致病性

Objective To analyze the genetic and antigenic characteristics of human H5N1 virus isolated from the mainland of China.

目的分析我国分离的人高致病性禽流感H5N1病毒的抗原性以及基因特性。

Alfalfa ; Crown and root rot ; Fusarium spp ; Pathogenicity ; Resistance

苜蓿；根和根颈腐烂病；镰刀菌；致病性；抗病性

As showed above, we could draw the conclusion that H3 viruses could cause outbreaks or local epidemics in Shanghai for the immune of population to the new emerging antigenic drift was still unknown though there was strong immune barrier to the previous vaccine strain, H1 viruses also may caused epidemics as the population had a weak immune protection to the previous reference strains A/New Caledonia/20/99-like and part of the recent isolates were distingwishing from them and continued to evolute on the new reference strain, and H5N1 HPAI activities has expanded its geographical range thus increasing the size of the population at risk as the continuing emergence of human cases which give the virus an opportunity to evolve towards a fully transmissible pandemic strain. We should keep eyes on the human cases of avian influenza virus an its variation for the H5 isolates in Shanghai also has the possibility to infect human directly and the infection of H5, H9 viruses had previously occurred in the population especially in those contacting with animals.

综合上述分析结果，我们认为上海地区人群虽然对原有的H3亚型参考病毒株有较高的免疫保护，但H3亚型病毒HA已出现新的抗原漂移，人群现在对新变异株的保护水平尚未知，有可能在未来引起局限性暴发甚至地方性流行；人群对H1亚型流感病毒免疫保护水平低，同时H1亚型流感病毒株部分与原推荐疫苗株抗原性差别较大，并在现推荐疫苗株基础上继续变异，需警惕发生流行的可能性；H5N1亚型高致病性禽流感地域范围扩大，人间病例不断发生，存在演变成大流行株的威胁，上海市H5亚型禽流感病毒株存在跨宿主屏障感染人类的可能性，而且已发现人群尤其禽、畜类动物接触人群中存在H5、H9亚型流感病毒的既往感染，应警惕禽流感病毒的变异和人间病例的发生。

Four field strains of infectious bronchitis viruswere isolated from chicken kidney, trachea and lung of the young layer flocks in some regions of Shaanxi province. Biological characterizations of the virus were investigated by virus pathogenicity to chicken embryo and healthy chickens, hemagglutination test, hemagglutination inhibition test, dwarfing embryonated chicken eggs, electron microscopy and reverse transcription polymerase chain reaction. It demonstrated that allantoic fluid of each passage virus could hemagglutinate chicken red blood cells by treatment with 1% trypsin. The standard positive serum to IBV could inhibited the hemagglutination. The isolates could make respiratory and kidney diseases in chickens.

采集陕西省宝鸡市、扶风县、兴平市和榆林市等地鸡场疑似传染性支气管炎发病鸡病料，通过9～11 日龄非免疫鸡胚进行了病毒的实验室分离和传代，并对分离毒株进行了病毒的血凝性、血凝抑制性、致病性、鸡胚矮小化、电镜特征等生物学特性鉴定，结果表明，4 株分离株经1%胰酶处理后的各代病毒尿囊液均可凝集鸡红细胞，标准阳性血清可特异性的抑制其凝集性，回归试验可复制出与自然发病相同的病例，病毒传代物有明显的致鸡胚矮小化作用，透射电镜下可见有近似球形、直径100 nm左右的冠状病毒粒子，将分离鉴定的4 株IBV 定名为BJ-04、FF-04、XP-03 和YL-04。

Different from the importation characteristic before 90s, strains after 90s were highly isogenous, suggested that the cholera epidemics in Sichuan province after 90s were endemic source. Inaba 1d strains from national wide epidemic in 2001 and 2002 were the same RT. Strains typed as different phagetypes (phagetype 6, phagetype 13 and phagetype 1) might be from a same clone.

除82-007、95-001外，所试菌株均具有致病性；20世纪90年代以四川省发生的霍乱为输入性，90年代后四川省流行的菌株高度同源，具有地方疫源性；2001、2002年在四川省乃至全国引起流行的稻叶1d为同 RT型，为传入性霍乱；噬菌体分型6型、13型菌株和1型菌株可能来自同一克隆系。

Different from the importation characteristic before 90s, strains after 90s were highly isogenous, suggested that the cholera epidemics in Sichuan province after 90s were endemic source. Inaba 1d strains from national wide epidemic in 2001 and 2002 were the same RT. Strains typed as different phagetypes (phagetype 6, phagetype 13 and phagetype 1) might be from a same clone.

除82-007、95-001外，所试菌株均具有致病性；20世纪90年代以前四川省发生的霍乱为输入性，90年代后四川省流行的菌株高度同源，具有地方疫源性；2001、2002年在四川省乃至全国引起大流行的稻叶1d为同一RT型，为传入性霍乱；噬菌体分型6型、13型菌株和1型菌株可能来自同一克隆系。

All of the hygromycin B-resistant transformants tested were mitotically stable after several subcultures onto complete medium without hygromycin.

用大麦叶片离体接种的方法快速测定部分稻瘟病菌转化子的致病性，发现一个致病缺陷突变体：Al-412。

There are postulations that some positions of GP is the structural basis for some important biologic features of rabies virus, neurotropic, pathogenicity and antigenicity.

狂犬病毒GP基因上某些位点推测是狂犬病毒一些重要生物学特性，如：组织嗜性、致病性和免疫原性等的结构基础，因此这些部位的变异有可能导致这些特性的改变。

Specific pathogen free chicken ; Escherichia coli ; mildly pathogenic avian influenza virus ; synergistic pathopoiesis effects ; immunosuppression

SPF鸡；大肠杆菌；低致病性禽流感病毒；协同致病；免疫抑制

Previously, it was found that the hemolytic activity of the extracellular product of V. harveyi was involved in pathogenesis in salmonids, and the most pathogenic isolate, VIB 645, contains two closely related hemolysin genes, i.e. vhhA and vhhB.

已发现哈维氏弧菌对鱼类的致病性与其分泌的胞外产物中的溶血素相关，致病力最强的菌株VIB 645有2个碱基序列非常相似的溶血素基因，vhhA和vhhB。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。