Effective testing for Helicobacter pylori bacteria

Specialists of the Gamalei Research Institute of Epidemiology and Microbiology, Russian Academy of Medical Sciences, and the Botkin Clinical Hospital have developed the method that allows to significantly simplify examination of patients suffering from stomach and duodenal diseases caused by the Helicobacter pylori bacteria. The researchers have created immunological test-system capable to discover the pathogene toxin in the patients’ saliva and faeces without resorting to traditional complicated and expensive diagnostics methods.

Stomach and duodenal ulcers are often of bacterial nature. The ulser pathogene, the Helicobacter pylori bacterium, is dangerous by its cytotoxin, in the presence of which the ulcer more often develops into a malignant form. The contemporary medicine possesses a lot of sensitive methods for diagnostics of bacteria and their proteins, but, unfortunately, many of them are complicated and expensive. The majority of methods require penetration into the stomach or the duodenum, thus they are not always suitable for examination of children and bad cases. The necessity for a simplier examination method is obviously imminent.

Physicians suggest to use diagnostic antiserum to VacA toxin protein for simplified diagnostics of Helicobacteriosis. The researchers have cloned a small tail fragment of this protein’s gene. The gene worked duly in the E. coli and produced the protein in the quantities sufficient for immunization. Rabbits were immunized by the purified protein, and serum specific for Helicobacter cytotoxin was produced from their blood. The test-system was tried on real clinical material – saliva and faeces samples of chronic invalids during various exacerbation periods, and before the deiseas and after the conducted treatment.

It has turned out that the method allows to discover the antigen in very low concentrations, upon first indications of the disease exacerbation. Frequency of occurrence and the level of toxin in biological material correlate with severity of siptoms and apparantly indicate to active bacteria reproduction in the organism. The test-system allows to control the course of treatment – if it is efficient, the level of antigen abruptly decreases first in faeces and somewhat later – in saliva.

Such a noninvasive and secure method may be used, according to the researchers, in clinics primarily for children to diagnose Helicobacter infection, to observe the course of disease and to assess the treatment.