Campylobacteriosis: genotypic characteristics of the pathogen and immunological status of patients

Abstract

Introduction. Campylobacteriosis is among the leading causes of acute gastrointestinal infections. The severity of campylobacteriosis and the development of long-term complications may be influenced by the genotype of the pathogen, whose biological properties can affect immune response parameters. The aim of the study was to identify common genotypes of epidemic clones of Campylobacter pathogens and to investigate characteristics of the immune response and severity of the disease. Materials and methods. The study included 203 patients aged from 1 month to 17 years with campylobacteriosis who underwent treatment at the clinic of the Federal State Budgetary Institution "DNKCIB FMBA" in 2019–2021. The diagnosis was confirmed using polymerase chain reaction method. Patient samples were also analyzed using culture-based methods. Total DNA was extracted using the QIAamp DNA Mini Kit. Genetic determinants encoding virulence factors and MLST typing were performed using the ResFinder program. The immune status of patients was assessed on days 1 and 7 of the illness. Immunological investigation included measurement of serum immunoglobulin concentrations (IgA, IgM, IgG), C-reactive protein, and cytokines (IL-1β, IL-1, IL-2, IL-4, IL-5, IL-6, IL- 7, IL-8, IL-10, TNF-α, and IFN-γ). Results. When analyzing the frequency of detection of Campylobacter sequence types in children with clinical intestinal infections, it was found that the profile of isolated isolates is most similar to those from countries of North America (USA and Canada), Northern Europe (Great Britain, Holland ) and Scandinavia (Denmark, Sweden, Finland). Identification of a pathogen with the flgE+, cdtA+, cdtC+ genotype was accompanied by a statistically significant increase in the level of IL-8 and a decrease in the content of IgA in the peripheral blood serum, which reflected the low efficiency of the immune response during infection with Campylobacter and predetermined the severe course of the infectious process during the disease.