ASSAY OF THE CYTOTOXICITY OF BROTH CULTURE FILTRATES OF HELICOBACTER-PYLORI ISOLATED IN INDIA

Cytopathic effects produced by broth culture filtrates of 12 Helicobac ter pylori clinical isolates from the local population in Madras, one urease-negative mutant and a reference strain were tested on an epithe lial cell line (HeLa). Seven of 12 strains (58.3%) from the clinical i solates caused intracellular vacuolation. No difference was observed i n the production of cytotoxin between the clinical isolates that were urease-positive and the urease-negative mutant. However, one strain of H. pylori from an endoscopically normal individual also produced the cytotoxin. Long-term follow-up of these individuals infected with thes e cytotoxic-positive strains of H. pylori is needed to confirm the rol e of these cytotoxins in the disease process.