Biofilm Formation and Antibiotic Resistance in Uropathogenic Escherichia coli : A Molecular Characterization and Antibiogram Study

Abstract

Biofilm formation is a key virulence factor in urinary tract infections, and Escherichia coli (E. coli) serves as a prominent causative agent, more resistant to antimicrobial agents. This study focused on isolation and phenotypic and genotypic characterization of E. coli from urine samples on the basis of their biofilm-forming capacity. In the present study, a total of 804 human urine samples were collected from different clinical facilities of Faisalabad. After phenotypic and genotypic affirmation, biofilm forming potential of uropathogenic E. coli (UPEC) was determined by using microtiter plate assay (MPA) and the Congo red agar method. Antimicrobial susceptibility testing was conducted, and a comparison was executed between biofilm formers and non-formers. Biofilm production by the MPA and Congo red agar methods was 88% and 68%, respectively. UPEC isolates showed maximum resistance to amoxicillin-clavulanate (97%), cefoparazone (93%), cefotaxime (91%), and ampicillin (90%). Significant association between resistance to antibiotic and biofilm formation with p value <0.05 was observed in case of piperacillin-tazobactam, imipenem, meropenem, amikacin, norfloxacin, nitrofurantoin, polymyxin B, and nalidixic acid. Biofilm producer strains were progressed for molecular characterization using polymerase chain reaction for biofilm-forming genes including fimH, csgA, bcsA, agn43, papC, and focG, which showed prevalence of 89% (118/132), 87% (116/132), 86% (114/132), 81% (107/132), 47% (61/132), and 33% (43/132), respectively.