抗菌药物联合使用对耐达氟沙星鸡毒支原体的体外抑制作用研究

为探究抗菌药物联合使用对耐达氟沙星鸡毒支原体的体外抑制效果,选择鸡毒支原体标准株S6和对达氟沙星MIC升高程度不同的突变株M1、M2和M4,分别测定泰乐菌素、大观霉素、林可霉素、泰妙菌素、替米考星和多西环素种对4株鸡毒支原体的最低抑菌浓度,并使用达氟沙星分别联合上述6种抗菌药物进行体外抑菌试验。结果显示:除达氟沙星外,其余抗生素对S6、M1、M2和M4的最低抑菌浓度均相同,且泰妙菌素的敏感性最高(0.0016μg/mL),林可霉素敏感性最低(4μg/mL);联合抑菌试验结果显示,达氟沙星与大观霉素联合对S6、M1、M2和M4均为相加作用;达氟沙星联合林可霉素对S6和M2表现为相加作用,对M1与M4均表现为无关作用,达氟沙星与泰乐菌素、泰妙菌素、替米考星和多西环素联合均为无关作用。研究结果显示达氟沙星联合大观霉素的作用效果最好。     

峨眉千里光对小鼠急性毒性及蓄积毒性研究

评价峨眉千里光毒性作用,采用机率单位法（Bliss法）和固定剂量蓄积系数法考察了峨眉千里光叶和全草水提物对小鼠经口急性毒性及蓄积毒性。急性毒性结果显示,不同剂量的峨眉千里光叶和全草水提物均能导致小鼠发生中毒和死亡,引起小鼠肺和肝脏损伤;叶水提物LD50为62.28 g/kg,95%可信限为52.68-73.65 g/kg;全草水提物LD50为81.65 g/kg,95%可信限为70.15-94.53 g/kg。蓄积毒性结果显示,峨眉千里光叶和全草的蓄积系数K〉5。结果表明,峨眉千里光叶和全草水提物对小鼠有急性毒性作用,叶的毒性比全草强,肺和肝脏为毒性靶器官;两种水提物均有轻度蓄积毒性。     

鸡毒支原体敏感药物的筛选

用泰乐菌素、强力霉素、罗红霉素、红霉素、丁胺卡那霉素、庆大霉素、环丙沙星、双氟沙星、呋喃唑酮、呋喃他酮、泰妙菌素等药物对3株鸡毒支原体进行体外抑菌试验。结果证明，它们对鸡毒支原体均有抑菌作用，但以泰乐菌素、泰妙菌素、环丙沙星和双氟沙星抑菌效果最好，达到10^-8g／L。     

塞拉菌素口服与透皮给药对小鼠和大鼠的急性毒性试验

为阐明塞拉菌素的毒性,指导临床用药,对其原料药和制剂进行了口服和经皮2个途径给药对小鼠和大鼠的急性毒性试验。预试验中小鼠和大鼠一次性口服不同剂量的塞拉菌素原料药和制剂,测定LD0和LD100,再根据简化寇氏法分组正式试验,测定LD50和95%可信限。结果测得小鼠口服塞拉菌素原料药的LD0、LD100、LD50和95%可信限分别为4 g/kg、12.6 g/kg、8.72 g/kg和7.73～9.82 g/kg;大鼠口服塞拉菌素原料药的LD0、LD100、LD50和95%可信限分别为1.6 g/kg、5 g/kg、2.51 g/kg和2.24～2.82 g/kg;小鼠口服塞拉菌素制剂的LD0、LD100、LD50和95%可信限分别为4.2 g/kg、8.4 g/kg、7.71 g/kg和7.26～8.19 g/kg;大鼠口服塞拉菌素制剂的LD0、LD100、LD50和95%可信限分别为3.4 g/kg、8.4 g/kg、6.62 g/kg和6.10～7.53 g/kg。由于LD50值均在501～150 00 mg/kg,故塞拉菌素原料及制剂判断为低毒或实际无毒物质。小鼠和大鼠分别透皮给予高剂量塞拉菌素制剂10 g/kg,未见毒副反应,表明临床用药是安全的。     

黄药子的体外抑菌及毒性试验

为了观察中草药黄药子的不同溶剂提取物对畜禽常见病原菌的体外抑制作用及其急性毒性试验,采用杯碟法进行抑菌试验,并用寇氏法进行了小鼠急性毒性试验。结果表明,黄药子有机溶剂提取物对试验所用的病原菌均有不同程度的抑制作用,其中黄药子丙酮和乙酸乙酯提取物的抑菌效果较显著,其急性毒性试验LD50分别为:7.20 g/kg±1.84 g/kg,9.22 g/kg±2.57 g/kg。     

复方泰妙菌素对实验性鸡败血霉形体病疗效的再评价

本文就复方泰妙菌素对鸡败血霉形体的临床疗效进行了再评价。体外抑制试验和治疗试验证实,鸡败血霉形体对复方泰妙菌素敏感。复方泰妙菌素对鸡败血霉形体BG44T株的体外抑制作用与泰妙菌素相当。复方泰妙菌素200 g/mL饮水给药与泰妙菌素250 g/mL的疗效基本相当。     

牛至油前体化合物的促生长、体外抑菌及一般毒性研究

对牛至油前体化合物进行了药效学和一般毒性的研究,为该药在临床中的合理使用提供依据。促生长试验结果显示:牛至油对鸡具有显著的促生长作用(P<0.05);体外抑菌试验表明:牛至油前体化合物的代谢成分香芹酚和百里酚,对大肠杆菌和猪链球菌具有抑菌作用;小鼠的急性毒性试验结果表明:牛至油前体化合物对小鼠的经口LD50为1.660 g/kg,按国际急性毒性分级标准判断为低毒;90 d亚慢性毒性试验结果表明:牛至油的安全范围大,该物质90 d喂养亚慢性毒性试验对小鼠各项观察指标未产生明显影响。上述结果显示:牛至油前体化合物为安全有效的药物,在临床中有潜在的应用价值。     

鸡毒支原体的分离鉴定和最低抑菌浓度测定

从山东、河北、北京和天津等不同地区分离、鉴定了4株鸡毒支原体，通过体外最低抑菌浓度测定发现泰妙菌素、泰乐菌素、百里霉索、罗红霉素、林可霉素／壮观霉素合剂、氧氟杀星、乳酸红霉素和盐酸林可霉素对该4个菌株的最低抑菌浓度(MIC)平均值分别是0．0062μg/ml、0．0171μg/ml、0．0682μg/ml、8．5248μg/ml、8．5248μg/ml、0．1024μg/ml、0．4550μg/ml和15．4944μg/ml，同时发现不同菌株之间的最低抑菌浓度有明显的差异。该试验结果表明鸡毒支原体容易对抗菌药物产生抗药性，目前临床预防或治疗鸡毒支原体感染可选用泰妙菌素、泰乐菌素、百里霉素和氧氟杀星等药物，而常规使用的红霉素和罗红霉素效果不佳。     

中草药饲料添加剂的毒性试验和体外抑菌试验

试验旨在研究中草药饲料添加剂的毒性和体外抑菌活性。毒性试验和体外抑菌试验显示中草药饲料添加剂经小鼠灌胃给药后,未出现明显急性毒性症状,小鼠1日最大给药剂量150g／kg,相当于奶牛用量的3000倍（含量为0．9％时为1667倍）、肉牛用量的6000倍（含量为0．9％时为3333倍）。表明所用的中草药饲料添加剂对牛、羊等动物基本无毒害作用。体外抑菌试验中,液体稀释法表明中药配方1以1：16稀释对沙门氏菌有明显抑菌效果,为其最低抑菌浓度;琼脂稀释法表明配方1和2以1：2稀释对金黄色葡萄球菌原液有抑菌作用,配方1作用稍强于配方2。试验表明中草药饲料添加剂对动物基本无毒,且在体外具有一定的抑菌活性。     

金霉素,泰妙菌素联合应用对鸡败血霉形体病的药效研究

观察了金霉素、泰妙菌素联合用药的体外抗鸡败血霉形体的作用与体内治疗鸡败血霉形体病的疗效。体外抑菌试验中，金霉素、泰妙菌素、金霉素与泰妙菌素（３∶１）合用，对鸡败血霉形体ＢＧ４４Ｔ株的最小抑菌浓度分别为２．０、０．０１６、０．０１６ｍｇ／Ｌ；棋盘法试验进一步证明，金霉素、泰妙菌素合用对鸡败血霉形体ＢＧ４４Ｔ株的ＦＩＣ指数为０．５～０．７５，两药表现有协同作用。饮水给药对实验性鸡败血霉形体病的治疗试验表明，金霉素、泰妙菌素按３∶１合用，以２００、１００ｍｇ／Ｌ剂量给药５ｄ，在死亡率、治愈率、有效率等几个指标方面优于泰妙菌素、金霉素单独给药（２００ｍｇ／Ｌ）。     

Acaricidal activity of extract from Eupatorium adenophorum against the Psoroptes cuniculi and Sarcoptes scabiei in vitro

The possible acaricidal activity of Eupatorium adenophorum was analyzed using extracts created by water decocting, ethanol thermal circumfluence, and steam distillation. The toxic effect of each extract was tested against Psoroptes cuniculi and Sarcoptes scabiei in vitro. Ethanol thermal circumfluence extract had strong toxicity against mites, killing all S. scabiei at 0.5 and 1.0 g/ml (w/v) concentration, while 1g/ml extract was also found to kill all P. cuniculi within a 4-h period. Similarly, 0.25, 0.5 and 1.0 g/ml concentration of extract had strong toxicity against S. scabiei, with median lethal time (LT(50)) values at 0.866, 0.785 and 0.517 h, respectively. 0.5 g/ml and 1g/ml showed strong acaricidal action against P. cuniculi; the LT(50) values were 0.93 h and 1.29 h, respectively. The median lethal concentration (LC(50)) values were 0.22 g/ml for Scabies mite and 0.64 g/ml for P. cuniculi in 1h. The results indicated that E. adenophorum contains potent acaricidal ingredients; as a first step in the potential development of novel drugs, it may provide new acaricidal compounds for the effective control of animal acariasis.     

Discrepancy between minimal inhibitory concentration to enrofloxacin and mutations present in the quinolone-resistance determining regions of Mycoplasma gallisepticum field strains

This study evaluated the in vitro activity of diphenyl diselenide against 19 Pythium insidiosum isolates and the in vivo therapeutic response of rabbits with experimentally induced pythiosis. In vitro: susceptibility tests were performed using the broth macrodilution method in accordance with the CLSI document M38-A2. The criteria for interpretation were as follows: MIC-1 and MIC-2 (inhibition of 90% and 100% of mycelium growth, respectively) and the minimum fungicide concentration (MIC-3). In vivo: twenty rabbits were divided into four groups with five animals each and treated for 40 consecutive days: groups 1 and 2 (experimentally induced pythiosis) were treated with diphenyl diselenide (10mg/kg/day) and canola oil (1 mL/kg/day), respectively; groups 3 and 4 (controls) were treated with canola oil (1 mL/kg/day) and diphenyl diselenide (10mg/kg/day), respectively. Toxicity was evaluated using biochemical and haematological parameters. In vitro susceptibility tests showed that 89.4% of isolates had a MIC-1 ≤ 0.5 μg/mL, 84.2% of isolates had a MIC-2 ≤ 1.0 μg/mL and 94.7% of isolates had a MIC-3 ≤ 2.0 μg/mL. The in vivo assay suggested that this compound has a fungistatic activity, and the biochemical and haematological parameters indicated that there was no renal, hepatic or haematological toxicity. The comparison of the unsaturated iron binding capacity levels between animals with and without pythiosis suggested the involvement of iron metabolism in the pathogenesis of pythiosis. This study demonstrated the absence of detectable toxicity caused by diphenyl diselenide and the in vitro fungicidal and in vivo fungistatic activities of this drug, which makes it an option for future therapeutic approaches in the treatment of pythiosis.     

抗球虫新化合物纳川珠利的一般毒理学研究

为评价新型抗球虫化合物纳川珠利的一般毒理学特性,选用昆明小鼠进行经口给药的急性毒性试验,以剂量递增法计算蓄积系数(K),于连续给药后第21天一次灌服1个LD50剂量,观察各组小鼠对化合物的耐受性。结果显示,该化合物采用寇氏改良法计算的LD50为768 mg/kg,95%可信限为644～916 mg/kg;采用机率单位加权回归法(Bliss法)计算的LD50为769 mg/kg,95%可信限为615～960 mg/kg;计算的蓄积系数为4.26,中度蓄积;耐受性试验中试验组和对照组的小鼠死亡率差异无统计学意义(P>0.05),小鼠对化合物的耐受性无明显变化。可初步认为该新化合物的毒性较低,在临床上应用相对安全,具有较好的成药性基础。     

不同剂量新疆阿魏对血吸虫活性的影响

为了探讨新疆阿魏杀灭血吸虫的功效,分别用新疆阿魏蒸馏萃取物以0.1、0.2、0.3、0.4 g/kg浓度药液灌服治疗感染血吸虫病家兔,每隔3 d灌服1次,4次后停止给药,4周后剖检,门静脉灌注法收集虫体、计算减虫率,并以组织切片检查该药对血吸虫感染兔肝脏的治疗作用。结果显示,减虫率分别为12.30%、17.20%、46.40%、40.80%;经组织切片观察,家兔肝脏肉芽肿明显减小。表明新疆阿魏具有很强的杀灭血吸虫活性的作用,最佳杀虫剂量为0.3 g/kg。     

The effects of plastic slatted floor or straw bedding on performance, liver weight and liver copper concentrations in intensively reared lambs

One hundred and eight Texel sired lambs were weaned at 37 days old and allocated three days later to one of two treatments, using two pens per treatment, in order to evaluate lamb hepatic copper (Cu) values. In Treatment 1 (T1) the lambs were confined to pens having recycled plastic slatted flooring, while in Treatment 2 (T2) the lambs were confined to pens having straw bedded floors, with fresh straw added on alternate days. The lambs had ad libitum access to a coarse lamb concentrate. The crude protein (g/kg DM), crude fibre (g/kg DM), total zinc (mg/kg) and background levels of copper (Cu) (mg/kg) and molybdenum (Mo) (mg/kg) of the diet were 17.2, 10.9, 152, 9.7 and 0.92, respectively. The lambs were slaughtered when they reached about 39 kg live weight. Following slaughter, the liver was removed and weighed and the caudal lobe frozen for subsequent Cu analysis. The livers of lambs on the plastic floor treatment had higher liver weights (843 vs. 804 g, S.E.M. 11.0; P < 0.05) and higher hepatic copper (396 vs. 315 mg/kg DM, S.E.M. 18.2; P < 0.05) than those from lambs that were bedded with straw. The Cu accumulation per kg of liver DM per week was estimated to be 8.4 and 13.7 mg for lambs on the straw bedding and plastic slated treatments, respectively. It is concluded that when lambs are housed on plastic slatted flooring, relative to straw bedding, there is a higher accumulation of hepatic copper levels likely to result in a greater risk of Cu toxicity when lambs are reared on all concentrate diets.     

国产三氯苯咪唑驱除山羊肝片形吸虫效果试验

以国产三氯苯咪唑对自然感染肝片形吸虫的山羊进行了驱虫试验，并以硝氯酚为药物对照。结果表明，三氯本咪唑5mg/kg体重的剂量对肝片形吸虫成虫和童虫的驱虫率分别为99.3%和92.9%，驱净率为75％；三氯苯咪唑10mg/kg体重的剂量对肝片形吸虫成虫和童虫的驱虫率均为100％，驱净率为100％；硝氯酚5mg/kg体重剂量对肝片形吸虫成虫驱虫率为100％，但对童虫的仅为74.3%，而驱净率仅为60％。在整个试验期间试验羊均无不良反应。     

中草药“杀虫补”防治鸡球虫病实验研究

中药"杀虫补"以杀虫燥湿、清热解毒遣药组方,主要由攻毒杀虫、去腐敛疮类药组成。实验结果表明,1%"杀虫补"组ACI为181.7,相对增重率达88.7%;0.5%"杀虫补"组ACI为173.4,相对增重率达82.4%;磺胺氯吡嗪钠组ACI为173.5,相对增重率达80.5%,表明"杀虫补"治疗鸡球虫病的效果确切,1%治疗剂量属高效杀虫药。用5%和10%剂量进行慢性毒性实验,未发现明显的中毒反应,但平均增重率分别为43.1%和32.0%,增重效果明显受到影响(P0.01),说明长期大剂量使用,会造成鸡的生长抑制。5 g/kg和3 g/kg剂量急性毒性实验表明,大剂量一次性使用不会造成鸡的死亡,但会抑制鸡的生长。以上实验结果表明,该中药组方对肉鸡球虫病具有治疗、预防以及增重的效果,按治疗剂量使用安全有效。     

蚕用抗菌药物亚迪丰的抗菌活性和药物动力学研究

采取试管稀释法进行体外抗菌试验,证明蚕用抗菌药物亚迪丰对苏云金杆菌、卒倒菌、短小芽孢杆菌、青头败血病菌、灵菌、八联球菌和产气杆菌等有明显的抑制作用,对上述细菌的M IC为0.5μg/mL、MBC为1.0~2.0μg/mL。体内抗菌试验测得亚迪丰对卒倒菌感染家蚕有良好的保护作用,其ED50为9.82 mg/kg;对灵菌的ED50为139.33 mg/kg。5龄家蚕食下亚迪丰后血清药物浓度-时间数据符合一级吸收动力学和单室模型特征。     

Studies on the toxic interaction between monensin and tiamulin in rats: toxicity and pathology

The characteristics of the toxic interaction between monensin and tiamulin were investigated in rats. A three-day comparative oral repeated-dose toxicity study was performed in Phase I, when the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively). In Phase II, the two compounds were administered simultaneously to study the toxic interaction (monensin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). Monensin proved to be toxic to rats at doses of 30 and 50 mg/kg. Tiamulin was well tolerated up to the dose of 200 mg/kg. After combined administration, signs of toxicity were seen (including lethality in females). Monensin caused a dose-dependent cardiotoxic effect and vacuolar degeneration of the skeletal muscles in the animals given 50 mg/kg. Both compounds exerted a toxic effect on the liver in high doses. After simultaneous administration of the two compounds, there was a mild effect on the liver (females only), hydropic degeneration of the myocardium and vacuolar degeneration of the skeletal muscles. The alteration seen in the skeletal muscles was more marked than that seen after the administration of 50 mg/kg monensin alone.