ABSTRACT
Background: Acinetobacter baumannii is anopportunistic pathogen associated with nosocomialinfections. Extensive use of quinolones has resulted inan increase of resistance in this organism worldwide.Aim and Objectives: To study the association betweenPMQR genes, integron carriage as well as the possiblerole of AdeABC efflux pump in ciprofloxacinresistance as well as multidrug resistance in clinicalisolates of A. baumannii. We studied the presence ofPlasmid-Mediated-Quinolone Resistance (PMQR);AdeABC efflux pump genes and integron carriage inIntensive Care Unit (ICU) isolates of A. baumannii.Material and Methods: Fifty six non-duplicate clinicalisolates of A. baumannii were obtained from twoth th hospital ICUs in Tehran from March 5 2014 to July 202015. Susceptibility to 10 antibiotics was determinedby disc diffusion. Presence of PMQR (aac(6')-Ib-cr,qnrA, qnrB, qnrC, qnrD and qnrS), adeABC efflux andclass I and II integron genes were detected byPolymerase Chain Reaction (PCR). Results: Allisolates were Multidrug-Resistant (MDR) amongwhich, qnrB and aac(6')-Ib-cr were detected in 7.1%and 26.8% of the isolates, respectively. However, qnrA,qnrC, qnrD and qnrS were not observed. Presence ofadeA and adeB was observed in 100% and adeC in73.2% of the isolates. Overall, integron carriage wasobserved in (94.6%) of the isolates including qnrBpositive and 73.3% of the aac(6')-Ib-cr carryingisolates. Conclusion: Our results show that quinoloneresistance is not associated with PMQR genes. On theother hand, the AdeABC efflux pump is clearlyresponsible for MDR in our A. baumannii isolates including resistance to quinolones. No association wasfound between PMQR and integron carriage.
ABSTRACT
In this study, the discriminatory power of pulsed field gel electrophoresis (PFGE) and random amplified polymorphic DNA (RAPD) methods for subtyping of 54 clinical isolates of Klebsiella pneumoniae were compared. All isolates were typeable by RAPD, while 3.6% of them were not typeable by PFGE. The repeatability of both typing methods were 100% with satisfying reproducibility (≥ 95%). Although the discriminatory power of PFGE was greater than RAPD, both methods showed sufficient discriminatory power (DI > 0.95) which reflects the heterogeneity among the K. pneumoniae isolates. An optimized RAPD protocol is less technically demanding and time consuming that makes it a reliable typing method and competitive with PFGE.