奶牛乳房炎病原菌的分离鉴定及药敏试验

乳房炎是奶牛的常见病和多发病，给奶牛业带来巨大的经济损失。乳房炎不仅影响奶牛产奶量（下降10％～15％）、降低牛奶的品质，还易延长产后发情和妊娠时间，甚至使病牛失去生产性能，造成严重的经济损失。临床乳房炎由于不合理的长期应用抗生素，使耐药菌株越来越多，为临床治疗带来困难。药物在乳汁中的残留，影响食品卫生，危害人民健康。     

应用PCR方法检测奶牛乳房炎主要病原菌

为建立一种在分子水平快速检测乳房炎主要病原菌的方法,根据GenBank已发表的序列设计了3对特异性引物,结果可同时检测奶牛乳房炎的3种主要病原菌:金黄色葡萄球菌、大肠杆菌和无乳链球菌.其特异性为100%,敏感性检测的最低浓度为:1.25×103 cfu/mL.     

应用PCR方法检测奶牛乳房炎主要病原菌

为建立一种在分子水平快速检测乳房炎主要病原菌的方法,根据GenBank已发表的序列设计了3对特异性引物,结果可同时检测奶牛乳房炎的3种主要病原菌:金黄色葡萄球菌、大肠杆菌和无乳链球菌。其特异性为100%,敏感性检测的最低浓度为:1.25×103cfu/mL。     

奶牛乳房炎主要病原菌及其分离鉴定方法研究进展

导致奶牛乳房炎的因素很多,但病原微生物是导致乳房炎的最主要病因.了解奶牛乳房炎病原菌及其分离鉴定方法,对于乳房炎的预防和治疗以及疫苗的研制均有非常重要的指导作用.文章就奶牛乳房炎病菌种类、特点及分离鉴定方法的研究进行了综述,为奶牛乳房炎的预防、治疗提供可靠的依据.     

奶牛乳房炎病原菌的PCR诊断技术研究进展

奶牛乳房炎是奶牛最常见的疾病之一,不仅给养殖者造成重大的经济损失,还影响乳的品质,危及人类的健康.目前,乳房炎病原菌的常规微生物检测方法存在时间较长、灵敏度不高、费用较高、操作繁琐等缺点.随着分子生物学技术的快速发展,分子诊断技术的应用愈发广泛.本文就普通PCR法、多重PCR法和实时荧光定量PCR法等分子生物学技术在奶牛乳房炎病原菌诊断上的应用研究作一综述,并对其发展前景进行了分析展望.     

奶牛乳房炎病原菌的分离鉴定

对西安地区某些奶牛场50头乳房炎阳性奶牛的50个乳样进行细菌分离鉴定,共分离出细菌122株,鉴定出17种细菌。其中葡萄球菌检出47次,占38.53%;链球菌检出22次,占18.04%;大肠埃希菌检出15次,占12.30%;由葡萄球菌、链球菌和大肠埃希菌引起的乳房炎检出次数,占68.87%。引起该地区奶牛乳房炎的主要病原菌以金黄色葡萄球菌为主,且多数是由2种~3种病原菌引起,混合感染率为78%。     

奶牛隐性乳房炎的主要病原菌的PCR鉴定

基于细菌16SrRNA和（或）23SrRNA序列设计引物，利用PCR的方法鉴定出了奶牛隐性乳房炎的主要病原菌，包括金色葡萄球菌、大肠杆菌和无乳链球菌，避免了繁琐的培养过程，表明PCR技术是细菌鉴定非常有效、特异性高而又快速的方法，对隐乳的诊断很有价值。     

奶牛乳房炎病原菌的分离鉴定

在1年的时间里,对北方的1个规模化牧场乳房炎病牛连续采集45个样品,进行分离鉴定,分离到葡萄球菌、大肠杆菌、克雷伯菌和无乳链球菌4种乳房炎病原菌,在发病时间分布上有明显的特点,6-10月期间,大肠杆菌为乳房炎的主要病原菌,12月至次年4月期间,无乳链球菌为乳房炎的主要病原菌。     

如何预防奶牛乳房炎

奶牛乳房炎是奶牛养殖过程中的一种常见的多发性疾病。奶牛乳房炎的发生，对牛奶的产量和质量将会造成严重的影响，并能延长产后发情和妊娠时间，甚至使病牛失去生产性能，给我国奶牛业的发展造成了极其严重的经济损失。引起乳房炎的主要因素是微生物感染，如大肠杆菌、绿脓杆菌、链球菌等：其次是乳房创伤所引起。奶牛乳房炎，预防是关键。     

奶山羊急性乳房炎病原菌的分离鉴定

至今，人们已从奶牛乳房中分离出130多种病原微生物，其中包括多种细菌、真菌、病毒、支原体等。但是，引起羊的隐性乳房炎和急性乳房炎的病原菌是否与奶牛一致，还未见相应的报道。本试验对奶山羊急性乳房炎进行细菌的分离鉴定，为防治提供参考。     

Prevalence of pathogens causing subclinical mastitis in 15 dairy herds in the Republic of Ireland

: Milk samples from 285 cows in 15 dairy herds were collected for bacteriological analysis. Cows were selected on the basis of a somatic cell count (SCC) exceeding 200,000 cells per ml at the three most recent milk recordings prior to sampling. Staphylococcus aureus and Streptococcus uberis were the predominant isolates accounting for 21% (n = 61) and 19% (n = 53) of isolates, respectively. Streptococcus uberis was more frequently isolated from split-calving herds than from spring-calving herds and this difference was statistically significant (P < 0.005). Herds with suboptimal housing had a significantly greater prevalence of S. uberis than did herds where housing was adequate (P < 0.005). The isolation rates for S. aureus was significantly greater in herds where parlour hygiene was suboptimal (P < 0.05).     

基因芯片法检测奶牛乳房炎主要致病菌

奶牛乳房炎不但严重影响乳的品质,而且危害人类健康.目前已知的奶牛乳房炎致病菌大约有220多种,其中常见的有20多种[1],基因芯片技术以其集成化、微型化、可对靶致病菌实现平行化检测的特点在动物疫病诊断方面显示出强大的优势[2-4],本试验旨在建立快速、灵敏、特异、准确检测奶牛乳房炎5种主要致病菌的基因芯片检测技术,为乳业生产上有效预防控制奶牛乳房炎提供检测依据.     

The effect of multiplex-PCR-assessed major pathogens causing subclinical mastitis on somatic cell profiles

The major pathogens causing mastitis were evaluated by multiplex-polymerase chain reaction (M-PCR) with self-designed primers in four quarters of the first, third, and fifth parities in industrial, semi-industrial, and traditional dairy cattle farms in Iran. With the incidence of infection in the quarters by Staphylococcus aureus and Streptococcus agalactiae, the mean log somatic cell count (log SCC) increased from 5.06 to 5.77. The smallest changes occurred with Escherichia coli. Contagious pathogens, when compared with environmental pathogens, were more prevalent and common and created more profound quantitative and qualitative changes in SCC profiles. The second part of the study surveyed the diversity of contaminating pathogens and their effect on quantitative and qualitative profiles of somatic cells. M-PCR was used to determine the absence (M-PCR(-)) and presence of one (M-PCR(+1)), two (M-PCR(+2)), and three (M-PCR(+3)) major pathogens in raw milk samples. Quarter log SCC increased from 5.06 (for M-PCR(-1)) to 5.5 (for M-PCR(+1)), 5.7 (for M-PCR(+2)), and 6 (for M-PCR(+3)). Percent changes in polymorphonuclears (PMNs) were not significant between different quarters and parities but were significant between different farms in terms of pathogen diversity (P?相似文献   

多重PCR快速检测奶牛乳房炎3种主要病原体

奶牛乳房炎是引起奶牛业经济损失的一种重要疫病,目前还没有快速、特异检测奶牛乳房炎主要致病原的方法。本试验根据金黄色葡萄球菌、无乳链球菌、大肠杆菌各自保守的16S或23S rRNA基因序列,合成了3对特异性引物,建立了三重PCR检测方法。特异性试验表明,该方法对所有参与测试的金黄色葡萄球菌、无乳链球菌和大肠杆菌都能扩增出各自的阳性条带,而对所有参与测试的对照菌株则不能扩增出任何条带。敏感性试验表明该方法能检测到4个菌的金黄色葡萄球菌、无乳链球菌和2个菌的大肠杆菌。对送检的乳房炎奶样36份直接进行PCR检测,金黄色葡萄球菌阳性7份,无乳链球菌阳性2份,大肠杆菌阳性6份。     

Flotation of mastitis pathogens with cream from subclinically infected quarters. Prospects for developing a cream-rising test for detecting mastitis caused by major mastitis pathogens

Bacterial isolates, originating from 36 subclinically infected quarter milk samples, were labelled with 75Se and checked for cream-rising at various temperatures in a system analogous to the ABR test ("Abortus Bang Ringprobe"; the cream-rising test based on stained brucella organisms for detection of brucellosis). Diagnostic specificity and sensitivity were analyzed in experiments where labelled bacterial isolates were mixed with a number of quarter milk samples with known bacteriological status as well as samples from healthy control quarters. Creaming at 37 degrees C resulted in specific "recognization" as the bacterial isolates showed preferential flotation in the milk samples from which they had been isolated as well as is milk samples harbouring the same bacterial species. At lower creaming temperatures, the specificity was lost since all the isolates became concentrated in the cream phase irrespective of the milk sample. When comparing the specific recognization by cream of the respective bacteria, bacterial species vary: The prospects for developing diagnostic cream-rising tests for Streptococcus agalactiae, Staphylococcus aureus and Escherichia coli seems promising, but less so for coagulase-negative staphylococci, Streptococcus dysgalactiae, and Streptococcus uberis. The mechanism behind the cream-rising of labelled bacteria at 37 degrees C seems to lie in specific fat globule membrane-bound immunity of IgA type. Therefore the milk fat globules from chronically infected quarters function as absorbents for the respective isolates. Flotation of bacteria with cream indicates an in vivo mechanism enabling bacteria to invade the upper parts of milk ducts within the udder.(ABSTRACT TRUNCATED AT 250 WORDS)     

In vitro growth inhibition of major mastitis pathogens by Staphylococcus chromogenes originating from teat apices of dairy heifers

Earlier field observations suggest that teat apex colonization by Staphylococcus chromogenes pre-partum in dairy heifers protects udder quarters against elevated somatic cell counts early post-partum. To explain these findings, the in vitro inhibitory capability of S. chromogenes from teat apices of heifers towards some major mastitis pathogens was tested using a modified cross-streaking method. Two out of 10 S. chromogenes isolates, both originating from two different teats from the same heifer, consistently inhibited growth of all Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis strains, but none of the Escherichia coli strains. The present study, therefore, supports the protective effect of teat apex colonization by S. chromogenes by in vitro production of inhibitory substances.     

17种中药对奶牛乳腺炎4种病原菌的抑菌试验

奶牛乳腺炎是危害奶牛养殖业最常见的疾病之一,虽然对其的研究已经有100年的历史,取得了一些令人可喜的成果,但仍然是当今奶牛场难以防治的疾病之一。奶牛乳腺炎给奶牛养殖带来巨大的经济损失,包括兽医的治疗、废弃的牛奶、增加的劳动     

检测奶牛乳房炎主要病原菌的多重PCR方法的建立与应用

本试验针对金黄色葡萄球茵、无乳链球菌、大肠杆菌3种主要的乳房炎病原茵设计了3对特异性引物,建立了多重PCR检测方法.结果表明,本方法的特异性为100%,最低检测浓度为1.25×103cfu/mL,充分表明该方法具有快速,准确和特异的优点.     

双重PCR检测奶牛隐性乳房炎大肠杆菌与无乳链球菌方法的建立及应用

为快速检测奶牛隐性乳房炎主要致病菌大肠杆菌和无乳链球菌,分别针对2种致病菌16S-23S rRNA和16S rRNA基因设计2对特异性引物,优化并确立双重PCR反应体系。特异性检测表明,对其他对照菌株未扩增出目的条带;敏感性试验表明,该双重PCR对大肠杆菌、无乳链球菌的最小检测浓度分别为10~2、10~3cfu/mL。同时采用双重PCR与细菌学检查法对送检的96份奶样进行检测,结果双重PCR检出63份大肠杆菌阳性、54份链球菌阳性;细菌学方法检出29份大肠杆菌阳性、37份链球菌阳性。说明本研究建立的双重PCR方法敏感、快速,可用于检测大肠杆菌和无乳链球菌引起的奶牛隐性乳房炎。     

奶牛乳腺炎主要病原菌的药物敏感性检测

为调查甘肃及周边地区奶牛乳腺炎主要病原菌的药物敏感性情况,对于从甘肃兰州市、宁夏吴忠市及青海民和县的382个临床型和隐性乳腺炎奶样中分离到的101株细菌,采用96孔板微量肉汤稀释法,以美国临床检验标准委员会(NCCLS)的临界浓度参数为标准,测定了这些分离菌株对11种抗生素的药物敏感性并计算其体外最小抑菌浓度(MIC)。结果表明,99株分离菌株(98.02%)对红霉素、青霉素G、万古霉素和四环素不敏感,不适宜作为奶牛乳腺炎的临床用药,96株分离菌株(95.05%)对喹诺酮类及氨基糖苷类抗生素仍具有较高的敏感性,其中环丙沙星、诺氟沙星、卡那霉素抑菌效果最好,可在临床实践中参考选用。