A comparative parasitologic study on Biomphalaria glabrata snail and C3H/He mice infected with human and murine isolates of Schistosoma mansoni derived from Sumidouro, Rio de Janeiro, Brazil.
Experiments were carried out to analyze the biological characteristics of two sympatric isolates of Schistosoma mansoni derived from humans and murines in a low endemic transmission area (Sumidouro county, state of Rio de Janeiro, Brazil). Sympatric reared-laboratory Biomphalaria glabrata and C3H/He mice were used as experimental hosts. Parameters assessed comprised: precercarial period, infectivity and mortality (snails), prepatent period, infectivity (percentage of cercariae maturation into adult worm) and intestinal egg count (mice). The murine isolate showed a shorter precercarial period and higher infectivity than human isolate (p<0.05). This biological heterogenicity did not correspond to the vertebrate data because any biological parameter presented significant difference (p>0.05). These data suggest that both isolates are local sub-populations, providing support for the hypotheses that in a same biotope mixed populations or sub-populations circulate among their main host (human beings) and/or rodent as an anfixenous infection.
Laboratório de Helmintologia Romero Lascasas Porto, Departamento de Patologia e Laboratórios, Faculdade de Ciências Médicas, Uerj, 20550-031 Rio de Janeiro, RJ, Brasil.
Nilcéa
N
Freire
Rosângela
R
Rodrigues-Silva
José Roberto
JR
Machado-Silva
Luís
L
Rey
D000818:Animals; D001700:Biomphalaria / Q000469:parasitology*; D001938:Brazil; D006790:Host-Parasite Interactions / Q000502:physiology*; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H / Q000469:parasitology*; D010270:Parasite Egg Count; D012550:Schistosoma mansoni / Q000254:growth & development* / Q000472:pathogenicity; D013045:Species Specificity