[Two trichostrongyloid nematodes parasitic in an African murid. III. Physiologic duality of infective larvae; as correlated with seasonal rhythms].
The third stage (the infective stage) of both species, Neoheligmonella dossoi and N. tranieri, appears simultaneously in the coprocultures in two different forms: sheathed larvae and exsheathed larvae. The exsheathed larvae show a much higher infection rate than the sheathed ones, but the last ones could exsheathed under some conditions. These larvae are called: "larvae exsheathed by aging". The percentage of exsheathed larvae is higher from April to October, this period corresponding to the rainy season on the Ivory Coast. Considering the host biological characteristics (sedentary, isolated, humid burrows) and the fact that the infection lasts 2 to 4 months, the transmission of the two Trichostrongylid species seems particularly well adapted to local conditions. Transmission appears to follow two infestation strategies, depending on the season: --A "rainy season strategy" characterized by an important initial production of larvae of which a great number are exsheathed larvae, with strong infective potential. --A "dry season strategy" characterized by sheathed larvae, produced more regularly, having a weaker infective potential, and able to exsheathe progressively.
Durette-Desset
M C
MC
Laboratoire de Zoologie-Vers, Muséum National d'Histoire Naturelle, Paris.
Cassone
J
J
D000064:Acclimatization; D000818:Animals; D007814:Larva; D009115:Muridae / Q000469:parasitology*; D010507:Periodicity; D012621:Seasons; D014251:Trichostrongyloidea / Q000469:parasitology / Q000502:physiology*
Sur deux Nématodes trichostrongyloides parasites d'un Muridé africain. III. Dualité physiologique des larves infestantes, liée aux rythmes saisonniers.