title: The effect of in vitro bacterial association on virulence of Entamoeba histolytica.
abstract: When trophozoites of axenic E. histolytica strains NIH : 200 were associated in vitro with Escherichia coli K12 for three hours at 37 degrees C, the virulence was enhanced as shown by increased cytopathogenicity to baby hamster kidney (BHK) cell monolayer. Further, the trophozoites were observed to adhere to the polystyrene surface, a hitherto unreported phenomenon. The co-association of E. histolytica trophozoites with Bacteroides fragilis and Clostridium perfringens for three hours duration at 37 degrees C neither led to increase in cytotoxicity potential nor to adherence phenomenon; in contrast significant inhibition of cytotoxicity was observed. We have thus shown that while co-association of E. histolytica (NIH : 200) with E. coli K12 leads to enhanced amoebic virulence, that with anaerobic bacteric leads to its inhibition.
authors.affiliation: Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow.
authors.forename: P
authors.initials: P
authors.lastname: Sinha
authors.forename: S
authors.initials: S
authors.lastname: Naik
authors.forename: A
authors.initials: A
authors.lastname: Ayyagari
authors.forename: S R
authors.initials: SR
authors.lastname: Naik
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D004748:Entamoeba histolytica / Q000472:pathogenicity*; D014774:Virulence