Investigation of genes coding siderophores in uropathogenicEscherichia Coli in Iraqi patients

This study is aimed to investigate the influence of iron ions on the expression of siderophore genes (iucA, iroN, and irp2) in uropathogenic Escherichia coli (UPEC) isolates that isolated from Iraqi patients with urinary tract infections (UTIs). Urine samples (230) were collected from patients suspected of urinary tract infections (UTIs) at different ages. After culturing these samples on different culture media, 109 (68.81%) of samples were infected with E. coli while 51 (22.17%) of samples were negative growth. According to the gender, women were more effected with UTIs than men with significant differences (p≤0.05) the percentage of infection was 68.81% and 31.19% respectively. The resistance of UPEC isolates to antibiotics was investigaed, the isolates were high resist (98%) to ampicillin and amoxicillin/clavulanic acid. The most important factor in the persistence and recurrence of UTIs is the ability of UPEC to form a biofilm, and in this study 77.5% of UPEC isolates were biofilm producers. The siderophore production as urovirulence marker in biofilm-producing UPEC isolates was detected by amplifying genes encoding siderophore production, yersiniabactin gene (irp2), salmochelin gene (iroN), and aerobactin gene (iucA) using PCR. The results demonstrated a positive correlation between biofilm formation and siderophore production in bacteria. Furthermore, the effect of 1 mM of iron ions (Fe 2+, Fe 3+) on expression level of siderophore genes (irp2, iroN, and iucA) in UPEC isolates was investigated using realtime quantitative PCR. The results indicaed ferrous ion induced the expression of the genes encoding siderophore production, particularly a significant (p≤0.05) upregulation was noticed in the expression of icuA gene. In contrast, 1 mM ferrric ion was significantly (p≤0.05) downregulated siderophore genes.