title: Inflammatory diarrhea due to enteroaggregative Escherichia coli: evidence from clinical and mice model studies.
abstract: BACKGROUND
  This study was conducted to determine the role of enteroaggregative Escherichia coli (EAEC) in inflammatory diarrhea among hospitalized patients in Kolkata. The inflammatory pathogenesis of EAEC was established in mice model and histopathological studies. Presence of fecal leucocytes (FLCs) can be suspected for EAEC infection solely or as a mixed with other enteric pathogens.
  
  
  METHODS
  Active surveillance was conducted for 2 years on 2 random days per week with every 5th patient admitted to the Infectious Diseases Hospital (IDH). Diarrheal samples were processed by conventional culture, microscopy, ELISA and molecular methods. Two EAEC isolated as sole pathogens were examined in mice after induced intestinal infection. The intestinal tissue samples were processed to analyze the histological changes.
  
  
  RESULTS
  Of the 2519 samples screened, fecal leucocytes, erythrocytes and occult blood were detected in 1629 samples. Most of the patients had acute watery diarrhea (75%) and vomiting (78%). Vibrio cholerae O1 was the main pathogen in patients of 5-10 years age group (33%). Shigellosis was more in children from 2-5 years of age (19%), whereas children <2 years appeared to be susceptible for infection caused by EAEC (16%). When tested for the pathogenicity, the EAEC strains colonized well and caused inflammatory infection in the gut mucosa of BALB/C mice.
  
  
  CONCLUSIONS
  This hospital-based surveillance revealed prevalence of large number of inflammatory diarrhea. EAEC was the suspected pathogen and <2 years children appeared to be the most susceptible age group. BALB/C mice may be a suitable animal model to study the EAEC-mediated pathogenesis.
authors.affiliation: Division of Histology & Electron microscopy, National Institute of Cholera and Enteric Diseases, P-33, C,I,T Road, Scheme XM, Beliaghata, Kolkata 700 010, West Bengal, India. dhira.saha@gmail.com.
authors.forename: Dhira Rani
authors.initials: DR
authors.lastname: Saha
authors.forename: Sucharita
authors.initials: S
authors.lastname: Guin
authors.forename: Rajendran
authors.initials: R
authors.lastname: Krishnan
authors.forename: Dhrubajyoti
authors.initials: D
authors.lastname: Nag
authors.forename: Hemanta
authors.initials: H
authors.lastname: Koley
authors.forename: Sumio
authors.initials: S
authors.lastname: Shinoda
authors.forename: Thandavarayan
authors.initials: T
authors.lastname: Ramamurthy