Abstract

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 fluroquin-olone-resistant Pseudomonas aeruginosa isolates. The strains with hot spot SNP mutations may rise a huge concern from epidemiologic aspect for antibiotic therapy treatment. © 2014, Baqiyatallah university of medical sciences. All rights reserved.