Antibacterial activity of unifloral honeys against clinical isolates of methicillin-resistant Staphylococcus aureus

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
A Hannan ◽  
MB Hussain ◽  
M Absar
2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Courtney M. Starks ◽  
Vanessa L. Norman ◽  
Russell B. Williams ◽  
Matt G. Goering ◽  
Stephanie M. Rice ◽  
...  

One new and seven known diterpenes were identified from an antibacterial chromatographic fraction of Taxodium ascendens. Of these, demethylcryptojaponol (2), 6-hydroxysalvinolone (3), hydroxyferruginol (4), and hinokiol (5) demonstrated potent activity against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). These compounds represent a class of synthetically accessible compounds that could be further developed for treatment of drug-resistant bacterial infections.


2020 ◽  
Vol 13 (11) ◽  
pp. 369
Author(s):  
Fethi Ben Abdallah ◽  
Rihab Lagha ◽  
Ahmed Gaber

Methicillin-resistant Staphylococcus aureus is a major human pathogen that poses a high risk to patients due to the development of biofilm. Biofilms, are complex biological systems difficult to treat by conventional antibiotic therapy, which contributes to >80% of humans infections. In this report, we examined the antibacterial activity of Origanum majorana, Rosmarinus officinalis, and Thymus zygis medicinal plant essential oils against MRSA clinical isolates using disc diffusion and MIC methods. Moreover, biofilm inhibition and eradication activities of oils were evaluated by crystal violet. Gas chromatography–mass spectrometry analysis revealed variations between oils in terms of component numbers in addition to their percentages. Antibacterial activity testing showed a strong effect of these oils against MRSA isolates, and T. zygis had the highest activity succeeded by O. majorana and R. officinalis. Investigated oils demonstrated high biofilm inhibition and eradication actions, with the percentage of inhibition ranging from 10.20 to 95.91%, and the percentage of eradication ranging from 12.65 to 98.01%. O. majorana oil had the highest biofilm inhibition and eradication activities. Accordingly, oils revealed powerful antibacterial and antibiofilm activities against MRSA isolates and could be a good alternative for antibiotics substitution.


Author(s):  
Manipriya B ◽  
Tasneem Banu ◽  
Prem Kumar L ◽  
Kalyani M

 Objective: To determine the virulence factors-biofilm, nuclease and phosphatase production in Staphylococcus aureus isolates. To determine the effect of silver nano particles and antibiotics on MRSA by MIC determination and kirby baeur method respectively and finally to compare antibacterial activity of silver nano particles and antibiotics.Methods: In the present study, we explore the antibacterial activity of silver nanoparticles (Ag-NPs) dispersion (10 nm) against reference strain and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). We evaluated the antibacterial activity of Ag-NPs against MRSA isolated from patients in Saveetha Medical College and Hospital, a tertiary care centre in Chennai, Tamil Nadu. The bactericidal activity of different concentrations of Ag-NPs (200, 100, 50, 25, 12.5, 6.25, 3.125, and 1.5625 μg/ml) was tested by determining MIC using microbroth dilution and MBC by agar dilution methods.. In addition, the virulence factors phosphatase, nuclease, and biofilm production were tested.Result: The values of minimal inhibitory concentration and minimal bactericidal concentration of Ag-NPs against all clinical isolates of MRSA and a single of S. aureus were found in the range of 12.5–50 μg/ml and 12.5–25 μg/ml, respectively, indicating very good bactericidal activity. Ag-NPs with the highest concentration showed almost no growth for up to 16 h representing a bactericidal effect at this concentration. Effect was proportional to dose since 50.0 μg/ml was the most effective dose since the bacterial population did not recover and 12.5 μg/ml was the least effective. All the MRSA isolates were positive for the virulence factors.Conclusion: The study result suggests that Ag-NPs could be used as an effective alternative antibacterial agent.


2021 ◽  
Vol 10 (6) ◽  
pp. e14210615469
Author(s):  
Pérola Paloma Silva do Nascimento ◽  
Rafaela de Siqueira Ferraz-Carvalho ◽  
Thaís Soares da Silva ◽  
Thiago Antônio de Sousa Araújo ◽  
Elba Lúcia Cavalcanti de Amorim ◽  
...  

Anadenanthera colubrina var. cebil (Griseb.) Altschul, a plant often found in areas of the Caatinga in northeastern Brazil, is widely used in unconventional medicine for the treatment of infections and inflammations. Thus, the aim of the present study was to evaluate the antibacterial activity of A. colubrina bark extracts against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates, to investigate if intact and regenerated bark extracts have the same effect against MRSA and to determine the interaction between these extracts and antibiotics. The antibacterial activity was performed by the determination of the minimum inhibitory concentration (MIC) according to the Clinical and Laboratory Standards Institute (CLSI) and the interaction assay was performed by the checkerboard method. A. colubrina extracts showed bacteriostatic activity (MIC = 8-32 mg/L) against MRSA clinical strains and no difference was found in antibacterial activity between intact and regenerated barks, suggesting that even after regeneration, the barks of this species have the same antibacterial activity. Moreover, the in vitro interaction of A. colubrina extracts with ciprofloxacin or erythromycin was additive (FICI = 0.52). Thus, the bark extracts of Anadenanthera colubrina exhibit antibacterial activity and can be used alone or in combination with antibiotics against MRSA clinical isolates.


2008 ◽  
Vol 52 (8) ◽  
pp. 2849-2854 ◽  
Author(s):  
Tetsufumi Koga ◽  
Nobuhisa Masuda ◽  
Masayo Kakuta ◽  
Eiko Namba ◽  
Chika Sugihara ◽  
...  

ABSTRACT Tomopenem (formerly CS-023) is a novel 1β-methylcarbapenem with broad-spectrum coverage of gram-positive and gram-negative pathogens. Its antibacterial activity against European clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa was compared with those of imipenem and meropenem. The MICs of tomopenem against MRSA and P. aeruginosa at which 90% of the isolates tested were inhibited were 8 and 4 μg/ml, respectively, and were equal to or more than fourfold lower than those of imipenem and meropenem. The antibacterial activity of tomopenem against MRSA was correlated with a higher affinity for the penicillin-binding protein (PBP) 2a. Its activity against laboratory mutants of P. aeruginosa with (i) overproduction of chromosomally coded AmpC β-lactamase; (ii) overproduction of the multidrug efflux pumps MexAB-OprM, MexCD-OprJ, and MexEF-OprN; (iii) deficiency in OprD; and (iv) various combinations of AmpC overproduction, MexAB-OprM overproduction, and OprD deficiency were tested. The increases in the MIC of tomopenem against each single mutant compared with that against its parent strain were within a fourfold range. Tomopenem exhibited antibacterial activity against all mutants, with an observed MIC range of 0.5 to 8 μg/ml. These results suggest that the antibacterial activity of tomopenem against the clinical isolates of MRSA and P. aeruginosa should be ascribed to its high affinity for PBP 2a and its activity against the mutants of P. aeruginosa, respectively.


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