scholarly journals Anti-methicillin resistant Staphylococcus aureus (MRSA) activity of an acetone extract from the leaves of Canarium odontophyllum (Miq.)

2018 ◽  
Vol 7 (3) ◽  
pp. 225-229
Author(s):  
Nur Amira Mohd Shamsuddin ◽  
◽  
Dayang Fredalina Basri ◽  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Acetone Extract ◽  
Health Concern ◽  
Antimicrobial Drugs ◽  
Methicillin Resistant ◽  
Bacteriostatic Action ◽  
Broth Microdilution Method ◽  
Canarium Odontophyllum ◽  
Time Kill

Methicillin-resistant Staphylococcus aureus (MRSA) is a global health concern that has caused nosocomial and community infections over the past decade. The emergence of multi-drug resistant strains and limitations of present antimicrobial drugs have led to continuous search for natural products as curative agents for MRSA infections. Canarium odontophyllum Miq., locally known as dabai, has been considered an alternative phytotherapeutic treatment for MRSA. The aim of this study was to evaluate the bacteriostatic activity of an acetone extract from C. odontophyllum leaves against MRSA. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against the ATCC 33591 and Mu50 strains were determined using the broth microdilution method, and a time-kill assay was employed to assess the type of bacteriostatic action of the extract against the Mu50 strain only. The MIC and MBC values of the extract against Mu50 were 312.5 µg/ml and 625 µg/ml, respectively, whereas the MIC and MBC values for ATCC 33591 were 625 µg/ml and 1,250 µg/ml, respectively, confirming the bacteriostatic effect against both MRSA strains. A time-kill assay showed that the acetone extract of C. odontophyllum leaves exhibited concentrationdependent bacteriostatic action against the Mu50 strain at 1/2× MIC, 1× MIC and 2× MIC. However, the extract was bactericidal only at the highest concentration (4× MIC) with a reduction in cell viability of more than 3 log10 within 24 hours. These findings confirm that an acetone extract from C. odontophyllum leaves inhibited growth of MRSA at low concentration and could be utilised as an alternative anti-MRSA agent in immune uncompromised hosts

scholarly journals Allyl isothiocyanate from crucifers potentiates β-lactam activity against methicillin-resistant Staphylococcus aureus

2014 ◽  
Vol 2 (4) ◽  
pp. 189-193
Author(s):  
Sultan Beevi S ◽  
Vikram B ◽  
Lakshmi Narasu M
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Allyl Isothiocyanate ◽  
Resistance Mechanisms ◽  
Clinical Isolates ◽  
Health Concern ◽  
Multi Drug Resistance ◽  
Methicillin Resistant ◽  
Potentiation Effect ◽  
Broth Microdilution Method

Introduction: Increasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) worldwide with limited therapeutic options is a growing public health concern. Isothiocyanates (ITCs) from crucifers have been shown to possess antibacterial actions against MRSA by antagonizing its resistance mechanisms. Allyl isothiocyanates (AITC) is the predominant isothiocyanates (ITC) of commonly consumed cruciferous vegetables such as brussels, mustard, cabbage, cauliflower and kale. Objectives: The aim of this study is to evaluate the potentiation effect of AITC on ampicillin and cefixime against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) using broth microdilution method and checkerboard methods. Results: AITC showed a promising antibacterial activity against a panel of clinical isolates of MRSA when used in alone. However, β-lactam antibiotics like ampicillin and cefixime had little or no activity against MRSA confirming their multi-drug resistance. When AITC combined with ampicillin and cefixime, MIC was reduced by ≥ 4 fold as compared to their monotherapy, evidencing a synergistic effect of AITC, as defined by a FICI of ≤0.5. Conclusions: AITC showed promising synergistic and potentiation effect on ampicillin and cefixime at sub-MIC level against multi-drug resistant MRSA. This modulatory effect of AITC on β-lactam antibiotics could be useful as a synergistic therapeutic pair in combating MRSA infection in a hospital or community settings.

scholarly journals A Molecular Insight into the Synergistic Mechanism of Nigella sativa (Black Cumin) with β-Lactam Antibiotics against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 11 (7) ◽  
pp. 3206
Author(s):  
Lorina I. Badger-Emeka ◽  
Promise Madu Emeka ◽  
Hairul Islam M. Ibrahim
Keyword(s):  
Staphylococcus Aureus ◽  
Mechanism Of Action ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Nigella Sativa ◽  
Synergistic Effects ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Cell Wall Disruption ◽  
Time Kill ◽  
Insight Into

Methicillin-resistant Staphylococcus aureus (MRSA) infection is detrimental to hospitalized patients. With diminishing choices of antibiotics and the worry about resistance to colistin in synergistic combined therapy, there are suggestions for the use of herbal derivatives. This investigation evaluated the synergistic effects of Nigella sativa (NS) in combination with beta-lactam (β-lactam) antibiotics on extreme drug-resistant (XDR) MRSA isolates. NS concentrations of 10, 7.5, 5.0, 2.5, 1.0, and 0.1 µg/mL, alone and in combination with β-lactam antibiotics, were used to determine the antimicrobial susceptibility of MRSA isolates by the well diffusion method. Time–kill assays were performed using a spectrophotometer, with time–kill curves plotted and synergism ascertained by the fractional inhibitory concentration (FIC). Scanning and transmission electron microscopy were used to gain insight into the mechanism of action of treated groups. Isolates were inhibited by the NS concentrations, with differences in the zones of inhibition being statistically insignificant at p < 0.05. There were statistically significant differences in the time–kill assay for the MRSA isolates. In addition, NS combined with augmentin showed better killing than oxacillin and cefuroxime. The mechanism of action shown by the SEM and TEM results revealed cell wall disruption, which probably created interference that led to bacterial lysis.

scholarly journals Trans-Cinnamaldehyde Exhibits Synergy with Conventional Antibiotic against Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 22 (5) ◽  
pp. 2752
Author(s):  
Shu Wang ◽  
Ok-Hwa Kang ◽  
Dong-Yeul Kwon
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Synergistic Effects ◽  
Regulatory Gene ◽  
Western Blot Assay ◽  
Methicillin Resistant ◽  
Wide Range ◽  
Kill Curve ◽  
Conventional Antibiotics ◽  
Time Kill

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen worldwide and has acquired multiple resistance to a wide range of antibiotics. Hence, there is a pressing need to explore novel strategies to overcome the increase in antimicrobial resistance. The present study aims to investigate the efficacy and mechanism of plant-derived antimicrobials, trans-cinnamaldehyde (TCA) in decreasing MRSA’s resistance to eight conventional antibiotics. A checkerboard dilution test and time–kill curve assay are used to determine the synergistic effects of TCA combined with the antibiotics. The results indicated that TCA increased the antibacterial activity of the antibiotics by 2-16-fold. To study the mechanism of the synergism, we analyzed the mecA transcription gene and the penicillin-binding protein 2a level of MRSA treated with TCA by quantitative RT-PCR or Western blot assay. The gene transcription and the protein level were significantly inhibited. Additionally, it was verified that TCA can significantly inhibit the biofilm, which is highly resistant to antibiotics. The expression of the biofilm regulatory gene hld of MRSA after TCA treatment was also significantly downregulated. These findings suggest that TCA maybe is an exceptionally potent modulator of antibiotics.

scholarly journals In Vitro Killing of Community-Associated Methicillin-Resistant Staphylococcus aureus with Drug Combinations

2004 ◽  
Vol 48 (10) ◽  
pp. 4016-4019 ◽  
Author(s):  
Samuel A. Shelburne ◽  
Daniel M. Musher ◽  
Kristina Hulten ◽  
Heather Ceasar ◽  
Michael Y. Lu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Drug Combinations ◽  
Methicillin Resistant ◽  
Common Drug ◽  
Time Kill ◽  
Hospital Acquired

ABSTRACT This study employs time-kill techniques to examine the most common drug combinations used in the therapy of methicillin-resistant Staphylococcus aureus (MRSA) infections, vancomycin plus either gentamicin or rifampin. Community-associated MRSA were more likely to be synergistically inhibited by combinations of vancomycin and gentamicin versus vancomycin alone compared to inhibition associated with hospital-acquired strains.

scholarly journals Novel Antibiotic Combinations of Diverse Subclasses for Effective Suppression of Extensively Drug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA)

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shumyila Nasir ◽  
Muhammad Sufyan Vohra ◽  
Danish Gul ◽  
Umm E Swaiba ◽  
Maira Aleem ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clavulanic Acid ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Methicillin Resistant ◽  
Development Of Resistance ◽  
Amoxicillin Clavulanic Acid ◽  
Combination Antibiotics ◽  
Time Kill

The emergence of multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), the chief etiological agent for a range of refractory infections, has rendered all β-lactams ineffective against it. The treatment process is further complicated with the development of resistance to glycopeptides, primary antibiotics for treatment of MRSA. Antibiotic combination therapy with existing antimicrobial agents may provide an immediate treatment option. Minimum inhibitory concentrations (MICs) of 18 different commercially available antibiotics were determined along with their 90 possible pairwise combinations and 64 triple combinations to filter out 5 best combinations. Time-Kill kinetics of these combinations were then analyzed to find collateral bactericidal combinations which were then tested on other randomly selected MRSA isolates. Among the top 5 combinations including levofloxacin-ceftazidime; amoxicillin/clavulanic acid-tobramycin; amoxicillin/clavulanic acid-cephradine; amoxicillin/clavulanic acid-ofloxacin; and piperacillin/tazobactam-tobramycin, three combinations were found to be collaterally effective. Levofloxacin-ceftazidime acted synergistically in 80% of the tested clinical MRSA isolates. First-line β-lactams of lower generations can be used effectively against MRSA infection when used in combination. Antibiotics other than glycopeptides may still work in combination.

scholarly journals Synergism between β-Lactams and Glycopeptides against VanA-Type Methicillin-Resistant Staphylococcus aureus and Heterologous Expression of the vanA Operon

2006 ◽  
Vol 50 (11) ◽  
pp. 3622-3630 ◽  
Author(s):  
Bruno Périchon ◽  
Patrice Courvalin
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Vancomycin Resistance ◽  
Glycopeptide Resistance ◽  
Methicillin Resistant ◽  
Antagonistic Effects ◽  
Resistance Induction ◽  
The Stability ◽  
Time Kill

ABSTRACT Vancomycin resistance of Staphylococcus aureus NY-VRSA and VRSA-5 is due to acquisition of a vanA operon located in a Tn1546-like element. The vanA gene cluster of NY-VRSA contained one copy of insertion sequences IS1251 and IS1216V relative to that of VRSA-5. As evidenced by the nature of the late peptidoglycan precursors and by quantification of d,d-peptidase activities, the vancomycin resistance genes were efficiently expressed in both strains. Study of the stability and inducibility of glycopeptide resistance suggested that low-level glycopeptide resistance of NY-VRSA was most probably due to plasmid instability combined with a long delay for resistance induction. The activity of combinations of vancomycin or teicoplanin with oxacillin against the four VanA-type S. aureus strains already reported was tested by single and double disk diffusion, E-test on agar alone or supplemented with antibiotics, the checkerboard technique, and by determining time-kill curves. A strong synergism against the four clinical isolates, with fractional inhibitory concentration indexes from 0.008 to 0.024, was reproducibly observed between the two antibiotics by all methods. These observations indicate that cell wall inhibitors of the β-lactam and glycopeptide classes exert strong and mutual antagonistic effects on resistance to each other against VanA-type methicillin-resistant S. aureus.

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