scholarly journals Antimicrobial Diterpenes from Azorella Species against Gram-Positive Bacteria

2015 ◽  
Vol 10 (11) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Viviana Donoso ◽  
Mitchell Bacho ◽  
Solange Núñez ◽  
Juana Rovirosa ◽  
Aurelio San-Martín ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Mycobacterium Smegmatis ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Andean Plants

The present study was aimed at evaluating the antibacterial activity of mulinane and azorellane diterpenes isolated from the Andean plants Azorella compacta and A. trifoliolata and semisynthetic derivatives against reference and multidrug-resistant strains. The results revealed that the semisynthetic compound 7-acetoxy-mulin-9,12-diene (5) exhibited antibacterial activity against reference and multidrug-resistant strains of Staphylococcus aureus and moderate antimycobacterial activity against Mycobacterium smegmatis ATCC 14468.

scholarly journals Chromone Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus Penicillium erubescens KUFA0220 and Their Antibacterial Activity

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 289 ◽  
Author(s):  
Decha Kumla ◽  
José Pereira ◽  
Tida Dethoup ◽  
Luis Gales ◽  
Joana Freitas-Silva ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Growth Inhibition ◽  
Marine Sponge ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
Chromone Derivatives ◽  
Gram Positive Bacteria ◽  
Resistant Strains

A previously unreported chromene derivative, 1-hydroxy-12-methoxycitromycin (1c), and four previously undescribed chromone derivatives, including pyanochromone (3b), spirofuranochromone (4), 7-hydroxy-6-methoxy-4-oxo-3-[(1E)-3-oxobut-1-en-1-yl]-4H-chromene-5-carboxylic acid (5), a pyranochromone dimer (6) were isolated, together with thirteen known compounds: β-sitostenone, ergosterol 5,8-endoperoxide, citromycin (1a), 12-methoxycitromycin (1b), myxotrichin D (1d), 12-methoxycitromycetin (1e), anhydrofulvic acid (2a), myxotrichin C (2b), penialidin D (2c), penialidin F (3a), SPF-3059-30 (7), GKK1032B (8) and secalonic acid A (9), from cultures of the marine sponge- associated fungus Penicillium erubescens KUFA0220. Compounds 1a–e, 2a, 3a, 4, 7–9, were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment. Only 8 exhibited an in vitro growth inhibition of all Gram-positive bacteria whereas 9 showed growth inhibition of methicillin-resistant Staphyllococus aureus (MRSA). None of the compounds were active against Gram-negative bacteria tested.

scholarly journals Antibacterial Activity of Pharmaceutical-Grade Rose Bengal: An Application of a Synthetic Dye in Antibacterial Therapies

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 322
Author(s):  
Michio Kurosu ◽  
Katsuhiko Mitachi ◽  
Junshu Yang ◽  
Edward V. Pershing ◽  
Bruce D. Horowitz ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Rose Bengal ◽  
Multidrug Resistant ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Skin Cells ◽  
Microbial Invasion ◽  
Low Concentrations ◽  
Resistant Strains ◽  
Drug Resistant Strains

Rose bengal has been used in the diagnosis of ophthalmic disorders and liver function, and has been studied for the treatment of solid tumor cancers. To date, the antibacterial activity of rose bengal has been sporadically reported; however, these data have been generated with a commercial grade of rose bengal, which contains major uncontrolled impurities generated by the manufacturing process (80–95% dye content). A high-purity form of rose bengal formulation (HP-RBf, >99.5% dye content) kills a battery of Gram-positive bacteria, including drug-resistant strains at low concentrations (0.01–3.13 μg/mL) under fluorescent, LED, and natural light in a few minutes. Significantly, HP-RBf effectively eradicates Gram-positive bacterial biofilms. The frequency that Gram-positive bacteria spontaneously developed resistance to HP-RB is extremely low (less than 1 × 10−13). Toxicity data obtained through our research programs indicate that HP-RB is feasible as an anti-infective drug for the treatment of skin and soft tissue infections (SSTIs) involving multidrug-resistant (MDR) microbial invasion of the skin, and for eradicating biofilms. This article summarizes the antibacterial activity of pharmaceutical-grade rose bengal, HP-RB, against Gram-positive bacteria, its cytotoxicity against skin cells under illumination conditions, and mechanistic insights into rose bengal’s bactericidal activity under dark conditions.

scholarly journals Chemical Composition and Antibacterial Activity of the Essential Oil of Espeletia nana

2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Alexis Peña ◽  
Luis Rojas ◽  
Rosa Aparicio ◽  
Libia Alarcón ◽  
José Gregorio Baptista ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
Gram Positive Bacteria

The essential oil of the leaves of Espeletia nana Cuatrec, obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were α-pinene (38.1%), β-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), α-zingiberene (4.0%), and γhimachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923(200 μg/mL) and Enterococcus faecalis ATCC 29212 (600 μg/mL).

scholarly journals In Vitro Activities of RWJ-54428 (MC-02,479) against Multiresistant Gram-Positive Bacteria

2001 ◽  
Vol 45 (5) ◽  
pp. 1422-1430 ◽  
Author(s):  
Suzanne Chamberland ◽  
Johanne Blais ◽  
Monica Hoang ◽  
Cynthia Dinh ◽  
Dylan Cotter ◽  
...  
Keyword(s):  
Multidrug Resistant ◽  
Penicillin G ◽  
Significant Activity ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Level Of Activity ◽  
Resistant Strains ◽  
High Level

ABSTRACT RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC90) of 2 μg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC90 of 2 μg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, ≤0.0625 to 1 μg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC90, 0.5 μg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC90 of 0.125 μg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between ≤0.0625 and 1 μg/ml for ampicillin-susceptible strains and 0.125 and 8 μg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains ofStreptococcus pneumoniae (MIC90s, 0.25, 0.125, and ≤0.0625 μg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae andMoraxella catarrhalis (MIC90s, 0.25 and 0.5 μg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.

scholarly journals Postantibiotic Suppression of Growth of Erythromycin A-Susceptible and -Resistant Gram-Positive Bacteria by the Ketolides Telithromycin (HMR 3647) and HMR 3004

2000 ◽  
Vol 44 (6) ◽  
pp. 1749-1753 ◽  
Author(s):  
Wendy J. Munckhof ◽  
Glenn Borlace ◽  
John D. Turnidge
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Streptococcus Pyogenes ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Erythromycin A

ABSTRACT We investigated the in vitro postantibiotic effects (PAEs) of the ketolides telithromycin (HMR 3647) and HMR 3004 and analyzed the results using the sigmoid E max model. Mean maximum telithromycin PAEs against erythromycin A-susceptible strains of Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae were 3.7, 8.9, and 9.7 h, respectively, while maximum PAEs for erythromycin A-resistant strains were much shorter. Mean maximum HMR 3004 PAEs were 3.2 to 4.4 h for all species.

scholarly journals Structural basis for the O-acetyltransferase function of the extracytoplasmic domain of OatA from Staphylococcus aureus

2020 ◽  
Vol 295 (24) ◽  
pp. 8204-8213 ◽  
Author(s):  
Carys S. Jones ◽  
David Sychantha ◽  
P. Lynne Howell ◽  
Anthony J. Clarke
Keyword(s):  
Staphylococcus Aureus ◽  
Biochemical Characterization ◽  
Multidrug Resistant ◽  
Catalytic Triad ◽  
Structural Basis ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Hydrolase Fold ◽  
Acetyl Transfer ◽  
Human Infections

Many bacteria possess enzymes that modify the essential cell-wall polymer peptidoglycan by O-acetylation. This modification occurs in numerous Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, a common cause of human infections. O-Acetylation of peptidoglycan protects bacteria from the lytic activity of lysozyme, a mammalian innate immune enzyme, and as such is important for bacterial virulence. The O-acetylating enzyme in Gram-positive bacteria, O-acetyltransferase A (OatA), is a two-domain protein consisting of an N-terminal integral membrane domain and a C-terminal extracytoplasmic domain. Here, we present the X-ray crystal structure at 1.71 Å resolution and the biochemical characterization of the C-terminal domain of S. aureus OatA. The structure revealed that this OatA domain adopts an SGNH-hydrolase fold and possesses a canonical catalytic triad. Site-specific replacement of active-site amino acids revealed the presence of a water-coordinating aspartate residue that limits esterase activity. This residue, although conserved in staphyloccocal OatA and most other homologs, is not present in the previously characterized streptococcal OatA. These results provide insights into the mechanism of acetyl transfer in the SGNH/GDSL hydrolase family and highlight important evolutionary differences between homologous OatA enzymes. Furthermore, this study enhances our understanding of PG O-acetyltransferases, which could guide the development of novel antibacterial drugs to combat infections with multidrug-resistant bacterial pathogens.

scholarly journals Chemical Composition and Antibacterial Activity of the Essential Oil of Baccharis latifolia Pers. and B. Prunifolia H. B. &K. (Asteraceae)

2007 ◽  
Vol 2 (12) ◽  
pp. 1934578X0700201 ◽  
Author(s):  
Janne Rojas ◽  
Judith Velasco ◽  
Luis B. Rojas ◽  
Tulia Díaz ◽  
Juan Carmona ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Enterococcus Faecalis ◽  
Mass Spectra ◽  
Retention Indices ◽  
Gram Positive ◽  
Gram Positive Bacteria

The essential oils from leaves of Baccharis latifolia and B. prunifolia collected in January 2006 were analyzed by GC/MS. The yields of oils extracted by hydrodistillation were 0.27 and 0.29% for B. latifolia and B. prunifolia, respectively. Sixteen (B. latifolia) and twenty nine (B. prunifolia) components were identified by comparison of their mass spectra with the Wiley GC-MS Library data and by their retention indices (RI). The identified products may be divided into four different groups: monoterpenes (9.0% B. latifolia; 43.9% B. prunifolia), oxygenated monoterpenes (0.8% B. latifolia; 5.4% B. prunifolia), sesquiterpenes (20.4% B. latifolia; 45.9% B. prunifolia) and oxygenated sesquiterpenes (69.8% B. latifolia; 1.9% B. prunifolia). The oils showed antibacterial activity only against Gram positive bacteria, with MIC values for Staphylococcus aureus (ATCC 25923) of 80 μg/mL (B. latifolia) and Enterococcus faecalis (ATCC 29212) of 90 μg/mL and 260 μg/mL (B latifolia and B. prunifolia, respectively).

scholarly journals Pharmacodynamics of Telavancin (TD-6424), a Novel Bactericidal Agent, against Gram-Positive Bacteria

2004 ◽  
Vol 48 (8) ◽  
pp. 3043-3050 ◽  
Author(s):  
Sharath S. Hegde ◽  
Noe Reyes ◽  
Tania Wiens ◽  
Nicole Vanasse ◽  
Robert Skinner ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gram Positive ◽  
Time Curve ◽  
Once Daily ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Dose Dependent

ABSTRACT Telavancin (TD-6424) is a novel lipoglycopeptide that produces rapid and concentration-dependent killing of clinically relevant gram-positive organisms in vitro. The present studies evaluated the in vivo pharmacodynamics of telavancin in the mouse neutropenic thigh (MNT) and mouse subcutaneous infection (MSI) animal models. Pharmacokinetic-pharmacodynamic studies in the MNT model demonstrated that the 24-h area under the concentration-time curve (AUC)/MIC ratio was the best predictor of efficacy. Telavancin produced dose-dependent reduction of thigh titers of several organisms, including methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA), penicillin-susceptible and -resistant strains of Streptococcus pneumoniae, and vancomycin-resistant Enterococcus faecalis. The 50% effective dose (ED50) estimates for telavancin ranged from 0.5 to 6.6 mg/kg of body weight (administered intravenously), and titers were reduced by up to 3 log10 CFU/g from pretreatment values. Against MRSA ATCC 33591, telavancin was 4- and 30-fold more potent (on an ED50 basis) than vancomycin and linezolid, respectively. Against MSSA ATCC 13709, telavancin was 16- and 40-fold more potent than vancomycin and nafcillin, respectively. Telavancin, vancomycin, and linezolid were all efficacious and more potent against MRSA ATCC 33591 in the MSI model compared to the MNT model. This deviation in potency was, however, disproportionately greater for vancomycin and linezolid than for telavancin, suggesting that activity of telavancin is less affected by the immune status. The findings of these studies collectively suggest that once-daily dosing of telavancin may provide an effective approach for the treatment of clinically relevant infections with gram-positive organisms.

scholarly journals In-vitro analysis of potential antibacterial activity of three medicinal plants

2016 ◽  
Vol 8 (3) ◽  
pp. 1497-1500
Author(s):  
Vandana Gupta ◽  
Rakesh Kumar ◽  
Deepika Chaudhary ◽  
Nirmal Yadav
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Medicinal Plants ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

The present study was aimed to examine and compare the antibacterial activity of hot methanolic extract of medicinal plants viz. Portulaca oleracea (purslane), Syzygium cumini (L.) (jamun), Psidium guajava (L.) (guava). Antibacterial activity was carried by using agar well diffusion method, against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and Gram-negative bacteria (Escherichia coli). Results indicated that all the three plant extracts possess antibacterial property against Gram-positive bacteria and no activity was found against Gram-negative bacteria. Moderate zone of inhibition against Staphylococcus aureus and Bacillus subtilis was exhibited by S. cumini (L.) (11mm and 12mm) and P. guajava (L.) (10mm and 11mm) and weak zone of inhibition was exhibited by P. oleracea (5 mm and 6mm). In conclusion, S. cumini (L.) and P. guajava (L.) possess bettercapabilities of being a good candidate in search for natural antibacterial agent against infections and diseases causing Gram-positive bacteria as compared to P. oleracea.

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