Variation of extracellular proteases produced by Vibrio vulnificus clinical isolates: Genetic diversity of the metalloprotease gene (vvp), and serine protease secretion by vvp-negative strains

• Published in: Microbial pathogenesis Vol. 44; no. 6; pp. 494 - 500
• Main Authors: Wang, Jiyou, Sasaki, Tomoko, Maehara, Yoko, Nakao, Hiroshi, Tsuchiya, Tomofusa, Miyoshi, Shin-ichi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2008; Elsevier
• Subjects: Amino Acid Sequence; Animals; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biological and medical sciences; Eels - microbiology; Extracellular protease; Extracellular Space - enzymology; Fish Diseases - microbiology; Fundamental and applied biological sciences. Psychology; Gene Expression; Genetic Variation; Humans; Japan; Metalloproteases - chemistry; Metalloproteases - genetics; Metalloproteases - metabolism; Microbiology; Miscellaneous; Molecular Sequence Data; PCR; Protein Transport; Sequence Alignment; Serine Endopeptidases - chemistry; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Spain; Subtyping; Vibrio Infections - microbiology; Vibrio Infections - veterinary; Vibrio parahaemolyticus; Vibrio vulnificus; Vibrio vulnificus - enzymology; Vibrio vulnificus - genetics; Vibrio vulnificus - isolation & purification; Japan; Spain; Subtyping; PCR; Vibrio vulnificus; Extracellular protease; Microbiology; Enzyme; Secretion; Serine; Genetic diversity; Strain; Polymerase chain reaction; Peptidases; Gene; Aminoacid; Bacteria; Hydrolases; Vibrionaceae; Clinical isolate
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2008.01.001

Vibrio vulnificus is a causative agent of septicemia or wound infection in human and eel; however, the genetic variation between human and eel isolates has been reported. In the present study, the difference in the vvp gene encoding a tissue-damaging metalloprotease was investigated. The gene of strain E86 from a diseased eel (type B vvp) was 95.2% identical with that of strain L-180 from human blood (type A vvp). PCR using oligonucleotide primers designed to differentiate two types of the gene showed that eel avirulent strains (9 isolates) commonly carry type A vvp, whereas eel virulent strains (18 isolates) revealed significant genetic variation. The vvp genes from 12 strains including strain E86 were placed on type B while those from 3 strains were on type A. Other strains were found to be vvp-negative, but PAGE and amino acid sequencing analysis showed that they secreted a serine protease (VVA0302) instead of the metalloprotease. This protease is an orthologue of a toxic protease from Vibrio parahaemolyticus, a human pathogen causing wound infection as well as gastroenteritis. These findings suggest that, in addition to metalloprotease, the extracellular serine protease may contribute to pathogenicity of V. vulnificus.