Potentially pathogenic bacteria and antimicrobial resistance in bioaerosols from cage-housed and floor-housed poultry operations. - Related Documents




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524401.0000Potentially pathogenic bacteria and antimicrobial resistance in bioaerosols from cage-housed and floor-housed poultry operations. BACKGROUND: Antibiotics are used in animal confinement buildings, such as cage-housed (CH) and floor-housed (FH) poultry operations, to lower the likeliness of disease transmission. In FH facilities, antibiotics may also be used at sub-therapeutic levels for growth promotion. Low levels of antibiotic create a selective pressure toward antimicrobial resistance (AMR) in chicken fecal bacteria. OBJECTIVE: The objective of this study was to compare bacteria and AMR genes in bioaerosols from CH and FH poultry facilities. METHODS: Bioaerosols were collected from 15 CH and 15 FH poultry operations, using stationary area samplers as well as personal sampling devices. Bacteria concentrations were determined by genus- or species-specific quantitative polymerase chain reaction (PCR) and AMR genes were detected using endpoint PCR. RESULTS: Enterococcus spp., Escherichia coli, and Staphylococcus spp. were significantly higher in bioaerosols of FH poultry operations than CH bioaerosols (P < 0.001) while Clostridium perfringens was significantly higher in area bioaerosols of CH operations than FH area bioaerosols (P < 0.05). Campylobacter spp. were detected only in bioaerosols of FH facilities. Zinc bacitracin resistance gene, bcrR, erythromycin resistance gene, ermA, and tetracycline resistance gene, tetA/C, were more prevalent in bioaerosols of FH facilities than CH bioaerosols (P < 0.01, P < 0.01, and P < 0.05, respectively). CONCLUSIONS: Most bacteria are more concentrated and most AMR genes are more prevalent in bioaerosols of FH poultry operations, where growth-promoting antibiotics may be used.201222156572
312910.9992Effect of therapeutic administration of β-lactam antibiotics on the bacterial community and antibiotic resistance patterns in milk. Dairy cows with mastitis are frequently treated with antibiotics. The potential effect of antibiotics on the milk microbiome is still not clear. Therefore, the objective of this research was to investigate the effect of 2 commonly used cephalosporins on the milk microbiota of dairy cows and the antibiotic resistance genes in the milk. The milk samples were collected from 7 dairy cows at the period before medication (d 0), medication (d 1, 2, 3), withdrawal period (d 4, 6, 8), and the period after withdrawal (d 9, 11, 13, 15). We applied 16S rRNA sequencing to explore the microbiota changes, and antibiotic resistance patterns were investigated by quantitative PCR. The microbiota richness and diversity in each sample were calculated using the Chao 1 (richness), Shannon (diversity), and Simpson (diversity) indices. The cephalosporins treatment lowered the Simpson diversity value at the period of withdrawal. Members of the Enterobacter genera were the most affected bacteria associated with mastitis. Meanwhile, antibiotic resistance genes in the milk were also influenced by antibiotic treatment. The cephalosporins treatment raised the proportion of bla(TEM) in milk samples at the period of withdrawal. Therefore, the treatment of cephalosporins led to change in the milk microbiota and increase of β-lactam resistance gene in the milk at the time of withdrawal period.202133741154
287720.9992Metagenomic insights into isolable bacterial communities and antimicrobial resistance in airborne dust from pig farms. This study aims to investigate bacterial communities and antimicrobial resistance (AMR) in airborne dust from pig farms. Airborne dust, pig feces and feed were collected from nine pig farms in Thailand. Airborne dust samples were collected from upwind and downwind (25 meters from pig house), and inside (in the middle of the pig house) of the selected pig house. Pig feces and feed samples were individually collected from the pen floor and feed trough from the same pig house where airborne dust was collected. A direct total bacteria count on each sampling plate was conducted and averaged. The ESKAPE pathogens together with Escherichia coli, Salmonella, and Streptococcus were examined. A total of 163 bacterial isolates were collected and tested for MICs. Pooled bacteria from the inside airborne dust samples were analyzed using Metagenomic Sequencing. The highest bacterial concentration (1.9-11.2 × 10(3) CFU/m(3)) was found inside pig houses. Staphylococcus (n = 37) and Enterococcus (n = 36) were most frequent bacterial species. Salmonella (n = 3) were exclusively isolated from feed and feces. Target bacteria showed a variety of resistance phenotypes, and the same bacterial species with the same resistance phenotype were found in airborne dust, feed and fecal from each farm. Metagenomic Sequencing analysis revealed 1,652 bacterial species across all pig farms, of which the predominant bacterial phylum was Bacillota. One hundred fifty-nine AMR genes of 12 different antibiotic classes were identified, with aminoglycoside resistance genes (24%) being the most prevalent. A total of 251 different plasmids were discovered, and the same plasmid was detected in multiple farms. In conclusion, the phenotypic and metagenomic results demonstrated that airborne dust from pig farms contained a diverse array of bacterial species and genes encoding resistance to a range of clinically important antimicrobial agents, indicating the significant role in the spread of AMR bacterial pathogens with potential hazards to human health. Policy measurements to address AMR in airborne dust from livestock farms are mandatory.202438872793
311130.9992The abundance and diversity of antibiotic resistance genes in layer chicken ceca is associated with farm enviroment. Industrialized layer chicken feedlots harbor complex environmental microbial communities that affect the enrichment and exchange of gut bacteria and antibiotic resistance genes (ARGs). However, the contribution of different environmental sources to the gut ARGs of layer chickens is not clear. Here, layer chicken gut and environmental samples (air, water, feed, cage, feather, maternal hen feces, uropygial glands) were collected during the early 3 month period before the laying of eggs, and the source and characteristics of the gut microorganisms and ARGs were analyzed by performing 16S rRNA and metagenomic sequencing. The results showed that the abundances of Bacteroidetes and Actinobacteria in cecum of layer chickens gradually increased, while that of Proteobacteria decreased with age, and the number and relative abundance of ARGs decreased significantly with age. On day 5, 57% of the layer chicken cecal ARGs were from feather samples, and 30% were from cage samples. Subsequently, the contribution of cage ARGs became progressively more prominent over time. At days 30 and 57, the contribution of cage ARGs to the chick cecal ARGs reached 63.3 and 69.5%, respectively. The bacterial community composition (especially the abundances of Klebsiella pneumoniae and Escherichia coli) was the major factor impacting the ARG profile. K. pneumoniae and E. coli were mainly transmitted from feathers to the layer chicken cecum, and the contribution rates were 32 and 3.4%, respectively. In addition, we observed the transmission of ARG-carrying bacteria (Bacteroides fragilis) from the cage to the gut, with a contribution rate of 11.5%. It is noteworthy that B. fragilis is an opportunistic pathogen that may cause diarrhea in laying hens. These results can provide reference data for the healthy breeding of layer chickens and the prevention and control of ARG pollution.202337455745
311040.9991Microbial community, pathogenic bacteria and high-risk anti-biotic resistance genes at two tropical coastal beaches adjacent to villages in Hainan, China. OBJECTIVE: The aim of the study was to explore the correlation between characteristics of microbial community, pathogenic bacteria and high-risk antibiotic-resistant genes, between coastal beaches and a multi-warm-blooded host, as well as to determine potential species biomarkers for faecal source contamination on tropical coastal beaches in China. MATERIAL AND METHODS: The 'One-Health' approach was used in a microbiological study of beaches and warm-blooded hosts. The microbial.community was analyzed using 16S rRNA gene amplicons and shotgun metagenomics on Illumina NovaSeq. RESULTS: The Chao, Simpson, Shannon, and ACE indices of non-salt beach were greater than those of salt beaches at the genus and OTU levels (P < 0.001). Bacteroidota, Halanaerobiaeota, Cyanobacteria, and Firmicutes were abundant on salt beaches (P<0.01). Human-sourced microorganisms were more abundant on salt beaches, which accounted for 0.57%. Faecalibacterium prausnitzii and Eubacterium hallii were considered as reliable indicators for the contamination of human faeces. High-risk carbapenem-resistant Klebsiella pneumoniae and the genotypes KPC-14 and KPC-24 were observed on salt beaches. Tet(X3)/tet(X4) genes and four types of MCR genes co-occurred on beaches and humans; MCR9.1 accounted for the majority. Tet(X4) found among Cyanobacteria. Although rarely reported at Chinese beaches, pathogens, such as Vibrio vulnificus, Legionella pneumophila, and Helicobacter pylori, were observed. CONCLUSIONS: The low microbial community diversity, however, did not indicate a reduced risk. The transfer of high-risk ARGs to extreme coastal environments should be given sufficient attention.202338153067
707650.9991Indoor Air Quality and Potential Health Risk Impacts of Exposure to Antibiotic Resistant Bacteria in an Office Rooms in Southern Poland. The aims of this article are to characterize: the quantity of culturable bacterial aerosol (QCBA) and the quality of culturable bacterial aerosol (QlCBA) in an office building in Southern Poland during the spring. The average concentration of culturable bacterial aerosol (CCBA) in this building ranged from 424 CFU m(-3) to 821 CFU m(-3), below Polish proposals for threshold limit values. Size distributions were unimodal, with a peak of particle bacterial aerodynamic diameters less than 3.3 μm, increasing potentially adverse health effects due to their inhalation. The spring office exposure dose (SPED) of bacterial aerosol was estimated. The highest value of SPED was in April (218 CFU kg(-1)), whereas the lowest was in June (113 CFU kg(-1)). Analysis was undertaken to determine the antibiotic resistance of isolated strains and their ability to form biofilms, which may facilitate the spread of antibiotic resistance genes. In the course of the study, it was found that Staphylococcus xylosus had the greatest ability to form biofilms, while the strains with the highest antibiotic resistance were Micrococcus luteus D and Macrococcus equipercicus. Given that mainly antibiotic-sensitive bacteria from bioaerosol were isolated, which transfers resistance genes to their plasmids, this shows the need for increased monitoring of indoor air quality in workplaces.201830469413
528760.9991Presence of antibiotic-resistant commensal bacteria in samples from agricultural, city, and national park environments evaluated by standard culture and real-time PCR methods. This study examined the presence of antibiotic-resistant commensal bacteria among cattle operations representing areas heavily affected by agriculture, city locations representing areas affected by urban activities and indirectly affected by agriculture, and a national park representing an area not affected by agriculture. A total of 288 soil, fecal floor, and water samples were collected from cattle operations, from the city of Fort Collins, and from Rocky Mountain National Park (RMNP) in Colorado. In addition, a total of 42 new and unused feed, unused bedding, compost, and manure samples were obtained from the cattle operations. Total, tetracycline-resistant, and ceftiofur-resistant bacterial populations were enumerated by both standard culture plating and real-time PCR methods. Only wastewater samples from the cattle operations demonstrated both higher tetracycline-resistant bacterial counts (enumerated by the culture plating method) and tetracycline resistance gene copies (quantified by real-time PCR) compared to water samples collected from non-farm environments. The ceftiofur resistance gene, blaCMY-2, was not detectable in any of the samples, while the tetracycline resistance genes examined in this study, tet(B), tet(C), tet(W), and tet(O), were detected in all types of tested samples, except soil samples from RMNP. Tetracycline resistance gene pools quantified from the tet(O) and tet(W) genes were bigger than those from the tet(B) and tet(C) genes in fecal and water samples. Although only limited resistance genes, instead of a full set, were selected for real-time PCR quantification in this study, our results point to the need for further studies to determine natural and urban impacts on antibiotic resistance.201020921986
528270.9991Occupational Exposure and Carriage of Antimicrobial Resistance Genes (tetW, ermB) in Pig Slaughterhouse Workers. OBJECTIVES: Slaughterhouse staff is occupationally exposed to antimicrobial resistant bacteria. Studies reported high antimicrobial resistance gene (ARG) abundances in slaughter pigs. This cross-sectional study investigated occupational exposure to tetracycline (tetW) and macrolide (ermB) resistance genes and assessed determinants for faecal tetW and ermB carriage among pig slaughterhouse workers. METHODS: During 2015-2016, 483 faecal samples and personal questionnaires were collected from workers in a Dutch pig abattoir, together with 60 pig faecal samples. Human dermal and respiratory exposure was assessed by examining 198 carcass, 326 gloves, and 33 air samples along the line, next to 198 packed pork chops to indicate potential consumer exposure. Samples were analyzed by qPCR (tetW, ermB). A job exposure matrix was created by calculating the percentage of tetW and ermB positive carcasses or gloves for each job position. Multiple linear regression models were used to link exposure to tetW and ermB carriage. RESULTS: Workers are exposed to tetracycline and macrolide resistance genes along the slaughter line. Tetw and ermB gradients were found for carcasses, gloves, and air filters. One packed pork chop contained tetW, ermB was non-detectable. Human faecal tetW and ermB concentrations were lower than in pig faeces. Associations were found between occupational tetW exposure and human faecal tetW carriage, yet, not after model adjustments. Sampling round, nationality, and smoking were determinants for ARG carriage. CONCLUSION: We demonstrated clear environmental tetracycline and macrolide resistance gene exposure gradients along the slaughter line. No robust link was found between ARG exposure and human faecal ARG carriage.202031883001
531080.9991Antimicrobial-Resistant Bacterial Populations and Antimicrobial Resistance Genes Obtained from Environments Impacted by Livestock and Municipal Waste. 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 and concentrations of antimicrobial-resistant bacteria and antimicrobial resistance genes exist in cattle, human, and swine waste streams, but a higher diversity of antimicrobial resistance genes are present in treated human waste discharged from municipal wastewater treatment plants than in livestock environments.201526197056
534590.9991Spread of antimicrobial resistance genes via pig manure from organic and conventional farms in the presence or absence of antibiotic use. AIMS: Antibiotic-resistant bacteria affect human and animal health. Hence, their environmental spread represents a potential hazard for mankind. Livestock farming is suspected to be a key factor for spreading antibiotic resistance; consumers expect organic farming to imply less environmental health risk. This study aimed to assess the role of manure from organic and conventional farms for spreading antimicrobial resistance (AMR) genes. METHODS AND RESULTS: AMR-genes-namely tet(A), tet(B), tet(M), sul2 and qacE/qacEΔ1 (potentially associated with multiresistance) were quantified by qPCR. Antimicrobial use during the study period was qualitatively assessed from official records in a binary mode (yes/no). Median concentrations were between 6.44 log copy-equivalents/g for tet(A) and 7.85 for tet(M) in organic liquid manure, and between 7.48 for tet(A) and 8.3 for sul2 in organic farmyard manure. In conventional manure, median concentrations were 6.67 log copy-equivalents/g for sul2, 6.89 for tet(A), 6.77 for tet(B) and 8.36 for tet(M). Integron-associated qac-genes reached median concentrations of 7.06 log copy-equivalents/g in organic liquid manure, 7.13 in conventional manure and 8.18 in organic farmyard manure. The use of tetracyclines or sulfonamides increased concentrations of tet(A) and tet(M), or of sul2, respectively. Comparing farms that did not apply tetracyclines during the study, the relative abundance of tet(A) and tet(M) was still higher for conventional piggeries than for organic ones. CONCLUSIONS: Relative abundances of AMR genes were higher in conventional farms, compared to organic ones. Antibiotic use was linked to the relative abundance of AMR-genes. However, due to the bacterial load, absolute concentrations of AMR-genes were comparable between fertilizers of organic and conventional farms. SIGNIFICANCE AND IMPACT OF STUDY: To our knowledge, this is the first absolute quantification of AMR-genes in manure from organic farms. Our study underlines the importance of long-term reduction in the use of antimicrobial agents in order to minimize antibiotic resistance.202235835564
3157100.9991Reservoirs of antimicrobial resistance genes in retail raw milk. BACKGROUND: It has been estimated that at least 3% of the USA population consumes unpasteurized (raw) milk from animal sources, and the demand to legalize raw milk sales continues to increase. However, consumption of raw milk can cause foodborne illness and be a source of bacteria containing transferrable antimicrobial resistance genes (ARGs). To obtain a comprehensive understanding of the microbiome and antibiotic resistome in both raw and processed milk, we systematically analyzed 2034 retail milk samples including unpasteurized milk and pasteurized milk via vat pasteurization, high-temperature-short-time pasteurization, and ultra-pasteurization from the United States using complementary culture-based, 16S rRNA gene, and metagenomic sequencing techniques. RESULTS: Raw milk samples had the highest prevalence of viable bacteria which were measured as all aerobic bacteria, coliform, and Escherichia coli counts, and their microbiota was distinct from other types of milk. 16S rRNA gene sequencing revealed that Pseudomonadaceae dominated raw milk with limited levels of lactic acid bacteria. Among all milk samples, the microbiota remained stable with constant bacterial populations when stored at 4 °C. In contrast, storage at room temperature dramatically enriched the bacterial populations present in raw milk samples and, in parallel, significantly increased the richness and abundance of ARGs. Metagenomic sequencing indicated raw milk possessed dramatically more ARGs than pasteurized milk, and a conjugation assay documented the active transfer of bla(CMY-2), one ceftazidime resistance gene present in raw milk-borne E. coli, across bacterial species. The room temperature-enriched resistome differed in raw milk from distinct geographic locations, a difference likely associated with regionally distinct milk microbiota. CONCLUSION: Despite advertised "probiotic" effects, our results indicate that raw milk microbiota has minimal lactic acid bacteria. In addition, retail raw milk serves as a reservoir of ARGs, populations of which are readily amplified by spontaneous fermentation. There is an increased need to understand potential food safety risks from improper transportation and storage of raw milk with regard to ARGs. Video Abstract.202032591006
2938110.9991Detection of antibiotic resistance genes in the feces of young adult Japanese. Antibiotic resistance genes in the feces of healthy young adult Japanese were analyzed with polymerase chain reaction using specific primers. Antibiotic resistance genes against macrolides (ermB, ermF, ermX, and mefA/E), tetracyclines (tetW, tetQ, tetO, and tetX), β-lactam antibiotics (bla(TEM) ), and streptomycin (aadE) were detected in more than 50% of subjects. These antibiotic resistance genes are likely widespread in the large intestinal bacteria of young adult Japanese.201729038771
3087120.9991Diversity and abundance of antibiotic resistance of bacteria during the seedling period in marine fish cage-culture areas of Hainan, China. Antibiotic resistance has become an important focus of research in the aquaculture environment. However, few studies have evaluated antibiotic resistance during the seedling period in marine fish cage-culture areas. In this study, culture-dependent methods and quantitative polymerase chain reaction were used to identify and detect cultivable heterotrophic antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs), respectively, during the seedling period in a marine fish cage-culture areas of Hainan, China. Bacterial resistance to amoxicillin, erythromycin, and gentamicin was generally high (average on 27.67%, 23.61% and 37.32%, respectively), whereas resistance to furazolidone and nitrofurantoin was generally low (average on 0.14% and 7.425%). Alteromonas (32.72%) and Vibrio (24.77%) were the dominant genus of ARB. Most ARB were opportunistic pathogens, belonging to the phylum Proteobacteria (96.02%). The abundance of sul family genes was higher than that of tet family genes. Overall, the abundance of ARGs and the resistance rates in HW was highest.201930955742
3088130.9991Occurrence of sulfonamide and tetracycline-resistant bacteria and resistance genes in aquaculture environment. The occurrence of sulfonamide and tetracycline resistance and their pollution profile in the aquaculture environment of Tianjin, northern China, were investigated. The presence of antibiotic-resistant bacteria was identified and the corresponding antibiotic resistance genes (ARGs) were quantified at 6 aquaculture farms in Tianjin. Sulfonamide-resistance genes were prevalent and their concentrations were the highest detected (3.0 × 10(-5) to 3.3 × 10(-4) for sul1/16S rDNA, 2.0 × 10(-4) to 1.8 × 10(-3) for sul2/16S rDNA) among the various ARGs, most likely because the use of sulfonamides is more prevalent than tetracyclines in this area. Bacillus was the most dominant bacterial genus in both sulfamethoxazole resistant bacteria (63.27% of the total resistant bacteria) and tetracycline-resistant bacteria (57.14% of the total resistant bacteria). At least two of those genes (tetM, tetO, tetT, tetW, sul1 and sul2) were detected in the isolates of Bacillus cereus, Bacillus subtilis, Bacillus megaterium and Acinetobacter lwofii, and all of the above genes were detected in B. cereus, suggesting the occurrence of multi-resistance in the studied area. The genetic transfer of sul1 between intestinal bacteria (e.g., Enterococcus spp.) and indigenous bacteria (e.g., Bacillus spp.) was implied by phylogenetic analysis. Several strains of resistant opportunistic pathogens (e.g., Acinetobacter spp.) were found in indigenous bacteria, which increase the risk of ARGs to public health. Overall, this is the first study to comprehensively investigate the antibiotic resistance profile by analyzing the species of antibiotic-resistant bacteria and adopting qualitative and quantitative methods to investigate ARGs at a typical aquaculture area in northern China.201222377146
3204140.9991Spread of airborne antibiotic resistance from animal farms to the environment: Dispersal pattern and exposure risk. Animal farms have been considered as the critical reservoir of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB). Spread of antibiotic resistance from animal farms to the surrounding environments via aerosols has become a growing concern. Here we investigated the dispersal pattern and exposure risk of airborne ARGs (especially in zoonotic pathogens) in the environment of chicken and dairy farms. Aerosol, dust and animal feces samples were collected from the livestock houses and surrounding environments (upwind and downwind areas) for assessing ARG profiles. Antibiotic resistance phenotype and genotype of airborne Staphylococcus spp. was especially analyzed to reveal the exposure risk of airborne ARGs. Results showed that airborne ARGs were detected from upwind (50 m/100 m) and downwind (50 m/100 m/150 m) air environment, wherein at least 30% of bacterial taxa dispersed from the animal houses. Moreover, atmospheric dispersion modeling showed that airborne ARGs can disperse from the animal houses to a distance of 10 km along the wind direction. Clinically important pathogens were identified in airborne culturable bacteria. Genus of Staphylococcus, Sphingomonas and Acinetobacter were potential bacterial host of airborne ARGs. Airborne Staphylococcus spp. were isolated from the environment of chicken farm (n = 148) and dairy farm (n = 87). It is notable that all isolates from chicken-related environment were multidrug-resistance (>3 clinical-relevant antibiotics), with more than 80% of them carrying methicillin resistance gene (mecA) and associated ARGs and MGEs. Presence of numerous ARGs and diverse pathogens in dust from animal houses and the downwind residential areas indicated the accumulation of animal feces origin ARGs in bioaerosols. Employees and local residents in the chick farming environment are exposed to chicken originated ARGs and multidrug resistant Staphylococcus spp. via inhalation. This study highlights the potential exposure risks of airborne ARGs and antibiotic resistant pathogens to human health.202234673316
2813150.9991Quantity 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
3493160.9991Studies on the airborne bacterial communities and antimicrobial resistance genes in duck houses based on metagenome and PCR analysis. The threat of antimicrobial resistance (AMR) is on the rise globally, especially with the development of animal husbandry and the increased demand for antibiotics. Livestock and poultry farms, as key sites for prevalence of antibiotic-resistant bacteria (ARB), can spread antimicrobial resistance genes (ARGs) through microbial aerosols and affect public health. In this study, total suspended particulate matter (TSP) and airborne culturable microorganisms were collected from duck houses in Tai'an, Shandong Province, and the bacterial communities and airborne ARGs were analyzed using metagenomics and PCR methods. The results showed that the bacterial communities in the air of duck houses were mainly Actinobacteria, Firmicutes, Proteobactria, Chlamydia, and Bcateroidetes at the phylum level. At the genus level, the air was dominated by Corynebacterium, Jeotgalicoccus, Staphylococcus, Brevibacterium, and Megacoccus, and contained some pathogenic bacteria such as Staphylococcus aureus, Corynebacterium diphtheriae, Klebsiella oxytoca, Acinetobacter baumannii, and Pseudomonas aeruginosa, which were also potential hosts for ARGs. The airborne ARGs were mainly macrolides (10.97%), penicillins (10.73%), cephalosporins (8.91%), streptozotocin (8.91%), and aminoglycosides (8.02%). PCR detected 27 ARGs in airborne culturable microorganisms, and comparative analysis between PCR and the metagenomic data revealed that a total of 9 ARGs were found to the same, including macrolides ErmA, ErmF, tetracyclines tetG, tetX, methicarbamazepines dfrA12, dfrA15, aminoglycosides APH3-VI, ANT2-Ⅰ, and sulfonamides sul2. Moreover, inhalation exposure modeling showed that the workers in duck houses inhaled higher concentrations of ARB, human pathogenic bacteria (HPB) and human pathogenic antibiotic-resistant bacteria (HPARB) than hospital workers. These results provide new insights into airborne microorganisms and ARGs in animal farms and lay the foundation for further study.202438157791
2583170.9990From Farm to Slaughter: Tracing Antimicrobial Resistance in a Poultry Short Food Chain. Background: Short food supply chains are commonly perceived as more sustainable and safer alternatives to conventional production systems, often linked to organic, free-range livestock practices. Materials and methods: This study investigates, for the first time, the distribution of antimicrobial resistance genes (ARGs) and characterizes the microbial communities' composition, using 16S rRNA sequencing and real-time PCR, respectively. Eleven fecal, 76 slaughterhouse surface, 11 cecal, and 11 carcass samples, from 11 poultry farms belonging to the same short food chain, were analyzed in the study. Results: While cleaning and disinfection procedures appeared to reduce the bacterial load on slaughterhouse surfaces, diverse and potentially resistant bacteria, including genera such as Staphylococcus and Streptococcus, persisted both before and after slaughter. ARGs conferring resistance to high-priority critically important antimicrobials (HPCIAs), such as fluoroquinolones and third-generation cephalosporins, were frequently detected on carcasses, with qnrS (76.15%, 95%CI 68.02-84.28%) and bla(CMY2) (57.8%, 95%CI 48.38-67.22%) being the most prevalent. The slaughtering process emerged as a critical step for ARG dissemination via intestinal bacteria, such as genus Lactobacillus. Additionally, the detection of mcr genes and bla(NDM) on carcasses but not in the bird gut samples suggests possible anthropogenic contamination. Discussion: These findings highlight that the evisceration process, slaughterhouse environment, and personnel are all contributing factors in ARG spread and underscore the need for enhanced hygiene protocols and reduced gut ARG carriage in domestic birds to mitigate the risk for the consumer.202540558194
2846180.9990Class 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
5300190.9990From Pig Breeding Environment to Subsequently Produced Pork: Comparative Analysis of Antibiotic Resistance Genes and Bacterial Community Composition. It is well verified that pig farms are an important reservoir and supplier of antibiotic resistance genes (ARGs). However, little is known about the transmission of ARGs between the breeding environment and subsequently produced pork. This study was conducted to investigate if ARGs and associated host bacteria spread from the breeding environment onto the meat through the food production chain. We thus analyzed the occurrence and abundance of ARGs, as well as comparing both ARG and bacterial community compositions in farm soil, pig feces and pork samples from a large-scale pig farm located in Xiamen, People's Republic of China. Among the 26 target ARGs, genes conferring resistance to sulfonamide, trimethoprim, aminoglycoside, chloramphenicol, macrolide, florfenicol, and tetracycline were observed at high frequency in both the pig breeding environment and pork. The prevalence of ARGs in pork was surprisingly consistent with breeding environments, especially between the pork and feces. The relative abundance of 10 representative ARGs conferring resistance to six classes of antibiotics ranged from 3.01 × 10(-1) to 1.55 × 10(-6) copies/16S rRNA copies. The ARGs conferring resistance to sulfanilamide (sulI and sulII), aminoglycoside (aadA), and tetracycline [tet(A) and tet(M)] were most highly abundant across most samples. Samples from feces and meat possessed a higher similarity in ARG compositions than samples from the farms soil. Enterobacteriaceae found on the meat samples were further identical with previously isolated multidrug-resistant bacteria from the same pig farm. Our results strongly indicate that ARGs can be potentially spreading from pig breeding environment to meat via the pork industry chain, such as feed supply, pig feeding and pork production.201930761096