title: Drug-abbreviated infections of Trichostrongylus colubriformis and development of immunity in jirds (Meriones unguiculatus).
abstract: The objective of this study was to examine the development and the duration of immunity achieved with drug-abbreviated infections of Trichostrongylus colubriformis in jirds (Meriones unguiculatus). Jirds were primarily infected either by trickle infection with 6 x 100 infective larvae (L3) of T. colubriformis at 3-day intervals or by a single infection with 600 L3. On day 35 post-infection, one batch of jirds from each group was autopsied; the others were treated with oxfendazole at a dose of 5 mg/kg and were challenged with 1,000 L3 on either day 7 or day 42 post-treatment. All jirds were autopsied at 17 days post-challenge. Trickle infection resulted in lower levels of egg production during the primary infection period. The systemic IgM and IgG antibody response was significantly stronger in trickle- and single-infected groups as compared with the negative control group (P < 0.01-P < 0.05). Significantly higher levels of intestinal IgA were demonstrated in trickle- and single-infected groups than in the negative control group (P < 0.01). Numbers of mucosal mast cells increased following infection, but this was not dependent on the type of immunisation. After challenge the extent of worm reduction was greater in trickle-infected than in single-infected subgroups. The IgM and IgG response was significantly stronger in challenged subgroups as compared with negative control subgroups (P < 0.01). However, the IgG response was weaker in control challenged subgroups than in challenged subgroups (P < 0.01). There was a negative correlation between the IgG response and the worm burden after the second challenge (r = -0.73). The acquired immunity to T. colubriformis infection in jirds developed within 5 weeks of primary infection. The level of immunity was higher after trickle infection than after single infection. Furthermore, the immunity persisted for at least 6 weeks after oxfendazole treatment in the absence of a worm burden and larval intake, which is very similar to the situation in domestic ruminant hosts.
authors.affiliation: Institute of Tropical Medicine, Antwerpen, Belgium.
authors.forename: H
authors.initials: H
authors.lastname: Ziam
authors.forename: V S
authors.initials: VS
authors.lastname: Pandey
authors.forename: E
authors.initials: E
authors.lastname: Elegbe
authors.forename: V
authors.initials: V
authors.lastname: Kumar
authors.forename: P
authors.initials: P
authors.lastname: Dorny
authors.forename: J F
authors.initials: JF
authors.lastname: Huntley
authors.forename: L
authors.initials: L
authors.lastname: Maes
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000969:Antinematodal Agents / Q000494:pharmacology; D001562:Benzimidazoles / Q000627:therapeutic use; D005243:Feces / Q000469:parasitology; D005260:Female; D005849:Gerbillinae; D007413:Intestinal Mucosa / Q000276:immunology; D007422:Intestines / Q000469:parasitology; D008297:Male; D010270:Parasite Egg Count; D014253:Trichostrongylosis / Q000188:drug therapy / Q000276:immunology / Q000517:prevention & control*; D014611:Vaccination
chemical_list: D000909:Antibodies, Helminth; D000969:Antinematodal Agents; D001562:Benzimidazoles; C011030:oxfendazole