Related Experiment Videos
An ultrastructural study of enteropathogenic Escherichia coli infection in human infants
Insights
Enteropathogenic Escherichia coli O119 causes protracted diarrhea in infants by damaging intestinal epithelial cells. This leads to villous atrophy and reduced nutrient absorption, impacting the entire infant intestinal tract.
Area of Science:
- Pediatric Gastroenterology
- Microbiology
- Pathology
Background:
- Protracted diarrhea in infants can be a severe condition.
- Enteropathogenic Escherichia coli (EPEC) is a known cause of infant diarrhea.
- The specific mechanisms of EPEC O119-induced intestinal damage require further elucidation.
Purpose of the Study:
- To investigate the pathological effects of enteropathogenic Escherichia coli serogroup O119 (EPEC O119) in infants with protracted diarrhea.
- To characterize the histological and ultrastructural changes in the infant intestinal tract caused by EPEC O119.
Main Methods:
- Study and treatment of 18 infants diagnosed with protracted diarrhea.
- Analysis of jejunal and rectal mucosal biopsies using light and electron microscopy.
- Identification and characterization of E. coli O119 in stool and jejunal samples.
Main Results:
- Persistent E. coli O119 infection and jejunal overgrowth were observed in all patients.
- Histological examination revealed villous atrophy, chronic inflammation, and epithelial cell damage throughout the small intestine and rectum.
- Electron microscopy demonstrated E. coli O119 adherence to enterocytes, loss of microvilli, and intracellular damage.
Conclusions:
- E. coli O119 causes significant epithelial cell damage and ultrastructural alterations in the infant intestinal tract.
- This damage results in villous atrophy and a reduced absorptive surface area, leading to protracted diarrhea.
- E. coli O119 is a critical pathogen responsible for severe intestinal injury and malabsorption in affected infants.
Abstract:
Over the past 2 years, we have studied and treated 18 infants with protracted diarrhea due to an enteropathogenic Escherichia coli serogroup 0119. All patients had persistent stool escretion and jejunal over-growth with this pathogenic E. coli. Jejunal biopsy revealed atrophy of villi with a chronic inflammatory cell infiltrate in the lamina propria. E. coli 0119 adhered to the luminal surface of enterocytes. Electron microscopy showed disappearance of glycocalyx and microvilli at the areas of bacterial adherence. Intracellular damage was indicated by dilatation of rough endoplasmic reticulum, mitochondrial changes, and cytoplasmic pallor. Similar changes in histology and ultrastructure occurred in ileal epithelial cells. Glandular crypt epithelium showed prominent subnuclear vacuolation and separation of lateral intercellular junctions throughout the small intestine. Rectal mucosal biopsy showed mucus depletion and irregular atrophy of the epithelium, with E. coli 0119 adherent to the luminal surface. Ultrastructural damage paralleled that in the small intestine. E. coli 0119 causes damage to epithelial cells throughout the infant intestinal tract. This damage leads to atrophy of villi and a marked reduction in absorptive surface area, resulting in protracted diarrhea.