Prevalence of qacEΔ1, qacE, oqxA, oqxB, acrA, cepA and zitB genes among multidrug-resistant Klebsiella pneumoniae isolated in a cardiac hospital

Background. Infections caused by multidrug-resistant (MDR) Klebsiella pneumoniae are the leading cause of mortality worldwide. The widespread use of disinfectants and antiseptics has caused the emergence of K. pneumoniae with reduced sensitivity to them, which, in combination with MDR, can pose a significant epidemiological threat. The aim of the study was to assess the prevalence of efflux pump and transporter genes associated with biocide resistance and their association with antibiotic resistance among K. pneumoniae isolated in a cardiac surgical hospital. Materials and methods. K. pneumoniae isolates (n = 50) from the patients and medical equipment were tested by polymerase chain reaction for the presence of genes of 4 types of efflux pumps (qacEΔ1, qacE, oqxA, oqxB, acrA) and 2 transporters involved in the outflow of cations (cepA) and zinc ions (zitB). Spearman's rank correlation test was used to assess the strength of the association between the efflux pumps, beta-lactamase genes and mobile genetic elements. Results. The occurrence of K. pneumoniae containing qacEΔ1, qacE, oqxA, oqxB, acrA, cepA and zitB was high: 54, 62, 100, 84, 100, 72 и 96% respectively. K. pneumoniae with a combination of all the studied pumps was most often detected (32%), and these isolates were MDR in 100% of cases. The qacE, qacEΔ1 genes were closely associated with resistance to cephalosporins, carbapenems, fluoroquinolones, carbapenemase genes, and integrons. The results of the study showed that the genes of various efflux pumps associated with biocide resistance and their combinations were widely represented among the clinical isolates of MDR K. pneumoniae. Conclusion. The high prevalence of efflux pump genes associated with resistance to quaternary ammonium compounds, chlorhexidine and zinc salts and their significant association with antibiotic resistance in nosocomial K. pneumoniae underlines the importance of further studying the mechanisms of cross-resistance to biocides to improve methods of combating MDR nosocomial pathogens.