鼠疫菌、副溶血性弧菌及肺炎克雷伯菌CRP蛋白的表达及其DNA结合活性分析

目的表达有活性的鼠疫耶尔森菌（鼠疫菌）、副溶血性弧菌以及肺炎克雷伯菌的cAMP受体蛋白（CRP）并进行DNA体外结合活性分析,为深入研究3种CRP蛋白间的交互转录调控作用奠定基础。方法应用大肠埃希菌pET系统体外表达鼠疫菌201株、副溶血性弧菌5421株以及肺炎克雷伯菌tw518株的CRP蛋白;应用生物信息学对3种CRP蛋白进行同源性比较,并对CRP与靶DNA的结合基序（CRP consensus）进行分析预测;通过体外凝胶阻滞实验（EMSA）和DNaseⅠ足迹实验验证His？CRP与DNA的结合活性。结果成功表达出3种菌有活性的His？CRP融合蛋白,3种CRP蛋白对鼠疫菌pla、副溶血性弧菌toxR及肺炎克雷伯菌kfuA基因均有结合活性。结论 3种CRP蛋白都能直接结合到鼠疫菌pla、副溶血性弧菌toxR及肺炎克雷伯菌kfuA基因的启动子区,说明上述3种CRP蛋白对3种病原菌的重要毒力基因的转录可能具有交互调控作用。     

Y型嗅觉仪在蚤类对宿主选择性研究中的应用

目的应用Y型嗅觉仪,建立蚤类对宿主动物气味选择的测定方法,并研究猫栉首蚤、印鼠客蚤和缓慢细蚤对大白鼠和小白鼠的选择行为,为探究不同蚤种对不同宿主动物的特异性选择和了解＂蚤类-宿主动物或人-相关传染病＂的关系提供理论依据。方法以印鼠客蚤为试虫,用Y型嗅觉仪测定风速、Y型管臂管的几何位置、光照对其选择行为的影响,以猫栉首蚤、印鼠客蚤和缓慢细蚤成蚤为试虫分别测定对大白鼠和小白鼠的选择行为。结果在测定的20min内,当空气流速为0.6～1.5L/min时,Y型管臂管的几何位置和测定环境的光照（30W日光灯）与黑暗在印鼠客蚤对小白鼠的选择行为中没有显著影响。猫栉首蚤对大白鼠气味具有显著的选择性,而印鼠客蚤和缓慢细蚤对大白鼠和小白鼠气味的选择性差异无统计学意义。结论可以用Y型嗅觉仪测定蚤类对宿主动物的选择行为。通过研究蚤的选择行为可以了解其宿主特异性,进一步分析＂蚤类-宿主动物或人-相关传染病＂的相关关系。     

青海省海东地区鼠类种群特征的调查研究

目的研究青海省海东地区鼠类种群特征。方法采用夹夜法,按不同生境调查海东地区鼠类,对生态学资料进行数据分析。结果在海东地区共捕获鼠类427只,隶属2目6科15种,其中在针阔混交林捕获鼠类7种82只,捕获率3.90%;林缘灌丛捕获鼠类6种112只,捕获率4.53%;高山灌丛捕获鼠类7种77只,捕获率3.35%;高山草原捕获鼠类7种95只,捕获率2.94%;农田居民区捕获鼠类9种61只,捕获率2.60%;高山草原中的生物量最高,为35.95;林缘灌丛次之,为34.70;高山灌丛最低,为21.59;小家鼠及褐家鼠的肥满度在农田居民区中最高,为5.18和4.05;长尾仓鼠在高山草原中的肥满度最高,为3.80;大林姬鼠在林缘灌丛中的肥满度最高,为2.97。同一鼠种在不同生境中的生物量、肥满度各有其特点和差异。结论青海省海东地区鼠类区系构成较为混杂,降低优势害鼠的种群密度,防止鼠害发生是今后工作的重点。     

广东省2006-2011年登革热时空分布特征

目的分析2006-2011年广东省登革热的时空分布特征,为登革热防控提供科学依据。方法计算2006-2011年广东省登革热县（区）级年发病率水平,利用空间自相关分析确定登革热高风险地区。结果广东省珠江三角洲和韩江三角洲登革热发病率分别为〉4/10万和〉2.5/10万,Moran’sⅠ统计量在2006-2007年（P=0.005）和2009-2011年（P=0.001）有统计学意义,2007-2008年无统计学意义（P=0.814）。结论广东省登革热分布是非随机的,珠江三角洲和韩江三角洲是登革热的高危地区。     

福氏志贺菌O-抗原修饰及血清型转换机制研究进展

该项研究结果说明采用血清型转换噬菌体位点特异性整合系统修饰O-抗原血清型的方法, 可以有效介导外源基因进入细菌染色体的特异性位点, 而不会干扰宿主菌中任何重要基因的表达, 对疫苗的研究具有重要意义。     

Pharmacology on microfluidics: multimodal analysis for studying cell–cell interaction

1. Download : Download high-res image (150KB)
2. Download : Download full-size image

     

Evaluation of large genotypic Mycobacterium tuberculosis clusters: contributions from remote and recent transmission

Tuberculosis genotypic clustering is used as a proxy for recent transmission. The association between clustering and recent transmission becomes problematic when the genotyping method lacks specificity in defining a cluster, as well as for clusters with extensive jurisdictional histories and/or common genotypes.We investigated the four largest spoligotype/12 loci MIRU-VNTR-defined clusters in Harris County, Texas from 2006–2012 to determine their historical contribution to tuberculosis morbidity, estimate the contributions from recent and remote transmission, and determine the impact of secondary genotyping on cluster definition. The clusters contained 189, 64, 51 and 38 cases. Each cluster was linked to cluster(s) previously identified by Houston Tuberculosis Initiative; 3 since 1995 and the fourth in 2002. Among cases for which timing of Mycobacterium tuberculosis transmission relative to tuberculosis disease could be ascertained, nearly equal proportions were associated with recent and remote transmission. The extent to which genotyping with an additional 12 MIRU-VNTR loci modified the cluster definition varied from little or no impact for the two smaller clusters to moderate impact for the larger clusters.Tuberculosis control measures to reduce morbidity associated with large clusters must involve strategies to identify and treat individuals who recently acquired infection, as well as persons infected for years.     

Characterization of Class 1 Integron Gene Cassettes among Clinical Bacteria Isolated from One Large Hospital in Northern China

The class 1 integron and complex gene cassettes among different species of clinical isolates in northern China were characterized in this study. 383 clinical isolates were obtained from northern China, and class 1 integrons containing gene cassettes widely distributed among gram negative clinical isolates was observed. We find that the class 1 integron showed positive correlation with multidrug resistance phenotype of gram negative bacteria. In addition, we find that isolates belonged to one species harbored different types of gene cassette arrays, while same types of gene cassette arrays were observed in different species of isolates. The diversity of gene cassette arrays among the isolates indicated the complexity of multidrug resistance in clinical isolates in northern China.     

肠出血性大肠埃希菌O157 ∶ H7质粒 pO157 上毒力因子的研究进展

肠出血性大肠埃希菌O157 ∶ H7是一种重要的致病菌,可以引起不同程度人类疾病。目前已知的O157 ∶ H7的致病因子有3个,志贺毒素、粘附抹平效应毒力岛和特异性质粒pO157。其中pO157在致病过程中的作用并不十分清楚。本文结合近年来的研究进展,介绍了pO157上与细菌致病性有关的毒力因子。     

Serological investigation of vector-borne disease in dogs from rural areas of China

Objective

To evaluate the Anaplasma phagocytophilum (A. phagocytophilum), Ehrlichia canis (E. canis), Dirofilaria immitis (D. immitis) (canine heartworm), Borrelia burgdorferi (B. burgdorferi) infections in countryside dogs from Yunnan, Hainan and Anhui provinces.

Methods

Serum samples were collected from 26 dogs in Yunnan, Hainan and Anhui provinces. The samples were tested using a commercial ELISA rapid diagnostic assay kit (SNAP^® 4Dx^®; IDEXX Laboratories, Inc. U.S.A.). Meanwhile, indirect immunofluorescence assay (IFA) recommended by WHO was conducted to detect IgG to A. phagocytophilum. Two methods were analyzed and compared.

Results

The number of serologically positive dogs for IgG to A. phagocytophilum was only 2 which was from Hainan province and none of the 26 dogs responded positive for E. canis, D. immitis (canine heartworm), and B. burgdorferi by ELISA rapid diagnostic method. The number of serologically positive dogs for IgG to A. phagocytophilum was 13 (50%) by IFA method. Data of the two methods were analyzed by statistical software and the difference was statistically significant (P=0.002).

Conclusions

It can be concluded that IFA method was more sensitive than ELISA rapid diagnostic method. However, we need conduct further and intensive epidemiology survey on tick-born diseases pathogens including A. phagocytophilum, E. canis, D. immitis (canine heartworm), and B. burgdorferi which have public health significance.