Kinetics of serum immunoglobulin isotype response in experimental bovine tropical fasciolosis.
ABSTRACT The present communication reports on the kinetics of immunoglobulin isotype response in Fasciola gigantica infected bovine calves. Fifteen Holstein-Friesian cross-bred male calves were assigned to 3 groups (Gr) of 5 calves each and infected with 4-month (Gr-A) and 16-month-old (Gr-B) F. gigantica metacercariae (n=400), respectively, while Gr-C calves served as uninfected control. Infection was terminated by treating the animals with triclabendazole on 28 weeks post-infection (WPI). Sera were collected on 0, 4, 10 and 14 days post-infection (DPI) and subsequently at weekly interval up to 32 WPI. The immunoglobulin isotype response was analyzed by ELISA, using anion exchange purified antigen fraction. An IgG response against F. gigantica infection was evoked by 3 and 2 WPI in animals of Gr-A and Gr-B, respectively with peak antibody response at 13 WPI. Elicitation of an early IgG1 response by 10 and 14 DPI but a delayed IgG2 response at 6 and 4 WPI, in animals of Gr-A and Gr-B, respectively was recorded. An early IgM response was evoked by 10 and 14 DPI and the level peaked at 13 and 12 WPI, with no detectable level at 21 and 15 WPI in animals of Gr-A and Gr-B, respectively. IgA response was elicited at 4 WPI in both the groups and showed the highest titre at 25 and 27 WPI in animals of Gr-A and Gr-B, respectively. Present study indicated an early and predominant response of IgG1, with concurrent expression of delayed and weak IgG2 in calves experimentally infected with F. gigantica.
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ABSTRACT: Freshwater snails of the family Lymnaeidae are the intermediate hosts of the liver fluke Fasciola worldwide. While distinct species have been identified at the molecular level in other parts of the world such data have not been published for Thailand. In this study we collected Lymnaeidae from different localities across Thailand and analyzed their 16S rDNA sequences as a molecular signature for classification. In addition to the ubiquitous Radix rubiginosa, we have confirmed the presence of Austropeplea viridis and Radix swinhoei, for the latter of which the ribosomal rDNA sequences are reported for the first time, in North-Thailand. Based on the obtained 16S rDNA data three primer pairs were designed that allowed rapid identification of these snail species by PCR. To determine their infection status, PCR primers for F.gigantica cathepsin L were used in parallel with the snail 16S rDNA species-specific primers in multiplex PCR analyses. Western blot analysis of total snail protein with a monoclonal anti-F.gigantica cathepsin L antibody confirmed positive cathepsin L PCR results. The developed diagnostic PCR will be of use in risk assessment for transmission of fascioliasis in Thailand.Experimental Parasitology 12/2010; 126(4):482-8. · 1.86 Impact Factor