Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-06-20T03:15:50.717Z Has data issue: false hasContentIssue false
  • English
  • Français

Studies on Trypanosoma grayi. III. Life-Cycle in the Tsetse-fly and in the Crocodile

Published online by Cambridge University Press:  06 April 2009

Cecil A. Hoare
Cecil A. Hoare
Affiliation:
From the Wellcome Bureau of Scientific Research, London, and the Human Trypanosomiasis Institute, Entebbe, Uganda.
Get access Rights & Permissions [Opens in a new window]

Extract

An account is given of the life cycle and morphology of T. grayi in the crocodile (Crocodilus niloticus) and in the tsetse-fly (Glossina palpalis). The immunological relations of this trypanosome to its hosts and its affinities to other species are also dealt with.

T. grayi belongs to the group of trypanosomes developing in the posteriorstation of the invertebrate host and transmitted by the contaminative method (“lewisi group”).

T. grayi occurs in very small numbers in the crocodile and is concentrated chiefly in the peripheral circulation of the skin (about 200 parasites per 1 c.c. of blood). It is one of the largest trypanosomes, the blood forms measuring up to 91μ

When fed on an infected crocodile the tsetse-fiy takes up not more than about six trypanosomes. These commence their development in the mid-gut, giving rise to crithidial and trypanosome forms, and later extend to the hind-gut where their evolution is completed and the infective metacyclic trypanosomes are produced. These, when voided with the faeces, serve to infect the crocodile per os.

Since the incubation period of T. grayi in the crocodile is about four days, this is the time required for the small metacyclic trypanosomes to develop into the large blood forms.

The distribution of T. grayi in the gut of the fly in the course of its development is determined by the presence of the peritrophic membrane and involves three successive waves of migration in opposite directions: (1) From the intraperitrophic space backwards, into the colon, thence (2) forwards into the extraperitrophic space up to and including the mid-gut; and finally (3) they again migrate backwards, to the hind-gut. (Diagrams of the life cycle and distribution of T. grayi in Glossina are given in Text-figs. 2 and 3.)

Evidence is produced to show that the so-called “cysts” of T. grayi described by previour authors are really artifacts.

Apparently the majority of crocodiles in Victoria Nyanza harbour T. grayi. The trypanosome has no harmful efleet upon the crocodile and it was proved that the infection can persist for more than two years.

The crocodile appears to possess a natural partial or tolerance immunity against T. grayi, which does not protect it from invasion by the parasite, but maintains its numbers at a constantly low level.

The infection rate in the experimental tsetse-ffies is very high (average 61 per cent.) in the early days of infection, but later f ails to an average of 17·3 per cent. The majority of the flies, originally fully susceptible to infection, appear to acquire an immunity after the fifth day.

The average degree of infection in “wild” flies is 11·2 per cent. This compares closely with that in the experimental flies. Hence it is inferred that the majority of these flies had fed in nature on infected crocodiles.

T. grayi is closely allied to trypanosomes of the “lewisi group” and to some of the trypanosomes of land reptiles and amphibia. On the strength of the clifterence existing between these two groups of trypanosomes, some modification in the accepted classification of these species is introduced.

A name, T. theodori sp.n., is proposed for the goat trypanosome described by Theodor (1928).

Type
Research Article
Information
Parasitology , Volume 23 , Issue 4 , October 1931 , pp. 449 - 484
Copyright
Copyright © Cambridge University Press 1931

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bruce, D., Hamerton, A. E., Bateman, H. R., Mackie, F. P. and Lady, Bruce (1911). A trypanosome found in the blood of a crocodile. Rep. Sleep. Sickn. Comm. Roy. Soc. 11, 184.Google Scholar
Bruce, D., Harvey, D., Hamerton, A. E., Davey, J. B. and Lady, Bruce (1915). Dis section of wild Glossina brevipalpis to ascertain with what species of trypanosomes, if any, they are infected. Rep. Sleep. Sickn. Comm. Roy. Soc. 16, 26.Google Scholar
Carpenter, G. D. H. (1920). A Naturalist on Lake Victoria. (London.)Google Scholar
Chatton, É. (1920). Les membranes péritrophiques des Drosophiles (Diptkrès) et des Daphnides (Cladocères); leur genèse et leur r^le à l'égard des parasites intestinaux. Bull. Soc. Zool. France, 45, 265.Google Scholar
Duke, H. L. (1928). Studies on the bionomics of the polymorphic trypanosomes of man and ruminants. Final Rept. League of Nations Internat. Comm. on Hum. Trypanosomiasis (Geneva). C.H. 629, 25.Google Scholar
França, C. (1925). Notes parasitologiques sur l'Angola. Ann. Parasitol. 3, 255.CrossRefGoogle Scholar
Gray, A. C. H. and Tulloch, F. M. G. (1905). The multiplication of Trypanosoma gambiease in the alimentary canal of Glossina palpalis. Rep. Sleep. Sickn. Comm. Roy. Soc. 6, 282.Google Scholar
Hoare, C. A. (1923). An experimental study of the sheep trypanosome (T. melophagium Flu 1908) and its transmission by the sheep ked (Melophagus ovinus L.). Parasitology, 15, 365.CrossRefGoogle Scholar
Hoare, C. A. (1925). The present state of our knowledge regarding the origin, evolution and classification of trypanosornes and allied forms. Arch. Russes Protistol. 3, 177. (In Russian, with English résumé.)Google Scholar
Hoare, C. A. (1928). Studies on Trypanosoma grayi: I. The effects of goat's blood. Trans. Roy. Soc. Trop. Med. and Hyg. 22, 131.CrossRefGoogle Scholar
Hoare, C. A. (1929). Studies on Trypanosoma grayi: II. Experimental transmission to the crocodile. Trans. Roy. Soc. Trop. Med. and Hyg. 23, 39.CrossRefGoogle Scholar
Hoare, C. A. (1929 a). Protozoologist's Report. In Ann. Rept. Lab. Services Div., Med. Dept., and Hum. Trypanosomias. Res. Inst. Uganda, for 1928.Google Scholar
Hoare, C. A. (1931). The peritrophic membrane of Glossince paipalis, and its bearing upon the life cycle of Trypanosoma grayi. Trans. Roy. Soc. Trop. Med. and Hyg., 25, 57.CrossRefGoogle Scholar
Hornby, H. E. and Bailey, H. W. (1931). Diurnal variation in the concentration of Trypanosoma congolense in the blood vessels of the ox's ear. Trans. Roy. Soc. Trop. Med. and Hyg. 24, 557.CrossRefGoogle Scholar
Huff, C. G. (1929). The effects of selection upon susceptibifity to bird malaria in Culex pipiens Linn. Ann. Trop. Med. and Parasit. 23, 427.CrossRefGoogle Scholar
Huff, C. G. (1930). Individual immunity and susceptibility of Culex pipiens to various species of bird malaria as studied by means of double infectious feedings. Amer. J. Hyg. 12, 424.Google Scholar
Kleine, F. K. (1910). Trypanosomenbefunde am Tanganyika und andere Beobachtungen. Deutsch. med. Wochenschr. 36, 1400.Google Scholar
Kleine, F. K. (1919). Beitrag zur Kenntnis des Trypanosoma melophagium Flu. Deutech. tierärztl. Wochenschr. 38, 408.Google Scholar
Kleine, F. K. and Taute, M. (1911). Trypanosomenstudien (Sonderabdruck d. Abhandl.: Erganzungen zu unseren Trypanosomenstudien). Arb. a. d. k. Gesundheitsamte, 31, 2.Google Scholar
Koch, H. (1905). Vorläufige Mitteilungen über die Ergebnisse einer Forschungsreise nach Ostafrika. Deutsch. med. Wochenschr. 31, 1865.CrossRefGoogle Scholar
Koch, H. (1905 a). Ueber die Unterscheidung der Trypanosomenarten. Sitzungsber. K. Preuns. Akad. Wiss. 46, 958.Google Scholar
Koch, H. (1906). Ueber den bisherigen Verlauf der deutschen Expedition zur Erforschung der Schlafkrankheit in Ostafrika. Deutsch. med. Wochenschr. 32 (Suppl. to No. 51), 1.Google Scholar
Laveran, A. and Mesnil, F. (1912). Trypanosomes et Trypanosomiases. 2nd ed. (Paris).CrossRefGoogle Scholar
Lloyd, L. and Johnson, W. B. (1924). The trypanosome infections of tsetse-flies in Northern Nigeria and a new method of estimation. Bull. Entomol. Res. 14, 265.CrossRefGoogle Scholar
Lloyd, L. (1925). Notes for demonstration of properties illustrating the diagnostic characters of the flagellate parasites of tsetse-ffies. Trans. Roy. Soc. Trop. Med. and Hyg. 18, 243.Google Scholar
Lloyd, L., Johnson, W. B., Young, W. A. and Morrison, H. (1924). Second report of the tsetse-fly investigation in the Northern Provinces of Nigeria. Bull. Entomol. Res. 15, 1.CrossRefGoogle Scholar
Lwoff, A. and Lwoff, M. (1931). Recherches morphologiques sur Leptomonas ctenocephali Fanth. (Trypanosomide). Remarques sur l'appareil parabasal. Bull. Biol. France et Belgique, 65, 170.Google Scholar
Lwoff, M. and Lwoff, M. (1931). Recherches sur la morphologie de Leptomonas oncopelti Noguchi et Tilden et Leptomonas fasciculata Novy, MacNeal et Torrey. Arch. Zool. Exp. et Gén. (Notes and Rev. No. 1), 71, 21.Google Scholar
Minchin, E. A. (1907). On the occurrence of encystation in Trypanosoma grayi Novy, with remarks on the method of infection in trypanosomes generally. Proc. Roy. Soc. B, 79, 35; Rep. Sleep. Sickn. Comm. Roy. Soc. 8, 122.Google Scholar
Minchin, E. A. (1908). Investigations on the development of trypanosomes in the tsetse-flies and other Diptera. Quart. J. Microsc. Sci. 52, 159.Google Scholar
Minchin, E. A.(1912). An introduction, to the study of the protozoa (London).Google Scholar
Minchin, E. A.(1914). The development of trypanosomes in the invertebrate host. Nature, 94, 406; Rept. Brit. Assoc. [1915], 404.Google Scholar
Minchin, E. A., Gray, A. C. H. and Tulloch, F. M. G. (1906, 1907). Glossina palpalis in its relation to Trypanosoma gambiense and other trypanosomes. Proc. Roy. Soc. B, 78, 242; Rep. Sleep. Sickn. Comm. Roy. Soc. 8, 122.Google Scholar
Newstead, R. (1924). Guide to the study of tsetse-flies. Liverpool School of Trop. Med., Mem. (N.S.), No. 1. (London.)Google Scholar
Novy, F. G. (1906). The trypanosoines of tsetse.flies. J. Infect. Dis. 3, 394.CrossRefGoogle Scholar
Prates, M. M. (1928). Study on the presence of haemoparasites in Glossinae with a view to the identification of the blood in their intestines. Brief notes on these microorganisms. Final Rept. League of Nations Internat. Comm. on Hum. Trypanosomiasie (Geneva), C.H. 629, 227.Google Scholar
Robertson, M. (1913). Notes on the life history of Trypanosoma gambiense with a brief reference to the cycles of Trypanosoma nanum and Trypanosoma pecorum in Glossina palpalis. Phil. Trans. Roy. Soc. B, 203, 161.Google Scholar
Roubaud, E. (1912). Cysto-trypanosorna grayi (Novy), trypanosome propre de Glossina paipalis. Polymorphisme, affinités; intérêt phylogenétique. C.R. Soc. Biol. 72, 440.Google Scholar
Stuhlmann, F. (1907). Beiträge zur Kenntnis der Tsetsefliege (Glossina fusca und Gl. tachinoidee). Arb. a. d. k. Gesundheitsamte, 26, 301.Google Scholar
Taylor, A. W. (1929). Note on the occurrence of crithidia in Phlebotomus minutus var. africanus in Northern Nigeria. Ann. Trop. Med. and Parasit. 23, 33.CrossRefGoogle Scholar
Theodor, O. (1928). Ueber em nicht pathogenes Trypanosoma aus der Ziege und seine Uebertragung durch Lipoptena caprina Aust. Zeitschr. Parasitenk. 1, 283.CrossRefGoogle Scholar
Wenyon, C. M. (1926). Protozoology. Vol. I, (London.)Google Scholar
Wigglesworth, V. B. (1929). Digestion in the tsetse-fly: a study of structure and function. Parasitology, 21, 288.CrossRefGoogle Scholar