Risk factors for antimicrobial resistance among fecal Escherichia coli from residents on forty-three swine farms. - Related Documents




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287801.0000Risk factors for antimicrobial resistance among fecal Escherichia coli from residents on forty-three swine farms. Fecal Escherichia coli (n = 555) were isolated from 115 residents on 43 farrow-to-finish swine farms to determine the prevalence of antimicrobial resistance and associated risk factors. Susceptibility to 21 antimicrobials was determined and the overall prevalence of antimicrobial resistance was 25.8%. Pair-wise difference in prevalences of resistance to individual antimicrobials was significant between isolates from residents on farms that fed medicated swine rations compared to those that did not (p = 0.013). Cross-resistance among antimicrobials of same class and multidrug-resistance were observed. Logistic regression models revealed the following risk factors positively associated with antimicrobial resistance: use of antimicrobials in pigs on farms; number of hours per week that farmers spent in their pig barns; handling of sick pigs; and intake of antimicrobials by farm residents. This study indicates that occupational exposure of farmers to resistant bacteria and use of antimicrobials in pig farming may constitute a source of resistance in humans, although the human health impacts of such resistance is unknown. The consumption of antimicrobials by farmers appeared to constitute a significant risk for resistance development. Fecal E. coli from farm residents may act as a reservoir of resistance genes for animal and/or human pathogens.200717536936
193210.9998Prevalence of Plasmid-Associated Tetracycline Resistance Genes in Multidrug-Resistant Escherichia coli Strains Isolated from Environmental, Animal and Human Samples in Panama. Antimicrobial resistance bacteria are nowadays ubiquitous. Its presence has been reported in almost every type of source, from water for agricultural and recreative use, water distribution pipes, and wastewater, to food, fomites, and clinical samples. Enterobacteriaceae, especially Escherichia coli, are not the exception, showing an increased resistance to several antibiotics, causing a global health and economic burden. Therefore, the monitoring of fecal microbiota is important because it is present in numerous reservoirs where gene transfer between commensal and virulent bacteria can take place, representing a potential source of resistant E. coli. In this work, antibiotic resistance profiles of 150 E. coli isolates from environmental, animal, and human samples, collected in three rural areas in Panama, were analyzed. A total of 116 isolates were resistant to at least one of the nine antibiotics tested. Remarkably, almost 100% of these exhibited resistance to tetracycline. Plasmid-associated tetA and tetB genes were detected in 42.86% of the isolates analyzed, tetA being the most prevalent. These results suggest that tetracycline resistance would be used as a convenient indicator of genetic horizontal transfer within a community.202336830191
554520.9998Healthy broilers disseminate antibiotic resistance in response to tetracycline input in feed concentrates. Wide varieties of antibiotics are used in poultry farms to improve the growth and also to control the infection in broiler chicken. To identify the seriousness of the same in the poultry sector, current study has been designed to analyze the presence of tetracycline in poultry feed and also the tetracycline resistance among the bacteria released through the excreta of poultry. In the study, 27 bacteria belonging to the Escherichiacoli and Klebsiellapneumoniae. were isolated from the faecal samples collected from five different farms. Antibiotic susceptibility analysis showed 77% of E. coli and 100% of the K. pneumoniae. to be resistant to tetracycline. Further, molecular screening for tetA and tetB genes showed 85.18% of isolates to have tetA and 22.22% with tetB. The presence of tetracycline in collected feed samples was also analysed quantitatively by Liquid chromatography-mass spectrometry (LC-MS). Here, three out of five feed samples were found to be positive for tetracycline. The study showed a direct correlation between the antibiotic supplemented feed and the emergence of antimicrobial resistance among the intestinal microflora. The results of the study indicate the need for strict control over antibiotic use in animal feed to limit the rapid evolution and spread of antimicrobial resistance.202033039593
193330.9998Antibiotic Resistance Genes Occurrence in Conventional and Antibiotic-Free Poultry Farming, Italy. Antimicrobial resistance is a complex and widespread problem threatening human and animal health. In poultry farms, a wide distribution of resistant bacteria and their relative genes is described worldwide, including in Italy. In this paper, a comparison of resistance gene distribution in litter samples, recovered from four conventional and four antibiotic-free broiler flocks, was performed to highlight any influence of farming systems on the spreading and maintenance of resistance determinants. Conventional PCR tests, targeting the resistance genes related to the most used antibiotics in poultry farming, along with some critically important antibiotics for human medicine, were applied. In conventional farms, n. 10 out of n. 30 investigated genes were present in at least one sample, the most abundant fragments being the tet genes specific for tetracyclines, followed by those for aminoglycosides and chloramphenicol. All conventional samples resulted negative for colistin, carbapenems, and vancomycin resistance genes. A similar trend was observed for antibiotic-free herds, with n. 13 out of n. 30 amplified genes, while a positivity for the mcr-1 gene, specific for colistin, was observed in one antibiotic-free flock. The statistical analysis revealed a significant difference for the tetM gene, which was found more frequently in the antibiotic-free category. The analysis carried out in this study allowed us to obtain new data about the distribution of resistance patterns in the poultry industry in relation to farming types. The PCR test is a quick and non-expensive laboratory tool for the environmental monitoring of resistance determinants identifying potential indicators of AMR dissemination.202236139170
287240.9998Escherichia coli Antibiotic Resistance Patterns from Co-Grazing and Non-Co-Grazing Livestock and Wildlife Species from Two Farms in the Western Cape, South Africa. Although limited, studies have found conflicting results on whether co-grazing results in significant antibiotic resistance transfer between species. This type of farming system can act as a vector in the geographical spread of antibiotic-resistant bacteria in the environment. The aim of this study was to determine the antibiotic-resistant patterns between co-grazing and non-co-grazing livestock and wildlife species in South Africa. Escherichia coli was isolated from the faeces of various wildlife and livestock species from two farms in South Africa and was tested for antibiotic resistance using the Kirby-Bauer disk diffusion method against chloramphenicol, nalidixic acid, ampicillin, streptomycin, sulphafurazole, and tetracycline. A selection of some common antibiotic-resistant genes (blaCMY, aadA1, sul1, sul2, tetA, and tetB) were detected using PCR. The E. coli isolates from wildlife and livestock that co-grazed showed no significant differences in antibiotic resistance patterns. However, this was not the case for tetracycline resistance as the livestock isolates were significantly more resistant than the co-grazing wildlife isolates. The E. coli isolates from the non-co-grazing livestock and wildlife had significant differences in their antibiotic susceptibility patterns; the wildlife E. coli isolates were significantly more resistant to sulphafurazole and streptomycin than the livestock isolates, whilst those isolated from the cattle were significantly more resistant to ampicillin than the wildlife and sheep isolates. The results of this study suggest that there could be an exchange of antibiotic-resistant bacteria and genes between livestock and wildlife that co-graze.202134067232
284450.9998High throughput qPCR analyses suggest that Enterobacterales of French sheep and cow cheese rarely carry genes conferring resistances to critically important antibiotics for human medicine. Bacteria present in raw milk can carry acquired or intrinsic antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs). However, only a few studies have evaluated raw milk cheese as a potential reservoir of ARGs. This study thus aimed at providing new data regarding resistance markers present in raw milk cheese. Sheep (n = 360) and cow (n = 360) cheese samples produced in France were incubated in buffered peptone water supplemented with acriflavin or novobiocin; as corroborated by 16S metabarcoding, samples were enriched in Gram-negative bacteria since Escherichia coli and Hafnia alvei respectively accounted for 40 % and 20 % of the samples' microbiota. Screening of the samples for the presence of 30 ARGs and 16 MGEs by high throughput qPCR array showed that nine ARGs conferring resistances to 1st-generation beta-lactams, aminoglycosides, trimethoprim/sulfonamides and tetracyclines occurred in >75 % of both sheep and cow samples. This is neither surprising nor alarming since these resistance genes are widely spread across the One Health human, animal and environmental sectors. Conversely, genes conferring resistances to last-generations cephalosporins were rarely identified, while those conferring resistances to carbapenems or amikacin, which are restricted to human use, were never detected. Multiple MGEs were detected, the most frequent ones being IncF plasmids, confirming the potential transmission of ARGs. Our results are in line with the few studies of the resistome of milk or milk cheese showing that genes conferring resistances to 1st-generation beta-lactams, aminoglycosides and tetracyclines families are widespread, while those conferring resistances to critically important antibiotics are rare or absent.202337384974
256360.9998Dissemination of Resistant Escherichia coli Among Wild Birds, Rodents, Flies, and Calves on Dairy Farms. Antimicrobial resistance (AMR) in bacteria in the livestock is a growing problem, partly due to inappropriate use of antimicrobial drugs. Antimicrobial use (AMU) occurs in Swedish dairy farming but is restricted to the treatment of sick animals based on prescription by a veterinary practitioner. Despite these strict rules, calves shedding antimicrobial resistant Enterobacteriaceae have been recorded both in dairy farms and in slaughterhouses. Yet, not much is known how these bacteria disseminate into the local environment around dairy farms. In this study, we collected samples from four animal sources (fecal samples from calves, birds and rodents, and whole flies) and two environmental sources (cow manure drains and manure pits). From the samples, Escherichia coli was isolated and antimicrobial susceptibility testing performed. A subset of isolates was whole genome sequenced to evaluate relatedness between sources and genomic determinants such as antimicrobial resistance genes (ARGs) and the presence of plasmids were assessed. We detected both ARGs, mobile genetic elements and low rates of AMR. In particular, we observed four potential instances of bacterial clonal sharing in two different animal sources. This demonstrates resistant E. coli dissemination potential within the dairy farm, between calves and scavenger animals (rodents and flies). AMR dissemination and the zoonotic AMR risk is generally low in countries with low and restricted AMU. However, we show that interspecies dissemination does occur, and in countries that have little to no AMU restrictions this risk could be under-estimated.202235432261
256270.9998Characterisation of Antimicrobial Resistance in Special-Fed Veal Production Environments. INTRODUCTION: Antimicrobial resistance (AMR) is one of the leading public health threats globally. AMR genes can be transferred between bacteria through lateral gene transfer, and AMR organisms can spread through environments by contaminated water, agriculture and animals. Thus, widespread environmental dissemination of bacteria and lateral gene transfer facilitate AMR transmission pathways. Farm environments in dairy and calf production are known to harbour AMR bacteria that pose a risk for food contamination and to workers in direct or indirect contact with animals. Escherichia coli is present in farm environments and is known to participate in lateral gene transfer, providing a good marker of resistance genes in each environment. METHODS: In this study, E. coli from nine cohorts of calves was isolated at different time points from nine barns, nine trailers and one slaughterhouse environment in a single special-fed veal calf production facility. The antimicrobial susceptibility to 15 antimicrobials, classified as highly or critically important by the World Health Organization, was characterised for E. coli isolates using Kirby-Bauer disk diffusion. RESULTS: The highest proportion of isolates showing multidrug resistance was present in barn environments (51.7%), where calves were housed from their arrival at < 2 weeks of age until they were transported to slaughter. Additionally, 15 E. coli isolates were resistant to 11 of the 15 antimicrobials tested. Trailer and slaughterhouse environments had greater prevalence of resistance after accommodating calves, including resistance to third-generation cephalosporins. CONCLUSION: These data highlight the importance of calf environments in the dissemination of resistant bacteria and gives insight into where interventions could be most effective in combatting antimicrobial-resistant bacteria that could infect humans and livestock.202539402773
284680.9998Class 1 integron and Enterococcus spp. abundances in swine farms from the " Suckling piglets" to the "Fatteners" production category. Swine farms are considered a hotspot of antimicrobial resistance and may contribute to the spread of antibiotic-resistant and/or pathogenic bacteria into the environment as well as to farm workers. In this study, swine fecal samples have been collected over the primary production, selecting three categories, i.e., "Suckling piglets", "Weaning pigs" and "Fatteners", in six intensive swine farms, for two years. Feces were analysed for the detection and abundance of class 1 integrons (used as proxy of antibiotic resistance and of anthropogenic pollution), and of enterococci [fecal indicator bacteria (FIB) and potentially pathogenic for humans] by quantitative Real Time PCR. Furthermore, Enterococcus faecalis and Enterococcus faecium were isolated, analysed for the presence of the intI1 gene by Real Time PCR and genetically typed by Pulsed-Field Gel Electrophoresis. Both enterococci and class 1 integrons were significantly more abundant in the Suckling piglets (p = 0.0316 and 0.0242, respectively). About 8% of the isolated enterococci were positive for the intI1 gene by Real Time PCR. E. faecalis and E. faecium were found genetically heterogeneous and no specific pattern could be identified as the driver for their presence along the pig primary production. These findings suggest that the "Suckling piglets" category of production represents the key point where to mitigate the risk of transmission of enterococci and class 1 integrons with associated antibiotic resistance genes to humans and spread into the environment.202236155350
255690.9998Distribution of Antimicrobial Resistance Genes Across Salmonella enterica Isolates from Animal and Nonanimal Foods. ABSTRACT: Antimicrobial-resistant bacteria are a major public health problem. Of particular importance in the context of food safety is the prevalence of antimicrobial resistance (AMR) genes within nontyphoidal Salmonella, which is a leading bacterial cause of foodborne disease. We determined the prevalence of AMR genes across a very large number of Salmonella genomes (n = 25,647) collected from isolates from 16 common food sources. The average percentage of isolates from nonanimal foods, such as fruit, nuts and seeds, and vegetables, harboring at least one AMR gene was only marginally lower (72%) than that observed in isolates from animal foods such as beef, chicken, turkey, and pork (74%). This high prevalence of AMR genes was primarily driven by the high prevalence of aminoglycoside resistance genes in nearly all food isolates; genes for resistance to tetracycline and sulfonamide also were highly prevalent. However, evaluation of the number of genes per isolate revealed that the prevalence of AMR genes was higher in animal food isolates than in nonanimal food isolates (P = 0.018). A random forest analysis provided evidence that within a given serovar, resistance gene profiles differed according to isolate food source. AMR gene profiles could be used to correctly predict the food of origin for 71% of the isolates, but success differed according to serovar. This information can help inform AMR risk assessments of food commodities and refine processes for targeting interventions to limit the spread of AMR through the food supply.202031961231
2871100.9997Antimicrobial resistance in generic Escherichia coli isolates from wild small mammals living in swine farm, residential, landfill, and natural environments in southern Ontario, Canada. To assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic Escherichia coli and Salmonella enterica isolates from fecal samples collected from wild small mammals living in four environments: swine farms, residential areas, landfills, and natural habitats. Resistance to antimicrobials was observed in E. coli isolates from animals in all environments: 25/52 (48%) animals trapped at swine farms, 6/69 (9%) animals trapped in residential areas, 3/20 (15%) animals trapped at landfills, and 1/22 (5%) animals trapped in natural habitats. Animals trapped on farms were significantly more likely to carry E. coli isolates with resistance to tetracycline, ampicillin, sulfisoxazole, and streptomycin than animals trapped in residential areas. The resistance genes sul2, aadA, and tet(A) were significantly more likely to be detected in E. coli isolates from animals trapped on farms than from those trapped in residential areas. Three S. enterica serotypes (Give, Typhimurium, and Newport) were recovered from the feces of 4/302 (1%) wild small mammals. All Salmonella isolates were pansusceptible. Our results show that swine farm origin is significantly associated with the presence of resistant bacteria and resistance genes in wild small mammals in southern Ontario, Canada. However, resistant fecal bacteria were found in small mammals living in all environments studied, indicating that environmental exposure to antimicrobials, antimicrobial residues, resistant bacteria, or resistance genes is widespread.201121131524
2849110.9997Antibiotic-resistant bacteria and gut microbiome communities associated with wild-caught shrimp from the United States versus imported farm-raised retail shrimp. In the United States, farm-raised shrimp accounts for ~ 80% of the market share. Farmed shrimp are cultivated as monoculture and are susceptible to infections. The aquaculture industry is dependent on the application of antibiotics for disease prevention, resulting in the selection of antibiotic-resistant bacteria. We aimed to characterize the prevalence of antibiotic-resistant bacteria and gut microbiome communities in commercially available shrimp. Thirty-one raw and cooked shrimp samples were purchased from supermarkets in Florida and Georgia (U.S.) between March-September 2019. The samples were processed for the isolation of antibiotic-resistant bacteria, and isolates were characterized using an array of molecular and antibiotic susceptibility tests. Aerobic plate counts of the cooked samples (n = 13) varied from < 25 to 6.2 log CFU/g. Isolates obtained (n = 110) were spread across 18 genera, comprised of coliforms and opportunistic pathogens. Interestingly, isolates from cooked shrimp showed higher resistance towards chloramphenicol (18.6%) and tetracycline (20%), while those from raw shrimp exhibited low levels of resistance towards nalidixic acid (10%) and tetracycline (8.2%). Compared to wild-caught shrimp, the imported farm-raised shrimp harbored distinct gut microbiota communities and a higher prevalence of antibiotic-resistance genes in their gut. The presence of antibiotic-resistant strains in cooked shrimps calls for change in processing for their mitigation.202133558614
3131120.9997Integron-containing bacteria in faeces of cattle from different production systems at slaughter. AIMS: To determine the prevalence and characteristics of integron-containing bacteria in faeces of cattle from grass-fed, lot-fed, or organically produced cattle. METHODS AND RESULTS: Faecal samples from grass-fed (n = 125), lot-fed (n = 125) and organic (n = 135) cattle were tested for the presence of class 1 and class 2 integrons by using PCR and colony hybridisation. The prevalence of class 1 and class 2 integrase were higher in lot-fed cattle (71% and 62%) than grass-fed cattle (52% and 30%) which in turn were higher than organic cattle (25% and 11%). Isolation rates of integron-containing bacteria were reflective of PCR prevalence results. CONCLUSIONS: The antimicrobial resistance genes harboured by the integrons differed little across the three systems and were typically to antimicrobials that would rarely be used therapeutically or for growth promotion purposes. The differences in prevalence observed between the systems may be a function of the intensiveness of each system. SIGNIFICANCE AND IMPACT OF THE STUDY: Integron-containing bacteria may be present in all cattle production systems regardless of the amount of antimicrobial use and confirms that the prudent use of antimicrobials is required so that the development of integrons harbouring genes significant to human medicine is avoided.200919302491
1930130.9997Changes in dominant Escherichia coli and antimicrobial resistance after 24 hr in fecal matter. Intestinal bacteria carry antimicrobial resistance (AMR) genes in mobile genetic elements which have the potential to spread to bacteria in other animal hosts including humans. In fecal matter, Escherichia coli can continue to multiply for 48 hr after being excreted, and in certain environments, E. coli survive long periods of time. It is unclear the extent to which AMR in E. coli changes in the environment outside of its host. In this study, we analyzed changes in the population structure, plasmid content, and AMR patterns of 30 E. coli isolates isolated from 6 chickens (cloacal swabs), and 30 E. coli isolates from fecal samples (from the same 6 chickens) after 24 hr of incubation. Clonality of isolates was screened using the fumC gene sequence and confirmed in a subset of isolates (n = 14) by multi-locus sequence typing. Major shifts in the population structure (i.e., sequence types) and antibiotic resistance patterns were observed among the numerically dominant E. coli isolates after 24 hr. Four E. coli clones isolated from the cloaca swabs and the corresponding fecal samples (after 24 hr incubation) showed different antibiotic resistance patterns. Our study reveals that fecal matter in the environment is an intermediate habitat where rapid and striking changes occur in E. coli populations and antibiotic resistance patterns.201929896865
1929140.9997Research Note: Detection of antibiotic-resistance genes in commercial poultry and turkey flocks from Italy. Antibiotics are routinely used in commercial poultry farms for the treatment of economically important bacterial diseases. Repeated use of antibiotics, usually administered in the feed or drinking water, may also result in the selection of resistant bacteria in animal feces, able to transfer their antimicrobial-resistance genes (ARG), residing on mobile elements, to other microorganisms, including human pathogens. In this study, single and multiplex PCR protocols were performed to detect tetracycline-, lincomycin-, chloramphenicol-, aminoglycoside-, colistin-, vancomycin-, and carbapenem-resistance genes, starting from 38 litter samples collected from 6 poultry and 2 turkey Italian flocks. The ARG were confirmed for all investigated classes of antimicrobials, except for colistin (mcr-1, mcr-2, mcr-3,mcr-4 mcr-5) and carbapenem (IMP, OXA-48, NDM, KPC), while the vanB gene was only detected for vancomycin. The highest positivity was obtained for tetracycline (tet[L], tet[M], tet[K], tetA[P]] and aminoglycoside (aadA2) ARG, confirming the predominant use of these antimicrobials in the veterinary practice and their potential to enhance the resistance patterns also in humans as a consequence of environmental contamination. On the contrary, the dissemination by poultry of ARG for critically important antimicrobials seems to be of minor concern, suggesting a negligible environmental dissemination by these genes in the Italian poultry industry. Finally, the molecular screening performed in this study using a noninvasive sampling method represents a simple and rapid tool for monitoring the ARG patterns at the farm level.202133799114
1928150.9997Targeted Antimicrobial Resistance Gene Screening from Metagenomic DNA of Raw Milk Samples Identifies the Presence of Multiple Genes Including the mcr9. The current study has investigated the prevalence of antimicrobial resistance (AMR) genes in cow and goat raw milk samples. The misuse of antibiotics in the livestock sector has already been reported to be a major factor contributing to AMR risk. For the study, milk samples were collected from five different farms, and metagenomic DNA was extracted. Then, PCR amplification was carried out using primers specific to 15 different AMR genes. From the results obtained, the prevalence of β-lactam resistance genes, particularly blaTEM (24%), along with other genes like blaZ (12%) and blaSHV (8%), were observed in addition to the transmissible mcr9 gene (12%) conferring resistance to colistin. These findings underscore the urgent need for monitoring AMR genes and regulating antibiotic use in dairy farming to safeguard public health, as it poses a potential risk with the consumption of unpasteurized milk.202540488653
2853160.9997Antibiotic resistance and virulence genes in coliform water isolates. Widespread fecal pollution of surface water may present a major health risk and a significant pathway for dissemination of antibiotic resistance bacteria. The River Rhine is one of the longest and most important rivers in Europe and an important raw water source for drinking water production. A total of 100 coliform isolates obtained from River Rhine (Germany) were examined for their susceptibility to seven antimicrobial agents. Resistances against amoxicillin, trimethoprim/sulfamethoxazole and tetracycline were detected in 48%, 11% and 9% of isolates respectively. The antibiotic resistance could be traced back to the resistance genes bla(TEM), bla(SHV), ampC, sul1, sul2, dfrA1, tet(A) and tet(B). Whereby, the ampC gene represents a special case, because its presence is not inevitably linked to a phenotypic antibiotic resistance. Multiple antibiotics resistance was often accompanied by the occurrence of class 1 or 2 integrons. E. coli isolates belonging to phylogenetic groups A and B1 (commensal) were more predominant (57%) compared to B2 and D groups (43%) which are known to carry virulent genes. Additionally, six E. coli virulence genes were also detected. However, the prevalence of virulence genes in the E. coli isolates was low (not exceeding 4.3% per gene) and no diarrheagenic E. coli pathotypes were detected. This study demonstrates that surface water is an important reservoir of ARGs for a number of antibiotic classes such as sulfonamide, trimethoprim, beta-lactam-antibiotics and tetracycline. The occurrence of antibiotic resistance in coliform bacteria isolated from River Rhine provides evidence for the need to develop management strategies to limit the spread of antibiotic resistant bacteria in aquatic environment.201627497615
2813170.9997Quantity of the tetracycline resistance gene tet(M) differs substantially between meat at slaughterhouses and at retail. Concentrations of the tetracycline resistance gene tet(M) per square centimeter were assessed in meat from the slaughterhouse (n = 100) and from retail (n = 100) by real-time quantitative PCR. The study revealed a substantial contamination of retail meat with the tetracycline resistance gene tet(M), with a mean of 4.34 log copies per cm² fasces in chicken and 5.58 log copies per cm² fasces in pork. Quantitative resistance gene analysis provides an interesting tool for risk assessment and is becoming increasingly important. For both chicken and pork, tet(M) concentrations were significantly higher in meat at retail, compared to meat at slaughter. Cultural investigations revealed substantial differences in the prevalence of listeria and enterococci, and of E. coli and coliforms, between meat at slaughter (n = 500) and at retail (n = 500). However, the differences in the prevalence of 2 investigated groups of potential tet(M)-carriers (enterococci, listeria) could not sufficiently explain the differences in tet(M) concentrations, since increasing concentrations of tet(M) were accompanied by decreasing prevalences of these potential tet(M)-carriers. The percentage of tetracycline susceptible indicator bacteria (E. faecalis, E. coli) did not differ between meat at slaughter and meat at retail. Higher concentrations of tet(M) at retail might correlate with the proliferation of other genera than enterococci and listeria, but there is also a reason to discuss whether secondary contaminants might carry tet(M) more often than the primary flora of meat. PRACTICAL APPLICATION: We successfully applied the direct quantitative monitoring of resistance genes in meat, which generally might aid as a useful and rapid additional tool for risk assessment. We know that bacteria provide a large pool of resistance genes, which are widely shared between each other-the larger the pool is, the more genes might be exchanged. Thus, in terms of resistance gene monitoring, we should sometimes overcome the restricted view on single bacteria and look at the gene pool, instead.201121729069
2821180.9997Antibiotic resistant enterococci and staphylococci isolated from flies collected near confined poultry feeding operations. Use of antibiotics as feed additives in poultry production has been linked to the presence of antibiotic resistant bacteria in farm workers, consumer poultry products and the environs of confined poultry operations. There are concerns that these resistant bacteria may be transferred to communities near these operations; however, environmental pathways of exposure are not well documented. We assessed the prevalence of antibiotic resistant enterococci and staphylococci in stored poultry litter and flies collected near broiler chicken houses. Drug resistant enterococci and staphylococci were isolated from flies caught near confined poultry feeding operations in the summer of 2006. Susceptibility testing was conducted on isolates using antibiotics selected on the basis of their importance to human medicine and use in poultry production. Resistant isolates were then screened for genetic determinants of antibiotic resistance. A total of 142 enterococcal isolates and 144 staphylococcal isolates from both fly and poultry litter samples were identified. Resistance genes erm(B), erm(A), msr(C), msr(A/B) and mobile genetic elements associated with the conjugative transposon Tn916, were found in isolates recovered from both poultry litter and flies. Erm(B) was the most common resistance gene in enterococci, while erm(A) was the most common in staphylococci. We report that flies collected near broiler poultry operations may be involved in the spread of drug resistant bacteria from these operations and may increase the potential for human exposure to drug resistant bacteria.200919157515
5565190.9997Vancomycin resistance and virulence genes evaluation in Enterococci isolated from pork and wild boar meat. Enterococci are considered valuable sentinel Gram-positive bacteria for monitoring vancomycin antibiotic resistance due to their widespread presence and characteristics. The use of antimicrobials in farming animals has a role in the increasing of Antimicrobial Resistance (AMR) and the anthropogenic transformation of the landscape has forced wildlife into greater contact with humans and their livestock. The transmission of resistant bacteria by their meat products is a significant contributor to AMR development. The present study aimed to assess the prevalence of vancomycin resistant Enterococci spp. In antimicrobial-treated farmed pigs meat and in antimicrobial-free wild boars meat. A total of 341 Enterococci were isolated from 598 pork meat samples (57 %) and 173 Enterococci were isolated from 404 wild boar meat samples (42.8 %). Data found showed that low-resistance was detected more in wild boars meat Enterococci (52.6 %) than in pork meat once (48.4 %). However, the prevalence of resistance genes was at low level (33.9 % in pork meat Enterococci and 4.4 % in wild boar meat ones) and the only gene found was vanC1/C2, related to intrinsic AMR. Normally, Enterococci persist in the normal intestinal flora of animals including humans. However, the presence of resistance genes was frequently linked to the detection of pathogenic genes, mostly gelE in pork meat isolates and asa1 in wild boars meat isolates. Pathogenic bacteria can cause severe infections in human that can become more risky if associated to the presence of AMR. Pathogenic bacteria were characterized and a high presence of E. gallinarum and E. casseliflavus was found. Given the growing interest in wild game meat consumption the monitoring of AMR in these matrices is essential. Further surveillance studies are needed to fully evaluate the emergence and spread of vancomycin-resistant Enterococci (VRE) and pathogenic Enterococci from animal-derived food to humans, including the role of wildlife in this phenomenon. Giving the higher interest in wild animals meat consumption, it is important to better evaluate the spread of AMR phenomenon in the future and intensify hygienic control of wild animals derived food.202439104496