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Sample records for acquired antibiotic resistance

  1. Acquired Antibiotic Resistance Genes: An Overview

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2015-06-16

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

  3. Targets for Combating the Evolution of Acquired Antibiotic Resistance

    PubMed Central

    2015-01-01

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

  4. Acquired Antibiotic Resistance: Are We Born with It? ▿

    PubMed Central

    Zhang, Lu; Kinkelaar, Daniel; Huang, Ying; Li, Yingli; Li, Xiaojing; Wang, Hua H.

    2011-01-01

    The rapid emergence of antibiotic resistance (AR) is a major public health concern. Recent findings on the prevalence of food-borne antibiotic-resistant (ART) commensal bacteria in ready-to-consume food products suggested that daily food consumption likely serves as a major avenue for dissemination of ART bacteria from the food chain to human hosts. To properly assess the impact of various factors, including the food chain, on AR development in hosts, it is important to determine the baseline of ART bacteria in the human gastrointestinal (GI) tract. We thus examined the gut microbiota of 16 infant subjects, from the newborn stage to 1 year of age, who fed on breast milk and/or infant formula during the early stages of development and had no prior exposure to antibiotics. Predominant bacterial populations resistant to several antibiotics and multiple resistance genes were found in the infant GI tracts within the first week of age. Several ART population transitions were also observed in the absence of antibiotic exposure and dietary changes. Representative AR gene pools including tet(M), ermB, sul2, and blaTEM were detected in infant subjects. Enterococcus spp., Staphylococcus spp., Klebsiella spp., Streptococcus spp., and Escherichia coli/Shigella spp. were among the identified AR gene carriers. ART bacteria were not detected in the infant formula and infant foods examined, but small numbers of skin-associated ART bacteria were found in certain breast milk samples. The data suggest that the early development of AR in the human gut microbiota is independent of infants' exposure to antibiotics but is likely impacted by exposure to maternal and environmental microbes during and after delivery and that the ART population is significantly amplified within the host even in the absence of antibiotic selective pressure. PMID:21821748

  5. Socioeconomic and behavioral factors leading to acquired bacterial resistance to antibiotics in developing countries.

    PubMed Central

    Okeke, I. N.; Lamikanra, A.; Edelman, R.

    1999-01-01

    In developing countries, acquired bacterial resistance to antimicrobial agents is common in isolates from healthy persons and from persons with community-acquired infections. Complex socioeconomic and behavioral factors associated with antibiotic resistance, particularly regarding diarrheal and respiratory pathogens, in developing tropical countries, include misuse of antibiotics by health professionals, unskilled practitioners, and laypersons; poor drug quality; unhygienic conditions accounting for spread of resistant bacteria; and inadequate surveillance. PMID:10081668

  6. Bacteriology and antibiotic resistance pattern in community acquired urinary tract infection.

    PubMed

    Sharan, Rajiv; Kumar, Dhananjay; Mukherjee, B

    2013-07-01

    Extensive use of antibiotics have resulted in development of resistance among most commonly used drugs in community acquired urinary tract infection (UTI). This study was conducted to identify the resistance pattern in community acquired UTI .We collected urine for routine examination and culture from suprapubic urine in all the cases to avoid any contamination. E. Coli was the most common organism identified. Among oral antibiotics, there was high degree of resistance to penicillin group and cephalosporin groups. Among parentral antibiotics, all the cephalosporins were variably resistant except cephaperazone-salbactum.

  7. [Antibiotic therapy for community acquired Streptococcus pneumoniae pneumonia: clinical relevance of antibiotic resistance].

    PubMed

    Bédos, J-P; Bruneel, F

    2006-01-01

    The emergence of Streptococcus pneumoniae strains with reduced susceptibility to beta-lactams and with multiple drug resistance has not led to major changes in recommendations for antibiotic therapy in patients with acute community-acquired pneumococcal pneumonia. Numerous factors explain the limited clinical impact of this major microbiological change. The frequency of intermediate strains is high but the frequency of resistant strains to beta-lactams is very low. There is a complex relation between the acquisition of resistance to beta-lactams and the decreased virulence of S. pneumoniae strains. The only finding in studies of humanized experimental animal models of lethal bacteremic pneumonia caused by resistance and tolerant strains was a slowing in the kinetics of beta-lactams bactericidal activity, especially for amoxicillin. Taken together, this preclinical data shows that microbiological resistance of pneumococci to beta-lactams has very little influence on a possible failure of recommanded treatment regimens for pneumococcal pneumonia. The high rate of multiple drug resistance, particularly among beta-lactam resistant strains, rules out the probabilistic use of macrolides. Conversely, fluoroquinolone (FQ) resistance remains low, inferior to 3%, and the same is true for ketolides (<1%). Only a global strategy of patient management in the use of these new drugs could ensure their long-term activity. The high mortality rate of hospitalized S. pneumoniae pneumonia will only be improved with a better understanding of the complex host-bacteria interactions.

  8. Acquired antibiotic resistance among wild animals: the case of Iberian Lynx (Lynx pardinus).

    PubMed

    Sousa, Margarida; Gonçalves, Alexandre; Silva, Nuno; Serra, Rodrigo; Alcaide, Eva; Zorrilla, Irene; Torres, Carmen; Caniça, Manuela; Igrejas, Gilberto; Poeta, Patrícia

    2014-01-01

    The selective pressure generated by the clinical misuse of antibiotics has been the major driving force leading to the emergence of antibiotic resistance among bacteria. Antibiotics or even resistant bacteria are released into the environment and contaminate the surrounding areas. Human and animal populations in contact with these sources are able to become reservoirs of these resistant organisms. Then, due to the convergence between habitats, the contact of wild animals with other animals, humans, or human sources is now more common and this leads to an increase in the exchange of resistance determinants between their microbiota. Indeed, it seems that wildlife populations living in closer proximity to humans have higher levels of antibiotic resistance. Now, the Iberian Lynx (Lynx pardinus) is a part of this issue, being suggested as natural reservoir of acquired resistant bacteria. The emerging public health concern regarding microbial resistance to antibiotics is becoming true: the bacteria are evolving and are now affecting unintentional hosts.

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

    PubMed Central

    Haaber, Jakob; Leisner, Jørgen J.; Cohn, Marianne T.; Catalan-Moreno, Arancha; Nielsen, Jesper B.; Westh, Henrik; Penadés, José R.; Ingmer, Hanne

    2016-01-01

    Prophages are quiescent viruses located in the chromosomes of bacteria. In the human pathogen, Staphylococcus aureus, prophages are omnipresent and are believed to be responsible for the spread of some antibiotic resistance genes. Here we demonstrate that release of phages from a subpopulation of S. aureus cells enables the intact, prophage-containing population to acquire beneficial genes from competing, phage-susceptible strains present in the same environment. Phage infection kills competitor cells and bits of their DNA are occasionally captured in viral transducing particles. Return of such particles to the prophage-containing population can drive the transfer of genes encoding potentially useful traits such as antibiotic resistance. This process, which can be viewed as ‘auto-transduction', allows S. aureus to efficiently acquire antibiotic resistance both in vitro and in an in vivo virulence model (wax moth larvae) and enables it to proliferate under strong antibiotic selection pressure. Our results may help to explain the rapid exchange of antibiotic resistance genes observed in S. aureus. PMID:27819286

  10. Bacteraemia and antibiotic-resistant pathogens in community acquired pneumonia: risk and prognosis.

    PubMed

    Torres, Antoni; Cillóniz, Catia; Ferrer, Miquel; Gabarrús, Albert; Polverino, Eva; Villegas, Santiago; Marco, Francesc; Mensa, Josep; Menéndez, Rosario; Niederman, Michael

    2015-05-01

    The sensitivity of blood cultures in the diagnosis of bacteraemia for community-acquired pneumonia is low. Recommendations, by guidelines, to perform blood cultures are discordant. We aimed to determine the incidence, microbial aetiology, risk factors and outcomes of bacteraemic patients with community-acquired pneumonia, including cases with antibiotic-resistant pathogens (ARP). A prospective, observational study was undertaken on consecutive adult patients admitted to the Hospital Clinic of Barcelona (Barcelona, Spain) with community-acquired pneumonia and blood cultures were obtained. Of the 2892 patients included, bacteraemia was present in 297 (10%) patients; 30 (10%) of whom had ARP (multidrug-resistant Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and an extended spectrum of beta-lactamase producing Enterobacteriaceae). In multivariate analyses, pleuritic pain, C-reactive protein ≥21.6 mg·dL(-1) and intensive care unit admissions were independently associated with bacteraemia, while prior antibiotic treatment and pneumococcal vaccine were protective factors. The risk factors for ARP bacteraemia were previous antibiotics and C-reactive protein <22.2 mg·dL(-1), while pleuritic pain was the only protective factor in the multivariate analysis. Bacteraemia (excluding ARP), appropriate empiric treatment, neurological disease, arterial oxygen tension/inspiratory oxygen fraction <250, pneumonia severity index risk classes IV and V, and intensive care unit admission were independently associated with a 30-day hospital mortality in the multivariate analysis. Inappropriate therapy was more frequent in ARP bacteraemia, compared with other bacteraemias (27% versus 3%, respectively, p<0.001). Antibiotic therapy protected against bacteraemia, but increased specifically the risk of bacteraemia from ARP due to the inappropriate coverage of these pathogens. Identifying patients at risk of ARP bacteraemia would help in

  11. Community Acquired Enterococcal Urinary Tract Infections and Antibiotic Resistance Profile in North India

    PubMed Central

    Goel, Varun; Kumar, Dinesh; Kumar, Rajendra; Mathur, Purva; Singh, Sarman

    2016-01-01

    Background: Urinary tract infections (UTIs) remain a major problem both in hospitalized and outdoor patients. Multidrug-resistant enterococci are emerging as a major nosocomial pathogen with increasing frequency. However, the incidence of community-acquired enterococcal infections and species prevalent in India is not thoroughly investigated. Objectives: This study aims to estimate the burden of community-acquired UTIs seen at a tertiary care hospital and to identify the Enterococcus species isolated from these patients. The study also aims to determine the antibiotic susceptibility pattern with reference to high-level aminoglycosides and vancomycin. Materials and Methods: Semi-quantitative cultures from a total of 22,810 urine samples obtained from patients seen at various Outpatient Departments were analyzed. From them 115 nonduplicate isolates of enterococci were obtained as significant pure growth (>105 cfu/ml) and speciated. Antibiotic susceptibility was performed by Kirby–Bauer disc diffusion method. Vancomycin resistance screening was performed by the vancomycin screen agar method recommended by Clinical and Laboratory Standards Institute and confirmed by determination of minimum inhibitory concentration by agar dilution method. Results: Of 115 enterococcal isolates, 61 were identified as Enterococcus faecalis, 42 as Enterococcus faecium, 3 each as Enterococcus dispar, and Enterococcus pseudoavium. High-level gentamicin resistance (HLGR) was higher in E. faecium (47.6%) than E. faecalis (32.7%) and HLSR also showed the same pattern with 47.6% and 27.9% resistance, respectively. Vancomycin resistant enterococci accounted for 11.3% of the isolates, and out of them 53.8% were E. faecium by agar dilution method. Conclusion: High rate of resistance to antibiotics of penicillin group and aminoglycosides was observed in our tertiary care hospital even in community acquired UTIs. Hence, there is an urgent need for more rational and restricted use of antimicrobials

  12. Emergence of antibiotic resistance and prudent use of antibiotic therapy in nosocomially acquired urinary tract infections.

    PubMed

    Wagenlehner, F M E; Naber, K G

    2004-03-01

    Nosocomially acquired urinary tract infections (NAUTI) are common. The reported rates, however, depend very much on the definitions used and the number of investigations requested. In a prospective study on a surgical intensive care unit and adhering closely to the CDC criteria, NAUTI was diagnosed in about 17% of the patients. The urinary catheter associated UTI rate per 1000 catheter days was 14.5 much higher than otherwise reported. Whereas the rates of symptomatic NAUTI and other nosocomially acquired infections were similar, the main difference was found for asymptomatic UTI which depends very much on the effort to search for it systematically. In a prospective study on a urological ward it could be demonstrated that cross-transmission probably plays a much greater role than so far suggested. Continuous surveillance of the bacterial spectrum and resistance is necessary not only on a global but also on a local level. Selection of an appropriate agent for empirical antibacterial therapy can be better tailored if not only the total bacterial spectrum is considered but if all information already available during the identification process is used, such as Gram stain and other simple and rapid tests for stratification of the pathogens. Since in NAUTI usually some kind of biofilm infection is involved, the fluoroquinolones can be considered agents of choice. Only those substances with high antibacterial activity, good bioavailability and those that are mainly excreted by the kidneys should be chosen and they have to be administered at sufficiently high doses.

  13. Antibacterial mechanisms of rhodomyrtone against important hospital-acquired antibiotic-resistant pathogenic bacteria.

    PubMed

    Leejae, Sukanlaya; Taylor, Peter William; Voravuthikunchai, Supayang Piyawan

    2013-01-01

    The antibacterial mechanisms of rhodomyrtone, a member of the acylphloroglucinols isolated from Rhodomyrtus tomentosa leaves, against important hospital-acquired antibiotic-resistant pathogenic bacteria were assessed. The results indicated that rhodomyrtone exhibited pronounced antibacterial activity against key antibiotic-resistant pathogens including epidemic meticillin-resistant Staphylococcus aureus (EMRSA), vancomycin-intermediate S. aureus and vancomycin-resistant enterococcal strains. The strains EMRSA-16, Enterococcus faecalis ATCC 29212 and VRE-3 demonstrated a significant decrease in survival ability after treatment with rhodomyrtone at 1× (0.5 µg ml(-1)), 2×, 4× and 8× MIC for 24 h. Moreover, the compound was observed in the cytoplasmic fraction of rhodomyrtone-treated S. aureus, and only a very fine band of the compound was seen following separation of the cell-wall and cell-membrane fractions of the treated cells. In addition, exposure of S. aureus to rhodomyrtone at 4×, 2× and 1× MIC for 24 h produced no significant effect on the bacterial cell membrane and cell lysis, suggesting that neither of these is the main target of rhodomyrtone action in these organisms. Stepwise isolation of the bacterial cells with increasing resistance to rhodomyrtone was not induced in either S. aureus or EMRSA-16 after 45 passages on Luria-Bertani agar supplemented with rhodomyrtone. In addition, in vitro toxicity of rhodomyrtone at 128× MIC on human erythrocytes was not observed. These results provide evidence to support therapeutic challenges of rhodomyrtone against Gram-positive pathogens.

  14. Pentamidine sensitizes Gram-negative pathogens to antibiotics and overcomes acquired colistin resistance.

    PubMed

    Stokes, Jonathan M; MacNair, Craig R; Ilyas, Bushra; French, Shawn; Côté, Jean-Philippe; Bouwman, Catrien; Farha, Maya A; Sieron, Arthur O; Whitfield, Chris; Coombes, Brian K; Brown, Eric D

    2017-03-06

    The increasing use of polymyxins(1) in addition to the dissemination of plasmid-borne colistin resistance threatens to cause a serious breach in our last line of defence against multidrug-resistant Gram-negative pathogens, and heralds the emergence of truly pan-resistant infections. Colistin resistance often arises through covalent modification of lipid A with cationic residues such as phosphoethanolamine-as is mediated by Mcr-1 (ref. 2)-which reduce the affinity of polymyxins for lipopolysaccharide(3). Thus, new strategies are needed to address the rapidly diminishing number of treatment options for Gram-negative infections(4). The difficulty in eradicating Gram-negative bacteria is largely due to their highly impermeable outer membrane, which serves as a barrier to many otherwise effective antibiotics(5). Here, we describe an unconventional screening platform designed to enrich for non-lethal, outer-membrane-active compounds with potential as adjuvants for conventional antibiotics. This approach identified the antiprotozoal drug pentamidine(6) as an effective perturbant of the Gram-negative outer membrane through its interaction with lipopolysaccharide. Pentamidine displayed synergy with antibiotics typically restricted to Gram-positive bacteria, yielding effective drug combinations with activity against a wide range of Gram-negative pathogens in vitro, and against systemic Acinetobacter baumannii infections in mice. Notably, the adjuvant activity of pentamidine persisted in polymyxin-resistant bacteria in vitro and in vivo. Overall, pentamidine and its structural analogues represent unexploited molecules for the treatment of Gram-negative infections, particularly those having acquired polymyxin resistance determinants.

  15. At the threshold: defining clinically meaningful resistance thresholds for antibiotic choice in community-acquired pneumonia.

    PubMed

    Daneman, Nick; Low, Donald E; McGeer, Alison; Green, Karen A; Fisman, David N

    2008-04-15

    Community-acquired pneumonia caused by Streptococcus pneumoniae is a major source of morbidity and mortality. Macrolide antibiotics are recommended as empirical first-line therapy for patients with community-acquired pneumonia. Guidelines suggest a 25% rate of high-level macrolide resistance in the community as the threshold beyond which macrolides should not be used. We evaluated the implications of this threshold for clinical failure rates. We developed a theoretical model linking the prevalence of macrolide resistance to patient outcomes, based on the epidemiological concept of risk difference. We estimated the risk of clinical failure as a function of the likelihood and impact of discordant therapy and of the probability of clinical failure even in the presence of optimal therapy. The model was parameterized on the basis of the best available data derived from the published medical literature, and clinical failures were valued monetarily using an expected net benefit approach. Under the proposed 25% resistance threshold, the risk difference for such therapy would be 1.2% (95% credible interval, 0.5%-3.1%) for death, 1.6% (95% credible interval, 0.5%-3.2%) for bacteremia, and 3.3% (95% credible interval, 1.1%-5.7%) for prolonged clinical course; excess risks of death were valued at >$10,000 per empirical treatment of community-acquired pneumonia and were further elevated in high-risk populations. Excluding low-level resistance resulted in a 4-fold underestimation of projected risks. A 25% resistance threshold that fails to consider low-level resistance will result in high excess rates of morbidity and mortality because of discordant therapy. Whether projected failure rates are classified as unacceptable is an important health policy question, because risk of clinical failure needs to be weighed against other considerations.

  16. Community-acquired bacteraemia in a rural area: predominant bacterial species and antibiotic resistance.

    PubMed

    Nimri, L F; Batchoun, R

    2004-10-01

    The invasion of the bloodstream represents one of the most important sequelae of infection. This study was conducted over an 18-month period to determine the predominant bacterial agents of a community-acquired bacteraemia seen at health centres in a rural area of Jordan, and their antibiotic susceptibilities. Blood samples were collected and cultured from 215 patients who presented with fever and presumed diagnosis of a bacteraemia. Isolates were identified and tested for antibiotic susceptibility. The variables included the age and sex of the patients, aetiology, sources of the bacteraemia, risk factors, treatment and outcome. One hundred and twenty-six (58.6%) blood cultures were positive. Children less than 14 years old accounted for 34.9% of these, and 38% were from patients that were more than 50 years old. The most frequent aetiologic agents were Staphylococcus aureus, followed by Brucella melitensis and Streptococcus pneumoniae. A wide range of resistance to commonly used antimicrobial agents and multidrug resistance was documented in 44.4% of the isolates. The most frequent sources of the bacteraemia were urinary (15.9%), respiratory (14.3%), no source of the bacteraemia identified (primary bacteraemia) (13.5%), gastrointestinal (12.7%) and soft-tissue infection (7.9%). No identifiable risk factor for infection could be determined in 34% of the patients. The predominant pathogens identified and the relatively high prevalence of antibiotic resistance of the isolates are most probably due to the nature and lifestyle of this rural population and the use of empiric treatment. Characteristics permitting recognition of patients with such strains would aid infection control efforts in the community.

  17. Effect of United States buckwheat honey on antibiotic-resistant hospital acquired pathogens

    PubMed Central

    Hammond, Eric Nee-Armah; Duster, Megan; Musuuza, Jackson Ssentalo; Safdar, Nasia

    2016-01-01

    Introduction Due to an upsurge in antibiotic-resistant infections and lack of therapeutic options, new approaches are needed for treatment. Honey may be one such potential therapeutic option. We investigated the susceptibility of hospital acquired pathogens to four honeys from Wisconsin, United States, and then determined if the antibacterial effect of each honey against these pathogens is primarily due to the high sugar content. Methods Thirteen pathogens including: four Clostridium difficile, two Methicillin-resistant Staphylococcus aureus, two Pseudomonas aeruginosa, one Methicillin-Susceptible Staphylococcus aureus, two Vancomycin-resistance Enterococcus, one Enterococcus faecalis and one Klebsiella pneumoniae were exposed to 1-50% (w/v) four Wisconsin honeys and Artificial honey to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the broth dilution method. Results Buckwheat honey predominantly exhibited a bactericidal mode of action against the tested pathogens, and this varied with each pathogen. C. difficile isolates were more sensitive to the Wisconsin buckwheat honey as compared to the other pathogens. Artificial honey at 50% (w/v) failed to kill any of the pathogens. The high sugar content of Wisconsin buckwheat honey is not the only factor responsible for its bactericidal activity. Conclusion Wisconsin buckwheat honey has the potential to be an important addition to therapeutic armamentarium against resistant pathogens and should be investigated further. PMID:28292167

  18. Effect of United States buckwheat honey on antibiotic-resistant hospital acquired pathogens.

    PubMed

    Hammond, Eric Nee-Armah; Duster, Megan; Musuuza, Jackson Ssentalo; Safdar, Nasia

    2016-01-01

    Due to an upsurge in antibiotic-resistant infections and lack of therapeutic options, new approaches are needed for treatment. Honey may be one such potential therapeutic option. We investigated the susceptibility of hospital acquired pathogens to four honeys from Wisconsin, United States, and then determined if the antibacterial effect of each honey against these pathogens is primarily due to the high sugar content. Thirteen pathogens including: four Clostridium difficile, two Methicillin-resistant Staphylococcus aureus, two Pseudomonas aeruginosa, one Methicillin-Susceptible Staphylococcus aureus, two Vancomycin-resistance Enterococcus, one Enterococcus faecalis and one Klebsiella pneumoniae were exposed to 1-50% (w/v) four Wisconsin honeys and Artificial honey to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the broth dilution method. Buckwheat honey predominantly exhibited a bactericidal mode of action against the tested pathogens, and this varied with each pathogen. C. difficile isolates were more sensitive to the Wisconsin buckwheat honey as compared to the other pathogens. Artificial honey at 50% (w/v) failed to kill any of the pathogens. The high sugar content of Wisconsin buckwheat honey is not the only factor responsible for its bactericidal activity. Wisconsin buckwheat honey has the potential to be an important addition to therapeutic armamentarium against resistant pathogens and should be investigated further.

  19. Antibiotic resistance in Chlamydiae.

    PubMed

    Sandoz, Kelsi M; Rockey, Daniel D

    2010-09-01

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

  20. Antibiotic Resistance, Virulence, and Genetic Background of Community-Acquired Uropathogenic Escherichia coli from Algeria.

    PubMed

    Yahiaoui, Merzouk; Robin, Frédéric; Bakour, Rabah; Hamidi, Moufida; Bonnet, Richard; Messai, Yamina

    2015-10-01

    The aim of the study was to investigate antibiotic resistance mechanisms, virulence traits, and genetic background of 150 nonrepetitive community-acquired uropathogenic Escherichia coli (CA-UPEC) from Algeria. A rate of 46.7% of isolates was multidrug resistant. bla genes detected were blaTEM (96.8% of amoxicillin-resistant isolates), blaCTX-M-15 (4%), overexpressed blaAmpC (4%), blaSHV-2a, blaTEM-4, blaTEM-31, and blaTEM-35 (0.7%). All tetracycline-resistant isolates (51.3%) had tetA and/or tetB genes. Sulfonamides and trimethoprim resistance genes were sul2 (60.8%), sul1 (45.9%), sul3 (6.7%), dfrA14 (25.4%), dfrA1 (18.2%), dfrA12 (16.3%), and dfrA25 (5.4%). High-level fluoroquinolone resistance (22.7%) was mediated by mutations in gyrA (S83L-D87N) and parC (S80I-E84G/V or S80I) genes. qnrB5, qnrS1, and aac(6')-Ib-cr were rare (5.3%). Class 1 and/or class 2 integrons were detected (40.7%). Isolates belonged to phylogroups B2+D (50%), A+B1 (36%), and F+C+Clade I (13%). Most of D (72.2%) and 38.6% of B2 isolates were multidrug resistant; they belong to 14 different sequence types, including international successful ST131, ST73, and ST69, reported for the first time in the community in Algeria and new ST4494 and ST4529 described in this study. Besides multidrug resistance, B2 and D isolates possessed virulence factors of colonization, invasion, and long-term persistence. The study highlighted multidrug-resistant CA-UPEC with high virulence traits and an epidemic genetic background.

  1. Antibiotic Resistance

    MedlinePlus

    ... are even stronger. Bacteria and Viruses Questions about Antibiotic Resistance Bacteria and Viruses Bacteria and viruses are the two ... even help us to digest food. But other bacteria cause bad diseases like TB and lyme disease. Questions about Antibiotic Resistance Does this affect me? If you have a ...

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

    PubMed Central

    Gonsu, Hortense Kamga; Koulla-Shiro, Sinata

    2016-01-01

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

  3. Emerging resistance to antibiotics against respiratory bacteria: impact on therapy of community-acquired pneumonia in children.

    PubMed

    Esposito, Susanna; Principi, Nicola

    2002-04-01

    Perhaps because of its etiologic complexity, community-acquired pneumonia (CAP) in infants and children remains a significant problem worldwide. Over the last few years, difficulties related to CAP treatment in children have greatly increased because of the emergence of resistance to the most widely used antibiotics against some of the bacterial pathogens involved in the development of the disease. There are few data describing the impact of antibiotic resistance on clinical outcomes in CAP, but many experts believe that the clinical impact is limited. We here discuss the prevalence of different etiologic agents in CAP of children, the diagnostic criteria, problems related to antibiotic resistance, therapeutic strategies, and future implications. Copyright 2002 Elsevier Science Ltd.

  4. [Antibiotic resistance of strains isolated from community acquired urinary tract infections between 2007 and 2011 in Guelma (Algeria)].

    PubMed

    Bentroki, Ahmed Aimen; Gouri, Adel; Yakhlef, Amina; Touaref, Amel; Gueroudj, Abderrahim; Bensouilah, Takieddine

    2012-01-01

    Urinary tract infections are a real public health problem. They are a frequent reason for consultation as they entail a significant and sometimes inappropriate prescription of antibiotics. This is a retrospective study which involved 1,334 patients between October 2007 and February 2011. Enterobacteriaceae accounted for 85% of isolated bacteria, predominantly Escherichia coli (60%). Gram-positive bacteria account for only 11%. The highest rate of acquired resistance of Escherichia coli was observed with ampicillin (70%). This study give an idea on the rates of antibiotic resistance of the main bacteria involved in urinary tract infections and illustrate the importance of the proper use of antibiotics coupled to surveillance in order to control the spread of these resistances.

  5. Acquired and Native Resistance of Staphylococcus aureus to Cephalexin and Other β-Lactam Antibiotics 1

    PubMed Central

    Kayser, Fritz H.; Benner, E. Jack; Hoeprich, Paul D.

    1970-01-01

    Staphylococcus aureus cells that are initially susceptible to cephalexin can be induced to acquire intrinsic resistance to cephalexin in comparatively few steps. Concomitantly, resistance to cephalothin, oxacillin, and dicloxacillin increases. By population analysis, there is heteroresistance to cephalexin in some strains of S. aureus. Heterogeneity in colonial morphology on prolonged incubation in the presence of subinhibitory concentrations of cephalexin may constitute an expression of such heteroresistance. Images PMID:5201887

  6. Genetic diversity of Streptococcus suis isolated from three pig farms of China obtained by acquiring antibiotic resistance genes.

    PubMed

    Huang, Jinhu; Shang, Kexin; Kashif, Jam; Wang, Liping

    2015-05-01

    Acquiring antibiotic resistance genes may change an organism's genetic characteristics and the effect of antibiotics, resulting in a rapid transmission of microbial pathogens. The objectives of this experiment were to identify the features of Streptococcus suis (S. suis) isolated from three pig farms in China which are geographically isolated. Among the isolates, 56.52% were sequence type 7 (ST7), followed by ST1 (26.09%), indicating that ST7 prevails in China, as revealed by multi-locus sequence typing (MLST). Statistical analysis indicated an association between geography, sequence types and antibiotic resistance genotypes. 66.67% of the isolates in Sichuan province presented a (ermB(-) + mefA(-) + tetO(-) + tetM(-)) + ST7 type. The tetM(+) +ST7 type was the most prevalent in Jiangsu province, whereas the strains from Hebei province had a phenotype ermB(+) +tetO(+) +ST1 (63.64%). Pulsed-field gel electrophoresis (PGFE) pattern A2 with 100% similarity reflected the clonal dissemination between Sichuan and Jiangsu provinces. Strains carrying or not carrying antibiotic resistance genes presented different PFGE patterns in Hebei province. ST7 is widespread in many regions of China and a clonal dissemination occurred between Sichuan and Jiangsu provinces in diseased pigs. However, ST1 strains with macrolide and tetracycline resistance (ermB(+) +tetO(+) +ST1) isolated from a farm in Hebei province demonstrated that the genetic diversity was contributed by horizontal acquiring of ermB and tetO carrying elements. © 2014 Society of Chemical Industry.

  7. Role of Acinetobacter baumannii UmuD homologs in antibiotic resistance acquired through DNA damage-induced mutagenesis.

    PubMed

    Aranda, Jesús; López, Mario; Leiva, Enoy; Magán, Andrés; Adler, Ben; Bou, Germán; Barbé, Jordi

    2014-01-01

    The role of Acinetobacter baumannii ATCC 17978 UmuDC homologs A1S_0636-A1S_0637, A1S_1174-A1S_1173, and A1S_1389 (UmuDAb) in antibiotic resistance acquired through UV-induced mutagenesis was evaluated. Neither the growth rate nor the UV-related survival of any of the three mutants was significantly different from that of the wild-type parental strain. However, all mutants, and especially the umuDAb mutant, were less able to acquire resistance to rifampin and streptomycin through the activities of their error-prone DNA polymerases. Furthermore, in the A. baumannii mutant defective in the umuDAb gene, the spectrum of mutations included a dramatic reduction in the frequency of transition mutations, the mutagenic signature of the DNA polymerase V encoded by umuDC.

  8. Etiology and antibiotic resistance patterns of community-acquired urinary tract infections in J N M C Hospital Aligarh, India

    PubMed Central

    Akram, Mohammed; Shahid, Mohammed; Khan, Asad U

    2007-01-01

    Background Urinary tract infections (UTIs) remain the common infections diagnosed in outpatients as well as hospitalized patients. Current knowledge on antimicrobial susceptibility pattern is essential for appropriate therapy. Extended-Spectrum beta-Lactamase (ESBL) producing bacteria may not be detected by routine disk diffusion susceptibility test, leading to inappropriate use of antibiotics and treatment failure. The aim of this study was to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from patients with community acquired urinary tract infections (UTIs) at Aligarh hospital in India as well as identification of ESBL producers in the population of different uropathogens. Methods Urinary isolates from symptomatic UTI cases attending to the JN Medical College and hospital at Aligarh were identified by conventional methods. Antimicrobial susceptibility testing was performed by Kirby Bauer's disc diffusion method. Isolates resistant to third generation cephalosporin were tested for ESBL production by double disk synergy test method. Results Of the 920 tested sample 100 samples showed growth of pathogens among which the most prevalent were E. coli (61%) followed by Klebsiella spp (22%). The majority (66.66%) of the isolates were from female while the remaining were from male. Among the gram-negative enteric bacilli high prevalence of resistance was observed against ampicillin and co-trimoxazole. Most of the isolates were resistant to 4 or more number of antibiotics. Forty two percent of isolates were detected to produce ESBL among which 34.42 % were E. coli isolates. Conclusion This study revealed that E. coli was the predominant bacterial pathogen of community acquired UTIs in Aligarh, India. It also demonstrated an increasing resistance to Co-trimoxazole and production of extended spectrum β-lactamase among UTI pathogens in the community. This study is useful for clinician in order to improve the empiric treatment

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

    PubMed

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

    2016-01-15

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

  10. Resistance-resistant antibiotics.

    PubMed

    Oldfield, Eric; Feng, Xinxin

    2014-12-01

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

  11. Molecular mechanisms of antibiotic resistance.

    PubMed

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

    2015-01-01

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

  12. Draft Genome Sequence of a Pathogenic O86:H25 Sequence Type 57 Escherichia coli Strain Isolated from Poultry and Carrying 12 Acquired Antibiotic Resistance Genes.

    PubMed

    Jones-Dias, Daniela; Manageiro, Vera; Sampaio, Daniel Ataíde; Vieira, Luís; Caniça, Manuela

    2015-09-24

    Escherichia coli is a commensal bacterium that is frequently associated with multidrug-resistant zoonotic and foodborne infections. Here, we report the 5.6-Mbp draft genome sequence of an E. coli recovered from poultry, which encodes multiple acquired antibiotic resistance determinants, virulence factors, pathogenicity determinants, and mobile genetic elements. Copyright © 2015 Jones-Dias et al.

  13. Draft Genome Sequence of a Pathogenic O86:H25 Sequence Type 57 Escherichia coli Strain Isolated from Poultry and Carrying 12 Acquired Antibiotic Resistance Genes

    PubMed Central

    Jones-Dias, Daniela; Sampaio, Daniel Ataíde; Vieira, Luís; Caniça, Manuela

    2015-01-01

    Escherichia coli is a commensal bacterium that is frequently associated with multidrug-resistant zoonotic and foodborne infections. Here, we report the 5.6-Mbp draft genome sequence of an E. coli recovered from poultry, which encodes multiple acquired antibiotic resistance determinants, virulence factors, pathogenicity determinants, and mobile genetic elements. PMID:26404585

  14. Pneumococcal resistance to antibiotics.

    PubMed Central

    Klugman, K P

    1990-01-01

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

  15. Bacterial cheating limits antibiotic resistance

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  16. Resistance-Resistant Antibiotics

    PubMed Central

    Oldfield, Eric; Feng, Xinxin

    2014-01-01

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

  17. Intrinsic and acquired resistance mechanisms in enterococcus.

    PubMed

    Hollenbeck, Brian L; Rice, Louis B

    2012-08-15

    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.

  18. Community-acquired meticillin-resistant Staphylococcus aureus strain USA300 resists staphylococcal protein A modulation by antibiotics and antimicrobial peptides.

    PubMed

    Cardot Martin, E; Michel, A; Raynal, B; Badiou, C; Laurent, F; Vandenesch, F; Etienne, J; Lina, G; Dumitrescu, O

    2015-01-01

    Community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) causes severe diseases through virulence factors such as staphylococcal protein A (SpA), which favours immune evasion. We have previously shown that antimicrobial peptides (AMPs) and antibiotics decrease SpA expression in CA-MRSA strains. Here we examined the effects of antibiotics and AMPs, alone and in combination, on SpA expression in various CA-MRSA strains. Six S. aureus isolates corresponding to the major worldwide CA-MRSA clones (ST8-USA300, ST80 and ST30) were selected. Strains were cultured to exponential growth phase and were subsequently incubated with antibiotics (tigecycline, linezolid, clindamycin and vancomycin) at 0.25× MIC or with AMPs [human neutrophil peptide (HNP)-1-3] at the LD50, alone and in combination. After 6h, cultures were assessed for spa mRNA by RT-PCR, whilst SpA protein was measured by specific ELISA after 18h. When used alone, antibiotics (clindamycin, linezolid and tigecycline) or HNPs significantly reduced both SpA production and mRNA levels in ST30 and ST80 strains. When used in combination, HNPs and clindamycin, linezolid or tigecycline synergistically reduced SpA production (6-100-fold) and spa mRNA levels (4-20-fold) in ST80 and ST30 strains. In contrast, for USA300 strains, among all antibiotics, clindamycin alone reduced SpA production (3.5-fold), whereas with combined treatments including HNPs, only a slight reduction in SpA production (1.7-2.2-fold) was observed. In conclusion, antibiotics and AMPs do not modulate SpA expression in USA300, unlike in other CA-MRSA clones. This observation suggests that the virulence and successful spread of USA300 strains is associated with a specific regulatory network.

  19. Combating Antibiotic Resistance

    MedlinePlus

    ... For Consumers Home For Consumers Consumer Updates Combating Antibiotic Resistance Share Tweet Linkedin Pin it More sharing options ... however, have contributed to a phenomenon known as antibiotic resistance. This resistance develops when potentially harmful bacteria change ...

  20. Addressing antibiotic resistance.

    PubMed

    Gupta, Kalpana

    2002-07-08

    Management of uncomplicated urinary tract infections (UTIs) has traditionally been based on 2 important principles: the spectrum of organisms causing acute UTI is highly predictable (Escherichia coli accounts for 75% to 90% and Staphylococcus saprophyticus accounts for 5% to 15% of isolates), and the susceptibility patterns of these organisms have also been relatively predictable. As a result, empiric therapy with short-course trimethoprim-sulfamethoxazole (TMP-SMX) has been a standard management approach for uncomplicated cystitis.However, antibiotic resistance is now becoming a major factor not only in nosocomial complicated UTIs, but also in uncomplicated community-acquired UTIs. Resistance to TMP-SMX now approaches 18% to 22% in some regions of the United States, and nearly 1 in 3 bacterial strains causing cystitis or pyelonephritis demonstrate resistance to amoxicillin. Fortunately, resistance to other agents, such as nitrofurantoin and the fluoroquinolones, has remained low, at approximately 2%. Preliminary data suggest that the increase in TMP-SMX resistance is associated with poorer bacteriologic and clinical outcomes when TMP-SMX is used for therapy. As a result, these trends have necessitated a change in the management approach to community-acquired UTI. The use of TMP-SMX as a first-line agent for empiric therapy of uncomplicated cystitis is only appropriate in areas where TMP-SMX resistance prevalence is <10% to 20%. In areas where resistance to TMP-SMX exceeds this rate, alternative agents need to be considered.

  1. Addressing antibiotic resistance.

    PubMed

    Gupta, Kalpana

    2003-02-01

    Management of uncomplicated urinary tract infections (UTIs) has traditionally been based on 2 important principles: the spectrum of organisms causing acute UTI is highly predictable (Escherichia coli accounts for 75% to 90% and Staphylococcus saprophyticus accounts for 5% to 15% of isolates), and the susceptibility patterns of these organisms have also been relatively predictable. As a result, empiric therapy with short-course trimethoprim-sulfamethoxazole (TMP-SMX) has been a standard management approach for uncomplicated cystitis.However, antibiotic resistance is now becoming a major factor not only in nosocomial complicated UTIs, but also in uncomplicated community-acquired UTIs. Resistance to TMP-SMX now approaches 18% to 22% in some regions of the United States, and nearly 1 in 3 bacterial strains causing cystitis or pyelonephritis demonstrate resistance to amoxicillin. Fortunately, resistance to other agents, such as nitrofurantoin and the fluoroquinolones, has remained low, at approximately 2%. Preliminary data suggest that the increase in TMP-SMX resistance is associated with poorer bacteriologic and clinical outcomes when TMP-SMX is used for therapy. As a result, these trends have necessitated a change in the management approach to community-acquired UTI. The use of TMP-SMX as a first-line agent for empiric therapy of uncomplicated cystitis is only appropriate in areas where TMP-SMX resistance prevalence is <10% to 20%. In areas where resistance to TMP-SMX exceeds this rate, alternative agents need to be considered.

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

    PubMed Central

    Jamal, Wafaa Y.; Rotimi, Vincent O.

    2016-01-01

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

  3. [Mechanisms of antibiotic resistance].

    PubMed

    Mühlemann, K

    2002-01-01

    Antibiotics interfere with structural and regulatory elements of bacterial cells leading to growth arrest or cell death. Bacteria have evolved a variety of strategies to overcome the effects of antibiotics. Examples are enzymatic destruction, alteration of the target, efflux and permeability changes. Resistance towards the same substance can be mediated by several mechanisms. Efflux pumps can probably act as mediators of higher resistance development. Alteration of common targets can lead to cross-resistance against several classes of antibiotics. Genetic events, such as point mutations, transfer of plasmids and gen regulation, can mediate a rapid emergence of resistance. Therefore, substances like rifampicin should be only used in combination with other drugs. Accumulation of resistance genes under common regulatory control in integrons induces co-resistance against substances of different specificity. Detailed knowledge of resistance mechanisms, their evolution and dynamics is important for a rational use of antibiotics and other strategies against antibiotic resistance.

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

    PubMed Central

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

    2017-01-01

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

  5. Evolution of antibiotic resistance without antibiotic exposure.

    PubMed

    Knöppel, Anna; Näsvall, Joakim; Andersson, Dan I

    2017-09-11

    Antibiotic use is the main driver in the emergence of antibiotic resistance. Another unexplored possibility is that resistance evolves coincidentally in response to other selective pressures. We show that selection in the absence of antibiotics can co-select for decreased susceptibility to several antibiotics. Thus, genetic adaptation of bacteria to natural environments may drive resistance evolution by generating a pool of resistance mutations that selection could act on to enrich resistant mutants when antibiotic exposure occurs. Copyright © 2017 Knöppel et al.

  6. Targeting Antibiotic Resistance

    PubMed Central

    Chellat, Mathieu F.; Raguž, Luka

    2016-01-01

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

  7. Antibiotic-Resistant Bacteria.

    ERIC Educational Resources Information Center

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

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

  8. Antibiotic-Resistant Bacteria.

    ERIC Educational Resources Information Center

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

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

  9. Antibiotic Resistance in Acne Treatment.

    PubMed

    Adler, Brandon L; Kornmehl, Heather; Armstrong, April W

    2017-08-01

    What is the evidence for antibiotic resistance in acne, and how does resistance affect treatment? Use of topical and systemic antibiotics for acne is associated with formation of resistance in Propionibacterium acnes and other bacteria, with clinical consequences. Guidelines recommend resistance reduction strategies including avoidance of antibiotic monotherapy, combination treatment with topical modalities, and limiting the duration of oral antibiotic use.

  10. Hospital Acquired Pneumonia Due to Achromobacter spp. in a Geriatric Ward in China: Clinical Characteristic, Genome Variability, Biofilm Production, Antibiotic Resistance and Integron in Isolated Strains

    PubMed Central

    Liu, Chao; Pan, Fei; Guo, Jun; Yan, Weifeng; Jin, Yi; Liu, Changting; Qin, Long; Fang, Xiangqun

    2016-01-01

    Background: Hospital-acquired pneumonia (HAP) due to Achromobacter has become a substantial concern in recent years. However, HAP due to Achromobacter in the elderly is rare. Methods: A retrospective analysis was performed on 15 elderly patients with HAP due to Achromobacter spp., in which the sequence types (STs), integrons, biofilm production and antibiotic resistance of the Achromobacter spp. were examined. Results: The mean age of the 15 elderly patients was 88.8 ± 5.4 years. All patients had at least three underlying diseases and catheters. Clinical outcomes improved in 10 of the 15 patients after antibiotic and/or mechanical ventilation treatment, but three patients had chronic infections lasting more than 1 year. The mortality rate was 33.3% (5/15). All strains were resistant to aminoglycosides, aztreonam, nitrofurantoin, and third- and fourth-generation cephalosporins (except ceftazidime and cefoperazone). Six new STs were detected. The most frequent ST was ST306. ST5 was identified in two separate buildings of the hospital. ST313 showed higher MIC in cephalosporins, quinolones and carbapenems, which should be more closely considered in clinical practice. All strains produced biofilm and had integron I and blaOXA-114-like. The main type was blaOXA-114q. The variable region of integron I was different among strains, and the resistance gene of the aminoglycosides was most commonly inserted in integron I. Additionally, blaPSE-1 was first reported in this isolate. Conclusion: Achromobacter spp. infection often occurs in severely ill elders with underlying diseases. The variable region of integrons differs, suggesting that Achromobacter spp. is a reservoir of various resistance genes. PMID:27242678

  11. Hospital Acquired Pneumonia Due to Achromobacter spp. in a Geriatric Ward in China: Clinical Characteristic, Genome Variability, Biofilm Production, Antibiotic Resistance and Integron in Isolated Strains.

    PubMed

    Liu, Chao; Pan, Fei; Guo, Jun; Yan, Weifeng; Jin, Yi; Liu, Changting; Qin, Long; Fang, Xiangqun

    2016-01-01

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

  12. Principles of Antibiotic Management of Community-Acquired Pneumonia.

    PubMed

    Bender, Michael T; Niederman, Michael S

    2016-12-01

    Community-acquired pneumonia (CAP) encompasses a broad spectrum of disease severity and may require outpatient, inpatient, or intensive care management. Successful treatment hinges on expedient delivery of appropriate antibiotic therapy tailored to both the likely offending pathogens and the severity of disease. This review summarizes key principles in starting treatment and provides recommended empiric therapy regimens for each site of care. In addition, we discuss the antimicrobial and anti-inflammatory role macrolides play in CAP, as well as specific information for managing individual CAP pathogens such as community-acquired methicillin-resistant Staphylococcus aureus and drug-resistant Streptococcus pneumoniae. We also examine several novel antibiotics being developed for CAP and review the evidence guiding duration of therapy and current best practices for the transition of hospitalized patients from intravenous antibiotics to oral therapy. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Changing prevalence and antibiotic drug resistance pattern of pathogens seen in community-acquired pediatric urinary tract infections at a tertiary care hospital of North India.

    PubMed

    Patwardhan, Vrushali; Kumar, Dinesh; Goel, Varun; Singh, Sarman

    2017-01-01

    The aim and objective of this study was to assess the temporal changes in the microbiological profiles and antimicrobial resistance patterns of uropathogens in pediatric community-acquired UTI. This is a retrospective analysis of data collected over a Scattered period of 5 years. The baseline data collected were from January to December 2009, and the second period considered for comparison was from January to December 2014. Urine specimens from children (<17 years) suspected of UTI were cultured by a semi-quantitative method on cysteine lactose electrolyte-deficient medium. Antibiotic sensitivity was put up by Kirby-Bauer disc diffusion method as per the Clinical and Laboratory Standard Institute guidelines. In the year 2009, 340 of 2104 (16.15%) urine specimens yielded significant colony count, whereas in 2014, it was 407 of 2212 (18.39%) (P = 0.051). Escherichia coli was the predominant pathogen and was significantly more prevalent in girls than in boys (P < 0.0001) during both periods. There was a significant overall increase in resistance to ampicillin (from 40.29% to 58.72%), amoxyclav (from 26.17% to 40.54%), nitrofurantoin (from 28.82% to 39.06%), and norfloxacin (from 30% to 41.42%). However, the maximum increase in the resistance was noted for co-trimoxazole from 35.58% in 2009 to 63.39% in 2014 (P = 0.0000058). The prevalence of extended-spectrum beta-lactamases (ESBLs) has also significantly increased from 21.7% to 33.16% (P = 0.0045). Although E. coli remains the prime pathogen in pediatric UTI, the prevalence of resistance has dramatically increased over the 5-year study period. Our study highlights the emergence of community-acquired ESBL-producing uropathogens in children proclaiming treatment challenges.

  14. Antibiotic resistance among autochthonous aquatic environmental bacteria.

    PubMed

    Schreiber, Christiane; Kistemann, Thomas

    2013-01-01

    Antibiotics are widely used in both human and veterinary medicine and antibiotic-resistant bacteria cause problems in antibiotic therapy. The current study was conducted in the catchment area of the river Swist (Germany) and focuses on the resistance of environmental Rhodospirillaceae to antibiotics used in human medicine. The samples collected reflect different levels of human impact on the environment. In total, 614 isolates were tested for antibiotic susceptibility. About half of these isolates were susceptible to all substances tested. Oxacillin resistance was observed most frequently (41%). Resistant Rhodospirillaceae were detected in wastewater effluent from a municipal sewage treatment plant, as well as in non-polluted upper reaches. The highest multi-resistance level was detected in small tributaries and it surprisingly decreased with an increasing influence of municipal wastewater. It could be shown that the detected resistances were acquired rather than intrinsic. Besides natural occurrence of multi-resistance among non-sulphur purple bacteria, horizontal gene transfer and acquired cross-resistance against veterinary antibiotics are assumed to be important factors. To the authors' knowledge, this is the first study investigating the potential of Rhodospirillaceae as a reservoir for resistance to antibiotics used in human medicine. The consequence for resistance prevalence in human pathogens and for their antibiotic therapy needs evaluation.

  15. Mechanisms of Antibiotic Resistance

    PubMed Central

    Munita, Jose M.; Arias, Cesar A.

    2015-01-01

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

  16. Predicting antibiotic resistance.

    PubMed

    Martínez, José L; Baquero, Fernando; Andersson, Dan I

    2007-12-01

    The treatment of bacterial infections is increasingly complicated because microorganisms can develop resistance to antimicrobial agents. This article discusses the information that is required to predict when antibiotic resistance is likely to emerge in a bacterial population. Indeed, the development of the conceptual and methodological tools required for this type of prediction represents an important goal for microbiological research. To this end, we propose the establishment of methodological guidelines that will allow researchers to predict the emergence of resistance to a new antibiotic before its clinical introduction.

  17. Tetracycline Antibiotics and Resistance.

    PubMed

    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.

  18. Antibiotic-Resistant Gonorrhea (ARG)

    MedlinePlus

    ... please visit this page: About CDC.gov . Gonorrhea Antibiotic Resistance Basic Information Laboratory Information Resources & References Combating the ... Page Surveillance Trends and Treatment Challenges Laboratory Issues Antibiotic resistance (AR) is the ability of bacteria to resist ...

  19. In vivo bioluminescence imaging to evaluate systemic and topical antibiotics against community-acquired methicillin-resistant Staphylococcus aureus-infected skin wounds in mice.

    PubMed

    Guo, Yi; Ramos, Romela Irene; Cho, John S; Donegan, Niles P; Cheung, Ambrose L; Miller, Lloyd S

    2013-02-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes skin and soft tissue infections, including impetigo, cellulitis, folliculitis, and infected wounds and ulcers. Uncomplicated CA-MRSA skin infections are typically managed in an outpatient setting with oral and topical antibiotics and/or incision and drainage, whereas complicated skin infections often require hospitalization, intravenous antibiotics, and sometimes surgery. The aim of this study was to develop a mouse model of CA-MRSA wound infection to compare the efficacy of commonly used systemic and topical antibiotics. A bioluminescent USA300 CA-MRSA strain was inoculated into full-thickness scalpel wounds on the backs of mice and digital photography/image analysis and in vivo bioluminescence imaging were used to measure wound healing and the bacterial burden. Subcutaneous vancomycin, daptomycin, and linezolid similarly reduced the lesion sizes and bacterial burden. Oral linezolid, clindamycin, and doxycycline all decreased the lesion sizes and bacterial burden. Oral trimethoprim-sulfamethoxazole decreased the bacterial burden but did not decrease the lesion size. Topical mupirocin and retapamulin ointments both reduced the bacterial burden. However, the petrolatum vehicle ointment for retapamulin, but not the polyethylene glycol vehicle ointment for mupirocin, promoted wound healing and initially increased the bacterial burden. Finally, in type 2 diabetic mice, subcutaneous linezolid and daptomycin had the most rapid therapeutic effect compared with vancomycin. Taken together, this mouse model of CA-MRSA wound infection, which utilizes in vivo bioluminescence imaging to monitor the bacterial burden, represents an alternative method to evaluate the preclinical in vivo efficacy of systemic and topical antimicrobial agents.

  20. In Vivo Bioluminescence Imaging To Evaluate Systemic and Topical Antibiotics against Community-Acquired Methicillin-Resistant Staphylococcus aureus-Infected Skin Wounds in Mice

    PubMed Central

    Guo, Yi; Ramos, Romela Irene; Cho, John S.; Donegan, Niles P.; Cheung, Ambrose L.

    2013-01-01

    Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes skin and soft tissue infections, including impetigo, cellulitis, folliculitis, and infected wounds and ulcers. Uncomplicated CA-MRSA skin infections are typically managed in an outpatient setting with oral and topical antibiotics and/or incision and drainage, whereas complicated skin infections often require hospitalization, intravenous antibiotics, and sometimes surgery. The aim of this study was to develop a mouse model of CA-MRSA wound infection to compare the efficacy of commonly used systemic and topical antibiotics. A bioluminescent USA300 CA-MRSA strain was inoculated into full-thickness scalpel wounds on the backs of mice and digital photography/image analysis and in vivo bioluminescence imaging were used to measure wound healing and the bacterial burden. Subcutaneous vancomycin, daptomycin, and linezolid similarly reduced the lesion sizes and bacterial burden. Oral linezolid, clindamycin, and doxycycline all decreased the lesion sizes and bacterial burden. Oral trimethoprim-sulfamethoxazole decreased the bacterial burden but did not decrease the lesion size. Topical mupirocin and retapamulin ointments both reduced the bacterial burden. However, the petrolatum vehicle ointment for retapamulin, but not the polyethylene glycol vehicle ointment for mupirocin, promoted wound healing and initially increased the bacterial burden. Finally, in type 2 diabetic mice, subcutaneous linezolid and daptomycin had the most rapid therapeutic effect compared with vancomycin. Taken together, this mouse model of CA-MRSA wound infection, which utilizes in vivo bioluminescence imaging to monitor the bacterial burden, represents an alternative method to evaluate the preclinical in vivo efficacy of systemic and topical antimicrobial agents. PMID:23208713

  1. Antibiotic Resistance in Pediatric Urinary Tract Infections.

    PubMed

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

    2016-12-01

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

  2. Tackling antibiotic resistance

    PubMed Central

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

    2014-01-01

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

  3. [Resistance to antibiotics].

    PubMed

    Sánchez, Jesús Silva

    2006-01-01

    Bacterial resistance to antibiotics is a major public health problem around the world causing high rates of morbi-mortality and economic problems in hospital settings. Major bacterial causing nosocomial infections are: extended-spectrum beta-lactameses (ESBL) producing enterobacteria, methicillin resistance Staphylococcus aureus, coagulase negative Staphylococcus, metallo fl-lactamases (MBL) producing Pseudomonas aeruginosa, Streptococcus pneumoniae, Enterococcus spp, Acinetobacter baumani. This last bacteria is not very often isolated in hospital settings yet, but it is multi-resistance pathogen causing high mortality. Helicobacter pylori, which is not a nosocomial pathogen but is associated to gastric diseases (from gastritis to gastric cancer). Infections prevention, to obtain an accuracy diagnostic and effective treatment, use antibiotic wisely and pathogen dissemination prevention (hand washing), are important steps to control the bacterial resistance.

  4. Investigating the Antibiotic Resistance Problem.

    ERIC Educational Resources Information Center

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

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

  5. Investigating the Antibiotic Resistance Problem.

    ERIC Educational Resources Information Center

    Lawson, Michael; Lawson, Amy L.

    1998-01-01

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

  6. Strategies to Minimize Antibiotic Resistance

    PubMed Central

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

    2013-01-01

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

  7. Strategies to minimize antibiotic resistance.

    PubMed

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

    2013-09-12

    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. Selective decontamination and antibiotic resistance in ICUs.

    PubMed

    Plantinga, Nienke L; Bonten, Marc J M

    2015-06-24

    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 decontamination (SDD/SOD) in areas where multidrug-resistant Gram-negative bacteria are endemic is less clear. It will be important to determine whether SDD/SOD improves patient outcome in such settings and how these measures affect the epidemiology of multidrug-resistant Gram-negative bacteria. Here we review the current evidence on the effects of SDD/SOD on antibiotic resistance development in individual ICU patients as well as the effect on ICU ecology, the latter including both ICU-level antibiotic resistance and antibiotic resistance development during long-term use of SDD/SOD.

  9. [Antibiotic therapy of hospital-acquired pneumonia and its pharmacoeconomics].

    PubMed

    Kolář, Milan; Htoutou Sedláková, Miroslava; Urbánek, Karel; Uvízl, Radomír; Adamus, Milan; Imwensi, O P

    2016-03-01

    Important hospital-acquired infections include pneumonia, mainly because of the increasing resistance of bacterial pathogens to antimicrobials and the associated potential failure of antibiotic therapy. The present study aimed at determining the most frequent etiological agents of hospital-acquired pneumonia (HAP) and assessing the relationship between 30-day mortality and adequacy of antibiotic therapy. Based on the obtained information, optimal patterns of antibiotic therapy were to be defined, including a pharmacoeconomic perspective. In patients with clinically confirmed HAP, bacterial etiological agents were identified, their susceptibility to antimicrobials was determined and statistical methods were used to assess the relationship between adequacy of antibiotic therapy and 30-day mortality. The study comprised 68 patients with clinically confirmed HAP. The most common etiological agents were strains of Pseudomonas aeruginosa (30.8 %), Klebsiella pneumoniae (23.1 %) and Burkholderia cepacia complex (15.4 %). Gram-negative bacteria accounted for 86.5 % of all bacterial pathogens. The overall mortality reached 42.5 %. In the subgroup of patients with inadequate antibiotic therapy, 30-day mortality was significantly higher (83.3 %) than in the subgroup with adequate therapy (30.0 %; p = 0.002). The risk for 30-day mortality was 2.78 times higher in case of inadequate antibiotic therapy (95%CI: 1.52-5.07). The proportion of Pseudomonas aeruginosa strains was significantly higher in the subgroup of patients with inadequate antibiotic therapy than in those with adequate therapy (67 % vs. 27 %; p = 0.032). Results of the present study suggest a significant relationship between mortality of patients with HAP and ineffective antibiotic therapy due to resistance of the bacterial pathogen. Thus, it is clear that initial antibiotic therapy must be based on qualified assumption of sufficient activity against the most common bacterial pathogens and results of surveillance

  10. Surveillance of antibiotic resistance

    PubMed Central

    Johnson, Alan P.

    2015-01-01

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

  11. Endless Resistance. Endless Antibiotics?

    PubMed Central

    Fisher, Jed F.; Mobashery, Shahriar

    2016-01-01

    The practice of medicine was profoundly transformed by the introduction of the antibiotics (compounds isolated from Nature) and the antibacterials (compounds prepared by synthesis) for the control of bacterial infection. As a result of the extraordinary success of these compounds over decades of time, a timeless biological activity for these compounds has been presumed. This presumption is no longer. The inexorable acquisition of resistance mechanisms by bacteria is retransforming medical practice. Credible answers to this dilemma are far better recognized than they are being implemented. In this perspective we examine (and in key respects, reiterate) the chemical and biological strategies being used to address the challenge of bacterial resistance. PMID:27746889

  12. Antibiotic resistance in nosocomial respiratory infections.

    PubMed

    Denys, Gerald A; Relich, Ryan F

    2014-06-01

    Nosocomial respiratory infections are the most common acquired infections in patients with severe underlying conditions and are responsible for high morbidity and mortality in this patient population. Multidrug-resistant (MDR) pathogens are associated with hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). This article describes the etiology, epidemiology, pathogenesis, diagnosis, and treatment of HAP and VAP associated with antibiotic-resistant bacterial pathogens. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. [Antibiotic therapy: impact and resistance].

    PubMed

    Weiler, S; Corti, N

    2014-04-01

    Many achievements in modern medicine, such as in transplantation medicine, cancer therapy, surgery, and intensive care medicine would have been impossible without effective treatment of bacterial infections. Antibiotic resistance is on the rise; the reasons for this are complex and vary greatly. Knowledge about the impact of antibiotics and mechanisms of antibiotic resistance, which are the cornerstones of calculated and targeted antibiotic therapy, is imperative. This review describes the pharmacodynamics of relevant antibiotics in emergency and intensive care medicine. Commonly resistant bacteria with clinical relevance and the respective mechanisms of resistance are highlighted. Furthermore, the use of antiinfectives for reserve treatment of severe infections is discussed. Understanding the mechanisms of resistance and effects of antibiotics are fundamental for efficient and successful treatment of bacterial infections and for the reduction of resistant species.

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

    PubMed Central

    Olaitan, Abiola O.; Morand, Serge; Rolain, Jean-Marc

    2014-01-01

    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. PMID:25505462

  15. Mechanisms of antibiotic resistance in Staphylococcus aureus.

    PubMed

    Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

    2007-06-01

    Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

  16. Natural and acquired macrolide resistance in mycobacteria.

    PubMed

    Doucet-Populaire, F; Buriánková, K; Weiser, J; Pernodet, J-L

    2002-12-01

    The genus Mycobacterium contains two of the most important human pathogens, Mycobacterium tuberculosis and Mycobacterium leprae, the etiologic agents of tuberculosis and leprosy, respectively. Other mycobacteria are mostly saprophytic organisms, living in soil and water, but some of them can cause opportunistic infections. The increasing incidence of tuberculosis as well as infections with non-tuberculous mycobacteria (NTM) in AIDS patients has renewed interest in molecular mechanisms of drug resistance in these pathogens. Mycobacteria show a high degree of intrinsic resistance to most common antibiotics. For instance, species from the M. tuberculosis complex (MTC) are intrinsically resistant to macrolides. Nevertheless, some semi-synthetic macrolides as the erythromycin derivatives clarithromycin, azithromycin and most recently the ketolides, are active against NTM, particularly Mycobacterium avium, and some of them are widely used for infection treatment. However, shortly after the introduction of these new drugs, resistant strains appeared due to mutations in the macrolide target, the ribosome. The mycobacterial cell wall with its specific composition and structure is considered to be a major factor in promoting the natural resistance of mycobacteria to various antibiotics. However, to explain the difference in macrolide sensitivity between the MTC and NTM, the synergistic contribution of a specific resistance mechanism might be required, in addition to possible differences in cell wall permeability. This mini-review summarizes the current knowledge on the natural and acquired macrolide resistance in mycobacteria, gives an overview of potential mechanisms implicated in the intrinsic resistance and brings recent data concerning a macrolide resistance determinant in the MTC.

  17. Antibiotic and Antimicrobial Resistance: Threat Report 2013

    MedlinePlus

    ... with Antibiotic-Resistant Bacteria [page 18] Assessment of Domestic Antibiotic-Resistant Threats [page 20] Running Out of ... Preventing the Spread of Resistance [page 32] CDC's Work to Prevent Infections and Antibiotic Resistance in Healthcare ...

  18. Antibiotic control of antibiotic resistance in hospitals: a simulation study.

    PubMed

    Haber, Michael; Levin, Bruce R; Kramarz, Piotr

    2010-08-25

    Using mathematical deterministic models of the epidemiology of hospital-acquired infections and antibiotic resistance, it has been shown that the rates of hospital-acquired bacterial infection and frequency of antibiotic infections can be reduced by (i) restricting the admission of patients colonized with resistant bacteria, (ii) increasing the rate of turnover of patients, (iii) reducing transmission by infection control measures, and (iv) the use of second-line drugs for which there is no resistance. In an effort to explore the generality and robustness of the predictions of these deterministic models to the real world of hospitals, where there is variation in all of the factors contributing to the incidence of infection, we developed and used a stochastic model of the epidemiology of hospital-acquired infections and resistance. In our analysis of the properties of this model we give particular consideration different regimes of using second-line drugs in this process. We developed a simple model that describes the transmission of drug-sensitive and drug-resistant bacteria in a small hospital. Colonized patients may be treated with a standard drug, for which there is some resistance, and with a second-line drug, for which there is no resistance. We then ran deterministic and stochastic simulation programs, based on this model, to predict the effectiveness of various treatment strategies. The results of the analysis using our stochastic model support the predictions of the deterministic models; not only will the implementation of any of the above listed measures substantially reduce the incidences of hospital-acquired infections and the frequency of resistance, the effects of their implementation should be seen in months rather than the years or decades anticipated to control resistance in open communities. How effectively and how rapidly the application of second-line drugs will contribute to the decline in the frequency of resistance to the first-line drugs

  19. WAAR (World Alliance against Antibiotic Resistance): Safeguarding antibiotics

    PubMed Central

    2012-01-01

    Summary Resistance to antibiotics has increased recently to a dramatic extend, and the pipeline of new antibiotics is almost dry for the five next years. Failures happen already for trivial community acquired infections, like pyelonephritis, or peritonitis, and this is likely to increase. Difficult surgical procedures, transplants, and other immunosuppressive therapies will become far more risky. Resistance is mainly due to an excessive usage of antibiotics, in all sectors, including the animal one. Action is urgently needed. Therefore, an alliance against MDRO has been recently created, which includes health care professionals, consumers, health managers, and politicians. The document highlights the different proposed measures, and represents a strong consensus between the different professionals, including general practicionners, and veterinarians. PMID:22958542

  20. Combination antibiotic therapy for community-acquired pneumonia.

    PubMed

    Caballero, Jesus; Rello, Jordi

    2011-11-23

    Community-acquired pneumonia (CAP) is a common and potentially serious illness that is associated with morbidity and mortality. Although medical care has improved during the past decades, it is still potentially lethal. Streptococcus pneumoniae is the most frequent microorganism isolated. Treatment includes mandatory antibiotic therapy and organ support as needed. There are several antibiotic therapy regimens that include β-lactams or macrolides or fluoroquinolones alone or in combination. Combination antibiotic therapy achieves a better outcome compared with monotherapy and it should be given in the following subset of patients with CAP: outpatients with comorbidities and previous antibiotic therapy, nursing home patients with CAP, hospitalized patients with severe CAP, bacteremic pneumococcal CAP, presence of shock, and necessity of mechanical ventilation. Better outcome is associated with combination therapy that includes a macrolide for wide coverage of atypical pneumonia, polymicrobial pneumonia, or resistant Streptococcus pneumoniae. Macrolides have shown different properties other than antimicrobial activity, such as anti-inflammatory properties. Although this evidence comes from observational, most of them retrospective and nonblinded studies, the findings are consistent. Ideally, a prospective, multicenter, randomized trial should be performed to confirm these findings.

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

    PubMed

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

    2015-01-01

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

  2. Antibiotic resistant in microorganisms

    USDA-ARS?s Scientific Manuscript database

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

  3. Molecular mechanisms of antibiotic resistance.

    PubMed

    Wright, Gerard D

    2011-04-14

    Over the past decade, resistance to antibiotics has emerged as a crisis of global proportion. Microbes resistant to many and even all clinically approved antibiotics are increasingly common and easily spread across continents. At the same time there are fewer new antibiotic drugs coming to market. We are reaching a point where we are no longer able to confidently treat a growing number of bacterial infections. The molecular mechanisms of drug resistance provide the essential knowledge on new drug development and clinical use. These mechanisms include enzyme catalyzed antibiotic modifications, bypass of antibiotic targets and active efflux of drugs from the cell. Understanding the chemical rationale and underpinnings of resistance is an essential component of our response to this clinical challenge.

  4. Antibiotic Resistance: MedlinePlus Health Topic

    MedlinePlus

    ... and Tests Susceptibility Testing (American Association for Clinical Chemistry) Prevention and Risk Factors Antibiotic Resistance (Food and Drug Administration) Antibiotic Resistance Threats in the ...

  5. Evolutionary Trajectories to Antibiotic Resistance.

    PubMed

    Hughes, Diarmaid; Andersson, Dan I

    2017-09-08

    The ability to predict the evolutionary trajectories of antibiotic resistance would be of great value in tailoring dosing regimens of antibiotics so as to maximize the duration of their usefulness. Useful prediction of resistance evolution requires information about (a) the mutation supply rate, (b) the level of resistance conferred by the resistance mechanism, (c) the fitness of the antibiotic-resistant mutant bacteria as a function of drug concentration, and (d) the strength of selective pressures. In addition, processes including epistatic interactions and compensatory evolution, coselection of drug resistances, and population bottlenecks and clonal interference can strongly influence resistance evolution and thereby complicate attempts at prediction. Currently, the very limited quantitative data on most of these parameters severely limit attempts to accurately predict trajectories of resistance evolution.

  6. Bacterial Cheating Limits the Evolution of Antibiotic Resistance

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  7. Pseudomonas pseudoalcaligenes KF707 upon biofilm formation on a polystyrene surface acquire a strong antibiotic resistance with minor changes in their tolerance to metal cations and metalloid oxyanions.

    PubMed

    Tremaroli, Valentina; Fedi, Stefano; Turner, Raymond J; Ceri, Howard; Zannoni, Davide

    2008-07-01

    The susceptibility to various biocides was examined in planktonic cells and biofilms of the obligate aerobe, PCBs degrader, Pseudomonas pseudoalcaligenes KF707. The toxicity of two antibiotics, amikacin and rifampicin, three metalloid oxyanions (AsO2(-), SeO3(2-), TeO3(2-)) and three metal cations (Cd2+, Ni2+, Al3+) was tested at two stages of the biofilm-development (4 and 24 h) and compared to planktonic cells susceptibility. Mature biofilms formed in rich (LB, Luria-Bertani) medium were thicker (23 microm) than biofilms grown in minimal (SA saccarose-arginine) medium (13 microm). Early grown (4 h) SA-biofilms, which consisted of a few sparse/attached cells, were 50-100 times more resistant to antibiotics than planktonic cells. Conversely, minor changes in tolerance to metal(loid)s were seen in both SA- and LB-grown biofilms. In contrast to planktonic cells, no reduction of TeO3(2-) to elemental Te0 or SeO3(2-) to elemental Se0 was seen in KF707 biofilms. The data indicate that: (a) metal tolerance in KF707 biofilms, under the growth and exposure conditions described here, is different than antibiotic tolerance; (b) KF707 planktonic cells and biofilms, are almost equally susceptible to killing by metal cations and oxyanions, and (c) biofilm-tolerance to TeO3(2-) and SeO3(2-) is not linked to metalloid reduction; this means that KF707 planktonic cells and biofilms differ in their physiology and strategy to counteract metalloid toxicity.

  8. The role of antibiotics and antibiotic resistance in nature.

    PubMed

    Aminov, Rustam I

    2009-12-01

    Investigations of antibiotic resistance from an environmental prospective shed new light on a problem that was traditionally confined to a subset of clinically relevant antibiotic-resistant bacterial pathogens. It is clear that the environmental microbiota, even in apparently antibiotic-free environments, possess an enormous number and diversity of antibiotic resistance genes, some of which are very similar to the genes circulating in pathogenic microbiota. It is difficult to explain the role of antibiotics and antibiotic resistance in natural environments from an anthropocentric point of view, which is focused on clinical aspects such as the efficiency of antibiotics in clearing infections and pathogens that are resistant to antibiotic treatment. A broader overview of the role of antibiotics and antibiotic resistance in nature from the evolutionary and ecological prospective suggests that antibiotics have evolved as another way of intra- and inter-domain communication in various ecosystems. This signalling by non-clinical concentrations of antibiotics in the environment results in adaptive phenotypic and genotypic responses of microbiota and other members of the community. Understanding the complex picture of evolution and ecology of antibiotics and antibiotic resistance may help to understand the processes leading to the emergence and dissemination of antibiotic resistance and also help to control it, at least in relation to the newer antibiotics now entering clinical practice.

  9. Acquired inducible antimicrobial resistance in Gram-positive bacteria

    PubMed Central

    Chancey, Scott T; Zähner, Dorothea; Stephens, David S

    2012-01-01

    A major contributor to the emergence of antibiotic resistance in Gram-positive bacterial pathogens is the expansion of acquired, inducible genetic elements. Although acquired, inducible antibiotic resistance is not new, the interest in its molecular basis has been accelerated by the widening distribution and often ‘silent’ spread of the elements responsible, the diagnostic challenges of such resistance and the mounting limitations of available agents to treat Gram-positive infections. Acquired, inducible antibiotic resistance elements belong to the accessory genome of a species and are horizontally acquired by transformation/recombination or through the transfer of mobile DNA elements. The two key, but mechanistically very different, induction mechanisms are: ribosome-sensed induction, characteristic of the macrolide–lincosamide–streptogramin B antibiotics and tetracycline resistance, leading to ribosomal modifications or efflux pump activation; and resistance by cell surface-associated sensing of β-lactams (e.g., oxacillin), glycopeptides (e.g., vancomycin) and the polypeptide bacitracin, leading to drug inactivation or resistance due to cell wall alterations. PMID:22913355

  10. Antibiotic resistance: An ethical challenge.

    PubMed

    Littmann, Jasper; Buyx, Alena; Cars, Otto

    2015-10-01

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

  11. Antibiotics and Resistance: Glossary

    MedlinePlus

    ... bacteria are stained dark purple. Cell walls of gram-negative bacteria are more permeable - they do not retain much of the dye, and so their cell walls do not show much stain. Growth promoters A class of substances, usually antibiotics, ...

  12. Antibiotic resistance in probiotic bacteria

    PubMed Central

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

    2013-01-01

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

  13. Antibiotic / Antimicrobial Resistance Glossary

    MedlinePlus

    ... chemicals, or other agents to cure or prevent infections. Epidemiology The study of the spread of disease, or ... are also called microorganisms. Nosocomial Referring to an infection acquired by a patient while ... living thing. Organisms include humans, animals, plants, bacteria , ...

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

    PubMed

    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.

  15. Antibiotic resistance: A current epilogue.

    PubMed

    Dodds, David R

    2017-06-15

    The history of the first commercial antibiotics is briefly reviewed, together with data from the US and WHO, showing the decrease in death due to infectious diseases over the 20th century, from just under half of all deaths, to less than 10%. The second half of the 20th century saw the new use of antibiotics as growth promoters for food animals in the human diet, and the end of the 20th century and beginning of the 21st saw the beginning and rapid rise of advanced microbial resistance to antibiotics. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. [Diagnosis and management of antibiotic-resistant bacteria].

    PubMed

    Yanagihara, Katsunori; Kamihira, Shimeru

    2012-06-01

    Antibiotic-resistant infections acquired in hospitals are of great concern, and have become a serious public issue. Antibiotic-resistant infections can be associated with a variety of bacteria, such as methicillin resistant Staphylococcus aureus(MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRP). Since clinical laboratories are responsible for detecting information regarding antibiotic-resistant bacteria, they are required to perform analysis and dissemination of the information. Currently, rapid methods for detecting antibiotic-resistant bacteria using molecular techniques are being developed in response to the problem of the conventional methods for bacteriological testing, which require a few days to obtain results. This article presents the diagnosis and management of antibiotic-resistant bacteria, which comprise a serious health care issue.

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

    PubMed Central

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

    2013-01-01

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

  18. The determinants of the antibiotic resistance process

    PubMed Central

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

    2009-01-01

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

  19. Advances in pneumococcal antibiotic resistance.

    PubMed

    Song, Jae-Hoon

    2013-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

  1. Selection of antibiotic resistance at very low antibiotic concentrations

    PubMed Central

    2014-01-01

    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. PMID:24694026

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

    PubMed

    Sandegren, Linus

    2014-05-01

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

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

    PubMed

    Suzuki, Shingo; Horinouchi, Takaaki; Furusawa, Chikara

    2015-10-01

    We analyzed the effect of combinatorial use of antibiotics with a trade-off relationship of resistance, i.e., resistance acquisition to one drug causes susceptibility to the other drug, and vice versa, on the evolution of antibiotic resistance. We demonstrated that this combinatorial use of antibiotics significantly suppressed the acquisition of resistance. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    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

  6. [Antibiotic resistance: A global crisis].

    PubMed

    Alós, Juan-Ignacio

    2015-12-01

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

  7. Antibiotic resistance in Burkholderia species.

    PubMed

    Rhodes, Katherine A; Schweizer, Herbert P

    2016-09-01

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

  8. Antibiotic Resistance in Burkholderia Species

    PubMed Central

    Rhodes, Katherine A.; Schweizer, Herbert P.

    2016-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

    We propose a simple causal model depicting relationships involved in dissemination of antibiotics and antibiotic resistance in agroecosystems and potential effects on human health, functioning of natural ecosystems, and agricultural productivity. Available evidence for each causal link is briefly su...

  10. Spatial mapping of antibiotic resistance

    USDA-ARS?s Scientific Manuscript database

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

  11. Antibiotic resistance: a geopolitical issue.

    PubMed

    Carlet, J; Pulcini, C; Piddock, L J V

    2014-10-01

    Antimicrobial resistance (AMR), associated with a lack of new antibiotics, is a major threat. Some countries have been able to contain resistance, but in most countries the numbers of antibiotic-resistant bacteria continue to increase, along with antibiotic consumption by humans and animals. AMR is a global issue, and concerns all decision-makers worldwide. Some initiatives have been undertaken in the last 15 years, in particular by the WHO, the European Centre for Disease Prevention and Control, and the CDC, but those initiatives were partial and poorly implemented, without coordination. Very recently, some important initiatives have been implemented by the WHO. Since 2009, a US and European joint task force, the Trans-Atlantic Task Force on Antibiotic Resistance, has been working on common recommendations. At a national level, some important initiatives have been implemented, in particular in European countries and in the USA. The Chennai declaration, in India, is also a good example of a multidisciplinary and national initiative that was highly political. Finally, several non-governmental non-profit organizations are also very active, and have helped to raise awareness about the problem of AMR. In the future, this global issue will need political involvement and strong cooperation between countries and between international agencies.

  12. Persistence of Antibiotic Resistance Plasmids in Biofilms

    DTIC Science & Technology

    2014-10-01

    useful in the care of patients with combat-related wound infections. 15. SUBJECT TERMS Antibiotic resistance, plasmid, biofilm, coevolution , bacteria...Antibiotic!resistance,!plasmid,!biofilm,! coevolution ,!bacteria,!wound!infections! ! ! ! 3! 3. OVERALL PROJECT SUMMARY: The! successful! persistence

  13. Staphylococci in community-acquired infections: Increased resistance to penicillin.

    PubMed Central

    Hughes, G B; Chidi, C C; Macon, W L

    1976-01-01

    One hundred patients with community-acquired staphylococcal infections of the skin and soft tissues were treated in the Emergency Ward of Cleveland Metropolitan General Hospital from June to October of 1974. Each staphylococcal infection was considered community-acquired if, within two weeks prior to being treated for the first time, the patient had not received antibiotics, had not been hospitalized, and had not been in contact with other recently hospitalized persons. Of 100 community-acquired staphylococcal infections, 85 were resistant to penicillin. Almost no resistance to other tested antibiotics was observed. Unless indicated otherwise by bacteriologic testing, penicillin is a poor drug of choice in those skin and soft tissue infections suspected of harboring staphylococci. PMID:1267491

  14. Mathematical analysis of multi-antibiotic resistance.

    PubMed

    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.

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

    PubMed

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

    2011-11-01

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

  16. Genomics and the evolution of antibiotic resistance.

    PubMed

    Gillings, Michael R; Paulsen, Ian T; Tetu, Sasha G

    2017-01-01

    Antibiotic resistance arises as a consequence of complex interactions among genes, mobile elements, and their bacterial hosts, coupled with the intense selection pressures imposed by humans in an attempt to control bacterial growth. Understanding the evolution of resistance requires an understanding of interacting cellular and genetic components. Here, we review how DNA analysis has helped reconstruct the origins of the mosaic, multiresistant mobile elements that have spread through pathogens in the last 60 years. This history helps inform the future, such that resistance might be better managed. Whole-genome sequencing has great potential for epidemiological tracking and for understanding the development of resistance via experimental evolution. DNA analysis also offers the opportunity for constructing databases that record genes of interest, the mobile elements that move these genes, and the cells or species that acquire such genes. Linking these DNA elements to their human and animal hosts and to the environments where they occur should help us establish a more robust ecological and evolutionary framework for controlling and managing resistance. Such efforts need to be well coordinated because, like many other issues that face humanity, antibiotic resistance is a global problem that requires global solutions. © 2016 New York Academy of Sciences.

  17. Antibiotic resistance in Helicobacter pylori.

    PubMed

    Alba, Claudio; Blanco, Ana; Alarcón, Teresa

    2017-10-01

    Treatment of Helicobacter pylori is difficult nowadays because of its high resistance. The prevalence and mechanism of resistance, the different methods to detect it and the clinical implication of resistance were addressed in several research papers last year. Clarithromycin-resistant H. pylori has been recognized by the WHO as 'high priority', for which new antibiotics are needed. Moreover, the Maastricht consensus recommended, in areas with high resistance, that susceptibility tests should be performed, at least after a treatment failure. Metronidazole and clarithromycin resistance rates are alarming although they vary among populations. Tetracycline and amoxicillin-resistance are very low in most countries. H. pylori resistance can be detected by phenotypic or by molecular methods. Different break points may be used when performing an antimicrobial susceptibility test, so comparing resistance among different populations is challenging. Genomic techniques open new possibilities in the diagnosis of H. pylori, and the detection of H. pylori and its antimicrobial resistance in faeces is an interesting approach. Eradication rates are dependent on the susceptibility of the strain to metronidazole and clarithromycin, being lower in patients infected with a resistant strain.

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

    PubMed Central

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

    2013-01-01

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

  19. Approaching zero: temporal effects of a restrictive antibiotic policy on hospital-acquired Clostridium difficile, extended-spectrum β-lactamase-producing coliforms and meticillin-resistant Staphylococcus aureus.

    PubMed

    Dancer, S J; Kirkpatrick, P; Corcoran, D S; Christison, F; Farmer, D; Robertson, C

    2013-02-01

    A restrictive antibiotic policy banning routine use of ceftriaxone and ciprofloxacin was implemented in a 450-bed district general hospital following an educational campaign. Monthly consumption of nine antibiotics was monitored in defined daily doses (DDDs) per 1000 patient-occupied bed-days (1000 pt-bds) 9 months before until 16 months after policy introduction. Hospital-acquired Clostridium difficile, meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing coliform cases per month/1000 pt-bds were identified and reviewed throughout the hospital. Between the first and final 6 months of the study, average monthly consumption of ceftriaxone reduced by 95% (from 46.213 to 2.129 DDDs/1000 pt-bds) and that for ciprofloxacin by 72.5% (109.804 to 30.205 DDDs/1000 pt-bds). Over the same periods, hospital-acquisition rates for C. difficile reduced by 77% (2.398 to 0.549 cases/1000 pt-bds), for MRSA by 25% (1.187 to 0.894 cases/1000 pt-bds) and for ESBL-producing coliforms by 17% (1.480 to 1.224 cases/1000 pt-bds). Time-lag modelling confirmed significant associations between ceftriaxone and C. difficile cases at 1 month (correlation 0.83; P<0.005), and between ciprofloxacin and ESBL-producing coliform cases at 2 months (correlation 0.649; P=0.002). An audit performed 3 years after the policy showed sustained reduction in C. difficile rates (0.259 cases/1000 pt-bds), with additional decreases for MRSA (0.409 cases/1000 pt-bds) and ESBL-producing coliforms (0.809 cases/1000 pt-bds). In conclusion, banning two antibiotics resulted in an immediate and profound reduction in hospital-acquired C. difficile, with possible longer-term effects on MRSA and ESBL-producing coliform rates. Antibiotic stewardship is fundamental in the control of major hospital pathogens.

  20. Antibiotic resistance in cancer patients.

    PubMed

    Gudiol, Carlota; Carratalà, Jordi

    2014-08-01

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

  1. Comparative study of isolates from community-acquired and catheter-associated urinary tract infections with reference to biofilm-producing property, antibiotic sensitivity and multi-drug resistance.

    PubMed

    Bardoloi, Vishwajeet; Yogeesha Babu, K V

    2017-07-01

    Urinary tract infection (UTI) can be community-acquired (Com-UTI) or catheter-associated (CAUTI) and may be associated with biofilm-producing organisms. A comparative analysis of biofilm-producing property (BPP), antibiotic-sensitivity and multi-drug resistance (MDR) and their relation with the BPP of isolates from Com-UTI and CAUTI has not yet been performed and necessitated this study. (1) isolation of bacteria from CAUTI and Com-UTI and identification of their BPP, antibiotic-sensitivity and MDR status; (2) comparison of the isolates from CAUTI and Com-UTI as regards BPP, MDR status and their relation with BPP. isolates from 100 cases each of Com-UTI and CAUTI were subjected to Congo redagar (CRA) and Safranin tube tests. Antibiotic susceptibility was investigated using the disc diffusion method. Both groups were compared regarding BPP, drug sensitivity and MDR status. Statistical analyses were performed using χ2 and Fisher's exact tests. 76.19 % of isolates from Com-UTI and 60.72 % from CAUTI had BPP (P=0.0252; significant). The Safranin tube test detected more isolates with BPP than the CRA test. MDR is greater in CAUTI than Com-UTI (83.33 % versus 64.76 %; P=0.0039; significant). MDR is greater in isolates with BPP in both Com-UTI and CAUTI (76.47 and 62.35 %; non-significant). BPP was found in both Com-UTI and CAUTI. When used together, the Safranin tube test and the CRA test increased the sensitivity of detecting BPP. MDR was higher in CAUTI than Com-UTI. MDR and BPP are not interrelated or associated, especially in settings where it is not certain that isolates were obtained from a well-formed biofilm. However, this does not rule out a higher incidence or prevalence of MDR in isolates with BPP taken directly from the biofilms.

  2. Resistance to Antibiotics Mediated by Target Alterations

    NASA Astrophysics Data System (ADS)

    Spratt, Brian G.

    1994-04-01

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

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

    PubMed Central

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

    2015-01-01

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

  4. Origins and Evolution of Antibiotic Resistance

    PubMed Central

    Davies, Julian; Davies, Dorothy

    2010-01-01

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

  5. Origins and evolution of antibiotic resistance.

    PubMed

    Davies, Julian; Davies, Dorothy

    2010-09-01

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

  6. Probiotic approach to prevent antibiotic resistance.

    PubMed

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

    2016-01-01

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

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

    PubMed

    Ganguly, Nirmal K; Arora, N K; Chandy, Sujith J; Fairoze, Mohamed Nadeem; Gill, J P S; Gupta, Usha; Hossain, Shah; Joglekar, Sadhna; Joshi, P C; Kakkar, Manish; Kotwani, Anita; Rattan, Ashok; Sudarshan, H; Thomas, Kurien; Wattal, Chand; Easton, Alice; Laxminarayan, Ramanan

    2011-09-01

    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.

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

    PubMed Central

    2011-01-01

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

  9. Integron Involvement in Environmental Spread of Antibiotic Resistance

    PubMed Central

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

    2012-01-01

    The spread of antibiotic-resistant bacteria is a growing problem and a public health issue. In recent decades, various genetic mechanisms involved in the spread of resistance genes among bacteria have been identified. Integrons – genetic elements that acquire, exchange, and express genes embedded within gene cassettes (GC) – are one of these mechanisms. Integrons are widely distributed, especially in Gram-negative bacteria; they are carried by mobile genetic elements, plasmids, and transposons, which promote their spread within bacterial communities. Initially studied mainly in the clinical setting for their involvement in antibiotic resistance, their role in the environment is now an increasing focus of attention. The aim of this review is to provide an in-depth analysis of recent studies of antibiotic-resistance integrons in the environment, highlighting their potential involvement in antibiotic-resistance outside the clinical context. We will focus particularly on the impact of human activities (agriculture, industries, wastewater treatment, etc.). PMID:22509175

  10. The global problem of antibiotic resistance.

    PubMed

    Gootz, Thomas D

    2010-01-01

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

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

    PubMed Central

    Garneau-Tsodikova, Sylvie

    2015-01-01

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

  12. Insights into antibiotic resistance through metagenomic approaches.

    PubMed

    Schmieder, Robert; Edwards, Robert

    2012-01-01

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

  13. Presence of antibiotic resistance genes in a sewage treatment plant in Thibodaux, Louisiana, USA.

    PubMed

    Naquin, Anthony; Shrestha, Arsen; Sherpa, Mingma; Nathaniel, Rajkumar; Boopathy, Raj

    2015-01-01

    Increasing uses and disposals of antibiotics to the environment have increased emergence of various antibiotic resistance. One of the sources for the spread of antibiotic resistance is wastewater treatment plant, where bacteria and antibiotics can come in contact and can acquire antibiotics resistance. There are very few studies on this subject from a small town sewage treatment plant. Therefore, this study was conducted using raw sewage as well as treated sewage from a sewage treatment plant in Thibodaux in rural southeast Louisiana in USA. Samples were collected monthly from the Thibodaux sewage treatment plant and the presence of antibiotic resistance genes was monitored. The study showed the presence of antibiotic resistance genes in both raw and treated sewage in every month of the study period. The genetic transformation assay showed the successful transformation of methicillin resistant gene, mecA to an antibiotic sensitive Staphylococcus aureus, which became antibiotic resistant within 24h.

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

    PubMed

    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.

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

    PubMed

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

    2015-12-01

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

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

    PubMed

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

    2016-05-01

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

  17. Tackling antibiotic resistance: the environmental framework.

    PubMed

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

    2015-05-01

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

  18. Antibiotic resistance in the opportunistic pathogen Stenotrophomonas maltophilia.

    PubMed

    Sánchez, María B

    2015-01-01

    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 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.

  19. The antibiotic treatment of community-acquired, atypical, and nosocomial pneumonias.

    PubMed

    Cunha, B A

    1995-05-01

    Optimal antibiotic regimens and duration of treatment are not universally agreed on for community-acquired or nosocomial pneumonias. Experience suggests that community-acquired pneumonias may be treated for less than 2 weeks with a combination of intravenous and oral antibiotics of appropriate spectrum that penetrate the lung, have a good safety profile, do not foster the development of resistance, and are cost-effective. After initial intravenous therapy, oral switch therapy may be begun as soon as the patient defervesces clinically, which is usually 3 days after admission. Switching to oral therapy does not invariably lead to earlier hospital discharge. There is no "standard of care" for pneumonias, but guidelines for empiric use have existed for decades. The least expensive beta-lactamase stable antibiotic should be used as monotherapy for the empiric treatment of community-acquired pneumonia. Because community-acquired atypical pneumonias are clinically distinct from bacterial pneumonias owing to their extrapulmonary features, clinicians should be able to differentiate atypical pneumonias from bacterial pneumonias, which permits prompt and appropriate treatment. Nosocomial pneumonias remain a difficult diagnostic challenge. Therapeutically the most important principle in treating nosocomial pneumonia is to provide for double-drug coverage against P. aeruginosa. Differentiation of respiratory tract colonization from respiratory tract invasion remains the central key issue in patients with pulmonary infiltrates acquired during hospitalization. Most patients complete their course of intravenous therapy for nosocomial pneumonia leaving little or no time for completion of their therapy by oral antibiotics. Hospital-acquired atypical pneumonias are largely limited to legionnaires' disease, which is a more difficult diagnosis than in the community-acquired setting. Clinicians taking care of patients with pneumonia should employ a simplified therapeutic approach using

  20. General principles of antibiotic resistance in bacteria.

    PubMed

    Martinez, Jose L

    2014-03-01

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

  1. Bacterial cheating limits the evolution of antibiotic resistance

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

  2. Inhibition of Mutation and Combating the Evolution of Antibiotic Resistance

    PubMed Central

    Cirz, Ryan T; Chin, Jodie K; Andes, David R; de Crécy-Lagard, Valérie; Craig, William A

    2005-01-01

    The emergence of drug-resistant bacteria poses a serious threat to human health. In the case of several antibiotics, including those of the quinolone and rifamycin classes, bacteria rapidly acquire resistance through mutation of chromosomal genes during therapy. In this work, we show that preventing induction of the SOS response by interfering with the activity of the protease LexA renders pathogenic Escherichia coli unable to evolve resistance in vivo to ciprofloxacin or rifampicin, important quinolone and rifamycin antibiotics. We show in vitro that LexA cleavage is induced during RecBC-mediated repair of ciprofloxacin-mediated DNA damage and that this results in the derepression of the SOS-regulated polymerases Pol II, Pol IV and Pol V, which collaborate to induce resistance-conferring mutations. Our findings indicate that the inhibition of mutation could serve as a novel therapeutic strategy to combat the evolution of antibiotic resistance. PMID:15869329

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

    PubMed

    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.

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

    PubMed

    Xia, Jufeng; Gao, Jianjun; Tang, Wei

    2016-02-01

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

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

    PubMed

    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.

  6. Update on the antibiotic resistance crisis.

    PubMed

    Rossolini, Gian Maria; Arena, Fabio; Pecile, Patrizia; Pollini, Simona

    2014-10-01

    Antibiotics tend to lose their efficacy over time due to the emergence and dissemination of resistance among bacterial pathogens. Strains with resistance to multiple antibiotic classes have emerged among major Gram-positive and Gram-negative species including Staphylococcus aureus, Enterococcus spp., Pseudomonas aeruginosa, Acinetobacter spp. Enterobacteriaceae, and Neisseria gonorrhoeae. With some Gram-negatives, resistance may involve most or even all the available antimicrobial options, resulting in extremely drug-resistant or totally drug-resistant phenotypes. This so-called 'antibiotic resistance crisis' has been compounded by the lagging in antibiotic discovery and development programs occurred in recent years, and is jeopardizing the essential role played by antibiotics in current medical practices.

  7. Comparative Effectiveness of Empiric Antibiotics for Community-Acquired Pneumonia

    PubMed Central

    Myers, Angela L.; Hall, Matthew; Shah, Samir S.; Williams, Derek J.; Auger, Katherine A.; Jerardi, Karen E.; Statile, Angela M.; Tieder, Joel S.

    2014-01-01

    BACKGROUND AND OBJECTIVE: Narrow-spectrum antibiotics are recommended as the first-line agent for children hospitalized with community-acquired pneumonia (CAP). There is little scientific evidence to support that this consensus-based recommendation is as effective as the more commonly used broad-spectrum antibiotics. The objective was to compare the effectiveness of empiric treatment with narrow-spectrum therapy versus broad-spectrum therapy for children hospitalized with uncomplicated CAP. METHODS: This multicenter retrospective cohort study using medical records included children aged 2 months to 18 years at 4 children's hospitals in 2010 with a discharge diagnosis of CAP. Patients receiving either narrow-spectrum or broad-spectrum therapy in the first 2 days of hospitalization were eligible. Patients were matched by using propensity scores that determined each patient’s likelihood of receiving empiric narrow or broad coverage. A multivariate logistic regression analysis evaluated the relationship between antibiotic and hospital length of stay (LOS), 7-day readmission, standardized daily costs, duration of fever, and duration of supplemental oxygen. RESULTS: Among 492 patients, 52% were empirically treated with a narrow-spectrum agent and 48% with a broad-spectrum agent. In the adjusted analysis, the narrow-spectrum group had a 10-hour shorter LOS (P = .04). There was no significant difference in duration of oxygen, duration of fever, or readmission. When modeled for LOS, there was no difference in average daily standardized cost (P = .62) or average daily standardized pharmacy cost (P = .26). CONCLUSIONS: Compared with broad-spectrum agents, narrow-spectrum antibiotic coverage is associated with similar outcomes. Our findings support national consensus recommendations for the use of narrow-spectrum antibiotics in children hospitalized with CAP. PMID:24324001

  8. Inadequate Empirical Antibiotic Therapy in Hospital Acquired Pneumonia.

    PubMed

    Dahal, S; Rijal, B P; Yogi, K N; Sherchand, J B; Parajuli, K; Parajuli, N; Pokhrel, B M

    2015-01-01

    Inadequate empirical antibiotic therapy for HAP is a common phenomena and one of the indicators of the poor stewardship. This study intended to analyze the efficacy of empirical antibiotics in the light of microbiological data in HAP cases. Suspected cases of HAP were followed for clinico-bacterial evidence, antimicrobial resistance and pre and post culture antibiotic use. The study was taken from February,2014 to July 2014 in department of Microbiology and department of Respiratory medicine prospectively. Data was analyzed by Microsoft Office Excel 2007. Out of 758 cases investigated, 77(10 %) cases were HAP, 65(84%) of them were culture positive and 48(74 %) were late in onset. In early onset cases, isolates were Acinetobacter 10(42%), Escherichia coli 5(21%), S.aureus 4(17%), Klebsiella 1(4%) and Pseudomonas 1(4%). From the late onset cases Acinetobacter 15(28%), Klebsiella 17(32%) and Pseudomonas 13(24%) were isolated. All Acinetobacter, 78% Klebsiella and 36% Pseudomonas isolates were multi drug resistant. Empirical therapies were inadequate in 12(70%) of early onset cases and 44(92%) of late onset type. Cephalosporins were used in 7(41%) of early onset infections but found to be adequate only in 2(12%) cases. Polymyxins were avoided empirically but after cultures were used in 9(19%) cases. Empirical antibiotics were vastly inadequate, more frequently so in late onset infections. Use of cephalosporins empirically in early onset infections and avoiding empirical use of polymyxin antibiotics in late onset infections contributed largely to the findings. Inadequate empirical regimen is a real time feedback for a practitioner to update his knowledge on the local microbiological trends.

  9. Antibiotic Resistance Spreads Internationally Across Borders.

    PubMed

    Barlam, Tamar F; Gupta, Kalpana

    2015-01-01

    Antibiotic-resistant (ABR) bacteria develop when bacteria are exposed to antibiotics either during treatments in humans or animals or through environmental sources contaminated with antibiotic residues. Resistant bacteria selected by medical, agricultural, and industrial use spread globally through international travel, the export of animals and retail products, and the environment. It is essential that nations work together to identify how to reduce emergence and amplification of resistant bacteria through sensible antibiotic treatment guidelines and restrictions, concerted efforts for surveillance, and infection control. © 2015 American Society of Law, Medicine & Ethics, Inc.

  10. Antibiotics and Antibiotic Resistance in Agroecosystems: State of the Science.

    PubMed

    Williams-Nguyen, Jessica; Sallach, J Brett; Bartelt-Hunt, Shannon; Boxall, Alistair B; Durso, Lisa M; McLain, Jean E; Singer, Randall S; Snow, Daniel D; Zilles, Julie L

    2016-03-01

    We propose a simple causal model depicting relationships involved in dissemination of antibiotics and antibiotic resistance in agroecosystems and potential effects on human health, functioning of natural ecosystems, and agricultural productivity. Available evidence for each causal link is briefly summarized, and key knowledge gaps are highlighted. A lack of quantitative estimates of human exposure to environmental bacteria, in general, and antibiotic-resistant bacteria, specifically, is a significant data gap hindering the assessment of effects on human health. The contribution of horizontal gene transfer to resistance in the environment and conditions that might foster the horizontal transfer of antibiotic resistance genes into human pathogens also need further research. Existing research has focused heavily on human health effects, with relatively little known about the effects of antibiotics and antibiotic resistance on natural and agricultural ecosystems. The proposed causal model is used to elucidate gaps in knowledge that must be addressed by the research community and may provide a useful starting point for the design and analysis of future research efforts. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Antibiotic resistance: a physicist’s view

    NASA Astrophysics Data System (ADS)

    Allen, Rosalind; Waclaw, Bartłomiej

    2016-08-01

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

  12. Antibiotic resistance: a physicist’s view

    PubMed Central

    Allen, Rosalind; Waclaw, Bartłomiej

    2016-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  14. Antibiotics and Bacterial Resistance in the 21st Century

    PubMed Central

    Fair, Richard J; Tor, Yitzhak

    2014-01-01

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

  15. Counteracting selection for antibiotic-resistant bacteria

    PubMed Central

    Yosef, Ido; Manor, Miriam; Qimron, Udi

    2016-01-01

    ABSTRACT The occurrence of antibiotic-resistant bacterial pathogens is on the rise because antibiotics exert selection pressure that kills only the antibiotic-sensitive pathogens. Sanitation and cleansing of hospital surfaces and the skin of medical personnel do not counteract this selective pressure, but rather indiscriminately reduce total pathogens on treated surfaces. Here, we discuss two recently introduced genetic strategies, based on temperate bacteriophages as DNA-delivery vehicles, that aim to sensitize bacteria to antibiotics and selectively kill the antibiotic-resistant ones. Outlooks for rendering one such approach more efficient and applicable are proposed. We believe that using an end product designed according to the provided principles on hospital surfaces and in hand-sanitizers will facilitate substitution of antibiotic-resistant pathogens with sensitive ones. PMID:27144084

  16. Counteracting selection for antibiotic-resistant bacteria.

    PubMed

    Yosef, Ido; Manor, Miriam; Qimron, Udi

    2016-01-01

    The occurrence of antibiotic-resistant bacterial pathogens is on the rise because antibiotics exert selection pressure that kills only the antibiotic-sensitive pathogens. Sanitation and cleansing of hospital surfaces and the skin of medical personnel do not counteract this selective pressure, but rather indiscriminately reduce total pathogens on treated surfaces. Here, we discuss two recently introduced genetic strategies, based on temperate bacteriophages as DNA-delivery vehicles, that aim to sensitize bacteria to antibiotics and selectively kill the antibiotic-resistant ones. Outlooks for rendering one such approach more efficient and applicable are proposed. We believe that using an end product designed according to the provided principles on hospital surfaces and in hand-sanitizers will facilitate substitution of antibiotic-resistant pathogens with sensitive ones.

  17. The Goldilocks Principle and Antibiotic Resistance in Bacteria

    PubMed Central

    Zhang, Qiucen; Robin, Kristelle; Liao, David; Lambert, Guillaume; Austin, Robert H.

    2011-01-01

    We have designed and fabricated a micro-ecology to mimic the naturally occurring bacterial culture, which includes stress gradient, metapopulation and cellular motility. In this micro-ecology, we show it is possible to fix resistance to the mutagenic antibiotic ciprofloxacin in wild-type E. coli within 10 hours. We found the evolution of resistance is further accelerated in micro-ecology if bacteria have already acquired the phenotype of growth advantage at stationary phase (GASP). PMID:22085251

  18. Antibiotic resistance in ocular bacterial pathogens.

    PubMed

    Sharma, S

    2011-01-01

    Bacterial infections of the eye are common and ophthalmologists are spoilt for choice with a variety of antibiotics available in the market. Antibiotics can be administered in the eye by a number of routes; topical, subconjunctival, subtenon and intraocular. Apart from a gamut of eye drops available, ophthalmologists also have the option of preparing fortified eye drops from parenteral formulations, thereby, achieving high concentrations; often much above the minimum inhibitory concentration (MIC), of antibiotics in ocular tissues during therapy. Antibiotic resistance among ocular pathogens is increasing in parallel with the increase seen over the years in bacteria associated with systemic infections. Although it is believed that the rise in resistant ocular bacterial isolates is linked to the rise in resistant systemic pathogens, recent evidence has correlated the emergence of resistant bacteria in the eye to prior topical antibiotic therapy. One would like to believe that either of these contributes to the emergence of resistance to antibiotics among ocular pathogens. Until recently, ocular pathogens resistant to fluoroquinolones have been minimal but the pattern is currently alarming. The new 8-fluoroquinolone on the scene-besifloxacin, is developed exclusively for ophthalmic use and it is hoped that it will escape the selective pressure for resistance because of lack of systemic use. In addition to development of new antibacterial agents, the strategies to halt or control further development of resistant ocular pathogens should always include judicious use of antibiotics in the treatment of human, animal or plant diseases.

  19. Influence of population density on antibiotic resistance.

    PubMed

    Bruinsma, N; Hutchinson, J M; van den Bogaard, A E; Giamarellou, H; Degener, J; Stobberingh, E E

    2003-02-01

    Antibiotic consumption and population density as a measure of crowding in the community were related to the prevalence of antibiotic resistance of three cities in three different countries: St Johns in Newfoundland (Canada), Athens in Greece and Groningen in The Netherlands. Antibiotic consumption was expressed in DDD (defined daily dose), as DID (DDD/1000 inhabitants/day) and as DSD (DDD/km(2)). The prevalence of antibiotic-resistant Escherichia coli and enterococci was determined in faecal samples of healthy volunteers. In both Newfoundland (28 DID) and Greece (29 DID) the overall consumption of antibiotics was more than three times higher compared with that of The Netherlands (9 DID). The lowest prevalence of resistant E. coli against the majority of antibiotics tested was found for the samples from Newfoundland and was significant (P < 0.05) for cefazolin, oxytetracycline and trimethoprim. A poor correlation between the number of DID and the prevalence of resistance was observed [the Pearson correlation coefficient (Pcc) ranged between -0.93 and 0.87]. However, when population density was taken into consideration and antibiotic consumption was expressed in DSD, a strong correlation was observed (and Pcc ranged between 0.86 and 1.00). This study suggests that population density is an important factor in the development of antibiotic resistance and warrants special attention as a factor in resistance epidemiology.

  20. Persistence of antibiotic resistance in bacterial populations.

    PubMed

    Andersson, Dan I; Hughes, Diarmaid

    2011-09-01

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

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

    PubMed

    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.

  2. Antibiotic resistance: are we all doomed?

    PubMed

    Collignon, P

    2015-11-01

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

  3. Mechanisms of antibiotic resistance in enterococci

    PubMed Central

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

    2015-01-01

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

  4. The epidemiology of antibiotic resistance in hospitals: paradoxes and prescriptions.

    PubMed

    Lipsitch, M; Bergstrom, C T; Levin, B R

    2000-02-15

    A simple mathematical model of bacterial transmission within a hospital was used to study the effects of measures to control nosocomial transmission of bacteria and reduce antimicrobial resistance in nosocomial pathogens. The model predicts that: (i) Use of an antibiotic for which resistance is not yet present in a hospital will be positively associated at the individual level (odds ratio) with carriage of bacteria resistant to other antibiotics, but negatively associated at the population level (prevalence). Thus inferences from individual risk factors can yield misleading conclusions about the effect of antibiotic use on resistance to another antibiotic. (ii) Nonspecific interventions that reduce transmission of all bacteria within a hospital will disproportionately reduce the prevalence of colonization with resistant bacteria. (iii) Changes in the prevalence of resistance after a successful intervention will occur on a time scale of weeks to months, considerably faster than in community-acquired infections. Moreover, resistance can decline rapidly in a hospital even if it does not carry a fitness cost. The predictions of the model are compared with those of other models and published data. The implications for resistance control and study design are discussed, along with the limitations and assumptions of the model.

  5. Antibiotic resistance: challenges and successes in respiratory infection.

    PubMed

    Sethi, Sanjay; Bryan, Jenny

    2016-01-01

    European Respiratory Society Congress, Amsterdam, 26-30 September 2015, and CHEST 2015, Montréal, Canada, 24-28 October 2015 With approximately 50,000 deaths in the US and EU attributed to antibacterial resistance each year, together with several million days of hospital care [1], the need to address resistance mechanisms and find new targets for novel antibiotics has never been greater. At the annual congresses of the European Respiratory Society and the American College of Chest Physicians, presenters reported advances in understanding of the mechanisms of antibiotic resistance and how these may be overcome. The latest clinical trial data on antibiotic treatment for hospital- and community-acquired pneumonia, including the potential for novel nebulized forms of therapy, were also discussed.

  6. Urinary tract infections: bacteriology and antibiotic resistance patterns.

    PubMed

    Mashouf, Rasoul Yousefi; Babalhavaeji, Hooshang; Yousef, Javad

    2009-07-01

    The aim of this study was to identify the bacteria causing community acquired urinary tract infections (UTI) and detection of antibiotics resistance of isolates in 912 children below 18 years in the west of Iran. Data were analyzed for 4 age groups: infants, toddlers, preteens and teens. Fourteen antibiotics were tested by gel-diffusion method. Of 912 patients, 34.2% had positive bacterial cultures. The most common isolates were E. coli (57.4 %), K. pneumoniae (9.7 %), S. aureus (5.8%) and A. baumannii (2.2%). Most isolates showed high resistance against ampicillin, cotrimoxazole, nalidixic acid, tobramycin and nitrofurantoin. Klebsiella isolates showed more resistance against tested antibiotics than E. coli isolates.

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

    PubMed

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

    2016-08-01

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

  8. Antibiotic tolerance facilitates the evolution of resistance.

    PubMed

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

    2017-02-24

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

  9. Acquired macrolide resistance genes in Haemophilus influenzae?

    PubMed

    Atkinson, Christopher T; Kunde, Dale A; Tristram, Stephen G

    2015-08-01

    The objective of this study was to determine the prevalence of specific acquired macrolide resistance genes previously reported as present in clinical isolates of Haemophilus influenzae. A collection of 172 clinical respiratory isolates of H. influenzae, including 59 isolates from cystic fibrosis patients and 27 from non-cystic fibrosis bronchiectasis patients with significant prior macrolide use, was established. This collection was tested for azithromycin susceptibility using Etest and screened for the presence of erm(A), erm(B), erm(C), erm(F), mef(A) and mef(E) using locked nucleic acid dual-labelled hydrolysis probes. The azithromycin MICs ranged from 0.09 to >256 mg/L, with 2 (1.2%) isolates susceptible, 163 (94.8%) intermediate and 7 (4%) resistant according to EUCAST breakpoints (susceptible, ≤0.12 mg/L; resistant, >4 mg/L). None of the acquired macrolide resistance genes erm(A), erm(B), erm(C), erm(F), mef(A) or mef(E) was detected in any of the isolates. The specific acquired macrolide resistance genes are not widespread in H. influenzae and the high prevalence of these genes previously reported might be unique to the specific circumstances of that study. © 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.

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

    PubMed

    Watkins, Richard R; Bonomo, Robert A

    2016-06-01

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

  11. Boosting bacterial metabolism to combat antibiotic resistance.

    PubMed

    Bhargava, Prerna; Collins, James J

    2015-02-03

    The metabolic state of a bacterial cell influences its susceptibility to antibiotics. In this issue, Peng et al. (2015) show that resistant bacteria can be sensitized to antibiotic treatment through the addition of exogenous metabolites that stimulate central metabolic pathways and increase drug uptake.

  12. Mining metagenomic datasets for antibiotic resistance genes

    USDA-ARS?s Scientific Manuscript database

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

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  15. The Antibiotic Resistance Problem Revisited

    ERIC Educational Resources Information Center

    Lawson, Michael A.

    2008-01-01

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

  16. The Antibiotic Resistance Problem Revisited

    ERIC Educational Resources Information Center

    Lawson, Michael A.

    2008-01-01

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

  17. Therapeutic strategies to combat antibiotic resistance.

    PubMed

    Brooks, Benjamin D; Brooks, Amanda E

    2014-11-30

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

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

    PubMed

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

    2012-06-01

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

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

    ERIC Educational Resources Information Center

    Omoto, Charlotte K.; Malm, Kirstin

    2003-01-01

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

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

    ERIC Educational Resources Information Center

    Omoto, Charlotte K.; Malm, Kirstin

    2003-01-01

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

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

    PubMed

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

    2012-06-01

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

  2. Antibiotic resistance: Italian awareness survey 2016.

    PubMed

    Prigitano, Anna; Romanò, Luisa; Auxilia, Francesco; Castaldi, Silvana; Tortorano, Anna M

    2017-03-09

    Antimicrobial resistance has become a public health priority worldwide. The WHO conducted a survey concerning the personal use of antibiotics, knowledge of appropriate use and awareness of the issue of resistance. A similar survey was conducted in Italy involving 666 young university students and 131 seniors attending courses of the University of the third age. Antibiotics seem to be taken with moderate frequency and appropriately: 30% of respondents took them in the past six months and 94% took these drugs only prescribed by a doctor, in the correct dose and for the proper duration. Notable confusion concerning the conditions treatable with antibiotics was detected (only 30% indicated gonorrhea, and 30-40% believed that antibiotics should be employed for fever, cold, and flu), while 94% of participants seemed aware of the problem of antibiotic resistance. Most of the respondents identified the behaviors that can reduce the phenomenon of resistance (regular handwashing and use of antibiotics only when prescribed and needed). The results of our survey, that involved people of high level of instruction and living in urban areas of northern regions, cannot be extended to all the Italian population. However, they provide valid elements to promote initiatives aimed to a more aware use of antibiotics.

  3. The genomic enzymology of antibiotic resistance.

    PubMed

    Morar, Mariya; Wright, Gerard D

    2010-01-01

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

  4. The fitness costs of antibiotic resistance mutations

    PubMed Central

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

    2015-01-01

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

  5. Antibiotic Resistance Related to Biofilm Formation in Klebsiella pneumoniae

    PubMed Central

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

    2014-01-01

    The Gram-negative opportunistic pathogen, Klebsiella pneumoniae, is responsible for causing a spectrum of community-acquired and nosocomial infections and typically infects patients with indwelling medical devices, especially urinary catheters, on which this microorganism is able to grow as a biofilm. The increasingly frequent acquisition of antibiotic resistance by K. pneumoniae strains has given rise to a global spread of this multidrug-resistant pathogen, mostly at the hospital level. This scenario is exacerbated when it is noted that intrinsic resistance to antimicrobial agents dramatically increases when K. pneumoniae strains grow as a biofilm. This review will summarize the findings about the antibiotic resistance related to biofilm formation in K. pneumoniae. PMID:25438022

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

    PubMed

    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.

  7. Are new antibiotics better than beta-lactams for non-critical inpatients with community-acquired pneumonia?

    PubMed

    Reyes B, Tomás; Ortega G, Marcos; Saldías P, Fernando

    2016-08-05

    Treatment for community-acquired pneumonia in immunocompetent adults is mainly empirical. Beta-lactam antibiotics have been traditionally considered first-line therapy. New antibiotics could be more effective but the evidence is not clear until now, and its use could entail greater costs, an increase in bacterial resistance and other adverse effects. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified six systematic reviews including 36 randomized trials addressing this question. We combined the evidence using meta-analysis and generated a summary of findings table following the GRADE approach. We concluded new antibiotics are not better than beta-lactam antibiotics for the treatment of non-critical inpatients with community-acquired pneumonia in relation to clinical failure or adverse effects.

  8. Adaptive modulation of antibiotic resistance through intragenomic coevolution.

    PubMed

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

    2017-09-01

    Bacteria gain antibiotic resistance genes by horizontal acquisition of mobile genetic elements (MGE) from other lineages. Newly acquired MGEs are often poorly adapted causing intragenomic conflicts, resolved by compensatory adaptation of the chromosome, the MGE or reciprocal coadaptation. The footprints of such intragenomic coevolution are present in bacterial genomes, suggesting an important role promoting genomic integration of horizontally acquired genes, but direct experimental evidence of the process is limited. Here we show adaptive modulation of tetracycline resistance via intragenomic coevolution between Escherichia coli and the multi-drug resistant (MDR) plasmid RK2. Tetracycline treatments, including monotherapy or combination therapies with ampicillin, favoured de novo chromosomal resistance mutations coupled with mutations on RK2 impairing the plasmid-encoded tetracycline efflux-pump. These mutations together provided increased tetracycline resistance at reduced cost. Additionally, the chromosomal resistance mutations conferred cross-resistance to chloramphenicol. Reciprocal coadaptation was not observed under ampicillin-only or no antibiotic selection. Intragenomic coevolution can create genomes comprised of multiple replicons that together provide high-level, low-cost resistance, but the resulting co-dependence may limit the spread of coadapted MGEs to other lineages.

  9. Poor compliance with community-acquired pneumonia antibiotic guidelines in a large Australian private hospital emergency department.

    PubMed

    Robinson, Helen L; Robinson, Philip C; Whitby, Michael

    2014-12-01

    This study evaluated guideline concordance and time to administration of antibiotics in community-acquired pneumonia (CAP) in a private Australian emergency department (ED). Two key components in the management of CAP are timely administration and appropriate choice of antibiotic therapy. The use of antibiotics outside of guidelines can potentially increase rates of antibiotic resistance. Previous studies that evaluate guideline concordance have largely been conducted in Australian public hospitals; however, private hospitals comprise a significant portion of Australian health care. One hundred and thirty patients admitted to a private Brisbane hospital between 01/01/2011 and 28/03/2012 with an admission diagnosis of CAP were included. Data were collected on administration time and choice of antibiotic therapy in the ED. This was compared with local and national CAP guidelines. Concordance with antibiotic guidelines was low (6.9%). Antibiotics with broader spectrum of action than that recommended in guidelines were frequently prescribed. Eighty-one percent of patients received their first antibiotic within 4 hours of arriving in the ED. Mortality was low at 0.9% in a cohort where 31% of patients were aged under 65. We found low rates of concordance with CAP antibiotic guidelines and high use of broad-spectrum antibiotics. This has the potential to lead to increased rates of antibiotic resistance. A subtle alteration to the restrictions within the pharmaceutical benefit scheme formulary could potentially decrease the high usage of broad-spectrum antibiotics. However, the low mortality rate, nontoxic nature of these antibiotics, and the ease of their administration pose a challenge to convincing clinicians to alter their practice.

  10. Collateral sensitivity of antibiotic-resistant microbes.

    PubMed

    Pál, Csaba; Papp, Balázs; Lázár, Viktória

    2015-07-01

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

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

    PubMed Central

    Cassir, Nadim; Rolain, Jean-Marc; Brouqui, Philippe

    2014-01-01

    The increasing prevalence of hospital and community-acquired infections caused by multidrug-resistant (MDR) bacterial pathogens is limiting the options for effective antibiotic therapy. Moreover, this alarming spread of antimicrobial resistance has not been paralleled by the development of novel antimicrobials. Resistance to the scarce new antibiotics is also emerging. In this context, the rational use of older antibiotics could represent an alternative to the treatment of MDR bacterial pathogens. It would help to optimize the armamentarium of antibiotics in the way to preserve new antibiotics and avoid the prescription of molecules known to favor the spread of resistance (i.e., quinolones). Furthermore, in a global economical perspective, this could represent a useful public health orientation knowing that several of these cheapest “forgotten” antibiotics are not available in many countries. We will review here the successful treatment of MDR bacterial infections with the use of old antibiotics and discuss their place in current practice. PMID:25368610

  12. Antibiotic-Resistant Vibrios in Farmed Shrimp

    PubMed Central

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

    2015-01-01

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

  13. Usefulness of aetiological tests for guiding antibiotic therapy in community-acquired pneumonia.

    PubMed

    Strålin, K

    2008-01-01

    The goal with antibiotic therapy in community-acquired pneumonia (CAP) is to cure the patient, ideally without causing side effects and without contributing to the further development of antibiotic resistance. Although patients with severe CAP should be treated with broad-spectrum antibiotics, patients with non-severe CAP should preferably receive pathogen-directed therapy. Rapid aetiological tests, such as sputum Gram stain and urinary antigen tests, are useful for targeting initial pathogen-directed therapy. Non-rapid tests, such as cultures, can subsequently support a switch from initial broad-spectrum therapy to narrow-spectrum therapy and direct therapy changes in case of treatment failure. As conventional diagnostic methods often fail to identify the aetiology of CAP, PCR (polymerase chain reaction) tests for respiratory pathogens have become useful and should be further developed. Based on the test specificities, aetiological tests may provide diagnoses with varying reliability, i.e. definite aetiologies (e.g., blood culture and Legionella urinary antigen test), probable aetiologies (e.g., sputum culture and PCR for Mycoplasma pneumoniae), or possible aetiologies (e.g., culture of nasopharyngeal secretions and PCR for Streptococcus pneumoniae). A definite or probable aetiology can often be used to target antibiotic therapy.

  14. Antibiotic Resistance and the Biology of History.

    PubMed

    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.

  15. Antibiotic Resistance and the Biology of History

    PubMed Central

    2015-01-01

    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. PMID:28458609

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

    USDA-ARS?s Scientific Manuscript database

    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...

  17. Strength of Selection Pressure Is an Important Parameter Contributing to the Complexity of Antibiotic Resistance Evolution

    PubMed Central

    Oz, Tugce; Guvenek, Aysegul; Yildiz, Sadik; Karaboga, Enes; Tamer, Yusuf Talha; Mumcuyan, Nirva; Ozan, Vedat Burak; Senturk, Gizem Hazal; Cokol, Murat; Yeh, Pamela; Toprak, Erdal

    2014-01-01

    Revealing the genetic changes responsible for antibiotic resistance can be critical for developing novel antibiotic therapies. However, systematic studies correlating genotype to phenotype in the context of antibiotic resistance have been missing. In order to fill in this gap, we evolved 88 isogenic Escherichia coli populations against 22 antibiotics for 3 weeks. For every drug, two populations were evolved under strong selection and two populations were evolved under mild selection. By quantifying evolved populations’ resistances against all 22 drugs, we constructed two separate cross-resistance networks for strongly and mildly selected populations. Subsequently, we sequenced representative colonies isolated from evolved populations for revealing the genetic basis for novel phenotypes. Bacterial populations that evolved resistance against antibiotics under strong selection acquired high levels of cross-resistance against several antibiotics, whereas other bacterial populations evolved under milder selection acquired relatively weaker cross-resistance. In addition, we found that strongly selected strains against aminoglycosides became more susceptible to five other drug classes compared with their wild-type ancestor as a result of a point mutation on TrkH, an ion transporter protein. Our findings suggest that selection strength is an important parameter contributing to the complexity of antibiotic resistance problem and use of high doses of antibiotics to clear infections has the potential to promote increase of cross-resistance in clinics. PMID:24962091

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

    PubMed

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

    2017-02-21

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

  19. The cost of antibiotic resistance depends on evolutionary history in Escherichia coli.

    PubMed

    Angst, Daniel C; Hall, Alex R

    2013-08-02

    The persistence of antibiotic resistance depends on the fitness effects of resistance elements in the absence of antibiotics. Recent work shows that the fitness effect of a given resistance mutation is influenced by other resistance mutations on the same genome. However, resistant bacteria acquire additional beneficial mutations during evolution in the absence of antibiotics that do not alter resistance directly but may modify the fitness effects of new resistance mutations. We experimentally evolved rifampicin-resistant and sensitive Escherichia coli in a drug-free environment, before measuring the effects of new resistance elements on fitness in antibiotic-free conditions. Streptomycin-resistance mutations had small fitness effects in rifampicin-resistant genotypes that had adapted to antibiotic-free growth medium, compared to the same genotypes without adaptation. We observed a similar effect when resistance was encoded by a different mechanism and carried on a plasmid. Antibiotic-sensitive bacteria that adapted to the same conditions showed the same pattern for some resistance elements but not others. Epistatic variation of costs of resistance can result from evolution in the absence of antibiotics, as well as the presence of other resistance mutations.

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

    PubMed

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

    2012-01-01

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

  1. Risk of antibiotic resistance from metal contaminated soils

    NASA Astrophysics Data System (ADS)

    Knapp, Charles

    2013-04-01

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

  2. Signal regulators of systemic acquired resistance

    PubMed Central

    Gao, Qing-Ming; Zhu, Shifeng; Kachroo, Pradeep; Kachroo, Aardra

    2015-01-01

    Salicylic acid (SA) is an important phytohormone that plays a vital role in a number of physiological responses, including plant defense. The last two decades have witnessed a number of breakthroughs related to biosynthesis, transport, perception and signaling mediated by SA. These findings demonstrate that SA plays a crictical role in both local and systemic defense responses. Systemic acquired resistance (SAR) is one such SA-dependent response. SAR is a long distance signaling mechanism that provides broad spectrum and long-lasting resistance to secondary infections throughout the plant. This unique feature makes SAR a highly desirable trait in crop production. This review summarizes the recent advances in the role of SA in SAR and discusses its relationship to other SAR inducers. PMID:25918514

  3. Antibiotic resistance genes & susceptibility patterns in staphylococci.

    PubMed

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

    2012-03-01

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

  4. Antibiotic resistance in human chronic periodontitis microbiota.

    PubMed

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

    2014-01-01

    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 patients with CP. Subgingival biofilm specimens from inflamed deep periodontal pockets were removed before treatment from 400 adults with CP in the United States. The samples were cultured, and selected periodontal pathogens were tested in vitro for susceptibility to amoxicillin at 8 mg/L, clindamycin at 4 mg/L, doxycycline at 4 mg/L, and metronidazole at 16 mg/L, with a post hoc combination of data for amoxicillin and metronidazole. Gram-negative enteric rods/pseudomonads were subjected to ciprofloxacin disk-diffusion testing. Overall, 74.2% of the patients with CP revealed subgingival periodontal pathogens resistant to at least one of the test antibiotics. One or more test species, most often Prevotella intermedia/nigrescens, Streptococcus constellatus, or Aggregatibacter actinomycetemcomitans, were resistant in vitro to doxycycline, amoxicillin, metronidazole, or clindamycin, in 55%, 43.3%, 30.3%, and 26.5% of the patients with CP, respectively. Fifteen percent of patients harbored subgingival periodontal pathogens resistant to both amoxicillin and metronidazole, which were mostly either S. constellatus (45 individuals) or ciprofloxacin-susceptible strains of Gram-negative enteric rods/pseudomonads (nine individuals). Patients with CP in the United States frequently yielded subgingival periodontal pathogens resistant in vitro to therapeutic concentrations of antibiotics commonly used in clinical periodontal practice. The wide variability found in periodontal pathogen antibiotic-resistance patterns should concern clinicians empirically selecting antibiotic treatment regimens for patients with CP.

  5. Resistance to Macrolide Antibiotics in Public Health Pathogens.

    PubMed

    Fyfe, Corey; Grossman, Trudy H; Kerstein, Kathy; Sutcliffe, Joyce

    2016-10-03

    Macrolide resistance mechanisms can be target-based with a change in a 23S ribosomal RNA (rRNA) residue or a mutation in ribosomal protein L4 or L22 affecting the ribosome's interaction with the antibiotic. Alternatively, mono- or dimethylation of A2058 in domain V of the 23S rRNA by an acquired rRNA methyltransferase, the product of an erm (erythromycin ribosome methylation) gene, can interfere with antibiotic binding. Acquired genes encoding efflux pumps, most predominantly mef(A) + msr(D) in pneumococci/streptococci and msr(A/B) in staphylococci, also mediate resistance. Drug-inactivating mechanisms include phosphorylation of the 2'-hydroxyl of the amino sugar found at position C5 by phosphotransferases and hydrolysis of the macrocyclic lactone by esterases. These acquired genes are regulated by either translation or transcription attenuation, largely because cells are less fit when these genes, especially the rRNA methyltransferases, are highly induced or constitutively expressed. The induction of gene expression is cleverly tied to the mechanism of action of macrolides, relying on antibiotic-bound ribosomes stalled at specific sequences of nascent polypeptides to promote transcription or translation of downstream sequences. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

  6. Acquired Genetic Mechanisms of a Multiresistant Bacterium Isolated from a Treatment Plant Receiving Wastewater from Antibiotic Production

    PubMed Central

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

    2013-01-01

    The external environment, particularly wastewater treatment plants (WWTPs), where environmental bacteria meet human commensals and pathogens in large numbers, has been highlighted as a potential breeding ground for antibiotic resistance. We have isolated the extensively drug-resistant Ochrobactrum intermedium CCUG 57381 from an Indian WWTP receiving industrial wastewater from pharmaceutical production contaminated with high levels of quinolones. Antibiotic susceptibility testing against 47 antibiotics showed that the strain was 4 to >500 times more resistant to sulfonamides, quinolones, tetracyclines, macrolides, and the aminoglycoside streptomycin than the type strain O. intermedium LMG 3301T. Whole-genome sequencing identified mutations in the Indian strain causing amino acid substitutions in the target enzymes of quinolones. We also characterized three acquired regions containing resistance genes to sulfonamides (sul1), tetracyclines [tet(G) and tetR], and chloramphenicol/florfenicol (floR). Furthermore, the Indian strain harbored acquired mechanisms for horizontal gene transfer, including a type I mating pair-forming system (MPFI), a MOBP relaxase, and insertion sequence transposons. Our results highlight that WWTPs serving antibiotic manufacturing may provide nearly ideal conditions for the recruitment of resistance genes into human commensal and pathogenic bacteria. PMID:24038701

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

    PubMed

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

    2013-12-01

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

  8. Multidrug evolutionary strategies to reverse antibiotic resistance.

    PubMed

    Baym, Michael; Stone, Laura K; Kishony, Roy

    2016-01-01

    Antibiotic treatment has two conflicting effects: the desired, immediate effect of inhibiting bacterial growth and the undesired, long-term effect of promoting the evolution of resistance. Although these contrasting outcomes seem inextricably linked, recent work has revealed several ways by which antibiotics can be combined to inhibit bacterial growth while, counterintuitively, selecting against resistant mutants. Decoupling treatment efficacy from the risk of resistance can be achieved by exploiting specific interactions between drugs, and the ways in which resistance mutations to a given drug can modulate these interactions or increase the sensitivity of the bacteria to other compounds. Although their practical application requires much further development and validation, and relies on advances in genomic diagnostics, these discoveries suggest novel paradigms that may restrict or even reverse the evolution of resistance. Copyright © 2016, American Association for the Advancement of Science.

  9. Multidrug evolutionary strategies to reverse antibiotic resistance

    PubMed Central

    Baym, Michael; Stone, Laura K.; Kishony, Roy

    2017-01-01

    Antibiotic treatment has two conflicting effects: the desired, immediate effect of inhibiting bacterial growth and the undesired, long-term effect of promoting the evolution of resistance. Although these contrasting outcomes seem inextricably linked, recent work has revealed several ways by which antibiotics can be combined to inhibit bacterial growth while, counterintuitively, selecting against resistant mutants. Decoupling treatment efficacy from the risk of resistance can be achieved by exploiting specific interactions between drugs, and the ways in which resistance mutations to a given drug can modulate these interactions or increase the sensitivity of the bacteria to other compounds. Although their practical application requires much further development and validation, and relies on advances in genomic diagnostics, these discoveries suggest novel paradigms that may restrict or even reverse the evolution of resistance. PMID:26722002

  10. Does antifouling paint select for antibiotic resistance?

    PubMed

    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

  11. Proteome studies of bacterial antibiotic resistance mechanisms.

    PubMed

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

    2014-01-31

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

  12. Antibiotic policies and control of resistance.

    PubMed

    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.

  13. Priorities for antibiotic resistance surveillance in Europe.

    PubMed

    Fluit, A C; van der Bruggen, J T; Aarestrup, F M; Verhoef, J; Jansen, W T M

    2006-05-01

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

  14. Collective Antibiotic Resistance: Mechanisms and Implications

    PubMed Central

    Vega, Nicole M.; Gore, Jeff

    2015-01-01

    In collective resistance, microbial communities are able to survive antibiotic exposures that would be lethal to individual cells. In this review, we explore recent advances in understanding collective resistance in bacteria. The population dynamics of “cheating” in a system with cooperative antibiotic inactivation have been described, providing insight into the demographic factors that determine resistance allele frequency in bacteria. Extensive work has elucidated mechanisms underlying collective resistance in biofilms and addressed questions about the role of cooperation in these structures. Additionally, recent investigations of “bet-hedging” strategies in bacteria have explored the contributions of stochasticity and regulation to bacterial phenotypic heterogeneity and examined the effects of these strategies on community survival. PMID:25271119

  15. NOTE: Dielectrophoretic assay of bacterial resistance to antibiotics

    NASA Astrophysics Data System (ADS)

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

    2003-07-01

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

  16. The negative impact of antibiotic resistance.

    PubMed

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

    2016-05-01

    Antibacterial therapy is one of the most important medical developments of the twentieth century; however, the spread of resistance in healthcare settings and in the community threatens the enormous gains made by the availability of antibiotic therapy. Infections caused by resistant bacteria lead to up to two-fold higher rates of adverse outcomes compared with similar infections caused by susceptible strains. These adverse outcomes may be clinical or economic and reflect primarily the failure or delay of antibiotic treatment. The magnitude of these adverse outcomes will be more pronounced as disease severity, strain virulence, or host vulnerability increases. The negative impacts of antibacterial resistance can be measured at the patient level by increased morbidity and mortality, at the healthcare level by increased resource utilization, higher costs and reduced hospital activity and at the society level by antibiotic treatment guidelines favouring increasingly broad-spectrum empiric therapy. In this review we will discuss the negative impact of antibiotic resistance on patients, the healthcare system and society. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  17. Mass spectrometry methods for predicting antibiotic resistance.

    PubMed

    Charretier, Yannick; Schrenzel, Jacques

    2016-10-01

    Developing elaborate techniques for clinical applications can be a complicated process. Whole-cell MALDI-TOF MS revolutionized reliable microorganism identification in clinical microbiology laboratories and is now replacing phenotypic microbial identification. This technique is a generic, accurate, rapid, and cost-effective growth-based method. Antibiotic resistance keeps emerging in environmental and clinical microorganisms, leading to clinical therapeutic challenges, especially for Gram-negative bacteria. Antimicrobial susceptibility testing is used to reliably predict antimicrobial success in treating infection, but it is inherently limited by the need to isolate and grow cultures, delaying the application of appropriate therapies. Antibiotic resistance prediction by growth-independent methods is expected to reduce the turnaround time. Recently, the potential of next-generation sequencing and microarrays in predicting microbial resistance has been demonstrated, and this review evaluates the potential of MS in this field. First, technological advances are described, and the possibility of predicting antibiotic resistance by MS is then illustrated for three prototypical human pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Clearly, MS methods can identify antimicrobial resistance mediated by horizontal gene transfers or by mutations that affect the quantity of a gene product, whereas antimicrobial resistance mediated by target mutations remains difficult to detect.

  18. Antibiotic bacterial resistance in ambulatory patients.

    PubMed

    Yawn, B P; Wollan, P; Cockerill, F; Lydick, E

    2000-10-01

    This study evaluates trends in antibiotic resistance in patients who were treated in an ambulatory setting. The authors compiled the data from all lower respiratory track(sputum) cultures collected from ambulatory patients who visited the Olmsted Medical Center and Mayo Clinic between 1985 and 1998. Cultured organisms were identified, and Minimal Inhibitory Concentration (MIC) values were presented and categorized as susceptible, intermediate, or resistant based on the National Committee for Clinical Laboratory Standards (NCCLS) guidelines for MIC and antibiotic susceptibility. 4,297 potentially pathogenic organisms were obtained from sputum cultures for 1,921 patients. The most discernible changes in antibiotic resistance appeared to be in cultures positive for Pseudomonas aeruginosa. A trend toward increasing resistance of isolates of Streptococcus pneumoniae to beta-lactam drugs was observed in a portion of the population. An emerging intermediate susceptibility among isolates of Klebsiella pneumoniae and Pseudoumonas species was noted. Trends in antimicrobial resistance of respiratory pathogens from ambulatory patients are less clear than those from hospitalized patients, but must be monitored because of the high percentage of ambulatory patients who receive empirical therapies. Trends in intermediate susceptibility patterns may help reveal emerging antimicrobial resistance.

  19. [Selection and spreading of antibiotic resistance in bacteria].

    PubMed

    Frimodt-Møller, Niels; Kolmos, Hans Jørn

    2011-11-07

    Use of an antibiotic may not only select for resistance against the agent itself, but may at the same time co-select for resistance against other antibiotics if resistance genes are linked on e.g. a plasmid. Resistance plasmids may also carry genes mediating resistance against metals and disinfectants. Therefore, abundant use of metals, e.g. copper and zinc for growth promotion in animals used for food, may also co-select for antibiotic resistance. The same applies to disinfectants, e.g. silver and chlorhexidine. Prudent use of antibiotics and these other agents is essential to control antibiotic resistance.

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

    USDA-ARS?s Scientific Manuscript database

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

  1. The public's perspectives on antibiotic resistance and abuse among Chinese in Hong Kong.

    PubMed

    Wun, Yuk Tsan; Lam, Tai Pong; Lam, Kwok Fai; Ho, Pak Leung; Yung, Wai Hung Raymond

    2013-03-01

    Antibiotic abuse and resistance impose a continuing threat to the world. The awareness of antibiotic resistance is said to be inversely associated with the prevalence of abuse. We examined the public's perspectives on antibiotic resistance in our study of the public's knowledge, attitude and practice with antibiotics. The study adopted a combined qualitative and quantitative approach. Eight focus groups were conducted with 56 participants purposively selected from community centres and of different socio-economic strata. The qualitative data collected were used to construct a questionnaire for the telephone survey which surveyed 2471 adults from randomly selected residential numbers. The focus-group participants were unclear about the nature and causes of antibiotic resistance; they also attributed antibiotic abuse to the doctors' responsibility. Of the questionnaire respondents, 9.0% had not heard of the term, 7.8% had ever acquired non-prescribed antibiotics, 6.6% had ever kept the leftover and only 69.8% had always finished the full course of antibiotics. Furthermore, 77.3 % and 75.1%, respectively, agreed that the purchase of antibiotics without prescription and incomplete courses of antibiotics would lead to undesirable consequences. Of the respondents who had heard about antibiotic resistance, 38.7% agreed that they could help the prevention of resistance. They were more likely to complete the full course of antibiotics and less likely to keep the leftovers. The public in general was not aware of the causes of, nor their role and capability in preventing, antibiotic resistance. Future campaigns and health education should empower everyone to restrain antibiotic resistance. Copyright © 2012 John Wiley & Sons, Ltd.

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

    MedlinePlus

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

  3. Ecology and evolution of antibiotic resistance.

    PubMed

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

    2009-12-01

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

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

    PubMed

    Brown, David

    2015-12-01

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

  5. Free radicals mediate systemic acquired resistance.

    PubMed

    Wang, Caixia; El-Shetehy, Mohamed; Shine, M B; Yu, Keshun; Navarre, Duroy; Wendehenne, David; Kachroo, Aardra; Kachroo, Pradeep

    2014-04-24

    Systemic acquired resistance (SAR) is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO) and reactive oxygen species (ROS) serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR]) abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azelaic acid (AzA), which in turn induces production of the SAR inducer glycerol-3-phosphate (G3P). Notably, this NO/ROS→AzA→G3P-induced signaling functions in parallel with salicylic acid-derived signaling. We propose that the parallel operation of NO/ROS and SA pathways facilitates coordinated regulation in order to ensure optimal induction of SAR.

  6. Persistence of Antibiotic Resistance Plasmids in Biofilms

    DTIC Science & Technology

    2013-10-01

    TERMS Antibiotic resistance, plasmid, biofilm, coevolution , bacteria, wound infections. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...suitable  candidate   for  plasmid  persistence  tests  in  biofilms  and  for   coevolution  experiments.   Plasmid   pB10...under   antibiotic  selection.   Coevolution  experiment:  methods   Prior  to  commencing  the  evolution  experiments,  we

  7. Chemical Countermeasures for Antibiotic Resistance

    DTIC Science & Technology

    2012-04-01

    focusing on Pseudomonas aeruginosa , methicillin resistant Staphylococcus aureus (MRSA), and MDR Acinetobacter baumannii (MDRAB); 2) re-sensitize MDR...sensitive S. aureus, A. baumannii and Escherichia coli, and discovered that this class of small molecules was microbicidal primarily against Gram...GRC New Antibacterial Discover and Development, Lucca Italy, April 15-20, 2012. Abstracts: ICAAC, San Francisco, Sep 9-12, 2012, submitted 15

  8. [The international surveillance of antibiotics resistance].

    PubMed

    Frimodt-Møller, Niels

    2011-11-07

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

  9. Reprogramming of plants during systemic acquired resistance

    PubMed Central

    Gruner, Katrin; Griebel, Thomas; Návarová, Hana; Attaran, Elham; Zeier, Jürgen

    2013-01-01

    Genome-wide microarray analyses revealed that during biological activation of systemic acquired resistance (SAR) in Arabidopsis, the transcript levels of several hundred plant genes were consistently up- (SAR+ genes) or down-regulated (SAR− genes) in systemic, non-inoculated leaf tissue. This transcriptional reprogramming fully depended on the SAR regulator FLAVIN-DEPENDENT MONOOXYGENASE1 (FMO1). Functional gene categorization showed that genes associated with salicylic acid (SA)-associated defenses, signal transduction, transport, and the secretory machinery are overrepresented in the group of SAR+ genes, and that the group of SAR− genes is enriched in genes activated via the jasmonate (JA)/ethylene (ET)-defense pathway, as well as in genes associated with cell wall remodeling and biosynthesis of constitutively produced secondary metabolites. This suggests that SAR-induced plants reallocate part of their physiological activity from vegetative growth towards SA-related defense activation. Alignment of the SAR expression data with other microarray information allowed us to define three clusters of SAR+ genes. Cluster I consists of genes tightly regulated by SA. Cluster II genes can be expressed independently of SA, and this group is moderately enriched in H2O2- and abscisic acid (ABA)-responsive genes. The expression of the cluster III SAR+ genes is partly SA-dependent. We propose that SA-independent signaling events in early stages of SAR activation enable the biosynthesis of SA and thus initiate SA-dependent SAR signaling. Both SA-independent and SA-dependent events tightly co-operate to realize SAR. SAR+ genes function in the establishment of diverse resistance layers, in the direct execution of resistance against different (hemi-)biotrophic pathogen types, in suppression of the JA- and ABA-signaling pathways, in redox homeostasis, and in the containment of defense response activation. Our data further indicated that SAR-associated defense priming can be

  10. Mechanisms of bacterial resistance to macrolide antibiotics.

    PubMed

    Nakajima, Yoshinori

    1999-06-01

    Macrolides have been used in the treatment of infectious diseases since the late 1950s. Since that time, a finding of antagonistic action between erythromycin and spiramycin in clinical isolates1 led to evidence of the biochemical mechanism and to the current understanding of inducible or constitutive resistance to macrolides mediated by erm genes containing, respectively, the functional regulation mechanism or constitutively mutated regulatory region. These resistant mechanisms to macrolides are recognized in clinically isolated bacteria. (1) A methylase encoded by the erm gene can transform an adenine residue at 2058 (Escherichia coli equivalent) position of 23S rRNA into an 6N, 6N-dimethyladenine. Position 2058 is known to reside either in peptidyltransferase or in the vicinity of the enzyme region of domain V. Dimethylation renders the ribosome resistant to macrolides (MLS). Moreover, another finding adduced as evidence is that a mutation in the domain plays an important role in MLS resistance: one of several mutations (transition and transversion) such as A2058G, A2058C or U, and A2059G, is usually associated with MLS resistance in a few genera of bacteria. (2) M (macrolide antibiotics)- and MS (macrolide and streptogramin type B antibiotics)- or PMS (partial macrolide and streptogramin type B antibiotics)-phenotype resistant bacteria cause decreased accumulation of macrolides, occasionally including streptogramin type B antibiotics. The decreased accumulation, probably via enhanced efflux, is usually inferred from two findings: (i) the extent of the accumulated drug in a resistant cell increases as much as that in a susceptible cell in the presence of an uncoupling agent such as carbonylcyanide-m-chlorophenylhydrazone (CCCP), 2,4-dinitrophenol (DNP), and arsenate; (ii) transporter proteins, in M-type resistants, have mutual similarity to the 12-transmembrane domain present in efflux protein driven by proton-motive force, and in MS- or PMS-type resistants

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed

    Amábile-Cuevas, Carlos F

    2013-04-01

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

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

    PubMed

    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.

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

    PubMed Central

    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

  16. Antibiotic resistance genes & susceptibility patterns in staphylococci

    PubMed Central

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

    2012-01-01

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

  17. Origin and Evolution of Antibiotic Resistance: The Common Mechanisms of Emergence and Spread in Water Bodies

    PubMed Central

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

    2011-01-01

    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. PMID:22303296

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

    PubMed

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

    2012-06-15

    Staphylococcus pseudintermedius is the most frequent staphylococcal species isolated from canine pyoderma. The control of S. pseudintermedius infection is often difficult due to the expanded antimicrobial resistance phenotypes. Antibiotic resistance in staphylococcal pathogens is often associated to mobile genetic elements such as the insertion sequence IS256 that was first described as a part of the transposon Tn4001, which confers aminoglycoside resistance in Staphylococcus aureus and in Staphylococcus epidermidis. In this study a collection of 70 S. pseudintermedius isolates from canine pyoderma was used to investigate antimicrobial susceptibility to 15 antibiotics and the presence of IS256, not revealed in S. pseudintermedius yet. Antibiotic resistance profiling demonstrated that all S. pseudintermedius isolates had a multi-drug resistance phenotype, exhibiting simultaneous resistance to at least five antibiotics; indeed methicillin resistant S. pseudintermedius isolates were simultaneously resistant to at least nine antibiotics and all were also gentamicin resistant. PCR analyses revealed the presence of IS256 in 43/70 S. pseudintemedius isolates. The association between the presence of IS256 and the resistance was particularly significant for certain antibiotics: cefovecin, amikacin, gentamicin and oxacillin (χ(2)p-value<0.05). However, there was a striking result in frequency of strains resistant to gentamicin and oxacillin, suggesting a specific association between the presence of the IS256 element and the determinants for the resistance to these antibiotics. To the best of our knowledge, this is the first report showing the detection of IS256 in S. pseudintermedius isolates and its association with antibiotic resistance. Our findings suggest that S. pseudintermedius may acquire antibiotic resistance genes through mobile genetic elements which may play a predominant role in the dissemination of multi-drug resistance.

  19. Alternating antibiotic treatments constrain evolutionary paths to multidrug resistance.

    PubMed

    Kim, Seungsoo; Lieberman, Tami D; Kishony, Roy

    2014-10-07

    Alternating antibiotic therapy, in which pairs of drugs are cycled during treatment, has been suggested as a means to inhibit the evolution of de novo resistance while avoiding the toxicity associated with more traditional combination therapy. However, it remains unclear under which conditions and by what means such alternating treatments impede the evolution of resistance. Here, we tracked multistep evolution of resistance in replicate populations of Staphylococcus aureus during 22 d of continuously increasing single-, mixed-, and alternating-drug treatment. In all three tested drug pairs, the alternating treatment reduced the overall rate of resistance by slowing the acquisition of resistance to one of the two component drugs, sometimes as effectively as mixed treatment. This slower rate of evolution is reflected in the genome-wide mutational profiles; under alternating treatments, bacteria acquire mutations in different genes than under corresponding single-drug treatments. To test whether this observed constraint on adaptive paths reflects trade-offs in which resistance to one drug is accompanied by sensitivity to a second drug, we profiled many single-step mutants for cross-resistance. Indeed, the average cross-resistance of single-step mutants can help predict whether or not evolution was slower in alternating drugs. Together, these results show that despite the complex evolutionary landscape of multidrug resistance, alternating-drug therapy can slow evolution by constraining the mutational paths toward resistance.

  20. Antibiotic resistance in Campylobacter: emergence, transmission and persistence

    PubMed Central

    Luangtongkum, Taradon; Jeon, Byeonghwa; Han, Jing; Plummer, Paul; Logue, Catherine M; Zhang, Qijing

    2009-01-01

    Campylobacter is a leading foodborne bacterial pathogen, which causes gastroenteritis in humans. This pathogenic organism is increasingly resistant to antibiotics, especially fluoroquinolones and macrolides, which are the most frequently used antimicrobials for the treatment of campylobacteriosis when clinical therapy is warranted. As a zoonotic pathogen, Campylobacter has a broad animal reservoir and infects humans via contaminated food, water or milk. Antibiotic usage in both animal agriculture and human medicine, can influence the development of antibiotic-resistant Campylobacter. This review will describe the trend in fluoroquinolone and macrolide resistance in Campylobacter, summarize the mechanisms underlying the resistance to various antibiotics and discuss the unique features associated with the emergence, transmission and persistence of antibiotic-resistant Campylobacter. Special attention will be given to recent findings and emphasis will be placed on Campylobacter resistance to fluoroquinolones and macrolides. A future perspective on antibiotic resistance and potential approaches for the control of antibiotic-resistant Campylobacter, will also be discussed. PMID:19257846

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

    PubMed

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

    2013-09-01

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

  2. Antibiotic resistance in sputum isolates of Streptococcus pneumoniae in chronic obstructive pulmonary disease is related to antibiotic exposure.

    PubMed

    Desai, Himanshu; Richter, Sandra; Doern, Gary; Heilmann, Kris; Dohrn, Cassie; Johnson, Antoinette; Brauer, Aimee; Murphy, Timothy; Sethi, Sanjay

    2010-10-01

    Streptococcus pneumoniae (S. pneumoniae) is recovered from sputum of patients with chronic obstructive pulmonary disease (COPD) during stable disease and exacerbations. In patients with community acquired pneumonia, antibiotic exposure in the prior 3-6 months is associated with recovery of antibiotic resistant isolates of S. pneumoniae. Whether the same relationship is seen in COPD is not known. From April 1994 to June 2004, 127 adults with COPD were enrolled in a prospective longitudinal study. Sputum isolates of S. pneumoniae were characterized with susceptibility testing and pulsed-field gel electrophoresis (PFGE). The relationship between antibiotic use in the previous 3 and 6 months with either new acquisition of a resistant pneumococcal isolate or development of resistance (4-fold increase in MIC) in a pre-existing colonizing pneumococcal strain was determined. A total of 194 pneumococcal isolates were recovered from 38 patients. Among 71 newly acquired and 4 resistance-emergent strains analyzed further, rates of resistance to penicillin (MIC ≥2), erythromycin (MIC ≥1), tetracycline (MIC ≥8) and trimethoprim/sulfamethoxazole (MIC ≥4) were 8%, 24%, 17% and 16% respectively. Flouroquinolone resistance was not seen. Among strains isolated from patients exposed to a macrolide within 6 months, 53.6% displayed erythromycin resistance vs. 14% of strains without such exposure (p = 0.00085). Similar associations were not seen for other antibiotics. Macrolide use in the previous 6 months is associated with macrolide resistance in sputum isolates of S. pneumoniae. Recent antibiotic exposure may help in determining appropriate antibiotic treatment in these patients.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  5. Assessment of Bacterial Antibiotic Resistance Transfer in the Gut

    PubMed Central

    Schjørring, Susanne; Krogfelt, Karen A.

    2011-01-01

    We assessed horizontal gene transfer between bacteria in the gastrointestinal (GI) tract. During the last decades, the emergence of antibiotic resistant strains and treatment failures of bacterial infections have increased the public awareness of antibiotic usage. The use of broad spectrum antibiotics creates a selective pressure on the bacterial flora, thus increasing the emergence of multiresistant bacteria, which results in a vicious circle of treatments and emergence of new antibiotic resistant bacteria. The human gastrointestinal tract is a massive reservoir of bacteria with a potential for both receiving and transferring antibiotic resistance genes. The increased use of fermented food products and probiotics, as food supplements and health promoting products containing massive amounts of bacteria acting as either donors and/or recipients of antibiotic resistance genes in the human GI tract, also contributes to the emergence of antibiotic resistant strains. This paper deals with the assessment of antibiotic resistance gene transfer occurring in the gut. PMID:21318188

  6. Enterobacter cloacae complex: clinical impact and emerging antibiotic resistance.

    PubMed

    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.

  7. Community-Acquired Methicillin-Resistant Pyogenic Liver Abscess

    PubMed Central

    Cherian, Joel; Singh, Rahul; Varma, Muralidhar; Vidyasagar, Sudha; Mukhopadhyay, Chiranjay

    2016-01-01

    Pyogenic liver abscesses are rare with an incidence of 0.5% to 0.8% and are mostly due to hepatobiliary causes (40% to 60%). Most are polymicrobial with less than 10% being caused by Staphylococcus aureus. Of these, few are caused by methicillin-resistant Staphylococcus aureus (MRSA) and fewer still by a community-acquired strain. Here we present a case study of a patient with a community-acquired MRSA liver abscess. The patient presented with fever since 1 month and tender hepatomegaly. Blood tests revealed elevated levels of alkaline phosphatase, C-reactive protein, erythrocyte sedimentation rate, and neutrophilic leukocytosis. Blood cultures were sterile. Ultrasound of the abdomen showed multiple abscesses, from which pus was drained and MRSA isolated. Computed tomography of the abdomen did not show any source of infection, and an amebic serology was negative. The patient was started on vancomycin for 2 weeks, following which he became afebrile and was discharged on oral linezolid for 4 more weeks. Normally a liver abscess is treated empirically with ceftriaxone for pyogenic liver abscess and metronidazole for amebic liver abscess. However, if the patient has risk factors for a Staphylococcal infection, it is imperative that antibiotics covering gram-positive organisms be added while waiting for culture reports. PMID:27540556

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

    PubMed

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

    2013-06-01

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

  9. Bacteriophage biosensors for antibiotic-resistant bacteria.

    PubMed

    Sorokulova, Irina; Olsen, Eric; Vodyanoy, Vitaly

    2014-03-01

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

  10. Biofilm-specific antibiotic tolerance and resistance.

    PubMed

    Olsen, I

    2015-05-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  12. Cooperative Antibiotic Resistance in a Multi-Drug Environment

    NASA Astrophysics Data System (ADS)

    Yurtsev, Eugene; Dai, Lei; Gore, Jeff

    2013-03-01

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

  13. Effects of antibiotics on acquired immunity in vivo--current state of knowledge.

    PubMed

    Pomorska-Mól, M; Pejsak, Z

    2012-01-01

    Antibiotics are widely used in the therapy of infections. Besides the respective interactions between antibiotics and pathogens it seems that antibiotics also directly interact with the immune system. Some commonly used antibiotics are currently known to have effects on the innate immune response, as shown by in vitro, ex vivo and also in vivo animal experiments and clinical studies. Most of the experimental papers published to date, as well as most reviews, relate to how antibiotics affect the innate immune response or non-specific monocyte or lymphocyte proliferation. However the effects of antibiotics on the adaptive immune response are still not well characterized. This review of the literature considering different in vivo experiments indicate the real importance of interrelations existing between acquired immune responses and antibiotics, however, the mechanism of immunomodulatory effects of antibiotics are still poorly understood. Currently, data on the immunomodulating effects of antibiotics often remain heterogeneous, contradictory or insufficient, but most results published to date revealed the immunosuppressive effect of antibiotics on the antigen-specific immune response in vivo. In pigs as well as in poultry herds, it is not uncommon practice to add antibiotics to drinking water or feed at the time of vaccination. Information on the effects of such practices on the immune system of animals is restricted and more in vivo studies are needed to investigate the effects of antimicrobial drugs on the immune system, especially in the field conditions.

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

    PubMed

    Bengtsson, Björn; Greko, Christina

    2014-05-01

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

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

    PubMed Central

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

    2017-01-01

    ABSTRACT 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. PMID:28292982

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

    USDA-ARS?s Scientific Manuscript database

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

  17. Antibiotrophs: The complexity of antibiotic-subsisting and antibiotic-resistant microorganisms.

    PubMed

    Woappi, Yvon; Gabani, Prashant; Singh, Arya; Singh, Om V

    2016-01-01

    Widespread overuse of antibiotics has led to the emergence of numerous antibiotic-resistant bacteria; among these are antibiotic-subsisting strains capable of surviving in environments with antibiotics as the sole carbon source. This unparalleled expansion of antibiotic resistance reveals the potent and diversified resistance abilities of certain bacterial strains. Moreover, these strains often possess hypermutator phenotypes and virulence transmissibility competent for genomic and proteomic propagation and pathogenicity. Pragmatic and prospicient approaches will be necessary to develop efficient therapeutic methods against such bacteria and to understand the extent of their genomic adaptability. This review aims to reveal the niches of these antibiotic-catabolizing microbes and assesses the underlying factors linking natural microbial antibiotic production, multidrug resistance, and antibiotic-subsistence.

  18. [Vancomycin-resistant enterococci (VRE). Recent results and trends in development of antibiotic resistance].

    PubMed

    Klare, I; Witte, W; Wendt, C; Werner, G

    2012-11-01

    Enterococci (mainly E. faecalis, E. faecium) are important nosocomial pathogens predominantly affecting older and/or immunocompromised patients. The bacteria possess a broad spectrum of intrinsic and acquired antibiotic resistance properties. Among these, the transferrable glycopeptide resistance of the vanA and vanB genotypes in vancomycin-resistant enterococci (VRE; reservoir: E. faecium) as well as resistance to last resort antibiotics (e.g. linezolid and tigecycline) are of special concern. Enterococci (including VRE) are easily transferred in hospitals; however, colonizations are far more frequent than infections. Resistance frequencies for vancomycin in clinical E. faecium isolates have remained at a relatively constant level of 8-15% (but with local or regional variations) in recent years whereas frequencies for teicoplanin resistance have shown a slight decrease. Glycopeptide resistance trends correlate with a spread of hospital-associated E. faecium strains carrying the vanA and, with rising frequency in recent years, the vanB gene cluster, the latter being associated with teicoplanin susceptibility. This increased occurrence of vanB-positive E. faecium strains may be caused by an increased use of antibiotics selecting enterococci and VRE as well as due to methodological reasons (e.g. reduced EUCAST MIC-breakpoints for glycopeptides; increased use and sensitive performance of chromogenic VRE agars, increased use of molecular diagnostic assays).

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

    PubMed

    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.

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

    PubMed Central

    Berglund, Björn

    2015-01-01

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

  1. Antibiotic resistant Staphylococcus aureus: a paradigm of adaptive power

    PubMed Central

    de Lencastre, Herminia; Oliveira, Duarte; Tomasz, Alexander

    2009-01-01

    Summary Nothing documents better the spectacular adaptive capacity of Staphylococcus aureus than the response of this important human and animal pathogen to the introduction of antimicrobial agents into the clinical environment. The effectiveness of penicillin introduced in the early 1940s was virtually annulled within a decade due to the plasmid epidemics that spread the ß-lactamase gene through the entire species of S. aureus. In 1960 within one to two years of the introduction of penicillinase resistant ß-lactams (methicillin), methicillin resistant S. aureus (MRSA) strains were identified in clinical specimens. By the 1980s, epidemic clones of MRSA acquired multidrug resistant traits and spread worldwide to become one of the most important causative agents of hospital acquired infections. In the early 2000s, MRSA strains carrying the Tn1546 transposon-based enterococcal vancomycin resistant mechanism were identified in clinical specimens, bringing the specter of a totally resistant bacterial pathogen closer to reality. Then, in the late 1990s, just as effective hygienic and antibiotic use policies managed to bring down the frequency of MRSA in hospitals of several countries, MRSA strains began to show up in the community. PMID:17921044

  2. Development of botanicals to combat antibiotic resistance.

    PubMed

    Gupta, Pooja D; Birdi, Tannaz J

    2017-08-30

    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. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

  3. Effects of a Syndrome-Specific Antibiotic Stewardship Intervention for Inpatient Community-Acquired Pneumonia.

    PubMed

    Haas, Michelle K; Dalton, Kristen; Knepper, Bryan C; Stella, Sarah A; Cervantes, Lilia; Price, Connie S; Burman, William J; Mehler, Philip S; Jenkins, Timothy C

    2016-10-01

    Background.  Syndrome-specific interventions are a recommended approach to antibiotic stewardship, but additional data are needed to understand their potential impact. We implemented an intervention to improve the management of inpatient community-acquired pneumonia (CAP) and evaluated its effects on antibiotic and resource utilization. Methods.  A stakeholder group developed and implemented a clinical practice guideline and order set for inpatient, non-intensive care unit CAP recommending a short course (5 days) of a fluoroquinolone-sparing antibiotic regimen in uncomplicated cases. Unless there was suspicion for complications or resistant pathogens, chest computed tomography (CT) and sputum cultures were discouraged. This was a retrospective preintervention postintervention study of patients hospitalized for CAP before (April 15, 2008-May 31, 2009) and after (July 1, 2011-July 31, 2012) implementation of the guideline. The primary comparison was the difference in duration of therapy during the baseline and intervention periods. Secondary outcomes included changes in use of levofloxacin, CT scans, and sputum culture. Results.  One hundred sixty-six and 84 cases during the baseline and intervention periods, respectively, were included. From the baseline to intervention period, the median duration of therapy decreased from 10 to 7 days (P < .0001). Prescription of levofloxacin at discharge decreased from 60% to 27% of cases (P < .0001). Use of chest CT and sputum culture decreased from 47% to 32% of cases (P = .02) and 51% to 31% of cases (P = .03), respectively. The frequency of clinical failure between the 2 periods was similar. Conclusions.  A syndrome-specific intervention for inpatient CAP was associated with shorter treatment durations and reductions in use of fluoroquinolones and low-yield diagnostic tests.

  4. Effects of a Syndrome-Specific Antibiotic Stewardship Intervention for Inpatient Community-Acquired Pneumonia

    PubMed Central

    Haas, Michelle K.; Dalton, Kristen; Knepper, Bryan C.; Stella, Sarah A.; Cervantes, Lilia; Price, Connie S.; Burman, William J.; Mehler, Philip S.; Jenkins, Timothy C.

    2016-01-01

    Background. Syndrome-specific interventions are a recommended approach to antibiotic stewardship, but additional data are needed to understand their potential impact. We implemented an intervention to improve the management of inpatient community-acquired pneumonia (CAP) and evaluated its effects on antibiotic and resource utilization. Methods. A stakeholder group developed and implemented a clinical practice guideline and order set for inpatient, non-intensive care unit CAP recommending a short course (5 days) of a fluoroquinolone-sparing antibiotic regimen in uncomplicated cases. Unless there was suspicion for complications or resistant pathogens, chest computed tomography (CT) and sputum cultures were discouraged. This was a retrospective preintervention postintervention study of patients hospitalized for CAP before (April 15, 2008–May 31, 2009) and after (July 1, 2011–July 31, 2012) implementation of the guideline. The primary comparison was the difference in duration of therapy during the baseline and intervention periods. Secondary outcomes included changes in use of levofloxacin, CT scans, and sputum culture. Results. One hundred sixty-six and 84 cases during the baseline and intervention periods, respectively, were included. From the baseline to intervention period, the median duration of therapy decreased from 10 to 7 days (P < .0001). Prescription of levofloxacin at discharge decreased from 60% to 27% of cases (P < .0001). Use of chest CT and sputum culture decreased from 47% to 32% of cases (P = .02) and 51% to 31% of cases (P = .03), respectively. The frequency of clinical failure between the 2 periods was similar. Conclusions. A syndrome-specific intervention for inpatient CAP was associated with shorter treatment durations and reductions in use of fluoroquinolones and low-yield diagnostic tests. PMID:27747254

  5. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7.

    PubMed

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

    2015-09-29

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

  6. Heavy Metal Induced Antibiotic Resistance in Bacterium LSJC7

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    Raghunath, D

    2008-11-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

    Kasanah, Noer; Hamann, Mark T

    2016-01-01

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

  10. Antibiotic resistance in Pseudomonas aeruginosa and alternative therapeutic options.

    PubMed

    Chatterjee, Maitrayee; Anju, C P; Biswas, Lalitha; Anil Kumar, V; Gopi Mohan, C; Biswas, Raja

    2016-01-01

    Pseudomonas aeruginosa is a leading cause of nosocomial infections and is responsible for ∼10% of all hospital-acquired infections worldwide. It continues to pose a therapeutic challenge because of the high rate of morbidity and mortality associated with it and the possibility of development of drug resistance during therapy. Standard antibiotic regimes against P. aeruginosa are increasingly becoming ineffective due to the rise in drug resistance. With the scope for developing new antibiotics being limited, alternative treatment options are gaining more and more attention. A number of recent studies reported complementary and alternative treatment options to combat P. aeruginosa infections. Quorum sensing inhibitors, phages, probiotics, anti-microbial peptides, vaccine antigens and antimicrobial nanoparticles have the potential to act against drug resistant strains. Unfortunately, most studies considering alternative treatment options are still confined in the pre-clinical stages, although some of these findings have tremendous potential to be turned into valuable therapeutics. This review is intended to raise awareness of several novel approaches that can be considered further for combating drug resistant P. aeruginosa infections. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Epidemiology of antibiotic resistance in Pseudomonas aeruginosa. Implications for empiric and definitive therapy.

    PubMed

    Ruiz-Garbajosa, P; Cantón, R

    2017-09-01

    Pseudomonas aeruginosa is one of the major pathogens causing hospital-acquired infections. It can easily develop antibiotic resistance through chromosomal mutations or by horizontal acquisition of resistant determinants. The increasing prevalence of multi-drug-resistant (MDR) or extensively-drug-resistant (XDR) P. aeruginosa isolates is associated with the dissemination of the so-called high-risk-clones, such as ST175. Infections caused by MDR/XDR are a cause of concern as they compromise the selection of appropriate empiric and definitive antimicrobial treatments. Introduction of new antibiotics with potent activity against MDR/XDR P. aeruginosa opens new horizons in the treatment of these infections.

  12. CURRENT ISSUES REGARDING ENDOCRINE DISRUPTING CHEMICALS AND ANTIBIOTIC RESISTANCE

    EPA Science Inventory

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

  13. CURRENT ISSUES REGARDING ENDOCRINE DISRUPTING CHEMICALS AND ANTIBIOTIC RESISTANCE

    EPA Science Inventory

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

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

    PubMed

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

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

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

  16. Antibiotic Resistance Threats in the U.S.

    MedlinePlus

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

  17. Multiple Resistance at No Cost: Rifampicin and Streptomycin a Dangerous Liaison in the Spread of Antibiotic Resistance

    PubMed Central

    Durão, Paulo; Trindade, Sandra; Sousa, Ana; Gordo, Isabel

    2015-01-01

    Evidence is mounting that epistasis is widespread among mutations. The cost of carrying two deleterious mutations, or the advantage of acquiring two beneficial alleles, is typically lower that the sum of their individual effects. Much less is known on epistasis between beneficial and deleterious mutations, even though this is key to the amount of genetic hitchhiking that may occur during evolution. This is particularly important in the context of antibiotic resistance: Most resistances are deleterious, but some can be beneficial and remarkably rifampicin resistance can emerge de novo in populations evolving without antibiotics. Here we show pervasive positive pairwise epistasis on Escherichia coli fitness between beneficial mutations, which confer resistance to rifampicin, and deleterious mutations, which confer resistance to streptomycin. We find that 65% of double resistant strains outcompete sensitive bacteria in an environment devoid of antibiotics. Weak beneficial mutations may therefore overcome strong deleterious mutations and can even render double mutants strong competitors. PMID:26130082

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

    PubMed

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

    2015-02-01

    As part of an ESCMID Study Group on Anaerobic Infections (ESGAI) project, a study was conducted to measure the antibiotic susceptibilities and corresponding gene contents of 53 Bacteroides fragilis group strains isolated in Romania. The antibiotic resistance data was comparable with the data found for other East-European countries. Here, no resistant isolate was found for imipenem, metronidazole and tigecycline. An increasing role of the cepA, cfxA and cfiA genes was observed in their corresponding antibiotic resistances. Moreover, no isolate was found that harbored the cfiA gene with a possible activating IS element. Clindamycin resistance was low, similarly to that the rate for the ermF gene. However, we did find some isolates with nimB, ermB, msrSA, linA, satG, tetX, tetM and bexA genes. This study was the first to provide antibiotic resistance data for clinical Bacteroides strains from Romania. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    PubMed Central

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

    2015-01-01

    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. PMID:26276674

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

    PubMed Central

    Khachatourians, G G

    1998-01-01

    Microbial Resistance to antibiotics is on the rise, in part because of inappropriate use of antibiotics in human medicine but also because of practices in the agricultural industry. Intensive animal production involves giving livestock animals large quantities of antibiotics to promote growth and prevent infection. These uses promote the selection of antibiotic resistance in bacterial populations. The resistant bacteria from agricultural environments may be transmitted to humans, in whom they cause disease that cannot be treated by conventional antibiotics. The author reviews trends in antibiotic use in animal husbandry and agriculture in general. The development of resistance is described, along with the genetic mechanisms that create resistance and facilitate its spread among bacterial species. Particular aspects of resistance in bacterial species common to both the human population and the agrifood industry are emphasized. Control measures that might reverse the current trends are highlighted. PMID:9835883

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

    PubMed

    Khachatourians, G G

    1998-11-03

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

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

    PubMed

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

    2016-06-01

    The emergence and spread of antibiotic resistance represents one of the most important public health concerns and has been linked to the widespread use of antibiotics in veterinary and human medicine. The overall elimination of antibiotics in conventional wastewater treatment plants is quite low; therefore, residual amounts of these compounds are continuously discharged to receiving surface waters, which may promote the emergence of antibiotic resistance. In this study, the ability of a fungal treatment as an alternative wastewater treatment for the elimination of forty-seven antibiotics belonging to seven different groups (β-lactams, fluoroquinolones, macrolides, metronidazoles, sulfonamides, tetracyclines, and trimethoprim) was evaluated. 77% of antibiotics were removed after the fungal treatment, which is higher than removal obtained in conventional treatment plants. Moreover, the effect of fungal treatment on the removal of some antibiotic resistance genes (ARGs) was evaluated. The fungal treatment was also efficient in removing ARGs, such as ermB (resistance to macrolides), tetW (resistance to tetracyclines), blaTEM (resistance to β-lactams), sulI (resistance to sulfonamides) and qnrS (reduced susceptibility to fluoroquinolones). However, it was not possible to establish a clear link between concentrations of antibiotics and corresponding ARGs in wastewater, which leads to the conclusion that there are other factors that should be taken into consideration besides the antibiotic concentrations that reach aquatic ecosystems in order to explain the emergence and spread of antibiotic resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. [Experimental transmission of antibiotic resistance in chicks].

    PubMed

    Todorov, T; Todorova, P; Kokosharov, T

    1977-01-01

    Multi-drug resistance of Salmonella heidelberg was transmitted to normal intestinal flora (E. coli organisms were resistant to ampicillin, streptomycin, tetracycline, erythromycin, and oleandomycin. The donor strains of Salmonella heidelberg used in the experiment was a carrier of the following nine markers of resistance: ampicillin, streptomycin, chloramphenicol, kanamycin, neomycin, novobiocin, tetracycline, erythromycin, and oleandomycin. The donor strains of Salmonella heidelberg used in the experiment was a carrier of the following nine markers of resistance: ampicillin, streptomycin, chloramphenicol, kanamycin, neomycin, novobiocin, tetracycline, erythromycin, and oeandomycin, novobiocin, tetracycline, erythromycin, and oleandomycin. The resistance to drugs was transmitted with the oral administration of the donor strain at the preliminary neutralization of the action of hydrochloric acid in the stomah secretion through sodium bicarbonate (1 cm3 of a 10 per cent sol.) an hour prior to feeding the birds with Salmonella heidelberg (1 cm3 of 10(10). In other experiments carboneum tetrachloratum was injected at rates of 0.08 to 0.15 cm3 (acocrting with the body weight of birds) one day prior to infection, followed by the administration of 0.20 to 0.40 cm3 of a 2 per cent solution of omnopon. Escherichia coli organisms acquired new markers of resistance--to chloramphenicol, kanamycin, neomycin and novobiocin. The level of resistance proved equal with that to the donor strain. A total of 1.8 to 5.4 per cent of the intestinal E. coli investigated proved to be carriers of the indicated markers of resitance. Highest level in acquiring markers of multi-drug resistance (13 per cent) showed E. coli organisms isolated from the liver of birds injected additionally with C. tetrachloratum omnopon.

  4. Acquired resistance of Mycobacterium tuberculosis to bedaquiline.

    PubMed

    Andries, Koen; Villellas, Cristina; Coeck, Nele; Thys, Kim; Gevers, Tom; Vranckx, Luc; Lounis, Nacer; de Jong, Bouke C; Koul, Anil

    2014-01-01

    Bedaquiline (BDQ), an ATP synthase inhibitor, is the first drug to be approved for treatment of multi-drug resistant tuberculosis in decades. In vitro resistance to BDQ was previously shown to be due to target-based mutations. Here we report that non-target based resistance to BDQ, and cross-resistance to clofazimine (CFZ), is due to mutations in Rv0678, a transcriptional repressor of the genes encoding the MmpS5-MmpL5 efflux pump. Efflux-based resistance was identified in paired isolates from patients treated with BDQ, as well as in mice, in which it was confirmed to decrease bactericidal efficacy. The efflux inhibitors verapamil and reserpine decreased the minimum inhibitory concentrations of BDQ and CFZ in vitro, but verapamil failed to increase the bactericidal effect of BDQ in mice and was unable to reverse efflux-based resistance in vivo. Cross-resistance between BDQ and CFZ may have important clinical implications.

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

    PubMed

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

    2015-09-01

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

  6. [The problem of growing resistance of microorganisms to antibiotic therapy and prospects for Helicobacter pylori eradication].

    PubMed

    Tsimmerman, Ia S

    2013-01-01

    The problem of growing resistance of microorganisms to antibiotic therapy acquires increasingly greater significance as threatening the loss of endosymbiotic bacteria. The causes, mechanisms, and consequences of this phenomenon are considered. Several groups of modern antibiotic drugs are characterized along with the methods for improving their efficacy and preventing side effects. The schemes for Helicobacter pylori eradication as recommended by the Maastricht consensus are discussed in conjunction with major mistakes accounting for marked reduction of their effectiveness. Terminological issues are briefly considered.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  8. Emerging trends in antibiotic resistance: Implications for emergency medicine.

    PubMed

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

    2017-08-01

    Many bacteria are demonstrating increasing levels of resistance to commonly used antibiotics. While this has implications for the healthcare system as a whole, many patients infected with these resistant organisms will initially present to the emergency department (ED). The purpose of this review is to provide a summary of current trends in infections caused by the most clinically relevant resistant organisms encountered in emergency medicine. Bacteria were selected based on the Centers for Disease Control and Prevention's National Action Plan for Combating Antibiotic Resistant Bacteria, and PubMed database. The following bacteria were included: methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococci, Escherichia coli, carbapenem-resistant Enterobacteriaceae, Neisseria gonorrhoeae, and Pseudomonas aeruginosa. All have shown increasing rates of resistance to one or more of the antibiotics commonly used to treat them. Increasing rates of antibiotic resistance are associated with worse clinical outcomes and greater healthcare costs. Antibiotic resistance is increasing and poses significant a risk to both the patient and public health as a whole. Appropriate choice of initial antibiotic is important in improving clinical outcomes, which is often the role of the ED provider. On a broader level, the ED must also take part in institutional efforts such as Antibiotic Stewardship Programs, which have been shown to decrease costs and rates of infection with resistant organisms. Ultimately, a multifaceted approach will be required to curb the threat of antibiotic-resistant bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. [Multiple antibiotic resistance of associative microflora during urogenital pathology].

    PubMed

    Akaeva, F S; Omarova, S M; Adieva, A A; Medzhidov, M M

    2008-01-01

    Susceptibility of associative microflora isolated from patients with inflammatory diseases of urogenital tract was investigated. Etiologic structure of the diseases and cross-resistance to antibiotics of Escherichia coli, Staphylococcusaureus, and Klebsiella pneumoniae strains isolated from women with endocervicitis and men with urethritiswas assessed. Ciprofloxacin and gentamycin had the highest activity, whereas beta-lactam antibiotics were mildly active. Isolated strainswere resistant to macrolides, penicillines and imipenem. Main types of multidrug resistance to antibiotics were presented in strains circulated in Dagestan.

  10. Multiple antibiotic resistance among gram negative bacteria isolated from poultry.

    PubMed

    Ansari, F A; Khatoon, H

    1994-03-01

    Gram negative bacteria, including species of Salmonella, Escherichia, Pseudomonas and Klebsiella, isolated from poultry, were screened for their resistance to the commonly used antibiotics: ampicillin, chloramphenicol, gentamycin, kanamycin, neomycin, polymyxin B, streptomycin and tetracycline. Of the 500 bacteria screened, 351 were found to be resistant to one or more antibiotics at the level of 50 micrograms/ml. Various patterns of antibiotic resistance observed during these studies have been reported.

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

    PubMed

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

    2014-08-01

    Antibiotic-producing bacteria encode antibiotic resistance genes that protect them from the biologically active molecules that they produce. The expression of these genes needs to occur in a timely manner: either in advance of or concomitantly with biosynthesis. It appears that there have been at least two general solutions to this problem. In many cases, the expression of resistance genes is tightly linked to that of antibiotic biosynthetic genes. In others, the resistance genes can be induced by their cognate antibiotics or by intermediate molecules from their biosynthetic pathways. The regulatory mechanisms that couple resistance to antibiotic biosynthesis are mechanistically diverse and potentially relevant to the origins of clinical antibiotic resistance. © 2014 John Wiley & Sons Ltd.

  12. [Antibiotic-resistant bacteria and new directions of antimicrobial chemotherapy].

    PubMed

    Tateda, Kazuhiro

    2012-05-01

    The emergence and spread of antibiotic-resistant organisms are becoming more and more serious and are a worldwide problem. Recent trends in new antibiotic-resistant organisms include multiple-drug resistant Pseudomonas aeruginosa (MDRP), MDR-Acinetobacter baumannii (MDR-AB) and New Deli metallo beta-lactamase-1 (NDM-1) -producing bacteria. Antibiotic combination therapy is an option to overcome these MDR organisms. A breakpoint checkerboard plate was created to measure antibiotic combination effects at breakpoint concentrations, making it possible to evaluate the synergy of antibiotic combination within 24 hours. In this article, recent topics regarding antibiotic-resistant organisms are briefly reviewed and the directions of antibiotic chemotherapy against these organisms are discussed.

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

    PubMed

    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.

  14. Antibiotic-resistant Streptococcus pneumoniae. Implications for medical practice.

    PubMed Central

    Wang, E. E.; Kellner, J. D.; Arnold, S.

    1998-01-01

    OBJECTIVE: To review the definition and prevalence of antibiotic-resistant Streptococcus pneumoniae, its links with antibiotic prescribing, data on antibiotic prescribing and prescribing appropriateness, and evidence-based treatment guidelines for common respiratory tract syndromes. QUALITY OF EVIDENCE: Primary studies consist of cross-sectional surveys and case-control studies. Treatment guidelines are based on clinical trials, meta-analyses, and cohort studies. Study designs were appropriate for the specific study questions. MAIN FINDINGS: The increasing prevalence of penicillin-resistant S pneumoniae is concurrent with increasing antibiotic prescribing. Individual patients show a twofold to ninefold increase in nasopharyngeal carriage of resistant bacteria or invasion with resistant bacteria (among those who have received antibiotics in the preceding 3 months). Cross-sectional data as well as data from medicaid and drug databases attest to overprescribing of antibiotics for respiratory tract infections. Physician surveys and focus groups blame this on parental pressure for antibiotic prescriptions. However, parents in focus groups and surveys deny they pressure their physicians and indicate their main purpose for office visits is to obtain a diagnosis and to seek reassurance that their children are not seriously ill. Evidence-based guidelines suggest treatment strategies that would reduce antibiotic prescribing. CONCLUSIONS: The few antibiotics that can be used with resistant organisms are expensive and are increasingly being needed. To control the rise of antibiotic resistance, it is important to limit antibiotic overprescribing. PMID:9789668

  15. Evolution of acquired resistance to anti-cancer therapy

    PubMed Central

    Foo, Jasmine; Michor, Franziska

    2014-01-01

    Acquired drug resistance is a major limitation for the successful treatment of cancer. Resistance can emerge due to a variety of reasons including host environmental factors as well as genetic or epigenetic alterations in the cancer cells. Evolutionary theory has contributed to the understanding of the dynamics of resistance mutations in a cancer cell population, the risk of resistance pre-existing before the initiation of therapy, the composition of drug cocktails necessary to prevent the emergence of resistance, and optimum drug administration schedules for patient populations at risk of evolving acquired resistance. Here we review recent advances towards elucidating the evolutionary dynamics of acquired drug resistance and outline how evolutionary thinking can contribute to outstanding questions in the field. PMID:24681298

  16. Primary care clinicians' perceptions of antibiotic resistance: a multi-country qualitative interview study.

    PubMed

    Wood, Fiona; Phillips, Carys; Brookes-Howell, Lucy; Hood, Kerenza; Verheij, Theo; Coenen, Samuel; Little, Paul; Melbye, Hasse; Godycki-Cwirko, Maciek; Jakobsen, Kristin; Worby, Patricia; Goossens, Herman; Butler, Christopher C

    2013-01-01

    To explore and compare primary care clinicians' perceptions of antibiotic resistance in relation to the management of community-acquired lower respiratory tract infection (LRTI) in contrasting European settings. Qualitative interview study with 80 primary care clinicians in nine European countries. Data were subjected to a five-stage analytical framework approach (familiarization; developing a thematic framework from the interview questions and the themes emerging from the data; indexing; charting; and mapping to search for interpretations in the data). Preliminary analysis reports were sent to all network facilitators for validation. Most clinicians stated that antibiotic resistance was not a problem in their practice. Some recommended enhanced feedback about local resistance rates. Northern European respondents generally favoured using the narrowest-spectrum agent, motivated by containing resistance, whereas southern/eastern European respondents were more motivated by maximizing the potential of a rapid treatment effect and so justified empirical use of broad-spectrum antibiotics. Antibiotic treatment failure was ascribed largely to viral aetiology rather than resistant bacteria. Clinicians generally agreed that resistance will become more serious without enhanced antibiotic stewardship or new drug discovery. If current rates of antibiotic resistance are likely to result in important treatment failures, then provision of local resistance data is likely to enhance clinicians' sense of importance of the issue. Interventions to enhance the quality of antibiotic prescribing in primary care should address perceptions, particularly in the south and east of Europe, that possible advantages to patients from antibiotic treatment in general, and from newer broad-spectrum compared with narrow-spectrum agents, outweigh disadvantages to patients and society from associated effects on antibiotic resistance.

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

    PubMed

    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.

  18. Community-acquired methicillin-resistant Staphylococcus aureus: an ongoing challenge for WOC nursing.

    PubMed

    Price, Molly

    2010-01-01

    Infection is a common complication of chronic wounds that delays healing. Community-acquired methicillin-resistant Staphylococcus aureus has emerged as a common pathogen and major impediment to healing affected chronic wounds. Community-acquired methicillin-resistant S aureus is virulent, highly communicable, and difficult to eradicate. Treatment options include incision and drainage, debridement, and systemic antimicrobials. Early aggressive wound management and appropriate antibiotic therapy are considered essential to successful treatment. Facility-specific protocols should be developed to minimize the spread of this organism to the general population, with particular attention focused on protecting patients burdened with chronic wounds. This article reviews current knowledge of community-acquired methicillin-resistant S aureus, focusing on its impact on persons with chronic wounds.

  19. Antibiotic Resistance Is Prevalent in an Isolated Cave Microbiome

    PubMed Central

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

    2012-01-01

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

  20. [Antibiotic resistance and siderophore production in enterococci].

    PubMed

    Lisiecki, Paweł

    2014-01-01

    Enterococci belong to the normal bacterial flora of the gastrointensinal tract of humans. Enterococci are regarded as harmless commensal, and are even believed to have probiotic characteristics. However, they can cause variety of infections, including endocarditis, bloodstream infections and urinary tract infections. During the past several decades, enterococci, and particularly Enterococcus faecalis and E. faecium, have been identified as an important cause of nosocomial infections. Enterococci are intrinsically resistant to a broad range of antimicrobials. Infection caused by resistant strains are difficult to treat. Iron is an essential element for bacteria, but is not easily available in host organisms. Enterococci are iron dependent bacteria. Competition for iron between the host and bacteria is an important factor determining the course of bacterial infections. A common strategy among bacteria living in iron-limited environments is the secretion of siderophores, which can bind poorly soluble iron and make it available to cells via active transport mechanisms. The aim of the presented study was to evaluate the correlation between antibiotic resistance and siderophore production of bacteria of the genus Enterococcus. The study included 55 bacterial strains from genus Enterococcus belonging to two species--Enterococcus faecalis and E. faecium. Antimicrobial susceptibility tests were carried out using disc diffusion methods with guidelines of European Committee on Antimicrobial Susceptibility Testing (EUCAST). Total siderophore activity in the culture supernatants was measured using chrome azurol S. Hydroxamate siderophores were assayed using a chemical-specific assay. Antibacterial susceptibility pattern reveals that E. faecium is more resistant than E. faecalis. A significant correlation was found between resistance to fluoroquinolnes and siderophores production. Ciprofloxacin- and norfloxacin-resistant enterococal strains produced siderophores in large

  1. Functional metagenomics for the investigation of antibiotic resistance.

    PubMed

    Mullany, Peter

    2014-04-01

    Antibiotic resistance is a major threat to human health and well-being. To effectively combat this problem we need to understand the range of different resistance genes that allow bacteria to resist antibiotics. To do this the whole microbiota needs to be investigated. As most bacteria cannot be cultivated in the laboratory, the reservoir of antibiotic resistance genes in the non-cultivatable majority remains relatively unexplored. Currently the only way to study antibiotic resistance in these organisms is to use metagenomic approaches. Furthermore, the only method that does not require any prior knowledge about the resistance genes is functional metagenomics, which involves expressing genes from metagenomic clones in surrogate hosts. In this review the methods and limitations of functional metagenomics to isolate new antibiotic resistance genes and the mobile genetic elements that mediate their spread are explored.

  2. Functional metagenomics for the investigation of antibiotic resistance

    PubMed Central

    Mullany, Peter

    2014-01-01

    Antibiotic resistance is a major threat to human health and well-being. To effectively combat this problem we need to understand the range of different resistance genes that allow bacteria to resist antibiotics. To do this the whole microbiota needs to be investigated. As most bacteria cannot be cultivated in the laboratory, the reservoir of antibiotic resistance genes in the non-cultivatable majority remains relatively unexplored. Currently the only way to study antibiotic resistance in these organisms is to use metagenomic approaches. Furthermore, the only method that does not require any prior knowledge about the resistance genes is functional metagenomics, which involves expressing genes from metagenomic clones in surrogate hosts. In this review the methods and limitations of functional metagenomics to isolate new antibiotic resistance genes and the mobile genetic elements that mediate their spread are explored. PMID:24556726

  3. Can landscape ecology untangle the complexity of antibiotic resistance?

    PubMed

    Singer, Randall S; Ward, Michael P; Maldonado, George

    2006-12-01

    Bacterial resistance to antibiotics continues to pose a serious threat to human and animal health. Given the considerable spatial and temporal heterogeneity in the distribution of resistance and the factors that affect its evolution, dissemination and persistence, we argue that antibiotic resistance must be viewed as an ecological problem. A fundamental difficulty in assessing the causal relationship between antibiotic use and resistance is the confounding influence of geography: the co-localization of resistant bacterial species with antibiotic use does not necessarily imply causation and could represent the presence of environmental conditions and factors that have independently contributed to the occurrence of resistance. Here, we show how landscape ecology, which links the biotic and abiotic factors of an ecosystem, might help to untangle the complexity of antibiotic resistance and improve the interpretation of ecological studies.

  4. Evidence of Increased Antibiotic Resistance in Phylogenetically-Diverse Aeromonas Isolates from Semi-Intensive Fish Ponds Treated with Antibiotics

    PubMed Central

    Patil, Hemant J.; Benet-Perelberg, Ayana; Naor, Alon; Smirnov, Margarita; Ofek, Tamir; Nasser, Ahmed; Minz, Dror; Cytryn, Eddie

    2016-01-01

    The genus Aeromonas is ubiquitous in aquatic environments encompassing a broad range of fish and human pathogens. Aeromonas strains are known for their enhanced capacity to acquire and exchange antibiotic resistance genes and therefore, are frequently targeted as indicator bacteria for monitoring antimicrobial resistance in aquatic environments. This study evaluated temporal trends in Aeromonas diversity and antibiotic resistance in two adjacent semi-intensive aquaculture facilities to ascertain the effects of antibiotic treatment on antimicrobial resistance. In the first facility, sulfadiazine-trimethoprim was added prophylactically to fingerling stocks and water column-associated Aeromonas were monitored periodically over an 11-month fish fattening cycle to assess temporal dynamics in taxonomy and antibiotic resistance. In the second facility, Aeromonas were isolated from fish skin ulcers sampled over a 3-year period and from pond water samples to assess associations between pathogenic strains to those in the water column. A total of 1200 Aeromonas isolates were initially screened for sulfadiazine resistance and further screened against five additional antimicrobials. In both facilities, strong correlations were observed between sulfadiazine resistance and trimethoprim and tetracycline resistances, whereas correlations between sulfadiazine resistance and ceftriaxone, gentamicin, and chloramphenicol resistances were low. Multidrug resistant strains as well as sul1, tetA, and intI1 gene-harboring strains were significantly higher in profiles sampled during the fish cycle than those isolated prior to stocking and these genes were extremely abundant in the pathogenic strains. Five phylogenetically distinct Aeromonas clusters were identified using partial rpoD gene sequence analysis. Interestingly, prior to fingerling stocking the diversity of water column strains was high, and representatives from all five clusters were identified, including an A. salmonicida cluster

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

    PubMed

    Niederman, M S

    2001-09-01

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

  6. Antibiotic-non-antibiotic combinations for combating extremely drug-resistant Gram-negative 'superbugs'.

    PubMed

    Schneider, Elena K; Reyes-Ortega, Felisa; Velkov, Tony; Li, Jian

    2017-02-28

    The emergence of antimicrobial resistance of Gram-negative pathogens has become a worldwide crisis. The status quo for combating resistance is to employ synergistic combinations of antibiotics. Faced with this fast-approaching post-antibiotic era, it is critical that we devise strategies to prolong and maximize the clinical efficacy of existing antibiotics. Unfortunately, reports of extremely drug-resistant (XDR) Gram-negative pathogens have become more common. Combining antibiotics such as polymyxin B or the broad-spectrum tetracycline and minocycline with various FDA-approved non-antibiotic drugs have emerged as a novel combination strategy against otherwise untreatable XDR pathogens. This review surveys the available literature on the potential benefits of employing antibiotic-non-antibiotic drug combination therapy. The apex of this review highlights the clinical utility of this novel therapeutic strategy for combating infections caused by 'superbugs'.

  7. Serotypes and antibiotic susceptibility of Streptococcus pneumoniae isolated from hospitalized patients with community-acquired pneumonia in Italy.

    PubMed

    Di Pasquale, Marta; Aliberti, Stefano; Azzari, Chara; Moriondo, Maria; Nieddu, Francesco; Blasi, Francesco; Mantero, Marco

    2017-01-01

    Pneumonia remain an important public health problem. The primary objective was to determine the proportion of community-acquired pneumonia that is attributable to Streptococcus pneumoniae infection; secondary objectives were the description of community-acquired pneumonia attributable to Streptococcus pneumoniae according to socio-demographic and clinical variables, the clinical evolution of community-acquired pneumonia and the description of the serotype distribution of vaccine-preventable disease and antibiotic resistance rate of pneumococcal infections. An observational, prospective study was conducted on consecutive patients coming from the community, who were hospitalized with pneumonia. Data on admission, at discharge and 30 days after discharge were collected. Logistic regression models were used to evaluate the risk factors independently associated with pneumococcal pneumonia. Among the 193 patients enrolled in the study, the etiology of community-acquired pneumonia was identified in 60 patients (33%) and 35 (18%) of evaluable patients had community-acquired pneumonia due to Streptococcus pneumoniae. Of all clinical characteristics, if no previous antibiotic treatment was performed, there was a 13-fold higher risk of presenting community-acquired pneumonia due to Streptococcus pneumoniae (odds ratio, 12.9; 95% confidence interval, 1.42-117.9). Moreover, the most frequent isolated serotypes were 35F, 3 and 24 (29%, 23% and 16%, respectively). The most frequent serotypes in pneumococcal community-acquired pneumonia are 35F, 3, 24, 6 and 7A, and thus almost 50% of Streptococcus pneumoniae strains could be covered by pneumococcal conjugate vaccine 13 in adult patients with risk factors for pneumococcal infections.

  8. Bacterial Enzymes and Antibiotic Resistance- Oral Presentation

    SciTech Connect

    Maltz, Lauren

    2015-08-25

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

  9. Genomic Insights into Intrinsic and Acquired Drug Resistance Mechanisms in Achromobacter xylosoxidans

    PubMed Central

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

    2014-01-01

    Achromobacter xylosoxidans is an opportunistic pathogen known to be resistant to a wide range of antibiotics; however, the knowledge about the drug resistance mechanisms is limited. We used a high-throughput sequencing approach to sequence the genomes of the A. xylosoxidans type strain ATCC 27061 and a clinical isolate, A. xylosoxidans X02736, and then we used different bioinformatics tools to analyze the drug resistance genes in these bacteria. We obtained the complete genome sequence for A. xylosoxidans ATCC 27061 and the draft sequence for X02736. We predicted a total of 50 drug resistance-associated genes in the type strain, including 5 genes for β-lactamases and 17 genes for efflux pump systems; these genes are also conserved among other A. xylosoxidans genomes. In the clinical isolate, except for the conserved resistance genes, we also identified several acquired resistance genes carried by a new transposon embedded in a novel integrative and conjugative element. Our study provides new insights into the intrinsic and acquired drug resistance mechanisms in A. xylosoxidans, which will be helpful for better understanding the physiology of A. xylosoxidans and the evolution of antibiotic resistance in this bacterium. PMID:25487802

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

    PubMed

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

    2015-02-01

    Achromobacter xylosoxidans is an opportunistic pathogen known to be resistant to a wide range of antibiotics; however, the knowledge about the drug resistance mechanisms is limited. We used a high-throughput sequencing approach to sequence the genomes of the A. xylosoxidans type strain ATCC 27061 and a clinical isolate, A. xylosoxidans X02736, and then we used different bioinformatics tools to analyze the drug resistance genes in these bacteria. We obtained the complete genome sequence for A. xylosoxidans ATCC 27061 and the draft sequence for X02736. We predicted a total of 50 drug resistance-associated genes in the type strain, including 5 genes for β-lactamases and 17 genes for efflux pump systems; these genes are also conserved among other A. xylosoxidans genomes. In the clinical isolate, except for the conserved resistance genes, we also identified several acquired resistance genes carried by a new transposon embedded in a novel integrative and conjugative element. Our study provides new insights into the intrinsic and acquired drug resistance mechanisms in A. xylosoxidans, which will be helpful for better understanding the physiology of A. xylosoxidans and the evolution of antibiotic resistance in this bacterium. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. The relationship between pneumococcal serotypes and antibiotic resistance.

    PubMed

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

    2012-04-05

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

  12. The role of healthcare strategies in controlling antibiotic resistance.

    PubMed

    Aziz, Ann-Marie

    In an interview in March 2013, the Chief Medical Officer described antibiotic resistance as a 'ticking time bomb' and ranked it along with terrorism on a list of threats to the nation. Her report Infections and the Rise of Antimicrobial Resistance (Department of Health, 2011) highlighted that, while a new infectious disease has been discovered nearly every year over the past three decades, there have been very few new antibiotics developed, leaving our armoury nearly empty. Antibiotic resistance is a universal problem that needs to be tackled by a wide variety of strategies and players. Our approach to tackling resistance to antibiotic agents must therefore also be dynamic. As well as reducing environmental use, we also need to lower antibiotic use in the healthcare setting. Healthcare workers have a huge role to play in combating antibiotic resistance. This article focuses on several issues related to antibiotic resistance, including antibiotic modes of action and the properties that confer resistance on bacteria. It includes information on antibiotic usage and describes current healthcare strategies we can adopt to help reduce the development of resistance.

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

    PubMed

    Brooks, J P; McLaughlin, M R

    2009-01-01

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

  14. Diverse antibiotic resistance genes in dairy cow manure.

    PubMed

    Wichmann, Fabienne; Udikovic-Kolic, Nikolina; Andrew, Sheila; Handelsman, Jo

    2014-04-22

    Application of manure from antibiotic-treated animals to crops facilitates the dissemination of antibiotic resistance determinants into the environment. However, our knowledge of the identity, diversity, and patterns of distribution of these antibiotic resistance determinants remains limited. We used a new combination of methods to examine the resistome of dairy cow manure, a common soil amendment. Metagenomic libraries constructed with DNA extracted from manure were screened for resistance to beta-lactams, phenicols, aminoglycosides, and tetracyclines. Functional screening of fosmid and small-insert libraries identified 80 different antibiotic resistance genes whose deduced protein sequences were on average 50 to 60% identical to sequences deposited in GenBank. The resistance genes were frequently found in clusters and originated from a taxonomically diverse set of species, suggesting that some microorganisms in manure harbor multiple resistance genes. Furthermore, amid the great genetic diversity in manure, we discovered a novel clade of chloramphenicol acetyltransferases. Our study combined functional metagenomics with third-generation PacBio sequencing to significantly extend the roster of functional antibiotic resistance genes found in animal gut bacteria, providing a particularly broad resource for understanding the origins and dispersal of antibiotic resistance genes in agriculture and clinical settings. IMPORTANCE The increasing prevalence of antibiotic resistance among bacteria is one of the most intractable challenges in 21st-century public health. The origins of resistance are complex, and a better understanding of the impacts of antibiotics used on farms would produce a more robust platform for public policy. Microbiomes of farm animals are reservoirs of antibiotic resistance genes, which may affect distribution of antibiotic resistance genes in human pathogens. Previous studies have focused on antibiotic resistance genes in manures of animals subjected

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

    PubMed

    Decimo, Marilù; Silvetti, Tiziana; Brasca, Milena

    2016-04-01

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

  16. Reversion of antibiotic resistance in Mycobacterium tuberculosis by spiroisoxazoline SMARt-420.

    PubMed

    Blondiaux, Nicolas; Moune, Martin; Desroses, Matthieu; Frita, Rosangela; Flipo, Marion; Mathys, Vanessa; Soetaert, Karine; Kiass, Mehdi; Delorme, Vincent; Djaout, Kamel; Trebosc, Vincent; Kemmer, Christian; Wintjens, René; Wohlkönig, Alexandre; Antoine, Rudy; Huot, Ludovic; Hot, David; Coscolla, Mireia; Feldmann, Julia; Gagneux, Sebastien; Locht, Camille; Brodin, Priscille; Gitzinger, Marc; Déprez, Benoit; Willand, Nicolas; Baulard, Alain R

    2017-03-17

    Antibiotic resistance is one of the biggest threats to human health globally. Alarmingly, multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis have now spread worldwide. Some key antituberculosis antibiotics are prodrugs, for which resistance mechanisms are mainly driven by mutations in the bacterial enzymatic pathway required for their bioactivation. We have developed drug-like molecules that activate a cryptic alternative bioactivation pathway of ethionamide in M. tuberculosis, circumventing the classic activation pathway in which resistance mutations have now been observed. The first-of-its-kind molecule, named SMARt-420 (Small Molecule Aborting Resistance), not only fully reverses ethionamide-acquired resistance and clears ethionamide-resistant infection in mice, it also increases the basal sensitivity of bacteria to ethionamide.

  17. Chlamydial Antibiotic Resistance and Treatment Failure in Veterinary and Human Medicine.

    PubMed

    Borel, Nicole; Leonard, Cory; Slade, Jessica; Schoborg, Robert V

    The Chlamydiaceae are widespread pathogens of both humans and animals. Chlamydia trachomatis infection causes blinding trachoma and reproductive complications in humans. Chlamydia pneumoniae causes human respiratory tract infections and atypical pneumonia. Chlamydia suis infection is associated with conjunctivitis, diarrhea, and failure to gain weight in domestic swine. Chlamydial infections in humans and domesticated animals are generally controlled by antibiotic treatment-particularly macrolides (usually azithromycin) and tetracyclines (tetracycline and doxycycline). Tetracycline-containing feed has also been used to limit infections and promote growth in livestock populations, although its use has decreased because of growing concerns about antimicrobial resistance development. Because Sandoz and Rockey published an elegant review of chlamydial anti-microbial resistance in 2010, we will review the following: (i) antibiotic resistance in C. suis, (ii) recent evidence for acquired resistance in human chlamydial infections, and (iii) recent non-genetic mechanisms of antibiotic resistance that may contribute to treatment failure.

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

    PubMed

    Shepherd, Jennifer; Ibba, Michael

    2013-09-17

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

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    Winkworth, Cynthia L

    2013-06-01

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

  2. Resistance to antibiotics in the normal flora of animals.

    PubMed

    Sørum, H; Sunde, M

    2001-01-01

    The normal bacterial flora contains antibiotic resistance genes to various degrees, even in individuals with no history of exposure to commercially prepared antibiotics. Several factors seem to increase the number of antibiotic-resistant bacteria in feces. One important factor is the exposure of the intestinal flora to antibacterial drugs. Antibiotics used as feed additives seem to play an important role in the development of antibiotic resistance in normal flora bacteria. The use of avoparcin as a feed additive has demonstrated that an antibiotic considered "safe" is responsible for increased levels of antibiotic resistance in the normal flora enterococci of animals fed with avoparcin and possibly in humans consuming products from these animals. However, other factors like stress from temperature, crowding, and management also seem to contribute to the occurrence of antibiotic resistance in normal flora bacteria. The normal flora of animals has been studied with respect to the development of antibiotic resistance over four decades, but there are few studies with the intestinal flora as the main focus. The results of earlier studies are valuable when focused against the recent understanding of mobile genetics responsible for bacterial antibiotic resistance. New studies should be undertaken to assess whether the development of antibiotic resistance in the normal flora is directly linked to the dramatic increase in antibiotic resistance of bacterial pathogens. Bacteria of the normal flora, often disregarded scientifically, should be studied with the intention of using them as active protection against infectious diseases and thereby contributing to the overall reduction of use of antibioties in both animals and humans.

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

    PubMed

    Heß, Stefanie; Gallert, Claudia

    2015-12-01

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

  4. Resistance diagnosis and the changing economics of antibiotic discovery.

    PubMed

    McAdams, David

    2017-01-01

    Point-of-care diagnostics that can determine an infection's antibiotic sensitivity increase the profitability of new antibiotics that enjoy patent protection, even when such diagnostics reduce the quantity of antibiotics sold. Advances in the science and technology underpinning rapid resistance diagnostics can therefore be expected to spur efforts to discover and develop new antibiotics, especially those with a narrow spectrum of activity that would otherwise fail to find a market. © 2017 New York Academy of Sciences.

  5. Characterization of In Vivo acquired resistance of Mycoplasma hyopneumoniae to macrolides and lincosamides.

    PubMed

    Stakenborg, Tim; Vicca, Jo; Butaye, Patrick; Maes, Dominiek; Minion, F Chris; Peeters, Johan; De Kruif, Aart; Haesebrouck, Freddy

    2005-01-01

    Macrolides and related antibiotics are used to control mycoplasma infections in the pig industry worldwide. Some porcine mycoplasmas, however, survive these treatments by acquiring resistance. The mechanism of acquired resistance to macrolides and lincosamides was studied in more detail for Mycoplasma hyopneumoniae by comparing both the phenotype and genotype of a resistant field isolate to five susceptible isolates. The MICs were significantly higher for the resistant strain for all antibiotics tested. The MICs for the 16-membered macrolide tylosin ranged from 8 to 16 microg for the resistant strain and from 0.03 to 0.125 microg/ml for the five susceptible strains. The MICs for the 15-membered macrolides and lincosamides were higher than 64 microg/ml for the resistant strain while only 0.06 to 0.5 microg/ml for the susceptible strains. Mycoplasma hyopneumoniae strains are intrinsically resistant to the 14-membered macrolides due to a G 2057 A transition (E. coli numbering) in their 23S rDNA. Therefore, high MICs were observed for all strains, although the MICs for the resistant strain were clearly increased. An additional, acquired A 2058 G point mutation was found in the 23S rRNA gene of the resistant strain. No differences linked to resistance were found in the ribosomal proteins L4 and L22. The present study showed that 23S rRNA mutations resulting in resistance to macrolides and lincosamides as described in other Mycoplasma spp. also occur under field conditions in M. hyopneumoniae.

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

    PubMed

    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.

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

    PubMed

    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.

  8. Antibiotic Resistance of Diverse Bacteria from Aquaculture in Borneo

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

    Baquero, Fernando

    2014-01-01

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

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

    PubMed

    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.

  11. [Duration of treatment and oral administrad on of antibiotics in community acquired pneumonia].

    PubMed

    Bernal-Vargas, Mónica A; Cortés, Jorge A

    2016-04-01

    Community acquired pneumonia (CAP) is an important cause of morbidity and mortality around the world, with high treatment costs due to hospitalization and complications (adverse events due to medications, antibiotic resistance, healthcare associated infections, etc.). It has been proposed administration of short courses and early switch of intravenous administration to oral therapy to avoid costs and complications. There are recommendations about these topics in national and intemational guidelines, based on clinical trials which do not demónstrate diffe-rences in mortality and complications when there is an early change from intravenous administration to the oral route. There are no statistically significant differences in safety and resolution of the disease when short and long treatment schemes were compared. In this review we present the most important guidelines and clinical studies, taking into account the pharmacological differences between different medications. It is considered that early switch from intravenous to oral administration route and use of short cycles in CAP is safe and brings benefits to patients and institutions.

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

    PubMed

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

    2015-01-01

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

  13. Antibiotic Resistance: A Primer and Call to Action

    PubMed Central

    Smith, Rachel A.; M’ikanatha, Nkuchia M.; Read, Andrew F.

    2014-01-01

    During the past century, discoveries of microorganisms as causes of infections and antibiotics as effective therapeutic agents have contributed to significant gains in public health in many parts of the world. Health agencies worldwide are galvanizing attention toward antibiotic resistance, which is a major threat to public health (Centers for Disease Control and Prevention [CDC], 2013; World Health Organization [WHO], 2014). Some life scientists believe that we are approaching the post-antibiotic age (Davies & Davies, 2010). The growing threat of antimicrobial resistance is fueled by complex factors with biological, behavioral and societal aspects. This primer provides an overview of antibiotic resistance and its growing burden on public health, the biological and behavioral mechanisms that increase antibiotic resistance, and examples of where health communication scholars can contribute to efforts to make our current antibiotic drugs last as long as possible. In addition, we identify compelling challenges for current communication theories and practices. PMID:25121990

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

    PubMed

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

    2015-05-01

    The effect of global antibiotic use practices in livestock on the emergence of antibiotic resistant pathogens is poorly understood. There is a paucity of data among African nations, which suffer from high rates of antibiotic resistant infections among the human population. Escherichia (29.5%), Staphylococcus (15.8%), and Proteus (15.79%) were the dominant bacterial genera isolated from chicken litter from four different farms in Zaria, Nigeria, all of which contain human pathogenic members. Escherichia isolates were uniformly susceptible to augmentin and cefuroxime, but resistant to sulfamethoxazole (54.5%), ampicillin (22.7%), ciprofloxacin (18.2%), cephalothin (13.6%) and gentamicin (13.6%). Staphylococcus isolates were susceptible to ciprofloxacin, gentamicin, and sulfamethoxazole, but resistant to tetracycline (86.7%), erythromycin (80%), clindamycin (60%), and penicillin (33.3%). Many of the isolates (65.4%) were resistant to multiple antibiotics, with a multiple antibiotic resistance index (MARI) ≥ 0.2. sul1, sul2, and vanA were the most commonly detected antibiotic resistance genes among the isolates. Chicken litter associated with antibiotic use and farming practices in Nigeria could be a public health concern given that the antibiotic resistant patterns among genera containing pathogens indicate the potential for antibiotic treatment failure. However, the MARI values were generally lower than reported for Escherichia coli from intensive poultry operations in industrial nations. © 2015 Poultry Science Association Inc.

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

    PubMed

    Carlet, Jean

    2015-06-15

    Antibiotic resistance is increasing worldwide and has become a very important threat to public health. The overconsumption of antibiotics is the most important cause of this problem. We created a World Alliance Against Antibiotic Resistance (WAAAR), which now includes 720 people from 55 different countries and is supported by 145 medical societies or various groups. In June 2014, WAAAR launched a declaration against antibiotic resistance. This article describes the process and the content of this declaration. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Intrinsic antibiotic resistance: mechanisms, origins, challenges and solutions.

    PubMed

    Cox, Georgina; Wright, Gerard D

    2013-08-01

    The intrinsic antibiotic resistome is a naturally occurring phenomenon that predates antibiotic chemotherapy and is present in all bacterial species. In addition to the intrinsic resistance mediated by the bacterial outer membrane and active efflux, studies have shown that a surprising number of additional genes and genetic loci also contribute to this phenotype. Antibiotic resistance is rife in both the clinic and the environment; novel therapeutic strategies need to be developed in order to prevent a major global clinical threat. The possibility of inhibiting elements comprising the intrinsic resistome in bacterial pathogens offers the promise for repurposing existing antibiotics against intrinsically resistant bacteria. Copyright © 2013 Elsevier GmbH. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

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

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

    PubMed

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

    2016-06-01

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

  19. Antibiotics for treating community-acquired pneumonia in people with sickle cell disease.

    PubMed

    Martí-Carvajal, Arturo J; Conterno, Lucieni O

    2016-11-14

    As a consequence of their condition, people with sickle cell disease are at high risk of developing an acute infection of the pulmonary parenchyma called community-acquired pneumonia. Many different bacteria can cause this infection and antibiotic treatment is generally needed to resolve it. There is no standardized approach to antibiotic therapy and treatment is likely to vary from country to country. Thus, there is a need to identify the efficacy and safety of different antibiotic treatment approaches for people with sickle cell disease suffering from community-acquired pneumonia. This is an update of a previously published Cochrane Review. To determine the efficacy and safety of the antibiotic treatment approaches (monotherapy or combined) for people with sickle cell disease suffering from community-acquired pneumonia. We searched The Group's Haemoglobinopathies Trials Register (01 September 2016), which comprises references identified from comprehensive electronic database searches and handsearching of relevant journals and abstract books of conference proceedings. We also searched LILACS (1982 to 01 September 2016), African Index Medicus (1982 to 20 October 2016) and WHO ICT Registry (20 October 2016). We searched for published or unpublished randomized controlled trials. We intended to summarise data by standard Cochrane methodologies, but no eligible randomized controlled trials were identified. We were unable to find any randomized controlled trials on antibiotic treatment approaches for community-acquired pneumonia in people with sickle cell disease. The updated review was unable to identify randomized controlled trials on efficacy and safety of the antibiotic treatment approaches for people with sickle cell disease suffering from community-acquired pneumonia. Randomized controlled trials are needed to establish the optimum antibiotic treatment for this condition. The trials regarding this issue should be structured and reported according to the CONSORT

  20. Within-host whole genome analysis of an antibiotic resistant Pseudomonas aeruginosa strain sub-type in cystic fibrosis

    PubMed Central

    Wee, Bryan A.; Ramsay, Kay A.; Kidd, Timothy J.; Ben Zakour, Nouri L.; Whiley, David M.; Beatson, Scott A.; Bell, Scott C.

    2017-01-01

    A Pseudomonas aeruginosa AUST-02 strain sub-type (M3L7) has been identified in Australia, infects the lungs of some people with cystic fibrosis and is associated with antibiotic resistance. Multiple clonal lineages may emerge during treatment with mutations in chromosomally encoded antibiotic resistance genes commonly observed. Here we describe the within-host diversity and antibiotic resistance of M3L7 during and after antibiotic treatment of an acute pulmonary exacerbation using whole genome sequencing and show both variation and shared mutations in important genes. Eleven isolates from an M3L7 population (n = 134) isolated over 3 months from an individual with cystic fibrosis underwent whole genome sequencing. A phylogeny based on core genome SNPs identified three distinct phylogenetic groups comprising two groups with higher rates of mutation (hypermutators) and one non-hypermutator group. Genomes were screened for acquired antibiotic resistance genes with the result suggesting that M3L7 resistance is principally driven by chromosomal mutations as no acquired mechanisms were detected. Small genetic variations, shared by all 11 isolates, were found in 49 genes associated with antibiotic resistance including frame-shift mutations (mexA, mexT), premature stop codons (oprD, mexB) and mutations in quinolone-resistance determining regions (gyrA, parE). However, whole genome sequencing also revealed mutations in 21 genes that were acquired following divergence of groups, which may also impact the activity of antibiotics and multi-drug efflux pumps. Comparison of mutations with minimum inhibitory concentrations of anti-pseudomonal antibiotics could not easily explain all resistance profiles observed. These data further demonstrate the complexity of chronic and antibiotic resistant P. aeruginosa infection where a multitude of co-existing genotypically diverse sub-lineages might co-exist during and after intravenous antibiotic treatment. PMID:28273168

  1. Within-host whole genome analysis of an antibiotic resistant Pseudomonas aeruginosa strain sub-type in cystic fibrosis.

    PubMed

    Sherrard, Laura J; Tai, Anna S; Wee, Bryan A; Ramsay, Kay A; Kidd, Timothy J; Ben Zakour, Nouri L; Whiley, David M; Beatson, Scott A; Bell, Scott C

    2017-01-01

    A Pseudomonas aeruginosa AUST-02 strain sub-type (M3L7) has been identified in Australia, infects the lungs of some people with cystic fibrosis and is associated with antibiotic resistance. Multiple clonal lineages may emerge during treatment with mutations in chromosomally encoded antibiotic resistance genes commonly observed. Here we describe the within-host diversity and antibiotic resistance of M3L7 during and after antibiotic treatment of an acute pulmonary exacerbation using whole genome sequencing and show both variation and shared mutations in important genes. Eleven isolates from an M3L7 population (n = 134) isolated over 3 months from an individual with cystic fibrosis underwent whole genome sequencing. A phylogeny based on core genome SNPs identified three distinct phylogenetic groups comprising two groups with higher rates of mutation (hypermutators) and one non-hypermutator group. Genomes were screened for acquired antibiotic resistance genes with the result suggesting that M3L7 resistance is principally driven by chromosomal mutations as no acquired mechanisms were detected. Small genetic variations, shared by all 11 isolates, were found in 49 genes associated with antibiotic resistance including frame-shift mutations (mexA, mexT), premature stop codons (oprD, mexB) and mutations in quinolone-resistance determining regions (gyrA, parE). However, whole genome sequencing also revealed mutations in 21 genes that were acquired following divergence of groups, which may also impact the activity of antibiotics and multi-drug efflux pumps. Comparison of mutations with minimum inhibitory concentrations of anti-pseudomonal antibiotics could not easily explain all resistance profiles observed. These data further demonstrate the complexity of chronic and antibiotic resistant P. aeruginosa infection where a multitude of co-existing genotypically diverse sub-lineages might co-exist during and after intravenous antibiotic treatment.

  2. Profile of antibiotic consumption, sensitivity and resistance in an urban area of Andhra Pradesh, India.

    PubMed

    Peripi, Sunita Bhargavi; Thadepalli, Venu Gopala Rao; Khagga, Mukkanti; Tripuraribhatla, Prasanna Krishna; Bharadwaj, Dinesh Kumar

    2012-04-01

    Antibiotics are an important category of drugs in which indiscriminate use can affect the susceptibility patterns among infectious organisms, resulting in antibiotic resistance. Data on antibiotic usage and susceptibility patterns were collected from public and private health centres in Vijayawada, Andhra Pradesh, India, through the use of questionnaires. The data collected were then coded, tabulated, computed and evaluated using statistical analysis. The consumption profile of the different categories of drugs used in public and private hospitals was as follows: nutrition and metabolism products 19.0%; gastrointestinal disorder-related drugs 18.5%; antibiotics 16.8%; anti-pyretics and anti-analgesics 20.6%. These drugs were found to be in high demand. Among the antibiotics, aminoglycosides (amikacin), quinolones (ofloxacin, ciprofloxacin), tetracyclines (doxycycline), penicillin (ampicillin) and sulphonamides (co-trimoxazole) were the most commonly prescribed drugs for antibiotic therapy. 46% of the culture laboratory reports were positive with the following organism profile: Escherichia coli (36%), Klebsiella pneumoniae (16%), Staphylococcus aureus (29%), Enterococcus faecalis (9%) and Pseudomonas aeruginosa (10%). In terms of the sensitivity profile of antibacterials, amikacin (66.9%) was the only antibiotic showing sensitivity patterns, while the majority of antibiotics, such as cotrimoxazole, nalidixic acid, amoxicillin, gentamycin and norfloxacin, had acquired a resistance rate of 55.1%-80.6%. The results of this study suggest that indiscriminate prescription and consumption of new broad-spectrum antibiotics against sensitive organisms results in the development of antimicrobial resistance. Therefore, there is an urgent need to curb the excessive use of antibiotics in local hospitals in order to control the trend of increasing antimicrobial resistance to antibiotics.

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

    PubMed Central

    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

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

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

    2016-05-09

    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.

  7. Streptococcus pneumoniae Serotypes and Antibiotic Susceptibility Patterns in Middle Ear Fluid Isolates During Acute Otitis Media and Nasopharyngeal Isolates During Community-acquired Alveolar Pneumonia in Central Romania.

    PubMed

    Lixandru, Raluca-Ileana; Falup-Pecurariu, Cristian; Bleotu, Laura; Mercas, Alice; Leibovitz, Eugene; Dagan, Ron; Greenberg, David; Falup-Pecurariu, Oana

    2017-02-01

    Streptococcus pneumoniae is a common cause of community-acquired alveolar pneumonia (CAAP) and acute otitis media (AOM) in children. Romania has high rates of S. pneumoniae antibiotic resistance. The pneumococcal conjugated vaccines (PCVs) are not being used routinely in this country. The aims of the study were as follows: 1) to compare pneumococcal antibiotic resistance patterns in AOM and CAAP in children from central Romania and 2) to compare differences in the distribution of pneumococcal serotypes isolated from the middle ear fluid (MEF) of children with AOM and from the nasopharynx (NP) of children with CAAP. Children younger than 5 years old with AOM or with radiologically confirmed CAAP were prospectively enrolled. Samples from MEF and NP were evaluated for antibiotic susceptibility and serotyping. Eighty-eight children with CAAP and 68 with AOM were enrolled. Of the MEF and CAAP isolates, 64 (94.1%) and 79 (89.7%) were penicillin nonsusceptible, respectively. The pneumococcal serotypes distribution in AOM was similar to those in CAAP except for serotype 19F, which was more common in AOM. Overall, 89.7% and 85.8% of all serotypes in AOM and CAAP patients, respectively, were covered by 13-valent PCV. MEF and NP-CAAP S. pneumoniae isolates were similar in regard to serotype distribution and antibiotic resistance. S. pneumoniae antibiotic resistance rates were extremely high. Thirteen-valent PCV has the potential to reduce both the burden of disease as well as the rates of antibiotic-resistant S. pneumoniae in both diseases.

  8. Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm

    PubMed Central

    Ramirez, Maria S.; Traglia, German M.; Lin, David L.; Tran, Tung; Tolmasky, Marcelo E.

    2015-01-01

    Summary Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae. This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections. PMID:25705573

  9. Electrooptical Analysis of Microbial Cell Suspensions forDetermination of Antibiotic Resistance.

    PubMed

    Guliy, Olga I; Bunin, Victor D; Korzhenevich, Vyacheslav I; Volkov, Alexey A; Ignatov, Oleg V

    2016-12-01

    The effects of ampicillin; kanamycin, chloramphenicol, and tetracycline on electrophysical characteristics of cells of sensitive (ampicillin; kanamycin, chloramphenicol) and resistant (ampicillin; kanamycin, chloramphenicol, tetracycline) Escherichia coli strains were studied. Under the action of antibiotics sensitive and resistant E. coli strains acquire different electro-optical properties. Changes in suspension-orientational spectra, that are observed under the action of ampicillin; kanamycin, chloramphenicol, and tetracycline can be used in determination of antibiotic resistance of the studied bacterial strains. In our opinion, the methods of microbial suspension electro-optical analysis can be used in microbiology, mеdicinе, veterinary, and are an effective tool for solving the problems connected with determination of microbial cell antibiotic resistance.

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

    PubMed Central

    2010-01-01

    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 the hospital wastewater

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

    PubMed

    Diwan, Vishal; Tamhankar, Ashok J; Khandal, Rakesh K; Sen, Shanta; Aggarwal, Manjeet; Marothi, Yogyata; Iyer, Rama V; Sundblad-Tonderski, Karin; Stålsby-Lundborg, Cecilia

    2010-07-13

    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. 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. 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 the hospital wastewater. Wastewater samples collected in

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

    PubMed

    Viberg, Nina; Kalala, Willbrord; Mujinja, Phare; Tomson, Göran; Lundborg, Cecilia Stålsby

    2010-09-16

    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. 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. Of 350 interviewed exit customers, 24% had bought antibiotics. Thirty percent had seen a health worker before coming and almost all of these had a prescription. Antibiotics were dispensed mainly for cough, stomachache, genital complaints and diarrhea but not for malaria or headache. Dispensed drugs were assessed as relevant for the symptoms or disease presented in 83% of all cases and 51% for antibiotics specifically. Non-prescribed drugs were assessed as more relevant than the prescribed. The knowledge level of the drugseller was ranked as high or very high by 75% of the respondents. Seventy-five drugsellers from three districts participated. Seventy-nine percent stated that diseases caused by bacteria can be treated with antibiotics but 24% of these also said that antibiotics can be used for treating viral disease. Most (85%) said that STI can be treated with antibiotics while 1% said the same about headache, 4% general weakness and 3% 'all diseases'. Seventy-two percent had heard of antibiotic resistance. When describing what an antibiotic is, the respondents used six different kinds of keywords. Descriptions of what antibiotic resistance is and how it occurs were quite rational from a biomedical point of view with some exceptions. They gave rise to five categories and one theme: Perceiving antibiotic resistance based on practical experience. The

  13. Probing minority population of antibiotic-resistant bacteria.

    PubMed

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

    2016-06-15

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

  14. Natural Products as Platforms To Overcome Antibiotic Resistance.

    PubMed

    Rossiter, Sean E; Fletcher, Madison H; Wuest, William M

    2017-09-27

    Natural products have served as powerful therapeutics against pathogenic bacteria since the golden age of antibiotics of the mid-20th century. However, the increasing frequency of antibiotic-resistant infections clearly demonstrates that new antibiotics are critical for modern medicine. Because combinatorial approaches have not yielded effective drugs, we propose that the development of new antibiotics around proven natural scaffolds is the best short-term solution to the rising crisis of antibiotic resistance. We analyze herein synthetic approaches aiming to reengineer natural products into potent antibiotics. Furthermore, we discuss approaches in modulating quorum sensing and biofilm formation as a nonlethal method, as well as narrow-spectrum pathogen-specific antibiotics, which are of interest given new insights into the implications of disrupting the microbiome.

  15. Distribution of antibiotic resistance genes in glacier environments.

    PubMed

    Segawa, Takahiro; Takeuchi, Nozomu; Rivera, Andres; Yamada, Akinori; Yoshimura, Yoshitaka; Barcaza, Gonzalo; Shinbori, Kunio; Motoyama, Hideaki; Kohshima, Shiro; Ushida, Kazunari

    2013-02-01

    Antibiotic resistance genes are biologically transmitted from microorganism to microorganism in particular micro-environments where dense microbial communities are often exposed to an intensive use of antibiotics, such as intestinal microflora, and the soil microflora of agricultural fields. However, recent studies have detected antibiotic-resistant bacteria and/or antibiotic resistance genes in the natural environment geographically isolated from such areas. Here we sought to examine the prevalence of antibiotic resistance genes in 54 snow and ice samples collected from the Arctic, Antarctic, Central Asia, North and South America and Africa, to evaluate the level of these genes in environments supposedly not affected by anthropogenic factors. We observed a widespread distribution of antibiotic resistance genes in samples from various glaciers in Central Asia, North and South America, Greenland and Africa. In contrast, Antarctic glaciers were virtually free from these genes. Antibiotic resistance genes, of both clinical (i.e. aac(3), blaIMP) and agricultural (i.e. strA and tetW) origin, were detected. Our results show regional geographical distribution of antibiotic resistance genes, with the most plausible modes of transmission through airborne bacteria and migrating birds.

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

    PubMed

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

    2016-08-01

    Antibiotic resistance is considered one of the greatest threats to global public health. Resistance is often conferred by the presence of antibiotic resistance genes (ARGs), which are readily found in the oral microbiome. In-depth genetic analyses of the oral microbiome through metagenomic techniques reveal a broad distribution of ARGs (including novel ARGs) in individuals not recently exposed to antibiotics, including humans in isolated indigenous populations. This has resulted in a paradigm shift from focusing on the carriage of antibiotic resistance in pathogenic bacteria to a broader concept of an oral resistome, which includes all resistance genes in the microbiome. Metagenomics is beginning to demonstrate the role of the oral resistome and horizontal gene transfer within and between commensals in the absence of selective pressure, such as an antibiotic. At the chairside, metagenomic data reinforce our need to adhere to current antibiotic guidelines to minimize the spread of resistance, as such data reveal the extent of ARGs without exposure to antimicrobials and the ecologic changes created in the oral microbiome by even a single dose of antibiotics. The aim of this review is to discuss the role of metagenomics in the investigation of the oral resistome, including the transmission of antibiotic resistance in the oral microbiome. Future perspectives, including clinical implications of the findings from metagenomic investigations of oral ARGs, are also considered. © International & American Associations for Dental Research 2016.

  17. Resistance to aminoglycoside antibiotics of gram-negative bacilli isolated in Canadian hospitals.

    PubMed Central

    Duncan, I B; Cheung, E Y; Haldane, E V; Jackson, F L; McNaughton, R D; Morisset, R A; Noble, M A; Rennie, R P; Ronald, A R; Smith, J A

    1981-01-01

    A survey was made of the frequency of resistance to amikacin, gentamicin and tobramycin among aerobic gram-negative bacilli isolated over a 4-week period in 1979 at six large, geographically separated Canadian hospitals. In the entire series of 4407 isolates the frequency of resistance was 2.5% to amikacin, 8.1% to gentamicin, 5.9% to tobramycin and 1.7% to all three. Most (81%) of the resistant bacteria were acquired by the patients after admission to hospital. The frequency of resistance to the three aminoglycoside antibiotics in each hospital largely reflected the local rate of cross-infection by endemic strains of resistant bacteria. PMID:7237336

  18. Enteric dysbiosis promotes antibiotic-resistant bacterial infection: systemic dissemination of resistant and commensal bacteria through epithelial transcytosis

    PubMed Central

    Yu, Linda Chia-Hui; Shih, Yi-An; Wu, Li-Ling; Lin, Yang-Ding; Kuo, Wei-Ting; Peng, Wei-Hao; Lu, Kuo-Shyan; Wei, Shu-Chen; Turner, Jerrold R.

    2014-01-01

    Antibiotic usage promotes intestinal colonization of antibiotic-resistant bacteria. However, whether resistant bacteria gain dominance in enteric microflora or disseminate to extraintestinal viscera remains unclear. Our aim was to investigate temporal diversity changes in microbiota and transepithelial routes of bacterial translocation after antibiotic-resistant enterobacterial colonization. Mice drinking water with or without antibiotics were intragastrically gavaged with ampicillin-resistant (Amp-r) nonpathogenic Escherichia coli (E. coli) and given normal water afterward. The composition and spatial distribution of intestinal bacteria were evaluated using 16S rDNA sequencing and fluorescence in situ hybridization. Bacterial endocytosis in epithelial cells was examined using gentamicin resistance assay and transmission electromicroscopy. Paracellular permeability was assessed by tight junctional immunostaining and measured by tissue conductance and luminal-to-serosal dextran fluxes. Our results showed that antibiotic treatment enabled intestinal colonization and transient dominance of orally acquired Amp-r E. coli in mice. The colonized Amp-r E. coli peaked on day 3 postinoculation and was competed out after 1 wk, as evidenced by the recovery of commensals, such as Escherichia, Bacteroides, Lachnospiraceae, Clostridium, and Lactobacillus. Mucosal penetration and extraintestinal dissemination of exogenous and endogenous enterobacteria were correlated with abnormal epithelial transcytosis but uncoupled with paracellular tight junctional damage. In conclusion, antibiotic-induced enteric dysbiosis predisposes to exogenous infection and causes systemic dissemination of both antibiotic-resistant and commensal enterobacteria through transcytotic routes across epithelial layers. These results may help explain the susceptibility to sepsis in antibiotic-resistant enteric bacterial infection. PMID:25059827

  19. Enteric dysbiosis promotes antibiotic-resistant bacterial infection: systemic dissemination of resistant and commensal bacteria through epithelial transcytosis.

    PubMed

    Yu, Linda Chia-Hui; Shih, Yi-An; Wu, Li-Ling; Lin, Yang-Ding; Kuo, Wei-Ting; Peng, Wei-Hao; Lu, Kuo-Shyan; Wei, Shu-Chen; Turner, Jerrold R; Ni, Yen-Hsuan

    2014-10-15

    Antibiotic usage promotes intestinal colonization of antibiotic-resistant bacteria. However, whether resistant bacteria gain dominance in enteric microflora or disseminate to extraintestinal viscera remains unclear. Our aim was to investigate temporal diversity changes in microbiota and transepithelial routes of bacterial translocation after antibiotic-resistant enterobacterial colonization. Mice drinking water with or without antibiotics were intragastrically gavaged with ampicillin-resistant (Amp-r) nonpathogenic Escherichia coli (E. coli) and given normal water afterward. The composition and spatial distribution of intestinal bacteria were evaluated using 16S rDNA sequencing and fluorescence in situ hybridization. Bacterial endocytosis in epithelial cells was examined using gentamicin resistance assay and transmission electromicroscopy. Paracellular permeability was assessed by tight junctional immunostaining and measured by tissue conductance and luminal-to-serosal dextran fluxes. Our results showed that antibiotic treatment enabled intestinal colonization and transient dominance of orally acquired Amp-r E. coli in mice. The colonized Amp-r E. coli peaked on day 3 postinoculation and was competed out after 1 wk, as evidenced by the recovery of commensals, such as Escherichia, Bacteroides, Lachnospiraceae, Clostridium, and Lactobacillus. Mucosal penetration and extraintestinal dissemination of exogenous and endogenous enterobacteria were correlated with abnormal epithelial transcytosis but uncoupled with paracellular tight junctional damage. In conclusion, antibiotic-induced enteric dysbiosis predisposes to exogenous infection and causes systemic dissemination of both antibiotic-resistant and commensal enterobacteria through transcytotic routes across epithelial layers. These results may help explain the susceptibility to sepsis in antibiotic-resistant enteric bacterial infection. Copyright © 2014 the American Physiological Society.

  20. A Research-Inspired Laboratory Sequence Investigating Acquired Drug Resistance

    ERIC Educational Resources Information Center

    Taylor, Elizabeth Vogel; Fortune, Jennifer A.; Drennan, Catherine L.

    2010-01-01

    Here, we present a six-session laboratory exercise designed to introduce students to standard biochemical techniques in the context of investigating a high impact research topic, acquired resistance to the cancer drug Gleevec. Students express a Gleevec-resistant mutant of the Abelson tyrosine kinase domain, the active domain of an oncogenic…

  1. A Research-Inspired Laboratory Sequence Investigating Acquired Drug Resistance

    ERIC Educational Resources Information Center

    Taylor, Elizabeth Vogel; Fortune, Jennifer A.; Drennan, Catherine L.

    2010-01-01

    Here, we present a six-session laboratory exercise designed to introduce students to standard biochemical techniques in the context of investigating a high impact research topic, acquired resistance to the cancer drug Gleevec. Students express a Gleevec-resistant mutant of the Abelson tyrosine kinase domain, the active domain of an oncogenic…

  2. A review of global initiatives to fight antibiotic resistance and recent antibiotics׳ discovery.

    PubMed

    Chaudhary, Arpana Sagwal

    2016-11-01

    Data from across the world have shown an overall decline in the antibiotic pipeline and continually rising resistance to all first-line and last-resort antibiotics. The gaps in our knowledge of existing prevalence and mechanisms of antibiotic resistance (ABR) are all too well known. Several decades of antibiotic abuse in humans, animals, and agricultural practices have created health emergency situations and huge socio-economic impact. This paper discusses key findings of the studies conducted by several national and international collaborative organizations on the current state of affairs in ABR. Alongside, a brief overview of the antibacterial agents׳ discovery in recent years approved by the US FDA is discussed.

  3. Antibiotic and synergistic effect of Leu-Lys rich peptide against antibiotic resistant microorganisms isolated from patients with cholelithiasis.

    PubMed

    Jeong, Nari; Kim, Jin-Young; Park, Seong-Cheol; Lee, Jong-Kook; Gopal, Ramamourthy; Yoo, Suyeon; Son, Byoung Kwan; Hahm, Joon Soo; Park, Yoonkyung; Hahm, Kyung-Soo

    2010-09-03

    Pseudomonas aeruginosa has eventually developed resistance against flomoxef sodium, isepamicin and cefpiramide. Therefore, in this study, the antibacterial activity and synergistic effects of the amphipathic-derived P5-18mer antimicrobial peptide were tested against pathogens associated with cholelithiasis that have developed resistance against commonly used antibiotics. The results were then compared with the activities of the amphipathic-derived peptide, P5-18mer, melittin and common antibiotics. Growth inhibition of planktonic bacteria was tested using the National Committee for Clinical Laboratory Standards (NCCLS). The bactericidal activity of the antimicrobial peptides was measured using time-kill curves. Synergistic effects were evaluated by testing the effects of P5-18mer alone and in combination with flomoxef sodium, isepamicin or cefpiramide at 0.5xMIC. P5-18mer peptide displayed strong activity against pathogens and flomoxef sodium, isepamicin and cefpiramide-resistant bacteria cell lines obtained from a patient with gallstones; however, it did not exert cytotoxicity against the human keratinocyte HaCat cell line. In addition, the results of time-kill curves indicated that P5-18mer peptide exerted bactericidal activity against four strains of P. aeruginosa. Finally, the use of P5-18mer and antibiotics exerted synergistic effects against cell lines that were resistant to commonly used antibiotics. These results indicate that this class of peptides has a rapid microbicidal effect on flomoxef sodium, isepamicin and cefpiramide-resistant strains of P. aeruginosa. Therefore, these peptides may be used as a lead drug for the treatment of acquired pathogens from patients with cholelithiasis who are affected with antibiotic-resistant bacteria. Copyright 2010 Elsevier Inc. All rights reserved.

  4. What Can Be Done about Antibiotic Resistance?

    MedlinePlus

    ... chosen by doctors whenever possible to avoid destroying populations of beneficial bacteria along with the disease-causing bacteria. In addition, non-therapeutic uses of antibiotics in farm animals and agriculture should be eliminated. Can new antibiotics ...

  5. Acquired resistance to chlorhexidine - is it time to establish an 'antiseptic stewardship' initiative?

    PubMed

    Kampf, G

    2016-11-01

    Chlorhexidine digluconate (CHG) is an antimicrobial agent used for different types of applications in hand hygiene, skin antisepsis, oral care, and patient washing. Increasing use raises concern regarding development of acquired bacterial resistance. Published data from clinical isolates with CHG minimum inhibitory concentrations (MICs) were reviewed and compared to epidemiological cut-off values to determine resistance. CHG resistance is rarely found in Escherichia coli, Salmonella spp., Staphylococcus aureus or coagulase-negative staphylococci. In Enterobacter spp., Pseudomonas spp., Proteus spp., Providencia spp. and Enterococcus spp., however, isolates are more often CHG resistant. CHG resistance may be detected in multi-resistant isolates such as extremely drug-resistant Klebsiella pneumoniae. Isolates with a higher MIC are often less susceptible to CHG for disinfection. Although cross-resistance to antibiotics remains controversial, some studies indicate that the overall exposure to CHG increases the risk for resistance to some antibiotic agents. Resistance to CHG has resulted in numerous outbreaks and healthcare-associated infections. On an average intensive care unit, most of the CHG exposure would be explained by hand hygiene agents when liquid soaps or alcohol-based hand rubs contain CHG. Exposure to sub-lethal CHG concentration may enhance resistance in Acinetobacter spp., K. pneumoniae, and Pseudomonas spp., all species well known for emerging antibiotic resistance. In order to reduce additional selection pressure in nosocomial pathogens it seems to make sense to restrict the valuable agent CHG to those indications with a clear patient benefit and to eliminate it from applications without any benefit or with a doubtful benefit. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

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

    PubMed

    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. Isolated cell behavior drives the evolution of antibiotic resistance.

    PubMed

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

    2015-07-29

    Bacterial antibiotic resistance is typically quantified by the minimum inhibitory concentration (MIC), which is defined as the minimal concentration of antibiotic that inhibits bacterial growth starting from a standard cell density. However, when antibiotic resistance is mediated by degradation, the collective inactivation of antibiotic by the bacterial population can cause the measured MIC to depend strongly on the initial cell density. In cases where this inoculum effect is strong, the relationship between MIC and bacterial fitness in the antibiotic is not well defined. Here, we demonstrate that the resistance of a single, isolated cell-which we call the single-cell MIC (scMIC)-provides a superior metric for quantifying antibiotic resistance. Unlike the MIC, we find that the scMIC predicts the direction of selection and also specifies the antibiotic concentration at which selection begins to favor new mutants. Understanding the cooperative nature of bacterial growth in antibiotics is therefore essential in predicting the evolution of antibiotic resistance. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

  8. Isolated cell behavior drives the evolution of antibiotic resistance

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Capita, Rosa; Alonso-Calleja, Carlos

    2013-01-01

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

  11. Epigenetic inheritance based evolution of antibiotic resistance in bacteria

    PubMed Central

    2008-01-01

    Background The evolution of antibiotic resistance in bacteria is a topic of major medical importance. Evolution is the result of natural selection acting on variant phenotypes. Both the rigid base sequence of DNA and the more plastic expression patterns of the genes present define phenotype. Results We investigated the evolution of resistant E. coli when exposed to low concentrations of antibiotic. We show that within an isogenic population there are heritable variations in gene expression patterns, providing phenotypic diversity for antibiotic selection to act on. We studied resistance to three different antibiotics, ampicillin, tetracycline and nalidixic acid, which act by inhibiting cell wall synthesis, protein synthesis and DNA synthesis, respectively. In each case survival rates were too high to be accounted for by spontaneous DNA mutation. In addition, resistance levels could be ramped higher by successive exposures to increasing antibiotic concentrations. Furthermore, reversion rates to antibiotic sensitivity were extremely high, generally over 50%, consistent with an epigenetic inheritance mode of resistance. The gene expression patterns of the antibiotic resistant E. coli were characterized with microarrays. Candidate genes, whose altered expression might confer survival, were tested by driving constitutive overexpression and determining antibiotic resistance. Three categories of resistance genes were identified. The endogenous β-lactamase gene represented a cryptic gene, normally inactive, but when by chance expressed capable of providing potent ampicillin resistance. The glutamate decarboxylase gene, in contrast, is normally expressed, but when overexpressed has the incidental capacity to give an increase in ampicillin resistance. And the DAM methylase gene is capable of regulating the expression of other genes, including multidrug efflux pumps. Conclusion In this report we describe the evolution of antibiotic resistance in bacteria mediated by the

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

    PubMed Central

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

    2017-01-01

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

  13. Bilateral blindness from orbital cellulitis caused by community-acquired methicillin-resistant Staphylococcus aureus.

    PubMed

    Rutar, Tina; Zwick, Orin M; Cockerham, Kimberly P; Horton, Jonathan C

    2005-10-01

    To describe bilateral blindness resulting from infection with community-acquired methicillin-resistant Staphylococcus aureus (MRSA). Observational case report. A 44-year-old man developed proptosis, ptosis, ophthalmoplegia, and no light perception vision after attempting to lance a nasal pustule. A nasal culture grew MRSA. Imaging showed bilateral orbital cellulitis, pansinusitis, and cavernous sinus thrombosis. The right fundus showed severe ischemia, but the left fundus was essentially normal. Despite initiation of appropriate antibiotics early in the course of infection, the patient lost sight in both eyes. Surgical drainage of the paranasal sinuses and use of intravenous corticosteroids and heparin led to the resolution of orbital cellulitis. MRSA orbital cellulitis can progress to irreversible blindness despite antibiotic treatment. A new, community-acquired clone of this organism has exhibited increased potential for tissue invasion.

  14. Community-Acquired Methicillin-Resistant Staphylococcus aureus in Institutionalized Adults with Developmental Disabilities1

    PubMed Central

    Borer, Abraham; Gilad, Jacob; Yagupsky, Pablo; Peled, Nechama; Porat, Nurith; Trefler, Ronit; Shprecher-Levy, Hannah; Riesenberg, Klaris; Shipman, Miriam

    2002-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has recently been reported to emerge in the community setting. We describe the investigation and control of a community-acquired outbreak of MRSA skin infections in a closed community of institutionalized adults with developmental disabilities. In a 9-month period in 1997, 20 (71%) of 28 residents had 73 infectious episodes. Of the cultures, 60% and 32% obtained from residents and personnel, respectively, grew S. aureus; 96% and 27% were MRSA. All isolates were genetically related by pulsed-field gel electrophoresis and belonged to a phage type not previously described in the region. No known risk factors for MRSA acquisition were found. However, 58 antibiotic courses had been administered to 16 residents during the preceding 9 months. Infection control measures, antibiotic restriction, and appropriate therapy resulted in successful termination of this outbreak. Selective antibiotic pressure may result in the emergence, persistence, and dissemination of MRSA strains, causing prolonged disease. PMID:12194775

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

    PubMed Central

    Pamer, Eric G.

    2016-01-01

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

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

    PubMed

    Pamer, Eric G

    2016-04-29

    The intestinal microbiota, which is composed of diverse populations of commensal bacterial species, provides resistance against colonization and invasion by pathogens. Antibiotic treatment can damage the intestinal microbiota and, paradoxically, increase susceptibility to infections. Reestablishing microbiota-mediated colonization resistance after antibiotic treatment could markedly reduce infections, particularly those caused by antibiotic-resistant bacteria. Ongoing studies are identifying commensal bacterial species that can be developed into next-generation probiotics to reestablish or enhance colonization resistance. These live medicines are at various stages of discovery, testing, and production and are being subjected to existing regulatory gauntlets for eventual introduction into clinical practice. The development of next-generation probiotics to reestablish colonization resistance and eliminate potential pathogens from the gut is warranted and will reduce health care-associated infections caused by highly antibiotic-resistant bacteria. Copyright © 2016, American Association for the Advancement of Science.

  17. The evolution of resistance through costly acquired immunity.

    PubMed Central

    Boots, Michael; Bowers, Roger G.

    2004-01-01

    We examine the evolutionary dynamics of resistance to parasites through acquired immunity. Resistance can be achieved through the innate mechanisms of avoidance of infection and reduced pathogenicity once infected, through recovery from infection and through remaining immune to infection: acquired immunity. We assume that each of these mechanisms is costly to the host and find that the evolutionary dynamics of innate immunity in hosts that also have acquired immunity are quantitatively the same as in hosts that possess only innate immunity. However, compared with resistance through avoidance or recovery, there is less likely to be polymorphism in the length of acquired immunity within populations. Long-lived organisms that can recover at intermediate rates faced with fast-transmitting pathogens that cause intermediate pathogenicity (mortality of infected individuals) are most likely to evolve long-lived acquired immunity. Our work emphasizes that because whether or not acquired immunity is beneficial depends on the characteristics of the disease, organisms may be selected to only develop acquired immunity to some of the diseases that they encounter. PMID:15209105

  18. Eight More Ways To Deal with Antibiotic Resistance

    PubMed Central

    Shlaes, David M.

    2014-01-01

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

  19. Eight more ways to deal with antibiotic resistance.

    PubMed

    Metz, Matthew; Shlaes, David M

    2014-08-01

    The fight against antibiotic resistance must be strengthened. We propose actions that U.S. government agencies and private sector entities can take to build a more comprehensive effort. These actions can increase the viability of investing in new antibiotics, ensure the quality and stewardship of all antibiotics, and make responses to emerging resistance more informed. Success requires the thoughtful exercise of federal authority and a firm commitment to share data and reward developers for the value generated with new, life-saving antibiotics. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Pneumococcal antimicrobial resistance: therapeutic strategy and management in community-acquired pneumonia.

    PubMed

    Aspa, Javier; Rajas, Olga; de Castro, Felipe Rodríguez

    2008-02-01

    Streptococcus pneumoniae has been consistently shown to represent the most frequent causative agent of community-acquired pneumonia (CAP) and pneumococcal antibiotic resistance towards different families of antibiotics continues to be a much-debated issue. Microbial resistance causes a great deal of confusion in choosing an empirical treatment for pneumonia and this makes it necessary to know which factors actually determine the real impact of antimicrobial resistance on the outcome of pneumococcal infections. Several different aspects have to be taken into account when analyzing this matter, such as the study design, the condition of the patient at the time of diagnosis, the choice of the initial antimicrobial regimen (combination or monotherapy) and the pharmacokinetic/pharmacodynamic variables of the chosen antibiotic. It is generally accepted that in the treatment of beta-lactam-resistant pneumococcal infections, the use of standard antipneumococcal beta-lactam agents is unlikely to impact negatively on the outcome of CAP when appropriate agents are given in sufficient doses. As a general rule, for infections with penicillin-sensitive strains, penicillin or an aminopenicillin in a standard dosage will be effective; in the cases of strains with intermediate resistance, beta-lactam agents are still considered appropriate treatment although higher dosages are recommended; finally, infections with isolates of high-level penicillin resistance should be treated with alternative agents such as the third-generation cephalosporins or the new antipneumococcal fluoroquinolones. In areas of high prevalence of high-level macrolide resistance, empirical monotherapy with a macrolide is not optimal for the treatment of hospitalised patients with moderate or moderately-severe CAP. Fluoroquinolones are considered to be excellent antibiotics in the treatment of pneumococcal CAP in adults, but their general recommendation has been withheld due to fears of a widespread development

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

    PubMed

    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.

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

    PubMed

    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.

  3. Inactivation of an integrated antibiotic resistance gene in mammalian cells to re-enable antibiotic selection.

    PubMed

    Ni, Peiling; Zhang, Qian; Chen, Haixia; Chen, Lingyi

    2014-01-01

    Removing an antibiotic resistance gene allows the same antibiotic to be re-used in the next round of genetic manipulation. Here we applied the CRISPR/Cas system to disrupt the puromycin resistance gene in an engineered mouse embryonic stem cell line and then re-used puromycin selection in the resulting cells to establish stable reporter cell lines. With the CRISPR/Cas system, pre-engineered sequences, such as loxP or FRT, are not required. Thus, this technique can be used to disrupt antibiotic resistance genes that cannot be removed by the Cre-loxP and Flp-FRT systems.

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

    PubMed

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

    2015-07-01

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

  5. Plasmid interference for curing antibiotic resistance plasmids in vivo

    PubMed Central

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

    2017-01-01

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

  6. Plasmid interference for curing antibiotic resistance plasmids in vivo.

    PubMed

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

    2017-01-01

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

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

    PubMed

    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.

  8. Antibiotic use and resistance in emerging economies: a situation analysis for Viet Nam

    PubMed Central

    2013-01-01

    Background Antimicrobial resistance is a major contemporary public health threat. Strategies to contain antimicrobial resistance have been comprehensively set forth, however in developing countries where the need for effective antimicrobials is greatest implementation has proved problematic. A better understanding of patterns and determinants of antibiotic use and resistance in emerging economies may permit more appropriately targeted interventions. Viet Nam, with a large population, high burden of infectious disease and relatively unrestricted access to medication, is an excellent case study of the difficulties faced by emerging economies in controlling antimicrobial resistance. Methods Our working group conducted a situation analysis of the current patterns and determinants of antibiotic use and resistance in Viet Nam. International publications and local reports published between 1-1-1990 and 31-8-2012 were reviewed. All stakeholders analyzed the findings at a policy workshop and feasible recommendations were suggested to improve antibiotic use in Viet Nam. Here we report the results of our situation analysis focusing on: the healthcare system, drug regulation and supply; antibiotic resistance and infection control; and agricultural antibiotic use. Results Market reforms have improved healthcare access in Viet Nam and contributed to better health outcomes. However, increased accessibility has been accompanied by injudicious antibiotic use in hospitals and the community, with predictable escalation in bacterial resistance. Prescribing practices are poor and self-medication is common – often being the most affordable way to access healthcare. Many policies exist to regulate antibiotic use but enforcement is insufficient or lacking. Pneumococcal penicillin-resistance rates are the highest in Asia and carbapenem-resistant bacteria (notably NDM-1) have recently emerged. Hospital acquired infections, predominantly with multi-drug resistant Gram-negative organisms

  9. Antibiotic use and resistance in emerging economies: a situation analysis for Viet Nam.

    PubMed

    Nguyen, Kinh Van; Thi Do, Nga Thuy; Chandna, Arjun; Nguyen, Trung Vu; Pham, Ca Van; Doan, Phuong Mai; Nguyen, An Quoc; Thi Nguyen, Chuc Kim; Larsson, Mattias; Escalante, Socorro; Olowokure, Babatunde; Laxminarayan, Ramanan; Gelband, Hellen; Horby, Peter; Thi Ngo, Ha Bich; Hoang, Mai Thanh; Farrar, Jeremy; Hien, Tran Tinh; Wertheim, Heiman F L

    2013-12-10

    Antimicrobial resistance is a major contemporary public health threat. Strategies to contain antimicrobial resistance have been comprehensively set forth, however in developing countries where the need for effective antimicrobials is greatest implementation has proved problematic. A better understanding of patterns and determinants of antibiotic use and resistance in emerging economies may permit more appropriately targeted interventions.Viet Nam, with a large population, high burden of infectious disease and relatively unrestricted access to medication, is an excellent case study of the difficulties faced by emerging economies in controlling antimicrobial resistance. Our working group conducted a situation analysis of the current patterns and determinants of antibiotic use and resistance in Viet Nam. International publications and local reports published between 1-1-1990 and 31-8-2012 were reviewed. All stakeholders analyzed the findings at a policy workshop and feasible recommendations were suggested to improve antibiotic use in Viet Nam.Here we report the results of our situation analysis focusing on: the healthcare system, drug regulation and supply; antibiotic resistance and infection control; and agricultural antibiotic use. Market reforms have improved healthcare access in Viet Nam and contributed to better health outcomes. However, increased accessibility has been accompanied by injudicious antibiotic use in hospitals and the community, with predictable escalation in bacterial resistance. Prescribing practices are poor and self-medication is common - often being the most affordable way to access healthcare. Many policies exist to regulate antibiotic use but enforcement is insufficient or lacking.Pneumococcal penicillin-resistance rates are the highest in Asia and carbapenem-resistant bacteria (notably NDM-1) have recently emerged. Hospital acquired infections, predominantly with multi-drug resistant Gram-negative organisms, place additional strain on

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

    PubMed

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

    2008-08-01

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

  11. Detection of antibiotic resistance in probiotics of dietary supplements.

    PubMed

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

    2015-09-14

    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. 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. 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.

  12. Metabolic constraints on the evolution of antibiotic resistance.

    PubMed

    Zampieri, Mattia; Enke, Tim; Chubukov, Victor; Ricci, Vito; Piddock, Laura; Sauer, Uwe

    2017-03-06

    Despite our continuous improvement in understanding antibiotic resistance, the interplay between natural selection of resistance mutations and the environment remains unclear. To investigate the role of bacterial metabolism in constraining the evolution of antibiotic resistance, we evolved Escherichia coli growing on glycolytic or gluconeogenic carbon sources to the selective pressure of three different antibiotics. Profiling more than 500 intracellular and extracellular putative metabolites in 190 evolved populations revealed that carbon and energy metabolism strongly constrained the evolutionary trajectories, both in terms of speed and mode of resistance acquisition. To interpret and explore the space of metabolome changes, we developed a novel constraint-based modeling approach using the concept of shadow prices. This analysis, together with genome resequencing of resistant populations, identified condition-dependent compensatory mechanisms of antibiotic resistance, such as the shift from respiratory to fermentative metabolism of glucose upon overexpression of efflux pumps. Moreover, metabolome-based predictions revealed emerging weaknesses in resistant strains, such as the hypersensitivity to fosfomycin of ampicillin-resistant strains. Overall, resolving metabolic adaptation throughout antibiotic-driven evolutionary trajectories opens new perspectives in the fight against emerging antibiotic resistance.

  13. Previous antibiotic exposure and evolution of antibiotic resistance in mechanically ventilated patients with nosocomial infections.

    PubMed

    Hui, Chun; Lin, Ming-Chih; Jao, Mei-Shin; Liu, Tu-Chen; Wu, Ren-Guang

    2013-10-01

    This study aimed to evaluate the impact of previous antibiotic exposure and the influence of time interval since exposure on the evolution of antibiotic-resistant infections. We retrospectively analyzed 167 mechanically ventilated patients with nosocomial infections over a 3-year period, with focus on infections in the bloodstream, urinary tract, lower respiratory tract, and surgical sites. Of 167 patients, 62% were confirmed as antibiotic resistant. The most common isolated pathogen was extended-spectrum β-lactamase Enterobacteriaceae (43.9%), followed by methicillin-resistant Staphylococcus aureus (22.8%), and carbapenem-resistant Acinetobacter baumannii (17.5%). Multivariate analysis revealed that the association between resistance and the time interval increased within 10 days (odds ratio [OR], 2.45; P=.133) and peaked at 11 to 20 days (OR, 7.17; P=.012). The data were categorized into 2 groups: when the time interval was more than 20 days, there was a 23.9% reduction in resistance rate compared with when the time interval was 20 days or less (OR, 0.36; P=.002). Although antibiotic exposure increased resistance rate in nosocomial infections, this association decreased as time interval increased. Antibiotic stewardship should consider the significance of time interval while investigating the evolution of subsequent antibiotic-resistant infections. Copyright © 2013 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2015-01-01

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

  15. New Insights in to the Intrinsic and Acquired Drug Resistance Mechanisms in Mycobacteria

    PubMed Central

    Nasiri, Mohammad J.; Haeili, Mehri; Ghazi, Mona; Goudarzi, Hossein; Pormohammad, Ali; Imani Fooladi, Abbas A.; Feizabadi, Mohammad M.

    2017-01-01

    Infectious diseases caused by clinically important Mycobacteria continue to be an important public health problem worldwide primarily due to emergence of drug resistance crisis. In recent years, the control of tuberculosis (TB), the disease caused by Mycobacterium tuberculosis (MTB), is hampered by the emergence of multidrug resistance (MDR), defined as resistance to at least isoniazid (INH) and rifampicin (RIF), two key drugs in the treatment of the disease. Despite the availability of curative anti-TB therapy, inappropriate and inadequate treatment has allowed MTB to acquire resistance to the most important anti-TB drugs. Likewise, for most mycobacteria other than MTB, the outcome of drug treatment is poor and is likely related to the high levels of antibiotic resistance. Thus, a better knowledge of the underlying mechanisms of drug resistance in mycobacteria could aid not only to select the best therapeutic options but also to develop novel drugs that can overwhelm the existing resistance mechanisms. In this article, we review the distinctive mechanisms of antibiotic resistance in mycobacteria. PMID:28487675

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

    PubMed

    Boni, Maciej F; Feldman, Marcus W

    2005-03-01

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

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

    PubMed

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

    2015-02-01

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

  18. Transfer of antibiotic resistance from Enterococcus faecium of fermented meat origin to Listeria monocytogenes and Listeria innocua.

    PubMed

    Jahan, M; Holley, R A

    2016-04-01

    Listeria monocytogenes is an important foodborne pathogen that can cause infection in children, pregnant women, the immunocompromised and the elderly. Antibiotic resistance in this species would represent a significant public health problem since the organism has a high fatality/case ratio and resistance may contribute to failure of therapeutic treatment. This study was designed to explore whether the in vitro transferability of antibiotic resistance from enterococci to Listeria spp. could occur. It was found that 2/8 Listeria strains were able to acquire tetracycline resistance from Enterococcus faecium. Listeria monocytogenes GLM-2 acquired the resistance determinant tet(M) and additional streptomycin resistance through in vitro mating with Ent. faecium S27 isolated from commercial fermented dry sausage. Similarly, Listeria innocua became more resistant to tetracycline, but the genetic basis for this change was not confirmed. It has been suggested that enterococci may transfer antibiotic resistance genes via transposons to Listeria spp., and this may explain, in part, the origin of their antibiotic resistance. Thus, the presence of enterococci in food should not be ignored since they may actively contribute to enhanced antibiotic resistance of L. monocytogenes and other pathogens. Acquisition of antibiotic resistance by pathogenic bacteria in the absence of antibiotic pressure represents an unquantified threat to human health. In the present work resistance to tetracycline and streptomycin were transferred by nonplasmid-based conjugation from Enterococcus faecium isolated from fermented sausage to Listeria monocytogenes and Listeria innocua. Thus, natural transfer of antibiotic resistance to Listeria strains may occur in the future which reinforces the concern about the safety of enterococcal strains present in foods. © 2016 The Society for Applied Microbiology.

  19. Fighting antibiotic resistance in Sweden--past, present and future.

    PubMed

    Struwe, Johan

    2008-01-01

    Sweden has been in the favorable situation of having limited antibiotic resistance and low antibiotic consumption. When pneumococci with reduced susceptibility to penicillin and methicillin-resistant Staphylococcus aureus emerged during the 1990s, professionals and relevant authorities called for extensive action plans to avoid the critical threshold levels of resistance experienced in other countries. The purpose of this paper is to examine Swedish experiences in light of new and future challenges by reviewing Swedish data on antibiotic resistance and antibiotic use, notifications, outbreak control, action plans and scientific papers. The tradition of liberal performance of clinical cultures, together with well functioning diagnostic laboratories, has formed a basis for close collaboration and development of surveillance within quality assurance programs. For more than 20 years the pharmacy monopoly in Sweden has made it possible to collect well defined data on antibiotic sales at the county level with almost 100% coverage. Multisectorial collaboration was set up in regional Strama (Swedish Strategic Programme Against Antibiotic Resistance) groups. Large diagnosis-prescribing surveys have been undertaken, and the concept of basic hygiene precautions was introduced, together with extensive programs for early case finding. However, surveillance has been hampered by inadequate IT systems and some difficulties in collecting relevant data on antibiotic sales at the national level. Also, a decentralized system with 21 counties and regions has resulted in divergence of action plans and rules. The containment of antibiotic resistance thus far may be explained by the early response in human and veterinary medicine and close multisectorial collaboration, supported by the government, before problems got out of hand. Nevertheless, rapidly growing problems with bacteria that produce extended beta-lactamases have recently emerged and antibiotic sales have started to increase

  20. Impact of antibiotic resistance in gram-negative bacilli on empirical and definitive antibiotic therapy.

    PubMed

    Paterson, David L

    2008-09-15

    Serious infections with gram-negative pathogens continue to be associated with considerable mortality. Increasing antibiotic resistance in organisms such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae is contributing to difficulties with choosing antibiotics to prescribe for these infections. Optimization of therapy against these organisms starts with the initial empirical antibiotic choice. Surveillance data and hospital or unit antibiograms may inform this decision, although individualization of the initial regimen on the basis of prior antibiotic use and prior isolation of resistant pathogens may be more important. Combinations of antibiotics are often required empirically, and "combination antibiograms" may need to be developed for this purpose. Preliminary data suggest that extending the time over which a dose of antipseudomonal beta-lactam antibiotics is infused may improve clinical outcomes; however, this idea remains to be confirmed in randomized trials. The role of direct susceptibility testing in aiding more-rapid initiation of appropriate antibiotic therapy is also being studied. When identification and susceptibility testing is complete, the antibiotic regimen for infections due to gram-negative pathogens can be "fine tuned." On some occasions, this fine tuning necessitates the introduction of "salvage" antibiotics, such as colistin or tigecycline; on others, it necessitates de-escalation and early termination of therapy. The lack of new antibiotic options against gram-negative pathogens underscores the need for optimization of current therapies and prevention of the spread of these organisms.

  1. Antibiotic Resistance Patterns of Pseudomonas spp. Isolated from the River Danube

    PubMed Central

    Kittinger, Clemens; Lipp, Michaela; Baumert, Rita; Folli, Bettina; Koraimann, Günther; Toplitsch, Daniela; Liebmann, Astrid; Grisold, Andrea J.; Farnleitner, Andreas H.; Kirschner, Alexander; Zarfel, Gernot

    2016-01-01

    Spread and persistence of antibiotic resistance pose a severe threat to human health, yet there is still lack of knowledge about reservoirs of antibiotic resistant bacteria in the environment. We took the opportunity of the Joint Danube Survey 3 (JDS3), the world's biggest river research expedition of its kind in 2013, to analyse samples originating from different sampling points along the whole length of the river. Due to its high clinical relevance, we concentrated on the characterization of Pseudomonas spp. and evaluated the resistance profiles of Pseudomonas spp. which were isolated from eight sampling points. In total, 520 Pseudomonas isolates were found, 344 (66.0%) isolates were identified as Pseudomonas putida, and 141 (27.1%) as Pseudomonas fluorescens, all other Pseudomonas species were represented by less than five isolates, among those two P. aeruginosa isolates. Thirty seven percent (37%) of all isolated Pseudomonas species showed resistance to at least one out of 10 tested antibiotics. The most common resistance was against meropenem (30.4%/158 isolates) piperacillin/tazobactam (10.6%/55 isolates) and ceftazidime (4.2%/22 isolates). 16 isolates (3.1%/16 isolates) were multi-resistant. For each tested antibiotic at least one resistant isolate could be detected. Sampling points from the upper stretch of the River Danube showed more resistant isolates than downriver. Our results suggest that antibiotic resistance can be acquired by and persists even in Pseudomonas species that are normally not in direct contact with humans. A possible scenario is that these bacteria provide a reservoir of antibiotic resistance genes that can spread to related human pathogens by horizontal gene transfer. PMID:27199920

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    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.

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

    PubMed

    Rudholm, Niklas

    2002-11-01

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

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

    PubMed

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

    2013-08-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    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.

  8. Diverse Antibiotic Resistance Genes in Dairy Cow Manure

    PubMed Central

    Wichmann, Fabienne; Udikovic-Kolic, Nikolina; Andrew, Sheila; Handelsman, Jo

    2014-01-01

    ABSTRACT Application of manure from antibiotic-treated animals to crops facilitates the dissemination of antibiotic resistance determinants into the environment. However, our knowledge of the identity, diversity, and patterns of distribution of these antibiotic resistance determinants remains limited. We used a new combination of methods to examine the resistome of dairy cow manure, a common soil amendment. Metagenomic libraries constructed with DNA extracted from manure were screened for resistance to beta-lactams, phenicols, aminoglycosides, and tetracyclines. Functional screening of fosmid and small-insert libraries identified 80 different antibiotic resistance genes whose deduced protein sequences were on average 50 to 60% identical to sequences deposited in GenBank. The resistance genes were frequently found in clusters and originated from a taxonomically diverse set of species, suggesting that some microorganisms in manure harbor multiple resistance genes. Furthermore, amid the great genetic diversity in manure, we discovered a novel clade of chloramphenicol acetyltransferases. Our study combined functional metagenomics with third-generation PacBio sequencing to significantly extend the roster of functional antibiotic resistance genes found in animal gut bacteria, providing a particularly broad resource for understanding the origins and dispersal of antibiotic resistance genes in agriculture and clinical settings. PMID:24757214

  9. Antibiotic Resistance of Escherichia coli Serotypes from Cochin Estuary

    PubMed Central

    Sukumaran, Divya P.; Durairaj, Srinivasan; Abdulla, Mohamed Hatha

    2012-01-01

    This study aimed at detecting the prevalence of antibiotic-resistant serotypes of Escherichia coli in Cochin estuary, India. E. coli strains were isolated during the period January 2010–December 2011 from five different stations set at Cochin estuary. Water samples from five different stations in Cochin estuary were collected on a monthly basis for a period of two years. Isolates were serotyped, antibiogram-phenotyped for twelve antimicrobial agents, and genotyped by polymerase chain reaction for uid gene that codes for β-D-glucuronidase. These E. coli strains from Cochin estuary were tested against twelve antibiotics to determine the prevalence of multiple antibiotic resistance among them. The results revealed that more than 53.33% of the isolates were multiple antibiotic resistant. Thirteen isolates showed resistance to sulphonamides and two of them contained the sul 1 gene. Class 1 integrons were detected in two E. coli strains which were resistant to more than seven antibiotics. In the present study, O serotyping, antibiotic sensitivity, and polymerase chain reaction were employed with the purpose of establishing the present distribution of multiple antibiotic-resistant serotypes, associated with E. coli isolated from different parts of Cochin estuary. PMID:23008708

  10. Review article: the global emergence of Helicobacter pylori antibiotic resistance.

    PubMed

    Thung, I; Aramin, H; Vavinskaya, V; Gupta, S; Park, J Y; Crowe, S E; Valasek, M A

    2016-02-01

    Helicobacter pylori is one of the most prevalent global pathogens and can lead to gastrointestinal disease including peptic ulcers, gastric marginal zone lymphoma and gastric carcinoma. To review recent trends in H. pylori antibiotic resistance rates, and to discuss diagnostics and treatment paradigms. A PubMed literature search using the following keywords: Helicobacter pylori, antibiotic resistance, clarithromycin, levofloxacin, metronidazole, prevalence, susceptibility testing. The prevalence of bacterial antibiotic resistance is regionally variable and appears to be markedly increasing with time in many countries. Concordantly, the antimicrobial eradication rate of H. pylori has been declining globally. In particular, clarithromycin resistance has been rapidly increasing in many countries over the past decade, with rates as high as approximately 30% in Japan and Italy, 50% in China and 40% in Turkey; whereas resistance rates are much lower in Sweden and Taiwan, at approximately 15%; there are limited data in the USA. Other antibiotics show similar trends, although less pronounced. Since the choice of empiric therapies should be predicated on accurate information regarding antibiotic resistance rates, there is a critical need for determination of current rates at a local scale, and perhaps in individual patients. Such information would not only guide selection of appropriate empiric antibiotic therapy but also inform the development of better methods to identify H. pylori antibiotic resistance at diagnosis. Patient-specific tailoring of effective antibiotic treatment strategies may lead to reduced treatment failures and less antibiotic resistance. © 2015 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.

  11. Community-acquired methicillin-resistant Staphylococcus aureus in a Malaysian tertiary centre.

    PubMed

    Rashid, Zetti Zainol; Bahari, Norazlah; Othman, Amizah; Jaafar, Roslinda; Mohamed, Nurul Azmawati; Jabbari, Idimaz; Sulong, Anita; Hashim, Rohaidah; Ahmad, Norazah

    2013-01-01

    Abstract. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is a pathogen recognized to be distinct in both phenotype and genotype from hospital-acquired MRSA. We have identified CA-MRSA cases in Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia, including their antibiotic susceptibility patterns and genotypic characteristics. Cases were identified during January to December 2009 from routine clinical specimens, where culture and antibiotic susceptibility results yielded pauci-resistant MRSA isolates suspected as being CA-MRSA. The patients' clinical data were collected and their specimens were sent for molecular confirmation and analysis. Five cases of CA-MRSA were identified, which had a multi-sensitive pattern on antibiotic susceptibility tests and were resistant to only penicillin and oxacillin. All cases were skin and soft-tissue infections, including diabetic foot with gangrene, infected scalp hematoma, philtrum abscess in a healthcare worker, thrombophlebitis complicated with abscess and infected bedsore. All five cases were confirmed MRSA by detection of mecA. SCCmec typing (ccr and mec complex) revealed SCCmec type IV for all cases except the infected bedsore case. Panton-Valentine leukocidin gene was positive in all isolates. As clinical features among methicillin-sensitive Staphylococcus aureus, CA-MRSA and "nosocomial CA-MRSA" are indistinct, early recognition is necessary in order to initiate appropriate antibiotics and infection control measures. Continual surveillance of pauci-resistant MRSA and molecular analysis are necessary in order to identify emerging strains as well as their epidemiology and transmission, both in the community and in healthcare setting.

  12. Antibiotic consumption and resistance: data from Europe and Germany.

    PubMed

    Meyer, Elisabeth; Gastmeier, Petra; Deja, Maria; Schwab, Frank

    2013-08-01

    The use of antibiotics - including the over- and misuse - in human and veterinary practices selected for resistant pathogens and led to their emergence and dissemination along with the transmission of resistant bacteria. The aim of this article is to prescribe the prerequisites for the surveillance of antibiotic use and bacterial resistance, to explain advantage and disadvantage of surveillance parameters used, to present new data from a surveillance network of intensive care units focusing on antibiotic use and resistance and to discuss the impact of antibiotic use on resistance. The Surveillance System of Antibiotic Use and Bacterial Resistance in Intensive Care Units (SARI) is an on-going project that collects data from its network of intensive care units (ICU) in Germany. Antimicrobial use was expressed as daily defined doses (DDD) and normalized per 1000 patient-days (pd). ICU decided either to provide monthly data on antibiotic and resistant pathogens or they decided to provide only yearly data on antibiotic use without resistance data. 85% of all antibiotics used in Germany are administered in animals; 85% of the antibiotics used in humans are prescribed in the outpatient setting and 85% of the antibiotics used in hospitals are prescribed on non-ICUs wards. The mostly widely used parameter for the surveillance of resistance is the percentage of resistant pathogens which is important to guide empirical therapy but does not measure the burden of resistance which is of interest to the public health perspective. The burden of MRSA did not increase over the last 11 years in ICUs and was 4.2MRSA/1000pd in 2011. The burden of 3rd generation resistant E. coli and K. pneumoniae more than quintupled (up to 2.6 and 1.2 respectively) and was followed by a three times increased use of carbapenems and correlated with quinolone and 3rd generation cephalosporin use. The burden VRE faecium also increased dramatically from 0.1 to 0.8 within 11 years; VRE faecium showed no

  13. Assessment of antibiotic resistance in runoff from cattle feedlots

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  15. Evaluating antibiotic resistance genes in soils with applied manures

    USDA-ARS?s Scientific Manuscript database

    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. Adjuvant strategies for potentiation of antibiotics to overcome antimicrobial resistance.

    PubMed

    Pieren, Michel; Tigges, Marcel

    2012-10-01

    Alarming facts about the occurrence and spreading of multiple antibiotic resistant bacteria have caught the attention of global surveillance authorities and public media. The demand for novel effective antimicrobial drugs is high and on the rise while, at the same time, the supply of fresh 'magic bullets' is drying up. This review summarizes examples of recent strategies for development of adjunctive antibiotic therapies that overcome microbial resistance and thus rejuvenate the existing arsenal of drugs. Recent studies have demonstrated the potential of compounds that inhibit the action of the repressor protein implicated in ethionamide resistance, thus stimulating activation of the drug and thereby restoring the activity of the antibiotic for treatment of Mycobacterium tuberculosis. Such specific interference with regulators or signal transduction mechanisms involved in antibiotic resistance or virulence provides a new toolbox for novel combinations of antimicrobial drugs with adjuvant molecules lacking intrinsic antibiotic activity. In addition to the development of new antibiotics and vaccination initiatives this strategy of restoring or potentiating the activity of existing antibiotics may help to postpone the day when antibiotics are no longer generally efficacious.

  17. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    EPA Science Inventory

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

  18. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    EPA Science Inventory

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

  19. Spatial analysis of antibiotic resistance along metal contaminated streams.

    PubMed

    Tuckfield, R Cary; McArthur, J Vaun

    2008-05-01

    The spatial pattern of antibiotic resistance in culturable sediment bacteria from four freshwater streams was examined. Previous research suggests that the prevalence of antibiotic resistance may increase in populations via indirect or coselection from heavy metal contamination. Sample bacteria from each stream were grown in media containing one of four antibiotics-tetracycline, chloramphenicol, kanamycin, and streptomycin-at concentrations greater than the minimum inhibitory concentration, plus a control. Bacteria showed high susceptibilities to the former two antibiotics. We summarized the latter two more prevalent (aminoglycoside) resistance responses and ten metals concentrations per sediment sample, by Principal Components Analysis. Respectively, 63 and 58% of the variability was explained in the first principal component of each variable set. We used these multivariate summary metrics [i.e., first principal component (PC) scores] as input measures for exploring the spatial correlation between antibiotic resistance and metal concentration for each stream sampled. Results show a significant and negative correlation between metals PC scores versus aminoglycoside resistance scores and suggest that selection for metal tolerance among sediment bacteria may influence selection for antibiotic resistance differently in sediments than in the water column. Our most important finding comes from geostatistical cross-variogram analysis, which shows that increasing metal concentration scores are spatially associated with decreasing aminoglycoside resistance scores--a negative correlation, but holds for contaminated streams only. We suspect our field results are influenced by metal bioavailability in the sediments and by a contaminant promoted interaction or "cocktail effect" from complex combinations of pollution mediated selection agents.

  20. Modes and Modulations of Antibiotic Resistance Gene Expression

    PubMed Central

    Depardieu, Florence; Podglajen, Isabelle; Leclercq, Roland; Collatz, Ekkehard; Courvalin, Patrice

    2007-01-01

    Since antibiotic resistance usually affords a gain of function, there is an associated biological cost resulting in a loss of fitness of the bacterial host. Considering that antibiotic resistance is most often only transiently advantageous to bacteria, an efficient and elegant way for them to escape the lethal action of drugs is the alteration of resistance gene expression. It appears that expression of bacterial resistance to antibiotics is frequently regulated, which indicates that modulation of gene expression probably reflects a good compromise between energy saving and adjustment to a rapidly evolving environment. Modulation of gene expression can occur at the transcriptional or translational level following mutations or the movement of mobile genetic elements and may involve induction by the antibiotic. In the latter case, the antibiotic can have a triple activity: as an antibacterial agent, as an inducer of resistance to itself, and as an inducer of the dissemination of resistance determinants. We will review certain mechanisms, all reversible, that bacteria have elaborated to achieve antibiotic resistance by the fine-tuning of the expression of genetic information. PMID:17223624

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

    PubMed

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

    2015-07-01

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

  2. Antibiotic-Resistant Bacteria: There is Hope.

    ERIC Educational Resources Information Center

    Offner, Susan

    1998-01-01

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

  3. Antibiotic-Resistant Bacteria: There is Hope.

    ERIC Educational Resources Information Center

    Offner, Susan

    1998-01-01

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

  4. Environmental and genetic modulation of the phenotypic expression of antibiotic resistance.

    PubMed

    Hughes, Diarmaid; Andersson, Dan I

    2017-03-08

    Antibiotic resistance can be acquired by mutation or horizontal transfer of a resistance gene, and generally an acquired mechanism results in a predictable increase in phenotypic resistance. However, recent findings suggest that the environment and/or the genetic context can modify the phenotypic expression of specific resistance genes/mutations. An important implication from these findings is that a given genotype does not always result in the expected phenotype. This dissociation of genotype and phenotype has important consequences for clinical bacteriology and for our ability to predict resistance phenotypes from genetics and DNA sequences. A related problem concerns the degree to which the genes/mutations currently identified in vitro can fully explain the in vivo resistance phenotype, or whether there is a significant additional amount of presently unknown mutations/genes (genetic 'dark matter') that could contribute to resistance in clinical isolates. Finally, a very important question is whether/how we can identify the genetic features that contribute to making a successful pathogen, and predict why some resistant clones are very successful and spread globally? In this review, we describe different environmental and genetic factors that influence phenotypic expression of antibiotic resistance genes/mutations and how this information is needed to understand why particular resistant clones spread worldwide and to what extent we can use DNA sequences to predict evolutionary success.

  5. Environmental and genetic modulation of the phenotypic expression of antibiotic resistance

    PubMed Central

    Andersson, Dan I

    2017-01-01

    Abstract Antibiotic resistance can be acquired by mutation or horizontal transfer of a resistance gene, and generally an acquired mechanism results in a predictable increase in phenotypic resistance. However, recent findings suggest that the environment and/or the genetic context can modify the phenotypic expression of specific resistance genes/mutations. An important implication from these findings is that a given genotype does not always result in the expected phenotype. This dissociation of genotype and phenotype has important consequences for clinical bacteriology and for our ability to predict resistance phenotypes from genetics and DNA sequences. A related problem concerns the degree to which the genes/mutations currently identified in vitro can fully explain the in vivo resistance phenotype, or whether there is a significant additional amount of presently unknown mutations/genes (genetic ‘dark matter’) that could contribute to resistance in clinical isolates. Finally, a very important question is whether/how we can identify the genetic features that contribute to making a successful pathogen, and predict why some resistant clones are very successful and spread globally? In this review, we describe different environmental and genetic factors that influence phenotypic expression of antibiotic resistance genes/mutations and how this information is needed to understand why particular resistant clones spread worldwide and to what extent we can use DNA sequences to predict evolutionary success. PMID:28333270

  6. Antibiotic transport in resistant bacteria: synchrotron UV fluorescence microscopy to determine antibiotic accumulation with single cell resolution.

    PubMed

    Kaščáková, Slávka; Maigre, Laure; Chevalier, Jacqueline; Réfrégiers, Matthieu; Pagès, Jean-Marie

    2012-01-01

    A molecular definition of the mechanism conferring bacterial multidrug resistance is clinically crucial and today methods for quantitative determination of the uptake of antimicrobial agents with single cell resolution are missing. Using the naturally occurring fluorescence of antibacterial agents after deep ultraviolet (DUV) excitation, we developed a method to non-invasively monitor the quinolones uptake in single bacteria. Our approach is based on a DUV fluorescence microscope coupled to a synchrotron beamline providing tuneable excitation from 200 to 600 nm. A full spectrum was acquired at each pixel of the image, to study the DUV excited fluorescence emitted from quinolones within single bacteria. Measuring spectra allowed us to separate the antibiotic fluorescence from the autofluorescence contribution. By performing spectroscopic analysis, the quantification of the antibiotic signal was possible. To our knowledge, this is the first time that the intracellular accumulation of a clinical antibiotic could be determined and discussed in relation with the level of drug susceptibility for a multiresistant strain. This method is especially important to follow the behavior of quinolone molecules at individual cell level, to quantify the intracellular concentration of the antibiotic and develop new strategies to combat the dissemination of MDR-bacteria. In addition, this original approach also indicates the heterogeneity of bacterial population when the same strain is under environmental stress like antibiotic attack.

  7. Antibiotic Resistance of Bacteria in Water Containing Ornamental Fishes

    PubMed Central

    Trust, T. J.; Whitby, J. L.

    1976-01-01

    Water containing ornamental fishes was found to frequently contain countable numbers of bacteria that were resistant to one or more antibiotic or chemotherapeutic agents. The multidrug-resistant strains most commonly isolated were lactose-fermenting Citrobacter freundii. The overall resistance of these aquaria strains was greater than the previously described resistance of clinical isolates of C. freundii. Although the strains examined appeared to lack R-factors, this pool of resistant bacteria may have public health implications. PMID:988781

  8. The Ecology of Antibiotic Use in the ICU: Homogeneous Prescribing of Cefepime but Not Tazocin Selects for Antibiotic Resistant Infection

    PubMed Central

    Ginn, Andrew N.; Wiklendt, Agnieszka M.; Gidding, Heather F.; George, Narelle; O’Driscoll, James S.; Partridge, Sally R.; O’Toole, Brian I.; Perri, Rita A.; Faoagali, Joan; Gallagher, John E.; Lipman, Jeffrey; Iredell, Jonathan R.

    2012-01-01

    Background Antibiotic homogeneity is thought to drive resistance but in vivo data are lacking. In this study, we determined the impact of antibiotic homogeneity per se, and of cefepime versus antipseudomonal penicillin/β-lactamase inhibitor combinations (APP-β), on the likelihood of infection or colonisation with antibiotic resistant bacteria and/or two commonly resistant nosocomial pathogens (methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa). A secondary question was whether antibiotic cycling was associated with adverse outcomes including mortality, length of stay, and antibiotic resistance. Methods We evaluated clinical and microbiological outcomes in two similar metropolitan ICUs, which both alternated cefepime with APP-β in four-month cycles. All microbiological isolates and commensal samples were analysed for the presence of antibiotic-resistant bacteria including MRSA and P. aeruginosa. Results Length of stay, mortality and overall antibiotic resistance were unchanged after sixteen months. However, increased colonisation and infection by antibiotic-resistant bacteria were observed in cefepime cycles, returning to baseline in APP-β cycles. Cefepime was the strongest risk factor for acquisition of antibiotic-resistant infection. Conclusions Ecological effects of different β-lactam antibiotics may be more important than specific activity against the causative agents or the effect of antibiotic homogeneity in selection for antibiotic resistance. This has important implications for antibiotic policy. PMID:22761698

  9. Prevalence of antibiotic-resistant bacteria in herbal products.

    PubMed

    Brown, Joseph C; Jiang, Xiuping

    2008-07-01

    The objective of this study was to determine the prevalence of antibiotic-resistant bacteria in various herbal products. Twenty-nine herbal supplements (18 traditional and 11 organic products) were purchased from stores and analyzed microbiologically. Total bacterial counts were determined by pour plate and surface spreading on tryptic soy agar (TSA). Antibiotic-resistant bacteria were enumerated on TSA supplemented with ceftriaxone (64 microg/ml) or tetracycline (16 microg/ml). Total bacterial counts ranged from <5 to 2.9 x 10(5) CFU/g. Ceftriaxone- and tetracycline-resistant bacteria were detected in ground garlic samples at 1.1 x 10(2) CFU/g and 3.0 x 102 CFU/g, respectively. Traditional and organic onion powder samples contained tetracycline-resistant bacteria at 17 and 28 CFU/g and ceftriaxone-resistant bacteria at 35 and 2.0 x 10(3) CFU/g, respectively. Other products such as ginger, rosemary, mustard, and goldenseal contained low levels of resistant bacteria. Fifty-two isolates were further evaluated against nine antibiotics, and the prevalence of antibiotic resistance was in the following order: ampicillin, nalidixic acid, trimethoprim, ceftriaxone, and streptomycin. Resistant bacteria were identified as Bacillus spp., Erwinia spp., and Ewingella americana. Staphylococcus spp., Enterobacter cloacae, and Stenotrophomonas maltophilia also were isolated. The presence of antibiotic-resistant bacteria and pathogens in these herbal products suggests that production and use of these products may need further evaluation.

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

    PubMed

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

    2016-06-01

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

  11. Assessing antibiotic resistance of microorganisms in sanitary sewage.

    PubMed

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

    2015-01-01

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

  12. Plasmid mediated antibiotic resistance in isolated bacteria from burned patients.

    PubMed

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

    2015-01-01

    Nowadays, the treatment of burned patients is difficult because of the high frequency of infection with antibiotic resistance bacteria. This study was conducted to evaluate the level of antibiotic resistance in Gram-negative bacteria and its relation with the existence of plasmid. The samples were collected from two hundred twenty hospitalized burned patients in Isfahan burn hospital during a three-month period (March 2012 to June 2012). The samples were isolated and the Gram-negative bacteria were identified using phenotypic method and API 20E System. Antibiotic susceptibility and plasmid profile were determined by standard Agar disc diffusion and plasmid spin column extraction methods. Totally 117 Gram-negative bacteria were isolated, the most common were Pseudomonas aerugionsa (37.6%), P. fluorescens (25.6%), Acinetobacter baumanii (20/5%) and Klebsiella pneumoniae (7.6%), respectively. The isolates showed high frequency of antibiotic resistance against ceftazidime and co-amoxiclave (100%) and low frequency of antibiotic resistance against amikacin with (70%).The results indicated that 60% of the isolates harboured plasmid. On the other hand, the patients infected with A. baumanii and P. aeruginosa were cured (with 60% frequency) whereas, those infected with P. fluorescens were not cured. Hence, probably antibiotic resistance markers of A. baumanii and P. aeruginosa are plasmid mediated; however, P. fluorescens is chromosomally mediated. Based on our findings, P. aerugionsa is a major causative agent of wound infections and amikacin could be considered as a more effective antibiotic for treatment of the burned patients.

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

    PubMed

    Laxminarayan, Ramanan; Chaudhury, Ranjit Roy

    2016-03-01

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

  14. Collective Resistance in Microbial Communities by Intracellular Antibiotic Deactivation.

    PubMed

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

    2016-12-01

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

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

    PubMed

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

    2016-08-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  17. [Antibiotic resistance analysis of Enterococcus spp. and Enterobacteriaceae spp. isolated from food].

    PubMed

    Korotkevich, Yu V

    2016-01-01

    The isolates from foods were screened for sensitivity to clinically significant antibiotics to assess the actual situation related to the prevalence of the antibiotic-resistant microorganisms in food. The goal of this work was to study the phenotypic characteristics of the antibiotic susceptibility of Enterobacteriaceae and Enterococcus spp. isolated from the good quality foods, and evaluation of the prevalence of tetracycline resistance in this groups of microbial contaminants. 68 strains of Enterobacteriaceae family and Enterococcus spp. isolated from poultry and livestock meat, pasteurized dairy products, acquired in the retail in the Moscow region, were studied. The disk-diffusion method (DDM) analysis showed a rather high prevalence of bacteria that are resistant and forming resistance to broad-spectrum antibiotics: in general 38% of Enterobacteriaceae strains and 40% of Enterococcus spp., isolated from meat products were resistant to tetracycline and doxycycline, and 21 and 33% - from dairy products, respectively; 26% of milk isolates and 54% of meat isolates were resistant to ampicillin. Considering that the tetracyclines is the most frequently used in animal husbandry and veterinary, the incidence and levels of tetracycline resistance were evaluated using tests with higher sensitivity to minimum inhibitory concentration (MIC), than the DDM. It was shown that among the Enterobacteriaceae strains 26% of isolates and 38% isolates were highly resistant to tetracycline (MIC ranged from 8 to 120 mg/kg) and 17-40% - among Enterococcus spp. These data obtained on a small number of samples, however, correspond to the frequency of tetracycline resistant strains detected in animal products in the EU (10-50%). Two multidrug-resistant enterobacteria strains - Klebsiella pneumoniae (farmer cheese) and Escherichia coli (minced turkey) were found among the .46 strains (4.4%), and they were resistant to 8 antibiotics.

  18. Epidemiological aspects of non-human antibiotic usage and resistance: implications for the control of antibiotic resistance in Ghana.

    PubMed

    Donkor, Eric S; Newman, Mercy J; Yeboah-Manu, Dorothy

    2012-04-01

    To provide insights into the epidemiology of antibiotic usage in animal husbandry in Ghana and its effect on resistance. Three hundred and ninety-five randomly sampled commercial livestock keepers who practised intensive or extensive farming were interviewed about their antibiotic usage practices using a structured questionnaire. Escherichia coli isolated from stool specimens of farmers and their animals were tested against eight antibiotics using the Kirby Bauer method. Ninety-eight percent (387) of the farmers used antibiotics on animals and the main purpose was to prevent infections in animals; 41% applied antibiotics monthly. The overall prevalence of multiple drug resistance among the E. coli isolates was 91.6%; rates in human and animal isolates were 70.6% and 97.7%, respectively. The prevalence of resistance in animal isolates to the various drugs ranged from 60.8% (amikacin) to 95.7% (ampicillin); the prevalence of resistance in human isolates to the drugs ranged from 2% (cefuroxime) to 94.1% (gentamicin). Animal E. coli isolates showed higher resistance than that of human isolates for five of eight drugs tested. It is concluded that antibiotic usage in animal husbandry in Ghana is more driven by the interest of livestock keepers to prevent and treat animal infections than growth enhancement. Both animal and human E. coli showed high levels of antibiotic resistance, although resistance of animal isolates appeared to be higher than that of humans. There is the need for the development of an antibiotic-resistance management programme in Ghana that will focus simultaneously on human and animal use of antibiotics. © 2012 Blackwell Publishing Ltd.

  19. Contribution of resistance-nodulation-cell division efflux systems to antibiotic resistance and biofilm formation in Acinetobacter baumannii.

    PubMed

    Yoon, Eun-Jeong; Chabane, Yassine Nait; Goussard, Sylvie; Snesrud, Erik; Courvalin, Patrice; Dé, Emmanuelle; Grillot-Courvalin, Catherine

    2015-03-24

    Acinetobacter baumannii is a nosocomial pathogen of increasing importance due to its multiple resistance to antibiotics and ability to survive in the hospital environment linked to its capacity to form biofilms. To fully characterize the contribution of AdeABC, AdeFGH, and AdeIJK resistance-nodulation-cell division (RND)-type efflux systems to acquired and intrinsic resistance, we constructed, from an entirely sequenced susceptible A. baumannii strain, a set of isogenic mutants overexpressing each system following introduction of a point mutation in their cognate regulator or a deletion for the pump by allelic replacement. Pairwise comparison of every derivative with the parental strain indicated that AdeABC and AdeFGH are tightly regulated and contribute to acquisition of antibiotic resistance when overproduced. AdeABC had a broad substrate range, including β-lactams, fluoroquinolones, tetracyclines-tigecycline, macrolides-lincosamides, and chloramphenicol, and conferred clinical resistance to aminoglycosides. Importantly, when combined with enzymatic resistance to carbapenems and aminoglycosides, this pump contributed in a synergistic fashion to the level of resistance of the host. In contrast, AdeIJK was expressed constitutively and was responsible for intrinsic resistance to the same major drug classes as AdeABC as well as antifolates and fusidic acid. Surprisingly, overproduction of AdeABC and AdeIJK altered bacterial membrane composition, resulting in decreased biofilm formation but not motility. Natural transformation and plasmid transfer were diminished in recipients overproducing AdeABC. It thus appears that alteration in the expression of efflux systems leads to multiple changes in the relationship between the host and its environment, in addition to antibiotic resistance. Increased expression of chromosomal genes for RND-type efflux systems plays a major role in bacterial multidrug resistance. Acinetobacter baumannii has recently emerged as an important

  20. Chloroquinolines block antibiotic efflux pumps in antibiotic-resistant Enterobacter aerogenes isolates.

    PubMed

    Ghisalberti, Didier; Mahamoud, Abdallah; Chevalier, Jacqueline; Baitiche, Milad; Martino, Michèle; Pagès, Jean-Marie; Barbe, Jacques

    2006-06-01

    Efflux mechanisms protect bacterial cells by pumping out toxic compounds and actively contribute to bacterial multidrug resistance. Agents inhibiting efflux pumps are of interest for the control of multidrug-resistant bacterial infections. Herein we report the effects of new chloroquinoline derivatives that render resistant Enterobacter aerogenes isolates noticeably more susceptible to structurally unrelated antibiotics. In addition, some of these chloroquinolines increase the intracellular concentration of chloramphenicol. Some of the molecules tested in this work are able to inhibit the main efflux pump (AcrAB-TolC), which is involved in E. aerogenes antibiotic resistance.

  1. Antibiotic resistance of microorganisms in agricultural soils in Russia

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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 blaTEM, blaSHV, 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.

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

    PubMed Central

    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

  4. Assessment of Antibiotic Resistant Commensal Bacteria in Food

    DTIC Science & Technology

    2006-01-01

    Campylobacter jejuni in the absence of antibiotic selection pressure. Proc Natl Acad Sci USA 102: 541–546. 12. Nandi, S., J.J. Maurer, C. Hofacre...Michel, L., and Zhang, Q. (2005) Enhanced in vivo fitness of fluoroquinolone-resistant Campylobacter jejuni in the absence of antibiotic selection...S. Pereira, O. Shin, J. Lin, S. Huang, L. Michel, and Q. Zhang. 2005a. Enhanced in vivo fitness of fluoroquinolone-resistant Campylobacter jejuni

  5. Rapid methods for detection of bacterial resistance to antibiotics.

    PubMed

    March-Rosselló, Gabriel Alberto

    2017-03-01

    The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24hours to obtain results. Here we review the main techniques for rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, microarrays, commercial methods used in work routine, immunochromatographic methods, colorimetric methods, image methods, nephelometry, MALDI-TOF mass spectrometry, flow cytometry, chemiluminescence and bioluminescence, microfluids and methods based on cell disruption are analysed in detail.

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

    PubMed

    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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  8. Antibiotic consumption and its influence on the resistance in Enterobacteriaceae.

    PubMed

    Sedláková, Miroslava Htoutou; Urbánek, Karel; Vojtová, Vladimíra; Suchánková, Hana; Imwensi, Peter; Kolář, Milan

    2014-07-16

    Increasing bacterial resistance to antibiotics is one of the most serious problems in current medicine. An important factor contributing to the growing prevalence of multiresistant bacteria is application of antibiotics. This study aimed at analyzing the development of resistance of Enterobacteriaceae to selected beta-lactam, fluoroquinolone and aminoglycoside antibiotics in the University Hospital Olomouc and assessing the effect of selection pressure of these antibiotics. For the period between 1 January 2000 and 31 December 2011, resistance of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Proteus mirabilis to third- and fourth-generation cephalosporins, meropenem, piperacillin/tazobactam, fluoroquinolones and aminoglycosides was retrospectively studied. For the assessment of selection pressure of antibiotics, a parameter of defined daily dose in absolute annual consumption (DDDatb) based on the ATC/DDD classification and in relative annual consumption (RDDDatb) as the number of defined daily doses per 100 bed-days was used. The relationship between frequency of strains resistant to a particular antibiotic and antibiotic consumption was assessed by linear regression analysis using Spearman's correlation. The level of statistical significance was set at p < 0.05. A total of 113,027 isolates from the Enterobacteriaceae family were analyzed. There was a significant effect of selection pressure of the primary antibiotic in the following cases: piperacillin/tazobactam in Klebsiella pneumoniae, gentamicin in Klebsiella pneumoniae and Escherichia coli and amikacin in Escherichia coli and Enterobacter cloacae. Also, there was significant correlation between resistance to ceftazidime and consumption of piperacillin/tazobactam in Klebsiella pneumoniae and Escherichia coli. No relationship was found between consumption of third- and fourth-generation cephalosporins and resistance to ceftazidime or between fluoroquinolone consumption and resistance to

  9. Antibiotic consumption and its influence on the resistance in Enterobacteriaceae

    PubMed Central

    2014-01-01

    Background Increasing bacterial resistance to antibiotics is one of the most serious problems in current medicine. An important factor contributing to the growing prevalence of multiresistant bacteria is application of antibiotics. This study aimed at analyzing the development of resistance of Enterobacteriaceae to selected beta-lactam, fluoroquinolone and aminoglycoside antibiotics in the University Hospital Olomouc and assessing the effect of selection pressure of these antibiotics. Methods For the period between 1 January 2000 and 31 December 2011, resistance of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Proteus mirabilis to third- and fourth-generation cephalosporins, meropenem, piperacillin/tazobactam, fluoroquinolones and aminoglycosides was retrospectively studied. For the assessment of selection pressure of antibiotics, a parameter of defined daily dose in absolute annual consumption (DDDatb) based on the ATC/DDD classification and in relative annual consumption (RDDDatb) as the number of defined daily doses per 100 bed-days was used. The relationship between frequency of strains resistant to a particular antibiotic and antibiotic consumption was assessed by linear regression analysis using Spearman’s correlation. The level of statistical significance was set at p < 0.05. Results A total of 113,027 isolates from the Enterobacteriaceae family were analyzed. There was a significant effect of selection pressure of the primary antibiotic in the following cases: piperacillin/tazobactam in Klebsiella pneumoniae, gentamicin in Klebsiella pneumoniae and Escherichia coli and amikacin in Escherichia coli and Enterobacter cloacae. Also, there was significant correlation between resistance to ceftazidime and consumption of piperacillin/tazobactam in Klebsiella pneumoniae and Escherichia coli. No relationship was found between consumption of third- and fourth-generation cephalosporins and resistance to ceftazidime or between fluoroquinolone

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

    PubMed

    Kirby, A; Santoni, N

    2015-04-01

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

  11. Horizontal gene transfer and antibiotic resistance plasmids in multi-drug resistant Salmonella enterica serovars

    USDA-ARS?s Scientific Manuscript database

    Antibiotic resistant foodborne pathogens pose serious public health concerns and increase the burden of disease treatment. Antibiotic resistance genes can reside on the bacterial chromosome or on other self-replicating DNA molecules such as plasmids. The resistance genes/DNA can be transferred int...

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

    USDA-ARS?s Scientific Manuscript database

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

  13. Antibiotic resistance: shifting the paradigm in topical acne treatment.

    PubMed

    Andriessen, Anneke; Lynde, Charles W

    2014-11-01

    Multiple topical therapies are available for mild to moderate acne vulgaris. The role of antibiotics and their resistance in the treatment of acne was reviewed by an expert panel of dermatologists who practice in Canada. Prior to the consensus meeting, the panel members filled out a survey on their current practice using topical treatment for acne. A literature review was carried out using information obtained from PubMed, Cochrane Library, Medline, and EMBASE. During a consensus meeting organized at the Spring Dermatology Update on April 27, 2014 in Toronto, ON, the panel had a blind vote on the issues at hand. The panel reached consensus on: 1) Antibiotics are an integral part of acne treatment not only due to their antibiotic effect but also by their anti-inflammatory action. 2) Oral antibiotics should be used for a short period of time if possible. 3) Topical antibiotics should not be used in monotherapy. 4) Retinoids are effective in reducing antibiotic resistance. 5) A benzoyl peroxide wash is as effective as topical benzoyl peroxide in reducing antibiotic resistance. 6) Therapy needs to be re-evaluated in 6-8 weeks versus 12 weeks. The recommendations given by the panel are to be disseminated to both general practitioners and dermatologists. For mild to moderate acne treatment, topical antibiotics in monotherapy are not to be used but may be combined with a retinoid or BPO to safely achieve more successful outcomes.

  14. Differences in antibiotic resistance patterns of Enterococcus faecalis and Enterococcus faecium strains isolated from farm and pet animals.

    PubMed

    Butaye, P; Devriese, L A; Haesebrouck, F

    2001-05-01

    The prevalence of acquired resistance in 146 Enterococcus faecium and 166 Enterococcus faecalis strains from farm and pet animals, isolated in 1998 and 1999 in Belgium, against antibiotics used for growth promotion and for therapy was determined. Acquired resistance against flavomycin and monensin, two antibiotics used solely for growth promotion, was not detected. Avoparcin (glycopeptide) resistance was found sporadically in E. faecium only. Avilamycin resistance was almost exclusively seen in strains from farm animals. Resistance rates were higher in E. faecium strains from broiler chickens than in strains from other animal groups with tylosin and virginiamycin and in E. faecalis as well as in E. faecium strains with narasin and bacitracin. Resistance against ampicillin was mainly found among E. faecium strains from pets and was absent in E. faecalis. Tetracycline resistance occurred most often in strains from farm animals, while enrofloxacin resistance, only found in E. faecalis, occurred equally among strains from all origins. Resistance against gentamicin was very rare in broiler strains, whereas resistance rates were high in strains from other origins. It can be concluded that resistance against antibiotics used solely for growth promotion was more prevalent in E. faecium strains than in E. faecalis strains. With few exceptions, resistance against the different categories of antibiotics was more prevalent in strains from farm animals than in those from pets.

  15. Differences in Antibiotic Resistance Patterns of Enterococcus faecalis and Enterococcus faecium Strains Isolated from Farm and Pet Animals

    PubMed Central

    Butaye, Patrick; Devriese, Luc A.; Haesebrouck, Freddy

    2001-01-01

    The prevalence of acquired resistance in 146 Enterococcus faecium and 166 Enterococcus faecalis strains from farm and pet animals, isolated in 1998 and 1999 in Belgium, against antibiotics used for growth promotion and for therapy was determined. Acquired resistance against flavomycin and monensin, two antibiotics used solely for growth promotion, was not detected. Avoparcin (glycopeptide) resistance was found sporadically in E. faecium only. Avilamycin resistance was almost exclusively seen in strains from farm animals. Resistance rates were higher in E. faecium strains from broiler chickens than in strains from other animal groups with tylosin and virginiamycin and in E. faecalis as well as in E. faecium strains with narasin and bacitracin. Resistance against ampicillin was mainly found among E. faecium strains from pets and was absent in E. faecalis. Tetracycline resistance occurred most often in strains from farm animals, while enrofloxacin resistance, only found in E. faecalis, occurred equally among strains from all origins. Resistance against gentamicin was very rare in broiler strains, whereas resistance rates were high in strains from other origins. It can be concluded that resistance against antibiotics used solely for growth promotion was more prevalent in E. faecium strains than in E. faecalis strains. With few exceptions, resistance against the different categories of antibiotics was more prevalent in strains from farm animals than in those from pets. PMID:11302798

  16. Antibiotic resistance - is resistance detected by surveillance relevant to predicting resistance in the clinical setting?

    PubMed

    Karlowsky, James A; Sahm, Daniel F

    2002-10-01

    Local, regional, national and global surveillance initiatives have several important functions, which include identifying shifts in antibiotic resistance, detecting the emergence of new resistance mechanisms and monitoring the impact of changes made to empiric prescribing, infection control and public health guidelines. Although the need for surveillance is indubitable and its use in the treatment of individual patients important, it cannot unequivocally predict outcomes in patients with infections. Treatment regimens for individual patients with suspected or demonstrated infections should be developed following consideration of symptoms, laboratory findings and relevant medical history, and in the context of appropriate local and widespread antibiotic resistance trends.

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

    PubMed

    Reis, Ana Carolina Costa; Santos, Susana Regia da Silva; Souza, Siane Campos de; Saldanha, Milena Góes; Pitanga, Thassila Nogueira; Oliveira, Ricardo Riccio

    2016-07-11

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

  18. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-