肉鸽大肠杆菌的分离鉴定与耐药性的研究

以南京市郊某肉鸽场病鸽为样本进行细菌分离鉴定,研究肉鸽大肠杆菌的耐药性。从病死鸽体内分离到14株大肠杆菌,鉴定出4种血清型,分别是O2、O18、O78、O101,其中O2型8株,为主要血清型,占血清型总数的66.67%。将分离到的菌株接种20～25日龄雏鸽进行动物回归试验,死亡率达85.17%,说明该分离菌株对雏鸽具有较强的致病性。对分离菌株进行药敏试验,结果表明,14株大肠杆菌对庆大霉素、卡那霉素、头孢拉定3种药物敏感率达100%,对环丙沙星、阿米卡星等13种药物均产生不同程度的耐药,对强力霉素和新霉素2种药物完全耐药。     

南阳市鸡致病性大肠杆菌的分离、鉴定及药敏试验

从南阳地区各养鸡场的发病鸡中分离出大肠杆菌,经常规方法培养、纯化、镜检及生理生化鉴定。分离出29株鸡致病性大肠杆菌。有14株分离株被鉴定出血清型,其中O1为4株,O2为3株,O78为7株,O1,O2和O78血清型占分离株总数的48．3％。未定型15株,用29株分离菌株分别接种供试雏鸡后,发病症状及剖检病变均符合本病特征,其中高致病性菌株有13株,中度致病菌株有9株,低致病性菌株有7株,分别占试验菌株总数的44．8％、31％和24．2％。采用22种药敏纸片对29株分离菌进行药敏试验,结果表明,分离出的大肠杆菌耐药性相当普遍,仅对头孢噻肟、丁胺卡那霉素、壮观霉素及新霉素等药物敏感性较高。     

大肠杆菌的分离与药敏鉴定

从20多个养鸡场的发病鸡中分离出可疑菌株,经常规方法培养、纯化、镜检及生理生化鉴定,分离鉴定出18株鸡致病性大肠杆菌(ED1、ED2、ED3、ED4、ED5、SD1、SD2、SD3、SD4、WD1、WD2、WD3、WD4、ND1、ND2、ND3、ND4、ND5),有12株分离株被鉴定出血清型,血清型主要有O78、O35、O36、O1、O2、O5、O18。其中O78共有4株,占33.3%,O35共有3株,占25%,药敏试验结果表明,分离的大肠杆菌对氟苯尼考,丁胺卡那霉素,新霉素,庆大霉素敏感,对环丙沙星,强力霉素,诺氟沙星中度敏感,而对红霉素,青霉素,链霉素产生了耐药性。     

鸡大肠杆菌的分离鉴定及耐药性分析

对鸡大肠杆菌进行分离鉴定，分离出的56株大肠杆菌中，共鉴定出47株菌株的血清型，分属O1、O2、O5、O35、O78、O1116种不同O抗原血清型，占分离菌株的83．9％。其中O1、O2、O78、O111最常见，占已定型菌株83％。同时，进行了药敏试验，为药物防治提供依据。     

鸡源致病性大肠杆菌血清型鉴定及耐药性分析

为了了解山东、河北和河南等省部分地区养殖场鸡源致病性大肠杆菌的血清型及耐药性,试验采用细菌分离和生化鉴定方法对鸡大肠杆菌进行分离和鉴定,通过动物试验确定分离大肠杆菌的致病性,应用血清学方法和药敏试验对致病性大肠杆菌的血清型及耐药性进行研究。结果表明:分离鉴定的119株大肠杆菌中致病性菌株有110株,其中92株致病性菌株能够定型,分别属于15个血清型,有5株出现交叉凝集,O14、O35、O1、O2、O78、O88为优势血清型;分离鉴定的致病性大肠杆菌对环丙沙星、头孢噻肟、头孢哌酮等最敏感,对林可霉素、头孢克肟、卡那霉素、庆大霉素、红霉素的耐药率达60%以上。说明分离的致病性大肠杆菌血清型存在复杂性,对大部分临床常用药物产生了不同程度的耐药。     

河南部分地区家兔大肠杆菌病病原分离鉴定与药敏试验

无菌采集不同地区临床上疑似为兔大肠杆菌病的10只病死兔典型材料，进行细菌学检验，鉴定出10株兔大肠杆菌。将分离菌株分别接种试验动物，对小白鼠致死率达100％。经大肠杆菌O因子血清鉴定，7株为01193株为O21。药敏试验表明，10株大肠杆菌中多数菌株对壮观霉素、头孢唑啉、新霉素和痢特灵敏感。     

山东滨州鸡大肠杆菌分离鉴定及耐药性分析

鸡大肠杆菌病是由大肠埃希菌的某些血清型引起的细菌性疾病,近几年来,由大肠杆菌引起的疾病逐年增多,病情复杂且混合感染,大肠杆菌可引起鸡的脐炎、气囊炎、眼球炎、心包炎、败血症、卵黄性腹膜炎及输卵管炎,一旦暴发常常给养殖户造成严重的经济损失。2016-2017年间,从滨州市3个县多家养殖场分离到10株大肠杆菌,并且进行了培养分离、显微镜下形态学观察和生化鉴定。对菌株进行大肠杆菌O抗原鉴定,共有O1(3株)、O2(2株)、O24(2株)和O7(3株)。分离菌株有高致病性。通过药敏试验结果分析发现大肠杆菌耐药性严重,多重耐药且耐药谱复杂。药敏试验结果表明,大肠杆菌对新霉素、恩诺沙星、阿奇霉素和头孢哌舒等较为敏感。新霉素与磷霉素、阿奇霉素和头孢哌舒之间的药物组合,效果更好。     

肉仔鸡病原大肠杆菌地方分离株的血清型鉴定

从河北的三河、滦南、乐亭、卢龙及昌黎等地 2 9个养鸡场 (户 )分离鉴定了 82株病原大肠杆菌 ,用 54种常见动物病原大肠杆菌单价 O抗血清进行了血清型鉴定。结果 82株分离菌有65株被鉴定出了相应 O血清群 (占鉴定菌株的79.2 6%) ,分属 6种不同血清型 ,其中以 O78和O45两种为优势血清型 (占定型菌株的64.61 %) ,其余 4种 O血清群占定型菌株的 3 5.3 9%,尚有 1 7株未能定型 (占鉴定菌株的 2 0 .74%)     

泰安地区鸡源致病性大肠杆菌流行病学调查与耐药性分析

正本调查对鸡场采集的疑似鸡大肠杆菌病例的相关病料进行大肠杆菌的分离鉴定,共分离鉴定出14株鸡源大肠杆菌,以微量平板凝集试验鉴定分离菌株的O抗原血清型,分别属于O78、O2和O1等3个血清型,其中O78(6/14)、O2(6/14)为主要流行血清型,占分离菌株总数的85.71%。选取了20种常用治疗肠杆菌病的抗生素对14株鸡源大肠杆菌分离株进行药敏试验,对14株大肠杆菌     

鸡致病性大肠杆菌的分离、鉴定及药敏试验

从南阳地区各养鸡场的发病鸡中分离出大肠杆菌,经常规方法培养、纯化、镜栓及生理生化鉴定,分离出29株鸡致病性大肠杆菌.有14株分离株被鉴定出血清型,其中O<,1>4株、O<,2>3株、O<,78>7株,未定型15株,O<,1>、O<,2>,和O<,78>血清型占分离株总数的48.3%.用29株分离菌株接种供试雏鸡后,发病症状及剖检病变均符合大肠杆菌病特征,其中高致病性菌株有13株,中度致病菌株有9株,低致病性菌株有7株,分别占试验菌株总数的44.8%、31.0%、24.2%.采用Kirby-Bauer纸片法,用22种药敏纸片对29株分离菌进行药敏试验,结果表明,分离出的大肠杆菌耐药性相当普遍,仅对头孢噻肟、丁胺卡那霉素、壮观霉素及新霉素等药物敏感性较高.     

Isolation,O Serogrouping and Drug Sensitivity Test of Avian Pathogenic Escherichia coli

One hundred and ninety four avian pathogenic Escherichia.coli (APEC) isolated from different pathotypes of chickens in Hebei province,Shandong province,Henan province,Jiangsu province,Shanxi province and Liaoning province in China between May 2005 and March 2016 were investigated by determination of biochemical characters,O serogroup identification and drug sensitivity test.Out of 194 isolates, 124 strains(63.9%) could be grouped to serogroups O1(3),O2(26),O57(15),O65(47) and O78(33).The drug sensitivity test used eight antibiotics (ampicillin, neomycin, doxycycline, sulfamonomethoxine,tilmicosin,ciprofloxacin ceftiofur and florfenicol) by one strain of O1,O2,O57,O65,O78 serogroup,respectively.The results showed that all strains were sensitive to ciprofloxacin and neomycin, and resistance to other drugs at varying degrees.This study demonstrated that the high prevalence of O65,O78,O2 and O57 isolates existed and provided the basis for the development of multivalent bacterin in future.     

Characterization of Escherichia coli isolated from cases of avian colibacillosis.

Forty-four western Canadian isolates of Escherichia coli associated with colibacillosis of turkeys and chickens were examined for serotype, antibiotic resistance, and production of aerobactin. The isolates belonged to fourteen O serogroups, with 39% of the strains being non-typeable. A high frequency of resistance to tetracycline, kanamycin, neomycin, cephalothin, streptomycin and erythromycin was observed. Most isolates produced aerobactin. Ten E. coli belonging to serogroups O1, O2 and O78 were also examined for pili production, hemagglutination, serum sensitivity, production of iron-regulated outer membrane proteins (IROMPS), and virulence. All isolates examined produced pili, exhibited mannose-sensitive hemagglutination of avian red blood cells and produced IROMPS under iron-restricted growth conditions. The five isolates of serogroup O1 and O2 were resistant to killing by turkey serum and were highly virulent. Only two of the five isolates of serogroup O78 were serum resistant. No correlation between serum resistance and virulence was observed in serogroup O78.     

Isolation,Identification and Drug Resistance Analysis of Avian Salmonella in Anhui

In order to investigate the situation of predominant strain and antibiotic resistance of avian Salmonella in Anhui province, 42 strains Salmonella were isolated and identified from 116 suspected samples by culture characteristics, microscopic examination, biochemical test, PCR and serological identification,then drug resistance was analyzed by Kindy-Bauer method. There were 5 groups of 11 serotypes in 42 strains Salmonella, of which 30 strains belonged to B serogroup, 2 strains to A serogroup, 7 strains to D serogroup, 2 strains to C₁ serogroup, 1 strain to C₂ serogroup, and Salmonella Typhimurium of B serogroup were the predominant serotypes. All Salmonella isolates resistant rates to amikacin, levofloxacin and ciprofloxacin were less than 20%, and the resistance rates to ampicillin, streptomycin, furazolidone, spectinomycin, cotrimoxazole and doxycycline were more than 50%, while resistance rate to ampicillin was 97.62%, and 41 isolates had multiple drug resistance. The results showed that Salmonella Typhimurium was the predominant serotypes of avian Salmonella in Anhui, and isolates showed multiple drug resistance. This study would provide the data basis for the comprehensive prevention and treatment of clinical medicine of avian Salmonella.     

安徽地区禽源沙门氏菌分离鉴定与耐药性研究

为了解安徽地区禽源沙门氏菌的流行菌株和耐药情况,本研究通过培养特性、镜检、生化试验、PCR和血清型鉴定等,对疑似发病禽的116份病料进行沙门氏菌分离鉴定,并采用Kindy-Bauer法对分离菌株进行耐药性分析。试验共分离到42株禽源沙门氏菌,其中包含5个大群11种血清型。B群30株、A群2株、D群7株、C₁群2株、C₂群1株,其中以B群鼠伤寒沙门氏菌为优势菌株。42株分离菌对阿米卡星、左氧氟沙星和环丙沙星的耐药率均低于20%,而对氨苄西林、链霉素、呋喃唑酮、大观霉素、复方新诺明和多西环素的耐药率达50%以上,其中对氨苄西林的耐药率达97.62%,且41株分离菌株存在多重耐药。结果表明,目前安徽地区禽源沙门氏菌优势流行株是鼠伤寒沙门氏菌,流行菌株呈现较严重的耐药性。本研究为指导临床用药及禽源沙门氏菌的综合防制提供数据支撑。     

一规模化猪场断奶仔猪腹泻大肠杆菌毒力因子的检测

从疑似断奶仔猪腹泻的仔猪中分离、鉴定出15株病原性大肠杆菌。经O血清型鉴定,11株为0131、4株未定型,所有O131血清型菌株呈β溶血。多重PCR检测毒素基因(STa、STb、LT、SLT-2e)和大肠杆菌粘附素单抗(F4、F5、F6、F41、F18)检测菌毛,O131菌株的毒素为STa、STb、SLT-2e,表达F18粘附素,未定型菌株的毒素为STa,共表达F6和F18粘附素。对15株大肠杆菌用16种抗生素进行药敏试验,结果表明:分离株对阿米卡星、痢特灵、新霉素敏感,而对多种抗生素产生了不同程度的耐药性。运用本场大肠杆菌分离株灭活苗免疫猪群,取得良好效果。     

Molecular epidemiology of avian pathogenic Escherichia coli (APEC) isolated from colisepticemia in poultry

The molecular biology and epidemiology of 150 avian pathogenic Escherichia coli strains (APEC) isolated from septicemic poultry in Germany was investigated by serotyping, pulsed field gel electrophoresis (PFGE), and polymerase chain reaction (PCR). Only 49.6% of the isolates could be grouped to serogroups O1, O2, and O78. Macrorestriction analyses data revealed two large clonal groups (clusters I and II) among the APEC strains with a similarity of 60.9% to each other. An association between restriction pattern and serogroup or origin of the strains was only present in a few subgroups of each clusters I and II, but was not evident. In contrast, our data revealed distinct combinations of virulence-associated genes in that 51.2% of the O2-strains harboured a combination of the genes fyuA, irp2, iucD, tsh, vat, fimC, and colV and 36.4% of the O78-strains possessed the same gene combination with exception of vat. With 34 different gene combinations the non-O1, -O2, -O78 isolates revealed a higher variability in their virulence gene pattern than O1-, O2-, and O78-strains with 6, 13, and 9 patterns, respectively. Our data indicate only a limited association between the virulence gene pattern and the serogroup of APEC strains and question the sensitivity of O-typing for APEC identification without the application of further diagnostic tools. Although a limited number of APEC clones exist, horizontal gene transfer seems to be common in these pathogens. These findings strengthen further research on the population structure of APEC and may be the reason for the lack of clear definition of this common E. coli pathotype.     

Biochemical and molecular characterization of minor serogroups of Shiga toxin-producing Escherichia coli isolated from humans in Osaka prefecture

We have investigated 37 minor serogroup Shiga toxin-producing Escherichia coli (STEC) strains other than O157, O26, and O111 isolated from human specimens in Osaka prefecture to determine their serological and biochemical characteristics, virulence-associated genes, and clinical signs in patients. The same serotype strains were genotyped by pulsed-field gel electrophoresis (PFGE). The O antigen of 33 strains were typed into 10 serogroups; O28, O63, O65, O91, O103, O119, O121, O126, O165, and O177, and other 4 strains were not agglutinated with any serum. Four different Shiga toxin (Stx) types (1, 2, 2c, and 2f) were distributed in these isolates. The intimin gene was present in 83.8% of the strains and subtyped into intimin alpha, beta, epsilon, and zeta. STEC O165, O177, and OUT isolated from hemolytic uremic syndrome (HUS) patients revealed atypical biochemical characters; negative reaction for lysine decarboxylase and gas production from glucose. Eleven strains including the isolates from HUS patients generated no colonies on cefixime-tellurite (CT)-sorbitol-MacConkey agar plates, since they showed high sensitivity (MIC 相似文献   

山东省部分地区禽源致病性大肠杆菌的血清流行病学调查与耐药性检测

为调查山东省禽源致病性大肠杆菌流行的血清型及耐药性,从山东部分地区的45家养禽场分离到致病性大肠杆菌96株,应用微量平板凝集试验进行了血清型鉴定,共鉴定出18种血清型,其中优势血清型6种,分别为O78、O2、O15、O18、O143、O88,占定型致病性菌株的64％。抗菌药物敏感性试验发现,96株大肠杆菌对20种药物有不同程度的耐药性。75％以上的菌株对氨苄青霉素、阿莫西林、土霉素等5种抗菌药耐药,50％以上的菌株对卡那霉素、多西环素、环丙沙星等7种抗菌药表现为耐药;所有分离株存在多重耐药现象,75％的受检菌对9种或9种以上的被测药物耐药。结果表明,O78、O2、O15、O18、O143、O886种血清型是山东省部分地区近年来禽源致病性大肠杆菌的优势血清型,且禽源致病性大肠杆菌的耐药现象严重,有必要加强耐药性检测,以指导兽医临床合理使用抗菌药物。     

华中地区鸡源沙门菌分离鉴定及耐药性分析

为了探明华中地区种鸡场沙门菌(Salmonella)的优势血清型和耐药情况,本研究从湖北、河南、湖南等省市22个规模化鸡场采集病鸡、死胚及弱雏组织样品3 724份,通过分离培养、生化试验、PCR鉴定及血清型试验确定分离菌种属及其血清型,并采用Kirby-Bauer法对分离菌株进行了耐药性分析。结果显示,本试验从3 724份病料中共分离鉴定出124株沙门菌,其中79株为D群肠炎沙门菌(63.71%,79/124),34株为D群鸡白痢沙门菌(27.42%,34/124),8株为B群鼠伤寒沙门菌(6.45%,8/124),有3株沙门菌未能确定血清型。O抗原鉴定79株肠炎沙门菌和34株鸡白痢沙门菌为O9,8株鼠伤寒沙门菌为O4。H抗原鉴定79株肠炎沙门菌为Hg,m,8株鼠伤寒沙门菌为Hi。药敏试验结果显示,124株分离菌株对萘啶酸、氨苄青霉素、四环素和多西环素耐药率分别为95.97%(119/124)、91.94%(114/124)、57.26%(71/124)和70.16%(87/124);对复方新诺明和红霉素耐药率分别为25.81%(32/124)和12.10%(15/124);对氯霉素、庆大霉素、头孢噻肟和卡那霉素耐药率分别为6.45%(8/124)、1.61%(2/124)、1.61%(2/124)和0.81%(1/124);对左氧氟沙星、阿米卡星和多黏菌素B完全敏感。99.19%(123/124)的分离株至少对一种药物耐药,87.10%(108/124)的分离株表现多重耐药。本研究为华中地区养鸡场沙门菌的诊断及防控提供了数据支撑。     

Virulence properties of Escherichia coli isolated from ostriches with respiratory disease

Eight Escherichia coli isolates from ostriches with respiratory disease were investigated for the presence of genes encoding the following adhesins: type 1 pili (fim), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afaI), temperature regulated adhesin, curli (crl, csgA) and temperature-sensitive hemagglutinin (tsh). Genes for heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf), alpha-haemolysin (hly) and aerobactin (aer) production were also investigated. Other characteristics investigated were the presence of hemagglutination activity, growth on an iron-deficient medium, aerobactin production, serum resistance, adherence to chicken tracheal cells, pathogenicity for day-old chicks, and serogroup. Serogrouping showed that four isolates belonged to serogroup O2, two to serogroup O78, one to serogroup O9, and one to serogroup O21. The virulence genes found were: fim in all eight isolates, csgA in seven, aer in six, and pap, crl and tsh in one isolate each. All isolates analyzed were positive for mannose-resistant hemagglutination, adhered in vitro to ciliated tracheal epithelium, grew on iron-deficient medium, and showed serum resistance. Pathogenicity tests on day-old chickens revealed one highly pathogenic isolate, three of low pathogenicity and four isolates with intermediate pathogenicity.