Genotyping of polyresistant microflora of the ICU as a method of selecting optimal therapeutic and epidemiological solutions

Avramov Aleksandr Aleksandrovich, Tsarenko Sergei Vasilevich, Zinina Elizaveta Pavlovna

Purpose and objectives: To study the microbial landscape of two independent intensive care units of one hospital, taking into account the following factors: antibiotic resistance, spread in the external environment and biological environments. To study the genetic characteristics of the prevailing bacteria. To trace the dynamics of the change of microorganisms in patients transferred to a specific intensive care unit from other departments and other hospitals. Material and methods: 101 samples collected in 2 intensive care units in the period 2018-2019 with an interval of 6 months were studied. The samples were both material obtained from patients, staff, and elements of the hospital environment. All samples were subjected to phenotypic and molecular genetic analysis, determination of antibiotic resistance, isolation and amplification of DNA, multilocus sequencing (MLST). Results and conclusions: The predominance of Gram-negative flora, microbes of the KAP group (K. pneumoniae, A. baummanii, P. aerouginosae) was revealed. In the course of MLST sequencing, it was shown that for each intensive care unit there is a different, predominant genotype of the pathogen. Strains of the same type of microorganisms in different departments have different genotypes and different levels of sensitivity to antibiotics. The analysis of antibiotic resistance showed that the dominant genotypes of the branches have the broadest resistance among all strains. It is shown that the strains introduced from other hospitals are not detected in any samples after 14 days. They are completely suppressed and replaced by the local flora. However, we have obtained data confirming the possibility of transferring nosocomial strains between departments by medical personnel. Based on the data obtained, we assume that the most promising epidemiological measures aimed at preventing the transfer of bacteria within and between ICUs. For the prevention of the transmission of K. pneumoniae and P. aeruginosa, the most important measures are personal hygiene of personnel, for A. baumannii – careful treatment of environmental objects is of paramount importance.

Keywords:Antibiotic resistance, genotyping, nosocomial infections, k. pneumoniae, a. baumannii, p. aeruginosa Multilocus sequencing