Surveillance of antimicrobial resistance in Escherichia coli, Salmonella, and Campylobacter recovered from laying hens, their environment and products in Canada indicated a stable level of resistance to critically important antimicrobials, in varying time periods between 2007 and 2021.

The study objective was to determine the occurrence and antimicrobial resistance (AMR) attributes of select foodborne bacteria recovered from egg-producing (layer) chickens between 2007 and 2021 using different sample matrices (Study 1: liquid whole eggs, Study 2: spent hen cecal samples, Study 3: environmental sponge swabs and fecal samples from layer chicken barns, and Study 4: fecal samples from layer chicken barns). Samples from each study were submitted for the culture of Escherichia coli and Salmonella. In addition, samples from layer chicken barns were submitted for the culture of Campylobacter. Isolates were tested by microbroth dilution and interpreted using both clinical breakpoints and epidemiological cut-offs (ECOFFs). The ECOFFs were applied to detect non-wild type (NWT) strains. The proportion of resistant, NWT, and distribution of minimum inhibitory concentrations (MIC) were assessed. Ceftriaxone resistance was detected at a low-level in E. coli (< 2 %, all studies) and Salmonella (4.3 %, Study 2). Very low-level ciprofloxacin resistance was detected in E. coli (<1 %, Study 1) but a slightly elevated ciprofloxacin NWT E. coli (1 % to 6 %) observed. Only the farm fecal samples in Studies 2 and 3 were tested for Campylobacter as part of its study design, and moderate level ciprofloxacin resistance (<15 %) was observed. The MIC distribution patterns were similar across the organisms tested/studies and no substantial shifts in the distributions were detected. This analysis demonstrated that resistance to very important antimicrobials in bacteria from layers in Canada remains low, however, the detection of ciprofloxacin-resistant Campylobacter and the implications of this observation to the safety of egg products, and the role of laying flocks (i.e., as reservoir for resistant organisms) needs to be investigated.

A scoping review of factors associated with antimicrobial-resistant Campylobacter species infections in humans.

Human infection with antimicrobial-resistant Campylobacter species is an important public health concern due to the potentially increased severity of illness and risk of death. Our objective was to synthesise the knowledge of factors associated with human infections with antimicrobial-resistant strains of Campylobacter. This scoping review followed systematic methods, including a protocol developed a priori. Comprehensive literature searches were developed in consultation with a research librarian and performed in five primary and three grey literature databases. Criteria for inclusion were analytical and English-language publications investigating human infections with an antimicrobial-resistant (macrolides, tetracyclines, fluoroquinolones, and/or quinolones) Campylobacter that reported factors potentially linked with the infection. The primary and secondary screening were completed by two independent reviewers using Distiller SR®. The search identified 8,527 unique articles and included 27 articles in the review. Factors were broadly categorised into animal contact, prior antimicrobial use, participant characteristics, food consumption and handling, travel, underlying health conditions, and water consumption/exposure. Important factors linked to an increased risk of infection with a fluoroquinolone-resistant strain included foreign travel and prior antimicrobial use. Identifying consistent risk factors was challenging due to the heterogeneity of results, inconsistent analysis, and the lack of data in low- and middle-income countries, highlighting the need for future research.

Factors associated with antimicrobial resistant enterococci in Canadian beef cattle: A scoping review.

Introduction: Antimicrobial resistance (AMR) is a global health concern, occurring when bacteria evolve to render antimicrobials no longer effective. Antimicrobials have important roles in beef production; however, the potential to introduce AMR to people through beef products is a concern. This scoping review identifies factors associated with changes in the prevalence of antimicrobial-resistant Enterococcus spp. applicable to the Canadian farm-to-fork beef continuum. Methods: Five databases (MEDLINE, BIOSIS, Web of Science, Embase, and CAB Abstracts) were searched for articles published from January 1984 to March 2022, using a priori inclusion criteria. Peer-reviewed articles were included if they met all the following criteria: written in English, applicable to the Canadian beef production context, primary research, in vivo research, describing an intervention or exposure, and specific to Enterococcus spp. Results: Out of 804 screened articles, 26 were selected for inclusion. The included articles discussed 37 factors potentially associated with AMR in enterococci, with multiple articles discussing at least two of the same factors. Factors discussed included antimicrobial administration (n = 16), raised without antimicrobials (n = 6), metal supplementation (n = 4), probiotics supplementation (n = 3), pen environment (n = 2), essential oil supplementation (n = 1), grass feeding (n = 1), therapeutic versus subtherapeutic antimicrobial use (n = 1), feeding wet distiller grains with solubles (n = 1), nutritional supplementation (n = 1) and processing plant type (n = 1). Results were included irrespective of their quality of evidence. Discussion: Comparability issues arising throughout the review process were related to data aggregation, hierarchical structures, study design, and inconsistent data reporting. Findings from articles were often temporally specific in that resistance was associated with AMR outcomes at sampling times closer to exposure compared to studies that sampled at longer intervals after exposure. Resistance was often nuanced to unique gene and phenotypic resistance patterns that varied with species of enterococci. Intrinsic resistance and interpretation of minimum inhibitory concentration varied greatly among enterococcal species, highlighting the importance of caution when comparing articles and generalizing findings. Systematic Review Registration: [http://hdl.handle.net/1880/113592].

A One Health Genomic Investigation of Gentamicin Resistance in Escherichia coli from Human and Chicken Sources in Canada, 2014 to 2017.

We investigated whether gentamicin resistance (Genr) in Escherichia coli isolates from human infections was related to Genr E. coli in chicken and whether resistance may be due to coselection from use of lincomycin-spectinomycin in chickens on farms. Whole-genome sequencing was performed on 483 Genr E. coli isolates isolated between 2014 and 2017. These included 205 human-source isolates collected by the Canadian Ward (CANWARD) program and 278 chicken-source isolates: 167 from live/recently slaughtered chickens (animals) and 111 from retail chicken meat collected by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). The predominant Genr gene was different in human and chicken sources; however, both sources carried aac(3)-IId, aac(3)-VIa, and aac(3)-IVa. Forty-one percent of human clinical isolates of Genr E. coli contained a blaCTX-M extended-spectrum beta-lactamase (ESBL) gene (84/205), and 53% of these were sequence type 131 (ST131). Phylogenomic analysis revealed a high diversity of Genr isolates; however, there were three small clusters of closely related isolates from human and chicken sources. Genr and spectinomycin resistance (Specr) genes were colocated in 148/167 (89%) chicken animal isolates, 94/111 (85%) chicken retail meat isolates, and 137/205 (67%) human-source isolates. Long-read sequencing of 23 isolates showed linkage of the Genr and Specr genes on the same plasmid in 14/15 (93%) isolates from chicken(s) and 6/8 (75%) isolates from humans. The use of lincomycin-spectinomycin on farms may be coselecting for gentamicin-resistant plasmids in E. coli in broiler chickens; however, Genr isolates and plasmids were mostly different in chickens and humans.

Antimicrobial Resistance in the Environment: Towards Elucidating the Roles of Bioaerosols in Transmission and Detection of Antibacterial Resistance Genes.

Antimicrobial resistance (AMR) is continuing to grow across the world. Though often thought of as a mostly public health issue, AMR is also a major agricultural and environmental problem. As such, many researchers refer to it as the preeminent One Health issue. Aerial transport of antimicrobial-resistant bacteria via bioaerosols is still poorly understood. Recent work has highlighted the presence of antibiotic resistance genes in bioaerosols. Emissions of AMR bacteria and genes have been detected from various sources, including wastewater treatment plants, hospitals, and agricultural practices; however, their impacts on the broader environment are poorly understood. Contextualizing the roles of bioaerosols in the dissemination of AMR necessitates a multidisciplinary approach. Environmental factors, industrial and medical practices, as well as ecological principles influence the aerial dissemination of resistant bacteria. This article introduces an ongoing project assessing the presence and fate of AMR in bioaerosols across Canada. Its various sub-studies include the assessment of the emissions of antibiotic resistance genes from many agricultural practices, their long-distance transport, new integrative methods of assessment, and the creation of dissemination models over short and long distances. Results from sub-studies are beginning to be published. Consequently, this paper explains the background behind the development of the various sub-studies and highlight their shared aspects.

A scoping review of factors potentially linked with antimicrobial-resistant bacteria from turkeys (iAM.AMR Project).

Antimicrobial resistance (AMR) is a complex problem that is a threat to global public health. Consumption of turkey meat may be an important source of foodborne exposure to resistant bacteria; recent outbreaks of multi-drug-resistant Salmonella Reading in Canada and the USA have implicated raw turkey products. To better understand the epidemiology of AMR in farmed turkey production, a scoping review was conducted. The objectives were to identify (1) modifiable factors potentially associated with antimicrobial-resistant Campylobacter, Enterococcus, Escherichia coli and Salmonella enterica along the farm-to-fork pathway in turkeys, and (2) data gaps with respect to factors potentially associated with AMR and Canadian commercial turkey production. A comprehensive search of the peer-reviewed literature was conducted in 2019 and updated in 2021. Thirteen references were included, reporting 36 factors. Antimicrobial use factors and their potential associations with AMR were most frequently reported (n = 15 factors; 42%), followed by biosecurity (n = 11; 31%) and management practices (n = 10; 28%). This review revealed important data gaps; no factors pertaining to S. enterica or to stages other than the farm (e.g. abattoir, retail) were identified, and only one Canadian reference was identified. These findings will inform priorities for future research and surveillance regarding turkeys and AMR.

One Health Genomic Analysis of Extended-Spectrum ß-Lactamase‒Producing Salmonella enterica, Canada, 2012‒2016.

Extended-spectrum ß-lactamases (ESBLs) confer resistance to extended-spectrum cephalosporins, a major class of clinical antimicrobial drugs. We used genomic analysis to investigate whether domestic food animals, retail meat, and pets were reservoirs of ESBL-producing Salmonella for human infection in Canada. Of 30,303 Salmonella isolates tested during 2012-2016, we detected 95 ESBL producers. ESBL serotypes and alleles were mostly different between humans (n = 54) and animals/meat (n = 41). Two exceptions were blaSHV-2 and blaCTX-M-1 IncI1 plasmids, which were found in both sources. A subclade of S. enterica serovar Heidelberg isolates carrying the same IncI1-blaSHV-2 plasmid differed by only 1-7 single nucleotide variants. The most common ESBL producer in humans was Salmonella Infantis carrying blaCTX-M-65, which has since emerged in poultry in other countries. There were few instances of similar isolates and plasmids, suggesting that domestic animals and retail meat might have been minor reservoirs of ESBL-producing Salmonella for human infection.

Antimicrobial use in lactating sows, piglets, nursery, and grower-finisher pigs on swine farms in Ontario, Canada during 2017 and 2018.

BACKGROUND: Data on antimicrobial use (AMU) in pig production are needed for the development of good antimicrobial stewardship practices to reduce the risk of antimicrobial resistance in bacteria that can cause illness in animals and humans. In Canada, there is a lack of quantitative data on AMU in the farrowing and nursery stages of pig production. This study aimed to determine which antimicrobial active ingredients are currently used in farrowing, nursery, and grower-finisher herds in the province of Ontario, Canada, and to quantify AMU using various metrics. We collected data on herd demographics, biosecurity, health status, and AMU during one production cycle from 25 farrowing and 25 nursery herds in Ontario, between May 2017 and April 2018, and obtained data from 23 Ontario grower-finisher herds during the same time frame from the Public Health Agency's Canadian Integrated Program for Antimicrobial Resistance Surveillance. We applied frequency measures, and weight-, and dose-based metrics to the data. RESULTS: In all pigs, the highest quantity of AMU was administered in-feed. By all routes of administration and compared to other production stages, nursery pigs used more antimicrobials in mg/kg biomass and the number of Canadian defined daily doses per 1000 pig-days (doseCA rate), while grower-finisher pigs used more antimicrobials in total kilograms and the number of Canadian defined daily doses per pig. In suckling pigs in some herds, there was routine disease prevention use of ceftiofur, an antimicrobial active ingredient categorized as very highly important in human medicine by Health Canada. The top antimicrobial used in each stage of pig production often varied by the metric used. There was producer-reported growth promotion use of antimicrobials in suckling and grower-finisher feed. CONCLUSIONS: The results of this study provide a current picture of AMU in pigs in Ontario and can be used as a basis for further research on AMU in farrowing and nursery herds in Canada. Our findings confirm that it would be useful to include farrowing and nursery herds in routine AMU surveillance in Canada. A future analysis using data from this project will examine factors that affect the quantity of AMU.

Using whole-genome sequence data to examine the epidemiology of antimicrobial resistance in Escherichia coli from wild meso-mammals and environmental sources on swine farms, conservation areas, and the Grand River watershed in southern Ontario, Canada.

Antimicrobial resistance (AMR) threatens the health of humans and animals and has repeatedly been detected in wild animal species across the world. This cross-sectional study integrates whole-genome sequence data from Escherichia coli isolates with demonstrated phenotypic resistance that originated from a previous longitudinal wildlife study in southern Ontario, as well as phenotypically resistant E. coli water isolates previously collected as part of a public health surveillance program. The objective of this work was to assess for evidence of possible transmission of antimicrobial resistance determinants between wild meso-mammals, swine manure pits, and environmental sources on a broad scale in the Grand River watershed, and at a local scale-for the subset of samples collected on both swine farms and conservation areas in the previous wildlife study. Logistic regression models were used to assess potential associations between sampling source, location type (swine farm vs. conservation area), and the occurrence of select resistance genes and predicted plasmids. In total, 200 isolates from the following sources were included: water (n = 20), wildlife (n = 73), swine manure pit (n = 31), soil (n = 73), and dumpsters (n = 3). Several genes and plasmid incompatibility types were significantly more likely to be identified on swine farms compared to conservation areas. Conversely, internationally distributed sequence types (e.g., ST131), extended-spectrum beta-lactamase- and AmpC-producing E. coli were isolated in lower prevalences (<10%) and were almost exclusively identified in water sources, or in raccoon and soil isolates obtained from conservation areas. Differences in the odds of detecting resistance genes and predicted plasmids among various sources and location types suggest different primary sources for individual AMR determinants, but, broadly, our findings suggest that raccoons, skunks and opossums in this region may be exposed to AMR pollution via water and agricultural sources, as well as anthropogenic sources in conservation areas.

A Clostridioides difficile surveillance study of Canadian retail meat samples from 2016-2018.

In this study, we isolated and molecularly characterized 10 (1.6%) C. difficile isolates from 644 commercially available raw meat samples. Molecular typing by PFGE and ribotyping revealed NAP and ribotypes commonly associated with human clinical cases, suggesting retail meat could be a possible source of transmission warranting further investigation.

Rural Raccoons (Procyon lotor) Not Likely to Be a Major Driver of Antimicrobial Resistant Human Salmonella Cases in Southern Ontario, Canada: A One Health Epidemiological Assessment Using Whole-Genome Sequence Data.

Non-typhoidal Salmonella infections represent a substantial burden of illness in humans, and the increasing prevalence of antimicrobial resistance among these infections is a growing concern. Using a combination of Salmonella isolate short-read whole-genome sequence data from select human cases, raccoons, livestock and environmental sources, and an epidemiological framework, our objective was to determine if there was evidence for potential transmission of Salmonella and associated antimicrobial resistance determinants between these different sources in the Grand River watershed in Ontario, Canada. Logistic regression models were used to assess the potential associations between source type and the presence of select resistance genes and plasmid incompatibility types. A total of 608 isolates were obtained from the following sources: humans (n = 58), raccoons (n = 92), livestock (n = 329), and environmental samples (n = 129). Resistance genes of public health importance, including bla CMY-2, were identified in humans, livestock, and environmental sources, but not in raccoons. Most resistance genes analyzed were significantly more likely to be identified in livestock and/or human isolates than in raccoon isolates. Based on a 3,002-loci core genome multi-locus sequence typing (cgMLST) scheme, human Salmonella isolates were often more similar to isolates from livestock and environmental sources, than with those from raccoons. Rare instances of serovars S. Heidelberg and S. Enteritidis in raccoons likely represent incidental infections and highlight possible acquisition and dissemination of predominantly poultry-associated Salmonella by raccoons within these ecosystems. Raccoon-predominant serovars were either not identified among human isolates (S. Agona, S. Thompson) or differed by more than 350 cgMLST loci (S. Newport). Collectively, our findings suggest that the rural population of raccoons on swine farms in the Grand River watershed are unlikely to be major contributors to antimicrobial resistant human Salmonella cases in this region.

Correlation between Phenotypic and In Silico Detection of Antimicrobial Resistance in Salmonella enterica in Canada Using Staramr.

Whole genome sequencing (WGS) of Salmonella supports both molecular typing and detection of antimicrobial resistance (AMR). Here, we evaluated the correlation between phenotypic antimicrobial susceptibility testing (AST) and in silico prediction of AMR from WGS in Salmonella enterica (n = 1321) isolated from human infections in Canada. Phenotypic AMR results from broth microdilution testing were used as the gold standard. To facilitate high-throughput prediction of AMR from genome assemblies, we created a tool called Staramr, which incorporates the ResFinder and PointFinder databases and a custom gene-drug key for antibiogram prediction. Overall, there was 99% concordance between phenotypic and genotypic detection of categorical resistance for 14 antimicrobials in 1321 isolates (18,305 of 18,494 results in agreement). We observed an average sensitivity of 91.2% (range 80.5-100%), a specificity of 99.7% (98.6-100%), a positive predictive value of 95.4% (68.2-100%), and a negative predictive value of 99.1% (95.6-100%). The positive predictive value of gentamicin was 68%, due to seven isolates that carried aac(3)-IVa, which conferred MICs just below the breakpoint of resistance. Genetic mechanisms of resistance in these 1321 isolates included 64 unique acquired alleles and mutations in three chromosomal genes. In general, in silico prediction of AMR in Salmonella was reliable compared to the gold standard of broth microdilution. WGS can provide higher-resolution data on the epidemiology of resistance mechanisms and the emergence of new resistance alleles.

Overview of Canada's Antimicrobial Resistance Network (AMRNet): A data-driven One Health approach to antimicrobial resistance surveillance.

The Antimicrobial Resistance Network (AMRNet) is a laboratory-based antimicrobial resistance (AMR) surveillance system under development at the Public Health Agency of Canada's (PHAC's) National Microbiology Laboratory. The AMRNet surveillance system captures information on antimicrobial susceptibility testing from clinical and veterinary laboratories including both public and private facilities. In the future, the AMRNet system will also capture relevant data from existing PHAC surveillance systems for AMR including the Canadian Integrated Program for Antimicrobial Resistance Surveillance, the Canadian Nosocomial Infection Surveillance Program and the Enhanced Surveillance of Antimicrobial-Resistant Gonorrhea program, and contribute to the Canadian Antimicrobial Resistance Surveillance System. AMRNet's integrated "One Health" approach will allow health professionals and researchers to take a multi-dimensional perspective of AMR in both human and animal health in Canada and will make Canada a leader in AMR surveillance. AMRNet is a collaboration between PHAC, provincial and territorial public health organizations as well as clinical and veterinary laboratories across the country. As part of a phased rollout, AMRNet is now collecting human clinical data from three provinces, from both inpatients and outpatients. Ultimately, AMRNet aims to capture all antimicrobial susceptibility testing results from all bacterial and fungal pathogens across Canada. This article describes the AMRNet surveillance system, including program objectives, system structure and the data collected. The integration of human and animal data in AMRNet will inform One Health responses to AMR issues. The capacity to collect and to disseminate data to stakeholders in real time is a critical step to addressing emerging AMR issues in Canada.

Using whole-genome sequence data to examine the epidemiology of Salmonella, Escherichia coli and associated antimicrobial resistance in raccoons (Procyon lotor), swine manure pits, and soil samples on swine farms in southern Ontario, Canada.

To better understand the contribution of wildlife to the dissemination of Salmonella and antimicrobial resistance in Salmonella and Escherichia coli, we examined whole-genome sequence data from Salmonella and E. coli isolates collected from raccoons (Procyon lotor) and environmental sources on farms in southern Ontario. All Salmonella and phenotypically resistant E. coli collected from raccoons, soil, and manure pits on five swine farms as part of a previous study were included. We assessed for evidence of potential transmission of these organisms between different sources and farms utilizing a combination of population structure assessments (using core-genome multi-locus sequence typing), direct comparisons of multi-drug resistant isolates, and epidemiological modeling of antimicrobial resistance (AMR) genes and plasmid incompatibility (Inc) types. Univariable logistic regression models were fit to assess the impact of source type, farm location, and sampling year on the occurrence of select resistance genes and Inc types. A total of 159 Salmonella and 96 resistant E. coli isolates were included. A diversity of Salmonella serovars and sequence types were identified, and, in some cases, we found similar or identical Salmonella isolates and resistance genes between raccoons, soil, and swine manure pits. Certain Inc types and resistance genes associated with source type were consistently more likely to be identified in isolates from raccoons than swine manure pits, suggesting that manure pits are not likely a primary source of those particular resistance determinants for raccoons. Overall, our data suggest that transmission of Salmonella and AMR determinants between raccoons and swine manure pits is uncommon, but soil-raccoon transmission appears to be occurring frequently. More comprehensive sampling of farms, and assessment of farms with other livestock species, as well as additional environmental sources (e.g., rivers) may help to further elucidate the movement of resistance genes between these various sources.

A One-Health Genomic Investigation of Gentamicin Resistance in Salmonella from Human and Chicken Sources in Canada, 2014 to 2017.

We investigated whether the increased prevalence of gentamicin resistance in Salmonella from human infections was related to a similar increased prevalence in isolates from broiler chickens and whether this increase may have been due to coselection from use of lincomycin-spectinomycin in chickens on farms. Whole-genome sequencing was performed on gentamicin-resistant (Genr) Salmonella isolates from human and chicken sources collected from 2014 to 2017 by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). We determined the genomic relatedness of strains and characterized resistance genes and plasmids. From 2014 to 2017, 247 isolates of Genr Salmonella were identified by CIPARS: 188 were from humans, and 59 were from chicken sources (26 from live animals on farm and 33 from retail meat). The five most common Genr serovars were Salmonella enterica serovars Heidelberg (n = 93; 31.5%), 4,[5],12:i:- (n = 42; 14.2%), Kentucky (n = 37; 12.5%), Infantis (n = 33; 11.2%), and Typhimurium (n = 23; 7.8%). Phylogenomic analysis revealed that for S. Heidelberg and S. Infantis, there were closely related isolates from human and chicken sources. In both sources, resistance to gentamicin and spectinomycin was most frequently conferred by aac(3)-VIa and ant(3'')-Ia, respectively. Plasmid closure confirmed linkages of gentamicin and spectinomycin resistance genes and revealed instances of similar plasmids from both sources. Gentamicin and spectinomycin resistance genes were linked on the same plasmids, and some plasmids and isolates from humans and chickens were genetically similar, suggesting that the use of lincomycin-spectinomycin in chickens may be selecting for gentamicin-resistant Salmonella in broiler chickens and that these resistant strains may be acquired by humans.

Evaluation of selective media in antimicrobial surveillance programs capturing broad-spectrum ß-lactamase producing Escherichia coli from chickens at slaughter.

Antimicrobial resistance surveillance targeting agricultural animals is practiced in many countries but does not often include media selective for cephalosporin resistance. Here, we compared the frequency of recovery of resistant Escherichia coli using selective and non-selective media from the cecal contents of 116 chickens collected by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). Third generation cephalosporin resistance was detected in 24 samples including 12, 10, and 2 on selective, non-selective, and both media, respectively. Isolates producing the CTX-M-1 ESBL were grown from 11 samples, 10 on selective medium only. Our results suggest that current surveillance approaches underestimate the true prevalence of resistance to critically important antimicrobials.

Évaluation de milieux sélectifs dans des programmes de surveillance antimicrobienne isolant Escherichia coli produisant des ß-lactamases à large spectre provenant de poulets à l'abattage. La surveillance de la résistance aux antimicrobiens ciblant les animaux d'élevage est pratiquée dans de nombreux pays mais n'inclut pas souvent les milieux sélectifs pour la résistance aux céphalosporines. Ici, nous avons comparé la fréquence d'isolement d'Escherichia coli résistants à l'aide de milieux sélectifs et non sélectifs à partir du contenu caecal de 116 poulets collectés dans le cadre du Programme intégré canadien de surveillance de la résistance aux antimicrobiens (PICRA). Une résistance aux céphalosporines de troisième génération a été détectée dans 24 échantillons dont 12, 10 et 2 sur des milieux sélectifs, non sélectifs et les deux, respectivement. Les isolats produisant les BLSE CTX-M-1 ont été cultivés à partir de 11 échantillons, 10 sur un milieu sélectif uniquement. Nos résultats suggèrent que les approches de surveillance actuelles sous-estiment la prévalence réelle de la résistance aux antimicrobiens d'importance critique.(Traduit par Dr Serge Messier).

Choosing which metrics to use when reporting antimicrobial use information to veterinarians in the Canadian swine industry.

The objective of this study was to evaluate preferences for various metrics and denominators among Canadian swine veterinarians, in order to improve reporting of antimicrobial use (AMU) information to these stakeholders and to facilitate enhanced stewardship decisions. An online survey was made available to swine veterinarians across Canada; 12 responses (estimated response rate 17.6%) were submitted and analyzed. Responses represented veterinarians from every major pig-producing province and from a range of year of graduation from veterinary college. Participants self-evaluated their understanding of dose-based metrics as higher than weight- and frequency-based metrics and interpreted most results of AMU analyses correctly. Participants preferred dose-based metrics over others, and had various objectives for AMU information, including improving AMU on their clients' farms and enabling comparisons with other farms. The results are useful to those making decisions about which AMU metrics to use in reports targeted to swine veterinarians.

Choix des paramètres à utiliser lors de la communication d'informations sur l'utilisation des antimicrobiens aux vétérinaires de l'industrie porcine canadienne. L'objectif de la présente étude était d'évaluer les préférences pour divers paramètres et dénominateurs chez les vétérinaires porcins canadiens, afin d'améliorer la déclaration de l'information sur l'utilisation d'antimicrobiens (UMA) à ces intervenants et de faciliter des décisions de gérance améliorées. Un sondage en ligne a été mis à la disposition des vétérinaires porcins partout au Canada; 12 réponses (taux de réponse estimé à 17,6 %) ont été soumises et analysées. Les réponses représentaient des vétérinaires de toutes les grandes provinces productrices de porcs et d'une gamme d'années d'obtention du diplôme d'un collège vétérinaire. Les participants ont auto-évalué leur compréhension des mesures basées sur la dose comme étant supérieure aux mesures basées sur le poids et la fréquence et ont interprété correctement la plupart des résultats des analyses UMA. Les participants préféraient les mesures basées sur la dose aux autres, et avaient divers objectifs pour l'information sur l'UMA, notamment l'amélioration de l'UMA dans les fermes de leurs clients et la possibilité de comparer avec d'autres fermes. Les résultats sont utiles à ceux qui prennent des décisions sur les paramètres d'UMA à utiliser dans les rapports destinés aux vétérinaires porcins.(Traduit par Dr Serge Messier).

Antimicrobial resistance and recovery of Salmonella, Campylobacter, and Escherichia coli from chicken egg layer flocks in Canadian sentinel surveillance sites using 2 types of sample matrices.

Eggs are important to the diet of Canadians. This product is one of the supply-managed commodities in Canada, but unlike other commodities, where food safety risks are extensively explored and reported, information on the prevalence of enteric organisms (e.g., Salmonella, Campylobacter) and antimicrobial resistance (AMR) in layers in Canada are limited. This study was conducted to determine the prevalence of select bacteria and the associated AMR patterns in layer flocks using 2 sample matrices. Farms were located within FoodNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance sentinel sites (SS). Fecal samples (Ontario: ONSS1a, ONSS1b) and environmental sponge swabs (British Columbia: BCSS2a) were collected. Salmonella prevalence was 29% and 8% in ONSS1a and ONSS1b, respectively, and 7% in BCSS2a. S. Kentucky and S. Livingstone were the most frequently isolated serovars and no S. Enteritidis was detected. Campylobacter was not detected in the BC sponge swabs but was isolated from 89% and 53% of Ontario fecal samples (ONSS1a and ONSS1b, respectively). Seven C. jejuni from Ontario were ciprofloxacin-resistant. Escherichia coli prevalence was high in both sample types (98%). Overall, tetracycline resistance among E. coli ranged from 26% to 69%. Resistance to ceftiofur (n = 2 isolates) and gentamicin (n = 2) was relatively low. There were diverse resistance patterns (excludes susceptible isolates) observed among E. coli in Ontario (10 patterns) and British Columbia (14 patterns). This study revealed that fecal samples are more informative for farm-level monitoring of pathogen and AMR prevalence. Without further validation, sponge swabs are limited in their utility for Campylobacter detection and thus, for public health surveillance.

Les oeufs sont importants pour l'alimentation des Canadiens. Ce produit est l'un des produits soumis à la gestion de l'offre au Canada, mais contrairement à d'autres produits, où les risques pour la salubrité des aliments sont largement étudiés et signalés, des informations sur la prévalence des organismes entériques (p. ex. Salmonella, Campylobacter) et la résistance aux antimicrobiens (RAM) chez les pondeuses au Canada sont limitées. Cette étude a été menée pour déterminer la prévalence de certaines bactéries et les patrons de résistance aux antimicrobiens associés dans les troupeaux de pondeuses en utilisant deux matrices d'échantillons. Les fermes étaient situées au sein de FoodNet Canada et des sites sentinelles (SS) du Programme intégré canadien de surveillance de la résistance aux antimicrobiens. Des échantillons de matières fécales (Ontario : ONSS1a, ONSS1b) et des éponges environnementales (Colombie-Britannique : BCSS2a) ont été prélevés. La prévalence de Salmonella était de 29 % et 8 % pour ONSS1a et ONSS1b, respectivement, et de 7 % pour BCSS2a. Salmonella Kentucky et S. Livingstone étaient les sérotypes les plus fréquemment isolés et aucun S. Enteritidis n'a été détecté. Campylobacter n'a pas été détecté dans les éponges de la Colombie-Britannique, mais a été isolé de 89 % et 53 % des échantillons de matières fécales de l'Ontario (ONSS1a et ONSS1b, respectivement). Sept C. jejuni de l'Ontario étaient résistants à la ciprofloxacine. La prévalence d'Escherichia coli était élevée dans les deux types d'échantillons (98 %). Dans l'ensemble, la résistance à la tétracycline chez E. coli variait de 26 % à 69 %. La résistance au ceftiofur (n = 2 isolats) et à la gentamicine (n = 2) était relativement faible. Divers profils de résistance (à l'exclusion des isolats sensibles) ont été observés chez E. coli en Ontario (10 profils) et en Colombie-Britannique (14 profils). Cette étude a révélé que les échantillons fécaux sont plus informatifs pour la surveillance au niveau de la ferme de la prévalence des agents pathogènes et de la résistance aux antimicrobiens. Sans validation supplémentaire, les éponge sont limitées dans leur utilité pour la détection de Campylobacter et donc pour la surveillance en santé publique.(Traduit par Docteur Serge Messier).

Antimicrobial Use Indices-The Value of Reporting Antimicrobial Use in Multiple Ways Using Data From Canadian Broiler Chicken and Turkey Farms.

We have previously described the importance of using multiple indicators for reporting national farm-level antimicrobial use (AMU) information, but the distribution of flock-level AMU and how these indicators relate to each other has not yet been fully explored. Using farm-level surveillance data (2013-2019), for broiler chickens (n = 947 flocks) and turkeys (n = 427), this study aims to (1) characterize flock-level AMU and identify high users, (2) identify appropriate AMU indicators and biomass denominator [population correction unit (PCU) vs. kg weight at pre-slaughter], and (3) make recommendations on the application to veterinarian-producer and national-level reporting. Diverse AMU patterns were identified in broiler chickens (156 patterns) and turkeys (68 patterns); of these, bacitracin, reported by 25% of broiler chicken and 19% of turkey producers, was the most frequently occurring pattern. Depending on the indicator chosen, variations in reported quantity of use, temporal trends and relative ranking of the antimicrobials changed. Quantitative AMU analysis yielded the following results for broiler chickens: mean 134 mg/PCU; 507 number (n) of Canadian (CA) defined daily doses (DDDvet) per 1,000 chicken-days and 18 nDDDvetCA/PCU. Analysis in turkey flocks yielded the following: mean 64 mg/PCU, 99 nDDDvetCA/1,000 turkey-days at risk and 9 nDDDvetCA/PCU. Flocks were categorized based on the percentiles of the mg/PCU distribution: "medium" to "low" users (≤75th percentile) and "high" users (>75th percentile). The odds of being a high user in both broiler chickens and turkeys were significantly increased: if water medications were used, and if trimethoprim-sulfonamides, bacitracins, and tetracyclines were used. Pairwise correlation analysis showed moderate correlation between mg/PCU and the nDDDvetCA/1,000 animal days at risk and between mg/PCU and nDDDvetCA/PCU. Significantly high correlation between nDDDvetCA/1,000 animal days at risk and nDDDvetCA/PCU was observed, suggestive that either of these could be used for routine monitoring of trends in AMU. One source of discrepancy between the indicators was the antimicrobial. Understanding the choice of parameter input and effects on reporting trends in AMU will inform surveillance reporting best practices to help industry understand the impacts of their AMU reduction strategies and to best communicate the information to veterinarians, their producers, and other stakeholders.