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 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.

scholarly journals Bacterial Induction of Beta Interferon in Mice Is a Function of the Lipopolysaccharide Component

2000 ◽  
Vol 68 (3) ◽  
pp. 1600-1607 ◽  
Author(s):  
Andreas Sing ◽  
Thomas Merlin ◽  
Hans-Peter Knopf ◽  
Peter J. Nielsen ◽  
Harald Loppnow ◽  
...  
Keyword(s):  
Mouse Strains ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Protein Levels ◽  
Gram Positive Bacteria ◽  
Beta Interferon

ABSTRACT We investigated the reason for the inability of lipopolysaccharide (LPS)-resistant (Lps-defective [Lpsd ]) C57BL/10ScCr mice to produce beta interferon (IFN-β) when stimulated with bacteria. For this purpose, the IFN-β and other macrophage cytokine responses induced by LPS and several killed gram-negative and gram-positive bacteria in LPS-sensitive (Lps-normal [Lpsn ]; C57BL/10ScSn and BALB/c) and Lpsd (C57BL/10ScCr and BALB/c/l) mice in vitro and in vivo were investigated on the mRNA and protein levels. In addition, double-stranded RNA (dsRNA) was used as a nonbacterial stimulus. LPS and all gram-negative bacteria employed induced IFN-β in the Lpsn mice but not in theLpsd mice. All gram-positive bacteria tested failed to induce significant amounts of IFN-β in all four of the mouse strains used. As expected, all other cytokines tested (tumor necrosis factor alpha, interleukin 1α [IL-1α], IL-6, and IL-10) were differentially induced by gram-negative and gram-positive bacteria. Stimulation with dsRNA induced IFN-β and all other cytokines mentioned above in all mouse strains, regardless of their LPS sensitivities. The results suggest strongly that LPS is the only bacterial component capable of inducing IFN-β in significant amounts that are readily detectable under the conditions used in this study. Consequently, in mice, IFN-β is inducible only by gram-negative bacteria, but not in C57BL/10ScCr or other LPS-resistant mice.

scholarly journals Small subunits of RNA polymerase: localization, levels and implications for core enzyme composition

Microbiology ◽  
2010 ◽  
Vol 156 (12) ◽  
pp. 3532-3543 ◽  
Author(s):  
Geoff P. Doherty ◽  
Mark J. Fogg ◽  
Anthony J. Wilkinson ◽  
Peter J. Lewis
Keyword(s):  
Fluorescent Protein ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The Core ◽  
Bacterial Rna ◽  
Green Fluorescent

Bacterial RNA polymerases (RNAPs) contain several small auxiliary subunits known to co-purify with the core α, β and β′ subunits. The ω subunit is conserved between Gram-positive and Gram-negative bacteria, while the δ subunit is conserved within, but restricted to, Gram-positive bacteria. Although various functions have been assigned to these subunits via in vitro assays, very little is known about their in vivo roles. In this work we constructed a pair of vectors to investigate the subcellular localization of the δ and ω subunits in Bacillus subtilis with respect to the core RNAP. We found these subunits to be closely associated with RNAP involved in transcribing both mRNA and rRNA operons. Quantification of these subunits revealed δ to be present at equimolar levels with RNAP and ω to be present at around half the level of core RNAP. For comparison, the localization and quantification of RNAP β′ and ω subunits in Escherichia coli was also investigated. Similar to B. subtilis, β′ and ω closely associated with the nucleoid and formed subnucleoid regions of high green fluorescent protein intensity, but, unlike ω in B. subtilis, ω levels in E. coli were close to parity with those of β′. These results indicate that δ is likely to be an integral RNAP subunit in Gram-positives, whereas ω levels differ substantially between Gram-positives and -negatives. The ω subunit may be required for RNAP assembly and subsequently be turned over at different rates or it may play roles in Gram-negative bacteria that are performed by other factors in Gram-positives.

scholarly journals IN VITRO ANTIMICROBIAL ACTIVITY OF CARVACROL AGAINST SHRIMP PATHOGENS AND ITS USE AS FEED ADDITIVE FOR THE PACIFIC WHITE SHRIMP

2021 ◽  
Vol 47 ◽  
pp. e645
Author(s):  
Jaqueline da Rosa COELHO ◽  
Karolina Victória ROSA ◽  
Jamilly Sousa ROCHA ◽  
Norha Constanza Bolívar RAMÍREZ ◽  
Marcelo MARASCHIN ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Vibrio Harveyi ◽  
Pacific White Shrimp ◽  
The Other ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Vitro Effect

This study aimed to evaluate the in vitro effect of carvacrol on different microorganisms of importance in shrimp farming, as well as its in vivo effect on zootechnical, immunological and microbiological performance, as well as resistance, of Litopenaeus vannamei challenged with Vibrio parahaemolyticus. In particular, the antimicrobial activity of carvacrol was evaluated in vitro by analysis of the minimum inhibitory concentration (MIC) and by agar diffusion disc with Gram-negative and Gram-positive bacteria. The in vivo experiment was conducted using different concentrations of carvacrol (1, 3, 4 and 6 mg mL-1) added to shrimp feed, together with a control diet without carvacrol. After four weeks, zootechnical, immunological and microbiological parameters, as well as resistance, of animals challenged with V. parahaemolyticus were evaluated. The MIC of Vibrio alginolyticus and Vibrio harveyi was 0.078 mg mL-1, while for the other bacteria, it was 0.156 mg mL-1 of carvacrol. The greatest halos of inhibition were observed in V. parahaemolyticus and Vibrio harveyi with significant differences demonstrated for the other microorganisms, except Escherichia coli. The in vivo results showed no significant differences among treatments. In conclusion, the antimicrobial activity of carvacrol was confirmed with Gram-negative and Gram-positive bacteria, and it is suggested that its antimicrobial potential is more effective against Vibrio spp. However, the concentrations of carvacrol used in vivo did not affect the parameters evaluated.

scholarly journals In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Infection Models ◽  
Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

Zinc oxide microrods and nanorods: different antibacterial activity and their mode of action against Gram-positive bacteria

RSC Advances ◽  
2014 ◽  
Vol 4 (99) ◽  
pp. 56031-56040 ◽  
Author(s):  
Ilaria Rago ◽  
Chandrakanth Reddy Chandraiahgari ◽  
Maria P. Bracciale ◽  
Giovanni De Bellis ◽  
Elena Zanni ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Mode Of Action ◽  
Gram Positive ◽  
Gram Positive Bacteria

ZnO micro and nanorods, produced through simple and inexpensive techniques, resulted to be strong antimicrobials against Gram-positive bacteria, in vitro as well as in vivo, by altering cell outer structures like membrane and exopolysaccharides.

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.

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