Amebas de vida livre no intestino humano: evidências de parasitismo

Abstract

Foram cultivadas fezes de 620 indivíduos para a pesquisa de amebas de vida livre, sendo 514 pacientes do Hospital Universitário Pedro Ernesto (UERJ) e 106 crianças e adultos de um orfanato. Foram positivas 70 amostras (11,2%) sendo 55 provenientes de pacientes do HU-UERJ e 15 de internos do orfanato. Foram isoladas 60 amostras de Acanthamoeba, 6 de Vahlkampfia, 5 de Hartmannella e 1 Echinamoeba. Alguns indivíduos tiveram cultura de fezes repetidamente positiva para Acanthamoeba durante dois meses de observação. Das amostras de Acanthamoeba isoladas, 28 foram inoculadas em camundongos por via intranasal, tendo sido reisoladas 16 (57,1%) amostras à partir de cérebro e (ou) pulmões dos animais. O estudo histopatológico demonstrou processo inflamatório agudo com presença de polimorfonucleares e amebas no cérebro e pulmões de alguns animais. O encontro de amostras patogênicas em fezes humanas reforça a hipótese do eventual desenvolvimento, em indivíduos portadores, de meningoencefalite amebiana granulomatosa, como infecção oportunística de origem endógena.Cultures for free-living amoebae were made from feces of 620 individuals of which 514 were patients from the University Hospital Pedro Ernesto (Rio de Janeiro) and, 106 were children and adults of an orphanage. Positive results were obtained in 70 specimens (11.2%), 55 from the hospital patients and 15 from the orphanage. 60 Acanthamoeba, 6 Vahlkampfia, 5 Hartmannella and, 1 Echinamoeba were isolated. Some individuals were repeatedly positive for Acanthamoeba during the 2 months of observation. Of the isolated Acanthamoeba, 28 were inoculated intranasally. 16 Strains (57.1%) were reisolated from brain and or lungs of the animals. The histopathology revealed an acute inflammatory process with polymorphonuclear neutrophils and amoebae in the brain and lungs of some of the animals. The isolation of pathogenic strains of Acanthamoeba from human feces supports the hypothesis of eventual development, in carriers, of granulomatous amebic meningoencephalitis as an opportunistic endogenous infection.