SEROLOGICAL AND MOLECULAR DETECTION OF TOXOPLASMA GONDII ASSOCIATED WITH ABORTIONS IN GOATS
Loading...
Date
2021-12-30
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
COLLEGE OF VETERINARY AND ANIMAL SCIENCES MANNUTHY, THRISSUR
Abstract
Toxoplasmosis, a cosmopolitan zoonotic parasitic infection prevalent
throughout the world affects all warm blooded animals and man. Although the
presence of parasites do not lead to fatal events, its impact on the goat population has
become a concern among the farmers. The present study was undertaken to determine
the prevalence of Toxoplasma gondii in recently aborted goats from the central
districts of Kerala viz., Thrissur, Palakkad and Ernakulam. In the study, a total of 72
blood samples, 108 foetal tissues from 27 aborted foetuses, and 25 milk samples from
recently aborted goats and from those with a history of abortion were collected during
a period from November 2019 to November 2020. Impression smears were also
prepared from the foetal tissues and examined. The samples collected were subjected
to different methods such as microscopy, ELISA and PCR for the detection of various
developmental stages of T. gondii. Milk samples and impression smears were examined by Giemsa staining
microscopically for parasitic stages of Toxoplasma but none of them revealed the
presence of the organism. Seventy two serum samples were subjected to ELISA for
the detection of IgG antibodies of T. gondii. The overall seroprevalence was
determined to be 56.94 per cent. A higher prevalence was observed in goats above
four years of age and in those that were let out for grazing. It was also observed that
majority of the abortions occurred in the second stage of gestation in goats that were
detected as positive by ELISA.
Serum samples collected from 27 goats in which a recent abortion had taken
place collected from Thrissur showed antibodies in 14 samples by ELISA (51.85 per
cent). Tissues such as heart, brain, liver and placenta collected from three of the
aborted foetuses from the same goats were simultaneously positive for B1 gene of T.
gondii in PCR, the molecular prevalence being 11.11 percent. Toxoplasma gondii
DNA was also detected in the foetal tissues of one of the goats that was detected as
negative by ELISA.
The same samples used for T. gondii detection were used for the detection of
NC-5 gene of Neospora caninum in the aborted foetal tissues and they revealed a
molecular occurrence of 7.40 per cent. Analysis of the sequences obtained from
positive DNA of T. gondii and N. caninum using BLAST demonstrated 100 per cent
homology. District–wise prevalence revealed relatively higher prevalence in
Ernakulam district (62.5 per cent) compared to Thrissur (56.09 per cent) and
Palakkad (53.33 per cent), even though the difference was not significant
Description
Submitted in partial fulfillment of the requirement for the degree of
MASTER OF VETERINARY SCIENCE in Veterinary Parasitology