徐州地区猪源致病性大肠杆菌耐药性检测

为了考察徐州地区猪源致病性大肠杆菌的耐药情况,采用传统微生物法对徐州周边地区52株猪大肠杆菌进行分离鉴定,试管二倍稀释法测定细菌对药物的敏感性,提取耐药菌质粒DNA,PCR扩增耐药基因目的片段。结果表明,氟苯尼考和阿莫西林对徐州周边临床大肠杆菌分离株的最小抑菌浓度(MIC)值与标准菌株相比较,分别提高20～512倍、10～800倍,个别临床分离株对恩诺沙星的MIC值高达80μg/mL,对头孢曲松的MIC值高达80μg/mL,对安普霉素的MIC值高达320μg/mL;经PCR检测临床分离株均扩增出氟苯尼考Flor耐药基因,Tem型ESBLs耐药基因目的片段。说明徐州周边临床大肠杆菌对氟苯尼考和阿莫西林已产生严重耐药性,对恩诺沙星和安普霉素已经耐药,但大部分菌株对头孢曲松敏感。提示徐州周边地区猪场应科学合理、有计划地轮换使用不同药物。     

动物源性大肠杆菌耐药性分析

目的:对吉林省长春市伊通地区分离出的113株动物源性大肠杆菌耐药性进行分析,了解猪源和鸡源大肠杆菌耐药程度及其耐药谱。方法:采用K-B纸片扩散法对大肠杆菌耐药性初步定性分析,并从中选出十株耐药谱不同的大肠杆菌测定其抗生素的最小抑菌浓度(MIC)。结果:113株均表现出不同程度的耐药,耐药谱广,且多表现为多重耐药。结论:动物源性大肠杆菌对抗生素的耐药性以多重耐药为主。113株对喹诺酮类、磺胺类、利福平耐药率达到90%以上,其中鸡源、猪源大肠杆菌耐药情况各不相同,二者均对丁胺卡那霉素、先锋必/舒巴坦较敏感,耐药率低于15%,可知丁胺卡那霉素、先锋必/舒巴坦可作为这些地区防治致病性大肠杆菌的首选药物。本实验结果对临床科学合理用药有重要指导意义。     

江西地区猪源致病性大肠杆菌的耐药性试验

对采自江苏周边地区规模化猪场的137株大肠杆菌耐药情况进行调查研究。通过分离纯化、生化鉴定以及致病性试验,得到67株致病性大肠杆菌。采用微量稀释法测定了8种药物对67株致病性大肠杆菌的最低抑菌浓度。结果显示,细菌对8种临床常用药物表现出较高的耐药性,多数细菌对5种药物耐药,甚至有些细菌对其中7种药物产生耐药性,其中细菌对头孢曲松、头孢曲松-舒巴坦和庆大霉素的耐药率最高,分别为100%、100%和97.01%。说明该地区采集的养殖场细菌耐药现象较为严重。     

宠物源性大肠杆菌耐药性调查

本试验采用微量肉汤稀释法对120株宠物医院分离的大肠杆菌进行头孢噻呋、恩诺沙星等13种抗生素的最小抑菌浓度(MIC)值测定,并利用WHONET 5.4软件对数据进行处理,以了解广州市宠物源性大肠杆菌的耐药情况。通过对其耐药谱型的调查,为指导宠物临床用药和耐药性及耐药性监测提供理论依据。     

宠物犬源大肠杆菌氟苯尼考耐药基因floR的检测及药物敏感性分析

floR是氟苯尼考特异性耐药基因之一,当前宠物犬源大肠杆菌氟苯尼考耐药基因floR的研究报道很少,故本试验利用PCR方法对宠物犬源大肠杆菌氟苯尼考耐药基因floR进行检测,并采用微量肉汤稀释法测定宠物犬源大肠杆菌对10种抗菌药物的最小抑菌浓度(MIC)。结果显示,20株宠物犬源大肠杆菌中floR耐药基因的阳性菌株数为9株,阳性检出率为45%;对氟苯尼考的耐药率为65%,并呈现3~7重的多重耐药性。结果表明,随着氟苯尼考在兽医临床的广泛应用,其耐药率越来越高,需不断加强对氟苯尼考等抗菌药物的耐药性监控。     

苗药白接骨醇提物对耐药性猪源大肠杆菌体外抑菌效果观察

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。     

艾叶提取物对禽源大肠杆菌耐药性消除作用的研究

为了探究艾叶对3株禽源大肠杆菌(编号为DRE1、DRE2、DRE3)的耐药消除作用及抑菌效果,采用琼脂稀释法测定最小抑菌浓度(MIC);利用亚抑菌浓度的艾叶提取物进行耐药消除试验,用平板影印法筛选耐药性消除的菌株,比较耐药消除率;用纸片扩散法检测艾叶作用后消除子对抗菌药物的敏感性。结果显示:艾叶水提物对3株耐药株的MIC值为62.50、31. 25、62.50 mg/mL,艾叶醇提物对3株耐药株的MIC值均为12.50 mg/mL;艾叶醇提物和水提物对菌株的耐药性有不同程度的消除作用,随着培养时间增长,消除率增高,醇提物消除率最高可达28.50%,水提物最高可达24.34%;艾叶提取物作用后的消除子抑菌圈有不同程度的增大,DRE2恢复了对庆大霉素(GEN)、氨曲南(AZN)、头孢他啶(CAZ)、头孢噻肟(CTX)、头孢吡肟(FEP) 5种抗菌药物的敏感性,DRE3恢复了对美罗培南(MEM)、阿莫西林/克拉维酸(AMC)的敏感性。提示:艾叶提取物一定程度上能够消除禽源大肠杆菌的耐药性,恢复对抗生素的敏感性,其醇提物组分作用效果更佳,可用于防控耐药大肠杆菌的传播。     

新疆某牛场不同日龄犊牛粪源大肠杆菌耐药性分析

观察不同日龄犊牛粪源大肠杆菌耐药性趋势动态变化,筛选新疆一某牛场进行分离粪源大肠杆菌株并分析临床常用抗菌药物耐药性情况,了解养殖场对抗生素治疗安全状况。选择新疆某一集约化程度较高的肉牛养殖场,分别采集0-30日龄、31-60日龄、61-90日龄犊牛的粪样。按照实验室常用大肠菌株分离法分离菌株,细菌药敏试验采用世界卫生组织(WHO)推荐的Kirby-Bauer法对分离出的大肠杆菌进行耐药性测定。200份不同日龄犊牛粪源大肠杆菌分离率为100%;犊牛日龄与耐药率成正比关系,耐药趋势为阿米卡星恩诺沙星诺氟沙星庆大霉素阿莫西林克拉维酸钾阿莫西林环丙沙星氨苄西林。大肠杆菌的耐药率较高,养殖户要正确使用抗菌药,通过药敏试验合理使用抗菌药物,要针对性用药以减少耐药菌株的产生。     

33株临床分离菌的药敏试验分析

收集标准菌株2株和临床分离菌株共33株,采用NCCLS推荐的微量稀释法测定6种抗生素对33株病原菌的最低抑菌浓度.33株临床分离菌株对临床上常用的6种抗生素的平均敏感率为27.7%,平均耐药率为64.8%.对金黄色葡萄球菌抗茵作用最强的是氯霉素,敏感率为82.6%,MIC50为2 mg/L,MIC90为64 mg/L;耐药性最强的是青霉素,耐药率达100%.肺炎克雷伯菌的耐药性较为严重,平均耐药率高达80%,抗茵作用最强的为新霉素,但其敏感率仅为40%.33株临床分离菌株的耐药性较为严重,存在交叉耐药性和多重耐药性现象.     

鸡肠杆菌科细菌β-内酰胺酶和超广谱β-内酰胺酶的检测及药敏分析

用全自动细菌鉴定系统对从临床分离鸡致病菌进行了鉴定,并进行了β-内酰胺酶(BLA)和超广谱β-内酰胺酶(ESBLs)的检测,同时测定了多种药物的最小抑菌浓度(MIC).经鉴定9株致病菌中1株为沙门菌,8株为大肠杆菌;9株致病菌均为BLA阳性,其中有1株为ESBLs阳性;9株细菌对部分抗生素耐药,β-内酰胺类抗生素/β-内酰胺酶抑制荆或多种抗生素的联合用药能部分的恢复细菌对药物的敏感性.旨在为新药的开发提供依据.     

Retrospective study on Escherichia coli infection in broilers subjected to postmortem examination and antibiotic resistance of isolates in Trinidad

An 8-yr retrospective study was conducted to evaluate the rate of Escherichia coli infection and antibiotic resistance of isolates from diseased broilers submitted for diagnosis in Trinidad from 1990 to 1997. Of a total of 906 cases of diseased birds subjected to postmortem examination, 603 (66.6%) had E. coli infection. The number of cases increased over the years from 16 in 1990 to a peak of 294 in 1996. For every year, at least 50% of all broiler cases had E. coli infection. The rate of infection was significantly higher during the rainy season (74.1 +/- 6.9%) than during the dry season (57.8 +/- 7.0%). Approximately 50% of all E. coli isolates were resistant to 9 out of a total of 11 antimicrobial drugs selected for the study. The isolates showed an increasing trend of resistance to amoxicillin, apramycin, gentamicin, nitrofurantoin, norfloxacin, and sulfamethoxazole-trimethoprim. However, only the trends of resistance to apramycin and norfloxacin were statistically significant. Overall, of the antimicrobial drugs selected, norfloxacin relatively appeared as the best choice for treatment. From this study, we conclude that the high rate of E. coli infection in broilers submitted for diagnosis along with the high resistance of isolates to antimicrobial drugs constitute a threat to the poultry industry on the island.     

新疆石河子地区奶牛乳房炎大肠杆菌的分离鉴定及耐药性分析简

本试验旨在调查新疆石河子地区奶牛乳房炎源大肠杆菌的某些生物学特性及其耐药状况,以提高药物疗效,减少牛奶中药物的残留。试验从新疆石河子地区患乳房炎奶牛的乳样中分离纯化并鉴定出21株大肠杆菌,并对大肠杆菌分离株进行抗菌药物敏感性分析。结果表明,21株大肠杆菌对21种抗菌药物中的6种药物耐药率超过50%,其中最多的耐药15种,最少的耐药5种,耐药6及6种以上的菌株共占到76.19%。提示,该地区奶牛乳房炎源大肠杆菌对多种药物已产生了不同程度的耐药性,且存在严重的多重耐药情况。     

鸡源大肠杆菌强毒株耐药基因的定位及耐药质粒消除

本试验对临床分离的多重耐药鸡源致病性大肠杆菌强毒株的耐药基因进行初步定位,为临床选择合适的治疗策略提供理论依据。从送检病死鸡的肝脏、心脏中分离鉴定致病菌,质粒提取试剂盒提取分离菌的耐药质粒,转化入基因工程菌JM109,通过质粒纯化、电泳和药敏试验对耐药基因进行了初步定位。并用艾叶水煮液对该菌株进行体外耐药质粒消除试验。结果分离鉴定到1株强毒力鸡源大肠杆菌,该菌呈多重耐药性,且仅对氟奇霉素和链霉素敏感;由质粒转化和药敏试验结果可初步将耐环丙沙星、青霉素、氧氟沙星、氟哌酸、林可霉素和复方新诺明的基因定位于耐药质粒上,并可随质粒的转移而使转化菌获得耐药性;用艾叶水煮液可使该菌的耐药质粒消除率达60%;质粒消除菌的药敏试验结果表明,消除耐药质粒的细菌恢复了对环丙沙星、青霉素、氧氟沙星、氟哌酸、林可霉素和复方新诺明的敏感性。本研究结果表明,分离菌的耐药基因分别位于质粒和染色体上,艾叶对耐药质粒有较强的消除作用,可作为临床治疗用药。     

新疆伊犁某牛场大肠杆菌耐药性调查

为了调查新疆伊犁某牛场饮水、饲料和粪样中分离的大肠杆菌对临床常用抗菌药物的耐药情况。本试验采用微量肉汤稀释法,对饮水源、饲料源、牛粪源样品中分离出的大肠杆菌进行最小抑菌浓度测定。结果显示,25份牛场饮水源样品,大肠杆菌分离率为100.0%（25/25）,对阿莫西林/克拉维酸（12.0%）、氨苄西林（4.0%）、诺氟沙星（4.0%）、恩诺沙星（8.0%）和安普霉素（8.0%）5种抗菌药物耐药;72份牛场饲料源样品,大肠杆菌分离率为65.3%（47/72）,对阿莫西林/克拉维酸（36.2%）、氨苄西林（19.1%）、诺氟沙星（4.3%）和安普霉素（4.3%）4种抗菌药物耐药;80份牛粪源样品,大肠杆菌分离率为100.0%（80/80）,对阿米卡星（12.5%）、氨苄西林（7.5%）、恩诺沙星（7.5%）、庆大霉素（5.0%）、诺氟沙星（2.5%）、环丙沙星（2.5%）、阿莫西林/克拉维酸（1.3%）和头孢噻呋（1.3%）8种抗菌药物耐药,仅对安普霉素敏感。该牛场分离的大肠杆菌对常用抗菌药物耐药情况一般,但中介率较高,须在临床治疗细菌性疾病中避免使用不敏感和中介率高的抗菌药物,养殖场饮水和饲料有被耐药大肠杆菌污染的风险。     

鸡大肠杆菌病病原的分离鉴定及药敏试验

自疑似大肠杆菌病例中分离到大肠杆菌44株，并对其病原特性进行了研究，结果表明这些菌的生化特性基本一致，与文献报道相符。对此44株大肠杆菌进行血清型鉴定，鉴定出血清型39株，其中O血清型13种，以O₇₈、O₃₅、O₂₄、O₁、O₁₅、O₇₆和O₈₈等7个血清型为主，占定型菌株的84.6%。其中血清型为O₇₈的菌株占定型菌株的38.5%，为优势血清型。用9种抗菌药物（头孢唑啉、庆大霉素、阿米卡星、链霉素、环丙沙星、诺氟沙星、青霉素、妥布霉素、红霉素）进行了药敏试验，结果表明分离菌株呈现出不同程度的耐药性，其中青霉素、红霉素的耐药率最高（均为97.7%），其次是环丙沙星（81.8%），大多数为多重联合耐药；而阿米卡星、妥布霉素和庆大霉素的敏感率较高，其中以阿米卡星（90.9%）最敏感。     

Antimicrobial susceptibility of pathogenic Escherichia coli isolated from pigs in Korea

The in vitro susceptibilities of 285 isolates of Escherichia coli from preweaned and postweaned pigs with diarrhea and edema disease were tested with the 15 commonly used antimicrobial drugs by an agar dilution minimal inhibitory concentration procedure according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines. All E. coli isolates tested in this study belonged to enterotoxigenic E. coli, attaching and effacing E. coli, or Shiga toxin-producing E. coli. Field isolates had low MIC90 for ceftiofur (1 microg/ml). No correlation in antimicrobial resistance was found in three types of E. coli.     

Prevalence of resistance to 11 antimicrobials among Campylobacter coill isolated from pigs on 80 grower-finisher farms in Ontario.

We carried out a cross-sectional study to investigate antimicrobial resistance patterns of Campylobacter coli isolated from Ontario grower-finisher pigs. From January to June 2004, 1200 samples were collected from 80 farms by obtaining a constant number (15) of fecal samples per farm. Susceptibility of the isolates to 11 antimicrobial drugs was determined by the agar-dilution technique. The overall prevalence of resistance to 1 or more antimicrobials among the isolates was 99.2%. High levels of resistance were observed for azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline: 91.7%, 82.5%, 81.4%, 70.7%, and 63.7%, respectively. For sulfamethoxazole, ampicillin, and nalidixic acid, resistance was observed in 40.3%, 26.6%, and 22.7% of the isolates, respectively. Although at very low levels, resistance was observed for ciprofloxacin (a fluoroquinolone), chloramphenicol, and gentamicin: in 2.4%, 1.7%, and 0.2%, respectively. Many of the isolates (29.7%) were resistant to 5 antimicrobials, the most common being azithromycin, clindamycin, erythromycin, streptomycin, and tetracycline. Isolates from the same farm showed at least 5 patterns of resistance. Results from this study indicate high levels of resistance to the antimicrobial drugs most commonly used in the Canadian swine industry (macrolides, lincosamides, and tetracyclines) among C. coli isolated from grower-finisher pigs in Ontario. Macrolides and fluoroquinolones are the drugs most commonly used to treat severe human campylobacteriosis. Fortunately, at present, there is little resistance to fluoroquinolones among C. coli from pigs in Ontario.     

3株猪源大肠埃希氏菌耐药基因的初步定位

本试验旨在对临床分离的猪源大肠埃希氏菌耐药基因进行初步定位。采用常规细菌分离培养、16S rRNA PCR扩增和序列测定方法从江西省3个规模化猪场送检的子宫脓液中分离鉴定病原菌,并通过质粒提取、转化大肠埃希氏菌DH5α感受态细胞及药敏试验对临床分离株的耐药基因进行初步定位。结果显示,分离鉴定到3株大肠埃希氏菌,其中JX-22分离株仅对氧氟沙星、大观霉素敏感,JX-26分离株仅对链霉素、氧氟沙星等4种药物敏感,JX-28分离株仅对氧氟沙星等3种药物敏感,均为多重耐药菌;3株大肠埃希氏菌均可纯化到分子质量大小不一的质粒。分离株、质粒转化菌及大肠埃希氏菌DH5α感受态细胞药敏试验对比结果显示,3株大肠埃希氏菌的耐链霉素、林可霉素、甲硝唑、氨苄西林、阿莫西林、大观霉素、丁胺卡那基因,JX-22和JX-26分离株的耐多西环素、氟苯尼考和复方新诺明基因,JX-22分离株的耐头孢曲松基因,JX-28分离株的耐头孢曲松、头孢噻肟、诺氟沙星基因均定位于细菌质粒上;JX-28分离株的耐多西环素、氟苯尼考和复方新诺明基因,JX-22分离株的耐诺氟沙星基因和JX-26分离株的耐头孢曲松、头孢噻肟基因均定位于其染色体上;3株分离株均无氧氟沙星耐药基因。本试验初步确定3株多重耐药猪源大肠埃希氏菌的大部分耐药基因定位于质粒上,为进一步研究猪源大肠埃希氏菌的耐药机理和有效控制措施奠定基础。     

The resistance to chemotherapeutic agents of Escherichia coli from domestic dogs and cats

The prevalence of antibiotic resistant Escherichia coli in the rectal flora of 168 healthy dogs and 93 cats in the Brisbane area was investigated. Rectal swabs were plated on MacConkey agar with and without antibiotics, and 690 isolates confirmed as faecal E. coli were tested for resistance to tetracycline, streptomycin, chloramphenicol, ampicillin, neomycin, furazolidone and sulphanilamide. Resistant isolates were obtained from 101 (60%) of the dogs and 24 (26%) of the cats sampled. A high percentage of the isolates was resistant to tetracycline, streptomycin, ampicillin and sulphanilamide. Multiple resistance to 3 or more of the drugs was exhibited by the majority of isolates and a total of 31 different multiple resistance patterns was demonstrated. Of the 50 strains tested for transfer of resistance, 30 (60%) transferred some or all of their resistance determinants to an E. coli K12F - recipient.     

Development of antimicrobial drug resistance in rectal Escherichia coli isolates from dogs hospitalized in an intensive care unit

OBJECTIVE: To determine whether duration of hospitalization in the intensive care unit (ICU) of a veterinary teaching hospital was associated with prevalence of antimicrobial resistance among rectal Escherichia coli isolates from dogs, whether antimicrobial treatment was associated with prevalence of antimicrobial resistance, and whether there were associations among antimicrobial drugs to which isolates were resistant. DESIGN: Prospective observational study. ANIMALS: 116 dogs hospitalized in an ICU for >or= 3 days. PROCEDURES: Rectal swab specimens were obtained every 3 days and submitted for bacterial culture for E coli. Isolates were tested for susceptibility to 12 antimicrobial agents by means of disk diffusion. RESULTS: For each additional day that a dog was hospitalized in the ICU, the odds of being colonized with an E coli isolate resistant to 1 or more of the 12 antimicrobials tested increased by a factor of 1.5, independent of antimicrobial treatment. Dogs that were treated with enrofloxacin were 25.6 times as likely to be colonized by a quinolone-resistant E coli strain as were dogs that did not receive any antimicrobials. Significant correlations were found for resistance to agents in the extended-spectrum cephalosporin group and the quinolone group. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the proportion of rectal E coli isolates obtained from dogs housed for >or= 3 days in a veterinary teaching hospital ICU that were resistant to antimicrobial agents increased as the duration of hospitalization in the ICU increased. Thus, ICU hospitalization time should be as short as possible to prevent development of antimicrobial resistance among rectal E coli isolates.