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Kerala Agricultural University, Thrissur

The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively. Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively. On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs. In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc. During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU). Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.

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Subject: Microbiology × Author: KAU × End date: 1997 × Start date: 1997 × Type: Thesis × Thesis Type: M.V.Sc. ×
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    ThesisItemOpen Access
    Influence of adaptation of the vaccine strain of duck plague virus in chicken embryo fibroblast on its immunogenicity
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1997) Senthil Kumar, K; KAU; Ponnoose, K T
    A chicken embryo adapted vaccine strain of duck plague virus was serially passaged in chicken embryo fibroblast cell cultures and its immunogenicity was evaluated at different passage levels. The vaccine strain of DPV received from VBI, Pal ode was revived in 11 day old chicken embryos by CAM route. The infected embryos died in 70 to 120 hr PI with lesions of congestion on the embryo and CAM and enlargement of liver and spleen. This embryo passaged virus was propagated in CEF cell culture, prepared from 12 day old embryonated chicken eggs. The virus produced CPE, characterised by rounding and clumping of cells, syncytium formation, vacuolation of cytoplasm and eosinophilic intranuclear inclusion bodies. The virus was adapted in CEF cultures by serial passage. It was passaged for ten times and the various characters of the fifth and 10th passaged viruses were studied. There was no change in the CPE but the time required for the appearance of CPE and total detachment of the cells decreased as the passages increased. The CPE appeared at 48 hr, 30 hr and 24 hr for first, fifth and 10th passages respectively. Similarly the time required for total detachment of cells also reduced from 120 hr at first passage to 90 hr at fifth passage and 80 hr at 10th passage. The rapid onset of CPE and desquamation of cells indicated the adaptation of the virus in CEF cell culture. The titres of fifth and 10th passage viruses in chicken embryos were 104.75 and 105.77 ELD50/ml respectively. The titres in CEF cultures were slightly higher. The values were 105.67 and 106.77 TCID50/ml respectively for the fifth and 10th passaged samples. The immunogenicity of the fifth and 10th passage viruses were studied by vaccinating six weeks old ducklings. Each duckling received 3.5 log10 TCID50 of either fifth or 10th passaged virus intramuscularly. The birds remained normal till the 20th day and when challenged with virulent virus. Birds that received the fifth passaged virus showed mean antibody titres of 64 and 32 by SNT and PHA respectively. All the birds withstood challenge indicating the effectiveness of fifth CEF passaged virus as a vaccine. In birds that received the 10th passaged virus, the antibody titres were low both by the SNT (1:54) and PHA (1:22). However all the ducks survived without manifesting any clinical signs. All the control ducks developed clinical signs of DP and died in seven to nine days time. The fifth and 10th CEF passaged viruses were sensitive to pH 3 and 11, but stable at pH 7.2. They were completely inactivated at 56°C in 30 min. These indicated that there was no change in the above physical characters of the virus though it was passaged in CEF cultures incubated at 38.5°C. Though the efficacy of the 10th passage virus was slightly lower as it was evident from the low antibody level, a detailed study is required to establish the present findings that an increase in the number of passages would result in decreased immunogenicity of the DPV vaccine strain. However from the results obtained during this study, it is evident that cell culture adapted DP vaccine strain could be recommended for production of vaccine against DP.
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    ThesisItemOpen Access
    Evaluation of enzyme immunoassays in the diagnosis of duck plague
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1997) Malmarugan, S; KAU; Sulochana, S
    Use of Enzyme immunoassays namely dot ELISA and plate ELISA were evaluated to detect DP viral antibodies in serum samples and in whole blood dried on filter paper strips and their efficacy was compared with standard passive haemagglutination test. Indirect immunoperoxidase test was also used to detect DP viral antigen in paraffin embedded liver and spleen. ASS at 33 per cent level was used for separation of duck globulins and antiduck globulins. The protein concentration of these globulins were 34 mg/ml and 15 mg/ml respectively. The purity of these globulins were tested by IEP and AGPT using antiduck whole serum raised in rabbits. Duck plague hyperimmune serum was raised in healthy ducklings with live attenuated DP vaccine having a virus titre of 3.5 log10 ELD50/0.5 ml. This serum was used as the positive control. A total of 200 serum samples, 35 liver and 30 spleen samples were collected from different localities for the detection of duck plague viral antibodies and antigen. Corresponding blood samples were also collected on filter paper strips and the serum was eluted and ELISA was carried out. The results in this test were then compared with whole serum ELISA. The percentage of positive reaction in PHA, Dot ELISA, plate ELISA and filter paper strip method are 64 per cent, 68 per cent 72.5 per cent and 70.5 per cent respectively. Comparative efficacy of PHA with Dot ELISA, plate ELISA and filter paper strip method were carried out and sensitivity of the tests are 71.87, 67.64 and 77.30 per cent respectively. The specificity of these tests were 38.88, 43.75, 70.90 and 67.79 per cent respectively. The concordance of PHA with these tests were 60, 75.5 and 74.5 per cent respectively. On statistical analysis high degree of association (P<0.05) was observed between PHA and Dot ELISA, plate ELISA and filter paper strip method. Highly significant different (P>0.05) was observed between PHA and plate ELISA, and PHA and filter paper strip method. Based on the results, it was concluded that because of the simplicity, easiness and accuracy, Dot ELISA is suitable for detection of DPV antibodies under field conditions. But plate ELISA was highly sensitive, specific and able to detect low titred sera. Hence this test may be recommended for titration of DPV antibodies in the laboratories, particularly when the potency of the vaccine is to be checked and the immune status of a flock is to be evaluated. Because of various advantages filter paper strip method will serve as an alternative to collection of whole serum for detection of DPV antibodies. For the detection of DPV antigen, IPT was considered as suitable one because of its ability to detect high positive (83%) cases and less non specific reactions.
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    ThesisItemOpen Access
    Characterization of structural proteins of duck-plague virus
    (Department of Microbiology, College of Veterinary and Animal Sciences, Mannuthy, 1997) Hudson Taylor, J; KAU; Krishnan Nair, G
    Two virulent strains of duck plague virus - DPV-I (IVRI) and DPV-A (Alleppey isolate) and a vaccine strain - DPV-V (VBI Palode) were investigated for the differences in clinical manifestations in naturally and experimentally infected ducks, morphological changes in developing duck/chicken embryo (DDE/DCE) and cytopathic effects in duck embryo fibroblast/ chicken embryo fibroblast culture (DEFC/CEFC) and chicken embryo fibroblast culture (CEFC). Typical symptoms and lesions of duck plague were produced by both the virulent strains. However, in DPV-A infection, the level of mortality and severity of lesions like gizzard muscle necrosis and haemorrhagic bands in the small intestine were more pronounced. DPV-V did not produce any symptoms or lesions on experimental inoculation into ducklings. Embryonated duck eggs were used for passaging DPV-l and isolating DPV-A, while embryonated chicken eggs were used for propagating DPV-V. All the three strains produced mortality of embryos with congestion on CAM and body of the embryo. DPV-A produced more congestion on the extremities of the embryos. Duck embryo fibroblast cultures were used for culturing the virulent strains while chicken embryo fibroblast cultures were used for culturing the vaccine strain. All the three strains produced characteristic CPE, with rounding and clumping of cells, syncytium formation, vacuolation of cytoplasm and formation of intranuclear inclusion bodies. The time for the production of CPE decreased on successive passage. Titration of the three strains of DPV was done in embryonated eggs (ELDso) and cell cultures (TCIDso). DPV-I, DPV-A and DPV-V had an ELD50 of 105.27, 104.86 and 104 per ml respectively. TCIDso of DPV-I and A in DEF culture were 105.75 per ml and 105.25 per ml respectively and that of DPV-V in CEFC was 104.5 per ml. The tissue culture system gives the best titre than the embryonating eggs for all the three DPV strains. On electron microscopy, the field isolate of DPV showed particles ranging from 170-190 nm in diameter. Protein analysis of the virulent strains viz. DPV-I and DPV-A by SDS-PAGE revealed sixteen and fourteen proteins respectively. Mild difference of two proteins (VP17 and VP22) was noticed between the two strains. DPV-A lacked the 28KD and 9KD protein bands. The vaccine strain DPV-V on electrophoresis showed a different pattern of protein bands from the virulent strains. Eighteen proteins could be resolved in the vaccine strain. The molecular weight of sixteen proteins of DPV-I ranged from 9KD to 107KD while the fourteen proteins of DPV-A ranged from l4KD to 107KD. The proteins of the vaccine strain also ranged from 9 KD to 107 KD. The possibility of the occurrence of strain variation as indicated by the difference in the protein patterns of the DP viruses under study is discussed.