Autor(es): Palmer C A,Wittrock D D,Christensen B M

Resumo: Ultrastructural examinations of Malpighian tubules of Aedes aegypti (black-eyed Liverpool strain) experimentally infected with Dirofilaria immitis (dog heartworm) larvae were made to assess pathology elicited by these worms. Tubules from uninfected mosquitoes and from mosquitoes at 2, 4, 6, 8, and 10 days postexposure (PE) to D. immitis microfilariae were studied with light and transmission electron microscopy (TEM). Uninfected tubules were composed of stellate and primary cells, the latter possessing apical microvilli containing many mitochondria, a cytoplasm containing nuclei, mitochondria, and vacuoles, and a highly infolded basal plasma membrane resting on a thin basal lamina. At 2 days PE apical microvilli of primary cells had fewer mitochondria and contained many vesicular structures. At 4 days PE mitochondria were absent from the apical microvilli and disruption of primary cell cytoplasm was evident. Cytoplasmic ground substance was highly disrupted by day 6 PE and cells appeared to be greatly inflated. By days 8-10 PE infoldings of the basal plasma membrane were no longer evident, and apical microvilli were destroyed as larvae moved through the apical membrane into the lumen of the Malpighian tubule. Data presented suggest that D. immitis larvae completely destroy Malpighian tubule cells in which they reside, and large worm burdens could be responsible for destruction of the excretory system and vector mortality.

Palavras-Chave: Dirofilaria immitis; Aedes aegypti; Malpighian tubules; Ultrastructure; Filarial worms; Mosquitoes; Dog heartworm

Imprenta: Journal of Invertebrate Pathology, v. 48, n. 3, p. 310-317

Identificador do objeto digital: 10.1016/0022-2011(86)90059-5

Descritores: Aedes aegypti - Pathogenesis

Data de publicação: 1986

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