Abstract: Campylobacter jejuni and Campylobacter coli contamination were investigated in the poultry industry chain in Zhejiang province and their characteristics of inactivation in the process of cold storage were described. Multiplex PCR was used for detecting the prevalence of C. jejuni and C. coli in poultry farms, slaughtering facilities and markets of Zhejiang province. Samples were collected as environmental swabs from farms and slaughtering facilities, meat from supermarket as well as wet markets. Simultaneously, two different models of best fit for mechanical characteristics of inactivation kinetics of C. jejuni and C. coli during the process of refrigeration of chicken meat were also evaluated by plate count method. The prevalence of C. jejuni was found to be 45.3% (n=182/402) and that of C. coli was 4.9% (n=20/402). The positive rate of C. jejuni and C. coli in poultry farms, slaughtering facilities and markets were 81.2%(65/80)and 0, 30.5% (48/157) and 5.1% (8/157), 41.8% (69/165) and 7.3% (12/165), respectively. Inactivation curves of C. jejuni and C. coli shared similar kinetics. During storage at 6 ℃ for 30 days, the lg cfu had decreased by 1.98 for C. jejuni and by 2.19 for C. coli. The decline in the number of bacteria for the first fourteen days was recorded to be at a faster rate as compared to the next 16 days. Comparison of Log-logistic model and Weibull model for inactivation kinetics revealed that the Log-logistic model gave a better inactivation curve for fitting of C. jejuni and C. coli.

Key words: poultry, Campylobacter jejuni, Campylobacter coli, inactivation kinetics, model