The genetic potential of toxigenic Escherichia coli isolated from calves and piglets

Abstract. The study aims to genetically characterize diarrhoeagenic Escherichia coli isolated from cattle and pigs. The main propose is genetic potential responsible for the production of exotoxins in pathogenic E. coli, the causative agents of escherichiosis in calves and piglets. The scientific novelty of the work consists in deciphering the genomes of diarrheogenic E. coli with the presence of nucleotide sequences of several exotoxins, including thermolabile, thermostable and shigap-like, as well as colicins, hemolysins and cyclomodulins, which have pathogenetic significance in the development of escherichia infection in calves and piglets. The study was carried out using microbiological and molecular genetic methods of research and mass spectrometric analysis. As a result, 135 E. coli isolates were subjected to genetic screening by polymerase chain reaction in agarose gel. It was found that 68 (50.36 %) escherichia had toxigenicity markers, while the thermolabile exotoxin gene was recorded more often than others (48.5 %), and the majority was recorded in E. coli isolated from piglets (29.4 %). In 19 (27.9 %) isolates, the presence of genes encoding the production of several exotoxins was established. According to the results of the polymerase-chain reaction, 4 E. coli isolates with a different set of nucleotide sequences responsible for the production of two or more exotoxins at the same time were subjected to genome-wide sequencing. The Escherichia genomes were assembled and annotated and deposited in the NCBI Prokaryotic Genome Annotation Pipeline database under the general number BioProject PRJNA887444. Further studies of E. coli genes and their role in the pathogenic potential of escherichiosis pathogens are needed for the subsequent development of effective means of preventing and controlling infection.