Типизација на campylobacter spp. во ланецот на храна

Abstract

Campylobacter spp. is currently the most common cause of acute gastroenteritis in humans in Europe. The majority of Campylobacter spp. infections in humans comes from contaminated chicken meat and chicken products. In the case of an infection with thermotolerant campylobacters, the replacement of fluids and electrolytes is the basic symptomatic therapy in most patients, and the infection is most often cured without the use of antimicrobial therapy. The outcome of the disease depends on the patient's immune status and the virulence characteristics of the campylobacteria. Therefore, in clinical cases where the patient has a high fever and bloody diarrhea or in cases including newborns, children, pregnant women and immunocompromised individuals, antibiotic therapy is necessary. In recent decades, antimicrobial resistance has become a phenomenon in Campylobacter spp. and other pathogenic microorganisms present in food. For the purposes of this study, a total of 283 different poultry samples were tested. From the stage of primary production i.e. broiler farm, 64 samples of cloacal swabs were taken. A total of 166 caecum samples were taken from the slaughtering phase and from the pre-sale phase, i.e. before distribution to the consumers, 53 specimens of carcass swabs were taken. The method described in ISO standard 10272-1 Microbiology of food and animal feeding stuffs - Horizontal method for detection and enumeration of Campylobacter spp. - Part 1: Detection method was used for isolation and confirmation of Campylobacter spp. The obtained isolates of Campylobacter spp., also called “thermotolerant campylobacteria” were also confirmed by PCR testing method for the identification of campylobacteria. The confirmed isolates of C. jejuni and C. coli in the further part of the study were analyzed by PCR method for detection of antimicrobial resistance genes (CmeB, BlaOXA-61, tet(O), aph-3-1 and aadE). In order to gain insight into the virulence characteristics of the most common representative of this species (C. jejuni), its isolates were tested using the PCR method for the presence of virulence genes (flaA, cadF, racR, virB11, dnaJ, ciaB, cdtA, cdtB, cdtC and wlaN). Campylobacter spp. was isolated from 169 samples (59.7%) of the total samples taken. The highest percentage of isolated campolibacteria was recorded at the farm and it was 73.4%. From the next phase - slaughterhouse, the percentage of isolated strains in the caecum samples was 61.4%, while in the cold storage phase the lowest percentage (37.7%) of identified Campylobacter species was recorded. In the study part aimed for detection of presence of resistance genes, the BlaOXA-61 gene was present in 25%, while the tet(O) and CmeB genes were confirmed in 19.4% of C. jejuni isolates. In C. coli isolates the gene CmeB was confirmed in 94.3%, while the tet(O) gene was detected in 40% of the isolates. From the aspect of virulence characteristics, the cadF and ciaB genes were detected in all of the isolates of C. jejuni. The cdtA and cdtB genes were detected in 52.7% of the tested isolates, while a lower prevalence was confirmed for the flaA (50%) and cdtC (47.2%) genes. Based on the findings of this study, it can be concluded that the colonization of poultry with campylobacteria is present and that chicken meat is a cause of alimentary gastrointestinal diseases in humans. Therefore, it is in the public health interest to implement all available strategies to reduce the percentage of colonized chicken and contaminated slaughterhouse carcasses.