【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV...【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV2感染C57BL/6小鼠,观察小鼠的临床症状及组织病理变化;qPCR测定组织中的病毒载量;血常规分析外周血中白细胞、红细胞和血小板的变化,流式细胞术分析外周血淋巴细胞的变化;RT-qPCR测定脾脏中IL-10、IL-6、TNF-α和IFN-αmRNA的表达。【结果】PCV2感染导致小鼠精神萎靡、体重下降,所有小鼠脾脏均出现肿大、坏死,部分肝脏色泽变浅、肺脏有出血;组织病理切片显示,脾脏均出现多核巨细胞浸润,感染第14天后含铁血黄素明显增多;脾脏中病毒载量约为(2.19±0.93)×10^(2)copies/mg;PCV2感染诱导小鼠外周血中红细胞、血小板数量显著减少,流式细胞术分析表明,在感染后第3、7、14天,小鼠外周血均出现淋巴细胞数量减少,主要涉及CD_(8)^(+)T细胞和CD_(4)^(+)T细胞。PCV2感染促进了小鼠脾脏中IL-10、IL-6、TNF-αmRNA的表达,而IFN-αmRNA的表达只在感染后第3天和第21天显著降低。【结论】本研究鉴定了一株PCV2d型毒株对C57BL/6小鼠的致病性,为PCV2小鼠模型建立及其致病性研究提供了参考。展开更多
Streptococcus pneumoniae is a known notorious cause of invasive pneumococcal diseases as well as asymptomatic host carriage. Efforts have been made to curb this infectious organism through various vaccine strategies. ...Streptococcus pneumoniae is a known notorious cause of invasive pneumococcal diseases as well as asymptomatic host carriage. Efforts have been made to curb this infectious organism through various vaccine strategies. However, its several strains and serotypes have necessitated various vaccine schedules and updates in the USA and globally. The evolution in pneumococcal vaccine schedules is not without challenges, such as cost, vaccine hesitancy, uptake and global disparities. This narrative review synopsizes the history of the Pneumococcal Vaccine and changes in its schedules in the last two decades based on published data. We focused on the impact of pneumococcal vaccination on invasive pneumococcal diseases, historical limitations, current challenges and future directions. Despite advancements in vaccination against S. pneumoniae infections, some pertinent issues exist that need to be swiftly fixed, to reduce national and thus global burden of pneumococcal diseases.展开更多
【目的】猪圆环病毒3型(porcine circovirus type 3,PCV3)与母猪繁殖障碍、仔猪皮炎及心肌炎等疾病的发生密切相关。病毒在细胞上难以稳定传代,阻碍了PCV3动物感染模型的构建及其致病性的研究。【方法】利用PCV3阳性断奶仔猪的淋巴结病...【目的】猪圆环病毒3型(porcine circovirus type 3,PCV3)与母猪繁殖障碍、仔猪皮炎及心肌炎等疾病的发生密切相关。病毒在细胞上难以稳定传代,阻碍了PCV3动物感染模型的构建及其致病性的研究。【方法】利用PCV3阳性断奶仔猪的淋巴结病料接种PK-15细胞进行病毒分离,通过PCR、间接免疫荧光试验和透射电镜观察等方法对毒株进行鉴定,成功分离到一株PCV3毒株(PCV3-HK株),并测定了该毒株的全基因组。使用毒价为106.4TCID50/mL的第15代病毒细胞培养物在接种21日龄未断奶仔猪,通过临床症状、体重变化、排毒情况和病理变化等评价该毒株的致病性。【结果】病毒分离鉴定结果表明,PCV3-HK株基因组全长2000 bp,属于PCV3c基因亚型,病毒粒子为圆球形、无囊膜、直径约15-20 nm的颗粒,能够与PCV3 Cap蛋白单克隆抗体发生特异性反应;仔猪感染试验结果显示,PCV3-HK株感染猪出现皮炎、增重缓慢甚至消瘦等症状,以及淋巴结水肿、间质性肺炎等剖检变化;在感染的第7-21天,口拭子和肛拭子中均可检测到病毒核酸,并出现病毒血症。该病毒感染仔猪的心、肺、肾和淋巴结等器官,尤其在肾脏和淋巴结中观察到炎性细胞浸润、坏死细胞聚集等病理变化。【结论】本研究分离到一株PCV3c毒株,建立了仔猪感染模型,为PCV3致病机制研究和疫苗研发提供了关键材料。展开更多
文摘【背景】猪圆环病毒2型(porcine circovirus type 2,PCV2)是引发猪群多种临床表现疾病的重要病原,对养猪业造成了重大经济损失。【目的】建立更适合PCV2感染的动物模型,分析一株PCV2d型毒株对C57BL/6小鼠的致病性。【方法】腹腔注射PCV2感染C57BL/6小鼠,观察小鼠的临床症状及组织病理变化;qPCR测定组织中的病毒载量;血常规分析外周血中白细胞、红细胞和血小板的变化,流式细胞术分析外周血淋巴细胞的变化;RT-qPCR测定脾脏中IL-10、IL-6、TNF-α和IFN-αmRNA的表达。【结果】PCV2感染导致小鼠精神萎靡、体重下降,所有小鼠脾脏均出现肿大、坏死,部分肝脏色泽变浅、肺脏有出血;组织病理切片显示,脾脏均出现多核巨细胞浸润,感染第14天后含铁血黄素明显增多;脾脏中病毒载量约为(2.19±0.93)×10^(2)copies/mg;PCV2感染诱导小鼠外周血中红细胞、血小板数量显著减少,流式细胞术分析表明,在感染后第3、7、14天,小鼠外周血均出现淋巴细胞数量减少,主要涉及CD_(8)^(+)T细胞和CD_(4)^(+)T细胞。PCV2感染促进了小鼠脾脏中IL-10、IL-6、TNF-αmRNA的表达,而IFN-αmRNA的表达只在感染后第3天和第21天显著降低。【结论】本研究鉴定了一株PCV2d型毒株对C57BL/6小鼠的致病性,为PCV2小鼠模型建立及其致病性研究提供了参考。
文摘Streptococcus pneumoniae is a known notorious cause of invasive pneumococcal diseases as well as asymptomatic host carriage. Efforts have been made to curb this infectious organism through various vaccine strategies. However, its several strains and serotypes have necessitated various vaccine schedules and updates in the USA and globally. The evolution in pneumococcal vaccine schedules is not without challenges, such as cost, vaccine hesitancy, uptake and global disparities. This narrative review synopsizes the history of the Pneumococcal Vaccine and changes in its schedules in the last two decades based on published data. We focused on the impact of pneumococcal vaccination on invasive pneumococcal diseases, historical limitations, current challenges and future directions. Despite advancements in vaccination against S. pneumoniae infections, some pertinent issues exist that need to be swiftly fixed, to reduce national and thus global burden of pneumococcal diseases.
