''Trichuris muris'' is a

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

. It is very similar to the human

roundworm The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...

parasite ''

Trichuris trichiura ''Trichuris trichiura, Trichocephalus trichiuris'' or whipworm, is a parasitism, parasitic nematode, roundworm (a type of helminth) that causes trichuriasis (a type of helminthiasis which is one of the neglected tropical diseases) when it infect ...

'' due to its immunological reactivity when crossed, and so is often used in related studies.Sanger Institute Wellcome Trust - T. muris Project
/ref>

Lifecycle

Ingesting material that contains embryonated eggs allows for transmission and infection to occur. The eggs travel down to the cecum - a pouch located at the start of the large intestine - where larval hatching is induced. The larvae proceed to penetrate through the mucosal epithelium, then molt into their secondary stage of infection after 9–11 days. About 17 days after infection, the larvae arrive at the tertiary stage followed by a quaternary molt 5 days later. The larvae complete their last molt 29 days after infection and transform into mature dioecious adults. These whipworms use their anterior ends to embed themselves into the cells that line the walls of the large intestine. After establishing their place in the intestinal wall, the adult worms mate and release unembryonated eggs into the environment via the feces.http://www.nematodes.org/nembase4/species_info.php?species=TMC ''Trichuris muris'' relies on direct contact with intestinal bacteria to promote hatching of the embryonated eggs. Using green fluorescent protein (GFP) and ''E. coli'' strains, the bacteria are seen to gather specifically around the opercula, which are located at the poles of the eggs. The bacteria contain type 1 fimbriae, which possess adhesin FimH at their fimbrial tips. FimH interacts with a mannosylated receptor found on the egg's surface. When bound, a signal transduction cascade is triggered and results in the worm emerging from the egg. Temperature, in particular at 37 °C, serves as an additional hatching cue; this specific temperature is thought to prevent ''T. muris'' eggs from hatching in unideal outside environments.Hayes et al 2010 Science 328: 1391
/ref> The relationship between ''T. muris'' and bacteria also has a significant effect on the host's immune response. The activation of type 2 helper cells (Th2) is decreased in the presence of antibiotics because fewer whipworms bind to the intestinal walls. This, in turn, drives up the proliferation and differentiation of Th17 and Th1 cells. About 18 days after infection, the worm burden in antibiotically treated mice was drastically reduced, further supporting the notion that bacteria are essential to the worms' establishment.

References

{{Taxonbar, from=Q7841097 Parasites of rodents Parasitic nematodes of mammals Trichocephalida

Lifecycle

See also

References