NOVOS ESTUDOS SÔBRE AMEBAS ENCONTRADAS EM ESGÔTO, COM REFERÊNCIA ESPECIAL A UMA ENDAMEBA (E. MOSHKOVSKII) SEMELHANTE À ENDAMOEBA HISTOLYTICA

Abstract

New studies on amebae found in sewage with special reference to an ENDAMOEBA (E. MOSHKOVSKII) which similar to E. HISTOLYTICA. The authors analyse the publications issued in Russia, U.S.A. and England about an endameba (E. moshkovskii), which is morphologically similar to E.histolytica and which has been isolated from sewage and used water in those countries. The authors who, in 1948, had isolated that protozoan from digested sludge in one of the sewage treatment plants of S. Paulo, Brazil, contim:ied their studies having found this Endamoeba again in material from two other sewage treat ment plants in that city. With endameha, an ameba similar to Hartmannella genus developed in the cultures. They observed that both are cultivated in temperatures ranging from 6 to 2 C but that an optimum is reached b~tween 15 and 37"C. From digested sludge with 78.5% and 41.0% of humidity the authors isolated the Endanweba and the Hartmannella. When humidity was lowered to 9% only this last organism was found and was ·also observed in material with 7.3% humidity kt>pt in the laboratory for 4 years. Although this Hartmannella resisted dessication and time it was affected in its vitality when associated with E. moshkovskii because at the end of 7 months of successive passages it disapeared from cultures. Relative anaerobiosis in the culture media seem harm the multiplication of these 2 amebae. The authors tried to inoculate guinea pigs with Endamoeba with intra-coecal culture injections, having found trophozoites on the intestinal contents only in the animais killed up to 48 hours after inoculation. The histopathological exam of fragment of coeca of the inoculated guinea pigs did not show lesions. The authors considered the fact that man can accidentally swallow cysts of E. moshkovskii and eliminate them with the stools a process which might interfere in the diagnosis of tool exams due to the impossibility of a morphological separation hetween this species and E. hislolytica. For this reason, the authors tried to isolate, from human stools that free living Endamoeba. They preserved at room temperature the cultures with material from cysts passers, because in such conditions the development of E. mosh~ovskii is satisfactory. Results have been nega tive to date. In two cases (of the 16 studies), there was growth of a free living ameba of the genus Hartmannella. The authors were ahle to exclude the hypothesis that the endameha from sewage was E. histolytica or E. ranarum. Finally, they call attention of analysts and epidemiologists to, when investigating E. histolytica from exposed material ~eep in mind the possibility of contamination. by E. moshkovskii due to its ubiquity for it has been found in well water, rivers and sewage. In such doubtfull · cases biological tests can be made because morphologically it is impossible to make a differential diagnosis between cysts and trophozoites of E. histolytica and E. moshkovskii.