Molecular analysis of citotoxic necrotizing factor, colibactin, cytoletal distension toxin in uropatogenic escheri̇chia coli (UPEC) from iraqi patients with urinary system infection

This study was aimed at determining the distribution of virulence toxin genes (cnf1, clb, and cdt) in UPEC isolates with hemolysin activity. In addition, investigating the expression level of regulatory small RNA, RfaH, in UPEC isolate with hemolysin activity and cytotoxic necrotizing factor. Urine samples (248) were collected from male, female, and children patients suspected of urinary tract infections (UTIs) at different ages. After culturing these samples on different bacteriological media, it was found that 157 samples were infected with pathogenic bacteria in which 93 (37.5%) samples were infected with E. coli, and 91(36.69 %) samples had no growth. According to the gender as risk factors, it was found UTIs are more incidences in females (70.97%) than males (29.03%) with significant differences (16.35, p≤ 0.0001). However, according to the age it was found adults were more susceptible (75.27%) to UTIs than children (24.7%), with significant differences (23.75, p≤0.0001). The hemolysin production of UPEC isolates was examined, results indicated that (5.1%) isolates (H22, H33, H40, H48, and H53) of E.coli isolates were produced hemolysin on human blood agar. The UPEC isolates were high resistance (100%) to ampicillin and amoxicillin/clavulanic acid, and sensitive (91%) to ciprofloxacin. The prevalence of virulence genes including cnf 1, cdtIII, and clbA in five Hemolytin-Producing UPEC isolates was detected by PCR. It was indicated among four of these isolates (H22, H40, H48, and H53) harbor toxin encoding genes (cnf 1 and clbA) with high frequency (100%), one isolate ( H33) was negative for both genes, cnf1, and clbA, while all five isolates had no cdtIII gene. Moreover, the expression level of regulatory small RNA, RfaH, in UPEC isolates with hemolysin activity and cytotoxic necrotizing factor was investigated by using RT-qPCR. The expression of Hly and cnf1 genes was correlated with the RfaH gene; the folding value was 2.51, 5.89, and 4.19 respectively.