title: Entamoeba histolytica: cysteine proteinase activity and virulence. Focus on cysteine proteinase 5 expression levels.
abstract: Cysteine proteinase (CP) activity and CP5 mRNA levels were analyzed in eleven samples of Entamoeba histolytica isolated from patients presenting different clinical profiles. The virulence degree of the isolates, determined in hamster liver, correlated well with the clinical form of the patient and culture conditions. CP5 mRNA levels were also determined in sample freshly picked up directly from liver amoebic abscess. Differences were not observed in the levels of CP5 mRNA and CP specific activity among the cultured samples. However, different levels of CP5 mRNA were observed in trophozoite freshly isolated from hepatic amoebic lesions. These results reinforce the importance of CP5 for the virulence of amoebae and the need for studies with the parasite present in lesions to validate mechanisms involved in pathogenesis of amoebiasis.
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: Michelle A R
authors.initials: MA
authors.lastname: Freitas
authors.forename: Helen C
authors.initials: HC
authors.lastname: Fernandes
authors.forename: Viviane C
authors.initials: VC
authors.lastname: Calixto
authors.forename: Almir S
authors.initials: AS
authors.lastname: Martins
authors.forename: Edward F
authors.initials: EF
authors.lastname: Silva
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Pesquero
authors.forename: Maria A
authors.initials: MA
authors.lastname: Gomes
mesh_terms: D000818:Animals; D006224:Cricetinae; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004748:Entamoeba histolytica / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D004749:Entamoebiasis / Q000469:parasitology* / Q000473:pathology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008099:Liver / Q000469:parasitology / Q000473:pathology; D008101:Liver Abscess, Amebic / Q000469:parasitology* / Q000473:pathology; D008647:Mesocricetus; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D014774:Virulence
chemical_list: D012333:RNA, Messenger; D003546:Cysteine Endopeptidases