Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Fasciola hepatica: an unusual case of adaptation to a Moroccan population of Galba truncatula

Fasciola hepatica: an unusual case of adaptation to a Moroccan population of Galba truncatula Parent snails, F1, and F2, originating from a Moroccan population of Galba truncatula, were experimentally subjected to sympatric miracidia of Fasciola hepatica at 20°C to determine the mode of adaptation of this parasite to the local intermediate host via the study of redial burdens and by following cercarial shedding. In spite of an increase in the global prevalences of infections, the frequencies recorded for immature or mature infections in dissected snails did not show any significant variations from parents to F2. If the redial burdens in mature infections were mainly composed of first-generation rediae in parent snails, the numbers of rediae belonging to subsequent generations significantly increased in the F1 and F2 generations. In mature infections, the lengths of first-generation rediae and their contents significantly decreased from parent snails to F2. Conversely, in the first redial cohort of the second generation (R2a rediae), only the intraredial contents increased significantly with snail generation. In mature infections, daughter redia production was ensured by all mother rediae of the first generation in parent snails, whereas it was progressively effected by the first mother redia in the F1 and F2 infections. The numbers of cercariae shed by snails increased significantly from parents to F2. If the cercariae produced by first-generation rediae decreased with snail generation, an inverse finding was noted in the case of R2a rediae. We suggest that snails impose a bottleneck on the development of the first mother redia, so that other mother rediae of the first generation react with greater growth (until 3.9 mm in parent snails), an important daughter redia production and a high cercarial production. As the first mother redia remained alive until day 49 post-exposure but without growth after week 2, this mode of development must be considered as a new developmental pattern of redial generations, and it is useful to determine its frequency in snails, as it has never been found in naturally or experimentally infected snails in central France. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Parasitology Research Springer Journals

Fasciola hepatica: an unusual case of adaptation to a Moroccan population of Galba truncatula

Belfaiza, M.; Moncef, M.; Rondelaud, D.
Parasitology Research , Volume 95 (6) – Feb 18, 2005
Download PDF
5 pages

Loading next page...
 
/lp/springer-journals/fasciola-hepatica-an-unusual-case-of-adaptation-to-a-moroccan-2zca00McHl

References (15)

Publisher
Springer Journals
Copyright
Copyright © 2005 by Springer-Verlag
Subject
Biomedicine; Medical Microbiology; Microbiology; Immunology
ISSN
0932-0113
eISSN
1432-1955
DOI
10.1007/s00436-004-1281-7
pmid
15719263
Publisher site
See Article on Publisher Site

Abstract

Parent snails, F1, and F2, originating from a Moroccan population of Galba truncatula, were experimentally subjected to sympatric miracidia of Fasciola hepatica at 20°C to determine the mode of adaptation of this parasite to the local intermediate host via the study of redial burdens and by following cercarial shedding. In spite of an increase in the global prevalences of infections, the frequencies recorded for immature or mature infections in dissected snails did not show any significant variations from parents to F2. If the redial burdens in mature infections were mainly composed of first-generation rediae in parent snails, the numbers of rediae belonging to subsequent generations significantly increased in the F1 and F2 generations. In mature infections, the lengths of first-generation rediae and their contents significantly decreased from parent snails to F2. Conversely, in the first redial cohort of the second generation (R2a rediae), only the intraredial contents increased significantly with snail generation. In mature infections, daughter redia production was ensured by all mother rediae of the first generation in parent snails, whereas it was progressively effected by the first mother redia in the F1 and F2 infections. The numbers of cercariae shed by snails increased significantly from parents to F2. If the cercariae produced by first-generation rediae decreased with snail generation, an inverse finding was noted in the case of R2a rediae. We suggest that snails impose a bottleneck on the development of the first mother redia, so that other mother rediae of the first generation react with greater growth (until 3.9 mm in parent snails), an important daughter redia production and a high cercarial production. As the first mother redia remained alive until day 49 post-exposure but without growth after week 2, this mode of development must be considered as a new developmental pattern of redial generations, and it is useful to determine its frequency in snails, as it has never been found in naturally or experimentally infected snails in central France.

Journal

Parasitology Research – Springer Journals

Published: Feb 18, 2005

There are no references for this article.