Classification Phylum- Protozoa Sub Phylum- Sarcomastigophora Class- Zoomastigophora Order- Kinetoplastida Genus- Trypanosoma spp.- gambiense

Classification Phylum- Protozoa Sub Phylum- Sarcomastigophora Class- Zoomastigophora Order- Kinetoplastida Genus- Trypanosoma spp.- g ambiense.

Historical Background of Trypanosoma Gambiense. Valentine was the first to report Trypanosoma in the blood of a Trout. Gruby established the genus and Lewis reported it from the blood of rat. Evans and Bruce described Trypanosoma from the blood of horses, camels and catties. Forde (1901) first observed this parasite in the blood of man. It was again confirmed by Dutton (1902). Castellani reported this parasite in the cerebrospinal fluid of man. Then, Bruce and Nabarro established the relationship of the disease sleeping sickness with this parasite. Bruce also discovered that the disease is transmitted by tsetse fly..

Distribution of Trypanosoma Gambiense. The different species of Trypanosoma are reported from Central and West Africa, Nigeria, Congo and Central America. Commonly, areas near the rivers and lakes having low marshy land have the greatest incidence of infection because the insect vector inhabits in these areas. Habit and Habitat of Trypanosoma Gambiense: Trypanosoma gambiense lives as a parasite in the blood, lymph, lymph nodes, spleen, or cerebrospinal fluid of man and in the intestine of blood-sucking fly Glossina palpalis (Tsetse fly)..

Fig. 13.2. Tsetse fly.. form red t*xxj form Fig. 13.1. Trypanosoma gambiense. Human smear to show its various forms..

Structure of Trypanosoma Gambiense:. nucleolus reserve flagellum undulating rnembrane attached blepharoplast or basal granule Fig. 13.3. Trypanosoma gambiense..

Shape and size. Trypanosoma gambiense has a slender, elongated, colourless, sickle-shaped and flattened microscopic body which is tapering at both the ends. The anterior end is more pointed than the posterior end which is blunt. Its body length varies from 15 to 30 microns and width from 1 to 3 microns. The shape and size of its body vary with the form in which it exists. Pellicle and Undulating Membrane The body is covered by a thin, elastic and firm pellicle. It maintains the general shape of the body. The pellicle is made of fine fibrils which run along the whole length of the body. These fibrils are called microtubules. The pellicle is pulled out into an irregular membranous fold to one side when its flagellum beats. This fold is called undulating membrane, which is supposed to be an adaptive structure for locomotion in a viscous environment (blood, lymph) where it lives..

Flagellum. Flagellum is single in Trypanosoma, i.e., it is uniflagellate. The flagellum arises from the basal granule situated near the posterior end of the body. The flagellum runs forward and remains attached all along the length of the body marking the boundary of undulating membrane. After reaching the anterior end of the body, the flagellum becomes free and hangs freely as free flagellum. Structurally, the flagellum is like that of Euglena’s and consists of the axoneme enclosed in a thin cytoplasmic sheath. Kinetoplast Just posterior to basal granule, there is a small, spherical or disc-shaped parabasal body or kinetoplast which contains extra-nuclear DNA and, hence, it is a self-duplicating body. The kinetoplast is related to locomotion..

Cytoplasm. Its cytoplasm is differentiated into ectoplasm and endoplasm. The cytoplasm contains numerous scattered greenish refractile deep staining granules called volutin granules. The volutin granules are metabolic food reserves and generally consist of glycogen and phosphates. In addition, cytoplasm also contains some small vacuoles having hydrolytic enzymes in them and all other cell ular components like Golgi apparatus, mitochondria, endoplasmic reticulum and nucleus. Nucleus A single, oval or spherical and vesicular nucleus (trophonucleus) is seen in the middle of its body. The nucleus contains a large endosome surrounded by chromatin ..

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