3种兽药及其主要代谢产物在猪粪中的排泄规律

以磺胺二甲嘧啶、金霉素和泰乐菌素为研究对象,探讨在饲粮中添加兽药后,猪粪中3种兽药原形及其主要代谢产物的排泄规律。试验选取60头33k左右的长大二元杂交母猪,在饲粮中加入200mg／kg的磺胺二甲嘧啶、75mg／kg的金霉素和100mg／kg的泰乐菌素,分用药期和休药期收集猪粪检测其中的兽药原形及其代谢产物残留。结果表明,7d用药期内猪粪中磺胺二甲嘧啶及其主要代谢产物对位氨基乙酰化磺胺二甲嘧啶的平均残留分别为59．50,15．98μg／g;金霉素及其代谢产物4位差向异构金霉素平均残留分别为239．92,217．79μg／g;泰乐菌素A及其代谢产物泰乐菌素D的平均残留分别为10．50,65．99／μg／g。进入休药期后,猪粪中兽药原型及其代谢产物残留下降很快,到休药期结束时,相应试验组的猪粪中已检测不出金霉素及其代谢产物残留,但仍可检出磺胺二甲嘧啶及其代谢产物和泰乐菌素A及其代谢产物。由此可知,兽药的体内代谢产物在兽药的排泄中占重要比例,提示除兽药原形外还应重视其代谢产物进入环境后的生态毒理学效应。     

替米考星与泰乐菌素对畜禽常见病原菌抑菌作用比较

采用试管2倍稀释法对国产替米考星与泰乐菌素进行了畜禽常见的20种病原菌体外抑菌活性比较试验。结果表明,替米考星和泰乐菌素具有类似的抗菌谱,二者对革兰氏阳性菌均有良好的抑制作用。对革兰氏阴性菌二者除对禽多杀性巴氏杆菌、红斑丹毒丝菌、胸膜肺炎放线杆菌和鸡毒支原体均有较强的抑菌效果外,对其他菌则表现为抑菌效果较弱或抗药性。替米考星对部分病原菌如鸡白痢沙门菌、鼠伤寒沙门菌、肺炎克雷伯菌抑菌效果明显强于酒石酸泰乐菌素。总体来看,替米考星对畜禽常见病原菌的抑菌活性比泰乐菌素要强一些。     

酒石酸泰乐菌素微球的制备及其稳定性的初步考察

文章采用二步法制备酒石酸泰乐菌素明胶微球,并对其工艺进行了优化。同时对微球的外观、粒径与其分布、含量、稳定性等进行研究。结果表明,其平均粒径为11.26μm,粒径范围5～25μm的微球占83.7%,球内含药量43.75%。冰箱或室温放置时稳定。     

Screening and degradation characteristics of a tylosin-degrading strain

Antibiotics residues have been accumulating in the environment day by day due to overuse of antibiotics. Recalcitrant antibiotic residues, such as tylosin(TYL), can cause serious environmental problems, which makes it important to eliminate TYL from the environment. It is important to eliminate TYL from the environment. In this study, a strain was isolated and purified from fermentation by-product that came from a TYL production factory. The TYL degrading strain was identified by its morphology, physiological and biochemical reactions and sequencing the PCR-amplified fragments of its 16 S r DNAcoding genes. The temperature, shaking speed, initial TYL concentration, p H and inoculum sizes were investigated under simulated conditions by using single factor tests. The results showed that TYL2, a high efficient strain was isolated and was identified as Brevibacillus borstelensis. The degradation rate of TYL by this strain could reach to 75% with an initial concentration of 25 mg L~(–1) within 7 days under conditions of 7% B. borstelensis(v/v, 2×108 CFU m L~(–1)) at p H 7.0 and at 35°C. It is interesting that this strain has a very strong ability to degrade the TYL in natural sewage with the degradation rate of 65% within 7 days. This result could be helpful for the degradation of TYL and provide guidance for the degradation of other antibiotics.     

紫外分光光度法测定泰乐菌素注射液含量方法的建立

以0.1 mol/L盐酸溶液为参比液,采用紫外分光光度法在290 nm波长处测定泰乐菌素注射液中泰乐菌素的含量.结果表明,泰乐菌素在5 U/mL～50 U/mL浓度范围内,其吸光度与浓度呈良好的线性关系,相关系数r=0.999 2,平均回收率为99.6%,RSD为0.4(n=6).该方法操作简便、快速、准确,适于作为生产企业中问产品的质量控制方法.     

滤纸管保藏法在泰乐菌素生产中的应用

通过对传统滤纸管保藏法的改良,应用于泰乐菌素生产菌的保藏,分别在不同的保藏周期时活化进行生产能力验证,结果显示改良滤纸管保藏法使用方便,摇瓶效价不低于沙土管保藏法,而且批间差异小,生产能力不随保藏时间的延长而降低.     

Increased bioavailability of tylosin phosphate as in-feed medication formulated for long-action pellets in broiler chickens

Circadian variation of serum concentrations of tylosin in broiler chickens after in-feed medication prompted a comparison study of the serum profiles of this drug after in-feed medication with standard tylosin phosphate (Tprf reference formulation group), and after in-feed medication with a sustained-release pellet formulation (Tpsr group), based on Patent No.MX/a/2012/013222 and PCT/MX2013/000137, in broiler chickens. Six hundred 4-week-old Ross broiler chickens were in-feed medicated with tylosin phosphate at an approximate dose of 25.2 mg/kg/d, based on daily feed consumption values and a final concentration of tylosin in feed of 200 mg/kg of feed. Approximately 2 to 3 mL of blood were obtained per 5 chickens every 2 h, avoiding the sampling of a bird more than once and during 72 h after making medicated feed available for the first time. Serum concentrations of tylosin were determined by HPLC. Gaussian multi-peak regressions were then fitted to serum concentration vs. time profiles. Day by d areas under the serum concentration vs. time profiles (AUC_0–24), as well as overall AUC_0–72, were statistically higher for the Tpsr group (P < 0.001). Also, maximum serum concentrations obtained and relative bioavailability for the Tpsr formulation were statistically higher (382.8%) as compared to the Tprf group (P < 0.01). Considering the referred improved values of AUC observed in the Tpsr formulation, as well as the fact that tylosin is a time-dependent antibacterial drug, better clinical responses are postulated with this pharmaceutical preparation intended for chickens. Tissue deposition studies for this new formulation of tylosin are required.     

酒石酸泰乐菌素联合阿莫西林钠缩小猪链球菌耐药突变选择窗的研究

为了使临床合理使用抗菌药物,防止细菌耐药性的产生提供理论依据。本研究探讨了在体外初步联合用药缩小猪链球菌(S.suis)的耐药突变选择窗(MSW)。应用肉汤法富集1010CFU/mL细菌,琼脂平板二倍稀释法分别测定酒石酸泰乐菌素(TLST)、阿莫西林(Amoxil)钠及两药联用后对S.suis分离株D10的防突变浓度(MPC)和MSW。TLST、Amoxil钠单药和两药联用对S.suis分离株D10的MSW分别为9.71、5.16和2.81。TLST和Amoxil钠联合用药使TLST对D10的MSW缩小3.5倍;TLST和Amoxil钠联合用药使Amoxil钠对D10的MSW缩小1.8倍。TLST和Amoxil钠联合用药可缩小各自单药对S.suis分离株D10的MSW。     

水产品中泰乐霉素残留检测技术研究进展

当前,对食品中农药残留的监控日益受到重视。泰乐霉素是我国规定的一种禁用渔药,但是该药物在水产品中残留量的检测方法尚无国家标准可以参考。本文主要分析比较了微生物效价法、酶联免疫法、紫外分光度法、高效液相色谱法、高效液相色谱-质谱联用法等检测方法的优劣,认为采用高效液相色谱法和高效液相色谱-质谱联用法检测泰乐霉素药物残留能够很好地满足标准限量的要求。