High throughput qPCR analyses suggest that Enterobacterales of French sheep and cow cheese rarely carry genes conferring resistances to critically important antibiotics for human medicine. - Related Documents




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284401.0000High 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
284310.9999High Throughput Screening of Antimicrobial Resistance Genes in Gram-Negative Seafood Bacteria. From a global view of antimicrobial resistance over different sectors, seafood and the marine environment are often considered as potential reservoirs of antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs); however, there are few studies and sparse results on this sector. This study aims to provide new data and insights regarding the content of resistance markers in various seafood samples and sources, and therefore the potential exposure to humans in a global One Health approach. An innovative high throughput qPCR screening was developed and validated in order to simultaneously investigate the presence of 41 ARGs and 33 MGEs including plasmid replicons, integrons, and insertion sequences in Gram-negative bacteria. Analysis of 268 seafood isolates from the bacterial microflora of cod (n = 24), shellfish (n = 66), flat fishes (n = 53), shrimp (n = 10), and horse mackerel (n = 115) show the occurrence of sul-1, ant(3″)-Ia, aph(3')-Ia, strA, strB, dfrA1, qnrA, and bla(CTX-M-9) genes in Pseudomonas spp., Providencia spp., Klebsiella spp., Proteus spp., and Shewanella spp. isolates and the presence of MGEs in all bacterial species investigated. We found that the occurrence of MGE may be associated with the seafood type and the environmental, farming, and harvest conditions. Moreover, even if MGE were detected in half of the seafood isolates investigated, association with ARG was only identified for twelve isolates. The results corroborate the hypothesis that the incidence of antimicrobial-resistant bacteria (ARB) and ARG decreases with increasing distance from potential sources of fecal contamination. This unique and original high throughput micro-array designed for the screening of ARG and MGE in Gram-negative bacteria could be easily implementable for monitoring antimicrobial resistance gene markers in diverse contexts.202235744743
193320.9999Antibiotic 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
192930.9999Research 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
570640.9999Comparative Genomic Analysis of Enterococci across Sectors of the One Health Continuum. Enterococci are Gram-positive bacteria that can be isolated from a variety of environments including soil, water, plants, and the intestinal tract of humans and animals. Although they are considered commensals in humans, Enterococcus spp. are important opportunistic pathogens. Due to their presence and persistence in diverse environments, Enterococcus spp. are ideal for studying antimicrobial resistance (AMR) from the One Health perspective. We undertook a comparative genomic analysis of the virulome, resistome, mobilome, and the association between the resistome and mobilome of 246 E. faecium and 376 E. faecalis recovered from livestock (swine, beef cattle, poultry, dairy cattle), human clinical samples, municipal wastewater, and environmental sources. Comparative genomics of E. faecium and E. faecalis identified 31 and 34 different antimicrobial resistance genes (ARGs), with 62% and 68% of the isolates having plasmid-associated ARGs, respectively. Across the One Health continuum, tetracycline (tetL and tetM) and macrolide resistance (ermB) were commonly identified in E. faecium and E. faecalis. These ARGs were frequently associated with mobile genetic elements along with other ARGs conferring resistance against aminoglycosides [ant(6)-la, aph(3')-IIIa], lincosamides [lnuG, lsaE], and streptogramins (sat4). Study of the core E. faecium genome identified two main clades, clade 'A' and 'B', with clade A isolates primarily originating from humans and municipal wastewater and carrying more virulence genes and ARGs related to category I antimicrobials. Overall, despite differences in antimicrobial usage across the continuum, tetracycline and macrolide resistance genes persisted in all sectors.202336985300
193250.9999Prevalence 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
572760.9999Genetic mechanisms of antimicrobial resistance identified in Salmonella enterica, Escherichia coli, and Enteroccocus spp. isolated from U.S. food animals. The prevalence of antimicrobial resistance (AR) in bacteria isolated from U.S. food animals has increased over the last several decades as have concerns of AR foodborne zoonotic human infections. Resistance mechanisms identified in U.S. animal isolates of Salmonella enterica included resistance to aminoglycosides (e.g., alleles of aacC, aadA, aadB, ant, aphA, and StrAB), β-lactams (e.g., bla CMY-2, TEM-1, PSE-1), chloramphenicol (e.g., floR, cmlA, cat1, cat2), folate pathway inhibitors (e.g., alleles of sul and dfr), and tetracycline [e.g., alleles of tet(A), (B), (C), (D), (G), and tetR]. In the U.S., multi-drug resistance (MDR) mechanisms in Salmonella animal isolates were associated with integrons, or mobile genetic elements (MGEs) such as IncA/C plasmids which can be transferred among bacteria. It is thought that AR Salmonella originates in food animals and is transmitted through food to humans. However, some AR Salmonella isolated from humans in the U.S. have different AR elements than those isolated from food animals, suggesting a different etiology for some AR human infections. The AR mechanisms identified in isolates from outside the U.S. are also predominantly different. For example the extended spectrum β-lactamases (ESBLs) are found in human and animal isolates globally; however, in the U.S., ESBLs thus far have only been found in human and not food animal isolates. Commensal bacteria in animals including Escherichia coli and Enterococcus spp. may be reservoirs for AR mechanisms. Many of the AR genes and MGEs found in E. coli isolated from U.S. animals are similar to those found in Salmonella. Enterococcus spp. isolated from animals frequently carry MGEs with AR genes, including resistances to aminoglycosides (e.g., alleles of aac, ant, and aph), macrolides [e.g., erm(A), erm(B), and msrC], and tetracyclines [e.g., tet(K), (L), (M), (O), (S)]. Continuing investigations are required to help understand and mitigate the impact of AR bacteria on human and animal health.201323734150
284570.9999Florfenicol administration in piglets co-selects for multiple antimicrobial resistance genes. Antimicrobial use in food-producing animals such as pigs is a significant issue due to its association with antimicrobial resistance. Florfenicol is a broad-spectrum phenicol antibiotic used in swine for various indications; however, its effect on the swine microbiome and resistome is largely unknown. This study investigated these effects in piglets treated intramuscularly with florfenicol at 1 and 7 days of age. Fecal samples were collected from treated (n = 30) and untreated (n = 30) pigs at nine different time points up until 140 days of age, and the fecal metagenomes were sequenced. The fecal microbiomes of the two groups of piglets were most dissimilar in the immediate period following florfenicol administration. These differences were driven in part by an increase in the relative abundance of Clostridium scindens, Enterococcus faecalis, and Escherichia spp. in the florfenicol-treated piglets and Fusobacterium spp., Pauljensenia hyovaginalis, and Ruminococcus gnavus in the control piglets. In addition to selecting for florfenicol resistance genes (floR, fexA, and fexB), florfenicol also selected for genes conferring resistance to the aminoglycosides, beta-lactams, or sulfonamides up until weaning at 21 days of age. Florfenicol-resistant Escherichia coli isolated from these piglets were found to carry a plasmid with floR, along with tet(A), aph(6)-Id, aph(3″)-Ib, sul2, and bla(TEM-1)/bla(CMY-2). A plasmid carrying fexB and poxtA (phenicols and oxazolidinones) was identified in florfenicol-resistant Enterococcus avium, Enterococcus faecium, and E. faecalis isolates from the treated piglets. This study highlights the potential for co-selection and perturbation of the fecal microbial community in pre-weaned piglets administered florfenicol.IMPORTANCEAntimicrobial use remains a serious challenge in food-animal production due to its linkage with antimicrobial resistance. Antimicrobial resistance can reduce the efficacy of veterinary treatment and can potentially be transferred to humans through the food chain or direct contact with animals and their environment. In this study, early-life florfenicol treatment in piglets altered the composition of the fecal microbiome and selected for many unrelated antimicrobial resistance genes up until weaning at 21 days of age. Part of this co-selection process appeared to involve an Escherichia coli plasmid carrying a florfenicol resistance gene along with genes conferring resistance to at least four other antimicrobial classes. In addition, florfenicol selected for certain genes that provide resistance to multiple antimicrobial classes, including the oxazolidinones. These results highlight that florfenicol can co-select for multiple antimicrobial resistance genes, and their presence on mobile genetic elements suggests the potential for transfer to other bacteria.202439584815
256580.9999Phenotypic and genotypic characterization of antibiotic-resistant bacteria from Swiss ready-to-eat meat products. Antimicrobial resistance is a global health concern, which is partly driven by rising meat consumption, which has led to the intensive farming of livestock that relies on antibiotics. ready-to-eat animal products can carry antibiotic-resistant bacteria, posing risks to humans since they are often consumed without further cooking. While countries such as Switzerland limit antibiotic use in agriculture, contamination of meat with antibiotic-resistant bacteria can still occur during meat processing, and non-antibiotic agents such as heavy metals may contribute to the co-selection of resistance. This study aimed to characterize antibiotic-resistant bacteria in ready-to-eat meat products from various Swiss butcheries. Presumptive resistant bacteria were isolated using selective plating and analyzed phenotypically and genotypically. A total of 53 bacteria-antibiotic resistance combinations were identified, including Enterobacterales resistant to third-generation cephalosporins, vancomycin-resistant Enterococci, and one strain of methicillin-resistant Staphylococcus aureus. Of the 804 products sampled, 177 antibiotic-resistant bacteria were isolated, 148 of which showed multidrug resistance. Notably, these strains remained susceptible to last-resort antibiotics such as carbapenems and colistin. Whole-genome sequencing of 31 selected isolates revealed 164 antibiotic resistance genes spanning 25 classes, confirming resistance to beta-lactams, cephalosporins, and tetracyclines. We also detected genes conferring resistance to metals, suggesting co-selection pressures. Long-read sequencing revealed that the majority of the antibiotic resistance genes were chromosomal, while others were plasmid-encoded, indicating the potential for horizontal gene transfer. This study demonstrates that ready-to-eat meat products are reservoirs of antibiotic and metal resistance genes, as well as antibiotic-resistant bacteria, even at low levels. From a One Health perspective, our results highlight the importance of extending AMR surveillance across the food chain and underscore the need to include non-traditional bacterial indicators.202541001059
281990.9998Prevalence of Antibiotic-Resistant Lactobacilli in Sepsis Patients with Long-Term Antibiotic Therapy. Lactobacilli are the most common probiotic bacteria found in the human gut microbiota, and the presence of acquired antibiotic resistance determinants carried on mobile genetic elements must be screened due to safety concerns. Unnecessary and inappropriate antibiotic therapy, as well as ingested antibiotic resistance bacteria (originating from food or food products), influence the abundance of antibiotic resistance genes in human guts, with serious clinical consequences. The current study looked into the antibiotic resistance of lactobacilli isolated from the guts of sepsis patients on long-term antibiotic therapy. The broth microdilution method was used to investigate the minimum inhibitory concentrations (MICs) of antibiotics such as imipenem, meropenem, erythromycin, tetracycline, cefepime, ciprofloxacin, and gentamycin, and the molecular genetic basis of resistance was studied based on the MIC values. The isolates were phenotypically resistant to tetracycline (20%), fluoroquinolone (20%), and macrolide (5%). Following that, resistance genes for tetracycline [tet(L), tet(O), tet(K), and tet(M)], macrolide [erm(B) and erm(C)], and beta-lactams [bla(CMY)] were investigated. Tetracycline or macrolide resistance genes were not found in the isolates, and only one isolate possessed the bla(CMY) resistance gene. The findings suggested that tetracycline and macrolide resistance may be linked to other resistance genes that were not investigated in this study. Because tetracyclines, fluoroquinolones, and macrolides are commonly used in clinics and animals, there has been concern about the spread of resistance in humans. If acquired antibiotic resistance is passed down through mobile genetic elements, it may serve as a reservoir of resistance for gut pathogens and other microbiome environments.202236088413
2821100.9998Antibiotic 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
2564110.9998Comparative metagenomics reveals poultry and swine farming are hotspots for multidrug and tetracycline resistance. Antibiotic misuse in livestock is a major threat to human health, as bacteria are quickly developing resistance to them. We performed a comparative analysis of 25 faecal metagenomes from swine, poultry, cattle, and humans to investigate their resistance profiles. Our analysis revealed that all genes conferring resistance to antibiotic classes assessed except tetracyclines were more prevalent in poultry manure than in the remaining species. We detected clinically relevant antibiotic resistance genes, such as mcr-1 which confers resistance to polymyxins. Among them, extended-spectrum β-lactamase blaCTX-M genes were particularly abundant in all species. Poultry manure was identified as a hotspot for multidrug resistance, which may compromise medical treatment options. Urgent actions in the livestock industry are imperative to hamper the emergence and spread of antibiotic resistance.202336758925
2820120.9998Direct detection of antibiotic resistance genes in specimens of chicken and pork meat. Antibiotic resistance (AR) in bacteria, a major threat to human health, has emerged in the last few decades as a consequence of the selective pressure exerted by the widespread use of antibiotics in medicine, agriculture and veterinary practice and as growth promoters in animal husbandry. The frequency of 11 genes [tet(M), tet(O), tet(K), erm(A), erm(B), erm(C), vanA, vanB, aac (6')-Ie aph (2'')-Ia, mecA, blaZ] encoding resistance to some antibiotics widely used in clinical practice was analysed in raw pork and chicken meat and in fermented sausages as well as in faecal samples from the relevant farm animals using a molecular approach based on PCR amplification of bacterial DNA directly extracted from specimens. Some of the 11 AR genes were highly prevalent, the largest number being detected in chicken meat and pig faeces. The genes found most frequently in meat were tet(K) and erm(B); vanB and mecA were the least represented. All 11 determinants were detected in faecal samples except mecA, which was found only in chicken faeces. erm(B) and erm(C) were detected in all faecal samples. The frequency of AR genes was not appreciably different in meat compared to faecal specimens of the relevant animal except for vanB, which was more prevalent in faeces. Our findings suggest that AR genes are highly prevalent in food-associated bacteria and that AR contamination is likely related to breeding rather than processing techniques. Finally, the cultivation-independent molecular method used in this work to determine the prevalence of AR genes in foods proved to be a rapid and reliable alternative to traditional tools.200717005283
1926130.9998Whole genome sequencing revealed high occurrence of antimicrobial resistance genes in bacteria isolated from poultry manure. BACKGROUND: Global demand for food has driven expansion and intensification of livestock production, particularly in developing nations where antibiotic use is often routine. Waste from poultry production, including manure, is commonly utilized as fertilizers in agroecosystems, risking environmental contamination with potentially zoonotic bacteria and antimicrobial resistance genes (ARGs). METHODS: Here, 33 bacterial isolates were recovered from broiler (n = 17) and layer (n = 16) chicken manure by aerobic culture using Luria Bertani agar. Antimicrobial susceptibility testing (AST) was performed using disc diffusion method. MALDI-ToF and 16S rRNA sequencing were used to identify and compare a subset of antibiotic-resistant isolates (n = 13). Comparison of whole genome sequence assemblies and phenotypic assays were used to assess capacity for biofilm formation, heavy metal tolerance and virulence. RESULTS: AST by disc diffusion revealed all isolates were resistant to a minimum of three antibiotics, with resistance to ampicillin, co-trimoxazole, fluoroquinolones, tetracyclines, streptomycin, rifampicin and/or chloramphenicol detected. Stutzerimonas sp. and Acinetobacter sp. were the common genera observed in this study. Genome sequencing of each selected isolate revealed carriage of multiple ARGs capable of conferring resistance to many antimicrobials commonly employed in poultry production and human medicine, including tetracyclines, quinolones, macrolides, sulfonamide and cephalosporins. CONCLUSIONS: The high occurrence of ARGs in studied bacterial isolates confirms that poultry manure could act as a source of genetic material that could be transferred to commensal microbiota and opportunistic pathogens of humans. Understanding the complex resistome interplay between humans, animals, and the environment requires a One Health approach, with implications for agricultural settings and public health.202539880102
1934140.9998Sulfonamide resistance evaluation in five animal species and first report of sul4 in companion animals. Sulfonamides are one of the oldest groups of antibacterial agents with a broad-spectrum, used as first line treatment in bacterial infections. Their widespread use produced a selective pressure on bacteria, as observed by the high incidence of sulfonamides resistance mainly in Gram negative bacteria isolated from animals. In this research, the presence of sulfonamide resistance genes (sul1, sul2, sul3, and sul4) in phenotypically resistant Escherichia coli isolates has been studied. These genes were amplified in isolates recovered from five animal species, with different interactions to humans: cattle, swine, poultry as livestock, and dogs and cats as companion animals. Isolates were collected according to their phenotypic resistance, and the magnetic bead-based Luminex technology was applied to simultaneously detect sul target genes. The frequency of sul genes was highest in swine, among livestock isolates. The sul1 and sul2 were the most frequently sulfonamide resistance genes detected in all phenotypically resistant isolates. Notably, in companion animals, with a closest interaction with human, sul4 gene was detected. To our knowledge, this is the first report of the presence of sul4 gene in E. coli collected from animals, whereas previously the presence of this gene was reported in environmental, municipal wastewater and human clinical isolates. These results highlighted the importance of continuous antimicrobial resistant genes monitoring in animal species, with a special care to companion animals.202439029236
1935150.9998Antibiotic Susceptibility Profile and Tetracycline Resistance Genes Detection in Salmonella spp. Strains Isolated from Animals and Food. Salmonella spp. is among the leading causes of foodborne infections in humans and a large number of animals. Salmonella spp. is a pathogen involved in the dissemination of antimicrobial resistance because it can accumulate antibiotic resistance genes (ARGs). In this study, the antibiotic resistance profile to 15 antibiotics, belonging to six different classes, of 60 strains of Salmonella spp. collected from pets, farm animals, wildlife, and food in Sicily (Italy) was investigated by the Kirby-Bauer method. Given that almost 33.3% of the Salmonella spp. strains were resistant to tetracycline, Real-Time PCR analysis was applied on all the 60 strains to detect the presence of eight selected tet resistance genes. Besides, the presence of the int1 gene, related to the horizontal gene transfer among bacteria, was also investigated in all the strains by Real-Time PCR analysis. Our data showed that 56% of the isolated strains harbored one or more tet resistance genes and that these strains were most frequently isolated from animals living in close contact with humans. Concerning int1, 17 strains (28.3%) harbored this genetic element and eight of these simultaneously contained tet genes. The results of this study highlight the importance of using a molecular approach to detect resistance genetic determinants, whose spread can increase the diffusion of multidrug-resistant strains. Besides, the study of zoonotic bacteria such as Salmonella spp. which significantly contribute to ARGs dissemination should always follow a One Health approach that considers the health of humans, animals, and the environment to be closely related.202134356729
5366160.9998Fresh produce as a reservoir of antimicrobial resistance genes: A case study of Switzerland. Antimicrobial resistance (AMR) can be transferred to humans through food and fresh produce can be an ideal vector as it is often consumed raw or minimally processed. The production environment of fresh produce and the agricultural practices and regulations can vary substantially worldwide, and consequently, the contamination sources of AMR. In this study, 75 imported and 75 non-imported fresh produce samples purchased from Swiss retailers were tested for the presence of antimicrobial resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). Moreover, the plasmidome of 4 selected samples was sequenced to have an insight on the diversity of mobile resistome. In total, 91 ARB were isolated from fresh produce, mainly cephalosporin-resistant Enterobacterales (n = 64) and carbapenem-resistant P. aeruginosa (n = 13). All P. aeruginosa, as well as 16 Enterobacterales' isolates were multidrug-resistant. No differences between imported and Swiss fresh produce were found regarding the number of ARB. In 95 % of samples at least one ARG was detected, being the most frequent sul1, bla(TEM), and ermB. Abundance of sul1 and intI1 correlated strongly with the total amount of ARGs, suggesting they could be good indicators for AMR in fresh produce. Furthermore, sul1 correlated with the fecal marker yccT, indicating that fecal contamination could be one of the sources of AMR. The gene sulI was significantly higher in most imported samples, suggesting higher anthropogenic contamination in the food production chain of imported produce. The analyses of the plasmidome of coriander and carrot samples revealed the presence of several ARGs as well as genes conferring resistance to antiseptics and disinfectants in mobile genetic elements. Overall, this study demonstrated that fresh produce contributes to the dissemination of ARGs and ARB.202437813266
1928170.9998Targeted 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
2864180.9998Case study on the soil antibiotic resistome in an urban community garden. Urban agricultural soils can be an important reservoir of antibiotic resistance, and have great food safety and public health indications. This study investigated antibiotic-resistant bacteria and antibiotic resistance genes in urban agricultural soils using phenotypic and metagenomic tools. In total, 207 soil bacteria were recovered from 41 soil samples collected from an urban agricultural garden in Detroit, MI, USA. The most prevalent antibiotic resistance phenotype demonstrated by Gram-negative bacteria was resistance to ampicillin (94.2%), followed by chloramphenicol (80.0%), cefoxitin (79.5%), gentamicin (78.4%) and ceftriaxone (71.1%). All Gram-positive bacteria were resistant to gentamicin, kanamycin and penicillin. Genes encoding resistance to quinolones, β-lactams and tetracyclines were the most prevalent and abundant in the soil. qepA and tetA, both encoding efflux pumps, predominated in the quinolone and tetracycline resistance genes tested, respectively. Positive correlation (P<0.05) was identified among groups of antibiotic resistance genes, and between antibiotic resistance genes and metal resistance genes. The data demonstrated a diverse population of antibiotic resistance in urban agricultural soils. Phenotypic determination together with soil metagenomics proved to be a valuable tool to study the nature and extent of antibiotic resistance in the environment.201829857032
5545190.9998Healthy 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