多重实时PCR快速同时检测沙门菌和志贺菌

目的 建立改良分子信标，多重实时PCR同时检测沙门菌和志贺菌的快速方法，应用于食源性致病菌的快速诊断。方法 根据GenBank公布的沙门菌侵袭性基因invA和ssaR基因，分别设计一对引物和改良分子信标探针，用同色荧光标记，用于同体系检测沙门菌。志贺菌根据ipaH基因的保守序列，设计引物和改良分子信标探针，加入沙门菌检测体系中，建立三重实时PCR一改良分子信标检测体系，应用于同时对沙门菌、志贺菌食物中毒的快速诊断和门诊肠道致病菌的检测。结果 改良分子信标一多重实时PCR反应体系DNA灵敏度为69～93fg/μl。菌液灵敏度为32～64CFU／ml或1～2CFu／PCR反应体系，无交叉反应。该反应体系同时检测134株沙门菌和67株志贺菌，均出现特异的荧光信号，两种细菌检测互不干扰。对细菌性食物中毒样本等共1100份同时进行沙门菌和志贺菌检测，569份沙门菌实时PCR阳性，其中551份沙门菌培养阳性；42份志贺菌实时PCR阳性，其中41份志贺菌培养阳性。从样品处理到检测结果仅需时间2h至1d。结论 改良分子信标-多重实时PCR检测体系快速、灵敏度高，特异性强，可用于沙门菌和志贺菌食物中毒的快速诊断，伤寒、痢疾等肠道传染病的初筛及预防医学门诊的健康人群体检，为食源性疾病的分子流行病学调查提供新的检测手段。     

fliC基因在快速分型鉴定伤寒沙门菌和甲型副伤寒沙门菌的应用

目的:探讨沙门菌1相鞭毛蛋白抗原fliC基因在快速分型鉴定伤寒沙门菌和甲型副伤寒沙门菌的应用。方法:根据伤寒沙门菌和甲型副伤寒沙门菌1相鞭毛蛋白fliC-d和fliC-a基因以及菌体抗原rfbS基因的核酸序列,设计针对fliC-d、fliC-a及rfbS基因的3对特异性引物,采用多重PCR法进行检测。结果:实验结果显示,伤寒沙门菌和甲型副伤寒沙门菌分别在750 bp和329 bp处扩增出2条特异性目的条带,在258 bp处扩增出1条相同条带,非伤寒沙门菌株和甲型副伤寒沙门菌株均为阴性。结论:fliC基因检测可用于伤寒沙门菌和甲型副伤寒沙门菌的分型鉴定,而rfbS基因则无助于分型鉴定。     

VaxArray assessment of influenza split vaccine potency and stability

Vaccine manufacturers require more rapid and accurate tools to characterize the potency and stability of their products. Currently, the gold standard for influenza vaccine potency is the single radial immunodiffusion (SRD) assay, which has inherent disadvantages. The primary objective of this study was to investigate the ability of the VaxArray Influenza (VXI) seasonal hemagglutinin (sHA) potency assay to accurately quantify potency and stability in finished vaccines as well as to quantify hemagglutinin protein (HA) within crude in-process samples. Monobulk intermediates and mono- and multivalent vaccines were tested using VXI. Quantification of HA in crude samples was evaluated by spiking known concentrations of HA into allantoic fluid. VXI generated SRD equivalent potency measurements with high accuracy (within ±10%) and precision (CV 10 ± 4%) for antigen components of monobulk intermediates and multivalent split vaccines. For these vaccines and vaccine intermediates, the VXI linear dynamic range was ∼0.01–0.6 μg/mL, which is 12× greater than the linear range of SRD. The measured sample limit of detection (LOD) for VXI varied from 0.005 to 0.01 μg/mL for the different subtypes, which in general is ≥600× lower than the LOD for SRD. VXI was able to quantify HA in crude samples where HA only accounts for 0.02% of the total protein content. Stability indication was investigated by tracking measured potency as a function of time at elevated temperature by both SRD and VXI. After 20 h at 56 °C, the ratio of VXI to SRD measured potency in a quadrivalent vaccine was 76%, 125%, 60%, and 98% for H1/California, H3/Switzerland, B/Phuket and B/Brisbane, respectively. Based on the study results, it is concluded that VXI is a rapid, multiplexed immunoassay that can be used to accurately determine flu vaccine potency and stability in finished product and in crude samples from upstream processes.     

少精症患者Y染色体微缺失基因诊断的研究

目的 建立稳定的少、弱精症患者Y染色体微缺失的基因诊断方法，研究 男性不育与Y染色体位点缺失的相关性。方法选取位于AZE区15个STR微卫星标记分成4组进行多重PCR的检测。结果 90例少弱精患者中，检出7例缺失，占患者的7.8％。其中有3例为单个位点的缺失，有4例为大片断缺失。结论 多重PCR是检测Y染色体微缺失的合适方法，AZEb和AZEc区与少弱精症密切相关。     

多重PCR法检测外周血单个核细胞中的HBVDNA与HBVcccDNA

目的建立多重聚合酶链反应法(Multiplex Polymerase chain reaction，M—PCR)，揭示慢性乙肝患者外周血单个核细胞(PBMC)中HBVDNA的存在状况。方法采用一种把一套扩增乙肝病毒基因组DNA(HBV genome DNA)的引物和一套特异性扩增乙肝病毒共价闭合环状DNA(HBVcccDNA)的引物掺入到一个体系中的PCR法，检测PBMC中的HBVDNA核酸分子。结果PCR法可使处于同一PBMC中的总HBVDNA和HBVcccDNA同时分别良好的扩增出来；30例慢性乙肝患者的PBMC中，总HBVDNA与HBVcccDNA同耐检出者23例，检出率76．6％；检出HBVcccDNA者占检出总HBVDNA者的82．1％。结论PBMC中的HBVDNA部分参与复制。成功的建立了能同时检测HBV基因组DNA与HBVcccDNA的M—PCR方法。     

Factory packed and expired – about emergency insect sting kits

Background: Patients allergic to insect venom are instructed to always carry emergency medication–an emergency kit. According to the current guidelines, these emergency kits should contain a H1‐receptor‐blocking antihistamine and corticosteroid for oral use, as well as an epinephrine inhaler and in particular situations an epinephrine auto‐injector. Patients and Methods: For quality management reasons patients with wasp venom allergy who presented for sting challenge provocation test were told to demonstrate their emergency kits. Concomitantly, constituents of the patient's emergency kits were checked for date of expiry of the medication and the patients were interviewed on storage and use of the emergency kits. Results: In total 42 patients with a median duration time of systemic immunotherapy of 2.5 year were evaluated. Medication post date of expiration was found in 54% of the kits (n = 39). Only 31% of the patients could demonstrate how to use the kits correctly. Problems were especially evident concerning for using the application of the inhaler and auto‐injector. 50% of the patients demonstrated using epinephrine auto‐injectors in such way that an accidental injection into the fingers would have resulted. Conclusion: To assure safe and effective handling of all components of the emergency kit, continuous training and repeated supervised practice is necessary.     

The development and evaluation of a single step multiplex PCR method for simultaneous detection of Brugia malayi and Wuchereria bancrofti

A single step novel multiplex polymerase chain reaction (PCR) has been developed for simultaneous detection of human filarial parasites, Brugia malayi and Wuchereria bancrofti, from blood samples and mosquitoes. The primers used were novel and have been tested with the parasite DNA amplifying 188bp (BM) and 129bp (WB) DNA fragments, specific to B. malayi and W. bancrofti, respectively, in a single reaction. The specificity of the PCR product was confirmed by DNA sequencing and slot blot hybridization assay. The test was found highly sensitive for both B. malayi and W. bancrofti by detecting the parasitaemia up to the level of one microfilaria per reaction. The assay was further evaluated on 98 blood samples and 144 mosquito samples collected from filarial endemic areas. The PCR was found to be more efficient in comparison to microscopy by detecting 8% and 5% more filarial parasites in field-collected blood and mosquito samples, respectively. This novel PCR that offers scope for simultaneous detection of both the parasites may be used as a diagnostic tool for the detection of filariasis in population and can be adopted for rapid surveillance and monitoring of mosquitoes for use in the effective control of filariasis.     

Comparison of pyridoxal phosphate-supplemented reagent kits for alanine aminotransferase using centrifugal analysis

The addition of pyridoxal-5-phosphate for assay of alanine aminotransferase has been recommended. The referral methods are inconvenient for high volume instrumentation due to use of multiple reagents and blanks. We adapted a well-documented method to the centrifugal analyzer as a reference for adaptation of two kit methods. Reference intervals obtained and linearity determined were all similar. The kit methods compared favorably to the referral method. Linear regression analysis yielded the following: DOW = 1.011 BERG + 1.666, r = 0.9965; SKI = 0.938 BERG + 4.559, r = 0.9926; and DSKI = 1.028 BERG + 1.051, r = 0.9889. Precision of the assays was acceptable. We concluded that automation of reagent kits incorporating pyridoxal-5-phosphate is feasible and the assays compared favorably to a recommended method. High volume instrumentation can be used without denigration of analytical quality and to allow comparability to a documented method for interlaboratory review.     

Rapid identification of Streptococcus pneumoniae serotypes by cpsB gene-based sequetyping combined with multiplex PCR

Background/purposeStreptococcus pneumoniae is an important human pathogen that causes invasive infections in adults and children. Accurate serotyping is important to study its epidemiological distribution and to assess vaccine efficacy.MethodsInvasive S. pneumoniae isolates (n = 300) from 27 teaching hospitals in China were studied. The Quellung reaction was used as the gold standard to identify the S. pneumoniae serotypes. Subsequently, multiplex PCR and cpsB gene-based sequetyping methods were used to identify the serotypes.ResultsBased on the Quellung reaction, 299 S. pneumoniae isolates were accurately identified to the serotype level and 40 different serotypes were detected. Only one strain was non-typeable, and five most common serotypes were identified: 23F (43, 14.3%), 19A (41, 13.7%), 19F (41, 13.7%), 3 (31, 10.3%), and 14 (27, 9.0%). Overall, the multiplex PCR method identified 73.3 and 20.7% of the isolates to the serotype and cluster levels, respectively, with 1.7% of the isolates misidentified. In contrast, the cpsB sequetyping method identified 59.0 and 30.3% of the isolates to the serotype and cluster levels, respectively, and 7% were misidentified.ConclusionsThe cpsB gene sequetyping method combined with multiplex PCR, can greatly improve the accuracy and efficiency of serotyping, besides reducing the associated costs.     

标准化配置换药包预防骨科PICC导管相关性感染的研究

目的探讨标准化配置换药包对预防骨科PICC导管相关性感染的疗效。方法选择急诊收治的98例符合PICC中心静脉置管适应症的骨科患者为研究对象,随机将其分为对照组和观察组,各49例,置管过程中对照组使用常规换药包,观察组使用标准化配置换药包,对比分析两组导管相关性感染相关指标。结果观察组患者导管相关性血流感染率、出口部位感染发生率、感染发生率均低于对照组(P0.05);2组PICC置管术后在白细胞计数、抗生素使用时间、维护依从性及住院时间等方面比较,观察组均优于对照组(P0.05)。结论标准化配置换药包在预防骨科PICC导管相关性感染方面疗效确切,值得临床推广应用。