Abstract:
We investigated the implied health benefits of retail chicken breast labeled as ‘‘organic’’ or ‘‘antibiotic-free’’
when compared to conventional products based on frequency of contamination by Salmonella spp., Campylobacter
spp., and coliform bacteria resistant to fluoroquinolones, extended-spectrum cephalosporins, or carbapenems.
We purchased 231 prepackaged chicken breasts from 99 grocery stores representing 17 retail chains
in Ohio, Michigan, and Pennsylvania from June to September 2012. Ninety-six (41.5%) packages were labeled
‘‘antibiotic free’’ and 40 (17.3%) were labeled ‘‘organic,’’ with the remaining 95 (41.1%) making neither label
claim. Salmonella were recovered from 56 (24.2%) packages, and the recovery rate was not different between
product types. Five percent of packages contained Salmonella carrying the extended-spectrum cephalosporin
resistance gene blaCMY-2, representing 21.4% of Salmonella isolates. Campylobacter spp. were recovered from
10.8% of packages, with observed recovery rates similar for the three product types. Using selective media, we
recovered Escherichia coli harboring blaCMY-2 from over half (53.7%) of packages, with similar recovery rates
for all product types. In addition, we recovered E. coli carrying blaCTX-M from 6.9% of packages, and E. coli
with QRDR mutations from 8.2% of packages. Fluoroquinolone-resistant E. coli recovered using selective
media were more common ( p < 0.05) in conventional (18.9%) compared to organic (0) and antibiotic-free
(2.1%) packages. Our results indicate that, regardless of product type, fresh retail chicken breast is commonly
contaminated with enteric pathogens associated with foodborne illness and commensal bacteria harboring genes
conferring resistance to critically important antimicrobial drugs.
