TY - JOUR
T1 - Lower prevalence of antibiotic-resistant Salmonella on large-scale U.S. conventional poultry farms that transitioned to organic practices
AU - Sapkota, Amy R.
AU - Kinney, Erinna L.
AU - George, Ashish
AU - Hulet, R. Michael
AU - Cruz-Cano, Raul
AU - Schwab, Kellogg J.
AU - Zhang, Guangyu
AU - Joseph, Sam W.
N1 - Funding Information:
We thank the poultry growers for providing access to their farms, and Denny Burns and Terry Cravener for sampling the poultry houses. We also thank Andrew Kim, Norman Wang, Zenas Chang and Jia Wang for assisting with laboratory and statistical analyses. This work was supported by the Center for a Livable Future, Johns Hopkins Bloomberg School of Public Health .
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/4/1
Y1 - 2014/4/1
N2 - As a result of the widespread use of antibiotics in large-scale U.S. poultry production, a significant proportion of Salmonella strains recovered from conventional poultry farms and retail poultry products express antibiotic resistance. We evaluated whether large-scale poultry farms that transitioned from conventional to organic practices and discontinued antibiotic use were characterized by differences in the prevalence of antibiotic-resistant Salmonella compared to farms that maintained conventional practices. We collected poultry litter, water and feed samples from 10 newly organic and 10 conventional poultry houses. Samples were analyzed for Salmonella using standard enrichment methods. Isolates were confirmed using standard biochemical tests and the Vitek®2 Compact System. Antimicrobial susceptibility testing was performed by Sensititre® microbroth dilution. Data were analyzed using Fisher's exact test and generalized linear mixed models. We detected Salmonella in both conventional and newly organic poultry houses. Salmonella Kentucky was the predominant serovar identified, followed by S. Orion, S. Enteritidis, S. Gostrup and S. Infantis. Among S. Kentucky isolates (n = 41), percent resistance was statistically significantly lower among isolates recovered from newly organic versus conventional poultry houses for: amoxicillin-clavulanate ( p= 0.049), ampicillin ( p= 0.042), cefoxitin ( p= 0.042), ceftiofur ( p= 0.043) and ceftriaxone ( p= 0.042). Percent multidrug resistance (resistance to ≥. 3 antimicrobial classes) was also statistically significantly lower among S. Kentucky isolates recovered from newly organic poultry houses (6%) compared to those recovered from conventional houses (44%) ( p= 0.015). To our knowledge, these are the first U.S. data to show immediate, on-farm changes in the prevalence of antibiotic-resistant Salmonella when antibiotics are voluntarily withdrawn from large-scale poultry facilities in the United States.
AB - As a result of the widespread use of antibiotics in large-scale U.S. poultry production, a significant proportion of Salmonella strains recovered from conventional poultry farms and retail poultry products express antibiotic resistance. We evaluated whether large-scale poultry farms that transitioned from conventional to organic practices and discontinued antibiotic use were characterized by differences in the prevalence of antibiotic-resistant Salmonella compared to farms that maintained conventional practices. We collected poultry litter, water and feed samples from 10 newly organic and 10 conventional poultry houses. Samples were analyzed for Salmonella using standard enrichment methods. Isolates were confirmed using standard biochemical tests and the Vitek®2 Compact System. Antimicrobial susceptibility testing was performed by Sensititre® microbroth dilution. Data were analyzed using Fisher's exact test and generalized linear mixed models. We detected Salmonella in both conventional and newly organic poultry houses. Salmonella Kentucky was the predominant serovar identified, followed by S. Orion, S. Enteritidis, S. Gostrup and S. Infantis. Among S. Kentucky isolates (n = 41), percent resistance was statistically significantly lower among isolates recovered from newly organic versus conventional poultry houses for: amoxicillin-clavulanate ( p= 0.049), ampicillin ( p= 0.042), cefoxitin ( p= 0.042), ceftiofur ( p= 0.043) and ceftriaxone ( p= 0.042). Percent multidrug resistance (resistance to ≥. 3 antimicrobial classes) was also statistically significantly lower among S. Kentucky isolates recovered from newly organic poultry houses (6%) compared to those recovered from conventional houses (44%) ( p= 0.015). To our knowledge, these are the first U.S. data to show immediate, on-farm changes in the prevalence of antibiotic-resistant Salmonella when antibiotics are voluntarily withdrawn from large-scale poultry facilities in the United States.
KW - Antibiotic-resistant bacteria
KW - Conventional poultry production
KW - Extended spectrum cephalosporin resistance
KW - Organic poultry production
KW - Salmonella
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U2 - 10.1016/j.scitotenv.2013.12.005
DO - 10.1016/j.scitotenv.2013.12.005
M3 - Article
C2 - 24486494
AN - SCOPUS:84893345410
SN - 0048-9697
VL - 476-477
SP - 387
EP - 392
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -