Open Access 
              
Copyright: The authors. This article is an open access 
article licensed under the terms of the Creative Commons Attribution License 
(http://creativecommons.org/licenses/by/2.0) which permits unrestricted use, 
distribution and reproduction in any medium, provided the work is properly 
cited.
              
              
              
              
              Research
              
              
2.   
                  
                  
                              
                              Studies of the antigenic relationships between 
                              bluetongue virus serotypes 2, 9 & 15 isolated in 
                              Andhra Pradesh, India - Deepthi Balam, Sreenivasulu Daggupati, Himaja 
                              Maddireddy
                              Vet World. 2011; 4(10): 444-448
               
              
              
              doi: 10.5455/vetworld.2011.444-448
              
              
               
              
              
              
   
 
              
               
               
               
              
              
              Abstract
              
                              
                              
                              
                              The presence of multiple serotypes of the 
                              midge-borne bluetongue virus and lack of effective 
                              vaccine are the major impediments in controlling 
                              bluetongue in sheep. Attempts are being made to 
                              develop a vaccine employing the available 
                              serotypes to control the disease in the state. 
                              Hence, it is essential to identify the antigenic 
                              relationships among the serotypes to identify the 
                              candidate strains to be incorporated in the 
                              preparation of vaccine. To understand the 
                              antigenic relationships between Bluetongue virus 
                              -2, 9 and 15 serotypes, the viruses were 
                              propagated in BHK21 cell lines, purified using PEG 
                              precipitation method and purified virus used to 
                              raise hyper immune serum in rabbits. Neutralizing 
                              antibodies for the BTV serotypes were detected by 
                              day 21 PI. Reciprocal cross neutralization test 
                              was employed to determine the R% values between 
                              BTV-2, 9 and 15 which indicated the extent of 
                              antigenic relationships among the serotypes. R% 
                              value between BTV-2 and BTV-9 was recorded as 2.8. 
                              R% value of 3.53 and 2.8 were observed between 
                              BTV-2 & 15 and BTV-9 & 15 respectively. The R% 
                              values recorded in the present study revealed a 
                              weak antigenic relationship between the BTV 
                              serotypes, indicating that the serotypes are 
                              highly divergent. 
              
                              
              Keywords: Bluetongue 
                              virus; serotypes; antigenic relationship.