雪貂感染流感病毒H3N2动物模型的建立

目的建立甲型流感病毒H3N2感染的雪貂动物模型。方法按实验要求筛选出流感抗体反应阴性的雪貂,经兽用氯胺酮轻度麻醉后进行滴鼻感染H3N2流感病毒株A/Brisbane/10/07,设立两个稀释度106和107 TCID50,每个稀释度接种3只雪貂,感染后第5天安乐处死。感染前采集鼻甲骨活检,感染后1～5 d鼻甲骨活检检测病毒载量,每天记录雪貂一般临床变化。处死时取雪貂肺、肝、脾、小肠、脑组织作病毒滴度检测,肺组织做病理检查。结果 106和107TCID50的H3N2病毒分别感染雪貂,没有雪貂死亡。雪貂感染后都出现一过性的体温升高,体重的下降,流涕、打喷嚏等症状。在鼻甲骨活检物中可测到病毒载量,肠组织可分离到病毒。肺组织以轻度性间质性肺炎为主要病理变化。结论雪貂感染H3N2病毒株A/Brisbane/10/07后,临床表现、病毒学、分子生物学、病理学方面的检测都可以证实雪貂感染H3N2病毒动物模型已建立,其中106 TCID50病毒滴度的是一个建立感染动物模型比较合适的剂量。

Establishment of a Ferret Model of H3N2 Influenza Virus Infection

Objective To establish a ferret model of H3N2 influenza virus infection.Methods Six ferrets were divided into two groups for three each.after anesthetized by ketamine,the ferrets were inoculated intranasally with 500 μL of 106 and 107 TCID50 H3N2 A/Brisbane/10/07 influenza virus,respectively.Clinical signs were monitored daily,and body temperature was recorded once every day postinfection.Nasal turbinate biopsies were taken every day from day 0 to postinfection day 5（d 0 to d.p.i.5） for real time PCR analysis,the ferrets were euthanized and the lung,liver,slpeen,small intestine and brain tissues were harvested at d.p.i.5.The lungs were further examined by histopathology.Results For each virus titer tested,transient elevation of body temperature,weight loss,nasal rattling and sneezing were observed in the infected ferrets,but no ferret died.Virus was detected positively in the nasal turbinates and small intestine from all the infected ferrets.The ferrets inoculated with H3N2 virus showed mild interstitial pneumonia in the lung.Conclusions The ferrets were successfully infected with H3N2 influenza virus proved by clinical signs,virus detection,and histological examination.Furthermore,106 TCID50 titer is a more appropriate dose for establishment of a ferret model of flu H3N2 virus infection.