高致病性猪蓝耳病的病理学观察

目的：研究高致病性猪蓝耳病的临床症状、解剖病变和组织病理学变化,为病理诊断和治疗提供参考材料。方法：对经血清学诊断为高致病性猪蓝耳病的患仔猪进行临床症状及解剖病变观察,对多个组织器官包埋、切片和HE染色后进行病理组织学观察。结果：患猪多系统器官发生充血、出血、炎性细胞浸润、变性和坏死等病变。结论：高致病性猪蓝耳病造成仔猪多器官功能衰竭,这可能是其死亡率高的原因。     

高致病性蓝耳病的临床症状和防控措施

高致病性蓝耳病具有传染性强、治疗效果差、发病急以及死亡率高的特征,对母猪、仔猪以及育肥猪等具有较大的危害.在本文中,将就高致病性蓝耳病的临床症状和防控措施进行一定的研究.     

高致病性猪蓝耳病的特点及其防治技术

高致病性猪蓝耳病是由猪繁殖与呼吸综合征病毒(PRRSV)变异株引起的一种免疫抑制性疾病。该病传播迅速,分布广泛,能引起严重经济损失。在总结猪高致病性蓝耳病的病原学特点、流行特点、临床症状、病理变化特点的基础上,提出高致病性猪蓝耳病的防治方法:增强生猪的特异性抗病力;加强母猪、断乳仔猪、保育仔猪、育肥猪的保健;提高猪场的管理水平。在治疗高致病性猪蓝耳病时还需预防继发感染并对症治疗;减少应激并正确使用各类药物。     

高致病性猪蓝耳病的预防

高致病性猪蓝耳病时养猪业的影响较大.笔者介绍了高致病性猪蓝耳病的病原、传播途径、临床症状、病理变化、诊断方法及预防高致病性猪蓝耳病的几点措施.     

猪瘟、蓝耳病及猪O型口蹄疫母源抗体消长规律

为了研究猪瘟、猪高致病性蓝耳病和猪O型口蹄疫母源抗体的消长规律,制定科学合理的免疫程序。本试验利用ELISA抗体检测试剂盒,对仔猪0、7、14、21、28、35、42、49、56日龄的猪瘟、猪高致病性蓝耳和猪O型口蹄疫母源抗体分别进行检测。结果表明仔猪猪瘟、猪高致病性蓝耳病和猪O型口蹄疫哺乳前抗体水平均与阴性对照相当,抗体为0,7日龄时各疾病抗体均达到最高水平;猪瘟抗体水平在28日龄时明显下降;猪高致病性蓝耳病35日龄时抗体水平明显下降;仔猪O型口蹄疫14日龄抗体明显下降。猪瘟、猪高致病性蓝耳和猪O型口蹄疫的母源抗体具有不同消长规律,为临床制定合理的首免日龄提供科学依据。     

高致病性猪蓝耳病的流行特点及其防治

高致病性猪蓝耳病也称“猪繁殖与呼吸障碍综合征”,是一种由猪繁殖与呼吸障碍综合征病毒所引起的,以成年猪生殖障碍、早产、死胎和仔猪呼吸异常为主要特征的免疫抑制传染病,具有高接触性、高死亡率的特点。本文结合高致病性猪蓝耳病的流行特点,对其临床症状、病理变化等进行了分析,并提出了相应的防治措施,希望能够为高致病性猪蓝耳病的预防和控制提供一些参考。     

高致病性猪蓝耳病的诊断与防控

高致病性猪蓝耳病具有传染性强的特点,最主要的临床症状是猪呼吸急促,对猪的健康成长起到严重的负面影响.因此,本文就对高致病性猪蓝耳病的临床表现进行分析,并提出高致病性猪蓝耳病的预防措施,以期为养猪人员提供参考依据.     

野猪高致病性蓝耳病与多杀性巴氏杆菌混合感染的诊断报告

高致病性猪蓝耳病是由猪繁殖与呼吸综合征（俗称蓝耳病）病毒变异引起的一种急性高致死性疫病。仔猪发病率可达100％,死亡率可达50％以上,母猪流产率可达30％以上,育肥猪也可发病死亡是其特征。2007年4月份宁夏某野猪场爆发以高热、呼吸症状为主的疫病。经临床剖检和实验室病原学诊断,确诊为高致病性猪蓝耳病和多杀性巴氏杆菌混合感染.     

高致病性猪蓝耳病的预防

高致病性猪蓝耳病对养猪业的影响较大。笔者介绍了高致病性猪蓝耳病的病原、传播途径、临床症状、病理变化、诊断方法及预防高致病性猪蓝耳病的几点措施。     

规模猪场仔猪腹泻病的诊治

某规模猪场反复发生仔猪腹泻疫情,仔猪死亡率很高。经临床症状观察,病理解剖,PCR及RT-PCR病原学检测,最终确诊为伪狂犬病毒和高致病性蓝耳病病毒混合感染。建议猪场净化厂区环境,猪群实行全进全出制,逐步实现伪狂犬病毒和高致病性蓝耳病毒的净化,从而根除反复发生的仔猪腹泻疫情。     

猪CD163游离受体的体内表达与抗猪繁殖与呼吸综合征病毒感染效果的研究

为了验证构建的重组腺病毒rAd-SRCR59-Fc能否在猪体内有效表达游离受体及其能否抑制PRRSV感染,将重组腺病毒注射断奶仔猪,用夹心ELISA检测SRCR59-Fc表达情况;选择PRRSV易感仔猪肌肉注射重组腺病毒rAd-SRCR59-Fc(4×109 TCID50/头),5 d后与JXA1株PRRSV人工感染猪同居饲养,定期测定体温、观察临床症状,采集血样和粪样进行PRRSV定量检测,对病死猪进行病理剖检和主要器官病毒载量测定。结果显示,重组腺病毒接种猪能表达SRCR59-Fc游离受体蛋白,并持续15 d左右;与感染对照组相比,rAd-SRCR59-Fc注射组首次高热时间和临床症状均推迟3 d,第5天~第13天临床症状评分显著低于感染组(P<0.01),至试验结束(25 d)仅有1头猪死亡;肺脏无明显肉眼病变,仅见少量坏死灶,病理切片显示肺泡壁轻微增厚;第3天~第13天病毒血症水平显著低于感染组(P<0.01),第5~第13天粪排毒量低于感染组(P<0.05),器官病毒载量均显著低于感染组(P<0.01)。研究表明CD163游离受体的重组腺病毒能有效阻断PRRSV毒株感染,可以作为PRRS预防或治疗性疫苗进一步研究。     

猪蓝耳病及其综合防控措施

猪繁殖与呼吸综合征（PRRS）俗称猪蓝耳病,是由PRRS病毒（PRRSV）引起的传染病,分为欧洲型和北美型,是目前养猪业最重要的猪病之一。PRRS每年给美国养猪业造成的损失为6.64亿美元（约40亿人民币）,中国的养猪量数倍于美国,因此该病在中国造成的损失应该远大于美国。该病对母猪群的影响主要是降低分娩率,降低产仔数和窝均断奶仔猪数。我国的PRRS以北美型为主,感染后会引起母猪群的繁殖障碍,仔猪、生长育肥猪群的呼吸道问题。2006年我国暴发了由变异株PRRSV引起的高致病性PRRS,该病在全国范围内流行,重创了中国养猪业^[1]。2013年以后,类NADC-30毒株开始在国内逐渐扩散传播,各种重组毒株也不断出现,PRRS的防控变得更加复杂^[2-3]。PRRSV容易变异、毒株多样、感染时间长、防控难度较大。猪群感染PRRS后会造成免疫抑制,易出现各种混合感染和继发感染,这增加防控的难度。文章回顾了PRRS的临床症状、病理变化、病原特性、传播途径、诊断方法与防控措施。在PRRS的防控上,猪场需要良好的生物安全、科学的疫苗免疫与正确的药物方案。文章还探讨了在发生了PRRS感染的猪场,使用替米考星进行控制的效果。     

Infection of growing swine with porcine reproductive and respiratory syndrome virus and Mycoplasma hyopneumoniae--effects on growth,serum metabolites,and insulin-like growth factor-I

This study evaluated the influence of concomitant infections with porcine reproductive and respiratory syndrome virus (PRRSV) and Mycoplasma hyopneumoniae on growth performance, serum metabolite concentrations, and serum insulin-like growth factor-I (IGF-I) in growing pigs. Twenty-two barrows (10 weeks of age) were treated with either an intranasal administration of PRRSV and an intratracheal infusion of M. hyopneumoniae (treatment; n = 8) or a sham inoculation with medium (sham; n = 8), or were not treated (control; n = 6). The sham pigs were matched by body weight and pair-wise fed with treatment pigs. Pigs were weighed on the day of inoculation (day 0) and at 4 weeks postinoculation (day 28). Blood samples were collected prior to inoculation and at weekly intervals for 4 weeks. Pigs in the treatment group exhibited clinical signs consistent with PRRSV infection and M. hyopneumoniae pneumonia. Diagnostic procedures confirmed that treatment pigs were inoculated with PRRSV and M. hyopneumoniae and that sham and control pigs remained free of both pathogens. Average daily gain and feed conversion did not differ among the 3 groups. The IGF-I levels differed (P < 0.05) between control and treatment pigs, even after feed intake returned to similar levels among groups. At day 7, IGF-I concentrations were greater in sham pigs compared with treatment pigs, despite similar feed intake. Sham inoculation and decreased feed intake in sham pigs did not alter serum IGF-I concentrations. Evidently, IGF-I status of pigs affected with disease is influenced by nutritional and nonnutritional factors during the disease process.     

CSFV免疫状态下外周血T淋巴细胞亚群变化及对PRRS的免疫保护作用

建立CSFV疫苗免疫状态下猪繁殖与呼吸综合征病毒（PRRSV）感染动物模型。测定CSFV抗体阻断率和PRRSV抗体S/P值,根据CSFV抗体阻断率和PRRSV感染情况分析猪外周血中T淋巴细胞亚群变化和对PRRS的保护促进作用。采用流式细胞术（FAC）检测猪外周血T淋巴细胞CD3、CD4、CD8亚群的变化。结果,CSFV...     

Threonine and tryptophan supplementation enhance porcine respiratory and reproductive syndrome (PRRS) vaccine‐induced immune responses of growing pigs

The aim of the present study was to investigate influences of threonine and tryptophan supplementation (TTS) on immune response of growing pigs inoculated with modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine. Twenty growing barrows (Landrace × Yorkshire) were randomly assigned to four groups according to the PRRS vaccination and TTS. Serum samples were collected from all pigs at days 0, 7, 14, 21, 28, 35, 49 post‐vaccination (day 0 defined as the day of vaccination). Pigs were euthanized and samples collected at day 49 post‐vaccination. The results showed that TTS tended to increase weight gain and average daily gain (ADG) of pigs (P < 0.1). PRRS vaccine enhanced serum PRRSV‐specific antibody, serum virus neutralizing (SVN) antibody and interferon‐γ, interleukin (IL)‐10 and IL‐1β concentrations (P < 0.05). The expression of TLR3 and TLR7 mRNA in lymph nodes were higher in TTS than in the control group after PRRS vaccine inoculation (P < 0.05). TTS diet mitigated lung damage which is induced by PRRS vaccination from microscopic evaluation. These results suggest that dietary TTS could improve growth performance of growing pigs, which may be ascribed to the improved immune response and mitigated lung damage.     

猪繁殖与呼吸综合征综合防控技术的研究

为探索猪繁殖与呼吸综合征(PRRS)的综合防控技术,采用现场调查、血清学监测和病原学诊断等方法,对贵州省2007年3月至2009年10月采集的PRRS样本进行了血清学流行病学调查和病原学诊断,对比了不同疫苗免疫效果,测定了仔猪母源抗体的消长规律,确定了不同免疫/感染状态下仔猪首免日龄,结果表明,PRRS易于7~10月份流行;仔猪和能繁母猪的感染率较高,达到96.15%和74.73%;弱毒疫苗免疫效果优于灭活疫苗;哺乳仔猪母源抗体水平随着日龄增长逐渐降低,因此免疫PRRSV母猪所产仔猪的首免日龄定为17~20日龄;曾感染PRRSV母猪所产仔猪首免日龄定为30~34日龄。同时调查了猪场中蚊蝇携带PRRSV情况,初步证明猪场中的蚊蝇均可携带PRRSV;通过消毒试验对比进行了综合防治措施效果初探,取得理想结果。为贵州省PRRS综合防控措施的实施和推广提供了技术支撑。     

Envision免疫组化技术在诊断猪繁殖与呼吸综合征中的应用

为探讨免疫组织化学Envision法在诊断猪繁殖与呼吸综合征(PRRS)中应用的可行性,采用免疫组织化学Envision二步法对30例疑似PRRS病猪肺组织的病毒抗原进行定位、半定量检测。结果表明,Envision法可原位检测病猪肺组织PRRSV抗原的分布;其抗原的阳性表达主要出现在肺巨噬细胞胞浆内,其次为肺泡上皮细胞和细支气管黏膜上皮细胞。依据阳性细胞百分率,进行染色结果判断,检出阳性病猪23例,阳性检出率为76.7%。试验证明,Envision法具有高敏感、低背景、快速简便的特点,可在PRRS诊断中推广应用。     

不同CSF免疫状态下猪PRRS易感性及IFN-γ分泌细胞应答

采用酶联免疫斑点检测技术（ELISpot）检测自然状态下猪外周血单核细胞（PBMC）中分泌IFN-γ的细胞数,并用带T细胞表位的猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus,PRRSV）特异性小分子多肽刺激培养的PBMC,观察IFN-γ的分泌变化。结果显示,猪瘟病毒（Classical fever virus,CSFV）抗体阳性组中感染PRRSV比率小于CSFV抗体阴性组。CSFV抗体阳性猪PBMC中IFN-γ分泌细胞数量均高于CS—FV抗体阴性组,CSFV抗体阴性且受PRRSV感染猪的PBMC对PRRSV多肽刺激不应答。结果表明,对CSFV疫苗应答好的猪对PRRSV感染有一定的抵抗,其细胞免疫处于活动状态,提示2种传染病的免疫应答机理有部分相关性。     

Antibody and cellular immune responses of swine following immunisation with plasmid DNA encoding the PRRS virus ORF's 4, 5, 6 and 7.

The objectives of this study was to investigate the role of DNA vaccines in the generation of an immune response and that elicited against individually encoded proteins of PRRSV. The genomic regions encoding ORF s 4, 5, 6 and 7 of the PRRS virus vaccine strain were cloned into the mammalian expression vector pc DNA 3.1 (+). Inoculations with the recombinant plasmids resulted in detection of PRRS virus-specific antibodies in 71 per cent of the immunized animals by ELISA, virus neutralization and/or Western blotting assays. In addition, cellular immune responses were detected in 86 per cent of the immunized pigs by interferon gamma assay and/or proliferation assay. Pigs in the control group had no detectable immune response to PRRS virus. The results obtained demonstrated that DNA immunization against PRRS virus results in the production of both humoral and cell mediated immune responses in pigs. The results also indicate that neutralization epitopes for PRRS virus are present on the viral envelope glycoproteins encoded by ORF 4 and ORF 5.     

A review of porcine reproductive and respiratory syndrome virus in Dutch breeding herds: population dynamics and clinical relevance

Understanding the spread of porcine reproductive and respiratory syndrome virus (PRRSV) in pig populations is essential to the development of effective PRRS prevention and control strategies. Moreover, knowledge of the field dynamics of PRRSV in pigs will provide insights into the clinical relevance of PRRS, and will enable the targeting of interventions. This review of PRRSV includes discussion on the occurrence of outbreaks, the persistence of infection and the fade-out of infection in Dutch breeding herds. The dynamic character of PRRSV infections in endemically infected herds and the relevance of the disease under Dutch field conditions are also highlighted. Furthermore, several strategies aimed at controlling the spread of PRRSV are discussed.