Estudo Grahamella legeri sp.n. (Rickettsiales: Bartonellaceae) hemoparasito de Rattus norvegicus (Berkenhout, 1769), no Estado do Rio de Janeiro

Abstract

A study of Grahamella legeri sp.n. (Rickettsiales, Bartonellaceae). Haemoparasite of Rattus norvegicus (Berkenhout, 1769), in the State of Rio de Janeiro, Brazil. It was observed that 21% of the Rattus norvegicus norvegicus examined from the State of Rio de Janeiro, Brazil, were parasitized by Grahamella legeri sp.n. being 38% in the rural and 4% in the urban zone. The rickettsia found in the blood smears and organ urban zone. The rickettsia found in the blood smears and organ impressions stained by the method of Giemsa was studied morphologically and biologically. The experimental transmission with infected blood was obtained only between individuals of the same species and the enhancement of its virulence by the stress of the host was obtained with Dexametazona or by splenectomy. The cultivation of the parasite was attempted in an artificial medium, specific for Grahamella spp. The pathogenicity of the organism was demonstrated. Its systematic position was 4 8 discussed and it was concluded that it represents a new species of Rickettsiales, Bartonellaceae, so far improperly denominated Grahamella muris Leger, 1913, for which it is proposed the name Grahamella legeri in honor of André Leger.