Plasmodium gallinaceum: density dependent limits on infectivity to Aedes aegypti.
Autor(es): Rosenberg R; Koontz L C
Resumo: In acute, blood-induced infections of chickens, the malarial parasite Plasmodium gallinaceum is most infective to the mosquito Aedes aegypti 1 day before gametocyte numbers peak. In an effort to account for this disynchrony , daily changes in parasite infectivity, parasitemia, hematocrit, and hemoglobin were measured during the course of infections. Three events were correlated with the loss of infectivity: (1) In the 24 hr between park infectivity and peak gametocytemia , schizont-induced hemolysis reduced the red blood cell volume 22%. (2) P. gallinaceum zygotes, fertilized in vitro and mixed with heavily infected red blood cells from which all viable, mature gametocytes had been removed, produced 67% fewer oocytes than when combined with uninfected red blood cells. (3) Zygotes fertilized in vitro on the day of peak parasitemia produced 47% fewer oocysts than zygotes prepared 24 hr earlier. It appears that high parasite density reduces infectiousness by destroying, through hemolysis and intraerythrocytic metabolism, a substance necessary to the sporogonic stages, and that there is also an intrinsic loss of infectivity, possibly due to decreased efficiency of fertilization.
Palavras-Chave: Plasmodium gallinaceum; Protozoa; Parasitic; Malaria; Avian; Infectivity; Chicken; Hemoglobin; Erythrocyte; Anemia; Aedes aegypti; Mosquito infection
Imprenta: Experimental Parasitology, v. 57, n. 3, p. 234-238, 1984
Identificador do objeto digital: 10.1016/0014-4894(84)90096-1
Descritores: Aedes aegypti - Cell ; Aedes aegypti - Pathogenesis
Data de publicação: 1984
