新疆不同动物源大肠埃希菌耐药性比较

为了比较新疆不同动物源大肠埃希菌对临床常用抗菌药物的耐药情况,从猪场、羊场和牛场分别分离猪源大肠埃希菌454株、羊源大肠埃希菌638株和牛源大肠埃希菌89株,用微量肉汤法对上述细菌进行临床常用β-内酰胺类、氟喹诺酮类、氨基糖苷类和酰胺醇类抗菌药物最小抑菌浓度测定。结果表面,猪源大肠埃希菌对氨苄西林(67.0%)和阿莫西林/克拉维酸(63.7%)耐药率较高,其他药物耐药率在10.4%~41.2%之间;羊源大肠埃希菌对安普霉素(33.9%)和阿莫西林/克拉维酸(21.2%)耐药率较高,其他药物耐药率在3.1%~15.6%之间;牛源大肠埃希菌对氨苄西林(24.4%)和阿莫西林/克拉维酸(8.9%)耐药率较高,其他药物耐药率在1.1%~6.7%之间。多药耐药结果,猪源大肠埃希菌以2耐~5耐为主,羊源大肠埃希菌以0耐~2耐为主,牛源大肠埃希菌以0耐~1耐为主。新疆猪源大肠埃希菌对临床常用抗菌药物耐药情况最严重,羊源菌次之,牛源菌最轻;猪源大肠埃希菌多药耐药现象严重。     

肉牛溶血性大肠埃希菌分离鉴定和毒力与耐药基因检测及药敏试验

为了解肉牛溶血性大肠埃希菌毒力基因和耐药基因分布情况及药物敏感性,从河北省围场县采集的健康肉牛鼻腔棉拭子中分离鉴定溶血性大肠埃希菌,采用PCR检测大肠埃希菌的4个毒力基因和12个耐药基因,并采用K-B法进行药敏试验。结果表明,从116份健康的肉牛鼻腔中分离鉴定出23株溶血性大肠埃希菌,分离率为19.8%;毒力基因检测结果显示,6株菌同时携带LEE(Ler、eaeA)毒力基因,携带率26.1%,18株同时携带高致病性毒力基因HPIirp2、fyuA,携带率78.3%,6株同时携带LEE和HPI毒力基因,携带率为26.1%;耐药基因检测结果显示,blaTEM、aadA1耐药基因的携带率最高,为100%;药敏试验结果显示,23株溶血性大肠埃希菌对头孢氨苄、复方新诺明、磺胺间甲氧嘧啶耐药。结果表明,溶血性大肠埃希菌普遍存在于健康肉牛鼻腔中,HPI毒力基因和β-内酰胺类和耐链霉素类耐药基因携带率高。对河北省围场县肉牛溶血性大肠埃希菌毒力基因和耐药基因进行了研究,并进行药物敏感性分析,结果提示溶血性大肠埃希菌对肉牛养殖存在潜在威胁。     

宁夏部分地区腹泻羔羊源大肠埃希菌的分离鉴定与药敏试验

为掌握宁夏地区羔羊腹泻源大肠埃希菌的耐药性,采集腹泻羔羊肛拭子90份,开展大肠埃希菌的分离鉴定及药敏试验。结果分离到78株大肠埃希菌,对头孢类、氨基糖苷类、喹诺酮类、氟苯尼考、青霉素类、四环素等抗菌药物有较高的敏感性,对万古霉素、复方新诺明、克林霉素耐药(耐药率78.21%~94.87%)。结果表明,宁夏地区羔羊腹泻源大肠埃希菌对抗菌药物保持较高的敏感率,耐药现象并不严重。     

新疆地区牛和新引进牛大肠埃希菌耐药性比较

为了解新疆地区牛和新引进牛大肠埃希菌对临床常用抗菌药物的耐药差异,采用微量肉汤稀释法对分离的大肠埃希菌进行耐药性检测,通过卡方检验比较新疆地区牛和引进牛大肠埃希菌耐药性的差异。结果显示,新疆地区牛大肠埃希菌和引进牛大肠埃希菌除对氨苄西林(地区牛为11.90%、引进牛为6.25%)和阿莫西林(地区牛为5.55%、引进牛为5.21%)有较高的耐药率外,对其他临床常用抗菌药物的耐药率均较低,但引进牛对氟苯尼考、庆大霉素和安普霉素的中度敏感率分别为82.81%、44.79%和33.33%。经卡方检验比较,新疆引进牛对氟苯尼考、庆大霉素、安普霉素、阿莫西林和氨苄西林的中度敏感率显著高于新疆地区牛(P0.05)。虽然被检牛源大肠埃希菌对常用抗菌药物耐药较低,但引进牛大肠埃希菌高中度敏感率会导致其耐药率短期内迅速增高,因此须在临床治疗引进牛细菌性疾病中避免使用中度敏感率高的抗菌药物。     

犬源大肠埃希菌对β-内酰胺类药物的耐药表型和耐药基因检测

为研究犬源大肠埃希菌的耐药情况,对成都地区采集的犬肛门拭子进行细菌分离鉴定,共分离156株大肠埃希菌,同时,进行5种抗生素耐药性检测和β-内酰胺类药物耐药基因的菌株筛选。结果显示,大肠埃希菌对β-内酰胺类耐药率较高,头孢喹肟100%,氨苄西林73.1%,但对美罗培南敏感率高达95.5%。采用PCR方法检测β-内酰胺类药物常见的3种耐药基因blaCTX-M、blaSHV和blaTEM,blaCTX-M检出率最高为89.74%,blaTEM为78.84%,blaSHV无检出。耐药性和耐药基因比较表明,犬源大肠埃希菌β-内酰胺类的耐药性与耐药基因型检出率基本呈正相关,为成都犬源大肠埃希菌β-内酰胺类药物的耐药现状和疾病治疗提供了理论依据。     

藏香猪源大肠埃希菌致病性和血清型检测及药敏试验

为了解四川省藏香猪源大肠埃希菌致病性、血清型及耐药性情况,从四川省藏香猪养殖场中无菌采集腹泻仔猪肝脏、肛拭子及粪便等组织病料253份中,分离得到155株大肠埃希菌。采用人工感染小鼠致病性试验、玻板凝集试验和KB药敏纸片法分别测定155株大肠埃希菌分离菌株的致病性、血清型及耐药性。结果显示,小鼠致病性试验表明155株分离菌中120株有致病性;玻板凝集试验表明120株致病性大肠埃希菌分离株属于14个血清型,以O111、O147、O109和O119为主要流行的优势血清型;耐药性试验表明120株致病性大肠埃希菌分离株对阿莫西林、氨苄西林、新霉素、磺胺间甲氧嘧啶4种药物耐药较严重,耐药率在94.2%~98.3%之间,对庆大霉素、氟苯尼考、多西环素等6种药物耐药率在44.2%~85.0%之间,对其他药物耐药率在15.0%~37.5%之间。说明该地区藏香猪源致病性大肠埃希菌血清型呈多样性分布,耐药性严重。     

奶牛子宫内膜炎源性大肠埃希菌药敏试验与耐药基因检测

为探索奶牛子宫内膜炎源性大肠埃希菌耐药基因及其耐药性之间的关系。采用K-B纸片法对临床分离的54株奶牛子宫内膜炎源性大肠埃希菌进行12种抗菌药物敏感性测定,应用PCR进行这些抗菌药物相关耐药基因的检测。结果显示,54株大肠埃希菌对复方新诺明、恩诺沙星和四环素的耐药率较高,分别为67%、39%和35%。分离的54株大肠埃希菌中有41株至少含有所检测耐药基因中的1种,CyrA、CyrB、ParC和Tet耐药基因较为普遍,其耐药菌基因检出率依次为96%、83%、100%和95%,13株没有检测到相应的耐药基因。奶牛子宫内膜炎源性大肠埃希菌对常见抗菌药物耐药严重,耐药基因普遍存在于耐药菌株中,除氨基糖苷类耐药菌株,其他3种抗菌药物类型耐药表型与耐药基因检测结果有较高一致性。     

不同地区猪源大肠埃希菌磺胺类药物耐药性研究

对不同地区猪源大肠埃希菌磺胺药物耐药性进行系统性调查研究.对从山东、内蒙古、山西分离到的161株猪源大肠埃希菌测定磺胺药物对其最低抑菌浓度(MIC值),结果表明大肠埃希菌对磺胺药物高度耐药,对磺胺异恶唑(SF)和新诺明(SMZ)的耐药率分别为91.30%和90.06%.同时根据GenBank上已有的二氢叶酸合成酶基因S...     

宠物源大肠埃希菌的分离鉴定和耐药性研究

为调查长春地区宠物源大肠埃希菌耐药流行情况,从2家宠物医院采集135份宠物肛拭子样品,分离和鉴定大肠埃希菌并进行多重PCR分群。测定大肠埃希菌分离株对19种抗菌药物的耐药性,并鉴定超广谱β-内酰胺酶(ESBLs)表型。共分离鉴定获得95株宠物源大肠埃希菌,它们对氨苄西林和哌拉西林的耐药率最高(78.9%和76.8%);其次是四环素(61.6%);对头孢唑林、头孢噻肟、头孢吡肟、庆大霉素、复方新诺明、环丙沙星和左氧氟沙星的耐药率均超过了50%;所有分离株均对亚胺培南和美罗培南敏感。其中15个分离株对受试的抗菌药物全部敏感(15.8%),63株呈多重耐药表型(66.3%)。ESBLs型菌株占53.7%。本研究探明了长春地区宠物源大肠埃希菌的耐药流行情况,对宠物临床上用药具有指导价值。     

狐狸源大肠埃希菌TEM1型耐药基因检测和耐药质粒消除研究

研究大肠埃希菌耐药性和耐药基因和十二烷基硫酸钠(SDS)对大肠埃希菌耐药质粒消除作用。以大肠埃希菌临床分离株为试验菌株,采用K-B药敏纸片法对6种抗菌药物进行药物敏感性检测,并对大肠埃希菌耐药质粒TEM1型耐药基因进行PCR检测,采用SDS消除大肠埃希菌临床分离菌株的耐药质粒,采用琼脂糖凝胶电泳检测质粒条带,药敏试验检测大肠埃希菌耐药质粒消除前后的药物敏感性。结果表明,大肠埃希菌对庆大霉素敏感,对大观霉素中敏,对氨苄西林、阿莫西林、头孢拉定、环丙沙星耐药;大肠埃希菌耐药质粒检测出TEM1型耐药基因;试验菌株经7.5g/L的SDS处理至第3代时,质粒条带有明显的减少,TEM1型耐药基因消失,并且恢复了对β内酰胺类抗生素的敏感性,说明耐药质粒已经成功消除。     

奶牛乳房炎金黄色葡萄球菌8种毒力基因的PCR检测

为研究奶牛乳房炎金黄色葡萄球菌(Staphylococcus aureus,SA)主要毒力因子的分布情况,本试验利用PCR对70株临床型乳房炎、55株隐性乳房炎金黄色葡萄球菌的8种主要毒力基因进行检测。结果显示,nuc、ClfA、TSST-1、PVL、Hla、Hlb、FnBPA和FnBPB 8种毒力基因在临床型乳房炎SA菌株中的检出率分别为:100.0%(70株)、100.0%(70株)、0(0株)、5.7%(4株)、100.0%(70株)、11.4%(8株)、97.1%(68株)和100.0%(70株);在隐性乳房炎SA菌株中的检出率分别为:100.0%(55株)、100.0%(55株)、0(0株)、70.9%(39株)、98.2%(54株)、9.1%(5株)、100.0%(55株)和100.0%(55株)。结果表明,nuc、ClfA、Hla、Hlb和FnBPA 5种毒力基因是引起奶牛乳房炎的SA的最主要毒力基因;PVL基因可能是引起隐性乳房炎的重要致病基因。     

High occurrence of multi-antimicrobial resistance in Staphylococcus intermedius isolates from healthy and diseased dogs and domesticated pigeons

Staphylococcus intermedius isolates (n=106), including 44 dog isolates and 62 pigeon isolates, were examined for their susceptibility to ampicillin, cephalexin, erythromycin, gentamicin, kanamycin, lincomycin, norfloxacin, oxacillin, tetracycline, and vancomycin by standard disk-diffusion test. The frequencies of resistance to ampicillin, kanamycin, and tetracycline were significantly higher in dog isolates than pigeon isolates (95.5% vs. 0%, 31.8% vs. 0%, and 45.5% vs. 9.7%, respectively; P<0.01). Antimicrobial resistance patterns of dog isolates and pigeon isolates were categorized respectively into nine and five distinct profiles. Significantly higher occurrence of resistance to two or more antimicrobials was observed in dog isolates than pigeon isolates (54.5% vs. 12.9%; P<0.01) and also in domesticated pigeon isolates than non-domesticated pigeon isolates (53.3% vs. 0%; P<0.01).     

Antimicrobial susceptibility of Arcanobacterium pyogenes isolated from cattle and pigs

The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents were determined for 49 Arcanobacterium pyogenes isolates (42 bovine isolates and 7 porcine isolates). Benzylpenicillin and ampicillin were the most active antibiotics, with MIC ranges of < or = 0.0125-0.05 microgram/ml for both bovine and porcine isolates. All isolates were susceptible to penicillins and cephems. MICs for 90% of the isolates of dihydrostreptomycin, gentamicin and oxytetracycline for bovine isolates were > 100 micrograms/ml, 1.56 micrograms/ml and 25 micrograms/ml, respectively. More resistance to dihydrostreptomycin appeared among porcine isolates (85.7%) than among bovine isolates (52.4%). Resistance to gentamicin occurred in only 3 (7.1%) of the bovine isolates. Resistance to oxytetracycline also appeared more frequent among porcine isolates (85.7%) than among bovine isolates (57.1%). All bovine isolates were susceptible to erythromycin, tilmocosin and lincomycin, but two porcine isolates (28.6%) were simultaneously resistant to these antibiotics. Tiamulin was as active as tilmicosin, with an MIC for 50% of the isolates (MIC50) of 0.05 microgram/ml for both bovine and porcine isolates. The MIC50s of chloramphenicol and its derivatives florfenicol and thiamphenicol were all 1.56 micrograms/ml. The fluoroquinolones enrofloxacin and ofloxacin were not so active as penicillins and macrolides, with MIC50s of 0.78 microgram/ml and 1.56 micrograms/ml, respectively, for both bovine and porcine isolates.     

鸭新城疫病毒分离株抗原表位和遗传演化分析

从规模化养殖场鸭群气管和泄殖腔试子分离到新城疫病毒(NDV)27株,用2株针对NDV HN单抗进行抗原表位分析,并选择4个分离株进行F基因高变区(374bp)和HN基因全长序列分析。抗原表位分析结果显示,27个鸭分离株均能与其中一株单抗C3-B7反应,而与另外一株单抗1E5反应为阴性。F基因(374bp)序列分析结果显示,4个鸭分离株均属于NDV ClassⅠ分支,分离株之间核苷酸同源性为99.2%～100%;分离株与NDV ClassⅡ毒株遗传距离为0.9%～9.9%,与NDV ClassⅠ毒株遗传距离为38.5%～41.7%。根据核苷酸序列推导的氨基酸序列表明,4个鸭NDV分离株F蛋白裂解位点氨基酸模式为:112-EROERL-117。HN基因序列分析结果显示,4个鸭NDV分离株HN基因全长1851bp,编码585个氨基酸;同源性比较发现4个鸭NDV分离株之间核苷酸同源性为99.7%～99.8%,与NDV ClassⅡ毒株核苷酸同源性为68.4%～70.5%,与NDV ClassⅠ毒株核苷酸同源性为95.8%～98.0%。本研究结果显示,鸭分离毒均属于NDV ClassⅠ弱毒,在抗原表位和基因序列上与广泛应用的NDV弱毒疫苗株(LaSota)不同,这些毒株的来源有待进一步深入研究。     

金黄色葡萄球菌耐药性及肠毒素分型研究

为了解从生鲜乳中分离得到的31株金黄色葡萄球菌的耐药性和肠毒素分布情况,用微量肉汤稀释法进行药敏试验,用PCR方法进行肠毒素的检测和分型。结果表明,31株金黄色葡萄球菌耐药率在50%以上的抗菌药有7种,药耐药率小于10%的有3种;敏感率大于50%的抗菌药有6种,敏感率小于10%的有5种。31株金黄色葡萄球菌毒素基因携带率为93.5%,同时携带2种及以上毒素的菌株占67.7%,有SEA基因的占38.7%,含其他传统的毒素基因类型SEB、SEC、SED和SEE基因的菌株只占40.4%,携带新发现的毒素基因SEG、SHE、SEI和SEJ的菌株占67.7%。说明本次试验中的31株金黄色葡萄球菌对6类13种抗菌药都有不同程度的耐药性,且多重耐药现象比较严重。生鲜乳中分离的金黄色葡萄球菌带毒率高,且携带新发现的肠毒素基因较多。     

Susceptibility of Pseudomonas isolates from the ears and skin of dogs to enrofloxacin, marbofloxacin, and ciprofloxacin

The purpose of this study was to compare susceptibilities of ear and skin Pseudomonas spp. isolates to enrofloxacin, marbofloxacin, and ciprofloxacin. Specimens were obtained from dogs examined in a veterinary dermatology referral hospital. Susceptibilities of ear isolates to enrofloxacin, marbofloxacin, and ciprofloxacin were 46.9%, 66.7%, and 75.0%, respectively. Susceptibilities of skin isolates to the same drugs were 76.2%, 81.0%, and 80.0%, respectively. Ear isolates were significantly less susceptible to enrofloxacin than to ciprofloxacin (P=0.021), and ear isolates were significantly less susceptible to enrofloxacin than were skin isolates (P=0.034). When fluoroquinolone resistance was present, ear isolates were significantly less susceptible to enrofloxacin than to ciprofloxacin (P<0.001) and marbofloxacin (P=0.014).     

猪圆环病毒2型广西流行株序列比较分析

参考GenBank发表的猪圆环病毒2型(Porcine circovirus type 2,PCV-2)全基因组序列,设计引物,通过反向PCR技术,从广西部分市区疑似"高热病"病猪的组织中,扩增9株PCV-2流行株的全基因,并进行了序列测定分析.结果表明,9个PCV-2分离株基因组全长为1 767 bp或1 768 bp.同源性比较发现,9个分离株之间的核苷酸同源性为94.6%～99.9%,与GenBank上已发表的国外分离株比较,同源性为94.4%～100%;9个分离株ORF2之间的核苷酸及其所推导的氨基酸序列同源性分别为93.7%～99.4%和93.6%～99.1%;系统发育树显示,其中7个分离株与法国株、新西兰株关系较近,与美国株和加拿大株关系较远;另外2个分离株与澳大利亚株、美国株亲缘关系较近.     

Pathotypes of avian Escherichia coli as related to tsh-, pap-, pil-, and iuc-DNA sequences, and antibiotic sensitivity of isolates from internal tissues and the cloacae of broilers

One hundred four Escherichia coli isolates were collected from internal tissues and the cloacae of broilers with colibacillosis or from the cloacae of healthy birds. The isolates were tested for the presence of DNA sequences for temperature-sensitive hemagglutinin (tsh), for P (pap) and F1 (pil) fimbriae, and for aerobactin synthesis (iuc) by DNA/DNA hybridization. The isolates were also tested for O1, O2, and O78 serogroups, serum and antibiotic resistance, and virulence in day-old chickens. The Tsh/Pil/Iuc was the major pathotype detected in 53.8% of isolates from internal tissues, as compared with only 28.8% of isolates from the cloacae. The Tsh/Pap/Iuc pathotype was detected at a lower frequency (15.4%) but only in isolates from internal tissues. Among the virulence-associated marker genes, tsh and iuc were detected in most of the isolates from internal tissues (90.4% and 92.3%), as compared with only 51.9% and 63.5% of isolates from the cloacae, respectively, pap was detected to a lesser extent, in 25% of isolates but only from internal tissues. In contrast to the pil gene, the tsh-, pap-, and iuc-DNA sequences were more frequently detected in isolates from internal tissues than in isolates from the cloacae. O-antigen typing revealed that 25% of isolates belonged to serogroups O1 (4.8%), O2 (9.6%), and O78 (10.6%). Although most isolates appeared to be resistant to serum, only isolates from internal tissues were virulent in day-old chickens in contrast to isolates from the cloacae. More than 10% of isolates were resistant to most of the antibiotics used for the study. However, less resistance to enrofloxacin and norfloxacin was observed. Our data suggest that the Tsh/Pil/Iuc and Tsh/Pap/Iuc pathotypes and Tsh and Iuc virulence-associated markers are important factors of avian pathogenic E. coli. Enrofloxacin appeared to be the best choice for treatment of the infection.     

Antimicrobial resistance of selected Salmonella isolates from food animals and food in Alberta

Salmonella isolates (n = 209) obtained from food animals and foods in Alberta during 1996 through 1999 were tested for sensitivity to 17 antimicrobials. Of the 3553 antimicrobial susceptibility tests on Salmonella isolates, 11.8% were positive for resistance. These isolates were commonly resistant to tetracycline (35.4%), streptomycin (32.5%), sulfamethoxazole (28.7%), ticarcillin (27.3%), and ampicillin (26.8%). Resistance to at least 1 antimicrobial was observed in 112 isolates (53.6%). Salmonella Typhimurium, S. Typhimurium var. Copenhagen, and S. Heidelberg were the most common serovars among isolates resistant to individual antimicrobials and multiple antimicrobials. The most common profile of multiple-antimicrobial resistance was that which included resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, tetracycline, and ticarcillin. The proportions of isolates that were resistant to antimicrobials were greater among bovine isolates of Salmonella than among poultry isolates, and this difference was greater among isolates from veterinary diagnostic sources than among those from monitoring sources.     

Characterisation of avian pathogenic Escherichia coli (APEC) associated with colisepticaemia compared to faecal isolates from healthy birds

A total of 114 avian pathogenic Escherichia coli (APEC) isolates were collected from cases of colisepticaemia occurring in broilers (77) and layers (37) within Ireland. In addition 45 strains isolated from faeces of healthy birds were included for comparison. All isolates were serogrouped, and examined for known virulence factors, mostly by PCR. The O78 serogroup represented 55 and 27% of broiler and layer colisepticaemic isolates respectively. All isolates were positive for curli fimbriae (crl, csg) and negative for afimbrial adhesin (afa). S-fimbrial (sfa) sequences were present in 8.8% of septicaemic isolates and 8.9% of healthy bird isolates. The majority of E. coli from cases of colisepticaemia (97.4%) and healthy bird (95.6%) isolates were positive for aerobactin (aer), and temperature sensitive haemagglutinin (tsh) was similarly detected in high numbers in 93.9 and 93.3%, respectively. In comparison to E. coli isolates from the faeces of healthy birds, a significantly higher percentage of isolates from septicaemic cases possessed Type 1 fimbriae (fimC) and increased serum survival (iss) gene sequences. Forty-seven (41.2%) isolates from septicaemic birds possessed P-fimbriae (pap) gene sequences, compared with only 15.6% from E. coli isolated from healthy birds. Haemolysin (hlyE) sequences were detected in 46.7% of isolates from healthy birds in comparison with 6.1% of septicaemic isolates. Sequences encoding colicin V (cvaC) were detected in 99.1% of septicaemic isolates and 82.2% of isolates from healthy birds. The K1 capsule was only present in two septicaemic isolates, both taken from layers. Motility was detected in 36.8% of E. coli isolated from cases of septicaemia, compared with 93.3% of isolates from healthy birds. These results demonstrate the presence of 11 virulence genes in E. coli isolated from cases of colisepticaemia within Ireland, and indicate the prevalence of iss and fimC.