Investigations by PCR analysis of neospora caninum prevalence and co-infection with toxoplasma gondii in naturally infected populations

Hughes, JM

Abstract

Neospora caninum and Toxoplasma gondii are closely related intracellular protozoan
parasites associated with abortion in mammals. TV! caninum was identified in 1984, described
as a new species in 1988 and often previously misidentified as T. gondii.
hi this study molecular techniques were used to investigate the presence of TV. caninum and T.
gondii in naturally infected populations.
To facilitate this a nested PCR technique, targeting the Nc5 region of N. caninum, was
developed. Using this and an established T. gondii specific PCR the prevalence ofN. caninum
and co-infection with T. gondii were investigated hi naturally infected mammals.
The fox has been identified as a potential definitive host of TV. caninum. PCR analysis of DNA
extracted from tongue tissue determined a low prevalence of 1.4% (1/70) hi British foxes.
None of these foxes had detectable T. gondii DNA. Small mammals are a potential source of
TV. caninum infection. TV. caninum was present in the brain tissues of all species investigated:
Mus domesticus 3.1% (4/130), Rattus norvegicus 4.4% (2/45), Apodemus sylvaticus 3.4%
(4/118) and Oryctolagus cuniculus 10.5% (6/57). T. gondii prevalences were significantly
higher in all species tested. Co-infection was observed hi all species except Rattus norvegicus.
Investigation of vertical transmission of T. gondii in wild Mus domesticus, determined it was
a common occurrence with 74.6% of foetuses from infected dams having detectable parasite
DNA.
A relatively high frequency of infection with TV. caninum was detected hi brain tissue of
aborted lambs (18.9%). No significant relationship was found between TV. caninum and T.
gondii infection. Detection of TV. caninum DNA was restricted to the brain in aborted lambs
but was more widely distributed in rabbits. T. gondii DNA was detected in multiple tissues of
both host species.
These studies demonstrate that TV. caninum is widely distributed in natural populations of
mammals.

Citation

Hughes, J. Investigations by PCR analysis of neospora caninum prevalence and co-infection with toxoplasma gondii in naturally infected populations. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2009