畜禽硒—维生素E缺乏病(续)

病理学变化本病的病理学变化,畜禽以出血性肝小叶坏死;心肌、骨骼肌及微血管的变性、坏死;渗出性素质,胰腺萎缩等为特征。但因家畜种类不同,病变各有不同。反刍动物牛和羊剖检患病死亡的牛、羊时,一般可见尸体瘦弱,皮下蜂窝组织充血和出血,有时在颈、背部皮下结缔组织有胶样浸润。在胸、腹腔中蓄积草黄色的液体,肺水肿,切开支气管流出     

鸡大肠植菌病的病理学研究

鸡大肠杆菌病在接种后４８小时的病理学变化，主要是急性败血症和亚急性炎症变化。其主要特征是各脏器均可见到细菌团块，组织发生充血、出血及水肿，大部分病鸡在脏器表面附有纤维蛋白性渗出物。在接种后１周时，病理学变化由急性、亚急性转为慢性阶段。各脏器表面的纤维蛋白性参出物发生机化，并在肺、心及肝脏等组织内出现肉芽肿性结节。     

1起竹鼠感染大肠杆菌的诊断

为诊断玉溪市峨山县某竹鼠养殖场竹鼠2013年6月所发疫病,试验对发病竹鼠进行了临床观察、病理剖检、病原分离鉴定、组织病理学观察等。临床观察表明,竹鼠感染后表现为精神沉郁、腹泻（肛门被粪便严重污染）、后肢瘫痪等。剖检可见胸腔、腹腔有大量淡黄色积液;胃黏膜溃疡、糜烂,内容物呈黑色;十二指肠肠管呈红褐色、肠系膜胶冻样,盲肠鼓气;肝脏有针尖大小的出血点;下颔淋巴结、肺门淋巴结肿胀,肺脏有大量出血点;尾根两侧皮下出血等。组织病理学观察可见心肌明显出血;肝细胞变性、坏死,淋巴细胞浸润,门管区化脓、出血和瘀血;脾脏广泛瘀血;肺脏瘀血,肺泡管内有炎性渗出物,肺泡壁增厚;肾出血和瘀血,肾小球肿大,管腔内充满大量积液;结肠固有层轻度出血和水肿,杯状细胞增多,呈卡他性肠炎等。表明,玉溪市峨山县某竹鼠养殖场竹鼠2013年6月所发疫病为大肠杆菌感染。     

仔猪神经症状疾病病原诊断

为了对湖南株洲某猪场出现神经症状的仔猪进行病原诊断,文章采用细菌分离、染色镜检、PCR、病毒分离、组织病理学检查等方法对病料进行鉴定。结果表明,细菌分离培养的巧克力平板上出现灰白色、光滑、卵圆形突起小菌落,有溶血现象;镜检呈链状排列;经PCR鉴定为猪链球菌;病毒鉴定结果表明PRV、PCV2为阴性,猪腺病毒(Padv)为阳性,PCR分型鉴定显示病毒为Padv3型,但未分离出猪腺病毒;组织病理学检查发现肺组织切片中有严重的出血、炎性细胞浸润及纤维素性增生并脱落,而脑组织中也有出血现象。通过以上实验室诊断方法可得出结论,猪只的神经症状是由猪链球菌引起。     

水貂犬瘟热病理组织学观察

为了加深对犬瘟热病理学损害的认识,为该病的诊断、治疗以及判定预后提供依据,对确诊为犬瘟热的水貂的主要脏器进行了病理组织学观察。病理学变化特征为心肌细胞间隙明显增宽,有淋巴细胞浸润;肝脏出血、瘀血,淋巴细胞浸润及肝细胞肿胀、坏死;脾脏出血,脾脏白髓体积缩小;肺脏出血,大量淋巴细胞浸润;肾脏淋巴细胞浸润,部分肾小管上皮细胞肿胀、坏死。结果表明:患貂出现了广泛的组织损伤,并伴随机体各器官明显的炎症反应。     

猪传染性胸膜肺炎病例报告

为了确诊猪场1例疑似猪传染性胸膜肺炎的病例，本试验首先对该猪死亡前的临床症状进行了解，然后对死亡猪进行剖检并利用收集的病料进行细菌分离培养、质谱分析、PCR检测和组织病理学等实验室诊断。结果显示，该猪死亡前表现出体温升高、呼吸窘迫和鼻内流出血色样泡沫分泌物等临床症状，剖检发现胸腔积液、肺脏出血和肿大等病理变化。实验室诊断结果显示，胸腔积液、血液和肺脏等病料中分离获得的菌株为血清型7型胸膜肺炎放线杆菌。组织病理学观察结果显示，肺脏组织表现为出血性纤维素性肺炎，肺泡渗出液中可见蓝染的菌团；心脏、肾脏、淋巴结、肝脏和脾脏等其他脏器均有不同程度的出血、淤血、水肿和淋巴细胞浸润等组织病理学变化。综合以上诊断结果，确诊该猪为猪胸膜肺炎放线杆菌感染。     

10种疾病可致猪猝死

1猪瘟 最急性型病猪发病很急。突然死亡。尸体剖检可见脏器上有程度不同的出血斑点,淋巴结肿大,肾脏皮质部有数量不等的小出血点,脾脏有紫黑色出血性梗死。典型特征是回盲瓣有纽扣状轮层样溃疡。     

阿拉善左旗绵羊青干病的诊断

对内蒙古阿拉善左旗发生的以消瘦和高度营养不良为特征,当地俗称为"青干病"的绵羊进行了临床诊断、病理学检查、血液学和生化指标测定。剖检可见血液稀薄,心脏肿大,变软,消化道萎缩,部分黏膜脱落。组织病理学检查可见肾小管上皮细胞肿胀;肝细胞肿胀,组织间隙可见含铁血黄素沉积;心肌部分肌纤维萎缩;脾组织间隙可见含铁血黄素沉积。血液学检测结果显示,红细胞数、血红蛋白含量、红细胞压积显著降低;葡萄糖、总蛋白、白蛋白含量降低;谷丙转氨酶、谷草转氨酶、总胆红素、肌酐、尿素含量显著升高。结果表明,绵羊青干病是以机体极度消瘦、贫血、肝肾损伤和机能下降为主要特征的营养不良性疾病。     

鹰尿酸盐沉积综合征的诊断及病理学观察

采用病原学检测、尿酸盐分析和病理组织学观察等方法,分别对来自某动物园疑似患有尿酸盐沉积综合征的5例病鹰进行了确诊和病理学研究。结果显示,病原学检测未检测到致病性病原,病鹰脏器表面白色石灰样物质经检测确证为尿酸盐结晶。病理组织学观察显示,眼观,病鹰内脏器官浆膜面有大量石灰样尿酸盐晶体沉积;肾脏肿大,表面与切面呈花斑状;膝关节等程度不等肿大。镜下,心、肝、脾、肺、肾、腺胃等器官组织中均可见数量不等、大小不一的尿酸盐晶体沉积区,沉积区中央原有组织变性坏死,并可见大量嗜酸性(HE染色呈红色)放射状晶体形成,其周围常有炎性细胞浸润(包括嗜酸粒细胞、巨噬细胞、淋巴细胞等),甚至可见巨细胞。病程较长时,尿酸盐晶体沉积部可形成特殊肉芽肿结节。结果表明,5例病鹰为尿酸盐沉积综合征,病理学变化表现为内脏器官尿酸盐晶体沉积和特殊肉芽肿结节形成。     

鸭病毒性肠炎的病理特点

<正>鸭病毒性肠炎(DVE)是一种急性、接触传染性疱疹病毒感染。DVE感染引起的病理学变化取决于被感染禽的品种、感染宿主的年龄、性别和易感性、感染阶段以及病毒毒力和感染强度。1病理变化感染鸭的心肌、其他内脏器官及肠系膜和浆膜等支持结构有出血点、出血斑或弥漫性血液外渗。心外膜,特别是冠状沟有密集的出血点,使其表面呈红色"漆刷样"。打开心腔可见心内膜和瓣膜出血,肝脏、胰腺、肠道、肺脏和肾表面有出血斑。成年产蛋鸭卵泡变     

贵州省某规模化猪场暴发猪瘟与链球菌病混合感染的诊断

为了解贵州某规模化猪场发病断奶仔猪死亡原因,本研究采用流行病学调查、临床症状观察、病理解剖诊断和RT-PCR检测等方法,对该规模化猪场发病猪进行了诊断。试验结果表明,通过流行病学调查、剖检病理和猪瘟抗体快速金标检测卡检测,初步诊断该猪场发病猪疑似猪瘟病毒和细菌混合感染;RT-PCR检测核酸确诊发病猪为猪瘟病毒感染;细菌培养分离、生化特性鉴定和动物致病性试验确诊为猪链球菌。造成该猪场断奶仔猪发病死亡的原因为猪瘟病毒和猪链球菌混合感染所致。     

Intestinal translocation of Streptococcus suis type 2 EF+ in pigs

Sepsis with subsequent multisystem organ failure after translocation of bacteria from the gut is a serious risk associated with stress situations. We showed that intestinal bacterial translocation could be one of the pathways for pathogenic Streptococcus suis infections in the pig. In 24 piglets weighing 10-14 kg, free of the extracellular factor (EF+) producing phenotype of S. suis serotype 2, a silicon canula was placed in the proximal jejunum to enable intestinal inoculation and bypassing the upper alimentary tract. The pigs were individually housed. After stress induction in 18 pigs by means of a truck drive in individual cages for 1h, pigs were inoculated through the intestinal canula either with S. suis type 2 EF+ or with growth medium only, and put back in their original housing. The six not transported pigs were also inoculated with the same strain. To prevent oral self-infection, faeces were collected in a bag that was glued around the anus. Clinical and behavioral symptoms were recorded for 72 h post inoculation, and then the animals were sacrificed for pathological and bacteriological examination. In three animals, the inoculation strain was re-isolated from mesenterial lymph nodes and typically affected organs. No S. suis type 2 EF+ was detected by specific polymerase chain reaction (PCR) in any of the tonsil-swabs and -homogenates. We concluded that infection of the organs had taken place after bacterial translocation out of the gut and that the intestinal tract can be a porte d'entree for S. suis type 2 EF+.     

Pathogenesis of porcine reproductive and respiratory syndrome virus-induced increase in susceptibility to Streptococcus suis infection

Eighty 3-week-old crossbred pigs were randomly assigned to six groups (13-14 pigs/group). Group 1 pigs served as uninoculated controls, group 2 pigs were inoculated intranasally (i.n.) with Streptococcus suis serotype 2, group 3 pigs were inoculated i.n. with a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine, group 4 pigs were inoculated i.n. with the same vaccine and with S. suis, group 5 pigs were inoculated i.n. with VR-2385 (a high-virulence strain of PRRSV), and group 6 pigs were inoculated i.n. with VR-2385 and S. suis. Pigs exposed to both PRRSV and S. suis were inoculated with PRRSV 7 days prior to S. suis inoculation. The pigs were 26 days old when inoculated with S. suis. Respiratory disease was significantly more severe in groups 5 and 6. Mortality rate was the highest in group 6 (87.5%). This rate was significantly higher than that observed in all other groups except group 4 (37.5%). The mortality rate in group 2, inoculated with S. suis alone, was 14.3%. No pigs from groups 1, 3, or 5 died prior to the scheduled necropsies at 10 and 28 days postinoculation with PRRSV (DPI). To study the effect of PRRSV and/or S. suis on pulmonary clearance by pulmonary intravascular macrophages, six pigs from each group were intravenously infused with 3% copper phthalocyanine tetrasulfonic acid in saline prior to necropsy at 10 DPI. Mean copper levels in the lungs of pigs in groups 2, 5, and 6 were significantly lower than those in control pigs. The mean percentage of lung tissue grossly affected by pneumonia at 10 DPI was 0%, 1%, 0%, 3%, 64%, and 62% for groups 1-6, respectively. Both gross and microscopic interstitial pneumonia lesions were significantly more severe in the VR2385-inoculated groups (5 and 6). PRRSV was isolated from bronchoalveolar lavage fluid collected at necropsy from 100% of the pigs in groups 5 and 6, 71.4% of pigs in group 4, 38.5% of pigs in group 3, and none of the pigs in groups 1 or 2. Streptococcus suis serotype 2 was cultured from the internal tissues of 7.7%, 28.6%, and 78.6% of the pigs in groups 2, 4, and 6, respectively. Streptococcus suis serotype 2 was isolated from whole blood at necropsy from 7.7%, 35.7%, and 78.6% of pigs in groups 2, 4, and 6, respectively. Significantly more pigs in group 6 had S. suis isolated from whole blood and internal tissues. In summary, both high-virulence PRRSV and S. suis decreased copper clearance, and the incidence of isolation of S. suis and PRRSV was higher in dually inoculated pigs. PRRSV-induced suppression of pulmonary intravascular macrophage function may in part explain PRRSV-associated increased susceptibility to S. suis infection.     

Pathogenicity of Eperythrozoon suis alone and when mixed with Babesia trautmanni in experimentally-infected pigs

The pathogenicity of a single infection with Eperythrozoon suis and of a mixed infection of E. suis and Babesia trautmanni in experimentally-infected pigs, was described. In the pigs with a single infection, parasitaemia of E. suis was observed 4 days after blood inoculation. Although parasitaemia with this parasite was also observed on the 4th day in a mixed infection, the parasitaemia of B. trautmanni was not noted until 14 days after inoculation at a period when that of E. suis had started to fall. No parasitaemia was observed in any of the pigs in the splenectomized and unsplenectomized uninoculated control animals. The pigs carrying either single or mixed infections had pyrexia and their temperatures were consistently higher than those of the control animals. Infected pigs also showed anaemia with significant decline in Pcv, Hb and RBC values. The total WBC count rose in the infected pigs and the rise was more pronounced in pigs carrying E. suis alone. In addition, it was only in pigs infected by E. suis alone that a decline in the percentage of neutrophils and a rise in percentage lymphocytes was observed.     

Decreased mortality of weaned pigs with Streptococcus suis with the use of in-water potassium penicillin G

This study evaluated the efficacy of potassium penicillin G in drinking water of weaned pigs to reduce mortality and spread of infection caused by Streptococcus suis. A total of 896 18-day-old weaned pigs were randomly assigned to either treatment with potassium penicillin G in-water (Treated), or no treatment (Control). The outcomes analyzed were total mortality, mortality due to S. suis, and overall counts of S. suis colonies. The risk of mortality due to S. suis and total mortality were significantly increased in the Control group compared with Treated pigs (P < 0.05). Bacterial culture of posterior pharyngeal swabs indicated that Control pigs were significantly more likely to have ≥ 1000 colonies of S. suis per plate than were Treated pigs (P < 0.05). This study demonstrates that potassium penicillin G administered in drinking water is effective in reducing mortality associated with S. suis infection and reducing tonsillar carriage of S. suis.     

Passive immunization of pigs against experimental infection with Streptococcus suis serotype 2

The safety and protective efficacy of a horse antiserum raised against inactivated whole cell preparations of Streptococcus suis serotype 2 was investigated in pigs by experimental challenge. The antiserum was evaluated in two similar experiments each comprising 12 4-week-old pigs treated with 6 ml of antiserum the day before challenge and four pigs used as challenge controls. Pigs were infected by subcutaneous injection with approximately 10(11) colony forming units of S. suis serotype 2. Clinical disease in the pigs that could be attributed to infection with S. suis was reduced from 88 to 35% (P = 0.015). The percentage of pigs with lesions that could be associated with S. suis was reduced from 88 to 22% (P = 0.002) and isolation of S. suis serotype 2 was reduced from five (63%) out of eight pigs in the combined challenge control groups to 3 (13%) out of 23 pigs in the combined treatment groups. These results indicate that passive immunization of pigs may be a way to reduce or control S. suis serotype 2 infections in pigs.     

Efficacy of tiamulin against experimentally induced Streptococcus suis type-2 infection in swine

Eighteen 4-week-old pigs were used in a study to evaluate tiamulin in drinking water for control of experimentally induced Streptococcus suis type-2 infection. Pigs in groups A and B (n = 6 pigs/group) were aerosolized with a logarithmic-growth phase culture of S suis type 2, whereas pigs in group C (n = 6 pigs) served as noninfected and nonmedicated controls. After exposure to S suis, pigs in group B were given 180 mg of tiamulin/L of drinking water for 5 days. Pigs in group B consumed more feed (P = 0.009) and gained body weight faster (P = 0.02) than did pigs in group A. Pigs in group A had higher rectal temperature (P = 0.05) for up to 7 days after S suis exposure, higher clinical sign scores (P = 0.008), higher serum cortisol concentration on days 7 and 14, higher gross lesion scores (P = 0.03), and higher microscopic lesion scores (P = 0.01) than did pigs in groups B and C. Gross and microscopic lesions in pigs of groups A and B included meningitis, pneumonia, pleuritis, pericarditis, peritonitis, and synovitis of variable severity. Streptococcus suis type 2 was recovered from tissue specimens of 2 group-A pigs and 1 group-B pig. Data indicated that tiamulin administered via drinking water significantly reduced the effects of S suis type-2 infection.     

Respiratory chlamydial infection based on experimental aerosol challenge of pigs with Chlamydia suis

An experimental study of aerogeneous challenge in pigs was conducted in order to reveal characteristic features of porcine respiratory chlamydiosis. Eight conventionally raised pigs were exposed to a pathogenic strain of Chlamydia (C.) suis, four controls were mock infected. Besides pathological changes, the acute-phase and humoral immune responses, as well as the dissemination and transmission of the challenge strain was monitored in the course of infection. The data from clinical investigations, LPS-binding protein assay, antibody ELISAs, confocal laser scanning and light microscopy, immunohistochemical staining and PCR provided extensive evidence of the pathogenic potential of C. suis for the porcine respiratory system. This model appears suitable for further pathophysiological and immunological investigations of chlamydial respiratory infections and can also be recommended for studies of Chlamydia-associated infections of the human lung.     

Streptococcus suis infections in humans: the Chinese experience and the situation in North America

Infections caused by Streptococcus suis are considered a global problem in the swine industry. In this animal species, S. suis is associated with septicemia, meningitis, endocarditis, arthritis and, occasionally, other infections. Moreover, it is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infection in humans have been reported, a large outbreak due to S. suis serotype 2 emerged in the summer of 2005 in Sichuan, China. A similar outbreak was observed in another Chinese province in 1998. Symptoms reported in these two outbreaks include high fever, malaise, nausea and vomiting, followed by nervous symptoms, subcutaneous hemorrhage, septic shock and coma in severe cases. The increased severity of S. suis infections in humans, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, underscores the critical need to better understand the factors associated with pathogenesis of S. suis infection. From the 35 capsular serotypes currently known, serotype 2 is considered the most virulent and frequently isolated in both swine and humans. Here, we review the epidemiological, clinical and immunopathological features of S. suis infection in humans.     

Rapid detection of Streptococcus suis serotype 2 in weaned pigs

A survey to detect Streptococcus suis serotype 2 in 1,716 weaned pigs was done in Quebec. Forty-nine sow herds were included in this survey: in 26 herds, S suis serotype 2 had been isolated during the preceding 12 months and in 23 herds (control), the organism had not been detected during a previous study. Swab specimens of the nasal cavity and tonsils of pigs were obtained for bacteriologic culture, and S suis serotype 2 was easily detected by the use of brain-heart infusion agar containing a Streptococcus-selective supplement and 5% goat antiserum raised against S suis serotype 2. After measurement of the diameter of the precipitation zone of 539 isolates, a slide agglutination test was performed to identify the S suis serotype 2 isolates. The mean precipitation zone diameter obtained for group S suis serotype 2 was larger (P less than 0.001) than that for the group designated as "others". With slide agglutination test results as reference and on the basis of discriminant analysis to stimulate detection of S suis serotype 2, 93.1% of all isolates were correctly classified, using the precipitation zone diameter as unique classification criterion. Relative specificity was 94.5% and relative sensitivity was 88.7%. Use of the precipitation zone diameter on a quantitative basis led to the proposal of a simple and reliable technique to screen swine herds for S suis serotype 2 in weaned pigs. Nasal and tonsillar swab specimens were obtained and analyzed concurrently for S suis serotype 2. The organism was found in both sites in only 20.4% of 103 carrier pigs.(ABSTRACT TRUNCATED AT 250 WORDS)