Detection of BPV-1 and -2 and quantification of BPV-1 by real-time PCR in cutaneous warts in cattle and buffaloes.

Bovine cutaneous warts (CWs) were investigated in Northern India. Of 49 cases, 44 were recorded in cattle and 5 in buffaloes. These animals had mild to moderate grade infections. Grossly, cases of CWs appeared to be of exophytic type, however, different types of growth patterns were observed. A total of 26 biopsies (cattle 21 and buffaloes 5) from CWs-affected animals studied histopathologically were diagnosed as exophytic and cauliflower-like fibropapilloma 13, exophytic and dome-shaped fibropapilloma 5, occult and/or fibroblastic type papilloma 3, cauliflower-like papilloma 3, endophytic fibropapilloma 1 and fibroma 1. On PCR analysis, 11 CWs and 2 normal skin samples showed BPV-1, -2 mixed infections. A rapid, sensitive and reliable real-time SYBR Green PCR test to detect BPV-1, BPV-2 and to quantify BPV-1 was developed. Results of amplification and dissociation plot of real-time PCR revealed that six samples were BPV-1 positive, eight were BPV-2 positive and six were positive for both BPV-1 and -2. CWs samples from different dairy farms testing positive for BPV-1 by PCR assay were also positive using Quantitative real-time SYBR Green PCR assay. For the first time, mixed infection of BPV-1 and -2 was detected in India and BPV-1 load was quantified by real-time SYBR Green PCR assay.