Molecular Typing and Antibiotic-Resistance of Diarrheagenic <i>Escherichia coli</i> Isolated from Diarrhea-Diseased Children in Wasit Province, Iraq

Diarrheagenic Escherichia coli (E. coli) is a common zoonotic bacterial pathogen that becomes increasingly resistant to antibiotics, making treatment difficult. Worldwide, almost E. coli infections are associated with the consumption of contaminated food and water causing a potential threat to the health and welfare of both humans and animals. Isolation and molecular confirmation of pathogenic E. coli from the fecal samples of diarrhea-diseased children, and then, estimation of the antibiotic susceptibility of the study isolates to determinate the antibiotics resistance pattern. A total of 80 fecal samples were collected from diarrhea diseased-children in Wasit province (Iraq) during September to November (2024). All samples were cultivated on McConkey agar, and the pure isolates were sub cultured on Nutrient agar. Targeting the 16S rRNA gene, the fresh positive colonies were confirmed molecularly using the conventional polymerase chain reaction (PCR). Also, the colonies of E. coli were inoculated on the Mueller-Hinton agar, and antibiotic susceptibility testing was conducted using the Kirby-Bauer method. An overall 36.25% (29/80) isolates were identified in diarrhea-diseased children. Targeting the 16S rRNA gene, 40.74% (11/29) were shown a positive reaction to pathogenic E. coli. Antibiotic susceptibility testing for pathogenic E. coli isolates revealed their significant sensitivity to Colisitin, Nitofurantion, Azithromycin, Ciprofloxacillin, Ofloxacine, Imipenem, Meropenem, Levofloxacine, and Nalidixic acid. However, significant high resistance was recorded to Amoxicillin, Amikacin, Ampicillin, Ceftazidime, Ceftriaxone, Cefotaxime and Cefepime; while intermediate resistance was identified to Gentamicin. The findings of MDR revealed that there was significant resistance to one type of Aminoglycosides (Amikacin), two types of Penicillin (Amoxicillin and Ampicillin), and four types of Cephalosporins (Ceftazidime, Ceftriaxone, Cefotaxine, and Cefepime). There is marginal relationship between the isolated pathotypes were isolated in this study and the multiple drug resistance and there is no association between pathotypes, virulence factors, and multiple drug resistance.