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EVALUATION OF IMMUNODIAGNOSTIC KITS TO ENTEROTOXAEMIA

KrishiKosh

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Title EVALUATION OF IMMUNODIAGNOSTIC KITS TO ENTEROTOXAEMIA
MVSC;CVSc;TPTY; Acc No:T997
 
Creator VIJAYALAKSHMI, SIDDAVATAM
 
Contributor SREENIVASULU, D (Major)
RAO, V.D.P
ALAHA SINGARI, N
 
Subject ENTEROTOXAEMIA ; IMMUNODIAGNOSTIC KITS
 
Description THESES
ABSTRACT :
The present study was undertaken to evaluate Latex agglutination test and Enzyme linked immunosorbent assay (developed earlier in the Department of Microbiology, College of Veterinary Science, Tirupati) for detection of epsilon toxin and monitoring of anti epsilon antibodies in vaccinated sheep, respectively.
Latex beads (0.8μ) sensitized with 2 mg/ml of rabbit antiepsilon IgG were found to be optimum for coating the latex beads. Latex agglutination test (LAT) was able to detect 250 MLD/ml of epsilon toxin clearly with in a minute. LAT detected the presence of epsilon toxin in all 15 faecal samples positive for mouse protection test. A total of 20 faecal samples negative for mouse protection test did not react with LAT. Latex reagent was found stable for four weeks at 37°C and 24 weeks (maximum period tested) at 4°C.
The LAT was validated at Hyderabad and reported to have worked satisfactorily identifying the samples having epsilon toxin. The LAT was evaluated using 160 samples collected from field and the results are in agreement with mouse protection test and counter immunoelectrophoresis in detecting the toxin.
Enzyme linked immunosorbent assay was standardized to detect the protective titer (0.2 IU/ml) of antiepsilon antibodies in vaccinated sheep. The samples showing percent positivity values 30 and above were considered as ELISA positive and having protective titer. A total of 20 mouse neutralization test positive and negative serum samples each were tested for the presence of protective titers using ELISA. The results of ELISA were in agreement with MNT. Repeatability and reproducibility studies were carried out to know the performance of the ELISA. Coefficient of variation of the tests, carried to study repeatability within -run and between-run, varied between 2.31 and 10.21 which are with in the acceptable limits. The test was carried out at College of Veterinary Science, Tirupati, Veterinary Biological Research Institute (VBRI), Hyderabad and Animal Health Centre, Chittoor to study the reproducibility. The variation among the results obtained from laboratories ranged between 2.17 to 12.53.
ELISA plates coated with epsilon toxin were found to be stable for four weeks at 37°C. The ELISA coated plates along with conjugate, substrate were found to be stable for 24 weeks (maximum period tested) at 4°C. The test was validated at VBRI, and Indian Immunologicals Limited, Hyderabad and reported that the tests are working satisfactorily in differentiating sera samples having protective and unprotective titers.
Evaluation of ELISA was carried out using 466 field serum samples collected from different parts of the state. Serum samples collected from sheep after booster vaccination showed protective titers. Protective titers of antiepsilon antibodies were decreased as postvaccination period increased.
It is concluded that LAT can be used as a field test for the diagnosis of enterotoxaemia and ELISA for monitoring Immune responses in sheep vaccinated against enterotoxaemia.
DEPARTMENT OF MICROBIOLOGY ,
College of Veterinary Science,
Tirupati - 517 502.
 
Date 2016-12-21T15:05:56Z
2016-12-21T15:05:56Z
2003-09
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/91905
 
Language en
 
Format application/pdf
 
Publisher Sri Venkateswara Veterinary University, TIRUPATI – 517 502,A.P