Mycoplasma hyosynoviae isolation from the upper respiratory tract and tonsils of pigs.

The occurrence of Mycoplasma hyosynoviae at different locations of the upper respiratory tract and tonsils of pigs was investigated in herds with problems of arthritis apparently caused by this microorganism. The isolation of M. hyosynoviae was facilitated by the use of a medium selectively suppressing the growth of Mycoplasma hyorhinis. M. hyosynoviae was cultured from 106 of 178 tonsils of slaughterhouse pigs from 8 herds but could not be isolated from the mucosa of the nasal cavity or the oral-pharyngeal area of 100 living, 10-20 weeks old pigs in 5 of the herds. The value of the selective principles in the medium appears from the circumstance that 86 of the 106 isolates were obtained despite the presence of M. hyorhinis. It is concluded that the tonsil is a reservoir for M. hyosynoviae and is probably the location of choice for an easy demonstration of the presence of this mycoplasma in a pig herd.     

Mycoplasma suipneumoniae and mycoplasma flocculare in the growth precipitation test.

A number of laboratory and field strains of Mycoplasma suipneumoniae and Mycoplasma flocculare were subjected to a comparative examination by the growth precipitation test. It was found that all the strains could readily be identified by that test. Slight evidence of cross-reaction was noted for a few of the laboratory strains, but not until late in the observation period. Only some of the field strains would form precipitates when primary cultures (from tissue suspensions) were used, but all strains could be identified already in the second and third passages. The test therefore seems well suited for distinguishing the two species from each other.     

Mycoplasma Hyorhinis in the Etiology of Serositis among Piglets

In a study on the involvement of Mycoplasma hyorhinis in serositis of piglets, 26 routine diagnostic animals, 3-7 weeks old, with distinct serofibrinous lesions in the pericardial, pleural and peritoneal cavities were examined. M. hyorhinis was isolated in 9 cases, non-haemolytic Escherichia coli in another 9 cases and in 4 cases both species were found. Neither of the microorganisms were found in the remaining 4 cases.The presence of M. hyorhinis in the serous cavities in the absence of non-haemolytic E. coli was always accompanied by a diagnosis of other disease conditions, mainly of the respiratory tract. In the cases infected with non-haemolytic E. coli complicating problems were absent.The pathogenicity of M. hyorhinis was further studied by inoculation of 2 young pigs in which the typical serofibrinous lesions of the serous cavities were produced. It therefore appears that M. hyorhinis can be regarded as a cause of polyserositis in piglets; under field conditions, however, the synergistic presence of other debilitating syndromes appears necessary for its haematogenous spread from the respiratory tract to the serous cavities.     

Evaluation of Some Serological Techniques for The Identification of Mycoplasma Hyorhinis and Mycoplasma Suipneumoniae

Eighteen strains of Mycoplasma hyorhinis and a strain of Mycoplasma suipneumoniae were tested in 4 serological tests, i. e., disc growth inhibition, metabolic inhibition, indirect haemagglutination and indirect epi-immunofluorescence. Only with immunofluorescence could all tested strains of M. hyorhinis be shown; no cross-reactions between M. hyorhinis and M. suipneumoniae could be detected. The other tests failed in many cases to identify strains of the same species, and they gave cross-reactions between M. hyorhinis and M. suipneumoniae.     

猪肺疫与猪附红细胞病继发感染治疗

猪肺疫又被称为猪巴氏杆菌病,是由致病性巴氏杆菌感染引发的一种急性呼吸道疾病,具有很高发病率和致死率。该种传染性疾病可以危害不同年龄、不同性别、不同品种的猪,一年四季均可发生,但以每年早春和晚秋季节发病率最高。猪附红细胞体病又被称为附红体、血虫病或红皮病,是由血液原虫所引发的一种以贫血、黄疸、发热为主要症状的体内寄生虫病。猪肺疫和猪附红细胞体病混合感染给疾病诊断工作带来很大难度。该文主要结合一个养殖场的实际发病经过,分析猪肺疫与猪附红细胞体病继发感染的治疗过程。     

The Occurrence of Mycoplasmas in the Lungs of Swine in Gran Canaria (Spain)

The study was conducted to investigate the mycoplasmal flora in the lungs of pigs with enzootic pneumonia at Gran Canaria (Spain). From 54 pneumonic lungs collected at an abattoir, 85 isolates were cultivated. On the basis of cultural and biochemical characteristics, the isolates were preliminarily identified as Mycoplasma species. Using different species-specific PCRs, 40, 27, 11 and 7 of the isolates were identified as M. hyorhinis, M. hyopneumoniae, M. hyosynoviae and M. flocculare, respectively. Nine of the M. hyopneumoniae cultures were found to be in mixed culture with M. flocculare as demonstrated by PCR. By use of a M. flocculare antiserum it was possible to eliminate M. flocculare from M. hyopneumoniae mixed cultures. This study is the first report on isolation of porcine mycoplasmas at Gran Canaria (Spain).     

An abattoir survey of pneumonia and pleuritis in slaughter weight swine from 9 selected herds. II. Enzootic pneumonia of pigs: microbiological findings and their relationship to pathomorphology

Lungs from 191 slaughter pigs with gross lesions indicative of enzootic pneumonia of pigs (EPP) and 80 grossly normal lungs, all originating from 9 different herds, were subjected to microbiological and pathological examinations. The microbiological studies included both bacterial and mycoplasmal culture and also testing for Mycoplasma hyopneumoniae antigen in tissue by indirect immunofluorescent technique. M. hyopneumoniae, Pasteurella multocida and Mycoplasma hyorhinis were detected in 83%, 43% and 37% of the pneumonic lungs, respectively. Mycoplasma flocculare was the most frequently isolated organism in the non-pneumonic lungs. The greatest amounts of macroscopic pneumonia (25.2%) were recorded in lungs with all the three agents M. hyopneumoniae, P. multocida and M. hyorhinis present. The amounts of pneumonia in lungs with M. hyopneumoniae alone and in concurrence with P. multocida, were 9.3% and 15.6%, respectively. M. hyorhinis was also, in this study, associated with higher frequency of diffuse pleuritis. These findings indicate that M. hyorhinis might be involved in the pathogenesis of pneumonia in slaughter pigs. Ninety-six per cent of the isolates of P. multocida from pneumonic lungs could be characterized as type A. In the herds which had the most severe pneumonia problems, toxin production was detected in 83% of the P. multocida strains while only 28% were toxigenic in herds with subclinical to moderate pneumonia problems.     

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。     

混合感染背景下的猪气喘病控制

混合感染背景下的猪气喘病较难控制,介绍了猪气喘病的发病特点,常用药物的敏感度评价、疫苗效果评价和猪场猪气喘病的检查检测方法,结合作者实际经验强调了饲养管理要点,指出了种猪场净化猪气喘病的方法步骤,为混合感染下控制猪气喘病提供参考。     

滇南某猪群致死性呼吸道传染病的病原学诊断

近期红河州某规模化养猪场在引种后,发生以发热、腹泻、呼吸困难、濒死前鼻孔出血为特征的仔猪传染病,尝试用多种药物治疗均不能有效控制病情,死亡率很高。为调查该病病因,本试验对采集自病死猪只的肺脏、脾脏、肾脏和淋巴结,取病料组织划线于血琼脂平板培养,对形成的溶血性菌落采用高盐培养、革兰染色、生化试验做初步鉴定,同时使用细菌16S rRNA基因通用引物扩增该菌株DNA片段,琼脂糖凝胶电泳回收扩增产物,经TA克隆后测序分析;取病料组织研磨上清,应用PCR技术扩增病原核酸,以类似方法分析核酸序列。结果发现,该溶血性菌株为革兰染色阳性球菌,葡萄糖、蔗糖、木糖、山梨醇和6.5%Na Cl利用试验呈阳性,麦芽糖、棉籽糖、蕈糖、七叶苷、水杨苷、VP、PYR、硝酸盐和触酶试验均呈阴性,PCR扩增出1542 bp的特异性条带,其基因序列与脲气球菌同源性最高(94%);应用PCR技术从病料中分别直接扩增出猪繁殖与呼吸综合征病毒(PRRSV)421 bp和支原体267 bp的特异性条带,前者为高致病性PRRSV毒株特有核酸片段,后者与猪鼻支原体(MHR)SK76菌株的DNA同源性达99%。试验结果表明,该猪群发生以高致病性PRRSV感染为主、伴有猪鼻支原体和类脲气球菌混合感染的急性传染病,提示必须高度重视引种携带PRRSV的风险。     

湖南省屠宰场生猪肺线虫感染情况调查

为了解湖南省生猪肺线虫的感染情况和危害程度,控制该虫的流行,对3个屠宰场猪进行解剖,采用常规的寄生虫实验室检查法检查气管、支气管、细支气管、肺脏等处的虫体。所获虫体用75%酒精保存,统计感染强度,计算感染率。检测结果显示,3个屠宰场生猪肺线虫感染率A(5.93%)B(4.26%)C(4.18%)。结果表明,湖南省生猪有肺线虫感染,应引起注意。     

猪繁殖与呼吸综合征病毒变异株感染猪超微结构研究

利用透射电镜对山西省PRRSV变异株感染猪的肺脏、脾脏、肝脏、肾脏、淋巴结等组织进行超微病理变化的观察。试验结果发现,肺脏、脾脏、肝脏、肾脏、淋巴结各组织细胞均被不同程度地感染,各种细胞器遭受普遍的膜结构损伤,而以线粒体和细胞核变化较为严重。本研究为阐明PRRSV变异株感染猪的致病机理提供了理论依据。     

2015—2021年广西部分猪场5种疫病的血清学检测

为了解广西猪群中猪瘟、猪繁殖与呼吸综合征、口蹄疫、猪圆环病毒病和伪狂犬病5种疫病的免疫水平及伪狂犬病病毒(PRV)感染状况,对2015—2021年广西地区1012个猪场送检的24263份血清样品进行猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、口蹄疫病毒(FMDV)、猪圆环病毒2型(PCV2)以及PRV-...     

犬肾（DK）传代细胞中霉形体的分离与鉴定

取经电镜观察证实有霉形体污染的ＤＫ传代细胞，分别接种于霉形体检验用液体、半流体和固体培养基，证明为霉形体混合感染，即该培养物在液体培养基和半流体培养基上，同时显示出水解精氨酸和发酵葡萄糖２种特性，前者使培养基ｐＨ上升，后者使ｐＨ下降。通过反复挑选单个菌落进行克隆传代和有目的地加入单一种属的霉形体抗血清的方法，将混合的２株霉形体纯化分开。经鉴定，一株为精氨酸霉形体，一株为莱氏无（需）胆甾醇霉形体。     

2018年河南省郑州市定点监测猪群伪狂犬病gE抗体检测

为了解河南省郑州市2018年规模猪场的伪狂犬病野毒感染情况,利用gE抗体ELSIA方法,对免疫过猪伪狂犬病gE基因缺失疫苗的36个不同养殖规模的定点监测猪场,进行gE抗体检测。2018年1—12月,共检测血清样品1 057份,检出阳性场27个,场群阳性率为75.0%(27/36);检出阳性样品309份,样品阳性率为29.2%(309/1 057)。结果表明,郑州市伪狂犬病野毒感染面较广,流行率较高,存在较高的疫情暴发风险。存栏500头以下规模猪场的gE抗体阳性率(69.8%)是存栏3 000头以上的规模场(19.1%)的3.65倍,表明养殖规模越小,伪狂犬病野毒感染风险越大。利用荧光PCR方法对gE抗体阳性样品进行检测,检出阳性32份,阳性检出率为35.6%(32/90),表明感染猪群的持续带毒、排毒现象较为严重。建议规模化养猪场加强gE基因缺失疫苗免疫和gE抗体检测,及时淘汰阳性猪,同时结合隔离、消毒等综合防控技术,逐步实现猪伪狂犬病的控制与净化。     

PCR在动物支原体检测中的应用

PCR是近年来发展起来的一项分子生物学新技术 ,具有灵敏、特异、快速、简便和适用面广等优点 ,因而在分子生物学检测与研究中具有广阔的应用前景。目前 ,PCR被广泛应用于众多领域 ,其在支原体检测中的应用与发展已经取得了可喜的成绩。文章简要介绍 PCR在动物支原体检测中的应用 ,包括应用通用 PCR引物与特异性引物检测支原体 ,以及 PCR在禽类、牛和猪支原体检测中的应用现状。表明在实验室和临床中应用 PCR检测支原体是一种有效的方法。     

从全长cDNA克隆恢复猪瘟病毒方法的研究

以携带猪瘟病毒Thiverval株全长cDNA克隆的pAC/F101/T1-7载体质粒为模板,在体外转录病毒基因组RNA,并转染PK-15和BHK-21细胞,通过传代、RT-PCR、免疫过氧化物酶细胞单层试验鉴定,成功地在两种细胞中拯救出具有感染性的病毒粒子。同时,通过2种细胞转染效率的对比试验,成功建立了利用高转染效率的其它真核细胞作为病毒拯救的过渡细胞,然后再在猪肾细胞系上进行增殖的病毒拯救方式,极大提高了猪瘟病毒拯救的效率。     

Antimicrobial susceptibility and molecular characterization of macrolide resistance of Mycoplasma bovis isolates from multiple provinces in China

Mycoplasma bovis has spread widely throughout the world via animal movement and has becomean important pathogen of bovine respiratory disease. However, the minimum inhibitory concentrations ofantimicrobials for Mycoplasma bovis have not been studied in China. The objective of thisstudy was to determine the prevalence and antibiotic resistance of Mycoplasma bovis isolatedfrom young cattle with respiratory infection in China. Mycoplasma bovis was detected in 32/45bovine respiratory infection outbreaks at beef farms in 8 provinces in China. The isolates were susceptible orhad medium sensitivity to ciprofloxacin, enrofloxacin and doxycycline, but were frequently resistant tomacrolides (13/32, 41%). An A2058G (Escherichia coli Numbering) mutation located in therrnA operon in domain V of 23S rRNA was observed in strains that were resistant tomacrolides. This single mutations at the rrnA operon in domain V of 23S rRNA may play an important role in theresistance of Mycoplasma bovis strains to macrolides.     

猪肺炎支原体中国分离株热休克蛋白Hsp70(Dnak)的全基因克隆及C末端基因的表达与免疫活性分析

猪肺炎支原体（Mycoplasma hyopneumoniae,MHP）是猪气喘病的病原。DnaK又称为热休克蛋白Hsp70,具有分子伴侣和免疫的作用。以MHP中国分离株Yin-1为模板,扩增了DnaK基因的全序列,将该序列克隆到pMD18-T载体上并测序。测序结果Yin-1株DnaK基因即Hsp70基因全长1803bp,编码600aa,第631～633位TGA在支原体编码色氨酸而不是作为终止密码子。将该序列与多种致病支原体DnaK基因进行分析比较,发现Yin-1株与232株、J株、7448株等MHP菌株的DNA同源性为99.3％～99．4％,氨基酸同源性为99．2％～99.3％,而与非同种支原体的DNA和氨基酸同源性仅为64．5％～74．4％和59.3％～77％。这表明DnaK基因在种内高度保守,种间差异较大。以pET28a为载体构建重组质粒,原核表达DnaKC末端大小为1kb左右的基因,对表达的蛋白进行纯化后,通过Westernblot检测它的免疫活性。原核表达得到大小为41ku的目的蛋白．经Westernblot证实．纯化蛋白可与MHP阳性猪血清反应,具有免疫活性。     

巢式PCR在动物疫苗支原体污染检测中的应用

在动物疫苗研制过程中,应用巢式PCR方法,设计两套引物,扩增支原体16S与23SrRNA基因间隔区序列,可以检测造成细胞污染的常见支原体种类。本试验应用该方法检测三批样品和阴性对照均无特异性目标条带,即三批疫苗样品支原体检测均为阴性。阳性对照样品在200-400bp之间出现特异性目标条带,实验表明所建立的巢式PCIL方法是一种快捷、灵敏、准确的检测方法,可以用于检测动物疫苗细胞培养物中支原体污染。