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1.
安徽省猪呼吸道疾病五种病原的分离与鉴定   总被引:1,自引:0,他引:1  
猪呼吸系统疾病目前是困扰我国养猪业主要疾病之一。为了弄清安徽省猪呼吸道疾病主要致病微生物,本研究利用细菌学鉴定技术、RT-PCR技术对2010年-2011年安徽省皖南、皖中、皖北地区采集的180份呼吸障碍性病(死)猪病料进行了猪繁殖与呼吸综合征病毒、圆环病毒2型、链球菌、巴氏杆菌、副猪嗜血杆菌等5种病原进行了分离鉴定。结果显示,猪繁殖与呼吸综合征病毒感染率高达68%,圆环病毒2型感染率高达83.3%;猪繁殖与呼吸综合征病毒与圆环病毒2型混合感染率达27.8%,猪链球菌感染率为22.8%。结果提示,猪繁殖与呼吸综合征病毒缺失株、圆环病毒2型、链球菌的普遍感染是近年安徽省猪呼吸道疾病的重要致病病原,研究结果为安徽省今后猪群呼吸道疫病防控策略的制定提供了参考依据。  相似文献   

2.
1猪呼吸道疾病综合征的病因 猪呼吸道疾病综合征(PRDC)主要由两类病原引起:一是潜在原发病原(原发性感染疾病),通常包括由猪繁殖与呼吸障碍综合征病毒(PRRSV)、猪伪狂犬病病毒(PRV)、猪流感病毒(SIV)、猪圆环病毒Ⅱ型(PCV2)、猪呼吸道冠状病毒(PRCV)等所致的病毒性疾病和猪肺炎支原体、胸膜肺炎放线杆菌及支气管败血性波氏杆菌等引起的细菌性疾病。二是继发病原(继发性感染疾病),  相似文献   

3.
猪呼吸道综合征 (PRDC)的防治是目前养猪业的难点之一 ,特别是高密度饲养的大型猪场 ,猪的呼吸道综合征问题显得更突出。其原发性病原包括猪繁殖与呼吸综合征病毒(PRRSV)、猪圆环病毒 2型 (PCV 2 )、猪瘟病毒 (HCV)、伪狂犬病病毒 (PrV)和猪气喘病等 ;继发性病原有副猪嗜血菌、胸膜肺炎放线杆菌和链球菌等。有报道认为 ,猪肺炎支原体和PRRSV是引起猪呼吸道疾病的主要元凶 ,也是最多发和最常见的病原。这 2个病原同时感染 ,往往出现严重的呼吸道症状。据报道支原体疫苗免疫接种会大大减少发生PRRSV所致肺炎的可能性 ,也会降低支原…  相似文献   

4.
<正>防控猪呼吸道疾病应冬夏互应、未病先防、防治相兼、放眼四季。猪呼吸道疾病综合征(PRDC)是一种由多病因相互作用引起的猪呼吸道疾病的总称。从母猪、哺乳仔猪、保育猪到育肥猪的各个阶段都能感染,混合与继发感染会导致猪群高发病率和高死亡率。一、致病因素猪呼吸道疾病综合征的病因有病毒、细菌及寄生虫等。以前认为猪呼吸道疾病综合征的主要病原体为肺炎支原体、蓝耳病病毒和猪流感病毒。自从发现圆环病毒Ⅱ型后,其主要病原转变为肺炎支原体、圆环病毒Ⅱ型、蓝耳病病毒和猪流感病毒。  相似文献   

5.
猪呼吸道疾病是一种由病毒、细菌、环境应激等多因素相互作用,造成猪群免疫力下降、呼吸困难、肺脏等多器官病变的传染性疾病,秋冬季节多发,引起该疾病的主-病原有猪蓝耳病病毒(PRRSV)、圆环病毒(PCV-2)、猪伪狂犬病病毒(PRV),支原体(MHP)、副猪嗜血杆菌(MHP)等。2014年9月至2016年8月,对我国猪场主-呼吸道病原进行流行性病学调查,结果显示,每年10月至次年2月是猪群呼吸道疾病高发时期,PRRSV、PCV-2的检出率超过70%,主要的病毒性病原在现有免疫压力下表现出明显的基因变异;本研究提出了我国猪场科学实施防控呼吸道疾病的检测手段及防控方案,为我国猪呼吸道疾病的防治提供了依据。  相似文献   

6.
猪呼吸道综合征是以生长速度降低、饲料利用率降低、食欲减退、咳嗽、呼吸困难为特征的疾病。目前猪呼吸道疾病综合征主要特点:一是表现为混合感染的病原体较多,主要以猪肺炎支原体、传染胸膜肺炎放线杆菌、猪繁殖呼吸综合症病毒、猪Ⅱ型圆环病毒等单独感染或混合感染为主;二是发病时间表现为断奶后各个阶段的猪均可发病,即从断奶后2周开始,一直到育肥期都可以发生呼吸道综合征。断奶2周后的仔猪发生呼吸道综合征,致死率通常为20%30%,不死者生长极其缓慢,给养猪业造成了严重经济损失。  相似文献   

7.
《中国猪业》2013,(6):76-76
呼吸道疾病是影响猪群健康的重要疾病。猪呼吸道疾病综合征(PRDC)是由多种病原引起的一种肺炎,以体重下降和死亡为主要特征。引起该病的多种病原(包括细菌和病毒)共同作用引发猪呼吸道疾病。  相似文献   

8.
为了解齐齐哈尔地区引起规模化猪场猪呼吸道疾病综合征病毒性病原的感染状况,笔者应用PCR或RT-PCR方法对2015年-2017年齐齐哈尔地区规模化猪场147份病料进行了猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪伪狂犬病毒(PRV)和猪圆环病毒2型(PCV2)4种主要病毒性病原检测。结果显示,CSFV阳性率为4.72%,PRRSV阳性率为5.44%,PRV阳性率为1.36%,PCV2阳性率为9.52%。PRRSV和PCV2的混合感染呈上升趋势,CSFV和PRV趋于稳定。研究结果表明,控制猪呼吸道疾病综合征的关键是控制好PRRSV和PCV2的传播,根本是开展主要病原的净化工作。  相似文献   

9.
猪2型圆环病毒(PCV2)是引起断奶仔猪多系统衰竭综合征(PMWS)的主要病原,此外,PCV2还可能与猪皮炎肾病综合征、猪呼吸系统综合征、仔猪先天性震颤等疾病有关.PMWS临床症状主要表现为进行性消瘦,生长发育受阻,皮肤苍白或有黄疸,体表淋巴结肿大,腹泻,贫血和呼吸道症状等.  相似文献   

10.
猪呼吸道疾病多病原继发、诱发、交叉或混合感染的疾病为猪呼吸道疾病综合征(PRDC)。PRDC是1种或多种病毒、细菌、寄生虫辅以环境、营养等应激因素和猪只本身的机体抵抗力、对疾病侵袭的免疫力下降等相互作用平衡紊乱而引起混合感染。临床上常见引起的猪呼吸道疾病的病原体分为原发性病原感染和继发性病原感染2大类。原发性病原感染包括猪霉形体肺炎、猪圆环病毒2型、猪伪狂犬病病  相似文献   

11.
Polymicrobial respiratory disease in pigs   总被引:2,自引:0,他引:2  
Respiratory disease in pigs is common in modern pork production worldwide and is often referred to as porcine respiratory disease complex (PRDC). PRDC is polymicrobial in nature, and results from infection with various combinations of primary and secondary respiratory pathogens. As a true multifactorial disease, environmental conditions, population size, management strategies and pig-specific factors such as age and genetics also play critical roles in the outcome of PRDC. While non-infectious factors are important in the initiation and outcome of cases of PRDC, the focus of this review is on infectious factors only. There are a variety of viral and bacterial pathogens commonly associated with PRDC including porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (MHYO) and Pasteurella multocida (PMULT). The pathogenesis of viral respiratory disease is typically associated with destruction of the mucocilliary apparatus and with interference and decrease of the function of pulmonary alveolar and intravascular macrophages. Bacterial pathogens often contribute to PRDC by activation of inflammation via enhanced cytokine responses. With recent advancements in pathogen detection methods, the importance of polymicrobial disease has become more evident, and identification of interactions of pathogens and their mechanisms of disease potentiation has become a topic of great interest. For example, combined infection of pigs with typically low pathogenic organisms like PCV2 and MHYO results in severe respiratory disease. Although the body of knowledge has advanced substantially in the last 15 years, much more needs to be learned about the pathogenesis and best practices for control of swine respiratory disease outbreaks caused by concurrent infection of two or more pathogens. This review discusses the latest findings on polymicrobial respiratory disease in pigs.  相似文献   

12.
Association of porcine circovirus 2 with porcine respiratory disease complex   总被引:31,自引:0,他引:31  
A retrospective study was performed on natural cases of porcine respiratory disease complex (PRDC) to determine the association and prevalence of PRDC with porcine circovirus 2 (PCV2) and other co-existing pathogens in Korea. Histologically, alveolar septa were markedly thickened by infiltrates of mononuclear cells. Moderate to marked multifocal peribronchial and peribronchiolar fibrosis were present and often extended into the airway lamina propria. Among the 105 pigs with PRDC, 85 were positive for PCV2, 66 were positive for porcine reproductive and respiratory syndrome virus (PRRSV), 60 were positive for porcine parvovirus (PPV), and 14 were positive for swine influenza virus (SIV). There were 80 co-infections and 25 single infections. A co-infection of PCV2 with another additional bacterial pathogen is frequently diagnosed in PRDC. The combination of PCV2 and Pasteurella multocida (38 cases) was most prevalent followed by PCV2 and Mycoplasma hyopneumoniae (33 cases). The consistent presence of PCV2, but lower prevalence of other viral and bacterial pathogens in all pigs examined with PRDC, has led us to speculate that PCV2 plays an important role in PRDC.  相似文献   

13.
The concentrations of haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA) were measured in wasted pigs, first to evaluate their usefulness in the diagnosis of infectious, wasting diseases in pigs, and second, to evaluate whether their concentrations can distinguish the lymphoid depletion score in the lymph tissues of wasted affected pigs. Fifty-three wasted pigs and seven specific pathogen free (SPF) pigs were postmortem examined. Gross lesions were evaluated and samples for histopathological, immunohistochemical, molecular biology and microbiological analysis were taken. Thirty-one pigs were diagnosed as postweaning multisystemic wasting syndrome (PMWS) and 22 as porcine respiratory disease complex (PRDC). Lymphoid depletion degree in lymph tissues of PMWS and PRDC affected pigs was determined. Serum Hp was significantly higher in pigs with PRDC in comparison with the PMWS affected pigs. Serum CRP concentration was significantly lower in pigs with PRDC than in PMWS affected pigs (P<0.001). CRP and SAA levels increased with the lymphoid depletion score, presenting statistical differences between pigs with no depletion and pigs with low, moderate or severe lymphoid depletion (P<0.05, P<0.05 and P<0.001 for CRP and P<0.01, P<0.01 and P<0.01 for SAA, respectively). Hp was higher in pigs with no or low depletion compared with the pigs suffering severe lymphoid depletion (P<0.001 and P<0.05, respectively).  相似文献   

14.
Immunology of the porcine respiratory disease complex.   总被引:1,自引:0,他引:1  
PRDC is a multifactorial respiratory syndrome that includes several respiratory pathogens. As can be observed in this article, although the pathogenesis of some of the respiratory pathogens of pigs is fairly well defined, the host response and the immune response necessary to control the pathogen often remain unclear. As our ability to evaluate the porcine immune system and its ability to respond to disease improves, the knowledge of how each of these respiratory pathogens alter and evade the immune system will increase. The pathogens most commonly isolated from pigs with clinical signs of PRDC either infect the cells of the immune system or induce significant immunopathology. Thus, PRRSV and M. hyopneumoniae, the two most common pathogens associated with PRDC, alter the ability of the respiratory immune system to respond to their presence and the presence of other pathogens. By changing the respiratory immune system, these two common pathogens increase the susceptibility to the many other pathogens associated with PRDC. As we learn more about the pathogens of the respiratory system, their interactions with each other, and the mechanisms by which they modulate the immune system, our ability to develop effective control measures will improve.  相似文献   

15.
The role of swine torque teno sus viruses (TTSuVs) as co-factors in disease syndromes involving porcine circovirus strain 2 (PCV2) and porcine reproductive and respiratory disease syndrome virus (PRRSV) has been a debatable subject. In this study, the prevalence of TTSuVs in Iowa, the leading pork producing state in the U.S., was estimated by a duplex PCR. The PCR is capable of simultaneously detecting both teno sus viruses 1 and 2 (TTSuV1 and 2). Based on an analysis of 300 random samples representing six major geographical regions of the state, the overall prevalence rates for TTSuV1 and 2 were 47.34% and 24.67% respectively while the combined prevalence rate was 52.33%. The epidemiological association of TTSuV1 and 2 with the common etiological agents of the porcine respiratory disease complex (PRDC) namely porcine PRRSV, PCV2, Mycoplasma hyopneumoniae and swine influenza virus (SIV) was estimated in lung tissue derived from 45 pigs showing clinical signs of PRDC. Notably, 86.67% of the PRDC-suspect samples were positive for TTSuV1 in comparison to the baseline population prevalence rate of 47.34%. However, the prevalence of TTSuV2 (26.67%) was not significantly different. TTSuV1 was detected in 80.00%, 81.81%, 75.00% and 77.78% of the PRRSV, SIV, M. hyopneumoniae and PCV2 positive PRDC-suspect samples respectively. Our results indicate that TTSuV1 is strongly associated with clinical PRDC and support the hypothesis that TTSuVs might function as co-factors in PRDC. Further studies to define their possible role in the pathogenesis of swine respiratory diseases are warranted.  相似文献   

16.
17.
The porcine respiratory disease complex (PRDC) is an increasingly important cause of decreased swine productivity and is characterized by slow growth, decreased feed efficiency, anorexia, cough, and dyspnea. Mycoplasma hyopneumoniae is among the most prevalent and important infectious agents associated with PRDC. Understanding of mycoplasmal pneumonia has been hindered by inadequate diagnostic methods. Many of the currently available tests are relatively insensitive or nonspecific when used in a diagnostic laboratory setting or are too costly or difficult for routine diagnostic use. Several polymerase chain reaction (PCR) assays have been described, but they are not sensitive enough to detect the microorganisms in live pigs, from either nasal or tracheal swabs. A nested PCR using 2 species-specific sets of primers from the 16S ribosomal DNA gave positive results with as little as 80 microorganisms and did not cross-react with other mycoplasma species or with other microorganisms commonly found in the respiratory tract of pigs. This assay was better suited for detection of M. hyopneumoniae from nasal swabs than was conventional PCR. Nasal swab samples were taken at different time periods following experimental challenge of 10 susceptible pigs. Only 2 of the 55 swabs examined gave a positive result with conventional PCR, whereas 30 of the 55 swabs gave a positive result using the nested PCR. Twenty of 40 (50%) nasal swabs from pigs experiencing a respiratory disease outbreak where M. hyopneumoniae had been diagnosed also gave a positive result with the nested PCR. To confirm that the amplified product was specific, 4 nested PCR products were purified, sequences were determined and aligned, and they were confirmed to be from M. hyopneumoniae.  相似文献   

18.
副猪嗜血杆菌的分离鉴定   总被引:1,自引:0,他引:1  
副猪嗜血杆菌(Hps)为猪呼吸道疾病综合征(PRDC)的重要病原之一。在对广西65个猪场281份病猪组织样品进行PRDC病原学调查的基础上,对PCR检测的Hps阳性样品进行了细菌分离,并进行了生化特性、药敏试验、16 S RNA基因片段序列分析和基因组DNA的PCR指纹图谱分析。结果显示,11份(3.91%)检测样品为Hps阳性,且均为混合感染;从南宁市四塘、桂林市永福、玉林市容县和钦州市浦北分离出5株Hps,分离菌株的生化鉴定结果均符合Hps生化特性,且对头孢噻呋和头孢菌素高度敏感;其中3株为血清5型,1株为血清12型,另1株未能定型;分离菌株16 S RNA基因片段之间及与GenBank其他一些代表菌株的核苷酸同源性在99%以上。  相似文献   

19.
The study observed the variety of cyclic AMP phosphodiesterase (cAMP-PDE) activity in polymorphonuclear neutrophils (PMN) and contents of cAMP,IL-6,TNF-α in plasma of porcine respiratory disease complex (PRDC),the therapeutic effect and influence of self-made Chinese herbal decoction,for accumulating information of respiratory inflammation pathological mechanism and its prevention.Divided pigs with PRDC into disease group and treatment group, and normal ones as control group. Drenched treatment group with 1 g crude drug/mL Chinese herbal decoction, which was composed of reed rhizome,mongolian milkvetch root,white peony root and liquorice root,twice a day and 1.5 mL/kg body weight for ten days. Observed changes of the number of white blood cell in peripheral blood,neutrophils were isolated from whole blood,HPLC was used to test its cAMP-PDE activity and ELISA kit was used to test the contents of IL-6,TNF-α in plasma.Compared with control group,the number of white blood cell in disease group increased significantly (P<0.05),cAMP-PDE activity and contents of TNF-α,IL-6 increased extremely significantly (P<0.01);but TNF-α in treatment group increased significantly (P<0.05). Compared with the disease group,the number of white blood cell,cAMP-PDE activity and content of TNF-α in treatment group decreased significantly (P<0.05), content of IL-6 decreased extremely significantly (P<0.01).The results showed that abnormal inflammatory reaction existed in PRDC,cAMP-PDE activity,the contents of IL-6 and TNF-α,the number of white blood cell increased significantly.Self-made Chinese herbal decoction could improve the clinical symptoms of the disease,of which the function mechanism was related to the reduction of the white blood cell number,inhibition of cAMP-PDE activity,and reduction of contents of IL-6 and TNF-α in plasma.  相似文献   

20.
猪呼吸道疾病综合征(PRDC)在养猪业中广泛流行,发病原因复杂,由多种细菌、病毒、寄生虫及环境应激等因素共同引发,普遍造成猪生长迟缓和猪肉品质下降,还有相当比例的病猪死亡,严重影响养猪业的发展。胸膜肺炎放线杆菌(APP)、副猪嗜血杆菌(Hps)、链球菌(SS)是常见的细菌性病原,而猪繁殖与呼吸障碍综合征病毒(PRRSV)、猪圆环病毒2型(PCV2)、伪狂犬病毒(PRV)是常见的病毒性病原,合理用药防治PRDC十分关键。头孢喹肟、氟苯尼考及加米霉素等抗生素因抗菌谱广、抗菌活性强、在猪体内药代动力学特征优良等优点被广泛用于防控细菌性感染的猪呼吸道疾病。对于病毒性感染的猪呼吸道疾病,常用的抗病毒药物有细胞因子及中药,尤其是中药,不仅可以抗病毒还可增强机体免疫力,应用前景非常广阔。文章系统地阐述了上述抗菌药物的抗菌机理、药效学及药动学,详细介绍了上述抗病毒药物的抗病毒机理及其在病毒性猪呼吸道疾病上的应用,以期为合理用药防控PRDC提供一定的建议。  相似文献   

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