Contamination of in crayfish for sale.

Crayfish () are economically important freshwater crustaceans. With the growth of the crayfish industry, the associated food-safety risks should be seriously considered. Although is commonly recognized as a halophilic foodborne pathogen associated with seafood, it has been found to be a major pathogen in crayfish-associated food poisoning cases. In this study, the contamination level in crayfish production-sale chain was investigated using crayfish and environmental samples collected from crayfish farms and markets. Serious contamination (detection rate of 66%) was found in the entire crayfish production-sale chain, while the contamination level of the market samples was extremely high (detection rate of 92%). The detection rate of crayfish surface was similar to that of whole crayfish, indicating that crayfish surface was important for contamination. The simulation experiments of crayfish for sale being contaminated by different sources were performed. All the contamination sources, containing positive tank, water, and crayfish, were found to be efficient to contaminate crayfish. The crayfish tank displayed the most significant contaminating role, while the water seemed to inhibit the contamination. The contamination extent of the crayfish increased with the number of cells the tank carried and the contact time of the crayfish and the tank, but decreased with the time that the crayfish were maintained in the water. It was also confirmed that the crayfish surface was more susceptible to contamination than the crayfish intestine. Furthermore, the adsorption of onto the crayfish shell was analyzed. Over 90% of the cells were adsorbed onto the crayfish shell in 6 h, indicating a significant adsorption effect between and the crayfish shell. In conclusion, within a water-free sale style, the fresh crayfish for sale in aquatic products markets uses its shell to capture cells from the abundant environments. The contamination in crayfish for sale exacerbates the crayfish-associated food-safety risk. This study sheds light on control and prevention in crayfish industry.