Browsing by Author "Krishnamohan Reddy, Y"
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ArticleItem Open Access DETECTION OF PESTE DES PETITS RUMINANTS VIRUS ANTIBODIES IN SERA OF BUFFALOES(2021) Giridharan, P; Krishnamohan Reddy, Y; TANUVASIn Indian state of Tamil Nadu, six districts were chosen and 120 serum samples collected from selected herds of buffaloes. These sera were screened for peste des petits ruminants virus (PPRV) antibodies using cELISA and micro SNT. Though the sample size is small to assess the extent of seropositivity, both the tests showed 15% (9/60) positivity for PPRV antibodies in selected herds of buffaloes in the areas without previous history of PPRV disease incidence and PPRV vaccination in goats and sheep, whereas, 28.3% (17/60) positivity was found in selected herds of buffaloes with previous history of PPRV disease incidence and PPRV vaccination in goats and sheep under field/ farmers’ holdings. The buffaloes did not exhibit any clinical sign though there was seropositivity.ArticleItem Open Access IMMUNE RESPONSE TO PESTE DES PETITS RUMINANTS VIRUS VACCINE IN GOATS(2020) Giridharan, P; Kaushik, S; Krishnamohan Reddy, Y; TANUVASA study was undertaken to assess the immune response of the commercially available peste des petits ruminants virus (PPRV) vaccines in goats of Tamil Nadu under field conditions. Two commercial PPRV vaccines from manufacturers A and B, available in the state were used from 2016 to 2018. The serum samples were collected from the PPRV vaccinated goats on 0, 28, 90, 180 and 365 days post vaccination (DPV) for the four groups and tested for PPRV antibodies by competitive enzyme-linked immunosorbant assay (c-ELISA) and micro serum neutralisation test (mSNT). Group 1 (4 months to 1 yr of age) and Gr 4 (45 days-old) goats were vaccinated with either PPRV vaccine from vaccine manufacturer A or B; Gr 2 goats (>1 yr of age) which were previously vaccinated once with PPRV vaccine and revaccinated with PPRV vaccine from the same manufacturer A or B; Gr 3 goats (>1 yr of age) revaccinated with PPRV vaccine from manufacturer A, which were previously vaccinated once with PPRV vaccine from different manufacturer B and vice versa. In all the four groups, the mean percentage inhibition (PI) values on c-ELISA continued to increase from 0 DPV (21.28±0.54) to 90 DPV (83.88±0.70). Thereafter there was decline in the average PI values with the presence of PPRV antibody even at 365 DPV (83.88±0.70 to 54.19±0.78). The study suggested that vaccine from either of the manufacturer can be used for subsequent revaccination so as to produce rapid immune response.PresentationItem Open Access Occurrence of Foot and Mouth Disease in exotic and crossbred sheep in the Nilgiris(2020-02) Anbu Kumar, K; Krishnamohan Reddy, Y; Krishnakumar, S; et al.; TANUVASFoot and mouth disease (FMD) is primarily a disease of cattle in India. Cross-bred cattle usually show severe form of the disease, while indigenous cattle and buffaloes are also affected with less severe forms. In general, the clinical disease of FMD in sheep and goats is rare and usually goes undetected. During 2013, several flocks of sheep and goats were affected with FMD resulting in mortality, abortions and neonatal mortality. The severe clinical manifestation of FMD in sheep was also observed in the year 2018. During 2018, there was an occurrence of FMD in exotic and crossbred sheep in the Sheep Breeding Research Station (SBRS), Sandynallah, the Nilgiris district of Tamil Nadu. Since there was no history of FMD and PPR in the farm, the sheep were not vaccinated with FMD or PPR vaccine. The sheep above three months of age were vaccinated with bluetongue vaccine. In the farm, about 1200 sheep of Dorset and Nilgiris cross, Garole andSandyno cross were present of which 140 were lambs, 270 were hoggets, 660 were ewes and 130 were rams. Initially, the infection was noticed in hoggetsand followed by adults. About 350 sheep showed symptoms of oral vesicular lesions, limping, dullness, anorexia, pyrexia and depressionfrom the second week of December, 2018 until the end of January 2019.About 50 ewes aborted from the onset of symptoms till end of January 2019. Lambs did not show any clinical symptoms suggestive of FMD throughout the period. During this period, some cattle and buffaloes in the Nilgiris have been reported with oral vesicular lesions and limping suggestive of FMD infection. Though FMD virus could not be detected in samples from the affected sheep, O-type was reported from cattle from other parts of Tamil Nadu during the same period. Besides cattle, severe clinical manifestation of FMD in indigenous cattle, buffaloes, sheep, goats and pigs was reported from parts of Tamil Nadu. Serology of the affected sheep at SBRS showed the presence of FMD antibodies, primarily O-type. In addition, antibodies to bluetongue and PPR were present in the serum samples. Hence it was advised to vaccinate the sheep against FMD, Bluetongue and PPR.ArticleItem Open Access Quantification of Mycobacterium avium subsp. paratuberculosis from the tissues of challenged mice using SYBR Green real time PCR assay for the assessment of vaccine efficacy(2019-07) Chaitanya, RK; Krishnamohan Reddy, Y; Dhinakar Raj, G, et al.; TANUVASA SYBR Green real time PCR assay amplifying F57 gene of Mycobacterium avium subsp. paratuberculosis (MAP) was developed to evaluate the protective efficacy of the inactivated vaccine to prevent the colonization of MAP in the tissues of BALB/c mice challenge model. Bacterial burden in the liver, spleen and intestine of vaccinated and sham immunized control mice, after intra peritoneal challenge with MAP were quantified by real time PCR assay. A 195 bp fragment of MAP F57 sequence was cloned into TA cloning vector and the resultant recombinant plasmid was used to generate a series of quantification standards with copy number ranging from 109 to 1 copy. This absolute quantification technique is rapid and able to detect as few as 10 MAP organisms per gram of tissue and the assay has the efficiency of 0.982.ArticleItem Open Access Rapid and Sensitive Faecal based PCR Assays for the Detection of Parvoviruses in Laboratory Rats(2020-08) Srinivasan, MR; Vijay, K; Ramesh, S; Karuppannan, AK; Krishnamohan Reddy, Y; TANUVASHealth status of laboratory rats indicates its suitability for the researches. They are prone to develop viral infections of subclinical nature caused by parvoviruses, which affects the research results adversely; Hence Implementation of health monitoring protocol is essential at the level of breeding colony itself. This study was intended to develop rapid and sensitive fecal-PCR assays to detect infections of multiple species of Parvoviruses affecting rats namely, Rat Minute Virus, Toolan’s Parvo Virus, Rat Parvo Virus and Kilham’s Rat Virus as an alternate approach to serology based health monitoring in a lab animal breeding unit. All the primers detected only in the presence of the respective templates. PCR assays of RMV and TPV consistently amplified as little as 40 fg and that of RPV and KRV consistently amplified as little as 4 fg of plasmid DNA. Specificity and sensitivity assays indicate that the PCR assays may be useful as diagnostic tools for rapid detection of natural acute viral infections. Further analysis of the primers in the positive laboratory animal colony is essential.ArticleItem Open Access STUDIES ON CO-INFECTION OF PESTE DES PETITS RUMINANTS VIRUS AND ORF VIRUS IN VITRO(2021) Giridharan, P; Krishnamohan Reddy, Y; TANUVASIn peste des petits ruminants (PPR) affected goat / sheep flocks the most commonly occurring mixed viral infection is orf. Hence the present study was aimed to study the interaction of PPR virus (PPRV) and orf virus by co-infecting both the viruses in vitro using Vero cells. Both the PPRV field isolate and orf virus field isolate, adapted in Vero cells were utilized for co-infection. Equal quantum of both the viruses (100 CCID50) was used for all the three methods of co-infection (Initial infection with PPRV virus followed by orf virus, Initial infection with orf virus followed by PPR Virus and Simultaneous infection with both the PPR virus and orf virus). Three types of control i.e. PPRV infected Vero cells, orf infected Vero cells and uninfected Vero cells were maintained. In all the three types of co-infection of PPRV and orf virus, the results revealed only the establishment of PPRV infection in Vero cells which was detected even at 5th passage whereas, the co-infected orf virus was not detected after second passage. Both the orf virus and PPRV were detected in all the five passages of their virus control Vero cells infected separately with respective viruses. The PPRV has dominated the co-infected orf virus and established the infection even at 5th passage in Vero cellsPresentationItem Open Access Usefullness of bluetongue vaccination in cattle(2020-02) Anbu Kumar, K; Krishnamohan Reddy, Y; Dharmesh, VK; Srinivas, K; TANUVASBluetongue (BT) is primarily a disease of sheep and hence they are vaccinated with BT multivalent inactivated vaccine containing bluetongue virus (BTV) serotypes 1,2,10,16 and 23 in India. Cattle, buffaloes and goats also show sero-positivity; though clinical symptoms due to BTV infection in these animals are not reported in India. However, in North America, Europe and Australia, clinical disease of BT is often reported in cattle and in Europe, cattle along with sheep are being vaccinated with BT inactivated vaccine. During 2018 monsoon period, the severe clinical manifestation of FMD was observed in crossbred cattle throughout Tamil Nadu. Indigenous cattle, buffaloes, sheep, goats and pigs were also affected with clinical manifestation. During this outbreak, FMD O-type was reported from cattle. Serum samples collected from cattle, buffaloes,sheep and goats showed FMD antibodies. Some of these samples collected during the FMD outbreak period in 2018 also showed sero-positivity for bluetongue antibodies in C- ELISA. When the serum samples were again collected from cattle and buffaloes from the same locations during 2019 showed more than 80% positivity for BTV antibodies. Previous reports have indicated FMD like lesions in the cattle and buffaloes vaccinated with FMD vaccine and BTV antibodies were present in the serum samples of these animals. It was also observed that sheep which were vaccinated with bluetongue vaccine and FMD vaccine did not exhibit any signs of disease during the FMD outbreak in 2018. Especially in one farm in an outbreak area, 10 cattle which were vaccinated with bluetongue did not exhibit any signs of disease during the FMD outbreak in 2018. The high percentage of sero-positivity in cattle and buffaloes and repeated occurrence of FMD like lesions in FMD vaccinated cattle taken together with the occurrence of clinical disease of BT in Cattle in North America, Europe and Australia necessitates BTV vaccination in cattle and buffaloes in India.