Comparison of Two Methods for the Recovery of Campylobacter from Chicken Carcasses

Abstract

Campylobacteriosis, one of the most common food-borne diseases in humans, is mainly caused by the consumption of chicken meat contaminated with Campylobacter. In this study, we examined the recovery rate of Campylobacter from carcass rinse using direct plating method and selective enrichment method. Campylobacter genotypes obtained from both methods were also determined using flaA-short variable region (flaA-SVR) sequencing. Results showed that Campylobacter recovery rates by the direct plating method and selective enrichment method were 40.00% and 46.86%, respectively. However, when a combination of the two methods was used, the recovery rate increased to 64.57%. For genetic characterization of Campylobacter, 9 flaA-SVR types were found by both methods. The most common allele types identified among Campylobacter isolates from these isolation methods were flaA-SVR allele 208, 769 and 783. High Simpson’s index of diversity (SID) was observed for both direct plating method (SID = 0.843) and selective enrichment method (SID = 0.820). Additionally, good strength of agreement between flaA-SVR types obtained from these two methods was noticed (Kappa = 0.629). In conclusion, this study reveals that the direct plating method may be used as an alternative method for Campylobacter isolation from chicken carcass rinse since the recovery rate and Campylobacter genotypes obtained from this method was quite similar to those obtained from the selective enrichment method. Moreover, the direct plating method is also simple, less labor-intensive and more cost-effective than the selective enrichment method.