Distribution of pathogenicity islands among Escherichia coli strains from Mansoura University Hospitals.

Background: The pathogenic side of Escherichia coli is afforded via horizontal transfers of genes encoding virulence factors that enables this bacterium to be responsible for intestinal or extraintestinal diseases in humans and animals. Pathogenicity islands (PAIs) are a group of large (>10 kb) integrative elements that encode one or more virulence genes which are absent from the genomes of non-pathogenic bacteria. Objective: This study was carried out to detect the pathogenicity islands (PAIs) of E. coli isolated from Mansoura University Hospitals. Methods: This study was conducted over one year from January 2022 to December 2022. Urine, stool and Bronchoalveolar lavage (BAL) samples were collected from adult patients who were admitted at Mansoura University Hospitals and showed manifestations of hospital acquired UTI, diarrhea or pneumonia. The samples were cultured on MacConkey's, blood, nutrient, and CLED agar, then identified by colony morphology, Gram stained film and API 20E. PAIs were detected by multiplex PCR reaction (A & B). Results: Thirty E. coli strains were isolated from 30 adult patients (18 female and 12 male) samples from 18 urine (60%), 6 stool (20%) and 6 BAL (20%). Among 30 isolates, PAIs were detected in 25 isolates (83.3%), while no PAIs were detected in 5 isolates. Less than four PAI were present in 11 isolates (36.6%) and more than or equal to four PAI were noticed in 14 ones (46.6%). The highest detected PAI was PAI IJ96 15 (60%) and the lowest detected one was PAI IV536 1 (4%), while PAI II J96 (0.0%) was absent in the present study. Conclusion: The highest PAIs detected among E. coli isolates of our study were PAI IJ96 and PAI III536.