Document Type : Original Article
Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University, Shahr-e-Qods Branch, Tehran, Iran
Applied Biotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
The broad consumption of antibiotics such as fluoroquinolones and the genetic adaption of opportunistic pathogenic bacteria including Pseudomonas aeruginosa, has led to develop of floroquinolone-resistant strains of Pseudomonas aeruginosa. Thus, the aim of the present study is to reveal the types of hot spot mutations occurring in selected DNA gyrase subunit A gene in fluoroquinolone-resistant Pseudomonas aeruginosa strains. For this purpose, 70 fluoroquinolone-resistant partial cds genes of Pseudomonas aeruginosa TOHO strains (P12-P377) for DNA gyrase subunit A have been aligned with wild genes for DNA gyrase subunit A by BLAST program and multiple alignment, to detect probable gyrA mutations. Based on analyses hot spot mutations including Thr-83→Ile (92.44%), Ile-83→Thr (1.33%), Asn-87→Asp (0.44%) existing as single and Thr-83→Ile & Asn-87→Asp (5.78%) as double substitutions were detected. According to this survey, the point mutations in DNA gyrase subunit A gene need more consideration about fluroquinolone-resistant Pseudomonas aeruginosa isolates. The strains with hot spot SNP mutations may rise a huge concern from the epidemiologic aspect for antibiotic therapy treatment.