Serotypes, Antimicrobial Resistance Profiles, and Virulence Factors of Salmonella Isolates in Chinese Edible Frogs ( Hoplobatrachus rugulosus ) Collected from Wet Markets in Hong Kong.

Salmonella is an important agent of gastrointestinal disease in humans. While livestock, such as cattle, poultry, and pigs, are well-recognised animal reservoirs of Salmonella , there is a lack of data on Salmonella in edible frogs, even though frog meat is a popular food worldwide. In this study, 103 live edible Chinese frogs ( Hoplobatrachus rugulosus ) were collected from wet markets throughout Hong Kong. After euthanasia, faeces or cloacal swabs were examined for Salmonella . Overall, Salmonella spp. were isolated from 67 (65%, CI: 0.554-0.736) of the samples. The serotypes included S . Saintpaul (33%), S . Newport (24%), S . Bareilly (7%), S . Braenderup (4%), S . Hvittingfoss (4%), S . Stanley (10%), and S . Wandsworth (16%). Many isolates were phylogenetically related. A high number of genes encoding for resistance to clinically relevant antimicrobials, and a high number of virulence determinants, were identified. Antimicrobial susceptibility testing (AST) identified multidrug resistance (MDR) in 21% of the isolates. Resistance to ampicillin, ciprofloxacin, nalidixic acid, and tetracycline was common. These results demonstrate that a high percentage of live frogs sold for human consumption in wet markets are carriers of multidrug-resistant Salmonella . Public health recommendations for handling edible frogs should be considered, to mitigate the risk of Salmonella transmission to humans.
Competing Interests: The authors declare no conflict of interest.