质粒介导的喹诺酮类耐药基因在社区泌尿系感染大肠埃希菌中的分布

目的:调查质粒介导的喹诺酮类耐药基因在社区泌尿系感染大肠埃希菌中的分布。方法:收集39株从社区获得性泌尿系感染病人分离的大肠埃希菌,PCR扩增qnrA、qnrB、qnrS、aac(6′)-Ib-cr、qepA等质粒介导的喹诺酮类耐药(PMQR)基因。结果:在39株社区获得性泌尿系感染大肠埃希菌中,PMQR基因携带率为15.4%(6/39)。其中,1株携带qnrB基因(1/39,2.6%),1株携带qnrS基因(1/39,2.6%),4株携带aac(6′)-Ib-cr基因(4/39,10.3%)。PMQR基因携带菌株均为ESBL阳性菌株。所有菌株中未检出qnrA和qepA基因。结论:在社区获得性泌尿系感染大肠埃希菌中,PMQR基因的检出率虽不高,但由于其位于质粒上,易于在细菌间传播,须引起高度关注。     

大肠埃希菌耐药特征及质粒介导喹诺酮耐药基因分布

目的调查临床分离大肠埃希菌的耐药特征及质粒介导喹诺酮耐药(PMQR)基因流行状况。方法收集本院住院患者分离的大肠埃希菌191株,经VITEK 2全自动鉴定药敏仪进行鉴定和药敏分析,PCR检测PMQR基因qnrA、qnrB、qnrC、qnrD、qnrS、aac(6′)-Ib-cr、oqxA、oqxB、qepA。接合试验分析PMQR基因的转移性。结果 191株菌株对美洛培南和亚胺培南均敏感。对阿米卡星、奈替米星、阿莫西林/克拉维酸、哌拉西林/他唑巴坦和头孢西丁耐药率均低于30%。环丙沙星耐药率为64.4%,PMQR基因检出率为37.7%,123株环丙沙星耐药株中qnrA阳性26.0%、qnrB阳性4.9%、qnrS阳性1.6%、aac(6′)-Ib-cr阳性43.1%、oqxA阳性8.9%、qepA阳性4.9%,未检出到qnrC、qnrD和oqxB。其中40株(32.5%)只检测到单一基因,其余32株(26.0%)检测到2种或2种以上PMQR基因。接合试验证明43株细菌携带的PMQR基因可转移。结论本院分离大肠埃希菌耐药较严重且呈多药耐药,对环丙沙星耐药较高,PMQR基因以qnr和aac(6′)-Ib-cr为主。     

肺炎克雷伯菌对喹诺酮类及氨基糖苷类耐药基因检测及耐药机制分析

目的了解临床分离的耐环丙沙星及庆大霉素肺炎克雷伯菌喹诺酮类耐药基因qnrA、qnrB、qnrS、qepA与氨基糖苷类耐药基因aac(6′)-Ⅰb的携带情况,并进行相关耐药机制分析。方法采用VITEK-2型全自动微生物检测系统鉴定细菌;采用K-B法检测细菌对16种常用抗菌药物的敏感性;采用聚合酶链反应检测耐药基因qnrS、qnrA、qnrB、qepA和aac(6′)-Ⅰb。结果 25株耐环丙沙星和庆大霉素的肺炎克雷伯菌中,12株(48.0%)检出aac(6′)-Ⅰb基因,7株(28.0%)检出qnrS基因,4株(16.0%)检出qnrB基因,未检出qnrA和qepA基因,其中1株同时检出qnrS和qnrB基因,qnr基因总的阳性率为40.0%;有6株肺炎克雷伯菌同时存在喹诺酮类和氨基糖苷类耐药基因(50.0%)。结论对环丙沙星和庆大霉素耐药的肺炎克雷伯菌携带aac(6′)-Ⅰb和qnrS、qnrB耐药基因,qnr基因的携带率高达40.0%,肺炎克雷伯菌对氨基糖苷类药物耐药主要由aac(6′)-Ⅰb引起,单株菌可同时存在多种耐药基因,从而介导对多种抗菌药物的耐药性。     

携带质粒介导喹诺酮基因aac-(6′)-Ib-cr的大肠埃希菌遗传学特征分析

目的阐明携带质粒介导喹诺酮基因aac-(6′)-Ⅰb-cr的大肠埃希菌遗传学特征。方法通过PCR方法,从8所3级甲等医院送检的579株大肠埃希菌中筛选出aac-(6′)-Ⅰb-cr基因阳性菌41株,对此41株大肠埃希菌进行了耐药谱测定、质粒介导喹诺酮耐药机制、喹诺酮耐药决定区突变、β-内酰胺酶基因和毒力基因分析,并运用脉冲场凝胶电泳(PFGE)方法对此41株菌进行了分子分型。结果 41株aac-(6′)-Ⅰb-cr基因阳性菌对萘啶酸、环丙沙星、左氧氟沙星的敏感率分别为2.4%、2.4%、4.8%,对三代头孢菌素的敏感率33.0%,对阿米卡星敏感率为88.1%;检出ESBLs阴性菌13株,占31.7%,ESBLs阳性菌占68.3%;aac-(6′)-Ⅰb-cr基因阳性菌主要分布在A群43.9%和D群46.3%,而B群仅为9.8%,其中3株为B2群,1株为B1群;38株在喹诺酮耐药决定区中至少在GyrA和ParC上存在3或4个点突变,仅3株菌在GyrA上检出1个点突变;对41株aac-(6′)-Ⅰb-cr基因阳性菌进行PFGE分析显示,这些菌株在遗传学上存在较大差异。结论 aac-(6′)-Ⅰb-cr基因存在于不同基因型的大肠埃希菌中,且多数菌株为多药耐药株。     

肠杆菌科细菌qnr耐药基因的流行现状及耐药分析

目的了解质粒介导喹诺酮类耐药基因qnrA、qnrB、qnrS在临床分离大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、鲍氏不动杆菌中的流行情况及其耐药特征。方法收集临床分离的4种肠杆菌科细菌共148株,用法国生物梅里埃公司VITEK-2全自动细菌鉴定仪进行菌株鉴定和药敏试验,用qnr特异性基因引物进行聚合酶链反应(PCR)扩增和基因型的测序分析,并通过网上GenBank进行比对以确定编码酶基因的类型。结果对喹诺酮类耐药的50株大肠埃希菌检出qnrA1株(2.0%)、qnrB5株(10.0%)、qnrS3株(6.0%),有1株同时携带qnrB、qnrS;30株肺炎克雷伯菌检出qnrA1株(3.3%)、qnrB8株(26.7%)、qnrS10株(33.3%),有3株同时携带qnrB、qnrS;18株阴沟肠杆菌检出qnrA13株(72.2%)、qnrB5株(27.8%)、qnrS4株(22.2%),有3株同时携带qnrA、qnrS,3株同时携带qnrA、qnrB;50株鲍氏不动杆菌未检出qnr基因;携带qnr基因肠杆菌科细菌对氨苄西林/舒巴坦、氨曲南、头孢他啶、头孢曲松、头孢吡肟、磺胺甲噁唑/甲氧苄啶的耐药率均>70.0%,呈现出多药耐药现象。结论医院临床分离4种对喹诺酮类药物耐药的肠杆菌中,除鲍氏不动杆菌未检出qnr基因,其余3种均检出qnrA、qnrB、qnrS基因,以阴沟肠杆菌检出率最高,其次为肺炎克雷伯菌;携带qnr基因肠杆菌科呈现出多药耐药现象;医院在抗菌药物选择压力下,存在质粒介导喹诺酮类耐药基因qnr的流行。     

门诊患者尿液分离大肠埃希菌喹诺酮类耐药机制研究

目的回顾性分析社区尿液分离大肠埃希菌喹诺酮类抗菌药物耐药机制,为临床抗感染治疗提供参考。方法收集2013年6月-2015年6月门诊就诊患者尿液标本中分离的环丙沙星耐药大肠埃希菌,经VITEK 2全自动鉴定药敏仪进行鉴定和药敏分析,PCR检测质粒介导喹诺酮耐药基因qnr A、qnr B、qnr C、qnr D、qnr S、aac(6')-Ib-cr、qep A、oqx A、oqx B,同时测序分析喹诺酮耐药决定区gyrA、gyrB、parC、parE突变情况。结果共分离到大肠埃希菌131株,其中环丙沙星耐药56株,耐药率为42.7%,qnr S检出1株(1.7%)、oqx A及oqx B阳性各4株(7.1%)、aac(6')-Ib-cr阳性26株(46.4%)、qnr A阳性10株(17.9%)、qnr B阳性3株(5.4%),未检出qnr C、qnr D、qep A。此外,gyrA基因发生Ser83→Leu突变3株(5.4%)、gyrB发生基因Asp87→Leu突变3株(5.4%);parC基因发生Ser80→Ile突变2株(3.6%)。结论门诊患者尿液分离大肠埃希菌喹诺酮类耐药机制以质粒介导为主,尤其是aac(6')-Ib-cr耐药基因。由于质粒介导喹诺酮耐药基因易在不同菌株中播散,应加强监测。     

1株携带qnrB4及aac(6′)-Ⅰb-suzhou型基因同时产ESBLs、AmpC酶多药耐药大肠埃希菌的调查

目的了解1株产ESBLs、AmpC酶大肠埃希菌的耐药机制。方法采用纸片扩散法检测1株大肠埃希菌对19种抗菌药物的敏感性,采用聚合酶链反应(PCR)检测6种耐药基因:qnrA、qnrB、qnrC、qnrS、qepA、aac(6′)-Ⅰb,并对qnrB、aac(6′)-Ⅰb基因测序后进行BLAST比对分析。结果该菌株除对碳青霉烯类、酶抑制剂复合抗菌药物类敏感外,对其余药物均耐药;PCR发现该菌株同时携带qnrB和aac(6′)-Ⅰb,经测序并分别与已在美国国立信息中心登录的DQ303921(qnrB4)和EF375621[aac(6′)-Ⅰb-suzhou]型比对,同源性均>99.0%。结论该菌株多药耐药的机制与产ESBLs、AmpC酶及携带qnrB4和aac(6′)-Ⅰb基因有关;该研究是第一篇从1株产ESBLs、AmpC酶大肠埃希菌中检出同时携带qnrB4和aac(6′)-Ⅰb-suzhou型基因的报道。     

铜绿假单胞菌对喹诺酮类药物耐药的分子机制研究

目的:研究铜绿假单胞菌对喹诺酮类药物耐药的分子机制,为临床抗感染治疗提供依据。方法:用PCR法检测染色体介导的喹诺酮类耐药基因gyrA、gyrB、parC、parE和质粒介导的喹诺酮类耐药基因qn-rA、qnrB、qnrC、qnrD、qnrS、qepA、aac(6’)-Ib-cr、oqxA和oqxB,并对gyrA和parC阳性结果进行测序分析。结果:98株耐环丙沙星的铜绿假单胞菌中未检出parE、qnrC和qnrS基因。gyrA、gyrB和parC的阳性率分别为96.9%、87.8%和75.5%。测序证实84株菌(85.7%)发生gyrA或parC基因突变。90株菌(91.8%)携带质粒介导的耐药基因,qnrA、qnrB、qnrD、qepA、aac(6’)-Ib-cr、oqxA和oqxB的阳性率分别为31.6%、86.7%、15.3%、11.2%、53.1%、8.2%和26.5%,其中qnrB和aac(6’)-Ib-cr具有高携带率。结论:染色体介导的喹诺酮类耐药基因突变以及质粒携带qnr、qepA、aac(6’)-Ib-cr和oqxAB耐药基因是铜绿假单胞菌耐喹诺酮类药物的主要机制。首次在铜绿假单胞菌中发现qnrB基因和qnrD基因。     

肺炎克雷伯菌染色体及质粒介导的喹诺酮类药物耐药机制研究

目的了解肺炎克雷伯菌染色体、质粒介导喹诺酮类耐药基因gyrA、qnrA、qnrB、qnrS、aac(6′)-Ⅰb-Cr和qepA基因的流行情况。方法采用PCR法对20株肺炎克雷伯菌进行gyrA、qnrA、qnrB、qnrS、aac(6′)-Ⅰb-Cr和qepA基因检测,稀释法检测20种抗菌药物的体外抗菌活性,PCR扩增产物经纯化后测序并进行序列分析。结果20株肺炎克雷伯菌均存在突变,aac(6′)-Ⅰb和qnrS基因各检出1株,经比对分别为aac(6′)-Ⅰb-Cr和qnrS1。结论老年患者产超广谱β-内酰胺酶肺炎克雷伯菌对环丙沙星耐药主要为gyrA基因突变所致,但也有aac(6′)-Ⅰb-Cr和qnrS的因素。     

2017-2018年包头地区耐喹诺酮大肠埃希菌临床分离株的耐药特征与机制分析

目的了解内蒙古包头地区临床分离的耐喹诺酮大肠埃希菌的耐药特征以及机制。方法收集2017-2018年内蒙古包头地区11所参与全国细菌耐药监测网医院的大肠埃希菌临床分离株,采用纸片扩散法或自动化仪器法按统一技术方案进行药敏试验,采用酶抑制剂增强试验测定超广谱β-内酰胺酶(ESBLs),分析病原菌耐药性。并且随机从大肠埃希菌喹诺酮类耐药(环丙沙星或/和左氧氟沙星耐药)组中筛选60株作为试验菌株,采用微量肉汤稀释法测定环丙沙星最低抑菌浓度(MIC)值,采用聚合酶链反应检测GyrA、GyrB、ParC、ParE、qnrA、qnrB、qnrS、aac(6′)-Ib以及qepA基因,限制性酶切反应确定aac(6′)-Ib-cr基因型。结果共收集上述医院非重复大肠埃希菌临床分离株4 262株。耐喹诺酮大肠埃希菌分离率居前3位的医院分别为包头市肿瘤医院(79.37%)、内蒙古包钢医院(74.45%)和包头市第八医院(72.52%);前3位科室分别为泌尿科(90.74%)、呼吸内科(87.58%)和肿瘤科(77.87%);前3位标本分别为尿液(73.77%)、痰液等呼吸道标本(65.63%)和引流液(63.27%)。4 262株大肠埃希菌中喹诺酮类耐药组和喹诺酮类非耐药组占比分别为66.31%和33.69%,喹诺酮类耐药组对绝大部分所测抗菌药物的耐药率和产ESBLs的检出率均高于喹诺酮类非耐药组(P<0.05)。60株试验菌株:GyrA、GyrB、ParC和ParE基因的阳性率均为100.00%;GyrA、ParC和ParE亚基突变发生率均为100.00%,GyrB亚基突变发生率为16.67%;发生最多的氨基酸取代种类是Ser83→Leu(100.00%),其次依次为Ser80→Ile(96.67%)和Asp87→Asn(91.67%);质粒介导的喹诺酮类耐药(PMQR)基因阳性率为18.33%,其中检出率由高到低分别为aac(6′)-Ib-cr基因(15.00%)、qnrS基因(6.67%)和qepA基因(3.33%)。在GyrA亚基双突变的基础上,发生ParC亚基单位点(Ser80或Glu84)突变的菌株对环丙沙星的MIC值多在32~64μg/ml范围内;发生ParC亚基双位点(Ser80和Glu84)突变的菌株对环丙沙星的MIC值多为128μg/ml。在所有发生ParE亚基Ser458→Ala突变的菌株中均检测到含有GyrA和ParC亚基突变,与无ParE亚基Ser458→Ala突变的菌株相比,含有ParE亚基Ser458→Ala突变的菌株对环丙沙星的MIC值更高。结论内蒙古包头地区为耐喹诺酮大肠埃希菌高流行地区,且耐药水平高,常呈多药耐药。编码DNA促旋酶和拓扑异构酶Ⅳ这两种药物作用靶蛋白的基因上喹诺酮类耐药决定区(QRDRs)存在多个位点突变是引起本地区大肠埃希菌对喹诺酮类抗菌药物产生高水平耐药的主要原因。     

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.     

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.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.