in silico analysis of amino acid substitutions in dna gyrase subunit a

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 epidemiologic aspect for antibiotic therapy treatment.