Perkinsus marinus extracellular protease modulates survival of Vibrio vulnificus in eastern oyster (Crassostrea virginica) hemocytes

The in vitro effects of the Perkinsus marinus serine protease on the intrac ellular survival of Vibrio vulnificus in oyster hemocytes were examined by using a time-course gentamicin internalization assay. Results showed that p rotease-treated hemocytes were initially slower to internalize V. vulnificu s than untreated hemocytes. After 1 h, the elimination of V. vulnificus by treated hemocytes was significantly suppressed compared with hemocytes infe cted with invasive and noninvasive controls. Our data suggest that the seri ne protease produced by P. marinas suppresses the vibriocidal activity of o yster hemocytes to effectively eliminate V. vulnificus, potentially leading to conditions favoring higher numbers of vibrios in oyster tissues.