Evaluation of biofilm formation in molecular identification E.coli strains that cause urinary tract infection in children and antibiotic resistance

Background Escherichia coli is the primary causative agent of urinary tract infections (UTIs), which are among the most common illnesses in humans and frequently occur in children. Because this bacterium has biofilm formation and multi-drug resistance, and other factors, managing these infections is getting harder. The purpose of this study is to identify the E. coli strains that cause UTIs in children, and study the correlation of biofilm formation, and antibiotic resistance of E coli isolates found in Diyala, Iraq. Patients and Methods: It was collected 290 cases of UTI patients from Al-Batoul Teaching Hospital in Diyala, Iraq. The ages of these patients from 1 day to 12 years who were treated in the Paediatrics Department from February 2023 to January 2024. It was identify the strains of E. coli that cause UTIs by using PCR and sequencing methods and evaluated antimicrobial susceptibility of them by means of the Kirby-Bauer technique. The microtiter-plate assay were used to assess the production of biofilms. Results The predominant bacteria responsible for UTI in children were E. coli (40%), and it was showed that are the lowest persentage of bacteria causing UTI in this study are Klebsiella oxytoka and Psuedomonas aureginosa as appeared in 5% of cases. It was identify the strains of E. coli that cause UTI in the current study, which are E. coli Y8-2 (14.8%), E. coli 106K88 (19.3%), E. coli UA32 (11.4%), E. coli RM11911 (20.5%), and E. coli EC1704-1 (34%). E. coli EC1704-1 showed multidrug-resistant (MDR) to ciprofloxacin (100%), sulfamethoxazole-trimethoprim (100%), cephalosporins and penicillin (100%), and aminoglycosides (93.3%). E. coli Y8-2, E. coli 106K88, and E. coli UA32 appeared less resistant to antibiotics related to E. coli EC1704-1 and E. coli EC1704-1. In addition, it was shown that biofilm formation and antimicrobial resistance correlated negatively among the isolates, strong biofilm production strains were found in less resistant strains and weak in multidrug resistant strains. Conclusion E. coli is the predominant cause of UTI in children and it was identified the E coli strains which are the most common strains that cause UTI in Diyala, Iraq. This research highlights the dissemination of resistance in E. coli strains in Diyala, Iraq. The evident correlation between biofilm and resistance suggests a resistance cost on bacterial cells, and that strains with lower resistance may depend on biofilms to enhance their survival. This emphasizes the importance of considering biofilm formation ability during the treatment of E.coli infections to avoid therapeutic failure and infection recurrence.