中药"肠宁"对致病性大肠杆菌K88的抑菌效果及对细菌形态影响的研究

为了探明中药“肠宁”的抑菌疗效,本试验以致病性大肠杆菌K88为试材,通过葡萄糖酚红肉汤稀释法,研究了不同提取方式提取的中药“肠宁”的抑菌效果及亚抑菌浓度下对细菌形态的影响。结果表明循环回流浸出法制得的中药“肠宁”最小抑菌浓度为0．0625g／mL,亚抑菌浓度为0．03125g／mL;煎煮法最小抑菌浓度为0．5g／mL,亚抑茵浓度为0．25g／mL;而冷浸法制得的1g／mL中药“肠宁”无抑菌作用。循环回流浸出法提取的中药“肠宁”在亚抑菌浓度下对细菌形态有明显的影响。     

山莓抗腹泻机制初步研究

为了探讨山莓抗腹泻机制,采用管碟法和试管法研究其体外抑菌效果,采用离体肠实验法观察其对离体肠管运动的影响.结果表明:山莓叶提取物对金黄色葡萄球菌、大肠杆菌和痢疾杆菌均有显著的抑菌效果,MIC分别为12.5 mg/ml、25 mg/ml和25 mg/ml;并能显著抑制家免离体十二指肠、空肠、回肠和结肠的运动,使其张力减小,但对其频率的变化影响不明显,山莓对十二指肠运动的抑制作用可能由胆碱能M受体介导.山莓抑菌和抑制肠管运动可能是其抗腹泻的机制.     

黄芩中黄芩苷的正交提取工艺及体外抑菌活性研究

采用正交提取法提取黄芩中黄芩苷,HPLC法检测其含量,并测定提取物对大肠埃希氏杆菌、金黄色葡萄球菌两种供试菌的体外最小抑菌浓度（MIC）。结果表明,最佳正交提取工艺为A2B2C3,即乙醇浓度70％、体积100mL、冷浸36h,提取物对大肠埃希氏杆菌、金黄色葡萄球菌的MIC分别为0．50mg／mL和0．20mg／mL。     

高速逆流色谱分离黄连生物碱及其抑菌活性初探

为了研究黄连生物碱的抑菌活性,采用高速逆流色谱(HSCCC)法分离黄连生物碱,K-B法检测其抑菌活性,测其对敏感菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果显示：从黄连中分离出黄连碱、掌叶防己碱、小檗碱、表小檗碱,提取率分别为44.41%、36.72%、68.54%、18.33%;对金黄色葡萄球菌的抑菌圈分别为10.00、29.50、21.00和12.50 mm;对无乳链球菌分别为11.40、27.50、14.00和15.50 mm;对粪肠球菌、大肠杆菌O157等均无效;黄连碱、表小檗碱对金黄色葡萄球菌、无乳链球菌的MIC和MBC均分别为136.36、272.73μg/mL;小檗碱对金黄色葡萄球菌的MIC和MBC分别为62.18、136.36μg/mL,对无乳链球菌的MIC和MBC分别为136.36、272.73μg/mL;掌叶防己碱对金黄色葡萄球菌、无乳链球菌的MIC和MBC均分别为62.18、136.36μg/mL。结果表明：用HSCCC制备生物碱,省时、方便,4种生物碱对金黄色葡萄球菌和无乳链球菌作用明显,对其余试验菌无效。     

头孢喹肟对大肠杆菌防突变浓度的测定

采用标准琼脂二倍稀释法测定了头孢喹肟对大肠杆菌的最低抑菌浓度;用肉汤法富集了大肠杆菌;用琼脂稀释法测定了头孢喹肟对大肠杆菌的暂定防突变浓度（MPCPr）及防突变浓度（MPC）。结果显示,头孢喹肟对大肠杆菌标准株（ATCC25922）的MIC和MIC99分别为0．125μg／mL和0．1μg／mLMPCPr和MPC分别为0．5μg／mL和0．256μg／mL,MPC／MIC99比值为2．56。头孢喹肟对50株大肠杆菌临床分离株的MIC90和MPC90分别为0．2μg／mL和0．8μg／mL,MPC90／MIC90比值为4。说明头孢喹肟限制大肠杆菌耐药突变的能力很强,ATCC25922的选择指数（SI）仅为2．56,临床分离株的SI为4。     

9种抗菌药物对禽多杀性巴氏杆菌体外抗菌活性研究

采用试管二倍稀释法，测定了9种抗菌药物对禽多杀性巴氏杆菌的体外抗菌活性（MIC和MBC）。结果表明氨苄西林、阿莫西林和诺氟沙星对禽多杀性巴氏杆菌的MIC均为0．125μg／mL，诺氟沙星MBC为0．5μg／mL，氨苄西林和阿莫西林的MBC都为1．0μg／mL。氟苯尼考、替米考星和卡那霉素对禽多杀性巴氏杆菌的MIC分别为：0．5、2和2μg／mL。     

骆驼蓬提取物抑菌活性的研究

以番茄灰霉菌、番茄早疫菌、黄瓜黑星菌、黄瓜枯萎菌、茄立枯丝核菌为供试菌,采用生长速率法对不同溶剂、不同方法获得的提取液进行了室内生物测定,结果表明：连续回流提取法和冷浸法为其适宜的提取方法,甲醇则为最适提取溶剂。在孢子萌发法试验中,骆驼蓬提取物（提取方法为冷浸法,提取溶剂为甲醇）对番茄灰霉菌、黄瓜枯萎菌、番茄早疫菌、黄瓜黑星菌等4种病原菌的孢子萌发均有一定的抑制作用,其EC50分别为0．060、0．199、0．105、0．223g／mL。在黄瓜子叶法测定中,处理36h后,骆驼蓬甲醇提取物对番茄灰霉菌保护作用和治疗作用的EC50分别为1．495和1．557g／mL。     

响应面法优化秃疮花中生物碱提取工艺及抑菌活性研究

以秃疮花为研究对象,在单因素水平测定的基础上,通过响应面法优化其提取工艺,并使用响应面法提取浓缩液进行抑菌活性测定,以大肠埃希氏杆菌为研究对象,进行透射电镜观察。结果显示,秃疮花生物碱最佳提取工艺条件为:液料比15 mL/g、超声时间35 min、回流时间2.5 h、乙醇浓度65%,在此工艺下秃疮花生物碱含量为9.33%;其响应面法提取浓缩液对大肠埃希氏杆菌、白色念珠菌、绿脓杆菌的最小抑菌浓度分别为0.20,0.15和0.35 mg/mL,最低杀菌浓度分别为0.15,0.10和0.30 mg/mL;在透射电镜下观察到对大肠埃希氏杆菌抑制效果显著。表明响应面法对秃疮花生物碱提取工艺的优化比较合理。     

夏枯草等14味中药对金黄色葡萄球菌的体外抑菌活性

采用索氏提取,超声波和水煎煮方法提取夏枯草等14味中药的有效部位,应用二倍试管稀释法分别测定其提取物对金黄色葡萄球菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。结果显示,夏枯草、虎杖、何首乌、连翘、柴胡、穿心莲、地榆7味中药有效部位对金黄色葡萄球菌的抗菌活性最强,其MIC为1．953～3lI250g／L,MBC为3．90～31．25g／L;佛手、黄柏2味中药有效部位具有较强的体外抗菌活性,其MIC值为62．5g／L,MBC值为125．0g／L;大青叶、板蓝根、金银花、杜仲、白头翁5味中药有效部位的抗菌活性较差,其MIC值为125．0g／L,MBC值为250．0,≥250．0g／L。不同中药有效部位对金黄色葡萄球菌的抗菌活性有所差异,其中夏枯草、虎杖、何首乌、地榆和佛手有效部位对金黄色葡萄球菌具有较好的抗菌活性。     

二甲脂和富马酸抗菌药对常见病原菌的作用效果试验

本试验用二甲脂和富马酸2种抗菌药，采用4种不同试验方法对常见病原菌进行了抑菌和杀菌试验，二甲脂对大肠杆菌、沙门氏菌、葡萄球菌、巴氏杆菌、链球菌的最低抑菌浓度(MIC)分别为0．5mg／mL、0．5mg／mL、0．25mg／mL、0．25m／mL、0．5mg／mL：富马酸对以上5种细菌的最低抑菌浓度分别为0．5mg／mL、0．25mg／mL、0．5mg／mL、0．5mg／mL和0．5mg／mL。二甲脂对以上5种细菌的最小杀菌浓度(MBC)分别为1mg／mL、1mg／mL、0．5rag／mL、0．5mg／mL、1mg／mL；富马酸的MBC分别为1mg／mL、0．5mg／mL、1mg／mL、1mg／mL、1mg／mL。在杀菌效果的测定中，二甲脂在1：600时作用10min．对沙门氏菌杀菌率为99％，对巴氏杆菌和链球菌的杀菌率为98％。富马酸在1：600时作用10min，沙门氏菌杀菌率为99％，对巴氏杆菌和链球菌的杀菌率为97．5％和97％，其各浓度的时间段的杀菌率均为100％，其余均为100％。用纸片扩散法，二甲脂在1：200时其抑菌圈为12～14mm，1：400时为12～13mm，1：600时为11．5～12mm；富马酸在1：200时其抑菌圈为12～14mm，1：400时为12～13mm，1：600时为11．5～12mm，其各浓度的时间段的杀茸均为100％。     

山莓粗提物对家兔离体十二指肠运动的影响

采用离体肠管试验法和Pclab生物信号采集处理系统,将兔的十二指肠置于恒温通气Tyrode氏液中,分别加入不同浓度的山莓根茎叶粗提物,以观察粗提物对离体十二指肠运动的影响。结果表明:山莓粗提物能使十二指肠收缩活动受到抑制,使其张力减小,对其频率的变化不明显;山莓不同部位的粗提物对十二指肠的运动影响存在差异,以叶最为明显,根茎次之;且随着浓度的增大对十二指肠的影响增大。     

谷精草有效成分分析及体外抗菌活性测定

采用试管法和圆形滤纸层析法分析鉴定了谷精草的化学成分,结果表明:谷精草含有生物碱、酚性成分、有机酸、黄酮及其甙类、挥发油、植物甾醇、鞣质等化学成分。用纸片法和试管法对谷精草水提取液进行了体外抗菌作用试验,结果表明:谷精草水提取液对金色葡萄球菌、链球菌、巴氏杆菌、沙门氏菌、大肠杆菌等兽医临床常见病原微生物都有较强的抗菌作用,抑菌圈直径分别为12.16±0.33mm,15.36±0.29mm,13.57±0.61mm,8.63±0.26mm,9.88±0.72mm;谷精草水提取液对金色葡萄球菌、链球菌、巴氏杆菌、沙门氏菌、大肠杆菌的最低抑菌浓度(MIC)分别为0.125g/ml、0.063g/ml、0.125g/ml、0.5g/ml、0.25g/m;最低杀菌浓度(MBC)分别为0.25g/ml、0.125g/ml、0.25g/ml、1g/ml、1g/ml。     

黔西北岩溶区九种灌木综合营养价值评价

灌木作为山羊日粮主要成分,能为家畜补充能量、蛋白质、矿质和多种维生素等,明晰灌木营养价值对野生灌木资源开发具重要意义。本研究定量分析了黔西北9种野生饲用灌木的矿质成分和营养价值,用隶属函数法和灰色关联法与聚类分析对其营养价值进行评价和分类。结果表明,9种灌木矿质含量为,Ca:0.56%~1.10%;P:0.08%~0.21%;Na:0.26%~0.36%;K:0.7%~1.8%;Mg:0.25%~1.00%;Fe:0.03%~0.06%;Cu:15.2~24.1 mg/kg;Mn:76.5~114.0 mg/kg;Zn:33.2~113.1 mg/kg。营养价值为,CP:7.5%~17.1%;WSC(除羊奶子):7.8%~13.6%;ADF:11.2%~26.5%;NDF:16.2%~45.1%;ME:5.9~7.9 MJ/kg;OMD:37.1%~49.4%。隶属函数法和灰色关联法与聚类分析对9种灌木矿质成分、营养价值和综合营养价值评价结果类似;矿质成分为,悬钩子和平枝栒子>老母七和中华柳>羊奶子和红果蔷薇>黄花香、醉鱼草和救军粮;营养价值为,救军粮>羊奶子>老母七>黄花香、醉鱼草、中华柳、红果蔷薇、悬钩子和平枝栒子。综合营养价值评价和聚类结果为,悬钩子和平枝栒子属优等饲料,老母七、中华柳、羊奶子、红果蔷薇和救军粮属良等饲料,黄花香和醉鱼草属中等价值饲料。营养价值评价应考虑植物矿质成分、营养价值和生物活性物质及家畜采食特性。     

In Vitro Antimicrobial Activity of Sarafloxacin against Clinical Isolates of Bacteria Pathogenic to Fish

Abstract

An in vitro susceptibility assay of sarafloxacin (A-56620), a new 4-quinolone, was performed against five important bacterial species that are pathogenic to fish. A collection of 44 clinical isolates and five corresponding type strains were included in the study. The objectives were to determine the minimal inhibitory concentrations (MICs) of sarafloxacin by a drug microdilution method and to compare the MIC values at two different temperatures, 4 and 15°C. Sarafloxacin was active against all species tested and showed the following mean MIC values at 15 and 4°C, respectively, against the bacterial pathogens investigated: Aeromonas salmonicida subspecies salmonicida, 0.029 and 0.045 μg/mL; atypical A. salmonicida, 0.053 and 0.041 μg/mL; Vibrio anguillarum, 0.085 and 0.054 μg/mL; V. salmonicida, 0.125 and 0.123 μg/mL; and Yersinia ruckeri, 0.023 and 0.031 μg/mL. The MICs ranged from 0.0025 μg/mL (or less) for two strains of A. salmonicida salmonicida to 0.32 μg/mL for one strain of atypical A. salmonicida and one strain of V anguillarum. A decrease in antimicrobial activity was observed as the incubation temperature was lowered from 15 to 4°C; however, no significant statistical difference between the measured values was demonstrated.     

库拉索芦荟提取物对维氏气单胞菌抑菌作用的研究

采用榨汁法、水煮法和醇提法制备库拉索芦荟提取物,通过K-B法和二倍稀释法测定3种方法芦荟提取物对维氏气单胞菌的抑菌作用。结果显示,用3种方法制备的库拉索芦荟提取物对维氏气单胞菌均有不同程度的抑制作用,榨汁法、水煮法和醇提法得到的库拉索芦荟提取物对3株维氏气单胞菌的平均最小抑菌浓度(minimal inhibitory concentration,MIC)分别为1、0.5和0.125 g/mL,最小杀菌浓度(minimal bactericidal concentration,MBC)分别为1、1和0.25 g/mL。库拉索芦荟提取物对3株维氏气单胞菌均有抑制作用,芦荟提取物浓度越高抑菌效果越明显,其中醇提法的抑菌效率高,水煮法的抑菌作用其次,榨汁法的抑菌效果较弱。     

建立水产品中己烯雌酚残留ELISA检测方法

本试验利用己烯雌酚(DES)单克隆抗体,通过优化反应条件,加标回收试验,确定ELISA检测方法相关参数,建立了己烯雌酚残留的酶联免疫吸附(ELISA)检测法。试验结果显示,包被抗原最佳浓度为2μg/mL,DES单克隆抗体最佳稀释倍数为1∶3×104;标准曲线呈线性相关,相关系数R2=0.9956,IC50=1.103 ng/mL,最适检测范围为0.125~128 ng/mL,检测敏感度为0.077 ng/g;批内和批间变异分别为6.14%和7.48%;鳝鱼肌肉组织的加标回收率为77.6%~94.6%;特异性试验结果表明,该单抗与己烯雌酚单羧丙基醚交叉反应率为112.7%,与其它水产禁用药物交叉反应率0.1%。     

Susceptibility of rapidly growing mycobacteria and Nocardia isolates from cats and dogs to pradofloxacin

Rapidly growing mycobacteria (RGM) and Nocardiae can cause severe or refractory infections in cats and dogs. Prolonged antibacterial therapy is required to cure these infections. As fluoroquinolones have been used in combination therapy for treating RGM infections, isolates from the Mycobacterium smegmatis cluster (n=64), Mycobacterium fortuitum cluster (n=17), and M. mageritense cluster (n=2), collected from feline and canine patients, underwent susceptibility testing to pradofloxacin. The MIC(50), MIC(90) and tentative epidemiological cut-off (ECOFF) values as determined by microbroth dilution susceptibility testing that inhibited growth of the M. smegmatis and M. fortuitum clusters were 0.063, 0.125 and ≤ 0.25; and 0.125, 0.250 and ≤ 1.0 μg/mL, respectively. E-Test results showed similar trends but MICs were lower than those for microbroth dilution. In summary, pradofloxacin demonstrated effective in vitro activity against RGM isolates. Additionally, veterinary isolates of Nocardia nova (n=18), Nocardia farcinica (n=3) and Nocardia cyriacigeorgica (n=1) underwent microbroth dilution testing to ciprofloxacin, enrofloxacin and pradofloxacin. The MIC(50) and MIC(90) of pradofloxacin, ciprofloxacin and enrofloxacin that inhibited growth of Nocardia nova isolates were 2 (4), 8 (16), 16 (32) μg/mL, respectively. The tentative ECOFF values for pradofloxacin and ciprofloxacin were 32 μg/mL and for enrofloxacin 64 μg/mL. The MIC or MIC range for the three N. farcinica isolates of pradofloxacin, ciprofloxacin and enrofloxacin were 0.25-0.5, 2 and 2 μg/mL and for the single N. cyriacigeorgica isolate were 1, 4 and 4 μg/mL, respectively. On the basis on these results, fluoroquinolones appear to have limited therapeutic potential for most Nocardia infections.     

联合固氮菌株分泌能力及其对燕麦的促生效应测定

测定了分离自草坪草和燕麦根际的固氮菌株的分泌植物生长素(IAA)能力及其对燕麦的促生效应。结果表明:11株固氮菌都能分泌IAA,其中加前体(色氨酸)浓度在2.16~22.3μg/mL的有9株浓度大于10μg/mL;不加前体浓度在0.81~13.8μg/mL的有6株浓度大于10μg/mL,有6株能够溶解有机磷,3株能够溶解无机磷,且溶磷强度在58~82μg/mL,1株既能溶解有机磷,又能溶解无机磷;试管试验中除了2株效果比对照差外,其他9株株高增加62.8%~142.8%、叶绿素增加2.78%~63.89%、地上植物量增加21.45%~150.48%、地下植物量增加2.04%~70.75%、总根长增加2.27%~41.27%、根表面积增加11.32%~84.9%;另外I017和I012两个菌株分泌激素能力较好,I016菌株综合能力较好。     

Epidemiological Cut-off Values (ECOFFs) of Salmonella from Chicken Intestinal Tract for Three Animal-specific Antibiotics

In order to establish epidemiological cut-off values (ECOFFs) of Salmonella for three animal-specific antibiotics (florfenicol,apramycin and danofloxacin) in Guangdong province.A total of 166 strains of Salmonella isolates from chicken intestinal tract from veterinary clinics and farms in Guangdong province in 2017 were recruited in this study,the minimum inhibitory concentrations (MIC) of florfenicol,apramycin and danofloxacin were determined in triplicate for each bacterial strain using the agar dilution method on Mueller-Hinton agar plates according to the CLSI reference method (CLSI-M100-S26).ECOFFs were calculated for the MIC data sets by application of nonlinear regression analysis,NRI(normalized resistance interpretation) and ECOFFinder software.MIC distribution of florfenicol,apramycin and danofloxacin against Salmonella from 2 to >512,4 to >512 and 0.015 to 64 μg/mL,respectively.MIC₅₀ and MIC₉₀ for apramycin,florfenicol and danofloxacin were 256 and >512,16 and >512,0.5 and 16 μg/mL,respectively.MIC distribution of apramycin and florfenicol presented obvious unimodal shape,while that of danofloxacin was a discontinuous multi-peak.The ECOFFs of florfenicol,apramycin and danofloxacin were recommended to be 16,16 and 0.125 μg/mL,respectively.In present study,the ECOFFs of Salmonella from chicken intestinal tract for apramycin,florfenicol and danofloxacin were determined,which provided scientific basis for resistance surveillance.