Prevalence of aminoglycoside resistance genes in Acinetobacter baumannii isolates from patients in Tabriz city

Subject Areas : Medical Microbiology

Katayoon  Aliakbarzadeh ¹ (MS.c., Department of Microbiology, Science and Research Branch, Islamic Azad University of Kerman, Iran.)
Safar  Farajnia ² (Associate Professor, Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.)
Ashraf  Karimi Nik ³ (Lecturer, Department of Microbiology, Science and Research Branch, Islamic Azad University of Kerman, Iran.)

Received: 2012-10-01 Accepted : 2013-01-29 Published : 2013-10-01

Keywords: Acinetobacter baumannii, aphA6, aadB, Aminoglycoside resistance,

Abstract :

Background and Objectives: Acinetobacter baumannii is one of the major causes of nosocomial infections resistant to most of available antibiotics, which is known as an important reason of nosocomial death. Although the aminoglycosides are still used as drugs of choice for treatment of Acinetobacter infections, resistance to aminoglycosides has been increasing in this bacterium. The present study investigated the prevalence of the encoding genes of aminoglycoside modifying enzymes, aphA6 and aadB, in Acinetobacter baumannii strains isolated from patients in Emam Reza hospital, in Tabriz city. Material & methods: This cross- sectional study was carried out on 103 Acinetobacter baumannii isolated from hospitalized patient in Imam Reza hospital located at Tabriz. Identification of the strains was performed based on differential and biochemical tests. Antimicrobial susceptibility patterns of the isolates to different aminoglycoside antibiotics including gentamicin, amikacin, tobramycin and kanamycin were evaluated by disc diffusion method. Then the PCR technique used to evaluate the presence of aphA6 and aadB genes. Results: A total of studied isolates, 52 (50.48%) and 16 (15.53%) cases were positive for aphA6 and aadB genes, respectively. Also, the highest resistance was recorded for kanamycin (94%), gentamicin (86%), amikacin (81%) and tobramycin (63%) antibiotics. Conclusion: The results of this study showed the remarkable prevalence of the encoding genes of aminoglycoside modifying enzymes in the A. baumannii isolates. Therefore, a widespread surveillance of resistance to antibiotics and prevention of distribution of these antibiotic-resistant genes is necessary.