The effect of enterocin produced from Enterococcus faecalis and Lactobacillus gasseri filtrates on Enteropathogenic Escherichia coli causing diarrhoea in Iraqi children

Abstract

Enteropathogenic Escherichia coli (EPEC) is one of the most prominent causative agents of diarrhea. This study aimed to isolate and identify pathogenic E. coli and to show their resistance to antibiotics, in addition to evaluating the inhibitory effect of enterocins produced by Enterococcus faecalis and Lactobacillus gasseri against these isolates. The results revealed the isolation of 103 EPEC isolates (68.66%), with isolation rates reaching 73% from stool samples and 60% from rectal swabs. Colonies exhibited diverse growth characteristics on selective and enriched media, and microscopic and biochemical examinations confirmed the diagnosis. Antibiotic susceptibility testing revealed that most EPEC isolates were multidrug-resistant (MDR), with the highest resistance to cefixime (39.80%) and Levofloxacin 40 (38.83%). Conversely, they showed the highest sensitivity to Amikacin 86 (83.49 %), and Azithromycin and Gentamicin 77 (74.75%). As for enterocin-producing bacteria, L. gasseri accounted for 40% of the isolated cases, while E. faecalis accounted for 26.6%. Diffusion tests in solid and liquid media showed that the filtrates from these isolates possessed inhibitory activity against EPEC, with inhibition zone diameters ranging from 8–14 mm for L. gasseri and 8–12 mm for E. faecalis. These results confirm that enterocins represent promising alternatives or complements to conventional antibiotics against multiresistant E. coli isolates, paving the way for their use as probiotics or future therapeutic agents, provided their safety and efficacy are clinically verified.