High Prevalence of Transferable Integron-Associated Drug Resistance in Escherichia coli Strains Isolated from Blood Cultures in a University Hospital in xxxxxxxx, xxxxxxxx

Abstract

Objective: In this study, we aimed to determine the the presence of transferable integron-associated drug resistance in Escherichia coli strains isolated from the blood cultures of patients with various infections at the Research and Application Center (………Hospital) of …………….., …………….., ……………... Methods: The presence of integrons was determined by integron-specific polymerase chain reactions, and the amplicons were analyzed by DNA sequencing. Plasmid transfer assays were carried out by the broth mating method. The clonal relationship of integron-containing strains was evaluated by pulsed-field gel electrophoresis (PFGE). Results: Resistance rates to the antibiotic groups used were between 0.9% to 63%. Thirty-eight (34,2%) strains contained class 1 integrons carrying dfrA7, dfr17-aadA5, dfrV, dfrA1-aadA1, and dfrA12-aadA2 gene cassette arrays. Seven (6,3%) strains contained class 2 integrons having dfrA1-sat2-aadA1 and dfrA1-sat2-aadA30 gene cassette arrays. Twenty-two conjugative resistance plasmids were harbored in integron-carrying isolates, and three of them were found to be in the IncN group. Four strains carrying class 1 integrons which were isolated from different clinics showed clonally similar patterns in PFGE analysis. Conclusion: We conclude that about 50% E. coli isolates in our hospital carry integron-associated transferable drug resistance, and may play a crucial role in horizontal dissemination. Further molecular epidemiological investigations are required in regard to explaining the relationship between the carriage of integrons in E. coli strains of blood origin in this hospital as well as countrywide.