FEATURES OF BIOFILM FORMATION OF SOME PATHOGENIC AND COMMENSAL ESCHERICHIA COLI ISOLATED FROM THE BODY OF DOGS AND CATS

Abstract

The relevance of this study is conditioned upon epidemic growth of nosocomial infections, which include Escherichia Coli (E. coli). One of the factors of pathogenicity of such microorganisms is the ability to form a biofilm – a complex community, within which bacteria acquire increased resistance to environmental factors, primarily to antibacterial drugs, which considerably complicates the course of the infectious process. In this regard, the purpose of this study was to determine the features of the formation and dependence of the density of the formed biofilm on the antibiotic resistance of pathogenic and commensal E. coli strains isolated from dogs and cats. The resistance of E. coli isolates to antibacterial drugs was established according to the disk diffusion method, according to EUCAST recommendations. The ability of microorganisms to form biofilms and determine their density was investigated in sterile plastic 96-well plates. The ability to form biofilms was assessed visually and microscopically, the density of biofilms was determined in units, spectrophotometrically, by the optical density of the washing solution. The paper presents the results of a study of 63 samples of pathological (wound infections) and biological material. From them, 10 E. coli isolates were obtained (6 from dogs and 4 from cats), which were selected for further research. It was established that all E. coli isolates had the ability to form phenotypic biofilm. The study investigated the interdependence of antibiotic resistance of E. coli isolates and their ability to form biofilms. Thus, isolates that were parted from pathological material and had a positive reaction on the CHROMagar™ ESBL medium for the determination of extended-spectrum beta-lactamases had greater resistance to various groups of antibacterial drugs and formed high- and medium-density biofilms, while E. coli isolates parted from pathological and biological materials with a negative reaction on CHROMagar™ ESBL medium formed a low-density biofilm and had less resistance to different groups of antibacterial drugs. The results obtained allow searching for innovative, sometimes alternative, methods of treatment and prevention of pathologies caused by them Keywords: microorganism, biofilm, antibiotic resistance, antibacterial drugs, wound infection