Zdvizhkova I.A., Andryuschenko S.V.
SCREENING OF THE GENETIC DETERMINANTS OF PATHOGENIC POTENTIAL OF ENTEROBACTERIA ^{[№ 9 ' 2017]}
Currently, to determine the microbiological safety of environmental objects requires expertise, which takes several days in the case of a bacteriological method. As a result of research on existing techniques, only species identification of microorganisms or, at best, determination of virulence factors, unconditionally pathogenic microorganisms, is carried out. Therefore, at the present time, not only the detection of pathogenic and conditionally pathogenic species of microorganisms becomes an urgent task, but also a one-stage determination of their pathogenic potential; first of all, the main factors of the persistence of microorganisms in relation to the host organism. Screening of the investigated genetic determinants among 30 strains of Escherichia coli and Klebsiella pneumoniae revealed 1 strain of Escherichia coli, carrying both determinants of hemolytic activity, as well as enterotoxin C gene, 3 strains of Escherichia coli carrying the markers of aerobactin production and 1 carrier strain detected in our work marker genes of colibactin. It has been established that three strains of Klebsiella pneumoniae, previously described as carriers of the megaplasmid of virulence, demonstrate simultaneous presence of all detected genes of three determinants of persistence: aerobactin, colibactin and periplasmic inhibitor of lysozyme.
The carried out researches allowed to establish that the prevalence of known carrier strains of genetic markers of known determinants of persistence and pathogenicity of enterobacteria in intestinal microbiota of clinically healthy subjects does not exceed 10 %. In this case, the adhesion of several determinants of different nature is observed in the detected carrier strains, including the marker of hemolytic activity The latter fact complements the data obtained with respect to the virulence factors of diarrheic Escherichia, allowing to divide the list of markers of highly virulent and conditionally pathogenic genetic profiles of enterobacteria.
In addition the developed test system will simultaneously reveal genetic markers of five known determinants of the persistence of opportunistic enterobacteria using a single amplification algorithm, which greatly simplifies the procedure of analysis.