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Revista do Instituto de Medicina Tropical de São Paulo

On-line version ISSN 1678-9946

Rev. Inst. Med. trop. S. Paulo vol.35 no.6 São Paulo Nov./Dec. 1993 



An attemp at reversibility and increase of the virulence of axenic strains of Entamoeba histolytica


Tentativa de reversibilidade e aumento de virulência de cepas axônicas de Entamoeba histolytica



Maria Aparecida GomesI; Adriana Oliveira CostaI; Washington Luiz TafuriII; Edward Félix SilvaI

IDepartment of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
IIDepartment of Biological Sciences, Institute of Biological and Exact Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil

Address for correspondence




In this study we have tried to verify whether the interaction "in vitro" with bacteria or small pieces of normal hamster liver would modify the pathogenic behavior of axenic strains of E. histolytica: avirulent ones (ICB-32 and ICB-RPS), of attenuated virulence (ICB-CSP and HM1) and of mean virulence (ICB-462). Every attempt to render virulent, recover or increase the virulence of axenic strains of E. histolytica has failed.

Keywords: Entamoeba histolytica; Axenic cultures; Ameba-bacterium interaction; Virulence.


Neste trabalho procuramos verificar se a interação "in vitro" com bactérias e fragmentos de fígado de hamster normal, modificaria o comportamento patogênico de cepas axênicas de E. histolytica avirulentas (ICB-32 e ICB-RPS); virulentas, porém atenuadas (ICB-CSP e HM1) e de média virulência (ICB-462). Todas as tentativas de tornar virulentas, restabelecer ou aumentar a virulência das cepas axênicas de E. histolytica utilizadas fracassaram.



Full text available only in PDF format.

Texto completo disponível apenas em PDF.




We are indebted with the Development Center of Nuclear Technology by irradiation service and to Marcia A. Silva for able technical assistance. We are grateful to Dr. Paul Williams for correcting the manuscript. This work was supported by CNPq, FINEP and FAPEMIG.



1. BOHL, K.C.; MUKHERJEE, R.M.; BANERJEE, M. & MAITRA, T.K. - Enhancement of virulence of Entamoeba histolytica by in vitro liver treatment. Ann. trop. Med. Parasit., 85: 341-344, 1991.         [ Links ]

2. BOS, H.J. & VAN DE GRIEND, R.J. - Virulence and toxicity of axenic Entamoeba histolytica. Nature, 265: 341-343, 1977         [ Links ]

3. BOS, H.J. - Entamoeba histolytica: cytopathogenicity of intact amoebae and cell free extracts: isolation and characterization of an intracelular toxin. Exp. Parasit., 47: 369-377, 1979.         [ Links ]

4. BRACHA, R. & MIRELMAN, D. - Adherence and ingestion of Escherichia coli serotype O55 by trophozoites of Entamoeba histolytica. Infect. Immun., 40: 882-887, 1983.         [ Links ]

5. BRACHA, R. & MIRELMAN, D. - Virulence of Entamoeba histolytica trophozoites: effects of bacteria, microaerobic conditions and metronidazole. J. exp. Med., 160: 353-368, 1984.         [ Links ]

6. BRUMPT, E. - Étude sommaire de 1' "Entamoeba dispar" n. sp. Amibe à quistes quadrinuclées, parasite de I'homme. Bull. Acad. Méd.(Paris), 94: 943-952, 1925.         [ Links ]

7. CHAIA, G.; SILVA, E.F.; VILELA, C.C. & CHIARI, L. - Isolation and maintenance of a strain of Entamoeba histolytica - Shaudinn, 1903 and possibility of its utilization in screening of drugs. Rev. Inst. Med. trop. S. Paulo, 19: 195-201, 1978.         [ Links ]

8. DAS, S.R. & GHOSHAL, S. - Restoration of virulence to rat of axenically grown by cholesterol and hamster liver passage. Ann. trop. Med. Parasit., 70: 439-443, 1976.         [ Links ]

9. DE LA TORRE, M.; DE LA HOZ, R.; LANDE, L. & SEPULVEDA, B. - Cultivos axênicos de Entamoeba histolytica. Arch. Invest. med. (Méx.), 2: 165-169, 1978.         [ Links ]

10. DIAMOND, L. - Techniques of axenic cultivation of Entamoeba histolytica Shaudinn, 1903 and Entamoeba histolytica like amebae. J. Protozool., 54: 1047-1056, 1968.         [ Links ]

11. DIAMOND, L.; PHILLIPS, B.P. & BARTGIS, I.L. - A comparison of the virulence of nine strains of axenically cultivated Entamoeba histolytica in hamster liver. Arch. Invest. med. (Méx.), 5: 423-426, 1974.         [ Links ]

12. DIAMOND, L.; HARLOW, D.R. & CUNNICK, C.C. - A new medium for the axenic cultivation of Entamoeba histolytica and other Entamoeba. Trans. roy. Soc. trop. Med. Hyg., 72: 431-432, 1978.         [ Links ]

13. GRAHAM CLARK, C.; CUNNICK, C.C. & DIAMOND, L. - Entamoeba histolytica: is conversion of "Nonpathogenic" amebae to the "Pathogenic" form a real phenomenon? Exp. Parasit., 74: 307-314, .1992.         [ Links ]

14. LUSHBAUGH, W.B.; KAIRALLA, A.; LOADHOLT, C.B. & PITTMAN, P.E. - Effect of hamster liver passage on the virulence of axenically cultivated Entamoeba histolytica. Amer. J. trop. Med. Hyg., 27: 248-254, 1978.         [ Links ]

15. MARTINEZ-PALOMO, A. - Parasite factors of virulence, in the biology of Entamoeba histolytica. Baffins' Lane, John Wiley & Sons, Research Studies Press, 1982. p.95-117.         [ Links ]

16. MATTERN, C.F.T.; KEISTER, D.B. & NATOVITZ, P.C. - Virulence of Entamoeba hitolytica upon continuous axenic cultivation. Arch. Invest. med.(Méx.), 13: 185-190, 1982.         [ Links ]

17. MIRELMAN, D.; BRACHA, R.; WEXLER, A. & CHAYEN, A. - Changes in isoenzyme patterns of a cloned culture of nonpathogenic Entamoeba histolytica during axenization. Infect. Immun., 54: 827-832, 1986.         [ Links ]

18. NEAL, R.A. & VINCENT, P. - I. Strain variation in Entamoeba histolytica. II. The effect of serial liver passage on the virulence. Parasitology, 46: 173-182, 1956.         [ Links ]

19. OROZCO, E.; MARTINEZ-PALOMO, A. & LOPEZ-REVILA, R. - Un modelo "in vitro" para el estudio cuantitativo de la virulencia de Entamoeba histolytica. Arch. Invest. med. (Méx.), 9: 257-260, 1978.         [ Links ]

20. OROZCO, E.; GUARNEROS, G.; MARTINEZ-PALOMO, A. & SANCHEZ, T. - Entamoeba histolytica. Phagocytosis as a virulence factor. J. exp. Med., 158: 1511-1521, 1983.         [ Links ]

21. PHILLIPS, B.P. & GORSTEIN, F. - Effects of different species of bacteria on the pathology of enteric amebiasis in monocontaminated Guinea pig. Amer. J. trop. Med. Hyg., 15: 863-868, 1966.         [ Links ]

22. PLILLIPS, B.P. - Entamoeba histolytica: concurrent irreversible loss of infectivity/pathogenicity and encystment potential after prolonged maintenance in axenic culture "in vitro". Exp. Parasit., 34: 163-167, 1973.         [ Links ]

23. RAVDIN, J.L. & GUERRANT, R.L. - Role of adherence in cytopha-togenic mechanisms of Entamoeba histolytica. Study with mammalian tissue cultures and human red blood cells. J. clin. Invest., 68: 1305-1313, 1981.         [ Links ]

24. SILVA, E.F.; CARVALHO, M.G. & BRANDÃO, M.G.L. - Monoaxenização e cultivo de amostras de Entamoeba histolytica isoladas no Brasil de pacientes sintomáticos e assintomáticos. In: CONGRESSO BRASILEIRO DE PARASITOLOGIA, 6, Belo Horizonte, 1981. Resumos. p. 18.         [ Links ]

25. SILVA, E.F. - Virulence of Entamoeba histolytica. Performance of various samples in axenic culture inoculated into hamsters at different ages. Mem. Inst. Oswaldo Cruz, 82 (suppl. 1): 29,1987. (Abstract PZ-30).         [ Links ]

26. SILVA, E.F.; TAFURI, W.L.; PENA, G.P. & PIRES, E.M. - Evolution of hepatic lesion experimentally induced the inoculation of axenic strains of Entamoeba histolytica into the liver of hamsters (Mesocri-cetus auratus). Mem. Inst. Oswaldo Cruz, 84 (suppl.): 163, 1989.         [ Links ]

27. TRISSL, D.; MARTINEZ-PALOMO, A.; DE LA TORRE, M.; DE LA HOZ, R. & PEREZ SUAREZ, E. - Surface properties of Entamoeba histolytica: increased rates of human erythrocyte phagocytosis in pathogenic strains. J. exp. Med., 148: 1137-1145,1978.         [ Links ]

28. WITTNER, M. & ROSEMBAUN, R.M. - Role of bacteria in modifying virulence of Entamoeba histolytica: studies of amebae from axenic cultures. Amer. J. trop. Med. Hyg., 19: 761-775, 1970.         [ Links ]



Address for correspondence:
Dr. Edward Félix Silva
Departamentode Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais
Av. Antônio Carlos, 6627
CEP 31270-010, Belo Horizonte, Minas Gerais, Brasil

Recebido para publicação em 15/02/1993
Aceito para publicação em 23/08/1993.

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