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Adhesion of Staphylococcus aureus and Escherichia coli to bovine udder epithelial cells 总被引:1,自引:0,他引:1
An assay for the adhesion of tritiated thymidine-labelled Staphylococcus aureus and Escherichia coli to bovine mammary ductular epithelial cell lines was developed. The relative adhesion of 15 strains of S. aureus to these cell lines was examined. Four strains did not adhere and the remaining 11 adhered at variable levels. Adhesion to different cell lines was generally similar. Adhesion to freshly collected bovine mammary epithelial cells was significantly greater than that to cells maintained in tissue culture. The system described was demonstrated to be a suitable model for studying adhesion of mastitis-causing organisms to bovine mammary epithelial cells. 相似文献
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对大肠杆菌和金黄色葡萄球菌进行正己酸的抗性试验,以研究正己酸对病原菌的抑制作用。试验采用等浓度梯度稀释、光密度值测定、平板涂布方法、牛津杯法,分别测定大肠杆菌及金黄色葡萄球菌的的最小抑菌浓度(minimum inhibitory concentration,MIC)以及最小杀菌浓度(minimum bactericidal concentration,MBC),绘制1/2MIC以及MIC处理过的大肠杆菌以及金黄色葡萄球菌的生长曲线,抑菌圈直径,结合扫描电镜图片分析最小杀菌浓度处理后的细胞形态结构的变化。结果表明:正己酸对大肠杆菌的最小抑菌浓度为700μg/mL、对金黄色葡萄球菌的最小抑菌浓度为1 000μg/mL;对大肠杆菌的最小杀菌浓度为1 000μg/mL、对金黄色葡萄球菌的最小杀菌浓度为1 300μg/mL;当正己酸浓度为1 600μg/mL时,电镜下,大肠杆菌数量较少,金黄色葡萄球菌数量少且呈现出细胞破裂萎缩现象。综上,正己酸对大肠杆菌和金黄葡萄球菌有抑制作用,破坏了金黄葡萄球菌的细胞膜结构。 相似文献
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对两种蒙药复方进行乙醇回流提取,然后分别用石油醚、乙酸乙酯、正丁醇萃取,得到石油醚层浸膏、乙酸乙酯层浸膏、正丁醇层浸膏和水母液浸膏,并分别对各种提取物进行奶牛乳腺炎两种主要致病菌大肠埃希菌和金黄色葡萄球菌的体外抑菌和体内抗菌作用,用牛津杯法测定提取物对大肠埃希菌和金黄色葡萄球菌抑菌圈直径,用二倍稀释法测定了其在体外的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。又以两种致病菌的混合菌感染小鼠,灌服蒙药复方提取物以测定其体内抗菌效果。结果表明,两种蒙药复方的体外抑菌成分主要集中在乙酸乙酯层浸膏和正丁醇层浸膏内,抑菌环直径均大于16.88 mm,最大达到21.61 mm;对两种致病菌的MIC和MBC最低可达到0.031 5 g/mL和0.062 5 g/mL;两种蒙药复方提取物的体内抗菌成分重要集中在石油醚层浸膏和水母液浸膏内,对小鼠死亡保护率明显高于阴性对照组,可达87.5%。 相似文献
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奶牛金黄色葡萄球菌性乳房炎研究进展 总被引:4,自引:0,他引:4
奶牛乳房炎是对世界奶牛业造成经济损失最大的疾病之一,它不仅直接导致乳品工业的经济损失,而且由于患乳房炎的奶牛其乳汁中经常含有大量的毒素、病原微生物以及治疗后残留的抗生素,使得该病日益引起公众的关注。金黄色葡萄球菌是奶牛乳房炎的主要病原,由于其极易产生耐药性,使得治疗变得相当困难,因此使用预防或治疗性疫苗防治乳房炎就成为首选。金黄色葡萄球菌对上皮细胞的黏附和侵袭力被认为是奶牛金黄色葡萄球菌性乳房炎的主要致病机制,金黄色葡萄球菌的致病力涉及到许多不同的毒力因子,如黏附素、荚膜、各种毒素和酶类等。研究表明,以这些毒力因子为靶位进行疫苗研究,可能是预防奶牛金黄色葡萄球菌性乳房炎的有效途径。 相似文献
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为深入了解畜禽粪污中金黄色葡萄球菌和大肠埃希氏菌的流行及耐药状况,采用建立的畜禽粪便中金黄色葡萄球菌和大肠埃希氏菌的环介导等温扩增技术(LAMP)检测方法对山东省内牛粪污、猪粪、鸡粪、鸭粪中的金黄色葡萄球菌和大肠埃希氏菌进行检测,进而对检测阳性样品进行分离,并对药敏试验中多重耐药性菌株进行耐药基因预测。结果表明,LAMP方法检测畜禽粪污中金黄色葡萄球菌和大肠埃希氏菌与国家标准方法检测结果符合率为100%,重复性好,特异性高。从80份畜禽粪污样品中分离到的3株金黄色葡萄球菌均对青霉素耐药;34株大肠埃希氏菌对氟苯尼考、利福平的耐药比例高于50%,高于25%以上的还有氨苄西林、四环素、多西环素、磺胺异噁唑、头孢噻吩和头孢噻呋;耐药基因预测结果显示,鸡粪、鸭粪、牛粪和猪粪中的4株大肠埃希氏菌分别携带10、8、20和15种耐药基因;鸡粪中的1株金黄色葡萄球菌携带11种耐药基因。说明山东地区畜禽粪污中金黄色葡萄球菌和大肠埃希氏菌耐药状况严峻,菌株普遍多重耐药,且携带多种耐药基因。 相似文献
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为建立家兔乳腺炎模型,本试验将从乳房炎患牛奶样中分离出的金黄色葡萄球菌制成104CFU/mL细菌悬液,并分别注入选取的16只3~4 kg健康泌乳家兔的第3对乳池内(1 mL/乳区),诱发乳腺发炎。观察临床表现,乳腺组织形态学病理变化,并于造模后72 h采集乳腺组织匀浆液进行回归试验。结果显示:①造模后动物出现急性炎症反应,表现为饮食欲降低,甚至废绝;体温、心率和呼吸频率显著升高;造模乳区严重肿胀。②造模乳区的乳腺组织镜检发现有炎性细胞浸润、组织结构破坏等现象。③回归试验全部呈阳性,其生长菌落为金黄色葡萄球菌。结果表明,金黄色葡萄球菌诱发家兔临床型乳腺炎模型与炎症的病理过程和炎性反应一致,可用作病理模型使用。 相似文献
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奶牛乳腺炎金黄色葡萄球菌疫苗研究进展 总被引:4,自引:0,他引:4
奶牛乳腺炎是由多种因素引起的严重影响奶牛业发展的重要疾病,金黄色葡萄球菌是引起奶牛乳腺炎的主要病原,至今还没有有效的方法预防金黄色葡萄球菌所致的乳腺炎.虽然已经研制了许多金黄色葡萄球茵疫苗,但是试验表明,这些疫苗的免疫效果并不理想,因此仍将继续搜索有效疫苗.目前,亚单位疫苗和DNA疫苗成为研究热点,研究集中在金黄色葡萄球茵的表面抗原上.利用金黄色葡萄球茵分泌的免疫原性蛋白而制成的疫苗可能具有高免疫效力,这些抗原将成为高效疫苗的候选者.同时,应用低毒的金黄色葡萄球菌突变株,也可能成为预防乳房炎的一种新工具. 相似文献
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T Mattila-Sandholm T Alivehmas L Kaartinen T Honkanen-Buzalski 《Acta veterinaria Scandinavica》1990,31(2):169-174
The growth of Staphylococcus aureus and Escherichia coli was followed in bovine whey samples which had been prepared from milk previously incubated with cultures of S. aureus or E. coli. Staphylococcal strains were divided into 2 groups according to their ability to form compact or diffuse colonies on serum soft agar, which is related to the absence or presence of capsule respectively. The growth of compact staphylococci was dependent on the bulk tank milk used whereas diffuse colony forming staphylococci grew equally well in all bulk milk, also in all inoculated milk. The growth of E. coli was markedly enhanced in whey samples prepared from milk preincubated with staphylococci. However, clear growth inhibition was seen with E. coli and S. aureus strains when grown in whey prepared from milk preincubated with E. coli. Results indicate that the growth promotion of pathogens due to compositional changes in milk are of importance during the course of infection because the growth pattern on staphylococci is dependent on these compositional changes. The growth-inhibitory effects caused by E. coli may explain difficulties in isolating this organism. 相似文献
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鸡大肠杆菌和金黄色葡萄球菌混合感染病原的分离与鉴定 总被引:1,自引:0,他引:1
通过对18份病死鸡的肝脏、脾脏、肾脏病料进行细菌分离培养与鉴定,结合流行病学、临床症状和病理剖检变化,确诊为鸡大肠杆菌和金黄色葡萄球菌混合感染.同时采用药物预防治疗,2周后,该病得到了控制. 相似文献
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DNA甲基化在奶牛金黄色葡萄球菌性乳房炎中的调控 总被引:1,自引:0,他引:1
旨在研究CSN1S1基因启动子区上游STAT5结合区域的DNA甲基化在奶牛金黄色葡萄球菌性乳房炎中的变化及其对CSN1S1基因表达的调控.本研究利用亚硫酸氢盐修饰和荧光定量PCR法检测受金黄色葡萄球菌侵染后12、24、36和196 h乳腺组织CSN1S1基因启动子区上游甲基化程度及CSN1S1基因表达量.结果,24 h内在细菌侵染的乳腺组织中甲基化程度随着时间的延长而增加;而CSN1S1基因表达量则显著降低(P<0.01),而在侵染后36和196 h,甲基化程度和基因表达水平与24 h无显著差异.结果表明,奶牛金黄色葡萄球菌性乳房炎能够促使乳腺组织DNA再甲基化,DNA再甲基化可能是奶牛乳房炎急性期的一种普遍调控. 相似文献
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Staphylococcus aureus(SA)bovine mastitis is a chronic and subclinical infectious disease, which is hard to control. It brings unpredictable losses to dairy-farming industry. Immune escape effect of SA plays an important role in the occurrence and development of mastitis, and some virulence factors are mostly associated with the immune evasion of bacteria. In this paper, some important immune evasion mechanisms of SA in recent researches were reviewed in order to provide theoretical reference for further prevention and treatment of mastitis in dairy cows. 相似文献
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Dilda F Gioia G Pisani L Restelli L Lecchi C Albonico F Bronzo V Mortarino M Ceciliani F 《Veterinary journal (London, England : 1997)》2012,192(3):514-516
MicroRNAs (miRNAs) are a family of regulatory molecules involved in many physiological processes, including activation of cells of the immune system. This study investigated the effect of Escherichia coli lipopolysaccharide (LPS) and Staphylococcus aureus enterotoxin B (SEB) on the expression of five miRNAs involved in the inflammatory response, including miR-9, miR-125 b, miR-155, miR-146 a and miR-223, in bovine CD14(+) cells (monocytes). Incubation of monocytes with SEB induced down-regulation of miR-155, miR-223 and miR-125 b, but not the anti-inflammatory miRNA miR-146 a. Conversely, incubation with LPS upregulated both miR-155 and miR-146 a. In vitro incubation of isolated CD14(+) bovine monocytes with LPS and SEB elicited different and opposite expression of miRNAs reportedly involved in inflammatory reactions. 相似文献