AHMED A. MHAWESH*, AHMED YASEEN AL-TARBOOLEE AND YASEEN ISMAEL MAMOORI
Department of Molecular and Medical Biotechnology, College of Biotechnology, Al-Nahrain University, Baghdad,
Iraq
*(e-mail: alshammariahmed.a.m@gmail.com; Mobile: +964 78277 46363)
(Received: January 23, 2023; Accepted: March 15, 2023)
ABSTRACT
Azithromycin is a proper antibiotic for eradication of infections caused by Gram-negative species. Our aim
was determination of azithromycin resistance levels among carbapenem-resistant E. coli (CR-E. coli). Two hundred E. coli were identified. The minimum inhibitory and bactericidal concentrations (MIC and MBC, respectively) of imipenem and azithromycin were determined using agar dilution method. PCR was implemented to verify the existence of resistance genes. One-hundred E. coli isolates were carbapenem- resistant. Thirty-five CR-E. coli and five carbapenem-susceptible E. coli (CS-E. coli) isolates were resistant to azithromycin, respectively. The azithromycin MIC ranged from 16-64 µg/ml and its MBC ranged from 32-64 µ/ml, respectively. The carbapenem resistance genes included blaIMP (32%) and blaOXA-48 (3%) genes. Furthermore, azithromycin resistance genes included mph (A) (12% in CR-E. coli and 3% in CS-E. coli) and erm (A) (4% in CR-E. coli) genes. Three CR-E. coli isolates had concomitantly the blaOXA-48, blaIMP, erm (A) and mph (A) genes. None of them were resistant to colistin. Azithromycin resistant E. coli was most probably developed from CR-E. coli than CS-E. coli. Spread of these strains in the era of Corona virus pandemic was a crisis to eradicate multidrug-resistant (MDR) strains.
Key words : Azithromycin resistance, carbapenem-resistant Escherichia coli, Iraq