CAJ | 학술논문

针对马立克病毒(MDV)毒力逐渐上升的现状,本研究对国内MDV流行强毒株进行了致弱研究.本实验采用近年来从东北、四川2地区免疫发病鸡场中分离的4株MDV流行强毒株(L-SY、L-MS、L-CZ、L-ZY),经噬斑纯化后,采用鸡胚成纤维细胞(CEF)传代培养至75代～85代,获得了4株高代次细胞毒株(L-SYp85C、L-MSp75C、L-CZp75C、L-ZYp75C).并分析了L-SYp85C和L-MSp75C毒株的体外、体内生长特性和对SPF鸡的致病力.结果表明,L-SYp85C和L-MSp75C株在CEF适应性显著提高;以10倍感染剂量感染的SPF鸡,在12周内均未发生MD肿瘤,体重平均值与对照组体重平均值差异不显著;检测7 d～45 d羽髓中病毒载量,均低于10~6copies/10~6cell,显著低于亲本毒株.同时,4株传代毒株132 bpr基因拷贝数显著增加.上述结果为MDV强毒株的致弱研究以及进一步筛选MDV弱毒疫苗株提供了实验依据.
침대마립극병독(MDV)독력축점상승적현상,본연구대국내MDV류행강독주진행료치약연구.본실험채용근년래종동북、사천2지구면역발병계장중분리적4주MDV류행강독주(L-SY、L-MS、L-CZ、L-ZY),경서반순화후,채용계배성섬유세포(CEF)전대배양지75대～85대,획득료4주고대차세포독주(L-SYp85C、L-MSp75C、L-CZp75C、L-ZYp75C).병분석료L-SYp85C화L-MSp75C독주적체외、체내생장특성화대SPF계적치병력.결과표명,L-SYp85C화L-MSp75C주재CEF괄응성현저제고;이10배감염제량감염적SPF계,재12주내균미발생MD종류,체중평균치여대조조체중평균치차이불현저;검측7 d～45 d우수중병독재량,균저우10~6copies/10~6cell,현저저우친본독주.동시,4주전대독주132 bpr기인고패수현저증가.상술결과위MDV강독주적치약연구이급진일보사선MDV약독역묘주제공료실험의거.
Recent years, the continuous evolution of Marek's disease virus (MDV) field strains towards greater virulence has highlighted the needs for new vaccine development. In this study, four MDV virulent isolates obtained from North Eastern and Sichuan area of China, L-SY, L-MS, L-CZ, L-ZY, were plaque purified and passaged in chick embryo fibroblast (CEF) cells for up to 85 passages, and high-passage MDV swains, L-SYp85C, L-MSp75C, L-CZp75C, L-ZYp75C, were obtained. The plaque sizes and replication rote of L-SY and L-MS swains were shown increased during passaging in CEF. The in vitro and in vivo growth characteristics and the pathogenicity of L-SYp85C and L-MSp75C were investigated further. Day old SPF chickens were inoculated with strain L-SYp85C and L-MSp75C in ten times doses and observed for 12 weeks, and no tumor was found and body weights not affected compared with control animals. The virus load of feather tips was lower than 10~6 copies/10~6 cell during the 7 to 45 day's detecting period, which was significantly lower than parent virus. Sequence analysis showed that copy number of the 132 bp repeats in the virus genome increased during passages. All together attenuated MD virus strain L-SYp85C and L-MSp75C were successfully generated, which could be developed for new MD vaccines strains.