Plasmids in antibiotic susceptible and antibiotic resistant commensal Escherichia coli from healthy Australian adults
Publication date: Available online 25 March 2015 Source:Plasmid Author(s): Robert A. Moran , Sashindran Anantham , Jeremy L. Pinyon , Ruth M. Hall A collection of 111 commensal Escherichia coli isolated from 84 faecal samples from healthy Australian adults were screened using PCR-based replicon typing. Each isolate represented a distinct strain found in a particular faecal sample. Fifty-one isolates were resistant to one or more of 12 antibiotics tested. FII and FIB replicons were most common and usually found together. The FII replicon was detected in 63 isolates (35 susceptible, 28 resistant), the FIB replicon wa...
Source: Plasmid - April 11, 2015 Category: Biotechnology Source Type: research
Completing the specificity swap: Single-stranded DNA recognition by F and R100 TraI relaxase domains
Publication date: Available online 1 April 2015 Source:Plasmid Author(s): Kip E. Guja , Joel F. Schildbach During conjugative plasmid transfer, one plasmid strand is cleaved and transported to the recipient bacterium. For F and related plasmids, TraI contains the relaxase or nickase activity that cleaves the plasmid DNA strand. F TraI36, the F TraI relaxase domain, binds a single-stranded origin of transfer (oriT) DNA sequence with high affinity and sequence specificity. The TraI36 domain from plasmid R100 shares 91% amino acid sequence identity with F TraI36, but its oriT DNA binding site differs by two of eleven ba...
Source: Plasmid - April 11, 2015 Category: Biotechnology Source Type: research
Co-expression of functional human Heme Oxygenase 1, Ecto-5′-Nucleotidase and ecto-nucleoside triphosphate diphosphohydrolase-1 by “self-cleaving” 2A peptide system
Publication date: May 2015 Source:Plasmid, Volume 79 Author(s): Marco De Giorgi , Alessandro Cinti , Iwona Pelikant-Malecka , Elisa Chisci , Marialuisa Lavitrano , Roberto Giovannoni , Ryszard T. Smolenski We developed an F2A-based multicistronic system to evaluate functional effects of co-expression of three proteins important for xenotransplantation: heme oxygenase 1 (HO1), ecto-5′-nucleotidase (E5NT) and ecto-nucleoside triphosphate diphosphohydrolase-1 (ENTPD1). The tricistronic p2A plasmid that we constructed was able to efficiently drive concurrent expression of HO1, E5NT and ENTPD1 in HEK293T cells. All...
Source: Plasmid - April 11, 2015 Category: Biotechnology Source Type: research
Construction of a directional T vector for cloning PCR products and expression in Escherichia coli
Publication date: May 2015 Source:Plasmid, Volume 79 Author(s): Xiu-Yi Liang , Zhi-Cheng Liang , Zhi Zhang , Jiao-Jiao Zhou , Shi-Yu Liu , Sheng-Li Tian In order to clone PCR products and express them effectively in Escherichia coli, a directional cloning system was constructed by generating a T vector based on pQE-30Xa. The vector was prepared by inserting an XcmI cassette containing an endonuclease XcmI site, a kanamycin selective marker, a multiple-cloning-site (MCS) region and an opposite endonuclease XcmI site into the vector pQE-30Xa. The T vector pQE-T with single overhanging dT residues at both 3′ ends ...
Source: Plasmid - April 11, 2015 Category: Biotechnology Source Type: research
An rpsL-based allelic exchange vector for staphylococcus aureus
We report rpsL-based counterselection vectors, with an improved temperature-sensitive replicon (pT181 repC3) that is completely blocked for replication in S. aureus at non-permissive and standard growth temperature (37°C). We also describe a set of temperature-sensitive vectors that can be cured at standard growth temperature. These vectors provide highly effective tools for rapidly generating allelic replacement mutations and curing expression plasmids, and expand the genetic tool set available for the study of S. aureus. (Source: Plasmid)
Source: Plasmid - February 8, 2015 Category: Biotechnology Source Type: research
Mutations in an antisense RNA, involved in the replication control of a repABC plasmid, that disrupt plasmid incompatibility and mediate plasmid speciation
Publication date: Available online 30 January 2015 Source:Plasmid Author(s): América Rivera-Urbalejo , Ángeles Pérez-Oseguera , Ofelia E. Carreón-Rodríguez , Miguel A. Cevallos The maintenance of large plasmid in a wide variety of alpha-proteobacteria depends on the repABC replication/ segregation unit. The intergenic repB-repC region of these plasmids encodes a countertranscribed RNA (ctRNA) that modulates the transcription/ translation rate of RepC, the initiator protein. The ctRNA acts as a strong incompatibility factor when expressed in trans. We followed a sitedirected mutagenesis approach to map those se...
Source: Plasmid - February 2, 2015 Category: Biotechnology Source Type: research
Structural and sequence requirements for the antisense RNA regulating replication of staphylococcal multiresistance plasmid pSK41
In this study, enzymatic probing was used to verify the predicted secondary structures of RNAI and its target RNA. We demonstrated that two stem-loop structures of RNAI, SLRNAI-II and SLRNAI-III, were important for inhibition. A putative U-turn motif detected in the loop of SL rep -I (5'–UUGG-3') was analysed for its significance to RNAI-mediated inhibition in vivo and Northern blotting suggested that rep mRNA was processed. Taken together, these observations support our previously proposed model but also raise new questions about the replication control mechanism. (Source: Plasmid)
Source: Plasmid - January 27, 2015 Category: Biotechnology Source Type: research
Transfer of antibiotic-resistance genes via phage-related mobile elements
Publication date: Available online 15 January 2015 Source:Plasmid Author(s): Maryury Brown-Jaque , William Calero-Cáceres , Maite Muniesa Antibiotic resistance is a major concern for society because it threatens the effective prevention of infectious diseases. While some bacterial strains display intrinsic resistance, others achieve antibiotic resistance by mutation, by the recombination of foreign DNA into the chromosome or by horizontal gene acquisition. In many cases, these three mechanisms operate together. Several mobile genetic elements (MGEs) have been reported to mobilize different types of resistance genes...
Source: Plasmid - January 16, 2015 Category: Biotechnology Source Type: research
Reviewer recognition
Publication date: January 2015 Source:Plasmid, Volume 77 (Source: Plasmid)
Source: Plasmid - January 15, 2015 Category: Biotechnology Source Type: research
Isolation of a novel plasmid from Couchioplanes caeruleus and construction of two plasmid vectors for gene expression in Actinoplanes missouriensis
Publication date: Available online 8 December 2014 Source:Plasmid Author(s): Moon-Sun Jang , Azusa Fujita , Satomi Ikawa , Keitaro Hanawa , Hideki Yamamura , Tomohiko Tamura , Masayuki Hayakawa , Takeaki Tezuka , Yasuo Ohnishi To date, no plasmid vector has been developed for the rare actinomycete Actinoplanes missouriensis. Moreover, no small circular plasmid has been reported to exist in the genus Actinoplanes. Here, a novel plasmid, designated pCAZ1, was isolated from Couchioplanes caeruleus subsp. azureus via screening for small circular plasmids in Actinoplanes (57 strains) and Couchioplanes (2 strains). ...
Source: Plasmid - December 21, 2014 Category: Biotechnology Source Type: research
Genetic analysis of maintenance of pEC156, a naturally occurring Escherichia coli plasmid that carries genes of the EcoVIII restriction–modification system
Publication date: Available online 8 December 2014 Source:Plasmid Author(s): Olesia Werbowy , Robert Boratynski , Agnieszka Dekowska , Tadeusz Kaczorowski In the present study the role of the mechanisms responsible for maintenance of a natural plasmid pEC156, that carries genes of the EcoVIII restriction–modification system was investigated. Analysis of this plasmid's genetic content revealed the presence of genetic determinants suggesting two such mechanisms. The first of them relies on site specific recombination utilizing the Xer/cer molecular machinery, while the second involves a restriction–modification s...
Source: Plasmid - December 21, 2014 Category: Biotechnology Source Type: research
Counter-transcribed rnas of rhizobium leguminosarum repABC plasmids exert incompatibility effects only when highly expressed
Publication date: Available online 18 December 2014 Source:Plasmid Author(s): Cynthia B. Yip , Hao Ding , Michael F. Hynes The six plasmids of Rhizobium leguminosarum VF39SM comprise nearly 35% of the bacterium's genome and are all repABC replicons. The repABC operons of the three largest plasmids of VF39SM were found to have strong incompatibility determinants in the non-protein coding regions. However, in all three repABC operons, the intergenic region between repB and repC was the strongest incompatibility factor; this intergenic region has been shown, for most repABC plasmids, to encode a counter-transcribed RNA...
Source: Plasmid - December 21, 2014 Category: Biotechnology Source Type: research
The use of the replication region of plasmid pRS7 from Oenococcus oeni as a putative tool to generate cloning vectors for lactic acid bacteria
Publication date: January 2015 Source:Plasmid, Volume 77 Author(s): M. Carmen Rodríguez , M. Teresa Alegre , M. Cruz Martín , Juan M. Mesas A chimeric plasmid, pRS7Rep (6.1 kb), was constructed using the replication region of pRS7, a large plasmid from Oenococcus oeni, and pEM64, a plasmid derived from pIJ2925 and containing a gene for resistance to chloramphenicol. pRS7Rep is a shuttle vector that replicates in Escherichia coli using its pIJ2925 component and in lactic acid bacteria (LAB) using the replication region of pRS7. High levels of transformants per µg of DNA were obtained by electroporation of pRS7R...
Source: Plasmid - December 21, 2014 Category: Biotechnology Source Type: research
Degenerate primer MOB typing of multiresistant clinical isolates of E. coli uncovers new plasmid backbones
Publication date: January 2015 Source:Plasmid, Volume 77 Author(s): M. Pilar Garcillán-Barcia , Belén Ruiz del Castillo , Andrés Alvarado , Fernando de la Cruz , Luis Martínez-Martínez Degenerate Primer MOB Typing is a PCR-based protocol for the classification of γ-proteobacterial transmissible plasmids in five phylogenetic relaxase MOB families. It was applied to a multiresistant E. coli collection, previously characterized by PCR-based replicon-typing, in order to compare both methods. Plasmids from 32 clinical isolates of multiresistant E. coli (19 extended spectrum beta-lactamase producers and 13 non pro...
Source: Plasmid - December 21, 2014 Category: Biotechnology Source Type: research
Plasmids in the driving seat: the regulatory RNA Rcd gives plasmid ColE1 control over division and growth of its E. coli host
Publication date: Available online 11 November 2014 Source:Plasmid Author(s): Hannah Gaimster , David Summers Regulation by non-coding RNAs was found to be widespread among plasmids and other mobile elements of bacteria well before its ubiquity in the eukaryotic world was suspected. As an increasing number of examples was characterised, a common mechanism began to emerge. Non-coding RNAs, such as CopA and Sok from plasmid R1, or RNAI from ColE1, exerted regulation by refolding the secondary structures of their target RNAs or modifying their translation. One regulatory RNA that seemed to swim against the tide was Rcd,...
Source: Plasmid - November 12, 2014 Category: Biotechnology Source Type: research
