HPLC-ELSD测定猪配合饲料中的大观霉素含量

大观霉素常被用于饲料添加剂中防治猪的细菌感染及支原体病,但是对于饲料中添加的大观霉素尚无检测方法.研究通过向空白猪配合饲料中添加不同质量浓度的大观霉素对照品,经提取和净化后,利用高效液相色谱-蒸发光散射检测器(HPLC-ELSD)对其中大观霉素的含量进行测定.结果表明:大观霉素在5～100 mg/kg内具有良好的线性关系,检测限和定量限分别为2和5 mg/kg;在样品中添加5、20和100 mg/kg的大观霉素,平均回收率为71.4 ％～88.6％,每质量浓度6个重复样品的变异系数分别为6.1％、4.8％和1.9％,满足对饲料样品检测的要求.该方法是首次利用高效液相色谱检测法测定猪配合饲料中大观霉素含量.     

盐酸林可霉素和硫酸大观霉素及其复方的体外抗菌试验

选取 2 0种临床常见畜禽病原微生物 ,观察其对盐酸林可霉素、硫酸大观霉素、盐酸林可霉素和硫酸大观霉素复方以及对照药物青霉素的敏感性。其结果为 :盐酸林可霉素、硫酸大观霉素、盐酸林可霉素和硫酸大观霉素、青霉素对2 0种病原微生物的最小抑菌浓度 (MIC)分别是0 .0 6～ 2 56,0 .98～ 2 56,0 .1 3 / 0 .2 6～ 3 2 / 64μg/m L和 0 .0 6～ 2 56μg/ m L。     

大观霉素间接竞争ELISA的建立

本研究的目的是建立大观霉素的间接竞争性ELISA(icELISA),用于动物源性食品的检测。在优化的条件下,建立了大观霉素icELISA的标准曲线,半抑制浓度IC50=1.78ng/mL。多克隆抗体对大观霉素的特异性较强,与其他氨基糖苷类化合物有微小的交叉。分别对20份空白的牛奶、猪肉、鸡肉进行检测,确定这些样本中大观霉素的检测限分别是4.8、9.3、10.0μg/kg。在样本中添加不同浓度的大观霉素,添加回收率的范围为77.1%~116.0%,变异系数为4.6%~9.7%;ELISA和GC/MS两种方法分析结果无显著性差异(P0.05)。结果表明,本研究成功建立了大观霉素的icELISA,用于检测牛奶、猪肉、鸡肉中大观霉素,准确度和精密度均满足兽药残留检测的要求。     

郑州牧专教授、硕士生导师,河南省康星药业公司技术总监李荣誉:根据药物动力学特征,制定合理的给药方案

<正>1选择有效抗菌药物在正确诊断的基础上,选择有效抗菌药物是确保疗效的前提。选用药物的原则是:首先能用窄谱不用广谱,能用一种不用两种,以保证高抗菌活性。例如能用大观霉素则不用氟苯尼考,能用大观霉素则不用大观霉素加氟苯尼考。     

HPLC-ECD法测定大观霉素的含量

建立了HPLC—ECD法测定大观霉素含量的分析方法。采用高效液相色谱-电化学检测器,Waters XBridge C18色谱柱（4．6mm×250mm,5μm）,以pH3．2的革酸盐缓冲溶液-乙腈（1000：105,V：V）为流动相,流速1．0mL／min;柱后衍生溶液为21g／L的NaOH溶液,流速0．5mL／min;ECD系统参数：极性为阳性,检波＋0．12V,氧化电位＋0．70V,还原电位-0．60V,范围5μA。结果表明,大观霉素及4R一二氢大观霉素在40～320μg／mL范围内呈良好的线性关系（大观霉素r=0．9999,4R-二氢大观霉素r=0．9992）,平均回收率为100．0％（n=9）,RSD为0．2％。该方法解决了微生物效价测定大观霉素含量偏高的难题,且操作简便、结果准确,可用于大观霉素及相关制剂产品的质量控制。     

大观霉素分析方法的研究进展

对近20年来大观霉素的分析检测方法进行了介绍，如微生物法、分光光度法、薄层色谱法HPLC法、气相色谱法、免疫分析法，以及它们在大观霉素在食品中残留检测中的应用实例。     

赛林注射液治疗猪气喘病的疗效观察

用赛林注射液(盐酸大观霉素、盐酸林可霉素)、盐酸大观霉素注射液、盐酸林可霉素注射液进行猪气喘病对比治疗。结果:赛林组(高、中、低剂量)治疗猪气喘病总有效率为93.3%,与盐酸林可霉素组有效率85%相比较,差异显著(P0.05);与盐酸大观霉素组有效率35%相比较,差异极显著(P0.01)。试验表明,赛林注射液治疗猪气喘病疗效确实。     

赛林注射液治疗猪喘气病的疗效观察

以广西柳州市某猪场爆发猪喘气病为对象,用赛林注射液（盐酸大观霉素盐酸林可霉素）、盐酸大观霉素注射液、盐酸林可霉素注射液进行对比治疗。结果表明,赛林组的高、中、低剂量治疗猪喘气病总有效率分别为95%、95%、90%;与盐酸林可霉素组的总有效率85%相比,差异显著（P〈0.05）;与盐酸大观霉素组的总有效率35%相比,差异极显著（P〈0.01）。     

液相色谱串联质谱法测定饲料中的盐酸大观霉素

本文研究了液相色谱和液相色谱-串联质谱检测饲料中大观霉素药物残留的方法,此方法简便、快捷,是一种可靠的检测方法,适用于对饲料中大观霉素进行确证分析。饲料中大观霉素的定量限为:2mg/kg,当添加量为2、20、50mg/kg三个添加浓度时回收率分别为70.06%～107.6%、70.5%～99.5%、70.1%～103.6%,批内批间变异系数小于20%,线性范围及定量限也在合理范围内。     

赛林(盐酸大观霉素盐酸林可霉素射注射液)治疗猪喘气病的疗效观察

以广西柳州市某猪场爆发猪喘气病为对象,用赛林(盐酸大观霉素盐酸林可霉素射注射液)、盐酸大观霉素注射液、盐酸林可霉素注射液进行了对比治疗。结果:赛林组高、中、低剂量治疗猪喘气病的总有效率分别为95%、95%和90%,与盐酸林可霉素组的总有效率85%相比较,差异显著(P0.05);与盐酸大观霉素组的总有效率35%相比较,差异极显著(P0.01)。试验表明,赛林治疗猪喘气病疗效确实。     

Quantitative susceptibility of Streptococcus suis strains isolated from diseased pigs in seven European countries to antimicrobial agents licensed in veterinary medicine

The susceptibility of Streptococcus suis strains (n=384) isolated from diseased pigs in seven European countries to 10 antimicrobial agents was determined. For that purpose a microbroth dilution method was used according to CLSI recommendations. The following antimicrobial agents were tested: ceftiofur, cefquinome, enrofloxacin, florfenicol, gentamicin, penicillin, spectinomycin, tetracycline, tilmicosin and trimethoprim/sulphamethoxazole. Using breakpoints established by CLSI for veterinary pathogens, all strains were susceptible to ceftiofur, florfenicol, enrofloxacin and penicillin. MIC-90 values of these antibiotics were < or = 0.03, 0.5, 2 and < or = 0.13 microg/mL, respectively. A low degree of resistance was observed for gentamicin (1.3%), spectinomycin (3.6%) and trimethoprim/sulphamethoxazole (6.0%). MIC-90 values of these antibiotics were 8, 16 and 2 microg/mL, respectively. A high level of resistance was observed for tetracycline (75.1%). A MIC-90 value of 64 microg/mL was found for this antibiotic. Serotype-associated differences in MIC-90 values were observed for tetracycline, tilmicosin and trimethoprim/suphamethoxazole.     

林可霉素-大观霉素复方混悬注射液中有效成分含量的HPLC法测定

建立了测定林可霉素-大观霉素复方油混悬注射液中盐酸林可霉素与盐酸大观霉素含量的高效液相色谱(HPLC)方法.采用C18色谱柱(4.6mm×250 mm,5 μm),检测林可霉素的流动相为0.05mol/L硼砂溶液(用850 mL/L磷酸调节pH至5.0)-甲醇-乙腈(60∶36∶4),检测波长为214 nm;检测大现霉...     

In vitro susceptibility of avian Escherichia coli and Pasteurella multocida to danofloxacin and five other antimicrobials.

The in vitro susceptibility of Escherichia coli and Pasteurella multocida isolated from poultry was determined to danofloxacin, a novel fluoroquinolone, and five other commonly used antimicrobials. A total of 1737 E. coli field isolates and 107 P. multocida isolates were tested by veterinary diagnostic laboratories in Europe, Japan, South Africa, and North America during the period 1989-91. The antimicrobial susceptibility of these isolates was determined using the Sensititre broth microdilution technique. The minimum inhibitory concentrations (MIC) of danofloxacin, furaltadone, lincomycin, oxytetracycline, spectinomycin, and trimethoprim:sulfamethoxazole that prevented growth of 90% of the bacteria were 0.25 > 64, > 64, > 64, > 128, and > 16 micrograms/ml, respectively, against E. coli isolates and 0.25, 64, 64, 16, 128, and 8 micrograms/ml, respectively, against P. multocida isolates. Danofloxacin demonstrated considerable in vitro potency against these important poultry pathogens, many of which showed extensive resistance to the other antimicrobials tested.     

超抗原及其在兽医科学上的应用

超抗原以极低的浓度就能引起机体免疫细胞、细胞因子和抗体的巨大变化,引起机体一系列病理生理过程。鉴于超抗原的这种特性,医学上已成功将其用于癌症和病毒病的辅助治疗。在兽医科学上,超抗原有望在兽医病理学、兽医药理学、兽医临床治疗和兽医预防方面得到广泛的应用。     

Antimicrobial sensitivity testing of Australian isolates of Bordetella avium and the Bordetella avium-like organism

SUMMARY: The in-vitro sensitivity of 16 Australian isolates of Bordetella avium and 15 isolates of B avium -like organism to 11 antimicrobial agents or combinations of agents was determined using a microtitre plate system to establish minimal inhibitory concentrations. All the B avium isolates were sensitive to ampicillin but resistant to erythromycin, lincomycin, spectinomycin, sulphamethoxazole, trimethoprim, and lincomycin + spectinomycin. Most of the B avium isolates were sensitive to tetracycline and resistant to streptomycin and sulphadiazine. All the B avium -like isolates were resistant to ampicillin, erythromycin, lincomycin, spectinomycin, streptomycin, tetracycline, trimethoprim, and lincomycin + spectinomycin. Most B avium -like isolates were sensitive to sulphadiazine, sulphamethoxazole and trimethoprim-sulphamethoxazole.     

宁夏规模养殖场（园区）兽药使用管理现状调研及规范化管理探讨

为了有的放矢地推进兽药使用管理和确保兽用使用安全,对宁夏省规模养殖场（园区）兽药使用管理的技术力量、兽药贮存条件、兽药来源及贮存方式、兽药使用及休药期执行情况等进行了调查分析,表明规范兽药使用管理已具备有利条件,同时探讨了规范兽药使用管理的主要内容和重点措施。     

Rapid isolation of Brachyspira hyodysenteriae and Brachyspira pilosicoli from pigs

The aim of this study was to compare and evaluate the time required to isolate Brachyspira hyodysenteriae and Brachyspira pilosicoli from porcine faeces. This was done using previously described selective media (spectinomycin) S400, (colistin, vancomycin and spectinomycin) CVS and (spectinomycin, vancomycin, colistin, spiramycin and rifampin with swine faecal extract) BJ, compared with the method based on blood agar modified medium, with spectinomycin and rifampin (BAM-SR), including a pre-treatment step. Fourteen spirochaetal strains were obtained in pure cultures after 5 days (48 h in BAM-SR primary plate and three passages every 24 h in brain heart infusion (BHI) without antibiotics) pre-treating simulated samples in brain heart infusion broth with spectinomycin (400 microg/ml) and rifampin (15 microg/ml), before streaking on the selective BAM-SR medium. Spirochaetes from samples in S400, CVS and BJ, with and without pre-treatment, were obtained in pure cultures only after repeatedly transferring on plates of the same selective medium requiring 15-18 days according to the strain. BAM-SR used after the pre-treatment step showed a detection limit ranging from 3.5 x 10(2) to 6.7 x 10(7) cells/g faeces and was the only method able to support the growth of spirochaetes after 48 h.     

Construction of a stable non-mucoid deletion mutant of the Streptococcus equi Pinnacle vaccine strain

Streptococcus equi causes equine strangles, a purulent lymphadenopathy of the head and neck. An avirulent, non-encapsulated strain (Pinnacle) has been used widely in North America as an intranasal vaccine. The aim of the study was to create a specific mutation of the hyaluronate synthase (hasA) gene in Pinnacle to permanently abolish the production of capsule and provide an easily recognisable genetic marker. An internal fragment of hasA was generated by PCR and cloned into pTW100 (Microscience, UK). An encapsulated revertant of Pinnacle was then transformed with the recombinant plasmid by electroporation and cultured under conditions to promote homologous recombination. Among 90 spectinomycin resistant transformants observed, one non-mucoid (non-encapsulated) spectinomycin resistant colony was detected. The presence of plasmid sequence within the hasA gene was confirmed by the PCR. After six passages in antibiotic-free medium, four non-mucoid spectinomycin sensitive colonies were found. Sequence analysis of one of these clones, designated Pinnacle HasNeg, revealed loss of the 3' end of the hasA and the 5' end of the hasB genes. This deletion mutant should serve as a useful candidate to replace Pinnacle since it cannot revert to a mucoid phenotype and can be distinguished genetically from wild type strains.     

《兽医药理学》教学改革探讨

《兽医药理学》是动物医学专业的一门重要基础课程,也是由基础学科向临床学科过渡的桥梁学科。按照培养目标和要求,从理论课和实验课教学方法及提高教师自身素质等环节入手进行了教学改革,对充分调动学生的学习积极性以及培养学生的实验创新能力具有重要的作用,并收到了良好的教学效果。