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大肠杆菌耐药性抑制剂作用机制的初步研究 总被引：11，自引：0，他引：11
20株人源和动物源性大肠杆菌在体外经黄连提取物(命名为耐药性抑制剂IT2)作用后,对氟喹诺酮类抗菌药、庆大霉素和多西环素的耐药性明显被抑制.选取经抑制剂IT2作用后耐药性变化显著的5对菌株进行质粒提取和电泳检测,发现J0、H004、J3、J2 等4株菌作用前均有质粒带,与其相对应的耐药性抑制剂作用后的菌株ITJ0、ITH004、ITJ3、ITJ2质粒带全部消失,只有菌株J1经抑制剂IT2作用前后质粒带无变化.提取外膜蛋白进行SDS-PAGE电泳分析,菌株J1、J3、J0缺少OmpF、OmpA, J2仅缺少OmpA,经耐药性抑制剂作用后,J1、J3、J0的OmpF均由缺失恢复为表达,OmpC的表达量呈显著增加,H004没有变化.结果表明耐药性抑制剂IT2对大肠杆菌的部分耐药性具有良好的抑制作用,其作用与阻碍耐药质粒拷贝、恢复外膜通道蛋白正常表达关系密切. 相似文献
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《中国兽医杂志》2020,(5)
筛选对临床分离多重耐药猪大肠杆菌有抑菌、杀菌作用的中药,并分析部分中药的联合抑菌效果。选用标准菌株ATCC83707作为对照菌株,采用纸片法测定分离菌株对临床常用抗生素的敏感性。微量2倍稀释法和平板法测定各味中药的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。微量棋盘稀释法测定2种中药的联合抑菌效果。结果表明,临床分离大肠杆菌对阿米卡星、庆大霉素、左氟沙星、青霉素G、链霉素、阿莫西林都耐药,仅对多黏菌素B呈现敏感。临床分离大肠杆菌对黄连等12味中药表现为中度敏感,对其他中药表现为不敏感;ATCC83707对黄连等10味中药中度敏感,对其他药物不敏感。黄连-芦荟、黄连-诃子、山楂-芦荟、山楂-诃子、山楂-诃子、芦荟-乌梅、诃子-白头翁等联合应用时,对临床分离大肠杆菌菌株呈现协同作用;黄连-山楂、黄连-乌梅、黄连-白头翁、山楂-香薷、芦荟-五味子、乌梅-香薷、乌梅-诃子、黄芩-诃子、诃子-五味子等联合应用时,对临床分离大肠杆菌菌株呈现相加作用;黄连-香薷、黄连-五味子等联合应用时,对临床分离大肠杆菌菌株呈现无关作用;其余药物联合应用时,对临床分离大肠杆菌菌株呈现拮抗作用。临床分离大肠杆菌对常用抗生素呈现了多药耐药趋势,但对中药仍然保持一定的敏感性;抗菌方面,中药之间存在着复杂的相互作用,部分中药间有协同作用,临床用药时须谨慎筛选。 相似文献
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【目的】筛选腹泻仔猪中携毒力基因且多重耐药的大肠杆菌菌株,评估中药水提物对该菌株的抑菌活性,并探索中药抑菌机制。【方法】通过PCR方法与Kirby-Bauer(K-B)药敏纸片法评估临床大肠杆菌菌株的肠毒素基因携带情况和耐药性;通过微量肉汤稀释法评估中药水提物对多重耐药大肠杆菌菌株的抑菌活性,确定最小抑菌浓度(minimal inhibitory concentration, MIC)和最小杀菌浓度(minimal bactericidal concentration, MBC);通过电导率仪以及相关试剂盒检测评估石榴皮水提物对多重耐药菌株作用不同时间后菌液电导率、碱性磷酸酶(alkaline phosphatase, AKP)含量及菌体内ATP含量的变化;通过SDS-PAGE和蛋白含量检测评估菌体内可溶性蛋白的含量变化;通过扫描电镜观察大肠杆菌形态变化。【结果】PCR检测14株临床大肠杆菌中肠毒素基因携带率达到78.57%,抗生素药敏试验结果显示,所有菌株至少对2种抗生素耐药,均属于多重耐药菌株。中药药敏试验结果显示,黄连、黄芩、石榴皮水提物对多重耐药菌株抑菌活性较好,其中石榴皮水提... 相似文献
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《畜牧兽医学报》2015,(6)
研究鸡源大肠杆菌耐药性及中药对大肠杆菌耐药性消除作用。选择22种抗生素采用Kirby-Bauer法对山西省部分地区分离的20株致病性鸡源大肠杆菌进行耐药性检测,对分离菌株进行质粒分析和耐药质粒转化试验,并分析多种中药对大肠杆菌耐药性的消除作用。结果显示,20株试验菌对测试抗生素均存在不同程度的耐药性,其中5耐及5耐以上的菌株占分离菌株的90%,试验菌对青霉素耐药率最高(90%),其次为恩诺沙星(85%),而对黏杆菌素和呋喃妥因的耐药性最低;分离出12种质粒谱型,同一地区、同一鸡场菌株的质粒图谱相同或相似,不同地区菌株的质粒图谱不同,仅有部分相同或相近的流行质粒共存;对其中5株菌株进行耐药质粒的转化试验,发现同一质粒可编码1个至数个耐药性基因,不同质粒可以携带相同的耐药性基因;中药单剂或合剂对大肠杆菌的耐药性有一定的消除作用,其中黄芩的消除效果最好,中药处理后部分菌株质粒图谱无变化,只有黄连和双黄连造成2条质粒带丢失;对中药提取物作用后的消除子进行药敏试验,结果发现大肠杆菌对环丙沙星等多种抗生素恢复了敏感性。研究结果提示联合使用中药治疗鸡源大肠杆菌病有显著效果。 相似文献
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中药口服液治疗人工感染仔猪大肠杆菌试验研究 总被引：1，自引：0，他引：1
用茜草秧、穿心莲、大青叶等13味中药组方,制成口服液口服给药,对仔猪大肠杆菌耐药菌株和非耐药菌株进行体外抑菌及临床治疗试验.结果,中药口服液对两菌株都有较好的体外抑菌效果;临床治疗有效率100%,治愈率达90%以上. 相似文献
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【目的】掌握浙江省德清县驯养朱鹮大肠杆菌的耐药性、耐药基因与分子特征,为治疗朱鹮大肠杆菌感染提供基础数据。【方法】采集该地驯养朱鹮新鲜粪便样本,采用分离培养、形态观察、生化鉴定及16S rDNA序列分析鉴定大肠杆菌;进而采用肉汤稀释法检测环丙沙星、庆大霉素、丁胺卡那等7种抗菌药对源自不同朱鹮的大肠杆菌分离株菌株的最小抑菌浓度(minimal inhibitory concentration, MIC);选择代表性菌株,通过PCR和测序鉴定其携带qnrS1、gyrA、gyrB等9种喹诺酮类耐药基因的情况,并分析其蛋白关键氨基酸位点突变与耐药性的关系,采用接合转移分析耐药质粒水平转移情况及其与耐药性的关系,应用卡方检验(Chi-square test)和费歇尔精确检验(Fisher exact test)分析分离株耐药表型与朱鹮年龄、耐药基因的相关性。【结果】本研究共采集了98只朱鹮的粪便,经分离鉴定均获得了大肠杆菌;源自不同朱鹮的98株大肠杆菌对喹诺酮类环丙沙星呈现高度耐药(耐药率为65.3%,64/98),对其余6种药物高度敏感(敏感率均>90%),朱鹮年龄与环丙沙星耐药性极显著... 相似文献
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为探究木犀草素联合庆大霉素对耐药化脓隐秘杆菌的抑制作用,采用微量肉汤稀释法分别测定木犀草素和庆大霉素对34株化脓隐秘杆菌的最小抑菌浓度(MIC)。选取对庆大霉素耐药的化脓隐秘杆菌,通过棋盘法测定两种药物联合抑菌效果。经亚抑菌浓度木犀草素作用耐药菌株,比较木犀草素作用前后化脓隐秘杆菌对庆大霉素的耐药性变化情况。结果表明,木犀草素对化脓隐秘杆菌的MIC值为39~156μg/m L,与庆大霉素联合的作用为不相关;耐药菌经亚抑菌浓度木犀草素(1/4MIC)作用36 h后,庆大霉素对耐药菌的MIC值下降2~32倍,且原菌株耐药水平越高,MIC下降倍数越高。提示木犀草素具有良好抗菌活性,且能够逆转化脓隐秘杆菌耐药性。 相似文献
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Gottlieb S Wigney DI Martin PA Norris JM Malik R Govendir M 《Australian veterinary journal》2008,86(4):147-152
OBJECTIVES AND DESIGN: 1) A prospective study to determine in vitro concentrations for a range of fluoroquinolones, gentamicin and amoxycillin-clavulanate required to inhibit growth of recently collected, feline and canine Escherichia coli and canine Staphylococcus intermedius isolates. 2) A comparative retrospective study to compare the minimum inhibitory concentrations (MICs) of ciprofloxacin, enrofloxacin and amoxycillin-clavulanate for archived canine E coli and S intermedius isolates collected ten to twenty years earlier, with those for recently collected isolates. PROCEDURE: Susceptibility was assessed using disk diffusion, agar dilution susceptibility testing and Epsilometer tests (E-tests) for both recently collected and archived isolates. RESULTS: All feline E coli isolates and recently collected canine S intermedius isolates were susceptible to all fluoroquinolones. There was a statistically significant increase in the MIC range of ciprofloxacin and enrofloxacin for recently collected E coli, and in the MIC range of amoxycillin-clavulanate for recently collected S intermedius isolates compared to archived isolates. Twelve of 59 recently collected canine E coli isolates were resistant to both ciprofloxacin and enrofloxacin. Resistant canine E coli isolates were associated with complicating host or infection site factors. CONCLUSION: This is the first report comparing the MICs for all veterinary fluoroquinolones currently available in Australia for a representative sample of canine and feline E coli and canine S intermedius isolates. Importantly, this study identified 12 of 59 canine E coli isolates resistant to fluoroquinolones and identified the development of low level resistance in canine E coli to ciprofloxacin and enrofloxacin and canine S intermedius to amoxycillin-clavulanate. 相似文献
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采用浓度梯度递增法对3株不同生物被膜形成能力的大肠埃希菌进行4种氨基糖苷类药物(阿米卡星、链霉素、庆大霉素和安普霉素)诱导,考察大肠埃希菌生物被膜对其余8种不同抗菌药物最小抑菌浓度和最小膜清除浓度的变化规律。结果表明,在氨基糖苷类药物诱导压力下,3株不同生物被膜形成能力的菌株对其余8种抗菌药物的最小膜清除浓度比最小抑菌浓度至少增加8倍以上,与诱导前相比,大肠埃希菌形成生物被膜后,其最小膜清除浓度增加的速率比最小抑菌浓度快。 相似文献
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考察马波沙星对猪临床分离病原菌的体外抑菌活性,以期为临床应用提供依据。采用琼脂二倍稀释法测定马波沙星对猪临床分离大肠杆菌、金黄色葡萄球菌和链球菌的最小抑菌浓度(MIC),并以土霉素、恩诺沙星、诺氟沙星、环丙沙星、庆大霉素和多西环素作为对照药物。结果表明:马波沙星对猪临床分离病原菌大肠杆菌、金黄色葡萄球菌和链球菌均有较低的最小抑菌浓度,对临床分离大肠杆菌、金黄色葡萄球菌和链球菌的抑菌活性明显高于诺氟沙星、环丙沙星、庆大霉素和强力霉素,对临床分离大肠杆菌的抑菌活性高于恩诺沙星。马波沙星对引起猪乳房炎-子宫炎-无乳综合征(MMA)的主要病原菌的抑菌活性优于常用抗菌药。 相似文献
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The in vitro activity of flumequine in comparison with several other drugs was tested against 17 P. multocida, 16 P. haemolytica, 21 S. dublin, 21 S. typhimurium and 21 E. coli strains, isolated in (veal) calves in the Netherlands. The MIC50 of flumequine for the respective pasteurellas was 0.25 and 1 microgram/ml, for the salmonellas and E. coli 0.5 micrograms/ml. In comparison with flumequine, enrofloxacin and ciprofloxacin showed higher in vitro activity, with MIC50 less than or equal to 0.008 micrograms/ml for ciprofloxacin. Decreased susceptibility of the pasteurellas was found for kanamycin, neomycin, streptomycin, gentamicin, oxytetracycline and doxycycline. The MIC50 of minocycline for P. multocida was 0.5 micrograms/ml and there was no cross resistance with the other tetracyclines. P. multocida was very susceptible to ampicillin (MIC50 less than or equal to 0.03 micrograms/ml), P. haemolytica, however, was 100% resistant to this drug. Both pasteurellas were susceptible to cephalothin and approximately 50% of the strains of both bacteria were resistant to chloramphenicol. The MIC50 of either spiramycin or tylosin was greater than or equal to their respective breakpoint-MIC values. Both pasteurellas were susceptible to the combination of trimethoprim and sulphamethoxazole. However, for P. multocida, the addition of sulphamethoxazole to trimethoprim had no synergistic effect on its MIC. In comparison with trimethorpim, aditoprim was less potent. Therefore only P. multocida was susceptible to aditoprim. 相似文献
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为研究防治鸡大肠杆菌病的新方法,减少抗生素的使用及耐药菌株的产生,试验选取黄连、乌梅、白术等中药制成黄连组方口服液,检测其对大肠杆菌O78的抑制作用与临床疗效。体外试验采用最小抑菌浓度（MIC）与最小杀菌浓度（MBC）检测口服液抑菌效果;应用流式细胞仪观察口服液对细菌死亡率的影响;利用扫描电镜和透射电镜观察口服液对菌体形态与结构的影响;临床试验检测口服液对鸡大肠杆菌病的治疗效果及免疫器官指数的影响。结果显示,口服液对大肠杆菌的MIC为62.5 mg/mL,MBC为250 mg/mL;流式细胞仪检测可见口服液组大肠杆菌的死亡率为74.1%,空白对照组大肠杆菌死亡率为37.2%;扫描电镜下可见口服液处理组的菌体溢缩、断裂,形成许多残体;透射电镜下可见菌体变形,质壁分离现象。临床疗效显示,黄连组方治愈率为86.67%,而西药组治愈率为63.33%;空白对照组和西药组脾脏指数与模型组差异极显著（P < 0.01）,空白对照组、西药组、黄连组方高剂量组的法氏囊指数极显著高于模型组（P < 0.01）,模型组的胸腺指数显著低于其余各组（P < 0.05）。本试验结果表明,黄连组方可使菌体发生变形、溢缩断裂、质壁分离等变化达到杀菌效果,并可通过提高动物体免疫力来防治雏鸡大肠杆菌病。 相似文献
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Altekruse SF Elvinger F Lee KY Tollefson LK Pierson EW Eifert J Sriranganathan N 《Journal of the American Veterinary Medical Association》2002,221(3):411-416
OBJECTIVE: To measure minimum inhibitory concentrations (MIC) of 17 antimicrobials for Escherichia coli isolates from a turkey operation and assess whether small samples provide precise estimates of geometric mean MIC. DESIGN: Prospective study. SAMPLE POPULATION: 105 clinical isolates from birds and 1,104 fecal isolates from 20 flocks (poults and finisher hens). PROCEDURE: A Mueller-Hinton broth dilution panel was used to measure MIC, and MIC of fecal and clinical isolates were compared. We drew random samples of 5,10, 15, 20, 25, 30, 35, 40, and 45 isolates from each finisher flock and between 100 and 105 isolates from 5, 7, 10, and 20 flocks. Antimicrobial usage was determined for enrolled flocks. RESULTS: Six of 12 poult and 18 of 20 finisher flocks had been treated with antimicrobials, often for respiratory illnesses consistent with colibacillosis. All birds received gentamicin at the hatchery. More fecal than clinical isolates were resistant to ampicillin; however, more clinical isolates were resistant to ciprofloxacin, gentamicin, and sulfamethoxazole. Precise estimates of geometric mean MIC for flocks were obtained when > or = 15 fecal isolates were obtained per flock and, for the operation, when 105 isolates were obtained from > or = 7 flocks. CONCLUSION AND CLINICAL RELEVANCE: Antimicrobial usage was common and may have contributed to the resistance patterns of isolates. With a modest allocation of laboratory resources, producers can monitor antimicrobial susceptibilities of clinical and fecal E coli to manage risks of antimicrobial usage and resistance. 相似文献
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Ciprofloxacin and ofloxacin aqueous humor concentrations after topical administration in dogs undergoing cataract surgery 总被引：1，自引：1，他引：0
OBJECTIVE: To determine if preoperative topical administration of ciprofloxacin or ofloxacin results in aqueous humor drug concentrations that exceed the MIC(90) of common ocular contaminants in dogs undergoing cataract surgery. PROCEDURES: Twelve dogs were treated with topical 0.3% ciprofloxacin and 13 dogs with topical 0.3% ofloxacin once the night before surgery, and then with 1 drop of ciprofloxacin or ofloxacin every 15 min for 2 h immediately before surgery. Aqueous humor samples were taken from each eye immediately before the incision was made and frozen at -70 degrees C. First eye samples (S1) were taken closer to the time of topical treatments than second eye samples (S2). Samples were analyzed by high performance liquid chromatography (HPLC) at the North Carolina State University (NCSU) Clinical Pharmacology laboratory. RESULTS: In ciprofloxacin patients, S1 concentrations were 0.03-0.69 (0.17 median) microg/mL, and S2 concentrations were 0.09-0.95 (0.36 median) microg/mL. Aqueous humor concentrations did not exceed the MIC90 of Streptococcus sp. Few eyes (1/12 OU) exceeded the MIC90 for Staphylococcus sp. or Corynebacterium sp.; moderate numbers (5/12 S1; 8/12 S2) exceeded the MIC90 for E. coli. In ofloxacin patients, S1 concentrations were 0.48-2.81 (1.05 median) microg/mL, and S2 concentrations were 0.45-3.63 (1.30 median) microg/mL. Although few eyes (相似文献
18.
Chao-Fu Chang Lin-Chu Chang Yung-Fu Chang Michael Chen Tai-Sheng Chiang 《Journal of veterinary diagnostic investigation》2002,14(2):153-157
Minimum inhibition concentrations (MICs) were determined for ampicillin, ceftiofur, cephalothin, chloramphenicol, enrofloxacin, gentamicin, lincomycin, lincospectin (lincomycin/spectinomycin), neomycin, premafloxacin, spectinomycin, sulfamethoxazole/trimethoprim, and tetracycline against a total of 180 isolates of Actinobacillus pleuropneumoniae, Escherichia coli, and Salmonella choleraesuis (60 each) clinically isolated from pigs on farms in Taiwan from 1994 to 1996. No more than 3 isolates per farm were used. Ceftiofur had the highest activity in vitro against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 0.03, 2, and 1 microg/ml, respectively. Premafloxacin was highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, with MIC90 values of 2, 8, and 0.5 microg/ml, respectively, which were lower than those with enrofloxacin (MIC90 8, 32, and 2 microg/ml, respectively). Neomycin was moderately active against A. pleuropneumoniae and E. coli, with MIC90 values of 8 and 64 microg/ml, respectively, but was inactive with S. choleraesuis. Gentamicin showed high activity against A. pleuropneumoniae (MIC90 of 2 microg/ml) but was only moderately active with E. coli and S. choleraesuis (MIC90 of 64 and 32 microg/ml). Cephalothin was highly active against isolates of A. pleuropneumoniae (MIC90 of 1 microg/ml) but was inactive with E. coli (MIC90 of 128 microg/ml). Lincomycin had moderate activity (MIC90 of 32 microg/ml) against A. pleuropneumoniae. Chloramphenicol, lincomycin, and tetracycline were inactive with E. coli and S. choleraesuis (MIC90 > 128 microg/ml). In conclusion, ceftiofur and premafloxacin were highly active against isolates of A. pleuropneumoniae, E. coli, and S. choleraesuis, enrofloxacin and gentamicin were highly to moderately active; cephalothin was highly active against A. pleuropneumoniae and moderately active against S. cholearesuis; chloramphenicol, lincomycin, and tetracycline were active only with A. pleuropneumoniae; neomycin was moderately active against A. pleuropneumoniae and E. coli. The other antimicrobials tested were inactive. 相似文献
19.
采用管碟法、微量稀释法和琼脂平板计数法,测定抑菌圈直径、最低抑菌浓度(MIC)和最低杀菌浓度(MBC),分析临床分离的大肠杆菌菌株的耐药性,并观察苗药白接骨醇提物对标准大肠杆菌菌株和临床分离的具有耐药性的猪源大肠杆菌菌株的抑菌效果。结果显示,临床分离的大肠杆菌菌株对甲氧苄啶/磺胺甲恶唑、头孢曲松、环丙沙星均无抑菌圈产生,表现多重耐药。而白接骨醇提物对两株细菌的抑菌圈直径分别达到33.20±0.82 mm和33.78±0.38 mm;MIC均为0.78 mg/m L;MBC均为1.56 mg/m L。苗药白接骨醇提物对具有耐药性的猪源大肠杆菌在体外有较好的抑菌效果。 相似文献
20.
Antimicrobial resistance of thermophilic Campylobacter spp. isolated from cattle in Poland 总被引：1，自引：0，他引：1
Campylobacter species are among the most frequently identified bacterial causes of human gastroenteritis. Because Campylobacter spp. harbored by cattle can be transmitted to humans, in this study we investigated antimicrobial resistance of thermophilic Campylobacter isolated from cows. Our study included 150 strains of Campylobacter (143 strains of C. jejuni and 7 strains of C. coli) isolated from cows in South-Western Poland. The minimal inhibitory concentration (MIC) to ciprofloxacin, erythromycin, gentamicin and tetracycline were determined using the agar dilution methodology. All strains of C. coli were susceptible to all four drugs studied. The most frequently detected resistance of C. jejuni was to ciprofloxacin (26 strains 18.2%). Resistance to tetracycline was observed in 5 strains (3.5%). All strains of C. jejuni were susceptible to erythromycin and gentamicin. 相似文献