Prevalence of foodborne microorganisms in retail foods in Thailand

Abstract

Worldwide, foodborne illness is often associated with consumption of meats and poultry products sold at retail markets. A cross-sectional retail food study was conducted in Bangkok, Thailand to assess the prevalence of bacterial pathogens on retail food samples. Raw chicken, beef, pork, and chicken eggs were purchased from fresh markets and supermarkets and tested for Salmonella spp., Campylobacter spp., Arcobacter spp., and Enterococcus spp. Suspect bacterial pathogens were isolated by differential culture and Salmonella species were serotyped. A total of 200 samples were collected from 50 markets between May and August 2003. Of the 200 samples tested, 121 (61%) were positive for at least one Salmonella spp. serogroup. A total of 175 Salmonella spp. were isolated. The most common serotype was Salmonella Anatum, followed by S. Corvallis and S. Derby. Campylobacter spp. were found in 31 (15.5%) of 200 samples. C. jejuni was isolated from 15% of fresh market chicken samples and 35% of supermarket chicken samples. Arcobacter spp. were isolated from 42 (21%) samples; fresh market chicken had significantly higher A. butzleri contamination than supermarket chicken. The presence of Enterococcus spp., an indication of fecal contamination, was detected in 188 (94%) samples, including 100% of the beef and pork sources. Few studies have examined retail food contamination in Thailand. In particular, the high prevalence of samples with Arcobacter spp. warrants further study to determine pathogenicity.