No evidence of bovine papillomavirus type 1 or 2 infection in healthy equids.

The research article presents a study investigating the presence of bovine papillomavirus types 1 and 2 (BPV1/2) in equids without sarcoids and finding no evidence of infection. The study used tumor-free equids to gain better insights into the role of these viruses in equine sarcoid disease.

Research Methods

• The researchers used a cross-sectional study design for their investigation. The study spanned over a decade, from 2007 to 2017.
• They obtained and analyzed tumor material from horses, donkeys, and mules with confirmed sarcoids (130 samples), suspected sarcoids (120 samples), non-sarcoid lesions (70 samples). Additionally, they secured skin biopsies from 102 tumor-free horses and dandruff/hair roots from 35 tumor-free donkeys and mules for the study.
• All these samples were screened for BPV1/2 infection. The researchers used a BPV1/2 E5-specific PCR method that could detect as few as 10 viral DNA molecules.
• They also carried out equine β-actin PCR for DNA extraction from the samples to validate them.
• 26 amplicons were bidirectionally sequenced and compared to known E5 variants using the BLAST program. This helped in the identification of different BPV1 E5 variants.

Research Findings

• The research found that BPV1/2 E5 PCR scored positive for 130 out of 130 diagnosed sarcoids, 63 out of 120 suspected sarcoids, and 13 out of 70 non-sarcoid lesions.
• In contrast, all 137 DNA aliquots derived from tumor-free equids tested negative for BPV1/2.
• On the protein level, six different BPV1 E5 variants were identified.

Conclusions

• The study concluded that there was no BPV1/2 E5 DNA found in tumor-free equids. This was notable, given the prevalent occurrence of sarcoid disease in young adults, suggesting a short gap between initial infection and sarcoid development.
• The absence of virus DNA in tumor-free equids contrasted with the long phase of virus latency associated with the human infections by carcinogenic papillomaviruses.
• The presence of BPV1/2 DNA in several cases of poor wound healing, and dermatitis suggests that these skin disorders could possibly be co-induced by BPV1/2.
• Finally, the research proposed that PCR screening of tumor tissue/scrapings for BPV1/2 DNA could serve as a reliable tool for quickly validating a clinical diagnosis of equine sarcoid.