常见分枝杆菌种内不同株之间16S rRNA基因和16S-23SrRNA ITS序列分析结果的比较

目的 针对常见分枝杆菌不同株对其基因序列进行分析,比较分析结果.方法 利用16S rRNA Gene和16S-23S rRNAITS(转录间隔区序列)分析法分别对97株共7种DSMZ/ATCC引进的常见分枝杆菌进行种内不同株之间基因差异性分析,对比两种分型结果的异同.结果 16S rRNA基因可将13株草分枝杆菌分为3...     

利奈唑胺耐药金黄色葡萄球菌耐药机制分析

目的调查临床分离金黄色葡萄球菌对利奈唑胺的耐药情况及耐药机制。方法用Vitek 2系统GP67卡对2019年1月至12月南京鼓楼医院临床分离905株金黄色葡萄球菌进行药敏试验,对检出的利奈唑胺耐药菌株用E-test法复测利奈唑胺最低抑菌浓度(MIC);用PCR扩增及测序技术分析利奈唑胺耐药决定基因cfr、optr A及23S rRNA基因V区;对菌株基因组DNA进行全基因组测序分析,对耐药基因、毒力基因进行生物信息学分析;用多位点序列分型(MLST)技术获得菌株ST分型。结果 905株金黄色葡萄球菌检出1株(0.1%)利奈唑胺耐药株(MIC为16 mg/L),该菌株除对万古霉素和复方磺胺甲噁唑敏感外,对其余常用抗菌药物均耐药。PCR及测序技术显示该菌株携带cfr基因,23S rRNA V区存在T2337G和C2370G核苷酸突变位点;全基因组序列分析显示基因组包含碱基数为2 949 411 bp,总基因数为3 023个,包含59个tRNA编码基因以及7个完整的rRNA基因编码操纵子,获得Gen Bank登录号JAANYO000000000,且该菌株携带包括cfr在内的多种耐药决定基因和毒力基因; MLST分型为新型ST5985。结论利奈唑胺耐药金黄色葡萄球菌临床分离率较低。检出由cfr基因和23S rRNA V区突变介导的新ST型利奈唑胺耐药株。     

结核分枝杆菌rpoB基因突变的测序研究

目的　了解南通地区耐利福平结核分枝杆菌rpoB基因突变特征。 方法　对 36株临床分离菌株rpoB基因 5 0 2～ 5 33位点进行序列测定。结果　耐利福平 (RFP)分离株 93 3% (2 8/30 )存在rpoB基因突变 ,5 31位突变率 5 3 3% (16 /30 ) ,5 2 6位2 3 3% (7/30 ) ,5 16位 6 7% (2 /30 ) ,联合突变 3 3% (1/30 ) ,敏感菌株均无突变。结论　rpoB基因突变与利福平耐药密切相关 ,以 5 31位突变为主。     

20株中国医学细菌保藏管理中心标准肺炎克雷伯菌分子生物学特征分析

目的对中国医学细菌保藏管理中心收集保藏的肺炎克雷伯菌(Klebsiella pneumoniae,KP)进行分子生物学特征分析。方法对20株保藏KP菌株采用16S rRNA扩增及测序和质谱技术进行菌种鉴定验证;拉丝试验确定黏液表型;PCR筛查6种常见高毒力荚膜血清型(K1、K2、K5、K20、K54和K57);采用多位点序列分型(MLST)对菌株进行分子分型。结果 20株菌种均扩增出预期大小的16S rRNA基因片段,与KP模式菌株参考序列的相似性均99%;质谱技术检测均为KP,其中有4株鉴定到亚种;拉丝试验阳性率30%(6/20);共检出K2型3株(15%)、K5型4株(20%)、K54型1株(5%)、K57型4株(20%)和未分型8株;20株菌种分为10个ST型。结论该研究完善了KP菌株的分子生物学方面的质控指标。     

不同分子生物学方法快速鉴别非结核分枝杆菌的应用评价

目的 评价3种分子生物学方法快速鉴定非结核分枝杆菌的优缺点.方法 收集41株临床分离的非结核分枝杆菌,以16S rRNA基因测序方法为标准,同时以hsp65基因测序方法及PCR-RFLP方法鉴定菌株,与16S rRNA基因测序结果进行比较.结果 41株非结核分枝杆菌16SrRNA基因测序结果:9株龟分枝杆菌复合群,7株偶发分枝杆菌,7株胞内分枝杆菌,3株鸟分枝杆菌,3株堪萨斯分枝杆菌复合群,3株耻垢分枝杆菌,3株土分枝杆菌,2株草分枝杆菌,2株无色分枝杆菌,1株瘰疬分枝杆菌,1株M.arupense.与16S rRNA基因测序相比较,hs65 PCR-RFLP能鉴定9株龟分枝杆菌复合群至亚种脓肿分枝杆菌,3株堪萨斯分枝杆菌复合群鉴定至亚种堪萨斯分枝杆菌;1株偶发分枝杆菌及1株无色分枝杆菌与其不符;其余菌株鉴定结果一致,符合率为95.1%(39/41).hsp65基因测序结果显示,1株爱尔兰分枝杆菌与16S rRNA测序结果不符,其余菌株鉴定结果与其一致,符合率为97.6%(40/41),并且能进一步将9株龟分枝杆菌复合群鉴定至亚种脓肿分枝杆菌,3株堪萨斯分枝杆菌复合群鉴定至亚种堪萨斯分枝杆菌.结论 3种方法均能快速鉴定非结核分枝杆菌.与16S rRNA基因测序相比,hsp65基因测序及hsp65 PCR-RFLP更容易鉴定临床最常见非结核分枝杆菌(如堪萨斯分枝杆菌和脓肿分枝杆菌),可在临床推广使用.     

基于16S rRNA和gyrB基因的施万菌种水平鉴定分析

  目的   构建基于16S rRNA和gyrB基因对施万菌(Shewanella)进行种水平鉴定的方法,比较2个基因的鉴定能力差异。   方法   利用DnaSP 6.0软件对施万菌16S rRNA 和gyrB 基因的信息位点数及其百分比、核苷酸多态性值、平均G＋C含量、非同义突变率与同义突变率的比值（Ka/Ks）、Tajima检验进行基因多态性分析。 用MEGA 6.06软件的邻接距离矩阵法对90株测试菌株和54株模式菌株构建16S rRNA 和gyrB 基因的进化树。 用MEGA 6.06软件的Kimura’s 2-parameter模型,确定90株测试菌株的菌种后,计算16S rRNA 和gyrB 基因的遗传距离和序列相似性。 比较两者对施万菌种水平鉴定能力差异。   结果   16S rRNA和gyrB基因序列相似性平均值分别为95.0%、80.8%。 在16S rRNA基因进化树中,S. marinintestina和S. sairae、S. livingstonensis和S. vesiculosa的进化分支几乎完全相同,gyrB基因则能在种水平将所有菌株区分开。 16S rRNA基因的种内和种间相似性范围小。   结论   与16S rRNA基因相比,gyrB基因能够更准确的用于施万菌的种水平鉴定。     

4种中国常见致病性基因种钩端螺旋体标准菌株的建立与评价

目的 依据《病原微生物菌(毒)种国家标准株评价技术标准》(WS/T 812—2022),建立Leptospira interrogans、L.borgpetersenii、L. alexanderi和L. weilii 4种中国常见致病性基因种钩端螺旋体标准菌株。方法 以56601、56604、56615、566554株致病性代表菌株为研究对象,利用暗视野显微镜开展形态学观察。以16S rRNA基因为靶基因进行聚合酶链式反应扩增、测序确定所属基因种。通过多位点序列分型(MLST)方法,对4株代表株进行分子分型分析,确定每株菌株7个位点等位基因号和序列型别(ST)。综合暗视野显微镜形态学观察、16S rRNA基因测序和MLST分型结果系统评价4株代表菌株经不同传代次数后的分子遗传学稳定性。同时通过Illumina NovaSeq测序平台对56604、56615和56655开展全基因组测序分析,了解菌株基因组特征。结果 暗视野显微镜下,4株代表菌株均具有典型的钩端螺旋体形态。16S rRNA基因序列分析显示,56601、56604、56615和56655分别隶属于L. interrogan...     

幽门螺杆菌克拉霉素耐药基因芯片的制备和应用

目的 建立一种寡核苷酸微阵列检测幽门螺杆菌23S rRNA基因A2142G、A2143G及C2182T点突变的方法.方法 根据23S rRNA基因A2142G、A2143G及C2182T突变位点设计相应探针,样本经不对称PCR扩增后,其产物与芯片杂交.非荧光标记引物扩增PCR产物克隆至T载体,测序验证芯片结果,并结合临床最低抑菌浓度实验判断该方法的正确性.结果 寡核苷酸微阵列技术与测序检测幽门螺杆菌23S rRNA基因多态性结果完全一致.经培养及鉴定幽门螺杆菌阳性的54份标本,杂交结果显示A2142位点均为野生型(54/54);A2143G突变率为11.11%(6/54),尚未发现A2143C和A2143T的突变;C2182T突变率为12.96%(7/54),尚未发现C2182A和C2182G的突变,其余均为野生型,上述结果与菌株体外试验MIC结果完全一致.结论 建立一种寡核苷酸微阵列技术检测幽门螺杆菌克拉霉素耐药的23S rRNA基因多态性的方法,可以高通量并直接检测胃黏膜而不需进行细菌培养,推动个体化治疗方案的实施.     

食品检验用标准菌株分子水平质控方法的建立与应用

目的 建立食品检验用标准菌株分子水平质控方法,并进行应用。 方法 使用16S rRNA基因序列分析、脉冲场凝胶电泳（PFGE）、多位点序列分型等分子生物学技术手段,对食品安全国家标准中使用的标准菌株进行分子确认,并对不同的批号进行验证。 结果 16S rRNA基因序列比对结果符合该菌株所在的菌属,并获得标准菌株16S rRNA基因标准序列,不同批号的标准菌株16S rRNA基因序列完全一致;确定了每株标准菌株的ST型和基因型,并对不同批号的菌株进行了基因型比较,未发现型别改变;对无PulseNet标准操作方法的菌株,开展方法学研究,获得了最适用的限制性内切酶和电泳参数,建立了标准菌株分子指纹图谱,比较不同批号菌株的PFGE图谱,相似性均为100%。 结论 本研究首次将分子生物学技术应用到标准菌株的质量控制,突破了使用传统质控方法的瓶颈,从分子水平实现对标准菌株稳定性的评价,保证了标准菌株在食品检验过程中的稳定性和一致性。      

一株死亡患者分离的致死创伤弧菌菌株的耐药表型与分子特征

目的 对培养分离的创伤弧菌菌株(2014-DJH)进行耐药表型与分子特征分析。方法 采用全自动微生物鉴定及药敏分析系统进行生化鉴定和耐药分析;采用PCR方法检测vvhA基因和pilF基因,及vcg和16S rRNA基因分型;应用多位点序列分析进行分子分型。结果 分离菌株2014-DJH经生化鉴定为革兰阴性的生物1型创伤弧菌;对大多数常用抗生素都敏感,对妥布霉素中度敏感;PCR检测vvhA和pilF阳性,为vcgC-16S rRNA B(CB)基因型;菌株的多位点序列型为glp 5、gyrB 3、mdh 32、metG 68、purM 21、dtdS 39、lysA 115、pntA 4、pyrC 42、tnaA 75。结论 菌株2014-DJH为新ST型菌株,命名为ST 289,注册号为id-389。基因分型结果表明该菌具有较强的致病能力,加强创伤弧菌感染的监测与预警具有重要的意义。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.