Evaluation of antibiotic resistance and biofilm production in Escherichia coli isolated from clinical samples in Kirkuk city

Escherichia coli (E. coli) is a prominent etiological cause of bacterial infections. Biofilms form when cells are embedded within a matrix of extracellular polymeric substances that bond to each other or to either inert or living surfaces. It increases antibiotic resistance by maintaining cells. The study aims to determine the biofilm formation and antibiotic susceptibility patterns of E. coli isolates. A total of 200 clinical samples were collected from Kirkuk city hospitals, including urine, sputum, wound, and burn swabs. Forty isolates were classified as E. coli. An antibiotic sensitivity test was conducted using the disc diffusion method with fourteen antibiotic discs. A microtiter plate method was used to detect biofilm. The study revealed antibiotic resistance rates against Ceftriaxone 33 (82.5%), Ceftazidime and Trimethoprim-sulfamethoxazole 32 (80%), Tetracycline 28 (70%), Cefepime 27 (67.5%), Ciprofloxacin and Aztreonam 32 (57.5%), Amoxicillin-clavulanate 12 (30%), and Piperacillin-tazobactam 11 (27.5%). The most effective antibiotics were nitrofurantoin, meropenem, imipenem, chloramphenicol, and gentamycin, with susceptibilities (100%, 90%, 85%, 85%, 75%), respectively. The biofilm production of the E. coli isolates ranged from weak 30 (75%) to moderate 9 (22.5%), and strong 1 (2.5%). The study concluded that all antibiotic-resistant isolates were biofilm producers.