头孢噻呋的体外抗菌后效应研究

1材料与方法 1．1药物头孢噻呋钠原粉：批号0404002；规格1．0g；山东鲁抗舍里乐药业有限公司生产。     

头孢噻呋等抗菌药物对4种标准菌株的药效学研究

通过用头孢噻呋等抗菌药物对兽医 临床常见的4种标准菌株的体外抗菌活性的 研究,表明头孢噻呋等对4种标准菌株的抗 菌活性较强;头孢噻呋等对4种标准菌株的 杀菌速率均较大;与氨苄西林相比,头孢噻呋 的各个浓度(8,5,2MIC)对金黄色葡萄球菌、 猪链球菌的杀菌速率较小,即它们在3h内使 活菌减少的值差异显著(P<0.05),但头孢 噻呋的各个浓度(8,5,2MIC)对鸡大肠杆菌、 鸡白痢沙门氏菌的杀菌速率均大于氨苄西林 的各个浓度;头孢噻呋与头孢曲松的各个浓 度相比较,对4种标准菌株的杀菌速率差异 均不显著(P>0.05);头孢噻呋等3种β 内 酰胺类抗生素对4种菌株的杀菌速率均不随 浓度(8,5,2MIC)的增加而增大(P> 0.05),即它们均为非浓度依赖性的杀菌药 物。     

头孢噻呋等的体外抗菌活性研究

头孢噻呋又名赛得福(Ceftiofur)，是美国法玛西亚普强公司创制的第一个动物专用的头孢菌素类抗生素。其抗菌谱广、抗菌活性强，对临床及标准菌株均有较强抗菌活性；自从1988年被FDA批准用于治疗牛的呼吸系统感染以来，因其优良的抗菌活性及体内动力学过程，现在国内外兽医临床治疗上的应用日趋广泛。本文报道头孢噻呋等抗菌药物对兽医临床常见病原菌的体外抗菌活性研究。     

兽用头孢噻呋抗菌后效应的研究概况

头孢噻呋是第一种动物专用头孢菌素类抗生素,抗菌谱广,抗菌活性强,在国内外兽医临床上的应用日趋广泛.本文对头孢噻呋抗菌后效应(PAE)的发生机理、活性、影响因素及其临床意义综述,以期为临床用药提供指导.     

头孢噻呋与恩诺沙星联用体外抗菌活性研究

采用两倍稀释法、棋盘法测定头孢噻呋、恩诺沙星以及两者联用对鸡大肠杆菌标准株、临床分离株和鸡链球菌标准株、临床分离株的最小抑菌浓度(MIC)值。结果显示:单方头孢噻呋对五菌株的MIC值介于1～32μg/ml之间,恩诺沙星的MIC值介于0.5～64μg/ml之间,且两药对临床分离株的抗菌活性均明显较标准株低。两药联用对鸡大肠杆菌标准株和临床分离不产酶株、鸡链球菌标准株的部分抑菌浓度(FIC)指数均为0.75,呈现相加作用;对鸡大肠杆菌临床分离产酶株和鸡链球菌临床分离株的FIC指数为1.5,呈现无关作用,但头孢噻呋联用MIC值仅为单方的1/2。     

二氢杨梅素协同盐酸头孢噻呋抗MRSA作用研究

为确证二氢杨梅素联合β-内酰胺类抗菌药物抗耐甲氧西林金黄色葡萄球菌（Methicillin-resistant Staphylococcus aureus,MRSA）的作用,采用微量肉汤稀释法测定二氢杨梅素与β-内酰胺类抗菌药物对MRSA的最小抑菌浓度（Minimum Inhibitory Concentration,MIC）和最低杀菌浓度（Minimum Bactericidal Concentration,MBC）,应用棋盘试验确定二氢杨梅素与β-内酰胺类抗菌药物对MRSA的体外协同抗菌作用,并计算其分级抑菌浓度指数（Fractional Inhibitory Concentration Index,FICI）,并以棋盘法测试结果为依据,选择具有协同作用的组合进一步验证二氢杨梅素与β-内酰胺类抗菌药物联合的动态杀菌作用。结果显示：二氢杨梅素对ATCC 33591的MIC为64μg/mL,与盐酸头孢噻呋联用对ATCC33591均具有协同增效作用,FICI为0.5;64μg/mL的二氢杨梅素可达到杀菌作用,32μg/mL的二氢杨梅素可使盐酸头孢噻呋对ATCC 33591的MBC由256...     

不同配比头孢噻呋与舒巴坦的体外抗菌活性比较

试验旨在评价头孢噻呋与舒巴坦复方制剂的抗菌活性。用双纸片增效法检测超广谱β-内酰胺酶（ESBLs）;用二倍试管稀释法测定其对临床分离的46株大肠杆菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。结果表明：头孢噻呋与舒巴坦联用可显著降低产超广谱β-内酰胺酶（ESBLs）大肠杆菌对头孢噻呋的耐药率。其中,1：1配比对产酶菌的MIC粥为6．269μg／ml,约为头孢噻呋单药的1／10;1：1配比对产酶菌有着较强的杀菌作用,明显优于头孢噻呋单药。对于不产酶大肠杆菌,复方制剂与单药的作用效果几乎相当。     

头孢噻呋钠对21种畜禽常见病原菌的体外抑菌作用

目的:探讨头孢噻呋钠对21种畜禽常见病原菌的抑制作用,为人工感染试验和临床用药提供依据.方法:采用试管二倍稀释法体外抑菌试验.结果:国产头孢噻呋钠对猪链球菌、猪放线杆菌、猪鸡巴氏杆菌、猪鸡大肠杆菌、猪鸡沙门氏菌、鸡金葡菌、产气荚膜梭菌、肺炎克雷伯、停乳链球菌、无乳链球菌的MIC 0.5～0.06 μg/ml,对猪丹毒、奶牛乳房炎、链球菌、猪金葡菌、牛金葡菌的MIC 32～2 μg/ml,优于青霉素.对绿脓杆菌、、猪胃肠炎的MIC 64～125 μg/ml,高于青霉素.     

头孢噻呋体外抗菌活性及其对实验性感染鸡大肠杆菌病的疗效

采用肉汤微量稀释法测定头孢噻呋对大肠杆菌、沙门菌、溶血性巴氏杆菌、金黄色葡萄球菌、链球菌等病原菌的最小抑菌浓度,采用棋盘稀释法测定头孢噻呋与氧氟沙星、甲氧苄啶(TMP)的联合抑菌浓度指数.结果表明,头孢噻呋、氧氟沙星对5种病原菌都具有很强的抗菌活性;头孢噻呋与氧氟沙星联合使用时,对大肠杆菌、沙门菌、链球菌可产生协同作用,对溶血性巴氏杆菌和金黄色葡萄球菌表现为无关作用;头孢噻呋与TMP联合用药时,对上述5种病原菌均具有协同作用.对实验性感染鸡大肠杆菌病的药效学试验结果表明,头孢噻呋高(100mg/L)、中(50mg/L)剂量对感染鸡的有效率明显高于对照药物庆大霉素(P<0.05),极显著高于感染对照组(P<0.01);头孢噻呋高剂量组(100mg/L)感染鸡的增重率与健康对照组相比差异不显著(P>0.05).建议临床应用头孢噻呋治疗鸡大肠杆菌病时,可采用饮水给药,剂量为100mg/L.     

长效头孢噻呋混悬注射液在猪体内的药物动力学试验

头孢噻呋是半合成的第3代头孢菌素类抗生素,是第1个动物专用的头孢类抗生素.由于其抗菌活性强、抗菌谱广、药代动力学特征优良、毒副作用小、残留低.     

In vitro comparison of the activity of various antibiotics and drugs against new Taiwan isolates and standard strains of avian mycoplasma

Twenty-nine antibiotics or drugs were incorporated individually into mycoplasma agar to evaluate their inhibitory activity against avian mycoplasmas: 100 recent Taiwan isolates of 7 serotypes and 10 standard strains of 7 serotypes were tested. All of the standard strains were very sensitive to erythromycin, chlorotetracycline, doxycycline, minocycline, and tetracycline, but the local isolates were highly resistant to these antibiotics. The drugs or antibiotics that possessed an MIC90 of 50 micrograms/ml or less against the local isolates were tiamulin (less than 0.4 micrograms/ml), lincospectin (2.7), josamycin (2.7), lincomycin (3.0), spectinomycin (4.8), tylosin (6.0), kanamycin (6.0), chloramphenicol (6.0), gentamicin (7.5), apramycin (24.5), doxycycline (27.4), minocycline (29.0), spiramycin (30.0), colistin (44.3), leucomycin (45.0), and streptomycin (50.0). The MIC90 of the other antibiotics or drugs was greater than 50 micrograms/ml. None of the isolates or strains were sensitive to nalidixic acid, ronidazole, penicillin, ampicillin, cephalexin, carbadox, or four sulfa drugs at a concentration about 5 times the therapeutic level.     

The effects of ceftiofur sodium (Naxcel) on bovine oocyte and preimplantation embryonic development assessed by in vitro embryo production techniques

Ceftiofur sodium is a third-generation cephalosporin antibiotic with broad spectrum bactericidal activity against Gram-positive and Gram-negative bacteria including the beta-lactamase producing strains. In this study, we use in vitro techniques to examine the effects of low and high levels of ceftiofur sodium on the development of bovine oocytes/embryos during oocyte maturation, oocyte fertilization and embryo culture. A total of 8590 oocytes was used in six independent experiments, each in a randomized complete block design. Each replication within each experiment consisted of oocytes from the same abattoir collection of ovaries. There was no difference in embryo development when oocytes were exposed to ceftiofur sodium during oocyte maturation or fertilization at low (10 and 50 μg/mL) or high (100 and 200 μg/mL) concentrations. However, when fertilized oocytes were exposed to concentrations 50 μg/mL during culture, ceftiofur sodium significantly retarded embryo development (e.g. the numbers of ova developing to the morula and blastocyst stages were reduced, and a large proportion of embryos were blocked at the 8-cell stage). We conclude that ceftiofur sodium does not appear to have detrimental effects on oocyte maturation and fertilization. However, long term exposure to high dosages of ceftiofur sodium during post-fertilization culture adversely affects embryo development in vitro.     

木犀草素对4种细菌体外抗菌活性研究

为研究木犀草素的体外抗菌活性,本试验采用肉汤微量稀释法测定木犀草素对化脓隐秘杆菌、大肠埃希菌、沙门菌和链球菌的最小抑菌浓度(MIC),并测定亚抑菌浓度木犀草素对4种细菌生长曲线的影响。结果表明,木犀草素对化脓隐秘杆菌的抑制作用最强,MIC为0.078g/L;对沙门菌的抑制作用次之,MIC值为1.25g/L;对大肠埃希菌和链球菌的抑制作用相对较弱,MIC值均为2.5g/L。木犀草素对4种试验菌株的生长均具有抑制作用,且随浓度的升高其抑菌作用增强(P<0.05)。     

四种兽用抗生素的体外抑菌效果评价

本实验用试管药物稀释了四种兽用抗生素对猪常见病原菌和正常菌的最小抑菌浓度 （minimal inhibitory concentration, MIC） 和最小杀菌浓度 （minimal bactericidal concentration, MBC）。通过实验发现：各种菌对四种药物的敏感性存在很大的差异,大多数细菌对药物C和D较敏感而对药物A和B存在较严重的耐药。     

Pharmacokinetics of a long-acting ceftiofur formulation (ceftiofur crystalline free acid) in the ball python (Python regius)

The objective of this study was to determine the pharmacokinetics of a long-acting formulation of ceftiofur crystalline-free acid (CCFA) following intramuscular injection in ball pythons (Python regius). Six adult ball pythons received an injection of CCFA (15 mg/kg) in the epaxial muscles. Blood samples were collected by cardiocentesis immediately prior to and at 0.5, 1, 2, 4, 8, 12, 18, 24, 48, 72, 96, 144, 192, 240, 288, 384, 480, 576, 720, and 864 hr after CCFA administration. Plasma ceftiofur concentrations were determined by high-performance liquid chromatography. A noncompartmental pharmacokinetic analysis was applied to the data. Maximum plasma concentration (Cmax) was 7.096 +/- 1.95 microg/ml and occurred at (Tmax) 2.17 +/- 0.98 hr. The area under the curve (0 to infinity) for ceftiofur was 74.59 +/- 13.05 microg x h/ml and the elimination half-life associated with the terminal slope of the concentration-time curve was 64.31 +/- 14.2 hr. Mean residence time (0 to infinity) was 46.85 +/- 13.53 hr. CCFA at 15 mg/kg was well tolerated in all the pythons. Minimum inhibitory concentration (MIC) data for bacterial isolates from snakes are not well established. For MIC values of < or =0.1 microg/ml, a single dose of CCFA (15 mg/kg) provides adequate plasma concentrations for at least 5 days in the ball python. For MICs > or =0.5 microg/ml, more frequent dosing or a higher dosage may be required.     

3种抗生素对3种常见鱼类病原菌的抑菌活性研究

为研究盐酸恩诺沙星、乳酸恩诺沙星和乳酸诺氟沙星对嗜水气单胞菌(Aeromonas hydrophila)、鳗弧菌(Vibrio anguillarum)和哈维氏弧菌(Vibrioharveyi)的体外抑菌活性,本实验通过测定抑菌圈直径、最小抑菌浓度(MIC)、最小杀菌浓度(MBC)和杀菌曲线,研究3种常用喹诺酮类抗生素药物对3种水产病原菌的体外药效学特性.结果表明:乳酸诺氟沙星对嗜水气单胞菌和哈维氏弧菌抑菌效果最好,MIC分别为0.244μg/mL和1.954μg/mL:盐酸恩诺沙星对鳗弧菌抑菌效果最好,MIC为0.122μg/mL;8 MIC的乳酸诺氟沙星药液在12 h内完全杀灭嗜水气单胞菌,在24 h内也能全部杀灭哈维氏弧菌,8 MIC的盐酸恩诺沙星药液在24 h内全部杀灭鳗弧菌.本研究为3种抗生素在水产养殖中的应用提供实验依据.     

In vitro activity of five tetracyclines and some other antimicrobial agents against four porcine respiratory tract pathogens

The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.