Molecular Identification of Escherichia coli in Pediatric Diarrheal Illnesses

Abstract

 Background: Diarrheagenic Escherichia coli (DEC) continues to be a major contributor to morbidity and mortality in young children globally. This study sought to examine the prevalence, age distribution, and clinical correlations of E. coli pathotypes in pediatric patients both with and without diarrhea. 

Methods: Stool samples were collected and analyzed from 94 children aged between 1 and 5 years. Patients were classified according to clinical presentation (with diarrhea, without diarrhea, and with diarrhea alongside concurrent medication treatment) and age demographics. E. coli was isolated utilizing selective medium and verified through PCR amplification of specified genomic targets (16S rRNA gene, 520 bp). Statistical analyses encompassed chi-square tests, trend analysis, and post-hoc comparisons. 

Results: E. coli was effectively isolated and identified through characteristic colony morphology on selective media Eosin Methylene Blue agar (EMB agar), exhibiting typical tiny, round, white colonies with unusual green colouring. PCR analysis verified the presence of E. coli in 74 (78.72%) of the 94 samples, a statistically significant proportion (p<0.0021). Analysis of diarrheal case distribution indicated notable age-dependent trends (p<0.001), with a predominant occurrence of cases

(77.7%) in the initial two years of life. Patients experiencing diarrhea without pharmacological intervention represented the biggest cohort (55.3%), with the highest prevalence observed in the 1-2 year age group (60.0%, p=0.002). Instances of diarrhea accompanied by drug therapy (14.9%) shown a statistically significant decrease over time (p=0.008). A notable correlation was identified between the time period and diarrheal status (chi-square=26.4, df=8, p<0.001). 

Conclusions: This study reveals the considerable incidence of E. coli in pediatric patients and identifies substantial age-dependent distribution patterns of diarrhea. The prevalence of instances during the initial two years of life, especially within the 1-2 year age bracket, underscores a crucial period for monitoring and intervention. The notable relationship between age and clinical manifestation indicates that age-related pathogenic pathways or host variables may affect E. coli-related diarrheal illness in children.