What is the life cycle of Strongyloides?
The life cycle of Strongyloides stercoralis. Distinctive features include (a) random migration of autoinfective larvae, (b) embryonated egg rapidly hatches to rhabditiform larvae, and (c) single generation of free-living male and female adults.
Does Strongyloides stercoralis have a direct life cycle?
Strongyloides stercoralis has a very unique and complex life cycle. It alternates between free-living and parasitic cycles and has the potential to cause autoinfection and multiply within the host (a characteristic other nematodes do not possess). From the large intestine, rhabditiform larvae are excreted in the stool.
How do Strongyloides reproduce?
Compared with most other parasitic nematodes, the Strongyloides life cycle is unusual because it has two adult generations – one in the host and one outside (Fig. 1). The parasitic adult generation is female-only and these reproduce by parthenogenesis, which is genetically mitotic (Fig. 2).
Is Strongyloides stercoralis a nematode?
The rhabditid nematode (roundworm) Strongyloides stercoralis is the major causative agent of strongyloidiasis in humans. Rarer human-infecting species of Strongyloides are the zoonotic S. fuelleborni (fülleborni) subsp. fuelleborni and S.
How big is Strongyloides?
Strongyloides stercoralis free-living adults. Free-living adult males measure up to 0.75 mm long; free-living females measure up to 1.0 mm long.
How do Strongyloides penetrate skin?
Most of these larvae will be excreted in the stool, but some of the larvae may mature and immediately re-infect the host either by burrowing into the intestinal wall, or by penetrating the skin around the anus. This characteristic of S.
How autoinfection happens in relation to parasitic life cycle?
Autoinfection involves premature transformation of noninfective larvae (rhabditiform, 0.25 mm × 0.015 mm) into infective larvae (filariform, 0.5 mm × 0.015 mm), which can penetrate the intestinal mucosa (internal autoinfection) or the skin of the perineal area (external autoinfection), thus establishing a developmental …