Comparison of Automated Ribotyping,spa Typing,and MLST in 108 Clinical Isolates of Staphylococcus aureus from Orthopedic Infections

108 isolates of Staphylococcus aureus, belonging to six large ribogroups according to the automated Ribo-Printer^® system, were studied with two highly used molecular methods for epidemiological studies, namely multi-locus sequence typing (MLST) and spa typing, followed by BURP and eBURST v3 analysis for clustering spa types and sequence (ST) types. The aim was to evaluate whether automated ribotyping could be considered a useful screening tool for identifying S. aureus genetic lineages with respect to spa typing and MLST. Clarifying the relationship of riboprinting with these typing methods and establishing whether ribogroups fit single clonal complexes were two main objectives. Further information on the genetic profile of the isolates was obtained from agr typing and the search for the mecA, tst genes, and the IS256 insertion sequence. Automated ribotyping has been shown to predict spa clonal complexes and MLST clonal complexes. The high cost and lower discriminatory power of automated ribotyping compared to spa and MSLT typing could be an obstacle to fine genotyping analyzes, especially when high discriminatory power is required. On the other hand, numerous advantages such as automation, ease and speed of execution, stability, typeability and reproducibility make ribotyping a reliable method to be juxtaposed to gold standard methods.     

丙型肝炎病毒RNA室内质控品的制备及其临床应用评估

目的探讨自制丙型肝炎病毒(hepatitis C Virus,HCV)RNA定量检测室内质控品的可行性,并评估其临床应用价值。方法收集已发过HCV-RNA临床报告的血浆样本,分别将HCV-RNA阴性血浆(<50 IU/mL)、弱阳性血浆(102~103 IU/mL)和强阳性血浆(105~106 IU/mL)混合、离心后,获得阴性质控品(HCV-RNA-N)、弱阳性质控品(HCV-RNA-L)和强阳性质控品(HCV-RNA-H),小量分装后于-80℃冻存。确定靶值后,评价其均一性、重复性、准确性和稳定性。结果自制HCV RNA室内质控品具有良好的均一性、重复性和准确性,可在-80℃保持稳定至少12个月。结论HCV RNA室内质控品制备过程简单,样品均一,重复性好,准确性高,稳定性良好,可用于临床检测HCV-RNA。     

Narrow Genetic Diversity of Wolbachia Symbionts in Acrididae Grasshopper Hosts (Insecta,Orthoptera)

Bacteria of the Wolbachia genus are maternally inherited symbionts of Nematoda and numerous Arthropoda hosts. There are approximately 20 lineages of Wolbachia, which are called supergroups, and they are designated alphabetically. Wolbachia strains of the supergroups A and B are predominant in arthropods, especially in insects, and supergroup F seems to rank third. Host taxa have been studied very unevenly for Wolbachia symbionts, and here, we turn to one of largely unexplored insect families: Acrididae. On the basis of five genes subject to multilocus sequence typing, we investigated the incidence and genetic diversity of Wolbachia in 41 species belonging three subfamilies (Gomphocerinae, Oedipodinae, and Podisminae) collected in Turkey, Kazakhstan, Tajikistan, Russia, and Japan, making 501 specimens in total. Our results revealed a high incidence and very narrow genetic diversity of Wolbachia. Although only the strains belonging to supergroups A and B are commonly present in present, the Acrididae hosts here proved to be infected with supergroups B and F without A-supergroup variants. The only trace of an A-supergroup lineage was noted in one case of an inter-supergroup recombinant haplotype, where the ftsZ gene came from supergroup A, and the others from supergroup B. Variation in the Wolbachia haplotypes in Acrididae hosts within supergroups B and F was extremely low. A comprehensive genetic analysis of Wolbachia diversity confirmed specific features of the Wolbachia allelic set in Acrididae hosts. This result can help to elucidate the crucial issue of Wolbachia biology: the route(s) and mechanism(s) of Wolbachia horizontal transmission.     

半钢子午线轮胎全氮气硫化工艺研究

对蒸汽/氮气硫化工艺与全氮气硫化工艺进行对比,并对205/55R16 91V半钢子午线轮胎采用两种硫化工艺进行硫化测温和分析。结果表明,相对蒸汽/氮气硫化工艺,采用全氮气硫化工艺轮胎的上下模温差较低,硫化时间缩短,各部位硫化程度符合要求,成品轮胎性能提高,单胎硫化能耗成本降低40%。     

Plastid Transformation of Micro-Tom Tomato with a Hemipteran Double-Stranded RNA Results in RNA Interference in Multiple Insect Species

Plant-mediated RNA interference (RNAi) holds great promise for insect pest control, as plants can be transformed to produce double-stranded RNA (dsRNA) to selectively down-regulate insect genes essential for survival. For optimum potency, dsRNA can be produced in plant plastids, enabling the accumulation of unprocessed dsRNAs. However, the relative effectiveness of this strategy in inducing an RNAi response in insects using different feeding mechanisms is understudied. To investigate this, we first tested an in vitro-synthesized 189 bp dsRNA matching a highly conserved region of the v-ATPaseA gene from cotton mealybug (Phenacoccus solenopsis) on three insect species from two different orders that use leaf-chewing, lacerate-and-flush, or sap-sucking mechanisms to feed, and showed that the dsRNA significantly down-regulated the target gene. We then developed transplastomic Micro-tom tomato plants to produce the dsRNA in plant plastids and showed that the dsRNA is produced in leaf, flower, green fruit, red fruit, and roots, with the highest dsRNA levels found in the leaf. The plastid-produced dsRNA induced a significant gene down-regulation in insects using leaf-chewing and lacerate-and-flush feeding mechanisms, while sap-sucking insects were unaffected. Our results suggest that plastid-produced dsRNA can be used to control leaf-chewing and lacerate-and-flush feeding insects, but may not be useful for sap-sucking insects.     

河南省2016—2020年食品污染科瓦利斯沙门氏菌及食源性疾病的溯源状况

目的 研究河南省2016—2020年食品污染科瓦利斯沙门氏菌及食源性疾病的溯源状况。方法 2016—2020年河南省食品中分离出22株科瓦利斯沙门氏菌,从腹泻患者粪便中检出5株科瓦利斯沙门氏菌。参照国家食品安全风险监测手册进行血清分型、药敏试验和脉冲场凝胶电泳（PFGE）分子分型,PFGE和药敏数据使用BioNumerics 7.6软件包进行聚类分析。结果 22株科瓦利斯沙门氏菌均来生鲜禽肉食品。从耐药结果来看,食品来源的菌株多重耐药现象不是十分严重,而腹泻患者来源的菌株耐药谱比较复杂,有敏感株存在,也有2株对13种抗生素耐药的超级耐药菌出现;从PFGE分子分型结果来看,同一时期同一区域的食品株之间有相似度很高的现象出现,提示了污染食品在夏季某一区域有聚集的可能。从腹泻患者株和食品株的比对溯源来看,没有食品直接引起的疾病发生,可能是经过一定的传播途径后才致病的。结论 食品安全风险监测数据可以给市场监督提供有效的线索,耐药监测和分子分型技术的普及和应用推动了食源性疾病的溯源和精准化预防,更大限度地实现了疾病预防和保护健康的目标。     

聚合酶链式反应(PCR)技术鉴定啤酒腐败菌的最新进展

综述了PCR技术在啤酒腐败细菌鉴定方面的应用及最新进展 ;介绍了 3种PCR技术 ,特别讲述了利用这些技术对啤酒中乳酸菌的鉴定 ;并分析了PCR技术的局限性 ,对其应用前景进行了展望。     

Validation of a method for the detection of five species,serogroups, biotypes and virulence factors of Vibrio by multiplex PCR in fish and seafood

In this work a sequential multiplex PCR system was designed and validated for the detection of most frequent foodborne pathogen Vibrio species in fish and seafood (Vibrio cholerae, Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio alginoliticus and Vibrio mimicus). The method proposed functions in a hierarchical way, being composed of an end-point multiplex PCR to detect the presence of DNA belonging to the studied species, followed by multiplex PCR and fragment analysis allowing the viability assessment of the detected strains. The final multiplex PCR step of the method may be applied if identification of the serogroup, biotype and/or virulence factor level is necessary. Forty samples of commercial fish and seafood products were used at the method validation stage. Sixty three marine organism samples obtained from various estuarine areas of Spain including shrimps, crabs, bivalve mollusks and fishes were screened for presence of Vibrio species and 2 mussel samples were found positive for V. parahaemolyticus. On the whole, the proposed method is robust and readily adaptable in routine molecular diagnostic laboratories, allowing monitoring and simultaneous detection of all these bacterial pathogens in seafood samples, reducing the expenses and time consumed by other analytical methods.     

多重PCR方法检测食品中转基因成分

根据转基因农作物中最常用的花椰菜花叶病毒启动子 (CaMV 3 5S)和根癌农杆菌终止子(NOS)的序列 ,设计合成了两对不同的引物和相对应的两种荧光双链探针 (FDCP) ,分别建立了多重PCR、应用FDCP的实时荧光PCR同时检测转基因成分 3 5S启动子和NOS终止子的方法 .并利用该套方法对马铃薯、大豆、玉米、甜椒、番茄等实物样品进行了检测 ,发现 1 3份样品中有 6份检出3 5S启动子、NOS终止子 ,其余 7份样品的检测结果为阴性 .表明作者建立的多重PCR方法能有效检测出 3 5S和NOS成分 ,其中多重PCR法具有灵敏度高、特异性好的特点 ,多重荧光PCR法则更为简便、快速、准确     

酿造大麦品种及纯度的鉴定

在酿造工业中,大麦的品种对于啤酒质量有着极其重要的影响,目前我国每年需进口大量的大麦,而对其品种和纯度却没有行之有效的方法来进行鉴别。国外已对此进行了大量的研究,建立了多种准确的鉴别方法。其中以基因组分析法和蛋白质电泳法最为可行,它们都具有感官鉴别所没有的准确性和可信性,是将来大麦品种鉴定的首选方法。