千里光不同浓度乙醇提取物的体外抑菌作用研究

分别用4种不同浓度的乙醇溶液,通过过滤和乙醚萃取,然后进行冷冻干燥,对千里光粉末进行提取,制备千里光不同乙醇提取物冻干膏,再分别配成一定浓度的生理盐水溶液。用琼脂平板打洞法和试管稀释法,从最小抑菌浓度和最小杀菌浓度等方面,研究了千里光不同浓度乙醇提取物生理盐水溶液对大肠杆菌K88、鼠伤寒沙门氏菌、蜡样芽孢杆菌、金黄色葡萄球菌ATCC638、肺炎链球菌5种病原菌体外抑菌作用。结果表明,所制备的提取物水溶液对大肠杆菌K88、鼠伤寒沙门氏菌、蜡样杆菌和金黄色葡萄球菌ATCC638没有明显的抑菌作用;对肺炎链球菌抑菌作用很明显,其中以千里光70％乙醇提取物的抑菌效果最好。     

鸡血藤不同极性段提取物制备及体外抑菌作用初步研究

采用水、丙酮和乙醇等不同极性溶剂对鸡血藤有效成分进行提取,测定了鸡血藤不同极性段提取物对鸡大肠埃希菌、鸭大肠埃希菌及金黄色葡萄球菌等常见病原菌的体外抑菌效果。结果表明,鸡血藤的各种提取物对鸡大肠埃希菌的抑菌圈直径均小于13 mm,属低度敏感;对鸭大肠埃希菌有较好的抑制作用,属中度敏感,其抑菌圈直径大于13 mm,小于19 mm;对金黄色葡萄球菌为高度敏感,其抑菌圈直径在19 mm以上。鸡血藤微波提取物对鸡大肠埃希菌和金黄色葡萄球菌的抑菌作用最强,700 mL/L乙醇提取物对鸭大肠埃希菌的抑菌作用最强,最小抑菌浓度均为15.63 mg/mL。     

中草药提取物对常见食源性致病菌的体外抑菌试验

本文进行了8味中草药提取物对7种食源性致病菌的体外抑菌试验.结果显示,8种中草药对7种食源性致病菌有不同程度抑制作用.其中盐肤木提取物对所有食源性致病菌均有较高抑制活性;臭椿对4种致病弧菌抑菌活性较好,MIC均在7.81 mg/mL以下;连翘则对致病真菌抑制活性较强,对3种病原真菌抑制率均在70％以上.     

苦豆子及其复方药对奶牛子宫内膜炎5种致病菌的体外抑菌活性研究

采用酸法提取苦豆子(Sophoraalopecuroides L.)的有效成分,并用96孔板微量肉汤稀释法测定苦豆子生物总碱的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。采用(K-B)纸片扩散法,以盐酸小檗碱为对照,考察苦豆子提取物及其复方灌注剂对致病菌的抑菌效果。结果表明,苦豆子总生物碱对表皮葡萄球菌抑制效果最佳,MIC为16g/L,MBC为32g/L。苦豆子总生物碱、复方灌注剂及硫酸小檗碱的抑菌环平均直径分别为14.28,18.61和18.02mm。由此得出苦豆子总生物碱及其复方灌注剂有明显的抗菌作用。     

20味中药对奶牛隐性乳房炎主要病原菌体外抗菌效果

采用平板法和试管法,分别测定了20味中草药对奶牛隐性乳房炎临床分离主要病原菌金黄色葡萄球菌和无乳链球菌的抑菌直径、最小抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果发现,20味单味中草药对临床分离的金黄色葡萄球菌和无乳链球菌均有一定的抗菌活性,尤其是蒲公英、黄连、连翘、穿心莲、黄芩、红花、野菊花等7味中草药的体外抗菌效果明显。     

黄芪多糖对奶牛乳房炎主要致病菌的体外抑菌作用

采用水提醇治法提取黄芪多糖,并应用琼脂扩散法研究了黄芪多糖对几种奶牛乳房炎主要致病菌的抑制效果。结果表明,10 mg/mL的黄芪多糖对3种细菌都有一定的抑制效果,其中对大肠埃希菌的抑制作用最强,抑菌圈达11.05 mm±0.31 mm,对链球菌和金黄色葡萄球菌的抑菌圈分别为8.50 mm±0.71 mm和9.32 mm±0.21 mm。3种细菌的最小抑菌浓度不同,对大肠埃希菌的最小抑菌浓度为6.6 mg/mL,而对金黄色葡萄球菌和链球菌则为10.0 mg/mL。     

蒲公英提取物联合多种抗生素对奶牛乳房炎金黄色葡萄球菌的体外协同抑菌实验

为研究蒲公英提取物联合多种药物对奶牛乳房炎金黄色葡萄球菌的体外协同抑菌效果,以期应用于临床,减少抗菌药的使用量,降低细菌耐药性和兽药残留。试验选取3种来源(河北,东北,北京)的蒲公英提取物,通过高效液相色谱仪对3种不同来源的蒲公英提取物的主成分及含量进行测定并分析,选取后期试验所需的蒲公英提取物来源。并应用微量肉汤稀释法测定多种抗生素对金黄色葡萄球菌的MIC值(最小抑菌浓度),随后测试蒲公英提取物与抗菌药物联合用药,是否对金黄色葡萄球菌具有协同效果。试验结果表明,不同来源的蒲公英提取物主成分含量差异较大,含有单咖啡酰酒石酸、咖啡酸、菊苣酸、绿原酸,但含量比例不同。随之测得不同来源蒲公英提取物对金黄色葡萄球菌的敏感程度也有差异,临床用药前有必要进行药敏试验科学精准的选择更合适的药物。蒲公英提取物与金霉素、恩诺沙星、阿莫西林、氨苄西林、头孢噻呋、头孢喹肟等联合用药,对金葡菌的体外抑菌实验有良好的协同作用,体外能显著降低抗菌药物的用量。     

中草药对奶牛乳房炎致病菌的体外抑菌试验

奶牛乳房炎是影响奶牛业经济效益的重要疾病。对于乳房炎的治疗，一般都是采用抗生素等药物，但随着抗生素长期大剂量的广泛使用，细菌抗药性和乳中抗生素残留问题被普遍关注。另外奶牛乳腺炎多表现为炎症性疾病而非感染性疾病。因此，在治疗时不仅应注意杀菌更应注重促进炎症的消散。中草药是纯天然物质，具有抗菌、消炎、细菌不易产生耐药性、低毒等特点，具有抗生素无法比拟的优点。所以应用中草药替代抗生素防治奶牛乳腺炎，已日益为国内外学者所关注。笔者采用试管二倍稀释法，对中草药的体外抗菌活性进行了定量分析，旨在为研制防治奶牛乳腺炎中草药制剂的科学组方提供理论依据。     

苦豆子的研究进展

苦豆子(Sophora Alopecuroides L)是豆科(Leguminosae)槐属的多年生草本植物,又名苦豆草、苦豆根、苦甘草、欧苦参等,是我国西北地区常用的中药材,药用根、茎、全草及种子,主要化学成分除生物碱和黄酮外,还含有有机酸、氨基酸、蛋白质和多糖类成分.     

小檗碱对兔乳房炎病原菌的抑菌效果

试验分离培养了兔乳房炎病原菌,观察了兔乳房炎组织的病理学变化,并研究了病原菌对抗生素和小檗碱的敏感性及其形态学变化。结果发现,受感染的乳房组织出现炎性细胞浸润,腺泡上皮细胞坏死、脱落,腺泡结构改变,间质纤维增生等;兔乳房炎的致病菌主要是金黄色葡萄球菌、停乳链球菌和大肠杆菌,敏感的抗生素有恩诺沙星、头孢曲松和红霉素等;扫描电镜下观察到小檗碱使金黄色葡萄球菌和停乳链球菌菌体表面变粗糙,出现很多凸起物,大肠杆菌表面有一处或多处凹陷,菌体皱缩弯曲。上述结果说明,兔乳房炎的病原菌主要是常在菌,小檗碱对其有明显的抑菌效果,且对球菌和杆菌的抑菌机制可能不同。     

Non-oxidative antibacterial activity of bovine neutrophil granule proteins towards mastitis pathogens

Acid extracts of bovine neutrophil granules displayed potent antibacterial activity towards a number of mastitis pathogens in vitro. Killing of pathogens by acid extractable granule protein was dependent on incubation time, protein concentration, bacterial cell load, pH and ionic strength. Gram-negative and Gram-positive organisms showed variable sensitivity to granule extract. Strains of Staphylococcus aureus were the most resistant of tested organisms to granule extract. Gram-negative organisms were neither consistently more nor less sensitive than Gram-positive organisms. Maximal killing of Gram-positive pathogens, after 30 minutes exposure to granule extract at 37 degrees C, occurred between pH 7.0 and 8.0. The Gram-negative organism Escherichia coli B117 was more sensitive to neutrophil granule extract at pH 5.0.     

Pharmacokinetics of cefoperazone in the cow by the intramammary route and its effect on mastitis pathogens in vitro

The pharmacokinetic and microbiological properties of a new third generation cephalosporin, cefoperazone, when given by the intramammary route to the cow are described. Cefoperazone is excreted from the udder over a three- to five-day period following a single infusion of 250 mg in an oil base into each of all four quarters. By the fifth milking after treatment the mean bucket (composite) concentration of cefoperazone was below 0.01 microgram/ml. The minimal inhibitory concentrations for 470 pathogens isolated from cases of mastitis were determined. A few exotic species were resistant but all the usual isolates were sensitive. No signs of transferable drug resistance from known multiple drug-resistant strains were detected.     

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   

8味中药对奶牛乳房炎病原菌的体外抑菌试验

选用金银花、连翘、蒲公英等8味中药分别采用乙醇回流法进行提取,用试管二倍稀释法测定来自奶牛乳房炎的3种主要致病菌(金黄色葡萄球菌、无乳链球菌、停乳链球菌)的最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果显示,以金银花和连翘对金黄色葡萄球菌抑菌效果最强,MIC值均为15.63mg/mL,其MBC值为31.25mg/mL和62.5mg/mL;芙蓉花对大肠杆菌和无乳链球菌的效果最强,MIC值为31.25mg/mL和15.63mg/mL,MBC值为62.5mg/mL。本试验结果,对临床用药选取合适的中药有直接的指导意义,同时为体内用药的浓度提供参考依据。     

人参提取液体外抑制IHNV作用效果研究

探究人参提取液体外抑制CCB细胞感染IHNV的能力,构建体外CCB细胞模型,运用RTCA技术和MTT法测得不同浓度人参提取液对IHNV抑制作用曲线,并从阻断病毒复制和杀灭病毒两方面讨论人参提取液作用效果。结果表明,4%人参提取液对IHNV具有明显抑制作用,能够在16 h内保护细胞不受IHNV病毒的侵染,其中2 h时对病毒灭活抑制率最高达到51.5%,1~12 h内对病毒复制有持续抑制作用。研究可为IHVN防治药物的研发提供新的思路及参考。     

Resistance of mastitis pathogens in northern Germany

The data of 1692 susceptibility tests acquired from April 2003 through March 2004 in the mastitis laboratory of the Institute for Food Quality and Safety were summarized in order to help veterinarians confronted with acute mastitis in choosing the appropriate antibiotic. Two thirds of the milk samples were infected with gram-positive cocci. One third of these were identified as Streptococcus (S.) uberis, one fourth as Staphylococcus (S.) aureus. All isolates (100%) of S. uberis, S. dysgalactiae, S. agalactiae and Arcanobacterium pyogenes were susceptible to Penicillin and Ampicillin. Concering S. aureus, nearly 100% of the isolates were susceptible to Oxacillin, Cephalothin, Cefacetril, Cefquinom and Neomycin, but only 88% of the isolates were sensitive to Penicillin, Ampicillin and Cefoperazon. The gram-negative rods (Escherichia (E.) coli, Klebsiella spp. and Pseudomonas spp.) displayed an irregular resistance pattern. More than 93% of all examined isolates including Pseudomonas spp. were susceptible to Colistin. The sensitivity of E. coli and Klebsiella spp.to Marbofloxacin, Enrofloxacin and Cefquinom exceeded 96%. Thus, the susceptibility of gram-positive mastitis pathogens to common antibiotics is favourable. Because the highly effective Colistin is no longer approved for local therapy, the situation for gram-negative bacteria is more difficult.