Molecular evidences show human papillomavirus type 124 can be trans-species infection in horses

Abstract

Human papillomavirus type 124 (HPV124), a member of betapapillomavirus, is associated with viral warts, actinic keratosis, and squamous cell carcinoma incidence in human. No reports of HPV124 infection in mainland China have been reported to date. In a survey of Chinese horses, we detected HPV124 via next-generation sequencing (NGS) in nasal swabs from 42% (39/93) of Thoroughbred horses, 7% (2/30) of the Akhal-Teke horses, and 17/50 aborted fetal lung tissues of Yili mares that were initially found to be negative for equid herpesvirus 1, which indicated the virus can be trans-species infection in different breeding horses, and suggested that this pathogen may potentially contribute to abortion incidence among horses. Further investigation showed that some workers involved in horse farm were positive for HPV124, which strongly suggested that horse-origin HPV124 strain may be transmissible from human workers to horses. Sequence analyses of E6 gene sequences from 18 Chinese HPV124 samples were performed, revealing that the 7 of 18 HPV124 strain identified both horses and human in the present study shared 100% sequence identity with previously published HPV124 isolate. Phylogenetic analyses based on E6 gene sequences in GenBank further revealed that the HPV124 isolate identified herein was closely related to the NJ3900 HPV124 reference strain, clustering together with the established Beta 1 HPV lineage. These results provide first evidence that HPV124 can infect horses, may function as a causative agent for abortions in Yili horses, and come from HPV124-positive humans laboring.