JANAKIRAMA SARMA, B(MAJOR)NARASIMHA REDDY, YANAND KUMAR, AKEERTI MEENA2018-10-012018-10-012007-01http://krishikosh.egranth.ac.in/handle/1/5810074575THESESABSTRACT : Peste des petits ruminants (PPR) is a highly contagious viral disease of sheep and goats resulting in heavy mortality and morbidity and is considered to be one of the main constraints to improving productivity of small ruminants in the regions where it is endemic. Sever economic losses are reported annually from different parts of India due to absence of timely detection of the disease. Rapid and accurate detection of PPR is important for efficient control and epidemiological surveillance and to reduce losses to the livestock industry. Therefore, there is a need for the development of rapid diagnostic tests in order to have a better control over the disease. The present study was taken up with an aim to standardize and develop rapid diagnostic methods such as Latex agglutination test (LAT), capture ELISA and RT-PCR for the detection of PPR virus in infected cell culture fluid and clinical samples. The tests were standardized using PPR virus infected and uninfected cell culture (as control) fluids. The test were then used to detect PPR virus/ antigen in 34 clinical samples comprising of 4 oral, 4 nasal, 2 lachrymal and 2 fecal swabs and 22 tissue samples. PPR virus (vaccine strain) from infected cell culture fluid was purified and concentrated using PEG 6000. The concentrated virus was used for raising hyperimmune serum in rabbits. The levels of antibodies in the serum were monitored by AGID. Immunoglobulins were purified from serum using saturated ammonium sulphate. LAT was standardized using purified antiPPR rabbit Ig tagged to latex beads. Both coloured (blue) and white beads were used. The test was found to be simple and rapid. The shelf life of LAT reagents at room temperature and 4oC was also studied. The reagent was found to be stable for 2 wks. at room temperature and at 4oC for 7 wks. (maximum period tested). Thirty four clinical samples were screened by LAT, of which 20 (58.82%) were found to be positive for PPR. Capture ELISA was standardized employing reagents supplied by I.V.R.I and it identified 21 positives with a per cent positivity of 61.76. RT-PCR was standardized and nested PCR was done in order to confirm the first stage PCR product which yielded 309 bp products. Out of total 34 samples 18 samples were positive for presence of PPR virus by RT-PCR. None of the nasal, fecal and eye swabs were positive for amplification product by RT-PCR. Sensitivity and specificity of LAT was found to be 90.4 % and 92.3 % respectively when capture ELISA was reference method. When RT-PCR was reference method, LAT showed sensitivity of 88.8% and specificity of 75%. It may be concluded that in the present study LAT was found to be equally sensitive and specific to capture ELISA but inferior to RT-PCR. By using monoclonal antibody as in capture ELISA, the sensitivity and specificity of LAT could be improved further to make it an ideal field test for the rapid diagnosis of PPR in outbreak areas and to plan effective strategies to control disease.ennullThesis