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Exponential growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 μg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 μg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P < 0.05) than in the normal broth (0 out of 58, 0%). Furthermore, the number of agar plates with non-Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P < 0.05) than in the normal broth (58 out of 58, 100%).

In this study, changes in the prevalence of Salmonella during the processing of broiler chicken carcasses were investigated. A total of 1040 fecal swabs and chicken carcasses samples were collected from 2 processing plants at the 4 stages of broiler processing, which included live birds in slaughter line, postevisceration/prewashing, postwashing/prechilling, and postchilling, respectively. The intraspecific biodiversity of the Salmonella isolates was determined using a DiversiLab automated repetitive sequence-based PCR (rep-PCR) system. In both plants, the prevalence of Salmonella increased considerably after evisceration (from 4.6% to 30.8%, P 0.05). The most frequent Salmonella serovar in plant A was Infantis (35.8%), followed by Enteritidis (26.2%) and Montevideo (15.0%), while Montevideo (43.6%) and Enteritidis (35.9%) were most prevalent in plant B. A difference in the rep-PCR banding pattern was found to be related to the processing plant origin and serovar rather than sampling point or sampling day, although there were some exceptional strains.

Exponential growth of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in Campylobacter media has become a common problem for the detection of Campylobacter in chicken meats. We investigated the minimum inhibitory concentration of 40 ESBL-producing E. coli isolates from meats obtained from various countries against antibacterial agents in Bolton broth (cefoperazone, vancomycin, and trimethoprim). All ESBL-producing E. coli strains were resistant to cefoperazone and vancomycin, whereas 50% of them were resistant to trimethoprim and grew in Bolton broth. We found that 20 μg/mL of rifampicin inhibited the growth of trimethoprim-resistant E. coli strains. Hence, we added 20 μg/mL of rifampicin to Bolton broth to improve the isolation of Campylobacter from chicken carcass rinses. The isolation rate of Campylobacter was significantly higher in the modified broth (44 out of 58, 75.9%, P0.05) than in the normal broth (0 out of 58, 0%). Furthermore, the number of agar plates with non-Campylobacter spp. was much lower after enrichment in the modified broth (4 out of 58, 6.9%, P0.05) than in the normal broth (58 out of 58, 100%).

In this study, changes in the prevalence of Salmonella during the processing of broiler chicken carcasses were investigated. A total of 1040 fecal swabs and chicken carcasses samples were collected from 2 processing plants at the 4 stages of broiler processing, which included live birds in slaughter line, postevisceration/prewashing, postwashing/prechilling, and postchilling, respectively. The intraspecific biodiversity of the Salmonella isolates was determined using a DiversiLab automated repetitive sequence-based PCR (rep-PCR) system. In both plants, the prevalence of Salmonella increased considerably after evisceration (from 4.6% to 30.8%, P0.05) and decreased after washing (from 30.8% to 25.4%, P0.05). However, the chilling step had little effect on Salmonella prevalence (from 25.4% to 22.7%, P0.05). The most frequent Salmonella serovar in plant A was Infantis (35.8%), followed by Enteritidis (26.2%) and Montevideo (15.0%), while Montevideo (43.6%) and Enteritidis (35.9%) were most prevalent in plant B. A difference in the rep-PCR banding pattern was found to be related to the processing plant origin and serovar rather than sampling point or sampling day, although there were some exceptional strains.