Aspectos biologicos da interação entre Strongyloides venezuelensis e Schistosomamansoni em camundongos Swiss

AUTOR(ES)
DATA DE PUBLICAÇÃO

1995

RESUMO

This work is based on parasitological parameters, giving quantitative data about interaction between Schistosoma mansoni and Strongyloides venezuelensis foccusing on poliparasitism. Three experimental groups were formed, replicated three times, in order to obtain a simultaneous infection (group JUNT). Other two groups alternating the previous infection of one of the parasites (SVSM and SMSV groups). Two more groups were formed, one with S. venezuelensis (SVSV) infection and other with S. mansoni (SMSM) infection. Five experimental groups were composed of 21 animaIs each, being each replicated composed of 105 individuaIs, totalizing 315 mice. In each groups, the following parameters were evaluated: number of eggs eliminated in faeces and female fecundity; number of larva and adults recovered in necropsies; morphometry of adult worms. Swiss female mice SPF with approximately 30 days were infected by subcutaneous injection with 100 cercaria of S. mansoni and 1300 filariform larvae of S. venezuelensis. S. venezuelensis larvae were recovered from lungs of necropsied animaIs in 2nd DAI (day after infections), after fragmentation and incubation in incubator, 37° C. The parthenogenetic female were recovered from small intestine sectioned longitudinally of necropsied animaIs at the 5th, 7th ,10th DAI, after incubation, at 37° C, and scraped in saline solution. The score of eggs eliminated in faeces was done by Kato-Katz method. For morphometric study, the adult worms of S. venezuelensis were fixed in T AF and of S. mansoni in a1cohol. These worms were drawn in camara lucida and measured with curvimeter and digitizing table coupled to a microcomputer. In group with simultaneous infection (JUNT), we observed a synergetic interaction. There was a increase recuperation of S. venezuelensis females which showed high fecundity and high rate of egg elimination in addition to the fact that the infection persists for a long time. The worms burden of S. mansoni also increased, in spite a decrease of female fecundity and egg elimination. In those groups were an altemation took place the parasite of inoculated latter suffered an unfavourable effect, with decrease both in worm burden and in egg elimination. In these groups, S. venezuelensis females were more fertile than S. mansoni females and they were precociously eliminated. The parasite previously inoculated showed a increase in worms burden, but a decrease in female fecundity and in egg elimination. In relation to morphometry of adults worms, the observed measurement variations were small, therefore not characterizing interaction effect between the parasites

ASSUNTO(S)

strongylidae infecção esquistossomose mansonica camundongo

ACESSO AO ARTIGO

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