Recovery of Pasteurization-Resistant Vagococcus lutrae from Raw Seafoods Using a Two-Step Enrichment, Its Presumptive Prevalence, and Novel Classification Phenotypes

V. lutrae is an emerging human pathogen attributed to increasing hospitalization cases in humans; however, its biology and epidemiology are under-explored. The present study explored V. lutrae recovery, prevalence, and biology. A two-step enrichment method (i.e., step 1, nourishment; step 2, heat, 80 °C, 20 min) and thiosulfate–citrate–bile salts–sucrose (TCBS) agar were employed for recovering V. lutrae in raw seafood. Bacterial colonies were streaked for purification before 16S rRNA bacterial identification. Confirmed V. lutrae isolates were analyzed for their culture-challenged turbidity and virulence. Of 41 bacterial isolates, 9 confirmed V. lutrae, including regular (33%; nourished 24 h) and heat-resistant (67%; nourished 48 h plus heating) isolates, were exclusively from yellow colonies (i.e., TCBS) and were exclusively recovered from nourished shrimp (78%) and crab (22%) only. The culture and virulence biology revealed that they could diversely tolerate salinity (i.e., 0–17.5% additional NaCl), pasteurization (63 °C, 8 h), oxygen availability, and antibiotic sensitivity (i.e., erythromycin, gentamicin, and vancomycin). Further, this pathogen exhibited no visible hemolytic and alkalization activities. Emerging foodborne pathogens could readily evade the established food safety regime. The present study reveals systematic investigation and diverse phenotypes of V. lutrae to enhance its detection and contribute to public health initiatives.