炭疽杆菌的研究进展

从生物学角度，就炭疽杆菌的生物学特点、抗原与毒素研究、实验诊断手段、疫苗及解毒剂的研究进展作简要综述。     

炭疽芽孢杆菌基因芯片探针的制备

目的制备炭疽芽孢杆菌(BA)基因芯片探针,应用于BA基因芯片的检测。方法采用PCR方法,以BA疫苗株A16R基因组DNA为模板,扩增pXO1质粒上的8个特异性片段,连接至pMD19-T Simple载体,构建分别包含8个探针序列的重组质粒,以其为PCR扩增模板获取探针DNA。结果基因测序证明,成功获得BA的3个探针。结论 BA基因探针的成功获取,为炭疽芽孢杆菌基因芯片的制备奠定了基础。     

在沙土中保存15年后的炭疽杆菌芽胞特征研究

在沙土中保存１５年后的炭疽杆菌芽孢特征研究中国预防医学科学院流行病学微生物学研究所（１０２２０６）梁旭东，马凤琴，俞东征炭疽杆菌芽孢具有在外环境中长期生存的能力，但这种能力的研究报告很少。为此，我们对新疆自治区喀什地区卫生防疫站１９８２年从５７１份不...     

炭疽杆菌芽胞染色法的改进

芽胞是某些细菌在一定条件下形成的特殊结构 ,不同种类的细菌其芽胞的形态、染色和位置等有较大差异 ,因此直接观察细菌的芽胞可作为鉴定细菌的方法之一。常用的芽胞染色方法很多 ,但这些常规方法用于炭疽杆菌芽胞染色 ,效果总是不很满意。我们通过用微波多次加热菌液 ,对炭疽杆菌芽胞常规染色方法进行了改进 ,取得了较好的效果。1　材料和方法1 .1　材料　 1石碳酸复红染液 :取碱性复红酒精饱和溶液 1 0ml,加 5 %石碳酸水溶液 90 ml。 2 95 %酒精 ;3美兰染液 :取2 %美兰酒精饱和溶液 3 0 ml,加 0 .0 1 %KONa水溶液 1 0 0 ml。4炭疽杆菌…     

炭疽杆菌芽孢污染的消除技术及其应用

在已知病原微生物中,炭疽杆菌芽孢对理化因子的抵抗力较高,在环境中存活时间极长.日常医疗卫生机构常用的消毒方法,如巴氏消毒、煮沸消毒、酒精消毒、碘伏消毒、苯扎溴铵消毒、来苏尔消毒等方法,均不能将其杀灭.在自然界的土壤中,炭疽杆菌芽孢可以存活30年以上.因此,必须采用灭菌的剂量或高水平的消毒措施,才能达到消除污染的目的.现就2001年在美国发生的炭疽恐怖事件之后,实际应用的污染消除手段,以及最新研发的污染消除技术介绍如下.     

炭疽芽孢杆菌特异性基因序列双重TaqMan聚合酶链反应快速检测体系的建立

目的 以炭疽芽孢杆菌的主基因和致病毒素基因pagA特异性序列为检测标志，建立高敏感、高特异的荧光双重实时TaqMan聚合酶链反应快速检测体系。方法 根据炭疽杆菌主基因组特异性序列（Gs）和特异的毒力岛pagA基因序列（Pag）设计引物及探针，通过构建目的质粒获得标准模板，利用TaqMan标记探针和便携式Smartcycle实时聚合酶链反应检测平台探讨该检测体系的检测敏感性和特异性。结果该体系炭疽芽孢杆菌的检测敏感度为10^2拷贝每反应体系，与其他蜡样杆菌群细菌未出现非特异性扩增，具有较高的特异性。整个反应在1h内完成，适合于实验室或野外环境下炭疽芽孢杆菌的快速检测。结论 本研究建立的双重TaqMan实时聚合酶链反应检测体系可作为炭疽芽孢杆菌快速、准确、特异、敏感的检测手段。     

一种快速定量检测炭疽杆菌方法的建立

目的：建立一种快速、准确、特异定量检测炭疽杆菌的方法。方法：根据复合探针荧光定量分析原理，以炭疽杆菌染色体rpoB基因为靶序列，设计合成引物和探针，对炭疽杆菌进行实时定量聚合酶链反应（PCR）检测，并探讨荧光探针与淬灭探针用量及比例、镁子浓度、淬灭探针长度对定量结果的影响。结果：本法最适条件：荧光探针浓度300mmol/L、荧光探针与淬灭探针的比例为1／2，镁离子浓度为3mmol/L，淬灭探针长15个核苷酸，该法检测炭疽杆菌的灵敏度达10^3拷贝，能特异区分炭疽杆菌与其他蜡样杆菌。结论：复合探针荧光定量PCR技术能够快速准确、特异、敏感地对炭疽杆菌进行定量分析，可为临床诊断提供帮助。     

一起蜡样芽孢杆菌食物中毒的调查分析

2008年9月云南省玉溪市华宁县青龙镇一所学校发生一起由蜡样芽孢杆菌污染豆豉引起的食物中毒。进食可疑食物豆豉的31人,发病26例,罹患率为83.87%(26/31)。     

一起由蜡样芽孢杆菌污染引起食物中毒的分析

2005年7月29日，中卫市某凉皮店发生一起食物中毒事件，经过流行病学调查及实验室病原学检验，证明该起食物中毒是由蜡样芽孢杆菌污染引起的，现将调查分析结果报告如下：     

一起蜡样芽孢杆菌所致食物中毒的调查分析

目的查明食物中毒原因,及时采取应急措施,杜绝类似事件发生。方法制定统一调查表,对患者逐一调查,随机抽取部分病例和对照进行病例对照研究,分析可疑食物,采集患者呕吐物和可疑食物(豆豉)进行致病菌检测。结果此次食物中毒罹患率39.58%(95/240),潜伏期中位数1.67h,病例对照研究结果食用豆豉者与未食用者发病差异有统计学意义(P<0.01),食用豆豉者发病较高,患者呕吐物中检出蜡样芽孢杆菌,剩余豆豉中蜡样芽孢杆菌超标。结论该起食物中毒由蜡样芽孢杆菌污染豆豉引起,推测该批豆豉在生产过程中被蜡样芽孢杆菌污染。     

蜡样芽胞杆菌快速检测及其毒力基因筛选

目的筛选蜡样芽胞杆菌鉴定基因和快速检测毒力基因。方法选择分离自食品和土壤的代表性蜡样芽胞杆菌共329株,聚合酶链式反应（PCR）方法检测gyrB和groEL基因的种特异性,检测毒力基因在菌株中的分布特征。 基于检测结果,用多重PCR检测方案快速检测蜡样芽胞杆菌鉴定基因及其毒力因子。结果在蜡样芽胞杆菌及其近缘芽胞杆菌中,除1株苏云金芽胞杆菌扩增阳性外,gyrB基因具有蜡样芽胞杆菌种特异性;而groEL基因在4种芽胞杆菌中均有扩增。 6种毒力基因nheA、entFM、bceT、hblC、cytK和ces的携带率分别为84.19%、79.64%、49.24%、47.72%、47.11%和1.52%。 选择nheA、hblC、entFM、ces、cytK和gyrB用于快速鉴定蜡样芽胞杆菌及其毒力基因,获得了双重PCR扩增体系（gyrB和cytK）与4重PCR扩增体系（nheA、hblC、entFM和ces）的最佳检测方案。结论筛选的蜡样芽胞杆菌鉴定基因和毒力基因能够全面、特异、简便、高效地检测蜡样芽胞杆菌,可为食品安全检测及快速诊断提供依据,在实际检验工作中具有良好的应用前景。     

The small acid soluble proteins (SASP α and SASP β) of Bacillus weihenstephanensis and Bacillus mycoides group 2 are the most distinct among the Bacillus cereus group

The Bacillus cereus group includes Bacillus anthracis, B. cereus, Bacillus thuringiensis, Bacillus mycoides and Bacillus weihenstephanensis. The small acid soluble spore protein (SASP) β has been previously demonstrated to be among the biomarkers differentiating B. anthracis and B. cereus; SASP β of B. cereus most commonly exhibits one or two amino acid substitutions when compared to B. anthracis. SASP α is conserved in sequence among these two species. Neither SASP α nor β for B. thuringiensis, B. mycoides and B. weihenstephanensis have been previously characterized as taxonomic discriminators. In the current work molecular weight (MW) variation of these SASPs were determined by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for representative strains of the 5 species within the B. cereus group. The measured MWs also correlate with calculated MWs of translated amino acid sequences generated from whole genome sequencing projects. SASP α and β demonstrated consistent MW among B. cereus, B. thuringiensis, and B. mycoides strains (group 1). However B. mycoides (group 2) and B. weihenstephanensis SASP α and β were quite distinct making them unique among the B. cereus group. Limited sequence changes were observed in SASP α (at most 3 substitutions and 2 deletions) indicating it is a more conserved protein than SASP β (up to 6 substitutions and a deletion). Another even more conserved SASP, SASP α–β type, was described here for the first time.     

Lymphocytic vasculitis associated with the anthrax vaccine: case report and review of anthrax vaccination

Anthrax is caused by the spore-forming bacteria Bacillus anthracis. It occurs naturally, but recently has been manufactured as a biological warfare agent. This makes prophylaxis for anthrax an urgent concern and efforts are ongoing for the production of an efficient and safe vaccine. Side effects to the current anthrax vaccine are usually minor and mainly consist of local skin reactions. Occasionally an unusual complication may occur; a case of a patient with lymphocytic vasculitis temporally associated with the anthrax vaccine is reported.     

艰难拟梭菌重命名及相关致病因子研究进展

基于表型特征、化学分类学及系统发育学等研究,艰难梭菌已被归入拟梭菌属,并重命名为艰难拟梭菌.近年来,随着多重耐药艰难拟梭菌不断出现,导致抗生素治疗失效以及感染复发病例明显上升.目前欧美部分国家已建立完善的艰难拟梭菌感染监控体系及相应的临床诊疗指南,但我国相关工作起步较晚.同时,我国仍存在抗生素使用不规范甚至滥用等现象,...     

高毒力肺炎克雷伯菌毒力和耐药机制研究进展

肺炎克雷伯菌属于克雷伯菌属中需氧革兰阴性杆菌,是社区获得性感染和院内感染常见致病菌之一。 高毒力肺炎克雷伯菌（hypervirulent Klebsiella pneumoniae, hvKP）是从传统肺炎克雷伯菌中分离出来的具有高毒力、高黏液性的侵袭性细菌,当机体免疫功能降低时,可引起肺炎、肝脓肿、泌尿系统感染和血流感染,严重时还可导致脓毒血症等危急重症,治疗难度大且病死率高。 为更好地了解hvKP特性,对其流行现状、高毒力相关因子、耐药以及相关机制等进行综述,以助于临床更好地预防和控制 hvKP感染。     

Fulminant septicemia of Bacillus cereus resistant to carbapenem in a patient with biphenotypic acute leukemia

We report a case of fulminant septicemia with Bacillus cereus resistant to carbapenem. A 33-year-old man was suffering from febrile neutropenia (FN) on day 15 after the start of remission-induction therapy for biphenotypic acute leukemia under gut decontamination with polymyxin B and nystatin. Meropenem, a carbapenem, was administered according to the guideline for FN. Two days later (on day 17), he complained of severe abdominal pain, lost consciousness, went into sudden cardiopulmonary arrest, and died. Autopsy showed multiple spots of hemorrhage and necrosis caused by bacterial plaque in the brain, lungs, and liver. B. cereus was isolated from a blood sample obtained in the morning on day 17 and it was after his death that the isolated B. cereus was revealed to be resistant to carbapenem. B. cereus obtained from blood samples has been reported to be usually sensitive to carbapenem and also to vancomycin, new quinolones, and clindamycin. If B. cereus resistant to carbapem increases, our method of gut decontamination with polymyxin B and nystatin may have to be changed to one containing a new quinolone for the prevention of septicemia. Careful watching to determine whether B. cereus resistant to carbapem increases may be also important for empiric therapy, because carbapenem is often selected as the initial therapy for FN in patients with severe neutropenia.     

炭疽高发地区土壤样本中常见芽胞杆菌的分离及鉴定

目的 通过分离鉴定炭疽可疑污染土壤样本的芽胞杆菌,评价消毒效果和了解监测地区土壤中的芽胞杆菌分布情况。 方法 采集炭疽监测点土壤样本60份,对炭疽芽胞杆菌和其他芽胞杆菌进行分离培养和聚合酶链反应扩增鉴定。 结果 在可疑污染土壤样本中未分离到炭疽芽胞杆菌;从分离到的48个单克隆菌落中扩增到33个目的片段,经测序和blast比对,确定得到地衣芽胞杆菌13株,枯草芽胞杆菌8株,短小芽胞杆菌扩增11株,蜡样芽胞杆菌扩增到1株,巨大芽胞杆菌引物和环状芽胞杆菌引物特异性不好。 结论 本研究提示该监测点炭疽疫情消毒效果可信,但需要进一步研究验证;几种芽胞杆菌在土壤中广泛存在,在炭疽监测工作中进行病原体分离时需要加以鉴别,可通过特异基因扩增来辅助检验。     

Sensitivity and specificity of the suspected blood identification system in video capsule enteroscopy

BACKGROUND AND STUDY AIMS: Capsule enteroscopy has become a standard tool for the evaluation of obscure gastrointestinal bleeding. Reviewing the video recordings of capsule examinations is time-consuming and requires prolonged attention. Recently, software that can recognize the frames containing "red spots", the Suspected Blood Identification system (SBIS), has been developed with the aim of assisting in the analysis of video recordings. We assessed the sensitivity and specificity of the SBIS in patients undergoing capsule enteroscopy. PATIENTS AND METHODS: 100 consecutive patients underwent capsule enteroscopy at our tertiary referral center, for the following indications: obscure gastrointestinal bleeding (75 patients), metastatic carcinoid (7 patients) known or suspected Crohn's disease (5 patients), miscellaneous (13 patients). Capsule endoscopy was carried out by the standard method. Four gastroenterologists, experienced in capsule endoscopy, reviewed the recordings. RESULTS: Small-bowel visualization was obtained in 95 cases. The physicians identified 209 "red spots", 54 of which (25.8%) were also identified by the SBIS. The overall sensitivity, specificity, and positive and negative predictive values of the SBIS, calculated on the number of true-positive, true-negative, false-positive and false-negative results, were 40.9%, 70.7%, 69.2% and 42.6%, respectively. Sensitivity was higher for the identification of red blood (60.9%) than for nonbleeding "red" lesions such as arteriovenous malformations (25.8%). CONCLUSIONS: The SBIS has low sensitivity and specificity. It can be used as a complementary and rapid screening tool, but complete review of the recordings is still necessary.     

百日咳杆菌百日咳毒素基因遗传变异分析

目的 了解百日咳毒素(pt)基因启动子区及不同亚基编码区遗传变异特点及进化规律,为分子流行病学监控和疫苗研究提供参考依据.方法 从GenBank数据库中下载已公开发表的百日咳菌株pt基因启动子区序列及S1～S5亚基编码序列,利用PhyML 3.0软件构建系统发育树,确定进化簇;利用MEGA 7.0软件计算遗传距离;通过...     

Bench-to-bedside review: Understanding the impact of resistance and virulence factors on methicillin-resistant Staphylococcus aureus infections in the intensive care unit

Methicillin-resistant Staphylococcus aureus (MRSA) displays a remarkable array of resistance and virulence factors, which have contributed to its prominent role in infections of the critically ill. We are beginning to understand the function and regulation of some of these factors and efforts are ongoing to better characterize the complex interplay between the microorganism and host response. It is important that clinicians recognize the changing resistance patterns and epidemiology of Staphylococcus spp., as these factors may impact patient outcomes. Community-associated MRSA clones have emerged as an increasingly important subset of Staphyloccocus aureus and MRSA can no longer be considered as solely a nosocomial pathogen. When initiating empiric antibiotics, it is of vital importance that this therapy be timely and appropriate, as delays in treatment are associated with adverse outcomes. Although vancomycin has long been considered a first-line therapy for serious MRSA infections, multiple concerns with this agent have opened the door for existing and investigational agents demonstrating efficacy in this role.