scholarly journals Mobilizable Rolling-Circle Replicating Plasmids from Gram-Positive Bacteria: A Low-Cost Conjugative Transfer

2014 ◽  
Vol 2 (5) ◽  
Author(s):  
Cris Fernández-López ◽  
Alicia Bravo ◽  
Sofía Ruiz-Cruz ◽  
Virtu Solano-Collado ◽  
Danielle A. Garsin ◽  
...  
Keyword(s):  
Low Cost ◽  
Conjugative Transfer ◽  
Gram Positive ◽  
Rolling Circle ◽  
Gram Positive Bacteria

scholarly journals Mobilizable Rolling-Circle Replicating Plasmids from Gram-Positive Bacteria: A Low-Cost Conjugative Transfer

Plasmids ◽  
2015 ◽  
pp. 257-276
Author(s):  
Cris Fernández-López ◽  
Alicia Bravo ◽  
Sofía Ruiz-Cruz ◽  
Virtu Solano-Collado ◽  
Danielle A. Garsin ◽  
...  
Keyword(s):  
Low Cost ◽  
Conjugative Transfer ◽  
Gram Positive ◽  
Rolling Circle ◽  
Gram Positive Bacteria

scholarly journals Bacillus anthracis and Bacillus cereus PcrA Helicases Can Support DNA Unwinding and In Vitro Rolling-Circle Replication of Plasmid pT181 of Staphylococcus aureus

2004 ◽  
Vol 186 (7) ◽  
pp. 2195-2199 ◽  
Author(s):  
Syam P. Anand ◽  
Poulami Mitra ◽  
Asma Naqvi ◽  
Saleem A. Khan
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Bacillus Anthracis ◽  
Broad Host Range ◽  
Gram Positive ◽  
Rolling Circle ◽  
Initiator Protein ◽  
Gram Positive Bacteria ◽  
Plasmid Pt181

ABSTRACT Replication of rolling-circle replicating (RCR) plasmids in gram-positive bacteria requires the unwinding of initiator protein-nicked plasmid DNA by the PcrA helicase. In this report, we demonstrate that heterologous PcrA helicases from Bacillus anthracis and Bacillus cereus are capable of unwinding Staphylococcus aureus plasmid pT181 from the initiator-generated nick and promoting in vitro replication of the plasmid. These helicases also physically interact with the RepC initiator protein of pT181. The ability of PcrA helicases to unwind noncognate RCR plasmids may contribute to the broad-host-range replication and dissemination of RCR plasmids in gram-positive bacteria.

scholarly journals A Novel Mobilizing Tool Based on the Conjugative Transfer System of the IncM Plasmid pCTX-M3

2020 ◽  
Vol 86 (17) ◽  
Author(s):  
Michał Dmowski ◽  
Izabela Kern-Zdanowicz
Keyword(s):  
Bacillus Subtilis ◽  
Lactococcus Lactis ◽  
Conjugative Transfer ◽  
Conjugation System ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Mobilizable Plasmid

ABSTRACT Conjugative plasmids are the main players in horizontal gene transfer in Gram-negative bacteria. DNA transfer tools constructed on the basis of such plasmids enable gene manipulation even in strains of clinical or environmental origin, which are often difficult to work with. The conjugation system of the IncM plasmid pCTX-M3 isolated from a clinical strain of Citrobacter freundii has been shown to enable efficient mobilization of oriTpCTX-M3-bearing plasmids into a broad range of hosts comprising Alpha-, Beta-, and Gammaproteobacteria. We constructed a helper plasmid, pMOBS, mediating such mobilization with an efficiency up to 1,000-fold higher than that achieved with native pCTX-M3. We also constructed Escherichia coli donor strains with chromosome-integrated conjugative transfer genes: S14 and S15, devoid of one putative regulator (orf35) of the pCTX-M3 tra genes, and S25 and S26, devoid of two putative regulators (orf35 and orf36) of the pCTX-M3 tra genes. Strains S14 and S15 and strains S25 and S26 are, respectively, up to 100 and 1,000 times more efficient in mobilization than pCTX-M3. Moreover, they also enable plasmid mobilization into the Gram-positive bacteria Bacillus subtilis and Lactococcus lactis. Additionally, the constructed E. coli strains carried no antibiotic resistance genes that are present in pCTX-M3 to facilitate manipulations with antibiotic-resistant recipient strains, such as those of clinical origin. To demonstrate possible application of the constructed tool, an antibacterial conjugation-based system was designed. Strain S26 was used for introduction of a mobilizable plasmid coding for a toxin, resulting in the elimination of over 90% of recipient E. coli cells. IMPORTANCE The conjugation of donor and recipient bacterial cells resulting in conjugative transfer of mobilizable plasmids is the preferred method enabling the introduction of DNA into strains for which other transfer methods are difficult to establish (e.g., clinical strains). We have constructed E. coli strains carrying the conjugation system of the IncM plasmid pCTX-M3 integrated into the chromosome. To increase the mobilization efficiency up to 1,000-fold, two putative regulators of this system, orf35 and orf36, were disabled. The constructed strains broaden the repertoire of tools for the introduction of DNA into the Gram-negative Alpha-, Beta-, and Gammaproteobacteria, as well as into Gram-positive bacteria such as Bacillus subtilis and Lactococcus lactis. The antibacterial procedure based on conjugation with the use of the orf35- and orf36-deficient strain lowered the recipient cell number by over 90% owing to the mobilizable plasmid-encoded toxin.

Fluorescent lactose-derived catanionic aggregates: synthesis, characterisation and potential use as antibacterial agents

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23340-23344
Author(s):  
Alexandre Bettoschi ◽  
Alain Brisson ◽  
Claudia Caltagirone ◽  
Angela M. Falchi ◽  
Francesco Isaia ◽  
...  
Keyword(s):  
Antibacterial Agents ◽  
Low Cost ◽  
Antibacterial Properties ◽  
Drug Resistant ◽  
Gram Positive ◽  
Organic Salts ◽  
Gram Positive Bacteria ◽  
Catanionic Surfactants ◽  
Potential Use

The antibacterial properties of catanionic surfactants based on fluorescent lactose-derivative organic salts using low-cost starting materials were investigated towards multi-drug-resistant Gram-positive bacteria.

scholarly journals A phytomass-inspired carbon and its importance as an antibacterial agent against human pathogens

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
N. Anvarsha ◽  
P. Kalyani
Keyword(s):  
Activated Carbon ◽  
Elemental Analysis ◽  
Antibacterial Agent ◽  
Low Cost ◽  
Diffusion Method ◽  
Vitex Negundo ◽  
Human Pathogens ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Background Imprudent use of antimicrobial drugs has resulted in the microbial resistance among the known microbes and hence we foresee a pressing need towards the development of novel, low-cost, and high potent antimicrobials which should be munificent by nature. In the pursuit of the above, phosphoric acid activated low-cost carbon was produced from a renewable phytomass precursor viz., leaves of Vitex negundo L. plant and explored for its antibacterial efficacy against four human pathogens viz., S. aureus, S. pyogenes (Gram-positive bacteria), and E. coli, P. aeruginosa (Gram-negative bacteria) by adopting well diffusion method. Carbon yield, burn-off, phase purity, elemental composition, particle morphology, and surface functionalities have been studied by ultimate elemental analysis, X-ray diffractometry, elemental analysis, scanning electron microscopy, and Fourier transform infrared spectrophotometry respectively. Minimal inhibition concentration (MIC) was also followed. Plausible mechanism of killing the pathogens by the above activated carbon was also provided. Results Vitex negundo leaves derived activated carbon (VNLAC) was found to contain large number of O-, S- and N-containing surface groups which are supposedly responsible for bestowing antibacterial properties to the carbon derived from Vitex negundo leaves. It has emerged as a potential antibacterial agent for many Gram-negative as well as Gram-positive bacteria. The inhibition zone of mean diameters ranged from 9 to 25 mm against all the pathogens was significantly (p < 0.05) less than that of the control viz., ciprofloxacin. Thus, the fundamental experimental results may extend the limits of carbon sources but also the conventional idea of obtaining active carbon to apply in technologies where carbon is inevitable. Conclusion The work not only demonstrates the promising potential of VNLAC as an efficient antibacterial agent but also presents a feasible mechanism of action of removing pathogens. Vitex negundo-derived carbon may become a cheap substitute for cost-prohibitive drugs. The findings of the work illustrate an easy choice as an antibacterial for topical application at infected sites.

scholarly journals Mobilization Function of the pBHR1 Plasmid, a Derivative of the Broad-Host-Range Plasmid pBBR1

2001 ◽  
Vol 183 (6) ◽  
pp. 2101-2110 ◽  
Author(s):  
Cédric Y. Szpirer ◽  
Michel Faelen ◽  
Martine Couturier
Keyword(s):  
Host Range ◽  
Broad Host Range ◽  
Gram Positive ◽  
Gram Negative ◽  
Rolling Circle ◽  
Gram Positive Bacteria ◽  
Broad Host Range Plasmid ◽  
Rolling Circle Mechanism ◽  
Transfer Origin

ABSTRACT The pBHR1 plasmid is a derivative of the small (2.6-kb), mobilizable broad-host-range plasmid pBBR1, which was isolated from the gram-negative bacterium Bordetella bronchiseptica (R. Antoine and C. Locht, Mol. Microbiol. 6:1785–1799, 1992). Plasmid pBBR1 consists of two functional cassettes and presents sequence similarities with the transfer origins of several plasmids and mobilizable transposons from gram-positive bacteria. We show that the Mob protein specifically recognizes a 52-bp sequence which contains, in addition to the transfer origin, the promoter of the mobgene. We demonstrate that this gene is autoregulated. The binding of the Mob protein to the 52-bp sequence could thus allow the formation of a protein-DNA complex with a double function: relaxosome formation andmob gene regulation. We show that the Mob protein is a relaxase, and we located the nic site position in vitro. After sequence alignment, the position of the nic site of pBBR1 corresponds with those of the nick sites of theBacteroides mobilizable transposon Tn4555 and the streptococcal plasmid pMV158. The oriT of the latter is characteristic of a family of mobilizable plasmids that are found in gram-positive bacteria and that replicate by the rolling-circle mechanism. Plasmid pBBR1 thus appears to be a new member of this group, even though it resides in gram-negative bacteria and does not replicate via a rolling-circle mechanism. In addition, we identified two amino acids of the Mob protein necessary for its activity, and we discuss their involvement in the mobilization mechanism.

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