibility of Listeria spp. and the genetic mechanisms that confer resistance. Forty-six Listeria spp. isolates were studied, and their minimal inhibitory concentrations of antibiotics were determined by microdilution using Sensititre standard susceptibility MIC plates. The isolates were screened for the presence of gyrA, parC, lde, lsa(A), lnu(A), and mprF by PCR, and the amplified genes were sequenced. All isolates were susceptible to penicillin, ampicillin, tetracycline, erythromycin, and carbapenems. Resistance to clindamycin, daptomycin, and oxacillin was found among L. monocytogenes and L. innocua, and all species possessed at least intermediate resistance to fluoroquinolones. GyrA, parC, and mprF were detected in all isolates; however, mutations were found only in gyrA sequences. A high daptomycin MIC, as reported previously, was observed, suggesting an intrinsic resistance of Listeria spp. to daptomycin. These results are consistent with reports of emerging resistance in Listeria spp. and emphasize the need for further genotypic characterization of antibiotic resistance in this genus.

  6. Antibiotics: Pharmacokinetics, toxicity, resistance and multidrug efflux pumps.

    Science.gov (United States)

    Yılmaz, Çiğdem; Özcengiz, Gülay

    2017-06-01

    The discovery of penicillin followed by streptomycin, tetracycline, cephalosporins and other natural, semi-synthetic and synthetic antimicrobials completely revolutionized medicine by reducing human morbidity and mortality from most of the common infections. However, shortly after they were introduced to clinical practice, the development of resistance was emerged. The decreasing interest from antibiotic industry in spite of rapid global emergence of antibiotic resistance is a tough dilemma from the pointview of public health. The efficiency of antimicrobial treatment is determined by both pharmacokinetics and pharmacodynamics. In spite of their selective toxicity, antibiotics still cause severe, life-threatening adverse reactions in host body mostly due to defective drug metabolism or excessive dosing regimen. The present article aims at updating current knowledge on pharmacokinetics/pharmacodynamics concepts and models, toxicity of antibiotics as well as antibiotic resistance mechanisms, resistome analyses and search for novel antibiotic resistance determinants with special emphasis given to the-state-of-the-art regarding multidrug efflux pumps and their additional physiological functions in stress adaptation and virulence of bacteria. All these issues are highly linked to each other and not only important for most efficient and prolonged use of current antibiotics, but also for discovery and development of new antibiotics and novel inhibitors of antibiotic resistance determinants of pathogens. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 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.

  8. 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...... of antibiotics, as observed in heavy users, could also be due to factors related to the GP, patient and parents' expectations or the influence exerted by the pharmaceutical industry (2). This article is protected by copyright. All rights reserved....

  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. Copyright © 2016, American Association for the Advancement of Science.

  10. Antibiotic Resistance in Sepsis Patients: Evaluation and Recommendation of Antibiotic Use

    Science.gov (United States)

    Pradipta, Ivan Surya; Sodik, Dian Chairunnisa; Lestari, Keri; Parwati, Ida; Halimah, Eli; Diantini, Ajeng; Abdulah, Rizky

    2013-01-01

    Background: The appropriate selection of empirical antibiotics based on the pattern of local antibiotic resistance can reduce the mortality rate and increase the rational use of antibiotics. Aims: We analyze the pattern of antibiotic use and the sensitivity patterns of antibiotics to support the rational use of antibiotics in patients with sepsis. Materials and Methods: A retrospective observational study was conducted in adult sepsis patient at one of Indonesian hospital during January-December 2011. Data were collected from the hospital medical record department. Descriptive analysis was used in the processing and interpretation of data. Results: A total of 76 patients were included as research subjects. Lung infection was the highest source of infection. In the 66.3% of clinical specimens that were culture positive for microbes, Klebsiella pneumoniae, Escherichia coli, Staphylococcus hominis were detected with the highest frequency. The six most frequently used antibiotics, levofloxacin, ceftazidime, ciprofloxacin, cefotaxime, ceftriaxone, and erythromycin, showed an average resistance above 50%. Conclusions: The high use of antibiotic with a high level resistance requires a policy to support its rational use. Local microbial pattern based on site infection and pattern of antibiotics sensitivity test can be used as supporting data to optimize appropriateness of empirical antibiotics therapy in sepsis patients. PMID:23923107

  11. Mechanisms of Helicobacter pylori antibiotic resistance and molecular testing

    Directory of Open Access Journals (Sweden)

    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. 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.

  13. Plant Agricultural Streptomycin Formulations Do Not Carry Antibiotic Resistance Genes▿

    OpenAIRE

    Rezzonico, Fabio; Stockwell, Virginia O.; Duffy, Brion

    2009-01-01

    Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extracti...

  14. Indirect resistance to several classes of antibiotics in cocultures with resistant bacteria expressing antibiotic-modifying or -degrading enzymes.

    Science.gov (United States)

    Nicoloff, Hervé; Andersson, Dan I

    2016-01-01

    Indirect resistance (IR), the ability of an antibiotic-resistant population of bacteria to protect a susceptible population, has been previously observed for β-lactamase-producing bacteria and associated with antimicrobial treatment failures. Here, we determined whether other resistance determinants could cause IR in the presence of five other classes of antibiotics. A test was designed to detect IR and 14 antibiotic resistance genes were tested in the presence of 13 antibiotics from six classes. A bioassay was used to measure the ability of resistance-causing enzymes to decrease the concentration of active antibiotics in the medium. We confirmed IR in the presence of β-lactam antibiotics (ampicillin and mecillinam) when TEM-1A was expressed. We found that bacteria expressing antibiotic-modifying or -degrading enzymes Ere(A), Tet(X2) or CatA1 caused IR in the presence of macrolides (erythromycin and clarithromycin), tetracyclines (tetracycline and tigecycline) and chloramphenicol, respectively. IR was not observed with resistance determinants that did not modify or destroy antibiotics or with enzymes modifying aminoglycosides or degrading fosfomycin. IR was dependent on the resistance enzymes decreasing the concentration of active antibiotics in the medium, hence allowing nearby susceptible bacteria to resume growth once the antibiotic concentration fell below their MIC. IR was not limited to β-lactamase-producing bacteria, but was also caused by resistant bacteria carrying cytoplasmic antibiotic-modifying or -degrading enzymes that catalyse energy-consuming reactions requiring complex cellular cofactors. Our results suggest that IR is common and further emphasizes that coinfecting agents and the human microflora can have a negative impact during antimicrobial therapy. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Pseudomonas aeruginosa antibiotic resistance in Australian cystic fibrosis centres.

    Science.gov (United States)

    Smith, Daniel J; Ramsay, Kay A; Yerkovich, Stephanie T; Reid, David W; Wainwright, Claire E; Grimwood, Keith; Bell, Scott C; Kidd, Timothy J

    2016-02-01

    In cystic fibrosis (CF), chronic Pseudomonas aeruginosa infection is associated with increased morbidity, antibiotic treatments and mortality. By linking Australian CF registry data with a national microbiological data set, we examined the association between where treatment was delivered, its intensity and P. aeruginosa antibiotic resistance. Sputa were collected from paediatric and adult CF patients attending 18 Australian CF centres. P. aeruginosa antibiotic susceptibilities determined by local laboratories were correlated with clinical characteristics, treatment intensity and infection with strains commonly shared among Australian CF patients. Between-centre differences in treatment and antibiotic resistance were also compared. Large variations in antibiotic usage, maintenance treatment practices and multi-antibiotic resistant P. aeruginosa (MARPA) prevalence exist between Australian CF centres, although the overall proportions of MARPA isolates were similar in paediatric and adult centres (31% vs 35%, P = 0.29). Among paediatric centres, MARPA correlated with intravenous antibiotic usage and the Australian state where treatment was delivered, while azithromycin, reduced lung function and treating state predicted intravenous antibiotic usage. In adult centres, body mass index (BMI) and treating state were associated with MARPA, while intravenous antibiotic use was predicted by gender, BMI, dornase-alpha, azithromycin, lung function and treating state. In adults, P. aeruginosa strains AUST-01 and AUST-02 independently predicted intravenous antibiotic usage. Increased treatment intensity in paediatric centres and the Australian state where treatment was received are both associated with greater risk of MARPA, but not worse clinical outcomes. © 2015 Asian Pacific Society of Respirology.

  16. Antibiotic resistance rates and physician antibiotic prescription patterns of uncomplicated urinary tract infections in southern Chinese primary care

    OpenAIRE

    Wong, Carmen Ka Man; Kung, Kenny; Au-Doung, Philip Lung Wai; Ip, Margaret; Lee, Nelson; Fung, Alice; Wong, Samuel Yeung Shan

    2017-01-01

    Uncomplicated urinary tract infections (UTI) are common in primary care. Whilst primary care physicians are called to be antimicrobial stewards, there is limited primary care antibiotic resistance surveillance and physician antibiotic prescription data available in southern Chinese primary care. The study aimed to investigate the antibiotic resistance rate and antibiotic prescription patterns in female patients with uncomplicated UTI. Factors associated with antibiotic resistance and prescrip...

  17. 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.

  18. Molecular typing of antibiotic-resistant Staphylococcus aureus in Nigeria.

    Science.gov (United States)

    O'Malley, S M; Emele, F E; Nwaokorie, F O; Idika, N; Umeizudike, A K; Emeka-Nwabunnia, I; Hanson, B M; Nair, R; Wardyn, S E; Smith, T C

    2015-01-01

    Antibiotic-resistant Staphylococcus aureus including methicillin-resistant strains (MRSA) are a major concern in densely populated urban areas. Initial studies of S. aureus in Nigeria indicated existence of antibiotic-resistant S. aureus strains in clinical and community settings. 73 biological samples (40 throat, 23 nasal, 10 wound) were collected from patients and healthcare workers in three populations in Nigeria: Lagos University Teaching Hospital, Nigerian Institute of Medical Research, and Owerri General Hospital. S. aureus was isolated from 38 of 73 samples (52%). Of the 38 S. aureus samples, 9 (24%) carried the Panton-Valentine leukocidin gene (PVL) while 16 (42%) possessed methicillin resistance genes (mecA). Antibiotic susceptibility profiles indicated resistance to several broad-spectrum antibiotics. Antibiotic-resistant S. aureus isolates were recovered from clinical and community settings in Nigeria. Insight about S. aureus in Nigeria may be used to improve antibiotic prescription methods and minimize the spread of antibiotic-resistant organisms in highly populated urban communities similar to Lagos, Nigeria. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  19. The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

    Science.gov (United States)

    Plésiat, Patrick

    2015-01-01

    SUMMARY 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. PMID:25788514

  20. 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

    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...... 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...... 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...

  1. 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..

  2. At the Nexus of Antibiotics and Metals: The Impact of Cu and Zn on Antibiotic Activity and Resistance.

    Science.gov (United States)

    Poole, Keith

    2017-10-01

    Environmental influences on antibiotic activity and resistance can wreak havoc with in vivo antibiotic efficacy and, ultimately, antimicrobial chemotherapy. In nature, bacteria encounter a variety of metal ions, particularly copper (Cu) and zinc (Zn), as contaminants in soil and water, as feed additives in agriculture, as clinically-used antimicrobials, and as components of human antibacterial responses. Importantly, there is a growing body of evidence for Cu/Zn driving antibiotic resistance development in metal-exposed bacteria, owing to metal selection of genetic elements harbouring both metal and antibiotic resistance genes, and metal recruitment of antibiotic resistance mechanisms. Many classes of antibiotics also form complexes with metal cations, including Cu and Zn, and this can hinder (or enhance) antibiotic activity. This review highlights the ways in which Cu/Zn influence antibiotic resistance development and antibiotic activity, and in so doing impact in vivo antibiotic efficacy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Better living through chemistry: Addressing emerging antibiotic resistance.

    Science.gov (United States)

    Coussens, Nathan P; Molinaro, Ashley L; Culbertson, Kayla J; Peryea, Tyler; Zahoránszky-Köhalmi, Gergely; Hall, Matthew D; Daines, Dayle A

    2018-03-01

    The increasing emergence of multidrug-resistant bacteria is recognized as a major threat to human health worldwide. While the use of small molecule antibiotics has enabled many modern medical advances, it has also facilitated the development of resistant organisms. This minireview provides an overview of current small molecule drugs approved by the US Food and Drug Administration (FDA) for use in humans, the unintended consequences of antibiotic use, and the mechanisms that underlie the development of drug resistance. Promising new approaches and strategies to counter antibiotic-resistant bacteria with small molecules are highlighted. However, continued public investment in this area is critical to maintain an edge in our evolutionary "arms race" against antibiotic-resistant microorganisms. Impact statement The alarming increase in antibiotic-resistant microorganisms is a rapidly emerging threat to human health throughout the world. Historically, small molecule drugs have played a major role in controlling bacterial infections and they continue to offer tremendous potential in countering resistant organisms. This minireview provides a broad overview of the relevant issues, including the diversity of FDA-approved small molecule drugs and mechanisms of drug resistance, unintended consequences of antibiotic use, the current state of development for small molecule antibacterials and financial challenges that impact progress towards novel therapies. The content will be informative to diverse stakeholders, including clinicians, basic scientists, translational scientists and policy makers, and may be used as a bridge between these key players to advance the development of much-needed therapeutics.

  4. Fitness costs associated with the acquisition of antibiotic resistance.

    Science.gov (United States)

    Hernando-Amado, Sara; Sanz-García, Fernando; Blanco, Paula; Martínez, José L

    2017-02-28

    Acquisition of antibiotic resistance is a relevant problem for human health. The selection and spread of antibiotic-resistant organisms not only compromise the treatment of infectious diseases, but also the implementation of different therapeutic procedures as organ transplantation, advanced surgery or chemotherapy, all of which require proficient methods for avoiding infections. It has been generally accepted that the acquisition of antibiotic resistance will produce a general metabolic burden: in the absence of selection, the resistant organisms would be outcompeted by the susceptible ones. If that was always true, discontinuation of antibiotic use would render the disappearance of resistant microorganisms. However, several studies have shown that, once resistance emerges, the recovery of a fully susceptible population even in the absence of antibiotics is not easy. In the present study, we review updated information on the effect of the acquisition of antibiotic resistance in bacterial physiology as well as on the mechanisms that allow the compensation of the fitness costs associated with the acquisition of resistance. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  5. 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.

  6. 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.

  7. Antibiotic resistance pattern of bacterial isolates in neonatal care unit

    Directory of Open Access Journals (Sweden)

    S Shrestha

    2010-12-01

    Full Text Available INTRODUCTION: Bacterial infections account for a huge proportion of neonatal deaths worldwide. The problem of antibiotic resistance among common bacterial pathogens mainly the gram negative bacteria is emerging globally which is of more serious concern in developing countries like Nepal. METHODS: A one year retrospective hospital based study was carried out to analyze the results of neonatal blood, cerebrospinal fluid, urine, stool and surface cultures and to look into the sensitivity pattern of the commonly used antibiotics. RESULTS: The positive yield of blood, urine, eye swab and CSF cultures were 19.56%, 38.5%, 60% and 0.36% respectively. The most common isolates in the blood culture were coagulase negative Staphylococcus, Acinetobacter, Enterobacter and non-haemolytic Streptococcus. A significant percent of the isolates were resistant to the first line antibiotics. Among the gram negative isolates more than 30% are resistant to cefotaxime and more than 50% are resistant to gentamicin. During the one year period we had Nursery outbreaks of methicillin resistant Staphylococcus aureus and Salmonella infections. With the help of environmental cultures we were able to trace the source and intervene appropriately. CONCLUSIONS: Continuous surveillance for antibiotic susceptibility, rational use of antibiotics and the strategy of antibiotic cycling can provide some answers to the emerging problem of antibiotic resistance.

  8. Antibiotic resistance pattern of bacterial isolates in neonatal care unit.

    Science.gov (United States)

    Shrestha, S; Adhikari, N; Rai, B K; Shreepaili, A

    2010-01-01

    Bacterial infections account for a huge proportion of neonatal deaths worldwide. The problem of antibiotic resistance among common bacterial pathogens mainly the gram negative bacteria is emerging globally which is of more serious concern in developing countries like Nepal. A one year retrospective hospital based study was carried out to analyze the results of neonatal blood, cerebrospinal fluid, urine, stool and surface cultures and to look into the sensitivity pattern of the commonly used antibiotics. The positive yield of blood, urine, eye swab and CSF cultures were 19.56%, 38.5%, 60% and 0.36% respectively. The most common isolates in the blood culture were coagulase negative Staphylococcus, Acinetobacter, Enterobacter and non-haemolytic Streptococcus. A significant percent of the isolates were resistant to the first line antibiotics. Among the gram negative isolates more than 30% are resistant to cefotaxime and more than 50% are resistant to gentamicin. During the one year period we had Nursery outbreaks of methicillin resistant Staphylococcus aureus and Salmonella infections. With the help of environmental cultures we were able to trace the source and intervene appropriately. Continuous surveillance for antibiotic susceptibility, rational use of antibiotics and the strategy of antibiotic cycling can provide some answers to the emerging problem of antibiotic resistance.

  9. Sponge Microbiota are a Reservoir of Functional Antibiotic Resistance Genes

    DEFF Research Database (Denmark)

    Versluis, Dennis; de Evgrafov, Mari Cristina Rodriguez; Sommer, Morten Otto Alexander

    2016-01-01

    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......). Fifteen of 37 inserts harbored resistance genes that shared 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...

  10. Resistance Elasticity of Antibiotic Demand in Intensive Care.

    Science.gov (United States)

    Heister, Thomas; Hagist, Christian; Kaier, Klaus

    2017-07-01

    The emergence and spread of antimicrobial resistance (AMR) is still an unresolved problem worldwide. In intensive care units (ICUs), first-line antibiotic therapy is highly standardized and widely empiric while treatment failure because of AMR often has severe consequences. Simultaneously, there is a limited number of reserve antibiotics, whose prices and/or side effects are substantially higher than first-line therapy. This paper explores the implications of resistance-induced substitution effects in ICUs. The extent of such substitution effects is shown in a dynamic fixed effect regression analysis using a panel of 66 German ICUs with monthly antibiotic use and resistance data between 2001 and 2012. Our findings support the hypothesis that demand for reserve antibiotics substantially increases when resistance towards first-line agents rises. For some analyses the lagged effect of resistance is also significant, supporting the conjecture that part of the substitution effect is caused by physicians changing antibiotic choices in empiric treatment by adapting their resistance expectation to new information on resistance prevalence. The available information about resistance rates allows physicians to efficiently balance the trade-off between exacerbating resistance and ensuring treatment success. However, resistance-induced substitution effects are not free of charge. These effects should be considered an indirect burden of AMR. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Plant agricultural streptomycin formulations do not carry antibiotic resistance genes.

    Science.gov (United States)

    Rezzonico, Fabio; Stockwell, Virginia O; Duffy, Brion

    2009-07-01

    Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extraction procedure, Streptomyces 16S rRNA genes and the streptomycin resistance gene strA were not detected in agricultural streptomycin formulations. This diminishes the likelihood for one potential factor in resistance development due to streptomycin use.

  12. Multiple roles for Enterococcus faecalis glycosyltransferases in biofilm-associated antibiotic resistance, cell envelope integrity, and conjugative transfer.

    Science.gov (United States)

    Dale, Jennifer L; Cagnazzo, Julian; Phan, Chi Q; Barnes, Aaron M T; Dunny, Gary M

    2015-07-01

    The emergence of multidrug-resistant bacteria and the limited availability of new antibiotics are of increasing clinical concern. A compounding factor is the ability of microorganisms to form biofilms (communities of cells encased in a protective extracellular matrix) that are intrinsically resistant to antibiotics. Enterococcus faecalis is an opportunistic pathogen that readily forms biofilms and also has the propensity to acquire resistance determinants via horizontal gene transfer. There is intense interest in the genetic basis for intrinsic and acquired antibiotic resistance in E. faecalis, since clinical isolates exhibiting resistance to multiple antibiotics are not uncommon. We performed a genetic screen using a library of transposon (Tn) mutants to identify E. faecalis biofilm-associated antibiotic resistance determinants. Five Tn mutants formed wild-type biofilms in the absence of antibiotics but produced decreased biofilm biomass in the presence of antibiotic concentrations that were subinhibitory to the parent strain. Genetic determinants responsible for biofilm-associated antibiotic resistance include components of the quorum-sensing system (fsrA, fsrC, and gelE) and two glycosyltransferase (GTF) genes (epaI and epaOX). We also found that the GTFs play additional roles in E. faecalis resistance to detergent and bile salts, maintenance of cell envelope integrity, determination of cell shape, polysaccharide composition, and conjugative transfer of the pheromone-inducible plasmid pCF10. The epaOX gene is located in a variable extended region of the enterococcal polysaccharide antigen (epa) locus. These data illustrate the importance of GTFs in E. faecalis adaptation to diverse growth conditions and suggest new targets for antimicrobial design. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. Antibiotic resistance and ndvB gene expression among biofilm ...

    African Journals Online (AJOL)

    A novel antibiotic resistant mechanism among biofilms is glucan-mediated sequestration in which ndvB gene encodes a glucosyltransferase involved in the formation of this glucans. We studied the biofilm formation and antibiotic susceptibility pattern of P. aeruginosa isolated from clinical samples, and measured the ...

  14. Strategies for the prevention and containment of antibiotic resistance ...

    African Journals Online (AJOL)

    Antibiotic resistance may emerge by antibiotic selection pressure but is perpetuated by diverse risk factors and maintained within environments as a result of poor infection control. Population-specific drug pharmacokinetics and pharmacodynamics also play a role. The WHO, US, UK and EU have initiated strategies for the ...

  15. 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...

  16. 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

    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

  17. Improving our understanding of antibiotic resistance: The relevance ...

    African Journals Online (AJOL)

    management. Clones of E. coli (each bacterial colony emanating from a single genome) were obtained from normal (non-diarrhoeal) stools of young children enrolled in MAL-ED SA, followed by antibiotic susceptibility and minimum inhibitory testing, and detection of genes coding for antibiotic resistance. Worthy of note is ...

  18. [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

  19. Antibiotic Resistance and Virulence Properties in Escherichia coli ...

    African Journals Online (AJOL)

    This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife, Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods.

  20. 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

  1. Genotypic diversity and antibiotic resistance in Sphingomonadaceae isolated from hospital tap water.

    Science.gov (United States)

    Narciso-da-Rocha, Carlos; Vaz-Moreira, Ivone; Manaia, Célia M

    2014-01-01

    The aim of this study was to infer about the modes and extent of dispersion of Sphingomonadaceae via tap water. Sphingomonadaceae isolated from tap water samples in different places of a hospital were compared, based on intra-species genetic variability and antibiotic resistance phenotypes. These isolates were also compared with others isolated before from houses and dental chairs, served by the same municipal water supply system. Sphingomonadaceae from hospital tap water comprised members of the genera Sphingomonas, Sphingobium, Novosphingobium and Blastomonas. In general, distinct genotypes of Sphingomonadaceae were detected in different hospital areas and in tap water outside the hospital, suggesting these bacteria are not persistent or widespread in the urban water distribution system. Possible intrinsic antibiotic resistance, observed in most or all members of the family or of a genus, was observed for colistin in Sphingomonadaceae, aminoglycosides in the genus Blastomonas and beta-lactams in the genus Sphingobium. Possible acquired resistance phenotypes, not common to all members of a given species, comprised fluoroquinolones, cephalosporins and sulphonamides. Although the potential of Sphingomonadaceae as opportunistic pathogens may be low, the capacity of these bacteria to thrive in water supply systems, combined with the intrinsic or acquired antibiotic resistance, may raise the risk associated with their occurrence in hospital tap water. © 2013 Elsevier B.V. All rights reserved.

  2. 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...

  3. Emerging antibiotic resistant enteric bacterial flora among food ...

    African Journals Online (AJOL)

    Bacterial resistance to antibiotic in food animals is an emerging public health concern as a result of increasing multi-resistant bacteria found in Abeokuta. Therefore, occurrence rate and resistant profile of the emerging enteric pathogens were determined in food animals in Abeokuta, Nigeria. Fecal and rectal samples of 82 ...

  4. [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.

  5. Antibiotic resistance in bacterial pathogens causing meningitis in ...

    African Journals Online (AJOL)

    Antibiotic resistance in bacterial pathogens causing meningitis in children at Harare Central Hospital, Zimbabwe. M Gudza-Mugabe, R.T. Mavenyengwa, M.P. Mapingure, S Mtapuri-Zinyowera, A Tarupiwa, V.J. Robertson ...

  6. Preliminary studies on antibiotic-resistant Escherichia coli isolated ...

    African Journals Online (AJOL)

    Preliminary studies on antibiotic-resistant Escherichia coli isolated from cattle and children in the pastoral community of Nyabushozi, Uganda. J Okwee-Acai, S Majalija, SG Okech, MBS Kisaka, J Acon ...

  7. 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. Copyright © 2016. Published by Elsevier Inc.

  8. Mathematical studies on nosocomial spread of antibiotic-resistant bacteria

    NARCIS (Netherlands)

    Gurieva, T.V.

    2017-01-01

    Infections with antibiotic-resistant bacteria are a worldwide problem in hospitals and their rates remain high in many countries despite efforts to reduce the rates. Infection prevention is complicated by asymptomatic carriers. Using mathematical modelling, different intervention strategies were

  9. Antibiotic resistance profiles and relatedness of enteric bacterial ...

    African Journals Online (AJOL)

    Antibiotic resistance profiles and relatedness of enteric bacterial pathogens isolated from HIV/AIDS patients with and without diarrhoea and their household drinking water in rural communities in Limpopo Province South Africa.

  10. Environmental cycle of antibiotic resistance encoded genes: A systematic review

    Directory of Open Access Journals (Sweden)

    R. ghanbari

    2017-12-01

    Full Text Available Antibiotic-resistant bacteria and genes enter the environment in different ways. The release of these factors into the environment has increased concerns related to public health. The aim of the study was to evaluate the antibiotic resistance genes (ARGs in the environmental resources. In this systematic review, the data were extracted from valid sources of information including ScienceDirect, PubMed, Google Scholar and SID. Evaluation and selection of articles were conducted on the basis of the PRISMA checklist. A total of 39 articles were included in the study, which were chosen from a total of 1249 papers. The inclusion criterion was the identification of genes encoding antibiotic resistance against the eight important groups of antibiotics determined by using the PCR technique in the environmental sources including municipal and hospital wastewater treatment plants, animal and agricultural wastes, effluents from treatment plants, natural waters, sediments, and drinking waters. In this study, 113 genes encoding antibiotic resistance to eight groups of antibiotics (beta-lactams, aminoglycosides, tetracyclines, macrolides, sulfonamides, chloramphenicol, glycopeptides and quinolones were identified in various environments. Antibiotic resistance genes were found in all the investigated environments. The investigation of microorganisms carrying these genes shows that most of the bacteria especially gram-negative bacteria are effective in the acquisition and the dissemination of these pollutants in the environment. Discharging the raw wastewaters and effluents from wastewater treatments acts as major routes in the dissemination of ARGs into environment sources and can pose hazards to public health.

  11. 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)

  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...

  13. 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.

  14. Antibiotic resistance of microorganisms in agricultural soils in Russia

    Science.gov (United States)

    Danilova, Natasha; Galitskaya, Polina; Selivanovskaya, Svetlana

    2017-04-01

    Antibiotics are medicines widely used to treat and prevent bacterial infections not only in human medicine but also in veterinary. Besides, in animal husbandry antibiotics are often used in for stimulation of animal's growth. Many antibiotics used for veterinary purposes are weakly absorbed in the animal's gut. So up to 90% of the administered antibiotics are excreted with manure and urine. Therefore use of manure as an organic fertilizer leads to formation and spreading of antibiotic resistance among soil microbes. Another reason of such spreading is the horizontal transfer of genes encoding antibiotic resistance from manure to soil microflora. The level of antibiotic resistance genes pollution of soils has not been properly studied yet. The aim of this study was to estimate the contamination of agricultural soils by antibiotic resistant genes. 30 samples of agricultural soils were selected around of Kazan city (Tatarstan Republic) with 1.3 Mio citizens. Since tetracycline is reported to be the most wide spread veterinary antibiotic in Russia, we estimated the level of soil contamination by tet(X) gene encoding tetracycline decomposition in microbial cell. Real time PCR method with specific primers was used as a method of investigation. Particle size type distribution of 31% of soil samples was estimated to be sandy clay, and 69% of soil samples - to silty clay. Content of dissoluble organic carbon ranged from 0,02 mg g -1 (sample 20) to 0,46 mg g -1 (sample 16). Respiration activity and microbial biomass of soils were estimated to be 0,80-5,28 CO2 C mg g -1 h-1 and 263,51-935,77 µg kg - 1 respectively. The values presented are typical for soils of Tatarstan Republic. In terms of the antibiotic resistant gene content, 27 of 30 samples investigated contained tet(X) gene, while 52% of the samples were highly contaminated, 34% of samples were middle contaminated and 14% of samples - weakly contaminated.

  15. 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; Novoa Reyes, Italo; Crowley, John J; Baker, Laurence H; Xi, Chuanwu

    2017-01-01

    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. 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. 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. 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.

  16. Antibiotic resistance and virulence genes in coliform water isolates.

    Science.gov (United States)

    Stange, C; Sidhu, J P S; Tiehm, A; Toze, S

    2016-11-01

    Widespread fecal pollution of surface water may present a major health risk and a significant pathway for dissemination of antibiotic resistance bacteria. The River Rhine is one of the longest and most important rivers in Europe and an important raw water source for drinking water production. A total of 100 coliform isolates obtained from River Rhine (Germany) were examined for their susceptibility to seven antimicrobial agents. Resistances against amoxicillin, trimethoprim/sulfamethoxazole and tetracycline were detected in 48%, 11% and 9% of isolates respectively. The antibiotic resistance could be traced back to the resistance genes bla TEM , bla SHV , ampC, sul1, sul2, dfrA1, tet(A) and tet(B). Whereby, the ampC gene represents a special case, because its presence is not inevitably linked to a phenotypic antibiotic resistance. Multiple antibiotics resistance was often accompanied by the occurrence of class 1 or 2 integrons. E. coli isolates belonging to phylogenetic groups A and B1 (commensal) were more predominant (57%) compared to B2 and D groups (43%) which are known to carry virulent genes. Additionally, six E. coli virulence genes were also detected. However, the prevalence of virulence genes in the E. coli isolates was low (not exceeding 4.3% per gene) and no diarrheagenic E. coli pathotypes were detected. This study demonstrates that surface water is an important reservoir of ARGs for a number of antibiotic classes such as sulfonamide, trimethoprim, beta-lactam-antibiotics and tetracycline. The occurrence of antibiotic resistance in coliform bacteria isolated from River Rhine provides evidence for the need to develop management strategies to limit the spread of antibiotic resistant bacteria in aquatic environment. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Nanostructured coatings for controlling bacterial biofilms and antibiotic resistance

    OpenAIRE

    Ivanova, Kristina Dimitrova

    2017-01-01

    The accelerated emergence of drug resistant bacteria is one of the most serious problems in healthcare and the difficulties in finding new antibiotics make it even more challenging. To overcome the action of antibiotics bacteria develop effective resistance mechanisms including the formation of biofilms. Biofilms are bacterial communities of cells embedded in a self-produced polymeric matrix commonly found on medical devices such as indwelling catheters. When pathogens adopt this mode of grow...

  18. 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

  19. Antibiotic resistance genes and residual antimicrobials in cattle feedlot surface soil

    Science.gov (United States)

    Cattle feedlot soils receive manure containing both antibiotic residues and antibiotic resistant bacteria. The fates of these constituents are largely unknown with potentially serious consequences for increased antibiotic resistance in the environment. Determine if common antimicrobials (tetracycl...

  20. Children as agents of change in combatting antibiotic resistance.

    Science.gov (United States)

    Molnar, Andreea

    2017-01-01

    Antibiotic resistance is a worldwide problem and changes are needed in the way antibiotics are used. The value of engaging children as key contributors in health care campaigns to increase the appropriate use of antibiotics has not been fully recognized. Little is known about how to design educational materials for children in order to enable them to be agents of change in their communities. Science education needs to improve the way it engages children so as to give them the tools needed to make responsible decisions on antibiotic use.

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

    International Nuclear Information System (INIS)

    Korshunov, V.M.; Pinegin, B.V.; Ivanova, N.P.; Maltsev, V.N.

    1982-01-01

    Elimination of intestinal dysbacteriosis in irradiated animals by combining antibiotics and peparations of bifidobacteria resistant to these antibiotics prolonging the life of these animals was investigated. Broad spectrum antibiotics are used to treat intestinal dysbacteriosis. Bifidobacterial preparations are used to restore the microbial cenosis and their administration is started after antibiotics are discontinued. There are some flaws to deferred administration of bifidobacteria, since the process of colonization of the intestine with commercial bifidobacterial preparations is rather lengthy, and there is slow elevation of bifidobacterium level in the intestinal tract, whereas exogenous recontamination of the intestine by conditionally pathogenic bacteria is possible after antibiotic therapy is discontinued. Use of antibiotics alone could be the cause of intestinal dysbacteriosis

  2. Taxing Meat: Taking Responsibility for One's Contribution to Antibiotic Resistance.

    Science.gov (United States)

    Giubilini, Alberto; Birkl, Patrick; Douglas, Thomas; Savulescu, Julian; Maslen, Hannah

    2017-04-01

    Antibiotic use in animal farming is one of the main drivers of antibiotic resistance both in animals and in humans. In this paper we propose that one feasible and fair way to address this problem is to tax animal products obtained with the use of antibiotics. We argue that such tax is supported both by (a) deontological arguments, which are based on the duty individuals have to compensate society for the antibiotic resistance to which they are contributing through consumption of animal products obtained with the use of antibiotics; and (b) a cost-benefit analysis of taxing such animal products and of using revenue from the tax to fund alternatives to use of antibiotics in animal farming. Finally, we argue that such a tax would be fair because individuals who consume animal products obtained with the use of antibiotics can be held morally responsible, i.e. blameworthy, for their contribution to antibiotic resistance, in spite of the fact that each individual contribution is imperceptible.

  3. 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...

  4. Antibiotic resistance along an urban river impacted by treated wastewaters.

    Science.gov (United States)

    Proia, Lorenzo; Anzil, Adriana; Subirats, Jessica; Borrego, Carles; Farrè, Marinella; Llorca, Marta; Balcázar, Jose Luis; Servais, Pierre

    2018-07-01

    Urban rivers are impacted ecosystems which may play an important role as reservoirs for antibiotic-resistant (AR) bacteria. The main objective of this study was to describe the prevalence of antibiotic resistance along a sewage-polluted urban river. Seven sites along the Zenne River (Belgium) were selected to study the prevalence of AR Escherichia coli and freshwater bacteria over a 1-year period. Culture-dependent methods were used to estimate E. coli and heterotrophic bacteria resistant to amoxicillin, sulfamethoxazole, nalidixic acid and tetracycline. The concentrations of these four antibiotics have been quantified in the studied river. The antibiotic resistance genes (ARGs), sul1, sul2, tetW, tetO, blaTEM and qnrS were also quantified in both particle-attached (PAB) and free-living (FLB) bacteria. Our results showed an effect of treated wastewaters release on the spread of antibiotic resistance along the river. Although an increase in the abundance of both AR E. coli and resistant heterotrophic bacteria was observed from upstream to downstream sites, the differences were only significant for AR E. coli. A significant positive regression was also found between AR E. coli and resistant heterotrophic bacteria. The concentration of ARGs increased from upstream to downstream sites for both particle-attached (PAB) and free-living bacteria (FLB). Particularly, a significant increase in the abundance of four among six ARGs analyzed was observed after crossing urban area. Although concentrations of tetracycline significantly correlated with tetracycline resistance genes, the antibiotic levels were likely too low to explain this correlation. The analysis of ARGs in different fractions revealed a significantly higher abundance in PAB compared to FLB for tetO and sul2 genes. This study demonstrated that urban activities may increase the spread of antibiotic resistance even in an already impacted river. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Intrinsic resistance of Escherichia coli to mureidomycin A and C due to expression of the multidrug efflux system AcrAB-TolC: comparison with the efflux systems of mureidomycin-susceptible Pseudomonas aeruginosa.

    Science.gov (United States)

    Gotoh, Naomasa; Murata, Takeshi; Ozaki, Toru; Kimura, Tadashi; Kondo, Akiko; Nishino, Takeshi

    2003-03-01

    Intrinsic resistance to mureidomycin is shown in Escherichia coli. This is in contrast to Pseudomonas aeruginosa, which generally displays intrinsic resistance to a variety of antimicrobial agents, but not to mureidomycin. Isogenic efflux system mutants from both species were subjected to antibiotic susceptibility tests. These studies showed that the differences regarding the susceptibility of E. coli and P. aeruginosa to mureidomycin A and C may be explained by the expression of efflux systems that mediate resistance to mureidomycin A and C.

  6. Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

    Directory of Open Access Journals (Sweden)

    Youngbeom Ahn

    2016-11-01

    Full Text Available Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl, dodecyldimethylbenzylammonium chloride (C12BDMA-Cl, decyldimethylbenzylammonium chloride (C10BDMA-Cl, hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread.

  7. Investigating antibiotic resistance in non-clinical environments

    Directory of Open Access Journals (Sweden)

    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.

  8. What Can Be Done about Antibiotic Resistance?

    Science.gov (United States)

    ... 300 million to bring a new antibiotic to market. Many efforts to find novel drugs in fungi ... sulbactam are already in use for blocking the beta-lactamase enzymes that destroy the penicillin family of ...

  9. Suppressive drug combinations and their potential to combat antibiotic resistance.

    Science.gov (United States)

    Singh, Nina; Yeh, Pamela J

    2017-11-01

    Antibiotic effectiveness often changes when two or more such drugs are administered simultaneously and unearthing antibiotic combinations with enhanced efficacy (synergy) has been a longstanding clinical goal. However, antibiotic resistance, which undermines individual drugs, threatens such combined treatments. Remarkably, it has emerged that antibiotic combinations whose combined effect is lower than that of at least one of the individual drugs can slow or even reverse the evolution of resistance. We synthesize and review studies of such so-called 'suppressive interactions' in the literature. We examine why these interactions have been largely disregarded in the past, the strategies used to identify them, their mechanistic basis, demonstrations of their potential to reverse the evolution of resistance and arguments for and against using them in clinical treatment. We suggest future directions for research on these interactions, aiming to expand the basic body of knowledge on suppression and to determine the applicability of suppressive interactions in the clinic.

  10. Intravenous antibiotics infusion and bacterial resistence: nursing responsability

    Directory of Open Access Journals (Sweden)

    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.

  11. 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....

  12. 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. Copyright © 2016 Sharkey et al.

  13. [Antibiotic Consumption and the Development of Antibiotic Resistance in Surgical Units].

    Science.gov (United States)

    Tammer, I; Geginat, G; Lange, S; Kropf, S; Lodes, U; Schlüter, D; Lippert, H; Meyer, F

    2016-02-01

    Antibiotic resistence is increasing worldwide. A longitudinal analysis of the influence of the density of antibiotic use on the development of resistance in surgical units was undertaken. Over five years the incidence of pathogens and the resistance rates of isolates from patients of normal surgical units and those of a surgical ICU at a university hospital were examined. The resistence rates were correlated with the density of antibiotic use - calculated from the antibiotic consumption (in DDD) and the number of patient-days. At both units, Enterobacteriaceae and Enterococci were mostly cultured. Among the Enterobacteriaceae, E. coli, Klebsiella spp., Proteus mirabilis and Enterobacter predominated. In the group of Enterococci, E. faecalis predominated at wards whereas at ICU E. faecium was the most frequent. Anaerobes ranked third at normal wards and Candida spp. at ICU. From 2007 to 2011, there was an increasing resistance against ciprofloxacin in P. mirabilis (r = 0.87; p = 0.054) and against imipenem (r = 0.86; p = 0.06) and piperacillin (r = 0.81; p = 0.09) in P. aeruginosa at normal wards. At ICU, the resistance rates of imipenem in P. aeruginosa rose (r = 0.88; p = 0.049). Resistance against ciprofloxacin in E. coli increased (r = 0.65; p = 0.23). Due to the increasing use of ciprofloxacin and meropenem at normal wards, the density of antibiotic usage rose 1.4 %/year (r = 0.94; p = 0.02). Despite the increase of meropenem use at ICU (r = 0.9; p = 0.035), the total antibiotic uptake rate remained almost constant. The antibiotic usage density was 3-fold higher at ICU than at normal wards. At normal wards, the ciprofloxacin usage correlated with the rate of resistance against ciprofloxacin in P. mirabilis P. m. At ICU, an association was detected between the uptake rate of ceftazidime and the rate of resistance against cefotaxime in the CES group. In P. aeruginosa, the use of piperacillin and the rate

  14. Antibiotics, bacteria, and antibiotic resistance genes: aerial transport from cattle feed yards via particulate matter.

    Science.gov (United States)

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

    2015-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Jolanta Godziszewska

    2016-07-01

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

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

    Science.gov (United States)

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

    2016-07-07

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

  17. Increases of Antibiotic Resistance in Excessive Use of Antibiotics in Smallholder Dairy Farms in Northern Thailand

    Directory of Open Access Journals (Sweden)

    W. Suriyasathaporn

    2012-09-01

    Full Text Available Antibiotic resistance patterns of bacterial isolates from both quarter teat-tip swabs and their quarter milk samples were evaluated in smallholder dairy farms in northern Thailand with excessive use of antibiotics (HIGH compared with normal use (NORM. Results from teat-tip swab samples showed that the percentage of Bacillus spp. resistance to overall antibiotics was significantly lower in the NORM group than that of the HIGH group, whereas, the resistance percentage of coagulase-negative staphylococci in the NORM group was higher than that of the HIGH one. The overall mastitis-causing bacteria isolated from milk samples were environmental streptococci (13.8%, coagulase-negative staphylococci (9.9%, Staphylococcus aureus (5.4%, and Corynebacterium bovis (4.5%. Both staphylococci and streptococci had significantly higher percentages of resistance to cloxacillin and oxacillin in the HIGH group when compared to the NORM one. An occurrence of vancomycin-resistant bacteria was also observed in the HIGH group. In conclusion, the smallholder dairy farms with excessive use of antibiotics had a higher probability of antibiotic-resistant pattern than the farms with normal use.

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

    OpenAIRE

    Editorial

    2017-01-01

    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-resis...

  19. Prevalence of antibiotic resistance genes in antibiotic-resistant Escherichia coli isolates in surface water of Taihu Lake Basin, China.

    Science.gov (United States)

    Zhang, Song He; Lv, Xiaoyang; Han, Bing; Gu, Xiucong; Wang, Pei Fang; Wang, Chao; He, Zhenli

    2015-08-01

    The rapid development of antibiotic-resistant bacteria (ARB) has been of concern worldwide. In this study, antibiotic resistance genes (ARGs) were investigated in antibiotic-resistant Escherichia coli isolated from surface water samples (rivers, n = 17; Taihu Lake, n = 16) and from human, chicken, swine, and Egretta garzetta sources in the Taihu Basin. E. coli showing resistance to at least five drugs occurred in 31, 67, 58, 27, and 18% of the isolates from surface water (n = 665), chicken (n = 27), swine (n = 29), human (n = 45), and E. garzetta (n = 15) sources, respectively. The mean multi-antibiotic resistance (MAR) index of surface water samples (0.44) was lower than that of chicken (0.64) and swine (0.57) sources but higher than that of human (0.30) and E. garzetta sources (0.15). Ten tetracycline, four sulfonamide, four quinolone, five β-lactamase, and two streptomycin resistance genes were detected in the corresponding antibiotic-resistant isolates. Most antibiotic-resistant E. coli harbored at least two similar functional ARGs. Int-I was detected in at least 57% of MAR E. coli isolates. The results of multiple correspondence analysis and Spearman correlation analysis suggest that antibiotic-resistant E. coli in water samples were mainly originated from swine, chicken, and/or human sources. Most of the ARGs detected in E. garzetta sources were prevalent in other sources. These data indicated that human activities may have contributed to the spread of ARB in the aquatic environment.

  20. 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

  1. Antibiotic dosing for multidrug-resistant pathogen pneumonia.

    Science.gov (United States)

    Abdul-Aziz, Mohd H; Lipman, Jeffrey; Roberts, Jason A

    2017-04-01

    Nosocomial pneumonia caused by multidrug-resistant pathogens is increasing in the ICU, and these infections are negatively associated with patient outcomes. Optimization of antibiotic dosing has been suggested as a key intervention to improve clinical outcomes in patients with nosocomial pneumonia. This review describes the recent pharmacokinetic/pharmacodynamic data relevant to antibiotic dosing for nosocomial pneumonia caused by multidrug-resistant pathogens. Optimal antibiotic treatment is challenging in critically ill patients with nosocomial pneumonia; most dosing guidelines do not consider the altered physiology and illness severity associated with severe lung infections. Antibiotic dosing can be guided by plasma drug concentrations, which do not reflect the concentrations at the site of infection. The application of aggressive dosing regimens, in accordance to the antibiotic's pharmacokinetic/pharmacodynamic characteristics, may be required to ensure rapid and effective drug exposure in infected lung tissues. Conventional antibiotic dosing increases the likelihood of therapeutic failure in critically ill patients with nosocomial pneumonia. Alternative dosing strategies, which exploit the pharmacokinetic/pharmacodynamic properties of an antibiotic, should be strongly considered to ensure optimal antibiotic exposure and better therapeutic outcomes in these patients.

  2. Selection and Transmission of Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Andersson, Dan I; Hughes, Diarmaid

    2017-07-01

    Ever since antibiotics were introduced into human and veterinary medicine to treat and prevent bacterial infections there has been a steady selection and increase in the frequency of antibiotic resistant bacteria. To be able to reduce the rate of resistance evolution, we need to understand how various biotic and abiotic factors interact to drive the complex processes of resistance emergence and transmission. We describe several of the fundamental factors that underlay resistance evolution, including rates and niches of emergence and persistence of resistant bacteria, time- and space-gradients of various selective agents, and rates and routes of transmission of resistant bacteria between humans, animals and other environments. Furthermore, we discuss the options available to reduce the rate of resistance evolution and/ or transmission and their advantages and disadvantages.

  3. Considering resistance in systematic reviews of antibiotic treatment.

    Science.gov (United States)

    Leibovici, Leonard; Soares-Weiser, Karla; Paul, Mical; Goldberg, Elad; Herxheimer, Andrew; Garner, Paul

    2003-10-01

    Microorganisms resistant to antibiotic drugs are a threat to the health and chances of survival of patients. Systematic reviews on antibiotic drugs that ignore the topic of resistance present readers with a skewed view, emphasizing short-term efficacy or effectiveness while ignoring long-term consequences. To examine whether systematic reviews of antibiotic treatment consider resistance; if not, to find out whether data on resistance were reported in the original trials; and based on that, to offer a framework for taking resistance into account in systematic reviews. The Cochrane Database of Systematic Reviews (the Cochrane Library, 2001, issue 2); and MEDLINE, 1996-2000. (i) Systematic reviews or meta-analyses of antimicrobial therapy, published during 1996-2000. (ii) Randomized, controlled trials abstracted in systematic reviews that addressed a topic highly relevant to antibiotic resistance. We examined each systematic review, and each article, to see whether the implications of resistance were discussed; and whether data on resistance were collected. Out of 111 systematic reviews, only 44 (40%) discussed resistance. Ten reviews (9%) planned or performed collection of data on the response of patients with susceptible or resistant isolates. In 22 systematic reviews (20%), collection of data on induction of resistance was planned or performed. The topic of 41 reviews was judged highly relevant to resistance, and these reviews extracted data from 337 articles, out of which we retrieved 279 articles (83%). In 201 (72%) articles, resistance was discussed or data pertaining to it were collected. Ninety-seven articles (35%) gave actual data on resistance of pathogens to the study drugs, 71 articles (25%) data on efficacy of antibiotic drugs in patients with susceptible and resistant pathogens, and 55 articles (20%) provided data on infection or colonization with resistant strains during treatment. Most systematic reviews on antibiotic treatment ignored the issue of

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

    Science.gov (United States)

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

    2015-10-01

    Most studies on the evolution of antibiotic resistance are focused on selection for resistance at lethal antibiotic concentrations, which has allowed the detection of mutant strains that show strong phenotypic traits. However, solely focusing on lethal concentrations of antibiotics narrowly limits our perspective of antibiotic resistance evolution. New high-resolution competition assays have shown that resistant bacteria are selected at relatively low concentrations of antibiotics. This finding is important because sublethal concentrations of antibiotics are found widely in patients undergoing antibiotic therapies, and in nonmedical conditions such as wastewater treatment plants, and food and water used in agriculture and farming. To understand the impacts of sublethal concentrations on selection, we measured 30 adaptive landscapes for a set of TEM β-lactamases containing all combinations of the four amino acid substitutions that exist in TEM-50 for 15 β-lactam antibiotics at multiple concentrations. We found that there are many evolutionary pathways within this collection of landscapes that lead to nearly every TEM-genotype that we studied. While it is known that the pathways change depending on the type of β-lactam, this study demonstrates that the landscapes including fitness optima also change dramatically as the concentrations of antibiotics change. Based on these results we conclude that the presence of multiple concentrations of β-lactams in an environment result in many different adaptive landscapes through which pathways to nearly every genotype are available. Ultimately this may increase the diversity of genotypes in microbial populations. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Microbial profile, antibiotic sensitivity and heat resistance of bacterial ...

    African Journals Online (AJOL)

    Aim: This study was aimed at determining the prevalence, antibiotic resistance and heat resistance profile of bacterial isolates obtained from ready to eat roasted beef (suya) sold in Abuja, Nigeria. Methods and Results: Fifty samples of suya were purchased from different vendors within the Federal Capital Territory and ...

  6. Prevalence, antibiotic-resistance properties and enterotoxin gene ...

    African Journals Online (AJOL)

    Prevalence, antibiotic-resistance properties and enterotoxin gene profile of Bacillus cereus strains isolated from milk-based baby foods. ... Conclusion: Considerable prevalence of resistant and toxigenic B. cereus and high consumption of milk-based infant foods in Iran, represent an important public health issue which ...

  7. Antibiotic resistant Salmonella and Escherichia coli isolated from ...

    African Journals Online (AJOL)

    Results: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern ...

  8. Collective resistance in microbial communities by intracellular antibiotic deactivation

    NARCIS (Netherlands)

    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

  9. A Survey of Antibiotic Resistant Staphylococcus Aureus Strains from ...

    African Journals Online (AJOL)

    A survey of antibiotic resistant Staphylococcus aureus strains from clinical specimens was carried out. A total of 100 different clinical specimens were investigated with a yield of 48 Staphylococcus aureus isolates. A high resistance of 95.8% to penicillin, 89.6% to ampicillin, 87.5% to tetracycline, and 75.0% to ...

  10. Codon-optimized antibiotic resistance gene improves efficiency of ...

    Indian Academy of Sciences (India)

    Success rate of transient transformation and cell growth in selective culture were significantly increased by use of fgmR instead of a native gentamicin resistance gene, suggesting that codon optimization improved translation efficiency of the marker gene and increased antibiotic resistance. Our result shows that similarity in ...

  11. Molecular screening of antibiotic-resistant determinants among ...

    African Journals Online (AJOL)

    otic susceptibility study using disc-diffusion method. Transferable resistance genes and MGEs were amplified using Polymerase chain reaction (PCR) analysis and amplicons sequenced. Results: Varied resistance was observed against all the antibiotics tested. About 56% of the isolates were MDR including those from ...

  12. Profile of sensitivity and resistance to antibiotics of Staphylococcus ...

    African Journals Online (AJOL)

    Staphylococcus aureus is a bacterial specie that opposed more resistance again many antibiotics. This study aimed to determine the resistance profile of Staphylococcus aureus isolated from biological patient's liquids. A total of 303 samples including urine and vaginal pus samples from human were collected.

  13. Antibiotic resistance profile of staphylococci from clinical sources ...

    African Journals Online (AJOL)

    Infants, children and the aged are among the groups most vulnerable to microbial infections more so when these microbial agents become resistant to antimicrobials. The antibiotic resistant profile of Staphylococcus aureus and selected coagulase negative staphylococci were determined by standard methods. Of the 178 ...

  14. A study of the intestinal carriage of antibiotic resistant ...

    African Journals Online (AJOL)

    Results: 14.0% of the faecal samples yielded S. aureus with the carriage rate among the subjects being found to be highest at about 1 month approximately in subjected ages. Sixty-five percent of the isolates were found to be resistant to more than three different antibiotics with more than 50% being resistant to penicillin, ...

  15. Antibiotic Resistance in Intensive Care Units: Dynamics of Colonization

    NARCIS (Netherlands)

    Nijssen, S.

    2006-01-01

    The dynamics of colonization of antibiotic-resistant bacteria in hospital settings are complex and depend on bacteria and healthcare worker related characteristics. Many factors influence colonization and in addition these factors interact with each other as well. Knowledge of local resistance

  16. Multi-antibiotics-resistance plasmid profile of enteric pathogens in ...

    African Journals Online (AJOL)

    Dr J. T. Ekanem

    from ≤0.55kbp to ≥1.14kbp. This indicates that plasmids allow the movement of genetic materials, including antimicrobial resistance genes between bacterial species and strains. Keywords: Diarrheagenic pathogens, antibiotics resistance plasmids profile. E-mail: yahclar@yahoo.com; Tel: 08053336108, 08063418265.

  17. Low prevalence of antibiotic-resistant gram-negative bacteria ...

    African Journals Online (AJOL)

    The objective of this study was to determine antibiotic resistance patterns and specific resistance genes in Gram-negative enteric bacteria recovered from 42 different drinking water sources servicing 2 rural villages in south-western Uganda. These water sites were prone to contamination by both human and cattle activity.

  18. Heavy metal and associated antibiotic resistance of fecal coliforms ...

    African Journals Online (AJOL)

    The present study aimed at assessing the resistance pattern to multiple heavy metals by wastewater bacteria and associated antibiotic resistance. Methodology and results: Standard microbiological methods were used to isolate fecal streptococci, fecal coliforms, Vibrio and Salmonella species from raw animal wastewaters ...

  19. Antibiotic Resistant Microbiota in the Swine Intestinal Tract

    Science.gov (United States)

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

  20. Antibiotic resistance in bacteria – an emerging public

    African Journals Online (AJOL)

    In spite of the many advances in microbiology, biochemistry and drug discovery and development in recent years, the world is not keeping pace with the ability of bacteria to adapt to and resist antibacterials. It is believed that the rise in bacterial resistance is partly because there have been no new classes of antibiotics.

  1. 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.

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

    Science.gov (United States)

    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. © 2013.

  3. Antibiotic resistance and irrational prescribing in paediatric clinics in Greece.

    Science.gov (United States)

    Toska, Aikaterini; Geitona, Mary

    Greece is among the countries with the highest rates of antimicrobial resistance (AMR) and simultaneous antibiotic consumption. The aim of this study was to assess the perceptions and knowledge of AMR and irrational antibiotic prescribing of nurses working in paediatric hospitals in Greece. A self-administered questionnaire was distributed to nurses in paediatric hospitals and paediatric clinics in Greece. Descriptive and multivariate statistical analyses were performed. Levels of significance were two-tailed and statistical significance was p=0.05. A total of 87% of participants reported irrational prescribing to be an important cause of AMR. Diagnostic uncertainty was stated by 55.5% as the main cause of irrational antibiotic prescribing and 94% suggested the use of protocols and guidelines as the main measure to control overprescribing. Parental demand for antibiotics in hospitals has increased according to 51.8% of respondents. Strong correlation was observed between social-demographic characteristics and antibiotic resistance, as well as irrational prescribing. Assessing nurses' knowledge and perceptions of antimicrobial resistance and irrational prescribing is vital as nurses actively participate in the antibiotics administration process and antimicrobial management in Greece. Their involvement could contribute to educate patients and parents on the public-health implications of overprescribing and antimicrobial resistance.

  4. 'Repeat' prescriptions and antibiotic resistance: findings from Australian community pharmacy.

    Science.gov (United States)

    Fredericks, Ian; Hollingworth, Samantha; Pudmenzky, Alex; Rossato, Laurence; Kairuz, Therése

    2017-02-01

    Australians are among the highest users of antibiotics in the developed world. The primary aim was to determine the 'age' of antibiotic prescriptions at the time of dispensing as a possible contributor to antibiotic misuse and ultimately, resistance. The secondary aim was to test customised software to permit extraction and de-identification of dispensing records for analysis. Data were extracted and de-identified from computerised dispensing systems in three community pharmacies in Brisbane, Australia, according to a strict ethical protocol. All prescription records dispensed between 1 January 2010 and 31 December 2012 were merged to form a complete dataset of 1 158 871 de-identified dispensing records which were analysed using Microsoft Excel ® . A retrospective drug utilisation study was conducted on a subset of 100 573 antibiotic records. In a substudy conducted at a single pharmacy site, all antibiotic records dispensed over a 4-month (winter) period were examined to determine the age of prescriptions. Nearly one in ten antibiotics (9.0%) was dispensed from prescriptions that were more than a month old, and over one in five (22.1%) were dispensed from a repeat prescription. Health system factors may contribute to inappropriate antibiotic use in Australia, including availability and validity of repeat antibiotic prescriptions. Government health departments, prescribers, pharmacists, other health professionals and consumers have to share the responsibility of ensuring that antibiotics are used appropriately. © 2016 Royal Pharmaceutical Society.

  5. Automated annotation of mobile antibiotic resistance in Gram-negative bacteria: the Multiple Antibiotic Resistance Annotator (MARA) and database.

    Science.gov (United States)

    Partridge, Sally R; Tsafnat, Guy

    2018-04-01

    Multiresistance in Gram-negative bacteria is often due to acquisition of several different antibiotic resistance genes, each associated with a different mobile genetic element, that tend to cluster together in complex conglomerations. Accurate, consistent annotation of resistance genes, the boundaries and fragments of mobile elements, and signatures of insertion, such as DR, facilitates comparative analysis of complex multiresistance regions and plasmids to better understand their evolution and how resistance genes spread. To extend the Repository of Antibiotic resistance Cassettes (RAC) web site, which includes a database of 'features', and the Attacca automatic DNA annotation system, to encompass additional resistance genes and all types of associated mobile elements. Antibiotic resistance genes and mobile elements were added to RAC, from existing registries where possible. Attacca grammars were extended to accommodate the expanded database, to allow overlapping features to be annotated and to identify and annotate features such as composite transposons and DR. The Multiple Antibiotic Resistance Annotator (MARA) database includes antibiotic resistance genes and selected mobile elements from Gram-negative bacteria, distinguishing important variants. Sequences can be submitted to the MARA web site for annotation. A list of positions and orientations of annotated features, indicating those that are truncated, DR and potential composite transposons is provided for each sequence, as well as a diagram showing annotated features approximately to scale. The MARA web site (http://mara.spokade.com) provides a comprehensive database for mobile antibiotic resistance in Gram-negative bacteria and accurately annotates resistance genes and associated mobile elements in submitted sequences to facilitate comparative analysis.

  6. [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.

  7. Antibiotic-Impregnated Central Venous Catheters Do Not Change Antibiotic Resistance Patterns.

    Science.gov (United States)

    Turnbull, Isaiah R; Buckman, Sara A; Horn, Christopher B; Bochicchio, Grant V; Mazuski, John E

    2018-01-01

    Antibiotic-impregnated central venous catheters (CVCs) decrease the incidence of infection in high-risk patients. However, use of these catheters carries the hypothetical risk of inducing antibiotic resistance. We hypothesized that routine use of minocycline and rifampin-impregnated catheters (MR-CVC) in a single intensive care unit (ICU) would change the resistance profile for Staphylococcus aureus. We reviewed antibiotic susceptibilities of S. aureus isolates obtained from blood cultures in a large urban teaching hospital from 2002-2015. Resistance patterns were compared before and after implementation of MR-CVC use in the surgical ICU (SICU) in August 2006. We also compared resistance patterns of S. aureus obtained in other ICUs and in non-ICU patients, in whom MR-CVCs were not used. Data for rifampin, oxacillin, and clindamycin were available for 9,703 cultures; tetracycline resistance data were available for 4,627 cultures. After implementation of MR-CVC use in the SICU, rifampin resistance remained unchanged, with rates the same as in other ICU and non-ICU populations (3%). After six years of use of MR-CVCs in the SICU, the rate of tetracycline resistance was unchanged in all facilities (1%-3%). The use of MR-CVCs was not associated with any change in S. aureus oxacillin-resistance rates in the SICU (66% vs. 60%). However, there was a significant decrease in S. aureus clindamycin resistance (59% vs. 34%; p resistance of S. aureus isolates to rifampin or tetracyclines.

  8. Antibiotic resistance in healthcare-related and nosocomial spontaneous bacterial peritonitis.

    Science.gov (United States)

    Lutz, Philipp; Nischalke, Hans Dieter; Krämer, Benjamin; Goeser, Felix; Kaczmarek, Dominik J; Schlabe, Stefan; Parcina, Marijo; Nattermann, Jacob; Hoerauf, Achim; Strassburg, Christian P; Spengler, Ulrich

    2017-01-01

    Spontaneous bacterial peritonitis (SBP) can be life threatening in patients with liver cirrhosis. In contrast to community-acquired SBP, no standard treatment has been established for healthcare-related and nosocomial SBP. We prospectively collected healthcare-related and nosocomial SBP cases from March 2012 till February 2016 at the Department of Internal Medicine I of the University of Bonn and analysed the prevalence of antibiotic resistance among the isolated bacteria. SBP was diagnosed according to international guidelines. Ciprofloxacin, ceftriaxone and meropenem were used as reference substance for resistance to quinolones, third-generation cephalosporins and carbapenems, respectively. Ninety-two SBP episodes in 86 patients were identified: 63 episodes (69%) were nosocomial. Escherichia coli, Klebsiella species, enterococci and streptococci were most frequently isolated. Frequencies of these microorganisms were comparable for healthcare-related and nosocomial SBP (14% vs. 11%, 14% vs. 8%, 14% vs. 5% and 10% vs. 6%, respectively). In general, antibiotic resistance was higher in isolates from nosocomial than from healthcare-related SBP (50% vs. 18% for quinolones, 30% vs. 11% for piperacillin-tazobactam; P > 0·05), but comparable concerning third-generation cephalosporins (30% vs. 33%). All microorganisms were sensitive to carbapenems apart from nosocomial infections with Enterococcus faecium (n = 3) and Candida albicans (n = 1) due to intrinsic resistance or lack of microbiological efficacy, respectively. No multidrug-resistant microorganisms were detected. Resistance to initial antibiotic treatment affected 30-day survival negatively (18% vs. 68%; P = 0·002). Resistance to initial antibiotic treatment was associated with increased mortality. With resistance to cephalosporins being frequent, piperacillin-tazobactam or carbapenems might be preferred as treatment of SBP. © 2016 Stichting European Society for Clinical Investigation Journal Foundation.

  9. On the contribution of reclaimed wastewater irrigation to the potential exposure of humans to antibiotics, antibiotic resistant bacteria and antibiotic resistance genes - NEREUS COST Action ES1403 position paper

    DEFF Research Database (Denmark)

    Piña, Benjamin; Bayona, Josep M.; Christou, Anastasis

    2018-01-01

    Antibiotic resistance (AR) is becoming a worldwide threat due to the increasing occurrence of antibiotic-resistant pathogenic bacterial strains. There is a general consensus about the potential implications of the use of antibiotics in livestock on the onset of antibiotic resistant bacteria (ARB)...

  10. 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.

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

    Science.gov (United States)

    Charretier, Yannick; Köhler, Thilo; Cecchini, Tiphaine; Bardet, Chloé; Cherkaoui, Abdessalam; Llanes, Catherine; Bogaerts, Pierre; Chatellier, Sonia; Charrier, Jean-Philippe; Schrenzel, Jacques

    2015-01-01

    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 β-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 with 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.

  12. The hidden societal cost of antibiotic resistance per antibiotic prescribed in the United States: an exploratory analysis.

    Science.gov (United States)

    Michaelidis, Constantinos I; Fine, Michael J; Lin, Chyongchiou Jeng; Linder, Jeffrey A; Nowalk, Mary Patricia; Shields, Ryan K; Zimmerman, Richard K; Smith, Kenneth J

    2016-11-08

    Ambulatory antibiotic prescribing contributes to the development of antibiotic resistance and increases societal costs. Here, we estimate the hidden societal cost of antibiotic resistance per antibiotic prescribed in the United States. In an exploratory analysis, we used published data to develop point and range estimates for the hidden societal cost of antibiotic resistance (SCAR) attributable to each ambulatory antibiotic prescription in the United States. We developed four estimation methods that focused on the antibiotic-resistance attributable costs of hospitalization, second-line inpatient antibiotic use, second-line outpatient antibiotic use, and antibiotic stewardship, then summed the estimates across all methods. The total SCAR attributable to each ambulatory antibiotic prescription was estimated to be $13 (range: $3-$95). The greatest contributor to the total SCAR was the cost of hospitalization ($9; 69 % of the total SCAR). The costs of second-line inpatient antibiotic use ($1; 8 % of the total SCAR), second-line outpatient antibiotic use ($2; 15 % of the total SCAR) and antibiotic stewardship ($1; 8 %). This apperars to be an error.; of the total SCAR) were modest contributors to the total SCAR. Assuming an average antibiotic cost of $20, the total SCAR attributable to each ambulatory antibiotic prescription would increase antibiotic costs by 65 % (range: 15-475 %) if incorporated into antibiotic costs paid by patients or payers. Each ambulatory antibiotic prescription is associated with a hidden SCAR that substantially increases the cost of an antibiotic prescription in the United States. This finding raises concerns regarding the magnitude of misalignment between individual and societal antibiotic costs.

  13. Urine Antibiotic Activity in Patients Presenting to Hospitals in Laos: Implications for Worsening Antibiotic Resistance

    OpenAIRE

    Khennavong, Manisone; Davone, Viengmon; Vongsouvath, Manivanh; Phetsouvanh, Rattanaphone; Silisouk, Joy; Rattana, Olay; Mayxay, Mayfong; Castonguay-Vanier, Josée; Moore, Catrin E.; Strobel, Michel; Newton, Paul N.

    2011-01-01

    Widespread use of antibiotics may be important in the spread of antimicrobial resistance. We estimated the proportion of Lao in- and outpatients who had taken antibiotics before medical consultation by detecting antibiotic activity in their urine added to lawns of Bacillus stearothermophilus, Escherichia coli, and Streptococcus pyogenes. In the retrospective (N = 2,058) and prospective studies (N = 1,153), 49.7% (95% confidence interval [CI] = 47.4–52.0) and 36.2% (95% CI = 33.4–38.9), respec...

  14. Excretion of Antibiotic Resistance Genes by Dairy Calves Fed Milk Replacers with Varying Doses of Antibiotics

    Science.gov (United States)

    Thames, Callie H.; Pruden, Amy; James, Robert E.; Ray, Partha P.; Knowlton, Katharine F.

    2012-01-01

    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 per gram 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 onward, and tetW and tetG significantly increased (P 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 nutritional intake applied

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

    Directory of Open Access Journals (Sweden)

    Sabiha Y. Essack

    2010-09-01

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

  16. Antibiotic resistance genes and residual antimicrobials in cattle feedlot surface soil

    Science.gov (United States)

    Antibiotic residues and resistant bacteria in cattle feedlot manure may impact antibiotic resistance in the environment. This study investigated common antimicrobials (tetracyclines and monensin) and associated resistance genes in cattle feedlot soils over time. Animal diets and other feedlot soil...

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

    Digital Repository Service at National Institute of Oceanography (India)

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

    in 68% of the isolates. Depending on the antibiotics the isolates showed different percentage of resistance. Multiple drug and metal-resistance were observed. High incidence of resistance to both antibiotics and metals were common among the pigmented...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Science.gov (United States)

    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.

  1. Functional Repertoire of Antibiotic Resistance Genes in Antibiotic Manufacturing Effluents and Receiving Freshwater Sediments

    Science.gov (United States)

    González-Plaza, Juan J.; Šimatović, Ana; Milaković, Milena; Bielen, Ana; Wichmann, Fabienne; Udiković-Kolić, Nikolina

    2018-01-01

    Environments polluted by direct discharges of effluents from antibiotic manufacturing are important reservoirs for antibiotic resistance genes (ARGs), which could potentially be transferred to human pathogens. However, our knowledge about the identity and diversity of ARGs in such polluted environments remains limited. We applied functional metagenomics to explore the resistome of two Croatian antibiotic manufacturing effluents and sediments collected upstream of and at the effluent discharge sites. Metagenomic libraries built from an azithromycin-production site were screened for resistance to macrolide antibiotics, whereas the libraries from a site producing veterinary antibiotics were screened for resistance to sulfonamides, tetracyclines, trimethoprim, and beta-lactams. Functional analysis of eight libraries identified a total of 82 unique, often clinically relevant ARGs, which were frequently found in clusters and flanked by mobile genetic elements. The majority of macrolide resistance genes identified from matrices exposed to high levels of macrolides were similar to known genes encoding ribosomal protection proteins, macrolide phosphotransferases, and transporters. Potentially novel macrolide resistance genes included one most similar to a 23S rRNA methyltransferase from Clostridium and another, derived from upstream unpolluted sediment, to a GTPase HflX from Emergencia. In libraries deriving from sediments exposed to lower levels of veterinary antibiotics, we found 8 potentially novel ARGs, including dihydrofolate reductases and beta-lactamases from classes A, B, and D. In addition, we detected 7 potentially novel ARGs in upstream sediment, including thymidylate synthases, dihydrofolate reductases, and class D beta-lactamase. Taken together, in addition to finding known gene types, we report the discovery of novel and diverse ARGs in antibiotic-polluted industrial effluents and sediments, providing a qualitative basis for monitoring the dispersal of ARGs

  2. Robust, cross-laboratory validated PCR methods to track antibiotic resistance in agricultural settings

    Science.gov (United States)

    In order to make informed decisions on how best to manage agricultural antibiotics, we need to be able to track and quantify the antibiotic resistant bacteria, and antibiotic resistance genes. PCR-based methods are widely used to both detect and quantify antibiotic resistance genes, however there ar...

  3. Enhancement of antibiotic activity by efflux inhibitors against multidrug resistant Mycobacterium tuberculosis clinical isolates from Brazil

    Directory of Open Access Journals (Sweden)

    Tatiane eCoelho

    2015-04-01

    Full Text Available Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay (TEMA to study single combinations between antituberculosis drugs and efflux inhibitors (EIs against multidrug resistant M. tuberculosis clinical isolates using the fully susceptible strain H37Rv as reference. Efflux activity was studied on a real-time basis by a fluorometric method that uses ethidium bromide as efflux substrate. Quantification of efflux pump genes mRNA transcriptional levels were performed by RT-qPCR. The fractional inhibitory concentrations (FIC indicated synergistic activity for the interactions between isoniazid, rifampicin, amikacin, ofloxacin, and ethidium bromide plus the EIs verapamil, thioridazine and chlorpromazine. The FICs ranged from 0.25, indicating a four-fold reduction on the MICs, to 0.015, 64-fold reduction. The detection of active efflux by real-time fluorometry showed that all strains presented intrinsic efflux activity that contributes to the overall resistance which can be inhibited in the presence of the EIs. The quantification of the mRNA levels of the most important efflux pump genes on these strains shows that they are intrinsically predisposed to expel toxic compounds as the exposure to subinhibitory concentrations of antibiotics were not necessary to increase the pump mRNA levels when compared with the non-exposed counterpart. The results obtained in this study confirm that the intrinsic efflux activity contributes to the overall resistance in multidrug resistant clinical isolates of M. tuberculosis and that the inhibition of efflux pumps by the EIs can enhance the clinical effect of antibiotics that are their substrates.

  4. Antibiotics resistance of Stenotrophomonas maltophilia strains ...

    African Journals Online (AJOL)

    BD Phoenixautomated microbiology system (Becton Dickinson, USA) was utilized for species level identification and antibiotic susceptibility testing. Results: Sixty seven of S. maltophilia strains were isolated from tracheal aspirate isolates, 17 from blood, 10 from sputum, 10 from wound and 14 from other clinical specimens.

  5. Diversity in Biochemical Characteristics and Antibiotics Resistant ...

    African Journals Online (AJOL)

    In this study, biochemical and antibiotic susceptibility tests were carried out on one hundred and fifty poultry isolates of Escherichia coli using Microscan® Dried Gram-negative Breakpoint Combo Pannels. The microscan panel analysed bacterial isolates for 24 biochemical tests and 23 to 25 antimicrobial agents following ...

  6. 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.

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

    Directory of Open Access Journals (Sweden)

    Songhe Zhang

    2015-01-01

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

  8. Persistence of Antibiotic Resistant Vibrio spp. in Shellfish Hatchery Environment.

    Science.gov (United States)

    Dubert, Javier; Osorio, Carlos R; Prado, Susana; Barja, Juan L

    2016-11-01

    The characterization of antibiotic-resistant vibrios isolated from shellfish aquaculture is necessary to elucidate the potential transfer of resistance and to establish effective strategies against vibriosis. With this aim, we analyzed a collection of bacterial isolates obtained from 15 failed hatchery larval cultures that, for the most part, had been treated experimentally with chloramphenicol to prevent vibriosis. Isolates were obtained during a 2-year study from experimental cultures of five different clam species. Among a total of 121 Vibrio isolates studied, 28 were found to be chloramphenicol resistant, suggesting that the shellfish hatchery had been using a sublethal concentration of the antibiotic. Interestingly, chloramphenicol-resistant vibrios showed also resistance to tetracycline and amoxicillin (group A; n = 19) or to streptomycin (group B; n = 9). Chloramphenicol-resistant vibrios were subjected to a PCR amplification and DNA sequencing of the chloramphenicol acetyltransferase genes (cat), and the same approach was followed to study the tetracycline resistance markers (tet). 16S ribosomal RNA (rRNA) gene sequencing revealed that chloramphenicol-resistant vibrios pertained mostly to the Splendidus clade. Conjugation assays demonstrated that various R-plasmids which harbored the cat II/tet(D) genes and cat III gene in groups A and B respectively, were transferred to E. coli and bivalve pathogenic vibrios. Most interestingly, transconjugants exhibited the antibiotic resistance patterns of the donors, despite having been selected only on the basis of chloramphenicol resistance. This is the first report carried out in a bivalve hatchery elucidating the persistence of resistant vibrios, the mechanisms of antibiotic resistance, and the transfer of different R-plasmids.

  9. [Mechanisms of microorganism resistance to beta-lactam antibiotics].

    Science.gov (United States)

    D'iachkova, V S; Bazhukova, T A

    2014-01-01

    Literature data on molecular mechanisms of resistance to beta-lactam antibiotics have been summarized. The following mechanisms are examined: appearance ofpenicillin-binding proteins (PBP) with lower affinity to beta-lactam antibiotics; production by microorganisms of enzymes (beta-lactamases) that hydrolyze beta-lactam ring; disruption of microbial cell outer membrane permeability and active secretion of antibiotics from the microbial cell (effiux-effect). Characterization of extended spectrum beta-lactamases (ESBL) as well as data on structure of SCCmec element of MRSA and bacterial efflux system (RND) is presented.

  10. 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.

  11. Anthropogenic antibiotic resistance genes mobilization to the polar regions

    Directory of Open Access Journals (Sweden)

    Jorge Hernández

    2016-12-01

    Full Text Available 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.

  12. Rapid determination of antibiotic resistance in E. coli using dielectrophoresis

    International Nuclear Information System (INIS)

    Hoettges, Kai F; Dale, Jeremy W; Hughes, Michael P

    2007-01-01

    In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which take approximately 24 h to complete and potentially place the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 h passes after isolating a culture from nutrient broth

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

    Science.gov (United States)

    Schechner, Vered; Temkin, Elizabeth; Harbarth, Stephan; Carmeli, Yehuda

    2013-01-01

    SUMMARY Bacterial resistance to antibiotics is a growing clinical problem and public health threat. Antibiotic use is a known risk factor for the emergence of antibiotic resistance, but demonstrating the causal link between antibiotic use and resistance is challenging. This review describes different study designs for assessing the association between antibiotic use and resistance and discusses strengths and limitations of each. Approaches to measuring antibiotic use and antibiotic resistance are presented. Important methodological issues such as confounding, establishing temporality, and control group selection are examined. PMID:23554418

  14. Lack of evidence that DNA in antibiotic preparations is a source of antibiotic resistance genes in bacteria from animal or human sources

    OpenAIRE

    Yuen, KY; Lau, SKP; Woo, PCY; Lau, ATK; To, APC

    2004-01-01

    Although DNA encoding antibiotic resistance has been discovered in antibiotic preparations, its significance for the development of antibiotic resistance in bacteria is unknown. No phylogenetic evidence was obtained for recent horizontal transfer of antibiotic resistance genes from antibiotic-producing organisms to bacteria from human or animal sources.

  15. Multidrug Efflux Pumps at the Crossroad between Antibiotic Resistance and Bacterial Virulence.

    Science.gov (United States)

    Alcalde-Rico, Manuel; Hernando-Amado, Sara; Blanco, Paula; Martínez, José L

    2016-01-01

    Multidrug efflux pumps can be involved in bacterial resistance to antibiotics at different levels. Some efflux pumps are constitutively expressed at low levels and contribute to intrinsic resistance. In addition, their overexpression may allow higher levels of resistance. This overexpression can be transient, in the presence of an effector (phenotypic resistance), or constitutive when mutants in the regulatory elements of the expression of efflux pumps are selected (acquired resistance). Efflux pumps are present in all cells, from human to bacteria and are highly conserved, which indicates that they are ancient elements in the evolution of different organisms. Consequently, it has been suggested that, besides antibiotic resistance, bacterial multidrug efflux pumps would likely contribute to other relevant processes of the microbial physiology. In the current article, we discuss some specific examples of the role that efflux pumps may have in the bacterial virulence of animals' and plants' pathogens, including the processes of intercellular communication. Based in these evidences, we propose that efflux pumps are at the crossroad between resistance and virulence of bacterial pathogens. Consequently, the comprehensive study of multidrug efflux pumps requires addressing these functions, which are of relevance for the bacterial-host interactions during infection.

  16. Multidrug efflux pumps at the crossroad between antibiotic resistance and bacterial virulence

    Directory of Open Access Journals (Sweden)

    Manuel Alcalde-Rico

    2016-09-01

    Full Text Available Multidrug efflux pumps can be involved in bacterial resistance to antibiotics at different levels. Some efflux pumps are constitutively expressed at low levels and contribute to intrinsic resistance. In addition, their overexpression may allow higher levels of resistance. This overexpression can be transient, in the presence of an effector (phenotypic resistance, or constitutive when mutants in the regulatory elements of the expression of efflux pumps are selected (acquired resistance. Efflux pumps are present in all cells, from human to bacteria and are highly conserved, which indicates that they are ancient elements in the evolution of different organisms. Consequently, it has been suggested that, besides antibiotic resistance, bacterial multidrug efflux pumps would likely contribute to other relevant process of the microbial physiology. In the current article, we discuss some specific examples of the role that efflux pumps may have in the bacterial virulence of animals' and plants' pathogens, including the processes of intercellular communication. Based in these evidences, we propose that efflux pumps are at the crossroad between resistance and virulence of bacterial pathogens. Consequently, the comprehensive study of multidrug efflux pumps requires addressing these functions, which are of relevance for the bacterial-host interactions during infection.

  17. Synergistic antibiotic combinations for colistin-resistant Klebsiella pneumoniae.

    Science.gov (United States)

    Kádár, Béla; Kocsis, Béla; Tóth, Ákos; Damjanova, Ivelina; Szász, Máté; Kristóf, Katalin; Nagy, Károly; Szabó, Dóra

    2013-06-01

    In this study antibiotic combinations for multidrug-resistant Klebsiella pneumoniae strains were investigated. The study included a colistin-susceptible and a colistin-resistant KPC-2 producing K. pneumoniae ST258 strains isolated in 2008 and 2009 during an outbreak in Hungary. Antibiotic combinations were analyzed by checkerboard technique and fractional inhibitory concentration indices were calculated. The following antibiotics were tested: ceftazidime, cefotaxime, ceftriaxone, ampicillin, imipenem, ertapenem, amikacin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, rifampicin, polymyxin B and colistin. Combinations including 0.25 μg/ml colistin plus 1 μg/ml rifampicin, 0.25 μg/ml polymyxin B plus 1 μg/ml rifampicin, 1 μg/ml imipenem plus 2 μg/ml tobramycin, were found synergistic.These in vitro synergistic combinations suggest potential therapeutical options against infections caused by KPC-2 producing, multidrug-resistant K. pneumoniae ST258.

  18. Antibiotic resistance of microorganisms in agricultural soils in Russia

    Science.gov (United States)

    Danilova, N. V.; Galitskaya, P. Yu; Selivanovskaya, S. Yu

    2018-01-01

    Antibiotics are medicines that are widely used in livestock production not only for the prevention and treatment of infectious diseases, but also for accelerating the growth of animals. The application of manure for fertilizing agricultural soils leads to the entry into the soil ecosystem not only of the antibiotics themselves, but also the resistance genes to them. In this study, 30 samples of arable soils were tested for the presence of the tet(X) gene, which encodes bacterial resistance to antibiotics of the tetracycline group. Using real-time PCR, it was found that 27 out of 30 soil samples contained tet(X). 52% of these samples were heavily contaminated, 34% had a medium level of contamination and 14% were slightly contaminated by the resistance gene tet(X).

  19. The Complex Relationship between Virulence and Antibiotic Resistance

    Science.gov (United States)

    Schroeder, Meredith; Brooks, Benjamin D.; Brooks, Amanda E.

    2017-01-01

    Antibiotic resistance, prompted by the overuse of antimicrobial agents, may arise from a variety of mechanisms, particularly horizontal gene transfer of virulence and antibiotic resistance genes, which is often facilitated by biofilm formation. The importance of phenotypic changes seen in a biofilm, which lead to genotypic alterations, cannot be overstated. Irrespective of if the biofilm is single microbe or polymicrobial, bacteria, protected within a biofilm from the external environment, communicate through signal transduction pathways (e.g., quorum sensing or two-component systems), leading to global changes in gene expression, enhancing virulence, and expediting the acquisition of antibiotic resistance. Thus, one must examine a genetic change in virulence and resistance not only in the context of the biofilm but also as inextricably linked pathologies. Observationally, it is clear that increased virulence and the advent of antibiotic resistance often arise almost simultaneously; however, their genetic connection has been relatively ignored. Although the complexities of genetic regulation in a multispecies community may obscure a causative relationship, uncovering key genetic interactions between virulence and resistance in biofilm bacteria is essential to identifying new druggable targets, ultimately providing a drug discovery and development pathway to improve treatment options for chronic and recurring infection. PMID:28106797

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

    Directory of Open Access Journals (Sweden)

    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.

  1. The Complex Relationship between Virulence and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Meredith Schroeder

    2017-01-01

    Full Text Available Antibiotic resistance, prompted by the overuse of antimicrobial agents, may arise from a variety of mechanisms, particularly horizontal gene transfer of virulence and antibiotic resistance genes, which is often facilitated by biofilm formation. The importance of phenotypic changes seen in a biofilm, which lead to genotypic alterations, cannot be overstated. Irrespective of if the biofilm is single microbe or polymicrobial, bacteria, protected within a biofilm from the external environment, communicate through signal transduction pathways (e.g., quorum sensing or two-component systems, leading to global changes in gene expression, enhancing virulence, and expediting the acquisition of antibiotic resistance. Thus, one must examine a genetic change in virulence and resistance not only in the context of the biofilm but also as inextricably linked pathologies. Observationally, it is clear that increased virulence and the advent of antibiotic resistance often arise almost simultaneously; however, their genetic connection has been relatively ignored. Although the complexities of genetic regulation in a multispecies community may obscure a causative relationship, uncovering key genetic interactions between virulence and resistance in biofilm bacteria is essential to identifying new druggable targets, ultimately providing a drug discovery and development pathway to improve treatment options for chronic and recurring infection.

  2. 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

  3. World alliance against antibiotic resistance: The WAAAR declaration against antibiotic resistance.

    Science.gov (United States)

    Carlet, Jean

    2015-01-01

    We must change how antibiotics are used and adopt proactive strategies, similar to those used to save endangered species. Preservation of the efficacy of antibiotics and to stabilization of antibiotic-susceptible bacterial ecosystems should be global goals. Copyright © 2014 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

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

    DEFF Research Database (Denmark)

    Boel, Jonas; 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 as a retrosp......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...... as a retrospective controlled interrupted time series (ITS) at two university teaching hospitals, intervention and control, with 736 and 552 beds, respectively. The study period was between January 2008 and September 2014. We used ITS analysis to determine significant changes in antibiotic use and resistance levels......% CI -177, -126)] and fluoroquinolones [-44.5 DDDs/1000 bed-days (95% CI -58.9, -30.1)]. Resistance of E. coli showed a significant change in slope for cefuroxime [-0.13 percentage points/month (95% CI -0.21, -0.057)] and ciprofloxacin [-0.15 percentage points/month (95% CI -0.26, -0.038)]. CONCLUSIONS...

  5. Primary Antibiotic Resistance of Helicobacter pylori in China.

    Science.gov (United States)

    Hu, Yi; Zhu, Yin; Lu, Nong-Hua

    2017-05-01

    Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China. We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed. Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively. In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

  6. Prediction of antibiotic resistance: time for a new preclinical paradigm?

    DEFF Research Database (Denmark)

    Sommer, Morten Otto Alexander; Munck, Christian; Toft-Kehler, Rasmus Vendler

    2017-01-01

    Predicting the future is difficult, especially for evolutionary processes that are influenced by numerous unknown factors. Still, this is what is required of drug developers when they assess the risk of resistance arising against a new antibiotic candidate during preclinical development....... In this Opinion article, we argue that the traditional procedures that are used for the prediction of antibiotic resistance today could be markedly improved by including a broader analysis of bacterial fitness, infection dynamics, horizontal gene transfer and other factors. This will lead to more informed...

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

    Directory of Open Access Journals (Sweden)

    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.      

  8. Antibiotic Resistance Escherichia coli isolated from Faecal of Healthy Human

    OpenAIRE

    , S. Budiarti

    2011-01-01

    The objective of this research was to examine antibiotic resistant of Escherechia coli as intestinal normal şora, isolated from healthy human. The samples were collected from faeces of new born children, children under 3 and 5years-old, and human adult. Bacteria were isolated at Eosin Methylen Blue solid media followed by biochemistry reaction for physiological E.coli identiŞcation. Antibiotic resistant test was carried out using Kirby-Bauer method. The result showed that 95 % bacterial strai...

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

    Directory of Open Access Journals (Sweden)

    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

  10. Assessment of antibiotic resistance in Klebsiella pneumoniae exposed to sequential in vitro antibiotic treatments.

    Science.gov (United States)

    Kim, Jeongjin; Jo, Ara; Chukeatirote, Ekachai; Ahn, Juhee

    2016-12-09

    Bacteria treated with different classes of antibiotics exhibit changes in susceptibility to successive antibiotic treatments. This study was designed to evaluate the influence of sequential antibiotic treatments on the development of antibiotic resistance in Klebsiella pneumoniae associated with β-lactamase and efflux pump activities. The antibiotic susceptibility, β-lactamase activity, and efflux activity were determined in K. pneumoniae grown at 37 °C by adding initial (0 h) and second antibiotics (8 or 12 h). Treatments include control (CON; no first and second antibiotic addition), no initial antibiotic addition followed by 1 MIC ciprofloxacin addition (CON-CIP), no initial antibiotic addition followed by 1 MIC meropenem addition (CON-MER), initial 1/4 MIC ciprofloxacin addition followed by no antibiotic addition (1/4CIP-CON), initial 1/4 MIC ciprofloxacin addition followed by 1 MIC ciprofloxacin addition (1/4CIP-CIP), and initial 1/4 MIC ciprofloxacin addition followed by 1 MIC meropenem addition (1/4CIP-MER). Compared to the CON, the initial addition of 1/4 MIC ciprofloxacin inhibited the growth of K. pneumoniae throughout the incubation period. The ciprofloxacin treatments (CON-CIP and 1/4CIP-CIP) showed significant reduction in the number of K. pneumoniae cells compared to meropenem (CON-MER and 1/4CIP-MER). The 1/4CIP-CIP achieved a further 1 log reduction of K. pneumoniae, when compared to the 1/4CIP-CON and 1/CIP-MER. The increase in sensitivity of K. pneumoniae to cefotaxime, kanamycin, levofloxacin, nalidixic acid was observed for CON-CIP. Noticeable cross-resistance pattern was observed at the 1/4CIP-CIP, showing the increased resistance of K. pneumoniae to chloramphenicol, ciprofloxacin, kanamycin, levofloxacin, nalidixic acid norfloxacin, sulphamethoxazole/trimethoprim, and tetracycline. The levels of β-lactamase activities were estimated to be 8.4 μmol/min/ml for CON, 7.7 μmol/min/ml for 1/4CIP-CON and as low as 2.9 μmol/min/ml for CON

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

    Science.gov (United States)

    Centner, Terence J

    2016-09-01

    As bacteria and diseases spread due to climatic change, greater amounts of antibiotics will be used thereby exacerbating the problem of antibiotic resistance. To help slacken the development of resistant bacteria, the medical community is attempting to reduce unnecessary and excessive usage of antibiotics. One of the targets is the use of antibiotics for enhancing animal growth and promoting feed efficiency in the production of food animals. While governments can adopt regulations prohibiting nontherapeutic uses of antibiotics in food animals and strategies to reduce antibiotic usage, another idea is to publicize when antibiotics are used in food animal production by allowing labeled meat products. This paper builds upon existing labeling and marketing efforts in the United States to show how a government can develop a verified antibiotic-free labeling program that would allow consumers to purchase meat products from animals that had never received antibiotics. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Multiple antibiotics resistant among environmental isolates of ...

    African Journals Online (AJOL)

    In this study we assessed the functionality of integrons, melanin-like pigment and biofilm formation on multidrug resistance among environmental isolates of Stenotrophomonas maltophilia. Marked resistances were noted against aztreonam (60%), cefepime (68%), ceftazidime (77%), ciprofloxacin (72%), gentamicin (65%), ...

  13. Increased survival of antibiotic-resistant Escherichia coli inside macrophages.

    Science.gov (United States)

    Miskinyte, Migla; Gordo, Isabel

    2013-01-01

    Mutations causing antibiotic resistance usually incur a fitness cost in the absence of antibiotics. The magnitude of such costs is known to vary with the environment. Little is known about the fitness effects of antibiotic resistance mutations when bacteria confront the host's immune system. Here, we study the fitness effects of mutations in the rpoB, rpsL, and gyrA genes, which confer resistance to rifampin, streptomycin, and nalidixic acid, respectively. These antibiotics are frequently used in the treatment of bacterial infections. We measured two important fitness traits-growth rate and survival ability-of 12 Escherichia coli K-12 strains, each carrying a single resistance mutation, in the presence of macrophages. Strikingly, we found that 67% of the mutants survived better than the susceptible bacteria in the intracellular niche of the phagocytic cells. In particular, all E. coli streptomycin-resistant mutants exhibited an intracellular advantage. On the other hand, 42% of the mutants incurred a high fitness cost when the bacteria were allowed to divide outside of macrophages. This study shows that single nonsynonymous changes affecting fundamental processes in the cell can contribute to prolonged survival of E. coli in the context of an infection.

  14. 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. © 2016 John Wiley & Sons Ltd.

  15. Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

    Directory of Open Access Journals (Sweden)

    mojtaba boniadian

    2017-01-01

    Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Antibiotic-resistant bacteria in the guts of insects feeding on plants: prospects for discovering plant-derived antibiotics

    OpenAIRE

    Ignasiak, Katarzyna; Maxwell, Anthony

    2017-01-01

    Background Although plants produce many secondary metabolites, currently none of these are commercial antibiotics. Insects feeding on specific plants can harbour bacterial strains resistant to known antibiotics suggesting that compounds in the plant have stimulated resistance development. We sought to determine whether the occurrence of antibiotic-resistant bacteria in insect guts was a widespread phenomenon, and whether this could be used as a part of a strategy to identify antibacterial com...

  18. 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.

  19. Strategies to Combat Antibiotic Resistance in the Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    Fateme Barancheshme

    2018-01-01

    Full Text Available The main goal of this manuscript is to review different treatment strategies and mechanisms for combating the antibiotic resistant bacteria (ARB and antibiotic resistant genes (ARGs in the wastewater environment. The high amount of antibiotics is released into the wastewater that may promote selection of ARB and ARGs which find their way into natural environments. Emerging microbial pathogens and increasing antibiotic resistance among them is a global public health issue. The propagation and spread of ARB and ARGs in the environment may result in an increase of antibiotic resistant microbial pathogens which is a worldwide environmental and public health concern. A proper treatment of wastewater is essential before its discharge into rivers, lake, or sewage system to prevent the spread of ARB and ARGs into the environment. This review discusses various treatment options applied for combating the spread of ARB and ARGs in wastewater treatment plants (WWTPs. It was reported that low-energy anaerobic–aerobic treatment reactors, constructed wetlands, and disinfection processes have shown good removal efficiencies. Nanomaterials and biochar combined with other treatment methods and coagulation process are very recent strategies regarding ARB and ARGs removal and need more investigation and research. Based on current studies a wide-ranging removal efficiency of ARGs can be achieved depending on the type of genes present and treatment processes used, still, there are gaps that need to be further investigated. In order to find solutions to control dissemination of antibiotic resistance in the environment, it is important to (1 study innovative strategies in large scale and over a long time to reach an actual evaluation, (2 develop risk assessment studies to precisely understand occurrence and abundance of ARB/ARGs so that their potential risks to human health can be determined, and (3 consider operating and environmental factors that affect the

  20. Chronological change of antibiotic use and antibiotic resistance in Escherichia coli causing urinary tract infections.

    Science.gov (United States)

    Shigemura, Katsumi; Tanaka, Kazushi; Adachi, Masayo; Yamashita, Masuo; Arakawa, Soichi; Fujisawa, Masato

    2011-10-01

    Overuse of antibiotics can cause the emergence of resistant bacterial strains. This study retrospectively investigated recent trends in Escherichia coli causing urinary tract infections (UTIs), focusing on antibiotic use and antibiotic susceptibilities. Patients diagnosed with UTIs caused by E. coli in Akashi Municipal Hospital between April 2004 and March 2010 were enrolled in the study. A total of 858 UTI cases were examined. Antibiotics used in our hospital during that period and the antibiotic susceptibilities of E. coli in UTI cases were assessed. We analyzed the data on a yearly basis, with the year being defined as the period from April to the following March (e.g., in this study the period from April 2004 to March 2005 represents 2004). The first 3 years (2004-2006) were compared to the last 3 years (2007-2009). The use of piperacillin, cephazolin, amikacin, oral cefotiam, and levofloxacin decreased significantly and the use of imipenem, gentamicin (GM), cefcapene, and oral minocycline (MINO) increased significantly in the last 3 years compared to the previous 3 years. The susceptibilities of MINO in complicated cystitis significantly increased and those of GM in uncomplicated pyelonephritis significantly decreased in these 3 years (2007-2009) compared to the previous 3 years (2004-2006) (P changes in our pattern of antibiotic use associated with changes in antibiotic susceptibilities and an increase in ESBL-producing E. coli isolated from our UTI cases. Monitoring of antibiotic use and emergence of resistant strains should be continued.

  1. 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.

  2. [Pathogenic microbes of biliary infection and their resistance to antibiotics].

    Science.gov (United States)

    Zhu, J; Tang, Y; Song, X; Wang, Y

    2000-05-01

    To understand the change of the main pathogenic microbes of biliary infection and their resistance rates to 12 antibiotics so as to instruct rational application of antibiotics clinically. All isolates were identified by analytic products incorporation (API) bioMerieux. The susceptibility of antibiotics to 470 pathogenic microbes was tested by minimal inhibition concentration (MIC). There were 470 pathogenic microbes with positive biliary culture. The percentage of Escherichia coli, intestinal cocci and Klebsiella pneumoniae was 129 (27.4%), 82 (17.4%) and 76 (16.2%), respectively. In the resistance rates of the gram negative bacilli to 12 antibiotics, the lowest was 4.0% for imipenem followed by. 14.1% Ceftazidime and 16.9% amikacin. In the resistant rates of the gram positive cocci to 12 antibiotics, and had the lowest rate was 6.0% for vancomycin and 16.4% for imipenem. The main pathogenic microbes of biliary infection were Escherichia coli, intestinal cocci and Klebsiella pneumoniae. Imipenem is the first used for biliary infection in dealing with multiresistant intestinal cocci.

  3. Patient age as a factor of antibiotic resistance in methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Garcia, Alexander; Delorme, Thierry; Nasr, Payman

    2017-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of nosocomial infections. A thorough understanding of the epidemiology and distribution of MRSA allows the development of better preventive measures and helps to control or reduce the rate of infection among the general population. A retrospective survey was performed on 511 cases of MRSA infections from inpatient, outpatient and nursing home populations over a 12-month period. To study the relationships between two continuous quantitative variables (patient age vs resistance percentage), a simple linear regression was calculated for each antibiotic to predict the antibiotic resistance percentage with respect to patient age.Results/Key findings. The pattern of antibiotic resistance with respect to the age of patients depended on the antibiotic mode of action. Antibiotics that target DNA synthesis (i.e. fluoroquinolones) display a direct correlation with the age of patients, with higher rates of resistance among the older population, while antibiotics that target ribosomal functions (i.e. aminoglycosides) or cell wall synthesis (i.e. cephalosporin) do not display an age-dependent pattern and have a consistent degree of resistance across all age classes. Antibiotics that target DNA synthesis result in a progressively higher number of resistant isolates among the older population. The results emphasize the importance of patient age on antibiotic selection as a preventive measure to reduce the rate of resistant infections in each susceptible population. This pattern suggests that physicians should take into consideration patient age as another factor in determining the best antibiotic regiment with the aim of curtailing the emergence of newer resistant phenotypes in the future.

  4. An evolutionary model to predict the frequency of antibiotic resistance under seasonal antibiotic use, and an application to Streptococcus pneumoniae.

    Science.gov (United States)

    Blanquart, François; Lehtinen, Sonja; Fraser, Christophe

    2017-05-31

    The frequency of resistance to antibiotics in Streptococcus pneumoniae has been stable over recent decades. For example, penicillin non-susceptibility in Europe has fluctuated between 12% and 16% without any major time trend. In spite of long-term stability, resistance fluctuates over short time scales, presumably in part due to seasonal fluctuations in antibiotic prescriptions. Here, we develop a model that describes the evolution of antibiotic resistance under selection by multiple antibiotics prescribed at seasonally changing rates. This model was inspired by, and fitted to, published data on monthly antibiotics prescriptions and frequency of resistance in two communities in Israel over 5 years. Seasonal fluctuations in antibiotic usage translate into small fluctuations of the frequency of resistance around the average value. We describe these dynamics using a perturbation approach that encapsulates all ecological and evolutionary forces into a generic model, whose parameters quantify a force stabilizing the frequency of resistance around the equilibrium and the sensitivity of the population to antibiotic selection. Fitting the model to the data revealed a strong stabilizing force, typically two to five times stronger than direct selection due to antibiotics. The strong stabilizing force explains that resistance fluctuates in phase with usage, as antibiotic selection alone would result in resistance fluctuating behind usage with a lag of three months when antibiotic use is seasonal. While most antibiotics selected for increased resistance, intriguingly, cephalosporins selected for decreased resistance to penicillins and macrolides, an effect consistent in the two communities. One extra monthly prescription of cephalosporins per 1000 children decreased the frequency of penicillin-resistant strains by 1.7%. This model emerges under minimal assumptions, quantifies the forces acting on resistance and explains up to 43% of the temporal variation in resistance.

  5. Fate and transport of antibiotic resistant bacteria and resistance genes in artificially drained agricultural fields receiving swine manure application

    Science.gov (United States)

    While previous studies have examined the occurrence of antibiotic resistant bacteria and antibiotic resistant genes around confined swine feeding operations, little information is known about their release and transport from artificially drained fields receiving swine manure application. Much of the...

  6. Molecular epidemiological survey of bacteremia by multidrug resistant Pseudomonas aeruginosa: the relevance of intrinsic resistance mechanisms.

    Directory of Open Access Journals (Sweden)

    Raquel Cristina Cavalcanti Dantas

    Full Text Available The bacterial factors associated with bacteremia by multidrug-resistant and extensively drug-resistant P. aeruginosa, including overexpression of efflux pumps, AmpC overproduction, and loss/alteration of the OprD porin in isolates that are non-Metallo-β-Lactamase producing were analyzed in a retrospective study. Molecular analyses included strain typing by Pulsed Field Gel Electrophoresis and identification of key genes via qualitative and quantitative PCR-based assays. Previous use of carbapenems and tracheostomy was independently associated with the development of bacteremia by extensively drug-resistant and multidrug-resistant strains of P. aeruginosa. A high consumption of antimicrobials was observed, and 75.0% of the isolates contained amplicons with the blaSPM-1 and blaVIM genes. Of the 47 non-Metallo-β-Lactamase isolates, none had another type of carbapenemase. However, the isolates exhibited high rates of hyperproduction of AmpC, loss of the OprD porin (71.4% and the presence of MexABOprM (57.1% and MexXY (64.3%. This study suggests that in non-Metallo-β-Lactamase isolates, the association of intrinsic resistance mechanisms could contributes to the expression of multidrug-resistant/extensively drug-resistant phenotypes.

  7. PRESENCE OF ENTEROCOCCI IN COW MILK AND THEIR ANTIBIOTIC RESISTANCE

    Directory of Open Access Journals (Sweden)

    Miroslav Kročko

    2010-05-01

    Full Text Available Enterococci represent an important part of contaminate microflora in raw milk and dairy products. They constitute significant part of nosocomial pathogens with a remarkable capacity of expressing resistance to several antimicrobial  agents. We aimed to assess occurrence and antibiotic resistance of enterococci in the raw milk samples and pasteurized milk samples. In this study total bacterial count, psychrotrophic count and count of enterococci were determine in raw milk cistern samples, storage tank milk samples and milk samples after pasteurization. A collection of 46 enterococcal isolates were identified and screened for their antibiotic resistance. Isolates of E. faecalis were dominant in raw milk samples (56.5 %. Sensitive to teicoplanine (30 mcg/disk were 97.9 % of enterococcal isolates and 15.2 % isolates were resistant to vankomycin (30 mcg/disk.  

  8. Evolutionary Origin of Antibiotic Resistance, A Historical Perspective

    Directory of Open Access Journals (Sweden)

    Yamile Adriana Celis Bustos

    2017-07-01

    Full Text Available Antimicrobial resistance is a natural aspect of bacterial evolution that can result from mutations or acquisition of foreign genes. Various views on the origin of this resistance explain the ability of these organisms to acquire new features. Lamarck andDarwin’s theories of evolution have led to experiments designed to explore the origin of bacterial variation and the emergence of new features. These experiments show that antimicrobial resistance is related to mutations in chromosomal genes and/or transfer of extrachromosomal genetic elements that can be expressed based on the antibiotic pressure exerted. The main experiments and findings that seek to explain the phenomenon of antibiotic resistance are reviewed here in.

  9. Detection of antibiotic resistance in clinical bacterial strains from pets

    OpenAIRE

    Poeta, P.; Rodrigues, J.

    2008-01-01

    The identification of different bacterial strains and the occurrence of antibiotic resistance were investigated in several infection processes of pets as skin abscess with purulent discharge, bronco alveolar fluid, earwax, urine, mammary, and eye fluid. Streptococcus spp. and Staphylococcus spp. were the most detected in the different samples. A high frequency of antimicrobial resistance has been observed and this could reflect the wide use of antimicrobials in pets, making the effectiveness ...

  10. Old and New Glycopeptide Antibiotics: Action and Resistance

    OpenAIRE

    Binda, Elisa; Marinelli, Flavia; Marcone, Giorgia Letizia

    2014-01-01

    Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycop...

  11. ENTEROCOCCI AND THEIR RESISTANCE TO ANTIBIOTICS AND THYME ESSENTIAL OIL

    Directory of Open Access Journals (Sweden)

    Viera Ducková

    2014-02-01

    Full Text Available Enterococci are important part of microflora of food animal origin. They have positive (probiotic effect, production flavor compounds during food ripening and also negative (production biogenic amine, antibiotic resistance, biofilm production properties. The aim of this work was to determine resistance to different concentrations of thyme essential oil and antibiotic resistance of enterococci isolated from pork (n=3 and poultry (n=17. The antibiotic resistance of isolates was determined by disc diffusion method and the antibacterial effect of thyme essential oil was assayed by a microdilution method in 96-well microtitration plates after determination of absorbance at 630 nm (A630. Of 20 tested enterococci, 85 % were resistant to tetracycline, 35 % to erythromycin, 15 % to ampicillin and 5 % to gentamicin. No resistance to vancomycin was detected. All tested strains of enterococci were able to grow and reproduce at concentrations of thyme essential oil 0.033 % and 0.066 %. Inhibitory effect of thyme essential oil began at a concentration of 0.099 %, but only for 10 % of the tested strains. Even the highest concentration tested thyme essential oil 0.166 % did not inhibit all the tested strains, because 25 % of enterococcal strains continued to grow. No correlation between antibiotic resistance and resistance to the thyme essential oil was detected for tested enterococci. The thyme essential oil has potential for using in food industry to inhibit spoilage or pathogenic microorganisms, but it is necessary to test antimicrobial activity in other in vitro and in vivo experiments and also in experiments with impact on the sensory properties of food.

  12. Importance and implications of antibiotic resistance development in ...

    African Journals Online (AJOL)

    Antibiotic resistance (ABR) is regarded as one of today's major global health challenges. The development of ABR in nature is a complex phenomenon with many influencing factors, of which the farming industry is labelled a significant contributor. The transfer of ABR to humans, which usually occurs via the food chain, is of ...

  13. Antibiotic Resistant Salmonella And Escherichia Coli Isolated From ...

    African Journals Online (AJOL)

    Our investigation revealed that Escherichia coli and Salmonella organisms were isolated in the outbreaks. A pattern of antibiotic resistance that seems to be increasing was also found. Considering the role of chickens and its products in the human food chain in Nigeria; and the close interaction between poultry and man, ...

  14. Emerging antibiotic resistance in bacteria with special reference to ...

    Indian Academy of Sciences (India)

    Prakash

    Sir Dorabji Tata Centre for Research in Tropical Diseases, Innovation Centre, Indian Institute of Science Campus,. Bangalore 560 012 ... The antibiotic era started in the 1940s and changed the profile of infectious diseases and human demography. The ... any resistance conferring factor, while the clinical term would cover ...

  15. Antibiotic resistant pattern of environmental isolates of Listeria ...

    African Journals Online (AJOL)

    Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which ...

  16. Antibiotic Resistant Salmonella And Escherichia Coli Isolated From ...

    African Journals Online (AJOL)

    We investigated the cause of death using several virological and bacteriological techniques, isolated the pathogenic agents and carried out sensitivity tests. Our investigation revealed that Escherichia coli and Salmonella organisms were isolated in the outbreaks. A pattern of antibiotic resistance that seems to be increasing ...

  17. 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

  18. A comparison of antibiotic resistance in microorganisms isolated ...

    African Journals Online (AJOL)

    Samples of fresh faeces were obtained from a free-range chicken source, three commercial chicken farms and a commercial ostrich farm, all located around Bulawayo City, Zimbabwe, in order to determine the antibiotic resistance profile of selected bacterial isolates of interest in food-related human infections. Samples were ...

  19. increasing incidence of bacterial resistance to antibiotics by isolates ...

    African Journals Online (AJOL)

    ABSTRACT. This a prospective study to determine the prevalence of antibiotic resistance among organisms causing urinary tract infections in a Teaching Hospitai between August 2003 and July 2004 and to compare them with an earlier study in 1993. A total of HM urine samples were collected in sterile universal ...

  20. Antibiotic resistance in children with complicated urinary tract infection

    International Nuclear Information System (INIS)

    Yildiz, B.; Kural, N.; Yarar, C.; Ak, I.; Akcar, N.

    2007-01-01

    Objective was to determine the resistance of antibiotics for complicated urinary tract infection (UTI), including urinary tract anomaly (UTA), for empirical antibiotic therapy of complicated UTI. Four hundred and twenty two urine isolates were obtained from 113 patients with recurrent UTI, who used prophylactic antibiotics between February 1999 and November 2004 in the Eskisehir Osmangazi University, Eskisehir, Turkey. Reflux was found to be most important predisposing factor for recurrent UTI (31.9%). Renal scar was detected more in patients with UTA than without UTA (59.2% versus 12.4%, p<0.05). Gram-negative organisms were dominant in patients with and without UTA (91.5% and 79.2%). Enterococci and Candida spp. were more prevalent in children with UTA than without UTA (p<0.001). Isolates were significantly more resistant to ampicillin, trimethoprim-sulfamethoxazole, amikacin, co-amoxiclav, ticarcillin-clvalanate and piperacillin-tazobactam in patients with UTA than without UTA. We found low resistance to ciprofloxacin and nitrofurantoin in UTI with and without UTA. Enterococci spp. was highly resistance to ampicillin and amikacin in patients with UTA. Aztreonam, meropenem and ciprofloxacin seemed to be the best choice for treatment of UTI with UTA due to Escherichia coli and Klebsiella spp. Nitrofurantoin and nalidixic acid may be first choice antibiotics for prophylaxis in UTI with and without UTA. The UTI with UTA caused by Enterococci spp. might not benefit from a combination of amikacin and ampicillin, it could be treated with glycopeptides. (author)

  1. 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…

  2. Evaluation of antibiotic resistance patterns and heavy metals ...

    African Journals Online (AJOL)

    This work investigated the antibiotic resistance patterns and heavy metals such as Lead (Pb), Zinc (Zn), Cadmium (Cd) and iron (Fe) tolerance of selected bacteria isolated from contaminated soils and sediments around Warri area of Delta State. The heterotrophic bacterial counts for the sampled soils and sediments ranged ...

  3. 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.

  4. 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…

  5. Molecular Detection of Virulence Genes and Antibiotic Resistance ...

    African Journals Online (AJOL)

    Escherichia coli O157:H7 is an important food-borne pathogen that can cause diarrhea, haemorrhagic colitis and haemolytic uremic syndrome. This study was conducted to investigate the prevalence, virulence genes and antibiotic resistance patterns of E. coli O157:H7 in raw beef meat sold in Abeokuta, South west Nigeria ...

  6. Distribution of multiple antibiotic resistant Vibrio spp across Palk Bay

    Digital Repository Service at National Institute of Oceanography (India)

    Sneha, K.G.; Anas, A.; Jayalakshmy, K.V.; Jasmin, C.; VipinDas, P.V.; Pai, S.S.; Pappu, S.; Nair, M.; Muraleedharan, K.R.; Sudheesh, K.; Nair, S.

    is the absence of blaNDM-1 gene, which confers microorganism with resistance against third generation carbapenem antibiotics. Among toxicity genes tested, toxR gene was found present and ctxA absent in all the isolates. The step up multiple regression model...

  7. Heavy metal and associated antibiotic resistance of fecal coliforms ...

    African Journals Online (AJOL)

    SARAH

    2013-04-25

    Apr 25, 2013 ... contamination of the wastewaters and sludge with heavy metals possibly from animal feeds or drinking waters, leading to co-selection of both metal tolerant and antibiotic resistant microbial species. This requires intervention measures to curb the potential health hazard that heavy metal pollution pose in ...

  8. Prevalence, antibiotic-resistance properties and enterotoxin gene ...

    African Journals Online (AJOL)

    milk-based infant foods in Iran, represent an important public health issue which should be considered ... Keywords: Prevalence, Bacillus cereus, Antibiotic resistance, Enterotoxigenic genes, Milk-based infant food. Tropical Journal of Pharmaceutical Research is indexed by Science ..... and cereals collected in Korea.

  9. Fungicide, antibiotic, heavy metal resistance and salt tolerance of ...

    African Journals Online (AJOL)

    user

    2011-03-28

    Mar 28, 2011 ... All of the rhizobial isolates showed resistance to the antibiotic (µg ml-1); streptomycin sulphate ... Using fungicides for crop diseases control in legume fields has contributed to increasing yield ..... on growth of Rhizobium japonicum and symbiotically grown soybean in soil under laboratory conditions. Prot.

  10. 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

  11. Antibiotic resistance in human peri-implantitis microbiota

    NARCIS (Netherlands)

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

    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

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

    Indian Academy of Sciences (India)

    Prakash

    The HIV/AIDS pandemic as well as emergent and reemergent infections have rekindled the interest in infectious diseases but the antibiotic scene remains ..... to control spread of resistant bacteria and investigation of outbreaks add to the cost of health care. On a national scale the burden is considerable amounting to about ...

  13. Risk of antibiotic resistance from metal contaminated soils

    Science.gov (United States)

    Knapp, Charles

    2013-04-01

    It is known that contaminated soils can lead to increased incidence of illness and disease, but it may also prevent our ability to fight disease. Many antibiotic resistant genes (ARG) acquired by bacteria originate from the environment. It is important to understand factors that influence levels of ARG in the environment, which could affect us clinically and agriculturally. The presence of elevated metal content in soils often promotes antibiotic resistance in exposed microorganisms. Using qPCR, the abundances of ARG to compare levels with geochemical conditions in randomly selected soils from several countries. Many ARG positively correlated with soil metal content, especially copper, chromium, nickel, lead, and iron. Results suggest that geochemical metal conditions influence the potential for antibiotic resistance in soil, which might be used to estimate baseline gene presence on various landscape scales and may translate to epidemiological risk of antibiotic-resistance transmission from the environment. This suggests that we may have to reconsider tolerances of metal pollution in the environment.

  14. Isolation of antibiotic-resistant pathogenic and potentially ...

    African Journals Online (AJOL)

    2010-09-13

    Sep 13, 2010 ... aureus. Conclusion: Contamination of carpets in mosques of Tripoli with antibiotic-resistant pathogenic and potentially pathogenic bacteria may pose a .... and S. aureus were detected in carpets from the mosques in Tripoli. Salmonella spp. are important foodborne pathogens worldwide. They are the most.

  15. Prevalence of multiple antibiotic resistant bacteria and chromosomal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... Prevalence of multiple antibiotic resistant bacteria and chromosomal determinants in surface water of. Bangladesh. Hasan M. Zahid1*, Zinat Mahal2, and Mamun R. Chowdhury2. 1Tissue Banking and Biomaterial Research Unit, Atomic Energy Research Establishment, Bangladesh Atomic Energy.

  16. Antibiotic resistant bacteria in faecal samples of apparently healthy ...

    African Journals Online (AJOL)

    The occurrence of antibiotic-resistant bacteria in faeces of apparently healthy individual volunteers was investigated. Faecal samples were collected from 216 individuals comprising 138 adults (70 males and 68 females) and 78 children aged between 4 months and 42 years (mean age was 30.2 months). Individuals on ...

  17. Antibiotic resistance in bacteria - an emerging public health problem ...

    African Journals Online (AJOL)

    The discovery and eventual introduction of anti-microbial agents to clinical medicine was one of the greatest medical triumphs of the twentieth century that revolutionized the treatment of bacterial diseases. However, the gradual emergence of populations of antibiotic-resistant bacteria resulting from use, misuse and outright ...

  18. Dispensing of antibiotics without prescription in Greece, 2008: another link in the antibiotic resistance chain.

    Science.gov (United States)

    Plachouras, D; Kavatha, D; Antoniadou, A; Giannitsioti, E; Poulakou, G; Kanellakopoulou, K; Giamarellou, H

    2010-02-18

    Antibiotic resistance has been associated with the use of antibiotics. The dispensing of antimicrobials without prescription is a potential source of inappropriate antibiotic use. In our study, antibiotics were requested without prescription from pharmacies in the metropolitan area of Athens in Greece in 2008. Twenty-one collaborators visited 174 pharmacies and asked for either amoxicillin/clavulanate acid or ciprofloxacin without providing a prescription or any other justification for the request. In Greece additional restrictions for fluoroquinolone prescriptions were implemented in 2003 after which a separate specific prescription form needs to be filled in by the prescriber, justifying the choice of any fluoroquinolone. Amoxicillin/clavulanate acid was dispensed in all cases. Furthermore, despite the regulation restricting the prescription of ciprofloxacin, this drug was dispensed by 53% of the pharmacies. It appears that the implementation of measures to restrict the use of certain antibiotics (e.g. ciprofloxacin that was studied in our case) was effective in reducing, although not eliminating, inappropriate dispensing. Overall, dispensing of antimicrobials without prescription is a widespread practice in the studied area and is contributing to the overuse of antibiotics.

  19. Monitoring Antibiotic Residues and Corresponding Antibiotic Resistance Genes in an Agroecosystem

    Directory of Open Access Journals (Sweden)

    Yasser M. Awad

    2015-01-01

    Full Text Available Antibiotic resistance genes (ARGs have been commonly reported due to the overuse worldwide of antibiotics. Antibiotic overuse disturbs the environment and threatens public human health. The objective of this study was to measure the residual concentrations of veterinary antibiotics in the tetracycline group (TCs, including tetracycline (TC and chlortetracycline (CTC, as well as those in the sulfonamide group (SAs, including sulfamethazine (SMT, sulfamethoxazole (SMX, and sulfathiazole (STZ. We also isolated the corresponding ARGs in the agroecosystem. Four sediment samples and two rice paddy soil samples were collected from sites near a swine composting facility along the Naerincheon River in Hongcheon, Korea. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS was employed with a solid-phase extraction method to measure the concentration of each antibiotic. ARGs were identified by the qualitative polymerase chain-reaction using synthetic primers. SAs and their corresponding ARGs were highly detected in sediment samples whereas TCs were not detected except for sediments sample #1. ARGs for TCs and SAs were detected in rice paddy soils, while ARGs for TCs were only found in sediment #2 and #4. Continuous monitoring of antibiotic residue and its comprehensive impact on the environment is needed to ensure environmental health.

  20. CDC Vital Signs: Making Health Care Safer -- Protect Patients from Antibiotic Resistance

    Science.gov (United States)

    ... About CDC.gov . Vital Signs Topics Covered Alcohol Antibiotic Resistance Cancer Cardiovascular Diseases Diseases & Conditions Food Safety Healthcare- ... Clips Making Health Care Safer Protect patients from antibiotic resistance Language: English (US) Español (Spanish) Recommend on Facebook ...

  1. Effects of Metals on Antibiotic Resistance and Conjugal Plasmid Transfer in Soil Bacterial Communities

    DEFF Research Database (Denmark)

    Song, Jianxiao

    Antibiotic resistance currently represents one of the biggest challenges for human health and in recent years the environmental dimension of antibiotic resistance has been increasingly recognized. The soil environment serves as an important reservoir of antibiotic resistance determinants....... In addition to direct selection of antibiotic resistance by antibiotics, metals may co-select for antibiotic resistance via different mechanisms causing environmental selection of antibiotic resistance in metal contaminated soils. Horizontal gene transfer of mobile genetic elements (MGEs) like plasmids...... is generally considered one of the most important co-selection mechanisms as multiple resistance genes can be located on the same MGE. This PhD thesis focused on the impact of metals (Cu and Zn) on the development of antibiotic resistance in bacterial communities in soils exposed to different degrees...

  2. 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...

  3. Antibiotic Resistance in Staphylococcus aureus Strains Isolated from Clinical Specimens

    Directory of Open Access Journals (Sweden)

    M. Sirin

    2016-04-01

    Full Text Available Aim: The aim of this study was to determine the antibiotic susceptibilities of S.aureus strains isolated from various clinical specimens between the years 2011-2014 and to investigate the changes of these susceptibilities over the years. Material and Method: Identification and antibiotic susceptibility testing of the strains were performed by Vitek 2 compact automated system (bioMérieux, France. The strains found to be intermediate susceptible to vancomycin and teicoplanin were also tested by E-test method. Results: S.aureus strains (n=1442 were most commonly isolated from wound, urine and blood samples. The isolation rates of methicillin-resistant S.aureus (MRSA in hospitalized patients were significantly higher than the isolation rates of MRSA in outpatients. All strains were susceptible to vancomycin, teicoplanin, linezolid and tigecycline. The total of four years resistance rates of MRSA strains to erythromycin, clindamycin, ciprofloxacin, moxifloxacin, gentamicin, co-trimoxazole, fusidic acid were significantly higher than the resistance rates of methicillin-sensitive S.aureus (MSSA. The changes in the rates of antibiotic resistance were not statistically significant in MSSA strains over the years, and statistically significant decrease was found in erythromycin, clindamycin, ciprofloxacin, moxifloxacin and gentamicin resistance in MRSA strains. Discussion: Glycopeptides, linezolid and tigecycline were the most effective antibiotics against S.aureus strains. It was considered as necessary to detect antimicrobial resistance profiles by effective surveillance studies and monitor the changes occurred over the years in order to prevent the development of resistance and control of infections.

  4. Enterobacteriaceae Antibiotic Resistance in Ready-to-Eat Foods Collected from Hospital and Community Canteens: Analysis of Prevalence.

    Science.gov (United States)

    Vincenti, Sara; Raponi, Matteo; Sezzatini, Romina; Giubbini, Gabriele; Laurenti, Patrizia

    2018-03-01

    Foodborne diseases and antibiotic resistance are serious widespread health problems in the contemporary world. In this study, we compared the microbiological quality of ready-to-eat (RTE) foods found in community canteens versus hospital canteens in Rome, Italy, focusing on detection and quantification of Enterobacteriaceae and the antibiotic resistance of these bacteria. Our findings show a remarkable difference in Enterobacteriaceae contamination between RTE foods distributed in community canteens (33.5% of samples) and those distributed in hospital canteens (5.3% of samples). This result highlights greater attention to good manufacturing practices and good hygiene practices by the food operators in hospitals compared with food operators in community canteens. As expected, a higher percentage of cold food samples (70.9%) than of hot food samples (10.8%) were positive for these bacteria. Excluding the intrinsic resistance of each bacterial strain, 92.3% of the isolated strains were resistant to at least one antibiotic, and about half of the isolated strains were classified as multidrug resistant. The prevalence of multidrug-resistant strains was 50% in the community samples and 33.3% in hospital canteens. Our results indicate that approximately 38% of RTE foods provided in community canteens is not compliant with microbiological food safety criteria and could be a special risk for consumers through spread of antibiotic-resistant strains. Hygienic processing and handling of foods is necessary for both hospital and community canteens.

  5. Antibiotic Resistance Pattern and Molecular Epidemiology of ...

    African Journals Online (AJOL)

    Data processing and Analysis. Gels images were taken by GEL DOC XR (Bio. Rad Milan, Italy) and analyzed with BioNumerics software Gel Compar II (Applied Maths, Kortrijk,. Belgium). ..... Gehanno JF, Louvel A, Nouvellon M, Caillard JF, Pestel-. Caron M. Aerial dispersal of methicillin-resistant. Staphylococcus aureus in ...

  6. ORIGINAL ARTICLE MULTIPLE ANTIBIOTIC RESISTANCE (MAR ...

    African Journals Online (AJOL)

    boaz

    ABSRACT. Background/Objectives: Pseudomonas and Klebsiella infections are important nosocomial infections because of the attendant significant morbidity, mortality and socio-economic impact. These infections are difficult to treat due to the innate and acquired resistance mediated by the organisms' genome and other ...

  7. Antibiotic resistance profile in community-associated ...

    African Journals Online (AJOL)

    Isolation, identification and susceptibility pattern of the isolates was determined. The methicillin resistant strains were confirmed by the polymerase chain reaction (PCR) detection of the mecA gene. The entire tests were done according to standard protocols. Forty S. aureus strains were identified and were observed to be ...

  8. Species Distribution and Antibiotic Resistance in Coagulase ...

    African Journals Online (AJOL)

    Purpose: The antimicrobial susceptibility of 149 coagulase-negative staphylococci (CoNS) isolates from faecal samples of children in Ile-Ife, Nigeria, was evaluated in order to determine their contribution to antimicrobial resistance in the community. Methods: The isolates were identified to the species level by conventional ...

  9. 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.

  10. Development of Methods for Genetic Assessment of Antibiotic Resistance In Animal Herds

    DEFF Research Database (Denmark)

    Schmidt, Gunilla Veslemøy

    should be tested in order to assist in understanding the antibiotic resistance gene variation. This study illustrates the immensity of the antibiotic resistance problem and the necessity for systematic surveillance of antibiotic consumption and resistance development at global, national, and local scales.......Antibiotic drugs are important in treating bacterial infectious diseases in humans and animals. There are severe consequences when infectious bacteria become resistant to antibiotics such as treatment failure and even death. Since antibiotics were discovered, their use has been associated...... with a parallel selection for resistant bacteria. Since the hazards related to antibiotic resistance development have been recognized, the prudent use of antibiotics has been in focus, especially concerning their use in animal production. For many years antibiotics have been, and still are, recklessly used...

  11. Nanotransformation of vancomycin overcomes the intrinsic resistance of Gram-negative bacteria

    OpenAIRE

    Ivanova, Kristina Dimitrova; Hoyo Pérez, Javier; Francesko, Antonio; Tzanov, Tzanko

    2017-01-01

    The increased emergence of antibiotic-resistant bacteria is a growing public health concern, and although new drugs are constantly being sought, the pace of development is slow compared with the evolution and spread of multidrug- resistant species. In this study, we developed a novel broad-spectrum antimicrobial agent by simply transforming vancomycin into nanoform using sonochemistry. Vancomycin is a glycopeptide antibiotic largely used for the treatment of infections caused by Gram-positive...

  12. 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.

  13. Rapid electrochemical phenotypic profiling of antibiotic-resistant bacteria.

    Science.gov (United States)

    Besant, Justin D; Sargent, Edward H; Kelley, Shana O

    2015-07-07

    Rapid phenotyping of bacteria to identify drug-resistant strains is an important capability for the treatment and management of infectious disease. At present, the rapid determination of antibiotic susceptibility is hindered by the requirement that, in existing devices, bacteria must be pre-cultured for 2-3 days to reach detectable levels. Here we report a novel electrochemical approach that achieves rapid readout of the antibiotic susceptibility profile of a bacterial infection within one hour. The electrochemical reduction of a redox-active molecule is monitored that reports on levels of metabolically-active bacteria. Bacteria are captured in miniaturized wells, incubated with antimicrobials and monitored for resistance. This electrochemical phenotyping approach is effective with clinically-relevant levels of bacteria, and provides results comparable to culture-based analysis. Results, however, are delivered on a much faster timescale, with resistance profiles available after a one hour incubation period.

  14. 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 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.

  15. The Antibiotic Resistant Target Seeker (ARTS), an exploration engine for antibiotic cluster prioritization and novel drug target discovery

    DEFF Research Database (Denmark)

    Alanjary, Mohammad; Kronmiller, Brent; Adamek, Martina

    2017-01-01

    With the rise of multi-drug resistant pathogens and the decline in number of potential new antibiotics in development there is a fervent need to reinvigorate the natural products discovery pipeline. Most antibiotics are derived from secondary metabolites produced by microorganisms and plants....... To avoid suicide, an antibiotic producer harbors resistance genes often found within the same biosynthetic gene cluster (BGC) responsible for manufacturing the antibiotic. Existing mining tools are excellent at detecting BGCs or resistant genes in general, but provide little help in prioritizing...... and identifying gene clusters for compounds active against specific and novel targets. Here we introduce the 'Antibiotic Resistant Target Seeker' (ARTS) available at https://arts.ziemertlab.com. ARTS allows for specific and efficient genome mining for antibiotics with interesting and novel targets. The aim...

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

    Science.gov (United States)

    Makoka, Mwai H; Miller, William C; Hoffman, Irving F; Cholera, Rushina; Gilligan, Peter H; Kamwendo, Debbie; Malunga, Gabriel; Joaki, George; Martinson, Francis; Hosseinipour, Mina C

    2012-03-21

    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. Culture and susceptibility testing was performed on various specimens from patients presenting with possible infectious diseases at Kamuzu Central Hospital, Lilongwe, Malawi. 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. 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.

  17. Complex migration of antibiotic resistance in natural aquatic environments.

    Science.gov (United States)

    Gao, Hui; Zhang, Linxiao; Lu, Zihao; He, Chunming; Li, Qianwei; Na, Guangshui

    2018-01-01

    Antibiotic resistance is a worsening global concern, and the environmental behaviors and migration patterns of antibiotic resistance genes (ARGs) have attracted considerable interest. Understanding the long-range transport of ARG pollution is crucial. In this study, we characterized the dynamics of ARG changes after their release into aquatic environments and demonstrated the importance of traditional chemical contaminants in the transmission mechanisms of ARGs. We hypothesized that the main route of ARG proliferation switches from active transmission to passive transmission. This antibiotic-dominated switch is motivated and affected by non-corresponding contaminants. The effect of anthropogenic activities gradually weakens from inland aquatic environments to ocean environments; however, the effect of changes in environmental conditions is enhanced along this gradient. The insights discussed in this study will help to improve the understanding of the distribution and migration of ARG pollution in various aquatic environments, and provide a modern perspective to reveal the effect of corresponding contaminants and non-corresponding contaminants in the process of antibiotic resistance proliferation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Antibiotic resistance rates and physician antibiotic prescription patterns of uncomplicated urinary tract infections in southern Chinese primary care.

    Science.gov (United States)

    Wong, Carmen Ka Man; Kung, Kenny; Au-Doung, Philip Lung Wai; Ip, Margaret; Lee, Nelson; Fung, Alice; Wong, Samuel Yeung Shan

    2017-01-01

    Uncomplicated urinary tract infections (UTI) are common in primary care. Whilst primary care physicians are called to be antimicrobial stewards, there is limited primary care antibiotic resistance surveillance and physician antibiotic prescription data available in southern Chinese primary care. The study aimed to investigate the antibiotic resistance rate and antibiotic prescription patterns in female patients with uncomplicated UTI. Factors associated with antibiotic resistance and prescription was explored. A prospective cohort study was conducted in 12 primary care group clinics in Hong Kong of patients presenting with symptoms of uncomplicated UTI from January 2012 to December 2013. Patients' characteristics such as age, comorbidity, presenting symptoms and prior antibiotic use were recorded by physicians, as well as any empirical antibiotic prescription given at presentation. Urine samples were collected to test for antibiotic resistance of uropathogens. Univariate analysis was conducted to identify factors associated with antibiotic resistance and prescription. A total of 298 patients were included in the study. E. coli was detected in 107 (76%) out of the 141 positive urine samples. Antibiotic resistance rates of E. coli isolates for ampicillin, co-trimoxazole, ciprofloxacin, amoxicillin and nitrofurantoin were 59.8%, 31.8%, 23.4%, 1.9% and 0.9% respectively. E. coli isolates were sensitive to nitrofurantoin (98.1%) followed by amoxicillin (78.5%). The overall physician antibiotic prescription rate was 82.2%. Amoxicillin (39.6%) and nitrofurantoin (28.6%) were the most common prescribed antibiotics. Meanwhile, whilst physicians in public primary care prescribed more amoxicillin (OR: 2.84, 95% CI: 1.67 to 4.85, Pantibiotic resistance and physician antibiotic prescription is recommended.

  19. 3. Multiple Antibiotic Resistance Index ofEscherichiaColi Isolates in ...

    African Journals Online (AJOL)

    user

    Resistance index > 0.2, 61 % were from inpatient samples. Conclusion: The high Multiple Antibiotic. Resistance index of the E. coli isolates indicates previous exposure to antibiotics and development of resistance to commonly prescribed antibiotics, hence, antimicrobial susceptibility testing is imperative in selecting ...

  20. 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

  1. Multiple Antibiotic Resistance Patterns of Escherichia coli Isolates from Swine Farms

    OpenAIRE

    Mathew, A. G.; Saxton, A. M.; Upchurch, W. G.; Chattin, S. E.

    1999-01-01

    Antibiotic resistance of Escherichia coli from sows and pigs was determined to compare patterns between pigs of various ages and degrees of antibiotic use. Resistance patterns differed between farm types and pigs of differing ages, indicating that pig age and degree of antibiotic use affect resistance of fecal E. coli.

  2. Antibiotic-resistant Escherichia coli in a government piggery farm in ...

    African Journals Online (AJOL)

    ). Total counts and antibiotic resistant counts declined with age (p<0.05), with the rate of decline in antibiotic resistant counts being greater than that for total counts (p<0.05). The cohort pigs rapidly acquired antibiotic-resistant bacteria shortly ...

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

    Science.gov (United States)

    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 and few details are known about how antibiotic resistance genes i...

  4. 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

  5. Diversity and antibiotic resistance of Aeromonas spp. in drinking and waste water treatment plants.

    Science.gov (United States)

    Figueira, Vânia; Vaz-Moreira, Ivone; Silva, Márcia; Manaia, Célia M

    2011-11-01

    The taxonomic diversity and antibiotic resistance phenotypes of aeromonads were examined in samples from drinking and waste water treatment plants (surface, ground and disinfected water in a drinking water treatment plant, and raw and treated waste water) and tap water. Bacteria identification and intra-species variation were determined based on the analysis of the 16S rRNA, gyrB and cpn60 gene sequences. Resistance phenotypes were determined using the disc diffusion method. Aeromonas veronii prevailed in raw surface water, Aeromonas hydrophyla in ozonated water, and Aeromonas media and Aeromonas puntacta in waste water. No aeromonads were detected in ground water, after the chlorination tank or in tap water. Resistance to ceftazidime or meropenem was detected in isolates from the drinking water treatment plant and waste water isolates were intrinsically resistant to nalidixic acid. Most of the times, quinolone resistance was associated with the gyrA mutation in serine 83. The gene qnrS, but not the genes qnrA, B, C, D or qepA, was detected in both surface and waste water isolates. The gene aac(6')-ib-cr was detected in different waste water strains isolated in the presence of ciprofloxacin. Both quinolone resistance genes were detected only in the species A. media. This is the first study tracking antimicrobial resistance in aeromonads in drinking, tap and waste water and the importance of these bacteria as vectors of resistance in aquatic environments is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria.

    Science.gov (United States)

    Geisinger, Edward; Isberg, Ralph R

    2017-02-15

    Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, email: journals.permissions@oup.com.

  7. Virulence and antibiotic resistance of Escherichia coli isolated from rooks.

    Science.gov (United States)

    Kmet, Vladimir; Drugdova, Zuzana; Kmetova, Marta; Stanko, Michal

    2013-01-01

    With regard to antibiotic resistance studies in various model animals in the urban environment, the presented study focused on the rook, many behavioural and ecological aspects of which are important from an epidemiological point of view. A total of 130 Escherichia coli strains isolated from rook faeces during a two-year period (2011-2012) were investigated for antibiotic resistance and virulence. Resistance to ampicillin (60%) and streptomycin (40%) were the most frequent, followed by resistance to fluoroquinolones (ciprofloxacin-22% and enrofloxacin-24%), tetracycline (18%), cotrimoxazol (17%) and florfenicol (14%). Ceftiofur resistance occured in 10.7% of strains and cefquinom resistance in 1.5% of strains. Twenty-five E.coli strains with a higher level of MICs of cephalosporins (over 2mg/L of ceftazidime and ceftriaxon) and fluoroquinolones were selected for detection of betalactamase genes (CTX-M, CMY), plasmid-mediated quinolone resistance qnrS, integrase 1, and for APEC (avian pathogenic E.coli) virulence factors (iutA, cvaC, iss, tsh, ibeA, papC, kpsII). Genes of CTX-M1, CMY-2, integrase 1, papC, cvaC, iutA were detected in one strain of E.coli, and qnrS, integrase 1, iss, cvaC, tsh were detected in another E.coli. DNA microarray revealed the absence of verotoxin and enterotoxin genes and pathogenicity islands. The results show that rooks can serve as a reservoir of antibiotic-resistant E. coli with avian pathogenic virulence factors for the human population, and potentially transmit such E.coli over long distances.

  8. 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.

  9. 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

    , be longitudinal, and cover a sufficiently large and representative population. However, many fall short of these requirements that define good surveillance studies. Moreover, current efforts are dispersed among many, mostly small, initiatives with different objectives. These studies must be tailored...... the diagnosis of hospitalised patients, and the DANMAP programme, which collects data in the veterinary sector. As already noted by the WHO, genetic studies that include both the typing of isolates and the characterisation of resistance determinants are necessary to understand fully the spread and development...

  10. Perceptions among Swedish hospital physicians on prescribing of antibiotics and antibiotic resistance.

    Science.gov (United States)

    Björkman, I; Berg, J; Röing, M; Erntell, M; Lundborg, C S

    2010-12-01

    To explore and describe perceptions of antibiotic prescribing among Swedish hospital physicians, with special reference to whether the perceptions included awareness of antibiotic resistance (AR). A phenomenographic approach was used and data were collected in face-to-face interviews. Hospitals in seven different counties in central Sweden. A strategic sample of 20 hospital physicians specialising in internal medicine, surgery or urology. The variation of perceptions of antibiotic prescribing. Five qualitative different perceptions were found. AR was considered in two of the perceptions. Reasons for not considering AR included a dominating focus on the care of the patient combined with lack of focus on restrictive antibiotic use, or uncertainty about how to manage infectious diseases or the pressure from the healthcare organisation. Parallels between the five perceptions and the stages in the transtheoretical model of health behaviour change were seen. In three of the perceptions, AR was not considered when antibiotics were prescribed. Physicians who primarily express these three perceptions do not seem to be prepared to change to restrictive prescribing. Our findings can be useful in designing activities that encourage AR prevention. Organisational changes are also needed.

  11. 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.

  12. Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Leng, Bingfeng; Haaber, Jakob

    2016-01-01

    that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We...... confirmed by E-test to display at least twofold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase...... with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets...

  13. Antibiotic resistance plasmids of Staphylococcus aureus and their clinical importance

    International Nuclear Information System (INIS)

    Lacey, R.W.

    1975-01-01

    A variety of plasmids were isolated physically, and most antibiotic resistance is thought to be plasmid mediated. A number of characters (e.g., resistance to erythromycin or methicillin, and production of pigment) are determined by genes that do not give clear indications of either plasmid or chromosomal location. Although the formation of a particular plasmid is probably, even in bacterial terms, a very rare event, once formed such an element can spread rapidly among the bacterial population. The spectacular increase in the incidence of penicillinase-producing hospital strains in the late 1940's could have been due in part to this process. Evidence is stronger, however, for the intercell transfer of recently isolated plasmids coding for resistance to fusidic acid (and penicillinase production), or for neomycin, or for tetracycline resistance. Study of bacterial plasmids can resolve fundamental biochemical problems, and give some insight into the life of the cell at the molecular level. But the immediate application of the study of staphylococcal plasmids may be directed towards improving the effectiveness of antibiotic therapy. The most important aspect of future anti-staphylococcal chemotherapy should thus be the limitation of the use of antibiotics, particularly for application to the skin and nose. (U.S.)

  14. [Sensitivity and antibiotic resistance in infections of the musculoskeletal system].

    Science.gov (United States)

    Mata-Hernández, Argenis; Rivera-Villa, Adrián Huematzin; Miguel-Pérez, Adrián; Pérez-Atanasio, José Manuel; Torres-González, Rubén

    2016-01-01

    Infections of the musculoskeletal system are a devastating complication for patients, due to it's long rehabilitation process and even sometimes the removal of the implant, the chronicity of infection, is often due to lack of coverage in empirical antibiotics. A retrospective, observational, descriptive cohort study was performed. All cultures form musculoskeletal system infected patients reported of sensitivity and resistance of germs isolated were analyzed. A total of 143 positive results were included. Reported more frequent germ Staphylococcus aureus accounted for 75 positive cases, followed by Escherichia coli with 31 positive results. Antibiotics with better sensitivity according to the type of microorganisms were trimethoprim-sulfamethoxazole and vancomycin, levofloxacin and linezolid, gentamicin, erythromycin and amikacin. Regarding antibiotic resistance, those reported with the highest percentage were penicillin G, amoxicillin with clavulanic acid and ampicillin. We recommend using empirical treatments in musculoskeletal system infections, trimethoprim-sulfamethoxazole are the best choice because they have the same sensitivity compare with vancomycin and a resistance rate of 7.6%. Betalactamics have a high percentage of resistance and low sensitivity so we must consider alternatives.

  15. Environmental factors influencing the development and spread of antibiotic resistance.

    Science.gov (United States)

    Bengtsson-Palme, Johan; Kristiansson, Erik; Larsson, D G Joakim

    2018-01-01

    Antibiotic resistance and its wider implications present us with a growing healthcare crisis. Recent research points to the environment as an important component for the transmission of resistant bacteria and in the emergence of resistant pathogens. However, a deeper understanding of the evolutionary and ecological processes that lead to clinical appearance of resistance genes is still lacking, as is knowledge of environmental dispersal barriers. This calls for better models of how resistance genes evolve, are mobilized, transferred and disseminated in the environment. Here, we attempt to define the ecological and evolutionary environmental factors that contribute to resistance development and transmission. Although mobilization of resistance genes likely occurs continuously, the great majority of such genetic events do not lead to the establishment of novel resistance factors in bacterial populations, unless there is a selection pressure for maintaining them or their fitness costs are negligible. To enable preventative measures it is therefore critical to investigate under what conditions and to what extent environmental selection for resistance takes place. In addition, understanding dispersal barriers is not only key to evaluate risks, but also to prevent resistant pathogens, as well as novel resistance genes, from reaching humans. © FEMS 2017.

  16. Environmental factors influencing the development and spread of antibiotic resistance

    Science.gov (United States)

    Kristiansson, Erik; Larsson, D G Joakim

    2017-01-01

    Abstract Antibiotic resistance and its wider implications present us with a growing healthcare crisis. Recent research points to the environment as an important component for the transmission of resistant bacteria and in the emergence of resistant pathogens. However, a deeper understanding of the evolutionary and ecological processes that lead to clinical appearance of resistance genes is still lacking, as is knowledge of environmental dispersal barriers. This calls for better models of how resistance genes evolve, are mobilized, transferred and disseminated in the environment. Here, we attempt to define the ecological and evolutionary environmental factors that contribute to resistance development and transmission. Although mobilization of resistance genes likely occurs continuously, the great majority of such genetic events do not lead to the establishment of novel resistance factors in bacterial populations, unless there is a selection pressure for maintaining them or their fitness costs are negligible. To enable preventative measures it is therefore critical to investigate under what conditions and to what extent environmental selection for resistance takes place. In addition, understanding dispersal barriers is not only key to evaluate risks, but also to prevent resistant pathogens, as well as novel resistance genes, from reaching humans. PMID:29069382

  17. Inappropriate use of antibiotics in hospitals: the complex relationship between antibiotic use and antimicrobial resistance.

    Science.gov (United States)

    Cantón, Rafael; Horcajada, Juan Pablo; Oliver, Antonio; Garbajosa, Patricia Ruiz; Vila, Jordi

    2013-09-01

    Hospitals are considered an excellent compartment for the selection of resistant and multi-drug resistant (MDR) bacteria. The overuse and misuse of antimicrobial agents are considered key points fuelling this situation. Antimicrobial stewardship programs have been designed for better use of these compounds to prevent the emergence of resistant microorganisms and to diminish the upward trend in resistance. Nevertheless, the relationship between antibiotic use and antimicrobial resistance is complex, and the desired objectives are difficult to reach. Various factors affecting this relationship have been advocated including, among others, antibiotic exposure and mutant selection windows, antimicrobial pharmacodynamics, the nature of the resistance (natural or acquired, including mutational and that associated with horizontal gene transfer) and the definition of resistance. Moreover, antimicrobial policies to promote better use of these drugs should be implemented not only in the hospital setting coupled with infection control programs, but also in the community, which should also include animal and environmental compartments. Within hospitals, the restriction of antimicrobials, cycling and mixing strategies and the use of combination therapies have been used to avoid resistance. Nevertheless, the results have not always been favorable and resistant bacteria have persisted despite the theoretical benefits of these strategies. Mathematical models as well as microbiological knowledge can explain this failure, which is mainly related to the current scenario involving MDR bacteria and overcoming the fitness associated with resistance. New antimicrobials, rapid diagnostic and antimicrobial susceptibility testing and biomarkers will be useful for future antimicrobial stewardship interventions. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  18. Inactivation Effect of Antibiotic-Resistant Gene Using Chlorine Disinfection

    Directory of Open Access Journals (Sweden)

    Takashi Furukawa

    2017-07-01

    Full Text Available The aim of this study was to elucidate the inactivation effects on the antibiotic-resistance gene (vanA of vancomycin-resistant enterococci (VRE using chlorination, a disinfection method widely used in various water treatment facilities. Suspensions of VRE were prepared by adding VRE to phosphate-buffered saline, or the sterilized secondary effluent of a wastewater treatment plant. The inactivation experiments were carried out at several chlorine concentrations and stirring time. Enterococci concentration and presence of vanA were determined. The enterococci concentration decreased as chlorine concentrations and stirring times increased, with more than 7.0 log reduction occurring under the following conditions: 40 min stirring at 0.5 mg Cl2/L, 20 min stirring at 1.0 mg Cl2/L, and 3 min stirring at 3.0 mg Cl2/L. In the inactivation experiment using VRE suspended in secondary effluent, the culturable enterococci required much higher chlorine concentration and longer treatment time for complete disinfection than the cases of suspension of VRE. However, vanA was detected in all chlorinated suspensions of VRE, even in samples where no enterococcal colonies were present on the medium agar plate. The chlorine disinfection was not able to destroy antibiotic-resistance genes, though it can inactivate and decrease bacterial counts of antibiotic-resistant bacteria (ARB. Therefore, it was suggested that remaining ARB and/or antibiotic-resistance gene in inactivated bacterial cells after chlorine disinfection tank could be discharged into water environments.

  19. 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...

  20. Meticillin-resistant Staphylococcus aureus isolated from Iranian hospitals: virulence factors and antibiotic resistance properties

    Directory of Open Access Journals (Sweden)

    Hassan Momtaz

    2014-10-01

    Full Text Available Staphylococcus aureus is an important opportunistic pathogen responsible for a variety of diseases. Indiscriminate prescription of antibiotics caused severe antibiotic resistance especially against commonly used drugs. The present investigation was carried out to study the distribution of Panton-Valentine Leukocidin gene, SCCmec types and antibiotic resistance properties of meticillin-resistant Staphylococcus aureus isolated from Iranian hospitals. A total of 132 clinical specimens were collected from two major Iranian hospitals. Samples were cultured and their positive results were subjected to several PCR methods. The patterns of antibiotic resistance were studied using the disk diffusion method. We found that 66 out of 132 samples (50% were positive for Staphylococcus aureus. The most commonly infected samples were superficial and surgical wounds (66.12%. The incidence of mecA, tetK, ermA, ermC, tetM, aacA-D, linA, msrA, vatA, vatC and vatB antibiotic resistance genes were 80.30%, 34.84%, 30.30%, 25.75%, 24.24%, 19.69%, 7.57%, 7.57%, 6.06%, 3.03% and 1.51%, respectively. Totally, 40.90% of isolates harbored the Panton-Valentine Leukocidin gene. Of 53 mec positive strains, the distribution of SCCmec V, SCCmec III, SCCmec IVa, SCCmec IVc and SCCmec IVb were 28 (52.83%, 13 (24.52%, 6 (11.32%, 4 (7.54% and 2 (3.77%, respectively. All isolates were resistant to penicillin, cephalothin, cefazoline and ceftriaxone. The high levels of Staphylococcus aureus resistance against commonly used antibiotics as well as high presence of SCCmec types of meticillin-resistant virulent strains of Staphylococcus aureus suggest that infections with these strains require more advanced hospital care with emerging demand for novel antibiotics.

  1. Old and New Glycopeptide Antibiotics: Action and Resistance

    Directory of Open Access Journals (Sweden)

    Elisa Binda

    2014-11-01

    Full Text Available Glycopeptides are considered antibiotics of last resort for the treatment of life-threatening infections caused by relevant Gram-positive human pathogens, such as Staphylococcus aureus, Enterococcus spp. and Clostridium difficile. The emergence of glycopeptide-resistant clinical isolates, first among enterococci and then in staphylococci, has prompted research for second generation glycopeptides and a flurry of activity aimed at understanding resistance mechanisms and their evolution. Glycopeptides are glycosylated non-ribosomal peptides produced by a diverse group of soil actinomycetes. They target Gram-positive bacteria by binding to the acyl-D-alanyl-D-alanine (D-Ala-D-Ala terminus of the growing peptidoglycan on the outer surface of the cytoplasmatic membrane. Glycopeptide-resistant organisms avoid such a fate by replacing the D-Ala-D-Ala terminus with D-alanyl-D-lactate (D-Ala-D-Lac or D-alanyl-D-serine (D-Ala-D-Ser, thus markedly reducing antibiotic affinity for the cellular target. Resistance has manifested itself in enterococci and staphylococci largely through the expression of genes (named van encoding proteins that reprogram cell wall biosynthesis and, thus, evade the action of the antibiotic. These resistance mechanisms were most likely co-opted from the glycopeptide producing actinomycetes, which use them to avoid suicide during antibiotic production, rather than being orchestrated by pathogen bacteria upon continued treatment. van-like gene clusters, similar to those described in enterococci, were in fact identified in many glycopeptide-producing actinomycetes, such as Actinoplanes teichomyceticus, which produces teicoplanin, and Streptomyces toyocaensis, which produces the A47934 glycopeptide. In this paper, we describe the natural and semi-synthetic glycopeptide antibiotics currently used as last resort drugs for Gram-positive infections and compare the van gene-based strategies of glycopeptide resistance among the pathogens and

  2. Antibiotic resistance of Helicobacter pylori in Mashhad, Iran

    International Nuclear Information System (INIS)

    Zendedel, A.; Almasi, V.; Moradimoghadam, F.; Zivarifar, H.

    2013-01-01

    Objective: To evaluate Helicobacter pylori resistance to amoxicillin, clarithromycin, metronidazole and tetracycline in Mashhad, Iran. Methods: The cross-sectional study was done from January to May 2008 in Mashhad, involving 185 patients who had been indicated for endoscopy and lesions had been found. Biopsy samples were assessed with histological evaluation, rapid urease test, and culture. Antibiotic resistance was assessed by the disc diffusion method. Data was analysed with SPSS 11.5 using chi-square and Fisher exact test. P values of < 0.05 were regarded as statistically significant. Results: Of the total patients, histological evaluations were positive in 124 (67%). Compared with histology, sensitivity and specificity of rapid urease test were 96.7% and 100%, respectively. In 82 (66.1%) patients with positive cultures, antibiotic resistance was found in 14 (17.1%) for clarithromycin; 53 (64.6%) for metronidazole; and 8 (9.8%) for amoxicillin. No resistance was observed for tetracycline. Moreover, 9 (64%) patients with resistance to clarithromycin had co-resistance to metronidazole. Conclusion: Metronidazole is not recommended for treatment of Helicobacter pylori as a first-line drug. Also, considering the sensitivity and specificity of rapid urease test, we suggest this method as a suitable alternative for histology. (author)

  3. Community perceptions of infectious diseases, antibiotic use and antibiotic resistance in context of environmental changes: a study in Odisha, India.

    Science.gov (United States)

    Sahoo, Krushna Chandra; Tamhankar, Ashok J; Johansson, Eva; Stålsby Lundborg, Cecilia

    2014-10-01

    The public health impact of environmental changes and the faceless threat of antibiotic resistance are currently among the top global health challenges. Community understanding of health, diseases and medicines in relation to the changing environment is necessary to mitigate the impact of these changes on health and for prudent use of antibiotics. The objective is to explore community perceptions of infectious diseases, antibiotic use and antibiotic resistance in the context of environmental changes. A qualitative study was conducted among community members with various backgrounds in education, gender, age and occupation of two districts of Odisha, India. Eight focus groups discussions and ten individual interviews were conducted. Data were analysed using content analysis. Two themes emerged: 'Interpretation of infectious diseases and health hazards in the context of environmental changes', and 'Understanding of antibiotic use and its consequences for resistance development and the environment'. The participants perceived that nowadays there is irregularity in the occurrence of seasons, particularly an increase in average temperature, which is influencing health. Participants' perceptions of infectious diseases, antibiotic use and resistance varied according to their social environment. Furthermore, they perceived that improved sanitation, choice of alternative medicine and awareness and education on prudent use of antibiotics are probably some ways to prevent antibiotic resistance. The participants perceived that climate variability is increasing and that this has health consequences for the community. They also hypothesized an interrelationship between the environment, infectious diseases and medicine use, particularly antibiotics. This is helpful for further empirical studies. © 2012 John Wiley & Sons Ltd.

  4. The Culturable Soil Antibiotic Resistome: A Community of Multi-Drug Resistant Bacteria

    OpenAIRE

    Walsh, Fiona; Duffy, Brion

    2013-01-01

    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 ...

  5. Antibiotics as selectors and accelerators of diversity in the mechanisms of resistance: from the resistome to genetic plasticity in the β-lactamases world

    Science.gov (United States)

    Galán, Juan-Carlos; González-Candelas, Fernando; Rolain, Jean-Marc; Cantón, Rafael

    2013-01-01

    Antibiotics and antibiotic resistance determinants, natural molecules closely related to bacterial physiology and consistent with an ancient origin, are not only present in antibiotic-producing bacteria. Throughput sequencing technologies have revealed an unexpected reservoir of antibiotic resistance in the environment. These data suggest that co-evolution between antibiotic and antibiotic resistance genes has occurred since the beginning of time. This evolutionary race has probably been slow because of highly regulated processes and low antibiotic concentrations. Therefore to understand this global problem, a new variable must be introduced, that the antibiotic resistance is a natural event, inherent to life. However, the industrial production of natural and synthetic antibiotics has dramatically accelerated this race, selecting some of the many resistance genes present in nature and contributing to their diversification. One of the best models available to understand the biological impact of selection and diversification are β-lactamases. They constitute the most widespread mechanism of resistance, at least among pathogenic bacteria, with more than 1000 enzymes identified in the literature. In the last years, there has been growing concern about the description, spread, and diversification of β-lactamases with carbapenemase activity and AmpC-type in plasmids. Phylogenies of these enzymes help the understanding of the evolutionary forces driving their selection. Moreover, understanding the adaptive potential of β-lactamases contribute to exploration the evolutionary antagonists trajectories through the design of more efficient synthetic molecules. In this review, we attempt to analyze the antibiotic resistance problem from intrinsic and environmental resistomes to the adaptive potential of resistance genes and the driving forces involved in their diversification, in order to provide a global perspective of the resistance problem. PMID:23404545

  6. Antibiotics as selectors and accelerators of diversity in the mechanisms of resistance: From the resistome to genetic plasticity in the beta-lactamases world

    Directory of Open Access Journals (Sweden)

    Juan- Carlos eGalán

    2013-02-01

    Full Text Available Antibiotics and antibiotic resistance determinants, natural molecules closely related to bacterial physiology and consistent with an ancient origin, are not only present in antibiotic-producing bacteria. Throughput sequencing technologies have revealed an unexpected reservoir of antibiotic resistance in the environment. These data suggest that co-evolution between antibiotic and antibiotic resistance genes has occurred since the beginning of time. This evolutionary race has probably been slow because of highly regulated processes and low antibiotic concentrations. Therefore to understand this global problem, a new variable must be introduced, that the antibiotic resistance is a natural event, inherent to life. However, the industrial production of natural and synthetic antibiotics has dramatically accelerated this race, selecting some of the many resistance genes present in nature and contributing to their diversification. One of the best models available to understand the biological impact of selection and diversification are -lactamases. They constitute the most widespread mechanism of resistance, at least among pathogenic bacteria, with more than 1000 enzymes identified in the literature. In the last years, there has been growing concern about the description, spread and diversification of -lactamases with carbapenemase activity and AmpC-type in plasmids. Phylogenies of these enzymes help the understanding of the evolutionary forces driving their selection. Moreover, understanding the adaptive potential of -lactamases contribute to exploration the evolutionary antagonists trajectories through the design of more efficient synthetic molecules. In this review, we attempt to analyse the antibiotic resistance problem from new perspectives. From intrinsic and environmental resistomes to the adaptive potential of resistance genes and the driving forces involved in their diversification, in order to provide a global perspective of the

  7. Antibiotic Stewardship Initiatives as Part of the UK 5-Year Antimicrobial Resistance Strategy

    OpenAIRE

    Johnson, Alan P.; Ashiru-Oredope, Diane; Beech, Elizabeth

    2015-01-01

    Antibiotic use is a major driver for the emergence and spread of antibiotic resistance. Antimicrobial stewardship programmes aim to improve antibiotic prescribing with the objectives of optimizing clinical outcomes while at the same time minimizing unintended consequences such as adverse effects and the selection of antibiotic resistance. In 2013, a five-year national strategy for tackling antimicrobial resistance was published in the UK. The overarching goal of the strategy is to slow the de...

  8. Zinc Finger Nuclease: A New Approach to Overcome Beta-Lactam Antibiotic Resistance

    OpenAIRE

    Shahbazi Dastjerdeh, Mansoureh; Kouhpayeh, Shirin; Sabzehei, Faezeh; Khanahmad, Hossein; Salehi, Mansour; Mohammadi, Zahra; Shariati, Laleh; Hejazi, Zahra; Rabiei, Parisa; Manian, Mostafa

    2016-01-01

    Background: The evolution of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) has been accelerated recently by the indiscriminate application of antibiotics. Antibiotic resistance has challenged the success of medical interventions and therefore is considered a hazardous threat to human health. Objectives: The present study aimed to describe the use of zinc finger nuclease (ZFN) technology to target and disrupt a plasmid-encoded ?-lactamase, which prevents horizontal...

  9. Antibiotic resistance and the risk of recurrent bacteremia.

    Science.gov (United States)

    Woudt, Sjoukje H S; de Greeff, Sabine C; Schoffelen, Annelot F; Vlek, Anne L M; Bonten, Marc J M

    2017-12-07

    Direct health effects of antibiotic resistance are difficult to assess. We quantified the risk of recurrent bacteremia associated with antibiotic resistance. We extracted antimicrobial susceptibility testing data on blood isolates of Enterobacteriaceae, Pseudomonas spp., Enterococcus spp. and Staphylococcus aureus from the Dutch surveillance system for antimicrobial resistance between 2008 and 2017. First and first recurrent (4-30days) bacteremia episodes were categorized as susceptible, single non-susceptible or co-non-susceptible (I/R), to 3rd generation cephalosporins -/+ carbapenems (Enterobacteriaceae), ceftazidime -/+ carbapenems (Pseudomonas spp.), aminopenicillins -/+ vancomycin (Enterococcus spp.), or MSSA/MRSA (S. aureus). We calculated absolute and relative risks of recurrent bacteremia after single- and co-non-susceptible vs. susceptible first bacteremia, estimated the crude population attributable effect of antibiotic resistance for the Netherlands, and calculated absolute risks of developing non-susceptible recurrent bacteremia after a susceptible first episode. Risk ratios for recurrent bacteremia after a first episode caused by a single- and co-non-susceptible bacteria, respectively, vs. susceptible first episodes, were 1.7 (95% CI 1.5-2.0) and 5.2 (2.1-12.4) for Enterobacteriaceae, 1.3 (0.5-3.1) and 5.0 (2.9-8.5) for Pseudomonas spp., 1.4 (1.2-1.7) and 1.6 (0.6-4.2) for Enterococcus spp., and 1.6 (1.1-2.4) for MRSA vs. MSSA. The estimated population annual number of recurrent bacteremias associated with non-susceptibility was 40. Risks of recurrent bacteremia caused by a non-susceptible pathogen after a susceptible first episode were at most 0.4% (Pseudomonas spp.). Although antibiotic non-susceptibility was consistently associated with higher risks of recurrent bacteremia, the estimated number of additional recurrent episodes in the Netherlands (40 per year) was rather limited. © The Author(s) 2017. Published by Oxford University Press for the

  10. 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 10-successive-y...

  11. Enterobacter cloacae complex: clinical impact and emerging antibiotic resistance.

    Science.gov (United States)

    Mezzatesta, Maria Lina; Gona, Floriana; Stefani, Stefania

    2012-07-01

    Species of the Enterobacter cloacae complex are widely encountered in nature, but they can act as pathogens. The biochemical and molecular studies on E. cloacae have shown genomic heterogeneity, comprising six species: Enterobacter cloacae, Enterobacter asburiae, Enterobacter hormaechei, Enterobacter kobei, Enterobacter ludwigii and Enterobacter nimipressuralis, E. cloacae and E. hormaechei are the most frequently isolated in human clinical specimens. Phenotypic identification of all species belonging to this taxon is usually difficult and not always reliable; therefore, molecular methods are often used. Although the E. cloacae complex strains are among the most common Enterobacter spp. causing nosocomial bloodstream infections in the last decade, little is known about their virulence-associated properties. By contrast, much has been published on the antibiotic-resistance features of these microorganisms. In fact, they are capable of overproducing AmpC β-lactamases by derepression of a chromosomal gene or by the acquisition of a transferable ampC gene on plasmids conferring the antibiotic resistance. Many other resistance determinants that are able to render ineffective almost all antibiotic families have been recently acquired. Most studies on antimicrobial susceptibility are focused on E. cloacae, E. hormaechei and E. asburiae; these studies reported small variations between the species, and the only significant differences had no discriminating features.

  12. [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. Copyright © 2012 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

  13. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Increasing burden of urinary tract infections due to intrinsic colistin-resistant bacteria in hospitals in Marseille, France.

    Science.gov (United States)

    Abat, Cédric; Desboves, Guillaume; Olaitan, Abiola Olumuyiwa; Chaudet, Hervé; Roattino, Nicole; Fournier, Pierre-Edouard; Colson, Philippe; Raoult, Didier; Rolain, Jean-Marc

    2015-02-01

    The emergence of multidrug-resistant (MDR) Gram-negative bacteria has become a major public health problem, eliciting renewed interest in colistin, an old antibiotic that is now routinely used to treat MDR bacterial infections. Here we investigated whether colistin use has affected the prevalence of infections due to intrinsic colistin-resistant bacteria (CRB) in university hospitals in Marseille (France) over a 5-year period. All data from patients infected by intrinsic CRB were compiled from January 2009 to December 2013. Escherichia coli infections were used for comparison. Colistin consumption data were also collected from pharmacy records from 2008 to 2013. A total of 4847 intrinsic CRB infections, including 3150 Proteus spp., 847 Morganella spp., 704 Serratia spp. and 146 Providencia spp., were collected between 2009 and 2013. During this period, the annual incidence rate of hospital-acquired CRB infections increased from 220 per 1000 patients to 230 per 1000 patients and that of community-acquired CRB infections increased from 100 per 1000 patients to 140 per 1000 patients. In parallel, colistin consumption increased 2.2-fold from 2008 to 2013, mainly because of an increase in the use of colistin aerosol forms (from 50 unitary doses to 2926 unitary doses; P<10(-5)) that was significantly correlated with an increase in the number of patients positive for CRB admitted to ICUs and units of long-term care between 2009 and 2013 (r=0.91; P=0.03). The global rise in infections due to intrinsic CRB is worrying and surveillance is warranted to better characterise this intriguing epidemiological change. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  16. Increasing transmission of antibiotic resistance from animals to humans

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Frimodt-Møller, Niels

    2011-01-01

    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 hum...... 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....

  17. 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...

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

    Science.gov (United States)

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

    2016-07-13

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

  19. Helicobacter pylori resistance to six antibiotics by two breakpoint systems and resistance evolution in Bulgaria.

    Science.gov (United States)

    Boyanova, Lyudmila; Gergova, Galina; Evstatiev, Ivailo; Spassova, Zoya; Kandilarov, Naiden; Yaneva, Penka; Markovska, Rumyana; Mitov, Ivan

    2016-01-01

    Helicobacter pylori resistance to antibiotics is the main cause for eradication failures. Antibiotic resistance in 299 H. pylori strains from 233 untreated adults, 26 treated adults, and 40 untreated children was assessed by E tests and, for metronidazole, by breakpoint susceptibility testing and two breakpoint systems. Using EUCAST breakpoints (EBPs) and previous breakpoints (PBPs), overall resistance rates were: amoxicillin 4.0 and 0.6%, metronidazole 33.8 and 33.8%, clarithromycin 28.1 and 27.4%, levofloxacin 19.4 and 19.4%, tetracycline 3.7 and 1.5%, respectively, and rifampin 8.3% (EBP). Multidrug resistance was detected in treated and untreated adults and an untreated child and included 17 (EBPs) and 15 strains (PBPs). Differences between susceptibility categories were found for amoxicillin (3.5% of strains), clarithromycin (0.7%), and tetracycline (2.2%). Using PBPs, from 2005-2007 to 2010-2015, overall primary clarithromycin resistance continued to increase (17.9-25.6%) as noted in our previous study. However, in 2010-2015, overall primary metronidazole (24.0-31.5%) and fluoroquinolone (7.6-18.3%) resistance rates also increased. Primary resistance rates in children and adults were comparable. Briefly, differences in resistance rates by the two breakpoint systems affected the results for three antibiotics. National antibiotic consumption was linked to macrolide resistance in adults. Current primary H. pylori resistance to three antibiotics increased in all untreated patients and in the untreated adults, with the sharpest rise for the fluoroquinolones. The presence of fivefold H. pylori resistance to metronidazole, clarithromycin, tetracycline, levofloxacin, and amoxicillin according to EBPs is alarming.

  20. ANTIBIOTIC RESISTANCE OF HELICOBACTER PYLORI AMONG CHILDREN AND THERAPY SELECTION

    Directory of Open Access Journals (Sweden)

    Ye.A. Kornienko

    2006-01-01

    Full Text Available The reason for the low therapy efficiency of many gastrobduodenal diseases is the increasing resistance to the antibiotics helicobacter pylori (Н. pylori, which is conditioned by the mutations of its various genes. The most practical importance is attributed to the 23s RRNA mutations, underlying resistance to claritromicin. According to the international consensus maastrichtb3, the scheme of treatment with the inhibitor of the proton pump, claritromicin and metronidasol is recommended as the 1st line therapy. The present work assesses the resistance of Н. pylori to claritromicin aided by pcrbdiagnostics of the 23s RRNA mutation of rna in the biopsy material of the mucous coat of stomach and standard treatment scheme efficiency if compared with the onebantibiotic scheme – amoxicillin, bismuth and inhibitor of the proton pump. 68 children with Н. pylori bassociated diseases have been examined. The frequency of resistance of Н. pylori to claritromicin made up 28%. The standard 10bday long scheme of treatment was efficient among 14% of the patients, the 7bday long schemes with amoxicillin, bismuth and omeprazole were efficient among 40% of the patients, the 10bday long schemes with amoxicillin, bismuth and omeprazole were efficient among 75% of the patients; with omeprazole replaced by esomeprazole the efficiency was observed among 83% of the patients along with the good treatment tolerance.Key words: helicobacter pylori, antibiotic resistance, eradication.