用分离法检测牛粪便中副结核分枝杆菌及其与高倍显微镜检查染色涂片的比较

作者比较了用分离法检测牛粪便中的副结核分枝杆菌和用镜检Ziehl-Ne-elsen染色粪便涂片中抗酸性副结核分枝杆菌菌块。粪便采自自然或人工感染副结核分枝杆菌的牛,以及未感染牛。结果表明,镜检粪便染色涂片法不是检测副结核分枝杆菌的可靠方法。因为在177份培养分离阳性粪便标本中,镜检涂片只检出99份(55.9%)为阳性。此外,在18份非副结核病牛粪标本涂片中有3份为阳性,37份培养分离为阴性的副结核病牛粪标本涂片中有18份为阳性。抗酸性菌块不能与副结核分枝杆菌区分。将副结核分枝杆菌加到未感染牛粪中时,需在每克粪便中加入15个以上的副结核分枝杆菌,分离即为阳性。     

一例羊皮下脓肿病原的分离鉴定及药敏试验

为确定某羊场一例羊皮下脓肿病的病原，将病料样本接种于TSA固体培养基进行病原分离，然后对分离菌进行革兰氏染色镜检、生化鉴定、药敏试验和生物信息学分析。结果分离到1株革兰氏阳性球菌和1株革兰氏阴性短杆菌，经生化鉴定以及16S rDNA PCR扩增、测序、同源性分析，鉴定该分离菌株为金黄色葡萄球菌和溶血性曼氏杆菌；2株细菌对头孢曲松、链霉素、四环素、多西环素、左氧氟沙星等多种药物敏感。     

绵羊副结核分枝杆菌的分离与分子分型

为了解绵羊副结核病的病原学特征,本研究对PCR检测阳性的绵羊肠系膜淋巴结样品开展细菌分离培养,对分离株进行形态观察,结果显示肠系膜淋巴结样品经培养后出现乳白色菌落;对分离菌株进行抗酸染色镜检后确定为抗酸染色阳性杆菌;PCR扩增该菌IS900基因与亚型分型片段,结果显示,IS900基因及亚型分型检测为Ⅱ型(牛型)副结核分...     

猪致病性链球菌的分离鉴定

采集33例临床症状疑似猪链球菌感染猪的全血及内脏器官进行涂(触)片染色镜检,取有球菌感染的样品16份进行血琼脂平板分离纯化试验;根据血琼脂平板上菌落形态、溶血情况及对单个菌落涂片染色镜检结果,共筛选出12份可疑样品,进一步采用液体培养基对12份样品进行增菌及纯化培养;选取纯化培养菌进行链球菌生化试验,结果共鉴定出11株纯化的猪链球菌;11株猪链球菌均对小鼠表现出高致病力.     

青年母乳牛子宫内膜炎病原的研究

无菌采集45头份患牛子宫炎性分泌物,涂片,姬姆萨染色,直接镜检未发现毛滴虫,而含有多量脓细胞及柱状上皮细胞碎片和红细胞。从鲜血平板上分离到的细菌,通过小白鼠接种,发现其中9株菌有致病性(占鉴定菌的69.2%)。样品经细菌滤器除菌后,注射小白鼠和9日龄鸡胚,观察7天不致死。对12株革兰氏阴性菌根据伯杰氏细菌学鉴定手册,按检索表的顺序进行鉴定,确定其中7株为大肠埃希氏菌(占致病菌的77.7%),4株为假单胞菌属,1株待进一步鉴定。致病菌中还有1株革兰氏阳性菌为金黄色葡萄球菌。因此认为大肠埃希氏菌(以下简称大肠杆菌)是引起青年母乳牛子宫内膜炎的主要病原菌。用康复牛血清与相应牛所分离到的大肠杆菌均可发生凝集反应和交叉凝集反应。根据药敏试验结果,本菌对妥布霉素和新霉素最敏感,氯霉素和链霉素次之。经临床论证性治疗,全部病牛痊愈,配种后均怀孕,收到明显的经济效益。     

2018年～2021年河北省部分地区鸡源沙门菌的生物学特性及致病性研究

为调查河北地区鸡源沙门菌及其血清型的流行及分布情况,并分析其的致病性,本研究于2018年～2021年在河北省7个地区34个养鸡场共收集631份发病鸡肛拭子和62份病料样品共计693份,分别接种普通琼脂培养基分离细菌并纯化后经革兰氏染色镜检;将分离菌分别接种不同的培养基培养,并对分离菌经生化及16S r RNA基因的PCR及测序鉴定,随机选择32条测序序列经NCBI的BLAST比对,并采用DNAStar软件分析该基因的同源性。采用玻片凝集法鉴定分离菌的血清群及血清型并统计各血清群与血清型在河北不同地区的分布。结果显示,从693份病料样品中共分离到238株沙门菌,除3株未定群外,其余分离菌分属于A、B、C、D、E、F 6个血清群,其中D群最多达69.7%(166/238);238株沙门菌分属于7个不同的血清型和未定型,依次为鸡白痢沙门菌(91/38.2%)、甲型副伤寒沙门菌(43/18.0%)、鸡伤寒沙门菌(40/16.8%)、肠炎沙门菌(39/16.4%)等。血清群与血清型分布的统计结果显示,除张家口地区流行A群血清群外,其余地区流行的血清群均为D群;张家口地区流行鸡白痢沙门菌;秦皇岛地...     

青海部分牧区牦牛酸奶中乳杆菌的分离与鉴定

利用MRS培养基,对青海部分牧区收集的15份牦牛酸奶,进行了乳杆菌的分离,对分离得到的9株疑似乳杆菌,对其中的3株进行生物学鉴定。结果:分离株均为兼性厌氧菌,在MRS培养基上,菌落较大、透明、灰白色,镜检为杆状细菌,革兰氏染色阳性,过氧化氢酶试验为阴性,乳糖发酵阳性,牛乳发酵试验阳性,符合乳杆菌的特性。     

猪、牛源非结核分枝杆菌的分离与鉴定

采集猪颌下淋巴结,猪肠系膜淋巴结,牛颌下淋巴结和牛肠系膜淋巴结各200份,使用改良罗氏培养基进行分离培养和传代培养,通过进行生长特性试验、生化鉴定试验和鉴别培养基生长试验对所分离出的分枝杆菌进行菌型鉴定。结果显示:猪颌下淋巴结中分离出耻垢分枝杆菌4株,鸟分枝杆菌4株,胞内分枝杆菌2株,胃分枝杆菌2株,蟾蜍分枝杆菌1株,龟分枝杆菌龟亚种杆菌1株;猪肠系膜淋巴结未分离出非结核分枝杆菌;牛肠系膜淋巴结分离出瘰疬分枝杆菌2株,加地斯分枝杆菌1株;牛肠系膜淋巴结分离出,瘰疬分枝杆菌5株,金色分枝杆菌2株,戈登分枝杆菌2株,蟾蜍分枝杆菌2株。猪、牛的感染率均为3.5%。     

肉鸽铜绿假单胞菌分离与鉴定

从南京某肉鸽养殖场死亡病鸽肝脏中分离到1株细菌,经分离培养、形态染色镜检、生化试验、药敏试验、实验动物致病性试验和16S rDNA基因片段PCR检测及基因测序试验,结果表明,该菌可以在普通营养琼脂和SS琼脂平板上生长,革兰染色镜检为革兰阴性菌,生化试验检测结果鉴定值为1 655,符合铜绿假单胞菌生化特性;药敏试验表明,该菌对磷霉素、环丙沙星和阿米卡星高度敏感,接种小鼠能导致其死亡并分离出同一细菌,16S rDNA基因片段测序后与GenBank中登录的铜绿假单胞菌同源性为99%。综合以上结果鉴定该分离菌为铜绿假单胞菌。     

致犊牛腹泻大肠杆菌云南株的分离鉴定及药敏试验

云南省某规模化肉牛养殖场2~6月龄犊牛持续出现轻度腹泻,粪便呈灰绿色水样。粪便样品经牛腺病毒(BAd V)3、7型、牛呼吸道合胞体病毒(BRSV)、牛疱疹病毒I型(BHV-I)、牛病毒性腹泻病毒(BVDV)、牛细小病毒(BPV)、牛冠状病毒(BCV)、牛轮状病毒(BRV)、隐孢子虫(Cryptosporidium parvum)real-time PCR及常规PCR检测均为阴性,将样品划线接种于血清琼脂、营养琼脂及麦康凯琼脂平板上37℃培养24 h,在血清琼脂及营养琼脂平板上生长出直径2~3 mm、稍突、圆形、湿润、灰白色、边缘整齐、不透明菌落,在麦康凯琼脂平板上菌落呈现粉红色。该分离株细菌经革兰氏染色镜检、细菌生化鉴定为大肠埃希氏菌,昆明小白鼠致病性实验显示致病力较强,实验组20只小白鼠接种后48 h内全部死亡,并从死亡小白鼠肝脏及心血成功分离出该株细菌。药敏试验结果显示该株细菌对环丙沙星、左氧氟沙星、氧氟沙星、头孢噻肟、头孢哌啶、头孢吡啶、头孢曲松钠高度敏感。     

奶牛结核病两种检测方法的比较试验

采用自制的牛结核病PCR快速诊断试剂盒,对某奶牛场100头份奶牛奶样进行检测,检出阳性牛16头;采用结核菌素皮内注射法（PPD）检出阳性牛17头,结果符合率为94.11％.用牛结核病PCR快速诊断试剂盒检测所需时间为6h,显示其快速、特异等优点,为今后牛结核病的检疫工作提供了1个新方法.     

应用TaqMan荧光定量PCR检测牛分枝杆菌

为建立快速检测牛分枝杆菌(M.bovis)的TaqMan荧光定量PCR方法,本研究以GenBank登录的M.bovis特有229 bp基因为研究对象,设计并合成引物及探针。该方法具有较好的特异性,与标准质控菌株呈阳性反应,与其他微生物样品呈阴性反应;灵敏性最低检测值可达1 pg/mL;对20阳性临床样品进行荧光定量PCR检测,均为阳性;而对培养为阴性的20份临床样品进行检测,6份为阳性。该研究结果表明,建立的方法特异性强,敏感性高,稳定性好,能够用于M.bovis的鉴别检测,对牛分枝杆菌病的快速检测和早期诊断具有重要意义。     

四种方法检测广西奶水牛结核病的比较

应用牛结核菌素对奶水牛进行牛结核病皮内变态反应的检测,然后对皮内变态反应阳性牛采样进行分离培养、γ-干扰素ELISA和聚合酶链反应检测,比较这四种检测方法的符合率。结果共对1850头奶水牛进行皮内变态反应检测,皮内变态反应阳性的奶水牛有78头,从78头反应阳性的奶水牛中分离鉴定为牛分枝杆菌的有2份,γ-干扰素ELISA方法检测为牛分枝杆菌阳性的有5份,PCR方法鉴定阳性的有4份;阳性检出率以变态反应为最高78/1850(4.21%),γ-干扰素ELISA方法为5/78(0.27%),PCR检测方法为4/78(0.21%),而分离培养为最低2/78(0.105%)。变态反应与分离鉴定的符合率最低,为0.105%;γ-干扰素ELISA方法、PCR方法与分离鉴定的符合率较接近,分别为40%和50%。γ-干扰素ELISA检测方法和PCR检测方法具有较好的特异性,可以作为变态反应检测的补充。     

Development of a real-time PCR for detection of Mycoplasma bovis in bovine milk and lung samples.

A real-time polymerase chain reaction (PCR) assay using hybridization probes on a LightCycler platform was developed for detection of Mycoplasma bovis from individual bovine mastitis milk and pneumonic lung tissues. The detection limit was 550 colony forming units (cfu)/ml of milk and 650 cfu/25 mg of lung tissue. A panel of bovine Mycoplasma and of other bovine-origin bacteria were tested; only M. bovis strains were positive, with a melting peak of 66.6 degrees C. Mycoplasma agalactiae PG2 was also positive and could be distinguished because it had a melting peak of 63.1 degrees C. In validation testing of clinical samples, the relative sensitivity and specificity were 100% and 99.3% for individual milks and 96.6% and 100% for the lung tissue. Using M. bovis real-time PCR, the M. bovis culture-positive milk samples were estimated to contain between 5 x 10(4) and 7.7 x 10(8) cfu/ml and the M. bovis culture-positive lungs between 1 x 10(3) and 1 x 10(9) cfu/25 mg. Isolation, confirmed with the real-time PCR and colony fluorescent antibody test, showed that at the herd level, the proportion of samples positive for M. bovis isolation in mastitis milk samples submitted to the Mastitis Laboratory, Animal Health Laboratory, University of Guelph, Ontario, Canada, was 2.4% (5/201). We conclude that this probe-based real-time PCR assay is a sensitive, specific, and rapid method to identify M. bovis infection in bovine milk and pneumonic lungs.     

牛分枝杆菌特异性PCR检测方法的建立及初步应用

根据已发表的牛分枝杆菌的pncA的基因序列，设计和合成了一对可扩增294bp目的片段的引物，建立了特异性检测牛分枝杆菌的PCR方法。对牛分枝杆菌国际参考株和国内分离株成功扩增出294bp的特异性基因片段；对人结核分枝杆菌、副结核分枝杆菌、鸟胞内分枝杆菌和草分枝杆菌DNA的PCR扩增结果均为阴性。本PCR方法检测的敏感度可达到50pg。对10份牛分枝杆菌培养阳性和10份阴性样品的DNA分别进行了PCR检测，结果10份阳性样品中有9份样品为PCR扩增阳性，阳性符合率为90％（9／10）；而10份阴性样品则PCR扩增全部为阴性，阴性符合率为100％（10／10）。本方法可做为牛分枝杆菌的快速检测和流行病学调查的工具。     

A one-tube nested polymerase chain reaction for the detection of mycobacterium bovis in spiked milk samples: an evaluation of concentration and lytic techniques.

The objective of this study was to evaluate the use of a one-tube nested polymerase chain reaction (OTN PCR) with 5 concentration and lytic treatments for the detection of Mycobacterium bovis in experimentally inoculated milk samples (spiked samples). OTN PCR and the following treatments were tested in inoculated samples: 1) centrifugation; 2) C18-carboxypropylbetaine + capture resin 1 + Proteinase K (CB18-CH-PK); 3) centrifugation + capture resin 1 + Proteinase K; 4) centrifugation + capture resin 2 + Proteinase K; and 5) centrifugation + immunomagnetic separation (IMS). The OTN PCR and the 5 treatments were evaluated in 2 different sets of spiked milk samples. One set consisted of 10-fold serial dilutions of a phenol-killed M. bovis in milk to final concentrations ranging from 5 to 50,000 cells/ml of milk. The other set of samples consisted of 2.5 serial dilutions of milk spiked with M. bovis to final concentrations ranging from 20.5 to 5,000 cells/ml of milk. Each treatment was repeated 5 times at each cell concentration. CB18-CH-PK and IMS were significantly more sensitive than other treatments. The lowest detection limit for these techniques was 20-50 cells/ ml of spiked milk. The specificity of OTN PCR in this study was high as demonstrated by the lack of DNA amplification products when M. bovis cells were not present in the samples. [The OTN PCR used in conjunction with CB18-CH-PK or IMS could be effectively used as a diagnostic and/or screening test for the detection of M. bovis in milk from herds with bovine tuberculosis.]     

Use of touch-down polymerase chain reaction to enhance the sensitivity of Mycobacterium bovis detection.

The confirmatory diagnosis of Mycobacterium bovis (M. bovis) in animal samples is carried out by culture in Stonebrink media. However, culture is very slow because of the extremely long duplication time of the bacillus and difficult because of the scarcity of bacilli in diagnostic samples. This study describes the development of a single-tube touch-down polymerase chain reaction (PCR) protocol for the detection of M. bovis using primers that target the IS6110 element. Spiked water and milk as well as routine diagnostic samples (milk and nasal swabs) from M. bovis-positive cattle were tested. This protocol allows the rapid and sensitive detection of M. bovis in bovine samples by enhancing the sensitivity of standard PCR amplification.     

水貂源牛分枝杆菌的分离与荧光PCR鉴定

目的探讨水貂源结核杆菌复合群的检测方法,并进行病原学调查。方法利用7H10培养基分离水貂结核病的病原,采用荧光探针PCR方法进行检测。结果经鉴定分离的病原菌为致病性牛分枝杆菌。结论通过荧光探针PCR能够直接对结核杆菌复合群进行亚种鉴定,该方法具有快速、敏感、特异性强的优点,能够减少动物检疫时间。     

High frequency of Mycobacterium bovis DNA in colostra from tuberculous cattle detected by nested PCR

We evaluated by nested PCR reaction, different cow secretions from a herd with 48% of prevalence of bovine tuberculosis (BTB), seeking to determine niches where Mycobacterium bovis could be found. Postmortem examination of 18 (75%) tuberculin reacting cows allowed demonstrates BTB-compatible lesions in six, all of them PCR positives in milk and four in colostra samples. Our results showed that up to 62% of the colostra analysed contained M. bovis DNA, whereas only 18% of milk gave a positive reaction. Moreover, in bronchoalveolar lavages from cattle with compatible lesions in lungs or lymph nodes, where macrophages account up to 90% of cells, we did not find evidences of M. bovis. Altogether, these results suggest that differences in the anti-bacterial capacity of bovine macrophages, dependent upon microenvironment and organ-specific factors, exist. Alternatively, we hypothesize that hypoxic conditions that are encountered in mammary glands macrophages could induce M. bovis entrance into a 'dormancy-like' state, and that the high number of colostra samples were M. bovis was detected, could be an indicator of reactivation during 'peripartum'.