Recently, there has been an increase in the prevalence of ulcerative colitis (UC), and inflammatory bowel diseases (IBD) worldwide, especially in certain recently industrialized countries like China and In¬dia. Globally, the prevalence of UC, a chronic illness that affects the large intestine, is rising. Fifty adherent invasive Escherichia coli (AIEC) isolates were identified from ulcerative colitis biopsy samples originating from the Gastrointestinal tract (GIT) and Hepatology teaching hospitals/medical city in Baghdad City. The test’s results demonstrated that the AIEC isolates had a high level of resistance to the majority of the an-tibiotics under investigation. Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) and multiplex PCR, two distinct amplification techniques, were used to genotype AIEC isolates from UC. The presence of genes was tested by multiplex PCR. The results showed that fimH, ibeA, and gipA were 50 (100%), 44 (88%), and 37 (74%), respectively. By using ERIC-PCR, the results showed a similarity level between iso¬lates 92% for AIEC. According to statistical analyses, a correlation was shown between seven clusters, and compared with cluster groups of UC patients, each group of them calculated the mean of virulence factor types, the mean of ERIC-PCR bands, and relative risk (significant differences at p < 0.05). AIEC plays an important role in the pathogenesis of UC according to the macrophage survival assay and genetic content. The content of virulence genes in AIEC isolated from UC showed that the most common is fimH, which plays an important role in adherence to enteric cells of UC patients.
