Metalloprotease Vsm Is the Major Determinant of Toxicity for Extracellular Products of Vibrio splendidus
|Author(s)||Binesse J1, Delsert Claude2, 3, Saulnier Denis2, Champomier Verges M4, Zagorec M4, Munier Lehmann H5, Mazel D1, Le Roux F1, 2|
|Affiliation(s)||1 : Inst Pasteur, CNRS, URA 2171, Unite Plast Genome Bacterien, F-75724 Paris, France.
2 : IFREMER, Lab Genet & Pathol, F-17390 La Tremblade, France.
3 : Ctr Rech Biochim Macromol, CNRS, UMR 5237, F-34293 Montpellier, France.
4 : INRA, Unite Flore Lact & Environm Carne UR309, F-78350 Jouy En Josas, France.
5 : Inst Pasteur, Unite Chim Organ, F-75015 Paris, France.
|Source||Applied and environmental microbiology (0099-2240) (American society for microbiology), 2008-12 , Vol. 74 , N. 23 , P. 7108-7117|
|WOS© Times Cited||55|
|Abstract||Genomic data combined with reverse genetic approaches have contributed to the characterization of major virulence factors of Vibrio species; however, these studies have targeted primarily human pathogens. Here, we investigate virulence factors in the oyster pathogen Vibrio splendidus LGP32 and show that toxicity is correlated to the presence of a metalloprotease and its corresponding vsm gene. Comparative genomics showed that an avirulent strain closely related to LGP32 lacked the metalloprotease. The toxicity of LGP32 metalloprotease was confirmed by exposing mollusk and mouse fibroblastic cell lines to extracellular products (ECPs) of the wild type (wt) and a vsm deletion mutant (Delta vsm mutant). The ECPs of the wt induced a strong cytopathic effect whose severity was cell type dependent, while those of the Delta vsm mutant were much less toxic, and exposure to purified protein demonstrated the direct toxicity of the Vsm metalloprotease. Finally, to investigate Vsm molecular targets, a proteomic analysis of the ECPs of both LGP32 and the Delta vsm mutant was performed, revealing a number of differentially expressed and/or processed proteins. One of these, the VSA1062 metalloprotease, was found to have significant identity to the immune inhibitor A precursor, a virulence factor of Bacillus thuringiensis. Deletion mutants corresponding to several of the major proteins were constructed by allelic exchange, and the ECPs of these mutants proved to be toxic to both cell cultures and animals. Taken together, these data demonstrate that Vsm is the major toxicity factor in the ECPs of V. splendidus.|