3种霍乱弧菌检测方法在外环境标本中的应用研究

目的：通过改进霍乱弧菌检测的技术手段，提高外环境标本中霍乱弧菌的检出率。方法：将常规分离鉴定法、PCR检测法和胶体金免疫层析试验法同时用于检测霍乱流行期间的外环境标本，并对其现场应用结果进行比较分析。结果：3种方法检测80份外环境标本霍乱弧菌的结果显示：它们均未出现假阳性，3种方法各有优势，且结果相互符合性好，但也存在各自弱点。结论：只用单一种方法来检测外环境标本霍乱弧菌存在明显不足。建议在外环境霍乱监测中选用胶体金法进行初筛，再用常规法和PCR法检测。最大限度减少漏检的可能性。     

El Tor型霍乱弧菌L型的某些生物学性状

本研究主要对El Tor型霍乱弧菌(Vibrio cholerae biotvpe eltor,EVC)L型的某些生物学特性如生化反应、抗生素敏感性及超微结构等进行了探讨.研究发现EVC不稳定L型的生化性状与EVC流行株的非常相似,而稳定L型则变化很大.抗生素敏感性试验显示EVC稳定L型对某些作用于细胞壁的抗生素的敏感性减弱,而对大多数作用于蛋白质合成的抗生素的敏感性增强.与流行株相比,EVC稳定L型和不稳定L型的超微结构的改变很明显.此外,本文还讨论了产生这些改变的可能机制.     

霍乱毒素B亚单位基因的克隆和表达

用DNA重组技术构建CT-B表达性质粒pXB1及进一步修饰的pXB2,使CT-B基因在大肠杆菌中得到较高水平的表达(280～350ng/ml),且有71.5％分泌率。表达动力学研究阐明,克隆子培养24h产物收率较高。一定浓度的Mg~(2+)、L-组氨酸和天冬酰胺能刺激CT-B的表达。GM1-ELISA、CHO细胞测毒结合间接免疫荧光检测和家兔肠段结扎试验证实,表达的CT-B能与游离的或活细胞膜上的GM1受体结合,但无细胞和肠段毒性。这种细胞测毒结合免疫荧光序贯试验,为客观证实CT-B的生物学活性开拓了新途径。     

衡阳市城区市售甲鱼中检测霍乱弧菌的采样调查

目的了解衡阳市城区市售甲鱼中有无霍乱弧菌的感染。方法共采样55份，其中甲鱼肛门涂抹样36份，甲鱼表面粘液涂抹样19份。采用霍乱弧菌食物中毒的国家标准的检验方法进行检测。结果衡阳市市售甲鱼55份样本中有1份检测出O139血清型霍乱弧菌的感染。结论需采取相应的预防措施以防止霍乱弧菌引起的疫情。     

副溶血弧菌染色体DNA指纹图及其质粒图谱研究

对不同来源、不同血清型的７１株副溶血弧菌染色体ＤＮＡ指纹图及其质粒图谱进行了分析研究。结果表明：不同血清型、不同来源菌株的ＤＮＡ指纹图有显著的不同，相同血清型而来源不同的菌株其ＤＮＡ指纹图亦有区别，来自同一起暴发的同一克隆菌株的ＤＮＡ指纹图则极为相似，而且该ＤＮＡ指纹图具有极好的稳定性和精确性。质粒分析显示，其检出率为８７．３２％，且图谱呈多样性，但未发现质粒分布与血清型及来源的相关性。     

Characterization of an anti-idiotypic MoAb bearing an internal image of the receptor-binding epitope of cholera toxin.

A mouse anti-cholera toxin (CT) MoAb, mAb1, specific for the GM1-binding epitope of CT, was used to raise a syngenic anti-idiotypic MoAb, mAb2. Purified mAb2 was specific for mAb1 as shown by latex particle counting immunoassay and ELISA. Several experiments of competition between mAb2 and CT for binding to mAb1 demonstrated that mAb2 bore an internal image of the GM1-binding epitope of CT. Binding of mAb2 to GM1 unambiguously corroborated the mAb1-paratopic specificity of mAb2. Furthermore, mAb2 acted as a CT-surrogate antigen: rabbits injected with mAb2 produced some anti-CT antibodies, Ab3, which resembled mAb1 in specificity as expected. The potential use of this mAb2 as vaccine or as prophylactic agent to prevent CT from binding to its cellular receptor is discussed.     

肠道革兰氏阴性杆菌及孤菌快速鉴定的研究

目的：为寻求肠道G杆菌及弧菌快速鉴定的方法。方法：菌种经增菌及分离培养后，取菌落接种于综合生化培养基，并在综合生化培养基管口悬挂硫化氢和靛基质试纸条。同时以克氏双糖铁培养基作对照，置37℃培养18-24h。取综合生化管培养基，外加测试氧化酶，共获取11项生化指标。结果：对689株不同菌种与综合生化管培养基和常规双糖铁培养的测试结果，符合率为99．97％，(7577/7579)和99．79％(7563/7579)。结论：综合生化管是适合医疗卫生单位微生物实验室的一种快速检验方法。     

The sites of origin of dopaminergic afferent fibers to the lateral habenular nucleus in the rat

The lateral habenular nucleus of the rat contains a dense plexus of dopaminergic fibers, which are more marked in the medial part of the lateral habenular nucleus than in its lateral counterpart. Employing a combination of fluorescent retrograde axonal tracing with fluorogold and tyrosine hydroxylase immunofluorescence histochemistry, we investigated the distribution of cells of origin of the dopaminergic afferent fibers to the lateral habenular nucleus in the rat. The cells double-labeled with both fluorogold injected into the lateral habenular nucleus and tyrosine hydroxylase antisera were seen in a variety of fore- and midbrain regions, including the bed nucleus of the stria terminalis, medial preoptic area, periventricular, ventromedial, and dorsomedial hypothalamic nuclei, ventral tegmental area, interfascicular nucleus, substantia nigra pars compacta, ventrolateral division of the midbrain periaqueductal gray, and dorsal raphe nucleus. The double-labeled cells were located bilaterally with an ipsilateral predominance, and constituted approximately 10% of the total fluorogold-positive cell population. We have further observed by anterograde axonal tracing with Phaseolus vulgaris–leucoagglutinin that projection fibers arising from the sites of origin of the dopaminergic afferent fibers to the lateral habenular nucleus terminate mainly in the medial part of the lateral habenular nucleus, and to a lesser extent in its lateral conterpart. Thus, we have found in the present study that the dopaminergic neurons sending their axons to the lateral habenular nucleus are widely distributed in the A9, A10, A14, and A15 dopaminergic cell groups. Such dopaminergic neurons may exert regulatory influences upon many limbic-associated brain regions via the lateral habenular nucleus. © 1993 Wiley-Liss, Inc.     

Comparative proteomic analysis of Vibrio cholerae O139, O22, O155 and El Tor biotype epidemic strains

Cholera ,as one of the most severe epidemic dis-eases inthe world,can occurin a short time ,andspread quicklyto a wide region.Until 1992 ,onlyV.choleraeserogroup O1 was recognized as thecause of epidemic cholera . However in October1992 ,a major outbreak of a cholera-like illnesscaused by a newserogroupstrain ofV.choleraee-mergedinIndia and Bangladesh.In contrast to allpreviously reported non-O1 strains , which induceonly sporadic cases of human diarrhea without epi-demic potential ,the new…     

Proteomic analysis of salt-sensitive outer membrane proteins of Vibrio parahaemolyticus

Vibrio parahaemolyticus, a universal marine pathogen with available genome sequences, could be used as a bacterial model to clarify the various physiological phenomena of its native and host environments. In the present study, proteomic methodologies were applied to investigate the expression pattern of outer membrane proteins (OMPs) of V. parahaemolyticus at different NaCl concentrations. OmpW, OmpV, elongation factor TU and polar flagellin were determined to be osmoregulation-sensitive OMPs, among which OmpW and OmpV were reported to vary with changed NaCl concentrations in the pattern of osmolarity regulation. Therefore, our results not only expand our knowledge on osmoregulation-related proteins, but also provide a valuable strategy for the screening of salt-sensitive proteins.