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1.
目的:探讨通用PCR法在痰标本真菌检测中的临床应用价值。方法:选择2015年9月至2017年9月本院收治的免疫力低下患者178例作为研究资料,各收集痰标本2份,其中一份用于PCR扩增,另一份经培养后若观察到真菌或可疑菌落,则提取后在此进行PCR扩增测序。比较3种方法对真菌的检出情况、真菌阳性率,与组织病理学结果进行比较,分析3种方法的诊断效能。结果:178份痰标本经平板培养可观察到107份真菌生长,其余71份未见真菌生长。挑取真菌及可疑菌落行PCR结果显示阳性、阴性分别115、63份。对痰标本直接PCR结果显示,阳性、阴性分别124、54份。PCR扩增产物测序结果显示大多是白色念珠菌感染,仅3份是曲霉菌感染。内对照扩增验证结果显示有1份阴性标本存在扩增抑制现象。3种方法的真菌阳性率:直接PCR法痰培养后PCR法痰培养,但组间无显著差异(P0.05)。3种方法诊断效能总体趋势:直接PCR法痰培养后PCR法痰培养,其中直接PCR法与痰培养后PCR法的特异度、准确度均显著高于痰培养法(P0.05),直接PCR法的敏感度显著高于痰培养法(P0.05)。结论:通用PCR法在痰标本真菌检测中的临床应用价值较高,直接PCR具有操作简单、快速等优势。  相似文献   

2.
目的对实时荧光核酸恒温扩增技术(simultaneous amplification and testing method,SAT)检测创面分泌物中耐甲氧西林金黄色葡萄球菌(MRSA)核酸试剂盒(RNA恒温扩增)应用进行评价。方法收集我院临床各科室于2016年12月至2017年1月送至检验科微生物室347份分泌物标本,分别用实时恒温扩增技术和ChromID MRSA产色平板筛选MRSA。当SAT法和MRSA培养结果不相符时,进行冻存的备用标本PCR扩增、第三方测序,以MRSA培养结果加PCR测序结果作为本次试验"扩大金标准",计算SAT的灵敏度、特异性、阳性预测值、阴性预测值,并进行相应的统计学分析。结果以ChromID MRSA产色平板筛选加PCR测序作为"扩大金标准",SAT法检测MRSA的敏感度为90.91%、特异度为99.40%、阳性预测值为83.33%、阴性预测值为99.40%,对MRSA的最低检出下线为102拷贝/mL,Kappa系数为0.85。结论 SAT技术在检测分泌物中MRSA具有很高的灵敏度、特异性,而且准确、可靠,与传统的细菌培养相比耗时短,为MRSA的实验室诊断提供新的检测方法。  相似文献   

3.
目的评价3种艰难梭菌实验室鉴定方法的快速性及准确性。方法 2013年6月至2013年11月,收集136名ICU患者共248份标本进行24 h、48 h厌氧培养,并进行鉴定,同时对大便标本提取DNA进行tcd B毒素基因检测。以48 h培养结果为参考标准,评价24小时培养法和PCR扩增tcd B基因法鉴定艰难梭菌的灵敏度、特异度、阳性预测值和阴性预测值。结果 136名ICU发生腹泻的患者中,11名患者共有12份标本48 h培养为艰难梭菌阳性,艰难梭菌感染率为8.09%(11/136),标本阳性率为4.84%(12/248)。24小时培养法及PCR扩增tcd B基因法的灵敏度、特异度、阳性预测值、阴性预测值分别为75.00%、100%、100%、98.74%和83.33%、99.15%、83.33%、99.15%。结论提取大便DNA tcd B毒素基因是最快速、灵敏度和特异度均较高的方法;48小时培养法时间相对较长,但稳定可靠,并可以保留菌株进行后续试验;24小时培养法,时间短、简便但会漏诊某些阳性病例。  相似文献   

4.
目的评价恒温扩增芯片法在重症监护病房肺部感染患者下呼吸道感染病原体检测中的效果。方法收集合格痰标本146例,通过恒温扩增芯片法和细菌培养法检测病原体,对两种方法检测结果进行分析。结果 146例痰液标本中,恒温扩增芯片法检出阳性标本114例(阳性率为78.1%),其中单一致病菌感染42例,2种及以上致病菌混合感染72例。45例标本检测到mecA基因,其中13例为耐甲氧西林金黄色葡萄球菌。146例痰标本中,有109例痰标本同时进行了痰培养检测,痰培养阳性率为67.9%(74/109),相应的恒温扩增芯片法检测阳性率为82.6%(90/109);痰培养结果阴性共计35例,与之相符合的恒温扩增芯片法检测阴性共计16例(阴性符合率45.7%)。恒温扩增芯片法对肺炎链球菌、肺炎克雷伯菌、铜绿假单胞菌、嗜麦芽窄食单胞菌、流感嗜血杆菌的阳性检出率明显高于痰培养,差异具有统计学意义。恒温扩增芯片法检测到2例结核分枝杆菌复合群、1例军团菌、1例肺炎支原体,痰培养检测到3例奇异变形杆菌。结论本实验室所开展的恒温扩增芯片法在重症监护病房肺部感染者下呼吸道病原体检测方面的优势体现在阳性率高、检测时间短,可为临床肺部感染诊断提供及时准确的参考依据。  相似文献   

5.
目的探讨血清(1,3)-β-D葡聚糖与尿真菌培养联合检测对泌尿系侵袭性真菌感染(IFI)的诊断价值。方法选取疑似泌尿系IFI患者157例,根据临床诊断,分为IFI组(48例)和非IFI组(109例),进行血清(1,3)-β-D葡聚糖检测(G试验)和尿真菌培养,比较两种方法单独和联合检测对泌尿系IFI诊断的灵敏度、特异度、阳性预测值、阴性预测值和Youden指数。结果 G试验和尿真菌培养的灵敏度、特异度、阳性预测值、阴性预测值和Youden指数依次为(87.5%、89.6%)、(77.1%、78.9%)、(62.7%、65.2%)、(93.3%、94.5%)和(0.646、0.685);联合检测的灵敏度、特异度、阳性预测值、阴性预测值和Youden指数依次为79.2%、98.2%、95.0%、91.5%和0.774。三者均具有较高阴性预测值,而联合检测的特异度、阳性预测值和Youden指数明显高于单独检测,差异有统计学意义(Ps0.05)。结论 G试验与尿真菌培养联合检测诊断泌尿系IFI具有较高的阴性预测值和阳性预测值,减少了假阳性结果,较单独检测具有更大的诊断价值。  相似文献   

6.
目的探讨尿干化学分析法与尿沉渣分析法在诊断患者尿路感染中的临床价值。方法收集2017年9月至2018年7月于重庆市黔江中心医院就诊的疑似尿路感染患者尿液标本400份,分别利用尿干化学分析及尿沉渣分析法检测标本,比较不同检测分析法的灵敏度、特异度、阳性预测值及阴性预测值。结果尿干化学分析法检测阳性率为42.25%(169/400),尿沉渣分析法检测阳性率为32.75%(131/400),尿沉渣分析法检测阳性率明显低于尿干化学分析法(X~2=7.7010,P=0.0070),差异有统计学意义。尿干化学分析法检测白细胞计数阳性率为25.25%(101/400)、亚硝酸盐阳性率为17.00%(68/400);尿沉渣分析法检测白细胞计数阳性率为24.25%(97/400),细菌计数阳性率为8.50%。尿沉渣分析法检测白细胞计数阳性率与尿干化学分析法比较,差异无统计学意义(X~2=0.1070,P=0.8060)。尿干化学分析法灵敏度为72.95%,特异度为90.67%,阳性预测值为89.35%,阴性预测值为75.76%;尿沉渣分析法灵敏度为57.97%,特异度为94.30%,阳性预测值为91.60%,阴性预测值为67.66%。尿干化学分析法检测的灵敏度及阴性预测值明显高于尿沉渣分析法(X~2=10.2660,P=0.0020;X~2=3.9930,P=0.0480),差异具有统计学意义。结论尿干化学分析法及尿沉渣分析法均有一定的临床诊断价值。可针对两种检测方法的联合应用进一步研究,以期提高尿路感染诊断的灵敏度及特异度。  相似文献   

7.
目的:探讨中枢神经系统感染患儿血清和脑脊液C反应蛋白(CRP)、降钙素原(PCT)、肿瘤坏死因子-α(TNF-α)及基质金属蛋白酶-9(MMP-9)水平及其临床意义。方法:选择2017年1月~2018年6月期间南京市第二医院收治的中枢神经系统感染患儿93例作为研究对象,其中化脓性脑膜炎62例记为化脓性脑膜炎组,病毒性脑炎31例记为病毒性脑炎组,另选取同期于我院治疗的非中枢神经系统感染患儿40例作为对照组,比较各组血清、脑脊液CRP、PCT、TNF-α、MMP-9水平及阳性率,并计算血清和脑脊液CRP、PCT、TNF-α、MMP-9诊断中枢神经系统感染的灵敏度、特异度及准确度。结果:化脓性脑膜炎组患儿血清、脑脊液CRP、PCT、TNF-α及MMP-9水平及阳性率高于病毒性脑炎组和对照组,病毒性脑炎组患儿血清、脑脊液CRP、TNF-α及MMP-9水平及阳性率高于对照组(P<0.05),病毒性脑炎组与对照组血清、脑脊液PCT水平及阳性率比较无统计学差异(P>0.05)。血清或脑脊液CRP+PCT+TNF-α+MMP-9联合检验对中枢神经系统感染具有一定的诊断价值。结论:中枢神经系统感染患儿血清、脑脊液CRP、TNF-α、PCT及MMP-9水平明显升高,其中化脓性脑膜炎患儿血清、脑脊液PCT水平高于病毒性脑炎患儿,血清或脑脊液CRP、PCT、TNF-α及MMP-9联合检验对儿童中枢神经系统感染的鉴别诊断具有较高的价值。  相似文献   

8.
目的评价实时荧光PCR(RT-PCR)用于检测呼吸道感染耐甲氧西林金黄色葡萄球菌(MRSA)中的方法学特性,为临床快速诊断呼吸道MRSA定植或感染提供可靠循证依据。方法通过RT-PCR技术对痰液标本中金黄色葡萄球菌(SA)特异性核酸酶编码基因nuc和MRSA的特异性耐药基因mec A进行定量检测,并同时以细菌培养、鉴定和MRSA耐药表型确诊实验作为参考方法,评价其灵敏度、特异度、阴阳性预测能力;用10倍梯度稀释法配制已知标准菌株菌悬液评估RT-PCR的最低检出限。结果 RT-PCR法较细菌培养法对MRSA检测的总符合率为97.5%,检测SA的敏感度为97.2%、特异度为98.2%、阳性预测值为92.1%、阴性预测值为99.4%,检测甲氧西林耐药性的敏感度为100%、特异度为97.7%、阳性预测值为85.2%、阴性预测值为100%;RT-PCR对nuc基因和mec A基因的最低检出限均为103/m L。结论RT-PCR法与细菌培养法对于检测MRSA差异无统计学意义,且灵敏度优于后者,是用于临床快速排除性筛查呼吸道感染MRSA的较佳检测方法。  相似文献   

9.
筛选117条炭疽芽胞杆菌(Bacillusanthracis)特异序列,经双重特异性验证后得到19条理想的特异序列(genomicsignatures),其中6条符合设计TaqMan探针建立实时定量PCR的要求,根据常规PCR检测结果选择其中C04片段与炭疽芽胞杆菌毒性质粒pX01、pX02上的pagA、capB基因建立实时定量PCR检测体系。经试验证实这一体系检测灵敏度达到每PCR反应10~100个拷贝。利用12种相关菌株评价后获得100%特异性,对10份模拟污染标本和20份对照标本检测,所有污染标本均被检出,所有对照标本均为阴性。此方法特异、灵敏、高效,在炭疽芽胞杆菌感染的诊断和环境污染的检测等领域有潜在的应用前景。  相似文献   

10.
摘要 目的:建立一种双通道TaqMan实时荧光PCR方法,应用于别嘌呤醇不良反应相关基因HLA-B*58:01的快速基因检测,并验证该方法的灵敏度、特异性、重复性及可靠性等性能指标。方法:针对HLA-B*58:01 等位基因序列设计引物和Taqman 探针,建立一种双通道TaqMan实时荧光PCR检测方法,收集陕西省人民医院、浙江大学医学院附属第二医院、浙江大学医学院附属邵逸夫医院三家医院收治的1158例临床诊断为痛风或血清尿酸高患者的外周血标本,采用双盲对照实验,分别采用双通道TaqMan实时荧光PCR法与已获审批的商业试剂盒共同检测所有标本,对比两种方法的检测结果进而评价该TaqMan实时荧光PCR方法的临床性能。结果:双通道TaqMan实时荧光PCR法特异性高,稳定可靠,可检测低至1 ng/?滋L的阳性样本;采用双通道TaqMan实时荧光PCR法与已获审批的商业试剂盒在1158份患者标本中检出的HLA-B*58:01阳性及阴性标本均相同,阳性标本147例,阴性标本1011例,该组患者HLA-B*58:01基因携带率为12.69%,两种方法符合率为100%(1158/1158),两组实验结果数据采用SPSS分析P=1.000,差异无统计学意义。所有受检者HLA-B* 58:01携带率为12.69 % (147 /1158)。结论:双通道TaqMan实时荧光PCR可以作为一种快速、特异、灵敏的HLA-B*58:01的基因检测方法,用于别嘌呤醇用药前的相关不良反应风险评估。  相似文献   

11.
BackgroundNeisseria meningitidis (Nm) is a leading causative agent of bacterial meningitis in humans. Traditionally, meningococcal meningitis has been diagnosed by bacterial culture. However, isolation of bacteria from patients’ cerebrospinal fluid (CSF) is time consuming and sometimes yields negative results. Recently, polymerase chain reaction (PCR)-based diagnostic methods of detecting Nm have been considered the gold standard because of their superior sensitivity and specificity compared with culture. In this study, we developed a loop-mediated isothermal amplification (LAMP) method and evaluated its ability to detect Nm in cerebrospinal fluid (CSF).Conclusions/SignificanceCompared to PCR, LAMP detected Nm with higher analytical and clinical sensitivity. This sensitive and specific LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.  相似文献   

12.
Diagnosis of bacterial meningitis has long been based on classical methods of Gram stain, serological tests, and culture of cerebrospinal fluid (CSF). The performance of these methods, especially culture and direct smear is thwarted by failure to detect bacteria following administration of antimicrobial agents and reluctance to performance lumbar punctures at admission. Indeed, patients with meningitis frequently receive antibiotics orally or by injection before the diagnosis is suspected or established Thus an alternative method has become necessary to help clinicians and epidemiologists to management and control of bacterial meningitis. We evaluate the application of a polymerase chain reaction-based (PCR) assay for amplification of pneumolysin gene (ply) to diagnosis of Streptococcus pneumoniae meningitis. The PCR assay sensitivity for CSF was 96% (95% confidence interval, CI, 90-99%) compared to a sensitivity of 59% for culture (95% CI 49-69%), 66% for Gram stain (95% CI 56-74%), and 78% for latex agglutination test (95% CI 69-86%); PCR specificity was 100% (95% CI 83-100%). PCR results were available within 4 h of the start of the assay. This molecular approach proved to be reliable and useful to identify this bacterium compared with other classical laboratory methods for identification of bacterial meningitis pathogens.  相似文献   

13.
A central nervous system (CNS) infection, such as meningitis, is a serious and life-threatening condition. Bacterial meningitis can be severe and may result in brain damage, disability or even death. Rapid diagnosis of CNS infections and identification of the pathogenic microorganisms are needed to improve the patient outcome. Bacterial culture of a patient??s cerebrospinal fluid (CSF) is currently considered the ??gold standard?? for diagnosing bacterial meningitis. From the CSF cultures researchers can assess the in vitro susceptibility of the causative microorganism to determine the best antibiotic treatment. However, many of the culture assays, such as microscopy and the latex agglutination test are not sensitive. To enhance pathogen detection in CSF samples we developed a multi-target real-time PCR assay that can rapidly identify six different microorganisms: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Streptococcus agalactiae, Listeria monocytogenes and Cryptococcus neoformans. In this study we applied this PCR analysis to 296 CSF samples from patients who were suspected of having meningitis. Of the 296 samples that were examined, 59 samples were positive according to the CSF culture and/or molecular assays. Forty-six CSF samples were positive for both the CSF culture and our real-time PCR assay, while 13 samples were positive for the real-time PCR but negative for the traditional assays. This discrepancy may have been caused by the fact that these samples were collected from 23 patients who were treated with antimicrobials before CSF sampling.  相似文献   

14.
A PCR amplification was performed to detectNeisseria meningitidis insertion sequence1106 (IS-1106) in the humancerebrospinalfluid (CSF) in cases of meningitis. The study included 27 CSF samples from suspected meningitis patients. Although the inflammatory response in most of the samples was slightly increased, the results showed that 7 (26%) and 8 (30%) CSF samples were diagnosed as meningococcal meningitis by Gram staining and by culture, respectively. The primers of theIS-1106 were used for direct diagnosis ofN. meningitidis in the human spinal fluid after a minor treatment of the CSF samples. The sample was diagnosed as meningococcal meningitis, if a DNA band of about 600 bp was detected in the ethidium bromide-stained agarose gel. The 27 CSF samples were analyzed in a random manner. Of these, 18 samples including the Gram staining- and culture-positive samples were also positive in PCR amplification. However, a CSF sample, which was diagnosed to be meningococcal meningitis in culture was negative in both Gram staining and PCR analysis. The specificity of theIS-1106 primers was determined to be 95%, with 100% sensitivity in comparison to Gram staining and culture. The primers were sensitive to 10 pg or more of meningococcal DNA. In addition, the PCR amplification showed high predictive values (89 and 100%) in diagnosing meningitis in patients that were negative and positive responders when tested by culture and by Gram staining. In conclusion, the PCR amplification ofIS-1106 ofN. meningitidis is specific and sensitive to both culture-positive and-negative meningococcal meningitis. Hence, PCR assay is highly recommended for use in a rapid diagnosis of suspected meningitis patients.  相似文献   

15.
We recently investigated three cases of bacterial meningitis that were reported from a midwestern radiology clinic where facemasks were not worn during spinal injection of contrast agent during myelography procedures. Using pulsed field gel electrophoresis we linked a case strain of S. salivarius to an oral specimen of a radiology physician assistant (RPA). We also used a real-time PCR assay to detect S. salivarius DNA within a culture-negative cerebrospinal fluid (CSF) specimen. Here we extend this investigation through using a nested PCR/sequencing strategy to link the culture-negative CSF specimen to the case strain. We also provide validation of the real-time PCR assay used, demonstrating that it is not solely specific for Streptococcus salivarius, but is also highly sensitive for detection of the closely related oral species Streptococcus vestibularis. Through using multilocus sequence typing and 16S rDNA sequencing we further strengthen the link between the CSF case isolate and the RPA carriage isolate. We also demonstrate that the newly characterized strains from this study are distinct from previously characterized S. salivarius strains associated with carriage and meningitis.  相似文献   

16.
DW Kim  PE Kilgore  EJ Kim  SA Kim  DD Anh  BQ Dong  JS Kim  M Seki 《PloS one》2012,7(8):e42954

Background

Streptococcus pneumoniae is a leading cause of invasive bacterial disease in developed and developing countries. We studied the loop-mediated isothermal amplification (LAMP) technique to assess its suitability for detecting S. pneumoniae nucleic acid in cerebrospinal fluid (CSF).

Methodology/Principal Findings

We established an improved LAMP assay targeting the lytA gene (Streptococcus pneumoniae [Sp] LAMP). The analytical specificity of the primers was validated by using 32 reference strains (10 Streptococcus and seven non-Streptococcus species) plus 25 clinical alpha-hemolytic streptococcal strains, including four S. pneumoniae strains and 21 other strains (3 S. oralis, 17 S. mitis, and one Streptococcus species) harboring virulence factor-encoding genes (lytA or ply). Within 30 minutes, the assay could detect as few as 10 copies of both purified DNA and spiked CSF specimens with greater sensitivity than conventional polymerase chain reaction (PCR). The linear determination range for this assay is 10 to 1,000,000 microorganisms per reaction mixture using real-time turbidimetry. We evaluated the clinical sensitivity and specificity of the Sp LAMP assay using 106 randomly selected CSF specimens from children with suspected meningitis in Korea, China and Vietnam. For comparison, CSF specimens were also tested against conventional PCR and culture tests. The detection rate of the LAMP method was substantially higher than the rates of PCR and culture tests. In this small sample, relative to the LAMP assay, the clinical sensitivity of PCR and culture tests was 54.5% and 33.3%, respectively, while clinical specificity of the two tests was 100%.

Conclusions/Significance

Compared to PCR, Sp LAMP detected S. pneumoniae with higher analytical and clinical sensitivity. This specific and sensitive LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.  相似文献   

17.
目的:比较结核性脑膜炎与化脓性脑膜炎脑脊液与血浆生化指标比值。方法:选择2010年2月~2014年12月我院结核性脑膜炎患者82例,化脓性脑膜炎98例,检测脑脊液与血浆中的蛋白、糖及氯化物含量,并计算比值。结果:两组患者脑脊液蛋白、糖含量的差异无统计学意义(P0.05),化脓性脑膜炎组的氯化物含量高于结核性脑膜炎组(P0.05);两组血浆糖含量的差异无统计学意义(P0.05),化脓性脑膜炎组蛋白和氯化物含量明显高于结核性脑膜炎组(P0.05);化脓性脑膜炎组蛋白比值低于结核性脑膜炎组,氯化物比值则高于化脓性脑膜炎组,差异均有统计学意义(P0.05);两组间糖比值比较,差异无统计学意义(P0.05)。结论:脑脊液与血浆生化指标比值对鉴别诊断结核性脑膜炎与化脓性脑膜炎有重要意义。  相似文献   

18.
Gene amplification using 16S rDNA primers has been proposed as a strategy for the diagnosis of bacterial meningitis. The aim of this study was to evaluate the performance of the MicroSeq 500 16S ribosomal DNA test (Applied Biosystems) from patients with suspected bacterial meningitis and CSF negative-culture in comparison to traditional methods. Twelve purulent culture-negative CSF samples were collected between January 2005 and January 2007. For DNA extraction, 500 microl of CSF samples were treated using the QIAamp mini kit (QIAGEN). The extracted DNA was examined amplifying 500 bp at the 5' end of 16S rRNA gene using MicroSeq500 16S rDNA Bacterial Identification PCR kit and the sequencing reactions were performed with the MicroSeq500 16S rDNA Bacterial Identification Sequencing kit (Applied Biosystems). The sequences were compared with those available in GenBank. For the culture-negative CSF samples the MicroSeq 500 16S rDNA yielded a positive result in 9 cases (75.0%): three samples were identified as Streptococcus. pneumoniae, three as Neisseria meningitidis, and the remaining 3 as Haemophilus influenzae, Abiotrophia defectiva and Porphyromonas gingivalis. The MicroSeq 500 16S ribosomal DNA test may improve the microbiological diagnosis of bacterial meningitis, especially when spinal fluid samples are obtained after the administration of antimicrobial therapy.  相似文献   

19.
目的:探讨两性霉素B联合氟康唑治疗艾滋病合并新型隐球菌性脑膜脑炎(简称"艾滋病合并隐脑")的疗效预测因素。方法:回顾性收集2010年1月1日-2016年12月31日58例在首都医科大学附属北京佑安医院住院治疗且接受两性霉素B联合氟康唑治疗的艾滋病合并隐脑患者的临床资料,分析其疗效预测因素及预测价值。结果:根据预后将患者分为好转组(38例)和死亡组(20例),单因素分析结果显示两组之间CD4+T细胞计数、脑脊液细胞计数比较有统计学差异(P分别为0.032,0.001)。Logistic回归多因素分析结果显示脑脊液细胞计数是两性霉素B联合氟康唑治疗艾滋病合并隐脑的疗效预测因素(P=0.023),Exp(B)=1.01,95%置信区间为1.00-1.03。ROC曲线对脑脊液细胞计数的预测价值进行分析,结果显示曲线下面积为0.889,预测阈值为261个/mm3,对应的敏感性=0.684,特异性=1.0。结论:脑脊液细胞计数是两性霉素B联合氟康唑治疗艾滋病合并新型隐球菌性脑膜脑炎良好的疗效预测参考因素。  相似文献   

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