Detection of toxoplasmosis in blood and tissue samples of experimentallay infected mice by polymerase chain

- 100 -8. SUMMARYDETECTION OF TOXOPLASMOSIS IN BLOOD AND TISSUE SAMPLESOF EXPERIMENTALLAYINFECTED MICE, BY POLYMERASE CHAINREACTIONToxoplasma gondii is the only species of Toxoplasma genuswhich able to infects humen and wingeds and other memelian. Theprimary infection is generally subclinical. The majority of infectedpopulation remains asemptomatic, but some patients present mildsaymptoms. However, the infection can cause morbidity and mortality. Thereactivation of the latent infection cause ocular toxoplasmosis andencephalitis in immunocompromised patients. Primary maternaltoxoplasmosis exposes the risk of transmission of the fetus leading tocongenital toxoplasmosis. Serological diagnosis can be difficult in theimmundeficiency or in the pregnancy. The use of molecular teqniques inthese group of patient gain importance particularly. Because molecularteqniques are not affected form the immu status of the patients. Thus,polymerase chain reaction (PCR) consider a valuable alternative for thediagnosis of toxoplasmosis.In our study, four groups of mice including 10 mice in each ofthese groups, were infected with 50.000 tachyzoites of sin mice. Brain,liver, spleen and blood samples were obtained from infected mice at 24,48, 72 and 96 houres of infection. Pathologic lesions were best visualised- 101 -macroscopically and microscopically at 96 houres of infection. DNA wereisolated from blood and tissue samples. The extracted DNA wereamplified with B1 gene specific primers by using a nested PCR protocol.Comparatively, 529 bp repeatative element were also amplified by using asingal step PCR. PCR products of B1 gene and the repeatative element of529 bp were both detected in tissue samples of the mice after 24 houersof infection. Detection limit was 1,4 x 104 tachyzoites/ ml by using B1primers, which it was 1,4 x 102 takyzoit/ ml by using primers selected formrepeatative element. Thus, repeatative element detection by PCR wasfound to be more (100 folf) sensitive than B1 detection.As a result of our study, PCR was evaluated as a rapid,highly sensitive method which is not effected from the immun system ofthe patient. For these reason, this method can be use as a complimentarymethod with conventional methods in the diagnosis of toxoplasmosis.Thus, repeatative element primer detection by PCR wasfound to be more sensitive than B1 gene primer detection.