The expression of VacA in BCF of Helicobacter pylori and its relationship to vacuolated effect.

The vacuolated effect of Helicobacter (H. pylori) and its relationship to vacuolated cytotoxin antigen (VacA) were investigated by the method of cytotoxic test and SDS-pobyacrylamide gel electrophoresis (SDS-PAGE). Of the 62 clinical isolates, the broth culture filter (BCF) of 43 strains caused the Vero cell intracytoplasmically vacuolated. H. pylori strains were divided into H. pylori (Toxin+) group with vacuolated effect and H. pylori (Toxin-) group without vacuolated effect. The analysis of the BCF of H. pylori (Toxin+) and that of H. pylori (Toxin-) was studied by SDS-PAGE and Scan reader. A kind of protein with 87 ku molecular weight was recognized in the BCF of 30.23% (13/43) H. pylori (Toxin+) strains but in none of that of H. pylori (Toxin-) strains, the difference was statistically significant (P < 0.05). There was a significant and concordant relationship between OD of the protein band with 87 ku molecular weight and titer of vacuolated activity of H. pylori (Toxin+) (r = 0.67 and P < 0.05 by linear regression analysis). H. pylori strains were divided into H. pylori (Toxin+) group with vacuolated effect and H. pylori (Toxin-) group without vacuolated effect. The vacuolated effect of H. pylori (Toxin+) was caused by the protein with 87 ku molecular weight (VacA).