Genetic Characterization of AmpC and Extended-Spectrum Beta-Lactamase Phenotypes in Escherichia coli and Salmonella From Alberta Broiler Chickens.

Horizontal gene transfer is an important mechanism which facilitates bacterial populations in overcoming antimicrobial treatment. In this study, a total of 120 Escherichia coli and 62 Salmonella enterica subsp. enterica isolates were isolated from broiler chicken farms in Alberta. Fourteen serovars were identified among Salmonella isolates. Thirty one percent of E. coli isolates (37/120) were multiclass drug resistant (resistant to ≥ 3 drug classes), while only about 16% of Salmonella isolates (10/62) were multiclass drug resistant. Among those, eight E. coli isolates had an AmpC-type phenotype, and one Salmonella isolate had an extended-spectrum beta-lactamase (ESBL)-type beta-lactamase phenotype. We identified both AmpC-type (blaCMY-2) and ESBL-type (blaTEM) genes in both E. coli and Salmonella isolates. Plasmids from eight of nine E. coli and Salmonella isolates were transferred to recipient strain E. coli J53 through conjugation. Transferable plasmids in the eight E. coli and Salmonella isolates were also transferred into a lab-made sodium azide-resistant Salmonella recipient through conjugation. The class 1 integrase gene, int1, was detected on plasmids from two E. coli isolates. Further investigation of class 1 integron cassette regions revealed the presence of an aadA gene encoding streptomycin 3''-adenylyltransferase, an aadA1a/aadA2 gene encoding aminoglycoside 3''-O-adenyltransferase, and a putative adenylyltransferase gene. This study provides some insight into potential horizontal gene transfer events of antimicrobial resistance genes between E. coli and Salmonella in broiler chicken production.

Salmonella spp. prevalence and antimicrobial resistance in broiler chicken and turkey flocks in Canada from 2013 to 2018.

Salmonella infections are a major human health concern. In the elderly and immunocompromised, infections can be life-threatening and may require antibiotic therapy. Where antibiotic therapy is required, antimicrobials of choice include fluoroquinolones and extended-spectrum cephalosporins (ESC). The aim of this study is to utilize data from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) to compare the prevalence of Salmonella serovars between broiler chicken and turkey flocks across Canada, and to gain an understanding of the prevalence of resistance to antimicrobials categorized as important to human health. There were 1,596 Salmonella isolates obtained from 514 broiler chicken flocks, and 659 Salmonella isolates obtained from 217 turkey flocks (2013-2018). All isolates were obtained from pooled faecal samples. Among broiler chicken flocks, the top three serovars were Kentucky (n = 573, 36%), Enteritidis (n = 314, 20%) and Heidelberg (n = 127, 8%). Resistance to ceftriaxone among Salmonella ser. Kentucky decreased from 27% in 2013 to 22% in 2018. There was no resistance among Salmonella ser. Enteritidis reported until 2018 when one isolate from British Columbia was resistant to ampicillin, streptomycin, sulphisoxazole and tetracycline. Salmonella ser. Heidelberg resistance to ceftriaxone decreased from 19% in 2013 to 14% in 2018. Among turkey flocks the top three serovars were Uganda (n = 109, 16.5%), Hadar (n = 85, 12%) and Muenchen (n = 66, 10%). No isolates of Salmonella ser. Uganda or Salmonella ser. Muenchen were resistant to any ß-lactams. Salmonella ser. Hadar (34/81, 42%) exhibited resistance to ampicillin. There was no resistance to quinolones among turkey isolates. Emerging resistance among Salmonella ser. Enteritidis, and resistance to ß-lactams and fluoroquinolones among Salmonella ser. Kentucky from broilers are cause for concern as these classes of antimicrobials are important for treatment of salmonellosis.

A cross-sectional study of the prevalence factors associated with fluoroquinolone resistant Campylobacter jejuni in broiler flocks in Canada.

Campylobacter infections in humans are usually self-limiting; however, antibiotic intervention may be necessary in the case of severe infection. Fluoroquinolones are often the drug of choice for treatment of campylobacteriosis; however, resistance to these drugs can develop rapidly, complicating treatment protocols. Increasing resistance to fluoroquinolones in human infections has coincided with approval of use of fluoroquinolones in animals, therefore, isolation of fluoroquinolone resistant (FQr) Campylobacter in broiler flocks is concerning. This cross-sectional study utilized data collected from 2013-2018 by the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) on-farm surveillance program to investigate prevalence factors associated with the isolation of FQr C. jejuni from broiler faecal samples. Mixed effects logistic regression models accounting for clustering of flocks within hatcheries, with and without a fixed effect for the presence of flock level tetracycline resistance were used to assess prevalence factors among 536 C. jejuni isolates from 158 flocks. Both models indicated that the type of bird used (Ross versus Cobb or mixed), the use of virginiamycin as a feed additive, the use of traps to control rodent populations in the barn, and the total number of birds in the barn were significant prevalence factors for increased FQr C. jejuni in a flock. In the model where flock level tetracycline resistance was included as a fixed effect, the odds of FQr C. jejuni increased by 16 (95% CI: 3.74, 68), and the magnitude of the effect of each of the identified prevalence factors was larger. Both models indicated that methods of disinfection of water lines between production cycles is important, with the use of chlorine being protective in the model where tetracycline resistance was included as a fixed effect, and the use of hydrogen peroxide being a risk factor in the model where tetracycline resistance was not included as a fixed effect. The use of hot water to wash the barn between production cycles was also a significant protective factor in the model where tetracycline resistance was not included as a fixed effect. These results indicate that biosecurity and sanitation procedures play a role in the dissemination of FQr C. jejuni in broiler flocks. Future analysis should seek to understand the effect of different disinfectant products on the isolation of FQr C. jejuni. Gaining a better understanding of the management of these critical practices may allow for the reduction of this enteric pathogen in broiler flocks in Canada.

Small Poultry Flocks in Alberta: Demographics and Practices.

The distribution, composition, and management characteristics of small "backyard" poultry flocks may have important implications in the spread of both avian diseases and zoonoses of public health concern. Although the prevalence of small poultry flocks has increased in Alberta, Canada, in recent years, there is minimal demographic information available for these populations. To gain initial epidemiologic insight into this growing population and potential areas of risk, a survey was conducted to characterize the sector. Information on flock demographics and bird health, as well as production and biosecurity practices, were gathered and analyzed from 206 surveys, representing respondents from 43 counties. These results revealed great diversity of both owners and flocks, characterized by wide variations in flock sizes and composition. Laying hens were the most commonly reported type of bird (93.4%), followed by ducks and geese (35.3%), turkeys, (33.8%), and broiler chickens (33.1%). Notably, 58.1% of owners reported having more than one type of bird in their flock, with many owners never, or only sometimes, separating flocks based on species or purpose. Personal consumption (81.8%) and sale of eggs (48.2%) were the most frequently cited purposes for owning a flock. Our findings suggest that owners in Alberta are predominantly new to production; most (73.1%) have kept birds for less than 5 yr and 25.6% for less than 1 yr. Flock health parameters revealed inconsistent use of medical interventions, such as vaccinations, treatments, and veterinary consultation. Data on the sourcing, housing, and movement of birds, as well as movement of people and visitors, reveal substantial potential for contact to occur directly and indirectly between flocks and humans. Additionally, basic husbandry and biosecurity practices were found to be inconsistent and often inadequate, highlighting important gaps and opportunities to improve the health of Alberta's small poultry flocks and mitigate risks to public health. These quantitative and qualitative results provide a baseline characterization of the sector and identify risks and challenges that may serve to inform the development and delivery of future study and interventions.

Evaluation of antimicrobial resistance profiles of escherichia coli isolates of broiler chickens at slaughter in Alberta, Canada.

This study was conducted to investigate antimicrobial resistance profiles of Escherichia coli isolates from broiler chickens in Alberta, Canada. Cecal contents of broiler chickens from 24 flocks were collected at slaughter between January and March 2005 for culture and antimicrobial susceptibility testing against a panel of 15 antimicrobials using a broth microdilution technique. Of 600 E. coli isolates tested, 475 (79.2%) were resistant to one or more antimicrobials, 326 (54.3%) were resistant to three or more antimicrobials, 65 (10.8%) were resistant to five or more antimicrobials, and 15 (2.5%) were resistant to seven or more antimicrobials. The most common resistance was to tetracycline (69.2%), followed by streptomycin (48.2%), kanamycin (40.3%), and sulfisoxazole (38.0%). None of the E. coli isolates were resistant to amikacin, ceftriaxone, or ciprofloxacin. Of the isolates that were resistant to two or more antimicrobials, the most common multidrug resistance patterns were streptomycinte-tracycline (44.0%), streptomycin-sulfisoxazole-tetracycline (30.7%), and kanamycin-streptomycin-sulfisoxazole-tetracycline (23.5%). Resistance to tetracycline and kanamycin (odds ratio = 46.7, P = 0.0001) was highly associated, followed by resistance to streptomycin and sulfisoxazole (odds ratio = 12.0, P = 0.0001), and streptomycin and tetracycline (odds ratio = 10.3, P = 0.0001). The flock level prevalence of resistance varied from 16.7% for chloramphenicol to 100.0% for ampicillin, streptomycin, sulfisoxazole, and tetracycline. The results of this study provided baseline information on antimicrobial susceptibility of E. coli isolates of broiler chickens at slaughter in Alberta, which can serve as a bench mark for future research.