Prevalence of yersinia plasmid-encoded outer protein (Yop) class-specific antibodies in multitransfused Greek patients with thalassemic syndromes

Objective: To evaluate the prevalence of class-specific antibodies (G, A, M) to Yersinia enterocolitica plasmid-encoded outer proteins (Yops), in a closely followed multitransfused population of patients with thalassemia.
Methods: Sera from 408 β-thalassemic patients and 386 healthy blood donors used as controls were analyzed with the enzyme-linked immunosorbent assay (ELISA) for IgG, IgA and IgM antibodies to yersinia outer proteins. The Yop antigen for the ELISA was prepared using a plasmid-bearing wild-type strain of Y. enterocolitica of serotype 0:8.
Results: Anti-Yop IgG antibodies were detected in 84 out of 408 β-thalassemic patients (20.6%) compared with only eight out of 386 (2.1%) healthy blood donors. None of the sera of either group was positive for anti-Yop IgA or IgM antibodies. On evaluating patients with registered clinical and laboratory signs of a previous yersinia infection in the period from 1978 to 1996, we found that those with a positive aggiutination test for Y. enterocolitica infection at the time of manifestation showed a higher rate of persisting IgG seropositivity to Yops than those with positive culture and clinical signs only. A significant percentage (9.49%) of the seropositive patients had no registered data of a past Y. enterocolitica infection. There was remarkable persistence of anti-Yop IgG antibodies in the thalassemic population, even in patients infected during the early years of our study period (1978–80).
Conclusions: The results suggest that the determination of class-specific antibodies to Yops, which are specific antigens for the pathogenic yersiniae ( Y. enterocolitica, Y. pseudotuberculosis and Y. pestis ), in addition to its usefulness in the diagnosis of infection, will be a very sensitive and specific index for epidemiologic studies.     

Suppression of T and B lymphocyte activation by a Yersinia pseudotuberculosis virulence factor, yopH.

The acquired immune responses are crucial to the survival of Yersinia-infected animals. Mice lacking T cells are sensitive to Yersinia infection, and a humoral response to Yersinia can be protective. Diverse mechanisms for Yersinia to impair and evade the host innate immune defense have been suggested, but the effects of Yersinia on lymphocytes are not known. Here, we demonstrate that after a transient exposure to Y. pseudotuberculosis, T and B cells are impaired in their ability to be activated through their antigen receptors. T cells are inhibited in their ability to produce cytokines, and B cells are unable to upregulate surface expression of the costimulatory molecule, B7.2, in response to antigenic stimulation. The block of lymphocyte activation results from the inhibition of early phosphorylation events of the antigen receptor signaling complex. Through the use of Y. pseudotuberculosis mutants, we show that the inhibitory effect in both T cells and B cells is dependent on the production of Yersinia outermembrane protein (Yop) H, a tyrosine phosphatase. Our results suggest a mechanism by which the pathogenic bacteria may modulate a wide range of T and B cell-mediated immune responses.     

鼠疫耶尔森氏菌IS 1541的研究

目的：研究鼠疫耶尔森氏菌的插入序列ＩＳ １５４１的插入位点的特性。方法：用一条锚定的ＩＳ １５４１内部锚定引物和一条随机引物进行ＰＣＲ扩增;核酸分子杂交技术;克隆;测序。结果：１４株鼠疫菌的扩增普谱基本相同,杂交图谱差异,可分成３种类型。克隆、测序其中一个片段,其序列仅在两端的引物区与ＩＳ １５４１同源,而与Ｅ．ｃｏｌｉ Ｋ－１２ ＭＧ １６５５的ｐｒｌｃ基因同源性较高。结论：ＩＳ １５４１在鼠疫     

小肠结肠炎耶氏菌L型的初步研究

5株小肠结肠炎耶氏菌用人工诱导方法获得二株L型细菌,血清型为O:5,27;O:37。与去氧胆酸钠-抗生素诱导法和溶菌酶诱导法结果一致。二株经抗生素诱导者在改良Kagan培养基上出现典型的L型菌落,涂片染色可见菌体呈长丝体和膨大的巨形体,能通过0.45μm的除菌滤膜,在高盐肉汤内呈颗粒状沉淀生长。L型细菌与抗血清试管凝集滴定比原型和返祖型低2～3个稀释度,生化反应出现对一些糖类的发酵能力减弱,水杨素、七叶灵、肌醇等由原型的阳性反应变为阳性,从而可致耶氏菌生化分型的改变。L型细菌对一些抗生素的敏感性与原型和返祖型有差异。     

国内首次从猪中检出假结核耶氏菌的报告

本文报告检验福建省市售28种食品标本764份,其中猪肉标本占177份。结果从猪肠中分离出一株假结核耶氏菌。该株根据形态学、血清学及生化的特征,鉴定为血清Ⅲ型,具有毒力,含有VW抗原,且能使小白鼠致死。这证明猪可自然携带假结核耶氏菌,是该病的传染源。     

鼠疫耶尔森菌201株和201△pCD1株蛋白表达谱比较研究

目的：分析缺失编码Ⅲ型分泌系统的大质粒pCD1对鼠疫耶尔森菌蛋白质表达谱的影响,探索鼠疫菌的潜在致病机制,为鼠疫疫苗研制提供新线索。方法通过双向电泳与质谱分析相结合的方法,比较鼠疫菌在26℃和37℃不同培养温度下,全菌蛋白表达谱差异,鉴定差异蛋白并对其功能进行初步分析。结果成功分离并鉴定了鼠疫菌201株和201△pCD1缺失突变株中的差异蛋白,其中26℃条件下鉴定到24个差异蛋白,37℃条件下鉴定到25个差异蛋白,内含7个由pCD1质粒编码的蛋白。结论通过比较蛋白质组学研究,发现大质粒pCD1缺失后,多种染色体编码蛋白的丰度发生了显著变化,暗示大质粒能调控染色体编码基因的表达。     

广东省非鼠疫疫源地三株耶尔森氏菌生物学特性的研究

目的研究三株耶尔森氏菌生物学特性,查明该菌株与鼠疫菌的免疫原性关系。方法采用生长特性、糖醇酵解试验、毒力因子和免疫原性交叉等试验方法。结果试验菌株的菌落呈圆形光滑、G^-短杆菌、22℃有动力、37℃无动力,生化测试葡萄糖、蔗糖、尿素、甘露醇和山梨醇阳性,鸟氨酸出现不稳定,而赖氨酸、鼠李糖、明胶和乳糖呈阴性,对氯霉素和链霉素呈高度敏感,而青霉素有耐药性,三株菌与鼠疫菌和假结核菌的抗血清不起凝集作用,而且与鼠疫反向试验的诊断液不发生凝集。三株菌抗血清与鼠疫间接血凝试验的诊断液不起凝集作用。结论153和271菌株属小肠结肠炎菌(生物Ⅰ型),而272菌株属中间型耶氏菌．它们与鼠疫菌和假结核菌无免疫原性交叉反应。     

鼠疫耶尔森菌基因组进化与生态位适应研究

目的 探索鼠疫耶尔森菌基因组进化的基本规律及其与该菌在自然界适应性演化之间的内在联系。方法 对36株鼠疫耶尔森菌和7株假结核耶尔森菌进行芯片比较基因组分析,鉴定差异区段(DFR),并对260株鼠疫耶尔森菌进行PCR验证,分析各DFR在这些鼠疫耶尔森菌中的分布,同时进行基因组岛分析。结果 在鼠疫耶尔森菌基因组中鉴定出22个DFR,基于DFR图谱,将鼠疫耶尔森菌中国分离株分成14个基因组型。鼠疫耶尔森菌共有21个基因组岛,其中18个已存在于假结核杆菌中,余下3个为鼠疫耶尔森菌独有。结论 探明了各基因组岛在鼠疫耶尔森菌和假结核耶尔森菌间的差异分布,探究了鼠疫耶尔森菌的起源进化;建立了鼠疫耶尔森菌基因组分型系统;建立了各基因组型别间的系统发育关系,初步揭示了鼠疫耶尔森菌基因组的进化规律及其与鼠疫耶尔森菌生态位适应和鼠疫疫源地扩展之间的关系,基本探明了鼠疫耶尔森菌在中国的演化规律。     

鼠疫耶尔森菌菌株91001的蛋白质组学初步研究

目的建立鼠疫耶尔森菌的蛋白质组学研究方法,获得鼠疫耶尔森菌的基本蛋白质组数据。方法以对人无致病能力的布氏田鼠疫源地菌株91001为研究对象,按照溶解性的不同分别收集菌体蛋白,以3种不同方法(Shotgun-LC-MS-MS,1D-LC-MS-MS和2D-MS)进行分析,将分析数据与基于91001菌株基因组全序列建立的蛋白质理论数据库进行比对,确定91001菌株本实验培养条件下所表达的蛋白组分。结果Shotgun-LC-MS-MS方法鉴定了971种蛋白,1D-LC-MS-MS鉴定了915种,而2D-MS方法则鉴定了233种蛋白质,三者合计为1193种蛋白质,占基因组预测CDS的28．7％(1193／4143)。结论不同的蛋白质组分析方法鉴定的蛋白质种类和数目都存在差异,为更全面地获得鼠疫耶尔森菌蛋白质组数据,有必要同时采取多种方法进行分析。