In vitro antibacterial activities of ethanolic extracted leaves of Thevetia peruviana (Pers.) K.Schum [Thevetia Yellow]

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.

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Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽

10.3390/molecules26061773 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1773

Author(s):

Patchima Sithisarn ◽

Piyanuch Rojsanga ◽

Pongtip Sithisarn

Keyword(s):

Antibacterial Activities ◽

Inhibitory Effect ◽

Total Flavonoid ◽

Total Phenolic ◽

Antibacterial Effects ◽

E Coli ◽

Young Fruit ◽

Oroxylum Indicum ◽

Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

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In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

Microorganisms ◽

10.3390/microorganisms9020450 ◽

2021 ◽

Vol 9 (2) ◽

pp. 450

Author(s):

Maigualida Cuenca ◽

María Carmen Sánchez ◽

Pedro Diz ◽

Lucía Martínez-Lamas ◽

Maximiliano Álvarez ◽

...

Keyword(s):

Antibacterial Activity ◽

Quantitative Polymerase Chain Reaction ◽

Bacterial Load ◽

Antibacterial Properties ◽

Antibacterial Activities ◽

Oral Bacteria ◽

Periodontal Pathogens ◽

Biofilm Model ◽

Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

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Tantalum doped SiO2-CaO-P2O5 based bioactive glasses: Investigation of in vitro bioactivity and antibacterial activities

Biomedical glasses ◽

10.1515/bglass-2020-0002 ◽

2020 ◽

Vol 6 (1) ◽

pp. 10-22

Author(s):

Zakaria Tabia ◽

Sihame Akhtach ◽

Khalil El Mabrouk ◽

Meriame Bricha ◽

Khalid Nouneh ◽

...

Keyword(s):

Antibacterial Activities ◽

Silica Matrix ◽

Morphological Properties ◽

Metallic Ions ◽

X Ray Diffraction ◽

Bioactive Glasses ◽

E Coli ◽

Fourier Transformed Infrared Spectroscopy ◽

Electron Scanning Microscopy

AbstractMultifunctionality can be achieved for bioactive glasses by endowing them with multiple other properties along with bioactivity. One way to address this topic is by doping these glasses with therapeutic metallic ions. In this work, we put under investigation a series of bioactive glasses doped with tantalum. We aim to study the effect of tantalum, on the structure, bioactivity and antibacterial property of a ternary bioactive glass composition based on SiO2-CaO-P2O5. Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Electron Scanning Microscopy (SEM) were used to assess the structural and morphological properties of these glasses and monitor their changes after in vitro acellular bioactivity test. Antibacterial activity was tested against gram positive and negative bacteria. Characterization results confirmed the presence of calcium carbonate crystallites along with the amorphous silica matrix. The assessment of bioactivity in SBF indicated that all compositions showed a fast bioactive response after only six hours of immersion period. However, analytical characterization revealed that tantalum introduced a slight latency in hydroxyapatite deposition at higher concentrations (0.8-1 %mol). Antibacterial test showed that tantalum ions had an inhibition effect on the growth of E. coli and S. aureus. This effect was more pronounced in compositions where mol% of tantalum is superior to 0.4%. These results proved that tantalum could be used, in intermediate proportions, as a promising multifunctional dopant element in bioactive glasses for bone regeneration applications.

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Chemical Composition, in vitro Trypanocidal and Antibacterial Activities of the Essential Oil from the Dried Leaves of Eugenia dysenterica DC from Brazil

Journal of Essential Oil Bearing Plants ◽

10.1080/0972060x.2019.1626293 ◽

2019 ◽

Vol 22 (2) ◽

pp. 347-355 ◽

Cited By ~ 4

Author(s):

Larissa Sousa Santos ◽

Cassia Cristina Fernandes Alves ◽

Elisângela Barbosa Borges Estevam ◽

Carlos Henrique Gomes Martins ◽

Thayná de Souza Silva ◽

...

Keyword(s):

Chemical Composition ◽

Essential Oil ◽

Antibacterial Activities ◽

Eugenia Dysenterica

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01407-05 ◽

2006 ◽

Vol 50 (6) ◽

pp. 2261-2264 ◽

Cited By ~ 36

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.

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Synthesis and in vitro antibacterial activities of 3-thiazol 4 yl-carba-l-dethiacephalosporins.

The Journal of Antibiotics ◽

10.7164/antibiotics.47.1052 ◽

1994 ◽

Vol 47 (9) ◽

pp. 1052-1064 ◽

Cited By ~ 3

Author(s):

WILLIAM J. HORNBACK ◽

JOHN E. MUNROE ◽

FRED T. COUNTER

Keyword(s):

Antibacterial Activities

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In VitroActivities of Daptomycin-, Vancomycin-, and Teicoplanin-Loaded Polymethylmethacrylate against Methicillin-Susceptible, Methicillin-Resistant, and Vancomycin-Intermediate Strains of Staphylococcus aureus

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05312-11 ◽

2011 ◽

Vol 55 (12) ◽

pp. 5480-5484 ◽

Cited By ~ 45

Author(s):

Yuhan Chang ◽

Wen-Chien Chen ◽

Pang-Hsin Hsieh ◽

Dave W. Chen ◽

Mel S. Lee ◽

...

Keyword(s):

Staphylococcus Aureus ◽

High Performance ◽

Low Dose ◽

Antibacterial Activities ◽

High Dose ◽

Bone Cements ◽

Antibacterial Effects ◽

Methicillin Resistant ◽

Content Type

ABSTRACTThe objective of this study was to evaluate the antibacterial effects of polymethylmethacrylate (PMMA) bone cements loaded with daptomycin, vancomycin, and teicoplanin against methicillin-susceptibleStaphylococcus aureus(MSSA), methicillin-resistantStaphylococcus aureus(MRSA), and vancomycin-intermediateStaphylococcus aureus(VISA) strains. Standardized cement specimens made from 40 g PMMA loaded with 1 g (low-dose), 4 g (middle-dose) or 8 g (high-dose) antibiotics were tested for elution characteristics and antibacterial activities. The patterns of release of antibiotics from the cement specimens were evaluated usingin vitrobroth elution assay with high-performance liquid chromatography. The activities of broth elution fluid against differentStaphylococcus aureusstrains (MSSA, MRSA, and VISA) were then determined. The antibacterial activities of all the tested antibiotics were maintained after being mixed with PMMA. The cements loaded with higher dosages of antibiotics showed longer elution periods. Regardless of the antibiotic loading dose, the teicoplanin-loaded cements showed better elution efficacy and provided longer inhibitory periods against MSSA, MRSA, and VISA than cements loaded with the same dose of vancomycin or daptomycin. Regarding the choice of antibiotics for cement loading in the treatment ofStaphylococcus aureusinfection, teicoplanin was superior in terms of antibacterial effects.

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