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Jack Schembri, Hayley D Gillis, Amanda L S Lang, Michelle Warhuus, Irene Martin, Walter Demczuk, May ElSherif, Shelly A McNeil, Jason J LeBlanc
BACKGROUND: Serotyping of Streptococcus pneumoniae is an integral part of disease surveillance, with over 92 serotypes characterized to date using traditional serotyping. To identify the most predominant disease causing serotypes, molecular serotyping methods are now increasingly being used, like conventional and real-time multiplex PCR (cmPCR and rmPCR, respectively). Given that cmPCR consists of eight reactions spanning 41 targets, and rmPCR consists of seven triplex reactions, standardizing positive controls for these assays is challenging...
September 11, 2018: Plasmid
Zhongcheng Liu, Lifang Hao, Nanan Wang, Su Zhang, Nan Zhang, Zhenzhen Xu, Yanlei Yang, Yanfen Zhang
IgE/FcεRI signal pathway plays a crucial role in triggering allergic reactions, and there is no cross-recognition between IgE and FcεRI in human and rats. In order to obtain the hFcεRIα/ RBL-2H3 cell line, total RNA was extracted from U937 cells, and the human FcεRIα gene was obtained by RT-PCR technology. Then the amplified product was digested and inserted into the pIRES2 -EGFP vector. After the plasmid was transfected into the RBL-2H3 cells using lipofectamine, and the RBL-2H3 cell lines of stable expression were screened by G418...
September 10, 2018: Plasmid
Deshui Yu, Libing Liao, Yi Zhang, Kedong Xu, Ju Zhang, Kun Liu, Xiaoli Li, Guangxuan Tan, Jurui Zheng, Yong He, Changling Xu, Jinjin Zhao, Beibei Fu, Jiaxing Xie, Jie Mao, Chengwei Li
RNA interference (RNAi), based on hairpin RNA (hpRNA) expression, plays an important role in functional analysis of plant genes. Traditional methods for making RNAi constructs usually involve multiple time-consuming cloning steps. We have developed a Gateway-compatible binary vector for RNAi-mediated gene knockdown in plants from pCAMBIA2301 and pHANNIBAL vectors. The new plant RNAi binary vector, named pCAMBIA2301-GW-RNAi, has two inverted repeated Gateway cassettes driven by the cauliflower mosaic virus 35S (CaMV 35S) promoter...
September 7, 2018: Plasmid
Akira Nagasaki, Yoshio Kato, Keiichi Meguro, Ayana Yamagishi, Chikashi Nakamura, Taro Q P Uyeda
The CRISPR/Cas9 system is a powerful genome editing tool for disrupting the expression of specific genes in a variety of cells. However, the genome editing procedure using currently available vectors is laborious, and there is room for improvement to obtain knockout cells more efficiently. Therefore, we constructed a novel vector for high efficiency genome editing, named pGedit, which contains EGFP-Bsr as a selection marker, expression units of Cas9, and sgRNA without a terminator sequence of the U6 promoter...
September 6, 2018: Plasmid
Jean-Yves Madec, Marisa Haenni
Antimicrobial resistance (AMR) plasmids have been recognized as important vectors for efficient spread of AMR phenotypes. The food reservoir includes both food-producing animals and food products, and a huge diversity of AMR plasmids have been reported in this sector. Based on molecular typing methods and/or whole genome sequencing approaches, certain AMR genes/plasmids combinations were found more frequently in food compared to other settings. However, the food source of a definite AMR plasmid is highly complex to confirm due to cross-sectorial transfers and international spread of AMR plasmids...
September 6, 2018: Plasmid
Fara Amelia Primelles Eguia, Henrique Roman Ramos, Stefanie Kraschowetz, Daniel Omote, Celso Raul Romero Ramos, Paulo Lee Ho, Eneas Carvalho, Viviane Maimoni Gonçalves
Expression vectors for industrial production should be stable and allow tight control of protein synthesis. This is necessary to ensure plasmid transmission to daughter cells in order to achieve a stable population capable of synthesizing high amounts of the target protein. A high-copy-number plasmid, pAE, was previously used for laboratory-scale production of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and the Schistosoma mansoni fatty acid binding protein (rSm14), but it was unstable for large-scale production...
September 5, 2018: Plasmid
Anne O Summers, Andrew G Wiggins, Stephen P LaVoie, Joy Wireman, Anne O Summers
No abstract text is available yet for this article.
September 4, 2018: Plasmid
Rafael Pinilla-Redondo, Valentine Cyriaque, Samuel Jacquiod, Søren J Sørensen, Leise Riber
The emergence of antimicrobial resistant bacteria constitutes an increasing global health concern. Although it is well recognized that the cornerstone underlying this phenomenon is the dissemination of antimicrobial resistance via plasmids and other mobile genetic elements, the antimicrobial resistance transfer routes remain largely uncharted. In this review, we describe different methods for assessing the transfer frequency and host ranges of plasmids within complex microbiomes. The discussion is centered around the critical evaluation of recent advances for monitoring the fate of fluorescently tagged plasmids in bacterial communities through the coupling of fluorescence activated cell sorting and next generation sequencing techniques...
August 4, 2018: Plasmid
Stephanie J Ambrose, Christopher J Harmer, Ruth M Hall
The large, broad host range IncC plasmids are important contributors to the spread of key antibiotic resistance genes and over 200 complete sequences of IncC plasmids have been reported. To track the spread of these plasmids accurate typing to identify the closest relatives is needed. However, typing can be complicated by the high variability in resistance gene content and various typing methods that rely on features of the conserved backbone have been developed. Plasmids can be broadly typed into two groups, type 1 and type 2, using four features that differentiate the otherwise closely related backbones...
August 3, 2018: Plasmid
Karen C Hernández-Ramírez, Rosa I Reyes-Gallegos, Víctor M Chávez-Jacobo, Amada Díaz-Magaña, Víctor Meza-Carmen, Martha I Ramírez-Díaz
Mobile plasmid-encoded elements are DNA segments that are transferred for horizontal gene transfer and that confer adaptive proprieties, as well as virulence and antibiotic and heavy metal resistance to bacteria. The conjugative plasmid pUM505, isolated from a clinical strain of Pseudomonas aeruginosa, possesses a putative 31.292 kb mobile element (denominated Mpe: Mobile plasmid- encoded element) that, in addition to possessing chr genes that confer chromate resistance to Pseudomonas, contains two putative mer operons that could confer mercury resistance...
July 29, 2018: Plasmid
Vicki Adams, Xiaoyan Han, Dena Lyras, Julian I Rood
Clostridium perfringens is an anaerobic bacterium that is a major human and animal pathogen. The key features of C. perfringens-mediated infections are that disease pathogenesis involves the production of protein toxins and that disease epidemiology generally involves the production of environmentally resistant endospores. Many of the toxins involved in these diseases are encoded on conjugative plasmids that are closely related to the paradigm tetracycline resistance plasmid pCW3. This plasmid encodes the Tet(P) tetracycline resistance determinant, and the tcp locus, which mediates conjugative transfer and is also present on the toxin plasmids...
July 26, 2018: Plasmid
Xiaojing Zhang, Xuwang Cai, Yi Qi, Yunbao Liu, Qi Cao, Xiangru Wang, Huanchun Chen, Xiaojuan Xu
Some Haemophilus parasuis strains display resistance to transformation with Escherichia.coli-derived plasmids. This property limits the application of genetic approaches previously developed for H. parasuis. The present study showed that natural transformation with the shuttle plasmid pS2UK led to allelic exchange in H. parasuis strains SH0165 and CF7066. Furthermore, natural transformation with pS2UK yielded allelic exchange mutants in 10 of 17 H. parasuis strains, similar to results using the suicide plasmid pK2UK...
July 9, 2018: Plasmid
Verena Kohler, Ankita Vaishampayan, Elisabeth Grohmann
Conjugative plasmid transfer is one of the major mechanisms responsible for the spread of antibiotic resistance and virulence genes. The incompatibility (Inc) 18 group of plasmids is a family of plasmids replicating by the theta-mechanism, whose members have been detected frequently in enterococci and streptococci. Inc18 plasmids encode a variety of antibiotic resistances, including resistance to vancomycin, chloramphenicol and the macrolide-lincosamide-streptogramine (MLS) group of antibiotics. These plasmids comprising insertions of Tn1546 were demonstrated to be responsible for the transfer of vancomycin resistance encoded by the vanA gene from vancomycin resistant enterococci (VRE) to methicillin resistant Staphylococcus aureus (MRSA)...
June 19, 2018: Plasmid
Andrea T Feßler, Yang Wang, Congming Wu, Stefan Schwarz
Lincosamide resistance in staphylococci is based on the expression of a number of genes which specify three major resistance mechanisms: (i) enzymatic inactivation by lincosamide nucleotidyltransferases, (ii) ribosome protection by ABC-F proteins, and (iii) methylation of the ribosomal target sites in the 23S rRNA by Cfr or Erm methylases. So far, only two lnu genes, lnu(A) and lnu(B), which code for different types of lincosamide nucleotidyltransferases, have been found in staphylococci. The ABC-F proteins are encoded by genes of the vga, lsa and sal classes...
June 19, 2018: Plasmid
Maysam Mansouri, Philipp Berger
Baculovirus is an insect virus which has been used for more than thirty years for production of recombinant proteins in insect cells. However, baculovirus can also be harnessed for efficient gene delivery to mammalian cells if it is equipped with mammalian promoters. This technology is known as BacMam and has been used for gene delivery to immortalized cell lines, stem cells, and primary cells, as well as for gene delivery in animals. Baculovirus has unique features when compared to mammalian viruses. Besides the fact that it is replication-incompetent and does not integrate into the host genome, it has large capacity for foreign DNA...
May 26, 2018: Plasmid
Andrea T Feßler, Yang Wang, Congming Wu, Stefan Schwarz
Macrolide resistance in staphylococci is based on the expression of a number of genes which specify four major resistance mechanisms: (i) target site modification by methylation of the ribosomal target site in the 23S rRNA, (ii) ribosome protection via ABC-F proteins, (iii) active efflux via Major Facilitator Superfamily (MFS) transporters, and (iv) enzymatic inactivation by phosphotransferases or esterases. So far, 14 different classes of erm genes, which code for 23S rRNA methylases, have been reported to occur in staphylococci from humans, animals and environmental sources...
May 26, 2018: Plasmid
Xinye Wang, Dongying Liu, Yantao Luo, Liang Zhao, Zhenshan Liu, Minxia Chou, Entao Wang, Gehong Wei
In the present study, complete genomic sequences retrieved from 57 rhizobial strains that covered four genera including 11 species were analyzed comprehensively. The four types of replicons: chromosomes, chromids, nonsymbiotic plasmids, and symbiotic plasmids were investigated and compared among these strains. Results showed that co-evolution occurred among these four replicons based on the similarities in average nucleotide identity. High correlation coefficient r values were observed between chromosomes and chromids, as well as between chromosomes and nonsymbiotic plasmids...
March 30, 2018: Plasmid
Jacob Amy, Dieter Bulach, Daniel Knight, Tom Riley, Priscilla Johanesen, Dena Lyras
Clostridioides (Clostridium) difficile is a major bacterial pathogen of both humans and animals. Several species of pathogenic clostridia are known to harbour large plasmids with combinations of virulence, antibiotic resistance and metabolism determinants. Small cryptic plasmids have been previously identified in C. difficile, but there is a lack of recent work examining the prevalence and heterogeneity of plasmids in this diverse bacterial species. A survey of clinical and historical isolates of C. difficile showed that several strains carry large plasmids...
March 2018: Plasmid
Stephanie J Ambrose, Christopher J Harmer, Ruth M Hall
In an early study, IncA and IncC plasmids that were reported to be compatible were grouped as the "A-C complex" based on similarities and on strong entry exclusion. However, recently, the term IncA/C has been used frequently to describe plasmids belonging to both of these two groups. Granted that the supporting data was not included in the original reports and that the consensus iteron sequences have since been shown to be essentially identical, we have addressed the question again. The original IncA plasmid, RA1, and the IncC plasmid pRMH760, were introduced into the same cell by transformation, and were found to be maintained stably for over 100 generations in the absence of selection for either plasmid, i...
March 2018: Plasmid
Shuai Shao, Xiaorong Zhang, G Paul H van Heusden, Paul J J Hooykaas
Agrobacterium tumefaciens strain Chry5 is hypervirulent on many plants including soybean that are poorly transformed by other A. tumefaciens strains. Therefore, it is considered as a preferred vector for genetic transformation of plants. Here we report the complete nucleotide sequence of its chrysopine-type Ti-plasmid pTiChry5. It is comprised of 197,268 bp with an overall GC content of 54.5%. Two T-DNA regions are present and 219 putative protein-coding sequences could be identified in pTiChry5. Roughly one half of the plasmid is highly similar to the agropine-type Ti plasmid pTiBo542, including the virulence genes with an identical virG gene, which is responsible for the supervirulence caused by pTiBo542...
March 2018: Plasmid
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