Molecular epidemiology of multidrug-resistant Escherichia coli in paediatric patients: Focus on extended spectrum beta lactamases, quinolones, tetracyclines and sulfonamides resistance genes.

In this study, the molecular determinants of antimicrobial resistance (AMR) among extended spectrum beta lactamase (ESBLs) producing Escherichia coli isolated from children were reported. The samples (n=183) were collected from Children Hospital, Faisalabad-Pakistan and subjected to molecular identification followed by antibiotic susceptibility testing against routine antibiotics. Different ESBLs and antimicrobial resistance genes (ARGs) were detected for quinolones, tetracyclines and sulfonamides. The study showed significant resistance to amoxicillin-clavulanate, ceftriaxone, ampicillin, trimethoprim-sulfamethoxazole, levofloxacin and ciprofloxacin. Molecular analysis showed higher prevalence of β-lactamases i.e. blaSHV (38.9%), blaTEM (100%) and blaCTX-M (100%); quinolones resistance genes as i.e. qnrA (19.4%), qnrB (66.7%), gyrA (47.2%) and parC (36.1%), tetracyclines resistance gene tetB (19.4%) and sulfonamides resistance genes Sul-1 and Sul-2 (100%). The age-group-specific pattern indicated the presence of blaTEM, blaCTX-M, Sul1 and Sul2 in children <4 years. gyrA was more frequently identified in children >4 years. A significant negative correlation was found between ciprofloxacin MIC and qnrB (-0.434, p= 0.010) indicating higher ciprofloxacin resistance. However, a strong negative association was observed between qnrA and qnrB (-0.789, p < 0.001). This study highlighted increasing resistant E. coli infections in children particularly >4 years, emphasizing the strengthening of national antimicrobial stewardship and interventions.