HELICOBACTER PYLORI – BIOLOGICAL FEATURES AND METHODS OF LABORATORY DIAGNOSIS

Abstract

The spring period - in that time the relevance of diagnostics related to Helicobacter pylori infection forces us to pay more attention to the cohort of patients with gastrointestinal tract pathology. Most often, these are patients with exacerbation of chronic gastritis (CH) and peptic ulcer disease (UD) of the stomach and duodenum, the typical course of which involves the seasonality of exacerbations: spring and autumn. Among other criteria of a "typical" course, infection with H. pylori, which is the cause of these diseases and without its destruction in the body, it is impossible to achieve clinical remission of H. pylori-associated diseases and prevent their recurrence. Before prescribing therapy, the causative agent must be identified, and after treatment, its eradication must be confirmed. The severity of chronic diseases of helicobacterial etiology depends on the degree of pathogenicity of the strains, the presence of certain cytotoxic genes. The review analyzes modern information on the biological properties of the causative agent of helicobacteriosis and methods of its diagnosis. They can be divided into invasive (requires taking a biopsy during endoscopic examination) and non-invasive. Bacteriological and morphological research methods are distinguished among the invasive ones. The histological method is recognized as the "gold standard" for the diagnosis of helicobacteriosis. The essence of the method consists in the preparation of preparations of the gastric mucosa and their Giemsa staining in order to detect bacterial cells in the preparation. The method allows you to determine the characteristics of the causative agent and assess the condition of the gastric mucosa. The bacteriological method is considered indispensable for checking strains for resistance to certain antibacterial drugs, which allows predicting the results of treatment. Currently, non-invasive diagnostic methods have become the most widespread. Along with the respiratory urease test, serological methods are used (immunoenzyme analysis, immunoblotting), as well as the immunochromatographic method. The molecular diagnostic method, namely PCR, is used to study the genotypic and phenotypic characteristics of H. pylori strains in gastric biopsy samples, saliva, stools, gastric juice, and dental plaque. PCR provides excellent sensitivity and specificity of over 95% compared to other tests.