Retortamonadidae

Chilomastix are retortamonad flagellates that have a pyriform and twisted cell body of about 20 µm in length with three anteriorly directed flagella and one short recurrent flagellum beating inside a ventral cytostomal pocket. The right fibril bordering the cytostomal pocket is thicker and forms a hook at its posterior end where food is phagocytosed. Cysts are pyriform and retain the internalised cytostomal fibers. They live in anoxic habitats but one species C. cuspidata is free-living. Among the 29 or so parasitic or endocommensal species described many live in the gut of vertebrates - such as C. mesnili in man and some in the gut of invertebrates such as C. aulastomi from the leech Aulastoma gulo. This species, Chilomastix caulleryi, is from the intestine of amphibia (haematoxylin staining).

Life cycle of Chilomastix mesnili The resistant cyst stage in the life cycle of Chilomastix is responsible for transmission. Both cysts and trophozoites can be found in the feces (diagnostic stages) (1). Infection occurs by the ingestion of cysts in contaminated water or food or by the fecal-oral route (via hands or fomites, i.e., inanimate objects such as towels that transmit infectious organisms to a host) (2). In the large (and possibly small) intestine, excystation releases trophozoites.From Centers for Disease Control Parasites and Health website.

From toads, scanning EM showing the three anteriorly directed flagella, the ventral cytostomal aperture that contains the recurrent flagellum (not visible).  

Chilomastix (kai-low-ma-sticks), a genus of retortamonad flagellates, mostly reported in association with animals, but we find this species (C. cuspidata) in anoxic sites. There are four flagella, we can only see three in this picture, inserting just subapically, and at the head of a large groove. One wall of the groove has a cusp. Posterior end drawn out as a long spike. Phase Contrast.

Chilomastix (kai-low-ma-sticks) cuspidata (Larsen and Patterson, 1990) Bernard et al., 1997. Cells are drop-shaped with a long posterior spike and about 20 - 32 microns long (including the spike) with a groove extending from the apex to the posterior end of the untapered part of the cell. The cells have 4 flagella inserting subapically and are directed anterior laterally, one is shorter than the cell and the other three are about the cell length. The short flagellum beats and lies within the ventral groove. The nucleus is situated subapically. Food vacuoles occur throughout the cell. The cells move slowly by swimming while rotating and may attach to the substrate by the tip of the spike.

Chilomastix cuspidata (Larsen and Patterson, 1990) Bernard et al., 1997. Cells are drop-shaped with a long posterior spike, they are about 20 - 32 microns long (including the spike) with a groove extending from the apex to the posterior end of the untapered part of the cell. The cells have 4 flagella inserting subapically and are directed anterior laterally, one is shorter than the cell and the other three are about the cell length. The short flagellum beats and lies within the ventral groove. The nucleus is situated subapically. Food vacuoles occur throughout the cell. The cells move slowly by swimming while rotating and may attach to the substrate by the tip of the spike.

Chilomastix (kai-low-ma-sticks), a genus of retortamonad flagellates, mostly reported in association with animals, but we find this species (C. cuspidata) in anoxic sites. There are four flagella, we can only see three in this picture, inserting just subapically, and at the head of a large groove. One wall of the groove has a cusp. Posterior end drawn out as a long spike. ATCC 50927 was isolated from a salt marsh.  

Description: Deutsch: Electron micrograph of Chilomastix cuspidata (excavates, retortamonads). The "9+2" axoneme and the enclosing membrane can be seen, the flagellum has two vanes. Date: Unknown dateUnknown date. Source: : This image is uploaded as image number 2258 at Tree of Life Web Project (tolweb.org).This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information.. Author: David J. Patterson.

Description: worm infections, humans. Date: 14 April 2014, 12:07. Source: Chilomastix mesnili. Author: Iqbal Osman1 from singapore.