Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-09T06:52:34.694Z Has data issue: false hasContentIssue false
  • English
  • Français

Researches on the intestinal protozoa of monkeys and man

IX. The life-history of Entamoeba coli, with special reference to metacystic development

Published online by Cambridge University Press:  06 April 2009

Clifford Dobell
Clifford Dobell
Affiliation:
National Institute for Medical Research, London, N.W. 3
Get access Rights & Permissions [Opens in a new window]

Extract

1. The life-history of Entamoeba coli (from a marmoset, several macaques, and Man), as observable in cultures, is here described and illustrated. It is found to be similar, in general outline, to that of E. histolytica, but to differ considerably in its excystation and metacystic stages.

2. At excystation, the entire contents of the cyst usually escapes, as a single multinucleate amoeba, through a large opening in the cyst wall, which is composed of two layers.

3. Normal ripe cysts frequently lose 1 to 4 of their 8 original nuclei before hatching, thus becoming “infranucleate” (i.e. containing only 4 to 7 nuclei instead of the “typical” 8).

4. During the metacystic stages no nuclear divisions occur. The hatched amoeba eventually produces, by a series of binary cytoplasmic fissions with random nuclear distribution, as many uninucleate amoebulae as it originally contained nuclei.

5. An originally 8-nucleate cyst may therefore produce 8 amoebulae finally –never more: but owing to the frequent development of infranucleate forms, it often produces only 7, 6, 5, or 4.

6. Development is complicated by occasional division into two within the cyst before hatching, or at the moment of hatching—such divisions being seen in both “typical” and “infranucleate” cysts; and also by the occurrence of supernucleate cysts (containing more than 8 nuclei), which are often viable but usually develop in an infranucleate condition. Consequently, amoebae containing any number of nuclei from 1 to 8—or even more—may hatch from the cysts of this species (unlike those of any other hitherto described).

7. The uninucleate amoebulae resulting from the metacystic divisions are young trophic amoebae—not gametes—and no sexual stages occur in the life-cycle. Division of the trophic amoebae is briefly described and figured.

8. The life-cycle of E. coli is finally compared with that of E. histolytica and related species: the relevant observations of other workers are briefly analysed: and the taxonomic implications are noted.

A memorandum is added on the genus Entamoeba, in an attempt to clarify the nomenclatural and taxonomic confusion created by Opinion 99 promulgated by the International Commission on Zoological Nomenclature. This leads to the conclusion that the Opinion itself is a dead letter, though the genus Entamoeba still lives and should therefore be retained, for the time being, with E. coli Casagrandi & Barbagallo, 1895, as its type.

Type
Research Article
Information
Parasitology , Volume 30 , Issue 2 , June 1938 , pp. 195 - 238
Copyright
Copyright © Cambridge University Press 1938

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

REFERENCES

Allen, E. A. (1926). Excystment of Councilmania lafleuri Kofoid and Swezy in culture in vitro. Univ. California Publ. Zool. 29, 175.Google Scholar
Bishop, A. (1932). Entamoeba aulastomi Nöller. Cultivation, morphology, and method of division; and cultivation of Hexamita sp. Parasitology, 24, 225.CrossRefGoogle Scholar
Bishop, A. (1937). Further observations upon Entamoeba aulastomi Nöller. Parasitology 29, 57.Google Scholar
Cannon, H. G. (1937). A new biological stain for general purposes. Nature, 139, 549.Google Scholar
Casagrandi, O. & Barbagallo, P. (1897). Entamoeba hominis s. Entamoeba coli (Lösch). Studio biologico e clinico. Ann. Igiene sperim. 7, 103.Google Scholar
Cleveland, L. R. & Sanders, E. P. (1930). Encystation, multiple fission without encystment, excystation, metacystic development, and variation in a pure line and nine strains of Entamoeba histolytica. Arch. Protistenk. 70, 223.Google Scholar
Dobell, C. (1919). The Amoebae living in Man: a Zoological Monograph. 8°. London.Google Scholar
Dobell, C. (1927). Further observations and experiments on the cultivation of Entamoeba histolytica from cysts. Parasitology, 19, 288.Google Scholar
Dobell, C. (1928). Researches on the intestinal Protozoa of Monkeys and Man.—I. General introduction, and II. Description of the whole life-history of Entamoeba histolytica in cultures. Parasitology 20, 357.Google Scholar
Dobell, C. with Bishop, A. (1929). Researches on the intestinal Protozoa of Monkeys and Man. III. The action of emetine on natural amoebic infections in macaques. Parasitology 21, 446.Google Scholar
Dobell, C. with Bishop, A.(1931). Researches on the intestinal Protozoa of Monkeys and Man. IV. An experimental study of the histolytica-like species of Entamoeba living naturally in macaques. Parasitology 23, 1.CrossRefGoogle Scholar
Dobell, C. with Bishop, A.(1933). Researches on the intestinal Protozoa of Monkeys and Man. V. The Endolimax of macaquas. Parasitology 25, 436.CrossRefGoogle Scholar
Dobell, C. with Bishop, A.(1934). Researches on the intestinal Protozoa of Monkeys and Man. VI. Experiments with the trichomonads of man and the macaques. Parasitology 26, 531.Google Scholar
Dobell, C. with Bishop, A.(1935). Researches on the intestinal Protozoa of Monkeys and Man. VII. On the Enteromonas of macaques and Embadomonas intestinalis. Parasitology 27, 564.Google Scholar
Dobell, C. with Bishop, A.(1936). Researches on the intestinal Protozoa of Monkeys and Man. VIII. An experimental study of some simian strains of “Entamoeba coli”. Parasitology 28, 541.CrossRefGoogle Scholar
Dobell, C. & Laidlaw, P. P. (1926). On the cultivation of Entamoeba histolytica and some other entozoic amoebae. Parasitology 18, 283.Google Scholar
Geiman, Q. M. & Ratcliffe, H. L. (1936). Morphology and life-cycle of an amoeba producing amoebiasis in reptiles. Parasitology 28, 208.Google Scholar
Grassi, B. & Feletti, R. (1892). Contribuzione allo studio dei parassiti malarici. Atti Accad. Gioenia, Catania, 5 (ser. 4), pp. 1–81.Google Scholar
Hegner, R. (1927). Excystation in vitro of human intestinal protozoa. Science, 65, 577.Google Scholar
Hegner, R. (1932). Studies on amoebiasis in Panama. J. Parasit. 18, 153.Google Scholar
Hegner, R., Johnson, C. M., & Stabler, R. M. (1932). Host-parasite relations in experimental amoebiasis in monkeys in Panama. Amer. J. Hyg. 15, 394.Google Scholar
Lucas, C. L. T. (1927). Two new species of amoeba found in cockroaches: with notes on the cysts of Nyctotherus ovalis Leidy. Parasitology, 19, 223.Google Scholar
Mathis, C. & Mercier, L. (1917). La schizogonie chez les entamibes intestinales de l'homme. Bull. Soc. Path. exot. 10, 311.Google Scholar
Morris, S. (1936). Studies of Endamoeba blattae (Bütschli). J. Morph. 59, 225.Google Scholar
Opinions Rendered By The International Commission On Zoological Nomenclature (1928). Opinions 98–104. Smithsonian Misc. Coll. vol. 73, No. 5. [Opinion 99, pp. 4–8. Opinion 116 will be found in vol. 73 No. 7 (1931), pp. 6–17.]Google Scholar
Sanders, E. P. (1931). The life-cycle of Entamoeba ranarum, Grassi (1879). Arch. Protistenk. 74, 365.Google Scholar
Sanders, E. P. & Cleveland, L. H. (1930). The morphology and life-cycle of Entamoeba terrapinae spec. nov from the terrapin, Chrysemys elegans. Arch. Protistenk. 70, 267.Google Scholar
Schaudinn, F. (1903). Untersuchungen über die Fortpflanzung einiger Rhizopoden. (Vorl. Mittheil.) Arb. Kais. GesundhAmt. 19, 547.Google Scholar
Smith, N. M. & Barret, H. P. (1928). The cultivation of a parasitic amoeba from the cockroach. J. Parasit. 14, 272.Google Scholar
Swartzwelder, J. C. (1937). Experimental studies on Endamoeba histolytica in the dog: a preliminary report. J. Trap. Med. Hyg. 40, 173.Google Scholar
Tanabe, M. (1934). The excystation and metacystic development of Entamoeba histolytica in the intestine of white rats. Keijo J. Med. 5, 238.Google Scholar
Wight, T. H., Toynbee, & Prince, L. H. (1927). Artifacts in endamoebae which have led to the naming of a new genus and species. Amer. J. Trap. Med. 7, 287.Google Scholar
Yorke, W. & Adams, A. R. D. (1926). Observations on Entamoeba histolytica. I. Development of cysts, excystation, and development of excysted amoebae, in vitro. Ann. Trop. Med. Parasit. 20, 279.Google Scholar
Yoshida, K. (1920). Reproduction in vitro of Entamoeba tetragena and Entamoeba coli from their cysts. J. Exp. Med. 32, 357.Google Scholar