Survey on Biofilm Production and Presence of Attachment Factors in Human Uropathogenic Strains of Escherichia coli

Background Escherichia coli is one of the most common causes of different infections. Biofilm structure allows the strains to persist on the biotic and abiotic surfaces for a long time and impairs eradication. Surface colonization of E. coli could be done with several extracellular appendages, which are effective productive events leading to biofilm maturity. Objectives In this study, the possible relationship between the presence of fimA (encoding large subunit of Type I fimbriae) and csgA (encoding curli fimbriae) genes with biofilm formation in extraintestinal pathogen E. coli isolates was evaluated. Methods For this study, 35 isolates of E. coli were collected from human urine samples of those referred to oil big hospital. After isolating and identifying E. coli strains by common biochemical tests, we examined the biofilm formation of isolates in brain heart infusion broth, which contained 3% sucrose, using microtiter plate crystal violet method. Presence of the 2 studied genes in the isolates was evaluated using multiplex polymerase chain reaction (m-PCR) assay. Results In the present study, 27 strains from 35 isolates were expressed in the 2 studied attachment- associated factors, but 5 and 2 strains were expressed by csgA and fimA, respectively. Except 2 strains that could not produce biofilm, 1 strain was detected as a moderate biofilm producer, and the 32 remaining strains were detected as weak biofilm producers. Conclusions All the positive and the 2 negative biofilm producer strains could be expressed in the 2 studied genes. The correlation between the presence of studied genes and biofilm production ability was suspected, but because of the high percentage of biofilm production in the studied strains, the need to use good hygiene practices is highly recommended.