1Division of Virology, Indian Veterinary Research Institute, Mukteswar, Nanital-263 138, Uttrakhand.
2JN Krishi Vishwa Vidyalaya, Jabalpur-482 001, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
Peste des Petits Ruminants (PPR) is an acute viral disease of goats, recorded first time in 1987 from Tamil Nadu, India. Presently it is considered as the major threats to small ruminant population of our country. PPR outbreaks have often been reported from neighboring states of MP, however, no study was carried out in this part of the country. During the present investigation, work was carried out to detect and characterize PPR virus isolates responsible for disease outbreak in goat population of central India. New primers were designed for N gene (NF/NR) and evaluated along with published primers (N1/N2) in the RT-PCR assay. The nucleodiagnsotic assay was standardized for detection of the virus in field samples. RT-PCR products amplified with N1/N2 and NF/NR primers produced expected amplicon of 463bp and 382bp. Primers were tested on naso-fecal samples collected from 45 clinically PPR suspected animals. Published primers amplified a total of 9 samples, while newly designed primers (NF/NR) successfully amplified 13 samples out of 45. The samples negative with N1/N2 primer were found positive in RT-PCR with NF/NR primers, while none of the sample positive in N1/N2 primer was negative with NF/NR primer. Field isolates were further characterized to assess the genetic variations among the PPR-MP-virus isolates and PPR vaccine strain by PCR restriction pattern analysis of the N gene fragments. RT-PCR products amplified with N1/N2 and NF/NR primers producing 463bp and 382bp amplicon, respectively, were digested with restriction enzyme AluI. The restriction pattern of NF/NR primer amplicon obtained with AluI enzymes with MP PPR virus isolates and vaccine strain was similar producing two fragments of 338bp and 44bp respectively. Whereas the restriction pattern of N1/N2 primer amplicon obtained with AluI enzymes with MP isolates and vaccine strain was different. Digestion of RT-PCR products of reference vaccine virus with AluI yielded a fragment of 395bp and 68bp, while the field samples digested with AluI produced four fragments of 273bp, 147bp, 25bp and 16bp, in which only 273bp and 147bp fragments were visible on the gel. The results of present study pointed out that variation/mutation occur in the N1/N2 primer region which makes it less sensitive in comparison to self design primer NF/NR. Study emphasizes further evaluation of these primers on large number of clinical samples.
