WITHDRAWN: First Study of Molecular detection of Ovine Herpesvirus 2 DNA using heminested PCR in Pakistan

Abstract

Background Malignant catarrhal fever (MCF) is a highly fatal lymphoproliferative disease of cattle, deer, bison, water buffalo and pigs caused by the gamma herpesviruses; alcelaphine herpesvirus 1 (AlHV-1) and ovine herpesvirus 2 (OvHV-2). AlHV-1 is known to cause wildebeest-associated MCF whereas OvHV-2 is known to cause sheep-associated MCF. AlHV-1 and OvHV-2 cause inapparent infection in their reservoir hosts (wildebeest for AlHV-1 and sheep for OvHV-2) but fatal lymphoproliferative disease in susceptible species. Methods This study was aimed to find prevalence of OvHV-2 in sheep, goat, cattle and buffalo in Rawalpindi and Islamabad cities of Pakistan, using molecular and phylogenetic methods. Blood samples were collected consisting of sheep (n = 54), goat (n = 50), cattle (n = 46) and buffaloes (n = 50) from slaughter houses and farms. The samples were subjected to hemi-nested PCR, sequencing, and phylogenetic analysis of OvHV-2 POL gene and OvHV-2 tegument protein gene. Results The highest percentage of positive samples was found to be in sheep (13%) whereas positive samples from goat, cattle and buffaloes had percentage of 11%, 9% and 6.5% respectively. Four positive PCR products from sheep samples were also sequenced. The sequences obtained were submitted to NCBI GenBank database under the accession numbers of MK852173 for POL gene, and MK840962, MK852171 and MK852172 for ORF75 tegument protein gene. Phylogenetic analysis revealed close identities with some sequences of this virus from worldwide including neighbouring countries including China, India and Iran. Conclusion This study is the first study in Pakistan on the prevalence of OvHV-2 in carrier and susceptible species. This report provides important data about the presence of OvHV-2 in apparently healthy cattle and buffaloes, which might transmitted to them from OvHV-2 positive sheep or goats. It is concluded that a countrywide, large scale OvHV-2 prevalence study should be conducted to avoid economic losses due to any outbreak of MCF.