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 th is 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.
