幽门弯曲菌的微生态学研究现状

近年来,关于幽门弯曲菌和慢性胃炎关系的研究报道层出不穷,但该课题进展不快,其主要限制因素是没有成功的动物模型。目前开展幽门弯曲菌的微生态学研究对该课题停滞不前的状态无疑有推劫作用。但至今这方面资料尚很少见。本文旨在初步探讨决定幽门弯曲菌胃粘液定植和生存的几个微生态学因素,以便引起有关研究者的重视。     

幽门弯曲菌的生物学特性的研究

我们对各型胃病患者共300例进行了幽门弯曲菌(Campylobacter pylori 以下简称CP)检查。以10%小牛血清布鲁氏菌肉汤为保存液,6%羊血布鲁氏菌琼脂平皿作培养基,在微氧条件下分离 CP,阳性率为65%。用改良尿素酶快速诊断的(4小时敏感性)阳性率为34.6%,及95.4%(24小时),特异性为100%。胃粘膜研磨液直接涂片,用0.3%碱性复红染色后镜检,二者阳性符合率为87.2%。CP 的生化试验表明,氧化酶、过氧化氢酶、尿素酶呈阳性反应;葡萄糖发酵、硝酸盐还原及3.5%NaCl 均为阴性。药敏试验的结果显示 CP 对庆大霉素、四环素、红霉素、氯霉素、羧苄青霉素,痢特灵、卡那霉素、先锋霉素等敏感;而对磺胺、萘啶酮酸、多粘菌素 B 等耐药。CP 经口感染小鼠 C57、及 BALb/c,与金黄色地鼠,均无致病性表现。     

幽门弯曲菌感染的快速诊断研究进展

<正>近年来各国学者对一类与胃炎、胃及十二指肠溃疡等疾病相关的微生物-幽门弯曲菌(Campylobacter pyloriclis,简称(P)研究报告日趋增多,并已引起全世界医学界的广泛兴趣和高度重视。自从1983年澳大利亚Marshall首次从胃窦活检标本中分离培养cp获得成功。随后Marshal等用自身试验和Girdwood等通过比较正常人及胃炎、胃、十二指肠溃疡的病人CP分离阳性率与疾病转归的关系以及对治疗效果的观察等,提出了CP胃炎的观点,并认为CP是引起CP胃炎及胃肠溃疡的病原菌。病人CP的分离率一般在50—90%以上,[4.6.7]但在正常的胃和十二指肠活检标本中却很少能查出此菌。曾有报道,让志愿者吞服10~9个CP后,引起低胃酸性胃炎,持续时间约2周,病理学检查和     

幽门螺杆菌无血培养方法的建立

目的比较幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒｐｙｌｏｒｉ，Ｈｐ）羊血培养基及自制的活性碳无血培养基培养效果。方法５２例Ｈｐ阳性患者胃粘膜，分别接种于经典的羊血培养基及自制的活性碳无血培养基，３７℃厌氧培养Ｈｐ。结果用羊血培养基培养，Ｈｐ阳性率均高于用活性碳无血培养基培养的阳性率，但没有统计学差异（ｐ＞００５）；两种培养基培养出来的Ｈｐ，菌落、镜下形态及生化特性完全一致，唯后者培养出来的Ｈｐ生长较慢、菌落较小。４位近期服过抑酸药、抗Ｈｐ药物的患者，用羊血培养基培养阴性，而用活性碳无血培养基却能分离培养出Ｈｐ。无论用哪种培养基，培养７天Ｈｐ阳性率均高于培养３天Ｈｐ阳性率，有极显著性差异（ｐ＜００１）。结论羊血培养基适合于一般Ｈｐ分离培养；特殊情况下，特别是抗Ｈｐ治疗后复查，则用活性碳无血培养基较合适。适当延长培养时间，可以提高阳性率。     

幽门弯曲菌与胃炎及消化性溃疡关系的研究现状和展望

早在十九世纪末,就有人注意到人的胃粘膜组织中存在一种螺旋形细菌,其后陆续有类似报道,但均未引起人们重视。1983年Warren和Marshall报告,从人胃粘膜活检组织中分离出这种细菌,提出该菌很可能是慢性胃炎及消化性溃疡的病原菌,从而引起各国学者的极大关注。近年来,我国也开展了这方面的研究。这种细菌已被正式命名为幽门弯曲菌(Campylobacter pylori,简称CP)。国内外的研究提示,CP在胃炎及消化性溃     

幽门弯曲菌与慢性胃炎和消化性溃疡关系的系列研究

我院自1986年6月至1989年6月检查了634例病人的胃粘膜,从幽门弯曲菌(CP)的细菌学、致病性、病理学、诊断方法及药物治疗等方面进行了研究,探讨CP与慢性胃炎及消化性溃疡的关系。结果发现CP有两种形态并与空弯菌不同,不产生肠毒素;消化性溃疡的CP检出率为80.9％,慢性胃炎为41.6％,显著高于正常胃粘膜(3.7％);CP与消化性溃疡、慢性胃炎,十二指肠炎特别是活动性炎症有密切关系;CP对胃型上皮或粘液有某种亲和性;观察到上皮细胞破溃处有大量细菌聚集,CP有致细胞病变的能力。用阿的平代替吖啶橙荧光染色,并制成CP感染快速诊断试剂盒。呋喃唑酮促进溃疡愈合,使45～73％病例CP消失,50～70％胃炎好转。但有复发,根除CP有困难。     

幽门,空肠弯曲菌长期保存前后染色体DNA酶切图谱的分析

对15株幽门弯曲菌及42株空肠弯曲菌,经6%羊血布氏琼脂培养后,于20%小牛血清布氏肉汤及全羊血中,在-70℃条件下,能保存3个月和10个月;并对其中的一些菌株,进行了研究,实验证明在保存前后,这些菌株的生物学性状和染色体 DNA 酶切图潜完全一致。     

安徽部分地区动物源弯曲菌的分离鉴定及多位点序列分型

【背景】弯曲菌是一种重要的食源性人兽共患病原菌,革兰氏阴性、微需氧、弯曲螺旋状。【目的】为了解安徽地区弯曲菌流行状况和分子遗传特征,对安徽6个不同地区动物源的弯曲菌进行分离鉴定,并研究分离株分子分型。【方法】通过形态学及培养特性观察、生化试验、PCR方法对菌株进行鉴定。以弯曲菌7个管家基因asp A、gln A、glt A、gly A、pgm、tkt和unc A为目的基因对分离株进行多位点序列分型,并制成遗传进化树。【结果】共分离到42株弯曲菌菌株,源自6个地区的分离株具有较为一致的形态特性和相似的生化特性。多位点序列分型结果显示,本研究中共获得32种ST型,共发现9种新的ST型(8190、8222、8223、8831、8833、8841、8832、8834和8843)和6个新的等位基因(gln A606、gln A607、glt A518、gly A680、pgm863和unc A541)。进化树结果显示,空肠弯曲菌与结肠弯曲菌遗传关系相差甚远,聚集归为两个大群,分别有5个分支和3个分支。【结论】安徽6个地区不同来源的空肠弯曲菌与结肠弯曲菌均有丰富的基因型,且没有明显优势的基因型。从遗传变异的角度来看,空肠弯曲菌复杂多样,结肠弯曲菌相对保守。     

Isolation and characterization of bacteriophages specific for Campylobacter jejuni

Human infection by Campylobacter jejuni is mainly through the consumption of contaminated poultry products, which results in gastroenteritis and, rarely, bacteremia and polyneuropathies. In this study, six C. jejuni -specific bacteriophages (CPS1–6) were isolated by the spot-on-the-lawn technique from chicken samples in Korea and characterized for potential use as biocontrol agents. All isolated bacteriophages exhibited a high specificity, being able to lyse only C. jejuni , but not other Gram–negative bacteria, including C. coli , Escherichia coli , Salmonella spp., and Gram–positive bacteria. Bacteriophages contain an icosahedral head and a contractile tail sheath in transmission electron microscopy, and possess ds-DNA with an average genome size of approximately 145 kb; therefore, all bacteriophages are categorized into the Myoviridae family. Bacterial lysis studies in liquid media revealed that CPS2 could be used to control the growth of C. jejuni .     

空肠弯曲菌生物学分型的研究

用马尿酸水解,28℃中生长及10种试剂抗性试验,研究了空肠弯曲菌的生物学分型,每株菌按3种方法,4组实验进行计数,我们对86株弯曲菌进行了生物学分型,其中空肠弯曲菌79株,分为17种类型,结肠弯曲菌5株为5种类型,海鸥弯曲菌2株为2种类型。这对菌株在流行病学上分析有一定意义。     

Blood-Free Medium for the Rapid Growth of Pasteurella tularensis

A medium composed of (in g/100 ml) Tryptose broth with thiamine (Difco), 2.6; cysteine-HCl, 0.12; glucose, 1; FeSO₄, 7H₂O, 0.005; KCl, 0.02; histidine, 0.1; tris(hydroxymethyl)aminomethane (tris) buffer, 0.3; and agar, 1; will support rapid growth of the fully virulent SCHU-S4 strain of Pasteurella tularensis. Although the test organism grew rapidly on medium from which KCl and tris buffer were omitted, these two components increased the stability of the medium upon storage at 4 C. It was necessary to (i) control carefully the relative concentration of the ferrous iron and cysteine-HCl, (ii) incubate the prepared medium overnight prior to use, and (iii) incubate the inoculated plates in an atmosphere of high relative humidity. Rapid growth of the organism was obtained also from very small inocula in the liquid form of the medium. Biochemical studies designed to elucidate the mechanisms involved in the enhancement of growth of P. tularensis in this relatively simple blood-free medium were initiated.     

Isolation of Campylobacter pyloridis from human gastric mucosa and characterization of the isolates

Biopsy specimens of human gastric mucosa of patients with gastric complaints and subjected to endoscopic examination were cultured microaerobically, and Campylobacter pyloridis was detected in 46 out of 80 cases (57.5%). The organism was found in 13 out of 22 patients with gastritis, 11 out of 16 with gastric ulcer scar, 7 out of 16 with gastric ulcer, 3 out of 9 with gastric polyp, 4 out of 5 with gastric carcinoma, 2 out of 2 with esophagus carcinoma, and 6 out of 9 with other gastric diseases. The isolates were identified as C. pyloridis, demonstrating its characteristic features such as positive for oxidase and catalase, negative for reduction of nitrite and nitrate, positive for urease, no growth at 25 C, growth at 37 C, not tolerant to 1% glycine, and resistant to nalidixic acid. Positive alkaline phosphatase activity was considered as an additional feature characteristic for the strains of C. pyloridis. The major cellular fatty acids were tetradecanoic acid and 19-carbon-cyclopropane acid. This pattern is unique among Campylobacter species. The survival of the organism for a longer period than 60 min at pH 2.5 indicates its significant resistance to acidic environment.     

Isolation and characterization of the flagellar hook of Campylobacter jejuni

Abstract A method for purification of the flagellar hook of Campylobacter jejuni is described. The hook was shown to be composed of a subunit protein, which has a molecular mass of 92,000 and an isoelectric point of pI 4.8. A monoclonal antibody and a polyvalent antiserum was raised against the purified flagellar hook of C. jejuni . Immuno-electronmicroscopy revealed that the epitope recognized by the monoclonal antibody is surface-located. However, this antibody reacted only with the hook of the immunization strain, but not with other strains or other flagellated bacteria. Thus, our data indicate that the immunodominant epitopes are located on the surface of the hook and that these epitopes are strain-specific.     

Development of a cytolethal distending toxin (cdt) gene-based species-specific multiplex PCR assay for the detection and identification of Campylobacter jejuni, Campylobacter coli and Campylobacter fetus

A cytolethal distending toxin (cdt) gene-based species-specific multiplex PCR assay for the detection of cdtA, cdtB or cdtC gene of Campylobacter jejuni, Campylobacter coli or Campylobacter fetus, respectively, was developed and evaluated with 76 Campylobacter strains belonging to seven different species and 131 other bacterial strains of eight different genera. The cdtA, cdtB or cdtC gene of C. jejuni, C. coli or C. fetus, respectively, could be successfully amplified using the corresponding set of primers in a highly species-specific manner. Furthermore, the specific primer set for the cdtA, cdtB or cdtC gene of a particular species could amplify the desired gene from a mixture of DNA templates of any of two or all three species. The detection limit of C. jejuni, C. coli or C. fetus was 10-100 CFU tube(-1) by the multiplex PCR assay on the basis of the presence of the cdtA, cdtB or cdtC gene. These data indicate that the cdt gene-based multiplex PCR assay may be useful for rapid and accurate detection as well as identification of Campylobacter strains in a species-specific manner.     

中国小型猪空肠弯曲菌的首次分离及其鉴定

目的对中国小型猪空肠弯曲菌进行分离鉴定。方法采集发病小型猪标本,采用细菌学分离培养、生化鉴定、药敏试验、血清学试验、PCR检测等方法进行鉴定,并对细菌的分子生物学特征进行分析。结果分离到1株细菌,经鉴定为空肠弯曲菌（CJp0812）。用空肠弯曲菌flaA基因特异引物对CJp0812细菌的PCR扩增为阳性,经核苷酸序列测定分析证实上述序列与空肠弯曲菌NCTC11168基因序列（GenBank登录号：NC002163）同源性高达99%。结论首次从中国小型猪中分离到了空肠弯曲菌,为进一步研究该菌及开展流行病学调查提供了科学依据。