PCR法直接检测鲜乳中金黄色葡萄球菌肠毒素A的研究

目的建立一种快速敏感检测鲜乳中金黄色葡萄球菌肠毒素A的方法。方法将金黄色葡萄球菌模拟污染鲜乳后,提取菌体DNA,以大肠杆菌作对照,用双重PCR法扩增金黄色葡萄球菌耐热核酸酶基因和肠毒素A基因。结果在含金黄色葡萄球菌(1×104个/ml)的模拟鲜乳样品中检出金黄色葡萄球菌耐热核酸酶基因和肠毒素A基因,而大肠杆菌对照未出现特异性片段;PCR方法灵敏度分析显示,其检测限为100 cfu/ml。结论建立的直接检测金黄色葡萄球菌耐热核酸酶基因和肠毒素A基因的双重PCR方法,具有速度快、特异性强、灵敏度高和易操作的特性,可用于金黄色葡萄球菌食源性疾病与食物中毒的实验室诊断。     

金黄色葡萄球菌肠毒素A、B、C、E快速分型检测

目的建立能在同一PCR反应条件下同时检测SEA、SEB、SEC、SEE的PCR快速检测方法,以用于金黄色葡萄球菌引起的食源性疾病的快速诊断。方法根据Gen Bank公布的SEA、SEB、SEC、SEE基因的保守序列,利用Vector NTI suite 8软件设计SEA/SEE、SEB/SEC通用PCR引物来特异性扩增相应的基因片段,通过优化反应条件,建立在同一PCR反应条件下同时检测SEs各型的PCR检测方法,同时进行常见食源性致病菌的特异性分析及灵敏度分析,扩增产物进行测序鉴定。结果金黄色葡萄球菌肠毒素SEA、SEE引物扩增后电泳片段位于目的片段330 bp处,SEB、SEC片段位于目的片段258 bp处,SEA、SEB、SEC和SEE基因PCR产物的电泳片段位于目的片段的579、602、601和125 bp处,结果均显示引物扩增和PCR扩增产物均有预期大小的目的 DNA片段。本方法中的基因引物的PCR扩增金黄色葡萄球菌、肠炎沙门菌、鼠伤寒沙门菌、伤寒沙门菌、痢疾志贺菌、大肠杆菌O157:H 7、副溶血性弧菌、奇异变形杆菌、福氏志贺菌、肠毒素型大肠埃希菌、肠侵袭型大肠埃希菌、肠致病型大肠埃希菌、肠出血型大肠埃希菌均未出现预期大小的目的条带。本方法敏感性达80~100 CFU/m L。结论本检测方法所建立的PCR可用于金黄色葡萄球菌肠毒素A、B、C、E型别食物中毒的快速诊断和分型检测。     

食物中毒和食品中金黄色葡萄球菌肠毒素基因分型研究

目的对食物中毒及食品样品中金黄色葡萄球菌进行肠毒素基因分型,比较两种分离株肠毒素基因分布及分型差异。方法用PCR法测定金黄色葡萄球菌肠毒素基因(SEA-SEJ)。结果 129株食品分离株中75株检出肠毒素基因(58.14%),78株食物中毒分离株中73株检出肠毒素基因(93.59%),食物中毒分离株肠毒素基因检出率明显高于食品分离株(P0.01),食品分离株中主要流行肠毒素基因为SEI(21.71%),食物中毒分离株中主要流行肠毒素基因为SEA(41.03%)。结论金黄色葡萄球菌食物中毒和食品分离株肠毒素基因的分型和分布上存在差异。     

单核细胞增生李斯特氏菌快速检测方法建立

[目的]建立单核细胞增生性李斯特氏菌(Lm)快速检测(PCR)方法.[方法]用PCR特异性检测方法,根据Lm的inlA、 plcA、 plcB、 hlyA基因设计4对相应的引物,检测不同浓度Lm纯培养物、金黄色葡萄球菌和乙型副伤寒沙门氏菌标准菌株的纯培养物以及Lm模拟污染的牛奶样品.[结果]Lm扩增出4个相应的产物(分别为255bp、 129bp、 260bp、 234bp),金黄色葡萄球菌和乙型副伤寒沙门氏菌菌株均未扩增出特异性的片段,其中inlA基因最低检出限为25.5μg/ml,其他3对引物最低检测限达2.55μg/ml.对模拟污染的牛奶TSBYE增菌培养液用PCR检测,只扩增出3个相应基因的产物(plcA、 plcB、 hlyA).[结论]扩增plcA、 plcB、 hlyA基因的PCR法对Lm的鉴定具有特异性强、灵敏度高、速度快和易操作等优点,可用于食品的Lm的分离.     

化妆品中金黄色葡萄球菌的PCR快速检测

目的研究化妆品中金黄色葡萄球菌的快检方法。方法将金黄色葡萄球菌基因nuc作为靶基因并设计引物,使用PCR扩增技术对17株金黄色葡萄球菌及4株干扰菌进行特异性扩增。同时采用传统细菌分离培养法及PCR扩增法对9份不同性状加标化妆品进行金黄色葡萄球菌实际样品检测。结果琼脂糖凝胶电泳检测显示,17株金黄色葡萄球菌全部扩增出280 bp的目的条带,准确率为100%。同时,当9种化妆品样品内金黄色葡萄球菌添加浓度为1 CFU/g(或ml)以上时样品增菌液均能扩增出清晰的目的条带。结论菌落PCR检测技术快捷简便,其灵敏性与准确性均能满足化妆品中金黄色葡萄球菌检测需求。     

实时荧光聚合酶链反应检测粪便标本中的金黄色葡萄球菌肠毒素A、D

目的:建立一种快速、准确、特异、定量检测金黄色葡萄球菌及其肠毒素A、D的方法并探讨肠毒素在食物中毒引起腹泻中的意义。方法:选择femB、SEA和SED基因分别作为金黄色葡萄球菌菌株、肠毒素A、肠毒素D的靶序列,设计合成引物和探针;收集食物中毒导致腹泻患者粪便标本487份,并对其进行检测分析。结果:采用荧光聚合酶链反应检测金黄色葡萄球菌和肠毒素A的灵敏度为1.0×102拷贝,而检测肠毒素D的灵敏度为1.0×103拷贝;487份粪便标本中检出金黄色葡萄球菌femB基因72例(14.8%),检出产肠毒素A菌株为11例(15.3%,11/72),产肠毒素D菌株为9例(12.5%,9/72),同时产肠毒素A、D菌株1例(1.4%,1/72)。结论:应用Taqm an探针实时荧光PCR技术能够快速、准确检测金黄色葡萄球菌及其肠毒素,适合于大样本筛查。     

一起食物中毒金黄色葡萄球菌肠毒素基因的检测

目的：检测从食物中毒中分离的金黄色葡萄球菌的肠毒素基因，明确肠毒素的基因型。对所分离的金黄色葡萄球菌进行药敏试验，检测其耐药性。方法：应用PCR扩增金黄色葡萄球菌SEA—SEJ基因，电泳检测扩增结果；用VITEK32检测药敏结果。结果：检测到金黄色葡萄球菌的肠毒素基因SEG和SEI，菌株的耐药性不强。结论：金黄色葡萄球菌的肠毒索SEG和SEI可能是这起食物中毒的因子。     

一起食物中毒事件的金黄色葡萄球菌分子分型研究

目的 运用分子分型方法分析一起在广州发生的由金黄色葡萄球菌所致的重大食物中毒事件,并进行溯源.方法 在常规分离的基础上,采用荧光定量PCR检测所获得的金黄色葡萄球菌特异耐热核酸酶基因(nuc)、耐甲氧西林决定基因(mecA)和其他5种肠毒素基因(sea,seb,sec,sed,see),并对16 S rRNA核苷酸进行序列扩增和使用DNAStar MegAlign 5.0软件分析,同时应用脉冲场凝胶电泳(PFGE)和BioNumerics Version 4.0软件进行聚类分析.结果 10株金黄色葡萄球菌特异性nuc基因均为阳性,其中7株分离菌的肠毒素sea,seb基因为阳性,分离菌可以分为4个16 SrRNA型别和5个PFGE型别.结论 本次食物中毒事件至少由3株以上亲缘关系相近的产毒金黄色葡萄球菌污染食物所致,分子分型方法可以为疫情溯源提供分子流行病学证据和支持.     

多重PCR技术在检测食源性金黄色葡萄球菌 肠毒素基因中的应用

摘要:目的　金黄色葡萄球菌A、B、C、D和E型肠毒素是引起食源性疾病的主要类型,采用多重PCR技术分析食源性金黄色葡萄球菌分离株肠毒素基因携带状况。方法　以19株食源性金黄色葡萄球菌分离株为研究对象,利用多重PCR技术对核酸酶基因以及肠毒素A、B、C、D和E型基因进行检测。结果　19株菌中均检出金黄色葡萄球菌特异性核酸酶基因,与传统菌落分离培养鉴定结果一致;9株菌含肠毒素SEA基因,1株同时含SEA和SEB基因,没有检测到肠毒素C、D和E基因。结论　在19株食源性金黄色葡萄球菌分离株中,10株携带肠毒素基因,以携带肠毒素A基因为主。     

日常食品及食物中毒样本中金黄色葡萄球菌肠毒素的分型检测分析

目的通过对北京市海淀区日常食品及食物中毒样本检出的金黄色葡萄球菌进行肠毒素分型检测,比较两种分离菌株的肠毒素分布差异。方法实验所用的金黄色葡萄球菌为2007-2012年海淀区日常食品和食物中毒样本中分离检出的菌株,依据GB 4789.10-2010采用ELISA方法测定金黄色葡萄球菌肠毒素(SEA-SEE)。结果 127株金黄色葡萄球菌中有108株肠毒素阳性,产肠毒素阳性率为85.0%。日常食品检出金黄色葡萄球菌93株,76株菌产肠毒素,产肠毒素阳性率为81.7%;食物中毒样本检出金黄色葡萄球菌34株,32株菌产肠毒素,产肠毒素阳性率为94.1%。产1种肠毒素和同时产3种肠毒素的菌株分别是47、37株,在产毒株中分别占43.5%和34.3%。食物中毒分离株产SEA和SED的比例(65.6%、65.6%)大于日常食品分离株(32.9%、30.3%).共有98株菌产SEE,在产毒株中占90.7%,肠毒素类型分布由高到低依次为E、A、D、C、B。结论食源性金黄色葡萄球菌产毒素能力较强,金黄色葡萄球菌食物中毒分离株和日常食品分离株在肠毒素分布上有差异。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.