Akademik Veri Yönetim Sistemi
MEANDROS MEDICAL AND DENTAL JOURNAL, cilt.25, sa.4, ss.436-450, 2024 (ESCI)
Objective: This study aimed to determine the carriage of transferable integron-associated drug resistance in
Escherichia coli (E. coli) strains isolated from blood cultures.
Materials and Methods: A total of 111 E. coli isolates were included in this study. Antimicrobial
susceptibility testing of the isolates against 17 antibiotics was performed using an automated microbiology
system. Integron-specific polymerase chain reactions (PCR) were used to detect the presence of integrons.
The antibiotic resistance gene cassettes in the variable regions of integrons were analyzed by DNA
sequencing. Plasmid transfer assays were performed using the broth mating method. The clonal
relationships among integron-carrying strains were evaluated by pulsed-field gel electrophoresis (PFGE).
Results: Resistance rates to antibiotics ranged from 0.9% to 63%. Thirty-eight strains carried gene cassettes
encoding dfrA7, dfr17-aadA5, dfrV, dfrA1-aadA1, and dfrA12-aadA2. Seven strains possessed class 2
integrons with gene arrays dfrA1-sat2-aadA1 and dfrA1-sat2-aadA30. Twenty-two integron-carrying
isolates harbored conjugative resistance plasmids, three of which were identified as belonging to the IncN
group. Two strains with class 1 integrons, isolated from different clinics, exhibited similar patterns in the
PFGE analysis.
Conclusion: Approximately 50% of E. coli isolates from blood cultures at our hospital were found to carry
integron-associated transferable drug resistance, suggesting their potential role in the horizontal
dissemination of resistance genes. Further research is needed to understand the prevalence of E. coli strains
of blood origin and the role of integrons and gene cassette arrays in the spread of resistance.