Record Display for the EPA National Library Catalog


Main Title Cross-Species Transmission of 'Giardia spp.: Inoculation of Beavers and Muskrats with Cysts of Human, Beaver, Mouse, and Muskrat Origin.
Author Erlandsen, S. L. ; Sherlock, L. A. ; Januschka, M. ; Schupp, D. G. ; Schaefer, F. W. ;
CORP Author Minnesota Univ., Minneapolis.;Health Effects Research Lab., Cincinnati, OH. Toxicology and Microbiology Div.
Publisher c1988
Year Published 1988
Report Number EPA/600/J-88/395;
Stock Number PB90-100579
Additional Subjects Giardia ; Inoculation ; Cysts ; Disease vectors ; Humans ; Mice ; Rodents ; Giardiasis ; Reprints ; Species specificity ; Zoonoses ; Drug therapy ; Scanning electron microscopy
Library Call Number Additional Info Location Last
NTIS  PB90-100579 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 11p
Giardia cysts isolated from humans, beavers, mice, and muskrats were tested in cross-species transmission experiments for their ability to infect either beavers or muskrats. Giardia cysts, derived from multiple symptomatic human donors and used for inoculation of beavers or muskrats, were shown to be viable by incorporation of fluorogenic dyes, excystation, and their ability to produce infections in the Mongolian gerbil model. Inoculation of beavers with 5 x 10 sup 5 Giardia lamblia cysts resulted in the infection of 75% of the animals (n = 8), as judged by the presence of fecal cysts or intestinal trophozoites at necropsy. The mean prepatent period was 13.1 days. An infective dose experiment, using 5 x 10 sup 1 to 5 x 10 sup 5 viable G. lamblia cysts collected by fluorescence-activated cell sorting, demonstrated that doses of between, less than 50, and less than 500 viable cysts were required to produce infection in beavers. Scanning electron microscopy of beaver small intestine revealed that attachment of G. lamblia trophozoites produced lesions in the microvillous border. Inoculation of muskrats with G. lamblia cysts produced infections when the dose of cysts was equal to or greater than 1.25 x 10 sup 5. The inoculation of beavers with Giardia ondatrae or Giardia muris cysts did not produce any infection; however, the administration to muskrats of Giardia cysts of beaver origin resulted in the infection of 62% of the animals (n = 8), with a prepatent period of 5 days. (Copyright (c) 1988, American Society for Microbiology.)