title: The invasive potential of Giardia intestinalis in an in vivo model.
abstract: Giardiasis is a neglected parasitic disease that affects primarily children, in whom it delays physical and mental development. The pathophysiology of giardiasis in not well understood, and most reports have identified Giardia intestinalis trophozoites only in the lumen and on the brush border of the small intestine. We identified Giardia trophozoites within the epithelium of the small intestine of a lactose intolerance patient. The Giardia trophozoites were obtained and cultured in vitro. In addition, we demonstrated Giardia trophozoite invasion in an animal model. Giardia trophozoites invaded the intestinal mucosa and submucosa of infected gerbils. The invasive trophozoites were observed at 21, 30 and 60 days age, and the average numbers of invaded sites were 17 ± 5, 15 ± 4, and 9 ± 3, respectively. We found trophozoites between epithelial cells, at the base of empty goblet cells, in lacteal vessels and within the submucosa. The morphological integrity of the invasive trophozoites was demonstrated via electron microscopy. The analysis of the gerbils infected with the trophozoites of the WB reference strain did not show intraepithelial trophozoites. These results demonstrate another Giardia pathogenic mechanism, opening the door to numerous future studies.
authors.affiliation: Laboratorio de Morfologia Celular y Tisular (Laboratory of Cell and Tissue Morphology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics), Insurgentes Sur No. 3700-C, Mexico, D. F. C. P. 04530, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Reynoso-Robles
authors.affiliation: Laboratorio de Parasitología Experimental (Laboratory of Experimental Parasitology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics).
authors.forename: M
authors.initials: M
authors.lastname: Ponce-Macotela
authors.affiliation: Laboratorio de Morfologia Celular y Tisular (Laboratory of Cell and Tissue Morphology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics), Insurgentes Sur No. 3700-C, Mexico, D. F. C. P. 04530, Mexico.
authors.forename: L E
authors.initials: LE
authors.lastname: Rosas-López
authors.affiliation: Laboratorio de Morfologia Celular y Tisular (Laboratory of Cell and Tissue Morphology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics), Insurgentes Sur No. 3700-C, Mexico, D. F. C. P. 04530, Mexico.
authors.forename: A
authors.initials: A
authors.lastname: Ramos-Morales
authors.affiliation: Laboratorio de Parasitología Experimental (Laboratory of Experimental Parasitology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics).
authors.forename: M N
authors.initials: MN
authors.lastname: Martínez-Gordillo
authors.affiliation: Laboratorio de Morfologia Celular y Tisular (Laboratory of Cell and Tissue Morphology), Instituto Nacional de Pediatría (Mexican National Institute of Paediatrics), Insurgentes Sur No. 3700-C, Mexico, D. F. C. P. 04530, Mexico.
authors.forename: A
authors.initials: A
authors.lastname: González-Maciel
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D002648:Child; D004195:Disease Models, Animal; D004386:Duodenum / Q000469:parasitology; D005849:Gerbillinae / Q000469:parasitology; D016829:Giardia lamblia / Q000254:growth & development / Q000502:physiology*; D005873:Giardiasis / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000469:parasitology; D008854:Microscopy, Electron; D053058:Trophozoites / Q000276:immunology / Q000502:physiology
chemical_list: D000906:Antibodies