志贺菌对喹诺酮类抗菌药物耐药性及耐药机制研究

目的检测志贺菌对喹诺酮类抗菌药物的耐药情况,探讨染色体介导DNA旋转酶和拓扑异构酶Ⅳ基因突变存在与志贺菌喹诺酮类药物耐药性的相关性。方法用琼脂稀释法对60株志贺菌进行耐药性检测;PCR法检测喹诺酮耐药决定区(QRDR)相关基因gyrA、gyrB、parC、parE,并对其中20株PCR扩增所得的阳性产物进行测序分析;分析志贺菌gyrA、gyrB、parC基因突变与喹诺酮类药物耐药性的关系。结果 60株志贺菌对萘啶酸、诺氟沙星、环丙沙星、左氧氟沙星的耐药率分别为90.0%、35.0%、28.3%和15.0%;测序结果显示gyrA、gyrB、parC基因突变率分别为85%、30%和100%,parE基因未发现突变。结论志贺菌对喹诺酮类耐药严重;靶基因突变是喹诺酮类药物耐药的主要机制之一,以DNA旋转酶GyrA基因突变为主,DNA拓扑异构酶IVparC基因突变次之。     

志贺菌对喹诺酮类药物耐药分子机制的研究

目的 研究志贺菌对喹诺酮类药物耐药性及其耐药基因gyrA和parC的变异。方法对73株临床分离的志贺菌及标准株51573进行吡哌酸(PI)、氧氟沙星(OFL)、诺氟沙星(NOR)、环丙沙星(CIP)4种药物的药敏试验,对其DNA旋转酶gyrA基因、拓扑异构酶ⅣparC基因N末端编码区分别进行聚合酶链反应(PCR)扩增后,对grA基因进行限制性片段长度多态性(RFLP)分析,对parC基因进行RFLP及单链构象多态性(SSCP)分析。结果 标准株51573对4种喹诺酮类药物均敏感;73株临床分离的志贺菌属细菌对PI、CIP、NOR、OFL的耐药率分别为79.5％、60.3％、41.1％和36.9％;67株(91.8％)菌株对喹诺酮类药物敏感性降低,其中gyrA基因突变率为91％,parC基因突变率为7.5％,6株临床敏感株及标准株51573均未检测出以上两基因突变。结论 志贺菌对喹诺酮类药物耐药严重;靶基因突变是其耐喹诺酮类药物的主要机制之一,以DNA旋转酶gyrA基因突变为主,拓扑异构酶ⅣparC基因突变次之。     

志贺菌对喹诺酮类药物的耐药性及其耐药机制

目的调查济南地区志贺菌对喹诺酮类药物的耐药情况,并研究其耐药机制,为临床抗感染治疗提供依据,以指导临床合理用药。方法采用K-B法测定菌株对萘啶酸、环丙沙星和左氧氟沙星3种喹诺酮类药物的敏感性,PCR扩增gyrA、parC和qnr基因,选取部分PCR扩增产物进行DNA测序。结果62株志贺菌对萘啶酸、环丙沙星和左氧氟沙星的耐药率分别是90.3%、29.0%和6.5%。所有菌株均扩增出了相应gyrA和parC基因产物,未检出qnr基因。耐药株均存在gyrA基因突变和parC基因突变;只对萘啶酸耐药的菌株gyrA基因存在83位氨基酸突变,而对萘啶酸和环丙沙星耐药株中则同时存在83位和87位氨基酸突变;parC基因存在80位SerIle的突变。结论该地区志贺菌对喹诺酮类药物耐药情况严重,而gyrA基因87位氨基酸突变是志贺菌对环丙沙星耐药的重要原因。     

鼠伤寒沙门菌耐药株拓扑异构酶基因突变分析

目的　探讨鼠伤寒沙门菌对氟喹诺酮类药物的耐药性与拓扑异构酶基因突变之间的关系。方法　三株鼠伤寒沙门菌分离株X2 ,X7,X11对氟喹诺酮类药物环丙沙星的MIC分别为 32、0 38和 0 0 2 3μg ml,X2为耐药株。利用聚合酶链反应 (PCR)对其拓扑异构酶四个耐药基因gyrA ,gyrB ,parC ,和parE进行扩增和序列分析。结果　发现分离株X2的gyrA基因同时在 2 4 8、2 5 9位点发生点突变 (Ser83→Phe ,Asp87→Asn)。分离株X7gyrA基因在 2 4 8位点发生点突变 (Ser83→Tyr)。分离株X11的gyrA基因没有发生突变。X2parC基因QRDR在 2 38位点发生点突变 (Ser80→Arg)。而分离株X7、X11的parC基因没有发生突变。三株鼠伤寒沙门菌分离株的gyrB和parE基因都没有发现突变。结论　gyrA和parC上同时发生突变会导致鼠伤寒沙门菌对环丙沙星的高耐药性     

耐喹诺酮类大肠埃希菌耐药机制的研究

目的探讨耐喹诺酮类大肠埃希菌的耐药机制。方法收集天津市第一中心医院2004年3月-2005年10月临床分离的大肠埃希菌,并随机选取40株作为研究对象,通过K-B药片试纸法和微量稀释法测40株目的菌株的耐药性;PCR扩增耐药株的gyrA QRDR区和parC基因,进行PCR-SSCP分析;同时,PCR扩增marOR基因,在耐药株中随机选取进行测序,检测marOR基因突变情况。结果37株对耐喹诺酮类菌株均出现了gyrA基因突变,除常见氨基酸改变外,还发现Asp87→Asn、Ala84→Pro;36株耐喹诺酮菌株发生了parC基因突变,只对萘啶酸耐药,对环丙沙星中介、氧氟沙星、加替沙星敏感的ECO24未出现parC基因突变;只对氟喹诺酮类耐药的ECO11未出现marOR区突变;存在多重耐药的ECO5 marOR区发现6处突变,且1 879 bp处的突变改变了marOR的终止密码子。结论gyrA和parC基因突变引起大肠埃希菌产生耐药,gyrA基因突变是产生对氟喹诺酮类耐药的主要原因,parC基因突变可引起菌株对氟喹诺酮类药物的高水平耐药,marOR的多位点突变在多重耐药机制中有一定的作用。     

耐环丙沙星鲍氏不动杆菌的gyrA基因及parC基因突变分析

目的 研究本地区临床分离鲍氏不动杆菌环丙沙星耐药表型与DNA旋转酶A亚单位gyrA基因及拓扑异构酶Ⅳ parC基因突变的关系。方法收集28株耐药株及2株敏感株，通过PCR扩增其gyrA基因及parC基因，并对扩增产物进行限制性片段长度多态性分析（PCR-RFLP）及DNA序列分析。结果敏感株的gyrA基因产物经HinfⅠ酶切后可产生两个片段，耐药株则产生1个片段；而parC基因产物经Hinf Ⅰ酶切后，敏感株及耐药株均产生两个片段；DNA测序显示，5株耐药株gyrA基因存在Ser83→Leu及Ala88→Thr突变，其中Ser83→Leu的突变是导致Hinf Ⅰ酶切位点消失的原因，而1株敏感株无突变；1株敏感株与1株耐药株的pcrC基因存在Ser108→Ile突变，另外14株耐药株存在多位点同义突变。结论与parC基因相比，gyrA基因突变是鲍氏不动杆菌对环丙沙星耐药的主要分子基础，环丙沙星的高水平耐药可能需要多种不同的突变。     

重症监护病房铜绿假单胞菌的耐药性分析及其耐氟喹诺酮的分子机制研究

目的 了解重症监护病房铜绿假单胞菌的耐药情况以及对氟喹诺酮类耐药的分子机制,为临床合理用药提供依据.方法 用E试验法测定83株铜绿假单胞菌对13种抗菌药物的最低抑菌浓度(MIC),从中筛选28株氟喹诺酮类耐药菌,以标准敏感菌株ATCC 27853作为质控菌株,PCR扩增gyrA及parC基因的喹诺酮耐药决定区(QRDR),扩增产物片段进行直接测序分析.结果 83株铜绿假单胞菌在痰标本的阳性率最高71.08%;28株氟喹诺酮耐药菌株的gyrA基因在83位(ACC-ATC)有突变,导致氨基酸Thr-Ile的改变;有11株高耐药菌gyrA基因同时在87位(GAC-GGC)有突变,导致氨基酸Asp-Gly的改变;有14株耐药菌株的parC基因在87位有TCG-TTG突变,导致氨基酸由Ser-Leu的改变,未发现parC突变单独存在.结论 重症监护病房铜绿假单胞菌对美罗培南保持较高的抑菌活性;而亚胺培南和氟喹诺酮类药物的滥用,已造成细菌对其耐药率急剧升高,gyrA和parC基因突变与铜绿假单胞菌耐喹诺酮类药物密切相关.     

大肠埃希菌对氟喹诺酮类的耐药性及其机制研究

目的 探讨大肠埃希菌(ECO)对氟喹诺酮类药物的耐药率及耐药机制.方法 K-B法测定100株ECO对5种氟喹诺酮抗菌药物的耐药性,试管稀释法测定耐环丙沙星和左氧氟沙星的最低抑菌浓度(MIC);错配PCR技术检测耐环丙沙星ECO gyrA基因和parC基因的突变.结果 100株ECO中耐环丙沙星有65株;环丙沙星MIC50、MIC90分别是32、128 μg/ml,左氧氟沙星MIC50、MIC90是16、64 μg/ml;基因位点结果显示,耐环丙沙星的65株中,有60株发生gyrA、parC一个或多个基因位点的突变,有5株未发生突变.结论 gyrA、parC基因突变是该地区ECO,对氟喹诺酮类药物耐药的重要机制,且基因突变位点越多其耐药程度越高.     

志贺菌对氟喹诺酮的耐药机制及流行状况研究

目的：研究志贺菌对氟喹诺酮的耐药机制及其流行状况。方法：对氟喹诺酮耐药志贺菌的gyrA基因和parC基因进行扩增、测序，查找突变点；用重复基因外回文序列-聚合酶链式反应（REP-PCR）对志贺菌进行基因分型。结果：两株耐氟喹诺酮的菌株都存在gyrA基因87位Asp（GAC）→Asn（AAC）和177位Gly（GGT）→Ser（AGT）的点突变，一株另有120位Met（ATG）→Leu（CTG）、203位Ile（ATC）→Leu（CTC）、204位Ser（AGC）→Thr（ACC）和205位Ile（ATT）→Leu（CTT）的点突变，另一株还有204位Set（AGC）→Ile（AAC）的点突变。除87位点突变外，其余突变位点均未见报道。parts基因未发现点突变。REP—PCR基因分型结果提示16株宋内志贺菌有7种指纹图谱，12株福氏志贺菌有两种指纹图谱。结论：两株志贺菌对氟喹诺酮耐药是由gytA基因点突变所致，耐药表型对突变的类型有一定的预见性，但耐药程度与突变频率的相关性不确定。2004年夏秋季武汉地区散发流行的志贺菌有相同或相似的克隆，血清型单一的宋内志贺菌存在基因多样性，福氏志贺菌中f2a比f4c的遗传多样性高。REP—PCR是一种快捷有效的基因分型法，可用于志贺菌同源性分析及暴发流行时的追根溯源。     

淋病奈瑟氏菌对环丙沙星耐药性与喹诺酮类耐药决定区突变的关系

目的了解上海地区淋球菌流行株对喹诺酮类抗生素的敏感性,探讨淋球菌耐药株gyrA与parC基因突变与淋球菌耐氟喹诺酮类药物之间的关系.方法采用琼脂扩散法对淋球菌临床分离株对行喹诺酮类抗生素敏感性测定,同时运用PCR技术扩增gyrA基因和parC基因的喹诺酮类耐药决定区,并对典型株的PCR产物直接进行测序分析.结果所分离的80株菌株对环丙沙星MIC为敏感、中介、耐药分别为1株、3株和76株;产物测序结果显示淋球菌敏感株只检出了gyrA基因在Asp95处的单位点突变;中介及耐药株在gyrA基因均检出有Ser-91→Phe突变并伴有Asp95或者Ala92位突变;6株检出有parC基因的86、87、91位点突变及其他位置的一些无义突变.结论gyrA基因突变是淋球菌耐喹诺酮类抗生素的重要机制,其中Ser-91→Phe更是引起对喹诺酮类耐药非常关键的突变,而parC基因的突变只会伴随gyrA基因突变同时出现,可能会对淋球菌耐喹诺酮类抗生素起促进作用.     

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 occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

Fatigue and health in a seafaring population

Background Occupational fatigue is relatively common withinthe general population and has been linked to reduced performance,injury and longer term ill-health. Despite growing acknowledgementof this problem in the maritime sector, little research hasbeen conducted into the risk factors, prevalence and consequencesof seafarers' fatigue. Aims To examine the prevalence of fatigue among seafarers, identifypotential risk factors and assess possible links with poor performanceand ill-health. Methods Cross-sectional questionnaire survey of seafarers workingin the offshore oil support, short-sea and deep-sea shippingindustries. A number of tools were used including the fatiguesubscale of the profile of fatigue-related symptoms, the CognitiveFailures Questionnaire, the General Health Questionnaire andthe SF36 General Health scale. Results In all, 1855 questionnaires were completed giving anoverall response rate of 20%. Fatigue symptoms were associatedwith a range of occupational and environmental factors, manyunique to seafaring. Reporting a greater number of risk factorswas associated with greater fatigue [e.g. OR = 2.53 (1.90–3.35)for those with three or four risk factors and OR = 9.54 (6.95–13.09)for those with five or more risk factors]. There was also astrong link between fatigue and poorer cognitive and healthoutcomes, with fatigue the most important of a number of riskfactors, accounting for 10–14% of the variance. Conclusions Seafarers' fatigue could impact on safety withinthe industry and may be linked to longer term individual ill-health.It can only be addressed by considering how multiple factorscombine to contribute to fatigue.     

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.     

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.     

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.