Isolation,Identification and Drug-sensitivity Test of Riemerella anatipestifer from Different Areas

In order to understand the prevalence of the duck infectious serositis in different regions,and further to determine the sensitivity of the commonly used drugs for the Riemerella anatipestifer in these area.Bacteria were isolated from suspected infected ducks in Yunfu, and Kaiping in Guangdong province and Changshan in Zhejiang province.The isolated bacteria were identified by differential culture, microscopic examination and biochemical test. Micro dilution method was carried out in drug sensitivity test, and the MIC values of the isolated strains to the commonly used drugs were determined.As a result, a total of 16 strains of Riemerella anatipestifer were isolated and identified from three areas. Data of the MIC showed that all isolates were highly sensitive to cephalosporins and florfenicol;Doxycycline andspectinomycin were sensitive too,but enrofloxacin, neomycin and other tested drugs showed different degrees of resistance.The present study provided a systematic method for the isolation and identification of the Riemerella anatipestifer and for the drug sensitivity test.At the same time, it also provided theoretical guidance for the rational drug control of the duck infectious serositis.     

中药常山散的体外抑菌作用研究

试验旨在研究中药常山散的体外抑菌活性。分别采用试管二倍稀释法联合琼脂平板稀释法及营养琼脂稀释法对选用的12种致病菌进行抑菌试验,测定最低抑菌浓度（MIC）,进行抗菌作用量效关系研究,并通过牛津杯法观察药物抑菌效果。试管二倍稀释法联合琼脂平板法结果表明,常山散对链球菌属和芽孢杆菌的抑菌效果较强,MIC在15.6~62.5 mg/mL之间;对金黄色葡萄球菌和肠杆菌有较弱的抑菌作用,MIC在250~500 mg/mL之间;对真菌的抑菌作用最弱,MIC值 > 500 mg/mL,其抑菌强度大小依次为：链球菌属、芽孢杆菌、肠杆菌、真菌。营养琼脂稀释法结果表明,常山散对变形杆菌、白色念珠菌及黑曲霉具有一定的抑菌作用,MIC约为500 mg/mL,而对其他链球菌属、肠杆菌属及芽孢杆菌属细菌的抑菌效果较弱,MIC值均 > 500 mg/mL。牛津杯法抑菌活性研究结果显示,常山散药液（500 mg/mL）对12种菌均有一定的抑菌效果,但抑菌效果较弱,绝大多数抑菌环直径≤10 mm。牛津杯周围可见明显的药物作用圈,作用圈内细菌数量较其他部位明显减少。综合以上试验结果,中药常山散对常见致病菌均具有一定抑菌效果,但由于药物本身的特性及有效组分含量较低,其抑菌作用效果较弱。     

临床常用几种抗菌药物对HPS抗菌活性研究

[目的]研究抗菌药物恩诺沙星、环丙沙星、加替沙星对27株副猪嗜血杆菌临床分离株体外抗菌活性,从而观察副猪嗜血杆菌对喹诺酮类抗菌药物的敏感性。[方法]采用微量肉汤稀释法测定MIC,参考标准为美国临床和实验室标准协会(CLSI)。[结果]恩诺沙星(MIC50,MIC90,0.25μg/mL,2μg/mL)、环丙沙星(MIC50,MIC90,0.125μg/mL,2μg/mL)、加替沙星(MIC50,MIC90,0.125μg/mL,1μg/mL)均表现出一定的抑菌活性,且加替沙星的抑菌活性最明显。在耐药性方面,副猪嗜血杆菌对恩诺沙星的耐药性最强(22.2%),环丙沙星(3.8%)和加替沙星(7.4%)具有轻微的耐药性。[结论]抗菌药物恩诺沙星、加替沙星以及环丙沙星对副猪嗜血杆菌临床分离株具有一定的抗菌活性,在耐药性方面,HPS已经对恩诺沙星表现出一定的耐药性,因此,今后在临床上遇到副猪嗜血杆菌引起的相关疾病,可以采用合理的给药方案进行疾病的治疗,对于预防耐药菌株产生至关重要。     

舟山野菊花序不同萃取物抑菌活性的研究

对野菊花序采用微波粗提,经石油醚、乙酸乙酯、正丁醇和水得萃取物,通过K-B法和倍比稀释法,分别对大肠埃希菌、金黄色葡萄球菌的标准、耐药菌株进行体外抑菌活性测试。结果表明：水相的抑菌活性〉正丁醇〉乙酸乙酯,石油醚萃取物无抑菌效果;水相对大肠埃希菌标准、耐药菌株的MIC分别为15.62 mg/mL和7.81 mg/mL,对金黄色葡萄球菌的标准、耐药菌株的MIC分别为3.90 mg/mL和1.95 mg/mL,正丁醇相的MIC在15.62~31.25 mg/mL之间。水相和正丁醇相呈现较强的广谱抑菌活性,且具有抗耐药菌作用。     

迷迭香酸与抗菌药联合对含fosA3基因细菌抑菌效果的研究

试验旨在探讨迷迭香酸与抗菌药联合体外抗含fosA3耐药基因大肠杆菌的效果。本试验对临床分离的细菌进行鉴定,确定细菌所含耐药基因种类,用牛津杯法测定迷迭香酸的抑菌活性,平板涂布法测定迷迭香酸的杀菌活性,采用96孔反应板二倍微量稀释法分别检测迷迭香酸与抗菌药的最小抑菌浓度(MIC),再用微量棋盘稀释法测定迷迭香酸与抗菌药联合作用后的分级抑菌浓度指数(FICI)。结果显示,分离到含fosA3耐药基因大肠杆菌;迷迭香酸的MIC为640 μg/mL,迷迭香酸与环丙沙星、左旋氧氟沙星、黏杆菌素、加替沙星、阿米卡星、头孢他啶、头孢噻呋钠联合应用后其FICI≤0.5,有协同作用;与头孢曲松钠、诺氟沙星、痢菌净联合应用后0.5fosA3基因大肠杆菌有一定的抑菌活性和杀菌活性,其与部分抗菌药联合应用后,抗菌药体外抗菌活性显著增强。     

Construction and expression of the eukaryotic expressed plasmid of MIC3 gene from Toxoplasma gondii in IBRS-2 cells

The sequence encoding MIC3 was obtained by amplification from genomic DNA of Toxoplasma gondii RH strain and cloned into the vector pMD18-T. The target gene was subcloned into the eukaryotic vector pcDNA3.1 after the identification of pMD18-T-MIC3 by enzyme digesting, PCR amplification and sequencing. Then the target recombinant plasmids pcMIC3 were transfected into IBRS-2 cells, and the positive cells containing pcMIC3 plasmids were obtained under the selection of G418. The expressed proteins from the positive cells were detected by SDS-PAGE, Western blot and ELISA. The results showed that the DNA sequence identity was 99.9% between amplified MIC3 and that from GenBank. The molecular weight of the recombinant MIC3 protein with good immuno-activity was about 39.2 ku. These available data would lay the foundation for further studies on DNA vaccine against Toxoplasma gondii. __________ Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38(8): 827–831 [译自: 畜牧兽医学报]     

金线莲乙醇提取物对金黄色葡萄球菌抑菌性能研究

用乙醇作为溶剂,提取出金线莲中的有效抑菌物质,采用二倍稀释法确定金线莲乙醇提取物对金黄色葡萄球菌的最小抑菌浓度(Minimal inhibition concentration,MIC)为5.000 mg/m L;并经介质pH、热处理和紫外线处理提取物,发现其抑菌圈直径在pH9.0和30℃下最大;分析金线莲乙醇提取物对供试菌蛋白质和还原糖的利用能力,表明金线莲乙醇提取物通过减弱蛋白质和还原糖的代谢来抑制细菌的生长繁殖。     

5种海洋致病弧菌对34种中草药敏感性的测定

采用纸片扩散(K-B)法,测试了溶藻弧菌、哈氏弧菌、副溶血弧菌、河流弧菌、麦氏弧菌对34种中草药的敏感性,结果表明:试验菌株对中草药乌梅、黄连、木瓜、五味子、五倍子、马齿苋、白头翁、地榆、公丁香、大黄具有较高的敏感性。采用倍比稀释法,测定10种敏感性较好的中草药对5种海洋致病弧菌的抑菌试验,并测定了最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果表明:五倍子抑菌和杀菌能力最强,五倍子对溶藻弧菌、副溶血弧菌、河流弧菌、麦氏弧菌的MIC和MBC均为1.56 mg/ml,对哈氏弧菌的MIC和MBC为3.125 mg/ml;其次是黄连,对溶藻弧菌、河流弧菌、麦氏弧菌的MIC和MBC分别为3.125 mg/ml和6.25 mg/ml,对哈氏弧菌、副溶血弧菌的MIC和MBC分别为6.25 mg/ml和12.5 mg/ml;乌梅对5种弧菌有相同的抑菌和杀菌作用,其MIC和MBC均为12.5 mg/ml。最终确定五倍子和黄连可以作为防治水产养殖动物弧菌病的首选中草药药物。     

丹皮酚和厚朴酚体外抗菌作用的研究

为开发高效、安全的中草药抗菌促生长剂,采用微量肉汤稀释法测定了丹皮酚和厚朴酚对13种临床常见病原菌的体外抑菌活性。结果：丹皮酚和厚朴酚对13种临床常见病原菌均有不同程度的抗菌作用,丹皮酚对嗜水气单胞杆菌的作用最好（MIC为160μg／ml）,对肠道革兰氏阴性杆菌（MIC为320μg／ml）作用稍好于厚朴酚（MIC为640μg／ml）;厚朴酚对葡萄球菌（MIC为160μg／ml）抑制作用强于丹皮酚（MIC为320μg／ml）。     

中药单味药及复方对嗜水气单胞菌的体外抑菌作用

本试验用煎煮法提取中药有效成分,采用琼脂平板扩散法探讨了黄连、五倍子、大黄、诃子等中药单味药及中药复方对嗜水气单胞菌(Aeromonas hydrophila)的体外抑菌作用,测定了抑菌圈大小.采用双倍试管稀释法测得了最小抑菌浓度(MIC)和最小杀菌浓度(MBC).试验结果表明,16种中药提取物对嗜水气单胞菌有不同程度的抑制作用,其中五倍子、黄连、诃子、大黄的水提物的抑菌效果最好,MIC值分别为7.81 mg/mL、15,63 mg/mL、31.25 mg/mL、62.50 mg/mL.五倍子作为主药,分别与诃子、黄连、大黄接一定比例组成的复方的MIC分别为3.906 mg/mL、7.813 mg/mL、15.625 mg/mL.通过对筛选的复方与市场上销售的3种成品复方的体外抑菌活性的比较,发现本实验室筛选的复方对嗜水气单胞菌的体外抑菌活性更强.