2023年贵州省六盘水市部分地区蜱传立克次体调查

目的 了解贵州省六盘水市部分地区蜱携带立克次体感染率,为当地蜱传立克次体病防控工作提供参考依据。方法 2023年4—6月在贵州省六盘水市盘州市大山镇高兴村捕捉牛、羊体表寄生蜱,采用形态学和分子生物学方法对蜱种进行鉴定。采用巢式PCR法检测蜱携带的立克次体,包括斑点热群立克次体、柯克斯体属、无形体属、埃立克体属和东方体属,扩增的阳性片段测序后与Gen Bank已知序列进行同源性比对。结果 共采集200只蜱,经鉴定均为微小扇头蜱。巢式PCR联合测序鉴定出蜱携带敬信立克次体暂定种(40.50%)、贝氏柯克斯体(1.50%)和柯克斯体共生菌(27.00%),未检测出无形体、埃立克体及东方体。结论 贵州省六盘水市部分地区微小扇头蜱携带敬信立克次体暂定种、贝氏柯克斯体和柯克斯体共生菌;当地有关部门需加强家畜和人群蜱传立克次体感染监测,减少蜱传立克次体病危害。

南京某医院中青年体检人群高血压前期和高血压病流行现状及其危险因素分析

目的通过分析中青年群体高血压前期和高血压病的患病现状及可能危险因素,为相应疾病防控提供研究依据。方法选取南京鼓楼医院体检中心2009—2016年的中青年(18~44岁为青年,45~59岁为中年)体检人群作为研究对象,通过分析该人群的体检资料,探讨高血压前期[收缩压120~139 mmHg(1 mmHg=0.133 kPa)和/或舒张压80~89 mmHg]和高血压病的流行现状及其危险因素。结果调查总人群为142857例,高血压前期患者有64220例,高血压患者有3912例,高血压总患病率为9.74%,男性为12.51%,女性为5.82%。高血压前期总患病率为44.95%,男性为53.31%,女性为33.15%。中年组中,高血压前期患病率为51.68%,高血压病患病率为15.13%,而这两个指标在青年组分别为37.95%和4.13%。2013—2016年高血压前期和高血压病患病率分别为45.37%和10.65%,均高于2009—2012年的44.52%和8.78%。此外,中青年体检人群中高血压前期组合并血糖、血脂、糖脂代谢异常的检出率均高于正常血压组,低于高血压组(P<0.001)。多因素分析显示,年龄、超重/肥胖、高血糖、高甘油三酯血症及高胆固醇血症与男性高血压前期密切相关,而年龄、超重/肥胖、高血糖、高甘油三酯血症、高胆固醇血症及高低密度胆固醇血症与男性高血压病和女性高血压前期及高血压病密切相关。结论中年、超重/肥胖、高血糖、高甘油三酯血症及高胆固醇血症均为中青年男性和女性体检人群高血压前期和高血压患病的可能危险因素,需要强化对上述因素的干预。

Protein array of Coxiella burnetii probed with Q fever sera

Coxiella burnetii is the etiological agent of Q fever.To identify its major seroreactive proteins,a subgenomic protein array was developed.A total of 101 assumed virulence-associated recombinant proteins of C.burnetii were probed with sera from mice experimentally infected with C.burnetii and sera from Q fever patients.Sixteen proteins were recognized as major seroreactive antigens by the mouse sera.Seven of these 16 proteins reacted positively with at least 45% of Q fever patient sera.Notably,HspB had the highest fluorescence intensity value and positive frequency of all the proteins on the array when probed with both Q fever patient sera and mouse sera.These results suggest that these seven major seroreactive proteins,particularly HspB,are potential serodiagnostic and subunit vaccine antigens of Q fever.

Protective immunity against Rickettsia heilongjiangensis in a C3H/HeN mouse model mediated by outer membrane protein B-pulsed dendritic cells

Rickettsia heilongjiangensis is an obligate intracellular bacterium that causes Far-Eastern tick-borne spotted fever. Outer membrane protein B(Omp B) is an important surface protein antigen of rickettsiae. In the present study, the omp B gene of R. heilongjiangensis was divided into four fragments, resulting in four recombinant proteins(OmpB-p1, Omp B-p2, Omp B-p3, and Omp B-p4). Each Omp B was used in vitro to stimulate murine bone marrow-derived dendritic cells(BMDCs) of C3H/He N mice, and the Omp B-pulsed BMDCs were transferred to naive C3H/He N mice. On day 14 post-transfer of BMDCs, the mice were challenged with R. heilongjiangensis and the rickettsial loads in the mice were quantitatively determined on day 7 post-challenge. Mice receiving BMDCs pulsed with Omp B-p2, Omp B-p3, or Omp B-p4 exhibited significantly lower bacterial load compared with mice receiving Omp B-p1-pulsed BMDCs. CD4+ and CD8+ T cells isolated from the spleen of C3H/He N mice receiving BMDCs pulsed with each OmpB were co-cultured with BMDCs pulsed with the respective cognate protein. In flow cytometric analysis, the expression level of CD69 on CD4+ or CD8+ T cells from mice receiving BMDCs pulsed with Omp B-p2, OmpB-p3, or Omp B-p4 was higher than that on cells from mice receiving Omp B-p1-pulsed BMDCs, while the expression level of tumor necrosis factor(TNF)-α on CD8+ T cells and interferon(IFN)-γ on the CD4+ and CD8+ T cells from mice receiving Omp B-p2,-p3, or-p4 was significantly higher than on cells from mice receiving Omp B-p1-pulsed BMDCs. Our results suggest that the protective Omp Bs could activate CD4+ and CD8+ T cells and drive their differentiation toward CD4+ Th1 and CD8+ Tcl cells, respectively, which produce greater amounts of TNF-α and, in particular, IFN-γ, to enhance rickettsicidal activity of host cells.

siRNA下调20S蛋白酶体β5亚基抑制立氏立克次体细胞内增殖

【目的】探究宿主20S蛋白酶体β5亚基(proteasome 20S subunit beta 5,PSMB5)对革兰氏阴性专性胞内寄生菌立氏立克次体胞内生长繁殖的影响。【方法】利用小干扰RNA转染Vero和THP-1宿主细胞,设置未转染细胞为空白对照组、无义小干扰RNA转染组为阴性对照组、PSMB5特异性小干扰RNA转染组为实验组,采用SYBR定量PCR和蛋白印迹法评价宿主细胞PSMB5变化水平;随后利用立氏立克次体以感染复数为0.1感染转染后细胞系,采用光镜观察、荧光显微镜观察和PCR定量方法检测细菌胞内繁殖变化水平。【结果】与si-NC阴性对照和空白对照相比,si-PSMB5能够显著降低宿主细胞PSMB5 mRNA转录水平和蛋白表水平;在随后立氏立克次体感染过程中,能够降低立氏立克次体的胞内细菌载量。【结论】下调宿主PSMB5基因表达能够抑制立氏立克次体胞内生长繁殖。