Effect of Sampling Method on the Representative Recovery of Microorganisms from the Surfaces of Aquacultured Finfish

The objective of this study was to determine if a gentle rinse procedure was equivalent to the combination of excision and homogenization with a stomacher for the relative removal of various microorganisms from finfish fillets. Fillets of hybrid striped bass and rainbow trout were obtained from local markets and sampled using three methods: rinse (R), excision followed by homogenization in a stomacher (S), and homogenization of fillets following a rinse (RS). Microorganisms were enumerated on selective and nonselective media, and randomly selected colonies from aerobic plate counts were identified using MIDI Sherlock and BIOLOG microbial identification systems. Enrichments and selective media were used for the isolation of Listeria monocytogenes, Salmonella spp., and Yersinia enterocolitica. This study confirms previous reports that stomaching is superior to rinsing for enumerating total microbial populations from fish fillets. Rinsing was more effective for rainbow trout than for striped bass. Sampling m...