Laboratory infection of the wild rodent, Sciurus alphonsei with Pasteurella pestis

The author studied the susceptibility of the wild rodent, Sciurus alphonsei (Sciuridae) from Brazil to Pasteurella pestis. Two strains of P. pestis isolated from wild rodents were used: one, P. EXU 19, was isolated from O. subflavus in the county of Em, Pernambuco (Brazil), and other, RANGEL, isolated from S. hispidus of Camp. Rangel (Venezuela) . Six animais were tested by inoculation through different routes (percutaneous, subcutaneous and peritoneal). All the animals died as a result of the infection.

About some trematodes parasites of Haemulon sciurus (Shaw, 1803)

From September, 1980 to August, 1981 forty specimens of Haemulon sciurus from "Praia da Ribeira, Ilha do Governador", Rio de Janeiro State, were examined for parasites. In this paper, parcial results concerning only the collected trematodes are reported: Diplomonorchis leiostomi Hopkins, 1941 (first record in Brazil and in a new host); Lasiotocus beauforti (Hopkins, 1941) Thomas, 1959 (new host record); Genolopa ampullacea Linton, 1910; Parahemiurus merus (Linton, 1910) Yamaguti, 1938 (new host record): Aponurus pyriformis (Linton, 1910) Overstreet, 1973 and Diplangus paxillus Linton, 1910. Figures, measurements and comments of each species are given.

Hepatozoon griseisciuri in grey squirrels (Sciurus carolinensis): changes of blood leucocyte numbers resulting from infection

Numbers of leucocytes in squirrels with gametocytes of Hepatozoon in their blood (infected) were compared with animals without gametocytes (uninfected). Typical values for leucocytes/mm(3) blood in uninfected squirrels were: leucocytes 5-7 x 10(3), granulocytes 3-4 x 10(3), lymphocytes 2-0 x 10(3) and monocytes 0-3 x 10(3) cells. Infection caused an increase in monocytes, lymphocytes and granulocytes, and there was a significant positive association between parasitaemia level and numbers of both total leucocytes and monocytes. Infected animals had more uninfected monocytes/mm(3) blood than did uninfected animals. The proportions of monocytes were more variable over time in infected animals, but no shift between infected and uninfected status was detected. Transfer of serum from infected squirrels to mice resulted in elevated counts of total blood leucocytes, monocytes and granulocytes, but not of lymphocytes, as compared with controls. Serum from squirrels with high parasitaemias had a more marked effect than serum from squirrels with low parasitaemias. Results indicate an infection - related monocytosis, possibly controlled by cytokines, that increases the number of cells available for invasion by gametocytes, thus enhancing the chances of parasite transmission.