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Sample records for antimicrobial resistance prevalence

  1. Prevalence and antimicrobial resistance of Salmonella recovered from processed poultry.

    PubMed

    Parveen, Salina; Taabodi, Maryam; Schwarz, Jurgen G; Oscar, Thomas P; Harter-Dennis, Jeanine; White, David G

    2007-11-01

    This study was conducted to determine the prevalence and antimicrobial resistance of Salmonella isolates recovered from processed poultry. Four hundred eighty pre- and postchill whole broiler chicken carcasses were collected from a poultry processing plant between July 2004 and June 2005. Water samples also were collected at the entrance and exit of the chiller. After preenrichment, carcass and water samples were analyzed for the presence of Salmonella using the automated BAX system followed by traditional culture methods. The proportions of pre- and postchill carcasses that were positive for Salmonella were 88.4 and 84.1%, respectively. Ninety-two percent of water samples collected at the entrance of the chiller were positive for Salmonella, but all exit samples were negative. There was no significant difference in the prevalence of Salmonella between pre- and postchill carcasses (P > 0.05). Salmonella isolates recovered were serotyped and tested for susceptibility to antimicrobials. Thirteen serotypes were identified; the most common were Salmonella Kentucky (59.5%) and Salmonella Typhimurium (17.8%). Three hundred thirty-nine (79.8%) of the isolates were resistant to at least one antimicrobial, and 53.4% were resistant to three or more antimicrobials. Resistance was most often observed to tetracycline (73.4% of isolates), ampicillin (52.9%), amoxicillin-clavulanic acid (52%), ceftiofur (51.7%), streptomycin (35.2%), and sulfisoxazole (21.8%). These results indicate the high prevalence of Salmonella contamination in whole broiler carcasses, and a large number of these Salmonella isolates were resistant to commonly used antimicrobials. PMID:18044422

  2. Prevalence and antimicrobial resistance in Escherichia coli from food and animals in Lagos, Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing ...

  3. Prevalence and antimicrobial resistance in Escherichia coli from food animals in Lagos, Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing animals fr...

  4. Prevalence, serotype and antimicrobial resistance of salmonellae isolated from commercially processed broiler carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was undertaken to determine the prevalence, serotype and antimicrobial resistance profiles of Salmonella on broiler carcasses collected from commercial processing plants. Twenty US commercial processing plants representing eight integrators in thirteen states were included in the survey....

  5. Effect of commercial broiler processing on prevalence and antimicrobial resistance of salmonellae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Broiler processing includes interventions specifically designed to lessen bacterial contamination of carcasses. Purpose: This study was undertaken to determine the prevalence, serotype and antimicrobial resistance profiles of Salmonella on broiler carcasses collected from commercial pr...

  6. Role of Antimicrobial Selective Pressure and Secondary Factors on Antimicrobial Resistance Prevalence in Escherichia coli from Food-Producing Animals in Japan

    PubMed Central

    Harada, Kazuki; Asai, Tetsuo

    2010-01-01

    The use of antimicrobial agents in the veterinary field affects the emergence, prevalence, and dissemination of antimicrobial resistance in bacteria isolated from food-producing animals. To control the emergence, prevalence, and dissemination of antimicrobial resistance, it is necessary to implement appropriate actions based on scientific evidence. In Japan, the Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM) was established in 1999 to monitor the antimicrobial susceptibility of foodborne and commensal bacteria from food-producing animals. The JVARM showed that the emergence and prevalence of resistant Escherichia coli were likely linked to the therapeutic antimicrobial use in food-producing animals through not only direct selection of the corresponding resistance but also indirect selections via cross-resistance and coresistance. In addition, relevant factors such as host animals and bacterial properties might affect the occurrence and prevalence of antimicrobial-resistant E. coli under the selective pressure from antimicrobial usage. This paper reviews the trends in antimicrobial resistance in E. coli and consumption of antimicrobials agents in Japan and introduces the relationship between antimicrobial usage and prevalence of antimicrobial-resistant bacteria, from food-producing animals under the JVARM program. In this paper, we will provide the underlying information about the significant factors that can help control antimicrobial resistance in bacteria in veterinary medicine. PMID:20589071

  7. Prevalence, Antimicrobial Resistance, and Genotypic Characterization of Vancomycin-Resistant Enterococci in Meat Preparations.

    PubMed

    Guerrero-Ramos, Emilia; Molina-González, Diana; Blanco-Morán, Sonia; Igrejas, Gilberto; Poeta, Patrícia; Alonso-Calleja, Carlos; Capita, Rosa

    2016-05-01

    A total of 160 samples of poultry (80), pork (40), and beef (40) preparations (red sausages, white sausages, hamburgers, meatballs, nuggets, minced meat, escalope, and crepes) were tested in northwestern Spain to determine the prevalence of vancomycin-resistant enterococci (VRE). VRE were detected in 38 (23.8%) samples (37.5% of poultry, 15.0% of pork, and 5.0% of beef samples). One strain per food sample was further characterized. Isolates were identified as Enterococcus faecium (14 strains), E. durans (10), E. hirae (7), E. gallinarum (5), and E. casseliflavus-E. flavescens (2). All strains showed resistance or intermediate susceptibility to three or more antimicrobials of clinical significance, in addition to vancomycin. High rates of resistance or intermediate susceptibility were observed for teicoplanin (81.6% of isolates), chloramphenicol (81.6%), erythromycin (100%), quinupristin-dalfopristin (89.5%), and ciprofloxacin (81.6%). A moderate rate of resistance or intermediate susceptibility emerged for ampicillin (34.2%) and tetracycline (36.8%). Genes encoding antimicrobial resistance and virulence were studied by PCR. The vanA, vanB, vanC-1, and vanC-2/3 genes were identified in 27, 1, 5, and 2 isolates, respectively. Other resistance genes or transposon sequences found were tet(L), tet(M), Tn5397 (tetracycline), erm(A), erm(B) (erythromycin), vat(D), and vat(E) (quinupristin-dalfopristin). Most isolates were free of virulence determinants (agg, hyl, and efaAfm genes were detected in one, one, and five strains, respectively). Strains were classified as not biofilm producers (crystal violet assay; 4 isolates) or weak biofilm producers (34 isolates). Cluster analysis (EcoRI ribotyping) suggested a strong genetic relationship among isolates from different types of meat preparations, animal species, and retail outlets. Meat preparations might play a role in the spread through the food chain of VRE with several resistance and virulence genes. PMID:27296421

  8. Prevalence and Antimicrobial Resistance of Salmonella spp. Recovered from Processed Poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study determined the prevalence and antimicrobial resistance of Salmonella spp. recovered from processed poultry. Four hundred and eighty pre- or post-chill whole broiler carcasses were collected from a poultry processing plant between July 2004 and June 2005. In addition, water samples were ...

  9. Prevalence and Antimicrobial Resistance in Escherichia coli from Food Animals in Lagos, Nigeria.

    PubMed

    Adenipekun, Eyitayo O; Jackson, Charlene R; Oluwadun, Afolabi; Iwalokun, Bamidele A; Frye, Jonathan G; Barrett, John B; Hiott, Lari M; Woodley, Tiffanie A

    2015-06-01

    Foodborne bacteria are often associated with human infections; these infections can become more complicated to treat if the bacteria are also resistant to antimicrobials. In this study, prevalence, antimicrobial resistance, and genetic relatedness of Escherichia coli among food producing animals from Lagos, Nigeria, was investigated. From December 2012 to June 2013, E. coli were isolated from fecal samples of healthy cattle, chicken, and swine. Antimicrobial susceptibility testing against 22 antimicrobials was performed using broth microdilution with the Sensititre™ system. Clonal types were determined by pulsed-field gel electrophoresis (PFGE). From the analysis, 211/238 (88.7%), 170/210 (81%), and 136/152 (89.5%) samples from cattle, chicken, and swine, respectively, were positive for E. coli. A subset of those isolates (n=211) selected based on β-lactamase production was chosen for further study. Overall, E. coli exhibited the highest resistance to tetracycline (124/211; 58.8%), trimethoprim/sulfamethoxazole (84/211; 39.8%), and ampicillin (72/211; 34.1%). Approximately 40% of the isolates were pan-susceptible, and none of the isolates were resistant to amikacin, cefepime, ceftazidime, ertapenem, meropenem, or tigecycline. Among the resistant isolates, 28 different resistance patterns were observed; 26 of those were characterized as multi-drug resistant (MDR; resistance to ≥2 antimicrobials). One isolate was resistant to 13 different antimicrobials representing five different antimicrobial classes. Using PFGE, MDR E. coli were genetically diverse and overall did not group based on source; identical PFGE patterns were detected among isolates from different sources. These results suggest that isolates cannot be attributed to specific sources, and some may be present across all of the sources. Results from this study indicate that food-producing animals in Nigeria are a reservoir of MDR E. coli that may be transferred to humans via the food chain. PMID

  10. Prevalence and antimicrobial resistance of Salmonella spp. in non-diarrhoeic dogs in Trinidad.

    PubMed

    Seepersadsingh, N; Adesiyun, A A; Seebaransingh, R

    2004-09-01

    The estimated prevalence and antimicrobial resistances of Salmonella spp. in non-diarrhoeic dogs across Trinidad was determined. The serotypes of Salmonella spp. isolated were also identified. Of a total of 1391 dogs sampled, 50 (3.6%) were positive for Salmonella spp. with 28 different serotypes, the predominant serotypes were Javiana (12), Newport (6), Arechavaleta (5) and Heidelberg (5). Fifty-seven (85.1%) of 67 isolates exhibited resistance to one or more antimicrobial agents. Of eight antimicrobial agents tested, resistance was exhibited to streptomycin (80.6%), cephalothin (37.3%), neomycin (38.8%) and gentamicin (9.0%). All isolates were sensitive to ampicillin, norfloxacin, choramphenicol and sulphamethoxazole/trimethoprim. It was concluded that the isolation of the Salmonella spp. from non-diarrhoeic dogs could pose health hazard to their owners as most serotypes are known to be virulent. Furthermore, the prevalence of resistance to antimicrobial agents amongst the Salmonella isolates from these animals indicates susceptibility testing may influence chemotherapeutic choices when treating these isolates. PMID:15525361

  11. Temporal Prevalence of Antimicrobial Resistance in Campylobacter spp. from Beef Cattle in Alberta Feedlots†

    PubMed Central

    Inglis, G. D.; Morck, D. W.; McAllister, T. A.; Entz, T.; Olson, M. E.; Yanke, L. J.; Read, R. R.

    2006-01-01

    Antimicrobial resistance (AMR) was temporally assessed in campylobacters isolated from beef cattle (7,738 fecal samples from 2,622 animals) in four commercial feedlots in Alberta. All calves were administered chlortetracycline and oxytetracycline in feed, and a majority of the animals (93%) were injected with long-acting oxytetracycline upon arrival at the feedlot. Fecal samples from individual animals were collected upon arrival (i.e., entry sample), 69 days (standard deviation [SD] = 3 days) after arrival (i.e., interim sample), and 189 days (SD = 33 days) after arrival (i.e., exit sample) at the feedlot. In total, 1,586 Campylobacter isolates consisting of Campylobacter coli (n = 154), Campylobacter fetus (n = 994), Campylobacter jejuni (n = 431), Campylobacter hyointestinalis (n = 4), and Campylobacter lanienae (n = 3) were recovered and characterized. The administration of antimicrobials did not decrease carriage rates of campylobacters, and minimal resistance (≤4%) to azithromycin, ciprofloxacin, enrofloxacin, gentamicin, and meropenem was observed. In contrast, substantive increases in the prevalence of isolates resistant to tetracycline and doxycycline (56 to 89%) for C. coli, C. fetus, and C. jejuni, as well as in the number of animals (7 to 42%) from which resistant isolates were recovered, were observed during the feedlot period. Increased resistance to erythromycin (total isolates and carriages rates) was also observed in isolates of C. coli over the three isolation times. The majority of C. fetus isolates recovered were resistant to nalidixic acid, but this was independent of when they were isolated. A relatively limited number of multidrug-resistant isolates were recovered and consisted primarily of C. coli resistant to tetracyclines and erythromycin (10% of isolates). Over the course of the feedlot period, considerable increases in antimicrobial resistance were observed in C. coli, C. fetus, and C. jejuni, but with the exception of erythromycin

  12. Prevalence of antimicrobial resistance in Escherichia coli and Klebsiella spp. in rural South India.

    PubMed

    Sekar, Ramalingam; Mythreyee, Manoharan; Srivani, Seetharaman; Amudhan, Murugesan

    2016-06-01

    The emergence and dissemination of antimicrobial resistance (AMR) is an important public health problem as resistant organisms cause difficult-to-treat infections. In this study, the prevalence of AMR in Escherichia coli and Klebsiella spp. in rural South India was examined in order to aid empirical therapy. A cross-sectional prospective study was conducted during the period from January 2012 to December 2014. Routine clinical isolates of E. coli and Klebsiella spp. were tested for antimicrobial susceptibility to β-lactams, aminoglycosides, fluoroquinolones, tetracyclines, colistin and nitrofurantoin by the Kirby-Bauer disk diffusion method and the data were documented and analyzed with one per patient analysis using WHONET software. A total of 2292 non-duplicate clinical isolates were recovered during the study period, including 1338 E. coli and 954 Klebsiella spp. The prevalence of AMR in the total isolates was as follows: amikacin, 17.3%; ertapenem, 14.4%; doripenem, 4.5%; colistin, 13.2%; and tigecycline, 4.1%. The study results indicate a high prevalence of carbapenem resistance in Klebsiella spp. especially from pus and urinary isolates, whilst the prevalence of aztreonam and fluoroquinolone resistance was very high in E. coli. PMID:27436473

  13. Prevalence and Antimicrobial Resistance of Campylobacter Isolated from Dressed Beef Carcasses and Raw Milk in Tanzania.

    PubMed

    Kashoma, Isaac P; Kassem, Issmat I; John, Julius; Kessy, Beda M; Gebreyes, Wondwossen; Kazwala, Rudovick R; Rajashekara, Gireesh

    2016-01-01

    Campylobacter species are commonly transmitted to humans through consumption of contaminated foods such as milk and meat. The aim of this study was to investigate the prevalence, antimicrobial resistance, and genetic determinants of resistance of Campylobacter isolated from raw milk and beef carcasses in Tanzania. The antimicrobial resistance genes tested included blaOXA-61 (ampicillin), aph-3-1 (aminoglycoside), tet(O) (tetracycline), and cmeB (multi-drug efflux pump). The prevalence of Campylobacter was 9.5% in beef carcasses and 13.4% in raw milk, respectively. Using multiplex-polymerase chain reaction (PCR), we identified 58.1% of the isolates as Campylobacter jejuni, 30.7% as Campylobacter coli, and 9.7% as other Campylobacter spp. One isolate (1.6%) was positive for both C. jejuni and C. coli specific PCR. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method showed resistance to: ampicillin (63% and 94.1%), ciprofloxacin (9.3% and 11.8%), erythromycin (53.7% and 70.6%), gentamicin (0% and 15.7%), streptomycin (35.2% and 84.3%), and tetracycline (18.5% and 17.7%), respectively. Resistance to azithromycin (42.6%), nalidixic acid (64.8%), and chloramphenicol (13%) was determined using the disk diffusion assay only, while resistance to tylosin (90.2%) was quantified using the broth microdilution method. The blaOXA-61 (52.6% and 28.1%), cmeB (26.3% and 31.3%), tet(O) (26.3% and 31.3%), and aph-3-1 (5.3% and 3.0%) were detected in C. coli and C. jejuni. These findings highlight the extent of antimicrobial resistance in Campylobacter occurring in important foods in Tanzania. The potential risks to consumers emphasize the need for adequate control approaches, including the prudent use of antimicrobials to minimize the spread of antimicrobial-resistant Campylobacter. PMID:26153978

  14. High prevalence of antimicrobial resistance among clinical Streptococcus pneumoniae isolates in Asia (an ANSORP study).

    PubMed

    Song, Jae-Hoon; Jung, Sook-In; Ko, Kwan Soo; Kim, Na Young; Son, Jun Seong; Chang, Hyun-Ha; Ki, Hyun Kyun; Oh, Won Sup; Suh, Ji Yoeun; Peck, Kyong Ran; Lee, Nam Yong; Yang, Yonghong; Lu, Quan; Chongthaleong, Anan; Chiu, Cheng-Hsun; Lalitha, M K; Perera, Jennifer; Yee, Ti Teow; Kumarasinghe, Gamini; Jamal, Farida; Kamarulzaman, Adeeba; Parasakthi, Navaratnam; Van, Pham Hung; Carlos, Celia; So, Thomas; Ng, Tak Keung; Shibl, Atef

    2004-06-01

    A total of 685 clinical Streptococcus pneumoniae isolates from patients with pneumococcal diseases were collected from 14 centers in 11 Asian countries from January 2000 to June 2001. The in vitro susceptibilities of the isolates to 14 antimicrobial agents were determined by the broth microdilution test. Among the isolates tested, 483 (52.4%) were not susceptible to penicillin, 23% were intermediate, and 29.4% were penicillin resistant (MICs >/= 2 mg/liter). Isolates from Vietnam showed the highest prevalence of penicillin resistance (71.4%), followed by those from Korea (54.8%), Hong Kong (43.2%), and Taiwan (38.6%). The penicillin MICs at which 90% of isolates are inhibited (MIC(90)s) were 4 mg/liter among isolates from Vietnam, Hong Kong, Korea, and Taiwan. The prevalence of erythromycin resistance was also very high in Vietnam (92.1%), Taiwan (86%), Korea (80.6%), Hong Kong (76.8%), and China (73.9%). The MIC(90)s of erythromycin were >32 mg/liter among isolates from Korea, Vietnam, China, Taiwan, Singapore, Malaysia, and Hong Kong. Isolates from Hong Kong showed the highest rate of ciprofloxacin resistance (11.8%), followed by isolates from Sri Lanka (9.5%), the Philippines (9.1%), and Korea (6.5%). Multilocus sequence typing showed that the spread of the Taiwan(19F) clone and the Spain(23F) clone could be one of the major reasons for the rapid increases in antimicrobial resistance among S. pneumoniae isolates in Asia. Data from the multinational surveillance study clearly documented distinctive increases in the prevalence rates and the levels of antimicrobial resistance among S. pneumoniae isolates in many Asian countries, which are among the highest in the world published to date. PMID:15155207

  15. Antimicrobial Resistance

    MedlinePlus

    ... antibiotic are known as methicillin-resistant S. aureus or MRSA. Antibiotics and other antimicrobial drugs first became widely ... factors for infection are known as community-associated MRSA (CA-MRSA). Recently, several cases overseas and in ...

  16. Prevalence and antimicrobial resistance of Salmonella isolated from meat and meat products in Algiers (Algeria).

    PubMed

    Mezali, Lynda; Hamdi, Taha Mossadak

    2012-06-01

    This study was conducted in order to estimate the proportion of raw meat and processed meat products contaminated by Salmonella in the region of Algiers, Algeria, to identify serovars and to determine the antimicrobial resistance patterns of isolates. Out of the total 314 samples (144 of raw red meat and meat products, 128 of raw poultry meat and poultry products, and 42 of processed meat products) collected from various retail outlets, 61 (19.43%) were tested positive for Salmonella. The most significant occurrences were recorded for the categories of red meat (23.61%, n=34) and poultry (17.97%, n=23). Among the 64 isolates recovered, 21 different serovars were identified and two strains were nontypable. The most prevalent serovars were Salmonella Anatum (14.6%, n=9), Salmonella Altona (12.50%, n=8), Salmonella Corvallis (7.81%, n=5), Salmonella Enteritidis (7.81%, n=5), and Salmonella Typhimurium (7.81%, n=5). Sixty-two Salmonella isolates were tested for their susceptibility to 32 selected antimicrobial agents. Fifty-six (90.32%) isolates were resistant to at least one antimicrobial, of which 20 (32.26%) showed multidrug resistance. Resistance to sulphonamides (87.10%, n=54) was the most common. Resistance rates were lower to nalidixic acid (16.13%, n=10), streptomycin (16.13%, n=10), and tetracycline (12.90%, n=8), while resistance to pefloxacin was estimated at 4.84% (n=3). Fourteen different resistance patterns were observed. The "ACSSuT" pentaresistance pattern was observed in three of the Salmonella Typhimurium strains. The obtained results show that these foodstuffs are a potential source of antimicrobial-resistant Salmonella for human infections. PMID:22571639

  17. Determination of the prevalence of antimicrobial resistance genes in canine Clostridium perfringens isolates.

    PubMed

    Kather, Elizabeth J; Marks, Stanley L; Foley, Janet E

    2006-03-10

    Clostridium perfringens is a well documented cause of a mild self-limiting diarrhea and a potentially fatal acute hemorrhagic diarrheal syndrome in the dog. A recent study documented that 21% of canine C. perfringens isolates had MIC's indicative of resistance to tetracycline, an antimicrobial commonly recommended for treatment of C. perfringens-associated diarrhea. The objective of the present study was to further evaluate the antimicrobial susceptibility profiles of these isolates by determining the prevalence of specific resistance genes, their expression, and ability for transference between bacteria. One hundred and twenty-four canine C. perfringens isolates from 124 dogs were evaluated. Minimum inhibitory concentrations of tetracycline, erythromycin, tylosin, and metronidazole were determined using the CLSI Reference Agar Dilution Method. All isolates were screened for three tetracycline resistance genes: tetA(P), tetB(P) and tetM, and two macrolide resistance genes: ermB and ermQ, via PCR using primer sequences previously described. Ninety-six percent (119/124) of the isolates were positive for the tetA(P) gene, and 41% (51/124) were positive for both the tetA(P) and tetB(P) genes. No isolates were positive for the tetB(P) gene alone. Highly susceptible isolates (MIC< or = 4 microg/ml) were significantly more likely to lack the tetB(P) gene. One isolate (0.8%) was positive for the ermB gene, and one isolate was positive for the ermQ gene. The tetM gene was not found in any of the isolates tested. Two out of 15 tested isolates (13%) demonstrated transfer of tetracycline resistance via bacterial conjugation. Tetracycline should be avoided for the treatment of C. perfringens-associated diarrhea in dogs because of the relatively high prevalence of in vitro resistance, and the potential for conjugative transfer of antimicrobial resistance. PMID:16330169

  18. Prevalence and Antimicrobial-Resistance of Pseudomonas aeruginosa in Swimming Pools and Hot Tubs

    PubMed Central

    Lutz, Jonathan K.; Lee, Jiyoung

    2011-01-01

    Pseudomonas aeruginosa is an important opportunistic pathogen in recreational waters and the primary cause of hot tub folliculitis and otitis externa. The aim of this surveillance study was to determine the background prevalence and antimicrobial resistance profile of P. aeruginosa in swimming pools and hot tubs. A convenience sample of 108 samples was obtained from three hot tubs and eight indoor swimming pools. Water and swab samples were processed using membrane filtration, followed by confirmation with polymerase chain reaction. Twenty-three samples (21%) were positive for P. aeruginosa, and 23 isolates underwent susceptibility testing using the microdilution method. Resistance was noted to several antibiotic agents, including amikacin (intermediate), aztreonam, ceftriaxone, gentamicin, imipenem, meropenem (intermediate), ticarcillin/clavulanic acid, tobramycin (intermediate), and trimethoprim/sulfamethoxazole. The results of this surveillance study indicate that 96% of P. aeruginosa isolates tested from swimming pools and hot tubs were multidrug resistant. These results may have important implications for cystic fibrosis patients and other immune-suppressed individuals, for whom infection with multidrug-resistant P. aeruginosa would have greater impact. Our results underlie the importance of rigorous facility maintenance, and provide prevalence data on the occurrence of antimicrobial resistant strains of this important recreational water-associated and nosocomial pathogen. PMID:21556203

  19. High Prevalence of Antimicrobial Resistance Among Common Bacterial Isolates in a Tertiary Healthcare Facility in Rwanda

    PubMed Central

    Ntirenganya, Cyprien; Manzi, Olivier; Muvunyi, Claude Mambo; Ogbuagu, Onyema

    2015-01-01

    Antimicrobial resistance (AMR) is a serious public health threat in both developed and developing countries. Many developing countries, including Rwanda, lack adequate surveillance systems, and therefore, the prevalence of AMR is not well-known. We conducted a prospective observational study to assess the prevalence of AMR among common bacterial isolates from clinical specimens obtained from patients on the medical wards of Kigali University Teaching Hospital (KUTH). We evaluated the antibiotic sensitivity patterns of bacterial pathogens cultured from urine, blood, sputum, and wound swab specimens obtained over a 6-month period (July 1 to December 30, 2013). There were 154 positive cultures from specimens obtained from 141 unique patients over the study period. Urine, blood, wound swab, and sputum cultures comprised 55.2%, 25.3%, 16.2%, and 3.3% of the total specimens evaluated; 31.4% and 58.7% of Escherichia coli and Klebsiella isolates, respectively, were resistant to at least one of the third generation cephalosporins. Eight percent of E. coli isolates were resistant to imipenem; 82% and 6% of Staphylococcus aureus strains were oxacillin- and vancomycin-resistant respectively. Antimicrobial resistance rates are high in Rwanda and pose a serious therapeutic challenge to the management of common infections. PMID:25646259

  20. Prevalence of antimicrobial resistance and resistance genes in faecal Escherichia coli isolates recovered from healthy pets.

    PubMed

    Costa, Daniela; Poeta, Patricia; Sáenz, Yolanda; Coelho, Ana Cláudia; Matos, Manuela; Vinué, Laura; Rodrigues, Jorge; Torres, Carmen

    2008-02-01

    Faecal samples of healthy dogs (n=39) and cats (n=36) obtained in Northern Portugal were seeded on Levine agar plates, and two Escherichia coli isolates per sample were recovered (78 of dogs and 66 of cats). The susceptibility to 16 antimicrobial agents was tested in this series of 144 E. coli isolates. Almost 20% of them showed tetracycline resistance and 12 and 15% presented ampicillin or streptomycin resistance, respectively. The percentage of resistance to the other antimicrobial agents was in all cases below 4%, and no resistant isolates were detected for ceftazidime, imipenem, cefoxitin or amikacin. Two isolates (from one dog) showed cefotaxime-resistance and harboured both the CTX-M-1 and OXA-30 beta-lactamases. A bla(TEM) gene was detected in 12 of 17 ampicillin-resistant isolates, the aac(3)-II gene in the three gentamicin-resistant isolates, aadA in 7 of 22 streptomycin-resistant isolates, and tet(A) and/or tet(B) gene in all 28 tetracycline-resistant isolates. The gene encoding class 1 integrase was detected in six E. coli isolates, including the four trimethoprim-sulfamethoxazole-resistant isolates and those two harbouring CTX-M-1 and OXA-30 beta-lactamases; different gene cassette arrangements were identified: dfrA1+aadA1 (two isolates), dfrA12+orfF+aadA2 (two isolates) and bla(OXA30)+aadA1 (two isolates). One amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in four nalidixic acid-resistant and ciprofloxacin-susceptible isolates and two amino acid changes in GyrA (Ser83Leu+Asp87Asn) and one in ParC (Ser80Ile) were identified in one nalidixic acid- and ciprofloxacin-resistant isolate. Faecal E. coli isolates of healthy pets could be a reservoir of antimicrobial resistance genes. PMID:17870255

  1. Effect of farm type on within-herd Salmonella prevalence, serovar distribution, and antimicrobial resistance.

    PubMed

    Rasschaert, G; Michiels, J; Arijs, D; Wildemauwe, C; De Smet, S; Heyndrickx, M

    2012-05-01

    Salmonella represents a major challenge to the pig industry, as pork presents a risk for human salmonellosis. In this study, we have examined the effect of farm type on the prevalence of fattening pigs shedding Salmonella on 12 farms at risk for harboring Salmonella. On six open (grow-to-finish) and six closed (farrow-to-finish) farms, the prevalence of pigs shedding Salmonella was determined on two occasions approximately 2 months apart. The serovar, phage type, and antimicrobial resistance of the obtained Salmonella isolates were determined. On all farms, pigs shedding Salmonella were detected on at least one of the two sampling days. The mean within-herd prevalence was 7.8%. Closed farms were two times less likely to have pigs shedding Salmonella than open farms. On open farms, the odds of finding Salmonella shedding in pigs were 1.9 times higher when sampling was performed at slaughter age than when samples were taken halfway through the fattening period. Salmonella enterica serovar Typhimurium was the most predominant serotype, with a prevalence of 62 to 63% on both farm types. Of all the Salmonella Typhimurium isolates, 65% had the tetraresistant profile ASSuT (ampicillin, streptomycin, sulfonamide, and tetracycline) with or without additional resistance to trimethoprim-sulfonamide. Phage type DT120 seemed to be especially associated with this antimicrobial-resistant profile. The prevalence of Salmonella Typhimurium isolates showing resistance to ampicillin, streptomycin, tetracycline, sulfonamide, trimethoprim-sulfonamide, and lincomycin hydrochloride and spectinomycin sulfate tetrahydrate was significantly higher on open farms than on closed farms. PMID:22564934

  2. Prevalence and antimicrobial resistance of Vibrio spp. in retail shrimps in Vietnam.

    PubMed

    Tra, Vu Thi Thu; Meng, Lu; Pichpol, Duangporn; Pham, Ngan Hong; Baumann, Maximilian; Alter, Thomas; Huehn, Stephan

    2016-01-01

    The aim of the study was to investigate the prevalence and the antimicrobial resistance patterns of Vibrio (V.) spp. isolated from retail shrimp in Hanoi, Vietnam A total of 202 shrimp samples were collected from retail markets located in ten urban districts of Hanoi. Among those, 201 (99.5%) samples were positive for Vibrio spp. The most common species detected was V parahaemolyticus (96.5%), followed by V. alginolyticus (56.4%), V. cholerae (2%) and V. vulnificus (1.5%). Multiple Vibrio spp. were found in 114 (56.4%) samples. None of the V. parahaemolyticus isolates carried the virulence-associated tdh (thermostable direct haemolysin) and trh (tdh-related haemolysin) genes. In total, 195 V. parahaemolyticus isolates, four V. cholerae isolates and three V. vulnificus isolates were tested for resistance to eight antimicrobial agents. V. parahaemolyticus isolates showed high rates of resistance against ampicillin (87.2%), while a moderate rate was observed for sulfamethoxazole/trimethoprim (18.5%) and intermediate resistance towards tetracycline (24.6%). Low resistance rates (0.5%) were recorded against both ciprofloxacin and cefalothin. Only one V. cholerae isolate with resistance to ampicillin and two V. cholerae isolates with resistance to sulfamethoxazole/trimethoprim were found. All V. vulnificus isolates were susceptible to the eight antimicrobial agents tested. However, the number of V. vulnificus and V. cholerae was small. Multi-resistant isolates were found in V. parahaemolyticus with a low frequency (16.9%). The results of this study revealed the ubiquitous nature of Vibrio spp. in shrimp at retail. To reduce the potential risk of Vibrio infections due to handling or consumption of undercooked seafood, good manufacturing practice as well as safe handling and processing should be encouraged. PMID:26904896

  3. Prevalence and Antimicrobial Resistance of Vibrio spp. in Retail and Farm Shrimps in Ecuador.

    PubMed

    Sperling, L; Alter, T; Huehn, S

    2015-11-01

    The aim of this study was to investigate the prevalence of Vibrio spp. in shrimp at retail and in shrimp farms in Ecuador and to determine the antimicrobial agent resistance patterns of farm isolates. The presence of genes linked to early mortality syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) also was evaluated. Vibrio spp. were isolated from retail shrimps in Cuenca, Ecuador, and farm shrimps originating from provinces El Oro and Guayas, Ecuador. A total of 229 shrimp samples were collected, of which 71 originated from retail markets in Cuenca and 158 came from shrimp farms. Overall, 219 (95.6%) samples tested positive for Vibrio spp. Vibrio parahaemolyticus (80.8%) was the most common species detected, followed by Vibrio alginolyticus (50.2%), Vibrio cholerae (11.3%), and Vibrio vulnificus (3.5%). None of the V. parahaemolyticus isolates carried the virulence-associated tdh and trh genes. In V. parahaemolyticus shrimp farm isolates, high resistance was found to ampicillin (92.2%), and intermediate resistance was found to tetracycline (51.3%) and amikacin (22.1%). Of the V. parahaemolyticus strains, 68 were resistant to at least three antimicrobial agents, and 2 were resistant to seven antimicrobial agents simultaneously. Up to 18 resistant isolates were found for V. alginolyticus, whereas V. vulnificus and V. cholerae isolates were more susceptible. None of the V. parahaemolyticus isolates carried the EMS-AHPND plasmid. The results of this study revealed the ubiquitous occurrence of Vibrio spp. in shrimps at retail and on shrimp farms in Ecuador. PMID:26555534

  4. Predicting Antimicrobial Resistance Prevalence and Incidence from Indicators of Antimicrobial Use: What Is the Most Accurate Indicator for Surveillance in Intensive Care Units?

    PubMed Central

    Fortin, Élise; Platt, Robert W.; Fontela, Patricia S.; Buckeridge, David L.; Quach, Caroline

    2015-01-01

    Objective The optimal way to measure antimicrobial use in hospital populations, as a complement to surveillance of resistance is still unclear. Using respiratory isolates and antimicrobial prescriptions of nine intensive care units (ICUs), this study aimed to identify the indicator of antimicrobial use that predicted prevalence and incidence rates of resistance with the best accuracy. Methods Retrospective cohort study including all patients admitted to three neonatal (NICU), two pediatric (PICU) and four adult ICUs between April 2006 and March 2010. Ten different resistance / antimicrobial use combinations were studied. After adjustment for ICU type, indicators of antimicrobial use were successively tested in regression models, to predict resistance prevalence and incidence rates, per 4-week time period, per ICU. Binomial regression and Poisson regression were used to model prevalence and incidence rates, respectively. Multiplicative and additive models were tested, as well as no time lag and a one 4-week-period time lag. For each model, the mean absolute error (MAE) in prediction of resistance was computed. The most accurate indicator was compared to other indicators using t-tests. Results Results for all indicators were equivalent, except for 1/20 scenarios studied. In this scenario, where prevalence of carbapenem-resistant Pseudomonas sp. was predicted with carbapenem use, recommended daily doses per 100 admissions were less accurate than courses per 100 patient-days (p = 0.0006). Conclusions A single best indicator to predict antimicrobial resistance might not exist. Feasibility considerations such as ease of computation or potential external comparisons could be decisive in the choice of an indicator for surveillance of healthcare antimicrobial use. PMID:26710322

  5. Prevalence, virulence and antimicrobial resistance patterns of Aeromonas spp. isolated from children with diarrhea

    PubMed Central

    Soltan Dallal, Mohammad Mehdi; Mazaheri Nezhad Fard, Ramin; Kavan Talkhabi, Morteza; Aghaiyan, Leyla; Salehipour, Zohre

    2016-01-01

    Background Aeromonas spp. cause various intestinal and extraintestinal diseases. These bacteria are usually isolated from fecal samples, especially in children under five years old. The aim of this study was to assess the prevalence of Aeromonas spp. and their antimicrobial resistance profile in children with diarrhea referred to the Children Medical Center in Tehran, between 2013 and 2014. Methods A total number of 391 stool samples were collected from children with ages between 1 day and 14 years old, with diarrhea (acute or chronic), referred to the Children Hospital, Tehran, Iran, between 2013 and 2014. Samples were enriched in alkaline peptone water broth for 24 hours at 37 °C and then cultured. Suspicious colonies were analyzed through biochemical tests. Furthermore, antimicrobial susceptibility tests were carried out for the isolates. Isolates were further studied for act, ast, alt, aerA and hlyA virulence genes using polymerase chain reaction. Results In total, 12 isolates (3.1%) were identified as Aeromonas spp.; all were confirmed using the API-20E test. Of these isolates, five A. caviae (42%), four A. veronii (33%) and three A. hydrophila (25%) were identified in cases with gastroenteritis. Second to ampicillin (which was included in the growth medium used), the highest rate of antimicrobial resistance was seen against nalidixic acid and trimethoprim-sulfamethoxazole (5 isolates each, 41.6%) and the lowest rate of antimicrobial resistance was seen against gentamicin, amikacin and cefepime (none of the isolates). Results included 76.4% act, 64.7% ast, 71.5% alt, 83.3% aerA and 11.7% hlyA genes. Conclusion Aeromonas spp. are important due to their role in diarrhea in children; therefore, isolation and identification of these fecal pathogens should seriously be considered in medical laboratories. Since virulence genes play a significant role in gastroenteritis symptoms caused by these bacteria, Aeromonas species that include virulence genes are potentially

  6. Prevalence, antimicrobial resistance and genetic diversity of Yersinia enterocolitica isolated from retail frozen foods in China.

    PubMed

    Ye, Qinghua; Wu, Qingping; Hu, Huijuan; Zhang, Jumei; Huang, Huixian

    2015-12-01

    In this study, our aim was to estimate the extent of Yersinia enterocolitica contamination in frozen foods in China and determine the bioserotype, virulotype, antimicrobial resistance, and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) genotyping profiles of recovered Y. enterocolitica isolates. Out of 455 samples collected between July 2011 and May 2014, 56 (12.3%) tested positive for Y. enterocolitica. The 70 isolated strains were grouped into five clusters and one singleton based on their ERIC-PCR fingerprint, at a similarity coefficient of 70%. All strains were of biotype 1A, and 35.7% were of bioserotype 1A/O:8. Most strains lacked the virulence genes ail, virF, ystA, and ystC, but harbored ystB, fepD, ymoA, fes and sat. All strains were sensitive to ticarcillin but resistant to two or more antibiotics, and 48.6% of the strains were resistant to four to nine antibiotics. High resistance rates were observed for ampicillin, cephalothin, trimethoprim/sulfamethoxazole, amoxicillin/clavulanic acid, nalidixic acid and chloramphenicol (98.6%, 95.7%, 74.3%, 28.6%, 18.6% and 12.9%, respectively). This study provides a systematic surveillance of Y. enterocolitica prevalence in frozen foods in China and indicates its high antibiotic resistance, which could serve as useful information for the government to control Y. enterocolitica contamination in frozen foods and the use of antibiotics. PMID:26472688

  7. Prevalence, Serotype, and Antimicrobial Resistance of Salmonella on Broiler Carcasses Postpick and Postchill in 20 U. S. Processing Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to measure the effect of broiler processing on the prevalence, serotype and antimicrobial resistance profiles of salmonellae. Twenty US commercial processing plants representing eight integrators in thirteen states were included in the survey. In each of four replic...

  8. Prevalence of Antimicrobial Resistance and Transfer of Tetracycline Resistance Genes in Escherichia coli Isolates from Beef Cattle.

    PubMed

    Shin, Seung Won; Shin, Min Kyoung; Jung, Myunghwan; Belaynehe, Kuastros Mekonnen; Yoo, Han Sang

    2015-08-15

    The aim of this study was to investigate the prevalence and transferability of resistance in tetracycline-resistant Escherichia coli isolates recovered from beef cattle in South Korea. A total of 155 E. coli isolates were collected from feces in South Korea, and 146 were confirmed to be resistant to tetracycline. The tetracycline resistance gene tet(A) (46.5%) was the most prevalent, followed by tet(B) (45.1%) and tet(C) (5.8%). Strains carrying tet(A) plus tet(B) and tet(B) plus tet(C) were detected in two isolates each. In terms of phylogenetic grouping, 101 (65.2%) isolates were classified as phylogenetic group B1, followed in decreasing order by D (17.4%), A (14.2%), and B2 (3.2%). Ninety-one (62.3%) isolates were determined to be multidrug resistant by the disk diffusion method. MIC testing using the principal tetracyclines, namely, tetracycline, chlortetracycline, oxytetracycline, doxycycline, and minocycline, revealed that isolates carrying tet(B) had higher MIC values than isolates carrying tet(A). Conjugation assays showed that 121 (82.9%) isolates could transfer a tetracycline resistance gene to a recipient via the IncFIB replicon (65.1%). This study suggests that the high prevalence of tetracycline-resistant E. coli isolates in beef cattle is due to the transferability of tetracycline resistance genes between E. coli populations which have survived the selective pressure caused by the use of antimicrobial agents. PMID:26048929

  9. Prevalence of Nontyphoidal Salmonella and Salmonella Strains with Conjugative Antimicrobial-Resistant Serovars Contaminating Animal Feed in Texas.

    PubMed

    Hsieh, Yi-Cheng; Poole, Toni L; Runyon, Mick; Hume, Michael; Herrman, Timothy J

    2016-02-01

    The objective of this study was to characterize 365 nontyphoidal Salmonella enterica isolates from animal feed. Among the 365 isolates, 78 serovars were identified. Twenty-four isolates (7.0%) were recovered from three of six medicated feed types. Three of these isolates derived from the medicated feed, Salmonella Newport, Salmonella Typhimurium var. O 5- (Copenhagen), and Salmonella Lexington var. 15+ (Manila), displayed antimicrobial resistance. Susceptibility testing revealed that only 3.0% (12) of the 365 isolates displayed resistance to any of the antimicrobial agents. These 12 isolates were recovered from unmedicated dry beef feed (n = 3), medicated dry beef feed (n = 3), cabbage culls (n = 2), animal protein products (n = 2), dry dairy cattle feed (n = 1), and fish meal (n = 1). Only Salmonella Newport and Salmonella Typhimurium var. O 5- (Copenhagen) were multidrug resistant. Both isolates possessed the IncA/C replicon and the blaCMY-2 gene associated with cephalosporin resistance. Plasmid replicons were amplified from 4 of 12 resistant isolates. Plasmids (40 kb) were Salmonella Montevideo and Salmonella Kentucky. Conjugation experiments were done using 7 of the 12 resistant isolates as donors. Only Salmonella Montevideo, possessing a plasmid and amplifying IncN, produced transconjugants. Transconjugants displayed the same antimicrobial resistance profile as did the donor isolate. Three isolates that amplified replicons corresponding to IncA/C or IncHI2 did not produce transconjugants at 30 or 37°C. The results of this study suggest that the prevalence of antimicrobial-resistant Salmonella contaminating animal feed is low in Texas. However, Salmonella was more prevalent in feed by-products; fish meal had the highest prevalence (84%) followed by animal protein products (48%). Ten of the 35 feed types had no Salmonella contamination. Further investigation is needed to understand the possible role of specific feed types in the dissemination of antimicrobial

  10. Prevalence, toxin gene profiles, and antimicrobial resistance of Staphylococcus aureus isolated from quick-frozen dumplings.

    PubMed

    Hao, Dan; Xing, Xiaonan; Li, Guanghui; Wang, Xin; Zhang, Min; Zhang, Weisong; Xia, Xiaodong; Meng, Jianghong

    2015-01-01

    The aim of this study was to investigate the prevalence of Staphylococcus aureus in quick-frozen dumplings and to characterize these strains. A total of 120 dumpling samples, including lamb (n = 13), vegetarian (n = 14), seafood (n = 12), and pork (n = 81) stuffing, were collected in Shaanxi province in China and screened for S. aureus. All S. aureus isolates were characterized by antimicrobial susceptibility testing, and detection of genes encoding staphylococcal enterotoxins, exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin 1 (tsst-1), and resistance to methicillin-oxacillin (mecA). In all, 60.0% of all samples were positive for S. aureus, and 117 S. aureus isolates, including seven mecA-positive strains, were recovered from these positive samples. In addition, all mecA-positive S. aureus isolates were recovered from products of animal origin. In these S. aureus isolates, resistance was observed most frequently to ampicillin (92.3%) and penicillin (86.3%), followed by clarithromycin, erythromycin, midecamycin, tetracycline, and kanahemycin (from 53.8 to 28.2%). All isolates were sensitive to cefoperazone, minocycline, vancomycin, and ofloxacin. The predominant toxin gene was sec (38.5%), followed by seg (19.7%), sej (16.2%), see (12.8%), sea (11.1%), and seb (10.3%), whereas eta, etb, and tsst-1 genes were not detected. These findings indicate that S. aureus was present commonly in quick-frozen dumplings, accompanied by multiple antimicrobial resistance and toxin genes. Our findings highlight the urgency for stricter hygiene strategies in food production and the prudent use of antibiotics in the breeding industry. PMID:25581200

  11. Prevalence of Virulence Determinants and Antimicrobial Resistance among Commensal Escherichia coli Derived from Dairy and Beef Cattle

    PubMed Central

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-01

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  12. Prevalence of virulence determinants and antimicrobial resistance among commensal Escherichia coli derived from dairy and beef cattle.

    PubMed

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-01

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  13. Evolution of the Antimicrobial Resistance of Staphylococcus spp. in Spain: Five Nationwide Prevalence Studies, 1986 to 2002

    PubMed Central

    Cuevas, Oscar; Cercenado, Emilia; Vindel, Ana; Guinea, Jesús; Sánchez-Conde, Matilde; Sánchez-Somolinos, Mar; Bouza, Emilio

    2004-01-01

    Data regarding the evolution of Staphylococcus resistance in a whole country have a definite influence on the design of empirical treatment regimens. Nevertheless, incidence studies over long periods of time are expensive and very difficult to carry out. In order to ascertain the present situation of the antimicrobial resistance of Staphylococcus in Spain and the change of this resistance over time, we performed five point prevalence studies (1986 to 2002) in a large group of Spanish hospitals (from 68 institutions in 1986 to 143 in 2002) collecting all Staphylococcus strains isolated on a single selected day. All microorganisms were identified in the five studies at the same laboratory, and antimicrobial susceptibility testing was performed against 17 antimicrobial agents by the agar dilution method and a microdilution method. During this period, there was an overall increase in resistance to most antimicrobials among Staphylococcus aureus/coagulase-negative staphylococci, mainly to oxacillin (1.5%/32.5% in 1986 versus 31.2%/61.3% in 2002) (P < 0.001), erythromycin (7%/41.1% in 1986 versus 31.7%/63% in 2002) (P < 0.001), gentamicin (5.2%/25.4% in 1986 versus 16.9%/27.8% in 2002) (P < 0.001; P = 0.5), and ciprofloxacin (0.6%/1.1% in 1986 versus 33.9%/44.9% in 2002) (P < 0.001). All of the isolates were uniformly susceptible to glycopeptides, linezolid, and quinupristin/dalfopristin. Resistance of S. aureus to trimethoprim/sulfamethoxazole was very low (from 0.5% to 2.1%) (P = 0.152). Periodic performance of prevalence studies is a useful, inexpensive, and easy tool to know the nationwide situation of a microorganism and its resistance to antimicrobials; it also helps us assess the emergence and spread of antimicrobial resistance. PMID:15504847

  14. Antimicrobial (Drug) Resistance

    MedlinePlus

    ... Antimicrobial (Drug) Resistance Antibiotic-Resistant Mycobacterium tuberculosis (TB) Methicillin-Resistant Staphylococcus aureus (MRSA) Vancomycin-Resistant Enterococci (VRE) Multidrug-Resistant Neisseria ...

  15. Moderate Prevalence of Antimicrobial Resistance in Escherichia coli Isolates from Lettuce, Irrigation Water, and Soil

    PubMed Central

    Holvoet, Kevin; Callens, Benedicte; Dewulf, Jeroen; Uyttendaele, Mieke

    2013-01-01

    Fresh produce is known to carry nonpathogenic epiphytic microorganisms. During agricultural production and harvesting, leafy greens can become contaminated with antibiotic-resistant pathogens or commensals from animal and human sources. As lettuce does not undergo any inactivation or preservation treatment during processing, consumers may be exposed directly to all of the (resistant) bacteria present. In this study, we investigated whether lettuce or its production environment (irrigation water, soil) is able to act as a vector or reservoir of antimicrobial-resistant Escherichia coli. Over a 1-year period, eight lettuce farms were visited multiple times and 738 samples, including lettuce seedlings (leaves and soil), soil, irrigation water, and lettuce leaves were collected. From these samples, 473 isolates of Escherichia coli were obtained and tested for resistance to 14 antimicrobials. Fifty-four isolates (11.4%) were resistant to one or more antimicrobials. The highest resistance rate was observed for ampicillin (7%), followed by cephalothin, amoxicillin-clavulanic acid, tetracycline, trimethoprim, and streptomycin, with resistance rates between 4.4 and 3.6%. No resistance to amikacin, ciprofloxacin, gentamicin, or kanamycin was observed. One isolate was resistant to cefotaxime. Among the multiresistant isolates (n = 37), ampicillin and cephalothin showed the highest resistance rates, at 76 and 52%, respectively. E. coli isolates from lettuce showed higher resistance rates than E. coli isolates obtained from soil or irrigation water samples. When the presence of resistance in E. coli isolates from lettuce production sites and their resistance patterns were compared with the profiles of animal-derived E. coli strains, they were found to be the most comparable with what is found in the cattle reservoir. This may suggest that cattle are a potential reservoir of antimicrobial-resistant E. coli strains in plant primary production. PMID:23974140

  16. Prevalence, species distribution and antimicrobial resistance of enterococci isolated from U.S. dairy cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To estimate prevalence and antimicrobial susceptibility of enterococci in feces collected in 2007 from U.S. dairy cattle. Methods and Results: A total of 718 fecal samples from 122 dairy cattle operations from 17 U.S. states were collected and cultured for the presence of enterococci. One ...

  17. Prevalence and characterization of antimicrobial-resistant Escherichia coli isolated from conventional and organic vegetables.

    PubMed

    Kim, Sara; Woo, Gun-Jo

    2014-10-01

    To compare the characteristics and to identify the epidemiological relationships of Escherichia coli isolated from organic and conventional vegetables, the antimicrobial resistance and genetic properties of E. coli were investigated from 2010 to 2011. E. coli was isolated from 1 of 111 (0.9%) organic vegetables and from 20 of 225 (8.9%) conventional vegetables. The majority of strains were isolated from the surrounding farming environment (n=27/150 vs. 49/97 in organic vs. conventional samples). The majority of the vegetable strains were isolated from the surrounding farming environments. E. coli isolated from organic vegetables showed very low antimicrobial resistance rates except for cephalothin, ranging from 0% to 17.9%, while the resistance rates to cephalothin (71%) were extremely high in both groups. E. coli isolates expressed various resistance genes, which most commonly included blaTEM, tet(A), strA, strB, and qnrS. However, none of the isolates harbored tet(D), tet(E), tet(K), tet(L), tet(M), or qnrA. The transferability of tet gene, tet(A), and tet(B) was identified in tetracycline-resistant E. coli, and the genetic relationship was confirmed in a few cases from different sources. With regard to the lower antimicrobial resistance found in organic produce, this production mode seems able to considerably reduce the selection of antimicrobial-resistant bacteria on vegetables. PMID:25140978

  18. Prevalence, antimicrobial resistance, and molecular characterization of methicillin-resistant Staphylococcus aureus from bulk tank milk of dairy herds.

    PubMed

    Kreausukon, K; Fetsch, A; Kraushaar, B; Alt, K; Müller, K; Krömker, V; Zessin, K-H; Käsbohrer, A; Tenhagen, B-A

    2012-08-01

    It was the objective of the study to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in bulk tank milk from German dairy herds and to characterize isolates from bulk tank milk with respect to their Staph. aureus protein A (spa) and staphylococcal cassette chromosome mec (SCCmec) type, their phenotypic antimicrobial resistance and resistance- resp. virulence-associated genes using broth microdilution and a microarray for Staph. aureus. Bulk tank milk samples (25 mL) were tested for MRSA using a 2-step selective enrichment protocol. Presumptive MRSA were confirmed by PCR. Thirty-six isolates collected from bulk tank milk of dairy herds in 2009 and 2010 were included in the characterization. All isolates displayed spa-types assigned to the clonal complex CC398. Based on the epidemiological cut-off values for the interpretation of minimum inhibitory concentrations isolates were resistant to tetracycline (100%), clindamycin (58%), erythromycin (52%), quinupristin/dalfopristin (36%), and kanamycin (27%). Isolates did not carry genes associated with typical virulence factors for Staph. aureus such as the Panton-Valentine leukocidin. However, they did carry hemolysin genes. Livestock-associated MRSA of CC398 does occur in German dairy herds and the strains have similar properties as described for strains from pigs. PMID:22818451

  19. Prevalence and antimicrobial resistance of Mycoplasmas and Chlamydiae in patients with genital tract infections in Shanghai, China.

    PubMed

    He, Meiling; Xie, Yanping; Zhang, Ruixia; Gao, Song; Xu, Guangmei; Zhang, Lei; Liu, Peipei; Li, Yuanyuan; Wu, Shuyan

    2016-08-01

    The infections of Mycoplasmas and Chlamydiae are still severe in patients with genital tract diseases and antimicrobial resistance for these organisms has been changing in recent years. In this study, we reported the prevalence status of Ureaplasma urealyticum, Mycoplasma hominis and Chlamydia trachomatis in 965 patients with genital tract infection in Shanghai from January 2011 to December 2014 and analyzed the antimicrobial resistance of U. urealyticum and M. hominis to 12 kinds of antimicrobial drugs by using commercial kits and SPSS13.0 software. Here, we found the infection of U. urealyticum was the most frequent among these three organisms. The total infection rate for containing any organisms of them was 49.5%, and it has been increasing in recent 4 years. Positive rate in female (53.3%) was higher than male's (34.8%), and the high risk population was 20-39 years old (56.7%). Besides, U. urealyticum and M. hominis displayed relative lower resistance rates to minocycline, doxycycline, josamycin and gatifloxacin (6.5%, 7.2%, 13.5% and 8.6%, respectively). However, for erythromycin, roxithromycin, thiamphenicol and clindamycin, the resistance rates were relatively high (41.9%, 47.2%, 62.3% and 74.9%, respectively). U. urealyticum and M. hominis displayed a declined trend of the antimicrobial resistance to 12 kinds of drugs detected in this study. In total, these preliminary data showed the prevalence of Mycoplasmas and Chlamydiae in patients and the antimicrobial resistance status of Mycoplasmas, which has use for reference on both prevention and treatment of diseases caused by them. PMID:27324895

  20. Prevalence of resistance to 11 antimicrobials among Campylobacter coli isolated from pigs on 80 grower-finisher farms in Ontario

    PubMed Central

    Varela, Norma P.; Friendship, Robert; Dewey, Cate

    2007-01-01

    We carried out a cross-sectional study to investigate antimicrobial resistance patterns of Campylobacter coli isolated from Ontario grower-finisher pigs. From January to June 2004, 1200 samples were collected from 80 farms by obtaining a constant number (15) of fecal samples per farm. Susceptibility of the isolates to 11 antimicrobial drugs was determined by the agar-dilution technique. The overall prevalence of resistance to 1 or more antimicrobials among the isolates was 99.2%. High levels of resistance were observed for azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline: 91.7%, 82.5%, 81.4%, 70.7%, and 63.7%, respectively. For sulfamethoxazole, ampicillin, and nalidixic acid, resistance was observed in 40.3%, 26.6%, and 22.7% of the isolates, respectively. Although at very low levels, resistance was observed for ciprofloxacin (a fluoroquinolone), chloramphenicol, and gentamicin: in 2.4%, 1.7%, and 0.2%, respectively. Many of the isolates (29.7%) were resistant to 5 antimicrobials, the most common being azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline. Isolates from the same farm showed at least 5 patterns of resistance. Results from this study indicate high levels of resistance to the antimicrobial drugs most commonly used in the Canadian swine industry (macrolides, lincosamides, and tetracyclines) among C. coli isolated from grower-finisher pigs in Ontario. Macrolides and fluoroquinolones are the drugs most commonly used to treat severe human campylobacteriosis. Fortunately, at present, there is little resistance to fluoroquinolones among C. coli from pigs in Ontario. PMID:17695593

  1. Prevalence, molecular characterization and antimicrobial resistance of Salmonella serovars isolated from northwestern Spanish broiler flocks (2011-2015).

    PubMed

    Lamas, A; Fernandez-No, I C; Miranda, J M; Vázquez, B; Cepeda, A; Franco, C M

    2016-09-01

    The present study investigated the prevalence, antimicrobial resistance to twenty antibiotics, and class 1 integron and virulence genes of Salmonella isolated from poultry houses of broilers in northwestern Spain between 2011 and 2015. Strains were classified to the serotype level using the Kauffman-White typing scheme and subtyping with enterobacterial repetitive intergenic consensus PCR. The prevalence of Salmonella spp. was 1.02%. Sixteen different serotypes were found, with S. typhimurium and S. arizonae 48:z4, z23:- being the most prevalent. A total of 59.70% of strains were resistant to at least one, and 19.70% were resistant to multiple drugs. All Salmonella spp. were susceptible to cefotaxime, ciprofloxacin, gentamicin, kanamycin, levofloxacin, neomycin, and trimethoprim. The highest level of resistance was to sulfamethoxazole (40.29%), doxycycline (17.91%), and nalidixic acid (17.91%). None of the isolates carried class 1 integron and only isolates of S. enterica subspecies enterica were positive for all virulence factors tested, whereas S. arizonae lacked genes related to replication and invasion in nonphagocytic cells. This study demonstrates that the prevalence and antimicrobial resistance of Salmonella spp. in poultry houses of broilers of northwestern Spain is low compared with those found in other studies and in other steps of the food chain. PMID:27143768

  2. Prevalence and Antimicrobial Resistance of Salmonella and Escherichia coli from Australian Cattle Populations at Slaughter.

    PubMed

    Barlow, Robert S; McMillan, Kate E; Duffy, Lesley L; Fegan, Narelle; Jordan, David; Mellor, Glen E

    2015-05-01

    Antimicrobial agents are used in cattle production systems for the prevention and control of bacteria associated with diseases. Australia is the world's third largest exporter of beef; however, this country does not have an ongoing surveillance system for antimicrobial resistance (AMR) in cattle or in foods derived from these animals. In this study, 910 beef cattle, 290 dairy cattle, and 300 veal calf fecal samples collected at slaughter were examined for the presence of Escherichia coli and Salmonella, and the phenotypic AMR of 800 E. coli and 217 Salmonella isolates was determined. E. coli was readily isolated from all types of samples (92.3% of total samples), whereas Salmonella was recovered from only 14.4% of samples and was more likely to be isolated from dairy cattle samples than from beef cattle or veal calf samples. The results of AMR testing corroborate previous Australian animal and retail food surveys, which have indicated a low level of AMR. Multidrug resistance in Salmonella isolates from beef cattle was detected infrequently; however, the resistance was to antimicrobials of low importance in human medicine. Although some differences in AMR between isolates from the different types of animals were observed, there is minimal evidence that specific production practices are responsible for disproportionate contributions to AMR development. In general, resistance to antimicrobials of critical and high importance in human medicine was low regardless of the isolate source. The low level of AMR in bacteria from Australian cattle is likely a result of strict regulation of antimicrobials in food animals in Australia and animal management systems that do not favor bacterial disease. PMID:25951384

  3. Animation of Antimicrobial Resistance

    MedlinePlus

    ... major obstacles to understanding the issue of antimicrobial resistance is that the subject material appears abstract and is complex. This video was designed to make the concept of antimicrobial resistance more real and understandable to veterinarians, livestock producers, ...

  4. Prevalence and antimicrobial resistance of diarrheagenic Escherichia coli and Shigella species associated with acute diarrhea in Tehran, Iran

    PubMed Central

    Jafari, Fereshteh; Hamidian, Mohammad; Rezadehbashi, Maryam; Doyle, Michael; Salmanzadeh-ahrabi, Siavosh; Derakhshan, Faramarz; Reza Zali, Mohammad

    2009-01-01

    A study was performed to determine the prevalence and antimicrobial resistance of Shigella species and diarrheagenic Escherichia coli isolates cultured from patients with acute diarrhea in Tehran, Iran. Between May 2003 and May 2005, 1120 diarrheal specimens were collected and assayed for bacterial enteropathogens by conventional and molecular methods. Etiological agents were isolated from 564 (50.3%) specimens, and included 305 (54%) E coli, 157 (27.8%) Shigella species, and 102 (18%) from other genera of bacteria. The predominant E coli was Shiga toxin-producing E coli (105 isolates [34.5%]) and the predominant Shigella serotype was Shigella sonnei (88 isolates [56.1%]). A high rate of antibiotic resistance was observed among E coli, with 40 of 53 (75.5%) Shiga toxin-producing E coli isolates resistant to amoxicillin and tetra-cycline, and eight (5.2%) E coli isolates resistant to more than six antibiotics. Most Shigella isolates were resistant to tetracycline (95%) and trimethoprim-sulfamethoxazole (91.7%), with greatest antibiotic resistance observed among S sonnei (53 of 88 [60.2%] isolates). Antibiotic resistance is widespread in diarrheagenic E coli and Shigella in children with acute diarrhea in Tehran, Iran; hence, updated strategies for appropriate use of antimicrobial agents in Iran are needed. PMID:20808457

  5. Salmonella species in piglets and weaners from Uganda: prevalence, antimicrobial resistance and herd-level risk factors.

    PubMed

    Ikwap, Kokas; Erume, Joseph; Owiny, David Okello; Nasinyama, George William; Melin, Lennart; Bengtsson, Björn; Lundeheim, Nils; Fellström, Claes; Jacobson, Magdalena

    2014-07-01

    Non-typhoidal salmonellosis is of concern in humans in sub-Saharan Africa, and this is partly due to the high number of immunocompromised persons. Pork and pork products could be among the sources of these non-typhi Salmonella spp. The aim of this study was to identify Salmonella spp. in piglets and weaners in northern and eastern Uganda, characterize their antimicrobial resistance patterns and determine herd-level risk factors. Fecal samples were collected from 465 piglets and weaners from 93 herds (49 and 44 from northern and eastern Uganda, respectively). In addition, information about the herd management and potential risk factors were collected. The fecal samples were cultured for the identification of Salmonella spp. The Salmonella spp. confirmed by serotyping were further characterized by determination of minimum inhibitory concentration (MIC) to 12 antimicrobials by broth microdilution. At individual level, the total prevalence of Salmonella spp. was 12% (12.2% in northern and 11.9% in eastern Uganda). At herd level, the total prevalence was 39% (43% in northern and 34% in eastern Uganda). From 56 samples with Salmonella spp., 20 serovars were identified including two serovars identified only by their antigenic formulae. The predominant serovars were S. Zanzibar, S. Heidelberg, S. Infantis, S. Typhimurium, S. Stanleyville, S. Aberdeen and S. Kampala. In total, 57% of the 53 Salmonella spp. analyzed, originating from 27% of the herds, were resistant to at least one antimicrobial agent. The majority of drug-resistant isolates (60%) were from northern Uganda. Eight multidrug-resistant (MDR) isolates were from northern Uganda and three MDR isolates were from eastern Uganda. Increased prevalence of Salmonella spp. was associated with feeding the young and adults separately as compared to feeding the young and adults together (p=0.043, OR=4.3; 95% CI 1.1, 17.38). Protective factors were "intensive" method of keeping the pigs versus "tethering and roaming" (p=0

  6. High Prevalence of Antimicrobial-resistant Gram-negative Colonization in Hospitalized Cambodian Infants

    PubMed Central

    Pol, Sreymom; Soeng, Sona; Sar, Poda; Neou, Leakhena; Chea, Phal; Day, Nicholas PJ; Cooper, Ben S.; Turner, Claudia

    2016-01-01

    Background: Antimicrobial-resistant Gram-negative infections are a significant cause of mortality in young infants. We aimed to determine characteristics of, and risk factors for, colonization and invasive infection caused by 3rd generation cephalosporin (3GC) or carbapenem-resistant organisms in outborn infants admitted to a neonatal unit (NU) in Cambodia. Methods: During the first year of operation, patients admitted to the Angkor Hospital for Children NU, Siem Reap, Cambodia, underwent rectal swabbing on admission and twice weekly until discharge. Swabs were taken also from 7 environmental sites. Swabs were cultured to identify 3GC or carbapenem-resistant Acinetobacter sp., Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Results: The study included 333 infants with a median age at NU admission of 10 days (range, 0–43). Colonization by ≥1 3GC-resistant organism was detected in 85.9% (286/333). Admission swabs were collected in 289 infants: 61.9% were colonized by a 3GC-resistant organism at the time of admission, and a further 23.2% were colonized during hospitalization, at a median of 4 days [95% confidence interval: 3–5]. Probiotic treatment (hazard ratio: 0.58; 95% confidence interval: 0.35–0.98) was associated with delayed colonization. Colonization by a carbapenem-resistant organism occurred in 25 (7.5%) infants. Six infants had NU-associated K. pneumoniae bacteremia; phenotypically identical colonizing strains were found in 3 infants. Environmental colonization occurred early. Conclusions: Colonization by antimicrobial-resistant Gram-negative organisms occurred early in hospitalized Cambodian infants and was associated with subsequent invasive infection. Trials of potential interventions such as probiotics are needed. PMID:27124686

  7. Prevalence and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus in Assam

    PubMed Central

    Saikia, Lahari; Nath, Reema; Choudhury, Basabdatta; Sarkar, Mili

    2009-01-01

    Aims: Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious problem in intensive care units, because of development of multiresistance, and also intrinsic resistance to β-lactam antibiotics. The present study was carried out to investigate the prevalence of MRSA and their rate of resistance to different antistaphylococcal antibiotics. Materials and Methods: Between January 2007 and February 2008, the clinical specimens submitted at the microbiology laboratory were processed and all S. aureus isolates were included in this study. All isolates were identified morphologically and biochemically by standard laboratory procedures and antibiotic susceptibility pattern was determined by modified Kirby Bauer disc diffusion method. Results: Methicillin resistance was observed in 34.78% of isolates, of which 37.5% were found to be resistant to all commonly used antibiotics. In MRSA isolates, 50% had constitutive resistance, 9.38% had inducible MLSB resistance and 18.75% had MS phenotype. Conclusions: There is a progressive increase in MRSA prevalence in the country but the present rate is still low in comparison to values found in some other institutes. The rate of inducible MLSB resistance was also lower in comparison with findings from other parts of the country. PMID:20040814

  8. Prevalence of virulence and antimicrobial resistance genes in Salmonella spp. isolated from commercial chickens and human clinical isolates from South Africa and Brazil.

    PubMed

    Zishiri, Oliver T; Mkhize, Nelisiwe; Mukaratirwa, Samson

    2016-01-01

    Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to

  9. Prevalence of antimicrobial resistance in faecal enterococci from vet-visiting pets and assessment of risk factors.

    PubMed

    Leite-Martins, L; Mahú, M I; Costa, A L; Bessa, L J; Vaz-Pires, P; Loureiro, L; Niza-Ribeiro, J; de Matos, A J F; Martins da Costa, P

    2015-06-27

    The objective of this study was to determine the prevalence of antimicrobial resistance (AMR) exhibited by enterococci isolated from faeces of pets and its underlying risk factors. From September 2009 to May 2012, rectal swabs were collected from 74 dogs and 17 cats, selected from the population of animals visiting the Veterinary Hospital of University of Porto, UPVet, through a systematic random procedure. Animal owners answered a questionnaire about the risk factors that could influence the presence of AMR in faecal enterococci. Enterococci isolation, identification and antimicrobial (AM) susceptibility testing were performed. Data analyses of multilevel, univariable and multivariable generalised linear mixed models were conducted. From all enterococci isolated (n=315), 61 per cent were considered multidrug-resistant, whereas only 9.2 per cent were susceptible to all AMs tested. Highest resistance was found to tetracycline (67.0 per cent), rifampicin (60.3 per cent), azithromycin (58.4 per cent), quinupristin/dalfopristin (54.0 per cent) and erythromycin (53.0 per cent). Previous fluoroquinolone treatments and coprophagic habits were the features more consistently associated with the presence of AMR for three (chloramphenicol, ciprofloxacin and azithromycin) and seven (tetracycline, rifampicin, gentamicin, chloramphenicol, ciprofloxacin, erythromycin and azithromycin), respectively, out of nine AMs assessed. Evaluating risk factors that determine the presence of drug-resistant bacteria in pets, a possible source of resistance determinants to human beings, is crucial for the selection of appropriate treatment guidelines by veterinary practitioners. PMID:26078332

  10. Antimicrobial Resistance

    MedlinePlus

    ... and health professionals can play their part; rewarding innovation and development of new treatment options and other ... and industry can help tackle resistance by: fostering innovation and research and development of new vaccines, diagnostics, ...

  11. Prevalence, Molecular Characterization, and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolated from Milk and Dairy Products.

    PubMed

    Al-Ashmawy, Maha Abdou; Sallam, Khalid Ibrahim; Abd-Elghany, Samir Mohammed; Elhadidy, Mohamed; Tamura, Tomohiro

    2016-03-01

    The present work was undertaken to study the prevalence, molecular characterization, virulence factors, and antimicrobial susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) in raw milk and dairy products in Mansoura City, Egypt. MRSA was detected in 53% (106/200) among all milk and dairy products with prevalence rates of 75%, 65%, 40%, 50%, and 35% in raw milk, Damietta cheese, Kareish cheese, ice cream, and yogurt samples, respectively. The mean S. aureus counts were 3.49, 3.71, 2.93, 3.40, and 3.23 log10 colony-forming units (CFU)/g among tested raw milk, Damietta cheese, Kareish cheese, ice cream and yogurt, respectively, with an overall count of 3.41 log10 CFU/g. Interestingly, all recovered S. aureus isolates were genetically verified as MRSA strains by molecular detection of the mecA gene. Furthermore, genes encoding α-hemolysin (hla) and staphylococcal enterotoxins (sea, seb, sec) were detected in all isolates. The antimicrobial susceptibility pattern of recovered MRSA isolates against 13 tested antimicrobials revealed that the least effective drugs were penicillin G, cloxacillin, tetracycline, and amoxicillin with bacterial resistance percentages of 87.9%, 75.9%, 65.2%, and 55.6%, respectively. These findings suggested that milk and dairy products represent a potential infection risk threat of multidrug-resistant and toxigenic S. aureus in Egypt due to neglected hygienic practices during production, retail, or storage stages. These findings highlighted the crucial importance of applying more restrictive hygienic measures in dairy production in Egypt for food safety. PMID:26836943

  12. Metagenomic Evidence of the Prevalence and Distribution Patterns of Antimicrobial Resistance Genes in Dairy Agroecosystems.

    PubMed

    Pitta, Dipti W; Dou, Zhengxia; Kumar, Sanjay; Indugu, Nagaraju; Toth, John Daniel; Vecchiarelli, Bonnie; Bhukya, Bhima

    2016-06-01

    Antimicrobial resistance (AR) is a global problem with serious implications for public health. AR genes are frequently detected on animal farms, but little is known about their origin and distribution patterns. We hypothesized that AR genes can transfer from animal feces to the environment through manure, and to this end, we characterized and compared the resistomes (collections of AR genes) of animal feces, manure, and soil samples collected from five dairy farms using a metagenomics approach. Resistomes constituted only up to 1% of the total gene content, but were variable by sector and also farm. Broadly, the identified AR genes were associated with 18 antibiotic resistances classes across all samples; however, the most abundant genes were classified under multidrug transporters (44.75%), followed by resistance to vancomycin (12.48%), tetracycline (10.52%), bacitracin (10.43%), beta-lactam resistance (7.12%), and MLS efflux pump (6.86%) antimicrobials. The AR gene profiles were variable between farms. Farm 09 was categorized as a high risk farm, as a greater proportion of AR genes were common to at least three sectors, suggesting possible horizontal transfer of AR genes. Taxonomic characterization of AR genes revealed that a majority of AR genes were associated with the phylum Proteobacteria. Nonetheless, there were several members of Bacteroidetes, particularly Bacteroides genus and several lineages from Firmicutes that carried similar AR genes in different sectors, suggesting a strong potential for horizontal transfer of AR genes between unrelated bacterial hosts in different sectors of the farms. Further studies are required to affirm the horizontal gene transfer mechanisms between microbiomes of different sectors in animal agroecosystems. PMID:27046731

  13. Prevalence of serogroups, virulence genotypes, antimicrobial resistance, and phylogenetic background of avian pathogenic Escherichia coli in south of China.

    PubMed

    Wang, Xiu-Mei; Liao, Xiao-Ping; Zhang, Wan-Jiang; Jiang, Hong-Xia; Sun, Jian; Zhang, Mei-Jun; He, Xue-Fang; Lao, Dong-Xing; Liu, Ya-Hong

    2010-09-01

    Avian pathogenic Escherichia coli (APEC) is an important respiratory pathogen of poultry. A variety of virulence-associated genes and serogroups are associated with avian colibacillosis caused by APEC strains. One hundred forty-eight E. coli isolates recovered from diagnosed cases of avian colibacillosis from Guangdong province between 2005 and 2008 were serotyped, and characterized for virulence-associated genes, phylogenetic backgrounds, antibiotic susceptibility, and genetic relatedness. Associations between virulence-associated genes and antimicrobial resistance were further analyzed. Although 148 APEC isolates belonged to 21 different serogroups, 81% were of one of eight serogroups: O65 (27%), O78 (10%), O8 (9%), O120 (9%), O2 (7%), O92 (6%), O108 (5%), and O26 (5%). Polymerase chain reaction analysis showed that the most prevalent gene was traT (90%), followed by iroN (63%), fimH (58%), hlyF (55%), cvaC (54%), and sitA (51%). The APEC strains mainly belonged to groups A (73%) and D (14%). Multiple antimicrobial-resistant phenotypes (greater than or equal to three antimicrobials) were detected in all E. coli isolates, with the majority of isolates displaying resistance to tetracycline (97%), sulfamethoxazole (93%) and fluoroquinolones (87% for ciprofloxacin and 84% for enrofloxacin), chloramphenicol (74%), and florfenicol (66%). All E. coli isolates were further genetically characterized by pulsed-field gel electrophoresis. A total of 125 different pulsed-field gel electrophoresis profiles were obtained, implying that the multiresistant E. coli isolates carrying virulence-associated genes and belonging to multiple serogroups were not derived from a specific clone, but represented a wide variety of chromosomal backgrounds. Statistical analysis showed that several virulence-associated genes were significantly present in APEC isolates susceptibility to multiple antimicrobials. The findings demonstrate that a wide variety of serogroups and potential virulence

  14. Prevalence and risk factors for carriage of antimicrobial-resistant Escherichia coli on household and small-scale chicken farms in the Mekong Delta of Vietnam

    PubMed Central

    Nguyen, Vinh Trung; Carrique-Mas, Juan J.; Ngo, Thi Hoa; Ho, Huynh Mai; Ha, Thanh Tuyen; Campbell, James I.; Nguyen, Thi Nhung; Hoang, Ngoc Nhung; Pham, Van Minh; Wagenaar, Jaap A.; Hardon, Anita; Thai, Quoc Hieu; Schultsz, Constance

    2015-01-01

    Objectives To describe the prevalence of antimicrobial resistance among commensal Escherichia coli isolates on household and small-scale chicken farms, common in southern Vietnam, and to investigate the association of antimicrobial resistance with farming practices and antimicrobial usage. Methods We collected data on farming and antimicrobial usage from 208 chicken farms. E. coli was isolated from boot swab samples using MacConkey agar (MA) and MA with ceftazidime, nalidixic acid or gentamicin. Isolates were tested for their susceptibility to 11 antimicrobials and for ESBL production. Risk factor analyses were carried out, using logistic regression, at both the bacterial population and farm levels. Results E. coli resistant to gentamicin, ciprofloxacin and third-generation cephalosporins was detected on 201 (96.6%), 191 (91.8%) and 77 (37.0%) of the farms, respectively. Of the 895 E. coli isolates, resistance to gentamicin, ciprofloxacin and third-generation cephalosporins was detected in 178 (19.9%), 291 (32.5%) and 29 (3.2%) of the isolates, respectively. Ciprofloxacin resistance was significantly associated with quinolone usage (OR = 2.26) and tetracycline usage (OR = 1.70). ESBL-producing E. coli were associated with farms containing fish ponds (OR = 4.82). Conclusions Household and small farms showed frequent antimicrobial usage associated with a high prevalence of resistance to the most commonly used antimicrobials. Given the weak biocontainment, the high prevalence of resistant E. coli could represent a risk to the environment and to humans. PMID:25755000

  15. Prevalence and Antimicrobial Resistance of Microbes Causing Bloodstream Infections in Unguja, Zanzibar

    PubMed Central

    Onken, Annette; Said, Abdulrahman K.; Jørstad, Melissa; Jenum, Pål A.; Blomberg, Bjørn

    2015-01-01

    Background Bloodstream infections (BSI) are frequent and cause high case-fatality rates. Urgent antibiotic treatment can save patients’ lives, but antibiotic resistance can render antibiotic therapy futile. This study is the first to collect epidemiological data on BSI from Unguja, Zanzibar. Methods Clinical data and blood for culturing and susceptibility testing of isolated microbes were obtained from 469 consecutively enrolled neonates, children and adults presenting with signs of systemic infections at Mnazi Mmoja Hospital (MMH), Zanzibar. Results Pathogenic bacteria were recovered from the blood of 14% of the patients (66/469). The most frequently isolated microbes were Klebsiella pneumoniae, Escherichia coli, Acinetobacter spp. and Staphylococcus aureus. Infections were community-acquired in 56 patients (85%) and hospital-acquired in 8 (12%) (data missing for 2 patients). BSI caused by extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae (E. coli, K. pneumoniae) was found in 5 cases, of which 3 were community-acquired and 2 hospital-acquired. Three of these patients died. Six of 7 Salmonella Typhi isolates were multidrug resistant. Streptococcus pneumoniae was found in one patient only. Conclusions This is the first report of ESBL-producing bacteria causing BSI from the Zanzibar archipelago. Our finding of community-acquired BSI caused by ESBL-producing bacteria is alarming, as it implies that these difficult-to-treat bacteria have already spread in the society. In the local setting these infections are virtually impossible to cure. The findings call for increased awareness of rational antibiotic use, infection control and surveillance to counteract the problem of emerging antimicrobial resistance. PMID:26700032

  16. Impact of wastewater from different sources on the prevalence of antimicrobial-resistant Escherichia coli in sewage treatment plants in South India.

    PubMed

    Akiba, Masato; Senba, Hironobu; Otagiri, Haruna; Prabhasankar, Valipparambil P; Taniyasu, Sachi; Yamashita, Nobuyoshi; Lee, Ken-ichi; Yamamoto, Takehisa; Tsutsui, Toshiyuki; Ian Joshua, Derrick; Balakrishna, Keshava; Bairy, Indira; Iwata, Taketoshi; Kusumoto, Masahiro; Kannan, Kurunthachalam; Guruge, Keerthi S

    2015-05-01

    The sewage treatment plant (STP) is one of the most important interfaces between the human population and the aquatic environment, leading to contamination of the latter by antimicrobial-resistant bacteria. To identify factors affecting the prevalence of antimicrobial-resistant bacteria, water samples were collected from three different STPs in South India. STP1 exclusively treats sewage generated by a domestic population. STP2 predominantly treats sewage generated by a domestic population with a mix of hospital effluent. STP3 treats effluents generated exclusively by a hospital. The water samples were collected between three intermediate treatment steps including equalization, aeration, and clarification, in addition to the outlet to assess the removal rates of bacteria as the effluent passed through the treatment plant. The samples were collected in three different seasons to study the effect of seasonal variation. Escherichia coli isolated from the water samples were tested for susceptibility to 12 antimicrobials. The results of logistic regression analysis suggest that the hospital wastewater inflow significantly increased the prevalence of antimicrobial-resistant E. coli, whereas the treatment processes and sampling seasons did not affect the prevalence of these isolates. A bias in the genotype distribution of E. coli was observed among the isolates obtained from STP3. In conclusion, hospital wastewaters should be carefully treated to prevent the contamination of Indian environment with antimicrobial-resistant bacteria. PMID:25704279

  17. Prevalence, risk factors, and antimicrobial resistance profiles of Salmonella from commercial broiler farms in two important poultry-producing regions of Colombia.

    PubMed

    Donado-Godoy, P; Gardner, I; Byrne, B A; Leon, M; Perez-Gutierrez, E; Ovalle, M V; Tafur, M A; Miller, W

    2012-05-01

    Salmonella is one of the most common foodborne pathogens associated with diarrheal disease in humans. Food animals, especially poultry, are important direct and indirect sources of human salmonellosis, and antimicrobial resistance is an emerging problem of public health concern. The use of antimicrobials benefits producers but contributes to the emergence of antimicrobial resistant bacteria. As a step toward implementing the Colombian Integrated Program for Antimicrobial Resistance Surveillance, this study was conducted to establish the prevalence, distribution of serovars, antimicrobial resistance profiles, and risk factors for Salmonella on poultry farms in the two largest states of poultry production in Colombia. Salmonella was isolated from 41% of farms and 65% of the 315 chicken houses sampled. Salmonella Paratyphi B variant Java was the most prevalent serovar (76%), followed by Salmonella Heidelberg (23%). All Salmonella isolates were resistant to 2 to 15 of the antimicrobial drugs tested in this study. For Salmonella Paratyphi B variant Java, 34 drug resistance patterns were present. The predominant resistance pattern was ciprofloxacin, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, ceftiofur, streptomycin, enrofloxacin, and nalidixic acid; this pattern was detected in 15% of isolates. The resistance pattern of tetracycline, ceftiofur, and nalidixic acid was found in over 40% of the isolates of Salmonella Heidelberg. Of the biosecurity practices considered, two factors were significantly associated with reduction in Salmonella: cleaning of fixed equipment and composting of dead birds on the farm. Findings from the present study provide scientific evidence to inform implementation of official policies that support new biosecurity legislation in an effort to decrease the prevalence of Salmonella on Colombian poultry farms. PMID:22564936

  18. Prevalence and antimicrobial resistance of Shigella flexneri serotype 2 variant in China

    PubMed Central

    Cui, Xianyan; Wang, Jian; Yang, Chaojie; Liang, Beibei; Ma, Qiuxia; Yi, Shengjie; Li, Hao; Liu, Hongbo; Li, Peng; Wu, Zhihao; Xie, Jing; Jia, Leili; Hao, Rongzhang; Wang, Ligui; Hua, Yuejin; Qiu, Shaofu; Song, Hongbin

    2015-01-01

    Shigella flexneri serotype 2 variant (II:3,4,7,8) was isolated in 2008 and first reported in China in 2013. In the present study, epidemiological surveillance from 2003 to 2013 in China suggested that this serotype first appeared in Guangxi in 2003; it then emerged in Shanghai and Xinjiang in 2004 and in Henan in 2008. Of the 1813 S. flexneri isolates, 58 S. flexneri serotype 2 variant strains were identified. Serotype 2 variant has emerged as a prominent serotype in recent years, with 2a (32.6%), X variant (25.2%), 1a (9.4%), X (6.3%), 2b (5.4%), and 1b (3.6%). According to phenotypic and genotypic analysis, the serotype 2 variant originated from 2a to 2b. A higher antibiotic resistance rate was observed between 2009 and 2013 than that between 2003 and 2008. Among 22 cephalosporin-resistant isolates, blaTEM-1, blaOXA-1, blaCTX-3, blaCTX-14, and blaCTX-79 were detected. Among 22 fluoroquinolone-resistant isolates, a Ser80Ile mutation in parC was present in all of the isolates. Moreover, 21 isolates had three gyrA point mutations (Ser83Leu, His211Tyr, Asp87Asn, or Gly) and one isolate had two gyrA point mutations (Ser83Leu and His211Tyr). The prevalence of His211Tyr in the fluoroquinolone-resistant isolates is concerning, and the mutation was first reported in China. Besides, 22 isolates harbored the aac(6′)-Ib-cr gene, and two isolates harbored qnrS1. In view of the increased epidemic frequency and multidrug-resistant strain emergence, continuous surveillance will be needed to understand the actual disease burden and provide guidance for shigellosis. PMID:25999941

  19. Prevalence, characterization, and antimicrobial resistance of Aeromonas strains from various retail food products in Mumbai, India.

    PubMed

    Nagar, Vandan; Shashidhar, Ravindranath; Bandekar, Jayant R

    2011-09-01

    A total of 154 food samples (chicken, fish, and ready-to-eat sprouts) from various retail outlets in Mumbai, India, were analyzed for the presence of Aeromonas spp. over a period of 2 y (January 2006 to March 2008). Twenty-two Aeromonas isolates belonging to 7 different species were isolated from 18 (11.7%) food samples. The highest percentages of isolation were from chicken (28.6%) followed by fish (20%) and sprout (2.5%) samples. Aeromonas caviae, A. veronii bv. sobria, and A. salmonicida were the most frequently isolated species from sprouts, chicken, and fish samples, respectively. The genes encoding for putative virulence factors, cytotoxic enterotoxin (act), hemolysin (hly), aerolysin (aer), elastase (ahyB), and lipase (lip) were detected using polymerase chain reaction method in 59.1%, 40.9%, 22.7%, 54.5%, and 31.8% of the strains, respectively. The isolated Aeromonas strains were found to be positive for virulence factors, that is, amylase, DNase, gelatinase, protease, and lipase production. More than 60% isolates were also positive for β-hemolytic activity. All these food isolates were found to be resistant to ampicillin and bacitracin, and sensitive to gentamicin, 3rd-generation cephalosporins (ceftazidime, cephotaxime, ceftriaxone), and chloramphenicol. Seventeen (77.2%) isolates harbored single and/or multiple plasmids (approximately 5 to >16 kb). The XbaI digestion patterns of chromosomal DNA of these isolates, using pulsed field gel electrophoresis, showed high genetic diversity among these isolates. Our results demonstrate the presence of various Aeromonas spp. with virulence potential and antimicrobial resistance in different food products marketed in Mumbai, India. The potential health risks posed by consumption of these raw or undercooked food products should not be underestimated. PMID:21824136

  20. Shigella in Brazilian children with acute diarrhoea: prevalence, antimicrobial resistance and virulence genes

    PubMed Central

    Sousa, Mireille Ângela Bernardes; Mendes, Edilberto Nogueira; Collares, Guilherme Birchal; Péret-Filho, Luciano Amedée; Penna, Francisco José; Magalhães, Paula Prazeres

    2013-01-01

    Diarrhoeal disease is still considered a major cause of morbidity and mortality among children. Among diarrhoeagenic agents, Shigella should be highlighted due to its prevalence and the severity of the associated disease. Here, we assessed Shigella prevalence, drug susceptibility and virulence factors. Faeces from 157 children with diarrhoea who sought treatment at the Children's Hospital João Paulo II, a reference children´s hospital in Belo Horizonte, state of Minas Gerais, Brazil, were cultured and drug susceptibility of the Shigella isolates was determined by the disk diffusion technique. Shigella virulence markers were identified by polymerase chain reaction. The bacterium was recovered from 10.8% of the children (88.2% Shigella sonnei). The ipaH, iuc, sen and ial genes were detected in strains isolated from all shigellosis patients; set1A was only detected in Shigella flexneri. Additionally, patients were infected by Shigella strains of different ial, sat, sen and set1A genotypes. Compared to previous studies, we observed a marked shift in the distribution of species from S. flexneri to S. sonnei and high rates of trimethoprim/sulfamethoxazole resistance. PMID:23440111

  1. USDA Data on Antimicrobial Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial susceptibility testing remains an important tool as investigators devise ways to arrest the development of antimicrobial resistance, particularly in food borne bacteria. In 1996, the Food and Drug Administration (FDA) initiated the National Antimicrobial Resistance Monitoring System -...

  2. Prevalence and antimicrobial resistance of Salmonella isolated from lactating cows and in contact humans in dairy farms of Addis Ababa: a cross sectional study

    PubMed Central

    2011-01-01

    Background Salmonella are the major pathogenic bacteria in humans as well as in animals. Salmonella species are leading causes of acute gastroenteritis in several countries and salmonellosis remains an important public health problem worldwide, particularly in the developing countries. The situation is more aggravated by the ever increasing rate of antimicrobial resistance strains. Cattle have been implicated as a source of human infection with antimicrobial resistant Salmonella through direct contact with livestock and through the isolation of antimicrobial resistant Salmonella from raw milk, cheddar cheese, and hamburger meat traced to dairy farms. Despiite the presence of many studies on the prevalence and antimicrobial susceptibility pattern of Salmonella in Ethiopia, nothing has been said on the degree of the situation among apparently healthy lactating cows and in contact humans. Hence this study was conducted to determine the prevalence and antimicrobial resistance pattern of Salmonella isolates from lactating cows and in contact humans in dairy farms of Addis Ababa. Methods a cross sectional study was conducted in Addis Ababa by collecting milk and faecal samples from lactating cows and stool samples from humans working in dairy farms. Samples were pre-enriched in buffered peptone water followed by selective enrichment using selenite cysteine and Rapaport-Vassilidis broths. Isolation and identification was made by inoculating the selectively enriched sample on to Xylose Lysine Deoxycholate agar followed by confirmation of presumptive colonies using different biochemical tests. The Kibry Bauer disk diffusion method was used for antimicrobial sensitivity testing. Results 10.7% (21/195) of cows and 13.6% (3/22) of the human subjects sheded Salmonella. 83% resistance to two or more antimicrobials and 100% resistance to ampicillin were observed. Most of the isolates were relatively sensitive to ciprofloxacin, cotrimoxazole, and chloramphenicol. Conclusion High

  3. [Surveillance of Antimicrobial Resistant Esherichia coli by Rectal Swab Method--Annual Change of Prevalence of Quinolone-resistant and ESBL Producing Strains from 2009 to 2013].

    PubMed

    Nasu, Yoshitsugu; Sako, Shinichi; Yano, Tomofumi; Kosaka, Noriko

    2015-09-01

    Although most of commonly used antimicrobial agents had been susceptible to Esherichia coli, recently there are a lot of reports concerning about community-acquired infection caused by resistant E. coli. The aim of this study is to define the prevalence of resistant E. coli in normal flora colonization by the rectal swab method. From June 2009 to December 2013, 251 male patients (50-85 year-old, median 68) planned to transrectal prostate biopsy participated in this study. Stools stuck on the glove at the digital examination were provided for culture specimen. Identification of E. coli and determination of MIC was performed by MicroScan WalkAway40plus (Siemens). Isolated E. coli were deemed quinolone-resistant strains when their MIC of levofloxacine was 4 μg/mL or above according to the breakpoint MIC by the CLSI criteria. ESBL producing ability was determined by the double disk method used by CVA contained ESBL definition disc (Eikenkagaku). Of the 251 study patients, 224 patients had positive cultures of E. coli. Twenty-four patients had quinolone-resistant strains and 9 patients had ESBL producing strains. The prevalence of quinolone-resistant strains in 2009, 2010, 2011, 2012 and 2013 were 5.9% (2 out of 34 strains), 13.5% (5 out of 37 strains), 12.5% (4 out of 32 strains), 9.0% (6 out of 67) and 13.0% (7 out of 54 strains), respectively. The prevalence of ESBL producing strains in 2009, 2010, 2011, 2012 and 2013 were 0% (0 out of 34 strains), 5.4% (2 out of 37 strains), 3.1% (1 out of 32 strains), 3.0% (2 out of 67 strains) and 7.4% (4 out of 54 strains), respectively. In 2013, the prevalence of antimicrobial resistant E. coli, both quinolone-resistant and ESBL producing strains, were increasing. We have to pay a close attention to the increase of resistant E. coli. PMID:26630790

  4. Prevalence of enterotoxin genes and antimicrobial resistance of coagulase-positive staphylococci recovered from raw cow milk.

    PubMed

    Rola, J G; Korpysa-Dzirba, W; Czubkowska, A; Osek, J

    2015-07-01

    Raw milk may be contaminated by enterotoxigenic coagulase-positive staphylococci (CPS). Several of these microorganisms show antimicrobial resistance, which poses a potential risk for consumers. The aim of this study was to determine the occurrence of enterotoxin genes and antimicrobial resistance of CPS isolated from cow milk. A total of 115 samples were analyzed for the presence of CPS according to the International Organization for Standardization standard (ISO 6888-2). The genes were identified using 2multiplex PCR assays. Resistance of the isolates to 10 antimicrobials was determined using the minimum inhibitory concentration method. Overall, 71 samples (62%) were contaminated with CPS and 69 isolates were further analyzed. Among them, 20 (29%) strains harbored the enterotoxin genes. The most commonly detected staphylococcal enterotoxin markers were sed, sej, and ser, whereas none of the analyzed isolates possessed the seb and see genes. Almost one-half of the tested strains (43%) were resistant to one or more antimicrobial agents. Resistance to penicillin was the most common, followed by sulfamethoxazole and chloramphenicol. On the other hand, all strains were susceptible to ciprofloxacin, erythromycin, gentamicin, cefoxitin, and streptomycin. None of the strains was positive for the mecA and mecC (methicillin-resistant Staphylococcus aureus) genes. These results indicate that enterotoxigenic and antimicrobial-resistant CPS strains are present in raw milk, which may be a potential risk for public health. PMID:25981078

  5. Short communication: Prevalence, antimicrobial resistance, and resistant traits of coagulase-negative staphylococci isolated from cheese samples in Turkey.

    PubMed

    Kürekci, Cemil

    2016-04-01

    A total of 17 coagulase-negative staphylococci (CNS) isolates obtained from 72 cheese samples were included in this study. Coagulase-negative staphylococci isolates obtained in this study comprised 6 (35.3%) Staphylococcus saprophyticus, 3 (17.6%) Staphylococcus epidermidis, 2 (11.8%) Staphylococcus hominis, 2 (11.8%) Staphylococcus haemolyticus, 1 (5.9%) Staphylococcus xylosus, 1 (5.9%) Staphylococcus vitulinus, 1 (5.9%) Staphylococcus lentus, and 1 (5.9%) Staphylococcus warneri. The disc diffusion assay revealed that the highest occurrence of resistance was found for penicillin (76.5%), erythromycin (35.3%), tetracycline (29.4%), and trimethoprim-sulfamethoxazole (17.6%) among CNS isolates. However, all CNS isolates were found to be susceptible to vancomycin, streptomycin, linezolid, and gentamycin. Of the isolates, 64.7% carried at least one of the following antimicrobial resistance genes: mecA, tet(M), erm(B), blaZ, ant(4')-la, aph(3')-IIIa, and lnu(A). The results suggest that improved hygienic conditions, such as safer handling of raw milk, proper cleaning, and sanitation during the manufacturing in the dairies, are urgently needed in Turkey. PMID:26874419

  6. Prevalence of antimicrobial resistance in fecal Escherichia coli isolates from stray pet dogs and hospitalized pet dogs in Korea.

    PubMed

    Nam, Hyang-Mi; Lee, Hee-Soo; Byun, Jae-Won; Yoon, Soon-Seek; Jung, Suk-Chan; Joo, Yi-Seok; Lim, Suk-Kyung

    2010-03-01

    A total of 628 Escherichia coli isolates recovered from 877 intestinal samples of stray pet dogs (n = 565) and hospitalized pet dogs (n = 312) in Korea were analyzed for resistance to 15 antimicrobial agents. Most common resistance observed in E. coli isolated from both groups of dogs was to tetracycline (52.4-53.6%), streptomycin (35.8-41.7%), ampicillin (32.9-47.1%), nalidixic acid (21.6-37.4%), and trimethoprim/sulfamethoxazole (19.7-36.4%). Resistance to chloramphenicol, gentamicin, and ciprofloxacin was observed in 19.4% (17.1-24.3%), 18% (16.1-21.8%), and 16.1% (13.5-21.4%) of the isolates, respectively. No E. coli isolated from hospitalized dogs showed resistance to imipenem and cefepime, whereas three (0.7%) isolates from stray dogs were resistant to cefepime. Some of the isolates from both groups showed resistance to cefotaxime (2.4-3.9%) and amikacin (0.5-1.5%). In general, the frequency of resistance tended to be higher in isolates from hospitalized dogs than isolates from stray dogs against most antimicrobials tested. Around 39% (162/422) and 27% (55/206) of E. coli isolates from stray dogs and hospitalized dogs were susceptible to all antimicrobials tested, respectively. Multiresistance (> or = 3 subclasses of antimicrobials) was observed in 32% and 48% of E. coli isolates from stray dogs and hospitalized dogs, respectively. More attention should be paid to the use of antimicrobials and the occurrence of antimicrobial resistance in companion animals. PMID:20192822

  7. Prevalence and antimicrobial resistance of Salmonella spp. in raw retail frozen imported freshwater fish to Eastern Province of Saudi Arabia

    PubMed Central

    Elhadi, Nasreldin

    2014-01-01

    Objective To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia. Methods A total of 223 frozen freshwater fish purchased from different supermarkets and grocery stores were analyzed for the presence of foodborne pathogen Salmonella. The isolation of Salmonella was determined and confirmed by using the methods of US Food and Drug Administration's Bacteriological Analytical Manual, CHROMagar Salmonella plus, biochemical tests and API 20E strips. Antimicrobial susceptibilities of Salmonella isolates were determined by the disk diffusion method on Muller-Hinton agar, as described by Kirby-Bauer, in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Results Out of the total 223 fish samples (20 of catfish, 18 of carfu, 20 of mirgal, 25 of milkfish, 35 of mackerel, 75 of tilapia, and 30 of rohu), 89 (39.9%) were tested positive for Salmonella. The prevalence of positive samples were reported for the freshwater fish of pangas (60.0%, n=12), carfu (27.7%, n=5), mirgal (35.0%, n=7), milkfish (52.0%, n=13), mackerel (31.4 %, n=11), tilapia imported from Thailand (64.0%, n=16), tilapia imported from India (28.0%, n=14), rohu imported from Thailand (26.6%, n=4) and rohu imported from Myanmar (46.6%, n=7). A total of 140 isolates of Salmonella spp. were yielded from at least seven different types of frozen freshwater fish imported from 5 different countries and were tested for their susceptibility to 16 selected antimicrobial agents. The highest antibiotic resistance was observed to tetracycline (90.71%) followed by ampicillin (70%) and amoxicillin-clavulanic acid (45%). Conclusions The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp. And the study recommend and suggest that there is a need for adequate consumer measures. PMID:25182443

  8. Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

    PubMed Central

    Biswal, Basanta Kumar; Khairallah, Ramzi; Bibi, Kareem; Mazza, Alberto; Gehr, Ronald; Masson, Luke

    2014-01-01

    Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2 and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters. PMID:24727265

  9. Prevalence, virulence, and antimicrobial resistance of Campylobacter jejuni and Campylobacter coli in white stork Ciconia ciconia in Poland.

    PubMed

    Szczepańska, Bernadeta; Kamiński, Piotr; Andrzejewska, Małgorzata; Śpica, Dorota; Kartanas, Edmund; Ulrich, Werner; Jerzak, Leszek; Kasprzak, Mariusz; Bocheński, Marcin; Klawe, Jacek J

    2015-01-01

    The aim of this study was to investigate the role of white stork Ciconia ciconia as a potential reservoir of Campylobacter spp. Antimicrobial resistance and the presence of putative virulence genes of the isolates were also examined. A total of 398 white stork chicks sampled in Western Poland in habitats with high density of breeding were examined. Rectal swabs were collected during breeding season 2009-2012 from storks developing in a relatively pure environment (Odra meadows), in polluted areas (a copper mining-smelting complex), and in suburbs. Of the anal swabs collected, 7.6% were positive for Campylobacter among chicks (5.3% samples positive for C. jejuni and 2.3% samples positive for C. coli). Samples from polluted areas had the highest prevalence of Campylobacter (12.2%). The prevalence of resistance among C. jejuni and C. coli isolates from young storks was as follows: to ciprofloxacin (52.4%, 44.4%), and to tetracycline (19%, 77.8%). All of the analyzed isolates were susceptible to macrolides. The resistance to both classes of antibiotics was found in the 23.3% of Campylobacter spp. All Campylobacter spp. isolates had cadF gene and flaA gene responsible for adherence and motility. CdtB gene associated with toxin production was present in 88.9% of C. coli isolates and 57.1% of C. jejuni isolates. The iam marker was found more often in C. coli strains (55.6%) compared to C. jejuni isolates (42.9%). Our results confirm the prevalence of Campylobacter spp. in the white stork in natural conditions and, because it lives in open farmlands with access to marshy wetlands, the environmental sources such as water reservoirs and soil-water can be contaminated from white stork feces and the pathogens can be widely disseminated. We can thus conclude that Campylobacter spp. may easily be transmitted to waterfowl, other birds, and humans via its environmental sources and/or by immediate contact. PMID:25456607

  10. Antimicrobial Drugs in Fighting against Antimicrobial Resistance

    PubMed Central

    Cheng, Guyue; Dai, Menghong; Ahmed, Saeed; Hao, Haihong; Wang, Xu; Yuan, Zonghui

    2016-01-01

    The outbreak of antimicrobial resistance, together with the lack of newly developed antimicrobial drugs, represents an alarming signal for both human and animal healthcare worldwide. Selection of rational dosage regimens for traditional antimicrobial drugs based on pharmacokinetic/pharmacodynamic principles as well as development of novel antimicrobials targeting new bacterial targets or resistance mechanisms are key approaches in tackling AMR. In addition to the cellular level resistance (i.e., mutation and horizontal gene transfer of resistance determinants), the community level resistance (i.e., bilofilms and persisters) is also an issue causing antimicrobial therapy difficulties. Therefore, anti-resistance and antibiofilm strategies have currently become research hotspot to combat antimicrobial resistance. Although metallic nanoparticles can both kill bacteria and inhibit biofilm formation, the toxicity is still a big challenge for their clinical applications. In conclusion, rational use of the existing antimicrobials and combinational use of new strategies fighting against antimicrobial resistance are powerful warranties to preserve potent antimicrobial drugs for both humans and animals. PMID:27092125

  11. Effects of subtherapeutic administration of antimicrobial agents to beef cattle on the prevalence of antimicrobial resistance in Campylobacter jejuni and Campylobacter hyointestinalis.

    PubMed

    Inglis, G D; McAllister, T A; Busz, H W; Yanke, L J; Morck, D W; Olson, M E; Read, R R

    2005-07-01

    The influence of antimicrobial agents on the development of antimicrobial resistance (AMR) in Campylobacter isolates recovered from 300 beef cattle maintained in an experimental feedlot was monitored over a 315-day period (11 sample times). Groups of calves were assigned to one of the following antimicrobial treatments: chlortetracycline and sulfamethazine (CS), chlortetracycline alone (Ct), virginiamycin, monensin, tylosin phosphate, and no antimicrobial agent (i.e., control treatment). In total, 3,283 fecal samples were processed for campylobacters over the course of the experiment. Of the 2,052 bacterial isolates recovered, 92% were Campylobacter (1,518 were Campylobacter hyointestinalis and 380 were C. jejuni). None of the antimicrobial treatments decreased the isolation frequency of C. jejuni relative to the control treatment. In contrast, C. hyointestinalis was isolated less frequently from animals treated with CS and to a lesser extent from animals treated with Ct. The majority (> or =94%) of C. jejuni isolates were sensitive to ampicillin, erythromycin, and ciprofloxacin, but more isolates with resistance to tetracycline were recovered from animals fed Ct. All of the 1,500 isolates of C. hyointestinalis examined were sensitive to ciprofloxacin. In contrast, 11%, 10%, and 1% of these isolates were resistant to tetracycline, erythromycin, and ampicillin, respectively. The number of animals from which C. hyointestinalis isolates with resistance to erythromycin and tetracycline were recovered differed among the antimicrobial treatments. Only Ct administration increased the carriage rates of erythromycin-resistant isolates of C. hyointestinalis, and the inclusion of CS in the diet increased the number of animals from which tetracycline-resistant isolates were recovered. The majority of C. hyointestinalis isolates with resistance to tetracycline were obtained from cohorts within a single pen, and most of these isolates were recovered from cattle during feeding of

  12. Effects of Subtherapeutic Administration of Antimicrobial Agents to Beef Cattle on the Prevalence of Antimicrobial Resistance in Campylobacter jejuni and Campylobacter hyointestinalis†

    PubMed Central

    Inglis, G. D.; McAllister, T. A.; Busz, H. W.; Yanke, L. J.; Morck, D. W.; Olson, M. E.; Read, R. R.

    2005-01-01

    The influence of antimicrobial agents on the development of antimicrobial resistance (AMR) in Campylobacter isolates recovered from 300 beef cattle maintained in an experimental feedlot was monitored over a 315-day period (11 sample times). Groups of calves were assigned to one of the following antimicrobial treatments: chlortetracycline and sulfamethazine (CS), chlortetracycline alone (Ct), virginiamycin, monensin, tylosin phosphate, and no antimicrobial agent (i.e., control treatment). In total, 3,283 fecal samples were processed for campylobacters over the course of the experiment. Of the 2,052 bacterial isolates recovered, 92% were Campylobacter (1,518 were Campylobacter hyointestinalis and 380 were C. jejuni). None of the antimicrobial treatments decreased the isolation frequency of C. jejuni relative to the control treatment. In contrast, C. hyointestinalis was isolated less frequently from animals treated with CS and to a lesser extent from animals treated with Ct. The majority (≥94%) of C. jejuni isolates were sensitive to ampicillin, erythromycin, and ciprofloxacin, but more isolates with resistance to tetracycline were recovered from animals fed Ct. All of the 1,500 isolates of C. hyointestinalis examined were sensitive to ciprofloxacin. In contrast, 11%, 10%, and 1% of these isolates were resistant to tetracycline, erythromycin, and ampicillin, respectively. The number of animals from which C. hyointestinalis isolates with resistance to erythromycin and tetracycline were recovered differed among the antimicrobial treatments. Only Ct administration increased the carriage rates of erythromycin-resistant isolates of C. hyointestinalis, and the inclusion of CS in the diet increased the number of animals from which tetracycline-resistant isolates were recovered. The majority of C. hyointestinalis isolates with resistance to tetracycline were obtained from cohorts within a single pen, and most of these isolates were recovered from cattle during feeding of a

  13. Prevalence, species distribution and antimicrobial resistance of enterococci isolated from dogs and cats in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of dogs and cats as reservoirs of antimicrobial resistant enterococci remains largely undefined. This is increasingly important considering the possibility of transfer of bacteria from companion animals to the human host. In this study, dogs and cats from veterinary clinics were s...

  14. Prevalence and antimicrobial resistance of Campylobacter in raw milk in the selected areas of Poland.

    PubMed

    Wysok, B; Wiszniewska-Łaszczych, A; Uradziński, J; Szteyn, J

    2011-01-01

    During the recent years, an immense increase in the number of food poisoning cases in people caused by Campylobacter (C.) species has occurred. Raw milk, next to poultry meat, is considered the most frequent cause of food poisoning in people caused by the subject bacteria, although it is not always possible to isolate Campylobacter cells from the incriminated milk. Most probably this difficulty is caused by low concentration of the pathogen in milk at the level of 2/3 cells/ml although even such low concentration represents risk to human health. The present study was aimed at determining the occurence of Campylobacter bacteria in milk originating from selected regions of Poland. The isolation method applied in this work was effective in recovering as few as 0.1 cell of Campylobacter per g of food. Among 150 bulk milk samples tested, Campylobacter spp. was isolated from 7 (4.6%) ones. The biochemical identification of the isolated strains conducted by means of conventional biochemical tests as well as by applying the API - Campy tests revealed that all the isolates belonged to the C. jejuni species. Determination of resistance to antibiotics was performed by means of the diffusion disks method for the following antibiotics: gentamicin, ciprofloxacin, ampicillin, chloramphenicol, erythromycin, doxycyclin and tetracycline. Among 7 isolates tested, all were susceptible to ampicillin, chloramphenicol, erythromycin and gentamicin, 28.5% to doxycyclin and 14.2% to tetracycline and ciprofloxacin. PMID:21957744

  15. Prevalence of antimicrobial resistance in enteric Escherichia coli from domestic pets and assessment of associated risk markers using a generalized linear mixed model.

    PubMed

    Leite-Martins, Liliana R; Mahú, Maria I M; Costa, Ana L; Mendes, Angelo; Lopes, Elisabete; Mendonça, Denisa M V; Niza-Ribeiro, João J R; de Matos, Augusto J F; da Costa, Paulo Martins

    2014-11-01

    Antimicrobial resistance (AMR) is a growing global public health problem, which is caused by the use of antimicrobials in both human and animal medical practice. The objectives of the present cross-sectional study were as follows: (1) to determine the prevalence of resistance in Escherichia coli isolated from the feces of pets from the Porto region of Portugal against 19 antimicrobial agents and (2) to assess the individual, clinical and environmental characteristics associated with each pet as risk markers for the AMR of the E. coli isolates. From September 2009 to May 2012, rectal swabs were collected from pets selected using a systematic random procedure from the ordinary population of animals attending the Veterinary Hospital of Porto University. A total of 78 dogs and 22 cats were sampled with the objective of isolating E. coli. The animals' owners, who allowed the collection of fecal samples from their pets, answered a questionnaire to collect information about the markers that could influence the AMR of the enteric E. coli. Chromocult tryptone bile X-glucuronide agar was used for E. coli isolation, and the disk diffusion method was used to determine the antimicrobial susceptibility. The data were analyzed using a multilevel, univariable and multivariable generalized linear mixed model (GLMM). Several (49.7%) of the 396 isolates obtained in this study were multidrug-resistant. The E. coli isolates exhibited resistance to the antimicrobial agent's ampicillin (51.3%), cephalothin (46.7%), tetracycline (45.2%) and streptomycin (43.4%). Previous quinolone treatment was the main risk marker for the presence of AMR for 12 (ampicillin, cephalothin, ceftazidime, cefotaxime, nalidixic acid, ciprofloxacin, gentamicin, tetracycline, streptomycin, chloramphenicol, trimethoprim-sulfamethoxazole and aztreonam) of the 15 antimicrobials assessed. Coprophagic habits were also positively associated with an increased risk of AMR for six drugs, ampicillin, amoxicillin

  16. Pathogen prevalence and influence of composted dairy manure application on antimicrobial resistance profiles of commensal soil bacteria.

    PubMed

    Edrington, Tom S; Fox, William E; Callaway, Todd R; Anderson, Robin C; Hoffman, Dennis W; Nisbet, David J

    2009-03-01

    Composting manure, if done properly, should kill pathogenic bacteria such as Salmonella and Escherichia coli O157:H7, providing for an environmentally safe product. Over a 3-year period, samples of composted dairy manure, representing 11 composting operations (two to six samples per producer; 100 total samples), were screened for Salmonella and E. coli O157:H7 and were all culture negative. Nonpathogenic bacteria were cultured from these compost samples that could theoretically facilitate the spread of antimicrobial resistance from the dairy to compost application sites. Therefore, we collected soil samples (three samples per plot; 10 plots/treatment; 90 total samples) from rangeland that received either composted dairy manure (CP), commercial fertilizer (F), or no treatment (control, CON). Two collections were made appoximately 2 and 7 months following treatment application. Soil samples were cultured for Pseudomonas and Enterobacter and confirmed isolates subjected to antimicrobial susceptibility testing. Three species of Enterobacter (cloacae, 27 isolates; aeroginosa, two isolates; sakazakii, one isolate) and two species of Pseudomonas (aeruginosa, 11 isolates; putida, seven isolates) were identified. Five Enterobacter isolates were resistant to ampicillin and one isolate was resistant to spectinomycin. All Pseudomonas isolates were resistant to ampicillin, ceftiofur, florfenicol, sulphachloropyridazine, sulphadimethoxine, and trimethoprim/sulfamethoxazole and most isolates were resistant to chlortetracycline and spectinomycin. Pseudomonas isolates were resistant to an average of 8.6, 7.9, and 8 antibiotics for CON, CP, and F treatments, respectively. No treatment differences were observed in antimicrobial resistance patterns in any of the soil isolates examined. Results reported herein support the use of composted dairy manure as an environmentally friendly soil amendment. PMID:19105635

  17. Prevalence of nontyphoidal Salmonella serogroups and their antimicrobial resistance patterns in a university teaching hospital in Eastern Province of Saudi Arabia

    PubMed Central

    Elhadi, Nasreldin; Aljindan, Reem; Aljeldah, Mohammed

    2013-01-01

    Background Nontyphoidal Salmonella (NTS) species are important food-borne pathogens that cause gastroenteritis and bacteremia, and are responsible for a huge global burden of morbidity and mortality. The aim of this study was to investigate the prevalent serogroups and antibiotic resistance of NTS in our region. Methods We reviewed the serogroup distribution and antimicrobial susceptibility patterns of NTS strains obtained from 158 stool specimens of patients with acute diarrheal infection attending the outpatient and inpatient department at a university hospital in the Eastern Province of Saudi Arabia in the period from September, 2008 to April, 2011. A retrospective analysis of the 158 patients with NTS infection was conducted to determine the most prevalent NTS serogroups causing acute gastroenteritis and their antimicrobial susceptibility patterns. Results At this teaching hospital, a total of 17,436 fecal samples were analyzed during the 2008–2011 study period. Of these specimens, 158 tested positive for NTS, giving an overall prevalence of 9.06 per 1,000. Of 158 NTS cases, serogroup D1 (25.3%) was the most prevalent, followed by serogroup B (19.6%), and serogroup C1 (18.9). One third of all NTS serogroup strains tested were resistant to tetracycline. The NTS strains showed resistance to ampicillin (31.3%), amoxicillin/clavulanic acid (29.9%), trimethoprim/sulfamethoxazole (20.9%), and cefotaxime (14.93%). Conclusion The findings of this study support the concern that use of antibiotics in animal feeds may contribute to acquisition of resistance in food-borne bacteria, such as Salmonella. Our study also concludes that the prevalence of NTS in the Eastern Province of Saudi Arabia is very low compared with other studies worldwide. PMID:24285925

  18. Antimicrobial Resistance in Agriculture

    PubMed Central

    Thanner, Sophie; Drissner, David

    2016-01-01

    ABSTRACT In this article, the current knowledge and knowledge gaps in the emergence and spread of antimicrobial resistance (AMR) in livestock and plants and importance in terms of animal and human health are discussed. Some recommendations are provided for generation of the data required in order to develop risk assessments for AMR within agriculture and for risks through the food chain to animals and humans. PMID:27094336

  19. Prevalence and antimicrobial resistance of porcine O157 and non-O157 Shiga toxin-producing Escherichia coli from India.

    PubMed

    Rajkhowa, Swaraj; Sarma, Dilip Kumar

    2014-08-01

    The aims of this study were to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) strains in pigs as a possible STEC reservoir in India as well as to characterize the STEC strains and to determine the antimicrobial resistance pattern of the strains. A total of 782 E. coli isolates from clinically healthy (n = 473) and diarrhoeic piglets (309) belonging to major pig-producing states of India were screened by the polymerase chain reaction (PCR) assay for the presence of virulence genes characteristic for STEC, that is, Shiga toxin-producing gene(s) (stx1, stx2), intimin (eae), enterohemolysin (hlyA) and STEC autoagglutinating adhesin (Saa). Overall STEC were detected in 113 (14.4%) piglets, and the prevalence of E. coli O157 and non-O157 STEC were 4 (0.5%) and 109 (13.9%), respectively. None of the O157 STEC isolates carried gene encoding for H7 antigen (fliCh7). The various combinations of virulence genes present in the strains studied were stx1 in 4.6%, stx1 in combination with stx2 gene in 5.1%, stx1 in combination with stx2 and ehxA in 0.6%, stx1 in combination with stx2 and eae in 0.2% and stx2 alone in 3.7%. All STEC isolates were found negative for STEC autoagglutinating adhesin (Saa). The number of STEC isolates which showed resistance to antimicrobials such as ampicillin, tetracycline, streptomycin, lincomycin, nalidixic acid, sulfadiazine, penicillin, gentamicin, kanamycin and ceftriaxone were 100, 99, 98, 97, 95, 94, 92, 88, 85 and 85, respectively. Ninety-seven isolates showed resistance to more than 2 antimicrobials, and 8 resistance groups (R1 to R8) were observed. This study demonstrates that pigs in India harbour both O157 and non-O157 STEC, and this may pose serious public health problems in future. PMID:24743858

  20. Prevalence, Antimicrobial Resistance and Risk Factors for Thermophilic Campylobacter Infections in Symptomatic and Asymptomatic Humans in Tanzania.

    PubMed

    Komba, E V G; Mdegela, R H; Msoffe, P L M; Nielsen, L N; Ingmer, H

    2015-11-01

    The genus Campylobacter comprises members known to be a leading cause of foodborne gastrointestinal illness worldwide. A study was conducted to determine the epidemiology and antimicrobial resistance of Campylobacter in humans in Morogoro, Eastern Tanzania. Isolation of Campylobacter from stool specimens adopted the Cape Town protocol. Campylobacter isolates were preliminarily identified by conventional phenotypic tests and subsequently confirmed by matrix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry and polymerase chain reaction. Antimicrobial resistance testing employed the disc diffusion method. A small proportion of the test isolates was also subjected to agar dilution method. Risk factors for human illness were determined in an unmatched case-control study. Thermophilic Campylobacter were isolated from 11.4% of the screened individuals (n = 1195). The agreement between PCR and MALDI-TOF was perfect (κ = 1.0). Symptomatics and young individuals were infected with higher numbers than asymptomatic and adults, respectively. The majority (84.6%) of the isolates were C. jejuni and the remaining were C. coli. Isolates had highest resistance (95.6%) for colistin sulphate and lowest for ciprofloxacin (22.1%). The rates of resistance for other antibiotics (azithromycin, erythromycin, tetracycline, cephalothin, gentamycin, nalidixic acid, ampicillin, amoxycillin, norfloxacin, chloramphenicol) ranged from 44.1% to 89%. Comparison between disc diffusion and agar dilution methods indicated a good correlation, and the tests were in agreement to each other (κ ≥ 0.75). Human illness was found to be associated with young age and consumption of chicken meat and pre-prepared salad. Our data indicate the presence of antibiotic-resistant thermophilic Campylobacter in humans in the study area. There is a need for routine investigation of the presence of the organisms in gastroenteritis aetiology, including determination of their antibiotic

  1. Prevalence, Enumeration, Serotypes, and Antimicrobial Resistance Phenotypes of Salmonella enterica Isolates from Carcasses at Two Large United States Pork Processing Plants

    PubMed Central

    Brichta-Harhay, Dayna M.; Kalchayanand, Norasak; Bosilevac, Joseph M.; Shackelford, Steven D.; Wheeler, Tommy L.; Koohmaraie, Mohammad

    2012-01-01

    The objective of this study was to characterize Salmonella enterica contamination on carcasses in two large U.S. commercial pork processing plants. The carcasses were sampled at three points, before scalding (prescald), after dehairing/polishing but before evisceration (preevisceration), and after chilling (chilled final). The overall prevalences of Salmonella on carcasses at these three sampling points, prescald, preevisceration, and after chilling, were 91.2%, 19.1%, and 3.7%, respectively. At one of the two plants, the prevalence of Salmonella was significantly higher (P < 0.01) for each of the carcass sampling points. The prevalences of carcasses with enumerable Salmonella at prescald, preevisceration, and after chilling were 37.7%, 4.8%, and 0.6%, respectively. A total of 294 prescald carcasses had Salmonella loads of >1.9 log CFU/100 cm2, but these carcasses were not equally distributed between the two plants, as 234 occurred at the plant with higher Salmonella prevalences. Forty-one serotypes were identified on prescald carcasses with Salmonella enterica serotypes Derby, Typhimurium, and Anatum predominating. S. enterica serotypes Typhimurium and London were the most common of the 24 serotypes isolated from preevisceration carcasses. The Salmonella serotypes Johannesburg and Typhimurium were the most frequently isolated serotypes of the 9 serotypes identified from chilled final carcasses. Antimicrobial susceptibility was determined for selected isolates from each carcass sampling point. Multiple drug resistance (MDR), defined as resistance to three or more classes of antimicrobial agents, was identified for 71.2%, 47.8%, and 77.5% of the tested isolates from prescald, preevisceration, and chilled final carcasses, respectively. The results of this study indicate that the interventions used by pork processing plants greatly reduce the prevalence of Salmonella on carcasses, but MDR Salmonella was isolated from 3.2% of the final carcasses sampled. PMID:22327585

  2. Identification and antimicrobial resistance prevalence of pathogenic Escherichia coli strains from treated wastewater effluents in Eastern Cape, South Africa.

    PubMed

    Adefisoye, Martins A; Okoh, Anthony I

    2016-02-01

    Antimicrobial resistance (AMR) is a global problem impeding the effective prevention/treatment of an ever-growing array of infections caused by pathogens; a huge challenge threatening the achievements of modern medicine. In this paper, we report the occurrence of multidrug resistance (MDR) in Escherichia coli strains isolated from discharged final effluents of two wastewater treatment facilities in the Eastern Cape Province of South Africa. Standard disk diffusion method was employed to determine the antibiotic susceptibility profile of 223 polymerase chain reaction (PCR)-confirmed E. coli isolates against 17 common antibiotics in human therapy and veterinary medicine. Seven virulence associated and fourteen antibiotic resistance genes were also evaluated by molecular methods. Molecular characterization revealed five pathotypes of E. coli in the following proportions: enterotoxigenic ETEC (1.4%), enteropathogenic EPEC (7.6%), enteroaggregative EAEC (7.6%), neonatal meningitis (NMEC) (14.8%), uropathogenic (41.7%), and others (26.9%). Isolates showed varying (1.7-70.6%) degrees of resistance to 15 of the test antibiotics. Multidrug resistance was exhibited by 32.7% of the isolates, with the commonest multiple antibiotic-resistant phenotype (MARP) being AP-T-CFX (12 isolates), while multiple antibiotic-resistant indices (MARI) estimated are 0.23 (Site 1) and 0.24 (Site 2). Associated antibiotic resistance genes detected in the isolates include: strA (88.2%), aadA (52.9%), cat I (15%), cmlA1 (4.6%), blaTEM (56.4%), tetA (30.4%), tetB (28.4%), tetC (42.2%), tetD (50%), tetK (11.8%), and tetM (68.6%). We conclude that municipal wastewater effluents are important reservoirs for the dissemination of potentially pathogenic E. coli (and possibly other pathogens) and antibiotic resistance genes in the aquatic milieu of the Eastern Cape and a risk to public health. PMID:26758686

  3. PROGRAMS FOR MONITORING ANTIMICROBIAL RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of antimicrobials has increased in both human and veterinary medicine and the emergence of resistance to antimicrobials has become a global problem. This is due, in part, to the widespread availability of antimicrobials and the efficacy they impart in control of certain infectious diseases. An...

  4. Prevalence of bacterial resistance to quinolones and other antimicrobials among avian Escherichia coli strains isolated from septicemic and healthy chickens in Spain.

    PubMed Central

    Blanco, J E; Blanco, M; Mora, A; Blanco, J

    1997-01-01

    Antimicrobial therapy is an important tool in reducing the enormous losses in the poultry industry caused by Escherichia coli infections (colibacillosis). However, resistance to existing antimicrobials is widespread and of concern to poultry veterinarians. Antimicrobial resistance testing of 468 avian E. coli strains isolated in Spain showed very high levels of resistance to trimethoprim-sulfamethoxazole (67%) and the new fluoroquinolones (13 to 24%). As these antimicrobial agents may cause cross-resistance with human enteric pathogens, prudent use of them in veterinary medicine is highly recommended. PMID:9230413

  5. Antimicrobial resistance status and prevalence rates of extended spectrum beta-lactamase producers isolated from a mixed human population

    PubMed Central

    Afunwa, Ruth A.; Odimegwu, Damian C.; Iroha, Romanus I.; Esimone, Charles O.

    2011-01-01

    Owing to the increasing epidemiological and therapeutic challenges associated with infections due to ESBL producers, ESBL prevalence rate among some bacteria isolates from healthy and non-healthy human population in a metropolitan Nigerian setting was evaluated. A total of one hundred and forty-five (145) bacteria strains were isolated from a total of four hundred and sixty (460) samples collected from urine, wound, throat and anal swabs of 220 healthy volunteers in the community and from 240 patients in 2 secondary and 2 tertiary hospitals (altogether, 4) in Enugu metropolis. The presumptive confirmatory test used for ESBL detection was the Double Disc Synergy Test (DDST) method. Conjugation and plasmid curing studies were also done for resistance factor determination. Of the 145 isolates, 20 were ESBL producers with 35% of these ESBL producers being of community origin and 65% from hospitals. This translates to 4.8% and 9% incidences (comparably higher than established prevalence of 4.4% and 7.5 respectively) for community and hospital infections respectively. The ESBL isolates showed high resistance to tetracycline, gentamicin, pefloxacin, ceftriaxone, cefuroxime, ciprofloxacin and Augmentin® (Amoxicilin and clavulanic acid combination). Conjugation studies for Resistance plasmid transfer showed non-transference of resistance determinants between the ESBL transconjugants and recipient strains. Correspondingly, the plasmid curing studies revealed that the acridine orange could not effect a cure on the isolates as they still retained high resistance to the antibiotics after the treatment. This study confirms the growing incidences/pool of ESBL strains in Nigeria and call for widespread and continuous monitoring towards an effective management of the potential therapeutic hurdle posed by this trend. PMID:21619555

  6. Prevalence and patterns of antimicrobial resistance among Escherichia coli isolated from Zambian dairy cattle across different production systems

    PubMed Central

    Mainda, Geoffrey; Bessell, Paul B.; Muma, John B.; McAteer, Sean P.; Chase-Topping, Margo E.; Gibbons, James; Stevens, Mark P.; Gally, David L.; deC. Bronsvoort, Barend M.

    2015-01-01

    This study focused on the use of antibiotics on small, medium and commercial-sized dairy farms in the central region of Zambia and its relationship to antibiotic resistance in Escherichia coli. A stratified random sample of 104 farms was studied, representing approximately 20% of all dairy farms in the region. On each farm, faecal samples were collected from a random sample of animals and a standardised questionnaire on the usage of antibiotics was completed. An E. coli isolate was obtained from 98.67% (371/376) of the sampled animals and tested for resistance to six classes of antibiotics. The estimated prevalence of resistance across the different farming systems was: tetracycline (10.61; 95%CI: 7.40–13.82), ampicillin (6.02; 95%CI: 3.31–8.73), sulfamethoxazole/ trimethoprim (4.49; 95%CI: 2.42–6.56), cefpodoxime (1.91; 95%CI: 0.46–3.36), gentamicin (0.89; 95%CI: 0.06–1.84) and ciprofloxacin (0%). Univariate analyses indicated certain diseases, exotic breeds, location, farm size and certain management practices as risk factors for detection of resistance, whereas multivariate analyses showed an association with lumpy skin disease and a protective effect for older animals (>25 months). This study has provided novel insights into the drivers of antibiotic use and their association with antibiotic resistance in an under-studied region of Southern Africa. PMID:26211388

  7. Antimicrobial resistance in bacteria from Swiss veal calves at slaughter.

    PubMed

    Di Labio, E; Regula, G; Steiner, A; Miserez, R; Thomann, A; Ledergerber, U

    2007-01-01

    Bacteria with antimicrobial resistance can be transferred from animals to humans and may compromise antimicrobial treatment in case of infection. To determine the antimicrobial resistance situation in bacteria from Swiss veal calves, faecal samples from 500 randomly selected calves originating from 129 farms were collected at four big slaughterhouses. Samples were cultured for Escherichia coli, Enterococcus sp. and Campylobacter sp. and isolated strains were tested for antimicrobial susceptibility to selected antimicrobial agents by the minimal inhibitory concentration technique using the broth microdilution method. From 100 farms, data on farm management, animal husbandry and antimicrobial treatments of the calves were collected by questionnaire. Risk factors associated with antimicrobial resistance were identified by logistic regression. In total, 467 E. coli, 413 Enterococcus sp. and 202 Campylobacter sp. were isolated. Of those, 68.7%, 98.7% and 67.8%, respectively, were resistant to at least one of the tested antimicrobial agents. Resistance was mainly observed to antimicrobials frequently used in farm animals. Prevalence of resistance to antimicrobials important for human treatment was generally low. However, a rather high number of quinupristin/dalfopristin-resistant Enterococcus faecium and ciprofloxacin-resistant Campylobacter sp. were detected. External calf purchase, large finishing groups, feeding of milk by-products and administration of antimicrobials through feed upon arrival of the animals on the farm significantly increased the risk of antimicrobial resistance at farm level. Participation in a quality assurance programme and injection of a macrolide upon arrival of the animals on the farm had a protective effect. The present study showed that veal calves may serve as a reservoir for resistant bacteria. To ensure food safety, veal calves should be included in the national monitoring programme for antimicrobial resistance in farm animals. By

  8. Engineering Antimicrobials Refractory to Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-drug resistant superbugs are a persistent problem in modern health care, demonstrating the need for a new class of antimicrobials that can address this concern. Triple-acting peptidoglycan hydrolase fusions are a novel class of antimicrobials which have qualities well suited to avoiding resis...

  9. Prevalence, antimicrobial susceptibility and molecular typing of Methicillin-Resistant Staphylococcus aureus (MRSA) in bulk tank milk from southern Italy.

    PubMed

    Parisi, A; Caruso, M; Normanno, G; Latorre, L; Sottili, R; Miccolupo, A; Fraccalvieri, R; Santagada, G

    2016-09-01

    This paper assesses the prevalence of MRSA in bulk tank milk (BTM) samples from southern Italy, and the relationship between the Coagulase Positive Staphylococci count (CPS) and MRSA prevalence. Of 486 BTM samples tested, 12 samples (2.5%) resulted positive for the presence of MRSA. Great genetic diversity was found among the isolates: ST1/t127 and t174/IVa, ST5/t688/V, ST8/t unknown/IVa/V, ST45/t015/IVa, ST71/t524/V, ST88/t786/Iva, ST398/t011 and t899/IVa/V and ST2781/t1730/V. All isolates were pvl-negative and icaA positive. The majority of strains (58%) carried the ses (sec, seh, seg, seo, sem and sen) genes. All tested strains resulted susceptible to amikacin, cephalotin, cloramphenicol, gentamycin, trimethoprim - sulfamethoxazole, tobramycin and vancomycin, and variably resistant to ampicillin, oxacillin and tetracycline. No statistical association between the CPS count and MRSA detection was found in the MRSA-positive samples. Although some of the spa-types and STs detected in our survey are known to cause human infections, raw milk from Italian herds in the considered area is not a common source of MRSA. Nonetheless, it is necessary to assess the risk of foodborne infection and the risk related to the handling of milk. PMID:27217357

  10. Combined ceftazidime and amikacin resistance among Gram-negative isolates in acute-onset postoperative endophthalmitis: prevalence, antimicrobial susceptibilities, and visual acuity outcome

    PubMed Central

    2013-01-01

    Background The purpose of this study is to evaluate the prevalence, antimicrobial susceptibilities, and visual acuity outcome of acute-onset postoperative Gram-negative bacterial endophthalmitis cases resistant to both ceftazidime and amikacin seen between 2005 and 2010 at L. V. Prasad Eye Institute, a tertiary care ophthalmic Centre in South India. Medical records of all patients with Gram-negative bacterial endophthalmitis resistant to both amikacin and ceftazidime between 1 January 2005 and 31 December 2010 were reviewed in this non-comparative, consecutive, retrospective case series. Favorable outcome was defined as a best-corrected visual acuity of ≥20/200. Results Sixty five (39.6%) of 164 culture-positive postoperative endophthalmitis were caused by Gram-negative organisms. Among these 65 isolates, 32 (49%; 95% confidence interval (CI) 37% to 61%) were resistant to ceftazidime, 17 (26%; 95% CI 15% to 37%) to amikacin, and 12 (18.5%; 95% CI 9% to 27%) to both ceftazidime and amikacin. Eight Pseudomonas isolates, three Enterobacter isolates, and one Haemophilus isolate were resistant to both ceftazidime and amikacin. The isolates were sensitive to fluoroquinolones (42%) and imipenem (50%). Presenting visual acuity was light perception in 10 (83.3%) cases. A final visual acuity ≥20/200 was achieved in 5/12 (41.7%) of these patients. Conclusion In the current study, Pseudomonas was the most common Gram-negative bacteria resistant to both amikacin and ceftazidime. The emergence of multidrug-resistant bacteria causing endophthalmitis is a matter of concern in India. Alternative antibiotics like imipenem or fluoroquinolones may be considered for the management of these resistant organisms. PMID:24161048

  11. Prevalence and transmission of antimicrobial resistance among Aeromonas populations from a duckweed aquaculture based hospital sewage water recycling system in Bangladesh.

    PubMed

    Rahman, Mokhlasur; Huys, Geert; Kühn, Inger; Rahman, Motiur; Möllby, Roland

    2009-10-01

    In order to investigate the influence of a duckweed aquaculture based hospital sewage water recycling plant on the prevalence and dissemination of antibiotic resistance, we made use of an existing collection of 1,315 Aeromonas isolates that were previously typed by the biochemical fingerprinting PhP-AE system. In these treatment plant, hospital raw sewage water is first collected in a settlement pond (referred to as sewage water in this study) and is then transferred to a lagoon, where the duckweed (Lemnaceae) is grown (referred to as lagoon). The duckweed is harvested and used as feed for the fish in a separate pond (referred to as fish pond). From this collection, representatives of 288 PhP types were subjected to antibiotic susceptibility testing for eight antimicrobials by broth microdilution method. The overall resistance rates among Aeromonas isolates from the treatment plant were highest for ampicillin (87%) and erythromycin (79%) followed by cephalothin (58%), nalidixic acid (52%), streptomycin (51%), tetracycline (31%), chloramphenicol (13%) and gentamicin (8%). A significantly lower prevalence of antibiotic resistance was found in Aeromonas from environmental control water, patient stool samples, duckweed and fish compared to sewage water isolates. The prevalence of resistance in the sewage water was not significantly reduced compared to the lagoon water and fish pond. Throughout the treatment system, the frequencies of resistant strains were found to diminish during the sewage water purification process, i.e. in the lagoon where sewage water is used to grow the duckweed. However, the frequency of resistant strains again increased in the fish pond where sewage grown duckweed is used for aquaculture. Among the selected isolates, two multiresistant clonal groups of Aeromonas caviae HG4 were identified that exhibited indistinguishable PhP and amplified fragment length polymorphism fingerprints and shared a common plasmid of approximately 5 kb

  12. Molecular Detection of Antimicrobial Resistance

    PubMed Central

    Fluit, Ad C.; Visser, Maarten R.; Schmitz, Franz-Josef

    2001-01-01

    The determination of antimicrobial susceptibility of a clinical isolate, especially with increasing resistance, is often crucial for the optimal antimicrobial therapy of infected patients. Nucleic acid-based assays for the detection of resistance may offer advantages over phenotypic assays. Examples are the detection of the methicillin resistance-encoding mecA gene in staphylococci, rifampin resistance in Mycobacterium tuberculosis, and the spread of resistance determinants across the globe. However, molecular assays for the detection of resistance have a number of limitations. New resistance mechanisms may be missed, and in some cases the number of different genes makes generating an assay too costly to compete with phenotypic assays. In addition, proper quality control for molecular assays poses a problem for many laboratories, and this results in questionable results at best. The development of new molecular techniques, e.g., PCR using molecular beacons and DNA chips, expands the possibilities for monitoring resistance. Although molecular techniques for the detection of antimicrobial resistance clearly are winning a place in routine diagnostics, phenotypic assays are still the method of choice for most resistance determinations. In this review, we describe the applications of molecular techniques for the detection of antimicrobial resistance and the current state of the art. PMID:11585788

  13. Prevalence, characterization, and antimicrobial resistance of Yersinia species and Yersinia enterocolitica isolated from raw milk in farm bulk tanks.

    PubMed

    Jamali, Hossein; Paydar, Mohammadjavad; Radmehr, Behrad; Ismail, Salmah

    2015-02-01

    The aims of this study were to investigate the prevalence and to characterize and determine the antibiotic resistance of Yersinia spp. isolates from raw milk. From September 2008 to August 2010, 446 raw milk samples were obtained from farm bulk milk tanks in Varamin, Iran. Yersinia spp. were detected in 29 (6.5%) samples, out of which 23 (79.3%), 5 (17.2%), and 1 (3.4%) were isolated from cow, sheep, and goat raw milk, respectively. The most common species isolated was Yersinia enterocolitica (65.5%), followed by Yersinia frederiksenii (31%), and Yersinia kristensenii (3.4%). Of the 19 Y. enterocolitica isolates, 14 (73.7%) were grouped into bioserotype 1A/O:9, 4 (21.1%) belonged to bioserotype 1B:O8, 1 (5.3%) belonged to bioserotype 4/O:3, and 1 isolate (biotype 1A) was not typable. All the isolates of biotypes 1B and 4harbored both the ystA and ail genes. However, all the isolates of biotype 1A were only positive for the ystB gene. The tested Yersinia spp. showed the highest percentages of resistance to tetracycline (48.3%), followed by ciprofloxacin and cephalothin (each 17.2%), ampicillin (13.8%), streptomycin (6.9%), and amoxicillin and nalidixic acid (each 3.4%). All of the tested isolates demonstrated significant sensitivity to gentamicin and chloramphenicol. Recovery of potentially pathogenic Y. enterocolitica from raw milk indicates high risks of yersiniosis associated with consumption of raw milk. PMID:25497824

  14. Prevalence of antimicrobial resistance in fecal generic Escherichia coli isolated in western Canadian beef herds. Part II — Cows and cow-calf pairs

    PubMed Central

    Gow, Sheryl P.; Waldner, Cheryl L.; Rajíc, Andrijana; McFall, Margaret E.; Reid-Smith, Richard

    2008-01-01

    The objective of this study was to describe antimicrobial resistance in fecal generic Escherichia coli isolated from cows and cow-calf pairs from western Canadian beef herds. Susceptibility testing was completed on 1555 E. coli isolates (n = 533 cows from 69 herds) harvested from fresh fecal samples in the spring of 2002, and 630 isolates (n = 105 cow-calf pairs from 10 herds) collected in the spring of 2003. Only 1 cow isolate was resistant to an antimicrobial classified by Health Canada as being of very high importance to human medicine. Resistance to at least 2 antimicrobials was detected in 7.1% of the 2002 cow isolates, in 3.4% of the 2003 cow isolates, and 23.2% of the 2003 calf isolates. In the cows, resistance to at least 1 antimicrobial was not associated with cow breed (P = 0.16), cow age (P = 0.14), or previous cow treatment (P = 0.56). In the calves, resistance to at least 1 antimicrobial was not predicted by whether or not its dam was resistant to at least 1 antimicrobial (P = 0.36). PMID:18505197

  15. Antimicrobial Resistance Mechanisms among Campylobacter

    PubMed Central

    2013-01-01

    Campylobacter jejuni and Campylobacter coli are recognized as the most common causative agents of bacterial gastroenteritis in the world. Humans most often become infected by ingesting contaminated food, especially undercooked chicken, but also other sources of bacteria have been described. Campylobacteriosis is normally a self-limiting disease. Antimicrobial treatment is needed only in patients with more severe disease and in those who are immunologically compromised. The most common antimicrobial agents used in the treatment of Campylobacter infections are macrolides, such as erythromycin, and fluoroquinolones, such as ciprofloxacin. Tetracyclines have been suggested as an alternative choice in the treatment of clinical campylobacteriosis but in practice are not often used. However, during the past few decades an increasing number of resistant Campylobacter isolates have developed resistance to fluoroquinolones and other antimicrobials such as macrolides, aminoglycosides, and beta-lactams. Trends in antimicrobial resistance have shown a clear correlation between use of antibiotics in the veterinary medicine and animal production and resistant isolates of Campylobacter in humans. In this review, the patterns of emerging resistance to the antimicrobial agents useful in treatment of the disease are presented and the mechanisms of resistance to these drugs in Campylobacter are discussed. PMID:23865047

  16. ANTIMICROBIAL RESISTANCE TRENDS IN SALMONELLA

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Antimicrobial use and antimicrobial resistance in nosocomial pathogens at a tertiary care hospital in Pune

    PubMed Central

    Nair, Velu; Sharma, Dinesh; Sahni, A.K.; Grover, Naveen; Shankar, S.; Jaiswal, S.S.; Dalal, S.S.; Basannar, D.R.; Phutane, Vivek S.; Kotwal, Atul; Gopal Rao, G.; Batura, Deepak; Venkatesh, M.D.; Sinha, Tapan; Kumar, Sushil; Joshi, D.P.

    2015-01-01

    Background Resistance to antimicrobial agents is emerging in wide variety of nosocomial and community acquired pathogens. Widespread and often inappropriate use of broad spectrum antimicrobial agents is recognized as a significant contributing factor to the development and spread of bacterial resistance. This study was conducted to gain insight into the prevalent antimicrobial prescribing practices, and antimicrobial resistance pattern in nosocomial pathogens at a tertiary care hospital in Pune, India. Methods Series of one day cross sectional point prevalence surveys were carried out on four days between March and August 2014. All eligible in patients were included in the study. A structured data entry form was used to collect the data for each patient. Relevant samples were collected for microbiological examination from all the clinically identified hospital acquired infection cases. Results 41.73% of the eligible patients (95% CI: 39.52–43.97) had been prescribed at least one antimicrobial during their stay in the hospital. Beta-lactams (38%) were the most prescribed antimicrobials, followed by Protein synthesis inhibitors (24%). Majority of the organisms isolated from Hospital acquired infection (HAI cases) were found to be resistant to the commonly used antimicrobials viz: Cefotaxime, Ceftriaxone, Amikacin, Gentamicin and Monobactams. Conclusion There is need to have regular antimicrobial susceptibility surveillance and dissemination of this information to the clinicians. In addition, emphasis on the rational use of antimicrobials, antimicrobial rotation and strict adherence to the standard treatment guidelines is very essential. PMID:25859071

  18. Antimicrobial resistance: a global response.

    PubMed Central

    Smith, Richard D.; Coast, Joanna

    2002-01-01

    Resistance to antimicrobial therapies reduces the effectiveness of these drugs, leading to increased morbidity, mortality, and health care expenditure. Because globalization increases the vulnerability of any country to diseases occurring in other countries, resistance presents a major threat to global public health, and no country acting on its own can adequately protect the health of its population against it. International collective action is therefore essential. Nevertheless, responsibility for health remains predominantly national. Consequently, there is a potentially significant disparity between the problems and solutions related to antimicrobial resistance and the institutions and mechanisms that are available to deal with them. This paper considers the capacity of national and international institutions and mechanisms to generate a collective response to antimicrobial resistance. Strategies for containing resistance are outlined, with particular reference to globally coordinated activities of countries. The adequacy of national and international responses to resistance is assessed, and the actions that international bodies could take to solve difficulties associated with present responses are highlighted. Approaches are suggested for securing international collective action for the containment of antimicrobial resistance. PMID:11953791

  19. Antimicrobial resistance in Libya: 1970–2011

    PubMed Central

    Ghenghesh, Khalifa Sifaw; Rahouma, Amal; Tawil, Khaled; Zorgani, Abdulaziz; Franka, Ezzedin

    2013-01-01

    Resistance to antimicrobial agents is a major health problem that affects the whole world. Providing information on the past state of antimicrobial resistance in Libya may assist the health authorities in addressing the problem more effectively in the future. Information was obtained mainly from Highwire Press (including PubMed) search for the period 1970–2011 using the terms ‘antibiotic resistance in Libya’, ‘antimicrobial resistance in Libya’, ‘tuberculosis in Libya’, and ‘primary and acquired resistance in Libya’ in title and abstract. From 1970 to 2011 little data was available on antimicrobial resistance in Libya due to lack of surveillance and few published studies. Available data shows high resistance rates for Salmonella species in the late 1970s and has remained high to the present day. High prevalence rates (54–68%) of methicillin-resistant Staphylococcus aureus (MRSA) were reported in the last decade among S. aureus from patients with burns and surgical wound infections. No reports were found of vancomycin-resistant S. aureus (VRSA) or vancomycin-intermediate-resistant S. aureus (VISA) using standard methods from Libya up to the end of 2011. Reported rates of primary (i.e. new cases) and acquired (i.e. retreatment cases) multidrug-resistant tuberculosis (MDR-TB) from the eastern region of Libya in 1971 were 16.6 and 33.3% and in 1976 were 8.6 and 14.7%, in western regions in 1984–1986 were 11 and 21.5% and in the whole country in 2011 were estimated at 3.4 and 29%, respectively. The problem of antibiotic resistance is very serious in Libya. The health authorities in particular and society in general should address this problem urgently. Establishing monitoring systems based on the routine testing of antimicrobial sensitivity and education of healthcare workers, pharmacists, and the community on the health risks associated with the problem and benefits of prudent use of antimicrobials are some steps that can be taken to tackle the

  20. Prevalence and Trends of Staphylococcus aureus Bacteraemia in Hospitalized Patients in South Africa, 2010 to 2012: Laboratory-Based Surveillance Mapping of Antimicrobial Resistance and Molecular Epidemiology

    PubMed Central

    Perovic, Olga; Iyaloo, Samantha; Kularatne, Ranmini; Lowman, Warren; Bosman, Noma; Wadula, Jeannette; Seetharam, Sharona; Duse, Adriano; Mbelle, Nontombi; Bamford, Colleen; Dawood, Halima; Mahabeer, Yesholata; Bhola, Prathna; Abrahams, Shareef; Singh-Moodley, Ashika

    2015-01-01

    Introduction We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB). Methods Thirteen academic centres in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST). Results S. aureus from 2709 patients were included, and 1231 (46%) were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003). Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001). Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01). The most prevalent SCCmec type was SCCmec type III (531 [41%]) followed by type IV (402 [31%]). Spa-typing discovered 47 different spa-types. The five (87%) most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8) (n = 7) followed by ST5 (CC5) (n = 4), ST36 (CC30) (n = 4) and ST239 (CC8) (n = 3). Conclusions MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41%) and type IV (31%), which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB. PMID:26719975

  1. Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste.

    PubMed

    Agga, Getahun E; Arthur, Terrance M; Durso, Lisa M; Harhay, Dayna M; Schmidt, John W

    2015-01-01

    This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact" environments (an urban lake and a relict prairie). Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR) Gram-negative (Escherichia coli and Salmonella enterica) and Gram-positive (enterococci) bacteria were determined from individual samples (n = 174). The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44) by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine), low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05) in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar prevalences

  2. Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste

    PubMed Central

    Durso, Lisa M.; Harhay, Dayna M.; Schmidt, John W.

    2015-01-01

    This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal wastewater treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two “low impact” environments (an urban lake and a relict prairie). Multiple liquid and solid samples were collected from each environment. The prevalences and concentrations of antimicrobial-resistant (AMR) Gram-negative (Escherichia coli and Salmonella enterica) and Gram-positive (enterococci) bacteria were determined from individual samples (n = 174). The prevalences of 84 antimicrobial resistance genes in metagenomic DNA isolated from samples pooled (n = 44) by collection date, location, and sample type were determined. The prevalences and concentrations of AMR E. coli and Salmonella were similar among the livestock and municipal sample sources. The levels of erythromycin-resistant enterococci were significantly higher in liquid samples from cattle catchment ponds and swine waste lagoons than in liquid samples from municipal wastewater treatment facilities, but solid samples from these environments did not differ significantly. Similarly, trimethoprim/sulfamethoxazole-resistant E. coli concentrations were significantly higher in swine liquid than in municipal liquid samples, but there was no difference in solid samples. Multivariate analysis of the distribution of antimicrobial resistance genes using principal coordinate analysis showed distinct clustering of samples with livestock (cattle and swine), low impact environment and municipal samples forming three separate clusters. The numbers of class A beta-lactamase, class C beta-lactamase, and fluoroquinolone resistance genes detected were significantly higher (P < 0.05) in municipal samples than in cattle runoff or swine lagoon samples. In conclusion, we report that AMR is a very widespread phenomenon and that similar

  3. High prevalence of multidrug-tolerant bacteria and associated antimicrobial resistance genes isolated from ornamental fish and their carriage water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: The aim of the study was to assess the extent to which ornamental fish and their carriage water harbour antibiotic resistant bacteria and associated antibiotic resistance genes. Methods: 129 Aeromonas spp. isolated from warm water and coldwater ornamental fish species were screened for r...

  4. Prevalence of antimicrobial resistance in Salmonella serotype Hadar isolated from humans, retail meat, and food animals at slaughter, United States, NARMS 1996-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background Non-Typhi Salmonella (NTS) is a leading cause of bacterial gastroenteritis in the United States. Although most infections are self-limited, antibiotic treatment is essential for severe illness. Use of antimicrobial agents in food animals contributes to resistance in NTS. Multidrug resis...

  5. Prevalence, antimicrobial resistance and relation to indicator and pathogenic microorganisms of Salmonella enterica isolated from surface waters within an agricultural landscape.

    PubMed

    Economou, Vangelis; Gousia, Panagiota; Kansouzidou, Athina; Sakkas, Hercules; Karanis, Panagiotis; Papadopoulou, Chrissanthy

    2013-07-01

    During a 12 month period (June 2007-May 2008), the prevalence and susceptibility of Salmonella serovars and their relation to specific pathogenic and indicator bacteria in river and coastal waters was investigated. A total of 240 water samples were collected from selected sites in Acheron and Kalamas Rivers and the Ionian Sea coast in north western Greece. The samples were analyzed for Salmonella spp., Listeria spp., Campylobacter spp., Escherichia coli O157, Staphylococci, Pseudomonas spp., Total Coliforms, Fecal Coliforms, Fecal Streptococci, Total Heterotrophic Flora at 20°C and at 37°C, fungi and protozoa (Cryptosporidium, Giardia). Susceptibility tests to nine antimicrobials (ampicillin, amikacin, amoxicillin/clavulavic acid, cefuroxime, ciprofloxacin, cefoxitin, tetracycline, ticarcillin/clavulanic acid, ampicillin/sulbactam) were performed using the disk diffusion method for Salmonella isolates. We isolated 28 serovars of Salmonella spp. identified as Salmonella enteritidis (23), Salmonella thompson (3) and Salmonella virchow (2). Multi-drug resistant Salmonella serovars were isolated from both river and marine waters, with 34.8% of S. enteritidis and 100% of S. virchow being resistant to more than 3 antibiotics. Also we isolated 42 strains of Listeria spp. identified as L. monocytogenes (20), L. innocua (9), L. seeligeri (2) and L. ivanovii (11). All the Listeria isolates were susceptible to the tested antibiotics. No Campylobacter spp., E. coli O157, Cryptosporidium and Giardia were detected. The overall ranges (and average counts) of the indicator bacteria were: Total Coliforms 0-4×10(4)cfu/100ml (3.7×10(3)cfu/100ml), Fecal Coliforms 0-9×10(3)cfu/100ml (9.2×10(2)cfu/100ml), Fecal Streptococci 0-3.5×10(4)cfu/100ml (1.4×10(3)cfu/100ml), Total Heterotrophic Flora at 20°C 0-6×10(3)cfu/ml (10(3)cfu/ml) and at 37°C 0-5×10(3)cfu/ml (4.9×10(2)cfu/ml). Weak or non significant positive Spearman correlations (p<0.05, rs range: 0.13-0.77) were obtained

  6. Bacteremia and Antimicrobial Drug Resistance over Time, Ghana

    PubMed Central

    Amuzu, Sylvarius K.; de Ciman, Ring; Kassimova, Iparkhan; Groß, Lisa; Rabsch, Wolfgang; Rosenberg, Ulrike; Schulze, Marco; Stich, August; Zimmermann, Ortrud

    2011-01-01

    Bacterial distribution and antimicrobial drug resistance were monitored in patients with bacterial bloodstream infections in rural hospitals in Ghana. In 2001–2002 and in 2009, Salmonella enterica serovar Typhi was the most prevalent pathogen. Although most S. enterica serovar Typhi isolates were chloramphenicol resistant, all isolates tested were susceptible to ciprofloxacin. PMID:22000360

  7. [Biofilms, tolerance and antimicrobial resistance].

    PubMed

    Bahar, Gül

    2002-01-01

    Virtually every surface examined in natural, industrial and pathogenic ecosystems are colonized by biofilms consisting of adherent populations of microorganisms surrounded with a glycocalyx matrix. The development of biofilms has important economic and medical consequences. The development and use of a broad range of medical devices made us recognize a variety of infections caused by microorganisms that were regarded previously as harmless. Infections caused by biofilms are difficult to eradicate with antimicrobial treatment, and in-vitro susceptibility tests show significant resistance of biofilm cells to be killed. Advances in our understanding of biofilm formation can assist in the development of novel strategies for the prevention and treatment of infections caused by biofilms. In this review article, structures, general properties and antimicrobial resistance mechanisms of biofilms were discussed under the light of recent literature. PMID:12838670

  8. Antimicrobial (Drug) Resistance Prevention

    MedlinePlus

    ... Action Plan for Combating Antibiotic-Resistant Bacteria (PDF) ​​​​​​ Javascript Error Your browser JavaScript is turned off causing certain features of the ... incorrectly. Please visit your browser settings and turn JavaScript on. Read more information on enabling JavaScript. Skip ...

  9. Source-Related Effects of Wastewater on Transcription Factor (AhR, CAR and PXR)-Mediated Induction of Gene Expression in Cultured Rat Hepatocytes and Their Association with the Prevalence of Antimicrobial-Resistant Escherichia coli.

    PubMed

    Guruge, Keerthi S; Yamanaka, Noriko; Sonobe, Miyuki; Fujizono, Wataru; Yoshioka, Miyako; Akiba, Masato; Yamamoto, Takehisa; Joshua, Derrick I; Balakrishna, Keshava; Yamashita, Nobuyoshi; Kannan, Kurunthachalam; Tsutsui, Toshiyuki

    2015-01-01

    Extracts of wastewater collected from 4 sewage treatment plants (STPs) receiving effluents from different sources in South India were investigated for their levels of transcription factor-mediated gene induction in primary cultured rat hepatocytes. In addition, the relation between gene induction levels and the prevalence of antimicrobial-resistant Escherichia coli (E. coli) in wastewater was examined. STP-3, which treats only hospital wastewater, exhibited significantly greater induction potency of all 6 drug metabolizing cytochrome P450 (CYP) genes examined, CYP1A1, 1A2, 1B1, 2B15, 3A1, and 3A2, whereas the wastewater at STP-1, which exclusively receives domestic sewage, showed significantly diminished levels of induction of 3 CYP genes when compared to the levels of CYP induction at STP-2, which receives mixed wastewater. Samples collected during the monsoon season showed a significantly altered gene induction capacity compared to that of samples from the pre-monsoon period. The data suggest that the toxicity of wastewater in STPs was not significantly diminished during the treatment process. The chemical-gene interaction data predicted that a vast number of chemicals present in the wastewater would stimulate the genes studied in the rat hepatocytes. The multivariable logistic regression analysis demonstrated that the prevalence of isolates resistant to cefotaxime, imipenem and streptomycin was significantly correlated with the levels of induction of at least three CYP-isozymes in STP wastewater. In addition, the resistance of isolates in treatment plants was not altered by the treatment steps, whereas the sampling season did have an impact on the resistance to specific antimicrobials. The identification of receptor-mediated gene regulation capacities offers important data not limited to the (synergistic) physiological role of chemicals in biological systems but may provide new insight into the link between the effects of known/unknown drugs and prevalence of

  10. Source-Related Effects of Wastewater on Transcription Factor (AhR, CAR and PXR)-Mediated Induction of Gene Expression in Cultured Rat Hepatocytes and Their Association with the Prevalence of Antimicrobial-Resistant Escherichia coli

    PubMed Central

    Guruge, Keerthi S.; Yamanaka, Noriko; Sonobe, Miyuki; Fujizono, Wataru; Yoshioka, Miyako; Akiba, Masato; Yamamoto, Takehisa; Joshua, Derrick I.; Balakrishna, Keshava; Yamashita, Nobuyoshi; Kannan, Kurunthachalam; Tsutsui, Toshiyuki

    2015-01-01

    Extracts of wastewater collected from 4 sewage treatment plants (STPs) receiving effluents from different sources in South India were investigated for their levels of transcription factor-mediated gene induction in primary cultured rat hepatocytes. In addition, the relation between gene induction levels and the prevalence of antimicrobial-resistant Escherichia coli (E. coli) in wastewater was examined. STP-3, which treats only hospital wastewater, exhibited significantly greater induction potency of all 6 drug metabolizing cytochrome P450 (CYP) genes examined, CYP1A1, 1A2, 1B1, 2B15, 3A1, and 3A2, whereas the wastewater at STP-1, which exclusively receives domestic sewage, showed significantly diminished levels of induction of 3 CYP genes when compared to the levels of CYP induction at STP-2, which receives mixed wastewater. Samples collected during the monsoon season showed a significantly altered gene induction capacity compared to that of samples from the pre-monsoon period. The data suggest that the toxicity of wastewater in STPs was not significantly diminished during the treatment process. The chemical-gene interaction data predicted that a vast number of chemicals present in the wastewater would stimulate the genes studied in the rat hepatocytes. The multivariable logistic regression analysis demonstrated that the prevalence of isolates resistant to cefotaxime, imipenem and streptomycin was significantly correlated with the levels of induction of at least three CYP-isozymes in STP wastewater. In addition, the resistance of isolates in treatment plants was not altered by the treatment steps, whereas the sampling season did have an impact on the resistance to specific antimicrobials. The identification of receptor-mediated gene regulation capacities offers important data not limited to the (synergistic) physiological role of chemicals in biological systems but may provide new insight into the link between the effects of known/unknown drugs and prevalence of

  11. Antimicrobial Resistance in the Environment.

    PubMed

    Williams, Maggie R; Stedtfeld, Robert D; Guo, Xueping; Hashsham, Syed A

    2016-10-01

    This review summarizes important publications from 2015 pertaining to the occurrence of antimicrobial resistance (AMR) in the environment. Emphasis is placed on sources of antibiotic resistance in the aquatic environment including wastewater treatment plants, hospitals, and agriculture, treatment and mitigation techniques, and surveillance and analysis methodologies for characterizing abundance data. As such, this review is organized into the following sections: i) occurrence of AMR in the environment, including surface waters, aquaculture, and wastewater ii) treatment technologies, and iii) technologies for rapid surveillance of AMR, iv) transmission between matrices, v) databases and analysis methods, and vi) gaps in AMR understanding. PMID:27620115

  12. The Relationship between Antimicrobial Use and Antimicrobial Resistance in Europe

    PubMed Central

    Cars, Otto; Buchholz, Udo; Mölstad, Sigvard; Goettsch, Wim; Veldhuijzen, Irene K.; Kool, Jacob L.; Sprenger, Marc J.W.; Degener, John E.

    2002-01-01

    In Europe, antimicrobial resistance has been monitored since 1998 by the European Antimicrobial Resistance Surveillance System (EARSS). We examined the relationship between penicillin nonsusceptibility of invasive isolates of Streptococcus pneumoniae (an indicator organism) and antibiotic sales. Information was collected on 1998-99 resistance data for invasive isolates of S. pneumoniae to penicillin, based on surveillance data from EARSS and on outpatient sales during 1997 for beta-lactam antibiotics and macrolides. Our results show that in Europe antimicrobial resistance is correlated with use of beta-lactam antibiotics and macrolides. PMID:11927025

  13. Can We Prevent Antimicrobial Resistance by Using Antimicrobials Better?

    PubMed Central

    Soothill, Germander; Hu, Yanmin; Coates, Anthony

    2013-01-01

    Since their development over 60 years ago, antimicrobials have become an integral part of healthcare practice worldwide. Recently, this has been put in jeopardy by the emergence of widespread antimicrobial resistance, which is one of the major problems facing modern medicine. In the past, the development of new antimicrobials kept us one step ahead of the problem of resistance, but only three new classes of antimicrobials have reached the market in the last thirty years. A time is therefore approaching when we may not have effective treatment against bacterial infections, particularly for those that are caused by Gram-negative organisms. An important strategy to reduce the development of antimicrobial resistance is to use antimicrobials more appropriately, in ways that will prevent resistance. This involves a consideration of the pharmacokinetic and pharmacodynamics properties of antimicrobials, the possible use of combinations, and more appropriate choice of antimicrobials, which may include rapid diagnostic testing and antimicrobial cycling. Examples given in this review include Mycobacterium tuberculosis, Gram-negative and Gram-positive organisms. We shall summarise the current evidence for these strategies and outline areas for future development. PMID:25437042

  14. Antimicrobial Resistance: Is the World UNprepared?

    PubMed

    2016-09-01

    Long Blurb: On September 21st 2016 the United Nations General Assembly convenes in New York, United States to tackle a looming and seemingly inevitable global challenge with the potential to threaten the health and wellbeing of all people: antimicrobial resistance. In an Editorial, the PLOS Medicine Editors reflect on the challenge of coordinating the response to antimicrobial resistance in order to ensure the viability of current antimicrobials and the development of new therapies against resistant pathogens. Short Blurb: In this month's Editorial, the PLOS Medicine Editors reflect on the upcoming United Nations General Assembly meeting which convenes to discuss the global challenge of antimicrobial resistance. PMID:27618631

  15. Correlations between Income Inequality and Antimicrobial Resistance

    PubMed Central

    Kirby, Andrew; Herbert, Annie

    2013-01-01

    Objectives The aim of this study is to investigate if correlations exist between income inequality and antimicrobial resistance. This study’s hypothesis is that income inequality at the national level is positively correlated with antimicrobial resistance within developed countries. Data collection and analysis Income inequality data were obtained from the Standardized World Income Inequality Database. Antimicrobial resistance data were obtained from the European antimicrobial Resistance Surveillance Network and outpatient antimicrobial consumption data, measured by Defined daily Doses per 1000 inhabitants per day, from the European Surveillance of antimicrobial Consumption group. Spearman’s correlation coefficient (r) defined strengths of correlations of: > 0.8 as strong, > 0.5 as moderate and > 0.2 as weak. Confidence intervals and p values were defined for all r values. Correlations were calculated for the time period 2003-10, for 15 European countries. Results Income inequality and antimicrobial resistance correlations which were moderate or strong, with 95% confidence intervals > 0, included the following. Enterococcus faecalis resistance to aminopenicillins, vancomycin and high level gentamicin was moderately associated with income inequality (r= ≥0.54 for all three antimicrobials). Escherichia coli resistance to aminoglycosides, aminopenicillins, third generation cephalosporins and fluoroquinolones was moderately-strongly associated with income inequality (r= ≥0.7 for all four antimicrobials). Klebsiella pneumoniae resistance to third generation cephalosporins, aminoglycosides and fluoroquinolones was moderately associated with income inequality (r= ≥0.5 for all three antimicrobials). Staphylococcus aureus methicillin resistance and income inequality were strongly associated (r=0.87). Conclusion As income inequality increases in European countries so do the rates of antimicrobial resistance for bacteria including E. faecalis, E. coli, K. pneumoniae

  16. Evaluation of feeding distiller's grains, containing virginiamycin, on antimicrobial susceptibilities in fecal isolates of Enterococcus and Escherichia coli and prevalence of resistance genes in cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried distiller’s grains (DG), produced from fermentations using no antibiotic (Control) or dosed with 2 or 20 ppm virginiamycin product and containing 0, 0.7, and 8.9 ppm virginiamycin, respectively, were fed to cattle and effects on antibiotic sensitivity and prevalence of resistance genes in comm...

  17. Antimicrobial Resistance in Haemophilus influenzae

    PubMed Central

    Tristram, Stephen; Jacobs, Michael R.; Appelbaum, Peter C.

    2007-01-01

    Haemophilus influenzae is a major community-acquired pathogen causing significant morbidity and mortality worldwide. Meningitis and bacteremia due to type b strains occur in areas where the protein-conjugated type b vaccine is not in use, whereas nontypeable strains are major causes of otitis media, sinusitis, acute exacerbations of chronic bronchitis, and pneumonia. Antibiotic resistance in this organism is more diverse and widespread than is commonly appreciated. Intrinsic efflux resistance mechanisms limit the activity of the macrolides, azalides, and ketolides. β-Lactamase production is highly prevalent worldwide and is associated with resistance to ampicillin and amoxicillin. Strains with alterations in penicillin binding proteins, particularly PBP3 (β-lactamase negative ampicillin resistant and β-lactamase positive amoxicillin-clavulanate resistant), are increasing in prevalence, particularly in Japan, with increasing resistance to ampicillin, amoxicillin, amoxicillin-clavulanate, and many cephalosporins, limiting the efficacy of expanded-spectrum cephalosporins against meningitis and of many oral cephalosporins against other diseases. Most strains remain susceptible to the carbapenems, which are not affected by penicillin binding protein changes, and the quinolones. The activity of many oral agents is limited by pharmacokinetics achieved with administration by this route, and the susceptibility of isolates based on pharmacokinetic and pharmacodynamic parameters is reviewed. PMID:17428889

  18. Antimicrobial (Drug) Resistance: Vancomycin-Resistant Enterococci (VRE) Frequently Asked Questions

    MedlinePlus

    ... Understanding Antimicrobial (Drug) Resistance Examples of Antimicrobial Resistance Methicillin-Resistant Staphylococcus aureus (MRSA) Vancomycin-Resistant Enterococci (VRE) Overview Transmission Diagnosis ...

  19. Antimicrobial resistance issues in beef production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance threats to human health as identified have been recognized as a critical global public health concern. Linkage of some threats to beef production is discussed. The relevance to beef production of recent government actions will be examined. Prominent antimicrobial resistance ...

  20. An Ecological Perspective on Antimicrobial Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacteria are ubiquitous, covering every ecological niche known to man. Within these ecological niches bacterial populations adapt to ensure their survival and the development of antimicrobial resistance is an example of a bacterium's ability to adapt and survive. Resistance to antimicrobials often ...

  1. Antimicrobial resistance in beef and dairy cattle production.

    PubMed

    Call, Douglas R; Davis, Margaret A; Sawant, Ashish A

    2008-12-01

    Observational studies of cattle production systems usually find that cattle from conventional dairies harbor a higher prevalence of antimicrobial resistant (AMR) enteric bacteria compared to organic dairies or beef-cow operations; given that dairies usually use more antimicrobials, this result is not unexpected. Experimental studies have usually verified that application of antimicrobials leads to at least a transient expansion of AMR bacterial populations in treated cattle. Nevertheless, on dairy farms the majority of antibiotics are used to treat mastitis and yet AMR remains relatively low in mastitis pathogens. Other studies have shown no correlation between antimicrobial use and prevalence of AMR bacteria including documented cases where the prevalence of AMR bacteria is non-responsive to antimicrobial applications or remains relatively high in the absence of antimicrobial use or any other obvious selective pressures. Thus, there are multi-factorial events and pressures that influence AMR bacterial populations in cattle production systems. We introduce a heuristic model that illustrates how repeated antimicrobial selection pressure can increase the probability of genetic linkage between AMR genes and niche- or growth-specific fitness traits. This linkage allows persistence of AMR bacteria at the herd level because subpopulations of AMR bacteria are able to reside long-term within the host animals even in the absence of antimicrobial selection pressure. This model highlights the need for multiple approaches to manage herd health so that the total amount of antimicrobials is limited in a manner that meets animal welfare and public health needs while reducing costs for producers and consumers over the long-term. PMID:18983724

  2. National Antimicrobial Resistance Monitoring System (NARMS) Program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Antimicrobial Resistance Monitoring System (NARMS) – Enteric Bacteria is a national public health surveillance system in the United States that tracks changes in the susceptibility of certain enteric bacteria to antimicrobial agents of human and veterinary medical importance. The NARMS ...

  3. Antimicrobial resistance and virulence of Enterococcus faecalis isolated from retail food

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although enterococci are considered opportunistic nosocomial pathogens, their contribution to food-borne illnesses via dissemination through retail food remains undefined. In this study, prevalence and association of antimicrobial resistance and virulence factors of 80 Enterococcus faecalis isolate...

  4. Antimicrobial resistance of enterococci from animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is increasing concern over antimicrobial resistance in bacteria of animal and human origin including the possibility of transfer of resistance genes between animal to human bacteria, particularly, those that may be pathogenic. The reported increases in resistance are thought to result from ant...

  5. Oral antimicrobials increase antimicrobial resistance in porcine E. coli--a systematic review.

    PubMed

    Burow, E; Simoneit, C; Tenhagen, B-A; Käsbohrer, A

    2014-03-01

    Administration of antimicrobials to livestock increases the risk of antimicrobial resistance (AMR) in commensal bacteria. Antimicrobials in pig production are usually administered per pen via feed which implies treatment of sick alongside with healthy animals. The objective of this systematic literature review was to investigate the effect of orally administered antimicrobials on AMR in Escherichia coli of swine. Studies published in peer reviewed journals were retrieved from the international online databases ISI Web of Knowledge, PubMed, Scopus and the national electronic literature data base of Deutsches Institut für Medizinische Dokumentation und Information. The studies were assessed using the eligibility criteria English or German language, access to full paper version, defined treatment and control group (initial value or non-treatment) as well as administration and resistance testing of the same antimicrobial class. In the qualitative synthesis, only studies were included presenting the summary measures odds ratio or prevalence of resistance, the category of the applied antimicrobial and the dosage. An effect of the antimicrobial on AMR in E. coli was evaluated as an "increase", "no effect" or "decrease" if the odds or alternatively the prevalence ratio were >1.0, 1.0 or <1.0, respectively. Eleven studies, describing 36 different trials, fulfilled the eligibility criteria and were finally assessed. An increase of AMR in E. coli was found in 10 out of 11 trials comparing AMR after with AMR prior to oral treatment and in 22 of the 25 trials comparing orally treated with untreated groups. Effects expressed as odds or prevalence ratios were highest for the use of aminoglycosides, quinolones and tetracycline. There was no clear association between the reported dosage and AMR towards tetracycline. Information on antimicrobial substance and dosage was missing in 4 and 5 of the 11 finally selected studies. The 36 identified trials were inhomogenous in usage and

  6. Mechanisms of Antimicrobial Resistance in ESKAPE Pathogens

    PubMed Central

    Santajit, Sirijan; Indrawattana, Nitaya

    2016-01-01

    The ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are the leading cause of nosocomial infections throughout the world. Most of them are multidrug resistant isolates, which is one of the greatest challenges in clinical practice. Multidrug resistance is amongst the top three threats to global public health and is usually caused by excessive drug usage or prescription, inappropriate use of antimicrobials, and substandard pharmaceuticals. Understanding the resistance mechanisms of these bacteria is crucial for the development of novel antimicrobial agents or other alternative tools to combat these public health challenges. Greater mechanistic understanding would also aid in the prediction of underlying or even unknown mechanisms of resistance, which could be applied to other emerging multidrug resistant pathogens. In this review, we summarize the known antimicrobial resistance mechanisms of ESKAPE pathogens. PMID:27274985

  7. Prevalence and Antimicrobial Susceptibility of Campylobacter spp. in Oklahoma Conventional and Organic Retail Poultry

    PubMed Central

    Noormohamed, Aneesa; Fakhr, Mohamed K

    2014-01-01

    Campylobacter is one of the most important foodborne pathogens that cause bacterial gastroenteritis.This study was conducted to investigate the prevalence and antimicrobial resistance of Campylobacter in conventional and organic retail poultry samples purchased from grocery stores in Tulsa, Oklahoma.One hundred and fifty six chilled retail chicken samples (85 conventional and 71 organic) and 65 chilled retail conventional turkey samples were collected in this study. The prevalence of Campylobacter in the conventional chicken samples 32/85 (38%) was higher than in the organic ones 21/71 (30%). The prevalence of Campylobacter in the conventional turkey samples was 11/65 (17%). Of the 53 positive chicken samples, 42 were C. jejuni, 8 were C. coli and three isolates were contaminated with both species. Of the 11 positive turkey samples, 8 contained C. jejuni and 3 harbored C. coli isolates. The antimicrobial susceptibility of one hundred and forty nine recovered Campylobacter isolates (130 chickens and 19 turkeys) towards sixteen antimicrobials was determined. The majority of the recovered turkey isolates (13/19) showed resistance to more than 7 antimicrobials while most of the recovered chicken ones (82/130) were resistant to 5 to 7 antimicrobials. Multidrug resistance was not limited to isolates from conventional sources but was also available in isolates of an organic background and was generally lower in C. jejuni isolates when compared to the C. coli ones. PMID:25408778

  8. Danish Integrated Antimicrobial Resistance Monitoring and Research Program

    PubMed Central

    Heuer, Ole E.; Emborg, Hanne-Dorthe; Bagger-Skjøt, Line; Jensen, Vibeke F.; Rogues, Anne-Marie; Skov, Robert L.; Agersø, Yvonne; Brandt, Christian T.; Seyfarth, Anne Mette; Muller, Arno; Hovgaard, Karin; Ajufo, Justin; Bager, Flemming; Aarestrup, Frank M.; Frimodt-Møller, Niels; Wegener, Henrik C.; Monnet, Dominique L.

    2007-01-01

    Resistance to antimicrobial agents is an emerging problem worldwide. Awareness of the undesirable consequences of its widespread occurrence has led to the initiation of antimicrobial agent resistance monitoring programs in several countries. In 1995, Denmark was the first country to establish a systematic and continuous monitoring program of antimicrobial drug consumption and antimicrobial agent resistance in animals, food, and humans, the Danish Integrated Antimicrobial Resistance Monitoring and Research Program (DANMAP). Monitoring of antimicrobial drug resistance and a range of research activities related to DANMAP have contributed to restrictions or bans of use of several antimicrobial agents in food animals in Denmark and other European Union countries. PMID:18217544

  9. Health and economic impacts of antimicrobial resistance.

    PubMed

    Holmberg, S D; Solomon, S L; Blake, P A

    1987-01-01

    For comparison of the impacts of infections due to antimicrobial-resistant bacteria with those of infections due to antimicrobial-susceptible strains of the same bacteria, data were evaluated from 175 published and unpublished reports of investigations of nosocomial and community-acquired infections with selected bacteria. The evaluation of outcomes of hospital-acquired infections with resistant organisms was often confounded by risk factors also associated with poor outcomes. Nevertheless, for both nosocomial and community-acquired infections, the mortality, the likelihood of hospitalization, and the length of hospital stay were usually at least twice as great for patients infected with drug-resistant strains as for those infected with drug-susceptible strains of the same bacteria. Poor outcomes could be attributed both to the expected effects of ineffective antimicrobial therapy and to the unexpected occurrence of drug-resistant infections complicated by prior antimicrobial therapy for other medical problems. Although the adverse economic and health effects of drug-resistant bacterial infections can only be roughly quantified, it is concluded that antimicrobial resistance is an important health problem and an economic burden to society. PMID:3321356

  10. Antimicrobial Resistance in Escherichia coli Recovered from Feedlot Cattle and Associations with Antimicrobial Use

    PubMed Central

    Benedict, Katharine M.; Gow, Sheryl P.; McAllister, Tim A.; Booker, Calvin W.; Hannon, Sherry J.; Checkley, Sylvia L.; Noyes, Noelle R.; Morley, Paul S.

    2015-01-01

    The objectives of this study were to estimate the prevalence of antimicrobial resistance (AMR) and to investigate the associations between exposures to antimicrobial drugs (AMDs) and AMR in fecal non-type specific Escherichia coli (NTSEC) recovered from a large population of feedlot cattle. Two-stage random sampling was used to select individually identified cattle for enrollment, which were sampled at arrival and then a second time later in the feeding period. Advanced regression techniques were used to estimate resistance prevalences, and to investigate associations between AMD exposures in enrolled cattle and penmates and AMR identified in NTSEC recovered from the second sample set. Resistance was most commonly detected to tetracycline, streptomycin, and sulfisoxazole, and was rarely identified for critically important AMDs. All cattle were exposed to AMDs in feed, and 45% were treated parenterally. While resistance prevalence generally increased during the feeding period, most AMD exposures were not significantly associated with AMR outcomes. Exposures of enrolled cattle to tetracycline were associated with increased resistance to tetracycline and trimethoprim sulfa, while beta-lactam exposures were associated with decreased likelihood of detecting streptomycin resistance. Pen-level AMD exposure measures were not associated with resistance outcomes. These findings suggest that tetracycline treatment of feedlot cattle can be associated with modest increases in risk for recovery of resistant NTSEC, but the numerous treatments with an advanced macrolide (tulathromycin) were not associated with detectable increases in resistance in NTSEC. All cattle were exposed to in-feed treatments of tetracycline and this could limit the ability to identify the full impact of these exposures, but these exposures varied for enrolled cattle varied, providing an opportunity to evaluate a dose response. While AMD exposures were not associated with detectably increased risks for

  11. Antimicrobial Resistance in Escherichia coli Recovered from Feedlot Cattle and Associations with Antimicrobial Use.

    PubMed

    Benedict, Katharine M; Gow, Sheryl P; McAllister, Tim A; Booker, Calvin W; Hannon, Sherry J; Checkley, Sylvia L; Noyes, Noelle R; Morley, Paul S

    2015-01-01

    The objectives of this study were to estimate the prevalence of antimicrobial resistance (AMR) and to investigate the associations between exposures to antimicrobial drugs (AMDs) and AMR in fecal non-type specific Escherichia coli (NTSEC) recovered from a large population of feedlot cattle. Two-stage random sampling was used to select individually identified cattle for enrollment, which were sampled at arrival and then a second time later in the feeding period. Advanced regression techniques were used to estimate resistance prevalences, and to investigate associations between AMD exposures in enrolled cattle and penmates and AMR identified in NTSEC recovered from the second sample set. Resistance was most commonly detected to tetracycline, streptomycin, and sulfisoxazole, and was rarely identified for critically important AMDs. All cattle were exposed to AMDs in feed, and 45% were treated parenterally. While resistance prevalence generally increased during the feeding period, most AMD exposures were not significantly associated with AMR outcomes. Exposures of enrolled cattle to tetracycline were associated with increased resistance to tetracycline and trimethoprim sulfa, while beta-lactam exposures were associated with decreased likelihood of detecting streptomycin resistance. Pen-level AMD exposure measures were not associated with resistance outcomes. These findings suggest that tetracycline treatment of feedlot cattle can be associated with modest increases in risk for recovery of resistant NTSEC, but the numerous treatments with an advanced macrolide (tulathromycin) were not associated with detectable increases in resistance in NTSEC. All cattle were exposed to in-feed treatments of tetracycline and this could limit the ability to identify the full impact of these exposures, but these exposures varied for enrolled cattle varied, providing an opportunity to evaluate a dose response. While AMD exposures were not associated with detectably increased risks for

  12. Prevalence and risk factors of early fecal carriage of Enterococcus faecalis and Staphylococcus spp and their antimicrobial resistant patterns among healthy neonates born in a hospital setting in central Saudi Arabia

    PubMed Central

    El-Kersh, Talat A.; Marie, Mohammed A.; Al-Sheikh, Yazeed A.; Al-Agamy, Mohamed H.; Al-Bloushy, Ahmad A.

    2016-01-01

    Objectives: To investigate the prevalence, antibiotic resistant profiles, and risk factors of early fecal carriage of Enterococcus faecalis (E. faecalis) and staphylococci among 150 healthy Saudi neonates born in a hospital setting in central Saudi Arabia. Methods: This prospective study was conducted in Al-Bukayriyah General Hospital, Qassim, Saudi Arabia, between June 2012 and January 2013. The E. faecalis and Staphylococcus spp. isolates were identified manually, and Vitek2 system was used for identity confirmation at the species level and minimum inhibitory concentration-susceptibility testing. Results: Enterococcus faecalis (n=73) and Staphylococcus spp. (n=18) were recovered. Unlike staphylococci, E. faecalis colonization did not significantly vary from day one up to 7 days of life, regardless of the type of feeding, but it was relatively higher among vaginally versus cesarean delivery. Both Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus carriage increase as the body weight increases, and this difference was significant (p=0.025) for S. epidermidis. High-level resistance in Gentamycin among E. faecalis isolates was 25% and 11% to Streptomycin. Thirty percent of S. epidermidis were resistant to oxacillin and exhibited multidrug-resistant (MDR) patterns of 5 resistant markers, which were also observed among 2/5 (40%) of Methicillin-resistant Staphylococcus aureus isolates. Conclusion: Enterococcus faecalis did not significantly vary in relation to type of delivery, age up to 7 days, and type of feeding. The neonatal fecal carriage of MDR isolates should be considered as a crucial reservoir to the further spread of antimicrobial resistance genes among hospitals, cross infections, and the community. PMID:26905350

  13. Low rates of antimicrobial-resistant Enterobacteriaceae in wildlife in Taï National Park, Côte d'Ivoire, surrounded by villages with high prevalence of multiresistant ESBL-producing Escherichia coli in people and domestic animals.

    PubMed

    Albrechtova, Katerina; Papousek, Ivo; De Nys, Helene; Pauly, Maude; Anoh, Etile; Mossoun, Arsene; Dolejska, Monika; Masarikova, Martina; Metzger, Sonya; Couacy-Hymann, Emmanuel; Akoua-Koffi, Chantal; Wittig, Roman M; Klimes, Jiri; Cizek, Alois; Leendertz, Fabian H; Literak, Ivan

    2014-01-01

    Antimicrobial resistance genes can be found in all ecosystems, including those where antibiotic selective pressure has never been exerted. We investigated resistance genes in a collection of faecal samples of wildlife (non-human primates, mice), people and domestic animals (dogs, cats) in Côte d'Ivoire; in the chimpanzee research area of Taï National Park (TNP) and adjacent villages. Single bacteria isolates were collected from antibiotic-containing agar plates and subjected to molecular analysis to detect Enterobacteriaceae isolates with plasmid-mediated genes of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR). While the prevalence of ESBL-producing E. coli in the villages was 27% in people (n = 77) and 32% in dogs (n = 38), no ESBL-producer was found in wildlife of TNP (n = 75). PMQR genes, mainly represented by qnrS1, were also present in human- and dog-originating isolates from the villages (36% and 42% in people and dogs, respectively), but no qnrS has been found in the park. In TNP, different variants of qnrB were detected in Citrobacter freundii isolates originating non-human primates and mice. In conclusion, ESBL and PMQR genes frequently found in humans and domestic animals in the villages were rather exceptional in wildlife living in the protected area. Although people enter the park, the strict biosecurity levels they are obliged to follow probably impede transmission of bacteria between them and wildlife. PMID:25474243

  14. Antimicrobial resistance trends among Salmonella isolates obtained from horses in the northeastern United States (2001-2013).

    PubMed

    Cummings, Kevin J; Perkins, Gillian A; Khatibzadeh, Sarah M; Warnick, Lorin D; Aprea, Victor A; Altier, Craig

    2016-05-01

    OBJECTIVE To describe the antimicrobial resistance patterns of Salmonella isolates obtained from horses in the northeastern United States and to identify trends in resistance to select antimicrobials over time. SAMPLE 462 Salmonella isolates from horses. PROCEDURES Retrospective data were collected for all Salmonella isolates obtained from equine specimens that were submitted to the Cornell University Animal Health Diagnostic Center between January 1, 2001, and December 31, 2013. Temporal trends in the prevalence of resistant Salmonella isolates were investigated for each of 13 antimicrobials by use of the Cochran-Armitage trend test. RESULTS The prevalence of resistant isolates varied among antimicrobials and ranged from 0% (imipenem) to 51.5% (chloramphenicol). During the observation period, the prevalence of resistant isolates decreased significantly for amoxicillin-clavulanic acid, ampicillin, cefazolin, cefoxitin, ceftiofur, chloramphenicol, and tetracycline and remained negligible for amikacin and enrofloxacin. Of the 337 isolates for which the susceptibility to all 13 antimicrobials was determined, 138 (40.9%) were pansusceptible and 192 (57.0%) were multidrug resistant (resistant to ≥ 3 antimicrobial classes). The most common serovar isolated was Salmonella Newport, and although the annual prevalence of that serovar decreased significantly over time, that decrease had only a minimal effect on the observed antimicrobial resistance trends. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that current antimicrobial use in horses is not promoting the emergence and dissemination of antimicrobial-resistant Salmonella strains in the region served by the laboratory. PMID:27111018

  15. Mechanisms of biofilm resistance to antimicrobial agents.

    PubMed

    Mah, T F; O'Toole, G A

    2001-01-01

    Biofilms are communities of microorganisms attached to a surface. It has become clear that biofilm-grown cells express properties distinct from planktonic cells, one of which is an increased resistance to antimicrobial agents. Recent work has indicated that slow growth and/or induction of an rpoS-mediated stress response could contribute to biocide resistance. The physical and/or chemical structure of exopolysaccharides or other aspects of biofilm architecture could also confer resistance by exclusion of biocides from the bacterial community. Finally, biofilm-grown bacteria might develop a biofilm-specific biocide-resistant phenotype. Owing to the heterogeneous nature of the biofilm, it is likely that there are multiple resistance mechanisms at work within a single community. Recent research has begun to shed light on how and why surface-attached microbial communities develop resistance to antimicrobial agents. PMID:11166241

  16. Identification of acquired antimicrobial resistance genes

    PubMed Central

    Zankari, Ea; Hasman, Henrik; Cosentino, Salvatore; Vestergaard, Martin; Rasmussen, Simon; Lund, Ole; Aarestrup, Frank M.; Larsen, Mette Voldby

    2012-01-01

    Objectives Identification of antimicrobial resistance genes is important for understanding the underlying mechanisms and the epidemiology of antimicrobial resistance. As the costs of whole-genome sequencing (WGS) continue to decline, it becomes increasingly available in routine diagnostic laboratories and is anticipated to substitute traditional methods for resistance gene identification. Thus, the current challenge is to extract the relevant information from the large amount of generated data. Methods We developed a web-based method, ResFinder that uses BLAST for identification of acquired antimicrobial resistance genes in whole-genome data. As input, the method can use both pre-assembled, complete or partial genomes, and short sequence reads from four different sequencing platforms. The method was evaluated on 1862 GenBank files containing 1411 different resistance genes, as well as on 23 de-novo-sequenced isolates. Results When testing the 1862 GenBank files, the method identified the resistance genes with an ID = 100% (100% identity) to the genes in ResFinder. Agreement between in silico predictions and phenotypic testing was found when the method was further tested on 23 isolates of five different bacterial species, with available phenotypes. Furthermore, ResFinder was evaluated on WGS chromosomes and plasmids of 30 isolates. Seven of these isolates were annotated to have antimicrobial resistance, and in all cases, annotations were compatible with the ResFinder results. Conclusions A web server providing a convenient way of identifying acquired antimicrobial resistance genes in completely sequenced isolates was created. ResFinder can be accessed at www.genomicepidemiology.org. ResFinder will continuously be updated as new resistance genes are identified. PMID:22782487

  17. Bacterial strategies of resistance to antimicrobial peptides.

    PubMed

    Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

    2016-05-26

    Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. PMID:27160595

  18. Understanding the mechanisms and drivers of antimicrobial resistance.

    PubMed

    Holmes, Alison H; Moore, Luke S P; Sundsfjord, Arnfinn; Steinbakk, Martin; Regmi, Sadie; Karkey, Abhilasha; Guerin, Philippe J; Piddock, Laura J V

    2016-01-01

    To combat the threat to human health and biosecurity from antimicrobial resistance, an understanding of its mechanisms and drivers is needed. Emergence of antimicrobial resistance in microorganisms is a natural phenomenon, yet antimicrobial resistance selection has been driven by antimicrobial exposure in health care, agriculture, and the environment. Onward transmission is affected by standards of infection control, sanitation, access to clean water, access to assured quality antimicrobials and diagnostics, travel, and migration. Strategies to reduce antimicrobial resistance by removing antimicrobial selective pressure alone rely upon resistance imparting a fitness cost, an effect not always apparent. Minimising resistance should therefore be considered comprehensively, by resistance mechanism, microorganism, antimicrobial drug, host, and context; parallel to new drug discovery, broad ranging, multidisciplinary research is needed across these five levels, interlinked across the health-care, agriculture, and environment sectors. Intelligent, integrated approaches, mindful of potential unintended results, are needed to ensure sustained, worldwide access to effective antimicrobials. PMID:26603922

  19. Antimicrobial resistance in internal medicine wards.

    PubMed

    Menichetti, Francesco; Tagliaferri, Enrico

    2012-10-01

    Antimicrobial resistance is a global medical problem, affecting most bacterial pathogens. The major challenges are currently posed by methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Enterobacteriaceae producing extended-spectrum-beta-lactamases (ESBL) and carbapenemases, and multi-resistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii. Therapeutic options are very limited and, in some cases, virtually unavailable. This article provides an overview of the recent epidemiological trends exhibited by the most important multi-resistant pathogens, and of the treatment options that are currently available for these infections. PMID:23073868

  20. Antimicrobial resistance and management of invasive Salmonella disease

    PubMed Central

    Kariuki, Samuel; Gordon, Melita A.; Feasey, Nicholas; Parry, Christopher M

    2015-01-01

    Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20–30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50–75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. PMID:25912288

  1. Antimicrobial resistance and management of invasive Salmonella disease.

    PubMed

    Kariuki, Samuel; Gordon, Melita A; Feasey, Nicholas; Parry, Christopher M

    2015-06-19

    Invasive Salmonella infections (typhoidal and non-typhoidal) cause a huge burden of illness estimated at nearly 3.4 million cases and over 600,000 deaths annually especially in resource-limited settings. Invasive non-typhoidal Salmonella (iNTS) infections are particularly important in immunosuppressed populations especially in sub-Saharan Africa, causing a mortality of 20-30% in vulnerable children below 5 years of age. In these settings, where routine surveillance for antimicrobial resistance is rare or non-existent, reports of 50-75% multidrug resistance (MDR) in NTS are common, including strains of NTS also resistant to flouroquinolones and 3rd generation cephalosporins. Typhoid (enteric) fever caused by Salmonella Typhi and Salmonella Paratyphi A remains a major public health problem in many parts of Asia and Africa. Currently over a third of isolates in many endemic areas are MDR, and diminished susceptibility or resistance to fluoroquinolones, the drugs of choice for MDR cases over the last decade is an increasing problem. The situation is particularly worrying in resource-limited settings where the few remaining effective antimicrobials are either unavailable or altogether too expensive to be afforded by either the general public or by public health services. Although the prudent use of effective antimicrobials, improved hygiene and sanitation and the discovery of new antimicrobial agents may offer hope for the management of invasive salmonella infections, it is essential to consider other interventions including the wider use of WHO recommended typhoid vaccines and the acceleration of trials for novel iNTS vaccines. The main objective of this review is to describe existing data on the prevalence and epidemiology of antimicrobial resistant invasive Salmonella infections and how this affects the management of these infections, especially in endemic developing countries. PMID:25912288

  2. Comparison of Prevalence and Antimicrobial Susceptibilities of Campylobacter spp. Isolates from Organic and Conventional Dairy Herds in Wisconsin

    PubMed Central

    Sato, K.; Bartlett, P. C.; Kaneene, J. B.; Downes, F. P.

    2004-01-01

    The prevalence and antimicrobial susceptibilities of Campylobacter spp. isolates from bovine feces were compared between organic and conventional dairy herds. Thirty organic dairy herds, where antimicrobials are rarely used for calves and never used for cows, were compared with 30 neighboring conventional dairy farms, where antimicrobials were routinely used for animals for all ages. Fecal specimens from 10 cows and 10 calves on 120 farm visits yielded 332 Campylobacter isolates. The prevalence of Campylobacter spp. in organic and conventional farms was 26.7 and 29.1%, and the prevalence was not statistically different between the two types of farms. Campylobacter prevalence was significantly higher in March than in September, higher in calves than in cows, and higher in smaller farms than in large farms. The rates of retained placenta, pneumonia, mastitis, and abortion were associated with the proportion of Campylobacter isolation from fecal samples. The gradient disk diffusion MIC method (Etest) was used for testing susceptibility to four antimicrobial agents: ciprofloxacin, gentamicin, erythromycin, and tetracycline. Two isolates were resistant to ciprofloxacin, and none of isolates was resistant to gentamicin or erythromycin. Resistance to tetracycline was 45% (148 of 332 isolates). Tetracycline resistance was found more frequently in calves than in cows (P = 0.042), but no difference was observed between organic and conventional farms. When we used Campylobacter spp. as indicator bacteria, we saw no evidence that restriction of antimicrobial use on dairy farms was associated with prevalence of resistance to ciprofloxacin, gentamicin, erythromycin, and tetracycline. PMID:15006764

  3. NATIONAL ANTIMICROBIAL RESISTANCE MONITORING SYSTEM (NARMS)

    EPA Science Inventory

    The main activity of NARMS is to monitor antimicrobial resistance of human enteric bacteria, including Campylobacter, Salmonella, Escherichia coli O157, and Shigella. NARMS is an active surveillance system that collects every 10th non-typhi Salmonella and Shigella isolate, every ...

  4. Antimicrobial Resistance and Virulence Characterization among Escherichia coli Clinical Isolates Causing Severe Obstetric Infections in Pregnant Women

    PubMed Central

    Guiral, Elisabet; Sáez-López, Emma; Bosch, Jordi; Goncé, Anna; López, Marta; Sanz, Sergi; Vila, Jordi

    2015-01-01

    The virulence markers and the antimicrobial resistance profiles of 78 Escherichia coli isolates causing obstetric infections accompanied by sepsis or not were studied. Adhesion-related virulence factors were the most prevalent markers. Low rates of resistance to the antimicrobial agents used as first-line therapy suggest their correct implementation in stewardship guidelines. PMID:25740771

  5. Antimicrobial Resistance in Wildlife: Implications for Public Health.

    PubMed

    Carroll, D; Wang, J; Fanning, S; McMahon, B J

    2015-11-01

    The emergence and spread of antimicrobial-resistant (AMR) bacteria in natural environments is a major concern with serious implications for human and animal health. The aim of this study was to determine the prevalence of AMR Escherichia coli (E. coli) in wild birds and mammalian species. Thirty faecal samples were collected from each of the following wildlife species: herring gulls (Larus argentatus), black-headed gulls (Larus ridibundus), lesser black-back gulls (Larus fuscus), hybrid deer species (Cervus elaphus x Cervus nippon) and twenty-six from starlings (Sturnus vulgaris). A total of 115 E. coli isolates were isolated from 81 of 146 samples. Confirmed E. coli isolates were tested for their susceptibility to seven antimicrobial agents by disc diffusion. In total, 5.4% (8/146) of samples exhibited multidrug-resistant phenotypes. The phylogenetic group and AMR-encoding genes of all multidrug resistance isolates were determined by PCR. Tetracycline-, ampicillin- and streptomycin-resistant isolates were the most common resistant phenotypes. The following genes were identified in E. coli: bla(TEM), strA, tet(A) and tet(B). Plasmids were identified in all samples that exhibited multidrug-resistant phenotypes. This study indicates that wild birds and mammals may function as important host reservoirs and potential vectors for the spread of resistant bacteria and genetic determinants of AMR. PMID:25639901

  6. Clinical implications of antimicrobial resistance: how big is the problem?

    PubMed

    Duckworth, Georgia

    2002-03-01

    This presentation addresses the question of the size of the antimicrobial resistance problem by examining the monitoring of antimicrobial use and resistance. It focuses on the main sources of information, possible pitfalls of the data and the susceptibility of the main pathogens responsible for bacteraemias in England and Wales. It addresses some of the difficulties in establishing the link between antimicrobial resistance and antimicrobial prescribing and concludes with some thoughts on necessary developments. PMID:12044283

  7. The changing landscape of antimicrobial resistance in New Zealand.

    PubMed

    Williamson, Deborah A; Heffernan, Helen

    2014-09-26

    Antimicrobial resistance is one of the biggest health threats of the modern age, threatening the routine treatment of many common infectious diseases. Resistance to many common antimicrobials is now endemic in New Zealand, in both community and healthcare settings. Over the past two decades, the landscape of antimicrobial resistance has changed considerably in New Zealand, with the emergence and spread of pathogens such as community-associated methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase-producing Enterobacteriaceae and multi- resistant Neisseria gonorrhoeae. Factors contributing to the emergence and spread of antimicrobial-resistant pathogens in New Zealand include the use and overuse of antimicrobials, transmission of resistant organisms in community and healthcare settings, and importation of resistant pathogens from areas where multi-resistant pathogens are endemic. In this review, we provide a summary of major antimicrobial-resistant bacteria in New Zealand, with a specific focus on those pathogens that pose major threats to human health. PMID:25290498

  8. Low Rates of Antimicrobial-Resistant Enterobacteriaceae in Wildlife in Taï National Park, Côte d’Ivoire, Surrounded by Villages with High Prevalence of Multiresistant ESBL-Producing Escherichia coli in People and Domestic Animals

    PubMed Central

    Albrechtova, Katerina; Papousek, Ivo; De Nys, Helene; Pauly, Maude; Anoh, Etile; Mossoun, Arsene; Dolejska, Monika; Masarikova, Martina; Metzger, Sonya; Couacy-Hymann, Emmanuel; Akoua-Koffi, Chantal; Wittig, Roman M.; Klimes, Jiri; Cizek, Alois; Leendertz, Fabian H.; Literak, Ivan

    2014-01-01

    Antimicrobial resistance genes can be found in all ecosystems, including those where antibiotic selective pressure has never been exerted. We investigated resistance genes in a collection of faecal samples of wildlife (non-human primates, mice), people and domestic animals (dogs, cats) in Côte d’Ivoire; in the chimpanzee research area of Taï National Park (TNP) and adjacent villages. Single bacteria isolates were collected from antibiotic-containing agar plates and subjected to molecular analysis to detect Enterobacteriaceae isolates with plasmid-mediated genes of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR). While the prevalence of ESBL-producing E. coli in the villages was 27% in people (n = 77) and 32% in dogs (n = 38), no ESBL-producer was found in wildlife of TNP (n = 75). PMQR genes, mainly represented by qnrS1, were also present in human- and dog-originating isolates from the villages (36% and 42% in people and dogs, respectively), but no qnrS has been found in the park. In TNP, different variants of qnrB were detected in Citrobacter freundii isolates originating non-human primates and mice. In conclusion, ESBL and PMQR genes frequently found in humans and domestic animals in the villages were rather exceptional in wildlife living in the protected area. Although people enter the park, the strict biosecurity levels they are obliged to follow probably impede transmission of bacteria between them and wildlife. PMID:25474243

  9. Analysis of antimicrobial resistance genes detected in multidrug-resistant salmonella enterica serovar typhimurium isolated from food animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of multi drug resistance (MDR) in foodborne pathogens such as Salmonella enterica is a concern for both animal and human health. MDR Salmonella enterica serovar Typhimurium is the most prevalent penta-resistant serovar isolated from animals as part of the National Antimicrobial Resis...

  10. Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

    NASA Astrophysics Data System (ADS)

    Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

    2012-06-01

    The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

  11. Antimicrobial Susceptibility/Resistance of Streptococcus Pneumoniae

    PubMed Central

    Karcic, Emina; Aljicevic, Mufida; Bektas, Sabaheta; Karcic, Bekir

    2015-01-01

    Introduction: Pneumococcal infections are a major cause of morbidity and mortality worldwide, whose treatment is threatened with an increase in the number of strains resistant to antibiotic therapy. Goal: The main goal of this research was to investigate the presence of antimicrobial susceptibility/resistance of S. pneumoniae. Material and methods: Taken are swabs of the nose and nasopharynx, eye and ear. In vitro tests that were made in order to study the antimicrobial resistance of pneumococci are: disk diffusion method and E-test. Results: The resistance to inhibitors of cell wall synthesis was recorded at 39.17%, protein synthesis inhibitors 19.67%, folate antagonists 47.78% and quinolone in 1.11%. S. pneumoniae has shown drug resistance to erythromycin in 45%, clindamycin in 45%, chloramphenicol–0.56%, rifampicin–6.11%, tetracycline–4.67%, penicillin-G in 4.44%, oxacillin in 73.89%, ciprofloxacin in 1.11% and trimethoprim-sulfamethoxazole in 5.34% of cases. Conclusion: The highest resistance pneumococcus showed to erythromycin, clindamycin and trimethoprim-sulfamethoxazole and these should be avoided in the treatment. The least resistance pneumococcus showed to tetracycline, rifampicin, chloramphenicol, penicillin-G and ciprofloxacin. PMID:26236165

  12. Antimicrobial Resistance in the Food Chain: A Review

    PubMed Central

    Verraes, Claire; Van Boxstael, Sigrid; Van Meervenne, Eva; Van Coillie, Els; Butaye, Patrick; Catry, Boudewijn; de Schaetzen, Marie-Athénaïs; Van Huffel, Xavier; Imberechts, Hein; Dierick, Katelijne; Daube, George; Saegerman, Claude; De Block, Jan; Dewulf, Jeroen; Herman, Lieve

    2013-01-01

    Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance. PMID:23812024

  13. Klebsiella pneumoniae Antimicrobial Drug Resistance, United States, 1998–2010

    PubMed Central

    Sanchez, Guillermo V.; Master, Ronald N.; Clark, Richard B.; Fyyaz, Madiha; Duvvuri, Padmaraj; Ekta, Gupta

    2013-01-01

    We studied antimicrobial-resistant Klebsiella pneumoniae for 1998–2010 by using data from The Surveillance Network. Susceptibility results (n = 3,132,354) demonstrated significant increases in resistance to all antimicrobial drugs studied, except tetracycline. Cross-resistance among carbapenem-resistant K. pneumoniae was lower for tetracycline and amikacin. PMID:23260464

  14. Antimicrobial Resistance in Salmonella Isolates Recovered from Cattle at Slaughter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Since 1997, the animal arm of the National Antimicrobial Resistance Monitoring System (NARMS) has monitored changes in antimicrobial susceptibilities of Salmonella isolates from animal origin. Additionally, since 2000, susceptibility of bovine Salmonella isolates collected in the US has ...

  15. Resistance to Antimicrobial Peptides in Vibrios

    PubMed Central

    Destoumieux-Garzón, Delphine; Duperthuy, Marylise; Vanhove, Audrey Sophie; Schmitt, Paulina; Wai, Sun Nyunt

    2014-01-01

    Vibrios are associated with a broad diversity of hosts that produce antimicrobial peptides (AMPs) as part of their defense against microbial infections. In particular, vibrios colonize epithelia, which function as protective barriers and express AMPs as a first line of chemical defense against pathogens. Recent studies have shown they can also colonize phagocytes, key components of the animal immune system. Phagocytes infiltrate infected tissues and use AMPs to kill the phagocytosed microorganisms intracellularly, or deliver their antimicrobial content extracellularly to circumvent tissue infection. We review here the mechanisms by which vibrios have evolved the capacity to evade or resist the potent antimicrobial defenses of the immune cells or tissues they colonize. Among their strategies to resist killing by AMPs, primarily vibrios use membrane remodeling mechanisms. In particular, some highly resistant strains substitute hexaacylated Lipid A with a diglycine residue to reduce their negative surface charge, thereby lowering their electrostatic interactions with cationic AMPs. As a response to envelope stress, which can be induced by membrane-active agents including AMPs, vibrios also release outer membrane vesicles to create a protective membranous shield that traps extracellular AMPs and prevents interaction of the peptides with their own membranes. Finally, once AMPs have breached the bacterial membrane barriers, vibrios use RND efflux pumps, similar to those of other species, to transport AMPs out of their cytoplasmic space. PMID:27025756

  16. How Can Vaccines Contribute to Solving the Antimicrobial Resistance Problem?

    PubMed Central

    Siber, George R.

    2016-01-01

    ABSTRACT There is a growing appreciation for the role of vaccines in confronting the problem of antimicrobial resistance (AMR). Vaccines can reduce the prevalence of resistance by reducing the need for antimicrobial use and can reduce its impact by reducing the total number of cases. By reducing the number of pathogens that may be responsible for a particular clinical syndrome, vaccines can permit the use of narrower-spectrum antibiotics for empirical therapy. These effects may be amplified by herd immunity, extending protection to unvaccinated persons in the population. Because much selection for resistance is due to selection on bystander members of the normal flora, vaccination can reduce pressure for resistance even in pathogens not included in the vaccine. Some vaccines have had disproportionate effects on drug-resistant lineages within the target species, a benefit that could be more deliberately exploited in vaccine design. We describe the effects of current vaccines in controlling AMR, survey some vaccines in development with the potential to do so further, and discuss strategies to amplify these benefits. We conclude with a discussion of research and policy priorities to more fully enlist vaccines in the battle against AMR. PMID:27273824

  17. Bacterial resistance to antimicrobials in urinary isolates.

    PubMed

    Muratani, Tetsuro; Matsumoto, Tetsuro

    2004-09-01

    Escherichia coli accounted for about 80% of organisms in uncomplicated urinary tract infections (UTIs), followed by Staphylococcus spp. especially Staphylococcus saprophyticus, and Proteus mirabilis. Against E. coli isolates from patients with uncomplicated UTI, faropenem was the most effective. Up to 1999, fluoroquinolone-resistant isolates were not observed in patients with uncomplicated UTI, but in 2001 fluoroquinolone-resistant E. coli isolates emerged and accounted for about 8%. Various types of organisms were isolated in patients with complicated UTI. Enterococcus faecalis, E. coli, and Pseudomonas aeruginosa were the three most frequent organisms isolated. These three organisms accounted for 44.6%. Amongst oral agents, faropenem showed the lowest rate of resistance against E. coli followed by cephems. The rates of highly fluoroquinolone-resistant and cefpodoxime-resistant E. coli isolates increased rapidly from 1998 to 2001. Fluoroquinolone-resistant P. aeruginosa isolates accounted for about 40% in 2001. Against this species, amikacin was the most effective antimicrobials among all agents tested. About 17% of Pseudomonas were resistant to carbapenem. Eight milligram per litre of ampicillin inhibited all E. faecalis isolates; about 60% of Enterococcus faecium were resistant to ampicillin. The rates of levofloxacin-resistant isolates of E. faecalis and E. faecium were 38 and 97% respectively. UTIs caused by vancomycin resistant enterococci (VRE) are rare in Japan. PMID:15364302

  18. Antimicrobial resistance in Acinetobacter baumannii: From bench to bedside

    PubMed Central

    Lin, Ming-Feng; Lan, Chung-Yu

    2014-01-01

    Acinetobacter baumannii (A. baumannii) is undoubtedly one of the most successful pathogens in the modern healthcare system. With invasive procedures, antibiotic use and immunocompromised hosts increasing in recent years, A. baumannii has become endemic in hospitals due to its versatile genetic machinery, which allows it to quickly evolve resistance factors, and to its remarkable ability to tolerate harsh environments. Infections and outbreaks caused by multidrug-resistant A. baumannii (MDRAB) are prevalent and have been reported worldwide over the past twenty or more years. To address this problem effectively, knowledge of species identification, typing methods, clinical manifestations, risk factors, and virulence factors is essential. The global epidemiology of MDRAB is monitored by persistent surveillance programs. Because few effective antibiotics are available, clinicians often face serious challenges when treating patients with MDRAB. Therefore, a deep understanding of the resistance mechanisms used by MDRAB can shed light on two possible strategies to combat the dissemination of antimicrobial resistance: stringent infection control and antibiotic treatments, of which colistin-based combination therapy is the mainstream strategy. However, due to the current unsatisfying therapeutic outcomes, there is a great need to develop and evaluate the efficacy of new antibiotics and to understand the role of other potential alternatives, such as antimicrobial peptides, in the treatment of MDRAB infections. PMID:25516853

  19. Antimicrobial resistance in commensal Escherichia coli isolated from animals at slaughter

    PubMed Central

    Wasyl, Dariusz; Hoszowski, Andrzej; Zając, Magdalena; Szulowski, Krzysztof

    2013-01-01

    Monitoring of antimicrobial resistance in commensal Escherichia coli (N = 3430) isolated from slaughtered broilers, laying hens, turkeys, swine, and cattle in Poland has been run between 2009 and 2012. Based on minimal inhibitory concentration (MIC) microbiological resistance to each of 14 tested antimicrobials was found reaching the highest values for tetracycline (43.3%), ampicillin (42.3%), and ciprofloxacin (39.0%) whereas the lowest for colistin (0.9%), cephalosporins (3.6 ÷ 3.8%), and florfenicol (3.8%). The highest prevalence of resistance was noted in broiler and turkey isolates, whereas it was rare in cattle. That finding along with resistance patterns specific to isolation source might reflect antimicrobial consumption, usage preferences or management practices in specific animals. Regression analysis has identified changes in prevalence of microbiological resistance and shifts of MIC values. Critically important fluoroquinolone resistance was worrisome in poultry isolates, but did not change over the study period. The difference (4.7%) between resistance to ciprofloxacin and nalidixic acid indicated the scale of plasmid-mediated quinolone resistance. Cephalosporin resistance were found in less than 3.8% of the isolates but an increasing trends were observed in poultry and MIC shift in the ones from cattle. Gentamycin resistance was also increasing in E. coli of turkey and cattle origin although prevalence of streptomycin resistance in laying hens decreased considerably. Simultaneously, decreasing MIC for phenicols observed in cattle and layers isolates as well as tetracycline values in E. coli from laying hens prove that antimicrobial resistance is multivariable phenomenon not only directly related to antimicrobial usage. Further studies should elucidate the scope of commensal E. coli as reservoirs of resistance genes, their spread and possible threats for human and animal health. PMID:23935596

  20. Prevalence of Antimicrobial Resistant and Virulent Salmonella spp. in Treated Effluent and Receiving Aquatic Milieu of Wastewater Treatment Plants in Durban, South Africa

    PubMed Central

    Odjadjare, Ejovwokoghene C.; Olaniran, Ademola O.

    2015-01-01

    In this study, we evaluated the impact of treated wastewater effluent from two wastewater treatment plants on the physicochemical parameters and Salmonella spp. load of receiving rivers. Presumptive Salmonella spp. were obtained at all sampled points including the discharge points, with counts ranging from 0 to 4.14 log cfu/mL at both plants. Turbidity, chemical and biological oxygen demand were found to be high and mostly above the required limit for treated wastewater discharge. However, recorded nitrate and phosphate values were very low. Of the 200 confirmed Salmonella spp. isolates recovered from the treated effluent and receiving surface waters, 93% harbored the spiC gene, 84% harbored the misL gene, and 87.5% harbored the orfL gene while 87% harbored the pipD gene. The antibiotic resistance profile revealed that the isolates were resistant to sulfamethoxazole, nalidixic acid and streptomycin, but susceptible to quinolones and third generation β-lactams. These results indicate that in South Africa treated effluents are still a major source of contamination of rivers with pathogens such as Salmonella. Appropriate steps by the regulatory authorities and workers at the treatment plants are needed to enforce stipulated guidelines in order to prevent pollution of surface water resources due to the discharge of poorly treated effluents. PMID:26295245

  1. Presentation of postweaning Escherichia coli diarrhea in southern Ontario, prevalence of hemolytic E. coli serogroups involved, and their antimicrobial resistance patterns

    PubMed Central

    Amezcua, Rocio; Friendship, Robert M.; Dewey, Catherine E.; Gyles, Carlton; Fairbrother, John M.

    2002-01-01

    Post-weaning Escherichia coli diarrhea (PWECD) in Ontario was investigated using a case-control study involving 50 Ontario nurseries. The clinical signs and the impact on productive parameters were determined by means of a producer survey. The hemolytic E. coli serogroups involved in PWECD (O149:K91:K88) were examined in this study. Based on a polymerase chain reaction test, the hemolytic E. coli from 82% of the case herds were positive for 3 enterotoxins (STa, STb, and LT), those from 12% of the case herds were positive for STb and LT only, and those from one herd (6%) were positive for 3 enterotoxins, as well as for verotoxin and F18 pili. The E. coli involved in disease were resistant to multiple antibiotics. Case farms commonly used a wide variety of antibiotics either in the feed or water, or as injectable drugs. The most common antibiotic used to treat PWECD on the study farms was apramycin, but evidence of resistance to this antibiotic was noted. The PWECD problem was commonly seen within a week of weaning but onset of diarrhea was reported as late as the grower-finisher stage. Growth rate was poorer in case herds and mortality was higher than in control herds, demonstrating that PWECD is an economically important disease in Ontario. PMID:11989737

  2. Prevalence of Antimicrobial Resistant and Virulent Salmonella spp. in Treated Effluent and Receiving Aquatic Milieu of Wastewater Treatment Plants in Durban, South Africa.

    PubMed

    Odjadjare, Ejovwokoghene C; Olaniran, Ademola O

    2015-08-01

    In this study, we evaluated the impact of treated wastewater effluent from two wastewater treatment plants on the physicochemical parameters and Salmonella spp. load of receiving rivers. Presumptive Salmonella spp. were obtained at all sampled points including the discharge points, with counts ranging from 0 to 4.14 log cfu/mL at both plants. Turbidity, chemical and biological oxygen demand were found to be high and mostly above the required limit for treated wastewater discharge. However, recorded nitrate and phosphate values were very low. Of the 200 confirmed Salmonella spp. isolates recovered from the treated effluent and receiving surface waters, 93% harbored the spiC gene, 84% harbored the misL gene, and 87.5% harbored the orfL gene while 87% harbored the pipD gene. The antibiotic resistance profile revealed that the isolates were resistant to sulfamethoxazole, nalidixic acid and streptomycin, but susceptible to quinolones and third generation β-lactams. These results indicate that in South Africa treated effluents are still a major source of contamination of rivers with pathogens such as Salmonella. Appropriate steps by the regulatory authorities and workers at the treatment plants are needed to enforce stipulated guidelines in order to prevent pollution of surface water resources due to the discharge of poorly treated effluents. PMID:26295245

  3. Serotypes and Antimicrobial Resistance of Human Nontyphoidal Isolates of Salmonella enterica from Crete, Greece

    PubMed Central

    Maraki, Sofia; Papadakis, Ioannis S.

    2014-01-01

    We report on the serotype distribution and the antimicrobial resistance patterns to 20 different antimicrobials of 150 Salmonella enterica strains isolated from stools of diarrhoeal patients on the island of Crete over the period January 2011-December 2012. Among the S. enterica serotypes recovered, Enteritidis was the most prevalent (37.3%), followed by Typhimurium (28.7%) and Newport (8.7%). No resistance was detected to extended-spectrum cephalosporins and carbapenems. Rates of resistance to ampicillin, amoxicillin/clavulanic acid, chloramphenicol, tetracycline, and cotrimoxazole were 9.3%, 4%, 2%, 15.3%, and 8.7%, respectively. Resistance to ≥4 antibiotics was primarily observed for serotypes Typhimurium and Hadar. Enteritidis remains the predominant serotype in Crete. Although low resistance to most antimicrobials was detected, continued surveillance of susceptibility is needed due to the risk of resistance. PMID:24860606

  4. Salt-resistant short antimicrobial peptides.

    PubMed

    Mohanram, Harini; Bhattacharjya, Surajit

    2016-05-01

    Antimicrobial peptides (AMPs) are promising leads for the development of antibiotics against drug resistant bacterial pathogens. However, in vivo applications of AMPs remain obscure due to salt and serum mediated inactivation. The high cost of chemical synthesis of AMPs also impedes potential clinical application. Consequently, short AMPs resistant toward salt and serum inactivation are desirable for the development of peptide antibiotics. In this work, we designed a 12-residue amphipathic helical peptide RR12 (R-R-L-I-R-L-I-L-R-L-L-R-amide) and two Trp containing analogs of RR12 namely RR12Wpolar (R-R-L-I-W-L-I-L-R-L-L-R-amide), and RR12Whydro (R-R-L-I-R-L-W-L-R-L-L-R-amide). Designed peptides demonstrated potent antibacterial activity; MIC ranging from 2 to 8 μM, in the presence of sodium chloride (150 mM and 300 mM). Antibacterial activity of these peptides was also detected in the presence of human serum. Designed peptides, in particular RR12 and RR12Whydro, were only poorly hemolytic. As a mode of action; these peptides demonstrated efficient permeabilization of bacterial cell membrane and lysis of cell structure. We further investigated interactions of the designed peptides with lipopolysaccharide (LPS), the major component of the outer membrane permeability barrier of Gram-negative bacteria. Designed peptides adopted helical conformations in complex with LPS. Binding of peptides with LPS has yielded dissociation the aggregated structures of LPS. Collectively, these designed peptides hold ability to be developed for salt-resistant antimicrobial compounds. Most importantly, current work provides insights for designing salt-resistant antimicrobial peptides. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 345-356, 2016. PMID:26849911

  5. Shigella Antimicrobial Drug Resistance Mechanisms, 2004-2014.

    PubMed

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert; Stephan, Roger

    2016-06-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004-2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis. PMID:27191035

  6. Shigella Antimicrobial Drug Resistance Mechanisms, 2004–2014

    PubMed Central

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert

    2016-01-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004–2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis. PMID:27191035

  7. Antimicrobial use in swine production and its effect on the swine gut microbiota and antimicrobial resistance.

    PubMed

    Holman, Devin B; Chénier, Martin R

    2015-11-01

    Antimicrobials have been used in swine production at subtherapeutic levels since the early 1950s to increase feed efficiency and promote growth. In North America, a number of antimicrobials are available for use in swine. However, the continuous administration of subtherapeutic, low concentrations of antimicrobials to pigs also provides selective pressure for antimicrobial-resistant bacteria and resistance determinants. For this reason, subtherapeutic antimicrobial use in livestock remains a source of controversy and concern. The swine gut microbiota demonstrates a number of changes in response to antimicrobial administration depending on the dosage, duration of treatment, age of the pigs, and gut location that is sampled. Both culture-independent and -dependent studies have also shown that the swine gut microbiota contains a large number of antimicrobial resistance determinants even in the absence of antimicrobial exposure. Heavy metals, such as zinc and copper, which are often added at relatively high doses to swine feed, may also play a role in maintaining antimicrobial resistance and in the stability of the swine gut microbiota. This review focuses on the use of antimicrobials in swine production, with an emphasis on the North American regulatory context, and their effect on the swine gut microbiota and on antimicrobial resistance determinants in the gut microbiota. PMID:26414105

  8. Application of a plasmid classification system to determine prevalence of replicon families among multidrug resistant enterococci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence and transfer of plasmids from commensal bacteria to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. However, prevalence of plasmids from commensal bacteria in food animals such as the enterococci remains largely unknown. In this study, the prevale...

  9. Antimicrobial Drug Use and Methicillin-resistant Staphylococcus aureus, Aberdeen, 1996–2000

    PubMed Central

    Monnet, Dominique L.; López-Lozano, José María; Beyaert, Arielle; Camacho, Máximo; Wilson, Rachel; Stuart, David; Gould, Ian M.

    2004-01-01

    Similar to many hospitals worldwide, Aberdeen Royal Infirmary has had an outbreak of methicillin-resistant Staphylococcus aureus (MRSA). In this setting, the outbreak is attributable to two major clones. The relationships between antimicrobial use and MRSA prevalence were analyzed by time-series analysis. From June 1997 to December 2000, dynamic, temporal relationships were found between monthly %MRSA and previous %MRSA, macrolide use, third-generation cephalosporin use, and fluoroquinolone use. This study suggests that use of antimicrobial drugs to which the MRSA outbreak strains are resistant may be an important factor in perpetuating the outbreak. Moreover, this study confirmed the ecologic effect of antimicrobial drug use (i.e., current antimicrobial use) may have an effect on resistance in future patients. Although these results may not be generalized to other hospitals, they suggest new directions for control of MRSA, which has thus far proved difficult and expensive. PMID:15496245

  10. Is Antimicrobial Resistance a Slowly Emerging Disaster?

    PubMed Central

    Viens, A. M.

    2015-01-01

    The problem of antimicrobial resistance is so dire that people are predicting that the era of antibiotics may be coming to an end, ushering in a ‘post-antibiotic’ era. A comprehensive policy response is therefore urgently needed. A part of this response will require framing the problem in such a way that adequately reflects its nature as well as encompassing an approach that has the best prospect of success. This paper considers framing the problem as a slowly emerging disaster, including its potential benefits and difficulties, from a conceptual and policy perspective. PMID:26566396

  11. Antimicrobial Resistance Prediction in PATRIC and RAST

    PubMed Central

    Davis, James J.; Boisvert, Sébastien; Brettin, Thomas; Kenyon, Ronald W.; Mao, Chunhong; Olson, Robert; Overbeek, Ross; Santerre, John; Shukla, Maulik; Wattam, Alice R.; Will, Rebecca; Xia, Fangfang; Stevens, Rick

    2016-01-01

    The emergence and spread of antimicrobial resistance (AMR) mechanisms in bacterial pathogens, coupled with the dwindling number of effective antibiotics, has created a global health crisis. Being able to identify the genetic mechanisms of AMR and predict the resistance phenotypes of bacterial pathogens prior to culturing could inform clinical decision-making and improve reaction time. At PATRIC (http://patricbrc.org/), we have been collecting bacterial genomes with AMR metadata for several years. In order to advance phenotype prediction and the identification of genomic regions relating to AMR, we have updated the PATRIC FTP server to enable access to genomes that are binned by their AMR phenotypes, as well as metadata including minimum inhibitory concentrations. Using this infrastructure, we custom built AdaBoost (adaptive boosting) machine learning classifiers for identifying carbapenem resistance in Acinetobacter baumannii, methicillin resistance in Staphylococcus aureus, and beta-lactam and co-trimoxazole resistance in Streptococcus pneumoniae with accuracies ranging from 88–99%. We also did this for isoniazid, kanamycin, ofloxacin, rifampicin, and streptomycin resistance in Mycobacterium tuberculosis, achieving accuracies ranging from 71–88%. This set of classifiers has been used to provide an initial framework for species-specific AMR phenotype and genomic feature prediction in the RAST and PATRIC annotation services. PMID:27297683

  12. Antimicrobial Resistance Prediction in PATRIC and RAST.

    PubMed

    Davis, James J; Boisvert, Sébastien; Brettin, Thomas; Kenyon, Ronald W; Mao, Chunhong; Olson, Robert; Overbeek, Ross; Santerre, John; Shukla, Maulik; Wattam, Alice R; Will, Rebecca; Xia, Fangfang; Stevens, Rick

    2016-01-01

    The emergence and spread of antimicrobial resistance (AMR) mechanisms in bacterial pathogens, coupled with the dwindling number of effective antibiotics, has created a global health crisis. Being able to identify the genetic mechanisms of AMR and predict the resistance phenotypes of bacterial pathogens prior to culturing could inform clinical decision-making and improve reaction time. At PATRIC (http://patricbrc.org/), we have been collecting bacterial genomes with AMR metadata for several years. In order to advance phenotype prediction and the identification of genomic regions relating to AMR, we have updated the PATRIC FTP server to enable access to genomes that are binned by their AMR phenotypes, as well as metadata including minimum inhibitory concentrations. Using this infrastructure, we custom built AdaBoost (adaptive boosting) machine learning classifiers for identifying carbapenem resistance in Acinetobacter baumannii, methicillin resistance in Staphylococcus aureus, and beta-lactam and co-trimoxazole resistance in Streptococcus pneumoniae with accuracies ranging from 88-99%. We also did this for isoniazid, kanamycin, ofloxacin, rifampicin, and streptomycin resistance in Mycobacterium tuberculosis, achieving accuracies ranging from 71-88%. This set of classifiers has been used to provide an initial framework for species-specific AMR phenotype and genomic feature prediction in the RAST and PATRIC annotation services. PMID:27297683

  13. Antimicrobial resistance prediction in PATRIC and RAST

    DOE PAGESBeta

    Davis, James J.; Boisvert, Sebastien; Brettin, Thomas; Kenyon, Ronald W.; Mao, Chunhong; Olson, Robert; Overbeek, Ross; Santerre, John; Shukla, Maulik; Wattam, Alice R.; et al

    2016-06-14

    The emergence and spread of antimicrobial resistance (AMR) mechanisms in bacterial pathogens, coupled with the dwindling number of effective antibiotics, has created a global health crisis. Being able to identify the genetic mechanisms of AMR and predict the resistance phenotypes of bacterial pathogens prior to culturing could inform clinical decision-making and improve reaction time. At PATRIC (http://patricbrc.org/), we have been collecting bacterial genomes with AMR metadata for several years. In order to advance phenotype prediction and the identification of genomic regions relating to AMR, we have updated the PATRIC FTP server to enable access to genomes that are binned bymore » their AMR phenotypes, as well as metadata including minimum inhibitory concentrations. Using this infrastructure, we custom built AdaBoost (adaptive boosting) machine learning classifiers for identifying carbapenem resistance in Acinetobacter baumannii, methicillin resistance in Staphylococcus aureus, and beta-lactam and co-trimoxazole resistance in Streptococcus pneumoniae with accuracies ranging from 88–99%. We also did this for isoniazid, kanamycin, ofloxacin, rifampicin, and streptomycin resistance in Mycobacterium tuberculosis, achieving accuracies ranging from 71–88%. Lastly, this set of classifiers has been used to provide an initial framework for species-specific AMR phenotype and genomic feature prediction in the RAST and PATRIC annotation services.« less

  14. Prevalence and antimicrobial susceptibility of Listeria monocytogenes on chicken carcasses in Bandung, Indonesia.

    PubMed

    Sugiri, Yoni Darmawan; Gölz, Greta; Meeyam, Tongkorn; Baumann, Maximilian P O; Kleer, Josef; Chaisowwong, Warangkhana; Alter, Thomas

    2014-08-01

    This study was conducted to determine the prevalence and quantify the number of Listeria monocytogenes in fresh chicken carcasses sold in traditional markets and supermarkets in Bandung, West Java, Indonesia, and to determine the antimicrobial resistance patterns of the isolated L. monocytogenes strains. The overall prevalence of L. monocytogenes in chicken carcasses was 15.8% (29/184). When comparing samples from traditional markets and supermarkets, no significant difference in the L. monocytogenes prevalence was detectable (15.2 versus 16.3%). Of the samples, 97.3% had L. monocytogenes counts <100 CFU/g, 2.2% had L. monocytogenes counts between 101 and 1,000 CFU/g, and 0.5% had L. monocytogenes counts of 1,001 to 10,000 CFU/g. Of the isolates, 27.6% were resistant to at least one of the 10 antimicrobials tested, with the major resistant phenotypes to penicillin (17.2%), ampicillin (6.9%), and erythromycin (6.9%). All 29 isolates recovered in this study were grouped into the molecular serogroup IIb, comprising the serovars 1/2b, 3b, and 7. PMID:25198605

  15. Curbing the menace of antimicrobial resistance in developing countries

    PubMed Central

    2009-01-01

    Several reports suggest that antimicrobial resistance is an increasing global problem; but like most pandemics, the greatest toll is in the less developed countries. The dismally low rate of discovery of antimicrobials compared to the rate of development of antimicrobial resistance places humanity on a very dangerous precipice. Since antimicrobial resistance is part of an organism's natural survival instinct, total eradication might be unachievable; however, it can be reduced to a level that it no longer poses a threat to humanity. While inappropriate antimicrobial consumption contributes to the development of antimicrobial resistance, other complex political, social, economic and biomedical factors are equally important. Tackling the menace therefore should go beyond the conventional sensitization of members of the public and occasional press releases to include a multi-sectoral intervention involving the formation of various alliances and partnerships. Involving civil society organisations like the media could greatly enhance the success of the interventions PMID:19922676

  16. Prevalence of Aminoglycoside Resistance Genes in Acinetobacter baumannii Isolates

    PubMed Central

    Aliakbarzade, Katayun; Farajnia, Safar; Karimi Nik, Ashraf; Zarei, Farzaneh; Tanomand, Asghar

    2014-01-01

    Background: Acinetobacter baumannii is one of the major causes of nosocomial infections and is resistant to most available antibiotics. Aminoglycosides remain as drugs of choice for treatment of Acinetobacter infections yet resistance to aminoglycosides has increased in the recent years. Objectives: The present study investigated the prevalence of genes encoding aminoglycoside-modifying enzymes in A. baumannii strains isolated from patients of Tabriz city, northwest of Iran. Materials and Methods: A total of 103 Acinetobacter isolates were collected from Imam Reza Hospital of Tabriz University of medical sciences. Antimicrobial susceptibility patterns of the isolates to different antimicrobial agents including cephalosporins, gentamicin, amikacin, tobramycin, colistin and polymyxin, were evaluated by the disc diffusion method. The frequency of aminoglycoside modifying enzymes encoding genes aacC1, aphA6, aadA1 and aadB was analyzed by the PCR method. Results: Antimicrobial susceptibility analysis showed that the highest resistance was towards beta−lactam antibiotics including cephalosporins whereas the highest sensitivity was observed towards colistin (77%) and polymyxin (84%). The resistance rate to aminoglycosides was 81%, 86% and 63% for amikacin, gentamicin and tobramycin, respectively. The PCR results showed that among the 103 A. baumannii isolates, 56 (65.11 %) were positive for aacC1, 52 (60.46 %) for aphA6, 24 (27.9 %) for aadA1 and 16 (18.6 %) for aadB resistant genes. Conclusions: The results of this study indicated that the genes encoding aminoglycoside-modifying enzymes are prevalent in A. baumannii isolates in the study region, which highlighted the necessity of considering preventive measures to control dissemination of these resistance genes. PMID:25632323

  17. The Ethical Significance of Antimicrobial Resistance

    PubMed Central

    Littmann, Jasper

    2015-01-01

    In this paper, we provide a state-of-the-art overview of the ethical challenges that arise in the context of antimicrobial resistance (AMR), which includes an introduction to the contributions to the symposium in this issue. We begin by discussing why AMR is a distinct ethical issue, and should not be viewed purely as a technical or medical problem. In the second section, we expand on some of these arguments and argue that AMR presents us with a broad range of ethical problems that must be addressed as part of a successful policy response to emerging drug resistance. In the third section, we discuss how some of these ethical challenges should be addressed, and we argue that this requires contributions from citizens, ethicists, policy makers, practitioners and industry. We conclude with an overview of steps that should be taken in moving forward and addressing the ethical problems of AMR. PMID:26566395

  18. A trend analysis of antimicrobial resistance in commensal Escherichia coli from several livestock species in Belgium (2011-2014).

    PubMed

    Hanon, Jean-Baptiste; Jaspers, Stijn; Butaye, Patrick; Wattiau, Pierre; Méroc, Estelle; Aerts, Marc; Imberechts, Hein; Vermeersch, Katie; Van der Stede, Yves

    2015-12-01

    A temporal trend analysis was performed on antimicrobial resistance data collected over 4 consecutive years (2011-2014) in the official Belgian antimicrobial resistance monitoring programme. Commensal Escherichia coli strains were isolated from faecal samples of four livestock categories (veal calves, young beef cattle, broiler chickens and slaughter pigs) and the trends of resistance profiles were analysed. The resistance prevalence remained high (>50%) during the study period for ampicillin in veal calves and chickens, for ciprofloxacin and nalidixic acid in chickens, for sulfamethoxazole in veal calves, chickens and pigs and for tetracycline in veal calves. Using logistic regression and Generalized Estimating Equation and after p value adjustment for multiple testing (Linear step-up method), statistically significant decreasing temporal trends were observed for several of the 11 tested antimicrobials in several livestock categories: in veal calves (10/11), in chickens (6/11) and in pigs (5/11). A significant increasing trend was observed for the prevalence of resistance to ciprofloxacin in chickens. Multi-resistance, considered as the resistance to at least three antimicrobials of different antibiotic classes, was observed in the four livestock categories but was significantly decreasing in veal calves, chickens and pigs. Overall, the prevalence of resistance and of multi-resistance was lowest in the beef cattle livestock category and highest in broiler chickens. These decreasing temporal trends of antimicrobial resistance might be due to a decrease of the total antimicrobial consumption for veterinary use in Belgium which was reported for the period between 2010 and 2013. The methodology and statistical tools developed in this study provide outputs which can detect shifts in resistance levels or resistance trends associated with particular antimicrobial classes and livestock categories. Such outputs can be used as objective evidence to evaluate the possible

  19. National Antimicrobial Resistance Monitoring System (NARMS) 2010 Report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to prospectively monitor the emergence of antimicrobial resistance in zoonotic pathogens, the National Antimicrobial Resistance Monitoring System (NARMS) was established in 1996 by the Food and Drug Administration’s Center for Veterinary Medicine in collaboration with the Centers for Di...

  20. Food Production and Antimicrobial Resistance – The Next 100 Years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of food is complex and ensuring the safety of food for human consumption provides serious challenges. Since 1996 the U.S. has conducted surveillance on food borne and commensal antimicrobial resistance bacteria through the National Antimicrobial Resistance Monitoring System - Enteric Bac...

  1. Antimicrobial resistance of foodborne pathogens in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance has become a global concern since antibiotics were first introduced for clinical treatment of human and animal infections. Surveillance systems that monitor for antimicrobial resistance are often quite valuable. In 1996, three U.S. federal agencies: the U.S. Food and Drug A...

  2. Engineering Antimicrobials that are Refractory to Resistance Development.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-drug resistant pathogens are a serious problem in modern health care and there is a need for novel antimicrobials that are refractory to resistance development. Several US government agencies (FDA, CDC and NIH) recommend avoiding the use of broad range antimicrobials, a practice that is known...

  3. Antimicrobial resistance in Escherichia coli isolates from food animals, animal food products and companion animals in China.

    PubMed

    Lei, Tao; Tian, Wei; He, Liu; Huang, Xian-Hui; Sun, Yong-Xue; Deng, Yu-Ting; Sun, Yan; Lv, Dian-Hong; Wu, Cong-Ming; Huang, Liang-Zong; Shen, Jian-Zhong; Liu, Jian-Hua

    2010-11-20

    One thousand and thirty Escherichia coli isolates from food animals, animals-derived foods, and companion animals between 2007 and 2008 in Southern China were used to investigate their antimicrobial susceptibility to 14 different antimicrobials by the standard agar dilution method. More than 70% of isolates showed resistance to tetracycline, trimethoprim-sulphamethoxazole, nalidixic acid, and ampicillin. In general, resistance was less frequent in companion animal isolates vs food animals isolates, but cephalosporin and amikacin resistance was more frequent in companion animal isolates, 42.6% to 56.2% vs 14.1% to 24.3%, and 28.5% vs 18.8%, respectively, which was most likely due to the common use of these antimicrobials as treatment in pet animals. Fluoroquinolones resistance was high in all animal isolates (>50%). Food products showed lowest resistance among isolates from these three resources. PFGE analysis indicated that a majority of multidrug-resistant E. coli isolates showed unique, unrelated PFGE profiles and were unlikely to be the spread of a specific clone. This study provides useful information about the prevalence of antimicrobial resistance in E. coli isolated from animals and food products in China and provided evidence of the linkage of the use of antimicrobials in animals and its selection of antimicrobial resistance in bacterial isolates. The data from this study further warns the prudent use of antimicrobials in food and pet animals to reduce the risks of transmission of antimicrobial resistance zoonotic pathogen to humans. PMID:20605690

  4. Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis.

    PubMed

    Rato, Márcia G; Bexiga, Ricardo; Florindo, Carlos; Cavaco, Lina M; Vilela, Cristina L; Santos-Sanches, Ilda

    2013-01-25

    Streptococcus agalactiae (Group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (Group C Streptococcus, GCS) and Streptococcus uberis are relevant mastitis pathogens, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production. The aims of this study were the evaluation of antimicrobial drug resistance patterns, particularly important for streptococcal mastitis control and the identification of strain molecular features. Antimicrobial resistance was assessed by disk diffusion against amoxicillin-clavulanic acid, cefazolin, cefoperazone, pirlimycin-PRL, rifaximin, streptomycin, chloramphenicol, erythromycin-ERY, gentamicin, tetracycline-TET and vancomycin. Genotypic relationships were identified using pulsed-field gel electrophoresis (PFGE), macrolide and/or tetracycline resistance gene profiling, GBS capsular typing, GBS virulence gene profiling and GBS and S. uberis multi locus sequence typing (MLST). The majority of the isolates were susceptible to all drugs except to aminoglycoside, macrolide, lincosamide and tetracycline. Close to half of the TET resistant isolates have tetO and tetK and almost all ERY-PRL resistant isolates have ermB. A high degree of intra-species polymorphism was found for GCS. The GBS belonged to ST-2, -554, -61, -23 lineages and five new molecular serotypes and human GBS insertion sequences in the cpsE gene were found. Also, GBS of serotype V with scpB and lmb seem to be related with GBS isolates of human origin (same ST-2 and similar PFGE). Overall our results suggested that different therapeutic programs may have been implemented in the different farms and that in most cases clones were herd-specific. PMID:22964008

  5. Antimicrobial-resistant bacterial populations and antimicrobial resistance genes obtained from environments impacted by livestock and municipal waste

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared the populations of antimicrobial-resistant bacteria and the repertoire of antimicrobial resistance genes in four environments: effluent of three municipal waste water treatment facilities, three cattle feedlot runoff catchment ponds, three swine waste lagoons, and two "low impact...

  6. Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment

    PubMed Central

    Buschmann, Alejandro H.; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A.; Henríquez, Luis A.; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P.; Cabello, Felipe C.

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments. PMID:22905164

  7. Antimicrobial resistant Escherichia coli isolates in cattle and house sparrows on two Czech dairy farms.

    PubMed

    Dolejská, M; Senk, D; Cízek, A; Rybaríková, J; Sychra, O; Literák, I

    2008-12-01

    Rectal smears of calves, cows and young bulls, as well as cloacal smears of house sparrows (Passer domesticus), from farms at the villages of Sumice and Troskotovice, Czech Republic, were examined for E. coli resistant to 12 antimicrobials. The resistant isolates were tested for antimicrobial-resistance genes and integrons. Totals of 40% (n=183), 3% (n=95), 0% (n=33), and 9% (n=54) of Escherichia coli isolates from calves, cows, young bulls and house sparrows, respectively, were antimicrobial resistant. The following genes were identified in cattle E. coli isolates: tetA, tetB (isolates resistant to tetracycline), bla(TEM) (beta-lactams), strA, aadA (streptomycin), sul1, sul2 (sulphonamides), and cat, floR (chloramphenicol). Seven of 16 antimicrobial-resistant calf isolates from the Sumice farm possessed class 1 integrons with the aadA1 gene cassette integrated, 1 kb in size. On the Troskotovice farm, eight of 57 antimicrobial-resistant calf isolates possessed class 1 integrons. Integrons of 1.5kb with the dhfr1- aadA1 gene cassette were found in four isolates, followed by a 1kb integron with the aadA1 gene found in three isolates, and a 1.7kb integron with the dhfr17-aadA5 gene cassette and the phenotype ASSuTSxtNaCipCCfG. The prevalence of resistant E. coli in calves compared to adult cattle was much higher and probably was influenced by oral antimicrobial usage in calves, feeding with milk and colostrum from treated cows, as well as mechanisms unrelated to antimicrobial drug selection. Although house sparrows lived together with the cattle and came into contact with cattle waste on the farm, they were not infected by resistant E. coli isolates with the same characteristics as those found in cattle. PMID:18471838

  8. Salmonella Prevalence and Antimicrobial Susceptibility Among Dairy Farm Environmental Samples Collected in Texas.

    PubMed

    Rodriguez-Rivera, Lorraine D; Cummings, Kevin J; Loneragan, Guy H; Rankin, Shelley C; Hanson, Devin L; Leone, William M; Edrington, Thomas S

    2016-04-01

    Dairy cattle are a reservoir of several Salmonella serovars that are leading causes of human salmonellosis. The objectives of this study were to estimate the environmental prevalence of Salmonella on dairy farms in Texas and to characterize the antimicrobial susceptibility of the isolates. Eleven dairy farms throughout Texas were sampled from August through October 2013, using a cross-sectional approach. Samples were collected from four locations within each farm (hospital pen, maternity pen, cow housing area, and calf housing area), and feces were collected from cull cows as available. Environmental and fecal samples were processed for Salmonella, and isolates were tested for susceptibility to 15 antimicrobial agents. Serovar characterization was performed on a subset of these isolates. Salmonella was isolated from 67.0% (236/352) of the environmental samples and 64.2% (43/67) of the cull cow fecal samples. Environmental samples from the maternity pen were significantly more likely to be Salmonella positive than samples from the cow and calf housing areas. Multidrug resistance was evident in 11.9% (27/226) of environmental isolates and 19.5% (8/41) of fecal isolates. Salmonella isolates from the calf housing area and maternity pen were significantly more likely to be multidrug resistant (MDR) than isolates from the cow housing area. The most common serovars found among the MDR isolates were Newport, Muenchen, and Typhimurium. These results help provide a focus for efforts to mitigate the burden of antimicrobial-resistant Salmonella at the preharvest level. PMID:26954516

  9. CNS species and antimicrobial resistance in clinical and subclinical bovine mastitis.

    PubMed

    Waller, K Persson; Aspán, A; Nyman, A; Persson, Y; Andersson, U Grönlund

    2011-08-26

    Coagulase-negative staphylococci (CNS) are often associated with bovine mastitis. Knowledge about the relative importance of specific CNS species in different types of mastitis, and differences in antimicrobial resistance among CNS species is, however, scarce. Therefore, the aims of this study were to compare prevalence and antimicrobial susceptibility of CNS species in clinical and subclinical mastitis using material from two national surveys. Overall, Staphylococcus chromogenes and Staphylococcus epidermidis were the most common CNS species found followed by Staphylococcus simulans and Staphylococcus haemolyticus. S. epidermidis was significantly more prevalent in subclinical than in clinical mastitis, and a similar trend was observed for Staphylococcus saprophyticus, while Staphylococcus hyicus was significantly more common in clinical mastitis. The prevalence of β-lactamase producing isolates varied markedly between CNS species, and was significantly higher in S. epidermidis and S. haemolyticus (∼ 40%), than in S. simulans and S. chromogenes where none or a few of the isolates produced β-lactamase. Resistance to more than one antimicrobial substance occurred in 9% and 7% of the clinical and subclinical isolates, respectively. In conclusion, the distribution of CNS species differed between clinical and subclinical mastitis indicating inter-species variation of pathogenicity and epidemiology. Overall, the prevalence of antimicrobial resistance was low, but some variation between CNS species was observed. PMID:21561725

  10. An economic perspective on policy to reduce antimicrobial resistance.

    PubMed

    Coast, J; Smith, R D; Millar, M R

    1998-01-01

    Resistance to antimicrobial drugs is increasing worldwide. This resistance is, at least in part, associated with high antimicrobial usage. Despite increasing awareness, economists (and policy analysts more generally) have paid little attention to the problem. In this paper antimicrobial resistance is conceptualised as a negative externality associated with the consumption of antimicrobials and is set within the broader context of the costs and benefits associated with antimicrobial usage. It is difficult to determine the overall impact of attempting to reduce resistance, given the extremely limited ability to model the epidemiology of resistant and sensitive micro-organisms. It is assumed for the purposes of the paper, however, that dealing with resistance by reducting antimicrobial usage would lead to a positive societal benefit. Three policy options traditionally associated with environmental economics (regulation, permits and charges) are examined in relation to their potential ability to impact upon the problem of resistance. The primary care sector of the U.K.'s National Health Service provides the context for this examination. Simple application of these policies to health care is likely to be problematic, with difficulties resulting particularly from the potential reduction in clinical freedom to prescribe when appropriate, and from the desire for equity in health care provision. The paper tentatively concludes that permits could offer the best policy response to antimicrobial resistance, with the caveat that empirical research is needed to develop the most practical and efficient system. This research must be conducted alongside the required epidemiological research. PMID:9464666

  11. Analysis of Antimicrobial Resistance Genes Detected in MDR Salmonella enterica Serovar Typhimurium animal isolates from the National Antimicrobial Resistance Monitoring System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The presence of Multi-Drug Resistant (MDR) Salmonella in food animals is concerning. To understand how antimicrobial resistance (AR) develops, the genetic elements responsible for MDR phenotypes in Salmonella animal isolates were investigated. National Antimicrobial Resistance Monitoring...

  12. Multilocus Sequence Typing and Antimicrobial Resistance of Campylobacter jejuni Isolated from Dairy Calves in Austria.

    PubMed

    Klein-Jöbstl, Daniela; Sofka, Dmitri; Iwersen, Michael; Drillich, Marc; Hilbert, Friederike

    2016-01-01

    Human campylobacteriosis is primarily associated with poultry but also cattle. In this study, 55 Campylobacter jejuni strains isolated from 382 dairy calves' feces were differentiated by multilocus sequence typing and tested for antimicrobial resistance. The most prevalent sequence type (ST) was ST883 (20.0%), followed by ST48 (14.5%), and ST50 (9.1%). In contrast to ST48 and ST50, ST883 has rarely been described in cattle previously. Furthermore, risk factor analysis was performed for the presence of the most prevalent STs in these calves. Multiple regression analysis revealed that the type of farm (organic vs. conventional) and calf housing (place, and individual vs. group) were identified as significantly (p < 0.05) associated with the presence of ST883 in calves, and ST50 was associated with calf diarrhea. Antimicrobial resistance was detected in 58.2% of the isolates. Most of the resistant isolates (81.3%) were resistant to more than one antimicrobial. Most frequently, resistance to ciprofloxacin (49.1%), followed by nalidixic acid (42.8%), and tetracycline (14.5%) was observed. The results of the present study support the hypothesis that dairy calves may serve as a potential reservoir for C. jejuni and pose a risk for transmission, including antimicrobial resistant isolates to the environment and to humans. PMID:26870027

  13. Nationwide surveillance of antimicrobial resistance among Enterobacteriaceae in intensive care units in Taiwan.

    PubMed

    Jean, S-S; Hsueh, P-R; Lee, W-S; Chang, H-T; Chou, M-Y; Chen, I-S; Wang, J-H; Lin, C-F; Shyr, J-M; Ko, W-C; Wu, J-J; Liu, Y-C; Huang, W-K; Teng, L-J; Liu, C-Y

    2009-02-01

    To determine the antimicrobial resistance profiles among clinical isolates of Enterobacteriaceae in Taiwanese intensive care units (ICUs), a national surveillance of antibiotic resistance among important Enterobacteriaceae was conducted from September 2005 through November 2005 at the ICUs of ten major teaching hospitals in Taiwan. A total of 574 Enterobacteriaceae isolates recovered from various clinical samples of our ICU patients were submitted for in vitro test. Minimum inhibitory concentrations (MICs) of these isolates to 18 antimicrobial agents were determined by the broth microdilution method. The prevalences of Enterobacteriaceae isolates with phenotypic extended-spectrum beta-lactamase (ESBL) production were 26% in Klebsiella pneumoniae, 16% in Serratia marcescens, 14% in Escherichia coli, and 13% in Proteus mirabilis, in which a significantly rising prevalence of ESBL production among K. pneumoniae was noted (p = 0.002) when compared with a previous Taiwanese survey in 2000. Heterogeneous resistance to various fluoroquinolones was found among our Enterobacteriaceae isolates, except for Enterobacter cloacae. Emergence of ertapenem-resistant isolates of E. coli, K. pneumoniae, E. cloacae, and S. marcescens was noted. Gradually increasing rates of drug-resistant Enterobacteriaceae were noted in Taiwanese ICUs. Periodic surveillance of the evolutionary trend of antimicrobial resistance among ICU isolates is crucial for starting appropriately empirical antimicrobial therapy in the future. PMID:18716805

  14. Multilocus Sequence Typing and Antimicrobial Resistance of Campylobacter jejuni Isolated from Dairy Calves in Austria

    PubMed Central

    Klein-Jöbstl, Daniela; Sofka, Dmitri; Iwersen, Michael; Drillich, Marc; Hilbert, Friederike

    2016-01-01

    Human campylobacteriosis is primarily associated with poultry but also cattle. In this study, 55 Campylobacter jejuni strains isolated from 382 dairy calves’ feces were differentiated by multilocus sequence typing and tested for antimicrobial resistance. The most prevalent sequence type (ST) was ST883 (20.0%), followed by ST48 (14.5%), and ST50 (9.1%). In contrast to ST48 and ST50, ST883 has rarely been described in cattle previously. Furthermore, risk factor analysis was performed for the presence of the most prevalent STs in these calves. Multiple regression analysis revealed that the type of farm (organic vs. conventional) and calf housing (place, and individual vs. group) were identified as significantly (p < 0.05) associated with the presence of ST883 in calves, and ST50 was associated with calf diarrhea. Antimicrobial resistance was detected in 58.2% of the isolates. Most of the resistant isolates (81.3%) were resistant to more than one antimicrobial. Most frequently, resistance to ciprofloxacin (49.1%), followed by nalidixic acid (42.8%), and tetracycline (14.5%) was observed. The results of the present study support the hypothesis that dairy calves may serve as a potential reservoir for C. jejuni and pose a risk for transmission, including antimicrobial resistant isolates to the environment and to humans. PMID:26870027

  15. Multiple antimicrobial resistance in Enterobacteriaceae isolates from pristine freshwater.

    PubMed

    Lima-Bittencourt, C I; Cursino, L; Gonçalves-Dornelas, H; Pontes, D S; Nardi, R M D; Callisto, M; Chartone-Souza, E; Nascimento, A M A

    2007-01-01

    A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to beta-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of bla(TEM) gene, may point to the fact that it has an important role in horizontal spread of resistance. PMID:17985304

  16. Ecology of antimicrobial resistance: humans, animals, food and environment.

    PubMed

    González-Zorn, Bruno; Escudero, José A

    2012-09-01

    Antimicrobial resistance is a major health problem. After decades of research, numerous difficulties in tackling resistance have emerged, from the paucity of new antimicrobials to the inefficient contingency plans to reduce the use of antimicrobials; consequently, resistance to these drugs is out of control. Today we know that bacteria from the environment are often at the very origin of the acquired resistance determinants found in hospitals worldwide. Here we define the genetic components that flow from the environment to pathogenic bacteria and thereby confer a quantum increase in resistance levels, as resistance units (RU). Environmental bacteria as well as microbiomes from humans, animals, and food represent an infinite reservoir of RU, which are based on genes that have had, or not, a resistance function in their original bacterial hosts. This brief review presents our current knowledge of antimicrobial resistance and its consequences, with special focus on the importance of an ecologic perspective of antimicrobial resistance. This discipline encompasses the study of the relationships of entities and events in the framework of curing and preventing disease, a definition that takes into account both microbial ecology and antimicrobial resistance. Understanding the flux of RU throughout the diverse ecosystems is crucial to assess, prevent and eventually predict emerging scaffolds before they colonize health institutions. Collaborative horizontal research scenarios should be envisaged and involve all actors working with humans, animals, food and the environment. PMID:23847814

  17. Update: The National Antimicrobial Resistance Monitoring System Enteric Bacteria (NARMS): Animal Arm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial susceptibility testing remains an important tool as investigators devise ways to arrest the development of antimicrobial resistance, particularly in food borne bacteria. In 1996, the Food and Drug Administration (FDA) initiated the National Antimicrobial Resistance Monitoring System -...

  18. Overview Of Antimicrobial Resistance In Food Borne Pathogens In The United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial susceptibility testing remains an important tool as investigators devise ways to arrest the development of antimicrobial resistance, particularly in food borne bacteria. In 1996, the Food and Drug Administration (FDA) initiated the National Antimicrobial Resistance Monitoring System -...

  19. Characterization and Tracking of Antimicrobial Resistant Pathogens at Various Points along the Poultry Production Chain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial susceptibility testing remains an important tool as investigators devise ways to arrest the development of antimicrobial resistance, particularly in food borne bacteria. In 1996, the Food and Drug Administration (FDA) initiated the National Antimicrobial Resistance Monitoring System -...

  20. Antimicrobial resistance of three species of Bacillus to thirty various antimicrobial agents.

    PubMed

    Moldenhauer, J E; Bass, S; Rubio, S L

    1996-01-01

    Three frequently used strains of Bacillus were tested using antimicrobial susceptibility test discs to determine their resistance to various antimicrobial drug agents. The organisms selected were B. subtilis ATCC 6633 (used for USP B and F tests), B. stearothermophilus ATCC 12980 (used as a biological indicator for steam sterilization) and B. coagulans ATCC 51232 (used as a biological indicator for steam sterilization). The results indicated that for the thirty antimicrobial drug agents tested, the only organisms which exhibited any resistance to these agents was B. subtilis, and it only showed resistance to two drugs (Aztreonam and Bacitracin). PMID:8973119

  1. Association between antimicrobial consumption and resistance in Escherichia coli.

    PubMed

    Bergman, Miika; Nyberg, Solja T; Huovinen, Pentti; Paakkari, Pirkko; Hakanen, Antti J

    2009-03-01

    During a 9-year study period from 1997 through 2005, the association between antimicrobial resistance rates in Escherichia coli and outpatient antimicrobial consumption was investigated in 20 hospital districts in Finland. A total of 754,293 E. coli isolates, mainly from urine samples, were tested for antimicrobial resistance in 26 clinical microbiology laboratories. The following antimicrobials were studied: ampicillin, amoxicillin-clavulanate, cephalosporins, fluoroquinolones, trimethoprim, trimethoprim-sulfamethoxazole, pivmecillinam, and nitrofurantoin. We applied a protocol used in earlier studies in which the level of antimicrobial consumption over 1 year was compared with the level of resistance in the next year. Statistically significant associations were found for nitrofurantoin use versus nitrofurantoin resistance (P < 0.0001), cephalosporin use versus nitrofurantoin resistance (P = 0.0293), amoxicillin use versus fluoroquinolone resistance (P = 0.0031), and fluoroquinolone use versus ampicillin resistance (P = 0.0046). Interestingly, we found only a few associations between resistance and antimicrobial consumption. The majority of the associations studied were not significant, including the association between fluoroquinolone use and fluoroquinolone resistance. PMID:19104012

  2. Acquired antimicrobial resistance in the intestinal microbiota of diverse cat populations.

    PubMed

    Moyaert, H; De Graef, E M; Haesebrouck, F; Decostere, A

    2006-08-01

    The aim of this study was to investigate the prevalence of acquired antimicrobial resistance in the resident intestinal microbiota of cats and to identify significant differences between various cat populations. Escherichia coli, Enterococcus faecalis, E. faecium and Streptococcus canis were isolated as faecal indicator bacteria from rectal swabs of 47 individually owned cats, 47 cattery cats and 18 hospitalised cats, and submitted through antimicrobial sensitivity tests. The results revealed that bacteria isolated from hospitalised and/or cattery cats were more frequently resistant than those from individually owned cats. E. coli isolates from hospitalised cats were particularly resistant to ampicillin, tetracycline and sulfonamide. Both enterococci and streptococci showed high resistance to tetracycline and in somewhat lesser extent to erythromycin and tylosin. Most E. faecium isolates were resistant to lincomycin and penicillin. One E. faecalis as well as one E. faecium isolate from hospitalised cats showed 'high-level resistance' (MIC > 500 microg/ml) against gentamicin, a commonly used antimicrobial agent in case of human enterococcal infections. The results of this research demonstrate that the extent of acquired antimicrobial resistance in the intestinal microbiota of cats depends on the social environment of the investigated population. It is obvious that the flora of healthy cats may act as a reservoir of resistance genes. PMID:16330058

  3. Antimicrobial resistance-a threat to the world's sustainable development.

    PubMed

    Jasovský, Dušan; Littmann, Jasper; Zorzet, Anna; Cars, Otto

    2016-08-01

    This commentary examines how specific sustainable development goals (SDGs) are affected by antimicrobial resistance and suggests how the issue can be better integrated into international policy processes. Moving beyond the importance of effective antibiotics for the treatment of acute infections and health care generally, we discuss how antimicrobial resistance also impacts on environmental, social, and economic targets in the SDG framework. The paper stresses the need for greater international collaboration and accountability distribution, and suggests steps towards a broader engagement of countries and United Nations agencies to foster global intersectoral action on antimicrobial resistance. PMID:27416324

  4. Surveillance of antimicrobial resistance in Lebanese hospitals: retrospective nationwide compiled data.

    PubMed

    Chamoun, Kamal; Farah, Maya; Araj, Georges; Daoud, Ziad; Moghnieh, Rima; Salameh, Pascale; Saade, Danielle; Mokhbat, Jacques; Abboud, Emme; Hamze, Monzer; Abboud, Edmond; Jisr, Tamima; Haddad, Antoine; Feghali, Rita; Azar, Nadim; El-Zaatari, Mohammad; Chedid, Marwan; Haddad, Christian; Zouain Dib Nehme, Mireille; Barakat, Angelique; Husni, Rola

    2016-05-01

    Antimicrobial resistance is closely linked to antimicrobial use and is a growing concern worldwide. Antimicrobial resistance increases healthcare costs substantially in many countries, including Lebanon. National data from Lebanon have, in the most part, been limited to a few academic hospitals. The Lebanese Society of Infectious Diseases conducted a retrospective study to better describe the antimicrobial susceptibility patterns of bacterial isolates in Lebanon. Data were based on records retrieved from the bacteriology laboratories of 16 different Lebanese hospitals between January 2011 and December 2013. The susceptibility results of a total 20684 Gram-positive and 55594 Gram-negative bacteria were analyzed. The prevalence rate of methicillin-resistant Staphylococcus aureus was 27.6% and of vancomycin-resistant Enterococcus spp was 1%. Streptococcus pneumoniae had susceptibilities of 46% to oxacillin, 63% to erythromycin, and 98% to levofloxacin. Streptococcus pyogenes had susceptibilities of 94% to erythromycin and 95% to clindamycin. The mean ampicillin susceptibility of Haemophilus influenzae, Salmonella spp, and Shigella spp isolates was 79%, 81.3%, and 62.2%, respectively. The extended-spectrum beta-lactamase production rate for Escherichia coli was 32.3% and for Klebsiella spp was 29.2%. Acinetobacter spp showed high resistance to most antimicrobials, with low resistance to colistin (17.1%). Pseudomonas spp susceptibilities to piperacillin-tazobactam and imipenem were lower than 80% (79.7% and 72.8%, respectively). This study provides population-specific data that are valuable in guiding antimicrobial use in Lebanon and neighbouring countries and will help in the establishment of a surveillance system for antimicrobial resistance following the implementation of a nationwide standardization of laboratory methods and data entry. PMID:26996458

  5. Antimicrobial resistance of Escherichia coli isolates from canine urinary tract infections.

    PubMed

    Chang, Shao-Kuang; Lo, Dan-Yuan; Wei, Hen-Wei; Kuo, Hung-Chih

    2015-01-01

    This study determined the antimicrobial resistance profiles of Escherichia coli isolates from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs with UTI diagnosed through clinical examination and urinalysis were processed for isolation of Escherichia coli. Colonies from pure cultures were identified by biochemical reactions (n=114) and were tested for susceptibility to 18 antimicrobials. The two most frequent antimicrobials showing resistance in Urinary E. coli isolates were oxytetracycline and ampicillin. Among the resistant isolates, 17 resistance patterns were observed, with 12 patterns involving multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli isolates, tet(B) was the predominant resistance determinant and was detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the tet(A) determinant. Most ampicillin and/or amoxicillin-resistant E. coli isolates carried blaTEM-1 genes. Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes that are implicated primarily in resistance to aminoglycosides and trimethoprim (dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant E. coli isolates, 38 were resistant to nalidixic acid, and 6 were resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene cmlA and the florfenicol resistant gene floR were also identified. This study revealed an alarming rate of antimicrobial resistance among E. coli isolates from dogs with UTIs. PMID:25720807

  6. Antimicrobial resistance of Escherichia coli isolates from canine urinary tract infections.

    PubMed

    Chang, Shao-Kuang; Lo, Dan-Yuan; Wei, Hen-Wei; Kuo, Hung-Chih

    2014-10-28

    This study determined the antimicrobial resistance profiles of Escherichia coli isolates from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs with UTI diagnosed through clinical examination and urinalysis were processed for isolation of Escherichia coli. Colonies from pure cultures were identified by biochemical reactions (n=114) and were tested for susceptibility to 18 antimicrobials. The two most frequent antimicrobials showing resistance in Urinary E. coli isolates were oxytetracycline and ampicillin. Among the resistant isolates, 17 resistance patterns were observed, with 12 patterns involving multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli isolates, tet(B) was the predominant resistance determinant and was detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the tet(A) determinant. Most ampicillin and/or amoxicillin-resistant E. coli isolates carried blaTEM-1 genes. Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes that are implicated primarily in resistance to aminoglycosides and trimethoprim (dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant E. coli isolates, 38 were resistant to nalidixic acid, and 6 were resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene cmlA and the florfenicol resistant gene floR were also identified. This study revealed an alarming rate of antimicrobial resistance among E. coli isolates from dogs with UTIs. PMID:25354649

  7. Antimicrobial resistance of Escherichia coli isolates from canine urinary tract infections

    PubMed Central

    CHANG, Shao-Kuang; LO, Dan-Yuan; WEI, Hen-Wei; KUO, Hung-Chih

    2014-01-01

    This study determined the antimicrobial resistance profiles of Escherichia coli isolates from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs with UTI diagnosed through clinical examination and urinalysis were processed for isolation of Escherichia coli. Colonies from pure cultures were identified by biochemical reactions (n=114) and were tested for susceptibility to 18 antimicrobials. The two most frequent antimicrobials showing resistance in Urinary E. coli isolates were oxytetracycline and ampicillin. Among the resistant isolates, 17 resistance patterns were observed, with 12 patterns involving multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli isolates, tet(B) was the predominant resistance determinant and was detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the tet(A) determinant. Most ampicillin and/or amoxicillin-resistant E. coli isolates carried blaTEM-1 genes. Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes that are implicated primarily in resistance to aminoglycosides and trimethoprim (dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant E. coli isolates, 38 were resistant to nalidixic acid, and 6 were resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene cmlA and the florfenicol resistant gene floR were also identified. This study revealed an alarming rate of antimicrobial resistance among E. coli isolates from dogs with UTIs. PMID:25720807

  8. ANTIMICROBIAL RESISTANCE PATTERNS OF SALMONELLA FROM RETAIL CHICKEN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is frequently reported as a cause of food-borne illness. The emergence of antimicrobial resistant Salmonella associated with meat products has heightened concerns regarding antimicrobial use in food animal production. Eighty Salmonella isolates recovered from fresh whole chicken carcass...

  9. Bacterial resistance to antimicrobial peptides: an evolving phenomenon.

    PubMed

    Fleitas, Osmel; Agbale, Caleb M; Franco, Octavio L

    2016-01-01

    Bacterial resistance to conventional antibiotics is currently a real problem all over the world, making novel antimicrobial compounds a real research priority. Some of the most promising compounds found to date are antimicrobial peptides (AMPs). The benefits of these drugs include their broad spectrum of activity that affects several microbial processes, making the emergence of resistance less likely. However, bacterial resistance to AMPs is an evolving phenomenon that compromises the therapeutic potential of these compounds. Therefore, it is mandatory to understand bacterial mechanisms of resistance to AMPs in depth, in order to develop more powerful AMPs that overcome the bacterial resistance response. PMID:27100488

  10. Increased survival of experimentally evolved antimicrobial peptide-resistant Staphylococcus aureus in an animal host

    PubMed Central

    Dobson, Adam J; Purves, Joanne; Rolff, Jens

    2014-01-01

    Antimicrobial peptides (AMPs) have been proposed as new class of antimicrobial drugs, following the increasing prevalence of bacteria resistant to antibiotics. Synthetic AMPs are functional analogues of highly evolutionarily conserved immune effectors in animals and plants, produced in response to microbial infection. Therefore, the proposed therapeutic use of AMPs bears the risk of ‘arming the enemy’: bacteria that evolve resistance to AMPs may be cross-resistant to immune effectors (AMPs) in their hosts. We used a panel of populations of Staphylococcus aureus that were experimentally selected for resistance to a suite of individual AMPs and antibiotics to investigate the ‘arming the enemy’ hypothesis. We tested whether the selected strains showed higher survival in an insect model (Tenebrio molitor) and cross-resistance against other antimicrobials in vitro. A population selected for resistance to the antimicrobial peptide iseganan showed increased in vivo survival, but was not more virulent. We suggest that increased survival of AMP-resistant bacteria almost certainly poses problems to immune-compromised hosts. PMID:25469169

  11. Antimicrobial Resistance and Virulence: a Successful or Deleterious Association in the Bacterial World?

    PubMed Central

    Beceiro, Alejandro; Tomás, María

    2013-01-01

    SUMMARY Hosts and bacteria have coevolved over millions of years, during which pathogenic bacteria have modified their virulence mechanisms to adapt to host defense systems. Although the spread of pathogens has been hindered by the discovery and widespread use of antimicrobial agents, antimicrobial resistance has increased globally. The emergence of resistant bacteria has accelerated in recent years, mainly as a result of increased selective pressure. However, although antimicrobial resistance and bacterial virulence have developed on different timescales, they share some common characteristics. This review considers how bacterial virulence and fitness are affected by antibiotic resistance and also how the relationship between virulence and resistance is affected by different genetic mechanisms (e.g., coselection and compensatory mutations) and by the most prevalent global responses. The interplay between these factors and the associated biological costs depend on four main factors: the bacterial species involved, virulence and resistance mechanisms, the ecological niche, and the host. The development of new strategies involving new antimicrobials or nonantimicrobial compounds and of novel diagnostic methods that focus on high-risk clones and rapid tests to detect virulence markers may help to resolve the increasing problem of the association between virulence and resistance, which is becoming more beneficial for pathogenic bacteria. PMID:23554414

  12. Antimicrobial resistance profiles in pathogens isolated from chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance profiles are frequently studied from the perspective of epidemiology and not so often from the perspective of population genetics. The population geneticist assumes that gene flow, vertically (generation to generation), horizontally (individual to individual) or migratory (...

  13. Surveillance for Antimicrobial Drug Resistance in Under-Resourced Countries

    PubMed Central

    Mary, Catherine; Altmann, Dany M.; Doumbo, Ogobara; Morpeth, Susan; Bhutta, Zulfiqar A.; Klugman, Keith P.

    2014-01-01

    Antimicrobial drug resistance is usually not monitored in under-resourced countries because they lack surveillance networks, laboratory capacity, and appropriate diagnostics. This accelerating problem accounts for substantial number of excess deaths, especially among infants. Infections particularly affected by antimicrobial drug resistance include tuberculosis, malaria, severe acute respiratory infections, and sepsis caused by gram-negative bacteria. Nonetheless, mapping antimicrobial drug resistance is feasible in under-resourced countries, and lessons can be learned from previous successful efforts. Specimen shipping conditions, data standardization, absence of contamination, and adequate diagnostics must be ensured. As a first step toward solving this problem, we propose that a road map be created at the international level to strengthen antimicrobial resistance surveillance in under-resourced countries. This effort should include a research agenda; a map of existing networks and recommendations to unite them; and a communication plan for national, regional, and international organizations and funding agencies. PMID:24564906

  14. Antimicrobial Resistance Profiles of Salmonella spp. from Agricultural Environments in Fruit Production Systems.

    PubMed

    Gomba, Annancietar; Chidamba, Lizyben; Korsten, Lise

    2016-09-01

    Foodborne disease outbreaks involving fresh produce have increased in recent years. The risk of infection from contaminated food is worsened by the increased prevalence of antibiotic-resistant strains. This study evaluated the prevalence of antibiotic resistance in Salmonella isolates (n = 263) from agricultural production systems through to the final packed product. Salmonella isolates were preliminarily identified by matrix-assisted laser desorption ionization-time-of-flight mass spectroscopy (MALDI-TOF MS) and API 20E and identities confirmed by invA gene polymerase chain reaction. Antimicrobial susceptibility was performed with 15 antimicrobial agents using the Kirby-Bauer disk diffusion test. Of the 263 Salmonella isolates assessed, 59.3% were resistant to one or more antimicrobials. The most frequently detected resistance was against chloramphenicol and kanamycin (46.7%), trimethoprim-sulfamethoxazole (28%), and streptomycin (14%), and the less frequently detected resistance was toward ampicillin (1.14%), amikacin (0.76%), and amoxicillin-clavulanic acid (0.38%). Multiple antimicrobial resistance (MAR) (resistance to ≥3 antibiotics) was found in 48.7% (76/156) isolates. The most common MAR phenotype was to chloramphenicol and trimethoprim/sulfamethoxazole-kanamycin (43.6%). Resistance to chloramphenicol, kanamycin, or trimethoprim/sulfamethoxazole was only observed in MAR phenotypes. All isolates were susceptible to ceftiofur, cefoxitin, ceftriaxone, ciprofloxacin, nalidixic acid, gentamicin, and tetracycline. This study confirms the importance of fresh produce production environments as potential reservoirs and fresh produce as carriers of antibiotic-resistant Salmonella spp. with significant clinical importance. Further studies to evaluate the actual level of health risk from these pathogens should include characterization of the antibiotic resistance determinant genes among the isolates. PMID:27294335

  15. Antimicrobial Use and Resistance in Swine Waste Treatment Systems▿

    PubMed Central

    Jindal, Archana; Kocherginskaya, Svetlana; Mehboob, Asma; Robert, Matthew; Mackie, Roderick I.; Raskin, Lutgarde; Zilles, Julie L.

    2006-01-01

    Chlortetracycline and the macrolide tylosin were identified as commonly used antimicrobials for growth promotion and prophylaxis in swine production. Resistance to these antimicrobials was measured throughout the waste treatment processes at five swine farms by culture-based and molecular methods. Conventional farm samples had the highest levels of resistance with both culture-based and molecular methods and had similar levels of resistance despite differences in antimicrobial usage. The levels of resistance in organic farm samples, where no antimicrobials were used, were very low by a culture-based method targeting fecal streptococci. However, when the same samples were analyzed with a molecular method detecting methylation of a specific nucleotide in the 23S rRNA that results in resistance to macrolides, lincosamides, and streptogramin B (MLSB), an unexpectedly high level of resistant rRNA (approximately 50%) was observed, suggesting that the fecal streptococci were not an appropriate target group to evaluate resistance in the overall microbial community and that background levels of MLSB resistance may be substantial. All of the feed samples tested, including those from the organic farm, contained tetracycline resistance genes. Generally, the same tetracycline resistance genes and frequency of detection were found in the manure and lagoon samples for each commercial farm. The levels of tetracycline and MLSB resistance remained high throughout the waste treatment systems, suggesting that the potential impact of land application of treated wastes and waste treatment by-products on environmental levels of resistance should be investigated further. PMID:17041160

  16. DETECTION OF ANTIMICROBIAL RESISTANCE GENES BY DNA MICROARRAY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To study the spread of antimicrobial resistance in bacteria it is necessary to identify the genes responsible for resistance. Currently, each gene must be screened individually in order to identify the gene(s) responsible for the observed resistance expressed by a bacterium. The inability to rapidly...

  17. Detection of antimicrobial resistance genes by DNA microarray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To study the spread of antimicrobial resistance in bacteria it is necessary to detect and characterize the genes responsible for resistance. Currently, each gene must be screened individually in order to identify the gene(s) responsible for the observed resistance expressed by a bacterium. The inabi...

  18. Detection of antimicrobial resistance genes by DNA microarray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To study the spread of antimicrobial resistance in bacteria it is necessary to identify the genes responsible for resistance. Currently, each gene must be screened individually in order to identify the gene(s) responsible for the observed resistance expressed by a bacterium. The inability to rapidly...

  19. Antimicrobial use and resistance in swine waste treatment systems.

    PubMed

    Jindal, Archana; Kocherginskaya, Svetlana; Mehboob, Asma; Robert, Matthew; Mackie, Roderick I; Raskin, Lutgarde; Zilles, Julie L

    2006-12-01

    Chlortetracycline and the macrolide tylosin were identified as commonly used antimicrobials for growth promotion and prophylaxis in swine production. Resistance to these antimicrobials was measured throughout the waste treatment processes at five swine farms by culture-based and molecular methods. Conventional farm samples had the highest levels of resistance with both culture-based and molecular methods and had similar levels of resistance despite differences in antimicrobial usage. The levels of resistance in organic farm samples, where no antimicrobials were used, were very low by a culture-based method targeting fecal streptococci. However, when the same samples were analyzed with a molecular method detecting methylation of a specific nucleotide in the 23S rRNA that results in resistance to macrolides, lincosamides, and streptogramin B (MLSB), an unexpectedly high level of resistant rRNA (approximately 50%) was observed, suggesting that the fecal streptococci were not an appropriate target group to evaluate resistance in the overall microbial community and that background levels of MLSB resistance may be substantial. All of the feed samples tested, including those from the organic farm, contained tetracycline resistance genes. Generally, the same tetracycline resistance genes and frequency of detection were found in the manure and lagoon samples for each commercial farm. The levels of tetracycline and MLSB resistance remained high throughout the waste treatment systems, suggesting that the potential impact of land application of treated wastes and waste treatment by-products on environmental levels of resistance should be investigated further. PMID:17041160

  20. The global threat of antimicrobial resistance: science for intervention

    PubMed Central

    Roca, I.; Akova, M.; Baquero, F.; Carlet, J.; Cavaleri, M.; Coenen, S.; Cohen, J.; Findlay, D.; Gyssens, I.; Heure, O.E.; Kahlmeter, G.; Kruse, H.; Laxminarayan, R.; Liébana, E.; López-Cerero, L.; MacGowan, A.; Martins, M.; Rodríguez-Baño, J.; Rolain, J.-M.; Segovia, C.; Sigauque, B.; Taconelli, E.; Wellington, E.; Vila, J.

    2015-01-01

    In the last decade we have witnessed a dramatic increase in the proportion and absolute number of bacterial pathogens resistant to multiple antibacterial agents. Multidrug-resistant bacteria are currently considered as an emergent global disease and a major public health problem. The B-Debate meeting brought together renowned experts representing the main stakeholders (i.e. policy makers, public health authorities, regulatory agencies, pharmaceutical companies and the scientific community at large) to review the global threat of antibiotic resistance and come up with a coordinated set of strategies to fight antimicrobial resistance in a multifaceted approach. We summarize the views of the B-Debate participants regarding the current situation of antimicrobial resistance in animals and the food chain, within the community and the healthcare setting as well as the role of the environment and the development of novel diagnostic and therapeutic strategies, providing expert recommendations to tackle the global threat of antimicrobial resistance. PMID:26029375

  1. The global threat of antimicrobial resistance: science for intervention.

    PubMed

    Roca, I; Akova, M; Baquero, F; Carlet, J; Cavaleri, M; Coenen, S; Cohen, J; Findlay, D; Gyssens, I; Heuer, O E; Kahlmeter, G; Kruse, H; Laxminarayan, R; Liébana, E; López-Cerero, L; MacGowan, A; Martins, M; Rodríguez-Baño, J; Rolain, J-M; Segovia, C; Sigauque, B; Tacconelli, E; Wellington, E; Vila, J

    2015-07-01

    In the last decade we have witnessed a dramatic increase in the proportion and absolute number of bacterial pathogens resistant to multiple antibacterial agents. Multidrug-resistant bacteria are currently considered as an emergent global disease and a major public health problem. The B-Debate meeting brought together renowned experts representing the main stakeholders (i.e. policy makers, public health authorities, regulatory agencies, pharmaceutical companies and the scientific community at large) to review the global threat of antibiotic resistance and come up with a coordinated set of strategies to fight antimicrobial resistance in a multifaceted approach. We summarize the views of the B-Debate participants regarding the current situation of antimicrobial resistance in animals and the food chain, within the community and the healthcare setting as well as the role of the environment and the development of novel diagnostic and therapeutic strategies, providing expert recommendations to tackle the global threat of antimicrobial resistance. PMID:26029375

  2. Antimicrobial resistance of Actinobacillus pleuropneumoniae isolated from swine.

    PubMed

    Vanni, Michele; Merenda, Marianna; Barigazzi, Giuseppe; Garbarino, Chiara; Luppi, Andrea; Tognetti, Rosalba; Intorre, Luigi

    2012-04-23

    The aim of this retrospective study was to evaluate the antimicrobial resistance rates and the trend in resistance of Actinobacillus pleuropneumoniae isolated from pigs in Italy from 1994 to 2009. A total of 992 A. pleuropneumoniae isolates were tested for their susceptibility to a panel of antimicrobial agents in a disk diffusion method. Resistance to 7 drugs (amoxicillin, amoxicillin/clavulanic acid, ampicillin, cefquinome, cotrimoxazole, penicillin G and tilmicosin) showed a significant increasing trend over the time, while for 2 drugs (gentamycin and marbofloxacin) a significant decrease was observed. Resistance to the remaining 14 antimicrobial agents tested did not change significantly over the study period. Most of the isolates retained high susceptibility to antimicrobials usually effective against A. pleuropneumoniae such as amphenicols, fluoroquinolones and ceftiofur. However, high rates of resistance were observed for potentiated sulfa drugs, tetracyclines and penicillins which are currently recommended antimicrobials for pig pleuropneumonia therapy. Our results suggest the importance of continued monitoring of A. pleuropneumoniae clinical isolates in order to choose the most appropriate treatment of infections and to control the increase of resistance to currently used antimicrobials. PMID:22104584

  3. Human health risks associated with antimicrobial-resistant enterococci and Staphylococcus aureus on poultry meat.

    PubMed

    Bortolaia, V; Espinosa-Gongora, C; Guardabassi, L

    2016-02-01

    Enterococci and staphylococci are frequent contaminants on poultry meat. Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus are also well-known aetiological agents of a wide variety of infections resulting in major healthcare costs. This review provides an overview of the human health risks associated with the occurrence of these opportunistic human pathogens on poultry meat with particular focus on the risk of food-borne transmission of antimicrobial resistance. In the absence of conclusive evidence of transmission, this risk was inferred using data from scientific articles and national reports on prevalence, bacterial load, antimicrobial resistance and clonal distribution of these three species on poultry meat. The risks associated with ingestion of antimicrobial-resistant enterococci of poultry origin comprise horizontal transfer of resistance genes and transmission of multidrug-resistant E. faecalis lineages such as sequence type ST16. Enterococcus faecium lineages occurring in poultry meat products are distantly related to those causing hospital-acquired infections but may act as donors of quinupristin/dalfopristin resistance and other resistance determinants of clinical interest to the human gut microbiota. Ingestion of poultry meat contaminated with S. aureus may lead to food poisoning. However, antimicrobial resistance in the toxin-producing strains does not have clinical implications because food poisoning is not managed by antimicrobial therapy. Recently methicillin-resistant S. aureus of livestock origin has been reported on poultry meat. In theory handling or ingestion of contaminated meat is a potential risk factor for colonization by methicillin-resistant S. aureus. However, this risk is presently regarded as negligible by public health authorities. PMID:26706616

  4. Antimicrobial Resistance of Faecal Escherichia coli Isolates from Pig Farms with Different Durations of In-feed Antimicrobial Use.

    PubMed

    Gibbons, J F; Boland, F; Egan, J; Fanning, S; Markey, B K; Leonard, F C

    2016-05-01

    Antimicrobial use and resistance in animal and food production are of concern to public health. The primary aims of this study were to determine the frequency of resistance to 12 antimicrobials in Escherichia coli isolates from 39 pig farms and to identify patterns of antimicrobial use on these farms. Further aims were to determine whether a categorization of farms based on the duration of in-feed antimicrobial use (long-term versus short-term) could predict the occurrence of resistance on these farms and to identify the usage of specific antimicrobial drugs associated with the occurrence of resistance. Escherichia coli were isolated from all production stages on these farms; susceptibility testing was carried out against a panel of antimicrobials. Antimicrobial prescribing data were collected, and farms were categorized as long term or short term based on these. Resistance frequencies and antimicrobial use were tabulated. Logistic regression models of resistance to each antimicrobial were constructed with stage of production, duration of antimicrobial use and the use of 5 antimicrobial classes included as explanatory variables in each model. The greatest frequencies of resistance were observed to tetracycline, trimethoprim/sulphamethoxazole and streptomycin with the highest levels of resistance observed in isolates from first-stage weaned pigs. Differences in the types of antimicrobial drugs used were noted between long-term and short-term use farms. Categorization of farms as long- or short-term use was sufficient to predict the likely occurrence of resistance to 3 antimicrobial classes and could provide an aid in the control of resistance in the food chain. Stage of production was a significant predictor variable in all models of resistance constructed and did not solely reflect antimicrobial use at each stage. Cross-selection and co-selection for resistance was evident in the models constructed, and the use of trimethoprim/sulphonamide drugs in particular was

  5. Population-Based Surveillance of Neisseria meningitidis Antimicrobial Resistance in the United States

    PubMed Central

    Harcourt, Brian H.; Anderson, Raydel D.; Wu, Henry M.; Cohn, Amanda C.; MacNeil, Jessica R.; Taylor, Thomas H.; Wang, Xin; Clark, Thomas A.; Messonnier, Nancy E.; Mayer, Leonard W.

    2015-01-01

    Background. Antimicrobial treatment and chemoprophylaxis of patients and their close contacts is critical to reduce the morbidity and mortality and prevent secondary cases of meningococcal disease. Through the 1990's, the prevalence of antimicrobial resistance to commonly used antimicrobials among Neisseria meningitidis was low in the United States. Susceptibility testing was performed to ascertain whether the proportions of isolates with reduced susceptibility to antimicrobials commonly used for N meningitidis have increased since 2004 in the United States. Methods. Antimicrobial susceptibility testing was performed by broth microdilution on 466 isolates of N meningitidis collected in 2004, 2008, 2010, and 2011 from an active, population-based surveillance system for susceptibility to ceftriaxone, ciprofloxacin, penicillin G, rifampin, and azithromycin. The molecular mechanism of reduced susceptibility was investigated for isolates with intermediate or resistant phenotypes. Results. All isolates were susceptible to ceftriaxone and azithromycin, 10.3% were penicillin G intermediate (range, 8% in 2008–16.7% in 2010), and <1% were ciprofloxacin, rifampin, or penicillin G resistant. Of the penicillin G intermediate or resistant isolates, 63% contained mutations in the penA gene associated with reduced susceptibility to penicillin G. All ciprofloxacin-resistant isolates contained mutations in the gyrA gene associated with reduced susceptibility. Conclusions. Resistance of N meningitidis to antimicrobials used for empirical treatment of meningitis in the United States has not been detected, and resistance to penicillin G and chemoprophylaxis agents remains uncommon. Therapeutic agent recommendations remain valid. Although periodic surveillance is warranted to monitor trends in susceptibility, routine clinical testing may be of little use. PMID:26357666

  6. Antimicrobial resistance and genetic diversity of Escherichia coli isolated from humans and foods

    PubMed Central

    Melo, Daniela Benevides; Menezes, Ana Paula de Oliveira; Reis, Joice Neves; Guimarães, Alaíse Gil

    2015-01-01

    Antibiotic resistance has increased in recent years, raising the concern of public health authorities. We conducted a study of Escherichia coli isolates obtained from human and food samples to assess the prevalence of antimicrobial resistance and to determine the genotype and clonal relationship of 84 E. coli isolates (48 from humans and 36 from foods). An antimicrobial susceptibility test was performed using the disk diffusion method. Virulence factors were evaluated by multiplex PCR, and the clonal relationship among the resistant isolates was studied by Pulsed Field Gel Electrophoresis (PFGE). All isolates were susceptible to ceftriaxone. Overall, 26%, 20.2%, 15.4% and 6% of the isolates were resistant to tetracycline, ampicillin, sulfamethoxazole/trimethoprim and cephalotin, respectively. Twenty two percent of the isolates exhibited resistance to more than one antimicrobial agent. Multiple-drug resistance was mostly observed in the human isolates and involved the antibiotics ampicillin and tetracycline. None of the six virulence genes were identified among the isolates. Analysis of genetic diversity by PFGE of 31 resistant isolates, revealed 29 distinct restriction patterns. In conclusion, E. coli from humans and foods are resistant to commonly used antibiotics and are highly genetically diverse. In this setting, inappropriate use of antibiotics may be a cause of high resistance rate instead of clonal spread. PMID:26691477

  7. Molecular Characterization and Antimicrobial Resistance Profile of Methicillin-Resistant Staphylococcus aureus in Retail Chicken.

    PubMed

    Sallam, Khalid Ibrahim; Abd-Elghany, Samir Mohammed; Elhadidy, Mohamed; Tamura, Tomohiro

    2015-10-01

    The emergence of livestock-associated methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals is of increasing interest, raising questions about the presence of MRSA in food of animal origin and potential sources of transmission to humans via the food chain. In this study, the prevalence, molecular characterization, virulence factors, and antimicrobial susceptibility patterns of MRSA isolates from 200 retail raw chicken samples in Egypt were determined. MRSA was detected by positive amplification of the mecA gene in 38% (76 of 200) of chicken samples analyzed. This represents a potential public health threat in Egypt, as this contamination rate seems to be the highest among other studies reported worldwide. Furthermore, genes encoding α-hemolysin (hla) and staphylococcal enterotoxins (sea, seb, and sec) were detected in all of the 288 MRSA isolates. Nonetheless, none of the strains tested carried tst, the gene encoding toxic shock syndrome toxin 1. Antimicrobial resistance of MRSA isolates was most frequently detected against penicillin (93.4%), ampicillin (88.9%), and cloxacillin (83.3%). These results suggest that retail chicken might be a significant potential source for transmission of multidrug-resistant and toxigenic S. aureus in Egypt. This underlines the need for stricter hygienic measures in chicken production in Egypt to minimize the risk of transmission of these strains to consumers. To the best of our knowledge, this is the first study that reports the isolation and molecular characterization of MRSA in retail chicken samples in Egypt. PMID:26408138

  8. Methicillin resistant Staphylococcus aureus (MRSA) in India: Prevalence & susceptibility pattern

    PubMed Central

    Joshi, Sangeeta; Ray, Pallab; Manchanda, Vikas; Bajaj, Jyoti; Chitnis, D.S.; Gautam, Vikas; Goswami, Parijath; Gupta, Varsha; Harish, B.N.; Kagal, Anju; Kapil, Arti; Rao, Ratna; Rodrigues, Camilla; Sardana, Raman; Devi, Kh Sulochana; Sharma, Anita; Balaji, Veeragaghavan

    2013-01-01

    Background & objectives: Methicillin resistant Staphylococcus aureus (MRSA) is endemic in India and is a dangerous pathogen for hospital acquired infections. This study was conducted in 15 Indian tertiary care centres during a two year period from January 2008 to December 2009 to determine the prevalence of MRSA and susceptibility pattern of S. aureus isolates in India. Methods: All S. aureus isolates obtained during the study period in the participating centres were included in the study. Each centre compiled their data in a predefined template which included data of the antimicrobial susceptibility pattern, location of the patient and specimen type. The data in the submitted templates were collated and analysed. Results: A total of 26310 isolates were included in the study. The overall prevalence of methicillin resistance during the study period was 41 per cent. Isolation rates for MRSA from outpatients, ward inpatients and ICU were 28, 42 and 43 per cent, respectively in 2008 and 27, 49 and 47 per cent, respectively in 2009. The majority of S. aureus isolates was obtained from patients with skin and soft tissue infections followed by those suffering from blood stream infections and respiratory infections. Susceptibility to ciprofloxacin was low in both MSSA (53%) and MRSA (21%). MSSA isolates showed a higher susceptibility to gentamicin, co-trimoxazole, erythromycin and clindamycin as compared to MRSA isolates. No isolate was found resistant to vancomycin or linezolid. Interpretation & conclusions: The study showed a high level of MRSA in our country. There is a need to study epidemiology of such infections. Robust antimicrobial stewardship and strengthened infection control measures are required to prevent spread and reduce emergence of resistance. PMID:23563381

  9. Associations between host characteristics and antimicrobial resistance of Salmonella typhimurium.

    PubMed

    Ruddat, I; Tietze, E; Ziehm, D; Kreienbrock, L

    2014-10-01

    A collection of Salmonella Typhimurium isolates obtained from sporadic salmonellosis cases in humans from Lower Saxony, Germany between June 2008 and May 2010 was used to perform an exploratory risk-factor analysis on antimicrobial resistance (AMR) using comprehensive host information on sociodemographic attributes, medical history, food habits and animal contact. Multivariate resistance profiles of minimum inhibitory concentrations for 13 antimicrobial agents were analysed using a non-parametric approach with multifactorial models adjusted for phage types. Statistically significant associations were observed for consumption of antimicrobial agents, region type and three factors on egg-purchasing behaviour, indicating that besides antimicrobial use the proximity to other community members, health consciousness and other lifestyle-related attributes may play a role in the dissemination of resistances. Furthermore, a statistically significant increase in AMR from the first study year to the second year was observed. PMID:24300336

  10. The World Health Assembly resolution on antimicrobial resistance.

    PubMed

    Shallcross, Laura J; Davies, Sally C

    2014-11-01

    Antimicrobial resistance is a global problem that can only be tackled successfully through strengthened international partnerships. A concerted political, scientific and media campaign has garnered support for the recent World Health Assembly resolution on antimicrobial resistance, mandating the WHO to develop a global action plan. This resolution has the 'One Health' approach at its core, emphasizing collaboration across human and animal health sectors at the international, national and regional levels, coupled with strong leadership and the political will to act. Key themes are communication, prevention of infection, using knowledge to guide action, sustainability and optimizing the use of antimicrobial medicines and diagnostic devices. Implementation of the global action plan will require member states to make a commitment to developing national action plans and strengthening capacity, building on collaborations between the WHO, the World Organisation for Animal Health, the World Bank, Codex Alimentarius and the Transatlantic Task Force on Antimicrobial Resistance. PMID:25204342

  11. Analysis of antimicrobial resistance mechanisms in MDR bacteria by microarray and high-throughput sequencing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance in pathogenic bacteria is a major concern in human and animal health. The National Antimicrobial Resistance Monitoring System (NARMS) was designed by the CDC, FDA, and USDA to monitor antimicrobial resistance in the U.S. The Bacterial Epidemiology and Antimicrobial Resistanc...

  12. 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

  13. Mechanobiology of Antimicrobial Resistant Escherichia coli and Listeria innocua

    PubMed Central

    Tajkarimi, Mehrdad; Harrison, Scott H.; Hung, Albert M.; Graves, Joseph L.

    2016-01-01

    A majority of antibiotic-resistant bacterial infections in the United States are associated with biofilms. Nanoscale biophysical measures are increasingly revealing that adhesive and viscoelastic properties of bacteria play essential roles across multiple stages of biofilm development. Atomic Force Microscopy (AFM) applied to strains with variation in antimicrobial resistance enables new opportunities for investigating the function of adhesive forces (stickiness) in biofilm formation. AFM force spectroscopy analysis of a field strain of Listeria innocua and the strain Escherichia coli K-12 MG1655 revealed differing adhesive forces between antimicrobial resistant and nonresistant strains. Significant increases in stickiness were found at the nanonewton level for strains of Listeria innocua and Escherichia coli in association with benzalkonium chloride and silver nanoparticle resistance respectively. This advancement in the usage of AFM provides for a fast and reliable avenue for analyzing antimicrobial resistant cells and the molecular dynamics of biofilm formation as a protective mechanism. PMID:26914334

  14. Campylobacter antimicrobial resistance in Peru: a ten-year observational study

    PubMed Central

    2012-01-01

    Background Campylobacter jejuni and Campylobacter coli are food-borne pathogens of great importance and feature prominently in the etiology of developing world enteritis and travellers’ diarrhoea. Increasing antimicrobial resistant Campylobacter prevalence has been described globally, yet data from Peru is limited. Our objective was to describe the prevalence trends of fluoroquinolone and macrolide-resistant C. jejuni and C. coli stool isolates from three regions in Peru over a ten-year period. Methods Surveillance for enteric pathogens was conducted in Lima, Iquitos and Cusco between 2001 and 2010. Campylobacter stool isolates were tested for susceptibilities to ciprofloxacin, azithromycin and erythromycin. Susceptibilities were reviewed for 4652 isolates from Lima ( n = 3419), Iquitos ( n = 625) and Cusco ( n = 608). Results Comparing the study periods of 2001-2005 and 2006-2010, prevalence of ciprofloxacin-resistant C. jejuni isolates rose in the study areas of Lima (73.1% to 89.8%, p < 0.001) and Iquitos (24.1% to 48.9%, p < 0.001). Ciprofloxacin-resistant C. coli rates also increased in Lima (48.1% to 87.4%, p < 0.001) and Cusco (10.0% to 65.9%, p = 0.005). Small but significant increases in azithromycin-resistant and erythromycin-resistant C. jejuni prevalence were noted in Iquitos (2.2% to 14.9%, p < 0.001; 3.2% to 14.9%, p = 0.002), and erythromycin-resistant C. coli rates increased in Lima (0.0% to 5.3%, p = 0.038). The prevalence of C. jejuni isolates resistant to both ciprofloxacin and azithromycin increased in Iquitos (0.3% to 14.9%, p < 0.001) and Lima (0.3% to 1.6%, p = 0.011), and prevalence of C. jejuni isolates resistant to both ciprofloxacin and erythromycin rose in Iquitos (0.0% to 14.9%, p < 0.001). Ciprofloxacin and erythromycin resistant C. coli prevalence increased in Lima (0.0% to 5.3%, p = 0.034). Conclusions These results have implications for the empirical management of

  15. Antimicrobial Resistance Profiles in Escherichia coli O157 Isolates from Northern Colorado Dairies.

    PubMed

    McConnel, Craig S; Stenkamp-Strahm, Chloe M; Rao, Sangeeta; Linke, Lyndsey M; Magnuson, Roberta J; Hyatt, Doreene R

    2016-03-01

    Escherichia coli O157 (EcO157) infections can lead to serious disease and death in humans. Although the ecology of EcO157 is complex, ruminant animals serve as an important reservoir for human infection. Dairy cattle are unique because they may be a source of contamination for milk, meat, and manure-fertilized crops. Foodborne dairy pathogens such as EcO157 are of primary importance to public health. Antimicrobial resistance (AMR) is a complex phenomenon that complicates the treatment of serious bacterial infections and is of increasing concern. In the face of recommended use restrictions for antimicrobial agents in livestock operations, current AMR patterns in known foodborne pathogens should be documented. The objective of this study was to document AMR patterns in EcO157 isolates from dairies in northern Colorado using antimicrobial agents commonly found on dairies and representative of medically important antimicrobial drug classes. Seventy-five EcO157 isolates were recovered from three dairies. Six isolates were resistant to at least 1 of the 10 tested antimicrobial agents: four were resistant to streptomycin, sulfisoxazole, and tetracycline; one was resistant to streptomycin and tetracycline; and one was resistant to only tetracycline. All resistant isolates were from a single dairy. Overall, a low prevalence (8%) of AMR was observed among the 75 EcO157 isolates. No significant effects on AMR profiles due to virulence genes, parity, or previous antimicrobial treatments within the current lactation period were detected. The results of this study provide background information for future comparative studies investigating AMR trends. Future studies should include more participating farms and more samples and should control for potential confounding factors of AMR that may underlie individual farm variation. PMID:26939660

  16. Antimicrobial resistance of Pseudomonas spp. isolated from wastewater and wastewater-impacted marine coastal zone.

    PubMed

    Luczkiewicz, Aneta; Kotlarska, Ewa; Artichowicz, Wojciech; Tarasewicz, Katarzyna; Fudala-Ksiazek, Sylwia

    2015-12-01

    In this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins, as well as their combination with the β-lactamase inhibitors, monobactams, fluoroquinolones, and polymyxins. Among identified species, resistance to all antimicrobials but colistin was shown by Pseudomonas putida, the predominant species in all sampling points. In other species, resistance was observed mainly against ceftazidime, ticarcillin, ticarcillin-clavulanate, and aztreonam, although some isolates of Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas pseudoalcaligenes, and Pseudomonas protegens showed multidrug-resistance (MDR) phenotype. Among P. putida, resistance to β-lactams and to fluoroquinolones as well as multidrug resistance become more prevalent after wastewater treatment, but the resistance rate decreased in marine water samples. Obtained data, however, suggests that Pseudomonas spp. are equipped or are able to acquire a wide range of antibiotic resistance mechanisms, and thus should be monitored as possible source of resistance genes. PMID:26286796

  17. Survival proteomes: the emerging proteotype of antimicrobial resistance.

    PubMed

    Park, Amber J; Krieger, Jonathan R; Khursigara, Cezar M

    2016-05-01

    Antimicrobial resistance is one of the greatest challenges in modern medicine. Infectious diseases that have historically been eliminated with routine antibiotic therapy are now re-emerging as life threatening illnesses. A better understanding of the specific mechanisms that contribute to resistance are required to optimize the treatment of infectious microorganisms and limit the survival of recalcitrant populations. This challenging area of research is made more problematic by the observation that multiple, overlapping, and/or compensatory resistance mechanism are often present within a single bacterial species. High-resolution proteomics has emerged as an effective tool to study antimicrobial resistance as it allows for the quantitative investigation of multiple systems concurrently. Furthermore, the ability to examine extracellular mechanisms of resistance and important post-translational modifications make this research tool well suited for the challenge. This review discusses how proteomics has contributed to the understanding of antimicrobial resistance and focuses on advances afforded by the more recent development of technologies that produce quantitative high-resolution proteomic information. We discuss current strategies for studying resistance, including comparative analysis of resistant and susceptible strains and protein-based responses to antimicrobial challenge. Lastly, we suggest specific experimental approaches aimed at advancing our understanding of protein-based resistance mechanisms and maximizing therapeutic outcomes in the future. PMID:26790948

  18. Antimicrobial susceptibility in gram-negative bacteremia: are nosocomial isolates really more resistant?

    PubMed Central

    McGowan, J E; Hall, E C; Parrott, P L

    1989-01-01

    Bloodstream isolates of gram-negative aerobic bacilli from nosocomial infections are more likely to be resistant to antimicrobial agents than isolates from community-acquired cases are. It is not clear, however, how much this is due to the markedly different distribution of organisms in the two groups. We compared the susceptibilities of organisms of a given species which caused community-acquired bacteremia with the susceptibilities of isolates from nosocomial cases. Nine antimicrobial agents were tested against 1,077 isolates which were obtained during a 4-year nonepidemic period. Marked differences in crude rates of resistance were noted for all isolates from nosocomial cases versus all isolates from cases acquired in the community. When results were adjusted for the different organism distributions in the two groups, statistically significant differences were found for only six drug-organism pairs; in each of these, resistance rates were higher in nosocomial isolates. However, when results were further adjusted for the effect of multiple analyses, no significant differences were seen. The major factor leading to the greater prevalence of antimicrobial resistance in our hospital organisms was the markedly different distribution of organisms in the nosocomial and community-acquired groups. For individual organisms, greater resistance in nosocomial strains was confined to certain drugs. Factors that influence differences in organism distribution may not be solely the result of antimicrobial use. PMID:2610495

  19. Oral administration of antimicrobials increase antimicrobial resistance in E. coli from chicken--a systematic review.

    PubMed

    Simoneit, C; Burow, E; Tenhagen, B-A; Käsbohrer, A

    2015-01-01

    Antimicrobials play an important role in animal and human health care. It was the aim of this systematic review to assess the effects of oral administration of antimicrobials on the development of antimicrobial resistance (AMR) in Escherichia coli (E. coli) from chickens. Moreover, the effects of the administration of more than one antimicrobial and of different dosages were studied. Literature was searched in November 2012 from the electronic databases ISI Web of Science, PubMed, Scopus and a national literature database (DIMDI) as well as the database ProQuest LLC. The search was updated in March 2014. Original studies describing a treatment (A) and a control group of either non-treatment (C) or initial value (0) and determining AMR in E. coli at different sample points (SP) were included. The literature search resulted in 35 full text articles on the topic, seven (20%) of which contained sufficient information on the administered antimicrobial and the impact of treatment on AMR. Most papers described the use of more than one antimicrobial, several dosages, controls (non-treatment or pre-treatment) and measured AMR at different SPs leading to a total of 227 SPs on the impact of the use of antimicrobials on AMR in chickens. 74% of the SPs (168/227) described a higher AMR-rate in E. coli from treated animals than from controls. After the administration of a single antimicrobial, AMR increased at 72% of the SPs. Administration of more than one antimicrobial increased AMR at 82% of the SPs. Higher dosages were associated with similar or higher AMR rates. The limited number of studies for each antimicrobial agent and the high variability in the resistance effect call for more well designed studies on the impact of oral administration on AMR development and spread. PMID:25433717

  20. Narrow grass hedges reduce tylosin and associated antimicrobial resistance genes in agricultural runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobial...

  1. Perception, Attitude, and Knowledge Regarding Antimicrobial Resistance, Appropriate Antimicrobial Use, and Infection Control Among Future Medical Practitioners: A Multicenter Study.

    PubMed

    Chuenchom, Nuttagarn; Thamlikitkul, Visanu; Chaiwarith, Romanee; Deoisares, Rawisut; Rattanaumpawan, Pinyo

    2016-05-01

    A questionnaire-based study was conducted among final-year Thai medical students. The problem of antimicrobial resistance is well recognized, but their knowledge of antimicrobial resistance, appropriate antimicrobial use, and infection control was substantially limited. Only half of these students recognized existence of an antimicrobial stewardship program or infection control unit in their hospitals. Infect Control Hosp Epidemiol 2016;37:603-605. PMID:26809753

  2. Antimicrobial Resistance in Salmonella Isolates Recovered from Slaughter Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    *Background*: Antimicrobial resistance is of global concern and first emerged in bacteria shortly after the introduction of penicillin. It is common to see resistance develop after new compounds (regardless of class) are released. However many factors influence the persistence and transmission of r...

  3. Hospitalization and Antimicrobial Resistance in Salmonella Outbreaks, 1984–2002

    PubMed Central

    Greene, Katherine D.; Ovitt, Jessa; Barrett, Timothy J.; Medalla, Felicita; Angulo, Frederick J.

    2005-01-01

    Few studies have evaluated the health consequences of antimicrobial-resistant Salmonella strains associated with outbreaks. Among 32 outbreaks occurring in the United States from 1984 to 2002, 22% of 13,286 persons in 10 Salmonella-resistant outbreaks were hospitalized, compared with 8% of 2,194 persons in 22 outbreaks caused by pansusceptible Salmonella strains (p<0.01). PMID:15963293

  4. Multiple Antimicrobial Resistance in Plague: An Emerging Public Health Risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance in Yersinia pestis is rare, yet constitutes a significant international public health and biodefense threat. In 1995, the first multidrug resistant (MDR) isolate of Y. pestis (strain IP275) was identified, and shown to contain a self-transmissible plasmid (pIP1202) that con...

  5. Antimicrobial resistance in aviary and enriched housing environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance continues to be a global problem. The purpose of this study was to elucidate the emergence of resistance in populations of bacteria over time in layers in different housing systems. Houses were newly constructed and tested for pathogens prior to placement of hens. Hens we...

  6. ANTIMICROBIAL RESISTANCE IN SALMONELLA ISOLATES RECOVERED FROM EGGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Antimicrobial resistance is of global concern and first emerged in bacteria shortly after the introduction of penicillin. It is common to see resistance develop after new compounds (regardless of class) are released. However many factors influence the persistence and transmission of r...

  7. Mycoplasma bovis: Mechanisms of Resistance and Trends in Antimicrobial Susceptibility.

    PubMed

    Lysnyansky, Inna; Ayling, Roger D

    2016-01-01

    Mycoplasma bovis is a cell-wall-less bacterium and belongs to the class Mollicutes. It is the most important etiological agent of bovine mycoplasmoses in North America and Europe, causing respiratory disease, mastitis, otitis media, arthritis, and reproductive disease. Clinical disease associated with M. bovis is often chronic, debilitating, and poorly responsive to antimicrobial therapy, resulting in significant economic loss, the full extent of which is difficult to estimate. Until M. bovis vaccines are universally available, sanitary control measures and antimicrobial treatment are the only approaches that can be used in attempts to control M. bovis infections. However, in vitro studies show that many of the current M. bovis isolates circulating in Europe have high minimum inhibitory concentrations (MIC) for many of the commercially available antimicrobials. In this review we summarize the current MIC trends indicating the development of antimicrobial resistance in M. bovis as well as the known molecular mechanisms by which resistance is acquired. PMID:27199926

  8. Mycoplasma bovis: Mechanisms of Resistance and Trends in Antimicrobial Susceptibility

    PubMed Central

    Lysnyansky, Inna; Ayling, Roger D.

    2016-01-01

    Mycoplasma bovis is a cell-wall-less bacterium and belongs to the class Mollicutes. It is the most important etiological agent of bovine mycoplasmoses in North America and Europe, causing respiratory disease, mastitis, otitis media, arthritis, and reproductive disease. Clinical disease associated with M. bovis is often chronic, debilitating, and poorly responsive to antimicrobial therapy, resulting in significant economic loss, the full extent of which is difficult to estimate. Until M. bovis vaccines are universally available, sanitary control measures and antimicrobial treatment are the only approaches that can be used in attempts to control M. bovis infections. However, in vitro studies show that many of the current M. bovis isolates circulating in Europe have high minimum inhibitory concentrations (MIC) for many of the commercially available antimicrobials. In this review we summarize the current MIC trends indicating the development of antimicrobial resistance in M. bovis as well as the known molecular mechanisms by which resistance is acquired. PMID:27199926

  9. Pseudomonas aeruginosa: arsenal of resistance mechanisms, decades of changing resistance profiles, and future antimicrobial therapies.

    PubMed

    El Zowalaty, Mohamed E; Al Thani, Asmaa A; Webster, Thomas J; El Zowalaty, Ahmed E; Schweizer, Herbert P; Nasrallah, Gheyath K; Marei, Hany E; Ashour, Hossam M

    2015-01-01

    Antimicrobial resistance is one of the most serious public health issues facing humans since the discovery of antimicrobial agents. The frequent, prolonged, and uncontrolled use of antimicrobial agents are major factors in the emergence of antimicrobial-resistant bacterial strains, including multidrug-resistant variants. Pseudomonas aeruginosa is a leading cause of nosocomial infections. The abundant data on the increased resistance to antipseudomonal agents support the need for global action. There is a paucity of new classes of antibiotics active against P. aeruginosa. Here, we discuss recent antibacterial resistance profiles and mechanisms of resistance by P. aeruginosa. We also review future potential methods for controlling antibiotic-resistant bacteria, such as phage therapy, nanotechnology and antipseudomonal vaccines. PMID:26439366

  10. Antimicrobial resistance and molecular epidemiology of vancomycin-resistant enterococci from North America and Europe: a report from the SENTRY antimicrobial surveillance program.

    PubMed

    Deshpande, Lalitagauri M; Fritsche, Thomas R; Moet, Gary J; Biedenbach, Douglas J; Jones, Ronald N

    2007-06-01

    Increases in prevalence of vancomycin-resistant enterococci (VRE) have been documented globally since its emergence in the 1980s. A SENTRY Antimicrobial Surveillance Program (2003) objective monitored VRE isolates with respect to antimicrobial susceptibility trends, geographic resistance variability, and clonal dissemination. In 2003, VRE isolates from North America (United States and Canada, n = 839, 26 sites) and Europe (n = 56, 10 sites) were susceptibility tested using Clinical and Laboratory Standards Institute (CLSI) reference methodologies. Based on resistance profiles, 155 isolates displayed similar multidrug-resistant (MDR) profiles and were temporally related; these were subsequently submitted for typing by pulsed-field gel electrophoresis (PFGE). Most of the submitted isolates were Enterococcus faecium (91.0%) and Enterococcus faecalis (7.8%). Among VRE, the VanA phenotype was more prevalent in North America (76%) than Europe (40%), and all isolates had elevated resistance rates to other antimicrobial classes including the following: 1) chloramphenicol resistance among E. faecalis being greater in North America than in Europe (28.6% versus 7.1%, respectively) but reversed among E. faecium (0.5% and 15.0%, the latter due to clonal occurrences); 2) ciprofloxacin resistance in North America >99% for both species and in Europe varying from 85.7% to 87.5%; 3) rare occurrences of linezolid resistance in North America (0.8% to 1.8%) due to G2576U ribosomal mutation; 4) higher quinupristin/dalfopristin resistance observed among European E. faecium strains (10.0% versus 0.6%); and 5) higher rifampin resistance rates among European E. faecalis (21.4% versus 5.4%). Thirty-five MDR epidemic clusters were identified by PFGE in 21 North American and 2 European medical centers including the following: 1) VanA (20 sites, 27 clonal occurrences) and VanB (1 site, 2 clonal occurrences); 2) elevated quinupristin/dalfopristin MIC results (not vatD/E, 3 sites); and 3

  11. Race Against Antimicrobial Resistance Requires Coordinated Action – An Overview

    PubMed Central

    Premanandh, J.; Samara, B. S.; Mazen, A. N.

    2016-01-01

    Resistance developed by microbes is challenging success stories of treatment of infectious diseases with anti-microbials. Developing new antimicrobials against these resistant organisms does not progress at the same speed. In an effort to address this key issue, this work overviews the role of different stakeholders and discusses preventative and control measures for effective management of available resources. Roles and concerns of physicians, pharmacists and the public are also discussed. More than anything, this situation requires immediate action to establish antimicrobial stewardship program, control over the counter sale and promote public awareness. The paper also confronts the idea of curbing the use of antimicrobials using mass media, while detailing the consequences of non-therapeutic use. The role of policy makers in taking global action is essential to establishing authority or agency for formulating national guidelines and regulations for prudently using antimicrobials. To do this, this paper recommend the establishment of a global fund. In conclusion, the race against resistance is a collective responsibility requiring coordinated action at local, national, regional and international levels to ensure sustained utilization of antimicrobials. PMID:26869998

  12. Race Against Antimicrobial Resistance Requires Coordinated Action - An Overview.

    PubMed

    Premanandh, J; Samara, B S; Mazen, A N

    2015-01-01

    Resistance developed by microbes is challenging success stories of treatment of infectious diseases with anti-microbials. Developing new antimicrobials against these resistant organisms does not progress at the same speed. In an effort to address this key issue, this work overviews the role of different stakeholders and discusses preventative and control measures for effective management of available resources. Roles and concerns of physicians, pharmacists and the public are also discussed. More than anything, this situation requires immediate action to establish antimicrobial stewardship program, control over the counter sale and promote public awareness. The paper also confronts the idea of curbing the use of antimicrobials using mass media, while detailing the consequences of non-therapeutic use. The role of policy makers in taking global action is essential to establishing authority or agency for formulating national guidelines and regulations for prudently using antimicrobials. To do this, this paper recommend the establishment of a global fund. In conclusion, the race against resistance is a collective responsibility requiring coordinated action at local, national, regional and international levels to ensure sustained utilization of antimicrobials. PMID:26869998

  13. Antimicrobial resistance of Aeromonas hydrophila isolated from different food sources: A mini-review.

    PubMed

    Stratev, Deyan; Odeyemi, Olumide A

    2016-01-01

    Aeromonas hydrophila is a Gram-negative, oxidase-positive, facultative, anaerobic, opportunistic aquatic pathogen. A. hydrophila produces virulence factors, such as hemolysins, aerolysins, adhesins, enterotoxins, phospholipase and lipase. In addition to isolation from aquatic sources, A. hydrophila has been isolated from meat and meat products, milk and dairy products, and vegetables. However, various studies showed that this opportunistic pathogen is resistant to commercial antibiotics. This is attributed to factors such as the indiscriminate use of antibiotics in aquaculture, plasmids or horizontal gene transfer. In this report, we highlight the occurrence, prevalence and antimicrobial resistance of A. hydrophila isolated from different food samples. The presence of antimicrobial-resistant A. hydrophila in food poses threats to public and aquatic animal health. PMID:26588876

  14. Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry.

    PubMed

    Mendonça, Nuno; Figueiredo, Rui; Mendes, Catarina; Card, Roderick M; Anjum, Muna F; da Silva, Gabriela Jorge

    2016-01-01

    The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70%) and ampicillin (63%). Extended-spectrum beta-lactamase (ESBL) phenotype was observed in 18% of the isolates. Multidrug resistance was found in 56% of isolates. A subset of 74 isolates were screened by DNA microarrays for the carriage of 88 antibiotic resistance genes and 62 virulence genes. Overall, 37 different resistance genes were detected. The most common were tet(A) (72%), blaTEM (68%), and sul1 (47%), while 21% isolates harbored an ESBL gene (blaCTX-M group 1, group 2, or group 9). Of these, 96% carried the increased serum survival (iss) virulence gene, while 89% presented the enterobactin siderophore receptor protein (iroN), 70% the temperature-sensitive hemagglutinin (tsh), and 68% the long polar fimbriae (lpfA) virulence genes associated with extraintestinal pathogenic E. coli. In conclusion, prevalence of antibiotic resistant E. coli from the microbiota of Portuguese chickens was high, including to extended spectrum cephalosporins. The majority of isolates seems to have the potential to trigger extraintestinal human infection due to the presence of some virulence genes. However, the absence of genes specific for enteropathogenic E. coli reduces the risk for human intestinal infection. PMID:27025519

  15. Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry

    PubMed Central

    Mendonça, Nuno; Figueiredo, Rui; Mendes, Catarina; Card, Roderick M.; Anjum, Muna F.; da Silva, Gabriela Jorge

    2016-01-01

    The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70%) and ampicillin (63%). Extended-spectrum beta-lactamase (ESBL) phenotype was observed in 18% of the isolates. Multidrug resistance was found in 56% of isolates. A subset of 74 isolates were screened by DNA microarrays for the carriage of 88 antibiotic resistance genes and 62 virulence genes. Overall, 37 different resistance genes were detected. The most common were tet(A) (72%), blaTEM (68%), and sul1 (47%), while 21% isolates harbored an ESBL gene (blaCTX-M group 1, group 2, or group 9). Of these, 96% carried the increased serum survival (iss) virulence gene, while 89% presented the enterobactin siderophore receptor protein (iroN), 70% the temperature-sensitive hemagglutinin (tsh), and 68% the long polar fimbriae (lpfA) virulence genes associated with extraintestinal pathogenic E. coli. In conclusion, prevalence of antibiotic resistant E. coli from the microbiota of Portuguese chickens was high, including to extended spectrum cephalosporins. The majority of isolates seems to have the potential to trigger extraintestinal human infection due to the presence of some virulence genes. However, the absence of genes specific for enteropathogenic E. coli reduces the risk for human intestinal infection. PMID:27025519

  16. Prevalence of streptogramin resistance in enterococci from animals: Identification of vatD from animal sources in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is considerable debate over the use of virginiamycin in animals to the contribution of Quinupristin/Dalfopristin (Q/D) resistance in humans as both are of the streptogramin class of antimicrobials. In this study, the prevalence and mechanisms of streptogramin resistance in enterococci from an...

  17. Public health measures to control the spread of antimicrobial resistance in Neisseria gonorrhoeae in men who have sex with men.

    PubMed

    Xiridou, M; Soetens, L C; Koedijk, F D H; VAN DER Sande, M A B; Wallinga, J

    2015-06-01

    Gonorrhoea is one of the most common sexually transmitted infections. The control of gonorrhoea is extremely challenging because of the repeated development of resistance to the antibiotics used for its treatment. We explored different strategies to control the spread of antimicrobial resistance and prevent increases in gonorrhoea prevalence. We used a mathematical model that describes gonorrhoea transmission among men who have sex with men and distinguishes gonorrhoea strains sensitive or resistant to three antibiotics. We investigated the impact of combination therapy, switching first-line antibiotics according to resistance thresholds, and other control efforts (reduced sexual risk behaviour, increased treatment rate). Combination therapy can delay the spread of resistance better than using the 5% resistance threshold. Increased treatment rates, expected to enhance gonorrhoea control, may reduce gonorrhoea prevalence only in the short term, but could lead to more resistance and higher prevalence in the long term. Re-treatment of resistant cases with alternative antibiotics can substantially delay the spread of resistance. In conclusion, combination therapy and re-treatment of resistant cases with alternative antibiotics could be the most effective strategies to prevent increases in gonorrhoea prevalence due to antimicrobial resistance. PMID:25275435

  18. Antimicrobial resistance: moving from professional engagement to public action.

    PubMed

    Ashiru-Oredope, D; Hopkins, S

    2015-11-01

    Antimicrobial-resistant infections claim ≥700 000 lives each year globally. It is therefore important that both healthcare professionals and the public know the threat antimicrobial resistance poses and the individual actions they can take to combat antimicrobial resistance. Antibiotic awareness campaigns in England using posters or leaflets have had little or no impact on knowledge, behaviour or prescription rates. Centrally coordinated, multimodal campaigns in two European countries (ongoing for several years and including print and mass media, web site and guidelines, as well as academic detailing and individual feedback to prescribers) have led to reductions in antibiotic use. To change behaviour and reduce antibiotic use in England, a coordinated and comprehensive interdisciplinary and multifaceted (multimodal) approach using behavioural science and targeted at specific groups (both professional and public) is required. Such campaigns should have an integrated evaluation plan using a combination of formative, process and summative measures from the outset to completion of a campaign. PMID:26377862

  19. A versatile plasmonic thermogel for disinfection of antimicrobial resistant bacteria.

    PubMed

    Abdou Mohamed, Mohamed A; Raeesi, Vahid; Turner, Patricia V; Rebbapragada, Anu; Banks, Kate; Chan, Warren C W

    2016-08-01

    The increasing occurrence of antimicrobial resistance among bacteria is a global problem that requires the development of alternative techniques to eradicate these superbugs. Herein, we used a combination of thermosensitive biocompatible polymer and gold nanorods to specifically deliver, preserve and confine heat to the area of interest. Our data demonstrates that this technique can be used to kill both Gram positive and Gram negative antimicrobial resistant bacteria in vitro. Our approach significantly reduces the antimicrobial resistant bacteria load in experimentally infected wounds by 98% without harming the surrounding tissues. More importantly, this polymer-nanocomposite can be prepared easily and applied to the wounds, can generate heat using a hand-held laser device, is safe for the operator, and does not have any adverse effects on the wound tissue and healing process. PMID:27174687

  20. Phenotypic and genotypic characteristics of antimicrobial resistant Escherichia coli isolated from symbovine flies, cattle and sympatric insectivorous house martins from a farm in the Czech Republic (2006-2007).

    PubMed

    Rybaríková, Jana; Dolejská, Monika; Materna, David; Literák, Ivan; Cízek, Alois

    2010-10-01

    The prevalence of antimicrobial resistant Escherichia coli was tested in symbovine flies and sympatric house martins (Delichon urbica) at a dairy farm. Antimicrobial resistant E. coli was detected in 89% (n=147) of isolates from flies within a calf barn. Isolates with the same antimicrobial resistance phenotypes, genes, and pulsotypes were found between both fly and calf E. coli isolates, suggesting that the calves were the initial source of the antimicrobial resistant strains in fly isolates. Symbovine flies were considered as important reservoirs of antimicrobial resistant E. coli strains at a dairy farm, due to their intensive contact with cattle feces and manure. House martin fecal samples from the same farm contained 4.5% (n=393) of antimicrobial resistant E. coli. House martin isolates displayed different macrorestriction profiles than fly isolates and the significance of house martins as a reservoir and vector of antimicrobial resistant E. coli appears low. PMID:20350731

  1. Genetic diversity and antimicrobial resistance of Escherichia coli from human and animal sources uncovers multiple resistances from human sources.

    PubMed

    Ibekwe, A Mark; Murinda, Shelton E; Graves, Alexandria K

    2011-01-01

    Escherichia coli are widely used as indicators of fecal contamination, and in some cases to identify host sources of fecal contamination in surface water. Prevalence, genetic diversity and antimicrobial susceptibility were determined for 600 generic E. coli isolates obtained from surface water and sediment from creeks and channels along the middle Santa Ana River (MSAR) watershed of southern California, USA, after a 12 month study. Evaluation of E. coli populations along the creeks and channels showed that E. coli were more prevalent in sediment compared to surface water. E. coli populations were not significantly different (P = 0.05) between urban runoff sources and agricultural sources, however, E. coli genotypes determined by pulsed-field gel electrophoresis (PFGE) were less diverse in the agricultural sources than in urban runoff sources. PFGE also showed that E. coli populations in surface water were more diverse than in the sediment, suggesting isolates in sediment may be dominated by clonal populations.Twenty four percent (144 isolates) of the 600 isolates exhibited resistance to more than one antimicrobial agent. Most multiple resistances were associated with inputs from urban runoff and involved the antimicrobials rifampicin, tetracycline, and erythromycin. The occurrence of a greater number of E. coli with multiple antibiotic resistances from urban runoff sources than agricultural sources in this watershed provides useful evidence in planning strategies for water quality management and public health protection. PMID:21687635

  2. The human microbiome as a reservoir of antimicrobial resistance.

    PubMed

    Penders, John; Stobberingh, Ellen E; Savelkoul, Paul H M; Wolffs, Petra F G

    2013-01-01

    The gut microbiota is amongst the most densely populated microbial ecosystem on earth. While the microbiome exerts numerous health beneficial functions, the high density of micro-organisms within this ecosystem also facilitates horizontal transfer of antimicrobial resistance (AMR) genes to potential pathogenic bacteria. Over the past decades antibiotic susceptibility testing of specific indicator bacteria from the microbiome, such as Escherichia coli, has been the method of choice in most studies. These studies have greatly enlarged our understanding on the prevalence and distribution of AMR and associated risk factors. Recent studies using (functional) metagenomics, however, highlighted the unappreciated diversity of AMR genes in the human microbiome and identified genes that had not been described previously. Next to metagenomics, more targeted approaches such as polymerase chain reaction for detection and quantification of AMR genes within a population are promising, in particular for large-scale epidemiological screening. Here we present an overview of the indigenous microbiota as a reservoir of AMR genes, the current knowledge on this "resistome" and the recent and upcoming advances in the molecular diagnostic approaches to unravel this reservoir. PMID:23616784

  3. The human microbiome as a reservoir of antimicrobial resistance

    PubMed Central

    Penders, John; Stobberingh, Ellen E.; Savelkoul, Paul H. M.; Wolffs, Petra F. G.

    2013-01-01

    The gut microbiota is amongst the most densely populated microbial ecosystem on earth. While the microbiome exerts numerous health beneficial functions, the high density of micro-organisms within this ecosystem also facilitates horizontal transfer of antimicrobial resistance (AMR) genes to potential pathogenic bacteria. Over the past decades antibiotic susceptibility testing of specific indicator bacteria from the microbiome, such as Escherichia coli, has been the method of choice in most studies. These studies have greatly enlarged our understanding on the prevalence and distribution of AMR and associated risk factors. Recent studies using (functional) metagenomics, however, highlighted the unappreciated diversity of AMR genes in the human microbiome and identified genes that had not been described previously. Next to metagenomics, more targeted approaches such as polymerase chain reaction for detection and quantification of AMR genes within a population are promising, in particular for large-scale epidemiological screening. Here we present an overview of the indigenous microbiota as a reservoir of AMR genes, the current knowledge on this “resistome” and the recent and upcoming advances in the molecular diagnostic approaches to unravel this reservoir. PMID:23616784

  4. Relationship of Antimicrobial Control Policies and Hospital and Infection Control Characteristics to Antimicrobial Resistance Rates

    PubMed Central

    Larson, Elaine L.; Quiros, Dave; Giblin, Tara; Lin, Susan

    2007-01-01

    Background Antibiotic misuse and noncompliance with infection control precautions have contributed to increasing levels of antimicrobial resistance in hospitals. Objectives To assess the extent to which resistance is monitored in infection control programs and to correlate resistance rates with characteristics of antimicrobial control policies, provider attitudes and practices, and systems-level indicators of implementation of the hand hygiene guideline of the Centers for Disease Control and Prevention. Methods An on-site survey of intensive care unit staff and infection control directors of 33 hospitals in the United States was conducted. The following data were collected: antimicrobial control policies; rates during the previous 12 months of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and ceftazidime-resistant Klebsiella pneumoniae; an implementation score of systems-level efforts to implement the guideline; staff attitudes toward practice guidelines; and observations of staff hand hygiene. Variables associated with resistance rates were examined for independent effects by using logistic regression. Results Resistance rates for S aureus, enterococci, and K pneumoniae were 52.5%, 18.2%, and 16.0%, respectively. Ten (30.3%) hospitals had an antibiotic control policy. No statistically significant correlation was observed between staff attitudes toward practice guidelines, observed hand hygiene behavior, or having an antibiotic use policy and resistance rates. In logistic regression analysis, higher scores on measures of systems-level efforts to implement the guideline were associated with lower rates of resistant S aureus and enterococci (P=.046). Conclusions Organizational-level factors independent of the practices of individual clinicians may be associated with rates of antimicrobial resistance. PMID:17322010

  5. Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China.

    PubMed

    Cheng, Vincent C C; Wong, Sally C Y; Ho, Pak-Leung; Yuen, Kwok-Yung

    2015-02-01

    Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for

  6. Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China

    PubMed Central

    Cheng, Vincent CC; Wong, Sally CY; Ho, Pak-Leung; Yuen, Kwok-Yung

    2015-01-01

    Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for

  7. Antimicrobial resistance of Salmonella enterica isolated from bulk tank milk and milk filters in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella isolates were recovered from bulk tank milk as part of the National Animal Health Monitoring System (NAHMS) Dairy 2002 and 2007 surveys. In-line milk filters were also tested in the 2007 survey. The objective of this study was to determine the prevalence of antimicrobial resistance among ...

  8. Longitudinal study of antimicrobial resistance among Escherichia coli isolated from integrated multi-site cohorts of humans and swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We examined the relationship between the prevalence of antimicrobial-resistant (AR) E. coli isolated from human wastewater and swine fecal samples and the risk factors: (host species, production type (swine), vocation (human swine workers, non-workers, and slaughter-plant workers), and season) in a ...

  9. Effect of Antimicrobial Use in Agricultural Animals on Drug-resistant Foodborne Campylobacteriosis in Humans: A Systematic Literature Review.

    PubMed

    McCrackin, M A; Helke, Kristi L; Galloway, Ashley M; Poole, Ann Z; Salgado, Cassandra D; Marriott, Bernadette P

    2016-10-01

    Controversy continues concerning antimicrobial use in food animals and its relationship to drug-resistant infections in humans. We systematically reviewed published literature for evidence of a relationship between antimicrobial use in agricultural animals and drug-resistant foodborne campylobacteriosis in humans. Based on publications from the United States (U.S.), Canada and Denmark from 2010 to July 2014, 195 articles were retained for abstract review, 50 met study criteria for full article review with 36 retained for which data are presented. Two publications reported increase in macrolide resistance of Campylobacter coli isolated from feces of swine receiving macrolides in feed, and one of these described similar findings for tetracyclines and fluoroquinolones. A study in growing turkeys demonstrated increased macrolide resistance associated with therapeutic dosing with Tylan® in drinking water. One publication linked tetracycline-resistant C. jejuni clone SA in raw cow's milk to a foodborne outbreak in humans. No studies that identified farm antimicrobial use also traced antimicrobial-resistant Campylobacter from farm to fork. Recent literature confirms that on farm antibiotic selection pressure can increase colonization of animals with drug-resistant Campylobacter spp. but is inadequately detailed to establish a causal relationship between use of antimicrobials in agricultural animals and prevalence of drug-resistant foodborne campylobacteriosis in humans. PMID:26580432

  10. Antimicrobial Resistance in Mycobacterium tuberculosis: The Odd One Out.

    PubMed

    Eldholm, Vegard; Balloux, François

    2016-08-01

    Antimicrobial resistance (AMR) threats are typically represented by bacteria capable of extensive horizontal gene transfer (HGT). One clear exception is Mycobacterium tuberculosis (Mtb). It is an obligate human pathogen with limited genetic diversity and a low mutation rate which lacks any evidence for HGT. Such features should, in principle, reduce its ability to rapidly evolve AMR. We identify key features in its biology and epidemiology that allow it to overcome its low adaptive potential. We focus in particular on its innate resistance to drugs, its unusual life cycle, including an often extensive latent phase, and its ability to shelter from exposure to antimicrobial drugs within cavities it induces in the lungs. PMID:27068531

  11. Fate and transport of antimicrobials and antimicrobial resistance genes in soil and runoff following land application of swine slurry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the use of antimicrobials in livestock production, residual antimicrobials and antimicrobial resistance genes (ARGs) could enter the environment following the land application of animal wastes and could further contaminate surface and groundwater. The objective of this study was to determine ...

  12. Diversity of plasmids and antimicrobial resistance genes in multidrug-resistant Escherichia coli isolated from healthy companion animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence and transfer of antimicrobial resistance genes from commensal bacteria in companion animals to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. The purpose of this study was to determine antimicrobial resistance gene content and the presence of gene...

  13. Strategies for achieving global collective action on antimicrobial resistance

    PubMed Central

    Caleo, Grazia M; Daulaire, Nils; Elbe, Stefan; Matsoso, Precious; Mossialos, Elias; Rizvi, Zain; Røttingen, John-Arne

    2015-01-01

    Abstract Global governance and market failures mean that it is not possible to ensure access to antimicrobial medicines of sustainable effectiveness. Many people work to overcome these failures, but their institutions and initiatives are insufficiently coordinated, led and financed. Options for promoting global collective action on antimicrobial access and effectiveness include building institutions, crafting incentives and mobilizing interests. No single option is sufficient to tackle all the challenges associated with antimicrobial resistance. Promising institutional options include monitored milestones and an inter-agency task force. A global pooled fund could be used to craft incentives and a special representative nominated as an interest mobilizer. There are three policy components to the problem of antimicrobials – ensuring access, conservation and innovation. To address all three components, the right mix of options needs to be matched with an effective forum and may need to be supported by an international legal framework. PMID:26668439

  14. Strategies for achieving global collective action on antimicrobial resistance.

    PubMed

    Hoffman, Steven J; Caleo, Grazia M; Daulaire, Nils; Elbe, Stefan; Matsoso, Precious; Mossialos, Elias; Rizvi, Zain; Røttingen, John-Arne

    2015-12-01

    Global governance and market failures mean that it is not possible to ensure access to antimicrobial medicines of sustainable effectiveness. Many people work to overcome these failures, but their institutions and initiatives are insufficiently coordinated, led and financed. Options for promoting global collective action on antimicrobial access and effectiveness include building institutions, crafting incentives and mobilizing interests. No single option is sufficient to tackle all the challenges associated with antimicrobial resistance. Promising institutional options include monitored milestones and an inter-agency task force. A global pooled fund could be used to craft incentives and a special representative nominated as an interest mobilizer. There are three policy components to the problem of antimicrobials--ensuring access, conservation and innovation. To address all three components, the right mix of options needs to be matched with an effective forum and may need to be supported by an international legal framework. PMID:26668439

  15. The Evolving Role of Antimicrobial Stewardship in Management of Multidrug Resistant Infections.

    PubMed

    Goff, Debra A; File, Thomas M

    2016-06-01

    This article summarizes the current literature describing how antimicrobial stewardship interventions impact antimicrobial resistance. Discussion includes why we need stewardship, how to collaborate with team members, and the evidence of stewardship's impact on resistance. PMID:27208772

  16. Detection of Rare Antimicrobial Resistance Profiles by Active and Passive Surveillance Approaches

    PubMed Central

    Mather, Alison E.; Reeve, Richard; Mellor, Dominic J.; Matthews, Louise; Reid-Smith, Richard J.; Haydon, Daniel T.; Reid, Stuart W. J.

    2016-01-01

    Antimicrobial resistance (AMR) surveillance systems are generally not specifically designed to detect emerging resistances and usually focus primarily on resistance to individual drugs. Evaluating the diversity of resistance, using ecological metrics, allows the assessment of sampling protocols with regard to the detection of rare phenotypes, comprising combinations of resistances. Surveillance data of phenotypic AMR of Canadian poultry Salmonella Heidelberg and swine Salmonella Typhimurium var. 5- were used to contrast active (representative isolates derived from healthy animals) and passive (diagnostic isolates) surveillance and assess their suitability for detecting emerging resistance patterns. Although in both datasets the prevalences of resistance to individual antimicrobials were not significantly different between the two surveillance systems, analysis of the diversity of entire resistance phenotypes demonstrated that passive surveillance of diagnostic isolates detected more unique phenotypes. Whilst the most appropriate surveillance method will depend on the relevant objectives, under the conditions of this study, passive surveillance of diagnostic isolates was more effective for the detection of rare and therefore potentially emerging resistance phenotypes. PMID:27391966

  17. Resistance to Antimicrobial Peptides and Stress Response in Mycoplasma pulmonis

    PubMed Central

    Fehri, Lina Fassi; Sirand-Pugnet, Pascal; Gourgues, Géraldine; Jan, Gwenaël; Wróblewski, Henri; Blanchard, Alain

    2005-01-01

    Antimicrobial peptides are widely distributed in nature, and in vertebrates, they play a key function in the innate immune defense system. It is generally agreed that these molecules may provide new antibiotics with therapeutic value. However, there are still many unsolved questions regarding the mechanisms underlying their antimicrobial activity as well as the mechanisms of resistance evolved by microorganisms against these molecules. The second point was addressed in this study. After determining the activity of 10 antimicrobial peptides against Mycoplasma pulmonis, a murine respiratory pathogen, the development of resistance was investigated. Following in vitro selection using subinhibitory concentrations of peptides, clones of this bacterium showing increased resistance to melittin or gramicidin D were obtained. For some of the clones, a cross-resistance was observed between these two peptides, in spite of their deep structural differences, and also with tetracycline. A proteomic analysis suggested that the stress response in these clones was constitutively activated, and this was confirmed by finding mutations in the hrcA gene; in mycoplasmas, bacteria which lack alternative sigma factors, the HrcA protein is supposed to play a key role as a negative regulator of heat shock proteins. By complementation of the hrcA mutants with the wild-type gene, the initial MICs of melittin and gramicidin D decreased to values close to the initial ones. This indicates that the resistance of M. pulmonis to these two antimicrobial peptides could result from a stress response involving HrcA-regulated genes. PMID:16189093

  18. High frequency of antimicrobial resistance of diarrheagenic E. coli in Peruvian infants

    PubMed Central

    Ochoa, Theresa J.; Ruiz, Joaquím; Molina, Margarita; del Valle, Luis J.; O, Martha Vargas; Gil, Ana I; Ecker, Lucie; Barletta, Francesca; Hall, Eric R.; Cleary, Thomas G.; Lanata, Claudio F.

    2010-01-01

    In a prospective passive diarrhea surveillance cohort study of 1034 infants of low-socioeconomic communities in Lima, Peru we determined the prevalence and antimicrobial susceptibility of the diarrheagenic Escherichia coli. The prevalence of diarrheagenic E. coli was 29% (161/557) in children with gastroenteritis and 30% (58/195) in the control group without diarrhea. The most common E. coli pathogens in diarrhea were enteroaggregative-EAEC (14%), enteropathogenic-EPEC (7%), diffusely adherent-DAEC (4%) and enterotoxigenic E.coli-ETEC (4%). Diarrheagenic E. coli as a group exhibited high levels of antimicrobial resistance in diarrheal cases to ampicillin-85%, cotrimoxazole-79%, tetracycline-65% and nalidixic acid-28%. Among the individual E. coli groups in diarrhea, DAEC and EAEC exhibited significant higher frequency of resistance to ampicillin, cotrimoxazole, tetracycline and nalidixic acid, than EPEC and ETEC. Antimicrobial resistance to ampicillin and cotrimoxazole were more frequent in E. coli isolated from diarrheal samples than controls, reflecting the greater antibiotic exposure in patients with gastroenteritis. PMID:19635887

  19. The Antimicrobial Resistance Crisis: Causes, Consequences, and Management

    PubMed Central

    Michael, Carolyn Anne; Dominey-Howes, Dale; Labbate, Maurizio

    2014-01-01

    The antimicrobial resistance (AMR) crisis is the increasing global incidence of infectious diseases affecting the human population, which are untreatable with any known antimicrobial agent. This crisis will have a devastating cost on human society as both debilitating and lethal diseases increase in frequency and scope. Three major factors determine this crisis: (1) the increasing frequency of AMR phenotypes among microbes is an evolutionary response to the widespread use of antimicrobials; (2) the large and globally connected human population allows pathogens in any environment access to all of humanity; and (3) the extensive and often unnecessary use of antimicrobials by humanity provides the strong selective pressure that is driving the evolutionary response in the microbial world. Of these factors, the size of the human population is least amenable to rapid change. In contrast, the remaining two factors may be affected, so offering a means of managing the crisis: the rate at which AMR, as well as virulence factors evolve in microbial world may be slowed by reducing the applied selective pressure. This may be accomplished by radically reducing the global use of current and prospective antimicrobials. Current management measures to legislate the use of antimicrobials and to educate the healthcare world in the issues, while useful, have not comprehensively addressed the problem of achieving an overall reduction in the human use of antimicrobials. We propose that in addition to current measures and increased research into new antimicrobials and diagnostics, a comprehensive education program will be required to change the public paradigm of antimicrobial usage from that of a first line treatment to that of a last resort when all other therapeutic options have failed. PMID:25279369

  20. ASSOCIATION OF ANTIMICROBIAL RESISTANCE PATTERNS AND REPORTED USAGE OF ANTIMICROBIALS IN COMMERCIAL GROWING PIGS PRODUCTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between microbial use and the development of resistance to antimicrobials has been demonstrated through both external models and has been observed clinically. However, the strength of this relationship in practical production systems has not been clearly quantified. We designed th...

  1. Acinetobacter baumannii: evolution of antimicrobial resistance-treatment options.

    PubMed

    Doi, Yohei; Murray, Gerald L; Peleg, Anton Y

    2015-02-01

    The first decade of the 20th century witnessed a surge in the incidence of infections due to several highly antimicrobial-resistant bacteria in hospitals worldwide. Acinetobacter baumannii is one such organism that turned from an occasional respiratory pathogen into a major nosocomial pathogen. An increasing number of A. baumannii genome sequences have broadened our understanding of the genetic makeup of these bacteria and highlighted the extent of horizontal transfer of DNA. Animal models of disease combined with bacterial mutagenesis have provided some valuable insights into mechanisms of A. baumannii pathogenesis. Bacterial factors known to be important for disease include outer membrane porins, surface structures including capsule and lipopolysaccharide, enzymes such as phospholipase D, iron acquisition systems, and regulatory proteins. A. baumannii has a propensity to accumulate resistance to various groups of antimicrobial agents. In particular, carbapenem resistance has become commonplace, accounting for the majority of A. baumannii strains in many hospitals today. Carbapenem-resistant strains are often resistant to all other routinely tested agents. Treatment of carbapenem-resistant A. baumannii infection therefore involves the use of combinations of last resort agents such as colistin and tigecycline, but the efficacy and safety of these approaches are yet to be defined. Antimicrobial-resistant A. baumannii has high potential to spread among ill patients in intensive care units. Early recognition and timely implementation of appropriate infection control measures is crucial in preventing outbreaks. PMID:25643273

  2. Geographical Patterns in Antimicrobial Resistance of Acinetobacter in Clinical Isolates

    PubMed Central

    Sehgal, Sonal; Prakash, S. Krishna

    2014-01-01

    Objectives: Acinetobacter spp. has emerged as a threat to the healthcare workers throughout the globe, owing to its property of multidrug resistance. The aim of the present study was to evaluate the antimicrobial resistance patterns of Acinetobacter spp. among indoor and out patients in our hospital and compare the resistance patterns in India and abroad. Materials and Methods: In this retrospective study, which was carried out between Over a period of one year, a total of 5593 clinical specimens of pus and purulent fluids were examined and antimicrobial resistance pattern for Acinetobacter spp. using Modified Stoke’s were evaluated. Also a comparison was done with the other similar studies. Statistical Analysis: Using the proportions of sensitive and resistant, the statistical analysis was done. The total, mean and percentage were calculated by using SPSS. Results: A high level of antimicrobial multidrug-resistance was found in almost all the clinical isolate. Our study was also found to be concordant with the results of other studies. Conclusion: There is an emerging need for identification of the genes and mechanisms for multidrug resistance among Acinetobacter spp. PMID:24959441

  3. Antimicrobial Resistance in Campylobacter Isolates Recovered from Chicken Carcass Rinsates in 2007

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Since the 1990’s there has been increasing concern regarding the development of antimicrobial resistance among food borne bacteria. To monitor resistance trends in food borne bacteria, the U.S. National Antimicrobial Resistance Monitoring System (NARMS) tracks antimicrobial susceptib...

  4. Repeated nationwide point-prevalence surveys of antimicrobial use in Swedish hospitals: data for actions 2003-2010.

    PubMed

    Skoog, Gunilla; Struwe, Johan; Cars, Otto; Hanberger, Håkan; Odenholt, Inga; Prag, Mårten; Skärlund, Katarina; Ulleryd, Peter; Erntell, Mats

    2016-06-23

    This study sought to analyse antimicrobial pressure, indications for treatment, and compliance with treatment recommendations and to identify possible problem areas where inappropriate use could be improved through interventions by the network of the local Swedish Strategic Programme Against Antibiotic Resistance (Strama) groups. Five point-prevalence surveys were performed in between 49 and 72 participating hospitals from 2003 to 2010. Treatments were recorded for 19 predefined diagnosis groups and whether they were for community-acquired infection, hospital-acquired infection, or prophylaxis. Approximately one-third of inpatients were treated with antimicrobials. Compliance with guidelines for treatment of community-acquired pneumonia with narrow-spectrum penicillin was 17.0% during baseline 2003-2004, and significantly improved to 24.2% in 2010. Corresponding figures for quinolone use in uncomplicated cystitis in women were 28.5% in 2003-2004, and significantly improved, decreasing to 15.3% in 2010. The length of surgical prophylaxis improved significantly when data for a single dose and 1 day were combined, from 56.3% in 2003-2004 to 66.6% in 2010. Improved compliance was possibly the effect of active local feedback, repeated surveys, and increasing awareness of antimicrobial resistance. Strama groups are important for successful local implementation of antimicrobial stewardship programs in Sweden. PMID:27367646

  5. Strategies and molecular tools to fight antimicrobial resistance: resistome, transcriptome, and antimicrobial peptides

    PubMed Central

    Tavares, Letícia S.; Silva, Carolina S. F.; de Souza, Vinicius C.; da Silva, Vânia L.; Diniz, Cláudio G.; Santos, Marcelo O.

    2013-01-01

    The increasing number of antibiotic resistant bacteria motivates prospective research toward discovery of new antimicrobial active substances. There are, however, controversies concerning the cost-effectiveness of such research with regards to the description of new substances with novel cellular interactions, or description of new uses of existing substances to overcome resistance. Although examination of bacteria isolated from remote locations with limited exposure to humans has revealed an absence of antibiotic resistance genes, it is accepted that these genes were both abundant and diverse in ancient living organisms, as detected in DNA recovered from Pleistocene deposits (30,000 years ago). Indeed, even before the first clinical use of antibiotics more than 60 years ago, resistant organisms had been isolated. Bacteria can exhibit different strategies for resistance against antibiotics. New genetic information may lead to the modification of protein structure affecting the antibiotic carriage into the cell, enzymatic inactivation of drugs, or even modification of cellular structure interfering in the drug-bacteria interaction. There are still plenty of new genes out there in the environment that can be appropriated by putative pathogenic bacteria to resist antimicrobial agents. On the other hand, there are several natural compounds with antibiotic activity that may be used to oppose them. Antimicrobial peptides (AMPs) are molecules which are wide-spread in all forms of life, from multi-cellular organisms to bacterial cells used to interfere with microbial growth. Several AMPs have been shown to be effective against multi-drug resistant bacteria and have low propensity to resistance development, probably due to their unique mode of action, different from well-known antimicrobial drugs. These substances may interact in different ways with bacterial cell membrane, protein synthesis, protein modulation, and protein folding. The analysis of bacterial transcriptome

  6. Molecular Characterization of Multidrug Resistant Hospital Isolates Using the Antimicrobial Resistance Determinant Microarray

    PubMed Central

    Leski, Tomasz A.; Vora, Gary J.; Barrows, Brian R.; Pimentel, Guillermo; House, Brent L.; Nicklasson, Matilda; Wasfy, Momtaz; Abdel-Maksoud, Mohamed; Taitt, Chris Rowe

    2013-01-01

    Molecular methods that enable the detection of antimicrobial resistance determinants are critical surveillance tools that are necessary to aid in curbing the spread of antibiotic resistance. In this study, we describe the use of the Antimicrobial Resistance Determinant Microarray (ARDM) that targets 239 unique genes that confer resistance to 12 classes of antimicrobial compounds, quaternary amines and streptothricin for the determination of multidrug resistance (MDR) gene profiles. Fourteen reference MDR strains, which either were genome, sequenced or possessed well characterized drug resistance profiles were used to optimize detection algorithms and threshold criteria to ensure the microarray's effectiveness for unbiased characterization of antimicrobial resistance determinants in MDR strains. The subsequent testing of Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae hospital isolates revealed the presence of several antibiotic resistance genes [e.g. belonging to TEM, SHV, OXA and CTX-M classes (and OXA and CTX-M subfamilies) of β-lactamases] and their assemblages which were confirmed by PCR and DNA sequence analysis. When combined with results from the reference strains, ∼25% of the ARDM content was confirmed as effective for representing allelic content from both Gram-positive and –negative species. Taken together, the ARDM identified MDR assemblages containing six to 18 unique resistance genes in each strain tested, demonstrating its utility as a powerful tool for molecular epidemiological investigations of antimicrobial resistance in clinically relevant bacterial pathogens. PMID:23936031

  7. Antimicrobial resistance, virulence, and phylogenetic characteristics of Escherichia coli isolates from clinically healthy swine.

    PubMed

    Lay, Khin Khin; Koowattananukul, Chailai; Chansong, Nisit; Chuanchuen, Rungtip

    2012-11-01

    A total of 344 commensal Escherichia coli isolates from clinically healthy pigs were examined for antimicrobial resistance phenotypes, class 1 integrons, resistance genes, virulence gene profile, and phylogenetic groups. The majority of E. coli isolates were resistant to tetracycline (96.2%) and ampicillin (91.6%). Up to 98% were multidrug resistant. Seventy-three percent of the isolates carried class 1 integrons. Inserted-gene cassette arrays in variable regions included incomplete sat, aadA22, aadA1, dfrA12-aadA2, and sat-psp-aadA2, of which the aadA2 gene cassette was most prevalent (42.9%). Horizontal transfer was detected in eight E. coli isolates carrying class 1 integrons with dfrA12-aadA2 gene cassette array. Sixteen resistance genes were identified among the E. coli isolates with corresponding resistance phenotype. Ten virulence genes (including elt, estA, estB, astA, faeG, fasA, fedA, eaeA, paa, and sepA) were detected, of which fasA was most commonly found (98.3%). Most of the E. coli isolates belonged to phylogenetic group B1. Significantly positive associations were observed between some virulence genes and some resistance phenotypes and genotypes (p < 0.05). The results support a finding that commensal E. coli have a role as reservoirs for antimicrobial resistance-encoding genes and virulence determinants. PMID:22953741

  8. Antimicrobial Photodynamic Therapy for Methicillin-Resistant Staphylococcus aureus Infection

    PubMed Central

    Fu, Xiu-jun; Fang, Yong; Yao, Min

    2013-01-01

    Nowadays methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common multidrug resistant bacteria both in hospitals and in the community. In the last two decades, there has been growing concern about the increasing resistance to MRSA of the most potent antibiotic glycopeptides. MRSA infection poses a serious problem for physicians and their patients. Photosensitizer-mediated antimicrobial photodynamic therapy (PDT) appears to be a promising and innovative approach for treating multidrug resistant infection. In spite of encouraging reports of the use of antimicrobial PDT to inactivate MRSA in large in vitro studies, there are only few in vivo studies. Therefore, applying PDT in the clinic for MRSA infection is still a long way off. PMID:23555074

  9. ANTIMICROBIAL RESISTANCE RATES IN CAMPYLOBACTER ISOLATES DERIVED FROM SWINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter, a microaerophilic gram-negative rod, is a major foodborne pathogen and commonly present in swine intestinal tract without causing any clinical disease. In this project, we investigated the antimicrobial resistance profiles of fecal Campylobacter isolates (n= 194) obtained from a swin...

  10. Evaluation of antimicrobial resistance of bovine bacteria to antibiotics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance (AMR) is one of the most formidable threats to human medicine today. Therefore, the research objective is to evaluate the susceptibility of Staphylococcus species isolated from beef cows to 12 antibiotics commonly used in treating human and animal infections. This research w...

  11. Microbial Ecology of and Antimicrobial Resistance in Stored Swine Manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial compounds such as tylosin have been commonly used as feed additives for domestic animals to reduce infection and promote growth. Recent reports have suggested such feeding practices may result in increased microbial resistance to antibiotics, which can have an impact on human health. ...

  12. Antimicrobial resistance and genetic characterization of fluoroquinolone resistance of Pseudomonas aeruginosa isolated from canine infections.

    PubMed

    Rubin, J; Walker, R D; Blickenstaff, K; Bodeis-Jones, S; Zhao, S

    2008-09-18

    Infections with antimicrobial-resistant bacteria are a great challenge in both human and veterinary medicine. The purpose of this study was to determine antimicrobial susceptibility of 106 strains of Pseudomonas aeruginosa isolated from dogs with otitis and pyoderma from 2003 to 2006 in the United States. Three antimicrobial panels, including 6 classes and 32 antimicrobial agents, were used. A wide range of susceptibility patterns were noted with some isolates being resistant to between 8 and 28 (mean 16) of the antimicrobials tested. Among the beta-lactams, all isolates were resistant to ampicillin, cefoxitin, cefpodoxime, cephalothin and cefazolin followed by amoxicillin/clavulanic acid (99%), ceftiofur (97%), ceftriaxone (39%), cefotaxime (26%), and cefotaxime/clavulanic acid (20%), whereas less than 7% of isolates were resistant to ceftazidime/clavulanic acid, ceftazidime, piperacillin/tazobactam or cefepime. Two isolates were resistant to the carbapenems. Among the quinolones and fluoroquinolones, the most isolates were resistant to naladixic acid (96%), followed by orbifloxacin (52%), difloxacin (43%), enrofloxacin (31%), marbofloxacin (27%), gatifloxacin (23%), levofloxacin (21%), and ciprofloxacin (16%). Among the aminoglycosides, the most resistance was seen to kanamycin (90%), followed by streptomycin (69%), gentamicin (7%), and amikacin (3%). Of the remaining antimicrobials 100% of the isolates were resistant to chloramphenicol followed by tetracycline (98%), trimethoprim/sulfamethoxazole (57%), and sulfisoxazole (51%). Point mutations were present in gyrA, gyrB, parC, and/or parE genes among 34 of the 102 naladixic acid-resistant isolates. Two isolates contained class 1 integrons carrying aadA gene conferring streptomycin and spectinomycin resistance. The findings suggest that many antimicrobial agents commonly used in companion animals may not constitute appropriate therapy for canine pseudomonas infections. PMID:18395369

  13. Australian Group on Antimicrobial Resistance Australian Enterobacteriaceae Sepsis Outcome Programme annual report, 2014.

    PubMed

    Bell, Jan M; Turnidge, John D; Coombs, Geoffrey W; Daley, Denise A; Gottlieb, Thomas; Robson, Jenny; George, Narelle

    2016-01-01

    The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2014 survey was the second year to focus on blood stream infections. During 2014, 5,798 Enterobacteriaceae species isolates were tested using commercial automated methods (Vitek 2, BioMérieux; Phoenix, BD) and results were analysed using the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints (January 2015). Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 9.0%/9.0% of Escherichia coli (CLSI/EUCAST criteria) and 7.8%/7.8% of Klebsiella pneumoniae, and 8.0%/8.0% K. oxytoca. Non-susceptibility rates to ciprofloxacin were 10.4%/11.6% for E. coli, 5.0%/7.7% for K. pneumoniae, 0.4%/0.4% for K. oxytoca, and 3.5%/6.5% in Enterobacter cloacae. Resistance rates to piperacillin-tazobactam were 3.2%/6.8%, 4.8%/7.2%, 11.1%/11.5%, and 19.0%/24.7% for the same 4 species respectively. Fourteen isolates were shown to harbour a carbapenemase gene, 7 blaIMP-4, 3 blaKPC-2, 3 blaVIM-1, 1 blaNDM-4, and 1 blaOXA-181-lke. PMID:27522134

  14. High prevalence of multidrug-resistance uropathogenic Escherichia coli strains, Isfahan, Iran

    PubMed Central

    Dehbanipour, Razieh; Rastaghi, Sedighe; Sedighi, Mansour; Maleki, Nafiseh; Faghri, Jamshid

    2016-01-01

    Background and Objectives: Urinary tract infection (UTI) is one of the most frequent infectious diseases and can occur in all age groups. Escherichia coli is the main cause of this infection. Multiple resistances to antimicrobial agents are increasing quickly in E. coli isolates and may complicate therapeutic strategies for UTI. The aim of this study was to determine the antibiotic resistance pattern and the multidrug-resistance (MDR) phenotypes in uropathogenic E. coli (UPEC). Materials and Methods: A total of 135 UPEC isolates were collected from both outpatients (91 isolates) and inpatients (44 isolates) between September, 2012 and February, 2013. In order to determine the MDR among UPEC isolates, we have tested 15 antimicrobial agents and antibiotic susceptibility was done by Kirby-Bauer disk diffusion method. Results: The percentage of MDR isolates (resistant to at least three drug classes such as aminoglycosides, fluoroquinolones, penicillins, cephalosporins, or carbapenems) was 68% in the inpatients and 61% in the outpatients. Antibiotic resistance to ampicillin, ceftazidim, nalidixic acid, and trimethoprim/sulfamethoxazole were higher than 50%. Amikacin, nitrofurantoin, and gentamicin showed markedly greater activity (89.1%, 85.9%, and 82.4% sensitivity, respectively) than other antimicrobial agents. Resistance to meropenem did show either in outpatients or in inpatients. Interpretation and Conclusions: The high prevalence of drug resistance among UTI patients calls for continuous monitoring of the incidence of drug resistance for appropriate empiric selection of antibiotic therapy. Empirical treatment of UTIs should be relied on susceptibility patterns from local studies. PMID:27003964

  15. Relationship between super antigenicity, antimicrobial resistance and origin of Staphylococcus aureus isolated

    PubMed Central

    Corredor Arias, Luisa Fernanda; Luligo Espinal, Jenna Samara; Santacruz Ibarra, Jorge Javier; Álvarez Aldana, Adalucy

    2016-01-01

    Introduction: Staphylococcus aureus is a pathogen that causes food poisoning as well as hospital and community acquired infections. Objective: Establish the profile of superantigen genes among hospital isolates in relation to clinical specimen type, susceptibility to antibiotics and hospital or community acquisition. Methods: Eighty one isolates obtained from patients at Colombian hospital, were classified by antimicrobial susceptibility, specimen type and hospital or community acquired . The PCR uniplex and multiplex was used for detection of 22 superantigen genes (18 enterotoxins, tsst-1 and three exfoliative toxins). Results: Ninety five point one percent of isolates harbored one or more of the genes with an average of 5.6 genes. Prevalence of individual genes was variable and the most prevalent was seg (51.9%). Thirty nine genotypes were obtained, and the genotype gimnou (complete egc cluster) was the most prevalent alone (16.0%) and in association with other genes (13.6%). The correlation between presence of superantigens and clinical specimen or antimicrobial susceptibility showed no significant difference. But there was significant difference between presence of superantigens and the origin of the isolates, hospital or community acquired (p= 0.049). Conclusions: The results show the variability of the superantigen genes profile in hospital isolates and shows no conclusive relationship with the clinical sample type and antimicrobial susceptibility, but there was correlation with community and hospital isolates. The analysis of the interplay between virulence, epidemic and antibiotic resistance of bacterial populations is needed to predict the future of infectious diseases. PMID:27226659

  16. Susceptibility and resistance of ruminal bacteria to antimicrobial feed additives.

    PubMed Central

    Nagaraja, T G; Taylor, M B

    1987-01-01

    Susceptibility and resistance of ruminal bacterial species to avoparcin, narasin, salinomycin, thiopeptin, tylosin, virginiamycin, and two new ionophore antibiotics, RO22-6924/004 and RO21-6447/009, were determined. Generally, antimicrobial compounds were inhibitory to gram-positive bacteria and those bacteria that have gram-positive-like cell wall structure. MICs ranged from 0.09 to 24.0 micrograms/ml. Gram-negative bacteria were resistant at the highest concentration tested (48.0 micrograms/ml). On the basis of their fermentation products, ruminal bacteria that produce lactic acid, butyric acid, formic acid, or hydrogen were susceptible and bacteria that produce succinic acid or ferment lactic acid were resistant to the antimicrobial compounds. Selenomonas ruminantium was the only major lactic acid-producing bacteria resistant to all the antimicrobial compounds tested. Avoparcin and tylosin appeared to be less inhibitory (MIC greater than 6.0 micrograms/ml) than the other compounds to the two major lactic acid-producing bacteria, Streptococcus bovis and Lactobacillus sp. Ionophore compounds seemed to be more inhibitory (MIC, 0.09 to 1.50 micrograms/ml) than nonionophore compounds (MIC, 0.75 to 12.0 micrograms/ml) to the major butyric acid-producing bacteria. Treponema bryantii, an anaerobic rumen spirochete, was less sensitive to virginiamycin than to the other antimicrobial compounds. Ionophore compounds were generally bacteriostatic, and nonionophore compounds were bactericidal. The specific growth rate of Bacteroides ruminicola was reduced by all the antimicrobial compounds except avoparcin. The antibacterial spectra of the feed additives were remarkably similar, and it appears that MICs may not be good indicators of the potency of the compounds in altering ruminal fermentation characteristics. PMID:3116929

  17. Salmonella enterica Genomics and Antimicrobial Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is a prevalent food-borne pathogen and a model system for the study of virulence and pathogenesis. The development of DNA microarray technology has furthered investigation of genome organization that leads to the variations in Salmonella serotypes. There are over 2400 Salmonella serotypes...

  18. Salmonella enterica Genomics and Antimicrobial Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella is a prevalent food-borne pathogen and a model system for the study of virulence and pathogenesis. The development of DNA microarray technology has furthered investigation of complicated regulatory pathways used during survival and pathogenesis as well as genome organization that leads to...

  19. Antimicrobial use: Alternatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For over fifty years, antimicrobials have been used in food animal production to maintain animal health and to increase productivity. The resulting increase in antimicrobial resistance among enteric bacteria has created two principal concerns: 1) the prevalence of drug-resistant pathogens leaves th...

  20. Insect Antimicrobial Peptide Complexes Prevent Resistance Development in Bacteria

    PubMed Central

    Chernysh, Sergey; Gordya, Natalia; Suborova, Tatyana

    2015-01-01

    In recent decades much attention has been paid to antimicrobial peptides (AMPs) as natural antibiotics, which are presumably protected from resistance development in bacteria. However, experimental evolution studies have revealed prompt resistance increase in bacteria to any individual AMP tested. Here we demonstrate that naturally occurring compounds containing insect AMP complexes have clear advantage over individual peptide and small molecule antibiotics in respect of drug resistance development. As a model we have used the compounds isolated from bacteria challenged maggots of Calliphoridae flies. The compound isolated from blow fly Calliphora vicina was found to contain three distinct families of cell membrane disrupting/permeabilizing peptides (defensins, cecropins and diptericins), one family of proline rich peptides and several unknown antimicrobial substances. Resistance changes under long term selective pressure of the compound and reference antibiotics cefotaxime, meropenem and polymyxin B were tested using Escherichia coli, Klebsiella pneumonia and Acinetobacter baumannii clinical strains. All the strains readily developed resistance to the reference antibiotics, while no signs of resistance growth to the compound were registered. Similar results were obtained with the compounds isolated from 3 other fly species. The experiments revealed that natural compounds containing insect AMP complexes, in contrast to individual AMP and small molecule antibiotics, are well protected from resistance development in bacteria. Further progress in the research of natural AMP complexes may provide novel solutions to the drug resistance problem. PMID:26177023

  1. Emergent and evolving antimicrobial resistance cassettes in community-associated fusidic acid and meticillin-resistant Staphylococcus aureus.

    PubMed

    Ellington, Matthew J; Reuter, Sandra; Harris, Simon R; Holden, Matthew T G; Cartwright, Edward J; Greaves, Daniel; Gerver, Sarah M; Hope, Russell; Brown, Nicholas M; Török, M Estee; Parkhill, Julian; Köser, Claudio U; Peacock, Sharon J

    2015-05-01

    Fusidic acid is a topical and systemic antimicrobial used for the treatment of staphylococcal infections in hospitals and the community. Sales of fusidic acid and resistance rates among meticillin-resistant Staphylococcus aureus (MRSA) doubled between 1990 and 2001. For the following decade, fusidic acid resistance rates among isolates from Addenbrooke's Hospital (Cambridge, UK) were compared with national resistance rates from MRSA bacteraemia surveillance data and with antimicrobial sales data. Sales of fusidic acid remained relatively constant between 2002 and 2012, whilst fusidic acid resistance increased two- and four-fold in MRSA bacteraemias nationally and in MRSA isolates from Cambridge, respectively. A subgroup of MRSA resistant only to fusidic acid increased after 2006 by 5-fold amongst bacteraemias nationally and 17-fold (to 7.7% in 2012) amongst Cambridge MRSA isolates. All of the available local isolates from 2011 to 2012 (n=23) were acquired in the community, were not related epidemiologically and belonged to multilocus sequence typing (MLST) groups ST1, 5, 8, 45 or 149 as revealed from analysis of whole-genome sequence data. All harboured the fusC gene on one of six distinct staphylococcal cassette chromosome (SCC) elements, four of which were dual-resistance chimeras that encoded β-lactam and fusidic acid resistance. In summary, fusidic acid-resistant MRSA increased in prevalence during the 2000s with notable rises after 2006. The development of chimeric cassettes that confer dual resistance to β-lactams and fusidic acid demonstrates that the genetics underpinning resistance in community-associated MRSA are evolving. PMID:25769787

  2. Emergent and evolving antimicrobial resistance cassettes in community-associated fusidic acid and meticillin-resistant Staphylococcus aureus

    PubMed Central

    Ellington, Matthew J.; Reuter, Sandra; Harris, Simon R.; Holden, Matthew T.G.; Cartwright, Edward J.; Greaves, Daniel; Gerver, Sarah M.; Hope, Russell; Brown, Nicholas M.; Török, M. Estee; Parkhill, Julian; Köser, Claudio U.; Peacock, Sharon J.

    2015-01-01

    Fusidic acid is a topical and systemic antimicrobial used for the treatment of staphylococcal infections in hospitals and the community. Sales of fusidic acid and resistance rates among meticillin-resistant Staphylococcus aureus (MRSA) doubled between 1990 and 2001. For the following decade, fusidic acid resistance rates among isolates from Addenbrooke's Hospital (Cambridge, UK) were compared with national resistance rates from MRSA bacteraemia surveillance data and with antimicrobial sales data. Sales of fusidic acid remained relatively constant between 2002 and 2012, whilst fusidic acid resistance increased two- and four-fold in MRSA bacteraemias nationally and in MRSA isolates from Cambridge, respectively. A subgroup of MRSA resistant only to fusidic acid increased after 2006 by 5-fold amongst bacteraemias nationally and 17-fold (to 7.7% in 2012) amongst Cambridge MRSA isolates. All of the available local isolates from 2011 to 2012 (n = 23) were acquired in the community, were not related epidemiologically and belonged to multilocus sequence typing (MLST) groups ST1, 5, 8, 45 or 149 as revealed from analysis of whole-genome sequence data. All harboured the fusC gene on one of six distinct staphylococcal cassette chromosome (SCC) elements, four of which were dual-resistance chimeras that encoded β-lactam and fusidic acid resistance. In summary, fusidic acid-resistant MRSA increased in prevalence during the 2000s with notable rises after 2006. The development of chimeric cassettes that confer dual resistance to β-lactams and fusidic acid demonstrates that the genetics underpinning resistance in community-associated MRSA are evolving. PMID:25769787

  3. Antimicrobial susceptibility and analysis of macrolide resistance genes in Streptococcus pneumoniae isolated in Hamadan

    PubMed Central

    Mosleh, Mohammad Najafi; Gharibi, Marzieh; Alikhani, Mohammad Yousef; Saidijam, Massoud; Vakhshiteh, Faezeh

    2014-01-01

    Objective(s): Macrolide resistant Streptococcus pneumoniae pose an emerging problem globally. The aim of this study was to investigate the prevalence of ermB and mefA genes (macrolide resistant genes) by polymerase chain reaction (PCR) method and to detect drug resistance patterns of S. pneumoniae isolated from clinical samples to macrolides and other antibiotic agents by E-test method. Materials and Methods: Fifty five isolates of S. pneumoniae were obtained from clinical samples with microbial tests. The antibiotic susceptibility of isolates for erythromycin, azithromycin, clarithromycin, ceftazidime, ciprofloxacin and vancomycin were determined by E-test method. Genotypic antibiotic resistance pattern was determined by PCR with primer designed for ermB and mefA genes. Results: The number of S. pneumoniae isolates resistance to erythromycin, azithromycin, clarithromycin, ceftazidim, ciprofloxacin were 25.5%, 18.2%, 16.4%, 21.8% and 10.9%, respectively while no resistance to vancomycin was observed. The macrolide resistance genes of ermB and mefA were found in 10.9% and 18.2% of the isolates, respectively. Conclusion: The result of the current study suggests the necessity of evaluation the changes in MIC (minimum inhibitory concentration) values as well as genetic mutations to estimate the prevalence of the resistance antimicrobial agents in S. pneumoniae. PMID:25422753

  4. Molecular approaches to enhance surveillance of gonococcal antimicrobial resistance.

    PubMed

    Goire, Namraj; Lahra, Monica M; Chen, Marcus; Donovan, Basil; Fairley, Christopher K; Guy, Rebecca; Kaldor, John; Regan, David; Ward, James; Nissen, Michael D; Sloots, Theo P; Whiley, David M

    2014-03-01

    The best available data indicate that the world is heading towards a pandemic of extensively drug-resistant Neisseria gonorrhoeae. At the same time, clinical microbiology laboratories have moved away from using culture-based methods to diagnose gonorrhoea, thus undermining our ability to detect antimicrobial resistance (AMR) using current technologies. In this Opinion article, we discuss the problem of N. gonorrhoeae AMR, particularly emerging resistance to the cephalosporin ceftriaxone, outline current concerns about the surveillance of N. gonorrhoeae AMR and propose the use of molecular methods on a large scale to systematically enhance surveillance. PMID:24509781

  5. Highly variable patterns of antimicrobial resistance in commensal Escherichia coli isolates from pigs, sympatric rodents, and flies.

    PubMed

    Literak, Ivan; Dolejska, Monika; Rybarikova, Jana; Cizek, Alois; Strejckova, Pavla; Vyskocilova, Martina; Friedman, Miroslava; Klimes, Jiri

    2009-09-01

    Antimicrobial-resistant Escherichia coli strains from pigs, sympatric rodents, and flies from two large farms in the Czech Republic with different antibiotic exposure histories were characterized based on antimicrobial resistance genes, integrons, and macrorestriction DNA profiles. Isolates of E. coli were tested for susceptibility to 12 antimicrobial agents according to the standard disk diffusion method. In resistant isolates, polymerase chain reaction was used to detect antibiotic resistance genes, integrase genes, and gene cassettes. Pulsed-field gel electrophoresis (PFGE) was used for molecular subtyping of E. coli. In farm A (long-term use of amoxicillin only), 75% (n = 198), 65% (n = 49), 11% (n = 139), and 82% (n = 177) of E. coli isolates from piglets, sows, sympatric rodents, and flies, respectively, were antibiotic resistant. In farm B (various antibiotics commonly used), 53% (n = 154), 69% (n = 98), and 54% (n = 74) of E. coli isolates from piglets, sows, and sympatric rodents, respectively, were antibiotic resistant. In both farms, the highest resistance prevalence was to tetracycline, and resistance patterns of isolates were greatly variable. Isolates with the same resistance phenotype, genes, and PFGE profile were found in pigs and flies. Isolates from rodents showed unique PFGE profiles. Close contact of sympatric rodents and flies with pigs or their products was associated with colonization of rodents and flies with resistant bacteria or transfer of resistance genes found in pig intestinal flora. PMID:19728783

  6. Efficacy of triclosan as an antimicrobial hand soap and its potential impact on antimicrobial resistance: a focused review.

    PubMed

    Giuliano, Christopher A; Rybak, Michael J

    2015-03-01

    Triclosan is a synthetic biocide found in many household products, including antimicrobial hand soap. Levels of triclosan have been found throughout the environment and in human urine, blood, and even breast milk. Increasing levels of exposure to triclosan have led to concerns over the development of resistance to triclosan and cross-resistance to other antimicrobials. We performed a literature search to assess whether the widespread use of triclosan displays a favorable benefit: risk ratio, defined by evaluation of triclosan's efficacy as an antimicrobial hand soap and its potential effect on the development of antimicrobial resistance. Data from laboratory-based studies regarding the efficacy of triclosan are conflicting, although well-designed studies suggest no significant difference in efficacy over nonantimicrobial soap. In addition, when triclosan was introduced in a community setting, no beneficial effects were observed on the reduction of infections over nonantimicrobial soap. Resistance to triclosan and cross-resistance to antimicrobials have been consistently demonstrated in laboratory settings, although overall resistance rates and cross-resistance rates in the community setting are low. Based on the available evidence, the risk of potential antimicrobial resistance outweighs the benefit of widespread triclosan use in antimicrobial soaps. PMID:25809180

  7. 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. PMID:22029522

  8. Enhancing US-Japan Cooperation to Combat Antimicrobial Resistance

    PubMed Central

    2014-01-01

    The Global Health Security Agenda (GHSA) is aimed at preventing, detecting, and responding to infectious disease threats. To move toward these goals, the United States has committed to partner with at least 30 countries around the world. One of the objectives of the GHSA includes “[p]reventing the emergence and spread of antimicrobial drug resistant organisms.” Antimicrobial resistance (AMR) has become a growing global health security problem, with inappropriate use of antimicrobial medications in humans and animals and a lack of new antimicrobial medications contributing to this problem. While AMR is a growing global concern, working on it regionally can make this multifaceted problem more manageable. The United States and Japan, both world leaders in the life sciences, are close allies that have established cooperative programs in medical research and global health that can be used to work on combating AMR and advance the GHSA. Although the United States and Japan have cooperated on health issues in the past, their cooperation on the growing problem of AMR has been limited. Their existing networks, cooperative programs, and close relationships can and should be used to work on combating this expanding problem. PMID:25470465

  9. Enhancing US-Japan cooperation to combat antimicrobial resistance.

    PubMed

    Gerbin, C Sachi

    2014-01-01

    The Global Health Security Agenda (GHSA) is aimed at preventing, detecting, and responding to infectious disease threats. To move toward these goals, the United States has committed to partner with at least 30 countries around the world. One of the objectives of the GHSA includes "[p]reventing the emergence and spread of antimicrobial drug resistant organisms." Antimicrobial resistance (AMR) has become a growing global health security problem, with inappropriate use of antimicrobial medications in humans and animals and a lack of new antimicrobial medications contributing to this problem. While AMR is a growing global concern, working on it regionally can make this multifaceted problem more manageable. The United States and Japan, both world leaders in the life sciences, are close allies that have established cooperative programs in medical research and global health that can be used to work on combating AMR and advance the GHSA. Although the United States and Japan have cooperated on health issues in the past, their cooperation on the growing problem of AMR has been limited. Their existing networks, cooperative programs, and close relationships can and should be used to work on combating this expanding problem. PMID:25470465

  10. Search Engine for Antimicrobial Resistance: A Cloud Compatible Pipeline and Web Interface for Rapidly Detecting Antimicrobial Resistance Genes Directly from Sequence Data

    PubMed Central

    Rowe, Will; Baker, Kate S.; Verner-Jeffreys, David; Baker-Austin, Craig; Ryan, Jim J.; Maskell, Duncan; Pearce, Gareth

    2015-01-01

    Background Antimicrobial resistance remains a growing and significant concern in human and veterinary medicine. Current laboratory methods for the detection and surveillance of antimicrobial resistant bacteria are limited in their effectiveness and scope. With the rapidly developing field of whole genome sequencing beginning to be utilised in clinical practice, the ability to interrogate sequencing data quickly and easily for the presence of antimicrobial resistance genes will become increasingly important and useful for informing clinical decisions. Additionally, use of such tools will provide insight into the dynamics of antimicrobial resistance genes in metagenomic samples such as those used in environmental monitoring. Results Here we present the Search Engine for Antimicrobial Resistance (SEAR), a pipeline and web interface for detection of horizontally acquired antimicrobial resistance genes in raw sequencing data. The pipeline provides gene information, abundance estimation and the reconstructed sequence of antimicrobial resistance genes; it also provides web links to additional information on each gene. The pipeline utilises clustering and read mapping to annotate full-length genes relative to a user-defined database. It also uses local alignment of annotated genes to a range of online databases to provide additional information. We demonstrate SEAR’s application in the detection and abundance estimation of antimicrobial resistance genes in two novel environmental metagenomes, 32 human faecal microbiome datasets and 126 clinical isolates of Shigella sonnei. Conclusions We have developed a pipeline that contributes to the improved capacity for antimicrobial resistance detection afforded by next generation sequencing technologies, allowing for rapid detection of antimicrobial resistance genes directly from sequencing data. SEAR uses raw sequencing data via an intuitive interface so can be run rapidly without requiring advanced bioinformatic skills or

  11. Cultivable Bacterial Microbiota of Northern Bobwhite (Colinus virginianus): A New Reservoir of Antimicrobial Resistance?

    PubMed Central

    Su, Hongwen; McKelvey, Jessica; Rollins, Dale; Zhang, Michael; Brightsmith, Donald J.; Derr, James; Zhang, Shuping

    2014-01-01

    The northern bobwhite (Colinus virginianus) is an ecologically and economically important avian species. At the present time, little is known about the microbial communities associated with these birds. As the first step to create a quail microbiology knowledge base, the current study conducted an inventory of cultivable quail tracheal, crop, cecal, and cloacal microbiota and associated antimicrobial resistance using a combined bacteriology and DNA sequencing approach. A total of 414 morphologically unique bacterial colonies were selected from nonselective aerobic and anaerobic cultures, as well as selective and enrichment cultures. Analysis of the first 500-bp 16S rRNA gene sequences in conjunction with biochemical identifications revealed 190 non-redundant species-level taxonomic units, representing 160 known bacterial species and 30 novel species. The bacterial species were classified into 4 phyla, 14 orders, 37 families, and 59 or more genera. Firmicutes was the most commonly encountered phylum (57%) followed by Actinobacteria (24%), Proteobacteria (17%) and Bacteroidetes (0.02%). Extensive diversity in the species composition of quail microbiota was observed among individual birds and anatomical locations. Quail microbiota harbored several opportunistic pathogens, such as E. coli and Ps. aeruginosa, as well as human commensal organisms, including Neisseria species. Phenotypic characterization of selected bacterial species demonstrated a high prevalence of resistance to the following classes of antimicrobials: phenicol, macrolide, lincosamide, quinolone, and sulphate. Data from the current investigation warrant further investigation on the source, transmission, pathology, and control of antimicrobial resistance in wild quail populations. PMID:24937705

  12. Antimicrobial resistance profiles and mechanisms of resistance in Campylobacter jejuni isolates from pets.

    PubMed

    Acke, Els; McGill, Kevina; Quinn, Teresa; Jones, Boyd R; Fanning, Seamus; Whyte, Paul

    2009-01-01

    The presence of antimicrobial resistance in 51 Campylobacter jejuni isolates obtained from cats and dogs was determined by E-testing. Resistance to nalidixic acid (37.3% of isolates), ciprofloxacin (19.6%), tetracycline (13.7%), ampicillin (13.7%), erythromycin (11.8%), and chloramphenicol (5.9%) was detected. Resistance to two antimicrobials or more was present in 31.4% of isolates, and one isolate was resistant to all six antimicrobials. Of the isolates with ciprofloxacin and/or nalidixic acid resistance, 54.5% had the gyrA substitution Thr-86-Ile on sequencing. The tet o gene was detected in 75.0% isolates with high-level resistance to tetracycline. With the observed antimicrobial resistance in C. jejuni isolates from pets in this study, and the detection of identical mechanisms for quinolone and tetracycline resistance in pets and humans, pets should be considered a potential source of (multi)resistant C. jejuni infections in humans. PMID:19580444

  13. Antimicrobial resistance and virulence gene profiles in multi-drug resistant enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea.

    PubMed

    Smith, M G; Jordan, D; Chapman, T A; Chin, J J-C; Barton, M D; Do, T N; Fahy, V A; Fairbrother, J M; Trott, D J

    2010-10-26

    This study aimed to characterize antimicrobial resistance and virulence genes in multi-drug resistant enterotoxigenic Escherichia coli (ETEC) isolates (n=117) collected from porcine post-weaning diarrhoea cases in Australia (1999-2005). Isolates were serotyped, antibiogram-phenotyped for 12 antimicrobial agents and genotyped by PCR for 30 plasmid-mediated antimicrobial resistance genes (ARGs), 22 intestinal and 38 extraintestinal E. coli virulence genes (VGs). Nine serogroups were identified, the most prevalent being O149 (46.2%), O141 (11.2%) and Ont (31.6%). None of the isolates showed resistance to ceftiofur or enrofloxacin and 9.4% were resistant to florfenicol. No corresponding extended-spectrum/AmpC β-lactamase, fluoroquinolone or floR ARGs were detected. An antimicrobial resistance index (ARI) was calculated from the combined data with a weighting for each antimicrobial agent dependent upon its significance to human health. Serogroup O141 isolates had a significantly higher ARI due to an elevated prevalence of aminoglycoside ARGs and possession of more virulence genes (VGs), including ExPEC or EHEC adhesins (bmaE, sfa/focDE, fimH, ihA) in toxin-producing strains that lacked the normally associated F4 and F18 fimbriae. Few associations between ARGs and VGs were apparent, apart from tetC, sfa/focDE and ompT which, for a sub-set of O141 isolates, suggest possible plasmid acquisition from ExPEC. The multi-drug resistant ETEC ARG/VG profiles indicate a high probability of considerable strain and plasmid diversity, reflecting various selection pressures at the individual farm level rather than emergence and lateral spread of MDR resistant/virulent clones. PMID:20688440

  14. Aquaculture as yet another environmental gateway to the development and globalisation of antimicrobial resistance.

    PubMed

    Cabello, Felipe C; Godfrey, Henry P; Buschmann, Alejandro H; Dölz, Humberto J

    2016-07-01

    Aquaculture uses hundreds of tonnes of antimicrobials annually to prevent and treat bacterial infection. The passage of these antimicrobials into the aquatic environment selects for resistant bacteria and resistance genes and stimulates bacterial mutation, recombination, and horizontal gene transfer. The potential bridging of aquatic and human pathogen resistomes leads to emergence of new antimicrobial-resistant bacteria and global dissemination of them and their antimicrobial resistance genes into animal and human populations. Efforts to prevent antimicrobial overuse in aquaculture must include education of all stakeholders about its detrimental effects on the health of fish, human beings, and the aquatic ecosystem (the notion of One Health), and encouragement of environmentally friendly measures of disease prevention, including vaccines, probiotics, and bacteriophages. Adoption of these measures is a crucial supplement to efforts dealing with antimicrobial resistance by developing new therapeutic agents, if headway is to be made against the increasing problem of antimicrobial resistance in human and veterinary medicine. PMID:27083976

  15. Effect of on-farm use of antimicrobial drugs on resistance in fecal Escherichia coli of preweaned dairy calves

    PubMed Central

    Pereira, R. V.; Siler, J. D.; Ng, J. C.; Davis, M. A.; Grohn, Y. T.; Warnick, L. D.

    2015-01-01

    Respiratory disease and diarrhea are the 2 most common diseases that result in the use of antimicrobial drugs in preweaned calves. Because the use of drugs in food animals, including dairy calves, has the potential for generating cross-resistance to drugs used in human medicine, it is vital to propose farm practices that foster the judicious use of antimicrobials while assuring animal health and productivity. The objective of this study was to use dairy farm calf treatment records to identify antimicrobial drug treatments in calves and to evaluate their effects on the prevalence of antimicrobial-resistant Escherichia coli from rectal swabs of preweaned dairy calves. Eight farms from central New York participated in the study, 3 farms using individual pen housing management and 5 farms using group pen housing management. Eligible study farms could not add antimicrobial drugs to the milk fed to preweaned calves and were required to have farm records documenting antimicrobial drug treatment of calves from birth to weaning. Three fecal E. coli isolates per calf were tested for susceptibility to 12 antimicrobial drugs using a Kirby-Bauer disk diffusion assay. A total of 473 calves were sampled, from which 1,423 commensal E. coli isolates were tested. Of the 9 antimicrobial drugs used on study farms, only enrofloxacin was significantly associated with reduced antimicrobial susceptibility of E. coli isolates, although treatment with ceftiofur was associated with reduced susceptibility to ceftriaxone. The median numbers of days from treatment with ceftiofur and enrofloxacin to rectal swab sampling of calves were 16 d (range: 1–39) and 12 d (range: 6–44), respectively. At the isolate level, treatment with enrofloxacin resulted in odds ratios of 2 [95% confidence interval (CI): 1–4] and 3 (95% CI: 2–6), respectively, for isolation of nonsusceptible E. coli to nalidixic acid and ciprofloxacin compared with calves not treated with enrofloxacin. Treatment with ceftiofur

  16. Stress responses as determinants of antimicrobial resistance in Pseudomonas aeruginosa: multidrug efflux and more.

    PubMed

    Poole, Keith

    2014-12-01

    Pseudomonas aeruginosa is a notoriously antimicrobial-resistant organism that is increasingly refractory to antimicrobial chemotherapy. While the usual array of acquired resistance mechanisms contribute to resistance development in this organism a multitude of endogenous genes also play a role. These include a variety of multidrug efflux loci that contribute to both intrinsic and acquired antimicrobial resistance. Despite their roles in resistance, however, it is clear that these efflux systems function in more than just antimicrobial efflux. Indeed, recent data indicate that they are recruited in response to environmental stress and, therefore, function as components of the organism's stress responses. In fact, a number of endogenous resistance-promoting genes are linked to environmental stress, functioning as part of known stress responses or recruited in response to a variety of environmental stress stimuli. Stress responses are, thus, important determinants of antimicrobial resistance in P. aeruginosa. As such, they represent possible therapeutic targets in countering antimicrobial resistance in this organism. PMID:25388098

  17. A three-year survey of the antimicrobial resistance of microorganisms at a Chinese hospital

    PubMed Central

    TANG, JING; WANG, LILI; XI, YUFEI; LIU, GAOLIN

    2016-01-01

    The present retrospective study aimed to investigate the antibiotic susceptibility of bacteria at Shanghai First People's Hospital (Shanghai, China) between 2009 and 2011. An increasing trend of antibiotic resistance was observed in this hospital between 2009 and 2011. Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus were the most prevalent resistant strains. Antimicrobial susceptibility was detected using standard Kirby-Bauer disk diffusion and analyzed using World Health Organization software. E. coli was demonstrated to be the most prevalent bacterium in the present survey between 2009 and 2011 (16.2, 20.0 and 19.6%, respectively); followed by A. baumannii (13.5, 13.3 and 10.6%, respectively) and S. aureus. Notably, >70% of E. coli and 70% of S. aureus were resistant to common antibiotics; whereas 60% of A. baumannii and 20% of Pseudomonas aeruginosa were resistant to the majority of the antibiotics investigated. In 2011, Enterococcus faecalis exhibited a resistance rate of 55.6% against levofloxacin and E. faecium exhibited a 53.2% resistance rate. The present survey demonstrated an increasing trend in bacterial resistance against antibiotics; therefore, more stringent guidelines for antibiotics should be advocated. PMID:26997986

  18. Genetic characterization of antimicrobial resistance in coagulase-negative staphylococci from bovine mastitis milk.

    PubMed

    Frey, Yvonne; Rodriguez, Joan Peña; Thomann, Andreas; Schwendener, Sybille; Perreten, Vincent

    2013-04-01

    Coagulase-negative staphylococci (CNS; n=417) were isolated from bovine milk and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Nineteen different species were identified, and Staphylococcus xylosus, Staphylococcus chromogenes, Staphylococcus haemolyticus, and Staphylococcus sciuri were the most prevalent species. Resistance to oxacillin (47.0% of the isolates), fusidic acid (33.8%), tiamulin (31.9%), penicillin (23.3%), tetracycline (15.8%), streptomycin (9.6%), erythromycin (7.0%), sulfonamides (5%), trimethoprim (4.3%), clindamycin (3.4%), kanamycin (2.4%), and gentamicin (2.4%) was detected. Resistance to oxacillin was attributed to the mecA gene in 9.7% of the oxacillin-resistant isolates. The remaining oxacillin-resistant CNS did not contain the mecC gene or mecA1 promoter mutations. The mecA gene was detected in Staphylococcus fleurettii, Staphylococcus epidermidis, Staph. haemolyticus, and Staph. xylosus. Resistance to tetracycline was attributed to the presence of tet(K) and tet(L), penicillin resistance to blaZ, streptomycin resistance to str and ant(6)-Ia, and erythromycin resistance to erm(C), erm(B), and msr. Resistance to tiamulin and fusidic acid could not be attributed to an acquired resistance gene. In total, 15.1% of the CNS isolates were multidrug resistant (i.e., resistant to 2 or more antimicrobials). The remaining CNS isolates were susceptible to antimicrobials commonly used in mastitis treatment. Methicillin-resistant CNS isolates were diverse, as determined by mecA gene sequence analysis, staphylococcal cassette chromosome mec typing, and pulsed-field gel electrophoresis. Arginine catabolic mobile element types 1 and 3 were detected in both methicillin-resistant and methicillin-susceptible Staph. epidermidis and were associated with sequence types ST59 and ST111. Because this study revealed the presence of multidrug-resistant CNS in a heterogeneous CNS population, we recommend antibiogram analysis

  19. Antimicrobial resistance in commensal Escherichia coli in veal calves is associated with antimicrobial drug use.

    PubMed

    Bosman, A B; Wagenaar, J A; Stegeman, J A; Vernooij, J C M; Mevius, D J

    2014-09-01

    The aim of this study was to determine the association between farm management factors, including antimicrobial drug usage, and resistance in commensal Escherichia coli isolates from the faeces of white veal calves. Ninety E. coli isolates from one pooled sample per farm (n = 48) were tested for their phenotypical resistance against amoxicillin, tetracycline, cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole (TMP/SMX). Logistic regression analysis revealed the following risk factors (P < 0·05); farmer wearing the same work clothes for several days [ciprofloxacin, odds ratio (OR) 2·6; tetracycline, OR 2·4], administration of trimethoprim-sulfonamide combinations (TMP/SMX, OR 3·0; amoxicillin, OR 3·1; tetracycline, OR 2·6), ⩾0·3 animal daily dosage per production cycle (ADD/pc), quinolones (ciprofloxacin, OR 2·8), ⩾1·3 ADD/pc, penicillins (ciprofloxacin, OR 3·3; tetracycline, OR 3·4), 20-40 ADD/pc, tetracyclines (tetracycline, OR 3·2) and >40 ADD/pc, tetracyclines (tetracycline, OR 13·1; amoxicillin, OR 6·5). In this study antimicrobial resistance in commensal E. coli was mainly associated with antimicrobial drug use. PMID:24152540

  20. Epidemiology, ecology, and molecular genetics of antimicrobial resistance in pathogenic and commensal bacteria from food animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The National Antimicrobial Resistance Monitoring System (NARMS) is a collaborative program between the Food and Drug Administration (FDA), the Centers for Disease Control (CDC), and the United States Department of Agriculture to prospectively monitor changes in antimicrobial susceptibilities of zoon...

  1. Antimicrobial resistance in humans, livestock and the wider environment.

    PubMed

    Woolhouse, Mark; Ward, Melissa; van Bunnik, Bram; Farrar, Jeremy

    2015-06-01

    Antimicrobial resistance (AMR) in humans is inter-linked with AMR in other populations, especially farm animals, and in the wider environment. The relatively few bacterial species that cause disease in humans, and are the targets of antibiotic treatment, constitute a tiny subset of the overall diversity of bacteria that includes the gut microbiota and vast numbers in the soil. However, resistance can pass between these different populations; and homologous resistance genes have been found in pathogens, normal flora and soil bacteria. Farm animals are an important component of this complex system: they are exposed to enormous quantities of antibiotics (despite attempts at reduction) and act as another reservoir of resistance genes. Whole genome sequencing is revealing and beginning to quantify the two-way traffic of AMR bacteria between the farm and the clinic. Surveillance of bacterial disease, drug usage and resistance in livestock is still relatively poor, though improving, but achieving better antimicrobial stewardship on the farm is challenging: antibiotics are an integral part of industrial agriculture and there are very few alternatives. Human production and use of antibiotics either on the farm or in the clinic is but a recent addition to the natural and ancient process of antibiotic production and resistance evolution that occurs on a global scale in the soil. Viewed in this way, AMR is somewhat analogous to climate change, and that suggests that an intergovernmental panel, akin to the Intergovernmental Panel on Climate Change, could be an appropriate vehicle to actively address the problem. PMID:25918441

  2. Antimicrobial resistance in humans, livestock and the wider environment

    PubMed Central

    Woolhouse, Mark; Ward, Melissa; van Bunnik, Bram; Farrar, Jeremy

    2015-01-01

    Antimicrobial resistance (AMR) in humans is inter-linked with AMR in other populations, especially farm animals, and in the wider environment. The relatively few bacterial species that cause disease in humans, and are the targets of antibiotic treatment, constitute a tiny subset of the overall diversity of bacteria that includes the gut microbiota and vast numbers in the soil. However, resistance can pass between these different populations; and homologous resistance genes have been found in pathogens, normal flora and soil bacteria. Farm animals are an important component of this complex system: they are exposed to enormous quantities of antibiotics (despite attempts at reduction) and act as another reservoir of resistance genes. Whole genome sequencing is revealing and beginning to quantify the two-way traffic of AMR bacteria between the farm and the clinic. Surveillance of bacterial disease, drug usage and resistance in livestock is still relatively poor, though improving, but achieving better antimicrobial stewardship on the farm is challenging: antibiotics are an integral part of industrial agriculture and there are very few alternatives. Human production and use of antibiotics either on the farm or in the clinic is but a recent addition to the natural and ancient process of antibiotic production and resistance evolution that occurs on a global scale in the soil. Viewed in this way, AMR is somewhat analogous to climate change, and that suggests that an intergovernmental panel, akin to the Intergovernmental Panel on Climate Change, could be an appropriate vehicle to actively address the problem. PMID:25918441

  3. Correlation between antimicrobial resistance and virulence in Klebsiella pneumoniae.

    PubMed

    Hennequin, C; Robin, F

    2016-03-01

    Klebsiella pneumoniae is responsible for a wide range of infections, including urinary tract infections, pneumonia, bacteremia, and liver abscesses. In addition to susceptible clinical isolates involved in nosocomial infections, multidrug-resistant (MDR) and hypervirulent (hvKP) strains have evolved separately in distinct clonal groups. The rapid geographic spread of these isolates is of particular concern. However, we still know little about the virulence of K. pneumoniae except for hvKP, whose secrets are beginning to be revealed. The treatment of K. pneumoniae infections is threatened by the emergence of antimicrobial resistance. The dissemination of resistance is associated with genetic mobile elements, such as plasmids that may also carry virulence determinants. A proficient pathogen should be virulent, resistant to antibiotics, and epidemic. However, the interplay between resistance and virulence is poorly understood. Here, we review current knowledge on the topic. PMID:26718943

  4. DNA microarray detection of antimicrobial resistance genes in Detection and Characterization of Antibiotic Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection of antimicrobial resistance genes is essential for research and an important tool for clinical diagnostics. Most techniques used to identify resistance genes can only detect one or a few genes per assay, whereas DNA microarray technology can detect thousands of genes in a single assay. Sev...

  5. Use of a bacterial antimicrobial resistance gene microarray for the identification of resistant Staphylococcus aureus.

    PubMed

    Garneau, P; Labrecque, O; Maynard, C; Messier, S; Masson, L; Archambault, M; Harel, J

    2010-11-01

    As diagnostic and surveillance activities are vital to determine measures needed to control antimicrobial resistance (AMR), new and rapid laboratory methods are necessary to facilitate this important effort. DNA microarray technology allows the detection of a large number of genes in a single reaction. This technology is simple, specific and high-throughput. We have developed a bacterial antimicrobial resistance gene DNA microarray that will allow rapid antimicrobial resistance gene screening for all Gram-positive and Gram-negative bacteria. A prototype microarray was designed using a 70-mer based oligonucleotide set targeting AMR genes of Gram-negative and Gram-positive bacteria. In the present version, the microarray consists of 182 oligonucleotides corresponding to 166 different acquired AMR gene targets, covering most of the resistance genes found in both Gram-negative and -positive bacteria. A test study was performed on a collection of Staphylococcus aureus isolates from milk samples from dairy farms in Québec, Canada. The reproducibility of the hybridizations was determined, and the microarray results were compared with those obtained by phenotypic resistance tests (either MIC or Kirby-Bauer). The microarray genotyping demonstrated a correlation between penicillin, tetracycline and erythromycin resistance phenotypes with the corresponding acquired resistance genes. The hybridizations showed that the 38 antimicrobial resistant S. aureus isolates possessed at least one AMR gene. PMID:21083822

  6. How could preventive therapy affect the prevalence of drug resistance? Causes and consequences.

    PubMed

    Kunkel, Amber; Colijn, Caroline; Lipsitch, Marc; Cohen, Ted

    2015-06-01

    Various forms of preventive and prophylactic antimicrobial therapies have been proposed to combat HIV (e.g. pre-exposure prophylaxis), tuberculosis (e.g. isoniazid preventive therapy) and malaria (e.g. intermittent preventive treatment). However, the potential population-level effects of preventative therapy (PT) on the prevalence of drug resistance are not well understood. PT can directly affect the rate at which resistance is acquired among those receiving PT. It can also indirectly affect resistance by altering the rate at which resistance is acquired through treatment for active disease and by modifying the level of competition between transmission of drug-resistant and drug-sensitive pathogens. We propose a general mathematical model to explore the ways in which PT can affect the long-term prevalence of drug resistance. Depending on the relative contributions of these three mechanisms, we find that increasing the level of coverage of PT may result in increases, decreases or non-monotonic changes in the overall prevalence of drug resistance. These results demonstrate the complexity of the relationship between PT and drug resistance in the population. Care should be taken when predicting population-level changes in drug resistance from small pilot studies of PT or estimates based solely on its direct effects. PMID:25918446

  7. Improving the timeliness of meticillin-resistant Staphylococcus aureus antimicrobial decolonization therapy administration: a descriptive account☆

    PubMed Central

    Brooks, H.L.; Hodson, J.; Richardson, S.J.; Stezhka, L.; Gill, M.J.; Coleman, J.J.

    2014-01-01

    Summary Background It is important to ensure that the timely administration of appropriate antimicrobial decolonization therapy occurs when patients are identified as meticillin-resistant Staphylococcus aureus (MRSA)-colonized. Computerized Provider Order Entry (CPOE) with embedded Clinical Decision Support (CDS) may help to facilitate this. Aim To investigate changes in the average time from patient admission to administration of MRSA decolonization antimicrobial therapy in the context of various national and local infection control interventions, including the use of CPOE. Methods Data concerning the time of admission and of administration of patients' first MRSA decolonization antimicrobials were extracted from a locally developed CPOE system (Prescribing Investigation and Communications System: PICS) which was introduced at a large university teaching hospital in the UK in 1998. Data were extracted retrospectively from January 2006 to March 2012. Findings A variety of relevant local and national interventions occurred from 2006 to 2012. Notably, the automatic charting of MRSA decolonization antimicrobial therapy was introduced in December 2007. There was a significant decline of 15.0% per year (95% confidence interval: 11.1–18.7%; P < 0.001) in the time taken from admission to administration of MRSA decolonization antimicrobial therapy during the study period. Conclusions Numerous factors may have contributed to the observed reductions in the time from admission to administration of MRSA decolonization antimicrobials, including the implementation of specific features within a CPOE system. By rapidly attending to positive MRSA colonizations there is decreased potential for MRSA to spread, which may help to reduce the prevalence of MRSA colonizations within hospitals and improve patient outcomes. PMID:24560977

  8. Animal husbandry practices in rural Bangladesh: potential risk factors for antimicrobial drug resistance and emerging diseases.

    PubMed

    Roess, Amira A; Winch, Peter J; Ali, Nabeel A; Akhter, Afsana; Afroz, Dilara; El Arifeen, Shams; Darmstadt, Gary L; Baqui, Abdullah H

    2013-11-01

    Antimicrobial drug administration to household livestock may put humans and animals at risk for acquisition of antimicrobial drug-resistant pathogens. To describe animal husbandry practices, including animal healthcare-seeking and antimicrobial drug use in rural Bangladesh, we conducted semi-structured in-depth interviews with key informants, including female household members (n = 79), village doctors (n = 10), and pharmaceutical representatives, veterinarians, and government officials (n = 27), and performed observations at animal health clinics (n = 3). Prevalent animal husbandry practices that may put persons at risk for acquisition of pathogens included shared housing and water for animals and humans, antimicrobial drug use for humans and animals, and crowding. Household members reported seeking human and animal healthcare from unlicensed village doctors rather than formal-sector healthcare providers and cited cost and convenience as reasons. Five times more per household was spent on animal than on human healthcare. Strengthening animal and human disease surveillance systems should be continued. Interventions are recommended to provide vulnerable populations with a means of protecting their livelihood and health. PMID:24062478

  9. Animal Husbandry Practices in Rural Bangladesh: Potential Risk Factors for Antimicrobial Drug Resistance and Emerging Diseases

    PubMed Central

    Roess, Amira A.; Winch, Peter J.; Ali, Nabeel A.; Akhter, Afsana; Afroz, Dilara; El Arifeen, Shams; Darmstadt, Gary L.; Baqui, Abdullah H.

    2013-01-01

    Antimicrobial drug administration to household livestock may put humans and animals at risk for acquisition of antimicrobial drug–resistant pathogens. To describe animal husbandry practices, including animal healthcare-seeking and antimicrobial drug use in rural Bangladesh, we conducted semi-structured in-depth interviews with key informants, including female household members (n = 79), village doctors (n = 10), and pharmaceutical representatives, veterinarians, and government officials (n = 27), and performed observations at animal health clinics (n = 3). Prevalent animal husbandry practices that may put persons at risk for acquisition of pathogens included shared housing and water for animals and humans, antimicrobial drug use for humans and animals, and crowding. Household members reported seeking human and animal healthcare from unlicensed village doctors rather than formal-sector healthcare providers and cited cost and convenience as reasons. Five times more per household was spent on animal than on human healthcare. Strengthening animal and human disease surveillance systems should be continued. Interventions are recommended to provide vulnerable populations with a means of protecting their livelihood and health. PMID:24062478

  10. Risk factors for antimicrobial resistance in Escherichia coli found in GB turkey flocks.

    PubMed

    Jones, E M; Snow, L C; Carrique-Mas, J J; Gosling, R J; Clouting, C; Davies, R H

    2013-11-01

    Four models are presented investigating risks present on Great Britain (GB) turkey farms in breeding and fattening flocks for ciprofloxacin and cephalosporin resistance. Risk factors for ciprofloxacin resistance in fattening flocks were sourcing of feed from national compounders, antimicrobial use in the flock and evidence of mice. Disinfection of floors and walls at depopulation, older flocks and division of the flock with partitions reduced the risk. In breeding farms holding over 10,000 birds, administration of fluoroquinolones within the last year and horses on the neighbouring farm all increased the risk, whereas replenishing foot dips more than once a week reduced the risk. For cephalosporin-resistant Escherichia coli on fattening farms, being an independent farm, having a watercourse near the poultry houses, dividing the flock with partitions and providing staff with gloves reduced the risk. Factors that increased the risk included if staff worked with other livestock and if there were pigs on neighbouring farms. This work suggests that good hygiene and biosecurity, rodent control and responsible use of antimicrobials on turkey farms might help minimise the prevalence of fluoroquinolone and cephalosporin resistance in E coli, and restrict the spread of resistance genes to other organisms. PMID:24097819

  11. Identification, antimicrobial resistance and genotypic characterization of Enterococcus spp. isolated in Porto Alegre, Brazil

    PubMed Central

    Bender, Eduardo André; de Freitas, Ana Lúcia Peixoto; Reiter, Keli Cristine; Lutz, Larissa; Barth, Afonso Luís

    2009-01-01

    In the past two decades the members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. In the present study, we evaluated the antimicrobial resistance and genotypic characteristics of 203 Enterococcus spp. recovered from different clinical sources from two hospitals in Porto Alegre, Rio Grande do Sul, Brazil. The species were identified by conventional biochemical tests and by an automated system. The genetic diversity of E. faecalis presenting high-level aminoglycoside resistance (HLAR) was assessed by pulsed-field gel electrophoresis of chromosomal DNA after SmaI digestion. The E. faecalis was the most frequent specie (93.6%), followed by E. faecium (4.4%). The antimicrobial resistance profile was: 2.5% to ampicillin, 0.5% to vancomycin, 0.5% teicoplanin, 33% to chloramphenicol, 2% to nitrofurantoin, 66.1% to erythromycin, 66.5% to tetracycline, 24.6% to rifampicin, 30% to ciprofloxacin and 87.2% to quinupristin-dalfopristin. A total of 10.3% of the isolates proved to be HLAR to both gentamicin and streptomycin (HLR-ST/GE), with 23.6% resistant only to gentamicin (HLR-GE) and 37.4% only to streptomycin (HLR-ST). One predominant clonal group was found among E. faecalis HLR-GE/ST. The prevalence of resistance among beta-lactam antibiotics and glycopeptides was very low. However, in this study there was an increased number of HLR Enterococcus which may be spreading intra and inter-hospital. PMID:24031416

  12. Antimicrobial resistance and characterisation of staphylococci isolated from healthy Labrador retrievers in the United Kingdom

    PubMed Central

    2014-01-01

    Background Coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci are normal commensals of the skin and mucosa, but are also opportunist pathogens. Meticillin-resistant (MR) and multidrug-resistant (MDR) isolates are increasing in human and veterinary healthcare. Healthy humans and other animals harbour a variety of staphylococci, including MR-CoPS and MR-CoNS. The main aims of the study were to characterise the population and antimicrobial resistance profiles of staphylococci from healthy non-vet visiting and non-antimicrobial treated Labrador retrievers in the UK. Results Nasal and perineal samples were collected from 73 Labrador retrievers; staphylococci isolated and identified using phenotypic and biochemical methods. They were also confirmed by matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), PCR of the nuc gene and PCR and sequencing of the tuf gene. Disc diffusion and minimum inhibitory concentration (MIC) susceptibility tests were determined for a range of antimicrobials. In total, 102 CoPS (S. pseudintermedius n = 91, S. aureus n = 11) and 334 CoNS isolates were detected from 99% of dogs in this study. In 52% of dogs CoNS only were detected, with both CoNS and CoPS detected in 43% dogs and CoPS only detected in 4% of dogs. Antimicrobial resistance was not common among CoPS, but at least one MDR-CoNS isolate was detected in 34% of dogs. MR-CoNS were detected from 42% of dogs but no MR-CoPS were isolated. S. epidermidis (52% of dogs) was the most common CoNS found followed by S. warneri (30%) and S. equorum (27%), with another 15 CoNS species isolated from ≤ 15% of dogs. S. pseudintermedius and S. aureus were detected in 44% and 8% of dogs respectively. Conclusions MR- and MDR-CoPS were rare. However a high prevalence of MR- and MDR-CoNS were found in these dogs, even though they had no prior antimicrobial treatment or admission to veterinary premises. These findings are of concern due to

  13. Australian Group on Antimicrobial Resistance Hospital-onset Staphylococcus aureus Surveillance Programme annual report, 2011.

    PubMed

    Coombs, Geoffrey W; Nimmo, Graeme R; Pearson, Julie C; Collignon, Peter J; Bell, Jan M; McLaws, Mary-Louise; Christiansen, Keryn J; Turnidge, John D

    2013-09-01

    In 2011, the Australian Group on Antimicrobial Resistance (AGAR) conducted a period-prevalence survey of clinical Staphylococcus aureus isolated from hospital inpatients. Twenty-nine microbiology laboratories from all states and mainland territories participated. Specimens were collected more than 48 hours post-admission. Isolates were tested by Vitek2® antimicrobial susceptibility card (AST-P612 card). Nationally, the proportion of S. aureus that were methicillin-resistant S. aureus (MRSA) was 30.3%; ranging from 19.9% in Western Australia to 36.8% in New South Wales/Australian Capital Territory. Resistance to the non-ß-lactam antimicrobials was common except for rifampicin, fusidic acid, high-level mupirocin and daptomycin. No resistance was detected for vancomycin, teicoplanin or linezolid. Antibiotic resistance in methicillin susceptible S. aureus (MSSA) was rare apart from erythromycin (13.2%) and there was no resistance to vancomycin, teicoplanin or linezolid. Inducible clindamycin resistance was the norm for erythromycin resistant, clindamycin intermediate/susceptible S. aureus in Australia with 90.6% of MRSA and 83.1% of MSSA with this phenotype having a positive double disc diffusion test (D-test). The proportion of S. aureus characterised as being healthcare-associated MRSA (HA-MRSA) was 18.2%, ranging from 4.5% in Western Australia to 28.0% in New South Wales/Australian Capital Territory. Four HA-MRSA clones were characterised and 98.8% of HA-MRSA isolates were classified as either ST22-IV [2B] (EMRSA-15) or ST239-III [3A] (Aus-2/3 EMRSA). Multiclonal community-associated MRSA (CA-MRSA) accounted for 11.7% of all S. aureus. In Australia, regional variation in resistance is due to the differential distribution of MRSA clones between regions, particularly for the major HA-MRSA clone, ST239-III [3A] (Aus-2/3 EMRSA), which is resistant to multiple non-ß-lactam antimicrobials. PMID:24890956

  14. Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples

    PubMed Central

    Pang, Zhizhao; Qin, Tian; Ren, Hongyu; Pan, Zhuo; Zhou, Jikun

    2016-01-01

    This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9%) K. pneumoniae strains were isolated; the frequencies were 8.2% (4/49) in fresh raw seafood, 13.8% (26/188) in fresh raw chicken, 11.4% (34/297) in frozen raw food and 7.5% (35/464) in cooked food samples. Antimicrobial resistance was observed against 16 antimicrobials. The highest resistance rate was observed for ampicillin (92.3%), followed by tetracycline (31.3%), trimethoprim-sulfamethoxazole (18.2%), and chloramphenicol (10.1%). Two K. pneumoniae strains were identified as extended-spectrum β-lactamase (ESBL)–one strain had three beta-lactamases genes (blaSHV, blaCTX-M-1, and blaCTX-M-10) and one had only the blaSHV gene. Nineteen multidrug-resistant (MDR) strains were detected; the percentage of MDR strains in fresh raw chicken samples was significantly higher than in other sample types (P<0.05). Six of the 18 trimethoprim-sulfamethoxazole-resistant strains carried the folate pathway inhibitor gene (dhfr). Four isolates were screened by PCR for quinolone resistance genes; aac(6’)-Ib-cr, qnrB, qnrA and qnrS were detected. In addition, gyrA gene mutations such as T247A (Ser83Ile), C248T (Ser83Phe), and A260C (Asp87Ala) and a parC C240T (Ser80Ile) mutation were identified. Five isolates were screened for aminoglycosides resistance genes; aacA4, aacC2, and aadA1 were detected. Pulsed-field gel electrophoresis-based subtyping identified 91 different patterns. Our results indicate that food, especially fresh raw chicken, is a reservoir of antimicrobial-resistant K. pneumoniae, and the potential health risks posed by such strains should not be underestimated. Our results demonstrated high prevalence, antibiotic resistance rate and genetic diversity of K. pneumoniae in food in China. Improved

  15. Frequency, Antimicrobial Resistance and Genetic Diversity of Klebsiella pneumoniae in Food Samples.

    PubMed

    Guo, Yumei; Zhou, Haijian; Qin, Liyun; Pang, Zhizhao; Qin, Tian; Ren, Hongyu; Pan, Zhuo; Zhou, Jikun

    2016-01-01

    This study aimed to assess the frequency of Klebsiella pneumoniae in food samples and to detect antibiotic resistance phenotypes, antimicrobial resistance genes and the molecular subtypes of the recovered isolates. A total of 998 food samples were collected, and 99 (9.9%) K. pneumoniae strains were isolated; the frequencies were 8.2% (4/49) in fresh raw seafood, 13.8% (26/188) in fresh raw chicken, 11.4% (34/297) in frozen raw food and 7.5% (35/464) in cooked food samples. Antimicrobial resistance was observed against 16 antimicrobials. The highest resistance rate was observed for ampicillin (92.3%), followed by tetracycline (31.3%), trimethoprim-sulfamethoxazole (18.2%), and chloramphenicol (10.1%). Two K. pneumoniae strains were identified as extended-spectrum β-lactamase (ESBL)-one strain had three beta-lactamases genes (blaSHV, blaCTX-M-1, and blaCTX-M-10) and one had only the blaSHV gene. Nineteen multidrug-resistant (MDR) strains were detected; the percentage of MDR strains in fresh raw chicken samples was significantly higher than in other sample types (P<0.05). Six of the 18 trimethoprim-sulfamethoxazole-resistant strains carried the folate pathway inhibitor gene (dhfr). Four isolates were screened by PCR for quinolone resistance genes; aac(6')-Ib-cr, qnrB, qnrA and qnrS were detected. In addition, gyrA gene mutations such as T247A (Ser83Ile), C248T (Ser83Phe), and A260C (Asp87Ala) and a parC C240T (Ser80Ile) mutation were identified. Five isolates were screened for aminoglycosides resistance genes; aacA4, aacC2, and aadA1 were detected. Pulsed-field gel electrophoresis-based subtyping identified 91 different patterns. Our results indicate that food, especially fresh raw chicken, is a reservoir of antimicrobial-resistant K. pneumoniae, and the potential health risks posed by such strains should not be underestimated. Our results demonstrated high prevalence, antibiotic resistance rate and genetic diversity of K. pneumoniae in food in China. Improved

  16. Comparison of two antimicrobial regimens on the prevalence of incisional infections after colic surgery.

    PubMed

    Durward-Akhurst, S A; Mair, T S; Boston, R; Dunkel, B

    2013-03-16

    Appropriate durations of perioperative antimicrobial therapy following exploratory coeliotomy in horses are controversial, and with the rising prevalence of multiresistant bacteria there is a strong incentive to use antimicrobials for the shortest time possible. Following exploratory coeliotomies, incisional infections are an important cause of morbidity in horses and could be influenced by the duration of systemic antimicrobial therapy. The aim of this study was to investigate whether 72 hours of perioperative antimicrobial therapy is as effective as 120 hours at preventing the development of postoperative incisional infections. Horses undergoing exploratory coeliotomy at two referral hospitals were assigned randomly into Group 1 (receiving 72 hours of perioperative antimicrobial therapy) and Group 2 (receiving 120 hours of perioperative antimicrobial therapy). Only horses recovering from surgery and surviving for >120 hours were included in the study. Ninety-two horses met the criteria for inclusion in the study, 42 in Group 1 and 50 in Group 2. The overall incisional complication rate was 42.2 per cent, and no significant difference in the number of incisional complications in the two groups was identified. Results of the study suggest that there is no benefit in using 120 hours over 72 hours of perioperative antimicrobial therapy to prevent incisional infections. PMID:23268187

  17. Salmonella prevalence and antimicrobial susceptibility among dairy farm environmental samples collected in Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dairy cattle are a reservoir of several Salmonella serovars that are leading causes of human salmonellosis. The objectives of this study were to determine the environmental prevalence of Salmonella on dairy farms in Texas and to characterize the antimicrobial susceptibility of the isolates. Eleven...

  18. Counts, serovars, and antimicrobial resistance phenotypes of Salmonella on raw chicken meat at retail in Colombia.

    PubMed

    Donado-Godoy, Pilar; Clavijo, Viviana; León, Maribel; Arevalo, Alejandra; Castellanos, Ricardo; Bernal, Johan; Tafur, Mc Allister; Ovalle, Maria Victoria; Alali, Walid Q; Hume, Michael; Romero-Zuñiga, Juan Jose; Walls, Isabel; Doyle, Michael P

    2014-02-01

    The objective of this study was to determine Salmonella counts, serovars, and antimicrobial-resistant phenotypes on retail raw chicken carcasses in Colombia. A total of 301 chicken carcasses were collected from six departments (one city per department) in Colombia. Samples were analyzed for Salmonella counts using the most-probable-number method as recommended by the U.S. Department of Agriculture, Food Safety Inspection Service protocol. A total of 378 isolates (268 from our previous study) were serotyped and tested for antimicrobial susceptibility. The overall Salmonella count (mean log most probable number per carcass ± 95% confidence interval) and prevalence were 2.1 (2.0 to 2.3) and 37%, respectively. There were significant differences (P < 0.05) by Salmonella levels (i.e., counts and prevalence) by storage temperature (i.e., frozen, chilled, or ambient), retail store type (wet markets, supermarkets, and independent markets), and poultry company (chicken produced by integrated or nonintegrated company). Frozen chicken had the lowest Salmonella levels compared with chicken stored at other temperatures, chickens from wet markets had higher levels than those from other retail store types, and chicken produced by integrated companies had lower levels than nonintegrated companies. Thirty-one Salmonella serovars were identified among 378 isolates, with Salmonella Paratyphi B tartrate-positive (i.e., Salmonella Paratyphi B dT+) the most prevalent (44.7%), followed by Heidelberg (19%), Enteritidis (17.7%), Typhimurium (5.3%), and Anatum (2.1%). Of all the Salmonella isolates, 35.2% were resistant to 1 to 5 antimicrobial agents, 24.6% to 6 to 10, and 33.9% to 11 to 15. Among all the serovars obtained, Salmonella Paratyphi B dT+ and Salmonella Heidelberg were the most antimicrobial resistant. Salmonella prevalence was determined to be high, whereas cell numbers were relatively low. These data can be used in developing risk assessment models for preventing the

  19. Prevalence and diversity of carbapenem-resistant bacteria in untreated drinking water in Portugal.

    PubMed

    Henriques, Isabel S; Araújo, Susana; Azevedo, Juliana S N; Alves, Marta Salgueiro; Chouchani, Chedly; Pereira, Anabela; Correia, António

    2012-10-01

    We examined the prevalence and diversity of carbapenem-resistant bacteria (CRB) in untreated drinking water. Prevalence was estimated in plate count agar (PCA) and R2A media with or without antibiotics. Clonal relatedness of isolates was established by repetitive extragenic palindroitic (REP)-PCR. Phylogeny was based on the 16S rRNA gene. Antimicrobial susceptibility was assessed by disc diffusion methods. Genes encoding beta-lactamases and integrases were inspected by PCR. CRB ranged from 0.02% to 15.9% of cultivable bacteria, while ampicillin-resistant bacteria ranged from 1.5% to 31.4%. Carbapenem-resistant isolates affiliated with genera Stenotrophomonas, Pseudomonas, Janthinobacterium, Chryseobacterium, Sphingobacterium, Acidovorax, Caulobacter, Cupriavidus, and Sphingomonas. CRB were highly resistant to beta-lactams, but mostly susceptible to other classes. Transmissible beta-lactamase genes and integrase genes were not detected. The genus-specific bla(L1) was detected in 61% of the Stenotrophomonas isolates. Contrarily to what has been reported for extensively used antibiotics, low levels of carbapenem resistance were detected in untreated drinking water, often represented by intrinsically resistant genera. Production of chromosomal-encoded carbapenemases was the prevalent carbapenem resistance mechanism. Results suggest that the dissemination of anthropogenic-derived carbapenem resistance is at an early stage. This presents an opportunity to rationally develop monitoring strategies to identify dissemination routes and assess the impact of human actions in the environmental resistome. PMID:22663561

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

    PubMed

    Cagliano, Stefano

    2015-06-01

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

  1. Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

    PubMed Central

    Di Giannatale, Elisabetta; Di Serafino, Gabriella; Zilli, Katiuscia; Alessiani, Alessandra; Sacchini, Lorena; Garofolo, Giuliano; Aprea, Giuseppe; Marotta, Francesca

    2014-01-01

    Campylobacter has developed resistance to several antimicrobial agents over the years, including macrolides, quinolones and fluoroquinolones, becoming a significant public health hazard. A total of 145 strains derived from raw milk, chicken faeces, chicken carcasses, cattle faeces and human faeces collected from various Italian regions, were screened for antimicrobial susceptibility, molecular characterization (SmaI pulsed-field gel electrophoresis) and detection of virulence genes (sequencing and DNA microarray analysis). The prevalence of C. jejuni and C. coli was 62.75% and 37.24% respectively. Antimicrobial susceptibility revealed a high level of resistance for ciprofloxacin (62.76%), tetracycline (55.86%) and nalidixic acid (55.17%). Genotyping of Campylobacter isolates using PFGE revealed a total of 86 unique SmaI patterns. Virulence gene profiles were determined using a new microbial diagnostic microarray composed of 70-mer oligonucleotide probes targeting genes implicated in Campylobacter pathogenicity. Correspondence between PFGE and microarray clusters was observed. Comparisons of PFGE and virulence profiles reflected the high genetic diversity of the strains examined, leading us to speculate different degrees of pathogenicity inside Campylobacter populations. PMID:24556669

  2. Low-level antimicrobial resistance of Enterobacteriaceae isolated from the nares of pig-exposed persons.

    PubMed

    Fischer, J; Hille, K; Mellmann, A; Schaumburg, F; Kreienbrock, L; Köck, R

    2016-03-01

    Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) have recently emerged in livestock and humans. Therefore, this study assessed the carriage of Enterobacteriaceae in the anterior nares and associated antimicrobial resistance in pig-exposed persons. Nasal swabs were enriched in non-selective broth and then plated on MacConkey and ESBL-selective agars. Species was confirmed by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry (MALDI-ToF MS). Antimicrobial susceptibility testing was performed according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Of 114 pig-exposed persons tested, Enterobacteriaceae were detected in the nares of 76 (66·7%) participants. The predominant species were Proteus mirabilis (n = 17, 14·9%), Pantoea agglomerans (n = 13, 11·4%), Morganella morganii (n = 9, 7·9%), Citrobacter koseri (n = 9, 7·9%), Klebsiella pneumoniae, Escherichia coli and Proteus vulgaris (each n = 8, 7·0%). ESBL-E were not detected. Of all isolates tested, 3·4% were resistant against ciprofloxacin, 2·3% against gentamicin, 23·9% against trimethoprim-sulfamethoxazole and 44·3% against tigecycline. Despite the high prevalence of ESBL-E in livestock, pig-exposed persons did not carry ESBL-E in their nares. This finding is important, because colonization of the nasal reservoir might cause endogenous infections or facilitate transmission of ESBL-E in the general population. PMID:26219671

  3. Serovars and antimicrobial resistance of non-typhoidal Salmonella from human patients in Shanghai, China, 2006-2010.

    PubMed

    Zhang, J; Jin, H; Hu, J; Yuan, Z; Shi, W; Ran, L; Zhao, S; Yang, X; Meng, J; Xu, X

    2014-04-01

    We conducted a retrospective study on non-typhoidal Salmonella isolates from patients with diarrhoea in Shanghai, China, 2006-2010. A total of 1484 isolates of 70 Salmonella serovars were recovered from about 18 000 stool specimens. Serovars Enteritidis and Typhimurium were the most prevalent with isolation rates of 27.6% and 25.5%, respectively. The majority (1151, 77.6%) of the isolates were resistant to at least one antimicrobial, and 598 (40.3%) to more than three antimicrobials. Approximately half (50.9%) of the isolates were resistant to nalidixic acid and other resistance rates were sulfisoxazole (47.9%), streptomycin (37.6%), ampicillin (31.3%) and tetracycline (30.5%). Co-resistance to fluoroquinolones and the third- and fourth-generation cephalosporins was also identified. PMID:23842508

  4. Antimicrobial resistance of Campylobacter jejuni and Campylobacter coli from poultry in Italy.

    PubMed

    Giacomelli, Martina; Salata, Cristiano; Martini, Marco; Montesissa, Clara; Piccirillo, Alessandra

    2014-04-01

    This study was aimed at assessing the antimicrobial resistance (AMR) of Campylobacter isolates from broilers and turkeys reared in industrial farms in Northern Italy, given the public health concern represented by resistant campylobacters in food-producing animals and the paucity of data about this topic in our country. Thirty-six Campylobacter jejuni and 24 Campylobacter coli isolated from broilers and 68 C. jejuni and 32 C. coli from turkeys were tested by disk diffusion for their susceptibility to apramycin, gentamicin, streptomycin, cephalothin, cefotaxime, ceftiofur, cefuroxime, ampicillin, amoxicillin+clavulanic acid, nalidixic acid, flumequine, enrofloxacin, ciprofloxacin, erythromycin, tilmicosin, tylosin, tiamulin, clindamycin, tetracycline, sulfamethoxazole+trimethoprim, chloramphenicol. Depending on the drug, breakpoints provided by Comité de l'antibiogramme de la Société Française de Microbiologie, Clinical and Laboratory Standards Institute, and the manufacturer were followed. All broiler strains and 92% turkey strains were multidrug resistant. Very high resistance rates were detected for quinolones, tetracycline, and sulfamethoxazole+trimethoprim, ranging from 65% to 100% in broilers and from 74% to 96% in turkeys. Prevalence of resistance was observed also against ampicillin (97% in broilers, 88% in turkeys) and at least three cephalosporins (93-100% in broilers, 100% in turkeys). Conversely, no isolates showed resistance to chloramphenicol and tiamulin. Susceptibility prevailed for amoxicillin+clavulanic acid and aminoglycosides in both poultry species, and for macrolides and clindamycin among turkey strains and among C. jejuni from broilers, whereas most C. coli strains from broilers (87.5%) were resistant. Other differences between C. jejuni and C. coli were observed markedly in broiler isolates, with the overall predominance of resistance in C. coli compared to C. jejuni. This study provides updates and novel data on the AMR of broiler and

  5. Transcriptome Profiling of Antimicrobial Resistance in Pseudomonas aeruginosa.

    PubMed

    Khaledi, Ariane; Schniederjans, Monika; Pohl, Sarah; Rainer, Roman; Bodenhofer, Ulrich; Xia, Boyang; Klawonn, Frank; Bruchmann, Sebastian; Preusse, Matthias; Eckweiler, Denitsa; Dötsch, Andreas; Häussler, Susanne

    2016-08-01

    Emerging resistance to antimicrobials and the lack of new antibiotic drug candidates underscore the need for optimization of current diagnostics and therapies to diminish the evolution and spread of multidrug resistance. As the antibiotic resistance status of a bacterial pathogen is defined by its genome, resistance profiling by applying next-generation sequencing (NGS) technologies may in the future accomplish pathogen identification, prompt initiation of targeted individualized treatment, and the implementation of optimized infection control measures. In this study, qualitative RNA sequencing was used to identify key genetic determinants of antibiotic resistance in 135 clinical Pseudomonas aeruginosa isolates from diverse geographic and infection site origins. By applying transcriptome-wide association studies, adaptive variations associated with resistance to the antibiotic classes fluoroquinolones, aminoglycosides, and β-lactams were identified. Besides potential novel biomarkers with a direct correlation to resistance, global patterns of phenotype-associated gene expression and sequence variations were identified by predictive machine learning approaches. Our research serves to establish genotype-based molecular diagnostic tools for the identification of the current resistance profiles of bacterial pathogens and paves the way for faster diagnostics for more efficient, targeted treatment strategies to also mitigate the future potential for resistance evolution. PMID:27216077

  6. Mechanisms of antimicrobial resistance in Gram-negative bacilli.

    PubMed

    Ruppé, Étienne; Woerther, Paul-Louis; Barbier, François

    2015-12-01

    The burden of multidrug resistance in Gram-negative bacilli (GNB) now represents a daily issue for the management of antimicrobial therapy in intensive care unit (ICU) patients. In Enterobacteriaceae, the dramatic increase in the rates of resistance to third-generation cephalosporins mainly results from the spread of plasmid-borne extended-spectrum beta-lactamase (ESBL), especially those belonging to the CTX-M family. The efficacy of beta-lactam/beta-lactamase inhibitor associations for severe infections due to ESBL-producing Enterobacteriaceae has not been adequately evaluated in critically ill patients, and carbapenems still stands as the first-line choice in this situation. However, carbapenemase-producing strains have emerged worldwide over the past decade. VIM- and NDM-type metallo-beta-lactamases, OXA-48 and KPC appear as the most successful enzymes and may threaten the efficacy of carbapenems in the near future. ESBL- and carbapenemase-encoding plasmids frequently bear resistance determinants for other antimicrobial classes, including aminoglycosides (aminoglycoside-modifying enzymes or 16S rRNA methylases) and fluoroquinolones (Qnr, AAC(6')-Ib-cr or efflux pumps), a key feature that fosters the spread of multidrug resistance in Enterobacteriaceae. In non-fermenting GNB such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, multidrug resistance may emerge following the sole occurrence of sequential chromosomal mutations, which may lead to the overproduction of intrinsic beta-lactamases, hyper-expression of efflux pumps, target modifications and permeability alterations. P. aeruginosa and A. baumannii also have the ability to acquire mobile genetic elements encoding resistance determinants, including carbapenemases. Available options for the treatment of ICU-acquired infections due to carbapenem-resistant GNB are currently scarce, and recent reports emphasizing the spread of colistin resistance in environments with high

  7. Fate of antimicrobials and antimicrobial resistance genes in simulated swine manure storage.

    PubMed

    Joy, Stacey R; Li, Xu; Snow, Daniel D; Gilley, John E; Woodbury, Bryan; Bartelt-Hunt, Shannon L

    2014-05-15

    The behavior of three antibiotics (bacitracin, chlortetracycline, and tylosin) and two classes of antibiotic resistance genes (ARGs), tet and erm, were monitored in swine manure slurry under anaerobic conditions. First-order decay rates were determined for each antibiotic with half-lives ranging from 1 day (chlortetracycline) to 10 days (tylosin). ARGs were monitored in the swine manure slurry, and losses of approximately 1 to 3 orders of magnitude in relative abundance were observed during the 40 day storage period. First-order degradation profiles were observed for chlortetracycline and its corresponding resistance genes, tet(X) and tet(Q). Tylosin was degraded to approximately 10% of the starting concentration by day 40; however, the relative abundance of erm(B) remained at 50-60% of the initial relative abundance while the relative abundance of erm(F) decreased by 80-90%, consistent with tylosin. These results indicate that tet resistance genes respond primarily to chlortetracycline antimicrobials, and may be lost when the parent tetracycline compound is degraded. In contrast, erm(B) resistance gene may respond to a range of antimicrobials in animal manure, and may persist despite losses of tylosin. PMID:24583946

  8. Staphylococcus aureus – antimicrobial resistance and the immunocompromised child

    PubMed Central

    McNeil, J Chase

    2014-01-01

    Children with immunocompromising conditions represent a unique group for the acquisition of antimicrobial resistant infections due to their frequent encounters with the health care system, need for empiric antimicrobials, and immune dysfunction. These infections are further complicated in that there is a relative paucity of literature on the clinical features and management of Staphylococcus aureus infections in immunocompromised children. The available literature on the clinical features, antimicrobial susceptibility, and management of S. aureus infections in immunocompromised children is reviewed. S. aureus infections in children with human immunodeficiency virus (HIV) are associated with higher HIV viral loads and a greater degree of CD4 T-cell suppression. In addition, staphylococcal infections in children with HIV often exhibit a multidrug resistant phenotype. Children with cancer have a high rate of S. aureus bacteremia and associated complications. Increased tolerance to antiseptics among staphylococcal isolates from pediatric oncology patients is an emerging area of research. The incidence of S. aureus infections among pediatric solid organ transplant recipients varies considerably by the organ transplanted; in general however, staphylococci figure prominently among infections in the early posttransplant period. Staphylococcal infections are also prominent pathogens among children with a number of immunodeficiencies, notably chronic granulomatous disease. Significant gaps in knowledge exist regarding the epidemiology and management of S. aureus infection in these vulnerable children. PMID:24855381

  9. MRSA in Africa: Filling the Global Map of Antimicrobial Resistance

    PubMed Central

    Falagas, Matthew E.; Karageorgopoulos, Drosos E.; Leptidis, John; Korbila, Ioanna P.

    2013-01-01

    We sought to assess the prevalence of methicillin-resistance among Staphylococcus aureus isolates in Africa. We included articles published in 2005 or later reporting for the prevalence of MRSA among S. aureus clinical isolates. Thirty-two studies were included. In Tunisia, the prevalence of MRSA increased from 16% to 41% between 2002–2007, while in Libya it was 31% in 2007. In South Africa, the prevalence decreased from 36% in 2006 to 24% during 2007–2011. In Botswana, the prevalence varied from 23–44% between 2000–2007. In Algeria and Egypt, the prevalence was 45% and 52% between 2003–2005, respectively. In Nigeria, the prevalence was greater in the northern than the southern part. In Ethiopia and the Ivory Coast, the prevalence was 55% and 39%, respectively. The prevalence of MRSA was lower than 50% in most of the African countries, although it appears to have risen since 2000 in many African countries, except for South Africa. PMID:23922652

  10. Sampling strategies in antimicrobial resistance monitoring: evaluating how precision and sensitivity vary with the number of animals sampled per farm.

    PubMed

    Yamamoto, Takehisa; Hayama, Yoko; Hidano, Arata; Kobayashi, Sota; Muroga, Norihiko; Ishikawa, Kiyoyasu; Ogura, Aki; Tsutsui, Toshiyuki

    2014-01-01

    Because antimicrobial resistance in food-producing animals is a major public health concern, many countries have implemented antimicrobial monitoring systems at a national level. When designing a sampling scheme for antimicrobial resistance monitoring, it is necessary to consider both cost effectiveness and statistical plausibility. In this study, we examined how sampling scheme precision and sensitivity can vary with the number of animals sampled from each farm, while keeping the overall sample size constant to avoid additional sampling costs. Five sampling strategies were investigated. These employed 1, 2, 3, 4 or 6 animal samples per farm, with a total of 12 animals sampled in each strategy. A total of 1,500 Escherichia coli isolates from 300 fattening pigs on 30 farms were tested for resistance against 12 antimicrobials. The performance of each sampling strategy was evaluated by bootstrap resampling from the observational data. In the bootstrapping procedure, farms, animals, and isolates were selected randomly with replacement, and a total of 10,000 replications were conducted. For each antimicrobial, we observed that the standard deviation and 2.5-97.5 percentile interval of resistance prevalence were smallest in the sampling strategy that employed 1 animal per farm. The proportion of bootstrap samples that included at least 1 isolate with resistance was also evaluated as an indicator of the sensitivity of the sampling strategy to previously unidentified antimicrobial resistance. The proportion was greatest with 1 sample per farm and decreased with larger samples per farm. We concluded that when the total number of samples is pre-specified, the most precise and sensitive sampling strategy involves collecting 1 sample per farm. PMID:24466335

  11. Effect of Tulathromycin on Colonization Resistance, Antimicrobial Resistance, and Virulence of Human Gut Microbiota in Chemostats

    PubMed Central

    Hao, Haihong; Zhou, Shengxi; Cheng, Guyue; Dai, Menghong; Wang, Xu; Liu, Zhenli; Wang, Yulian; Yuan, Zonghui

    2016-01-01

    To evaluate microbiological safety of tulathromycin on human intestinal bacteria, tulathromycin (0, 0.1, 1, 10, and 100 μg/mL) was added into Chemostats. Before and after drug exposure, we monitored (1) population, SCFA products, antimicrobial resistance, and colonization resistance of gut microbiota, and (2) the antimicrobial resistance genes, transferability, virulent genes, pathogenicity of Enterococus faecalis. Results showed that low level of tulathromycin did not exhibit microbiological hazard on resistance selection and colonization resistance. However, high level of tulathromycin (10 and 100 μg/mL) may disturb colonization resistance of human gut microbiota and select antimicrobial resistant E. faecalis. Most of the selected resistant E. faecalis carried resistant gene of ermB, transferable element of Tn1545 and three virulence genes (esp, cylA, and ace). One of them (E. faecalis 143) was confirmed to have higher horizontal transfer risk and higher pathogenicity. The calculated no observable adverse effect concentration (NOAEC) and microbiological acceptable daily intake (mADI) in our study was 1 μg/mL and 14.66 μg/kg.bw/day, respectively. PMID:27092131

  12. Antibiotic-resistant bacteria: prevalence in food and inactivation by food-compatible compounds and plant extracts.

    PubMed

    Friedman, Mendel

    2015-04-22

    Foodborne antibiotic-resistant pathogenic bacteria such as Campylobacter jejuni, Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella enterica, Staphylococcus aureus, Vibrio cholerae, and Vibrio parahemolyticus can adversely affect animal and human health, but a better understanding of the factors involved in their pathogenesis is needed. To help meet this need, this overview surveys and interprets much of our current knowledge of antibiotic (multidrug)-resistant bacteria in the food chain and the implications for microbial food safety and animal and human health. Topics covered include the origin and prevalence of resistant bacteria in the food chain (dairy, meat, poultry, seafood, and herbal products, produce, and eggs), their inactivation by different classes of compounds and plant extracts and by the use of chlorine and physicochemical methods (heat, UV light, pulsed electric fields, and high pressure), the synergistic antimicrobial effects of combinations of natural antimicrobials with medicinal antibiotics, and mechanisms of antimicrobial activities and resistant effects. Possible areas for future research are suggested. Plant-derived and other safe natural antimicrobial compounds have the potential to control the prevalence of both susceptible and resistant pathogens in various environments. The collated information and suggested research will hopefully contribute to a better understanding of approaches that could be used to minimize the presence of resistant pathogens in animal feed and human food, thus reducing adverse effects, improving microbial food safety, and helping to prevent or treat animal and human infections. PMID:25856120

  13. Australian Group on Antimicrobial Resistance Community-onset Gram-negative Surveillance Program annual report, 2010.

    PubMed

    Turnidge, John D; Gottlieb, Thomas; Mitchell, David H; Coombs, Geoffrey W; Pearson, Julie C; Bell, Jan M

    2013-09-01

    The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2010 survey focussed on community-onset infections, examining isolates from urinary tract infections from patients presenting to outpatient clinics, emergency departments or to community practitioners. Two thousand and ninety-two Escherichia coli, 578 Klebsiella species and 268 Enterobacter species were tested using a commercial automated method (Vitek 2, BioMérieux) and results were analysed using Clinical and Laboratory Standards Institute breakpoints from January 2012. Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 3.2% of E. coli and 3.2%-4.0% of Klebsiella spp. Non-susceptibility rates to ciprofloxacin were 5.4% for E. coli, 1.0%-2.3% for Klebsiella spp., and 2.5%-6.6% in Enterobacter spp, and resistance rates to piperacillin-tazobactam were 2.8%, 3.2%-6.9%, and 16.8%-18.0% for the same 3 groups respectively. Only 3 strains, 2 Klebsiella spp. and 1 Enterobacter spp, were shown to harbour a carbapenemase (IMP-4). PMID:24890957

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

    PubMed

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

    2013-09-01

    Hospitals are considered an excellent compartment for the selection of resistant and multi-drug resistant (MDR) bacteria. The overuse and misuse of antimicrobial agents are considered key points fuelling this situation. Antimicrobial stewardship programs have been designed for better use of these compounds to prevent the emergence of resistant microorganisms and to diminish the upward trend in resistance. Nevertheless, the relationship between antibiotic use and antimicrobial resistance is complex, and the desired objectives are difficult to reach. Various factors affecting this relationship have been advocated including, among others, antibiotic exposure and mutant selection windows, antimicrobial pharmacodynamics, the nature of the resistance (natural or acquired, including mutational and that associated with horizontal gene transfer) and the definition of resistance. Moreover, antimicrobial policies to promote better use of these drugs should be implemented not only in the hospital setting coupled with infection control programs, but also in the community, which should also include animal and environmental compartments. Within hospitals, the restriction of antimicrobials, cycling and mixing strategies and the use of combination therapies have been used to avoid resistance. Nevertheless, the results have not always been favorable and resistant bacteria have persisted despite the theoretical benefits of these strategies. Mathematical models as well as microbiological knowledge can explain this failure, which is mainly related to the current scenario involving MDR bacteria and overcoming the fitness associated with resistance. New antimicrobials, rapid diagnostic and antimicrobial susceptibility testing and biomarkers will be useful for future antimicrobial stewardship interventions. PMID:24129283

  15. A new chromogenic medium for isolation of Bacteroides fragilis suitable for screening for strains with antimicrobial resistance.

    PubMed

    Tierney, Daniel; Copsey, Sarah D; Morris, Trefor; Perry, John D

    2016-06-01

    There have been an increasing number of reports describing the acquisition of antimicrobial resistance by Bacteroides fragilis including the occurrence of strains with resistance to multiple antimicrobials that are relied upon for treatment of infections. The aim of this study was to design a chromogenic selective medium for isolation of B. fragilis that could be adapted for specific isolation of antimicrobial-resistant strains. Bacteroides chromogenic agar (BCA) was the result of this endeavour and allowed growth of Bacteroides spp. as black colonies and the efficient inhibition of almost all other genera tested. The medium also allowed some differentiation of B. fragilis from other members of the B. fragilis group. When compared with an adaptation of Bacteroides bile-esculin agar (BBE) for the isolation of B. fragilis from 100 stool samples, 30 isolates of B. fragilis were recovered on BCA compared with 19 isolates recovered on BBE (P = 0.022). When supplemented with meropenem (4 μg/ml) or metronidazole (2 μg/ml), BCA could be used to select for the growth of B. fragilis isolates with resistance to these agents. We conclude that BCA is a useful research tool for surveillance studies to assess the prevalence of B. fragilis and, in particular, the occurrence of antimicrobial-resistant strains. PMID:27060277

  16. Anatomical Distribution and Genetic Relatedness of Antimicrobial Resistant E. coli from Healthy Companion Animals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: Escherichia coli have been targeted for studying antimicrobial resistance in companion animals due to opportunistic infections and as a surrogate for resistance patterns in zoonotic organisms. The aim of our study examined antimicrobial resistance in E. coli isolated from various anatomical ...

  17. ANTIMICROBIAL RESISTANCE IN SALMONELLA FROM 1997-2003 NARMS SWINE SAMPLES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 3246 swine slaughter and 3147 swine diagnostic Salmonella isolates from the National Antimicrobial Resistance Monitoring System (NARMS) for the years 1997-2003 were tested for antimicrobial resistance. No resistance was detected in any Salmonella isolates for ciprofloxacin or amikacin. Fo...

  18. Characterization of antimicrobial resistance of foodborne Listeria monocytogenes.

    PubMed

    Conter, Mauro; Paludi, Domenico; Zanardi, Emanuela; Ghidini, Sergio; Vergara, Alberto; Ianieri, Adriana

    2009-01-15

    The objective of this study was to evaluate the susceptibility of 120 Listeria monocytogenes strains isolated from food and food-processing environments to 19 antibiotics currently used in veterinary and human therapy. Susceptibility tests were performed by using the automated VITEK2 system. Apart from penicillin, ampicillin and trimethoprim-sulfamethoxazole, for which clinical breakpoints for Listeria susceptibility testing are defined according to the Clinical and Laboratory Standard Institute (CLSI), in the present study the CLSI criteria for staphylococci were applied. Among the 120 tested strains, 14 (11.7%) displayed resistance to at least one antibiotic. In particular, resistance to one antibiotic was more common than multiple resistance, i.e., 10 (8.3%) isolates were resistant to one antibiotic, 3 (2.5%) to two antibiotics and one (0.8%) to five antibiotics. Resistance to clindamycin was the most common, followed by linezolid, ciprofloxacin, ampicillin and rifampicin, trimethoprim/sulphamethoxazole and, finally, vancomycin and tetracycline. This study shows that L. monocytogenes strains from food and food-processing environments are susceptible to the antibiotics commonly used in veterinary and human listeriosis treatment. Considering that L. monocytogenes is slowly becoming antibiotic resistant, a continued surveillance of emerging antimicrobial resistance of this pathogen is important to ensure effective treatment of human listeriosis. These data are useful in improving background data on antibiotic resistance of strains isolated from food and food environment. PMID:19012982

  19. Enteric pathogens and antimicrobial resistance in turkey vultures (Cathartes aura) feeding at the wildlife-livestock interface.

    PubMed

    Sulzner, Kate; Kelly, Terra; Smith, Woutrina; Johnson, Christine K

    2014-12-01

    Free-flying turkey vultures (Cathartes aura) were sampled in California to investigate the fecal shedding prevalence and antimicrobial susceptibility of Salmonella enterica, Campylobacter spp., and Escherichia coli. Nine different serotypes of Salmonella enterica were detected in cloacal swabs from turkey vultures, and 6% of vultures were shedding Campylobacter spp.. Turkey vultures sampled at a location with range sheep were more likely to shed tetracycline-resistant E. coli, suggesting that proximity to livestock facilities could facilitate acquisition of drug-resistant bacteria in avian scavengers. These findings illustrate the importance of assessing drug-resistant pathogen transfer at the livestock-wildlife interface. PMID:25632686

  20. Prevalence of multidrug resistant Staphylococcus aureus in milk from large- and small-scale producers in Kenya.

    PubMed

    Shitandi, A; Sternesjö, A

    2004-12-01

    This study evaluated the prevalence of multidrug resistant Staphylococcus aureus in Kenyan milk and investigated any differences in antimicrobial resistance between large- (>200 L/d) and small- (<50 L/d) scale producers. Susceptibility profiles for penicillin G, tetracycline, erythromycin, trimethoprim/sulfamethazine, and chloramphenicol were determined for Staph. aureus (n=402) isolated from cows with subclinical mastitis. There was a significant difference in the overall mean resistance profile between large- (7.1%) and small-scale farm (14.7%) isolates. The overall prevalence of multidrug resistance (> or =2 antibiotics) differed significantly between isolates from small farms (34.3%) and those from large farms (18.0%). Additionally, the producers were interviewed about their usage of antimicrobial drugs and their attitudes toward education in related fields. There was an evident difference between the producer types in their documentation of the use of antimicrobial drugs. Small-scale farms were less inclined to documentation, and treatment records were available from 22% of small-scale farms, compared with 73% of large-scale farms. Farmers expressed a need for more information in 5 areas, ranking preventive management highest (34.0%); followed by affordable tests to control residues in milk (22.8%); preparation of antimicrobial drugs (20.0%); public health concerns (11.2%); disposal of surplus antimicrobial drugs (7.8%); and antimicrobial drug residue persistence in milk (4.2%). It was concluded that herd size might be an indirect risk factor in the development of antimicrobial resistance in Staph. aureus within the region. PMID:15545376

  1. Characterization of Diarrheagenic Antimicrobial Resistant Escherichia coli Isolated From Pediatric Patients in Tehran, Iran

    PubMed Central

    Heidary, Maryam; Momtaz, Hassan; Madani, Mahboobeh

    2014-01-01

    Background: Acute infectious diarrhea is one of the most important causes of morbidity and mortality worldwide. Objectives: The objective of this study was to characterize antimicrobial resistant diarrheagenic Escherichia coli strains isolated from diarrheic children in Tehran, IR Iran. Patients and Methods: In total, 550 stool samples from diarrheic pediatric patients, aged less than 60 months, were collected and immediately transferred to the laboratory. Isolation and identification of E. coli strains was done using bacteriological methods. Antimicrobial susceptibility testing was performed using the disk diffusion technique. Multiplex PCR was used to detect aadA1, tetA, tetB, dfrA1, qnr, aac (3)-IV, sul1, blaSHV, CITM, cat1, and cmlA antibiotic resistance genes. Results: From the total of 550 fecal samples examined, 154 samples (28%) were positive for diarraheagenic E. coli. High rates of antibiotic resistance were seen against penicillin ﴾100%), ampicillin ﴾89.6%﴿ and tetracycline ﴾83.1%﴿. Resistance against ciprofloxacin was low ﴾28.6%﴿. The prevalence of different resistance genes in the studied strains varied from 96.10% for aadA1 gene to 40.25% for sul1 gene. The frequencies of aadA1, tetA, tetB, dfrA1, qnr, aac(3)-IV, sul1, blaSHV, CITM, cat1, and cmlA genes were 96.10%, 85.06%, 84.41%, 51.94%, 72.07%, 54.54%, 40.25%, 57.79%, 90.25%, 59.74% and 60.38%, respectively. Conclusions: Our results indicated that antibiotic resistance is increasing in diarraheagenic E. coli strains in Iran. It is imperative to develop strategies for prevention and control of resistant organisms. Changes in patterns of resistance against commonly used antibiotics in Iran indicate that an applied surveillance system and introduction of guidelines for appropriate antibiotic prescription are necessary. PMID:24910786

  2. Antimicrobial resistance of major foodborne pathogens from major meat products.

    PubMed

    Gousia, Panagiota; Economou, Vagelis; Sakkas, Hercules; Leveidiotou, Stamatina; Papadopoulou, Chrissanthy

    2011-01-01

    The bacterial contamination of raw and processed meat products with resistant pathogens was studied. The raw samples included sheep (40), goat (40), pork (120), beef (80), and chicken (19) meat, and the processed samples included turkey filets (33), salami (8), readymade mincemeat (16), stuffing (22), and roast-beef (50). The samples were collected from retail shops in Northwestern Greece over a period of 3 years. The isolated pathogens were evaluated for susceptibilities to 19 antimicrobial agents used in humans. Out of 428 samples, 157 strains of Escherichia coli, 25 of Yersinia enterocolitica, 57 of Staphylococcus aureus, 57 of Enterococcus spp., 4 of Salmonella spp., and 3 of Campylobacter jejuni were isolated. Among the isolates 14.6% of the E. coli, 10.5% of S. aureus, 4% of Y. enterocolitica, 25% of Salmonella spp., and 42.1% of Enterococcus spp. were susceptible to antibiotics. E. coli from chicken exhibited high rates of resistance to ciprofloxacin (62.5%) followed by lamb/goat (10.9%), pork (15.7%), and beef (27.9%) meat. Resistance to nitrofurantoin dominated in the lamb/goat isolates (60%). Resistance to tetracycline predominated in pork (68.2%) and chicken (62.5%), and resistance to aminoglycosides dominated in lamb/goat meat isolates. S. aureus resistance to clindamycin predominated in lamb/goat isolates (50%), whereas resistance to ciprofloxacin predominated in the pork strains, but no resistance to methicillin was observed. Of the enterococci isolates 21.1% were resistant to vancomycin. High resistance to ampicillin (96%) was observed in Y. enterocolitica and all of the C. jejuni isolates were resistant to ampicillin, cephalothin, and cefuroxime. These results indicate that meat can be a source of resistant bacteria, which could potentially be spread to the community through the food chain. PMID:21039131

  3. Antimicrobial Resistance and Genotypic Diversity of Campylobacter Isolated from Pigs, Dairy, and Beef Cattle in Tanzania.

    PubMed

    Kashoma, Isaac P; Kassem, Issmat I; Kumar, Anand; Kessy, Beda M; Gebreyes, Wondwossen; Kazwala, Rudovick R; Rajashekara, Gireesh

    2015-01-01

    Foodborne Campylobacter infections pose a serious threat to public health worldwide. However, the occurrence and characteristics of Campylobacter in food animals and products remain largely unknown in Tanzania. The objective of this study was to determine the prevalence, antibiotic resistance, and genetic profiles (sequence types, STs) of Campylobacter isolated from feces of pigs and dairy and beef cattle in Tanzania. Overall, 259 (~30%) of 864 samples were positive for Campylobacter spp, which were detected in 32.5, 35.4, and 19.6% of the pig, dairy, and beef cattle samples, respectively. Multiplex PCR analysis identified 64.5 and 29.3% of the Campylobacter isolates as C. coli and C. jejuni, respectively. The majority (91.9%) of the isolates from pig samples were identified as C. coli, while C. jejuni accounted for 65.5% of the isolates from cattle. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method revealed resistance to: ampicillin (Amp) (70.3% and 75.7%, respectively), gentamicin (Gen) (1.8% and 12.6%), streptomycin (Str) (65.8 and 74.8%), erythromycin (Ery) (41.4 and 48.7%), tetracycline (Tet) (18.9 and 23.4%), and ciprofloxacin (Cip) (14.4 and 7.2%). Resistance to nalidixic acid (Nal) (39.6%), azithromycin (Azm) (13.5%), and chloramphenicol (Chl) (4.5%) was determined using the disk diffusion assay only, while resistance to tylosin (Tyl) (38.7%) was quantified using the broth microdilution method. Multilocus sequence typing of 111 Campylobacter isolates resulted in the identification of 48 STs (26 C. jejuni and 22 C. coli) of which seven were novel (six C. jejuni and one C. coli). Taken together, this study revealed the high prevalence, genetic diversity and antimicrobial resistance of Campylobacter in important food animals in Tanzania, which highlights the urgent need for the surveillance and control of Campylobacter in this country. PMID:26617582

  4. Antimicrobial Resistance and Genotypic Diversity of Campylobacter Isolated from Pigs, Dairy, and Beef Cattle in Tanzania

    PubMed Central

    Kashoma, Isaac P.; Kassem, Issmat I.; Kumar, Anand; Kessy, Beda M.; Gebreyes, Wondwossen; Kazwala, Rudovick R.; Rajashekara, Gireesh

    2015-01-01

    Foodborne Campylobacter infections pose a serious threat to public health worldwide. However, the occurrence and characteristics of Campylobacter in food animals and products remain largely unknown in Tanzania. The objective of this study was to determine the prevalence, antibiotic resistance, and genetic profiles (sequence types, STs) of Campylobacter isolated from feces of pigs and dairy and beef cattle in Tanzania. Overall, 259 (~30%) of 864 samples were positive for Campylobacter spp, which were detected in 32.5, 35.4, and 19.6% of the pig, dairy, and beef cattle samples, respectively. Multiplex PCR analysis identified 64.5 and 29.3% of the Campylobacter isolates as C. coli and C. jejuni, respectively. The majority (91.9%) of the isolates from pig samples were identified as C. coli, while C. jejuni accounted for 65.5% of the isolates from cattle. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method revealed resistance to: ampicillin (Amp) (70.3% and 75.7%, respectively), gentamicin (Gen) (1.8% and 12.6%), streptomycin (Str) (65.8 and 74.8%), erythromycin (Ery) (41.4 and 48.7%), tetracycline (Tet) (18.9 and 23.4%), and ciprofloxacin (Cip) (14.4 and 7.2%). Resistance to nalidixic acid (Nal) (39.6%), azithromycin (Azm) (13.5%), and chloramphenicol (Chl) (4.5%) was determined using the disk diffusion assay only, while resistance to tylosin (Tyl) (38.7%) was quantified using the broth microdilution method. Multilocus sequence typing of 111 Campylobacter isolates resulted in the identification of 48 STs (26 C. jejuni and 22 C. coli) of which seven were novel (six C. jejuni and one C. coli). Taken together, this study revealed the high prevalence, genetic diversity and antimicrobial resistance of Campylobacter in important food animals in Tanzania, which highlights the urgent need for the surveillance and control of Campylobacter in this country. PMID:26617582

  5. Antimicrobial (Drug) Resistance: Methicillin-Resistant Staphylococcus aureus (MRSA)

    MedlinePlus

    ... NIAID invests in basic research to understand the biology of microbes, their behavior, and how drug resistance ... Nucleotide Polymorphism Phylogenetics & Ontology Proteomics & Protein Analysis Systems Biology Data Portals Software Applications BCBB Mobyle Interface Designer ( ...

  6. Characterization of antimicrobial resistance in Klebsiella species isolated from chicken broilers.

    PubMed

    Wu, Hao; Wang, Mingyu; Liu, Yuqing; Wang, Xinhua; Wang, Yunkun; Lu, Jinxing; Xu, Hai

    2016-09-01

    The prevalence of antimicrobial resistant Klebsiella pneumoniae in poultry products has been a public concern, as it severely endangers food safety and human health. In this study, we investigated 90 antimicrobial resistant Klebsiella strains that were isolated from a commercial broiler slaughter plant in Shandong province of China. Nearly all (89/90) of the isolates were identified as infectious phylogenetic group KpI-type K. pneumoniae. Out of these 90 strains, 87 (96.7%) were multidrug-resistant isolates, and 87 (96.7%) were extended-spectrum beta-lactamase (ESBL)-producing isolates. An analysis of the prevalence of quinolone resistance genes showed that 7.8%, 77.8%, 26.7%, and 2.2% of the strains carried the qnrA, qnrB, qnrS, and qepA genes, respectively. An analysis of beta-lactam resistance genes showed that a high percentage of the strains contain the blaTEM (76.7%), blaSHV (88.9%), and blaCTX-M (75.6%) genes, among which three blaSHV subtypes (blaSHV-1, n=30; blaSHV-11, n=38; blaSHV-12, n=12) and three blaCTX-M subtypes (blaCTX-M-14, n=14; blaCTX-M-15, n=35; blaCTX-M-55, n=19) were found. A further investigation of mobile genetic elements involved in horizontal multidrug resistance gene transfer showed the presence of class 1 and 2 integrons in 77 (85.6%) and five (5.6%) isolates, respectively, while no class 3 integrons were detected. Four types of class 1 integrons containing specific gene cassette arrays (dfrA12-orfF-aadA2, dfrA17-aadA5, dfrA1-aadA1, and empty) were identified. Only one gene cassette array (dfrA1-sat2-aadA1) was detected in the class 2 integrons. Furthermore, four different types of insertion sequence common region 1 (ISCR1)-mediated downstream structures were successfully identified in 46 class 1 integron-positive isolates, among which ISCR1-sapA-like-qnrB2-qacEΔ1 was the most commonly observed structure. Chi-square tests revealed a significant association between ESBL genes, plasmid-mediated quinolone resistance (PMQR) genes, and

  7. An update on antimicrobial resistance research activities in the ARS-BEAR Unit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the 1990’s, Because of the public health concerns associated with the use of antimicrobials in livestock were increasing, and the potential utility of antimicrobial susceptibility testing for monitoring trends in antimicrobial resistance development was recognized. To meet this challenge, an ant...

  8. [Antimicrobial resistance: is it really all going wrong now?].

    PubMed

    Bonten, Marc J M

    2016-01-01

    In November 2015, plasmid-mediated colistin resistance in Gram-negative bacteria was reported for the first time, and it was evident that this newly-identified resistance gene (mcr-1) was already prevalent in the animal and human reservoir in China. As well as massive media attention, there was also a massive scientific response. As of 22 January 2016, the interpretation of all the evidence is that the mcr-1 was already in existence in 2005 and is not bound to a single plasmid. Its presence has now been demonstrated on four continents and the gene seems widely prevalent in animal reservoirs across the globe, with a very low prevalence in collections of human isolates. Based on current findings there seems to be no reason to change clinical practices for Dutch patients. PMID:26860752

  9. Coping with the rising tide of resistance to antimicrobial agents.

    PubMed

    Hunter, P A

    2001-06-01

    The 11th European Congress of Clinical Microbiology and Infectious Diseases was held in Istanbul, Turkey, from April 2nd to April 4th, 2001. The meeting was attended by approximately 4,500 people. Sessions were well attended and included a number of workshops, keynote lectures, symposia, free papers and posters. As at many chemotherapy meetings in recent years, a major topic was the continuing growth of resistance among all microbes to antimicrobial agents, and this is the topic highlighted in this report. PMID:12813593

  10. Antimicrobial resistance trends in blood culture positive Salmonella Paratyphi A isolates from Pondicherry, India.

    PubMed

    Menezes, G A; Harish, B N; Khan, M A; Goessens, W; Hays, J P

    2016-01-01

    Enteric fever is a public health problem with the upsurge in the occurrence of Salmonella isolates that are resistant to ciprofloxacin. In this study, a total of 284 blood culture isolates of S. Paratyphi A were investigated. Of these isolates, 281 (98.9%) were nalidixic acid resistant. A high rate (6.3%) of high-level resistance (≥4 μg/mL) was found to ciprofloxacin. The isolates with ciprofloxacin minimum inhibitory concentrations (MICs) of ≥12 μg/mL had 4 mutations, 2 mutations within the quinolone resistance-determining region of gyrA and 2 mutations also in parC. According to the Clinical Laboratory Standards Institute 2012 MIC breakpoints, 75.0% of isolates were resistant to ciprofloxacin. Finally, 3 major pulsed-field gel electrophoresis patterns were observed among the S. Paratyphi A isolates. The spread of fluoroquinolone resistant S. Paratyphi A necessitates a change toward 'evidence-based' treatment for enteric fever. The research provides a perspective on the increasing prevalence of antimicrobial resistant S. Paratyphi A isolates in this region of India. PMID:27080779

  11. Phenothiazinium antimicrobial photosensitizers are substrates of bacterial multidrug resistance pumps.

    PubMed

    Tegos, George P; Hamblin, Michael R

    2006-01-01

    Antimicrobial photodynamic therapy (PDT) combines a nontoxic photoactivatable dye, or photosensitizer (PS), with harmless visible light to generate singlet oxygen and free radicals that kill microbial cells. Although the light can be focused on the diseased area, the best selectivity is achieved by choosing a PS that binds and penetrates microbial cells. Cationic phenothiazinium dyes, such as methylene blue and toluidine blue O, have been studied for many years and are the only PSs used clinically for antimicrobial PDT. Multidrug resistance pumps (MDRs) are membrane-localized proteins that pump drugs out of cells and have been identified for a wide range of organisms. We asked whether phenothiazinium salts with structures that are amphipathic cations could potentially be substrates of MDRs. We used MDR-deficient mutants of Staphylococcus aureus (NorA), Escherichia coli (TolC), and Pseudomonas aeruginosa (MexAB) and found 2 to 4 logs more killing than seen with wild-type strains by use of three different phenothiazinium PSs and red light. Mutants that overexpress MDRs were protected from killing compared to the wild type. Effective antimicrobial PSs of different chemical structures showed no difference in light-mediated killing depending on MDR phenotype. Differences in uptake of phenothiazinium PS by the cells depending on level of MDR expression were found. We propose that specific MDR inhibitors could be used in combination with phenothiazinium salts to enhance their photodestructive efficiency. PMID:16377686

  12. Strategies to potentiate antimicrobial photoinactivation by overcoming resistant phenotypes†

    PubMed Central

    Vera, D. Mariano A.; Haynes, Mark H; Ball, Anthony R.; Dai, D. Tianhong; Astrakas, Christos; Kelso, Michael J; Hamblin, Michael R; Tegos, George P.

    2012-01-01

    Conventional antimicrobial strategies have become increasingly ineffective due to the emergence of multidrug resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered the exploration of alternative treatments and unconventional approaches towards controlling microbial infections. Photodynamic therapy was originally established as an anti-cancer modality and is currently used in the treatment of age related macular degeneration. The concept of photodynamic inactivation requires cell exposure to light energy, typically wavelengths in the visible region that causes the excitation of photosensitizer molecules either exogenous or endogenous, which results in the production of reactive oxygen species. ROS produce cell inactivation and death through modification of intracellular components. The versatile characteristics of PDT prompted its investigation as an anti-infective discovery platform. Advances in understanding of microbial physiology have shed light on a series of pathways, and phenotypes that serve as putative targets for antimicrobial drug discovery. Investigations of these phenotypic elements in concert with PDT have been reported focused on multidrug efflux systems, biofilms, virulence and pathogenesis determinants. In many instances the results are promising but only preliminary and require further investigation. This review discusses the different antimicrobial PDT strategies and highlights the need for highly informative and comprehensive discovery approaches. PMID:22242675

  13. Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections.

    PubMed

    Crump, John A; Sjölund-Karlsson, Maria; Gordon, Melita A; Parry, Christopher M

    2015-10-01

    Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015. PMID:26180063

  14. Frequency, virulence genes and antimicrobial resistance of Listeria spp. isolated from bovine clinical mastitis.

    PubMed

    Jamali, Hossein; Radmehr, Behrad

    2013-11-01

    The aims of this study were to determine the prevalence, characteristics and antimicrobial resistance of Listeria spp. isolated from bovine clinical mastitis in Iran. Listeria spp. were detected in 21/207 bovine mastitic milk samples from dairy farms in Iran, comprising L. monocytogenes (n=17), L. innocua (n=3) and L. ivanovii (n=1). L. monocytogenes isolates were grouped into serogroups '4b, 4d, 4e', '1/2a, 3a', '1/2b, 3b, 7' and '1/2c, 3c'; all harboured inlA, inlC and inlJ virulence genes. Listeria spp. were most frequently resistant to penicillin G (14/21 isolates, 66.7%) and tetracyclines (11/21 isolates, 52.4%). PMID:23880504

  15. The contribution of class 1 integron to antimicrobial resistance in Stenotrophomonas maltophilia.

    PubMed

    Huang, Yi-Wei; Hu, Rouh-Mei; Lin, Yi-Tsung; Huang, Hsin-Hui; Yang, Tsuey-Ching

    2015-02-01

    Two hundred clinical isolates of Stenotrophomonas maltophilia were examined for the presence of class 1 integron and for the susceptibility to 12 different antimicrobials and detergents. The prevalence of class 1 integron in S. maltophilia isolates was 11%. The class 1 integron-positive isolates exhibited a higher resistance to kanamycin, tobramycin, and trimethoprim-sulfamethoxazole (SXT) than the class 1 integron-negative ones. Polymerase chain reaction (PCR), amplifying the variable region of the class 1 integron, showed the existence of six different amplicon sizes, indicating that there are at least six different class 1 integrons distributed in the 23 class 1 integron-positive isolates. Sequence analysis of six representative PCR amplicons revealed that qacK, aac(6')-Ib', qacK-aac(6')-Ib, qacK-aac(6')-Ib-aac(6')-Ib, and qacL-aadB-cmlA-aadA2 were identified in the 550-, 800-, 1,200-, 1,800, and 3,600-bp amplicons, respectively. The sequence analysis of the 150-bp PCR amplicon demonstrated no additional resistance-associated genes except the basic genetic elements of class 1 integron. The impact of class 1 integron acquisition on the antimicrobials susceptibility was assayed by isogenic integron deletion mutant construction and the susceptibility test. The most significant contribution of the class 1 integron acquisition to S. maltophilia is the increased resistance to SXT. PMID:25243757

  16. Characterization of multidrug-resistant Escherichia coli by antimicrobial resistance profiles, plasmid replicon typing, and pulsed-field gel electrophoresis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aim: Plasmid characterization has particular clinical importance because genes encoding significant traits including antimicrobial resistance are frequently carried on plasmids. The objective of this study was to examine the distribution of multidrug resistance (MDR) in Escherichia coli in relation ...

  17. [Susceptibility and resistence of Pseudomonas aeruginosa to antimicrobial agents].

    PubMed

    Gamero Delgado, M C; García-Mayorgas, A D; Rodríguez, F; Ibarra, A; Casal, M

    2007-06-01

    Pseudomonas aeruginosa is an opportunistic microorganism that is frequently the cause of nosocomial infections. Multiple mechanisms are involved in its natural and acquired resistance to many of the antimicrobial agents commonly used in clinical practice. The objective of this study was to assess the susceptibility and resistance patterns of P. aeruginosa strains isolated in Hospital Reina Sofia between 2000 and 2005, as well as to analyze the differences between intrahospital and extrahospital isolates in 2005 and to compare the results with those obtained in other studies. A total of 3,019 strains of P. aeruginosa from different hospitals and nonhospital settings were evaluated, taking into consideration their degree of sensitivity to different antibiotics. The MICs were determined by means of the Wider I automated system (Soria Melguizo), taking into consideration the criteria of susceptibility and resistance recommended by MENSURA. Results of the analysis showed that P. aeruginosa maintained similar levels of antimicrobial susceptibility during the period 2000-2005, with increased susceptibility to amikacin, gentamicin and tobramycin. There were also important differences in the degree of susceptibility between intrahospital and extrahospital strains, except for imipenem and fosfomycin. The intrahospital difference in susceptibility was also evaluated, emphasizing the importance of periodically studying susceptibility and resistance patterns of P. aeruginosa in each setting in order to evaluate different therapeutic guidelines, as it is not always advisable to extrapolate data from different regions. These differences can be explained by the different use of antibiotics in each center and the geographic variations of the resistance mechanisms of P. aeruginosa. PMID:17893761

  18. Antimicrobial resistance in food and clinical Aeromonas isolates.

    PubMed

    Palú, Angela Peres; Gomes, Luciana Martins; Miguel, Marco Antônio Lemos; Balassiano, Ilana Teruzkin; Queiroz, Mara Lucia Penna; Freitas-Almeida, Angela Corrêa; de Oliveira, Selma Soares

    2006-08-01

    This study highlights the incidence of resistance and the presence of plasmids in human and food isolates of Aeromonas in Brazil. A total of 83 Aeromonas spp. strains (28 isolated from human and 55 from fresh lettuce) were studied. Thirty-five were identified as A. hydrophila complex and 48 as A. caviae complex. All strains were shown to be susceptible to imipenem, amikacin, gentamicin, tobramycin and ciprofloxacin by the disk diffusion method. Resistance to antimicrobial agents was observed in strains of both food and clinical origin. The food strains were resistant to ampicillin/sulbactam, cefoxitin and tetracycline, while the clinical strains presented resistance to ampicillin/sulbactam, cefotaxime, ceftazidime, cefoxitin, sulfamethoxazole/trimethoprim, chloramphenicol and tetracycline. The minimal inhibitory concentrations of chloramphenicol, tetracycline and sulfamethoxazole/trimethoprim were tested by agar dilution. Thirteen strains isolated from vegetables were resistant to tetracycline (MIC 16 microg ml-1). Two A. hydrophila strains and one A. caviae strain presented extracromosomal DNA (3 and 15 kb plasmids, respectively). The tetracycline resistance phenotype determinant was related to the 15 kb plasmid according to cure and transformation experiments. PMID:16943044

  19. Antimicrobial resistance of Salmonella isolated from finishing swine and the environment of 60 Alberta swine farms.

    PubMed

    Rajić, Andrijana; McFall, Margaret E; Deckert, Anne E; Reid-Smith, Richard; Manninen, Ken; Poppe, Cornelius; Dewey, Catherine E; McEwen, Scott A

    2004-12-01

    The study objective was to describe and evaluate antimicrobial resistance profiles in Salmonella isolated from Alberta swine finishing farms. Salmonella isolates (n = 322) were obtained from 192 fecal and 84 environmental samples of the 60 Salmonella-positive swine finishing farms. Isolates were classified susceptible, intermediate or resistant based on NCCLS guidelines. More than half of the isolates (53.4%) were susceptible to all of the 18 antimicrobials in the testing panel. No resistance was observed to amikacin, amoxicillin/clavulanic acid, cefoxitin, ceftiofur, ceftriaxone, cephalothin, ciprofloxacin, imipenem or nalidixic acid. Less than 1% of isolates were resistant to apramycin, gentamicin and trimethoprim/sulfamethoxazole. Higher frequencies of resistance were observed for chloramphenicol (4.7%), ampicillin (7.8%), kanamycin (11.8%), sulfamethoxazole (21.1%), streptomycin (25.5%) and tetracycline (38.8%). Eleven Salmonella serovars had isolates with resistance to > or =3 antimicrobials. The most frequently resistant serovar was Salmonella Derby, with 27 (38.0%) isolates resistant to > or =3 antimicrobials, including resistance to five and six antimicrobials. An absence of resistance to cephalosporins and fluoroquniolones and a low proportion of isolates resistant to amikacin, amoxicillin/clavulanic acid, apramycin, gentamicin and trimethoprim/sulfamethoxazole are encouraging findings from public health and animal health perspectives. Frequent resistance observed for ampicillin, kanamycin, sulfamethoxazole, streptomycin and tetracycline, antimicrobials commonly used in veterinary medicine for decades, indicates an urgent need to utilize these antimicrobials more prudently if their benefits are to be preserved. PMID:15564027

  20. Treatment of Helicobacter pylori infection: Meeting the challenge of antimicrobial resistance

    PubMed Central

    Papastergiou, Vasilios; Georgopoulos, Sotirios D; Karatapanis, Stylianos

    2014-01-01

    Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders including peptic ulcer disease and gastric cancer. Due to the wide increase in prevalence of H. pylori resistance to antibiotics, clarithromycin-based triple therapies are not any more suitable for unconditional empiric use, and should not be recommended, unless local resistance to this antibiotic is low (< 20%). Alternative strategies have been proposed to overcome the issue of increasing clarithromycin resistance, and some of them are already implemented in clinical practice. These comprise: (1) adoption of novel, more effective, empirical treatments: bismuth quadruple, sequential, non-bismuth quadruple (concomitant), dual-concomitant (hybrid), and levofloxacin-based regimens, the latter mainly designated as second-line/rescue options; (2) perspectives for a susceptibility-guided (tailored) therapeutic approach based on culture-free molecular testing methods; and (3) adjunct use of probiotics to improve eradication rates. The present article is aimed to provide a comprehensive overview of current and emerging strategies in the treatment of H. pylori infection, focusing on the challenge of antimicrobial resistance. PMID:25110420

  1. Treatment of Helicobacter pylori infection: meeting the challenge of antimicrobial resistance.

    PubMed

    Papastergiou, Vasilios; Georgopoulos, Sotirios D; Karatapanis, Stylianos

    2014-08-01

    Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders including peptic ulcer disease and gastric cancer. Due to the wide increase in prevalence of H. pylori resistance to antibiotics, clarithromycin-based triple therapies are not any more suitable for unconditional empiric use, and should not be recommended, unless local resistance to this antibiotic is low (< 20%). Alternative strategies have been proposed to overcome the issue of increasing clarithromycin resistance, and some of them are already implemented in clinical practice. These comprise: (1) adoption of novel, more effective, empirical treatments: bismuth quadruple, sequential, non-bismuth quadruple (concomitant), dual-concomitant (hybrid), and levofloxacin-based regimens, the latter mainly designated as second-line/rescue options; (2) perspectives for a susceptibility-guided (tailored) therapeutic approach based on culture-free molecular testing methods; and (3) adjunct use of probiotics to improve eradication rates. The present article is aimed to provide a comprehensive overview of current and emerging strategies in the treatment of H. pylori infection, focusing on the challenge of antimicrobial resistance. PMID:25110420

  2. Use of Colistin and Other Critical Antimicrobials on Pig and Chicken Farms in Southern Vietnam and Its Association with Resistance in Commensal Escherichia coli Bacteria

    PubMed Central

    Nguyen, Hoa M.; Nguyen, Cuong V.; Nguyen, Trung V.; Nguyen, Men T.; Thai, Hieu Q.; Ho, Mai H.; Thwaites, Guy; Ngo, Hoa T.; Baker, Stephen; Carrique-Mas, Juan

    2016-01-01

    ABSTRACT Antimicrobial resistance (AMR) is a global health problem, and emerging semi-intensive farming systems in Southeast Asia are major contributors to the AMR burden. We accessed 12 pig and chicken farms at key stages of production in Tien Giang Province, Vietnam, to measure antimicrobial usage and to investigate the prevalence of AMR to five critical antimicrobials (β-lactams, third-generation cephalosporins, quinolones, aminoglycosides, and polymyxins) and their corresponding molecular mechanisms among 180 Escherichia coli isolates. Overall, 94.7 mg (interquartile range [IQR], 65.3 to 151.1) and 563.6 mg (IQR, 398.9 to 943.6) of antimicrobials was used to produce 1 kg (live weight) of chicken and pig, respectively. A median of 3 (out of 8) critical antimicrobials were used on pig farms. E. coli isolates exhibited a high prevalence of resistance to ampicillin (97.8% and 94.4% for chickens and pigs, respectively), ciprofloxacin (73.3% and 21.1%), gentamicin (42.2% and 35.6%), and colistin (22.2% and 24.4%). The prevalence of a recently discovered colistin resistance gene, mcr-1, was 19 to 22% and had strong agreement with phenotypic colistin resistance. We conducted plasmid conjugation experiments with 37 mcr-1 gene-positive E. coli isolates and successfully observed transfer of the gene in 54.0% of isolates through a plasmid of approximately 63 kb, consistent with one recently identified in China. We found no significant correlation between total use of antimicrobials at the farm level and AMR. These data provide additional insight into the role of mcr-1 in colistin resistance on farms and outline the dynamics of phenotypic and genotypic AMR in semi-intensive farming systems in Vietnam. IMPORTANCE Our study provides accurate baseline information on levels of antimicrobial use, as well as on the dynamics of phenotypic and genotypic resistance for antimicrobials of critical importance among E. coli over the different stages of production in emerging pig and

  3. Recent Exposure to Antimicrobials and Carbapenem-Resistant Enterobacteriaceae: The Role of Antimicrobial Stewardship

    PubMed Central

    Marchaim, Dror; Chopra, Teena; Bhargava, Ashish; Bogan, Christopher; Dhar, Sorabh; Hayakawa, Kayoko; Pogue, Jason M.; Bheemreddy, Suchitha; Blunden, Christopher; Shango, Maryann; Swan, Jessie; Lephart, Paul R.; Perez, Federico; Bonomo, Robert A.; Kaye, Keith S.

    2014-01-01

    BACKGROUND Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging worldwide. Control group selection is critically important when analyzing predictors of antimicrobial resistance. Focusing on modifiable risk factors can optimize prevention and resource expenditures. To identify specific predictors of CRE, patients with CRE were compared with 3 control groups: (1) patients with extended-spectrum β-lactamase (ESBL)–producing Enterobacteriaceae, (2) patients with non-ESBL-containing Enterobacteriaceae, and (3) uninfected controls. DESIGN Matched multivariable analyses. PATIENTS AND SETTING Patients possessing CRE that were isolated at Detroit Medical Center from September 1, 2008, to August 31, 2009. METHODS Patients were matched (1 : 1 ratio) to the 3 sets of controls. Matching parameters included (1) bacteria type, (2) hospital/facility, (3) unit/clinic, (4) calendar year, and (5) time at risk (ie, from admission to culture). Matched multivariable analyses were conducted between uninfected controls and patients with CRE, ESBL, and non-ESBL Enterobacteriaceae. Models were also designed comparing patients with CRE to patients with ESBL, patients with non-ESBL Enterobacteriaceae, and all 3 non-CRE groups combined. RESULTS Ninety-one unique patients with CRE were identified, and 6 matched models were constructed. Recent (less than 3 months) exposure to antibiotics was the only parameter that was consistently associated with CRE, regardless of the group to which CRE was compared, and was not independently associated with isolation of ESBL or non-ESBL Enterobacteriaceae. CONCLUSIONS Exposure to antibiotics within 3 months was an independent predictor that characterized patients with CRE isolation. As a result, antimicrobial stewardship efforts need to become a major focus of preventive interventions. Regulatory focus regarding appropriate antimicrobial use might decrease the detrimental effects of antibiotic misuse and spread of CRE. PMID:22759550

  4. Antimicrobial Resistance of Escherichia fergusonii Isolated from Broiler Chickens.

    PubMed

    Simmons, Karen; Islam, M Rashedul; Rempel, Heidi; Block, Glenn; Topp, Edward; Diarra, Moussa S

    2016-06-01

    The objective of this study was to investigate the antibiotic resistance of Escherichia fergusonii isolated from commercial broiler chicken farms. A total of 245 isolates from cloacal and cecal samples of 28- to 36-day-old chickens were collected from 32 farms. Isolates were identified using PCR, and their susceptibility to 16 antibiotics was determined by disk diffusion assay. All isolates were susceptible to meropenem, amikacin, and ciprofloxacin. The most common resistances were against ampicillin (75.1%), streptomycin (62.9%), and tetracycline (57.1%). Of the 184 ampicillin-resistant isolates, 127 were investigated using a DNA microarray carrying 75 probes for antibiotic resistance genetic determinants. Of these 127 isolates, the β-lactamase blaCMY2, blaTEM, blaACT, blaSHV, and blaCTX-M-15 genes were detected in 120 (94.5%), 31 (24.4%), 8 (6.3%), 6 (4.7%), and 4 (3.2%) isolates, respectively. Other detected genes included those conferring resistance to aminoglycosides (aadA1, strA, strB), trimethoprims (dfrV, dfrA1), tetracyclines (tetA, tetB, tetC, tetE), and sulfonamides (sul1, sul2). Class 1 integron was found in 35 (27.6%) of the ampicillin-resistant isolates. However, our data showed that the tested E. fergusonii did not carry any carbapenemase blaOXA genes. Pulsed-field gel electrophoresis revealed that the selected ampicillin-resistant E. fergusonii isolates were genetically diverse. The present study indicates that the monitoring of antimicrobial-resistant bacteria should include enteric bacteria such as E. fergusonii, which could be a reservoir of antibiotic resistance genes. The detection of isolates harboring extended-spectrum β-lactamase genes, particularly blaCTX-M-15, in this work suggests that further investigations on the occurrence of such genes in broilers are warranted. PMID:27296596

  5. Mechanisms and consequences of bacterial resistance to antimicrobial peptides.

    PubMed

    Andersson, D I; Hughes, D; Kubicek-Sutherland, J Z

    2016-05-01

    Cationic antimicrobial peptides (AMPs) are an intrinsic part of the human innate immune system. Over 100 different human AMPs are known to exhibit broad-spectrum antibacterial activity. Because of the increased frequency of resistance to conventional antibiotics there is an interest in developing AMPs as an alternative antibacterial therapy. Several cationic peptides that are derivatives of AMPs from the human innate immune system are currently in clinical development. There are also ongoing clinical studies aimed at modulating the expression of AMPs to boost the human innate immune response. In this review we discuss the potential problems associated with these therapeutic approaches. There is considerable experimental data describing mechanisms by which bacteria can develop resistance to AMPs. As for any type of drug resistance, the rate by which AMP resistance would emerge and spread in a population of bacteria in a natural setting will be determined by a complex interplay of several different factors, including the mutation supply rate, the fitness of the resistant mutant at different AMP concentrations, and the strength of the selective pressure. Several studies have already shown that AMP-resistant bacterial mutants display broad cross-resistance to a variety of AMPs with different structures and modes of action. Therefore, routine clinical administration of AMPs to treat bacterial infections may select for resistant bacterial pathogens capable of better evading the innate immune system. The ramifications of therapeutic levels of exposure on the development of AMP resistance and bacterial pathogenesis are not yet understood. This is something that needs to be carefully studied and monitored if AMPs are used in clinical settings. PMID:27180309

  6. Navigating the World Wide Web in search of resources on antimicrobial resistance.

    PubMed

    Harbarth, Stephan; Emonet, Stephane

    2006-07-01

    This overview gives information on navigating for English-language Web sites on antimicrobial resistance. Web sites were gathered on the basis of personal files, articles, and an exhaustive Web search of cross-links from other Web pages. The Web sites were categorized according to users' needs into 5 broad categories, as follows: comprehensive Web sites, with information on all aspects of antimicrobial resistance-related issues; Web sites with patient information about antimicrobial resistance and about methicillin-resistant Staphylococcus aureus, in particular; Web sites covering current multinational surveillance programs; Web sites on prevention of antimicrobial resistance in health care facilities; and Web sites on control of antimicrobial resistance in the community. We compiled a selection of Web sites that seemed to be useful as starting points for physicians, epidemiologists, researchers, or patients interested in this topic. PMID:16758421

  7. Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats

    PubMed Central

    Abdalrahman, Lubna S.; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K.

    2015-01-01

    Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

  8. Common antimicrobial resistance phenotypes and genotypes of fecal Escherichia coli isolates from a single family over a 6-month period.

    PubMed

    Al-Dweik, Manar R; Shehabi, Asem A

    2009-06-01

    This study investigated the antimicrobial resistance phenotypes and genotypes among fecal Escherichia coli isolates from the members of a single Jordanian family over a 6-month period. A total of 55 (51%) E. coli isolates were resistant to >2, and 21 (19%) to >3 of the 14 tested antimicrobial agents, respectively. The highest resistance rates were observed to tetracycline (42%), followed by coamoxyclav and cotrimoxazole (32%), gentamicin (31%), and nalidixic acid (27%). Sixteen out of 21 (76%) multiresistant E. coli isolates (resistant to >3 drugs) transferred most of their resistance markers in vitro to E. coli K12. Five out of the six family members were colonized with E. coli carrying one or two of the two common plasmid sizes (54.3 and 13.2 kb). Ten of these isolates (48%) were positive for class 1 integron genes and harbored four tet (A) and five tet (B) genes, respectively, but all were negative for tet (39). The genetic diversity of E. coli isolates using randomly amplified polymorphic DNA-PCR demonstrated 13 major clusters of genotype groups, and most of the isolates (63%) belonged to one genotype group. This study indicates that all six family members are colonized with fecal E. coli isolates exhibiting a common number of antimicrobial resistance phenotypes and at least one prevalent genotype. PMID:19432518

  9. Laboratory-based nationwide surveillance of antimicrobial resistance in Ghana

    PubMed Central

    Opintan, Japheth A; Newman, Mercy J; Arhin, Reuben E; Donkor, Eric S; Gyansa-Lutterodt, Martha; Mills-Pappoe, William

    2015-01-01

    Global efforts are underway to combat antimicrobial resistance (AMR). A key target in this intervention is surveillance for local and national action. Data on AMR in Ghana are limited, and monitoring of AMR is nonexistent. We sought to generate baseline data on AMR, and to assess the readiness of Ghana in laboratory-based surveillance. Biomedical scientists in laboratories across Ghana with capacity to perform bacteriological culture were selected and trained. In-house standard operating protocols were used to perform microbiological investigations on clinical specimens. Additional microbiological tests and data analyses were performed at a centralized laboratory. Surveillance data were stored and analyzed using WHONET program files. A total of 24 laboratories participated in the training, and 1,598 data sets were included in the final analysis. A majority of the bacterial species were isolated from outpatients (963 isolates; 60.3%). Urine (617 isolates; 38.6%) was the most common clinical specimen cultured, compared to blood (100 isolates; 6.3%). Ten of 18 laboratories performed blood culture. Bacteria isolated included Escherichia coli (27.5%), Pseudomonas spp. (14.0%), Staphylococcus aureus (11.5%), Streptococcus spp. (2.3%), and Salmonella enterica serovar Typhi (0.6%). Most of the isolates were multidrug-resistant, and over 80% of them were extended-spectrum beta-lactamases-producing. Minimum inhibitory concentration levels at 50% and at 90% for ciprofloxacin, ceftriaxone, and amikacin on selected multidrug-resistant bacteria species ranged between 2 µg/mL and >256 µg/mL. A range of clinical bacterial isolates were resistant to important commonly used antimicrobials in the country, necessitating an effective surveillance to continuously monitor AMR in Ghana. With local and international support, Ghana can participate in global AMR surveillance. PMID:26604806

  10. Antimicrobial resistance in Escherichia coli isolates from raccoons (Procyon lotor) in Southern Ontario, Canada.

    PubMed

    Jardine, Claire M; Janecko, Nicol; Allan, Mike; Boerlin, Patrick; Chalmers, Gabhan; Kozak, Gosia; McEwen, Scott A; Reid-Smith, Richard J

    2012-06-01

    We conducted a cross-sectional study to determine the prevalence of antimicrobial resistance (AMR) in fecal Escherichia coli isolates from raccoons (Procyon lotor) living in Ontario, Canada. From June to October 2007, we trapped raccoons in three areas: one primarily urban site around Niagara, one primarily rural site north of Guelph, and one at the Toronto Zoo. In addition, we conducted a longitudinal study at the Toronto Zoo site to investigate the temporal dynamics of fecal E. coli and AMR in raccoons. Reduced susceptibility to ≥1 antimicrobial agent was detected in E. coli isolates from 19% of 16 raccoons at the urban site, 17% of 29 raccoons from the rural site, and 42% of 130 samples collected from 59 raccoons at the zoo site. Raccoons from the zoo site were significantly more likely to shed E. coli with reduced susceptibility to ≥1 antimicrobial agent than animals from the rural site (odds ratio [OR], 3.41; 95% confidence interval [CI], 1.17 to 12.09; P = 0.02). Resistance to expanded-spectrum cephalosporins (and the associated bla(CMY-2) gene) was detected in two animals from the zoo site and one animal from the rural site. Serotyping and pulsed-field gel electrophoresis analysis show that raccoons on the zoo grounds harbor a diverse assemblage of E. coli, with rapid bacterial turnover within individuals over time. Our study indicates that raccoons may shed resistant bacteria of public health significance and that raccoons have the potential to disseminate these bacteria throughout their environment. PMID:22447599

  11. Changes in bacterial resistance patterns in children with urinary tract infections on antimicrobial prophylaxis at University Hospital in Split

    PubMed Central

    Ilić, Tanja; Gračan, Sanda; Arapović, Adela; Čapkun, Vesna; Šubat-Dežulović, Mirna; Saraga, Marijan

    2011-01-01

    Summary Background We assessed prevalence and resistance of uropathogens on antimicrobial agents (AA) from urine cultures (UC) in children hospitalized with urinary tract infections (UTI) at University Hospital in Split. Material/Methods During the 7-year period, children hospitalized only once with UTI alone were compared to those repeatedly hospitalized, and who received long-term antimicrobial prophylaxis (LTAP), as well as those with associated anomalies of the urinary system (US). Results E. coli was the most frequent isolate (67.7%) with resistance to ampicillin by 69.5%, amoxicillin/clavulonic acid by 3.5%, cephalexin by 6.6%, trimethoprim/sulfamethoxazole (TMP-SMX) by 27.5%, and nitrofurantoin by 0.4%. For other uropathogens, AA resistance rates were the following: 64.3%, 5.8%, 10.5%, 21.3%, and 7.9%. The high or increasing resistance to TMP-SMX is characterized by all uropathogens. Patients with anomalies of US showed a lower prevalence of E. coli and Enterococcus sp., but a higher prevalence of Pseudomonas sp., ESBL-producing E. coli and Klebsiella sp. than those without US anomalies. Repeatedly hospitalized patients showed a lower prevalence of E. coli, but a higher prevalence of Pseudomonas sp. and Klebsiella sp. than patients hospitalized only once. Both groups displayed significantly less resistance of Enterococcus sp. In patients receiving LTAP before hospitalization, E. coli was significantly more resistant to ampicillin, amoxicillin/clavulonic acid and TMP/SMX than in those without LTAP. Conclusions Based on our results, we recommend excluding ampicillin altogether, and reconsideration of further use of TMP-SMX, as well as use of nitrofurantoin, cephalexin and amoxicillin/clavulonic acid for LTAP in our region. PMID:21709628

  12. Antimicrobial resistance of Salmonella and E. coli from Pennsylvania dairy herds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial resistance in bacterial pathogens is an increasing public health concern. The objective of this study was to examine antimicrobial resistance in Salmonella and E. coli isolates from Pennsylvania dairy herds. Manure composite samples were collected from 76 farms: on each farm one sample...

  13. Antimicrobial resistance: a global view from the 2013 World Healthcare-Associated Infections Forum

    PubMed Central

    2013-01-01

    Antimicrobial resistance (AMR) is now a global threat. Its emergence rests on antimicrobial overuse in humans and food-producing animals; globalization and suboptimal infection control facilitate its spread. While aggressive measures in some countries have led to the containment of some resistant gram-positive organisms, extensively resistant gram-negative organisms such as carbapenem-resistant enterobacteriaceae and pan-resistant Acinetobacter spp. continue their rapid spread. Antimicrobial conservation/stewardship programs have seen some measure of success in reducing antimicrobial overuse in humans, but their reach is limited to acute-care settings in high-income countries. Outside the European Union, there is scant or no oversight of antimicrobial administration to food-producing animals, while evidence mounts that this administration leads directly to resistant human infections. Both horizontal and vertical infection control measures can interrupt transmission among humans, but many of these are costly and essentially limited to high-income countries as well. Novel antimicrobials are urgently needed; in recent decades pharmaceutical companies have largely abandoned antimicrobial discovery and development given their high costs and low yield. Against this backdrop, international and cross-disciplinary collaboration appears to be taking root in earnest, although specific strategies still need defining. Educational programs targeting both antimicrobial prescribers and consumers must be further developed and supported. The general public must continue to be made aware of the current scale of AMR’s threat, and must perceive antimicrobials as they are: a non-renewable and endangered resource. PMID:24237856

  14. Clostridium difficile with Moxifloxacin/Clindamycin Resistance in Vegetables in Ohio, USA, and Prevalence Meta-Analysis

    PubMed Central

    Rodriguez-Palacios, Alex; LeJeune, Jeffrey T.

    2014-01-01

    We (i) determined the prevalence of Clostridium difficile and their antimicrobial resistance to six antimicrobial classes, in a variety of fresh vegetables sold in retail in Ohio, USA, and (ii) conducted cumulative meta-analysis of reported prevalence in vegetables since the 1990s. Six antimicrobial classes were tested for their relevance as risk factors for C. difficile infections (CDIs) (clindamycin, moxifloxacin) or their clinical priority as exhaustive therapeutic options (metronidazole, vancomycin, linezolid, and tigecycline). By using an enrichment protocol we isolated C. difficile from three of 125 vegetable products (2.4%). All isolates were toxigenic, and originated from 4.6% of 65 vegetables cultivated above the ground (n = 3; outer leaves of iceberg lettuce, green pepper, and eggplant). Root vegetables yielded no C. difficile. The C. difficile isolates belonged to two PCR ribotypes, one with an unusual antimicrobial resistance for moxifloxacin and clindamycin (lettuce and pepper; 027-like, A+B+CDT+; tcdC 18 bp deletion); the other PCR ribotype (eggplant, A+B+ CDT−; classic tcdC) was susceptible to all antimicrobials. Results of the cumulative weighted meta-analysis (6 studies) indicate that the prevalence of C. difficile in vegetables is 2.1% and homogeneous (P < 0.001) since the first report in 1996 (2.4%). The present study is the first report of the isolation of C. difficile from retail vegetables in the USA. Of public health relevance, antimicrobial resistance to moxifloxacin/clindamycin (a bacterial-associated risk factor for severe CDIs) was identified on the surface of vegetables that are consumed raw. PMID:25580297

  15. Isolation and Characterization of Antimicrobial-Resistant Nontyphoidal Salmonella enterica Serovars from Imported Food Products.

    PubMed

    Bae, Dongryeoul; Kweon, Ohgew; Khan, Ashraf A

    2016-08-01

    The objective of this study was to determine antimicrobial resistance and elucidate the resistance mechanism in nontyphoidal Salmonella enterica serovars isolated from food products imported into the United States from 2011 to 2013. Food products contaminated with antimicrobial-resistant nontyphoidal S. enterica were mainly imported from Taiwan, Indonesia, Vietnam, and China. PCR, DNA sequencing, and plasmid analyses were used to characterize antimicrobial resistance determinants. Twentythree of 110 S. enterica isolates were resistant to various antimicrobial classes, including β-lactam, aminoglycoside, phenicol, glycopeptide, sulfonamide, trimethoprim, and/or fluoroquinolone antimicrobial agents. Twelve of the isolates were multidrug resistant strains. Antimicrobial resistance determinants blaTEM-1, blaCTX-M-9, blaOXA-1, tetA, tetB, tetD, dfrA1, dfrV, dhfrI, dhfrXII, drf17, aadA1, aadA2, aadA5, orfC, qnrS, and mutations of gyrA and parC were detected in one or more antimicrobial-resistant nontyphoidal S. enterica strains. Plasmid profiles revealed that 12 of the 23 antimicrobial-resistant strains harbored plasmids with incompatibility groups IncFIB, IncHI1, IncI1, IncN, IncW, and IncX. Epidemiologic and antimicrobial resistance monitoring data combined with molecular characterization of antimicrobial resistance determinants in Salmonella strains isolated from imported food products may provide information that can be used to establish or implement food safety programs to improve public health. PMID:27497122

  16. Virulence factors and mechanisms of antimicrobial resistance in Shigella strains from periurban areas of Lima (Peru)

    PubMed Central

    Lluque, Angela; Mosquito, Susan; Gomes, Cláudia; Riveros, Maribel; Durand, David; Tilley, Drake H.; Bernal, María; Prada, Ana; Ochoa, Theresa J.; Ruiz, Joaquim

    2015-01-01

    The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (4 isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri. Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul2 (95%), tet(B) (92%), cat (80%), dfrA1 (47%), blaOXA-1 like (40%), with intl1 and intl2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipaH (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region. PMID:25998616

  17. Virulence factors and mechanisms of antimicrobial resistance in Shigella strains from periurban areas of Lima (Peru).

    PubMed

    Lluque, Angela; Mosquito, Susan; Gomes, Cláudia; Riveros, Maribel; Durand, David; Tilley, Drake H; Bernal, María; Prada, Ana; Ochoa, Theresa J; Ruiz, Joaquim

    2015-01-01

    The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (four isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri. Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul2 (95%), tet(B) (92%), cat (80%), dfrA1 (47%), blaOXA-1like (40%), with intl1 and intl2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipaH (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region. PMID:25998616

  18. Bacteriophages Isolated from Chicken Meat and the Horizontal Transfer of Antimicrobial Resistance Genes.

    PubMed

    Shousha, Amira; Awaiwanont, Nattakarn; Sofka, Dmitrij; Smulders, Frans J M; Paulsen, Peter; Szostak, Michael P; Humphrey, Tom; Hilbert, Friederike

    2015-07-01

    Antimicrobial resistance in microbes poses a global and increasing threat to public health. The horizontal transfer of antimicrobial resistance genes was thought to be due largely to conjugative plasmids or transposons, with only a minor part being played by transduction through bacteriophages. However, whole-genome sequencing has recently shown that the latter mechanism could be highly important in the exchange of antimicrobial resistance genes between microorganisms and environments. The transfer of antimicrobial resistance genes by phages could underlie the origin of resistant bacteria found in food. We show that chicken meat carries a number of phages capable of transferring antimicrobial resistance. Of 243 phages randomly isolated from chicken meat, about a quarter (24.7%) were able to transduce resistance to one or more of the five antimicrobials tested into Escherichia coli ATCC 13706 (DSM 12242). Resistance to kanamycin was transduced the most often, followed by that to chloramphenicol, with four phages transducing tetracycline resistance and three transducing ampicillin resistance. Phages able to transduce antimicrobial resistance were isolated from 44% of the samples of chicken meat that we tested. The statistically significant (P = 0.01) relationship between the presence of phages transducing kanamycin resistance and E. coli isolates resistant to this antibiotic suggests that transduction may be an important mechanism for transferring kanamycin resistance to E. coli. It appears that the transduction of resistance to certain antimicrobials, e.g., kanamycin, not only is widely distributed in E. coli isolates found on meat but also could represent a major mechanism for resistance transfer. The result is of high importance for animal and human health. PMID:25934615

  19. Bacteriophages Isolated from Chicken Meat and the Horizontal Transfer of Antimicrobial Resistance Genes

    PubMed Central

    Shousha, Amira; Awaiwanont, Nattakarn; Sofka, Dmitrij; Smulders, Frans J. M.; Paulsen, Peter; Szostak, Michael P.; Humphrey, Tom

    2015-01-01

    Antimicrobial resistance in microbes poses a global and increasing threat to public health. The horizontal transfer of antimicrobial resistance genes was thought to be due largely to conjugative plasmids or transposons, with only a minor part being played by transduction through bacteriophages. However, whole-genome sequencing has recently shown that the latter mechanism could be highly important in the exchange of antimicrobial resistance genes between microorganisms and environments. The transfer of antimicrobial resistance genes by phages could underlie the origin of resistant bacteria found in food. We show that chicken meat carries a number of phages capable of transferring antimicrobial resistance. Of 243 phages randomly isolated from chicken meat, about a quarter (24.7%) were able to transduce resistance to one or more of the five antimicrobials tested into Escherichia coli ATCC 13706 (DSM 12242). Resistance to kanamycin was transduced the most often, followed by that to chloramphenicol, with four phages transducing tetracycline resistance and three transducing ampicillin resistance. Phages able to transduce antimicrobial resistance were isolated from 44% of the samples of chicken meat that we tested. The statistically significant (P = 0.01) relationship between the presence of phages transducing kanamycin resistance and E. coli isolates resistant to this antibiotic suggests that transduction may be an important mechanism for transferring kanamycin resistance to E. coli. It appears that the transduction of resistance to certain antimicrobials, e.g., kanamycin, not only is widely distributed in E. coli isolates found on meat but also could represent a major mechanism for resistance transfer. The result is of high importance for animal and human health. PMID:25934615

  20. Non-invasive pneumococcal pneumonia in Portugal--serotype distribution and antimicrobial resistance.

    PubMed

    Horácio, Andreia N; Lopes, Joana P; Ramirez, Mário; Melo-Cristino, José

    2014-01-01

    There is limited information on the serotypes causing non-invasive pneumococcal pneumonia (NIPP). Our aim was to characterize pneumococci causing NIPP in adults to determine recent changes in serotype prevalence, the potential coverage of pneumococcal vaccines and changes in antimicrobial resistance. Serotypes and antimicrobial susceptibility profiles of a sample of 1300 isolates recovered from adult patients (≥18 yrs) between 1999 and 2011 (13 years) were determined. Serotype 3 was the most frequent cause of NIPP accounting for 18% of the isolates. The other most common serotypes were 11A (7%), 19F (7%), 19A (5%), 14 (4%), 22F (4%), 23F (4%) and 9N (4%). Between 1999 and 2011, there were significant changes in the proportion of isolates expressing vaccine serotypes, with a steady decline of the serotypes included in the 7-valent conjugate vaccine from 31% (1999-2003) to 11% (2011) (P<0.001). Taking together the most recent study years (2009-2011), the potential coverage of the 13-valent conjugate vaccine was 44% and of the 23-valent polysaccharide vaccine was 66%. While erythromycin resistance increased from 8% in 1999-2003 to 18% in 2011 (P<0.001), no significant trend was identified for penicillin non-susceptibility, which had an average value of 18.5%. The serotype distribution found in this study for NIPP was very different from the one previously described for IPD, with only two serotypes in common to the ones responsible for half of each presentation in 2009-2011 - serotypes 3 and 19A. In spite of these differences, the overall prevalence of resistant isolates was similar in NIPP and in IPD. PMID:25075961

  1. Occurrence of antimicrobial resistant bacteria in healthy dogs and cats presented to private veterinary hospitals in southern Ontario: A preliminary study

    PubMed Central

    Murphy, Colleen; Reid-Smith, Richard J.; Prescott, John F.; Bonnett, Brenda N.; Poppe, Cornelis; Boerlin, Patrick; Weese, J. Scott; Janecko, Nicol; McEwen, Scott A.

    2009-01-01

    The prevalence and patterns of antimicrobial susceptibility of fecal Escherichia coli, Salmonella spp., extended β-lactamase producing E. coli (ESBL-E. coli), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus pseudintermedius (MRSP) were determined for healthy dogs (n = 188) and cats (n = 39) from veterinary hospitals in southern Ontario that had not had recent exposure to antimicrobials. The prevalence of antimicrobial resistance in E. coli was as follows: streptomycin (dogs — 17%, cats — 2%), ampicillin (dogs — 13%, cats — 4%), cephalothin (dogs — 13%, cats — < 1%), and tetracycline (dogs — 11%, cats — 2%). Eleven percent of dogs and 15% of cats had isolates that were resistant to at least 2 antimicrobials. Cephamycinase (CMY)-2 producing E. coli was cultured from 2 dogs. No Salmonella spp., ESBL-E. coli, MRSA, or MRSP isolates were recovered. The observed prevalence of resistance in commensal E. coli from this population was lower than that previously reported in companion animals, but a small percentage of dogs may be a reservoir for CMY-2 E. coli. PMID:20046603

  2. Molecular characterization of antimicrobial resistance in enterococci and Escherichia coli isolates from European wild rabbit (Oryctolagus cuniculus).

    PubMed

    Silva, Nuno; Igrejas, Gilberto; Figueiredo, Nicholas; Gonçalves, Alexandre; Radhouani, Hajer; Rodrigues, Jorge; Poeta, Patrícia

    2010-09-15

    A total of 44 Escherichia coli and 64 enterococci recovered from 77 intestinal samples of wild European rabbits in Portugal were analyzed for resistance to antimicrobial agents. Resistance in E. coli isolates was observed for ampicillin, tetracycline, sulfamethoxazole/trimethoprim, streptomycin, gentamicin, tobramycin, nalidixic acid, ciprofloxacin and chloramphenicol. None of the E. coli isolates produced extended-spectrum beta-lactamases (ESBLs). The bla(TEM), aadA, aac(3)-II, tet(A) and/or tet(B), and the catA genes were demonstrated in all ampicillin, streptomycin, gentamicin, tetracycline, and chloramphenicol-resistant isolates respectively, and the sul1 and/or sul2 and/or sul3 genes in 4 of 5 sulfamethoxazole/trimethoprim resistant isolates. Of the enterococcal isolates, Enterococcus faecalis was the most prevalent detected species (39 isolates), followed by E. faecium (21 isolates) and E. hirae (4 isolates). More than one-fourth (29.7%) of the isolates were resistant to tetracycline; 20.3% were resistant to erythromycin, 14.1% were resistant to ciprofloxacin and 10.9% were resistant to high-level-kanamycin. Lower level of resistance (<10%) was detected for ampicillin, quinupristin/dalfopristin and high-level-gentamicin, -streptomycin. No vancomycin-resistance was detected in the enterococci isolates. Resistance genes detected included aac(6')-aph(2''), ant(6)-Ia, tet(M) and/or tet(L) in all gentamicin, streptomycin and tetracycline-resistant isolates respectively. The aph(3')-IIIa gene was detected in 6 of 7 kanamycin-resistant isolates, the erm(B) gene in 11 of 13 erythromycin-resistant isolates and the vat(D) gene in the quinupristin/dalfopristin-resistant E. faecium isolate. This survey showed that faecal bacteria such as E. coli and enterococci of wild rabbits could be a reservoir of antimicrobial resistance genes. PMID:20624632

  3. Antimicrobial Resistance of Enteric Salmonella in Bangui, Central African Republic.

    PubMed

    Mossoro-Kpinde, Christian Diamant; Manirakiza, Alexandre; Mbecko, Jean-Robert; Misatou, Pembé; Le Faou, Alain; Frank, Thierry

    2015-01-01

    Introduction. The number of Salmonella isolated from clinical samples that are resistant to multiple antibiotics has increased worldwide. The aim of this study was to determine the prevalence of resistant Salmonella enterica isolated in Bangui. Methods. All enteric Salmonella strains isolated from patients in 2008 were identified and serotyped, and the phenotypes of resistance were determined by using the disk diffusion method. Nine resistance-associated genes, bla TEM , bla OXA , bla SHV , tetA, aadA1, catA1, dhfrA1, sul I, and sul II, were sought by genic amplification in seven S.e. Typhimurium strains. Results. The 94 strains isolated consisted of 47 S.e. Typhimurium (50%), 21 S.e. Stanleyville (22%), 18 S.e. Enteritidis (19%), 4 S.e. Dublin (4%), 4 S.e. Hadar (4%), and 1 S.e. Papuana (1%). Twenty-five (28%) were multiresistant, including 20 of the Typhimurium serovar (80%). Two main phenotypes of resistance were found: four antibiotics (56%) and to five antibiotics (40%). One S.e. Typhimurium isolate produced an extended-spectrum β-lactamase (ESBL). Only seven strains of S.e. Typhimurium could be amplified genically. Only phenotypic resistance to tetracycline and aminosides was found. Conclusion. S. Typhimurium is the predominant serovar of enteric S. enterica and is the most widely resistant. The search for resistance genes showed heterogeneity of the circulating strains. PMID:26880999

  4. Antimicrobial Resistance of Enteric Salmonella in Bangui, Central African Republic

    PubMed Central

    Mossoro-Kpinde, Christian Diamant; Manirakiza, Alexandre; Mbecko, Jean-Robert; Misatou, Pembé; Le Faou, Alain; Frank, Thierry

    2015-01-01

    Introduction. The number of Salmonella isolated from clinical samples that are resistant to multiple antibiotics has increased worldwide. The aim of this study was to determine the prevalence of resistant Salmonella enterica isolated in Bangui. Methods. All enteric Salmonella strains isolated from patients in 2008 were identified and serotyped, and the phenotypes of resistance were determined by using the disk diffusion method. Nine resistance-associated genes, blaTEM, blaOXA, blaSHV, tetA, aadA1, catA1, dhfrA1, sul I, and sul II, were sought by genic amplification in seven S.e. Typhimurium strains. Results. The 94 strains isolated consisted of 47 S.e. Typhimurium (50%), 21 S.e. Stanleyville (22%), 18 S.e. Enteritidis (19%), 4 S.e. Dublin (4%), 4 S.e. Hadar (4%), and 1 S.e. Papuana (1%). Twenty-five (28%) were multiresistant, including 20 of the Typhimurium serovar (80%). Two main phenotypes of resistance were found: four antibiotics (56%) and to five antibiotics (40%). One S.e. Typhimurium isolate produced an extended-spectrum β-lactamase (ESBL). Only seven strains of S.e. Typhimurium could be amplified genically. Only phenotypic resistance to tetracycline and aminosides was found. Conclusion. S. Typhimurium is the predominant serovar of enteric S. enterica and is the most widely resistant. The search for resistance genes showed heterogeneity of the circulating strains. PMID:26880999

  5. Prevalence, bacterial causes, and antimicrobial susceptibility profile of mastitis isolates from cows in large-scale dairy farms of Northern Ethiopia.

    PubMed

    Haftu, Rgbe; Taddele, Habtamu; Gugsa, Getachew; Kalayou, Shewit

    2012-10-01

    The study was undertaken to determine the prevalence of bovine mastitis, isolate mastitis causing bacteria, assess the association of some risk factors, and determine the antibiotic resistance pattern of bacterial isolates in cows in large-scale dairy farms of Northern Ethiopia. A total of 305 lactating and nonlactating cows were included in the present study. The overall prevalence of clinical and subclinical mastitis was 3.6 and 33.8 %, respectively. The quarter level prevalence was 15.4 %; from which, 11.9 and 1.1 % were subclinical form and blind teat, respectively, while the remaining 2.4 % were of clinical form. Staphylococcus aureus accounted for 36 % of the isolates followed by Escherichia coli (27.3 %). Risk factors including age (p < 0.001), parity (p < 0.001), and lactation stage (p = 0.02) showed significant association with the occurrence of mastitis. Higher prevalence was observed in both groups of older cows (i.e., 6-9 years (odds ratio (OR) = 4.65, 95 % confidence interval (CI) = 2.74-7.89) and >9 years (OR = 3.63, 95 % CI = 1.42-9.25)), cows with four to seven calves (OR = 3.39, 95 % CI = 2.06-5.60), and cows in late lactation stage (OR = 3.79, 95 % CI = 1.64-8.75). In multivariable logistic regression analysis, age (p = 0.005) and lactation stage (p = 0.027) showed statistically significant association with the occurrence of mastitis. The antimicrobial susceptibility pattern showed high susceptibility of S. aureus to nalidixic acid (82.4 %) followed by chloramphenicol (58.8 %); however, these species were resistant to the rest of the antimicrobials tested. Highest resistance was observed against clindamycin and ampicillin. Coliform bacteria (E. coli and Klebsiella pneumoniae) showed resistance to most of the antimicrobials used. Detailed investigation is needed to identify the interplay of managemental and environmental risk factors to design appropriate control measures. PMID:22476790

  6. A Transporter Interactome Is Essential for the Acquisition of Antimicrobial Resistance to Antibiotics

    PubMed Central

    Shuster, Yonatan; Steiner-Mordoch, Sonia; Alon Cudkowicz, Noemie; Schuldiner, Shimon

    2016-01-01

    Awareness of the problem of antimicrobial resistance (AMR) has escalated and drug-resistant infections are named among the most urgent problems facing clinicians today. Our experiments here identify a transporter interactome and portray its essential function in acquisition of antimicrobial resistance. By exposing E. coli cells to consecutive increasing concentrations of the fluoroquinolone norfloxacin we generated in the laboratory highly resistant strains that carry multiple mutations, most of them identical to those identified in clinical isolates. With this experimental paradigm, we show that the MDTs function in a coordinated mode to provide an essential first-line defense mechanism, preventing the drug reaching lethal concentrations, until a number of stable efficient alterations occur that allow survival. Single-component efflux transporters remove the toxic compounds from the cytoplasm to the periplasmic space where TolC-dependent transporters expel them from the cell. We postulate a close interaction between the two types of transporters to prevent rapid leak of the hydrophobic substrates back into the cell. The findings change the prevalent concept that in Gram-negative bacteria a single multidrug transporter, AcrAB-TolC type, is responsible for the resistance. The concept of a functional interactome, the process of identification of its members, the elucidation of the nature of the interactions and its role in cell physiology will change the existing paradigms in the field. We anticipate that our work will have an impact on the present strategy searching for inhibitors of AcrAB-TolC as adjuvants of existing antibiotics and provide novel targets for this urgent undertaking. PMID:27050393

  7. Multidrug resistance genes in staphylococci from animals that confer resistance to critically and highly important antimicrobial agents in human medicine.

    PubMed

    Wendlandt, Sarah; Shen, Jianzhong; Kadlec, Kristina; Wang, Yang; Li, Beibei; Zhang, Wan-Jiang; Feßler, Andrea T; Wu, Congming; Schwarz, Stefan

    2015-01-01

    Most antimicrobial resistance genes known so far to occur in staphylococci of animal origin confer resistance to a specific class of antimicrobial agents or to selected members within such a class. However, there are also a few examples of multidrug resistance (MDR) genes that confer resistance to antimicrobial agents of different classes by either target site methylation or active efflux via ATP-binding cassette (ABC) transporters. The present review provides an overview of these MDR genes with particular reference to those genes involved in resistance to critically or highly important antimicrobial agents used in human and veterinary medicine. Moreover, their location on mobile genetic elements and colocated resistance genes, which may play a role in coselection and persistence of the MDR genes, are addressed. PMID:25455417

  8. Widespread acquisition of antimicrobial resistance among Campylobacter isolates from UK retail poultry and evidence for clonal expansion of resistant lineages

    PubMed Central

    2013-01-01

    Background Antimicrobial resistance is increasing among clinical Campylobacter cases and is common among isolates from other sources, specifically retail poultry - a major source of human infection. In this study the antimicrobial susceptibility of isolates from a UK-wide survey of Campylobacter in retail poultry in 2001 and 2004–5 was investigated. The occurrence of phenotypes resistant to tetracycline, quinolones (ciprofloxacin and naladixic acid), erythromycin, chloramphenicol and aminoglycosides was quantified. This was compared with a phylogeny for these isolates based upon Multi Locus Sequence Typing (MLST) to investigate the pattern of antimicrobial resistance acquisition. Results Antimicrobial resistance was present in all lineage clusters, but statistical testing showed a non-random distribution. Erythromycin resistance was associated with Campylobacter coli. For all antimicrobials tested, resistant isolates were distributed among relatively distant lineages indicative of widespread acquisition. There was also evidence of clustering of resistance phenotypes within lineages; indicative of local expansion of resistant strains. Conclusions These results are consistent with the widespread acquisition of antimicrobial resistance among chicken associated Campylobacter isolates, either through mutation or horizontal gene transfer, and the expansion of these lineages as a proportion of the population. As Campylobacter are not known to multiply outside of the host and long-term carriage in humans is extremely infrequent in industrialized countries, the most likely location for the proliferation of resistant lineages is in farmed chickens. PMID:23855904

  9. Eight-year Surveillance of Antimicrobial Resistance among Enterococcus Spp. Isolated in the First Bethune Hospital

    NASA Astrophysics Data System (ADS)

    Xu, Jiancheng; Wang, Liqiang; Wang, Kai; Zhou, Qi

    This study was to investigate the antimicrobial resistance of Enterococcus spp. isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 1446 strains of Enterococcus spp. were collected from urine 640 (44.3%), sputum 315 (21.8%), secretions and pus 265 (18.3%) during the past 8 years. The rates of high-level aminoglycoside resistance in Enterococcus faecalis and Enterococcus faecium were 57.4%∼75.9% and 69.0%∼93.8% during the past 8 years, respectively. No Enterococcus spp. was resistant to vancomycin. The antimicrobial resistance of Enterococcus spp. had increased in recent 8 years. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

  10. Antimicrobial hydrogels: a new weapon in the arsenal against multidrug-resistant infections.

    PubMed

    Ng, Victor W L; Chan, Julian M W; Sardon, Haritz; Ono, Robert J; García, Jeannette M; Yang, Yi Yan; Hedrick, James L

    2014-11-30

    The rapid emergence of antibiotic resistance in pathogenic microbes is becoming an imminent global public health problem. Treatment with conventional antibiotics often leads to resistance development as the majority of these antibiotics act on intracellular targets, leaving the bacterial morphology intact. Thus, they are highly prone to develop resistance through mutation. Much effort has been made to develop macromolecular antimicrobial agents that are less susceptible to resistance as they function by microbial membrane disruption. Antimicrobial hydrogels constitute an important class of macromolecular antimicrobial agents, which have been shown to be effective in preventing and treating multidrug-resistant infections. Advances in synthetic chemistry have made it possible to tailor molecular structure and functionality to impart broad-spectrum antimicrobial activity as well as predictable mechanical and rheological properties. This has significantly broadened the scope of potential applications that range from medical device and implant coating, sterilization, wound dressing, to antimicrobial creams for the prevention and treatment of multidrug-resistant infections. In this review, advances in both chemically and physically cross-linked natural and synthetic hydrogels possessing intrinsic antimicrobial properties or loaded with antibiotics, antimicrobial polymers/peptides and metal nanoparticles are highlighted. Relationships between physicochemical properties and antimicrobial activity/selectivity, and possible antimicrobial mechanisms of the hydrogels are discussed. Approaches to mitigating toxicity of metal nanoparticles that are encapsulated in hydrogels are reviewed. In addition, challenges and future perspectives in the development of safe and effective antimicrobial hydrogel systems especially involving co-delivery of antimicrobial polymers/peptides and conventional antimicrobial agents for eventual clinical applications are presented. PMID:25450263

  11. Antimicrobial Resistance of Acinetobacter baumannii to Imipenem in Iran: A Systematic Review and Meta-Analysis

    PubMed Central

    Pourhajibagher, Maryam; Hashemi, Farhad B.; Pourakbari, Babak; Aziemzadeh, Masoud; Bahador, Abbas

    2016-01-01

    Imipenem-resistant multi-drug resistant (IR-MDR) Acinetobacter baumannii has been emerged as a morbidity successful nosocomial pathogen throughout the world.To address imipenem being yet the most effective antimicrobial agent against A. baumannii to control outbreaks and treat patients, a systematic review and meta-analysis was performed to evaluate the prevalence of IR-MDR A. baumannii. We systematically searched Web of Science, PubMed, MEDLINE, Science Direct, EMBASE, Scopus, Cochrane Library, Google Scholar, and Iranian databases to identify studies addressing the antibiotic resistance of A. baumannii to imipenem and the frequency of MDR strains in Iran. Out of 58 articles and after a secondary screening using inclusion and exclusion criteria and on the basis of title and abstract evaluation, 51 studies were selected for analysis. The meta-analysis revealed that 55% [95% confidence interval (CI), 53.0–56.5] of A. baumannii were resistant to imipenem and 74% (95% CI, 61.3–83.9) were MDR. The MDR A. baumannii population in Iran is rapidly changing toward a growing resistance to imipenem. Our findings highlight the critical need for a comprehensive monitoring and infection control policy as well as a national susceptibility review program that evaluates IR-MDR A. baumannii isolates from various parts of Iran. PMID:27099638

  12. Antimicrobial-resistant Enterobacteriaceae from humans and wildlife in Dzanga-Sangha Protected Area, Central African Republic.

    PubMed

    Janatova, Martina; Albrechtova, Katerina; Petrzelkova, Klara Judita; Dolejska, Monika; Papousek, Ivo; Masarikova, Martina; Cizek, Alois; Todd, Anguelique; Shutt, Kathryn; Kalousova, Bara; Profousova-Psenkova, Ilona; Modry, David; Literak, Ivan

    2014-07-16

    Antimicrobial resistance is a worldwide concern of public health. Unfortunately, resistant bacteria are spreading to all ecosystems, including the strictly protected ones. We investigated antimicrobial resistance in gastrointestinal Enterobacteriaceae of wild mammals and people living within Dzangha-Sangha Protected Areas, Central African Republic, with an emphasis on extended-spectrum β-lactamase (ESBL) and plasmid-mediated quinolone resistance (PMQR) genes. We compare resistance genes found in microbiota of humans, gorillas habituated and unhabituated to humans and other wildlife. In gorillas, we additionally investigate the presence of ESBL resistant isolates after treatment by ceftiofur. We found a considerable prevalence of multiresistant Enterobacteriaceae isolates with ESBL and PMQR genes in humans (10% and 31%, respectively). Among wildlife the most significant findings were CTX-M-15-producing Klebsiella pneumoniae in a habituated gorilla and a multiresistant Escherichia coli isolate with gene qepA in an unhabituated gorilla. Other isolates from wildlife were mostly represented by qnrB-harboring Citrobacter spp. The relatedness of resistant E. coli was investigated in a PFGE-based dendrogram; isolates from gorillas showed less than 80% similarity to each other and less than 80% similarity to human isolates. No ESBL-producing isolates were found in animals treated by ceftiofur. Although we did not detect any bacterial clone common to wildlife and humans, we detected an intersection in the spectrum of resistance genes found in humans and gorillas, represented by blaCTX-M-15 and qepA. PMID:24636162

  13. Mathematical modelling of antimicrobial resistance in agricultural waste highlights importance of gene transfer rate.

    PubMed

    Baker, Michelle; Hobman, Jon L; Dodd, Christine E R; Ramsden, Stephen J; Stekel, Dov J

    2016-04-01

    Antimicrobial resistance is of global concern. Most antimicrobial use is in agriculture; manures and slurry are especially important because they contain a mix of bacteria, including potential pathogens, antimicrobial resistance genes and antimicrobials. In many countries, manures and slurry are stored, especially over winter, before spreading onto fields as organic fertilizer. Thus, these are a potential location for gene exchange and selection for resistance. We develop and analyse a mathematical model to quantify the spread of antimicrobial resistance in stored agricultural waste. We use parameters from a slurry tank on a UK dairy farm as an exemplar. We show that the spread of resistance depends in a subtle way on the rates of gene transfer and antibiotic inflow. If the gene transfer rate is high, then its reduction controls resistance, while cutting antibiotic inflow has little impact. If the gene transfer rate is low, then reducing antibiotic inflow controls resistance. Reducing length of storage can also control spread of resistance. Bacterial growth rate, fitness costs of carrying antimicrobial resistance and proportion of resistant bacteria in animal faeces have little impact on spread of resistance. Therefore, effective treatment strategies depend critically on knowledge of gene transfer rates. PMID:26906100

  14. Vaginal versus Obstetric Infection Escherichia coli Isolates among Pregnant Women: Antimicrobial Resistance and Genetic Virulence Profile

    PubMed Central

    Sáez-López, Emma; Guiral, Elisabet; Fernández-Orth, Dietmar; Villanueva, Sonia; Goncé, Anna; López, Marta; Teixidó, Irene; Pericot, Anna; Figueras, Francesc; Palacio, Montse; Cobo, Teresa; Bosch, Jordi; Soto, Sara M.

    2016-01-01

    Vaginal Escherichia coli colonization is related to obstetric infections and the consequent development of infections in newborns. Ampicillin resistance among E. coli strains is increasing, which is the main choice for treating empirically many obstetric and neonatal infections. Vaginal E. coli strains are very similar to extraintestinal pathogenic E. coli with regards to the virulence factors and the belonging to phylogroup B2. We studied the antimicrobial resistance and the genetic virulence profile of 82 E. coli isolates from 638 vaginal samples and 63 isolated from endometrial aspirate, placental and amniotic fluid samples from pregnant women with obstetric infections. The prevalence of E. coli in the vaginal samples was 13%, which was significant among women with associated risk factors during pregnancy, especially premature preterm rupture of membranes (p<0.0001). Sixty-five percent of the strains were ampicillin-resistant. The E. coli isolates causing obstetric infections showed higher resistance levels than vaginal isolates, particularly for gentamicin (p = 0.001). The most prevalent virulence factor genes were those related to the iron uptake systems revealing clear targets for interventions. More than 50% of the isolates belonged to the virulent B2 group possessing the highest number of virulence factor genes. The ampicillin-resistant isolates had high number of virulence factors primarily related to pathogenicity islands, and the remarkable gentamicin resistance in E. coli isolates from women presenting obstetric infections, the choice of the most appropriate empiric treatment and clinical management of pregnant women and neonates should be carefully made. Taking into account host-susceptibility, the heterogeneity of E. coli due to evolution over time and the geographical area, characterization of E. coli isolates colonizing the vagina and causing obstetric infections in different regions may help to develop interventions and avoid the aetiological link

  15. Antimicrobial resistance and biological governance: explanations for policy failure.

    PubMed

    Wallinga, D; Rayner, G; Lang, T

    2015-10-01

    The paper reviews the state of policy on antimicrobial use and the growth of antimicrobial resistance (AMR). AMR was anticipated at the time of the first use of antibiotics by their originators. For decades, reports and scientific papers have expressed concern about AMR at global and national policy levels, yet the problem, first exposed a half-century ago, worsened. The paper considers the explanations for this policy failure and the state of arguments about ways forward. These include: a deficit of economic incentivisation; complex interventions in behavioural dynamics; joint and separate shifts in medical and animal health regimes; consumerism; belief in technology; and a narrative that in a 'war on bugs' nature can be beaten by human ingenuity. The paper suggests that these narratives underplay the biological realities of the human-animal-biosphere being in constant flux, an understanding which requires an ecological public health analysis of AMR policy development and failure. The paper suggests that effective policy change requires simultaneous actions across policy levels. No single solution is possible, since AMR is the result of long-term human intervention which has accelerated certain trends in the evolution of a microbial ecosystem shared by humans, animals and other biological organisms inhabiting that ecosystem. Viewing the AMR crisis today through an ecological public health lens has the advantage of reuniting the social-ecological and bio-ecological perspectives which have been separated within public health. PMID:26454427

  16. Antimicrobial resistance of 100 Salmonella strains isolated from Gallus gallus in 4 wilayas of Algeria.

    PubMed

    Bounar-Kechih, S; Hamdi, T M; Mezali, L; Assaous, F; Rahal, K

    2012-05-01

    This study aims at identifying serotypes and surveying the antimicrobial resistance and plasmid support of resistance of 100 Salmonella strains, which were isolated from 96 out of 506 (18.97%) samples taken from different production farms in the wilayas (i.e., Algerian states) of Tizi-Ouzou, Bouira, Bejaïa, and Boumerdes in 2007. The highest percentage of Salmonella (48%) was recorded in Bouira. Thirteen serotypes were identified among the 100 Salmonella strains used in this study. The most prevalent ones were Salmonella Heidelberg (24%), Salmonella Enteritidis (20%), Salmonella Albany (16%), and Salmonella Typhimurium (9%). The strains showed resistance to 8 of the 34 antibiotics tested. Fifty-three percent of strains were resistant to at least one antibiotic, among which 15.09% were multiresistant. The most frequently observed resistance was to quinolones (58.49%), with a contribution of 94.74% of Salmonella Heidelberg resistant strains. The plasmid transfer performed on 53 strains showed that only 11 exhibited one or more markers of resistance, the most frequent being ampicillin, followed by tetracycline, then cotrimoxazole, sulphonamides, and kanamycin, in that order. The tetracycline characteristics were present in 72.72% of transconjugants, those of the β-lactams and sulphonamides in 27.27% each and those of the aminosides in 9.09%. The incompatibility groups of plasmids belong to the F1me and Com1 classes, and the molecular weight of the plasmid DNA was greater than 100 kb. The phenotypic and genotypic results indicate a clonal dissemination in the Gallus gallus species in this particular study; this phenomenon could generate resistant bacteria and transferable genes of resistance to humans. PMID:22499877

  17. What Happens When "Germs Don't Get Killed and They Attack Again and Again": Perceptions of Antimicrobial Resistance in the Context of Diarrheal Disease Treatment Among Laypersons and Health-Care Providers in Karachi, Pakistan.

    PubMed

    Joseph, Heather A; Agboatwalla, Mubina; Hurd, Jacqueline; Jacobs-Slifka, Kara; Pitz, Adam; Bowen, Anna

    2016-07-01

    In south Asia, where diarrhea is common and antibiotics are accessible without prescription, antimicrobial resistance is an emerging and serious problem. However, beliefs and behaviors related to antimicrobial resistance are poorly understood. We explored laypersons' and health-care providers' (HCP) awareness and perceptions of antimicrobial resistance in the context of treatment of adult diarrheal disease in Karachi, Pakistan. In-depth, open-ended interviews were conducted with 40 laypersons and 45 HCPs in a lower-middle-class urban neighborhood. Interviews conducted in Urdu were audiotaped, transcribed, translated, and coded using applied thematic analysis. Slightly over half of laypersons and two-thirds of HCPs were aware that antimicrobial medication could lose effectiveness, but misperceptions were common. Laypersons and HCPs often believed that "the body becomes immune" or "bacteria attack more strongly" if medications are taken "improperly." Another prevalent theme was that causes and effects of antimicrobial resistance are limited to the individual taking the antimicrobial medication and to the specific diarrheal episode. Participants often attributed antimicrobial resistance to patient behaviors; HCP behavior was rarely discussed. Less than half of the HCPs were aware of treatment guidelines. To combat antimicrobial resistance in urban Pakistan, a health systems strategy and community-supported outreach campaigns on appropriate antimicrobial use are needed. PMID:27139438

  18. Antimicrobial Organometallic Dendrimers with Tunable Activity against Multidrug-Resistant Bacteria.

    PubMed

    Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola; Overy, David P; Lanteigne, Martin; McQuillan, Katherine; Kerr, Russell G

    2015-11-01

    Multidrug-resistant pathogens are an increasing threat to public health. In an effort to curb the virulence of these pathogens, new antimicrobial agents are sought. Here we report a new class of antimicrobial organometallic dendrimers with tunable activity against multidrug-resistant Gram-positive bacteria that included methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. Mechanistically, these redox-active, cationic organometallic dendrimers induced oxidative stress on bacteria and also disrupted the microbial cell membrane. The minimum inhibitory concentrations, which provide a quantitative measure of the antimicrobial activity of these dendrimers, were in the low micromolar range. AlamarBlue cell viability assay also confirms the antimicrobial activity of these dendrimers. Interestingly, these dendrimers were noncytotoxic to epidermal cell lines and to mammalian red blood cells, making them potential antimicrobial platforms for topical applications. PMID:26452022

  19. Intrinsic Antimicrobial Resistance Determinants in the Superbug Pseudomonas aeruginosa

    PubMed Central

    Murray, Justine L.; Kwon, Taejoon; Marcotte, Edward M.

    2015-01-01

    ABSTRACT Antimicrobial-resistant bacteria pose a serious threat in the clinic. This is particularly true for opportunistic pathogens that possess high intrinsic resistance. Though many studies have focused on understanding the acquisition of bacterial resistance upon exposure to antimicrobials, the mechanisms controlling intrinsic resistance are not well understood. In this study, we subjected the model opportunistic superbug Pseudomonas aeruginosa to 14 antimicrobials under highly controlled conditions and assessed its response using expression- and fitness-based genomic approaches. Our results reveal that gene expression changes and mutant fitness in response to sub-MIC antimicrobials do not correlate on a genomewide scale, indicating that gene expression is not a good predictor of fitness determinants. In general, fewer fitness determinants were identified for antiseptics and disinfectants than for antibiotics. Analysis of gene expression and fitness data together allowed the prediction of antagonistic interactions between antimicrobials and insight into the molecular mechanisms controlling these interactions. PMID:26507235

  20. Lower Prevalence of Antibiotic-Resistant Enterococci on U.S. Conventional Poultry Farms that Transitioned to Organic Practices

    PubMed Central

    Hulet, R. Michael; Zhang, Guangyu; McDermott, Patrick; Kinney, Erinna L.; Schwab, Kellogg J.; Joseph, Sam W.

    2011-01-01

    Background: In U.S. conventional poultry production, antimicrobials are used for therapeutic, prophylactic, and nontherapeutic purposes. Researchers have shown that this can select for antibiotic-resistant commensal and pathogenic bacteria on poultry farms and in poultry-derived products. However, no U.S. studies have investigated on-farm changes in resistance as conventional poultry farms transition to organic practices and cease using antibiotics. Objective: We investigated the prevalence of antibiotic-resistant Enterococcus on U.S. conventional poultry farms that transitioned to organic practices. Methods: Poultry litter, feed, and water samples were collected from 10 conventional and 10 newly organic poultry houses in 2008 and tested for Enterococcus. Enterococcus (n = 259) was identified using the Vitek® 2 Compact System and tested for susceptibility to 17 antimicrobials using the Sensititre™ microbroth dilution system. Data were analyzed using SAS software (version 9.2), and statistical associations were derived based on generalized linear mixed models. Results: Litter, feed, and water samples were Enterococcus positive. The percentages of resistant Enterococcus faecalis and resistant Enterococcus faecium were significantly lower (p < 0.05) among isolates from newly organic versus conventional poultry houses for two (erythromycin and tylosin) and five (ciprofloxacin, gentamicin, nitrofurantoin, penicillin, and tetracycline) antimicrobials, respectively. Forty-two percent of E. faecalis isolates from conventional poultry houses were multidrug resistant (MDR; resistant to three or more antimicrobial classes), compared with 10% of isolates from newly organic poultry houses (p = 0.02); 84% of E. faecium isolates from conventional poultry houses were MDR, compared with 17% of isolates from newly organic poultry houses (p < 0.001). Conclusions: Our findings suggest that the voluntary removal of antibiotics from large-scale U.S. poultry farms that transition to

  1. Field Trial Evaluating the Influence of Prophylactic and Therapeutic Antimicrobial Administration on Antimicrobial Resistance of Fecal Escherichia coli in Dairy Calves

    PubMed Central

    Berge, Anna Catharina B.; Moore, Dale A.; Sischo, William M.

    2006-01-01

    The objective of this study was to describe the influence of in-feed and therapeutic antimicrobials on resistance in commensal fecal Escherichia coli isolated from preweaned calves. Four groups of 30, day-old calf-ranch calves were enrolled and raised until 4 weeks of age. Groups 1 to 3 were raised without antimicrobials in the feed. Group 1 was isolated from the other groups and received no antimicrobial therapy. Group 2 was housed on the calf ranch and did not receive antimicrobial therapy, whereas groups 3 and 4 could be treated with antimicrobials. Group 4 was fed neomycin and tetracycline HCl in the milk replacer. Fecal samples were collected from calves on days 1, 14, and 28. Three E. coli isolates per sample were evaluated for susceptibility to 12 antimicrobials. Cluster analysis was used to group isolates having similar susceptibility patterns. Cumulative logistic regression was used to evaluate factors associated with increasing levels of multiple antimicrobial resistance. In-feed antimicrobials were associated with higher levels of multiple antimicrobial resistance in fecal E. coli.f In calves not receiving in-feed antimicrobials, older calves had higher levels of resistance compared to day-old calves. Individual antimicrobial therapy increased resistance in these calves but appeared to be transient. There was no environmental influence on resistance in E. coli populations among study groups. PMID:16751491

  2. Field trial evaluating the influence of prophylactic and therapeutic antimicrobial administration on antimicrobial resistance of fecal Escherichia coli in dairy calves.

    PubMed

    Berge, Anna Catharina B; Moore, Dale A; Sischo, William M

    2006-06-01

    The objective of this study was to describe the influence of in-feed and therapeutic antimicrobials on resistance in commensal fecal Escherichia coli isolated from preweaned calves. Four groups of 30, day-old calf-ranch calves were enrolled and raised until 4 weeks of age. Groups 1 to 3 were raised without antimicrobials in the feed. Group 1 was isolated from the other groups and received no antimicrobial therapy. Group 2 was housed on the calf ranch and did not receive antimicrobial therapy, whereas groups 3 and 4 could be treated with antimicrobials. Group 4 was fed neomycin and tetracycline HCl in the milk replacer. Fecal samples were collected from calves on days 1, 14, and 28. Three E. coli isolates per sample were evaluated for susceptibility to 12 antimicrobials. Cluster analysis was used to group isolates having similar susceptibility patterns. Cumulative logistic regression was used to evaluate factors associated with increasing levels of multiple antimicrobial resistance. In-feed antimicrobials were associated with higher levels of multiple antimicrobial resistance in fecal E. coli.f In calves not receiving in-feed antimicrobials, older calves had higher levels of resistance compared to day-old calves. Individual antimicrobial therapy increased resistance in these calves but appeared to be transient. There was no environmental influence on resistance in E. coli populations among study groups. PMID:16751491

  3. Importance of multidrug efflux pumps in the antimicrobial resistance property of clinical multidrug-resistant isolates of Neisseria gonorrhoeae.

    PubMed

    Golparian, Daniel; Shafer, William M; Ohnishi, Makoto; Unemo, Magnus

    2014-06-01

    The contribution of drug efflux pumps in clinical isolates of Neisseria gonorrhoeae that express extensively drug-resistant or multidrug-resistant phenotypes has heretofore not been examined. Accordingly, we assessed the effect on antimicrobial resistance of loss of the three gonococcal efflux pumps associated with a known capacity to export antimicrobials (MtrC-MtrD-MtrE, MacA-MacB, and NorM) in such clinical isolates. We report that the MIC of several antimicrobials, including seven previously and currently recommended for treatment was significantly impacted. PMID:24733458

  4. Understanding bacterial resistance to antimicrobial peptides: From the surface to deep inside.

    PubMed

    Maria-Neto, Simone; de Almeida, Keyla Caroline; Macedo, Maria Ligia Rodrigues; Franco, Octávio Luiz

    2015-11-01

    Resistant bacterial infections are a major health problem in many parts of the world. The major commercial antibiotic classes often fail to combat common bacteria. Although antimicrobial peptides are able to control bacterial infections by interfering with microbial metabolism and physiological processes in several ways, a large number of cases of resistance to antibiotic peptide classes have also been reported. To gain a better understanding of the resistance process various technologies have been applied. Here we discuss multiple strategies by which bacteria could develop enhanced antimicrobial peptide resistance, focusing on sub-cellular regions from the surface to deep inside, evaluating bacterial membranes, cell walls and cytoplasmic metabolism. Moreover, some high-throughput methods for antimicrobial resistance detection and discrimination are also examined. This article is part of a Special Issue entitled: Bacterial Resistance to Antimicrobial Peptides. PMID:25724815

  5. Eight-Year Surveillance of Antimicrobial Resistance among Enterobacter Cloacae Isolated in the First Bethune Hospital

    NASA Astrophysics Data System (ADS)

    Zhou, Qi; Zhang, Man; Wang, Ailin; Xu, Jiancheng; Yuan, Ye

    This study was to investigate the antimicrobial resistance of Enterobacter cloacae isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 683 strains of Enterobacter cloacae were collected from sputum 410 (60.0%), secretions and pus 105 (15.4%), urine 69 (10.1%) during the past 8 years. No Enterobacter cloacae was resistant to imipenem and meropenem in the First Bethune Hospital. The antimicrobial resistance of Enterobacter cloacae had increased in recent 8 years. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from b eing transmitted.

  6. Emerging resistance to newer antimicrobial agents among Shigella isolated from Finnish foreign travellers.

    PubMed

    Haukka, K; Siitonen, A

    2008-04-01

    In Finland, most cases of shigellosis are related to travel abroad. Antimicrobial drug resistance of 1814 Shigella strains isolated from Finnish patients during 1990-2005 was studied using discs of 12 antimicrobial agents. Since 2000, the E-test has been performed to determine ciprofloxacin minimum inhibitory concentrations of nalidixic acid-resistant isolates. The proportion of multi-resistant strains (resistant to >or =4 antimicrobials) was highest among isolates from China and India, but is increasing significantly in other parts of Asia. Resistance to nalidixic acid has become common among the strains from the Far East, and the first isolates also resistant to ciprofloxacin were detected during 2004-2005. All the ciprofloxacin-resistant isolates belonged to the S. flexneri 2a serotype. All the nalidixic acid-resistant S. flexneri strains had reduced susceptibility to ciprofloxacin, whereas 23% of the nalidixic acid-resistant S. sonnei strains were still completely susceptible to ciprofloxacin. PMID:17578602

  7. Antimicrobial resistance, toxinotype, and genotypic profiling of Clostridium difficile isolates of swine origin.

    PubMed

    Fry, Pamela R; Thakur, Siddhartha; Abley, Melanie; Gebreyes, Wondwossen A

    2012-07-01

    The occurrence of Clostridium difficile infections in patients that do not fulfill the classical risk factors prompted us to investigate new risk factors of disease. The goal of this study was to characterize strains and associated antimicrobial resistance determinants of C. difficile isolated from swine raised in Ohio and North Carolina. Genotypic approaches used include PCR detection, toxinotyping, DNA sequencing, and pulsed-field gel electrophoresis (PFGE) DNA fingerprinting. Thirty-one percent (37/119) of isolates carried both tetM and tetW genes. The ermB gene was found in 91% of isolates that were resistant to erythromycin (68/75). Eighty-five percent (521/609) of isolates were toxin gene tcdB and tcdA positive. A total of 81% (494/609) of isolates were positive for cdtB and carry a tcdC gene (a toxin gene negative regulator) with a 39-bp deletion. Overall, 88% (196/223) of pigs carry a single C. difficile strain, while 12% (27/223) of pigs carried multiple strains. To the best of our knowledge, this is the first report of individual pigs found to carry more than one strain type of C. difficile. A significant difference in toxinotype profiles in the two geographic locations was noted, with a significantly (P < 0.001) higher prevalence of toxinotype V found in North Carolina (84%; 189/224) than in Ohio (55%; 99/181). Overall, the study findings indicate that significant proportions of C. difficile in swine are toxigenic and often are associated with antimicrobial resistance genes, although they are not resistant to drugs that are used to treat C. difficile infections. PMID:22518873

  8. Analysis of Resistance to Antimicrobials and Presence of Virulence/Stress Response Genes in Campylobacter Isolates from Patients with Severe Diarrhoea

    PubMed Central

    Ghunaim, Haitham; Behnke, Jerzy M.; Aigha, Idil; Sharma, Aarti; Doiphode, Sanjay H.; Deshmukh, Anand; Abu-Madi, Marawan M.

    2015-01-01

    Campylobacter infections are a major cause of diarrhoea world-wide and two of the antimicrobials used for their control (erythromycin and ciprofloxacin) have been losing efficacy in recent years. In a sample of 174 genotyped isolates from the stools of patients with severe diarrhoea in Qatar, collected between 2005 and 2012, 63.2% showed resistance to ciprofloxacin, 8.6% to erythromycin, 0.57% to chloramphenicol and all were sensitive to gentamycin. While 33.9% of isolates were sensitive to all four antimicrobials, 59.8% were resistant to at least one, 6.3% were resistant to two and none showed resistance to three antimicrobials. There was no host sex- or age-dependence among isolates resistant to ciprofloxacin and erythromycin and no significant variation was found with the region of origin of the patients. All isolates were screened for the presence of 3 virulence factors (ciaB, cadF and cdtB) and two stress-response factors (htrB and clpP), all of which were present in more than 50% of the isolates. Host sex-, age- and region of origin-dependent variations in prevalence were found for some of these factors. Data analysis for the combination of virulence factors and their effect on antimicrobial resistance indicated that the prevalence of resistance to both erythromycin and ciprofloxacin was higher in isolates harbouring ciaB but not clpP. Prevalence of resistance to ciprofloxacin was similar in clpP positive and negative isolates also possessing htrB, while for htrB-negative isolates prevalence was higher in the absence of clpP. These results are discussed and their implications are highlighted. PMID:25781009

  9. Impact of medicated feed along with clay mineral supplementation on Escherichia coli resistance to antimicrobial agents in pigs after weaning in field conditions.

    PubMed

    Jahanbakhsh, Seyedehameneh; Kabore, Kiswendsida Paul; Fravalo, Philippe; Letellier, Ann; Fairbrother, John Morris

    2015-10-01

    The aim of this study was to examine changes in antimicrobial resistance (AMR) phenotype and virulence and AMR gene profiles in Escherichia coli from pigs receiving in-feed antimicrobial medication following weaning and the effect of feed supplementation with a clay mineral, clinoptilolite, on this dynamic. Eighty E. coli strains isolated from fecal samples of pigs receiving a diet containing chlortetracycline and penicillin, with or without 2% clinoptilolite, were examined for antimicrobial resistance to 15 antimicrobial agents. Overall, an increased resistance to 10 antimicrobials was observed with time. Supplementation with clinoptilolite was associated with an early increase but later decrease in blaCMY-2, in isolates, as shown by DNA probe. Concurrently, a later increase in the frequency of blaCMY-2 and the virulence genes iucD and tsh was observed in the control pig isolates, being significantly greater than in the supplemented pigs at day 28. Our results suggest that, in the long term, supplementation with clinoptilolite could decrease the prevalence of E. coli carrying certain antimicrobial resistance and virulence genes. PMID:26412523

  10. Multivariable Analysis of the Association Between Antimicrobial Use and Antimicrobial Resistance in Escherichia coli Isolated from Apparently Healthy Pigs in Japan.

    PubMed

    Makita, Kohei; Goto, Masaki; Ozawa, Manao; Kawanishi, Michiko; Koike, Ryoji; Asai, Tetsuo; Tamura, Yutaka

    2016-01-01

    The objective of this study was to investigate the association between antimicrobial agent use and antimicrobial resistance in Escherichia coli isolated from healthy pigs using data from 2004 to 2007 in the Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM). Fecal E. coli isolates from 250 pigs (one isolate each from a pig per farm) were examined for antimicrobial resistance. Information on the use of antimicrobials within preceding 6 months and types of farms recorded in JVARM was collected and statistically analyzed against the resistance patterns. In the univariate analysis, associations between both therapeutic and feed additive use of antimicrobials, and resistance to dihydrostreptomycin, gentamicin, kanamycin, ampicillin, cefazolin, ceftiofur, oxytetracycline, chloramphenicol, trimethoprim, nalidixic acid, enrofloxacin, colistin, and bicozamycin, and husbandry factors were investigated. In multivariable analysis, generalized estimating equations were used to control geographical intraclass correlation. Confounding for structurally unrelated associations was tested using generalized linear models. The results suggested direct and cross selections in the associations between use of aminoglycosides in reproduction farms and resistance to kanamycin, use of tetracyclines in larger farms and resistance to oxytetracycline, use of beta-lactams and resistance to ampicillin, use of phenicols and resistance to chloramphenicol, and use of fluoroquinolones and resistance to nalidixic acid and enrofloxacin. Coselection was suggested in the use of tetracyclines and chloramphenicol resistance. The associations between use of beta-lactams and dihydrostreptomycin resistance, use of macrolides and ampicillin and oxytetracycline resistance, and use of colistin and kanamycin resistance were significant, but were confounded by the simultaneous use of homologous antimicrobials. PMID:26296068

  11. Antimicrobial resistance of Salmonella enterica isolates from bulk tank milk and milk filters in the United States.

    PubMed

    Van Kessel, J S; Sonnier, J; Zhao, S; Karns, J S

    2013-01-01

    Salmonella isolates were recovered from bulk tank milk as part of the National Animal Health Monitoring System (NAHMS) Dairy 2002 and 2007 surveys. In-line milk filters were also tested in the 2007 survey. The objective of this study was to determine the prevalence of antimicrobial resistance among Salmonella enterica isolates from bulk milk and milk filters in the NAHMS Dairy 2002 and 2007 surveys and to further characterize resistant isolates. Susceptibilities to 15 antibiotics were determined for 176 Salmonella isolates of 26 serotypes using an automated antimicrobial susceptibility system. Resistant isolates were screened by PCR for the presence of the extended-spectrum β-lactamase (bla(CMY)) gene and class I integrons and further characterized by pulsed-field gel electrophoresis. Thirty isolates (17.0%) representing six S. enterica serotypes exhibited resistance to at least one antimicrobial agent (serotypes Newport [14 of 14 isolates exhibited resistance], Dublin [7 of 7], Typhimurium [3 of 5], Kentucky [4 of 22], Anatum [1 of 13], and Infantis [1 of 2]). Twenty isolates (11.4%), including all 14 Newport, 3 Dublin, 2 Typhimurium, and 1 Infantis isolate, displayed the typical multidrug-resistant, bla(CMY)-positive (MDR-AmpC) phenotype which included resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline, plus resistance to amoxicillin-clavulanic acid and extended-spectrum cephalosporins. Five of the MDR-AmpC isolates carried class I integrons (2.8%). Two-enzyme (XbaI and BlnI) pulsed-field gel electrophoresis discerned clades within serotypes and, together with the resistance profiles, identified strains that appeared to have persisted temporally and geographically. These results suggest that there is a low but appreciable risk of infection with MDR Salmonella from consumption of nonpasteurized milk and dairy products. PMID:23317852

  12. Characterization of antimicrobial resistance of Escherichia coli recovered from foods of animal and fish origin in Korea.

    PubMed

    Koo, Hyon-Ji; Woo, Gun-Jo

    2012-05-01

    Antimicrobial-resistant Escherichia coli is transferred from food-producing animals to humans through the food chain. We investigated the prevalence of antimicrobial resistance and resistance determinants and characterized the integrons of foodborne E. coli in Korea. In total, 162 E. coli isolates from commercial foods (raw meat, fish, and processed foods) were collected by the National Antimicrobial Resistance Management Program from 2004 to 2006. Susceptibility to 20 antibiotics was tested by disk diffusion, and resistance determinants were detected using PCR and genomic sequence analysis. The isolates were highly resistant to antibiotics commonly used in livestock farming. Resistance to tetracycline (74.7%) was the most frequently observed, followed by streptomycin (71%) and ampicillin (51.2%). Class 1 integrons were detected in 13 isolates (8%), and nine of these integrons were located on conjugative plasmids. None of the isolates produced extended-spectrum β -lactamase. One isolate (0.6%) harbored bla(CMY-2), which was located on a conjugative plasmid. Although the qnr gene was not detected, aac(6'9)-Ib-cr was present in two isolates (1.2%). This is the first report of aac(6'9)-Ib-cr in food isolates. Three or four amino acid substitutions at positions 83 and 87 in gyrA and at positions 80 and/or 84 in parC were found in six isolates, representing high resistance to ciprofloxacin (MIC ≥ 16 mg/liter). These results suggest that E. coli isolates carrying resistance genes and integrons are present in the Korean food chain. PMID:22564949

  13. Antimicrobial Resistance in Salmonella in the United States from 1948 to 1995.

    PubMed

    Tadesse, Daniel A; Singh, Aparna; Zhao, Shaohua; Bartholomew, Mary; Womack, Niketta; Ayers, Sherry; Fields, Patricia I; McDermott, Patrick F

    2016-04-01

    We conducted a retrospective study of 2,149 clinicalSalmonellastrains to help document the historical emergence of antimicrobial resistance. There were significant increases in resistance to older drugs, including ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline, which were most common inSalmonella entericaserotype Typhimurium. An increase in multidrug resistance was observed for each decade since the 1950s. These data help show howSalmonellaevolved over the past 6 decades, after the introduction of new antimicrobial agents. PMID:26856840

  14. Antimicrobial resistance in Neisseria gonorrhoeae in the 21st century: past, evolution, and future.

    PubMed

    Unemo, Magnus; Shafer, William M

    2014-07-01

    Neisseria gonorrhoeae is evolving into a superbug with resistance to previously and currently recommended antimicrobials for treatment of gonorrhea, which is a major public health concern globally. Given the global nature of gonorrhea, the high rate of usage of antimicrobials, suboptimal control and monitoring of antimicrobial resistance (AMR) and treatment failures, slow update of treatment guidelines in most geographical settings, and the extraordinary capacity of the gonococci to develop and retain AMR, it is likely that the global problem of gonococcal AMR will worsen in the foreseeable future and that the severe complications of gonorrhea will emerge as a silent epidemic. By understanding the evolution, emergence, and spread of AMR in N. gonorrhoeae, including its molecular and phenotypic mechanisms, resistance to antimicrobials used clinically can be anticipated, future methods for genetic testing for AMR might permit region-specific and tailor-made antimicrobial therapy, and the design of novel antimicrobials to circumvent the resistance problems can be undertaken more rationally. This review focuses on the history and evolution of gonorrhea treatment regimens and emerging resistance to them, on genetic and phenotypic determinants of gonococcal resistance to previously and currently recommended antimicrobials, including biological costs or benefits; and on crucial actions and future advances necessary to detect and treat resistant gonococcal strains and, ultimately, retain gonorrhea as a treatable infection. PMID:24982323

  15. Antimicrobial Resistance in Neisseria gonorrhoeae in the 21st Century: Past, Evolution, and Future

    PubMed Central

    Unemo, Magnus

    2014-01-01

    SUMMARY Neisseria gonorrhoeae is evolving into a superbug with resistance to previously and currently recommended antimicrobials for treatment of gonorrhea, which is a major public health concern globally. Given the global nature of gonorrhea, the high rate of usage of antimicrobials, suboptimal control and monitoring of antimicrobial resistance (AMR) and treatment failures, slow update of treatment guidelines in most geographical settings, and the extraordinary capacity of the gonococci to develop and retain AMR, it is likely that the global problem of gonococcal AMR will worsen in the foreseeable future and that the severe complications of gonorrhea will emerge as a silent epidemic. By understanding the evolution, emergence, and spread of AMR in N. gonorrhoeae, including its molecular and phenotypic mechanisms, resistance to antimicrobials used clinically can be anticipated, future methods for genetic testing for AMR might permit region-specific and tailor-made antimicrobial therapy, and the design of novel antimicrobials to circumvent the resistance problems can be undertaken more rationally. This review focuses on the history and evolution of gonorrhea treatment regimens and emerging resistance to them, on genetic and phenotypic determinants of gonococcal resistance to previously and currently recommended antimicrobials, including biological costs or benefits; and on crucial actions and future advances necessary to detect and treat resistant gonococcal strains and, ultimately, retain gonorrhea as a treatable infection. PMID:24982323

  16. Changes in antimicrobial resistance of Salmonella isolated from humans in the United States.

    PubMed

    MacDonald, K L; Cohen, M L; Hargrett-Bean, N T; Wells, J G; Puhr, N D; Collin, S F; Blake, P A

    1987-09-18

    Changes were examined that occurred in the antimicrobial susceptibility between 1979-1980 and 1984-1985 of Salmonella organisms isolated from humans who resided in a random sample of counties in the United States. Resistance to one or more antimicrobials rose significantly from 16% (82 of 511 isolates) in 1979-1980 to 24% (117 of 485 isolates) in 1984-1985. In addition, statistically significant increases occurred in the proportion of organisms resistant to only one antimicrobial (from 4% to 9%), the rate of resistance of Salmonella typhimurium (from 14% to 26%), and the rate of resistance to tetracycline. For one commonly occurring serotype, Salmonella heidelberg, the proportion of resistant strains fell significantly from 67% in 1979-1980 to 35% in 1984-1985. When epidemiologic characteristics of patients were examined, previous use of antimicrobials for treatment of other illnesses was a significant risk factor for acquiring clinically important infections with antimicrobial-resistant Salmonella. Changes detected in the antimicrobial resistance of Salmonella during this time will ultimately affect the efficacy of antimicrobial therapy in treating human disease. PMID:3625949

  17. Relationship between Antimicrobial Consumption and the Incidence of Antimicrobial Resistance in Escherichia coli and Klebsiella pneumoniae Isolates

    PubMed Central

    Joseph, Noyal Mariya; Shewade, Deepak Gopal; Harish, Belgode Narasimha

    2015-01-01

    Introduction: Gram negative organisms are one of the major causes of nosocomial diseases. Development of resistance to antibiotics by these organisms increases their risk in clinical treatment of patients. It also affects morbidity and mortality hence needs to be monitored and controlled. Aim: The aim of the present study was to analyse the correlation between consumption of parenteral antibiotics and the rates of antimicrobial resistance among the Escherichia coli and Klebsiella pneumoniae isolates collected during Dec 2010 - Jun 2013 from JIPMER hospital. Materials and Methods: Consumption data of parenteral antibiotics in J01 category of Anatomical Therapeutic Chemical (ATC) in JIPMER was obtained and expressed in Defined Daily Doses (DDD) per 1000 inhabitants. Valid consumption and resistance data during the period Dec 2010 to Jun 2013 were obtained at 6 month intervals and were correlated to draw a relationship between antimicrobial consumption and its impact on drug resistance for Escherichia coli and Klebsiella pneumoniae. Results: Escherichia coli isolates showed high resistance for increased use of gentamycin and ciprofloxacin. Increase in antibiotic consumption increases the resistance for Escherichia coli except for amikacin. Among the Klebsiella isolates, meropenem and gentamycin showed high correlations followed by ceftazidime, amikacin, ceftriaxone and ciprofloxacin. Conclusion: In summary, a statistically significant association was noticed between consumption of the studied antimicrobials and resistance of Escherichia coli isolates, except for amikacin and ceftazidime. In the case of Klebsiella pneumoniae, there was a statistically significant association between the resistance rates and consumption of gentamycin, ceftazidime and meropenem. Further, a linear relationship was noted between antimicrobial consumption and resistant isolates of Escherichia coli and Klebsiella pneumoniae, except for Escherichia coli resistance to amikacin. PMID:25859453

  18. Molecular diagnosis and anti-microbial resistance patterns among Shigella spp. isolated from patients with diarrhea

    PubMed Central

    Hosseini Nave, Hossein; Mansouri, Shahla; Sadeghi, Amin; Moradi, Mohammad

    2016-01-01

    Aim: This study aims to determine the serogroup distribution and molecular diagnosis, as well as antimicrobial resistance profiles among Shigella spp. isolated from patients with diarrhea in Kerman, southeast of Iran. Background: Shigella species are frequent cause of bacterial dysentery worldwide. Previous studies have been reported that S. sonnei and S. flexneri are the most prevalent serogroups in various parts of Iran. Patients and methods: A total of 624 stool samples were randomly collected from patients with diarrhea from June 2013 to August 2014. Biochemical and serological characterizations were performed for identifying Shigella spp. In addition, the multiplex PCR assay was carried out for the detection and differentiation of three pathogenic Shigella spp. Antibiotic susceptibility testing was performed according to the Clinical Laboratory Standards Institute (CLSI) guidelines. Results: Fifty six (9%) Shigella strains were isolated from stool samples. The most common species were S. flexneri 31(55.4%), followed by S .sonnei 18(32.1%) and S. boydii 7(12.5%). S. dysentery was not detected in the present study. All the isolates that identified by serological test as Shigella spp. were confirmed by the multiplex PCR method. The highest rate of resistance was observed for ampicillin and trimethoprim-sulphamethoxazole antibiotics with 52(92.9%) resistant, followed by tetracycline 44(78.6%) and cefotaxime 33(58.9%). All Shigella isolates were susceptible to ciprofloxacin. A significant relationship was found between the Shigella species and cefotaxime resistance (p<0.05). Conclusion: S. flexneri was found as the most prevalent serogroup causing shigellosis. The high rate of resistance to third-generation cephalosporins limits the treatment options available for the management of shigellosis in Kerman, Iran. PMID:27458513

  19. Antimicrobial resistance among Enterobacteriaceae in South America: history, current dissemination status and associated socioeconomic factors.

    PubMed

    Bonelli, Raquel Regina; Moreira, Beatriz Meurer; Picão, Renata Cristina

    2014-04-01

    South America exhibits some of the higher rates of antimicrobial resistance in Enterobactericeae worldwide. This continent includes 12 independent countries with huge socioeconomic differences, where the ample access to antimicrobials, including counterfeit ones, coexists with ineffective health systems and sanitation problems, favoring the emergence and dissemination of resistant strains. This work presents a literature review concerning the evolution and current status of antimicrobial resistance threats found among Enterobacteriaceae in South America. Resistance to β-lactams, fluoroquinolones and aminoglycosides was emphasized along with description of key epidemiological studies that highlight the success of specific resistance determinants in different parts of the continent. In addition, a discussion regarding political and socioeconomic factors possibly related to the dissemination of antimicrobial resistant strains in clinical settings and at the community is presented. Finally, in order to assess the possible sources of resistant bacteria, we compile the current knowledge about the occurrence of antimicrobial resistance in isolates in South American' food, food-producing animals and off-hospitals environments. By addressing that intensive intercontinental commerce and tourism neutralizes the protective effect of geographic barriers, we provide arguments reinforcing that globally integrated efforts are needed to decelerate the emergence and dissemination of antimicrobial resistant strains. PMID:24618111

  20. An electronic network for the surveillance of antimicrobial resistance in bacterial nosocomial isolates in Greece. The Greek Network for the Surveillance of Antimicrobial Resistance.

    PubMed Central

    Vatopoulos, A. C.; Kalapothaki, V.; Legakis, N. J.

    1999-01-01

    The present article reports an evaluation of the national electronic network for the continuous monitoring of antimicrobial resistance in Greece. The network employs a common electronic code and data format and uses WHONET software. Our four years' experience with the network confirms its practicality. A total of 22 hospitals in Greece are currently using the software, of which 19 participate in the network. Analysis of the information obtained has greatly helped in identifying the main factors responsible for the emergence of antimicrobial resistance in the participating hospitals. The data collected have also helped to identify priorities for further investigation of the genetic and molecular mechanisms responsible for the emergence of resistance and facilitated development of hospital-based empirical therapy of infections. In conclusion, the implementation of national networks for the surveillance of antimicrobial resistance should be regarded as a priority. PMID:10444883

  1. High Rates of Antimicrobial Drug Resistance Gene Acquisition after International Travel, the Netherlands

    PubMed Central

    von Wintersdorff, Christian J.H.; Penders, John; Stobberingh, Ellen E.; Lashof, Astrid M.L. Oude; Hoebe, Christian J.P.A.; Savelkoul, Paul H.M.

    2014-01-01

    We investigated the effect of international travel on the gut resistome of 122 healthy travelers from the Netherlands by using a targeted metagenomic approach. Our results confirm high acquisition rates of the extended-spectrum β-lactamase encoding gene blaCTX-M, documenting a rise in prevalence from 9.0% before travel to 33.6% after travel (p<0.001). The prevalence of quinolone resistance encoding genes qnrB and qnrS increased from 6.6% and 8.2% before travel to 36.9% and 55.7% after travel, respectively (both p<0.001). Travel to Southeast Asia and the Indian subcontinent was associated with the highest acquisition rates of qnrS and both blaCTX-M and qnrS, respectively. Investigation of the associations between the acquisitions of the blaCTX-M and qnr genes showed that acquisition of a blaCTX-M gene was not associated with that of a qnrB (p = 0.305) or qnrS (p = 0.080) gene. These findings support the increasing evidence that travelers contribute to the spread of antimicrobial drug resistance. PMID:24655888

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

    PubMed

    Krupp, Karl; Madhivanan, Purnima

    2015-01-01

    The emergence of multi-drug resistant sexually transmitted infections (STIs) is causing a treatment crisis across the globe. While cephalosporin-resistant gonorrhea is one of the most pressing issues, extensively antibiotic resistant Chlamydia trachomatis and Mycoplasma hominis are also becoming commonplace. Experts have suggested that the failure of current treatment regimens are "largely inevitable" and have called for entirely new classes of antimicrobial agents. With the exception of several new classes of drugs primarily targeting nosocomial infections, progress has been slow. While pharmaceutical companies continue to introduce new drugs, they are based on decade-old discoveries. While there is disagreement about what constitutes new classes of antibiotics, many experts suggest that the last truly new family of antimicrobials was discovered in 1987. This review summarizes the existing literature on antibiotic resistance in common bacterial and protozoal STIs. It also briefly discusses several of the most promising alternatives to current therapies, and further examines how advances in drug delivery, formulation, concentration, and timing are improving the efficacy of existing treatments. Finally, the paper discusses the current state of pharmaceutical development for multidrug-resistant STI. PMID:26392647

  3. Azithromycin-Resistant Syphilis-Causing Strains in Sydney, Australia: Prevalence and Risk Factors

    PubMed Central

    Jeoffreys, Neisha; Tagg, Kaitlin; Guy, Rebecca J.; Gilbert, Gwendolyn L.; Donovan, Basil

    2014-01-01

    Azithromycin has shown high efficacy in randomized trials when used for treating infectious syphilis in Africa. However, its use in clinical practice has been limited by the development of antimicrobial drug resistance. Resistance has not previously been reported from Australasia. The aim of this study was to determine the prevalence of and risk factors for azithromycin-resistant syphilis-causing strains in Sydney, Australia. We evaluated 409 samples that were PCR positive for Treponema pallidum DNA collected between 2004 and 2011 for the presence of the A2058G mutation, which confers resistance to macrolide antibiotics such as azithromycin. Overall, 84% of samples harbored the mutation. The prevalence of the mutation increased during the study period (P trend, 0.003). We also collected clinical and demographic data on 220 patients from whom these samples had been collected to determine factors associated with the A2058G mutation; 97% were from men who have sex with men. Reporting sex in countries other than Australia was associated with less macrolide resistance (adjusted odds ratio, 0.25; 95% confidence interval, 0.09 to 0.66; P = 0.005), with other study factors showing no association (age, HIV status, recent macrolide use, stage of syphilis, or history of prior syphilis). Azithromycin cannot be recommended as an alternative treatment for syphilis in Sydney. PMID:24850356

  4. An Assessment of Antimicrobial Resistant Disease Threats in Canada

    PubMed Central

    Garner, Michael J.; Carson, Carolee; Lingohr, Erika J.; Fazil, Aamir; Edge, Victoria L.; Trumble Waddell, Jan

    2015-01-01

    Background Antimicrobial resistance (AMR) of infectious agents is a growing concern for public health organizations. Given the complexity of this issue and how widespread the problem has become, resources are often insufficient to address all concerns, thus prioritization of AMR pathogens is essential for the optimal allocation of risk management attention. Since the epidemiology of AMR pathogens differs between countries, country-specific assessments are important for the determination of national priorities. Objective To develop a systematic and transparent approach to AMR risk prioritization in Canada. Methods Relevant AMR pathogens in Canada were selected through a transparent multi-step consensus process (n=32). Each pathogen was assessed using ten criteria: incidence, mortality, case-fatality, communicability, treatability, clinical impact, public/political attention, ten-year projection of incidence, economic impact, and preventability. For each pathogen, each criterion was assigned a numerical score of 0, 1, or 2, and multiplied by criteria-specific weighting determined through researcher consensus of importance. The scores for each AMR pathogen were summed and ranked by total score, where a higher score indicated greater importance. A sensitivity analysis was conducted to determine the effects of changing the criteria-specific weights. Results The AMR pathogen with the highest total weighted score was extended spectrum B-lactamase-producing (ESBL) Enterobacteriaceae (score=77). When grouped by percentile, ESBL Enterobacteriaceae, Clostridium difficile, carbapenem-resistant Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus were in the 80-100th percentile. Conclusion This assessment provides useful information for prioritising public health strategies regarding AMR resistance at the national level in Canada. As the AMR environment and challenges change over time and space, this systematic and transparent approach can be adapted for use by

  5. Antimicrobial susceptibility of Staphylococcus aureus and characterization of methicillin-resistant Staphylococcus aureus isolated from bovine mastitis in Korea.

    PubMed

    Nam, Hyang-Mi; Lee, Ae-Li; Jung, Suk-Chan; Kim, Mal-Nam; Jang, Geum-Chan; Wee, Sung-Hwan; Lim, Suk-Kyung

    2011-02-01

    A total of 402 Staphylococcus aureus isolates from bovine mastitis milk collected during 2003-2009 in Korea were tested for susceptibility to 20 antimicrobial agents. All S. aureus isolates were susceptible to 11 of 20 antimicrobials tested; no resistance was observed against pirlimycin, telithromycin, novobiocin, penicillin/novobiocin, quinupristin/dalfopristin, clindamycin, rifampin, ciprofloxacin, trimethprim/sulfamethoxazol, vancomycin, and linezolid. Over 66% of the S. aureus isolates were resistant to penicillin. Resistance was also seen for gentamicin (11.9%), erythromycin (7.7%), methicillin (oxacillin and cefoxitin, 6.2%), and tetracycline (4.2%). No noticeable change was observed in penicillin, gentamicin, and erythromycin resistance over the 7-year period. Tetracycline resistance appeared to decrease consistently, whereas methicillin resistance was observed from 2005. About 2.7% (11/402) were resistant to three or more antimicrobials. Genotyping of the 17 methicillin-resistant S. aureus (MRSA) isolated from each cow revealed two staphylococcal cassette chromosome mec (SCCmec) types (IV and IVa), three spa types (t286, t324, and untypable), and two sequence types (ST1 and ST72). Eleven of 17 (64.7%) MRSA strains belonged to SCCmec IVa-t324-ST72. The rest of strains belonged to SCCmec IVa-t286-ST1 (n = 3) and SCCmec IV-untypable-ST72 (n = 3). None of the MRSA carried the Panton-Valentine leukocidin gene. These characteristics are the same as those found in community-acquired (CA) MRSA strains prevalent in humans in Korea. Three pulsed-field gel electrophoresis types (A-C) were observed among the 17 MRSA strains examined, and 14 strains belonged to the same pulsed-field gel electrophoresis pattern regardless of their geographical origin and year of isolation. The results of this study provide evidence of CA-MRSA infection in dairy cattle for the first time in Korea. PMID:21034263

  6. Bisphosphocins: novel antimicrobials for enhanced killing of drug-resistant and biofilm-forming bacteria.

    PubMed

    Wong, Jonathan P; DiTullio, Paul; Parkinson, Steve

    2015-01-01

    The global prevalence of antibiotic resistance and the threat posed by drug-resistant superbugs are a leading challenge confronting modern medicine in the 21st century. However, the progress on the development of novel antibiotics to combat this problem is severely lagging. A more concerted effort to develop novel therapeutic agents with robust activity and unique mechanisms of action will be needed to overcome the problem of drug resistance. Furthermore, biofilm forming bacteria are known to be increasingly resistant to the actions of antibiotics and are a leading cause of mortality or morbidity in nosocomial infections. Bisphosphocins (also scientifically known as nubiotics) are novel small protonated deoxynucleotide molecules, and exert their antibacterial activity by depolarization of the bacterial cell membrane, causing bacterial cell death. Bisphosphocins may represent an effective weapon against antibiotic-resistant and biofilm-forming pathogenic bacteria. Preclinical efficacy studies in animals have shown that the compounds are safe and, efficacious against various bacterial infections, including drug-resistant pathogens. In vitro biochemical analysis confirmed that the bactericidal activity of bisphosphocins is mediated by depolarization of the bacterial cell membrane, and these compounds are better able to penetrate through bacterial biofilm and kill the biofilm encased bacteria. This article will cover the structure, mode of action, safety, efficacy and the current state of development of bisphosphocins. Together, the information presented here will present a strong case for bisphosphocins to be considered for use as new weapons to complement the existing arsenal of antimicrobial drugs and as a first line defence against drug-resistant and biofilm-forming bacteria. PMID:26597426

  7. Genetic Structure and Antimicrobial Resistance of Escherichia coli and Cryptic Clades in Birds with Diverse Human Associations

    PubMed Central

    Blyton, Michaela D. J.; Pi, Hongfei; Vangchhia, Belinda; Abraham, Sam; Trott, Darren J.; Johnson, James R.

    2015-01-01

    The manner and extent to which birds associate with humans may influence the genetic attributes and antimicrobial resistance of their commensal Escherichia communities through strain transmission and altered selection pressures. In this study, we determined whether the distribution of the different Escherichia coli phylogenetic groups and cryptic clades, the occurrence of 49 virulence associated genes, and/or the prevalence of resistance to 12 antimicrobials differed between four groups of birds from Australia with contrasting types of human association. We found that birds sampled in suburban and wilderness areas had similar Escherichia communities. The Escherichia communities of backyard domestic poultry were phylogenetically distinct from the Escherichia communities sourced from all other birds, with a large proportion (46%) of poultry strains belonging to phylogenetic group A and a significant minority (17%) belonging to the cryptic clades. Wild birds sampled from veterinary and wildlife rehabilitation centers (in-care birds) carried Escherichia isolates that possessed particular virulence-associated genes more often than Escherichia isolates from birds sampled in suburban and wilderness areas. The Escherichia isolates from both the backyard poultry and in-care birds were more likely to be multidrug resistant than the Escherichia isolates from wild birds. We also detected a multidrug-resistant E. coli strain circulating in a wildlife rehabilitation center, reinforcing the importance of adequate hygiene practices when handling and caring for wildlife. We suggest that the relatively high frequency of antimicrobial resistance in the in-care birds and backyard poultry is due primarily to the use of antimicrobials in these animals, and we recommend that the treatment protocols used for these birds be reviewed. PMID:26002899

  8. PREVALENCE OF SULFONAMIDE AND FLORFENICOL RESISTANCE GENES IN ESCHERICHIA COLI ISOLATED FROM YAKS (BOS GRUNNIENS) AND HERDSMEN IN THE TIBETAN PASTURE.

    PubMed

    Zhang, Anyun; Yang, Yunfei; Wang, Hongning; Lei, Changwei; Xu, Changwen; Guan, Zhongbin; Liu, Bihui; Huang, Xi; Peng, Linyao

    2015-07-01

    To determine the antimicrobial susceptibility profiles and prevalence of resistance genes in Escherichia coli isolated from yaks (Bos grunniens) and herdsmen in nine plateau pastures in Tibet, we isolated 184 nonidentical strains of E. coli from yaks and herdsmen. Antimicrobial susceptibility testing of 15 antimicrobials was conducted and the prevalence of sulfonamide resistance genes (sul1, sul2, and sul3) and florfenicol resistance genes (floR, cfr, cmlA, fexA, pexA, and estDL136) was determined. Escherichia coli isolated from yaks had a high resistance rate to sulfamethoxazole (44%), sulphafurazole (40.4%), and florfenicol (11.4%). Escherichia coli isolated from herdsmen had a high resistance rate to sulfamethoxazole (57%) and sulphafurazole (51%). In addition, sul genes were present in 93% of sulfonamide-resistant isolates (84/90), and 17 floR genes and four cmlA genes were found in 19 florfenicol-resistant isolates. Even though florfenicol is prohibited from use in humans, three floR genes were detected in strains isolated from herdsmen. The three floR-positive isolates from herdsmen had pulsed-field gel electrophoresis patterns similar to isolates from yaks. In addition to documenting the sul and floR genes in E. coli isolated from yaks and herdsmen in the Tibetan pasture, we demonstrated the potential risk that antimicrobial-resistant E. coli could spread among herdsmen and yaks. PMID:25973625

  9. SEROVARS AND ANTIMICROBIAL RESISTANCE OF Salmonella spp. ISOLATED FROM TURKEY AND BROILER CARCASSES IN SOUTHERN BRAZIL BETWEEN 2004 AND 2006.

    PubMed

    Palmeira, Andre; Santos, Luciana Ruschel dos; Borsoi, Anderlise; Rodrigues, Laura Beatriz; Calasans, Max; Nascimento, Vladimir Pinheiro do

    2016-01-01

    Salmonella spp. causes diseases in fowls, when species-specific serovars (Salmonella Pullorum and S.Gallinarum) are present in flocks, and public health problems, when non-typhoid serovars are isolated, as well as possible bacterial resistance induced by the preventive and therapeutic use of antimicrobials in animal production. This study describes the serovars and bacterial resistance of 280 Salmonella spp. strains isolated from turkey and broiler carcasses in Southern Brazil between 2004 and 2006. Salmonella Enteritidis was the most prevalent serovar (55.7%), followed by Heidelberg (5.0%), Agona (4.3%), Bredeney (3.9%), Hadar (3.2%), and Typhimurium (2.9%). Tennessee and S. Enterica subspecies enterica(O: 4.5) were isolated only in turkeys, and Hadar (18.6%) was the most prevalent serovar in this species. Antimicrobial susceptibility tests were performed in 178 isolates (43 from turkeys and 135 from broilers). All isolates were sensitive to amoxicillin + clavulanic acid, polymyxin B, ciprofloxacin, and norfloxacin, and were resistant to bacitracin and penicillin. Broiler carcass isolates showed resistance to nalidixic acid (48.9%), nitrofurantoin (34.3%), neomycin (9.6%), tetracycline (5.2%), and kanamycin (8.9%); and turkey carcass isolates were resistant to nalidixic acid (62.8%), tetracycline (34.9%), and neomycin (30.2%), with a significant difference in turkeys when compared to broiler carcass isolates. These results indicate the need for judicious use of antimicrobials in livestock production, given that the serovars identified are potential causes of food poisoning. PMID:27007562

  10. SEROVARS AND ANTIMICROBIAL RESISTANCE OF Salmonella spp. ISOLATED FROM TURKEY AND BROILER CARCASSES IN SOUTHERN BRAZIL BETWEEN 2004 AND 2006

    PubMed Central

    PALMEIRA, Andre; dos SANTOS, Luciana Ruschel; BORSOI, Anderlise; RODRIGUES, Laura Beatriz; CALASANS, Max; do NASCIMENTO, Vladimir Pinheiro

    2016-01-01

    Salmonella spp. causes diseases in fowls, when species-specific serovars (Salmonella Pullorum and S.Gallinarum) are present in flocks, and public health problems, when non-typhoid serovars are isolated, as well as possible bacterial resistance induced by the preventive and therapeutic use of antimicrobials in animal production. This study describes the serovars and bacterial resistance of 280Salmonella spp. strains isolated from turkey and broiler carcasses in Southern Brazil between 2004 and 2006. SalmonellaEnteritidis was the most prevalent serovar (55.7%), followed by Heidelberg (5.0%), Agona (4.3%), Bredeney (3.9%), Hadar (3.2%), and Typhimurium (2.9%). Tennessee and S. Enterica subspecies enterica(O: 4.5) were isolated only in turkeys, and Hadar (18.6%) was the most prevalent serovar in this species. Antimicrobial susceptibility tests were performed in 178 isolates (43 from turkeys and 135 from broilers). All isolates were sensitive to amoxicillin + clavulanic acid, polymyxin B, ciprofloxacin, and norfloxacin, and were resistant to bacitracin and penicillin. Broiler carcass isolates showed resistance to nalidixic acid (48.9%), nitrofurantoin (34.3%), neomycin (9.6%), tetracycline (5.2%), and kanamycin (8.9%); and turkey carcass isolates were resistant to nalidixic acid (62.8%), tetracycline (34.9%), and neomycin (30.2%), with a significant difference in turkeys when compared to broiler carcass isolates. These results indicate the need for judicious use of antimicrobials in livestock production, given that the serovars identified are potential causes of food poisoning. PMID:27007562

  11. Antimicrobial resistance and the standards of the World Organisation for Animal Health.

    PubMed

    Orand, J P

    2012-04-01

    Antimicrobial resistance and the use of antimicrobial agents in veterinary medicine are complex issues that are currently a source of major international concern. It is therefore essential for the World Organisation for Animal Health (OIE) to consider this issue, while at the same time continuing to address the problem of zoonotic diseases. That is why the OIE has included objectives for veterinary drugs, especially antimicrobials, in its Strategic Plan. The OIE plays an active part in discussions on this subject in conjunction with other international organisations working in this field, such as the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO). Furthermore, the OIE has adopted guidelines both for defining harmonised methodologies for antimicrobial resistance surveillance and monitoring and for helping countries to conduct a risk analysis tailored to their situation and to take appropriate management measures. The OIE has included this issue in its programme of assistance to countries by offering them structural enhancement tools: the Tool for the Evaluation of Performance of Veterinary Services (O1E PVS Tool), PVS Gap Analysis, veterinary legislation support, and training for veterinary national focal points, with the aid of its Collaborating Centres for veterinary medicinal products. Only by mobilising all countries to improve the quality of antimicrobials, to introduce antimicrobial resistance surveillance and to implement measures for the responsible and prudent use of antimicrobials, will it be possible to halt the spread of antimicrobial resistance. PMID:22849287

  12. Antimicrobial Drug Resistance of Vibrio cholerae, Democratic Republic of the Congo

    PubMed Central

    Miwanda, Berthe; Moore, Sandra; Muyembe, Jean-Jacques; Nguefack-Tsague, Georges; Kabangwa, Ickel Kakongo; Ndjakani, Daniel Yassa; Mutreja, Ankur; Thomson, Nicholas; Thefenne, Helene; Garnotel, Eric; Tshapenda, Gaston; Kakongo, Denis Kandolo; Kalambayi, Guy

    2015-01-01

    We analyzed 1,093 Vibrio cholerae isolates from the Democratic Republic of the Congo during 1997–2012 and found increasing antimicrobial drug resistance over time. Our study also demonstrated that the 2011–2012 epidemic was caused by an El Tor variant clonal complex with a single antimicrobial drug susceptibility profile. PMID:25897570

  13. Diversity and Antimicrobial Resistance of Salmonella enterica Isolates from Surface Water in Southeastern United States

    PubMed Central

    Vellidis, George; Liu, Huanli; Jay-Russell, Michele; Zhao, Shaohua; Hu, Zonglin; Wright, Anita; Elkins, Christopher A.

    2014-01-01

    A study of prevalence, diversity, and antimicrobial resistance of Salmonella enterica in surface water in the southeastern United States was conducted. A new scheme was developed for recovery of Salmonella from irrigation pond water and compared with the FDA's Bacteriological Analytical Manual (8th ed., 2014) (BAM) method. Fifty-one isolates were recovered from 10 irrigation ponds in produce farms over a 2-year period; nine Salmonella serovars were identified by pulsed-field gel electrophoresis analysis, and the major serovar was Salmonella enterica serovar Newport (S. Newport, n = 29), followed by S. enterica serovar Enteritidis (n = 6), S. enterica serovar Muenchen (n = 4), S. enterica serovar Javiana (n = 3), S. enterica serovar Thompson (n = 2), and other serovars. It is noteworthy that the PulseNet patterns of some of the isolates were identical to those of the strains that were associated with the S. Thompson outbreaks in 2010, 2012, and 2013, S. Enteritidis outbreaks in 2011 and 2013, and an S. Javiana outbreak in 2012. Antimicrobial susceptibility testing confirmed 16 S. Newport isolates of the multidrug resistant-AmpC (MDR-AmpC) phenotype, which exhibited resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (ACSSuT), and to the 1st, 2nd, and 3rd generations of cephalosporins (cephalothin, amoxicillin-clavulanic acid, and ceftriaxone). Moreover, the S. Newport MDR-AmpC isolates had a PFGE pattern indistinguishable from the patterns of the isolates from clinical settings. These findings suggest that the irrigation water may be a potential source of contamination of Salmonella in fresh produce. The new Salmonella isolation scheme significantly increased recovery efficiency from 21.2 (36/170) to 29.4% (50/170) (P = 0.0