Biofilm Formation and Antibiotic Resistance Pattern of Escherichia coli Isolated from Patients with Urinary Tract Infection

Introduction: Biofilm producing bacteria, which colonize the urinary tract and inherent catheters, indicate higher resistance to standard antibiotics used for the treatment of Urinary Tract Infections (UTI). Frequent studies of this type are required to formulate the impirical treatment strategy for UTI in a particular region. Aim: To compare biofilm formation and antibiotic resistance pattern of Escherichia coli isolated from patients with UTI. Materials and Methods: E. coli was isolated from 220 patients including hospitalized and OPD patients of a tertiary care hospital with symptoms of UTI was included in the study. The isolates were tested for biofilm production by microtiter plate method. The antibiotic susceptibility pattern of the isolates was determined by Kirby–Bauer disc diffusion method as per CLSI guidelines. Extended Spectrum β Lactamase (ESBL) production was detected by double disk approximation test using Ceftazidime 30μg and Ceftazidime/Clavulanic acid (30μg/10μg). Statistical analysis was done using Chi-Square test. Results: Of the 220 E. coli isolates, 109 (49.54%) were ESBL producers and 154 (70%) were biofilm producers. Of the 109 ESBL producing E. coli 108 were sensitive to fosfomycin (99%), 101 ertapenem (92.67%), 99 amikacin (90.8%), 84 imipenem (77%), 83 meropenem (76.14%), 77 netillin (70.64%), 73 tigecycline (66.97%), 71 cefoperazone/sulbactam (65.14%), 67 piperacillin/tazobactam (61.47%) and resistant to rest of the antibiotics under study. Among the biofilm producers 134 (87%) were moderate biofilm producers and 20 (13%) were strong biofilm producers. More numbers of the biofilm producers were resistant to tigecycline than the non biofilm producers (p=0.005). Conclusion: More numbers of ESBL producing E. coli were sensitive to fosfomycin, ertapenem, amikacin, imipenem, meropenem, netillin, tigecycline, cefoperazone/sulbactam, piperacillin/tazobactam and more numbers of the biofilm producers were resistant to tigecycline than the non biofilm producers.