Surveillance and Antimicrobial Resistance of Salmonella and Campylobacter in Poultry Products in Farmer, Organic and Conventional Markets

Introduction: Salmonella and Campylobacter are among the most frequently reported causative agents of foodborne illness in the US. They are often associated with poultry meat and other poultry products. Locally grown free-range pasture poultry and poultry products are mostly sold in farmer markets without any professional microbiological quality control. Therefore, it is important to understand the prevalence of these bacterial pathogens in poultry products in markets.

Purpose: Determination of the prevalence and antimicrobial resistance pattern of Salmonella and Campylobacter in poultry products in farmer and organic markets and comparison with the products available in conventional markets.

Methods: A total of 337 samples were collected and analyzed. Each of the samples was mixed vigorously at 1:9 (wt/vol) with buffered peptone water. Following enrichment in Luria-Bertani broth (for Salmonella) or Bolton Broth (for Campylobacter) supplemented both with 5% sheep blood, cultures were streaked out on Karmali or XLT-4 agar for the isolation of Salmonella and Campylobacter, respectively. Presumptive colonies were confirmed by biochemically and PCR analysis. Antimicrobial resistance was tested using the agar dilution method and χ² tests were used for statistical analysis. 

Results: Prevalence of Salmonella in poultry products from farmer, organic and conventional markets were significantly different (P = 0.0004), with rates of 6.7%, 35.9% and 17.9%, respectively. However, the antibiotic resistance of isolated Salmonella from these markets was not significantly different. For Campylobacter, their prevalence in poultry products from these three markets were significantly different (P = 0.029), with rates of 33.3%, 14.1%, and 28%, respectively. In addition, the antibiotic resistance of isolated Campylobacter from these markets was also significantly different (P < 0.0001) with rates of 10%, 18.2%, and 85.9%, respectively.

Significance: The results show higher prevalence of Salmonella in the product collected from organic markets whereas Campylobacter in farmer markets. Campylobacter isolates from conventional markets are comparatively more resistant to antibiotic.