Factors influencing the development and carbohydrate metabolism of Echinococcus granulosus in dogs.
Echinococcus granulosus adult worms, 35 days postinfection, were measured for dispersion in the intestines of 10 dogs, a range of morphological characters, and the excreted end products of carbohydrate catabolism following 4 hr incubation in vitro. Most worms were found in the proximal sections of the small intestine, but the pattern of dispersion differed between dogs. Worm development varied both between dogs and between different regions of the small intestine of individual dogs. Overall there was a high level of variability with no simple patterns. Worm metabolism was related to worm development and, also independently, to local population density within the intestine. Larger, more mature worms produced less lactate and, at higher densities, worms tended to produce more acetate and succinate (pathways with a higher energy yield than lactate) and less ethanol. Thus, both more developed worms and high population density are associated with a shift from cytosolic to mitochondrial metabolism. The variation between worm populations along the small intestine along with the observed variation between worm populations from sibling dogs infected with genetically identical parasites suggests that the local host environment has a significant effect on parasite development.
Constantine
C C
CC
Institute for Molecular Genetics and Animal Disease and Division of Veterinary and Biomedical Sciences, Murdoch University, Western Australia.
Bennet-Jenkins
E M
EM
Lymbery
A J
AJ
Jenkins
D J
DJ
Behm
C A
CA
Thompson
R C
RC
D000085:Acetates / Q000032:analysis; D000704:Analysis of Variance; D000818:Animals; D050260:Carbohydrate Metabolism; D003470:Culture Media; D004283:Dog Diseases / Q000469:parasitology*; D004285:Dogs; D004443:Echinococcosis / Q000469:parasitology / Q000662:veterinary*; D004446:Echinococcus / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D000431:Ethanol / Q000032:analysis; D005260:Female; D007421:Intestine, Small / Q000469:parasitology*; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D019802:Succinic Acid / Q000032:analysis
D000085:Acetates; D003470:Culture Media; D019344:Lactic Acid; D000431:Ethanol; D019802:Succinic Acid