Genotypic Study of Mutation in gyrA and parC Genes with Phylogenetic Tree in Escherichia Coli
Abstract. Urinary tract-infections (UTIs) remain among repeated bacterial infections. Escherichia coli was the furthermost cause of UTI. However, quinolone resistance confuses treatment. The present study aimed to determine the fluoroquinolone sensitivity profile, besides point mutation occured in them within quinolone-resistance determining regions (QRDRs) for E. coli, since this first study in Najaf that deals with sequencing analysis and phylogenetic relationship of gyrA and parC. The antibiotic resistance for the 30 isolates obtained from UTIs as follow: ofloxacin, nalidixic acid, Levofloxacin, ciprofloxacin, ceftriaxone, amikacin was 20(66.7), 21(70%), 18(60%), 18(60%), 26(86.7%), 25(83.3%), respectively, totally isolates sensitive to meropenem and imipenem, In PCR investigation show the elevated incidence of gyrA in isolates, 29 isolates were positive result, while the result of parC genes show that 27 isolates were positive result. Point mutations occur in gyrA in tested isolates at more than one site that cause ciprofloxacin resistance, the isolate no.2 has 3 Missense mutation, the isolate no.4 has 1 Missense mutation, also the isolate no.5 has 2 Missense mutation, the isolates no.7 has 3 Missense mutation, ParC amino acids sequencing for the isolate (no. 2, 3, 8, 9) have no mutation, isolate no. 7 has 1 Missense mutation Leu at position 122 converted to Cys. Local isolates looked more convergent towards India and Bangladesh isolates and to some extent for the USA, Greece, Egypt, Japan, Malaysia, and Brazil. Understanding the genetic basis of antibiotic resistance can guide treatment decisions then improve novel approaches for scrapping multi-drug resistant (MDR). This study revealed novelty through monitoring of E. coli evolution in clinical isolates.