Kiran Aqil (2008-VA-456)

Pathobiological Investigations Of Peste Des Petits Ruminants (Ppr) Virus With Reference To Antiviral Activity Of Nigella Sativa (Black Seed) - 2017. - 139p.;

Peste des Petits Ruminants (PPR) is a highly contagious, infectious, acute or sub-acute transboundary viral disease of domestic and wild small ruminants. It is an economically important viral disease of sheep and goats causing varying degree of morbidity and mortality in susceptible animals which may be as high as 100 and 90 per cent, respectively. PPR is responsible for serious socioeconomic problems. There is no data available regarding pathogenesis and field virus characterization to compare it with vaccinal strain for any difference. Nigella sativa(Black Seed) has antiviral activity against many viruses. Therefore present studywas undertaken to investigate the antiviral effect of Black Seed in vivo and in vitro against PPR virus. Further more time course detection of virus is still needed to be studied.
 Nigella sativa (Black seed) has antiviral activity against PPR virus.
 Pathogenesis can better be studied through histopathology, necropcy findings and morphometric changes.
A total of 250 clinically positive samples suspected for PPR virus were included in the study. Samples were consisted of nasal, ocular and anal swabs; whole blood in EDTA were collected from suspected animals. In case of mortality morbid material included lungs, liver, spleen and mysenteric lymph nodes were included in the study. Samples were subjected to immune capture Elisa for detection of viral antigen in suspected samples. Samples which found positive foe IC – Elisa were then subjected to RT-PCR for confirmation of virus. After confirmation of virus through IC – Elisa and RT-PCR the positive samples were subjected to virus isolation on vero cell. After isolation of virus, the TCID 50 of the virus was calculated for preparation of inoculum for further use. In this experiment mesenteric lymph nodes and spleen found to be major organ for isolation of PPRV.RT-PCR found to be most reliable and confirmatory diagnostic test for PPRV. Field Virus adaptation on vero cells found to be difficult to optimize.
In this experiment antiviral activity of black seed was checked on vero cells infected with PPRV. Three extracts of N. Sativa were prepared to check the in vitro antiviral activity of black seed. In this study poly saccharides extracted from black seed found to be more effective against PPRV. Adaptation of field virus was done on Vero cell line. Antiviral activity of Black Seed extract was determined in vitro on Vero cell on bases of CPE (Cytopathic effect). The ethanolic and aqueous extract were found to be more toxic to consistency of monolayer of vero cells. The TCID50 of virus was calculated after treating cells with different extracts. In this study poly saccharides extract exhibit lower TCID50‘s as compared to ethanolic and aqueous extract which showed higher TCID50’s.So less cytopethic effect was observed in vero cells treated with black seed extracts. Antiviral activity was determined on base of CPE.
Pathogenesis of virus in natural host was studied through time course detection of virus in body secretions, blood, organs. Histopathological changes were studied.20 goats were procured from market divided into four groups (n=5) A,B,C and D. In animals of group A prophylactic effect of N.Sativa was studied. In group B complete pathogenesis of PPR virus was studied without any prophylactic or therapeutic measure. In group C therapeutic effect of N. Sativa was studied after onset of clinical picture of disease. At the end of this experiment, clinical picture, gross pathology, histopathology, and morphometric changes revealed that N. Sativa has noticeable prophylactic effect on PPR infected goats. It can be used as a therapeutic agent in PPR infected goats but it can’t control pathological effect of virus after onset of infection.
Data collected were statistically analyzed by using Microsoft Excel (Microsoft Excel, 2007) and SPSS (for Windows, Version 16.0). The data were put the descriptive analysis and Chi square test was employed to test the significance and test of hypotheses
It was concluded that Black Seed therapy possessed marvelous prophylective effect against PPR virus and RT-PCR was the most efficient methodology to confirm the virus.

Phd. Thesis


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