用血清学方法检测发现一种具有混合核心型（R_1R_4）大肠杆菌

用血清学方法检测发现一种具有混合核心型（Ｒ＿１Ｒ＿４）大肠杆菌首都医学院微生物学教研室北京１０００５４安云庆用特异性抗血清鉴定Ｅ．ｃｏｌｉ核心型是一种新型的检测方法。我们用单克隆抗核心型抗体（ａｎｔｉ－Ｒ１、Ｒ２、Ｒ３）和吸收后多克隆抗核心型抗体（ａ...     

全菌ELISA用于致肾盂肾炎大肠杆菌的鉴定

全菌ＥＬＩＳＡ用于致肾盂肾炎大肠杆菌的鉴定天津医学院微生物学教研室３０００７０陈锦英，何建民，苏琦华，任中原引起上行性尿路感染（肾盂肾炎）的大肠杆菌称为致肾盂肾炎大肠杆菌（ｕｒｏｐａｔｈｏｇｅｎｉｃＥ．ｃｏｌｉ，ＵＰＥＣ）．该菌具有Ｐ菌毛，特异性地粘...     

人朊病毒多肽抗体的制备及应用

目的 利用人工合成人朊病毒蛋白（ＰｒＰ）多肽制备特异性抗ＰｒＰ抗体,以期用于朊病毒相关疾病的临床诊断。方法 根据ＰｒＰ基因编码的氨基酸序列合成多肽,与载体偶联合免疫动物,所制备的抗血清用ＥＬＩＳＡ及Ｗｅｓｔｅｒｎ ｂｌｏｔ鉴定。结果 ＥＬＩＳＡ检测表明所制备的抗血清可同多种ＰｒＰ发生一反应;Ｗｅｓｔｅｒｎ ｂｌｏｔ结果显示抗血清可与正常组织ＰｒＰ＾ｃ和病理组织的ＰｒＰ＾ｓｃ反应;用蛋白酶Ｋ处理,可     

乙脑病毒鼠源单链抗体的构建及表达

目的 获得乙脑病毒（ＪＥＶ）鼠源单链抗体基因（ＳｃＦｖ）并使其在Ｅ．ｃｏｌｉ中表达。方法 利用噬菌体表面呈现技术,从抗乙脑病毒杂交瘤细胞２Ｈ４中构建噬菌体抗体库,采用双抗体夹心模式对抗体库进行富集及检测。并将所获得的阳性克隆重基因插入ＧＳＴ融合表达载体中,构建融合表达克隆重,使其在Ｅ．ｃｏｌｉ中获得稳定表达产物。结果 所构建的噬菌体抗体库经３轮的吸附、洗脱及再感染的富集过程后,共检测到７株稳定的具     

抗细菌脂多糖核心糖脂域单克隆抗体在实验性菌血症中的保护作用

以小鼠菌血症模型对抗核心糖脂域ＭｃＡｂ（ＥＬ１、ＥＬ３和３Ｈ４）的免疫保护的效果进行了研究，结果表明，（１）３株ＭｃＡｂ能显著提高受Ｅ．ｃｏｌｉ攻击小鼠的存活率（Ｐ〈０．０５）；（２）ＥＬ３和３Ｈ４还分别有降低３ＬＤ５０绿脓杆菌和５ＬＤ５０鼠伤寒沙门氏菌感染小鼠病死率的作用（Ｐ〈０．０５）；（３）ＥＬ３和３Ｈ４对受５ＬＤ５０Ｅ．ｃｏｌｉ和１０ＬＤ５０绿脓杆菌攻小鼠有一定的协同保护作用；（４）在ＥＬ     

抗细菌脂多糖核心糖脂域单克隆抗体在实验性菌血症中的保护作用

以小鼠菌血症模型对抗核心糖脂域ＭｃＡｂ（ＥＬ１、ＥＬ３和３Ｈ４）的免疫保护的效果进行了研究。结果表明，（１）３株ＭｃＡｂ能显著提高受Ｅ．ｃｏｌｉ攻击小鼠的存活率（Ｐ＜０．０５）；（２）ＥＬ３和３Ｈ４还分别有降低３ＬＤ５０绿脓杆菌和５ＬＤ５０鼠伤寒沙门氏菌感染小鼠病死率的作用（Ｐ＜０．０５）；（３）ＥＬ３与３Ｈ４对受５ＬＤ５０Ｅ．ｃｏｌｉ和１０ＬＤ５０绿脓杆菌攻击小鼠有一定的协同保护作用；（４）在ＥＬ１预防性保护试验中发现，提前４周注入ＥＬ１，并于攻菌前１周加强一次，ＥＬ１可明显提高５ＬＤ５０Ｅ．ｃｏｌｉＪ５株攻击小鼠的存活率（Ｐ＜０．０５）。提示ＥＬ３和３Ｈ４对细菌感染小鼠具有一定的交叉保护作用。     

噬菌体表面呈现抗人红细胞血型A抗原单链抗体的研究

目的 构建表达抗人红细胞血型Ａ抗原５０Ａ杂交瘤细胞的单链抗体（ＳｃＦｖ）。方法 应用重组噬菌体抗体技术,从５０Ａ杂交瘤细胞中分离、构建单链抗体基因,并将其克隆入噬粒ｐＣＡＴＮＡＢ５Ｅ中,转化Ｅ．ｃｏｌｉ ＸＬ－Ｂｌｕｅ,辅助噬菌体援救构建５０Ａ噬菌体单链抗体库;采用完整红细胞亲和富集法淘选阳性重组噬菌体,鉴定重组噬菌体并进行序列测定分析;免疫印迹试验检测重组单链抗体的特异性抗原活性。结果 用Ｍ１３     

人α—干扰素与乙型肝炎病毒前S2嵌合蛋白的表达？…

目的 重组表达人α－干扰素与乙型肝炎病毒前Ｓ２融合蛋白（ＩＦＮ－Ｐｒｅ Ｓ２）,探索治疗ＨＢＶ感染的特异性免疫药物。方法 采用聚合酶链反应（ＰＣＲ０技术扩增出人ＩＦＮ－α２ｂ和ＨＢＶ Ｐｒｅ Ｓ２基因片段,分步克隆获取融合基因,构建ｐＢＶ－ＩＦＮ－Ｐｒｅ Ｓ２重组表达载体,转化Ｅ．ｃｏｌｉ后诱导表达ＩＦＮ－Ｐｒｅ Ｓ２融合蛋白。结果 在Ｅ．ｃｏｌｉ中表达了相对分子质量为２７０００的目标蛋白,后者以     

TSHR蛋白表达质粒的构建和TSHR蛋白的表达

目的：为获得足量的ＴＳＨＲ蛋白及建立Ｇｒａｖｅｓ’病的动物模型。方法：将构建于ｐＣＲ＾ＴＭ３中的ＴＳＨＲ ｃＤＮＡ经限制性内切酶处理后,重新构建于表达型载体ＰｉｎＰｏｉｎｔ Ｘ质粒中,经酶切分析和ＰＣＲ检测,并在Ｅ．ｃｏｌｉ ＪＭ１０９中表达,Ｗｅｓｔｅｒｎ ｂｌｏｔｉｎｇ免疫印迹法检测其免疫活性．结果：证明ＴＳＨＲ ｃＤＡ基因正确地重组于ＰｉｎＰｏｉｎｔ Ｘ中,并在Ｅ．ｃｏｌｉ ＪＭ１０９中表达     

抗内毒素单链抗体基因的构建、序列分析及表达

目的：构建抗内毒素（ＬＰＳ） 单链抗体基因, 并尝试其在Ｅ．ｃｏｌｉ 中的表达。方法： 采用ｌｉｎｋｅｒ Ｐｒｉｍ ｅｒ Ｍｉｘ ,按ＶＨｌｉｎｋｅｒＶＬ 的结构将鼠抗ＬＰＳ ｍ Ａｂ Ｃ３Ａ２ 的ＶＨ ,ＶＬ 基因拼接成单链抗体（ＳｃＦｖ） 基因;用ＰＥ３７３Ａ 型全自动ＤＮＡ序列分析仪测定其核苷酸序列。ＰＣＲ 扩增抗ＬＰＳ ＳｃＦｖ 基因并更换两端接头序列后,插入谷胱甘肽巯基转移酶（ＧＳＴ）融合表达载体ｐＧＥＸ４Ｔ１ ;转染Ｅ．ｃｏｌｉ ＪＭ１０９ ,以ＩＰＴＧ 诱导表达,ＳＤＳＰＡＧＥ 分析表达产物。结果：扩增出的ＳｃＦｖ基因长７３５ｂｐ , 序列分析表明,该序列完整、正确;ＳＤＳＰＡＧＥ 显示,转染入重组质粒ｐ４ＴＣ３Ａ２Ｆｖ 的ＪＭ１０９ 菌经诱导后,有相对分子质量（ Ｍｒ） 约为５２ ０００ 的外源蛋白表达。结论：成功地构建了鼠抗ＬＰＳ ＳｃＦｖ 基因,并在Ｅ．ｃｏｌｉ ＪＭ１０９中表达了ＧＳＴＳｃＦｖ 融合蛋白。     

Demonstration of enterobacterial common antigen by bacterial agglutination.

Potent antisera against the enterobacterial common antigen (ECA) agglutinate R bacteria of the Enterobacteriaceae family that possess unimpaired R-core structures of the Escherichia coli R1 or E. coli R4 core type. In these strains, known to be ECA immunogenic, ECA is most probably linked to the lipopolysaccharide R core. R mutants of other core types (e.g., Salmonella Ra, E. coli R2 or R3) or R mutants with incomplete core structures of the E. coli R1 type, as well as an rfaL mutant deficient in the O-translocase system, agglutinate to a much lesser extent or not at all. All the later mutants are nonimmunogenic; they possess the ECA in a free form, not linked to the R core. None of the S forms tested from many different enterobacterial genera was found to be agglutinable with the ECA antiserum. The dynamics of the ECA agglutinin formation in rabbits parallels the ECA hemagglutinin formation, indicating that the same antibody class might be involved in bacterial agglutination and hemagglutination.     

Cross-reactivity between six Enterobacteriaceae complete lipopolysaccharide core chemotypes

To gain insight into the value of lipopolysaccharide (LPS) core determinants for cross-protective immunisation the serological relationships between six complete (LPS) core types from Enterobacteriaceae were investigated. Hyperimmune sera were raised in mice by repeated immunisation with heat-killed strains of Salmonella choleraesuis (Ra core type) or Escherichia coli (core types R1, R2, R3, R4 and K12) and characterised for reactivity with complete and incomplete core chemotypes by ELISA and immunoblotting. Three sera (anti-Ra, anti-R2 and anti-R3) reacted strongly with 3-5 different complete core types whereas the other three (anti-R1, anti-R4 and anti-K12) reacted strongly only with their homologous core types in these assays. Two approaches were used to examine further the structural bases for cross-reactivity between these cores. By the first approach the anti-complete-core sera were tested for cross-reactivity with truncated forms of the Salmonella species core (incomplete cores) derived from core-defective mutants. By the second approach, antisera raised against some core-defective mutants were tested for cross-reactivity with complete cores. The results of these investigations revealed that several pair-wise combinations of core types can be used as immunogens to elicit immune responses that recognise all six core types and that the major determinants which mediate cross-reactivity between complete cores are localised in the outer core region.     

Biochemical Basis of the Immunogenicity of the Common Enterobacterial Antigen

Of the numerous members of the family Enterobacteriaceae only a few strains, notably Escherichia coli O14 and R mutants of the E. coli R1-core type, engender antibodies against the common enterobacterial antigen (CA) following immunization of rabbits with heated suspensions or culture supernatants; other members produce nonimmunogenic CA of identical serological specificity. The biochemical basis of the immunogenic properties of CA of the former strains was investigated by determining the relationship between the CA determinant and the lipopolysaccharide molecule. Lipopolysaccharides extracted from R mutants of the E. coli R1-core type or of E. coli O14 by the phenol-chloroform-petrol ether method contain the CA determinant, in contrast to extracts of other CA-producing R mutants. This is evident from the observation that only the former absorb CA antibodies, utilizing erythrocytes coated with alkali-treated lipopolysaccharide preparations. Based on the findings that CA of R mutants of E. coli R1-core type follows lipopolysaccharide during all purification steps and that alkali treatment increases its affinity for erythrocytes parallel to that of the lipopolysaccharide, it is concluded that the CA determinant either is part of the lipopolysaccharide molecule or is strongly complexed with it. It is suggested that this association between CA and the lipopolysaccharide of E. coli R1-core type and E. coli O14 accounts for the heat stability of the immunogenicity of CA of these unusual strains.     

Antigenic relationships of the lipopolysaccharides of Escherichia hermannii strains with those of Escherichia coli O157:H7, Brucella melitensis, and Brucella abortus.

Clinical isolates of Escherichia hermannii which showed serological cross-reaction with polyclonal antisera to the O-polysaccharide portion of the lipopolysaccharide of E. coli O157 strains and with antisera to the O antigens of Brucella abortus and B. melitensis were found by chemical and nuclear magnetic resonance analyses to have lipopolysaccharide O chains composed of linear polymers containing 1,2- and 1,3-linked 4-acetamido-4,6-dideoxy-alpha-D-mannopyranosyl (alpha-D-Rhap4NAc) residues. Two O-antigen structures were identified; each had an unbranched pentasaccharide repeating unit, and one was composed of three 1,2- and two 1,3-linked alpha-D-Rhap4NAc residues and the other had two 1,2- and three 1,3-linked alpha-D-Rhap4NAc residues. The above-described cross-serological reactivities, which have led to false-positive identifications, are related to the common occurrence of epitopes involving the presence of N-acyl derivatives of 4-amino-4,6-dideoxy-D-mannopyranosyl residues in the O-polysaccharide portions of the respective lipopolysaccharides of the organisms. Strains of E. hermannii which did not show serological cross-reactions with E. coli O157 and Brucella antisera were found to have unique lipopolysaccharide O chains devoid of D-Rhap4NAc residues, demonstrating the existence of serotypes of E. hermannii that are distinct on the basis of their lipopolysaccharide components.     

Distribution of core oligosaccharide types in lipopolysaccharides from Escherichia coli

In the lipopolysaccharides of Escherichia coli there are five distinct core oligosaccharide (core OS) structures, designated K-12 and R1 to R4. The objective of this work was to determine the prevalences of these core OS types within the species. Unique sequences in the waa (core OS biosynthesis) gene operon were used to develop a PCR-based system that facilitated unequivocal determination of the core OS types in isolates of E. coli. This system was applied to the 72 isolates in the E. coli ECOR collection, a compilation of isolates that is considered to be broadly representative of the genetic diversity of the species. Fifty (69. 4%) of the ECOR isolates contained the R1 core OS, 8 (11.1%) were representatives of R2, 8 (11.1%) were R3, 2 (2.8%) were R4, and only 4 (5.6%) were K-12. R1 is the only core OS type found in all four major phylogenetic groups (A, B1, B2, and D) in the ECOR collection. Virulent extraintestinal pathogenic E. coli isolates tend to be closely related to group B2 and, to a lesser extent, group D isolates. All of the ECOR representatives from the B2 and D groups had the R1 core OS. In contrast, commensal E. coli isolates are more closely related to group A, which contains isolates representing each of the five core OS structures. R3 was the only core OS type found in 38 verotoxigenic E. coli (VTEC) isolates from humans and cattle belonging to the common enterohemorrhagic E. coli serogroups O157, O111, and O26. Although isolates from other VTEC serogroups showed more core OS diversity, the R3 type (83.1% of all VTEC isolates) was still predominant. When non-VTEC commensal isolates from cattle were analyzed, it was found that most possessed the R1 core OS type.     

Subdivision of O serotypes of Pseudomonas aeruginosa with monoclonal antibodies.

Sixteen murine monoclonal antibodies (MAbs) against serotypes O2, O5, and O16 (serogroup II) and subtypes O2b and O5d of Pseudomonas aeruginosa were evaluated by agglutination and enzyme-linked immunosorbent assay. Six MAbs that exhibited different specificities were compared with absorbed rabbit O-type antisera for the serotyping of 55 clinical isolates of serogroup II. There was good agreement between the antibodies for strains of serotypes O2 and O2b, but MAbs revealed reproducible differences between strains that were indistinguishable with rabbit antisera. The greater serotype specificity of MAbs was illustrated by the fact that only 5 of 20 strains which were agglutinated by rabbit antiserum O16 reacted with the MAb to that serotype. One antibody, M89, that reacted with 27 of 55 serogroup II strains, apparently bound to core lipopolysaccharide epitopes. Three MAbs to the frequent serotype O6 identified six subtypes, one of which accounted for over half of the clinical strains, while two subtypes were represented by single strains only. Overall, MAbs provided a greater discrimination between strains of P. aeruginosa of the same serotype than did absorbed polyclonal antisera.     

Comparison of methods for detection of colonization factor antigens on enterotoxigenic Escherichia coli.

Fecal Escherichia coli isolates from 196 patients with watery diarrhea and 68 healthy individuals (controls) were analyzed in Bangladesh immediately after isolation for the presence of colonization factor antigen (CFA) I or II (CFA/I or CFA/II, respectively) by a mannose-resistant hemagglutination (MRHA) test with six species of erythrocytes and by a slide agglutination test with absorbed CFA/I or CFA/II antisera. The presence of CFAs was confirmed by immunodiffusion analyses done in Sweden. By these methods, it was found that 49 of 69 enterotoxin-producing E. coli strains isolated from patients carried CFA/I or CFA/II, whereas none of the nonenterotoxigenic E. coli isolates or the three toxin-positive strains isolated from healthy individuals carried these adhesins. All E. coli strains retained their MRHA ability after transportation to Sweden followed by one subculture and after storage at -70 degrees C (but not at room temperature) for 1 to 2 years without further subculturing. After 5 to 10 subcultures of the fresh isolates, however, 70% of the initially CFA/I- and 80% of the initially CFA/II-carrying strains analyzed did not hemagglutinate. The efficacy of different methods for detecting CFAs on the fresh isolates was compared with that of immunodiffusion. The sensitivity of MRHA with human blood group A erythrocytes for the detection of CFA/I was high (97%), but the specificity was only 69%. The sensitivity of MRHA with bovine erythrocytes for the detection of CFA/II in Bangladesh was very low but increased considerably when chicken erythrocytes were also used. Whereas both false-positive and false-negative reactions were obtained when absorbed CFA antisera were used for agglutination, antisera against purified CFAs were equally effective as immunodiffusion in identifying CFA/I and CFA/II-carrying strains.     

Characterization and diagnostic application of a lipopolysaccharide core oligosaccharide-protein conjugate

Shigella sonnei phase II core oligosaccharide (OSPhII) was linked covalently with protein (bovine serum albumin or tetanus toxoid) to obtain a conjugate (OSPhII-protein) of good immunogenicity in rabbits. Anti-OSPhII-protein conjugate sera contained high levels of immunoglobulin G antibodies against the complete core region of Sh. sonnei lipopolysaccharide. The antigenic relationships between lipopolysaccharides of R1, R3 and R4 core types using anti-OSPhII-protein sera were studied. These antisera may be used for the rapid determination of core types in unknown enterobacterial strains.     

Evaluation of antisera used for detecting enterotoxigenic Escherichia coli in Sao Paulo.

The usefulness of antisera in detecting enterotoxigenic Escherichia coli (ETEC) strains in Sao Paulo was evaluated. Polyvalent antisera detected 49% of ETEC isolates and were more effective in identifying E. coli that produced heat-labile and heat-stable enterotoxins and in strains that produced only heat-stable enterotoxin. ETEC strains not detected by the antisera belonged to different serogroups not isolated in Sao Paulo before; 34% of these strains had undetermined O antigens, and most of them produced only heat-labile toxin. A variation of serogroups over time was especially observed among strains that produced heat-stable toxin. The importance of H-antigen determinations in the effectiveness of ETEC diagnosis by serological methods became evident, as non-ETEC strains were also detected by polyvalent antisera, but their serotypes were different from those of ETEC strains. Although antisera can be used to identify O:H types of ETEC strains with accuracy, serotyping cannot be recommended for routine diagnosis. However, such a procedure may be useful for studying outbreaks of ETEC diarrhea if the involved serotypes are already known.     

Immunogenicity of an E. coli extract after oral or intraperitoneal administration: induction of antibodies against pathogenic bacterial strains

For the treatment of recurrent infections of the urinary tract, a bacterial extract (OM-89) consisting of immunostimulating components derived from 18 Escherichia coli strains is orally applied to patients. We investigated in a mouse model the immunogenicity of the bacterial extract after intraperitoneal or oral administration. After repeated administration of the extract, serum IgG and IgA responses against the E. coli strains used for the preparation of OM-89 were obtained. This antisera also recognized a number of bacterial strains isolated from patients with urinary tract and enterohemorrhagic E. coli infections, and bound to a variety of other pathogenic strains. Moreover, the supernatants of cell cultures prepared from the urogenital tract of mice immunized with OM-89 contained increased levels of strain specific and of total IgG and IgA. Our findings may contribute to explain the therapeutic effect of OM-89 demonstrated in clinical studies.