Prevalence of Escherichia coli strains with localized, diffuse, and aggregative adherence to HeLa cells in infants with diarrhea and matched controls
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T A Gomes1, P A Blake, L R Trabulsi
1Department of Microbiology, Immunology, and Parasitology, Escola Paulista de Medicina, São Paulo, Brazil.
Insights
Localized adherence Escherichia coli (E. coli) strains are a significant cause of infant diarrhea in Brazil. This finding highlights the importance of identifying specific E. coli adherence patterns for diagnosing pediatric diarrheal diseases.
Area of Science:
- Microbiology
- Pediatrics
- Infectious Diseases
Background:
- Diarrheal illnesses in infants pose a significant public health challenge globally.
- Escherichia coli (E. coli) can cause diarrhea through various adherence mechanisms to host cells.
- Understanding the specific roles of different E. coli adherence patterns is crucial for effective diagnosis and treatment.
Purpose of the Study:
- To investigate the association between distinct Escherichia coli adherence patterns to HeLa cells and infantile diarrhea in São Paulo, Brazil.
- To evaluate the prevalence of E. coli with localized, diffuse, and aggregative adherence in infants with acute diarrhea compared to healthy controls.
- To assess the diagnostic accuracy of a genetic probe for detecting localized adherence E. coli.
Main Methods:
- Stool specimens were collected from 100 infants with acute diarrhea and 100 age-matched controls.
- E. coli strains were isolated and characterized for adherence patterns (localized, diffuse, aggregative) to HeLa cells.
- A genetic probe targeting a plasmid-mediated adhesin for localized adherence was employed for detection and specificity testing.
Main Results:
- E. coli exhibiting localized adherence was significantly more prevalent in diarrheal patients (23%) than in controls (2%) (P < 0.0001).
- Localized adherence E. coli was detected more frequently than rotavirus in patients during the study period.
- No significant difference in the isolation rates of diffuse or aggregative adherence E. coli was observed between patients and controls.
Conclusions:
- E. coli strains with localized adherence to HeLa cells are strongly associated with acute diarrheal illness in Brazilian infants.
- The genetic probe demonstrated high sensitivity (100%) and specificity (99.9%) for identifying localized adherence E. coli.
- The etiological role of diffuse and aggregative adherence E. coli strains in infant diarrhea remains uncertain.
Abstract:
To determine the possible role of Escherichia coli strains with three different patterns of adherence to HeLa cells in causing diarrhea in infants in São Paulo, Brazil, we studied stool specimens from 100 infants up to 1 year of age with acute diarrheal illnesses and 100 age-matched control infants without recent diarrhea. E. coli with localized adherence to HeLa cells was much more common in patients (23%) than in controls (2%) (P less than 0.0001) and was detected more frequently than rotavirus (19%) was in patients, even though the study was conducted during the coldest months of the year. Most (80%) of the E. coli colonies with localized adherence were of traditional enteropathogenic E. coli serotypes. Little difference was found between patients and controls in the rate of isolation of E. coli with diffuse adherence (31 and 32%, respectively) or aggregative adherence (10 and 8%, respectively). A genetic probe used to detect a plasmid-mediated adhesin which confers expression of localized adherence proved to be 100% sensitive and 99.9% specific in detecting E. coli with localized adherence to HeLa cells. Although E. coli strains with localized adherence have now been shown to be enteric pathogens in several parts of the world, the role of strains showing diffuse adherence and aggregative adherence is still uncertain.