马源人乳头瘤病毒23型E2基因的遗传变异分析

Genetic analysis of E2 gene of human apillomavirus 23derived from equine

为调查马源人乳头瘤病毒(HPV)23型(HPV-23)在马群中的流行及遗传变异情况,本研究对413份马流产胎儿组织和20份马场工人鼻拭子样品经PCR检测,结果显示,在纯血马和伊犁马流产胎儿组织样品中均检出HPV-23,阳性率分别为4.3%(2/46)和9.3%(34/367),表明马流产胎儿携带HPV-23,该病毒可能导致马的流产;在马场工人鼻拭子样品中也检出HPV-23,阳性率为60%(12/20)。将其中12份检测为HPV-23阳性的样品进行E2基因的PCR扩增测序后,采用MegAlign7.1.0软件分析本研究获得的HPV-23 E2基因与GenBank中相关病毒参考株E2基因的同源性,并采用MEGA7.0.26软件构建人源与马源HPV-23 E2基因的进化树,分析其遗传进化特征。同源性分析结果显示,本研究测序的8株马源及4株人源HPV-23 E2基因与氨基酸序列的同源性均为100%,与国外2株人源HPV-23 E2基因序列的同源性为98.9%~99.2%,提示马源HPV-23可能来源于人。遗传进化分析显示,本研究鉴定的马源及人源HPV-23与国外人源HPV-23形成独立进化分支,且同处于β进化分支,与马乳头瘤病毒处于不同分支,进一步表明马源HPV-23可能来源于人。本研究首次在马流产胎儿组织中检测到HPV-23,提示该病毒可能导致马的流产,可能是人源HPV-23感染马,该结果为动物源HPV-23的流行病学研究提供了参考依据。

To investigate the prevalence of HPV-23 in horses,our study designed specific primers and used PCR to detect 413 aborted fetal tissues of horses and 20 nasal swabs of horse workers.The E2 genes were sequenced,revealing 12 HPV-23 positive samples.Sequence analysis of E2 genes obtained in this study and the reference strains in GenBank were performed.A phylogenetic tree was constructed based on E2 genes of HPV-23 from human and horse-origin,and the genetic characteristics were analyzed.The results showed that Yili horses and Thoroughbred horses aborted fetal samples were positive for HPV-23,with a positive rate of 4.3%(2/46)and 9.3%(34/367),indicating that horse aborted fetuses carried HPV-23,which may cause abortion in horses.Nasal swab samples from workers were positive for HPV-23,with a positive rate of 60%(12/20).Sequence analysis showed that the E2 gene nucleotide and amino acids homology between the eight horse-origin and four human-origin HPV-23 identified in this study was 100%and shared 98.9%-99.2%nucleotide sequence identity with the E2 gene of two foreign human-origin HPV-23,suggesting that horse-origin HPV-23 may be derived from human.Based on the E2 genes,the phylogenetic tree showed that horse-origin and human-origin HPV-23 strains in our study and foreign strains of HPV-23 have a close genetic relationship in the Beta branch.Still,they were in different branches with EcPV,which further suggested that horse-origin HPV-23 might come from humans.In this study,HPV-23 was first detected in aborted fetal tissues of horses,suggesting that the virus may lead to abortion in horses,possibly human-origin HPV-23 infecting horses.These findings provide a reference for epidemiological studies of animal-origin HPV-23.