Isolation and characterization of lineage-IV Peste des Petits Ruminants (PPR) virus strains from Pakistan

A total of 62 Peste des Petits ruminants (PPR) outbreaks in sheep and goat flocks were investigated in Pakistan during 2005-2007. The presence of PPR virus (PPRV) was confirmed by clinical picture, necropsy examination, Ic-ELISA, virus isolation and RT-PCR. Of 397 tissue samples, 65% tested positive by Ic-ELISA. Six PPR virus isolates were obtained through cell culture on VERO or GKC cell from 61Ic-ELISA positive samples identified by characteristic CPEs and confirmed by testing the cell culture supernatant by Ic-ELISA and RT-PCR using PPRV specific F gene based primers. The sequence data of F gene from 6 isolates was analyzed for identities and a phylogenetic tree was generated based on 372bp F gene sequences of PPRV. The isolates were clustered into lineage 4 along with other Asian isolates. The recent isolates and a previous isolate from Pakistan (PAK-2004) were found to be monophyletic having close relationship with an Indian isolate (IND-PON).