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无乳链球菌及其血清型的PCR方法鉴定 总被引：1，自引：0，他引：1
无乳链球菌(S.agalactiae)是引起奶牛乳房炎和新生儿期侵袭性感染(包括败血症、肺炎和脑膜炎)的重要病原菌.为快速准确地鉴定S.agalactiae及其血清型,本研究对22株从国内不同地区分离的牛源链球菌进行生化鉴定以及针对S.agalactiae保守基因sip进行PCR鉴定,并采用多重PCR技术扩增sip基因阳性菌株的cps基因进行血清分型.结果显示,PCR扩增sip基因阳性17株,其中15株生化试验与PCR结果一致;多重PCR扩增cps基因显示,其中Ia型4株、Ⅱ型11株、Ⅲ型2株.本研究为鉴定S.agalactiae及其血清型提供了参考. 相似文献
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《畜牧与兽医》2017,(10):113-116
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。 相似文献
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为研究引起奶牛乳房炎的病原菌停乳链球菌、无乳链球菌和乳房链球菌的gapC基因工程疫苗及其生物免疫活性,试验采用PCR方法扩增出停乳链球菌、无乳链球菌和乳房链球菌的gapC基因cDNA序列,克隆到pMD18-T载体上,将重组质粒pMD18-T-TRgapC、pMD18-T-WRgapC和pMD18-T-RFgapC经双酶切鉴定、测序及序列分析后,再将gapC基因亚克隆到pET-28a(+)原核表达载体上,构建停乳链球菌、无乳链球菌和乳房链球菌的gapC基因原核表达质粒pET-28-TRgapC、pET-28-WRgapC和pET-28-RFgapC;将构建好的原核表达质粒转化至宿主菌BL21(DH3)中,诱导表达目的蛋白。表达产物经SDS-PAGE电泳、纯化、复性后经Western blot检测,得到了约38 ku的条带,与预期大小相符。说明这3种蛋白有一定的免疫原性。 相似文献
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本试验对由患慢性奶牛乳房炎奶样中分离出的1株疑似金黄色葡萄球菌小菌落突变株(SCVs)进行形态观察、金黄色葡萄球菌相关保守基因片段(nuc、nucA、16S rDNA) 多重PCR扩增鉴定、药敏试验、生理生化特性研究及补偿试验。结果显示分离出1株金黄色葡萄球菌SCVs,该菌含有金黄色葡萄球菌菌种特异性基因nuc和nucA;与金黄色葡萄球菌质控菌株ATCC 25923的抑菌圈大小明显不同;菌落形态主要表现为菌落细小、生长缓慢、溶血能力下降;凝固酶活性下降;耐盐能力降低;革兰氏染色为革兰氏阳性球菌,呈葡萄状排列;补偿试验鉴定该金黄色葡萄球菌SCVs为胸腺嘧啶依赖型。结果表明成功分离鉴定出1株胸腺嘧啶依赖型金黄色葡萄球菌SCVs,为由金黄色葡萄球菌SCVs引起的奶牛慢性乳房炎的预防和控制及其致病机制的研究奠定前期基础。 相似文献
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【目的】明确规模化湖羊场乳房炎的主要病原菌种类及其耐药性和毒力基因分布情况,指导临床治疗湖羊乳房炎合理用药。【方法】在6个规模化羊场采集临床型乳房炎乳样43份,采用细菌形态学鉴定、生化鉴定及16S rDNA序列分析的方法确定引起湖羊乳房炎的主要病原菌,采用纸片扩散法检测其耐药性,并通过PCR方法检测相关毒力基因。【结果】革兰染色镜检显示获得了革兰阳性球菌和革兰阴性杆菌。革兰阳性球菌在Baird-Parker琼脂平板上呈现出边缘圆润,中间呈黑色的菌落;生化试验鉴定结果显示,分离株对甘露醇、过氧化氢和兔血浆凝固试验为阳性;经16S rDNA测序比对,与金黄色葡萄球菌高度相似的分离株共31株。革兰阴性杆菌在伊红-美蓝琼脂平板上呈现出黑紫色泛有金属光泽的菌落,在麦康凯琼脂平板上呈现出粉红色的菌落;生化试验鉴定显示,分离株对吲哚试验和甲基红试验为阳性,对VP试验和枸橼酸盐利用试验呈阴性;经16S rDNA测序比对,与大肠杆菌高度相似的分离株共12株。药敏试验结果显示,分离的金黄色葡萄球菌对环丙沙星、左氧氟沙星和头孢噻肟具有较高的敏感性,对青霉素、红霉素和链霉素耐药;分离的大肠杆菌对环丙沙星和左氧... 相似文献
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《黑龙江畜牧兽医》2014,(24)
为了弄清楚宁夏地区奶牛临床型乳房炎主要病原菌的种类、分布情况及药物敏感性,为临床型乳房炎综合防治提供理论依据,对在宁夏地区部分奶牛场(牧场、奶牛养殖小区)采集的94份临床型乳房炎乳样进行细菌分离鉴定,并对主要病原菌进行药敏试验。结果表明:奶样中检出细菌170株、酵母样真菌18株,其中葡萄球菌48株(25.53%),链球菌6株(3.19%),其他革兰阳性球菌24株(12.77%),革兰阴性杆菌92株(48.94%)。15种药物的药敏试验结果表明:病原菌对链霉素、磺胺类、林可胺类药物均已产生不同程度的耐药性,而对氨基糖苷类、喹诺酮类、头孢类药物则表现出较好的抑菌效果。 相似文献
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多重PCR快速检测奶牛乳房炎3种主要病原体 总被引：10，自引：0，他引：10
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。 相似文献
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[目的]了解奶牛子宫内膜炎乳房链球菌的耐药性和携带毒力基因。[方法]采集香河县5家奶牛场患子宫内膜炎奶牛的子宫黏液样本76份,用PCR鉴定分离菌株的乳房链球菌,采用微量肉汤稀释法测定8种抗菌药对乳房链球菌的最小抑菌浓度（MIC）,判断其耐药性。用PCR检测乳房链球菌携带的10种毒力基因。[结果]PCR检测出18株乳房链球菌,总分离率23.68%。18株乳房链球菌对克林霉素、庆大霉素、四环素耐药性较高,耐药率分别为66.67%、88.89%、72.22%。所有菌株均携带slp、sua、gapC、fpb、cfu和pauA,而hasA、hasB、acdA检出率分别为38.89%、50.00%、33.33%,未检出hasC。[结论]该地区乳房链球菌是奶牛子宫内膜炎主要致病菌之一,耐药性较严重,毒力基因流行广泛,应加强监测,合理用药。 相似文献
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奶牛乳房炎致病型耐甲氧西林金黄色葡萄球菌的分离鉴定 总被引：1，自引：0，他引：1
为探究引起奶牛乳房炎的耐药性致病菌,本研究针对西安地区显性乳房炎奶样中的耐甲氧西林金黄色葡萄球菌（MRSA）进行系统研究。采用常规细菌学鉴定法对34头（次）荷斯坦牛76个乳区152份奶样的金黄色葡萄球菌（Staphylococcus aureus,S.aureus）进行了分离培养,共检出92株阳性菌株,检出率为60.5%;对其进行S.aureus致病基因nuc的特异性PCR检测,共检出28株含nuc基因的阳性菌株,检出率为30.4%;进一步针对MRSA耐药基因mecA进行特异性PCR扩增,共检出5株MRSA,检出率为17.9%。研究结果为MRSA耐药菌的有效检测及奶牛乳房炎的治疗提供了指导。 相似文献
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根据GenBank登录的猪传染性胸膜肺炎放线杆菌(Actinobacillus pleuropneumoniae,APP)血清1~14型的表面抗原蛋白D15和16S rRNA基因序列,设计2对特异性引物,分别扩增出637、431 bp两条核苷酸片段,建立了APP的多重PCR检测方法。特异性结果表明,血清1、3、5a、8、10型能扩增出两条与预期大小的片段,而扩增的大肠杆菌、巴氏杆菌、沙门氏菌、链球菌、葡萄球菌均成阴性。敏感性试验结果表明,最低检出浓度为50/μL。对临床分离的5株疑似APP菌株进行PCR,结果表明,其中4株为阳性,1株为阴性。提示,该方法的特异性和敏感性均良好。 相似文献
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猪链球菌2型多重PCR检测方法的建立及应用 总被引：1，自引：0，他引：1
设计3对引物,分别扩增链球菌属特异性gdh、猪链球菌种特异性16S rRNA和猪链球菌2型特异性cps2J等基因,目的片段大小分别为725bp、523bp和387bp。利用合成的3对引物并通过对反应条件与反应体系的优化建立了多重PCR。应用该多重PCR检测了分离到的链球菌1105株,检出猪链球菌667株,猪链球菌2型33株。研究结果表明,该方法特异性高、敏感性强,可广泛应用于猪链球菌病的快速诊断及流行病学调查。 相似文献
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Klimiene I Ruzauskas M Spakauskas V Matusevicius A Mockeliūnas R Pereckiene A Butrimaite-Ambrozeviciene C Virgailis M 《Polish journal of veterinary sciences》2011,14(3):467-472
The aim of the study was to isolate gram-positive cocci from cows with mastitis and to determine their resistance to beta-lactamic antibiotics. Eight hundred and nine strains were isolated and identified as staphylococci (n=516), streptococci (n=199) and enterococci (n=94) from sub-clinical and clinical cases of bovine mastitis in Lithuania. The most common causative agents of udder disease included: S. epidermidis (n=176), S. aureus (n=176), S. agalactiae (n=134), S. hyicus (136) and E. hirae (n=68). Isolates were analysed for antimicrobial resistance to penicillin, ampicillin, amoxicillin, cephalothin, cephalexin, amoxicillin + clavulanate. The susceptibility patterns were analysed using the agar disk diffusion method. S. aureus showed the highest level of resistance to amoxicillin (81.3%), penicillin (76.7%) and ampicillin (78.4%). The corresponding values for CNS strains were 59.7%, 59.7% and 50.6% against penicillin, ampicillin and amoxicillin respectively. Streptococci were the most frequently resistant to amoxicillin (29.3%), and enterococci to penicillin (27%), amoxicillin (27.5%) and amoxicillin/clavulanic acid (23.8%). The resistance of all tested mastitis pathogens to aminopenicillins and penicillin highly correlated (r=0.83). Compared with other antibiotics, amoxicillin and clavulanic acid combination tended to be more effective (p<0.05) against all tested bacteria in vitro. However, S. aureus, in 38.1% of cases, was resistant to this combination of antimicrobials. This study demonstrates that S. epidermidis, S. aureus, S. hyicus, S. agalactiae and E. hirae remain the most frequent mastitis causative agents on Lithuanian cattle farms. The highest resistance in vitro to penicillins was demonstrated by S. aureus, S. hyicus and S. intermedius. Resistance to cephalosporins remains low, irrespective of bacterial species of gram-positive cocci. 相似文献
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Staphylococcus aureus is the most common causative agent of bovine mastitis and vaccines developed to control this disease showed limited protection due in part to the lack of common antigens among the mastitis isolates. We isolated and identified two genes encoding proteins with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity from a S. aureus strain isolated from bovine clinical mastitis. The GapB and GapC proteins share considerable homology to the GapB and GapC products of human strains of S. aureus. These two proteins could be distinguished by their different GAPDH activities and binding to bovine transferrin properties. Both gapB and gapC genes were conserved in 11 strains tested, and the GapC protein was present on the surface of all S. aureus strains. 相似文献
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本研究旨在了解甘肃地区奶牛乳房炎金黄色葡萄球菌的耐药性和耐甲氧西林金黄色葡萄球菌的感染情况,为奶牛乳房炎的防制提供理论依据。采用KB纸片扩散法,检测17株金黄色葡萄球菌对8种不同抗菌药物的敏感性;再用琼脂稀释法检测了苯唑西林、万古霉素对金黄色葡萄球菌的最小抑菌浓度(MICs);头孢西丁纸片扩散法和PCR扩增特异性mecA耐药基因对所有受试菌株进行全面的耐甲氧西林金黄色葡萄球菌检测。结果表明,菌株对青霉素、磺胺异恶唑具有较强抗性,而对环丙沙星、头孢唑啉、万古霉素和苯唑西林全敏感;头孢西丁纸片扩散法未能检测出表型为MRSA的阳性菌株,而PCR方法却检测出8株mecA基因阳性菌株,且这些菌株的苯唑西林MIC均小于2 μg/mL。菌株的耐药情况较严重,对甲氧西林敏感而携带mecA基因的菌株高频存在于被调查地区的奶牛场中。 相似文献
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Traditional microbiological methods for identification of Streptococcus spp. causing bovine mastitis have been demonstrated to be less than highly reliable. PCR-RFLP analysis of 16S-23S ribosomal DNA was used to characterise seven reference strains of streptococcal mastitis pathogens as well as four reference strains of other gram-positive, catalase-negative cocci of bovine origin to allow comparative identification of field isolates. RFLP analysis of PCR products, using a combination of two restriction endonucleases in single reactions (HaeIII and AluI, HaeIII and RsaI or AluI and RsaI) generated unique patterns for species of Streptococcus, Enterococcus and Lactococcus. One hundred field isolates of Streptococcus spp. collected from cows with clinical or subclinical mastitis were tested. Fifty-seven isolates, classified by conventional tests as S. uberis, were identified as 47 S. uberis and six S. parauberis by their unique RFLP patterns. The remaining four isolates had RFLP patterns distinct from the reference strains and two of these were identified as closely related to S. iniae and two to Aerococcus viridans by 16S rRNA sequencing. Conventional identification of 17 S. agalactiae and 26 S. dysgalactiae subsp. dysgalactiae was confirmed by RFLP. Use of a combination of restriction enzymes in a single tube enabled the rapid, accurate, cost effective and easily performed identification of all major streptococcal mastitis pathogens. 相似文献
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Detection of the enterotoxins A, B, and C genes in Staphylococcus aureus from goat and bovine mastitis in Brazilian dairy herds 总被引：2，自引：0，他引：2
To determine the distribution of genes that encode enterotoxins A, B and C, 36 strains of Staphylococcus aureus isolated from goat mastitis and 64 isolated from bovine mastitis were analyzed by Multiplex PCR. Of the total strains studied, 37 (37%) were detected to have some of the SEs genes. From the bovine mastitis strains, 4 (6.3%) co-amplified the sea and seb genes and 2 (3.1%) were positive for the sec gene. From the goat mastitis strains, 31 (86%) tested positive to the Multiplex, and the sec gene was detected in all of them. The production of SE was detected in all strains harboring the corresponding gene. The results demonstrated that S. aureus isolated from goat mastitis had a higher enterotoxigenic potential than those isolated from bovine mastitis. Additionally, the presence of the sec gene in the majority of goat mastitis strains suggests a possible involvement of SEC in goat mastitis pathogenesis. 相似文献
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Pattern of enterotoxin genes seg, seh, sei and sej positive Staphylococcus aureus isolated from bovine mastitis 总被引：4，自引：0，他引：4
PCR detection of the genes encoding the newly described staphylococcal enterotoxins (SE) SEG, SEH, SEI and SEJ was carried out for 104 randomly selected Staphylococcus aureus field strains isolated from cases of bovine mastitis. Sixty-one (58.7%) isolates were positive for one or more of these novel enterotoxin genes. Thirty-six field strains were classified as carrier of seg, 22 of sei gene and 23 were positive for sej gene. None of the 104 investigated ruminant S. aureus strains carried the seh gene. Thirty-seven of these S. aureus strains showed a combination of genes encoding enterotoxin types SEA to SEE or toxic shock syndrome toxin 1 (TSST 1). Thirteen cultures harboured only one, 28 two, 12 three and 8 four enterotoxin genes. Among the 61 S. aureus field strains 14 (23.0%) were positive for the genes encoding SEJ and SED and 10 (16.4%) isolates for those encoding SEG and SEI. Isolates harbouring the sed/sej genes were further characterized by macrorestriction analysis and pulsed-field-gelelectrophoresis (Pfge). Macrorestriction analysis revealed six patterns. Nine of these14 S. aureus isolates (64.3%) exhibited two patterns with a high degree of relationship (>80%). 相似文献