Pathogenicity of Entamoeba dispar under xenic and monoxenic cultivation compared to a virulent E. histolytica.
Two xenic isolates and cloned cultures of Entamoeba dispar were submitted to monoxenization using Crithidia fasciculata as the associated organism. Growth in monoxenic cultivation and ability of xenic and monoxenic trophozoites to destroy VERO cells and produce lesions in hamster livers were compared to those of a virulent E. histolytica. Parental and cloned E. dispar under monoxenic cultivation showed a remarkable lower growth than the monoxenic E. histolytica and were avirulent in both in vivo and in vitro tests. When xenically cultured, trophozoites of E. dispar showed a moderate lytic activity against VERO cells (1.5 to 41.8% of destruction) but caused severe hepatic lesions in hamsters as those caused by the virulent E. histolytica (29 to 100% in prevalence and 0.86 to 4.00 in lesion degree). Although E. dispar has not been associated with invasive disease in men, the ability of xenic trophozoites to produce prominent tissue damage in experimental conditions has indicated that some strains have a considerable pathogenic potential when in presence of bacteria.
Costa
Adriana Oliveira
AO
Departamento de Patologia Básica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Curitiba, PR, Brazil. adrincosta@ufpr.br
Gomes
Maria Aparecida
MA
Rocha
Orivaldo Alves
OA
Silva
Edward Felix
EF
D000818:Animals; D002522:Chlorocebus aethiops; D006224:Cricetinae; D016831:Crithidia fasciculata; D003470:Culture Media; D004747:Entamoeba / Q000254:growth & development / Q000472:pathogenicity*; D004748:Entamoeba histolytica / Q000254:growth & development / Q000472:pathogenicity; D006801:Humans; D008099:Liver / Q000469:parasitology* / Q000473:pathology; D014709:Vero Cells; D014774:Virulence
D003470:Culture Media