Influence de l'anhydrobiose sur l'infestation de Biomphalaria glabrata par un miracidium de Schistosoma mansoni

• Published in: Memórias do Instituto Oswaldo Cruz 1987-12, Vol.82 (4), p.551-556
• Main Authors: LANCASTRE, F, VIANEY-LIAUD, M, COUTRIS, G, BOLOGNINI-TRENEY, J, MOUGEOT, G, OUAGHLISSI, J.-P
• Format: Article
• Language: eng ; fre
• Subjects: Biomphalaria glabrata; dessiccation; Divers; développement larvaire; Helminthiases; monoinfestation; Médecine tropicale; PARASITOLOGY; Parasitoses; Pathologie infectieuse; productions cercariennes; Schistosoma mansoni; Schistosomiases; Sciences biologiques et medicales; Sciences medicales; TROPICAL MEDICINE; Trématodoses; variations périodiques
• ISSN: 0074-0276; 1678-8060; 1678-8060; 0074-0276
• DOI: 10.1590/s0074-02761987000400013

Sur 410 B. glabrata infestées par 1 miracidium de S. mansoni, 300 ont été placées dans des boîtes aérées, sur de la terre humide, et soumises à 6 semaines de dessiccation progressive. Au terme de l'expérience, il y avait 71 survivantes (23.66%), dont 9 positives. Les 110 autres planorbes ont cosntitué le lot témein, avec 106 survivantes (96.36%) à la première semaine d'apparition des cercaires. L'étude hebdomadaire des émissions cercariennes a montré des variations périodiques pour les deux sexes, une plus grande production de certaines femelles chez les témoins, mais une production de cercaires mâles ou femelles semblable chez les mollusques ayant subi l'anhydrobiose. Le faible nombre de ces dernies n'a pas permis une étude comparée significative de la survie des porteurs de formes larvaires mâles et femelles. La durée du développement du parasite chez son hôte ne semble pas modifiée si l'on tient compte de la phase d'estivation. 410 Biomphalaria glabrata (Caribbean strain of Guadeloupe) have been infected with one miracidium of Schistosoma mansoni, 110 snails, used as controls have been kept into water; the survival rate was 96.4% after 4 weeks and 25.4% produced cercariae. 300 snails were kept on wet soil, and submitted for 6 weeks to progressive desiccation. The survival rate was 23.4% but only 9 of them produced cercariae. Periodic variations of the production of male and female larvae have been shown by the weekly test of the cercariae productions. In previously desiccated snails, the production of male and female cercariae is similar while in controls the production of female larvae is more important. In experimental snails, the larval development seems to be stopped during anhydrobiosis. The production of cercariae is just delayed for the length of the dry keeping. Quatrocentos e dez B. glabrata (cepa de Guadelupe) foram infectadas por um miracídio de S. mansoni. Cento e dez caramujos, usados como controle, foram mantidos na água. A taxa de sobrevivência foi de 96,4% após quatro semanas e 25,4% eliminaram cercárias. Trezentos caramujos foram colocados sobre terra úmida e submetidos a uma dessecação progressiva durante seis semanas. A taxa de sobrevivência foi de 23,4% mas somente nove animais eliminaram cercárias. A observação semanal da eliminação de cercárias revelou variações periódicas da eliminação de larvas machos e fêmeas. Em caramujos previamente mantidos fora da água, a eliminação de cercárias machos e fêmeas é equivalente, enquanto a elim