It remains to be seen whether the virus will mutate into a more virulent strain.
该病毒是否会产生变异，成为毒性更强的病毒株，仍有等观察。
Conclusion The infection of virulent strain of mouse poxvirus exists in experimental mice.
结论实验用昆明小鼠中存在鼠痘病毒强毒株感染。
Half of the victims have been hospitalised, a high rate that may indicate an especially virulent strain of E. coli.
半数受害者都已住院，如此高的住院率表明这可能是一种毒性特别强的大肠杆菌菌株。
"At this point, there isn't a lot of data to suggest this is a more virulent strain, " said Dr. Ian Williams of the Centers for Disease Control and Prevention.
“在这件事上，没有充足的数据表明这是更严重的病毒体”，美国疾病控制防疫中心伊恩。威廉母斯博士说。
In order to study the attenuation of neurovirulence of SA14 14 2 attenuated vaccine virus, monkeys and mice were tested with the strain and its parent SA14 virulent strain.
为了解乙型脑炎（乙脑）减毒活疫苗弱毒株SA14142神经毒力的减弱程度，本文对弱毒株及其原株SA14强毒株进行了猴体和小白鼠的致病性和病理学变化的比较试验。
One in five lung cancer sufferers have a particularly virulent strain called small cell lung cancer which kills all but three per cent of sufferers within five years of diagnoses.
1/5的癌症患者带有一种特别的有毒病株，称为小细胞肺癌，这种肺癌五年内杀死了近3%的确诊患者。
After little more than an informal examination, the doctor concluded that Mr. Malcolm Smith's organism was infested with a particularly virulent strain of the influenza virus.
做完非正式的检查后，医生得出结论，马尔科姆·史密斯的机体大量滋生了一种非常致命的流感病毒。
The authors argue the version of the disease that caused the medieval plague is likely extinct, but suggest that further study could reveal how it may have evolved into a less virulent strain.
作者们称引起中世纪瘟疫的品种可能已经灭绝了，但是他们认为进一步的研究可以揭示它是如何进化到一种没那么致命的类型。
Before 1997 WNV was not considered pathogenic for birds, but at that time in Israel a more virulent strain caused the death of different bird species presenting signs of encephalitis and paralysis.
在1997年以前，西尼罗河病毒并未被认为对鸟类具有致病性，但就在那时，以色列出现了一种能够导致多种鸟类出现脑炎和麻痹症状继而死亡的毒力更强的毒株。
Having sequenced the new strain's genes, the researchers recreated it in a laboratory and exposed it to pigs. The strain proved contagious but only mildly virulent.
按顺序排好新菌株的基因，研究人员在实验室中重新构建了它，并把它与猪相接触。证明了该菌株会蔓延的，但只有轻微的毒性。
The strain proved contagious but only mildly virulent.
证明了该菌株会蔓延的，但只有轻微的毒性。
In Belgium and the Netherlands, a virulent new strain of avian flu was wiping out entire chicken farms.
在比利时和荷兰，一种新的恶性的禽流感病毒株系席卷了所有的养鸡场。
Ultrathin sectioning and transmission electron microscopy of infected duck embryo fibroblasts (DEF) were employed to investigate the morphology of virulent duck enteritis virus (DEV) strain CH.
通过超薄切片和透射电子显微镜技术对鸭病毒性肠炎病毒(DEV)CH强毒株在鸭胚成纤维细胞(DEF)中的形态结构进行了研究。
These showed that the isolate LX was a very virulent IBDV strain.
从而表明，该L X分离株为IBDV超强毒，具有超强毒株的致病特点。
Objective To improve immunity of KM murine against virulent RH strain of Toxoplasma, to extend its duration of life and provide model for related research.
目的提高昆明鼠抗弓形虫强毒株（RH株）的免疫力，延长其生存时间，为进行相关实验研究提供动物模型。
A virulent new strain of salmonella, DT104, has been created in part through the food industry's feeding antibiotics to chickens and livestock.
一个沙门氏菌，DT104的恶性的新负担，已经被部分透过食品工业喂抗菌素给鸡和家畜建立。
Subsequently, experiment on chickens challenged with virulent NDV strain showed that protection seems to be correlated with the ELISA antibody titer.
攻毒保护试验的结果显示，ELISA抗体效价与机体的保护力表现一定程度的相关性。
Subsequently, experiment on chickens challenged with virulent NDV strain showed that protection seems to be correlated with the ELISA antibody titer.
攻毒保护试验的结果显示，ELISA抗体效价与机体的保护力表现一定程度的相关性。
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