鳗鲡创伤弧菌的分子鉴定

目的对分离自发病欧洲鳗鲡的创伤弧菌疑似菌株进行准确的鉴定。方法首先尝试利用一对16SrRNA基因特异性通用引物PCR扩增一株鳗源创伤弧菌疑似株的基因组DNA，得到一个约500bp的DNA片段，将该DNA片段亚克隆至pMDl8-T载体，鉴定克隆化成功之后，送专业公司进行测序，得到一个502bp的DNA产物，NCBI上同源性比较表明，该片段与GeneBank上注册的创伤弧菌的16SrDNA序列同源性最高（100％），同时排除了哈维氏弧菌的可能。设计一对创伤弧菌溶血素特异性引物，实现了对鳗鲡创伤弧菌的分子鉴定。结果建立一种简洁的鳗鲡创伤弧菌的分子鉴定方法。结论国内首次自发病欧鳗分离到创伤弧菌，并给出分子鉴定证据。     

Quorum sensing in Vibrio spp.: the complexity of multiple signalling molecules in marine and aquatic environments

Abstract

Quorum sensing (QS) is a density-dependent mechanism enabling bacteria to coordinate their actions via the release of small diffusible molecules named autoinducers (AIs). Vibrio spp. are able to adapt to changing environmental conditions by using a wide range of physiological mechanisms and many species pose a threat for human health and diverse marine and estuarine ecosystems worldwide. Cell-to-cell communication controls many of their vital functions such as niche colonization, survival strategies, or virulence. In this review, I summarize (1) the different known QS pathways (2) the diversity of AIs as well as their biological functions, and (3) the QS-mediated interactions between Vibrio and other organisms. However, the current knowledge is limited to a few pathogenic or bioluminescent species and in order to provide a genus-wide view an inventory of QS genes among 87 Vibrio species has been made. The large diversity of signal molecules and their differential effects on a particular physiological function suggest that the complexity of multiple signalling systems within bacterial communities is far from being fully understood. I question here the real level of specificity of such communication in the environment and discuss the different perspectives in order to better apprehend QS in natural habitats.     

1854年的伦敦霍乱与传染病学之父——约翰·斯诺

19世纪初至20世纪末,霍乱4次出现于英国,传播速度快,患者死亡率高。1854年,约翰·斯诺(John Snow)首次发现霍乱在人体内繁殖并通过受污染的水传播。在其霍乱研究进程中,他将霍乱病例放置在地理网格上以及根据家庭供水来源比较霍乱发病率,这方面的独创性构成了传染病学方法发展的突破性创新。毫无疑问,斯诺为现代传染性疾病的微生物理论做出了重要贡献。本文将具体阐述1854年的伦敦霍乱发展进程以及传染病学之父斯诺对于传染病学建立的重要影响,并对霍乱弧菌的生态循环和致病机制进行阐述。     

基于上转发光免疫层析技术的常见食源性致病菌快速检测方法研究与评价

目的：研制针对4种常见食源性致病菌：甲型副伤寒沙门菌（ Salmonella paratyphi A）、乙型副伤寒沙门菌（Salmonella paratyphi B）、大肠埃希菌O157∶H7（Escherichia coli O157∶H7）、副溶血弧菌（Vibrio parahaemolyticus）的基于上转发光免疫层析技术（ UPT－LF）的快速定量检测试纸,并对其检测性能进行评价。方法以上转发光纳米颗粒（ UCP－NPs）作为示踪物,基于双抗体夹心检测模型,研制针对上述4种靶标菌的UPT－LF试纸;以4种靶标菌的系列浓度标准菌悬液作为标准样品,评价试纸的敏感性、特异性、线性和精密性,并进行模拟染菌食品的检测,评价模拟样品阳性检出率。结果针对4种靶标菌的UPT－LF试纸均具有良好的线性,相关系数r为0．985～0．996;检测敏感性达105～106 CFU／ml,与其他近缘菌株无交叉反应;对乳制品、饮料、小食品、水产、肉类等细菌污染的食品检出率较高。结论该研究建立的对4种常见食源性致病菌进行快速检测的UPT－LF,简便快速,具有良好的敏感性、特异性和线性定量能力,操作性能可满足食品安全检测的要求。     

副溶血性弧菌病原学和分子流行病学流行特征研究进展

副溶血性弧菌是导致我国细菌性食物中毒事件的首要原因.临床分离株和环境分离株的病原学特征有着明显的差异.临床分离株以O3:K6血清型为主,tdh和(或)trh基因携带率较高,一般在80%以上,脉冲场凝胶电泳(PFGE)基因图谱具有明显的优势图谱,并且与血清分型具有一致性.而环境分离株(包括食品)多无优势血清型和优势PFGE图谱,tdh和(或)trh基因携带率远低于临床分离株,多在6%以下.各地临床分离株的耐药性差异较大,但对氨苄西林等早期药物耐药率均较高.环境分离株较临床分离株的耐药性更为严重和复杂.     

Vaccines against gastroenteritis,current progress and challenges

ABSTRACT

Enteric viral and bacterial infections continue to be a leading cause of mortality and morbidity in young children in low-income and middle-income countries, the elderly, and immunocompromised individuals. Vaccines are considered an effective and practical preventive approach against the predominantly fecal-to-oral transmitted gastroenteritis particularly in the resource-limited countries or regions where implementation of sanitation systems and supply of safe drinking water are not quickly achievable. While vaccines are available for a few enteric pathogens including rotavirus and cholera, there are no vaccines licensed for many other enteric viral and bacterial pathogens. Challenges in enteric vaccine development include immunological heterogeneity among pathogen strains or isolates, a lack of animal challenge models to evaluate vaccine candidacy, undefined host immune correlates to protection, and a low protective efficacy among young children in endemic regions. In this article, we briefly updated the progress and challenges in vaccines and vaccine development for the leading enteric viral and bacterial pathogens including rotavirus, human calicivirus, Shigella, enterotoxigenic Escherichia coli (ETEC), cholera, nontyphoidal Salmonella, and Campylobacter, and introduced a novel epitope- and structure-based vaccinology platform known as MEFA (multiepitope fusion antigen) and the application of MEFA for developing broadly protective multivalent vaccines against heterogenous pathogens.     

一起副溶血性弧菌食物中毒的病原学分析

目的运用脉冲场凝胶电泳(PFGE)对一起食物中毒中分离的菌株进行同源性分析,为查明原因和溯源提供依据。方法采集患者、食品从业人员、环境样本以及留样食品进行分离、鉴定,对分离的菌株进行PFGE分析。结果本次事件共采集137份样本,检出11株副溶血性弧菌,其中5株来自病人样本,3株来自冷菜间厨师样本,1株来源于生扇贝样本,2株分别来自龙虾池、桂鱼池养殖水。11株菌株经PFGE分析,除1株患者样本与其余10株的同源性为60.0%外,其余10株副溶血性弧菌的同源性为100.0%。结论 PFGE分型技术揭示菌株之间的流行病学联系,为事件的分析和追溯来源提供分子流行病学证据。