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Strain variation in Entamoeba histolytica

II. The effect of serial liver passage on the virulence

Published online by Cambridge University Press:  06 April 2009

R. A. Neal
Affiliation:
Wellcome Laboratories of Tropical Medicine, London
Patricia Vincent
Affiliation:
Wellcome Laboratories of Tropical Medicine, London

Extract

1. Liver lesions were easily induced in hamsters with two strains of E. histolytica but not with six others.

2. Serial liver passage increased the invasiveness to the rat's caecum of one strain which had become attenuated by in vitro cultivation.

3. The invasiveness of one of the liver passage substrains was lost a second time after cultivation in vitro and a second series of liver passages restored some degree of virulence.

4. Serial liver passage did not increase the invasiveness of two avirulent strains.

5. The ease of production of amoebic liver lesions in hamsters is not correlated with invasiveness in the rat's caecum.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1956

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References

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