新城疫热稳定性天然弱毒株B95生物学与免疫学特性初步研究

Preliminary Study on the Biological and Immunological Characteristics of Newcastle Disease Virus Strain B95 Naturally Avirulent and Heat Stable Strain

新城疫病毒Ｂ９５（ＮＤＶ Ｂ９５）是从国外引进的一株热稳定性的天然弱毒株。本项研究证明：本毒株对鸡胚和鸡无毒副作用，ＩＣＰＩ和ＩＶＰＩ值分别为０；该病毒可凝集鸡、鸭、牛、绵羊、鹅、猪、小白鼠和人的红血球，血凝价与Ⅰ系、ＨＢ；和 Ｌａｓｏｔａ相似；将病毒置 ５６℃ ２ｈ，置 ３７℃保存１０ ｄ，仍见有血凝性和对鸡胚感染性；经点眼、饮水、非免疫鸡与免疫鸡同居，均能获得好的免疫效果，并能耐受新城疫强毒株的攻击。

Newcastle disease virus (NDV) avirulent strain B95 was newly introduced from abroad. The present study tested the biological and immunological characteristics of the strain. The mean death time (MDT) of embryonated egg inoculated with NDV strain B95 was over 120 hours. ICPI of 10 day-old chicken and IVPI of 6-week-old chicken were 0. B95 can agglutinate 1% red blood cell from chicken duck, cattle, sheep, goats, pigs, human and mice. The hemagglutination spectrum was similar with ND vaccine of Muktesw ar, HB1 and LaSota strains. Heated at 56℃ over 2 hours can not abrogate the hemaggluting activity. Incubation at 37℃ for 10 days didn't affect the HA titer. Inoculation of embryonated eggs showed that after incubation at 56℃ over 2 hours, 37℃ for 10 days, the virus still maintain its infectivity Administration once by eyedrop or water-drinking can protect vaccinated chicken against the challenge by NDV standard virulent strain F48E 8. Non-vaccinated chicken can get protection by contacting with vaccinated chicken in the same cage, this showed B95 may spread fast in a flock.