奶牛布鲁氏菌病的病原分离与鉴定

为给奶牛布鲁氏菌病实验室诊断提供技术参考,对疑似布鲁氏菌病病例进行了病原分离培养,并采用平板直接凝集试验、革兰氏染色镜检、柯兹洛夫鉴别染色镜检和PCR方法对分离菌株进行了鉴定.结果表明：分离的4株细菌均为布鲁氏菌属细菌.     

牛乳样品中布鲁氏菌的分离和鉴定

为进一步改良布鲁氏菌(Brucella)的分离和鉴定方法,本研究于2010年～2012年对新疆部分奶牛场进行Brucella病的监测,采用改良Brucella选择添加剂培养分离的方法,从试管凝集试验(SAT)检测阳性的25头奶牛的牛乳样中分离到9株分离菌,经VirB8-PCR方法扩增Brucella的VirB8基因对分离株进行鉴定,结果表明9个分离株均为Brucella。同时采用Brucella分子分型PCR及生物学分型方法进一步対分离株鉴定,结果显示其中7个分离株为牛3型,另外2个分离株为羊3型。本研究为奶牛Brucella病的检疫与防控提供了快速分离及鉴定方法。     

PCR检测奶牛布鲁氏菌病病原的方法探讨

为有效弥补血清学检测奶牛布鲁氏菌病的不足,根据牛种布鲁氏菌的核苷酸序列设计PCR引物,通过优化PCB扩增条件,建立PCR快速检测奶牛布鲁氏菌病病原的方法。     

奶牛布鲁氏菌的监测与分离鉴定

本试验采用SAT方法对乌鲁木齐地区某牛场进行了布鲁氏菌病监测,对阳性奶牛的乳汁进行细菌分离培养,用VirB8-PcR方法对分离株VirB8基因进行扩增鉴定。结果表明,2个分离株均为布鲁氏菌,布鲁氏菌分子分型PCR的鉴定结果显示该牛场感染的自然菌株为布鲁氏菌牛种（3b,5,6,9型）。     

不同的病原菌检测方法比较评价可疑布鲁氏菌

目的:寻找布鲁氏菌病病原学检测工作的一种便利、快速、特异及敏感性较高的快速诊断方法。方法:收集247份病料,并经细菌学方法分离方法得到26株可疑家畜布鲁氏菌株,接着用分子生物学Vir B8-PCR和AMOS-PCR方法对这批可疑菌株进行确诊鉴定,并对不同对比试验方法结果及应用价值进行了评价。结果:细菌学分离方法与Vir B-PCR及AMOS-PCR方法结果一致。AMO S-PCR方法结果同时还显示26株可疑家畜布鲁氏菌株包括19株菌为羊种布鲁氏菌和7株菌为牛种布鲁氏菌。结论:细菌学分离方法所需时间较长、繁琐有感染风险,且不能确定被检可疑布鲁氏菌的属性;Vir B-PCR方法虽然快速、敏感、比较安全等,但是只能确定布鲁氏菌,而不能鉴别菌株属性;AMOS-PCR方法快捷、经济、安全、便利、特异,敏感,且能鉴别菌株属性。     

四川部分地区犬布鲁氏菌病血清学调查以及典型病例的诊断

为了解四川地区犬是否存在布鲁氏菌病,采用虎红平板凝集试验(RBPT)、试管凝集试验(SAT)及外膜蛋白BCSP3基因的PCR(BCSP31-PCR)对110只门诊以及流浪犬进行了布鲁菌病的血清学及分子学调查。结果表明:110只犬中12只RBPT检测为阳性,表示疑似布鲁菌感染,而进一步采用SAT以及BCSP31-PCR诊断只有1只为阳性,其余11只犬均为阴性。说明四川地区犬布病感染不严重,临床中RBPT存在假阳性,诊断时应结合临床症状、分子生物学技术等进行鉴别诊断。     

甘肃省永靖县奶牛布鲁氏菌病监测与病原分离鉴定

为查明甘肃省永靖县奶牛布鲁氏菌病流行情况、感染菌种和类型,2013—2017年对永靖县8月龄以上奶牛进行了布鲁氏菌病监测,对2016年检出的3份疑似感染布鲁氏菌奶牛的脾脏进行了病原分离与鉴定。结果显示:2013—2014年检测奶牛444头,未检出阳性;2015—2016年检测奶牛706头,检出阳性63头,个体阳性率为8.92%;3份脾脏样本均为布鲁氏菌PCR检测阳性,细菌分离培养15 d,只有1份生长菌落;将分离菌株用AMOS-PCR进行检测,获得流产布鲁氏菌特征的扩增条带,且分离菌株的omp25基因测序结果与流产布鲁氏菌高度吻合。本监测和细菌分离鉴定结果为该地布鲁氏菌病防控提供了技术支撑。     

我国奶牛布鲁氏菌病防控的现状与防控措施

布鲁氏菌病是一种人畜共患传染病,世界动物卫生组织将其列为B类动物疫病.病牛可通过其产品和代谢产物排出病原菌,感染人和其他动物,引起其他动物发病.国家对奶牛布鲁氏菌病的防控投入了大量的人力、物力,但收效甚微.近年来,不断有人感染布病的报道出现.笔者根据多年的工作体会,对当前我国奶牛布鲁氏菌病的防控做了现状分析,并提出一些对策供大家参考.     

奶牛布鲁氏菌病的病原分离与鉴定

本试验对疑似布鲁氏菌病的样本进行了病原分离,采用血清学试验、染色镜检、PCR和基因克隆测序对分离菌株进行了鉴定。结果表明,4株分离菌株均为布鲁氏菌属细菌,与布鲁氏菌参考菌株的核苷酸同源性为99.52%~100%。采用AMOS PCR对4株分离菌株进行种特异性鉴定,结果显示,1株为猪种布鲁氏菌,3株为牛种布鲁氏菌。     

布鲁氏菌病VirB8-PCR诊断试剂盒的特异性评价

使用VirB8-PCR诊断试剂盒对布鲁氏菌标准株、疫苗株及新疆分离株共7株布鲁氏菌的VirB8基因序列扩增、克隆并与Genbank中发表的VirB8基因序列(AF226278)进行比较和分析,发现:该基因非常保守,7株布鲁氏菌的同源性在99.2%以上,其中A菌与Rev1基因序列100%同源,B菌与Genbank发表的基因序列100%同源;牛种(544A、A19)和羊种(M5、Rev1)分别各自在相同部位发生了相同的碱基突变,因此VirB8基因有可能做为布鲁氏菌疫苗菌的鉴定分类基因。VirB8基因在布鲁氏菌中高度保守,可作为布鲁氏菌检测模板,VirB8-PCR诊断试剂盒特异、敏感,检测结果可靠。     

Comparison of polymerase chain reaction and bacteriological culture for the diagnosis of sheep brucellosis using aborted fetus samples

PCR assay has been shown to be a promising option for the diagnosis of brucellosis. However, few studies have been performed with field samples in order to evaluate the assay as a diagnostic tool. In this study, routine use of a species-specific PCR assay previously developed for the identification of Brucella cultures was assessed for the detection of Brucella DNA directly from the stomach contents of aborted sheep fetuses. The assay is based on the insertion sequence IS711 in the Brucella chromosome. In the study, during 3 successive lambing seasons (1998-1999, 1999-2000 and 2000-2001) 126 aborted fetus samples each from different flocks and locations were examined. Brucella strains were isolated from 39 (31%) of the samples and all of the strains were identified as Brucella melitensis by biochemical characteristics, agglutination with monospecific A and M sera and PCR. Thirty-seven of 39 B. melitensis isolates were biotyped as biotype 3, and 2 isolates as biotype 1. From 38 of 39 culture positive fetal stomach contents B. melitensis-specific DNA was detected by PCR. PCR was found negative in all of the culture negative samples. Compared with culture, sensitivity and specificity of PCR were determined as 97.4 and 100%, respectively. The results indicate that this PCR procedure has a potential for use in routine diagnosis of sheep brucellosis.     

布鲁菌Cycling探针荧光定量PCR检测方法的建立

根据布鲁菌BCSP31基因序列设计布鲁菌通用检测引物和探针,建立了布鲁菌Cycling探针荧光定量PCR检测方法。以构建的含BCSP31基因的质粒标准品10倍递进稀释为模板检测其敏感性,结果显示,本方法能检测约10个拷贝的阳性质粒,且标准曲线的线性关系良好。用本方法检测5株不同种的布鲁菌以及猪大肠杆菌K99、巴氏杆菌C48-1、猪链球菌ST171、绿脓杆菌等4株对照菌。结果显示,5株不同种的布鲁菌均出现典型的"S"型扩增曲线,4株对照菌40个循环内均无CT值出现。用本方法和B4/B5-PCR方法对来自布鲁菌病流行地区3个不同牛场的40份血样、奶样和血清样进行平行检测。结果显示,本方法和B4/B5-PCR方法的结果符合率为80.0%。B4/B5-PCR检测为阳性的27份样品经本方法检测均为阳性;B4/B5-PCR检测为阴性的13份样本,经本方法检测,其中8份呈阳性,5份为阴性。本方法的敏感性明显高于B4/B5-PCR方法。试验表明,所建立的Cycling探针荧光定量PCR方法具有敏感、特异、稳定等特点,可用于布鲁菌感染的快速检测。     

Evaluation of a PCR test for the diagnosis of Brucella ovis infection in semen samples from rams

The sensitivity and specificity of a PCR assay with primers derived from the insertion sequence IS6501 was compared with that of bacteriological culture and serological tests for the diagnosis of Brucella ovis infection in rams. No amplifications were detected with DNAs from the strains phylogenetically related to Brucella and from the seven bacterial species considered as the main etiologic agents of epididymitis in rams. In addition, the specificity of the PCR was 100% when testing semen samples from Brucella-free rams. The comparison of the semen culture and PCR results from 192 semen samples tested, showed a proportion of agreement of 0.91 between both tests. The PCR-based test described has sensitivity similar to that of semen culture and could be used as a complementary test for the direct diagnosis of Brucella ovis in semen samples of rams.     

牛、羊布鲁菌多重PCR方法的建立与应用

根据布鲁菌属特异性基因BCSP31和布鲁菌种间特异性标志IS711插入序列,设计合成了3对引物,以牛种布鲁菌544A、104M和羊种布鲁菌16M基因组DNA为模板,通过优化反应条件,建立了可同时检测布鲁菌属、牛种布鲁菌和羊种布鲁菌的多重PCR方法。牛种布鲁菌可扩增出301和114 bp 2条带,羊种布鲁菌可扩增出301和253 bp 2条带,该方法对牛种布鲁菌544A和羊种布鲁菌16M混合DNA模板的最小检出量为100 pg,对大肠杆菌O157∶H7、小肠结肠炎耶尔森菌等15种参照菌的核酸扩增结果均为阴性。应用该方法对吉林省某牛场的106份粪便进行检测,虎红平板凝集试验作对照,结果PCR检测9份为阳性,且全为牛种布鲁菌阳性,对应的虎红平板凝集试验也为阳性。结果表明,建立的多重PCR方法具有良好的敏感性和特异性,为布鲁菌病的鉴别诊断提供了一种分子检测工具。     

Epidemiological survey for Brucella in wildlife and stray dogs, a cat and rodents captured on farms

Brucella infections in wildlife originate either from contact with infected livestock or from a natural sustainable reservoir in wildlife populations. As South Korea has set a goal of brucellosis eradication by 2013, it is necessary to determine the prevalence of Brucella in wildlife and wild rodents. This information will play an important role in the control of brucellosis. Because of the absence of prominent clinical signs, direct and indirect laboratory tests are essential for diagnosing brucellosis. In this study, tissue and blood samples were taken from wild animals, abandoned dogs, a cat and wild rodents, and they were tested for Brucella or Brucella-specific antibodies by isolation, PCR and serology. Results showed that 18.6% (33/177) of blood samples were positive by PCR, and 5.7% (11/194) were positive by C-ELISA. However, none of these samples yielded culturable bacteria. Of the tissue samples, 9.7% (8/82) were positive by PCR. Brucella was isolated from only one tissue culture from a Chinese water deer carcass. This Brucella species was identified as Brucella abortus biovar 1 by biotyping, 16S rRNA PCR and the Bruce-ladder PCR assay. In this study, we reported the prevalence of Brucella in wildlife, dogs, a cat and rodents by using serological and molecular methods, and we report the first isolation of B. abortus in wild Chinese water deer in South Korea.     

Brucella abortus detection by PCR assay in blood, milk and lymph tissue of serologically positive cows

Brucellosis is a highly infectious disease which is diagnosed using serological and microbiological methods. The objective of this study was to assess the viability of using conventional and real-time PCR assays as potential diagnostic tools for the detection of Brucella abortus in naturally infected cows. PCR assays that amplify various regions of the Brucella genome, IS711 genetic element, 31kDa outer membrane protein and 16S rRNA, were optimised using nine known Brucella strains. Real-time PCR was used to examine the detection efficiency of the IS711 assay which was estimated at 10 gene copies. Milk, blood and lymph tissue samples were collected from naturally infected animals. B. abortus was not detected in blood samples collected from naturally infected cows by conventional or real-time PCR, but was detected in a proportion of the culture-positive milk (44%) and lymph tissue (66% - retropharyngeal, 75% - supramammary) samples by the same methods. There was no difference between PCR and bacteriological detection methods. It is unlikely that conventional or real-time PCR will supersede current diagnostic methods for detection of B. abortus in clinical samples.     

Use of mgc2-polymerase chain reaction-restriction fragment length polymorphism for rapid differentiation between field isolates and vaccine strains of Mycoplasma gallisepticum in Israel

Increasing use of Mycoplasma gallisepticum (MG) live vaccines has led to a need for a rapid test for differentiation of MG field strains from the live vaccine strains ts-11 and 6/85. We examined the differentiating potential of diagnostic polymerase chain reaction (PCR) primers targeted to the gene mgc2, encoding a cytadherence-related surface protein uniquely present in MG. The mgc2-PCR diagnostic primers are specific for MG in tests of all avian mycoplasmas or bacteria present in the chicken trachea and are sensitive enough to readily detect MG in tracheal swabs from field outbreaks. Differentiation of vaccine strain ts-11 was based on identification of restriction enzyme sites in the 300-base-pair (bp) mgc2-PCR amplicon present in ts-11 and missing in MG isolates from field outbreaks in Israel. Restriction sites for the enzymes HaeII and SfaN1 were identified in the amplified region in strain ts-11 and were not found in 28 field isolates of MG, comprising a representative cross section of all the MG isolates from the period 1997-2003. In practice, differential diagnosis of MG is achieved within 1 day of submission of tracheal swab samples by mgc2-PCR amplification and restriction of the amplicon with HaeII, giving a 270-bp fragment for ts-11 or no restriction for other MG strains tested. Application of the mgc2-PCR-restriction fragment length polymorphism (mgc2-PCR-RFLP) assay enabled differential diagnosis of both components of a mixture of ts-11 and non-ts-11 DNA, detecting the field strain in the presence of a large excess of ts-11. The test was successfully applied in vivo for monitoring vaccinates in a ts-11 vaccine trial. In principle, the test may also be used to identify the 6/85 vaccine strain, which yields a 237-bp product, readily differentiated from the approximately 300-bp PCR product of all other strains tested. Further testing of field isolates will be necessary to determine the applicability of this test in the United States and other countries.     

布鲁氏菌环介导等温扩增（LAMP）可视化检测方法的建立

应用环介导等温扩增(LAMP)技术建立了布鲁氏菌可视化快速检测方法。针对布鲁氏菌外膜蛋白OMP25基因保守区设计6条特异引物,反应前加入染料羟基萘芬蓝(HNB)作为LAMP扩增的指示剂,63℃恒温反应60min,根据HNB的颜色变化进行结果判定。分别评价所建立LAMP方法的特异性和灵敏性,并对60份牛布鲁氏菌病虎红平板凝集试验(RBT)阳性血清样本,经LAMP和B4/B5-PCR方法进行平行检测。结果显示,本方法最低检出限约为17fg布鲁氏菌基因组DNA。本方法特异性良好,布鲁氏菌反应管均出现特异性LAMP扩增反应,而猪大肠杆菌K99、巴氏杆菌C48-1、猪链球菌ST171、绿脓杆菌等对照组均未出现扩增。针对60份RBT阳性血清的平行检测结果显示,LAMP和B4/B5-PCR这两种方法间的结果符合率为85.0%。B4/B5-PCR检测为阳性的43份样品,经本方法检测全部为阳性;B4/B5-PCR检测为阴性的17份样品,经本方法检测,9份为阳性,8份为阴性。LAMP的敏感性高于B4/B5-PCR方法。实验表明,本文所建立的基于颜色判定的布鲁氏菌LAMP检测方法具有特异、灵敏、设备要求简单等特点,适用于基层兽医部门进行布鲁氏菌的快速检测。     

A potential novel Brucella species isolated from mandibular lymph nodes of red foxes in Austria

The wild red fox (Vulpes vulpes) is a known indicator species for natural foci of brucellosis. Here, we describe phenotypic and molecular characteristics of two atypical Brucella strains isolated from two foxes hunted 2008 in Eastern Austria. Both strains agglutinated with monospecific anti-Brucella A serum and were positive in ELISA with monoclonal antibodies directed against various Brucella lipopolysaccharide epitopes. However, negative nitrate reductase- and negative oxidase-reaction were atypical traits. Affiliation to the genus Brucella was confirmed by 16S rRNA gene sequencing and by detection of the Brucella specific insertion element IS711 and gene bcsp31 using real-time PCR. Both fox strains showed identical IS711 Southern blot profiles but were distinct from known brucellae. The number of IS711 copies detected was as high as found in B. ovis or marine mammal Brucella strains. Molecular analyses of the recA and omp2a/b genes suggest that both strains possibly represent a novel Brucella species.