|KARCHER, DARRIN - Michigan State University|
Submitted to: Southern Poultry Science Society Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/25/2013
Publication Date: 1/27/2014
Citation: Cray, P.J., Jones, D.R., Karcher, D. 2014. Antimicrobial resistance in aviary and enriched housing environments. Southern Poultry Science Society Meeting Abstracts. January 27-28, 2014. Atlanta, Georgia.
Technical Abstract: Antimicrobial resistance continues to be a global problem. The purpose of this study was to elucidate the emergence of resistance in populations of bacteria over time in layers in different housing systems. Houses were newly constructed and tested for pathogens prior to placement of hens. Hens were placed in aviary or enriched systems and samples (feed, water, and environmental which consisted of multiple nest box, belt, scraper, and scratch pad swabs) were collected and cultured for Salmonella and Escherichia coli using standard laboratory methods. All isolates were tested for susceptibility to a panel of antimicrobials using the NARMS methods. Prior to placement of the birds only 2 feed samples were positive; both for S. Mbandaka and E. coli. Approximately 10 weeks later, 13/295 samples from the enriched system were positive for S. Altona or Kentucky while 2/99 from the aviary system were positive for S. Altona. Ten and 20 weeks later 11/123 and 14/122 from the enriched environment continued to be positive for either Altona or Kentucky while 1/25 at each sampling from the aviary system was positive for Altona. No Salmonella isolates were resistant to any antimicrobials tested. Both initial feed samples for E. coli were not resistant to any antimicrobials tested. At 10 weeks, 182/295 and 99/99 samples were positive for E. coli from the enriched and aviary systems, respectively. E. coli from the enriched system were susceptible to chloramphenicol, ciprofloxacin and kanamycin. At least 3 or more (range 3-28) isolates were resistant to all other antimicrobials tested including nalidixic acid (n=4). Conversely, from the aviary system, resistance was only observed to gentamicin, streptomycin, sulfisoxizole, tetracycline, and nalidixic acid; however, more isolates were resistant to these antimicrobials (range 6-36) and 26 isolates were resistant to nalidixic acid. The environment, but not the feed, was negative prior to placement of the hens. Mbandaka was only isolated from feed and not the environment. Kentucky has only been isolated from the enriched system. E. coli isolates from the aviary system are resistant to fewer antimicrobials but the prevalence of resistance is higher to some antimicrobials than those from the enriched system. This study shows a dynamic that has not been described previously. Additional collections will continue to elucidate the transmission of Salmonella as well as antimicrobial resistance attributes within a production system.