Vacuolizing toxin (VacA) Helicobacter pylori is an important factor of pathogenicity of Helicobacter pylori and a basic marker in the diagnosis of helicobacteriosis and related diseases. A coagulation-based diagnostic test-system was elaborated for the detection of VacA in clinical samples. A fragment of vacA was cloned, for the purpose, in Escherichia coli and expressed in preparative quantities; the coded protein was purified and used in raising the diagnostic serum. The thus designed coagulating test-system was successfully tested under the modeling conditions with clinical samples. Therefore, the designed express method can be used for the invasion-free determination of VacA in patients with gastric and duodenal pathologies.
The results of the immunophoretic analysis of H. pylori antigenic structure are presented. Along with H. pylori O-antigen, specific surface antigen of acidic nature, relatively thermolabile with characteristics similar to those of K-antigens, was detected. A diagnosticum based on the coagglutination test for the rapid detection of H. pylori specific antigens in the patients' biological fluids (coprofiltrate, saliva) by the noninvasive method was developed. The circulation mode of H. pylori in human body and its correlation with the clinical symptoms of the disease was shown. H. pylori antigens were very frequently detected (in 65 - 83% of cases) in patients with acute bacterial enteric infections: shigellosis, salmonellosis, yersiniosis, campylobacteriosis. The newly developed method seems to be promising for the rapid diagnosis of H. pylori associated infections, for the prolonged monitoring and evaluation of the effectiveness of antibacterial therapy.