Abstract
Abstract Vibrio vulnificus is a halophilic, Gram-negative, curved rod-shaped bacterium. This bacterium has the ability to cause serious wound infections and often-fatal septicemia in human. After the genome of V. vulnificus has been completely sequenced and annotated, we have identified a gene named lrv that contains Leucine-rich repeats (LRRs) domain, a common property involving in protein-protein interaction. Several bacterial genes encoding an LRR protein have been reported, which include the IpaH family in Shigella fexneri, YopM in Yersinia species, and internalin family in Listeria monocytogenes, and are normally associated with pathogenesis. In order to explore the possible function of lrv in V. vulnificus, I cloned and expressed the gene, and produced recombinant Lrv and an anti-Lrv antibody. I found that Lrv is an outer membrane protein and expressed in both biotypes 1 and 2 of V. vulnificus. Lrv expression is up regulated in iron-deficient condition. I have constructed a lrv deletion mutant by the allelic exchange technique, and found that the LD 50 of the mutant did not change in animal intraperitoneal (i.p.) model of infection. The mutant strain appeared to be less able to cause cell dispersion compared to the parental strain. In conclusion, our data suggest that Lrv may disturb the cell-cell junction and facilitate the invasive infection of V. vulnificus.