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In vivo killing of Giardia trophozoites harbouring bacterial endosymbionts by intestinal Paneth cells: an ultrastructural study

Published online by Cambridge University Press:  19 October 2004

K. A. EL-SHEWY  and
R. A. EID
K. A. EL-SHEWY
Affiliation:
Microbiology and Parasitology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
R. A. EID
Affiliation:
Electron Microscopy Center, Faculty of Sciences, Zagazig University, Egypt
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Abstract

To date Paneth cells have not previously been reported to kill Giardia trophozoites and other protozoa in vivo. Here we report the first evidence for in vivo killing of Giardia trophozoites by intestinal Paneth cells. Transmission electron microscopic (TEM) examination of duodenal specimens taken from naturally infected mice revealed that only Giardia trophozoites harbouring peripheral bacterial endosymbionts were destroyed and lysed in the vicinity of the activated Paneth cells. Additionally, intestinal epithelium was more affected by Giardia harbouring bacterial endosymbionts than Giardia with no endosymbionts. Our findings imply that the bacterial endosymbionts within Giardia trophozoites have a role in both host protective and pathological mechanisms, probably through altering the trophozoite antigencity. These observations might shed light on the diversity in infectivity and host specificity of Giardia species.

Keywords

endosymbiosisgiardiasiselectron microscopyPaneth cellsin vivo killingnaturally infected mice
Type
Research Article
Information
Parasitology , Volume 130 , Issue 3 , March 2005 , pp. 269 - 274
Copyright
2004 Cambridge University Press

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