HAEMAGGLUTINATION PATTERNS OF ENTEROPATHOGENIC ESCHERICHIA COLI ISOLATED FROM DIARRHEIC CHILDREN OF DIFFERENT BLOOD GROUPS

Background: Because of bacterial pili, the agglutination of erythrocytes with bacteria has been demonstrated to be facilitated. The usage of sugars such as mannose for inhibition of hemagglutination with certain bacterial strains giving d differential patterns of haemagglutination for different types of bacteria depending on types of pili including enteropathogenic Escherichia coli (EPEC). Materials and Methods: A total of 614 children feces samples (363 diarrhetic from children hospital and 251 healthy children from Mosul nurseries). All children were under three years of age. Fecal samples were transported to research laboratory using nutrient broth as transport medium for rectal swabs. EPEC identification, serotyping and haemagglutination were carried out. Results: The data indicated that blood group O exhibited the highest overall frequency of enteropathogenic E. coli infection (41.4%), followed by blood group B (31.7%), A (24.4%), and AB (2.4%). Cases from the hospital were predominantly associated with blood groups O and B, whereas blood group A was observed exclusively among nursery children. The present study revealed that serotypes O126 and O142 were the most common (7 isolates each). But Serotype O126 was strongly associated with blood group O (5 isolates) and serotype O142 was concentrated in blood groups A and B. Blood group AB contained only one isolate. Among the serotypes examined, O86, O142, and the mixed serogroup OI+II+III exhibited the broadest spectrum of positive reactions across multiple erythrocyte types, indicating stronger and more versatile adherence capabilities. Conversely, several isolates of O111, O125, O126, and O127 showed predominantly negative reactions, suggesting lower hemagglutinating potential. Conclusions: The data indicated that blood group O exhibited the highest overall frequency of enteropathogenic E. coli infection (41.4%), followed by blood group B (31.7%), A (24.4%), and AB (2.4%). Cases from the hospital were predominantly associated with blood groups O and B, whereas blood group A was observed exclusively among nursery children. Analysis of 600 pediatric subjects demonstrated an overall diarrhea prevalence of 6.8%. Blood group B exhibited the highest prevalence of Escherichia coli diarrhea (8.55%), followed by blood groups O (7.26%) and A (5.35%). Serotypes O126 and O142 were the dominant serotypes, accounting for the highest frequencies observed. Blood group A exhibited the highest frequency of positive hemagglutination reactions under both mannose-treated and untreated conditions, suggesting that A-group erythrocytes possess receptors that are highly favorable for EPEC attachment.