Search results for "plasmid"

Fine-tuning DNA/albumin polyelectrolyte interactions to produce the efficient transfection agent cBSA-147.

2010

We present the preparation and isolation of different chemically modified BSA species with varying numbers of primary amino groups at the surface. Highly cationic albumin proteins with increased numbers of amino groups were achieved and complex formation with plasmid DNA was carefully investigated. We compare the transfection results, polyelectrolyte complexes morphologies with their impact on complex stabilities, cytotoxicities and DNA accessibility. This knowledge-driven approach led to the identification of the efficient non-viral DNA delivery agent cBSA-147, which showed high transfection efficacies and stability.

Long-term therapeutic levels of human alpha-1 antitrypsin in plasma after hydrodynamic injection of nonviral DNA

2003

The transfection efficacy of several vectors containing the full genomic hAAT gene with its natural promoter (pTG7101) and others containing the cDNA of hAAT gene driven by cytomegalovirus immediate-early promoter or the 0.5 kb upstream of hAAT gene sequence has been studied by hydrodynamic tail-vein injection (20 microg/mouse). pTG7101 (but not the other plasmids) results in therapeutic and stable concentration of hAAT in plasma. A dose-response study with this plasmid (0.3-320 microg/mouse) confirms that hAAT remains long-term stable in plasma, with therapeutic concentrations of hAAT (>0.9 mg/ml). The parameters of the dose-response curve were: R: 0.98, E(max) 3449.0+/- 279.7 microg/ml an…

Characterization of Carbapenem-Resistant Enterobacteriaceae Clinical Isolates in Al Thawra University Hospital, Sana'a, Yemen

2020

International audience; Objective: The aim of this study was to investigate the resistance mechanisms of carbapenem-resistant Enterobacteriaceae clinical strains recovered from Al Thawra University Hospital, Sana'a, Yemen. Methods: A total of 27 isolates showing decreased susceptibility to carbapenems were obtained from different clinical specimens in Al Thawra Hospital, Sana'a, Yemen. Strains were identified by Matrix Assisted Laser Desorption Ionization Time-Of-Flight spectroscopy. Susceptibility to antibiotics was determined by the disk diffusion method on Mueller Hinton agar. Carbapenemases-encoding genes, extended-spectrum β-lactamases (ESBLs), and plasmid-mediated quinolone resistance…

Carbon nanotube – Protamine hybrid: Evaluation of DNA cell penetration

2016

International audience; Carbon nanotubes (CNTs) represent a class of nanomaterials with important potential for biomedical and biotechnological applications. CNT based vectorization is an emerging approach to the transport of nucleic acid through cell membrane but limited by detachment of DNA and degradation process. To increase DNA internalization, it was proved that cationic functionalized CNT was essential. In such a way, protamine efficiently used in several transfection processes is a cationic protein which was never associated to CNT.We propose here a novel nanovector based on single-walled carbon nanotubes (SWCNT) functionalized by protamine. Our results based on qPCR methods clearly…

Analysis of metabolic and gene expression changes after hydrodynamic DNA injection into mouse liver.

2011

The hydrodynamic injection in mice tail vein of a plasmid (40 mg DNA) bearing the human a1-antitrypsin gene mediates: a) good liver gene transfer resulting in therapeutic plasma levels of human protein (1 mg/ml, approximately) from days 1—10 after injection; b) low liver injury as demonstrated by a poor and transient increase of aspartate aminotransferase (AST) and alanine transaminase (ALT) in mouse plasma; 3) limited expression and metabolic changes in host liver genes and metabolites as evaluated on days 2 and 10 after injection. Groups of three mice were uninjected (control) or hydrodynamically injected with saline or plasmid DNA and then sacrificed on days 2 and 10 after injection. The…

The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis

2015

ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically id…

Genetic islands in pome fruit pathogenic and non-pathogenic Erwinia species and related plasmids

2015

New pathogenic bacteria species belonging to the genus Erwinia associated with pome fruit trees (Erwinia pyrifoliae, E. piriflorinigrans, E. uzenensis) have been increasingly described in the last years, and comparative analyses have found that all these species share several genetic characteristics. Studies at different level (whole genome comparison, virulence genes, plasmid content, etc.) show a high intraspecies homogeneity (i.e. among E. amylovora strains) and also abundant similarities appear between the different Erwinia species: presence of plasmids of similar size in the pathogenic species; high similarity in several genes associated with exopolysaccharide production and hence, wit…

2021

Antibiotic resistance genes of important Gram-negative bacterial pathogens are residing in mobile genetic elements such as conjugative plasmids. These elements rapidly disperse between cells when antibiotics are present and hence our continuous use of antimicrobials selects for elements that often harbor multiple resistance genes. Plasmid-dependent (or male-specific or, in some cases, pilus-dependent) bacteriophages are bacterial viruses that infect specifically bacteria that carry certain plasmids. The introduction of these specialized phages into a plasmid-abundant bacterial community has many beneficial effects from an anthropocentric viewpoint: the majority of the plasmids are lost whil…

Structural and Functional Analysis of BBA03, Borrelia burgdorferi Competitive Advantage Promoting Outer Surface Lipoprotein

2020

BBA03 is a Borrelia burgdorferi outer surface lipoprotein encoded on one of the most conserved plasmids in Borrelia genome, linear plasmid 54 (lp54). Although many of its genes have been identified as contributing or essential for spirochete fitness in vivo, the majority of the proteins encoded on this plasmid have no known function and lack homologs in other organisms. In this paper, we report the solution NMR structure of the B. burgdorferi outer surface lipoprotein BBA03, which is known to provide a competitive advantage to the bacteria during the transmission from tick vector to mammalian host. BBA03 shows structural homology to other outer surface lipoproteins reflecting their genetic …

Evolutionary rescue of bacteria via horizontal gene transfer under a lethal β-lactam concentration

2013

β-Lactams are a commonly used class of bactericidal antibiotics. The number of β-lactam-resistant pathogens is constantly increasing in hospitals around the world. Interestingly, most of the β-lactam-resistant bacteria carry mobile genetic elements, such as conjugative plasmids, that render the pathogen resistant. These elements mediate their own transfer from one bacterium to another, producing new resistant strains via horizontal gene transfer. Here we investigated whether it is possible that transfer of the resistance element from another bacterium may evolutionarily rescue a susceptible bacterium exposed to a lethal concentration of the β-lactam ampicillin. Indeed, the rescuing occurs e…