Giardia lamblia Infections in Mongolian Gerbils: An Animal Model

Abstract

Mongolian gerbils were susceptible to infection with Giardia lamblia cysts from patients. Inoculation of gerbils with 5 x 10(3) cysts each resulted in an infection characterized by the intermittent release of cysts for up to 39 days. The mean number of cysts released per gerbil in a 2-hr period was 8.8 x 10(2) (range, 0-5 x 10(3)). The highest number of trophozoites found in the intestine was on day 15 after infection, when the mean number of trophozoites per gerbil was 6.36 x 10(6). Administration of cysts from different patients to gerbils resulted in a similar pattern of cyst release during the first 30 days of infection. Mongolian gerbils were also susceptible to infection with cultured trophozoites (Portland 1 strain). The pattern of cyst release and the number of trophozoites in the intestines of orally and duodenally inoculated gerbils were similar. Gerbils were protected against reinfection with G. lamblia for up to eight months after primary infection.

Detection of Giardia duodenalis antigen in human fecal eluates by enzyme-linked immunosorbent assay using polyclonal antibodies

“…Trophozoites were obtained from experimentally infected gerbils with 14 different Giardia human isolates following the procedure described by Belosevic et al (1983). Their concentration was independently adjusted to 1x10 6 per 1 ml saline (Green et al 1985).…”

Impacto de la dieta sobre la inducción de infección con quistes de Giardia lamblia en ratas Sprague-Dawley

“…18 De igual manera, esta condición dietaria ha mostrado en estudios in vitro que la proliferación celular y la sín-tesis de ADN, se reducen. 19 En cuanto a la excreción, ésta se inició al cuarto día concordando con los resultados obtenidos por Craft, 9 y Belosevic y colaboradores, 8 quienes inocularon jerbos y observaron la excreción al octavo día. Por su parte, Schupp y colaboradores, 7 trabajando con ratones neonatos, detectaron la presencia de quistes en las heces al quinto día.…”

“…Estos resultados coinciden con los obtenidos por Belosevic y colaboradores, 8 quienes trabajando con jerbos también observaron intermitencia en esta especie. Empero, Roberts Thompson y colaboradores, 7 reportaron que ratones inoculados con Giardia muris no presentaban intermitencia.…”

“…En este último punto, la mayoría de los informes indican el uso de inóculos en concentraciones de 100 o más quistes. 7,8 De igual manera, la rata ha sido utilizada como modelo animal para reproducir la infección con Giardia lamblia, ya que se considera que la giardiosis provocada en este modelo tiene gran similitud con la manifestada en humanos y ratones. La rata como modelo se considera que proporciona una herramienta útil para la investigación de la patofisiología de la giardiosis.…”

Potential molecular tools for assessing the public health risk associated with waterborne Cryptosporidium oocysts

“…Giardia cysts and Cryptosporidium oocysts can excyst in the gastrointestinal tracts of other animals in addition to humans. Mongolian gerbils have been used as an experimental model for Giardia infection (Belosevic et al, 1983), and neonatal CD-1 mice have been used as a model for Cryptosporidium infection (Finch et al, 1993). However, as well as the problem of needing additional resources, funds and labour, the relevance of the data generated from such studies for risk assessment and for treatment purposes remains dubious.…”