Oral microbiota autobacteriocins directed against pathogens of bacterial complications of respiratory infections

Recent years have been marked by a wide spread of respiratory viral infections, which are often accompanied by the development of bacterial complications. The greatest danger is posed by nosocomial strains with multidrug resistance. One of the ways to combat antibiotic-resistant strains is the possibility of using bacteriocins produced by certain bacteria that are present in the human body, food, and the environment. The most interesting are the strains of autobacteriocins isolated from the human's own normal microbiota, which does not have immune rejection. The purpose of the study: to investigate the antibacterial effect of autobacteriocins of the oral microbiota against the main pathogens of bacterial complications in respiratory infections. Six reference strains from the ESKAPE group (Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) and 18 multi-resistant strains of the same group isolated from the respiratory tract of individuals with bacterial complications of viral infections were examined. The study used bacteriological, molecular biological, and statistical methods, as well as mass spectrometric research method. The autobacteriocins isolated from Enterococcus faecalis, Streptococcus salivarius, and Lactobacillus paracasei bacteria were the most effective against multidrug-resistant strains from the ESKAPE group. Notably, the concentration of bacteriocin-producing bacteria in the medium of co-cultivation was 500 and 1,000 times less than the strains against which they were directed. Suppression of the growth of multidrug-resistant strains by 2-3 times compared with the initial one was observed after 2 hours. Thus, the antibacterial effectiveness of autobacteriocins against resistant strains of bacteria isolated from the same individual suggests the possibility of a personalized approach to obtaining and using autoprobiotic strains of bacteria to combat bacterial complications of the respiratory tract.