Molecular Profile of Aminoglycoside, Fluoroquinolone, and Class 1 Integron Genes among Gentamicin-Resistant Escherichia coli in Najaf City, Iraq

Abstract

Escherichia coli has a major cause of women urinary tract infection, which it harbours various kinds of drug resistance-associated genes. So, the current study examined the prevalence and frequency of genes. These genes are responsible for the resistance of aminoglycoside and fluoroquinolone drugs in uropathogenic gentamicin-resistant E. coli isolated from urinary tract infections among women. Six hundred urine specimens were tested. The data revealed 348 (58%) and 70 (11.66%) had gram-positive and gram-negative, respectively. The other 182 (30.33%) were found without any growth. A total of 600 clinical specimens were 167(27.833%) identified as E.coli isolate according to biochemical tests and Vitek-2 System. The phenotypic gentamicin-resistant screening (MIC and disk diffusion) revealed out of 167(27.833%) E.coli isolates were 25(4.166%) gentamicin-resistance. Antibacterial agents susceptibility of 25 gentamicin-resistant E.coli isolates showed concern level of resistance among different categories of antibacterial agents, ranged from high resistance 25(100%) for nalidixic acid to less rate of resistance 4/25(16%) by imipenem drug. Molecular data have demonstrated the prevalence of associated resistance genes for both aminoglycosides and fluoroquinolones. Among 25 gentamicin-resistant E.coli isolates 24/25(96%) were harbours for the genes gyr-B, aac(6’)-Ib-cr, strA/B, and 23/25(92%) of isolates were harbouring for the genes gyrA, qnrS, and aacC-2. In contrast, qnr-B, aac(6′)/aph(2′), and aph(3)lla were identified in 20/25(80%), 11/25(44%) and 8/25(32%) respectively. At the same respect, aacC-1, qnrA, and qnrC genes were no detect in the current study. However, 24/25(96%) of isolates were carrying the class 1integron (intel-1) gene.