Effect of Splenectomy on a Latent Infection, Eperythrozoon Coccoides, in White Mice

Malária experimental: contaminação de cepas e animais de biotério por eperythrozoon coccoides

“…A seguir instala-se uma fase latente, que coincide com o aparecimento de anticorpos específicos, com diminuição importante no número de parasitas circulantes. Esta fase só é detectada quando o animal é submetido a manobras imunossupressoras, como a esplenectomia, que provocam um aumento no número de parasitas circulantes 9 . Com o uso de ciclofosfamida, a infecção aguda inicial se mantém, com 100% de latalidades.…”

Phylogenetic analysis and description of Eperythrozoon coccoides, proposal to transfer to the genus Mycoplasma as Mycoplasma coccoides comb. nov. and Request for an Opinion

“…The acute phase displays a haemolytic anaemia with the haematocrit falling from 50-55 % to 20-30 % but by day 8 haematocrit levels return to the normal range (Glasgow et al, 1971). A marked splenomegaly is a characteristic of the infection and there is a general lymphadenopathy (Marmorston, 1935;Ansari et al, 1963;Riley, 1964). There are no obvious clinical symptoms and mortality is rare.…”

“…Splenomegaly also persists in carrier mice presumably as long as they are infected (Baker et al, 1971) and low numbers of organisms may appear sporadically for brief periods in the peripheral blood of chronic carriers (Thurston, 1955). The existence of a latent infection is usually revealed by splenectomy which results in the reappearance of large numbers of organisms in the peripheral blood within 48 h; lower numbers of organisms then persist in the peripheral blood for several months (Schilling, 1928;Eliot & Ford, 1930;McCluskie & Niven, 1934;Marmorston, 1935;Thurston, 1954Thurston, , 1955.…”

“…Treatments that damage or stress the reticuloendothelial system (RES), such as X-irradiation, activated latent infection and in some instances infections were fatal (Furth, cited by Marmorston, 1935). Inoculating latently infected mice with Borrelia recurrentis or Trypanosoma lewisi (Dinger, 1929), malaria (Thurston, 1955; or lymphocytic leukaemia cells (Marmorston, 1935) activated latent infection.…”

“…Inoculating latently infected mice with Borrelia recurrentis or Trypanosoma lewisi (Dinger, 1929), malaria (Thurston, 1955; or lymphocytic leukaemia cells (Marmorston, 1935) activated latent infection. Also, chemical agents, such as ethyl palmitate, which damage the spleen are known to activate latent infection in other haemoplasmas (Finch & Jonas, 1973).…”