In this study, we investigated Campylobacter prevalence in chicken fecal samples and cross-contamination of chicken carcass surface samples at a slaughterhouse, with an aim toward the production of Campylobacter-free chicken meat. Twenty-four broiler flocks comprising a total of 120 chickens were examined. C. jejuni were isolated in fecal samples from 34 chickens (28.3%) in 12 flocks, and C. jejuni and C. coli were from 5 chickens (4.2%) in a flock, respectively. A total of 13 Campylobacter-positive flocks and 11 Campylobacter-free flocks existed in this research. Immediately after all Campylobacter-free flocks had been slaughtered, no Campylobacter could be detected from the chicken carcass surfaces. However, all slaughtered flocks, including those that were initially Campylobacter-free, were later found to have been cross-contaminated by Campylobacter-positive flocks slaughtered on the same day. Our results indicate that preventing cross-contamination from Campylobacter-positive flocks is a crucial consideration for chicken slaughterhouse to produce Campylobacter-free chicken meat.
Culture on CHROMagarTM Orientation medium supplemented with egg yolk emulsion (2.5% EY-CHROM) for 24 hr at 35℃ was comparable to the standard plate count for total bacteria counts, and the medium distinguished Staphylococcus aureus, Escherichia coli and coliforms from other bacteria. For culture of fungi and yeast on 2.5% EY-CHROM, incubation at 25℃ was suitable. It was difficult to test bacteria including S. aureus, E. coli and coliforms, fungi and yeast on a single culture medium under the same culture conditions. However, It claims to facilitate and expedite the differentiation of some bacteria and total bacteria counts on the basis of different contrasted colony colors and hallo produced by chromogenic substrates and egg-yolk.
Cronobacter spp., formerly Enterobacter sakazakii, are regarded as pathogens that cause rare but severe cases of disease in neonates and infants, and several cases were linked to the consumption of contaminated powdered infant formula. There are very few reports regarding methods which can identify Cronobacter spp. rapidly and easily. Hence, we developed a new identification protocol that can distinguish seven species of Cronobacter by using genus-, species-specific PCR assays. In addition, this study revealed Franconibacter pulveris is a false-positive bacterium in ISO/TS 22964. As a result of validation tests, it was confirmed that the accurate identification of Cronobacter spp. was able to be achieved without misidentifying F. pulveris as Cronobacter by the protocol shown in this study.