Contribution of the tdh1 gene of Kanagawa phenomenon-positive Vibrio parahaemolyticus to production of extracellular thermostable direct hemolysin.
Kanagawa phenomenon-positive strains of Vibrio parahaemolyticus contain two copies of the tdh gene (tdh 1 and tdh 2) encoding thermostable direct hemolysin (TDH). Previous studies suggested that the tdh 2 gene, but not the tdh 1 gene, was responsible for production of extracellular TDH. In this study, a tdh 2-deficient isogenic mutant of Kanagawa phenomenon-positive strain AQ3815 was constructed by a suicide vector-mediated in vivo recombination method. The intact tdh 1 gene in the mutant contributed little to Kanagawa phenomenon on Wagatsuma agar but produced TDH in broth media, accounting for 0.5-9.4% of total extracellular TDH of AQ3815.
Nishibuchi
M
M
Center for Vaccine Development, University of Maryland School of Medicine, Baltimore 21201.
Kumagai
K
K
Kaper
J B
JB
D005798:Genes, Bacterial / Q000502:physiology*; D006460:Hemolysin Proteins / Q000096:biosynthesis* / Q000235:genetics; D009154:Mutation / Q000235:genetics; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000472:pathogenicity*
D006460:Hemolysin Proteins