Evaluation of Antibiotic Resistance and Biofilm Formation Ability Uropathogenic E. coli (UPEC) Isolated From Pregnant Women in Karaj

 Uropathogenic Escherichia coli (UPEC) are the most common cause of urinary tract infections. The binding of these bacteria to epithelial cells and the formation of biofilms cause these bacteria to be further colonized and difficult to remove in the urinary tract. This study aimed to determine the antibiotic resistance and to evaluate the biofilm formation power in Escherichia coli isolated from pregnant women in the city of Karaj, Iran.

This descriptive-analytical study was performed on 64 isolates of UPEC. Identification of these bacteria was determined using biochemical tests and antibiotic resistance by Kirby – Bauer method and according to the recommendation of the Clinical and Laboratory Standards Institute (CLSI 2017) guideline. The ability to form biofilms, using the microtiter plate method and the presence of papC and sfa genes was examined by Duplex PCR.

Based on the results; the highest levels of resistance were related to cotrimoxazole (40.6%), and ampicillin (31.3%). The examination of biofilm formation by the phenotypic method also showed that of the isolates, 48.4% (strongly), 15.6% (moderately) and 21.8% (weakly) have biofilm formation power. Based on the obtained Duplex PCR results, 15 isolates had papC gene, 10 isolates had sfa gene and 9 isolates had both genes simultaneously. 100% of the isolates with both papC and sfa genes were able to produce biofilms.

The results showed that most UPEC causing urinary tract infections can form biofilms. Also, the abundance of papC and sfa genes encoding pili in these strains can act as one of the binding factors of this bacterium.