单诺沙星对大肠杆菌和金葡球菌的体外抗茵后效应

采用菌落计数法测定了单诺沙星在三种不同浓度下对大肠杆菌和金黄色葡萄球菌 (金葡球菌 )的体外抗菌后效应 (PAE)。当药物浓度为 0 .5MIC、2MIC、4MIC时 ,对大肠杆菌的PAE值为 (0 .6 4 6 4± 0 .0 2 94 )h、(1.2 0 77± 0 .0 2 84 )h、(1.6 5 2 9± 0 .0 4 96 )h ;对金葡球菌的PAE值为 (0 .5 6 6 0± 0 .0 0 75 )h、(1.174 6± 0 .0 0 5 7)h、(1.4 913± 0 .0 2 5 7)h。这表明单诺沙星对大肠杆菌、金葡球菌均有不同程度的较强的PAE ,且PAE值与药物浓度呈正相关     

单诺沙星在雏鸡体内的药动学及其抗菌后效应研究

本论文以高效液相色谱(HPLC)内标法为定量手段,研究了单诺沙星经静注、口服两种途径给药后在雏鸡体内的药物代谢动力学特征;以菌落计数法测定了单诺沙星对大肠杆菌、金黄色葡萄球菌(金葡球菌)的体外抗菌后效应。静注和内服给药后血药浓度-时间数据分别符合无吸收因素二室开放式模型和一级吸收一室开放式模型。静注给药的主要药动学参数为:t1/2α0.3313h、t1/2β5.9940h、Vd7.5246L/kg、AUC5.6916μg/(mL·h)、CLB0.8935/(kg·h)。内服给药后主要药动学参数为:t1/2Ka0.3029h、t1/2K6.5128h、tmax1.2100h、Cmax0.5159μg/mL、AUC5.1329μg/(mL·h),生物利用度为90.18%。抗菌后效应(PAE)结果如下,浓度分别为0.5MIC、2MIC、4.MIC的单诺沙星对大肠杆菌的PAE测定值分别为(0.6464±0.0294)h,(1.2077±0.0284)h,(1.6529±0.0496)h,对金葡球菌的PAE测定值分别为(0.5660±0.0075)h,(1.1746±0.0057)h,(1.4913±0.0257)h。     

单诺沙星对鸡败血支原体与大肠杆菌合并感染的药效学研究

采用试管二倍稀释法测得单诺沙星及其对照药物恩诺沙星、泰乐菌素对鸡败血支原体（MG）的最低抑菌浓度分别为0．0625、0.125、0.5mg/L。试验鸡每只左右气囊分别接种MG S6株菌液0.75ml、滴鼻约0.3ml，同时腹腔注射大肠杆菌菌液0.3ml,人工诱发鸡败血支原体与大肠杆菌合并感染的疾病模型。25、50、100mg/L的单诺沙星、500mg／L的恩诺沙星和500mg/L的泰乐菌素连续饮水5d给药，对人工合并感染鸡败血支原体与大肠杆菌病的治愈率分别为93.3%、96.6%、96.6%、93.3%、86.6%，而感染对照组的死亡率为23.3％。单诺沙星及其对照药物组的增重率显著高于感染对照组，并能极显著的降低感染鸡的死亡率、抗体反应阳性率、气囊损伤率及病原再分离率。     

单诺沙星对人工诱发鸡大肠肝菌病的药效试验

根据试管 2倍稀释法测定的单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度 ,对实验性大肠杆菌病鸡进行内服给药 (每隔 12h给药 1次 ,连续 3d)治疗试验。结果表明 ,单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别是 0 0 5及 1 6mg/L。单诺沙星以 5mg/kg、氯霉素以40mg/kg的剂量给鸡内服后 ,对大肠杆菌病的治愈率分别为 87 5%及 55 0 %。     

恩诺沙星和环丙沙星对金葡菌的抗菌后效应及抗菌后亚抑菌浓度效应

报告了抗菌后效应 (postantibiotic effect,PAE)、抗菌后亚抑菌浓度效应 (postantibiotic sub- MIC effect,PASME)、亚抑菌浓度效应 (sub- MIC effect,SME)研究的方法学和恩诺沙星、环丙沙星对金葡菌抗菌后效应及抗菌后亚抑菌浓度效应的研究结果。试验表明 :2、4MIC的恩诺沙星对金葡菌的 PAE为 1.0 3、1.5 0 h,1/2、1、2、4MIC的环丙沙星的 PAE为 0 .5 1、0 .88、1.47、1.92 h;1/8、1/4、1/2 MIC的恩诺沙星对经 4MIC药物诱导 1h的金葡菌可产生0 .38、1.15、>12 .31h的 PASME,1/8、1/4、1/2 MIC的环丙沙星的 PASME为 2 .6 9、>10 .17、>13.17h;1/8、1/4、1/2 MIC的恩诺沙星和环丙沙星对金葡菌产生的 SME分别为 0 .40、0 .91、>9.44 h和 0 .42、1.14、>9.0 2 h。上述结果说明 ,PAE、PASME和 SME的大小与药物浓度呈正相关 ,且环丙沙星比恩诺沙星对金葡菌有更长的效应     

恩诺沙星对雏鸭体内大肠杆菌抗菌作用观察

恩诺沙星广泛应用于兽医临床，尤其对革兰氏阴性菌具有很强的抗菌活性。此类药物抗菌活性的研究主要是进行体外抑菌试验和药效学研究。前者是在人工培养基上进行，其结果虽具一定参考价值，也有一定局限性；后者在多数情况下是以一两种剂量进行。研究抗菌药物的体内抗菌活性，对评价不同药物以及同一药物不同制剂的临床疗效更具实际意义。     

恩诺沙星对鸭大肠杆菌在体内抗菌活性的试验

以人工诱发雏鸭大肠杆菌感染模型,采用肌注不同剂量的恩诺沙星注射液评价恩诺沙星体内抗菌活性。实验性治疗结果表明,不同剂量恩诺沙星注射液(7.50,5.63,3.16,2.32,1.78mg/kg),对鸭大肠杆菌的保护率分别为100%,100%,80%,60%,50%,而大肠杆菌对照组的死亡率为100%。恩诺沙星对鸭大肠杆菌的ED50值为2.93mg/kg。实验显示,恩诺沙星注射液对鸭大肠杆菌具有较强的体内抗菌活性。     

单诺沙星在健康与支原体-大肠杆菌合并感染鸡体内的药动学研究

以高压液相色谱 (HPLC)法为定量手段研究了单诺沙星在健康和支原体与大肠杆菌合并感染鸡体内的药动学特征。 60只健康鸡和 60只合并感染鸡内服单诺沙星 (5mg/kg)后 ,血浆的药时数据均符合一级吸收二室模型。健康和合并感染鸡的主要动力学参数分别如下 :t1 /2ka为 0 2 4 2 8和 0 31 82h,t1 /2α为 0 891 7和 1 550 2h ,t1 /2 β为 8 793 6和 1 2 62 0 0h ,Tp为 0 9377和 1 1 1 0 7h ,Cmax为 0 5487和 0 51 0 6μg/mL ,每小时为3 0 52 3和 3 660 2mg/L ,Tcp为 31 1 1 5和 39 1 8h。单诺沙星在鸡体内的药动学特征是吸收迅速且完全 ,体内分布广泛 ,但消除缓慢 ,有效浓度维持时间长。合并感染使单诺沙星在感染鸡体内的吸收、分布和消除均减慢 ,达峰时间、有效浓度维持时间延长     

乳酸恩诺沙星对温和气单胞菌的体外抗菌后效应

为研究乳酸恩诺沙星对温和气单胞菌(A.sobria)的体外药效学,采用二倍稀释法测定了乳酸恩诺沙星对温和气单胞菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),在此基础上探究在温和气单胞菌的不同生长时期加入乳酸恩诺沙星后对其生长的影响,研究乳酸恩诺沙星不同药物浓度(2×MIC、4×MIC、8×MIC)作用对温和气单胞菌的杀菌动力学和抗菌后效应(PAE)。结果显示,乳酸恩诺沙星对温和气单胞菌的MIC和MBC分别为0.39μg/mL和1.56μg/mL,乳酸恩诺沙星对温和气单胞菌有较强的杀菌作用,其PAE与药物浓度呈正相关。     

泰拉霉素对猪胸膜肺炎放线杆菌体外抗菌后效应观察

泰拉霉素(Tulathromycin)是一种新近开发的动物专用大环内酯类半合成抗生素,其具有吸收迅速,生物利用度高,低残留,半衰期长,药效持久,胃肠外单次给药既能提供全程治疗等特点.     

Pharmacokinetics of enrofloxacin and danofloxacin in premature calves

The aim of this study was to determine the pharmacokinetics/pharmacodynamics of enrofloxacin (ENR) and danofloxacin (DNX) following intravenous (IV) and intramuscular (IM) administrations in premature calves. The study was performed on twenty‐four calves that were determined to be premature by anamnesis and general clinical examination. Premature calves were randomly divided into four groups (six premature calves/group) according to a parallel pharmacokinetic (PK) design as follows: ENR‐IV (10 mg/kg, IV), ENR‐IM (10 mg/kg, IM), DNX‐IV (8 mg/kg, IV), and DNX‐IM (8 mg/kg, IM). Plasma samples were collected for the determination of tested drugs by high‐pressure liquid chromatography with UV detector and analyzed by noncompartmental methods. Mean PK parameters of ENR and DNX following IV administration were as follows: elimination half‐life (t_1/2λz) 11.16 and 17.47 hr, area under the plasma concentration–time curve (AUC_0‐48) 139.75 and 38.90 hr*µg/ml, and volume of distribution at steady‐state 1.06 and 4.45 L/kg, respectively. Total body clearance of ENR and DNX was 0.07 and 0.18 L hr^?1 kg^?1, respectively. The PK parameters of ENR and DNX following IM injection were t_1/2λz 21.10 and 28.41 hr, AUC_0‐48 164.34 and 48.32 hr*µg/ml, respectively. The bioavailability (F) of ENR and DNX was determined to be 118% and 124%, respectively. The mean AUC_0‐48CPR/AUC_0‐48ENR ratio was 0.20 and 0.16 after IV and IM administration, respectively, in premature calves. The results showed that ENR (10 mg/kg) and DNX (8 mg/kg) following IV and IM administration produced sufficient plasma concentration for AUC_0‐24/minimum inhibitory concentration (MIC) and maximum concentration (C_max)/MIC ratios for susceptible bacteria, with the MIC₉₀ of 0.5 and 0.03 μg/ml, respectively. These findings may be helpful in planning the dosage regimen for ENR and DNX, but there is a need for further study in naturally infected premature calves.     

7种抗菌药物对金黄色葡萄球菌及大肠杆菌体外抗生素后效应的研究

采用稀释法去除抗生素，用菌落计数测定细菌生长曲线的方法测定环丙沙星、洛美沙星、诺氟沙星、恩诺沙星、庆大霉素、青霉素及氨苄西林对金葡球菌及大肠杆菌的抗生素后效应(PAE)。结果：几种药物在各浓度组对金黄色葡萄球菌均呈现明显的PAE，氟喹诺酮类药物及庆大霉素对大肠杆菌产生较长的PAE，而β-内酰胺类药物作用后的PAE则很短。PAE的存在提示：在兽医临床设计给药方案时，适当延长给药间隔时间，减少给药次数，仍能维持抗菌效果。     

抗猪大肠杆菌卵黄抗体变化规律及在体外对大肠杆菌生长的影响

试验研究抗猪大肠杆菌卵黄抗体变化规律及在体外对大肠杆菌生长和对肠黏膜细胞上粘附的影响。试验选用 30周龄海兰褐壳蛋鸡 2 4 0只 ,试验时间 80d。以K88、K99和 987P 3种大肠杆菌混合液为免疫原 ,免疫原中K88、K99和 987P的细菌数分别为 2 .5× 10 9、2 .5× 10 9、2 .5× 10 10 CFU/mL。免疫剂量为 0 .5、1.0、1.5、2 .0mL/只 ,在试验鸡胸腹部肌肉、分多点注射 (每点约 0 .2mL) ,每个免疫剂量免疫健康蛋鸡 5 0只 ,4 0只蛋鸡作对照 ,以个体为单位 ,每天收集鸡蛋 ,4℃保存。在每次免疫 5d后 ,翅静脉采血、分离血清 ,- 2 0℃保存。用盐析法和冷冻干燥法制备抗猪大肠杆菌卵黄抗体粉 ,配制不同蛋白含量的卵黄抗体溶液 ,用体外法研究卵黄抗体对大肠杆菌生长及对肠黏膜细胞粘附的影响。试验结果表明 :最佳免疫剂量为 1.0mL/只 ,卵黄与血清中的抗体水平没有差异 ;在大肠杆菌培养液中 ,添加蛋白含量为 0 .5mg/mL抗猪大肠杆菌卵黄抗体溶液时 ,大肠杆菌的生长受到抑制 (P <0 .0 5 ) ,不同卵黄抗体间没有交叉反应 ;蛋白含量为 0 .2 5mg/mL的抗猪大肠杆菌卵黄抗体溶液对大肠杆菌在肠黏膜细胞上的粘附有抑制作用 (P <0 .0 5 )。     

肉仔鸡大肠杆菌病的诊治

肉仔鸡大肠杆菌病是条件性传染病,多继发或并发于其它疾病,是肉鸡生产中常见的、最顽固的传染病之一,对养鸡生产造成损失较大.     

塔里木盆地36种植物对大肠杆菌、金黄色葡萄球菌的抑菌试验

抗生素在畜产品中的残留越来越受到人们的重视,开发植物药已成为研究者的热点,而生长于塔里木盆地的植物较少,因地理环境的不同,这些植物药是否有抑菌的药用价值,亟待研究.笔者通过对塔里木盆地的36种植物药进行体外抑菌试验,为进一步研究该植物,开发和保护塔里木盆地的植物药提供科学依据.     

青蒿素对腹泻仔猪病原大肠杆菌的抑菌效果

目前,常用抗生素防治仔猪大肠杆菌感染性腹泻,但动物长期大量滥用抗菌药物,易破坏肠道正常菌群,增加感染性,造成反复感染和继发感染,同时易造成细菌耐药性的增加.青蒿素是公认的中药产品,具有过氧基团的倍半萜内酯化合物,因其对疟疾具有"高效、速效、低毒"的突出疗效,已经成为越来     

Comparison of pharmacokinetics of danofloxacin and enrofloxacin in calves challenged with Mannheimia haemolytica

OBJECTIVE: To compare concentrations of danofloxacin, enrofloxacin, and ciprofloxacin in plasma and respiratory tissues of calves treated after challenge with Mannheimia haemolytica. ANIMALS: 75 calves. PROCEDURE: 24 hours after challenge with M. haemolytica, 72 calves with clinical signs of respiratory tract disease were randomly assigned to 1 of 12 equal treatment groups.Three nonchallenged, nontreated calves formed a control group. Challenged calves were treated with danofloxacin (6 and 8 mg/kg, SC) and enrofloxacin (8 mg/kg, SC) once. At 1, 2, 6, and 12 hours after treatment, 6 calves from each treatment group were euthanatized. Antimicrobial drug concentrations were assayed in various specimens. Peak plasma concentration (Cmax)-to-minimum inhibitory concentration (MIC; Cmax-to-MIC) ratios and the area under the concentration versus time curve over a 12-hour period-to-MIC ratios (AUC(12h)-to-MIC) were calculat-ed. RESULTS: Danofloxacin and enrofloxacin had MICs of 0.03 microg/mL for the M. haemolytica challenge isolate. Danofloxacin administered at doses of 6 and 8 mg/kg resulted in numerically higher geometric mean concentrations of danofloxacin in plasma and all respiratory tissues than geometric mean concentrations of enrofloxacin after treatment with enrofloxacin. Geometric mean concentrations of enrofloxacin were numerically higher than geometric mean concentrations of ciprofloxacin metabolite in plasma and almost all respiratory tissues. Danofloxacin and enrofloxacin achieved Cmax-to-MIC ratios >10 and AUC(12h)-to-MIC ratios >125 hours. CONCLUSIONS AND CLINICAL RELEVANCE: When used to treat pneumonic pasteurellosis in calves, danofloxacin and enrofloxacin can be expected to deliver concentration-dependent bactericidal activity against M. haemolytica, the bacteria most commonly associated with bovine respiratory tract disease.     

益生乳酸杆菌抑制大肠杆菌的研究

本试验在分离选育出一批抗逆性较强的乳酸杆菌之后 ,测定了从胃粘膜分离筛选出的三株乳酸杆菌的乳酸产量、乳酸杆菌前期代谢产物的抑菌作用和乳酸杆菌及其代谢产物的协同抑菌作用。结果表明 ,乳酸杆菌代谢产物中乳酸不是唯一起抑菌或灭菌作用的代谢物。乳酸杆菌代谢产物对不同血清型大肠杆菌的抑制效果和乳酸杆菌及其代谢产物联合对大肠杆菌的抑菌作用相似 ,即抑制或杀灭大肠杆菌K88和K99较强 ,而对 987P的抑制作用较弱。同时 ,乳酸杆菌的菌体及其代谢产物对大肠杆菌具有一定的协同抑制作用。     

The pharmacodynamic effect of amoxycillin and danofloxacin against Actinobacillus pleuropneumoniae in an in-vitro pharmacodynamic model.

The pharmacodynamic effect of amoxycillin and danofloxacin against two strains of Actinobacillus pleuropneumoniae was evaluated in an in-vitro pharmacodynamic model. For amoxycillin peak concentrations of 0.5, 1, and 4 microg ml(-1)and half-lives of 3 and 15 hours were examined. For danofloxacin peak concentrations of 0.125, 0.5, and 1. 5 microg ml(-1)and half-lives of 1.5 and 7 hours were evaluated. The initial bactericidal effect was measured as the reduction in colony count (log CFU ml(-1)) during the first three hours, and the overall pharmacodynamic effect as the area under the bacterial growth versus time curve (AUBC).The initial bactericidal effect of amoxycillin was maximal at peak concentrations of two to four times the MIC. Peak concentration and half-life only influenced the pharmacodynamic effect of amoxycillin if the antibiotic concentration fell below the MIC during the experiments, which is consistent with time >MIC as the most important parameter of pharmacodynamic effect of beta-lactam drugs.For danofloxacin maximal bactericidal effect initially was observed at peak concentrations of at least eight times the MIC. The pharmacodynamic effect was dependent on the peak concentration. The half-life only influenced the pharmacodynamic effect of danofloxacin in experiments with a peak concentration MIC ratio of less than eight. This indicated that for danofloxacin the peak concentration was the major determinant of pharmacodynamic effect.