Screening for Antimicrobial Resistance and Genes of Exotoxins in Isolates from Infected Dogs and Cats in Poland.

has assumed an increasingly prominent role as the aetiological agent in serious hard-to-treat infections in animals and humans. In this study, 271 strains collected from dogs and cats were investigated. The aim of the research was to screen these strains for antibiotic resistance and the presence of selected virulence factor genes. Antibiotic resistance was determined using the Kirby-Bauer method, while virulence genes were detected by polymerase chain reaction (PCR). The most frequently detected resistance was to fluoroquinolones, ranging in prevalence from 17.3% for ciprofloxacin up to 83% for enrofloxacin. The resistance to carbapenems was 14% and 4.8% for imipenem and meropenem, respectively. Almost all strains harboured the (97.8%) and (93.4%) genes, while the lowest prevalence was found for (17.3%) and (17.3%). strains isolated from dogs that harboured the gene were more frequently resistant to ceftazidime ( = 0.012), while the presence of the gene was found to be connected with resistance to marbofloxacin ( = 0.025) and amikacin ( = 0.056). In strains originating from cats, only the connection between the presence of the gene and resistance to enrofloxacin ( = 0.054) was observed. The confirmation of associations between virulence-factor-encoding genes and antibiotic resistance indicates that problems of antibiotic resistance may not only cause complications at the level of antibiotic dosage but also lead to changes in the virulence of the bacteria; thus, further studies in this area are required.