Investigating the correlation between carbapenem resistance and biofilm production in Escherichia coli isolates from urinary tract infections

Objective: The objective of the study was to examine carbapenem resistance and biofilm production in Escherichia coli isolates recovered from urinary tract infections (UTIs). Materials and Methods: A prospective, cross-sectional observational study was conducted in different labs in around Ludhiana and Chandigarh, India from September 2024 to February 2025. A total of 380 isolates were recovered from UTIs. Carbapenem resistance and biofilm production were checked phenotypically and the presence of β-lactamase genes by polymerase chain reaction (PCR). Isolate relatedness was determined by repetitive element based PCR, and enterobacterial repetitive intergenic consensus PCR. Results: From September 2024 to February 2025, in this study, out of 380 isolates, 269 (70%) were found to be extended-spectrum beta-lactamase producers resistant to ceftazidime, aztreonam, cefotaxime, and ceftriaxone (minimum inhibitory concentration [MIC] ≥16 μg/mL). Out of these, 28 (53.8%) exhibited reduced susceptibility to ertapenem meropenem and imipenem (MIC ≥8 μg/mL). Among these 380 isolates, 137 had shown metallo-beta lactamase enzyme production (36%). Conclusions: The significant presence of both metallo beta-lactamase genes and biofilm co-existence in the same isolates is worrisome.