To deter
mine the anti
microbial susceptibility patterns, the frequency of integrons and associated gene cassettes in
m>Acinetobacter baumanniim> (
m>A. baumanniim>) strains isolated fro
m selected hospital intensive care units.
Methods
During a ten-month period, 120 m>A. baumanniim> isolates were studied. The resistance rates to different classes of antimicrobial agents were determined. PCR was used to detect different types of integrons and associated gene cassettes.
Results
The resistance rates to the majority of antibiotics tested were found to be between 39.3% and 99.1%. No isolate was observed to be resistant to colistin and polymyxin B. The rate of extensive drug-resistance among these clinical isolates was 62.5%. The prevalence of class 1 and 2 integrons was found to be 74.1% and 12.5%, respectively. Seven different gene cassettes (m>ampCm>, m>aacA4-catB8m>, m>ISAba1-blam>m>OXA-23m>m>-GES-14m>, m>aadA2-cm1A6-GES-14-qacFm>, m>VIM-25-GES-24-qacFm>, m>dfrA5-ISAba1-blam>m>OXA-51m>m>-blam>m>OXA-40m> and m>aadA2-GES-11-IMP-1m>) were observed in Class 1 integron-carrying strains. Three gene cassettes (m>IMP-4m>, m>VIM-2-VEB-aacA4m> and m>dfrA2-sat-2-aadA4m>) were detected in class 2 integron-bearing m>A. baumanniim> strains.
Conclusions
A high prevalence of integron was described among multidrug resistant m>A. baumanniim> in the hospital. The findings highlighted the need for continuous surveillance in order to prevent dissemination of multidrug resistance among m>A. baumanniim> strains in Iran.