ANALYSIS OF THE PRESENCE OF TOXINS FROM ESCHERICHIA COLI, CLOSTRIDIUM PERFRINGENS, C. DIFFICILE IN BULK FEEDS OF SAINT-PETERSBURG AND LENINGRAD REGION

Background. Undesirable microflora can enter forage crops during harvesting with soil, which can contain various pathogenic microorganisms, including clostridia and enterobacteria, which enter it when manure is applied to fields as fertilizer. As a result, the silage may become unsuitable for use as animal feed. Purpose. Assess the presence of bacterial toxin genes in canned food on farms in the Leningrad region: shiga toxin (stx1, stx 2), intimin (eae), enterohemolysin (ehxA) of enterobacteria; alpha toxin (cpa), beta toxin (cpb) and epsilon toxin (etx) C. perfringens; binary toxin (cdtB), toxin A (tcdA) and B (tcdB) C. difficile. Materials and methods. The study used molecular biology methods: high-throughput sequencing of a fragment of the 16SpRNA gene to assess the microbial community of silage and PCR to assess the presence of toxin genes in the silage community. Based on the data obtained, a bioinformatics analysis was carried out. Results. As a result of the analysis of silage samples from most districts of the Leningrad region for the presence of genes for shiga toxin (stx1, stx 2), intimin (eae), enterohemolysin (ehxA) of enterobacteria; alpha toxin (cpa), beta toxin (cpb) and epsilon toxin (etx) C. perfringens; binary toxin (cdtB), toxin A (tcdA) and B (tcdB) C. difficile, silage samples were shown to be contaminated by several genetic determinants of bacterial toxicity using PCR. The genes for intimin, beta toxin and binary toxin were not identified in any of the samples examined. About 32% of the tested feeds were heavily contaminated with toxins. 23% of silos were found to be free of toxins. Conclusion. The data obtained indicate that rapid acidification of the silage mass by lactobacilli helps to reduce the development of pathogenic enterobacteria and clostridia.