Monitoring the presence of enteric pathogens in imported seafood

To monitor the presence of enteric pathogens in imported seafood, the authors of this paper collected a total of 140 seafood samples imported from eight overseas countries from Beijing, Dalian, Shanghai, Guangzhou, and Wuhan seafood markets from June to November 2019.

Additionally, 116 viral, environmental swab samples were also collected from the Wuhan and Guangzhou seafood markets. Five typical enteric bacterial pathogens (Aeromonasspp., Shigellaspp., Salmonellaspp., Vibriospp., and Listeria monocytogenes) and four viruses (Rotavirus, Norovirus, Astrovirus, and Sapovirus) were detected.

Results showed that eight Vibrio parahaemolyticus isolates appeared in seafood imported to Dalian, Wuhan, Shanghai, Guangzhou, and Beijing. In contrast, Vibrio fluvialis and Aeromonas were isolated in another two samples. Norovirus was detected in one oyster sample imported from France and an environmental surface in Guangzhou. The remaining pathogens were negative in all the samples being tested. With 120V. parahaemolyticus isolates from the above countries, the genomic analysis revealed that sequence type ST1152 isolates imported from Canada were clustered with two V. parahaemolyticus isolates from Canada.

This study presents a microbiological analysis of the Wuhan seafood market before the outbreak of COVID-19, which demonstrated that supervision should be strengthened to prevent enteric pathogens via imported seafood.