Evaluation of the presence of pap, sfa, and fimH genes in imipenem-resistant Escherichia coli isolated from the patients with urinary tract infections from the laboratories of Amol in 2018-2019

Urinary tract infection is one of the most common bacterial infections in the world and Europathogenic Escherichia coli is one of the main causes of this infection. The presence of fimbrial genes causes the bacteria to attach to the cells of the urinary tract. The aim of the present study was to evaluate the presence of 3 fimbrial genes papEF, sfaD, and fimH in Escherichia coli isolated from patients with urinary tract infections.

In the current cross-sectional study, 235 urine samples were randomly collected from patients referred to different laboratories in Amol between 2018-2019. First, each sample was cultured separately on EMB agar and then analyzed using biochemical tests, such as IMViC, TSI, and urease. In positive samples for the presence of Escherichia coli, antibiogram test was performed to evaluate the sensitivity to the imipenem. After DNA extraction from imipenem resistant samples via boiling method, the presence of papEF, sfaD, and fimH genes was examined using Polymerase Chain Reaction (PCR). The results of the study were analyzed in SPSS, version 22. Statistical analyses were performed running Man-Whitney and Chi-square tests with a significance level of P<0.05.

From among the 235 urine samples, 75 (31/9%) contained Escherichia coli bacteria. Also, 47 samples (62/7%) were detected from imipenem-resistant Escherichia coli isolates. After PCR reaction, it was found that 28 isolates (59/6%) were positive for fimH gene, 8 isolates (17%) were positive for papEF gene, and 19 isolates (40/42%) were positive for sfaD gene. The results showed that, among the studied strains, fimH gene was the most common gene encoding fimbriae in Escherichia coli isolated from urinary tract infection in Amol city. However, this finding was not statistically significant (P <0.05). Also, in the statistical study of the results of antibiotic resistance and the presence of fimbrial virulence genes, no significant relationship was observed between the variables (P <0.05).

It seems that fimH gene is the most common gene encoding fimbrial in Escherichia coli isolated from urinary tract infections in Amol city and is an important factor in the pathogenicity of this bacteria. Most cases of urinary tract infections are associated with Escherichia coli bacteria that contain these genes, so its early detection in patients with urinary tract infections can help treat patients in a faster and better way.