大肠杆菌对环丙沙星和恩诺沙星的敏感性恢复

为给制定临床使用抗菌药物的轮换用药方案,降低耐药性的危害提供科学依据,采用单因素试验和正交试验方法,研究不同细菌传代、营养因素和耐药菌下大肠杆菌耐药菌株D600对环丙沙星、恩诺沙星耐药水平的影响。结果表明:D600经210代传代,对环丙沙星的最小抑菌浓度(MIC)由128μg/mL(高度耐药)降至32μg/mL(中度耐药),而对恩诺沙星的MIC值没有变化;在稀释32倍的LB肉汤培养基中传代,D600对环丙沙星、恩诺沙星的MIC值由≥128μg/mL(高度耐药)分别降至0.25μg/mL和1μg/mL(敏感)。营养因素水平越低、传代次数越多、耐药菌比例越小,D600对药物的MIC值越小,直至恢复到敏感。且上述因子对环丙沙星敏感性恢复的作用强于恩诺沙星。     

Pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in freshwater crocodiles (Crocodylus siamensis) after intravenous and intramuscular administration

To the best of the authors’ knowledge, pharmacokinetic information to establish suitable therapeutic plans for freshwater crocodiles is limited. Therefore, the purpose of this study was to clarify the pharmacokinetic characteristics of enrofloxacin (ENR) in freshwater crocodiles, Crocodylus siamensis, following single intravenous and intramuscular administration at a dosage of 5 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 hr. The plasma concentrations of ENR and its metabolite ciprofloxacin (CIP) were measured by liquid chromatography tandem–mass spectrometry. The concentrations of ENR and CIP in the plasma were quantified up to 144 hr after both the administrations. The half-life was long (43–44 hr) and similar after both administrations. The absolute i.m. bioavailability was 82.65% and the binding percentage of ENR to plasma protein ranged from 9% to 18% with an average of 10.6%. Percentage of CIP (plasma concentrations) was 15.9% and 19.9% after i.v. and i.m. administration, respectively. Based on the pharmacokinetic data, susceptibility break point and PK-PD indexes, i.m. single administration of ENR at a dosage of 5 mg/kg b.w. might be appropriate for treatment of susceptible bacteria (MIC > 1 μg/mL) in freshwater crocodiles, C. siamensis.     

环丙沙星单克隆抗体的制备及其免疫学特性鉴定

用EDC法将BSA和OVA分别和环丙沙星（Ciprofloxacin, CIP）偶联作为免疫原和包被原,并经紫外扫描 (UV Scan)、聚丙烯酰胺凝胶电泳（SDS-PAGE）鉴定。用合成的BSA-CIP免疫BALB/c小鼠,经过3次免疫后,用间接ELISA和阻断ELISA选择细胞融合备用鼠,选择高效价、敏感的小鼠进行抗原超强免疫;取其脾细胞应用杂交瘤技术与骨髓瘤细胞建立分泌CIP单克隆抗体的杂交瘤细胞株;用体内诱生腹水法制备CIP mAb,对CIP mAb的效价、敏感性和特异性等免疫学特性进行鉴定。聚丙烯酰胺凝胶电泳鉴定表明BSA-CIP人工抗原偶联成功;免疫的3只小鼠血清抗体效价均达到10-4;其中2号小鼠血清CIP抑制效价较高且IC50最低,达48.59μg/L,融合后筛选出Z3G12B3和Z2H8C10两株敏感特异的杂交瘤细胞,其两株细胞培养上清液效价为1:512,腹水效价为1:2.56×105,Z3G12B3株对CIP的IC50为2.47μg/L,与二氟沙星、沙拉沙星有小于0.03％的交叉反应性,与其他抑制物无交叉反应性。本试验获得了高效价、敏感、特异的抗CIP mAb,为CIP残留ELISA检测试剂盒和试纸条的建立奠定了坚实的基础。     

桔梗提取液配伍环丙沙星治疗猪肺炎试验研究

为提高猪肺炎的临床治疗效果。将875头肺炎发病猪随机分为3组,第1组324头,为盐酸环丙沙星处理组;第2组165头,为桔梗水煎液处理组;第3组386头,为盐酸环丙沙星配合桔梗处理组。结果显示,桔梗水煎液配伍盐酸环丙沙星治愈率为84.9%,极显著高于(P0.01)盐酸环丙沙星(26.2%)和桔梗水煎液组(7.2%);桔梗水煎液配伍环盐酸丙沙星使用,总有效率高达94.8%,极显著高于二者单独使用组21.8%和54.3%(P0.01);桔梗水煎液配伍盐酸环丙沙星组死亡率为3.6%,比二者单独使用组13.9%和35.2%显著降低(P0.05),桔梗配伍盐酸环丙沙星可极显著提高猪肺炎疗效。     

环丙沙星的临床应用与合理用药

环丙沙星是第3 代喹诺酮类抗菌作用较强的药物,抗菌谱广,对细菌、支原体都有强烈的抑制和杀灭作用,对临床分离的一些耐青霉素类、头孢菌素类、氨基糖苷类抗生素的菌株也有较强的抗菌活性。临床上广泛用于控制由敏感病原体引起的胃肠道感染、肺部感染、泌乳和生殖系统感染和局部感染等,也用于水生动物和家禽的疾病防治。文章就其抗菌谱、临床应用、与其他抗菌药的联合应用以及不良反应等方面进行综述。     

反相高效液相色谱法测定复方替硝唑可溶性粉中替硝唑与盐酸环丙沙星含量

用反相高效液相色谱法测定复方替硝唑可溶性粉中替硝唑与盐酸环丙沙星的含量.采用Kromasil C18柱,流动相为乙腈-0.2%三乙胺(用磷酸调节pH值至2.7),检测波长为296 nm.在该色谱条件下,盐酸环丙沙星浓度在2～40 μg/mL范围内,线性方程为y1=49 292.4 x1 2 727.3,r=0.999 9;替硝唑浓度在2～40 μg/mL范围内,线性方程为y2=27 169.3 x2 7 035.2,r=0.999 9.盐酸环丙沙星和替硝唑的平均回收率分别为100.9%(RSD=1.37%)和100.3%(RSD=1.19%).该方法具有快速灵敏、准确实用、重现性好等特点.     

环丙沙星人工抗原的合成与鉴定

采用碳二亚胺法将半抗原环丙沙星与卵清蛋白和牛血清白蛋白进行偶联。采用非变性凝胶电泳法和紫外分光光度法对偶联物中环丙沙星与载体蛋白的分子结合比进行分析。紫外分光光度法表明，环丙沙星与卵清蛋白和牛血清白蛋白的分子结合比分剐为6：1和13：1。非变性凝胶电泳显示，即使只有6个环丙沙星分子与栽体蛋白偶联，偶联物在凝胶中的迁移轨迹与栽体蛋白和偶联剂处理的载体蛋白对照样品均有明显不同。结果表明，非变性凝胶电泳法和紫外分光光度法可用于环丙沙星与卵清蛋白和牛血清白蛋白分子结合比的定性分析和定量分析。     

微量环丙沙星对人源大肠杆菌和粪肠球菌体外敏感性的影响

建立人离体肠道模拟模型，研究微量环丙沙星对人源肠道大肠杆菌和粪肠球菌敏感性的影响，进而用聚合酶链反应法扩增耐药菌的gyrA基因的耐药决定区，并分析其耐药机制。结果显示，大肠杆菌连续培养后存活菌株对微量环丙沙星耐药，此耐药菌对其他抗菌药敏感；粪肠球菌绎连续培养，对环丙沙星和其他抗菌药物仍敏感；耐药大肠杆菌的gyrA基因发生突变，248位碱基由C变为T，259位由G变为T，相应地，该基因编码的蛋白质在83位的丝氨酸和87位的天冬氨酸分别改变为亮氨酸和酪氨酸。研究表明，微量环丙沙星对人肠道菌群具有不同的选择作用，能诱导大肠杆菌产生耐药性。这为动物源食品中环丙沙星残留的安全性评价提供了试验依据。     

Pharmacokinetics and tissue distribution of enrofloxacin after single intramuscular injection in Pacific white shrimp

The pharmacokinetic properties and tissue distribution of enrofloxacin (EF) were investigated after single intramuscular (i.m.) dose of 10 mg/kg body weight (b.w.) in Pacific white shrimp at 22 to 25°C. EF and its metabolite ciprofloxacin (CF) were determined by high‐performance liquid chromatography. After i.m. administration, EF was absorbed quickly, and the peak of EF concentration (C_max) reached at first time point in hemolymph. The volume of distribution V_d(area) of EF was 3.84 L/kg, indicating that the distribution of EF was good. The area under the concentration–time curve (AUC) of EF was 90.1 and 274.2 μg hr/ml in muscle and hepatopancreas, respectively, which was higher than 75.8 μg hr/ml in hemolymph. The EF elimination was slow in muscle and hepatopancreas with the half‐life (T_1/2β) of 52.3 and 75.8 hr, respectively. CF, the mainly metabolite of EF, was detected in hemolymph, muscle and hepatopancreas. The C_max was 0.030, 0.013 and 0.218 μg/ml, respectively. Based on a minimum inhibitory concentration (MIC) of 0.006–0.032 μg/ml for susceptible strains, EF i.m. injected at a dose 10 mg/kg could be efficacious against common pathogenic bacteria of Pacific white shrimp.     

内服盐酸环丙沙星糊剂治疗仔猪黄白痢的研究

应用盐酸环丙沙星糊剂,按盐酸环丙沙星１０ｍｇ／ｋｇ口服,每日２次,３ｄ为一疗程,对仔猪黄痢和白痢进行治疗研究,并和痢特灵治疗效果进行比较。结果发现：盐酸环丙沙星糊剂治疗组的治愈率为９２．９％,好转率为５．２％,无效率为１．８％．治愈率比痢特灵治疗组高４５个百分点,而无效率比痢特灵治疗组低２９．４个百分点。试验结果表明：盐酸环丙沙星糊剂治疗仔猪黄痢和白痢效果显著,可在生产实践中推广应用。