A role for Toll-like receptor 4 in the host response to the lung infection of Yersinia pseudotuberculosis in mice

Although a Yersinia pseudotuberculosis (Yptb) lung infection model has been developed to study Y. pestis pathogenesis, it is still necessary to establish a new animal model to mimic the pathophysiological features induced by Y. pestis infection. Here, we provide a new lung infection model using the Yptb strain, IP2777, which displayed rapid spread of bacteria to the liver, spleen, and blood. In addition, we examined whether TLR4 is involved in Yptb-induced pathogenesis in the lung infection model of mice we generated. Following lung infection of WT and TLR4-deficient mice with the Yptb strain IP2777, the survival rate, bacterial colonization, histopathology, and level of cytokines and chemokines in the lung, spleen, liver, and blood were analyzed. TLR4-deficient mice had a lower survival rate than WT mice in response to Yptb lung infection. Although the bacterial colonization and pathology of the lung were comparable between WT and TLR4-deficient mice, those of the spleen and liver were more severe in TLR4-deficient mice. In addition, the levels of TNF-α and CXCL2 in the liver and IL-6 and CXCL2 in the blood were higher in TLR4-deficient mice than in WT mice. Our results demonstrate that TLR4 is necessary for optimal host protection against Yptb lung infection and TLR4-deficient mice may serve as a better genetic model of Yptb infection for mimicking Y. pestis infection.     

胸膜肺炎放线杆菌对仔猪的感染试验

用作者分离鉴定的胸膜肺炎放线杆菌感染仔猪,临床特征为:呼吸困难,食欲不振,体温升高;病理解剖学变化为:胸腔有大量的积液,心包增厚,并且在肺脏和胸膜粘连胸膜增厚,肺脏萎缩,病灶区呈暗红色,轮廓清晰;病理组织学变化为:肺脏、肝脏和肾脏脉血管均有扩张出血,组织发生坏死.     

肺炎支原体感染大鼠实验模型的建立

本试验旨在建立肺炎支原体感染的Wistar大鼠模型 ,为研究肺炎支原体的发病机制及药物治疗理论提供基础。采用滴鼻法对实验大鼠进行肺炎支原体感染 ,利用PCR法进行咽拭子检测 ,并以透射电镜和光学显微镜进行肺部病理组织学检查。结果发现 ,实验大鼠在感染肺炎支原体 1 0d时 ,咽拭子PCR检测结果为阳性 ;透射电镜观察到肺脏细胞膜破裂 ,线粒体变性 ,嵴断裂 ;光镜下可见到支气管及肺血管周围有明显的淋巴细胞浸润 ,形成斑片状间质性支气管肺炎。结果表明了Wistar大鼠对肺炎支原体较易感 ,并产生以间质性肺炎为主要特征的肺部和呼吸道感染 ,也说明本次造模试验成功     

河北屠宰场高致病性猪蓝耳病带毒情况调查

为了了解河北省屠宰场猪只高致病性猪蓝耳病的带毒情况,采用RT-PCR方法对2006～2009年采自全省11个地市228个县级屠宰场1565份商品猪的肺脏或肺门淋巴结进行高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)病原学检测,结果4年间猪场的阳性比率分别为55.56％、72.50％、44.62％和28.74％;4年样品阳性检出率分别为28.45％、40.74％、12.01％和7.31％.HP-PRRSV同伪狂犬病病毒(PRV)、圆环病毒2型(PCV-2)和猪瘟病毒(CSFV)混合感染所占的比率为61.66％,多以PCV-2和PRV的二重或三重混合感染为主.总之,HP-PRRSV在河北省猪群中污染面积较大,值得高度重视.     

牛病毒性腹泻病毒在绵羊垂直感染中的抗原分布

将新疆分离的病毒性腹泻病毒（BVDV）野毒株SHN－98和标准毒株Oregon C-24分别接种无BVDV感染的羔羊和怀孕100天左右的母羊，建立BVDV在绵羊垂直感染的动物模型，应用病毒抗原定位检测的免疫组化染色技术，探求BVDV在实验性感染绵羊经胎盘感染胚胎、羔羊过程中，病毒在感染组织、靶器官、靶细胞中的分布规律。结果表明：BVDV通过母羊的胎盘感染胚胎。BVDV在感染妊娠母羊体内主要分布于心肌、肝、肺、脾、淋巴结、胃肠粘膜、脑神经、子宫粘膜、胎盘等器官组织，其中以胃肠粘膜、脾、淋巴结、脑神经、子宫粘膜、胎盘等器官组织中分布量较多；BVDV在垂直感染胚胎体内主要分布于胸腺、淋巴结、脑、肝、肾、心肌、脾、肺、胃肠粘膜、脐带等器官组织，其中以胸腺、胃肠粘膜、脑神经等器官组织中分布量较多；BVDV在垂直感染羔羊体内主要分布于心、肾、胃肠粘膜、脾、胸腺、淋巴结、大脑、小脑、海马、视丘、视神经、眼球脉络膜等器官组织，其中以胃肠粘膜、大小脑、用、视神经、淋巴结等器官组织中分布较多，在组织分布中，BVDV对上皮细胞、神经胶质细胞、淋巴细胞有较强的亲嗜性，SHN－98和OregonC-24在垂直传播中组织器官的分布无明显差异。     

卫氏与斯氏并殖吸虫在实验动物体内分布的比较观察

目的 比较两种主要对人体致病的肺吸虫在实验动物肺内与肺外（胸、腹腔）的分布，为临床诊断及药物治疗提供参考。方法 粪检肺吸虫卵阴性的猫犬分别经口感染卫氏并殖吸虫（P．W）与斯氏并殖吸虫（P．S）囊蚴，饲养3个月后粪检肺吸虫卵阳性时对犬、猫进行解剖，观察与统计内肺外虫数。结果 猫犬解剖所获得P．W与P．S成虫均以左、右肺下叶寄生成虫数最多，猫、犬感染P．W后检获肺外期与左、右肺的童虫数均无显著性差异（P〉0．05）。猫感染P．S后所检获肺外期童虫数与左、右肺的童虫数有显著性差异（P〈0．05），而犬感染P．S所检获肺外期童虫数与左、右肺的童虫数有高度显著性差异（P〈0．01）。猫感染P．W与P．S囊蚴后虫体平均回收率为41．84％，39．85％；犬感染P．w与P．S囊蚴后虫体平均回收率分别为47．44％，24．57％。经统计学处理猫感染两种虫体回收率显著高于犬（P〈0．05）。结论 两种肺吸虫在实验动物犬、猫肺部的分布均以左、右肺下叶寄生成虫数最多，猫犬感染P．S所检获的肺外期童虫数与检获左、右肺内的童虫数分别为有显著性差异（P〈0．05）与高度显著性差异（P〈0．01），猫感染虫体的回收率明显高于犬。     

猪传染性胃肠炎病毒呼吸道途径侵染后在体内的动态分布

应用猪传染性胃肠炎病毒（TGEV）分别对25日龄和40日龄的SPF仔猪进行气管内注射攻毒。攻毒后每24h致死1头仔猪．用免疫荧光染色检测各脏器内病毒的消长情况。并采血检测抗体。结果．在25日龄的仔猪中．仅3头出现腹泻症状。且很快耐过；剖检可见不同程度的肺部病理变化；攻毒后24h气管和肺脏样品的IFA呈阳性。抗体效价随着时间的延长而增高。40日龄仔猪临床表现和训检变化基本正常。所有的胃肠道样品的IFA均为阴性。结论：气管内注射后，TGEV可在呼吸系统中增殖．但未能在消化道系统中检出。     

猪丹毒和猪肺疫混合感染综合诊治

疫病一直是生猪养殖中影响猪群健康的重要因素,受到疾病影响的猪群会给养殖户带来巨大的经济损失,严重阻碍养殖业的发展。该文将简要概述猪丹毒和猪肺疫的病理状况,分析猪丹毒和猪肺疫混合感染的发病特征和临床症状,并研究综合诊治猪丹毒和猪肺疫混合感染的方法,降低猪丹毒和猪肺疫混合感染对生猪养殖的影响。     

PRRSV SC-1株在人工感染仔猪体内的分布

为研究猪繁殖与呼吸综合征病毒(PRRSV)在感染猪体内各器官组织的分布,用PRRSV SC-1株人工感染健康断奶仔猪,接毒后23 d,无菌采集试验猪器官组织,用RT-PCR检测其中病毒核酸分布情况。结果显示,心脏、脾脏、肺脏、肾脏、支气管淋巴结、肠系膜淋巴结、腹股沟淋巴结、髂内淋巴结内有病毒核酸,在所有试验猪的肺脏、腹股沟淋巴结都检测到了病毒核酸。本研究结果为PRRS诊断及病毒分离鉴定提供了一定参考依据。     

Experimental chlamydial pneumonia in pigs

Naturally occurring disease in pigs associated with chlamydial infections has not been reported in Britain, though evidence of chlamydial challenge has been demonstrated in two separate serological surveys. An isolate of Chlamydia psittaci (28/68) from an ovine pneumonia produced pneumonia in pigs following intratracheal inoculation. Transient pyrexia at 24 hr was followed by increased respiratory rates and inappetance which lasted for a further 48 hr in challenged pigs. Histologically acute exudative reactions were present in the lungs by 24 hr with proliferative changes predominating after 10 days. While variations in the concentrations of inocula were reflected by corresponding increases and/or decreases in gross lung damage, clinical signs and histological reactions were unaltered. Chlamydial organisms were recovered only from lung tissues.     

羊尤氏泰勒虫病的病理学观察

对尤氏泰勒虫人工感染的绵羊进行了病理学观察。主要的组织病变：淋巴结充血、出血及淋巴窦网状内皮细胞增生;肺脏出血,间质淋巴细胞和网状细胞增生,肺泡隔增厚;肾小球内皮细胞、血管内皮细胞增生,淋巴网状细胞灶状积累,甚至形成结节;心肌细胞变性、坏死,染色不均;肠道固有膜明显充血、出血;肝细胞颗粒变性,有散在细胞坏死,汇管区和小叶间有淋巴网状细胞增生;瘤胃黏膜下层有散在性出血,肌层见灶状出血。     

猪圆环病毒继发细菌感染的实验室诊断

采集临床病死仔猪脏器组织,用分子生物学和细菌学方法进行确定性诊断。结果:在病死仔猪肺脏与淋巴结中均检测到猪圆环病毒核酸,并分离到4株埃希氏大肠杆菌;药敏试验表明:分离细菌对头孢噻呋钠敏感,对其他抗生素均表现耐药性。诊断结果为贵州省规模场防制猪圆环病毒感染提供了一定的技术支持。     

Systemic Listeria monocytogenes infection and concurrent pleural mesothelioma in a cat

Herein we describe a rare case of systemic Listeria monocytogenes infection with concurrent pleural mesothelioma in a stray cat that was found dead and submitted for autopsy. Gross pathology changes consisted of thoracic clear yellow fluid admixed with suspended fibrin strands; clear-to-tan, variably sized, <3 mm diameter pulmonary nodules; and enlargement of the submandibular, retropharyngeal, and prescapular lymph nodes. Histologic changes consisted of extensive areas of suppurative inflammation and necrosis with mineralization that partially effaced the pulmonary parenchyma and lymph nodes. Random, distinct necrotic foci were present throughout the hepatic parenchyma. Extending from the pleura, within perinecrotic alveolar spaces, and infiltrating the submandibular, retropharyngeal, and prescapular lymph nodes were dense sheets of neoplastic epithelioid cells with moderate pleomorphism and occasional karyomegaly and multinucleation. Neoplastic cells exhibited immunolabeling for pancytokeratin AE1/AE3 and vimentin, consistent with pleural mesothelioma. Aerobic bacterial culture of lung yielded heavy growth of L. monocytogenes. Immunohistochemistry (IHC) for L. monocytogenes revealed clusters of bacteria in the lung, lymph node, and liver. Pathologic changes were consistent with systemic listeriosis, confirmed by bacterial culture and IHC, and concurrent pleural mesothelioma.     

副猪嗜血杆菌人工感染猪的病理学观察

用副猪嗜血杆菌分离株感染断奶仔猪,发病仔猪临床表现为体温中度升高、精神不振、被毛粗乱、站立不稳、厌食、呼吸困难。尸体剖检,可见胸腹腔纤维素渗出严重,有大量的渗出液、肺出血及脑充血等;病理组织学表现为,肺脏、心脏、脾脏等脏器含有大量的中性粒细胞的纤维蛋白性多发性浆膜炎、脑膜炎及支气管肺炎。结果表明,此分离株为一高致病潜力的菌株。     

肥胖影响呼吸系统抗感染的机制

肥胖是由多因素引起的一种慢性代谢性疾病,也是一种系统性的低度炎症,同时影响着机体的能量代谢和免疫状态。大量研究报道,肥胖在一定程度上影响了呼吸系统的功能,增加了呼吸道感染的风险,同时调节了机体清除病原体的能力,使机体预后出现两极化。目前这种机制尚不清楚,明确的是脂肪组织的大量堆积,使炎性细胞浸润增加,炎性介质和脂肪因子的表达水平提高,这可能是肥胖改变肺脏对病原微生物敏感性的主要原因。本文就肥胖影响呼吸道抗感染的可能机制作一简要阐述,为深入探究肥胖与呼吸道感染之间的关系奠定一定的基础。     

猪副嗜血杆菌感染的诊断与防治

吉林省长春市郊某猪场发生了疑似猪副嗜血杆菌引起的疾病。临床症状表现为体温升高，精神沉郁，食欲减退，消瘦，咳嗽，腹泻，关节肿胀。剖检见肺脏呈纤维素性胸膜肺炎，胸腔内有大量淡红色液体、纤维性渗出物及凝块；腹腔内有多量秀黄褐色漏出液，有的呈胶冻状凝块；心包膜上有奶酪样坏死，并与心脏粘连。肺臌胀，表面覆有大量纤维素性渗出物，并与胸壁粘连，镜检肺泡充满水肿液或纤维蛋白和红细胞。全身淋巴结肿大，呈浆液性卡他性炎，暗红色；取心血、肝、脾涂片，革兰氏染色，镜检，见有革兰氏阴性球杆菌。将病菌接种于血液琼脂平皿上，置37℃温箱培养48h，革兰氏染色，镜检该菌同涂片细菌。动物回归试验，病理变化同自然感染病例。用纸片法对32种药物进行药敏试验，结果该菌对阿米卡星、美西林、磺胺甲基异恶唑3种药物高度敏感。结合本病的流行情况、临床症状、病理变化和实验室检查，确诊为猪副嗜血杆菌感染。     

肺炎支原体感染对大鼠免疫功能和一些生化指标的影响

采用滴鼻法建立大鼠肺炎支原体感染模型 ,并对其体液免疫和细胞免疫功能进行了检测。与正常对照组相比 ,感染组大鼠血清中IgG、IgM明显降低 ,C3补体增加 ;血清中IL 2、IL 6降低 ,TNF α增高 ;全血中CD+ 8增加 ,CD+ 4/CD+ 8比值降低 ;血浆中NO、MDA含量增加 ,GSH Px活性增加。结果表明 ,细胞因子和免疫球蛋白的紊乱导致机体体液免疫和细胞免疫功能的低下 ,并诱发肺部广泛的炎症反应 ,提示它们在肺炎支原体感染的发病机制及肺外并发症的发生中起重要作用。     

Age-related viral load and severity of systemic pathological lesions in acute naturally occurring African swine fever virus genotype II infections

African swine fever (ASF) causes a contagious hemorrhagic disease in all ages of pigs without sex predilections. The objective of this study was to determine the age-related viral loads and severity of systemic pathological lesions among three different swine group ages (weaned pigs, fattening pigs, and sows) during a recent outbreak of acute ASF in Vietnam. Age-related viral loads were determined in 5 major organs (lung, liver, spleen, kidney, and lymph node) by immunohistochemistry as well as in the blood by real-time polymerase chain reaction (PCR). Age-related systemic pathological lesions were analyzed in the listed organs among three age groups.Weaned pigs had significantly (p < 0.05) higher levels of viral loads in their lung, liver, lymph nodes and blood than in those of fattening pigs and sows. Fattening pigs had significantly (p < 0.05) higher scores of macroscopic lung and lymphoid lesions, and microscopic liver lesions compared with those of weaned pigs and sows. The results of this study demonstrated that viral loads were age-related in acute naturally occurring ASF but the severity of pathological lesions was not correlated with the level of viral loads in the five major organs.     

广西出现猪繁殖与呼吸综合征病毒和猪圆环病毒2型混合感染

2004年4月以来,广西的桂林、玉林、南宁、崇左、贵港、来宾6市共8个规模化猪场均发生以肺部严重病变、淋巴结肿大出血为主要特征的疫病。在流行病学调查、临床症状、病理剖检的基础上,采用已建立的诊断猪繁殖与呼吸综合征病毒的RTPCR技术和诊断猪圆环病毒2型的PCR技术,从这几个规模化猪场的病料中均扩增出特异的目的基因片段,证实为猪繁殖与呼吸综合征病毒和猪圆环病毒2型混合感染。     

鸭源鸡杆菌对SPF雏鸡的感染特性研究

为研究鸭源鸡杆菌的流行病学特性,本研究采用从自然病例分离得到的鸭源鸡杆菌人工感染4日龄SPF雏鸡,通过形态学、PCR、荧光定量PCR和组织学等方法分别对感染后SPF雏鸡的组织脏器进行了细菌分离、检测和鉴定,用ELISA对其血清抗体水平进行检测.结果表明,人工感染鸡无临床症状,组织学检查感染鸡的肝脏、气管和肺脏组织均有损伤.人工感染后第3d和同居感染第2d鸡体内可分离出鸭源鸡杆菌,人工感染后第96d仍能够分离到鸡杆菌.ELISA方法证实人工感染后47 d和同居后32 d出现抗体高峰,持续2～3周,人工感染组和同居组抗体水平均高于对照组(p＜0.05);荧光定量PCR检测病料结果显示人工感染组和同居组的气管组织中细菌含量最高.本研究表明雏鸡在4日龄即可感染鸭源鸡杆菌,并能通过同居传播,长期带菌、排菌;感染后抗体产生缓慢、持续期短.本研究为鸭源鸡杆菌的流行病学、致病机理研究及防治措施的制定等提供了参考依据.