Molecular and genetic charac-teristics of pathogenicity of lactose-negative strains Escherichia coli isolated from COVID-19

We identified the genetic determinants of the pathogenicity of this species. Тhe prospective molecular genetic study of lactose-negative E. coli isolates was performed using PCR-RT. We determined the complete nucleotide sequences of the gene regions encoding the synthesis of fimbrial adhesins (fimH), aerobactin (aer), IbeA protein (ibeA) and hemolysin (hlyF) and performed a bioinformatic analysis of the conserved regions of the studied fragments of the genomes of lactose-negative E. coli. We found that the frequency of occurrence of oligonucleotide sequences of genes determining pathogenicity in the first group was 95.2%, in the second – 95.2%, in the third – 100% (in the control – 20.0% of isolates). This indicates an increased pathogenicity of the studied strains of lactose-negative E. coli in all groups. In the first group, the fimH gene was found in 81.0%, the aer gene in 33.3%, the ibeA gene in 23.8%, and the hlyF gene in 19.0% of the strains. In the second group, the fimH gene was detected in 88.3%, the ibeA gene in 26.2%, the aer gene in 31.0% and the hlyF gene in 9.5% of the strains. In the third group, the fimH gene was found in 100.0% of the strains, the aer gene – in 64.0%, the ibeA gene – in 56.0% and the hlyF gene – in 40.0%. In the control, the fimH gene and the aer gene were detected in 10.0% and 10% of the strains, respectively. Therefore, the fimН gene has the highest frequency of occurrence.