共查询到20条相似文献，搜索用时 203 毫秒
1.
2.
在世界范围内,细菌耐药性问题日益严重,已严重影响了感染性疾病的治疗。新型抗耐药菌药物的研究已成为抗菌药物研究的主要方向。噁唑烷酮类化合物是一类新型的治疗细菌性感染的化学全合成药物,具有抑制多重耐药的革兰阳性菌的功效。且作用机制独特,不易与其他药物发生交叉耐药性,从而得到了广泛的研究。在第一个噁唑烷酮类抗菌药物利奈唑胺成功上市后,又有新的化合物进入临床研究,并取得了良好的临床治疗效果。论文介绍了噁唑烷酮类抗菌药的作用机制、抗菌活性、构效关系及最新的噁唑烷酮类抗菌药的研究,为研发新型噁唑烷酮类抗菌药提供参考。 相似文献
3.
由于细菌耐药现象的日益严重,近些年来对新型抗菌药的需求不断增长。利用拼合原理将两种药物通过一定的方式连接而成的多靶点杂合物,为扩大药物的抗菌谱、增强药物对耐药菌的有效性及降低耐药性的出现提供了可能,已成为研发新型抗菌药物的一种新策略。与此同时,噁唑烷酮类和喹诺酮类抗菌药以其独特的作用机制和抗菌谱互补的特点吸引了研究者的关注,因此他们将这两类抗菌药物的药效基团进行拼合形成了一系列的噁唑烷酮—喹诺酮杂合物,并已表明它们对多种敏感和耐药菌株均有活性。本文就此类杂合物的设计合成、抗菌活性及目前处于临床研究阶段的噁唑烷酮—喹诺酮杂合物——咔哒唑胺的研究进展作一综述。 相似文献
4.
<正> 抗菌药包括抗生素类、磺胺类、抗菌增效剂、抗菌中草药及消毒药。这些药在畜禽疾病防治中起到了非常重要的作用。那么怎样正确使用呢?1 抗菌药物的正确使用方法遵照产品使用说明:兽药生产厂家对每种药物都明确规定了使用剂量、方法和疗程,应遵照执行。若为提高疗效,可根据具体情况适当提高药物的初次剂量,然后再按维持剂量使用。合理选择药物:一般预防感染或治疗轻度感染可只选用一种药物。重度感染、混合感染可两种抗菌药物联合使用,并要注意配伍禁忌和毒性反应。或与中草药合用;或遵照兽医指导使用。不同品种交替使用:选择几种有效药物交替使用可提高疗效(按疗程交替),避免抗药性产生。对于反复发生的疫病,应更换成长期为用的药物或新品种。疗效会更好。合理更换品种及停药:一般细菌 相似文献
5.
正一、严管的主要措施(一)背景1.兽药使用不规范。中药产品违法添加抗菌药物、抗菌药物和抗病毒药物组方使用 、使用人用重要抗菌药物以及禁用药物或物质;超范围、超剂量,不按规定休药,多种抗菌药物联合使用 、用药记录不规范;安 相似文献
6.
7.
8.
一、明确诊断、正确选用抗菌药正确选用抗菌药物是发挥抗菌药疗效的重要保证。滥用抗菌药可产生不良后果 ,既可产生敏感的病原体对药物产生耐药性 ,能使动物机体产生不良反应 ,甚至造成严重的经济损失。所以 ,抗菌药物的选择应以临床诊断为依据。二、根据药物特点 ,制定合理的给药方案抗菌药在机体内要发挥杀灭或抑制的作用 ,必须在靶组织或器官内达到有效的浓度 ,并能维持一定的时间。因此 ,必须有合适的剂量、间隔时间及疗程。给药途径既应根据药物体内过程特点 ,又应根据病情适当选择 ,严重感染多用注射给药 ,一般感染和消化系统的疾病以内服为宜 ,但严重消化道疾病伴有菌血症时 ,可选择内服与注射法给药并用 ,奶牛乳腺炎和子宫内膜炎宜用局部注射法给药。三、慎用抗菌药 ,防止细菌耐药性的产生1.常用抗菌药对病毒、真菌、寄生虫等感染无效。真菌性感染及寄生虫感染应对症选择用药。2.病情轻、病因不明的感染不宜轻易使用抗菌药物。3.严格控制抗菌药物的预防性使用 ,尽量减少长时间应用 ,污染场地应严格消毒 ,控制耐药菌株传播。使用抗菌药物 ,在可用可不用时尽量不用 ;宜用窄谱抗生素决不用广谱抗生素 ;一种抗菌药有效时 ,决不用多种抗菌药 ;将... 相似文献
9.
10.
防治畜禽疾病时,为增强疗效,常将两种抗菌药物联合使用。 一、联合使用抗菌药物 应有明确的临床特征,不可滥用。如出现下列情况可考虑联合使用。1、畜禽病情危急或病因未明的严重感染。2、一种抗菌药物不能抗制的混合感染。3、对某种抗菌药物产生耐药性的病例。4、当脑脊液出现感染病灶时,可联合用药。 相似文献
11.
水分胁迫下几种药剂对早熟毛豆抗逆性的影响 总被引：9，自引：1，他引：8
试验筛选三十烷醇、油菜素内酯、爱多收、绿风95、黄腐酸盐等几种药剂对早熟毛豆进行喷施处理,测定其在水分胁迫下对其幼苗某些生长、生理指标的影响及抗性评价。结果表明,采用几种药剂处理后,与相应的对照相比可促进苗增高、扩大叶面积、增加干物质的积累、促进根系的生长、提高根系活力、抑制丙二醛增生、降低细胞膜透性和增加叶绿素含量、脯氨酸含量、细胞保护酶的活性等,增强毛豆幼苗对水分胁迫逆境的抵抗能力;在逐渐干旱胁迫下,5种药剂处理以油菜素内酯为最好;在持续淹水胁迫下,5种药剂处理以绿风95为最优。 相似文献
12.
为探明泰州地区鸡源大肠杆菌产超广谱β-内酰胺酶(ESBLs)情况及耐药情况,对13株分离自泰州地区的鸡源大肠杆菌进行ESBLs检测,并采用微量肉汤稀释法测定不同药物对产ESBLs菌和非产ESBLs菌的最小抑菌浓度(MIC).结果显示,13株分离菌中有5株被确定为产ESBLs菌株,阳性率为38.5%.产ESBLs菌对β-内酰胺类抗菌药的耐药性极其严重,耐药率明显高于非产ESBLs菌,二者对氨苄西林的耐药率分别为100%和62.5%,对头孢噻呋的耐药率分别为100%和12.5%,对头孢曲松的耐药率分别为80%和20%,产ESBLs菌对其他抗菌药物的耐药率也明显高于非产ESBLs菌.氨苄西林与舒巴坦(2:1)联用与单用氨苄西林相比,对产ESBLs菌的MIC值降低至单用氨苄西林时的1/16~1/8,但对非产ESBLs菌的MIC值没有明显变化.氨苄西林与阿米卡星(1:1)联用与单用两者中的任何一种相比,对产ESBLs菌和非产ESBLs菌的MIC值均降低至单药时的1/16~1/2.结果表明,临床可选择β-内酰胺酶类抗生素与β-内酰胺酶抑制剂的混合制剂来治疗产ESBLs鸡大肠杆菌的感染,也可尝试将不同种类、不同作用机理药物联合应用来治疗鸡大肠杆菌感染,尤其是耐药性鸡大肠杆菌感染. 相似文献
13.
Nikaidou S Ishizuka M Maeda Y Hara Y Kazusaka A Fujita S 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(1):137-138
Green tea, one of the most popular beverages consumed in Asian countries, has been reported to possess anticarcinogenic and antimutagenic properties. The aim in this study is to test the radical scavenging effect of catechins and caffeine, which were major components of green tea, and if they really prevent oxygen radical-induced mutagenesis. We used TA102 strain of Salmonella typhimurium which is sensitive to hydroxyl radical in the Ames mutation assay. We found that caffeine did not show any effects on mutagenesis in this system, but catechin significantly reduced mutagenesis or genotoxicity caused by hydroxyl radical. This radical-scavenging action of catechins may indeed contribute to the anticarcinogenic activity of green tea as has been proposed. 相似文献
14.
15.
S D Folz R A Pax T R Klei E M Thomas K A Ash G A Conder J L Bennett 《Journal of veterinary pharmacology and therapeutics》1988,11(2):177-182
An in vitro assay involving the use of a horse strongyle (Strongylus edentatus) and the micromotility meter has been developed to test for equine anthelmintic activity. Three commercially available equine anthelmintics (dichlorvos, ivermectin, and pyrantel pamoate) and an investigational drug (p-toluoyl chloride phenylhydrazone) were evaluated in this assay at four concentrations. After a 24-h incubation, greater than or equal to 10 micrograms/ml of all four drug treatments significantly (P less than or equal to 0.05) reduced the motility of ensheathed L-3 S. edentatus larvae, thereby indicating anthelmintic activity. Pyrantel pamoate also reduced motility at 1 microgram/ml, while the hydrazone significantly increased movement at this level. At 0.1 microgram/ml, none of the treatments significantly reduced motility; one treatment (dichlorvos) significantly increased larval motility. Incubation for 48 h resulted in significant activity (reduction in motility) at greater than or equal to 1 microgram/ml with two drugs (ivermectin, pyrantel pamoate); dichlorvos and the hydrazone reduced motility at greater than or equal to 10 micrograms/ml. None of the treatments significantly reduced motility at the lowest concentration (0.1 microgram/ml); however, at 48 h, two treatments (dichlorvos, hydrazone) significantly increased motility at the lowest concentration (0.1 microgram/ml). The in vitro S. edentatus motility assay proved to be sensitive, accurate and rapid. This assay system should be a valuable addition to tests used to identify potential equine anthelmintics, monitor helminth resistance to drugs, and perhaps define the kinetics and mode of action for drugs. 相似文献
16.
17.
为了探究中药对大肠杆菌抗生素耐药性的消除机制,以小檗碱为处理药物,使用小檗碱浓度为250 μg/mL （1/2最小抑菌浓度（MIC））的LB肉汤培养临床分离的禽源耐药大肠杆菌,每隔24 h传一代,共传3代。对第3代菌液以影印法分离突变菌,以微板法测定突变菌的左氧氟沙星MIC。经测定发现突变菌对左氧氟沙星的MIC由16 μg/mL降至8 μg/mL,说明对左氧氟沙星的耐药性具有消除作用。为了解小檗碱作用大肠杆菌的分子机制,通过转录组测序方法对耐药性消除前后禽源大肠杆菌基因表达水平进行对比分析。结果显示,小檗碱作用后共有45个基因的表达量发生显著变化,其中有30个基因表达量上调,15个基因表达量下调。经过GO功能富集分析和KEGG代谢通路富集分析,发现上调主要为：与色氨酸合成有关的基因,磷酸吡哆醛结合相关3个基因,表达转酮酶基因;下调主要为：双组份系统中多个基因,十一异戊二烯焦磷酸磷酸酶（UppP）编码基因ybjG,酰基辅酶A脱氢酶合成有关的基因。推测大肠杆菌体内酶活性降低是小檗碱抑菌的主要机制;大肠杆菌多重耐药外排泵表达降低、细胞膜和细胞壁成分的改变是小檗碱耐药性消除的主要机制。 相似文献
18.
本试验以真菌防御素Plectasin衍生肽NZ2114和奶牛乳房炎源金黄色葡萄球菌为研究对象,旨在阐明抗菌肽NZ2114对金黄色葡萄球菌的体外抗菌机制及其阻遏金黄色葡萄球菌耐药性的效果。通过16S rRNA基因鉴定对55份乳房炎奶样中的病原菌进行分离鉴定,采用纸片扩散法检测其耐药性,通过微量稀释法测定抗菌肽NZ2114对金黄色葡萄球菌的抑菌活性,借助流式细胞术和扫描电镜观察抗菌肽NZ2114对金黄色葡萄球菌细胞膜完整性及细胞形态的影响,通过凝胶阻滞和圆二色谱分析抗菌肽NZ2114对金黄色葡萄球菌基因组DNA的影响,将抗菌肽NZ2114与金黄色葡萄球菌共同孵育以研究抗菌肽NZ2114对金黄色葡萄球菌耐药性的影响,通过PCR进一步分析抗菌肽NZ2114对金黄色葡萄球菌携带的耐药基因的影响。结果表明,共获得10株金黄色葡萄球菌,分离菌对青霉素等9种抗菌药具有耐药性,且50%为多重耐药。抗菌肽NZ2114对10株金黄色葡萄球菌具有强抑菌活性,最小抑菌浓度（MIC）为0.5~1.0 μg/mL。抗菌肽NZ2114可导致金黄色葡萄球菌S7细胞皱缩、细胞内容物泄漏,甚至细胞裂解,碘化丙啶（PI）细胞膜穿透率达5%,且抗菌肽NZ2114可与金黄色葡萄球菌S7基因组DNA结合并改变其DNA结构。金黄色葡萄球菌与1/4×MIC抗菌肽NZ2114孵育12 h后发现,除对阿莫西林和磺胺异噁唑的耐药率没有降低外,对其他抗菌药的耐药率均有不同程度的降低（10%~40%）,且抗菌肽NZ2114对β-内酰胺类耐药基因（blaZ）及杆菌肽类耐药基因（braRS）的消除率分别达28.57%（2/7）和22.22%（2/9）。上述结果证明,抗菌肽NZ2114对耐药金黄色葡萄球菌具有体外强抑菌活性,其干扰耐药金黄色葡萄球菌细胞膜并结合胞内DNA的作用机制为其低耐药杀菌机制奠定了细胞学基础。同时抗菌肽NZ2114对耐药菌株的耐药性及相关耐药基因均有一定消除作用。由此可见,抗菌肽NZ2114是一种极具前景的治疗金黄色葡萄球菌引起的奶牛乳房炎的抗生素替代品。 相似文献
19.
RJ DOBSON RB BESIER EH BARNES SCJ LOVE A VIZARD K BELL LF Le JAMBRE 《Australian veterinary journal》2001,79(11):756-761
OBJECTIVE: To provide principles for the appropriate use of avermectin/milbemycin or macrocyclic lactone (ML) anthelmintics in sheep, to ensure effective worm control and to minimise selection for ML resistance. STRATEGY: The principles were based on an assessment of the information currently available. The MLs were categorised into three groups (ivermectin [IVM], abamectin [ABA] and moxidectin [MOX]) based on structural differences, persistence and efficacy against ML resistant strains. The reported order of activity or efficacy against ML resistant worm strains was IVM相似文献
20.
P. G. C. Douch G. B. L. Harriston D. C. Elliott L. L. Buchanan K. S. Greer 《Veterinary parasitology》1986,20(4):315-331
Changes in the numbers of globule leucocytes, mast cells, eosinophils and goblet cells in the gastrointestinal mucosa were examined in relation to the development of resistance and elimination of nematodes in grazing sheep in their firsty year of life. Sheep immunised against Trichostrongylus colubriformis, and sheep treated with dexamethansone were also examined. A strong association between resistance to infection and the presence of globule leucocytes was found. In contrast, the numbers of mast cells or goblet cells were not correlated with resistance. Globule leucocyte and eosinophil numbers were also correlated with antiparasite activity in mucus.
Immunising infections of T. colubriformis given to 10-month-old sheep, their duration limited by thiabendazole treatment, gave rise to considerable immunity to homologous challenge infections. Larvae that developed to the 4th stage were as effective at stimulating immunity as those that developed to the 5th stage. Dexamethasone treatment abrogated resistance to trickle challenge infection with T. colubriformis and reduced mucosal globule leucocyte and mast cell numbers. After cessation of drug treatment, the re-establishment of resistance and adult worm elimination were associated with repopulation of the mucosa with large numbers of globule leucocytes and high antiparasite activities in mucus. 相似文献