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.

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 In Vitro and In Vivo Antibacterial Activities of DW-224a, a New Fluoronaphthyridone

2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
The Other ◽  
Vitro Activity ◽  
Gram Negative Bacteria ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.

PTS 50: Past, Present and Future, or Diauxie Revisited

2015 ◽  
Vol 25 (2-3) ◽  
pp. 79-93 ◽  
Author(s):  
Joseph W. Lengeler
Keyword(s):  
Catabolite Repression ◽  
Biological Significance ◽  
Cellular Growth ◽  
Gram Positive ◽  
Gram Negative ◽  
Inducer Exclusion ◽  
Gram Positive Bacteria ◽  
Cellular Control

<b><i>Past:</i></b> The title ‘PTS 50 or The PTS after 50 years' relies on the first description in 1964 of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system (PTS) by Kundig, Gosh and Roseman [Proc Natl Acad Sci USA 1964;52:1067-1074]. The system comprised proteins named Enzyme I, HPr and Enzymes II, as part of a novel PTS for carbohydrates in Gram-negative and Gram-positive bacteria, whose ‘biological significance remained unclear'. In contrast, studies which would eventually lead to the discovery of the central role of the PTS in bacterial metabolism had been published since before 1942. They are primarily linked to names like Epps and Gale, J. Monod, Cohn and Horibata, and B. Magasanik, and to phenomena like ‘glucose effects', ‘diauxie', ‘catabolite repression' and carbohydrate transport. <b><i>Present:</i></b> The pioneering work from Roseman's group initiated a flood of publications. The extraordinary progress from 1964 to this day in the qualitative and in vitro description of the genes and enzymes of the PTS, and of its multiple roles in global cellular control through ‘inducer exclusion', gene induction and ‘catabolite repression', in cellular growth, in cell differentiation and in chemotaxis, as well as the differences of its functions between Gram-positive and Gram-negative bacteria, was one theme of the meeting and will not be treated in detail here. <b><i>Future:</i></b> At the 1988 Paris meeting entitled ‘The PTS after 25 years', Saul Roseman predicted that ‘we must describe these interactions [of the PTS components] in a quantitative way [under] in vivo conditions'. I will present some results obtained by our group during recent years on the old phenomenon of diauxie by means of very fast and quantitative tests, measured in vivo, and obtained from cultures of isogenic mutant strains growing under chemostat conditions. The results begin to hint at the problems relating to future PTS research, but also to the ‘true science' of Roseman.

scholarly journals Promoters of the broad host range plasmid RK2: analysis of transcription (initiation) in five species of gram-negative bacteria.

Genetics ◽  
1992 ◽  
Vol 130 (1) ◽  
pp. 27-36 ◽  
Author(s):  
A Greener ◽  
S M Lehman ◽  
D R Helinski
Keyword(s):  
Host Range ◽  
Transcription Initiation ◽  
Promoter Activity ◽  
Firefly Luciferase ◽  
Broad Host Range ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Broad Host Range Plasmid ◽  
Transcriptional Start Sites ◽  
Plasmid Rk2

Abstract A broad host range cloning vector was constructed, suitable for monitoring promoter activity in diverse Gram-negative bacteria. This vector, derived from plasmid RSF1010, utilized the firefly luciferase gene as the reporter, since the assay for its bioluminescent product is sensitive, and measurements can be made without background from the host. Twelve DNA fragments with promoter activity were obtained from broad host range plasmid RK2 and inserted into the RSF1010 derived vector. The relative luciferase activities were determined for these fragments in five species of Gram-negative bacteria. In addition, four promoters were analyzed by primer extension to locate transcriptional start sites in each host. The results show that several of the promoters vary substantially in relative strengths or utilize different transcriptional start sites in different bacteria. Other promoters exhibited similar activities and identical start sites in the five hosts examined.

scholarly journals A Type IV-Secretion-Like System Is Required for Conjugative DNA Transport of Broad-Host-Range Plasmid pIP501 in Gram-Positive Bacteria

2007 ◽  
Vol 189 (6) ◽  
pp. 2487-2496 ◽  
Author(s):  
Mohammad Y. Abajy ◽  
Jolanta Kopeć ◽  
Katarzyna Schiwon ◽  
Michal Burzynski ◽  
Mike Döring ◽  
...  
Keyword(s):  
Host Range ◽  
Sequence Similarity ◽  
Type Iv Secretion ◽  
Conjugative Plasmid ◽  
Computer Assisted ◽  
Transcriptional Level ◽  
Broad Host Range ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Type Iv

ABSTRACT Plasmid pIP501 has a very broad host range for conjugative transfer among a wide variety of gram-positive bacteria and gram-negative Escherichia coli. Functionality of the pIP501 transfer (tra) genes in E. coli was proven by pIP501 retrotransfer to Enterococcus faecalis (B. Kurenbach, C. Bohn, J. Prabhu, M. Abudukerim, U. Szewzyk, and E. Grohmann, Plasmid 50:86-93, 2003). The 15 pIP501 tra genes are organized in a single operon (B. Kurenbach, J. Kopeć, M. Mägdefrau, K. Andreas, W. Keller, C. Bohn, M. Y. Abajy, and E. Grohmann, Microbiology 152:637-645, 2006). The pIP501 tra operon is negatively autoregulated at the transcriptional level by the conjugative DNA relaxase TraA. Three of the 15 pIP501-encoded Tra proteins show significant sequence similarity to the Agrobacterium type IV secretion system proteins VirB1, VirB4, and VirD4. Here we report a comprehensive protein-protein interaction map of all of the pIP501-encoded Tra proteins determined by the yeast two-hybrid assay. Most of the interactions were verified in vitro by isolation of the protein complexes with pull-down assays. In conjunction with known or postulated functions of the pIP501-encoded Tra proteins and computer-assisted prediction of their cellular location, we propose a model for the first type IV-secretion-like system encoded by a conjugative plasmid from gram-positive bacteria.

Działanie in vitro olejku cyprysowego (Oleum Cupressi) na bakterie beztlenowe

2019 ◽  
Vol 20 (2) ◽  
Author(s):  
Anna Kędzia ◽  
Elżbieta Hołderna-Kędzia
Keyword(s):  
Anaerobic Bacteria ◽  
Growth Control ◽  
Cupressus Sempervirens ◽  
Tannerella Forsythia ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Gram Positive Cocci ◽  
Porphyromonas Levii

Introduction. Cypress (Cupressus sempervirens L.) belongs to the family Cupressaceae. It is evergreen, and grows in Mediterranean region. The Cypress leaves and young branches are utilized to produce the essential oil. Cypress oil contain a number of components, in it α-pinene, Δ3-carene, α-terpinyl acetate, cedrol, α-terpinolene, β-myrcene, limonene, α-terpineolene, terpinen-4-ol, β-pinene, δ-cadinene and sabinene. The oil is used in therapy different diseases. It to have antimicrobial activity. Aim. The aim of the date was evaluation the susceptibility of anaerobic bacteria to Cypress oil. Material and methods. The anaerobic bacteria were isolated from patients. The 62 microorganisms, in it 36 strains of Gram-negative rods, 14 Gram-positive cocci and 12 Gram-positive rods, and 7 reference strains were tested. Susceptibility (MIC) was determined by means of plate dilution technique in Brucella agar supplemented with 5% defibrynated sheep blood, menadione and hemin. The Cypress oil was dissolved in DMSO and distilled water to obtain final following concentrations: 2.5, 5.0, 7.5, 10.0, 15.0 and 20.0 mg/ml. Inoculum containing 106 CFU per 1 ml was seeded with Steers replicator upon the agar with oil or without the oil (strains growth control). The agar plates was incubated in anaerobic condition in anaerobic jar in 37°C for 48 hrs. The MIC was interpreted as the lowest concentration of Cypress oil inhibiting the growth of tested bacteria. Results. The results indicated that from among Gram-negative rods the most susceptible to Cypress oil was the strains from genus Tannerella forsythia (MIC < 2.5-5.0 mg/ml), Bacteroides uniformis (MIC = 5.0 mg/ml), Bacteroides vulgatus and Porphyromonas asaccharolytica (MIC 5.0-7.5 mg/ml) and Porphyromonas levii (MIC = 7.5 mg/ml). The strains from genera Fusobacterium and of Bacteroides fragilis were the susceptible to 2.5-≥ 20.0 mg/ml. The Cypress oil was least active towards Prevotella and Parabacteroides strains (MIC ≥ 20.0 mg/ml).The tested Gram-positive cocci were more susceptible. The growth of the strains were inhibited by concentrations in ranges ≤ 2.5-7.5 mg/ml. The oil was minor active towards Gram-positive rods (MIC ≤ 2.5-20.0 mg/ml). Among the strains the genus of Actinomyces odontolyticus (MIC = 5.0 mg/ml) and Actinomyces viscosus (MIC ≤ 2.5-7.5 mg/ml) were the most susceptible. The growth of rods of Bifidobacterium breve was inhibited by concentrations 10.0 mg/ml. The data indicates that the Gram-negative rods were the less susceptible than Gram-positive bacteria to cypress oil. Conclusions. Among Gram-negative rods the most susceptible were the strains Tannerella forsythia, Bacteroides uniformis, Bacteroides vulgatus, Porphyromonas asaccharolytica and Porphyromonas levii. The oil was more active against Gram-positive cocci. Gram-positive anaerobic bacteria demonstrate the more susceptible to Cypress oil then Gram-positive rods.

scholarly journals Type I and Type II mechanisms of antimicrobial photodynamic therapy: An in vitro study on gram-negative and gram-positive bacteria

2012 ◽  
Vol 44 (6) ◽  
pp. 490-499 ◽  
Author(s):  
Liyi Huang ◽  
Yi Xuan ◽  
Yuichiro Koide ◽  
Timur Zhiyentayev ◽  
Masamitsu Tanaka ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
In Vitro Study ◽  
Vitro Study ◽  
Type I ◽  
Antimicrobial Photodynamic Therapy ◽  
Type Ii ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria
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