天津地区部分猪源大肠杆菌的OMP型

从天津各区主要养猪场分离的16株(7种血清型O20、O21、O139、O141、O93、O108、O147)大肠杆菌中提取外膜蛋白(OMP),经SDS-PAGE分析表明,5株O21菌株有2个OMP型(OMP-1和OMP-3型).3株O1s9菌株和3株O20菌株各出现2个OMP型(OMP-1和OMP-2型).2株O141菌株共出现2个OMP型(OMP-2和OMP-3).1株O93菌株、1株O108菌株和1株O147菌株均为OMP-1型.结果表明,相同血清型的菌株可以有不同的OMP型,不同血清型的菌株可以有相同的OMP型.     

鸡源大肠杆菌OMP和OmpT基因与血清型相关性

为了解禽致病性大肠杆菌分离株OMP、OmpT基因与血清型相关性,对6种血清型(O78、O38、O9、O91、O11、O157)的7株鸡源大肠杆菌菌株进行了外膜蛋白(OMP)和外膜蛋白酶T(OmpT)基因的研究.用N-十二烷酰肌氨酸法提取其外膜蛋白,经SDS-PAGE电泳后考马斯亮蓝染色,对鸡源大肠杆菌菌株进行了外膜蛋白分型;用PCR和生物信息学的方法对OmpT基因进行检测与分析.7株大肠杆菌共有3个OMP型,其中,分离株5,32,9主要由相对分子质量接近的2条带组成,为OMP-1型;分离株11主要由相对分子质量接近的3条带组成,为OMP-2型;分离株14,7主要由相对分子质量接近的1条带组成,为OMP-3型.这表明同一血清型的菌株可能属于不同的OMP型,而血清型不同的分离株之间却可具有相同的OMP型.PCR检测结果显示7株鸡源大肠杆菌均携带OmpT基因,与GenBank登录的序列比较发现其同源性为91.9％～100.0％,不同血清型菌株间的同源性为91.9％～98.0％.该试验证实了同一血清型分离株之间可发生遗传分化,而不同血清型分离株之间也可具有不同程度的遗传相关性;不同血清型分离株间的OmpT基因的同源性存在一定的差异.     

天津地区鸡致病性大肠杆菌血清型分布及其优势血清型的外膜蛋白型研究

从天津地区各区县养鸡场分离 ,鉴定出 45株鸡致病性大肠杆菌。对 45株致病性大肠杆菌进行血清型鉴定 ,共定型出 3 1株 ,分属 1 4个血清型 ,其中 O78、O88、O2 、O4 5、O53、O14 5为优势血清型 ,占定型菌株的 58.3 %。提取 O78、O88、O2 、O4 5、O53和O14 56个血清型 1 8个分离株的外膜蛋白 ( Outermembrane protein,OMP) ,测定外膜蛋白型 ( Outmembrane protein patterns,OMPS) ,SDS-PAGE分析表明这些分离株共产生了 3个 OMP型 ( 1～ 3型 )。 OMP-1型为 O78、O88、O2 、O53、O14 55个血清型分离株所共有 ,OMP-2型为 O78、O4 5、O14 53个血清型分离株所共有。这表明同一血清的菌株可能属于完全不同的 OMP型 ,而血清型不同的菌株也可能为同一 OMP型。     

肉鸡源致病性大肠杆菌外膜蛋白型的研究

对分离自陕西省的16株肉鸡源致病性大肠杆菌的外膜蛋白（outer membrane proteins,OMP)进行提取，采用SDS-PAGE法进行分型，结果发现有3种外膜蛋白型，其中2株O4、2株O35、2株89，1株O18、1株O78属OMPⅠ型，2株O35，1株O4，1株O18属OMPⅡ型；1株O2，1株O75，1株O78，1株O89属OMPⅢ型，表明肉鸡源E.coli同一血清型中有不同OMP型，而不同血清型间也有相同OMP型，其中有2株菌OMP型表达丰富。     

禽多杀性巴氏杆菌血清型与外膜蛋白型相关性研究

为了解禽多杀性巴氏杆菌(Pasteurella multocida,Pm)分离菌株的荚膜血清型、菌体血清型与外膜蛋白型之间的相关性,首先对自行分离的10个菌株采用间接血凝试验和琼脂扩散试验进行鉴定(均为A:1);然后采用超声波破碎、高速离心和十二烷基肌氨酸钠提取外膜蛋白,通过SDS-PAGE电泳的方法对上述10个菌株与C48-1(A:1)、X73(A:1)、P1059(A:3)、CU(A:3,4)等一起进行外膜蛋白(Outer membrane proteins,OMP)分型研究。结果表明:14个禽多杀性巴氏杆菌菌株以2个主要蛋白OmpH和OmpA的差异为依据分为3种主要OMP型;依据次要蛋白的差异,OMP-1,3菌株进一步分为OMP型1.1,1.2和3.1,3.2,其中OMP型1.1有6个菌株,OMP型1.2有5个菌株;OMP型2有1株(YZ7031);P1059为OMP型3.1;CU为OMP型3.2;另外,血清型为A:1的12个菌株中有11个菌株外膜蛋白型均为OMP-1型,血清型为A:3、A:3,4的菌株外膜蛋白型属于3型。说明禽多杀性巴氏杆菌血清型与特定的外膜蛋白型具有很强的相关性。     

鸡大肠杆菌异型外膜蛋白原生质体融合菌株的构建

以鸡大肠杆菌Wwl株(O78，OMP-3．Amp^R，K^5)和WD2株(O2，OMP-1，Amp^5．K^R)作为亲本菌株，采用溶菌酶-EDTA法制备原生质体，以PEG作为助溶剂，进行原生质体融合，得到4株双耐药融合菌株，融合菌株的形态、染色特性和生化特性均符合大肠杆菌的特性，且均能同时表达两个亲本菌株的外膜蛋白(OMP)抗原(OMP-3，OMP-1)和O抗原(O78，O2)．表明两个亲本菌株发生了融合和染色体重组。经多次传代证明融合菌株是稳定的。     

鸡大肠杆菌异型外膜蛋白原生质体融合菌株的构建

以鸡大肠杆菌Ww1株(O78,OMP-3,AmpR,KS)和WD2株(O2,OMP-1,AmpS,KR)作为亲本菌株,采用溶菌酶-EDTA法制备原生质体,以PEG作为助溶剂,进行原生质体融合,得到4株双耐药融合菌株,融合菌株的形态、染色特性和生化特性均符合大肠杆菌的特性,且均能同时表达两个亲本菌株的外膜蛋白(OMP)抗原(OMP-3,OMP-1)和O抗原(O78,O2),表明两个亲本菌株发生了融合和染色体重组。经多次传代证明融合菌株是稳定的。     

天津地区部分猪源大肠杆菌的OMP型

从天津各区主要养猪场分离的16株（7种血清型O20，O21，O139，O141，O93，O108，O147）大肠杆菌中提取外膜蛋白（OMP），经SDS－PAGE分析表明，5株O21菌株有2个OMP型（OMP－1和OMP－3型），3株130菌株和3株O20菌株各出现2个OMP型（OMP－1和OMP－2型），2株O141菌株共出现2个OMP型（OMP－2和OMP－3）。1株O93菌株，1株O108菌株和1株O147菌株均为OMP－1型，结果表明，相同血清型的菌株可以有不同的OMP型，不同血清型的菌株可以有相同的OMP型。     

广东地区5种优势血清型猪大肠杆菌的外膜蛋白型研究

对从广东地区部分猪场分离的大肠杆菌进行血清型鉴定后,选取优势血清型O₉、O₂₆、O₆₀、O₁₀₁和O₁₀₇的8个致病性较强的分离株,采用超声波裂解、N-十二烷基肌氨酸钠处理和超速离心技术提取大肠杆菌的外膜蛋白（OMP）,利用SDS-PAGE电泳进行OMP分型。结果8个菌株共有3个OMP型（Ⅰ～Ⅲ型）,其中O₂₆、O₁₀₁、O₁₀₇型的3个分离株的外膜蛋白型由1条带组成,为OMP-Ⅰ型;O₆₀、O₁₀₁、O₁₀₇型的4个分离株的外膜蛋白型由2条带组成,为OMP-Ⅱ型;O₉型的1个分离株的外膜蛋白型由3条带组成,为OMP-Ⅲ型。这表明,优势血清型O₉、O₂₆、O₆₀、O₁₀₁、O₁₀₇的分离株OMP型不单一;同一血清型的分离株,存在不同OMP型;而不同血清型的分离株却可有相同的OMP型。     

鸭致病性大肠杆菌外膜蛋白型研究

测定了从我国分离到的130株鸭病原性大肠杆菌外膜蛋白型（Outer membrane protein patterns,OMP型）,其中O93、O92、O78和O76优势血清型53株,O46等30个其他血清型分离株77株,这些分离株共产生了4个OMP型,其中OMP-1型81株,占62.3%（81/130）,覆盖O93、O92、O78和O76等29个血清型,占85.3%（29/34）,为主要的OMP型;根据GenBank中大肠杆菌K-12外膜蛋白A基因（ompA）的核苷酸序列设计引物,从9株优势血清型和1株O46血清型的鸭大肠杆菌中分别扩增得到ompA基因,进行序列测定及分析,发现优势血清型9个菌株的ompA均由1 171个碱基组成,均只有1个大的开放阅读框（ORF）,长1 053 bp,编码由350个氨基酸组成的前外膜蛋白A（pro-OmpA）,前21个氨基酸残基组成信号肽,成熟的OmpA由329个氨基酸残基组成;O46菌株的ORF全长1 041 bp,在400-411 bp位缺失了12个碱基,成熟的OmpA由325个氨基酸残基组成;10个鸭致病性E.coli的ompA基因核苷酸序列高度同源,相似性达95.8%~100%。     

禽源大肠杆菌O2,O78分离株外膜蛋白型的研究

从１７个禽大肠杆菌病病例的Ｏ２、Ｏ７８分离株提取的主要外膜蛋白（ＯＭＦ），在ＳＤＳ－ｐＡＧＥ中出现了２个ＯＭＰ型。其中，９个Ｏ２分离株属２个ＯＭＰ型，８个Ｏ７８分离株均属其中的１个ＯＭＰ型。结果表明，分离到的Ｏ２、Ｏ７８大肠杆菌具有多样性的ＯＭＰ型，而且两者存在着共同的ＯＭＰ型。     

禽大肠杆菌病免疫保护机理的研究

以禽病原性大肠杆菌O18、O78分离株制成超声波裂解铝佐剂灭活苗免疫14日龄鸡，以相同或不同外膜蛋白型（Outer membrane protein pattern,OMP型）的O18、O78分离株攻毒。结果表明：O78血清相同和不同OMP型分离株间能获得最大保护；O18血清型相同OMP型分离株间获得最大保护，而不同OMP型分离株间不能保护；上述两个血清型的分离株间不论OMP型是否相同，均缺乏保护。以间接ELISA试验、间接血凝试验分别测定了试验鸡临攻毒前针对大肠杆菌OMPs和脂多糖(Lipopolysaccharide,LPS）的抗体。结果表明：免疫组鸡血清上述两种抗体明显高于攻毒对照组；在免疫组，存活鸡临攻毒前血清中上述两种抗体滴度恒高于死亡鸡，但除3个组外，多数组差异不显著。攻毒对照组这一关系不稳定。结果说明：禽大肠杆菌疫苗的免疫保护，主要与O血清型有关，部分与OMP型有关，如O18分离株，免疫保护性抗原含OMPs,LPS等多个抗原表位。     

Fimbriae and enterotoxins associated with Escherichia coli serogroups isolated from pigs with colibacillosis

A comprehensive study of 223 Escherichia coli isolates from pigs with colibacillosis included determination of O serogroups, detection of heat-labile enterotoxin, heat-stable enterotoxin (STa and STb), and identification of K88, K99, 987-P, F-41, and type 1 fimbriae. The incidence of the various E coli types among isolates of pigs of different ages was also determined. Escherichia coli bearing K88 fimbriae accounted for 48% of all isolates studied, were most often of serogroup O157, O149, or O8, and usually produced labile toxin alone or in combination with STa or STb. These E coli were commonly isolated from pigs in each age group studied (0 to 5 days, 6 to 10 days, 11 to 24 days, and greater than 24 days). Escherichia coli bearing 987-P accounted for 30% of the isolates, were most often of serogroup O141 or O20, and usually produced STa. Escherichia coli bearing K99 accounted for 13% of the isolates, usually were of serogroup O101 or O8, and almost always produced STa. Escherichia coli bearing 987-P or K99 were most often isolated from pigs less than 6 days of age. Fimbriae F-41, when identified, were usually on E coli of serotype O101:K99. Although infrequently found, type 1 fimbriae were on E coli of most of the serogroups identified in this study.     

Phenotypic and genotypic characterization of virulence factors of Escherichia coli isolated from broiler chickens with simultaneous occurrence of cellulitis and other colibacillosis lesions.

The objective of this study was to characterize virulence factors of Escherichia coli isolates from broilers with simultaneous occurrence of cellulitis and other colibacillosis lesions. Thirty flocks were sampled and 237 birds with cellulitis were examined. Eighty-two (34.6%) of 237 birds condemned for cellulitis had gross lesions in the heart, air sacs, joints, or liver. In 58 chickens, E. coli was isolated from both the cellulitis and other lesions of colibacillosis, and 18.9% of the E. coli isolates from the 2 types of lesions belonged to the same O group. Escherichia coli of serogroups O78, O1, and O2 predominated. Isolates of the same serogroup that were derived from different lesions in the same birds had similar patterns of biotype, aerobactin production, serum sensitivity profile, antibiotic sensitivity, and K1 capsule production. Escherichia coli derived from cellulitis lesions produced virulence factors similar to those found in E. coli isolated from other colibacillosis lesions in poultry.     

A longitudinal study of verotoxin-producing Escherichia coli in two dairy goat herds

A longitudinal study was conducted on two dairy farms to investigate the pattern of shedding of verotoxin-producing Escherichia coli (VTEC) in goats. Faecal samples were taken from 20 goat kids once weekly during the first 4 weeks of life and then once every month for the next 5 months of life, and from 18 replacement animals and 15 adults once every month for 12 months. The proportion of samples containing VTEC was higher for replacement animals and adults (85.7% and 78.7%, respectively) than for goat kids (25.4%). About 90% of the VTEC colonies isolated from healthy goats belonged to five serogroups (O33, O76, O126, O146 and O166) but the most frequent serogroups of these isolates, except one, were different in the two herds studied. E. coli O157:H7 was found in three goat kids on only one occasion. None of the VTEC isolates, except the three E. coli O157:H7 isolates, was eae-positive. The patterns of shedding of VTEC in goat kids were variable, but, in contrast, most of the replacement animals and adults were persistent VTEC shedders. Our results show that isolates of VTEC O33, O76, O126, O146 and O166 are adapted for colonising the intestine of goats but that, in contrast, infection with VTEC O157:H7 in goats seems to be transient.     

Intestinal microflora in 45 crows in Ueno Zoo and the in vitro susceptibilities of 29 Escherichia coli isolates to 14 antimicrobial agents

Microorganisms from 45 jungle crows (Corvus macrorhynchos) captured from July to December 2002 at Ueno Zoo, Tokyo were identified as Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter aerogenes, Enterobacter cloacae, Enterobacter agglomerans, Pseudomonas maltophila, Staphylococcus spp., Micrococcus spp., and Streptococcus spp. E. coli showed the highest rate of isolation (21.6%). In an in vitro susceptibility test for 29 isolates of E. coli to 14 antimicrobial agents, all the isolates were resistant to penicillin G, vancomycin, erythromycin, lincomycin, bicozamycin, sulfadimethoxine, and olaquindox. Several isolates of them were also resistant to tetracycline, oxytetracycline, streptomycin, chloramphenicol, and ampicillin. Twenty-nine isolates were divided into 19 serogroups and the most frequently identified serogroups were O8, O114 and O144, which showed the same multidrug-resistant patterns.     

某大型鸡场鸡大肠杆菌病流行病学调查

某大型鸡场的28个分场分离到的菌株，经生化检验为大肠杆菌的有87株，经O血清测定定型65株，4株自凝，18株未能定型，其中O78占20株，O1占14株，O2占5株，这些分离株中O78、O1、O2有39株占定型菌株的60．0％，因此可以认定O78、O1和O2为该大型鸡场的优势血清型，以不同场分离的菌株，以每分离株10^7菌落形成单位(CFU)细菌气管接种1日龄易感鸡，根据接种后7天内发生死亡和病变鸡的比例，确定出高致病株、中等致病株和低致病株分别为87．36％、8．05％和4．59％。     

O-serogroups, eae gene and EAF plasmid in Escherichia coli isolates from cases of bovine mastitis in Brazil

Mastitis has been recognized for some time as the most costly disease in dairy herds. From March 1997 to August 1998, 2144 samples of bovine mastitic milk were collected, from which 182 Escherichia coli isolates were made, and from which 141 isolates had the somatic antigen (serogroup) determined. Twelve different serogroups were isolated from mastitic milk, and among them were O26, O55, O111 and O119, all of them classic enteropathogenic E. coli (EPEC) serogroups. These represented 40.0% of the isolates. The 20 of 57 isolates tested had plasmids and in dot blot hybridization, nine isolates were positive for an EaeA probe and an EPEC adherence factor (EAF) probe while two isolates were negative for EaeA probe but positive for the EAF probe. The nine isolates were characterized as attaching and effacing (A/E) E. coli (AEEC) isolates.     

不同地区101个禽源性大肠杆菌分离株的致病性试验

从国内１８个省、市、自治区大肠杆菌病疑似病禽中分离并鉴定出大肠杆菌５９５株,鉴定出其中４４０个分离株的血清型。采用Ｒｏｓｅｎｂｅｒｇ氏报道的方法,测定了来自不同地区的６０个优势血清型分离株对ＳＰＦ鸡、３０个其他常见血清型及１１个国内少见血清型分离株对普通易感鸡的致病性。结果表明：所测定的１０１个分离株均为致病株,且９０％以上属高、中度致病株。     

Biochemical characteristics of enterotoxigenic and nonenterotoxigenic Escherichia coli isolated from calves with diarrhea.

Eighteen isolates of enterotoxigenic Escherichia coli (ETEC) and 15 isolates of nonenterotoxigenic E coli (NETEC) obtained from calves with diarrheal disease were characterized biochemically. Of 64 biochemical tests employed, none allowed making differentiation of ETEC from NETEC. Eleven tests were used to separate ETEC isolates into 1 of 5 biotypes, although the ability to ferment dulcitol, salicin, sucrose, and sorbose gave sufficient information to identify the 5 biotypes of ETEC. The biotype data were confirmed upon testing 159 additional isolates of ETEC of bovine origin. All isolates of ETEC studied belong to serogroups O9:K35, O101:K30, O8:K85, O20:K? O8:K25, and O101:K28. The ETEC in different serogroups were also different biotypically, with the exception that isolates in serogroups O101:K28 and O101:K30 were of the same biotype. The K99 antigen was detected in 172 of the 177 isolates of ETEC and in 1 of 15 isolates of NETEC. Marked biochemical differences were not found between K99 + and K99- isolates of E coli.