Author/Authors :
-، - نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran Maleki, Mohammad Hossein , -، - نويسنده Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University of Putra, Malaysia Sekawi, Zamberi , -، - نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran.Department of Microbiology, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran Soroush, Setareh , -، - نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
2 Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University of Putra, Malaysia Azizi-Jalilian, Farid , -، - نويسنده Psychosocial Injuries Research Center, Ilam University of Medical Sciences, Ilam, Ira Asadollahi, Khairollah , -، - نويسنده Department of Microbiology, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran Mohammadi, Sattar , -، - نويسنده Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Emaneini, Mohammad , -، - نويسنده Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam, Iran
2 Department of Medical Microbiology and Parasitology, Faculty of Medicine and Health Sciences, University of Putra, Malaysia Taherikalani, Morovat
Abstract :
Objective(s):To date, the most important genes responsible for tetracycline resistance among Acinetobacter baumannii isolates have been identified as tet A and tet B. This study was carried out to determine the rate of resistance to tetracycline and related antibiotics, and mechanisms of resistance. Materials and Methods: During the years 2010 and 2011, a total of 100 A. baumannii isolates were recovered from patients in different hospitals of Tehran, Iran. Antimicrobial susceptibility to tetracycline, minocycline, doxicycline and tigecycline was evaluated by E-test. Polymerase chain reaction (PCR) of the tet A and tet B genes was performed using specific primers, after which the isolates were subjected to Repetitive Extragenic Palindromic-PCR (PCR) to identify the major genotypes. Results: Of all isolates, 89% were resistant to tetracycline (MIC50 = 32 μg/ml, MIC90 = 512 μg/ml). Minocycline with the resistant rate of 35% (MIC50 = 16 μg/ml, MIC90 =32 μg/ml) and doxicycline with the resistant rate of 25% (MIC50 = 16 μg/ml, MIC90= 32 μg/ml) have a good activity against A. baumannii isolates. All isolates were sensitive to tigecycline. Frequencies of tet B and tet A genes and coexistence of tet A and tet B among the isolates resistant to tetracycline, were 87.6%, 2.2% and 1.1%, respectively. Distribution of REP-types among A. baumannii isolates was types A (40%), B (30%), C (10%), D (5%) and E (5%). Conclusion: It seems that tet A and tet B genes play an important role in the induction of resistance towards tetracyclines used in this study. It is suggested that further studies focus on other antimicrobial drugs and combinations in order to achieve a successful therapy against multi drug resistance (MDR) A. baumannii strains in Iran.
