Estudo das caracteristicas biologicas e morfologicas da linhagem MAP de Schistosoma mansoni

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

The appearance of drug resistant strains of Schistosoma mansoni is well know. Previous studies have shown that MAP strain is resistant to oxamniquine and hycanthone but sensitive to niridazole and praziquantel. The objectives of this study were to evaluate the suscetibility of snails to S. mansoni infection and to determine morphologial aspects of the 41st generation of MAP strain. The study was developing using as experimental model swiss mice-Biomphalaria glabrata. Snails were divided in 3 groups of 60 individuals each: I) Control group; II) Exposed to 1 miracidium; III)Exposed to 10 miracidia. Eighty mice were divided into 4 groups of 20 animais each: A) Control; B) Infected and not treated; C) Infected and treated by OXA (100mg/kg, single dosis, by oral route) and O) infected and treated by PZQ (100mg/kg/5 days, by oral route). Sixty mice were infected with 70 cercariae by immersion of the tail in water. After 3 weeks the animals of the groups C and O were treated and were killed 2 weeks later and evaluated following this analysis: ability of cercarial penetration and worm recovery; body weights of liver and spleen; mortality rate; diameter of hepatic granuloma and morphometry of adults worms and eggs. The mortality rate and suscetibility of snails to infection up to 77 days of exposure were, respectively 30.0% and 28.6% for group 111 25.0% and 17.8% for group 11, and also 25.0% for group I, indicating that the worm is well adapted to its intermediate host. Experimental chemotherapy revealed efficacy levels of 93.9% to PZQ and 15.8% to OXA, while the percentage of surviving worms was of only 6.08% to the first drug and of 84.2% to the second one. We verified higer rate of cercariae penetration (92.05%) and fine rate of recovery worms (34.12%) in the infected mice, alteration of the ponderal growth from infected animais succeding in a decrease of the weight whem compared to the control group, in the period between the administration of the two antischistosomal drugs and the killing of the animais, we notice body weight gain of treated animais, hepatomegaly (2.68g .± 0.68) and splenomegaly (0.41 9 ± 0.15) showing a gain of 54% and 128%, respectively, when compared to these viscera of control group; granulomatosus hepatic reactions measured 268.04j.Jm2. The measurements of worms was 7.78mm±1.40 for male and 7.03mm ± 0.98 for female; and the eggs showed 64.24j.Jm ±2.75 of width and 148.46j.Jm ± 8.82 of lenghí. F41 MAP strain maintened its resistance when compared to previous generations. This strain showed different characteristics from strain of other regions of São Paulo State

ASSUNTO(S)

esquistossomose mansonica drogas - dosagem

ACESSO AO ARTIGO

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