Biomaterial Database

The fate and migration of microfilariae of a Guatemalan strain of Onchocerca volvulus in Simulium ochraceum and S. metallicum, and the role of the buccopharyngeal armature in the destruction of microfilariae. 1975

M S Omar, and R Garms

The migration and fate of microfilariae of a Guatemalan strain of Onchocerca volvulus in Simulium ochraceum and S. metallicum was studied. The anatomical distribution of microfilariae at various times after ingestion was recorded from a study of histological sections of the flies. S. ochraceum showed higher microfilarial intakes than S. metallicum which is probably attributed to an inherent difference in their ability to ingest. The migration of microfilariae out of the mid-gut took place essentially through the expanded part (the stomach). Despite the high microfilarial intakes by S. ochraceum, only a few microfilariae were able to migrate successfully into the thorax (2.6%) whereas in S. metallicum showing a low microfilarial intake, a higher rate of migration was noted (74.5%). The main bulk of microfilariae ingested by S. ochraceum died and disintegrated in the stomach. This was due to the presence of a well-developed cibarial armature in the buccopharyngeal apparatus of S. ochraceum in contrast to S. metallicum where such an armature is lacking. Microfilariae were severely damaged by the cibarial teeth while en route to the stomach. They rapidly underwent profound changes in morphology and staining properties and were often surrounded by clusters of the phagocytic leucocytes in the blood mass. In some flies, microfilariae, apparently damaged, were still entangled in the cibarial teeth 5 minutes to 3 hours after taking a blood-meal.

UI	MeSH Term	Description	Entries
D007303	Insect Vectors	Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.	Insect Vector,Vector, Insect,Vectors, Insect
D008842	Microfilariae	The prelarval stage of Filarioidea found in the blood and tissues of mammals, birds and intermediate hosts (vector).	Microfilaria
D009055	Mouth	The oval-shaped oral cavity located at the apex of the digestive tract and consisting of two parts: the vestibule and the oral cavity proper.	Oral Cavity,Cavitas Oris,Cavitas oris propria,Mouth Cavity Proper,Oral Cavity Proper,Vestibule Oris,Vestibule of the Mouth,Cavity, Oral
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009854	Onchocerca	A genus of parasitic nematodes whose organisms live and breed in skin and subcutaneous tissues. Onchocercal microfilariae may also be found in the urine, blood, or sputum.	Onchocercas
D009855	Onchocerciasis	Infection with nematodes of the genus ONCHOCERCA. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, PRURITUS, and ocular lesions.	Onchocerciases
D004175	Diptera	An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).	Flies, True,Flies,Dipteras,Fly,Fly, True,True Flies,True Fly
D005426	Flight, Animal	The use of wings or wing-like appendages to remain aloft and move through the air.	Animal Flight,Animal Flights,Flights, Animal
D006166	Guatemala	A country in CENTRAL AMERICA bordering the North Pacific Ocean, between EL SALVADOR and MEXICO, and bordering the Gulf of Honduras (Caribbean Sea) between HONDURAS and BELIZE.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man