scholarly journals A Time-Kill Assay Study on the Synergistic Bactericidal Activity of Pomegranate Rind Extract and Zn (II) against Methicillin-Resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1889
Author(s):  
Amal Alrashidi ◽  
Mohammed Jafar ◽  
Niamh Higgins ◽  
Ciara Mulligan ◽  
Carmine Varricchio ◽  
...  

There is a need for new antimicrobial systems due to increased global resistance to current antimicrobials. Pomegranate rind extract (PRE) and Zn (II) ions both possess a level of antimicrobial activity and work has previously shown that PRE/Zn (II) in combination possesses synergistic activity against Herpes simplex virus and Micrococcus luteus. Here, we determined whether such synergistic activity extended to other, more pathogenic, bacteria. Reference strains of methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa were cultured and subjected to challenge by PRE, Zn (II), or PRE + Zn (II), in time-kill assays. Data were obtained independently by two researchers using different PRE preparations. Statistically significant synergistic activity for PRE + Zn (II) was shown for all four bacterial strains tested compared to untreated controls, although the extent of efficacy and timescales varied. Zn (II) exerted activity and at 1 h, it was not possible to distinguish with PRE + Zn (II) combination treatment in all cases. PRE alone showed low activity against all four bacteria. Reproducible synergistic bactericidal activity involving PRE and Zn (II) has been confirmed. Potential mechanisms are discussed. The development of a therapeutic system that possesses demonstrable antimicrobial activity is supported which lends itself particularly to topical delivery applications, for example MRSA infections.

Author(s):  
SUNDAR MADASAMY ◽  
SURESH SUNDAN ◽  
LINGAKUMAR KRISHNASAMY

Objective: A simple formulation of cold cream from methanolic extract Caralluma adscendens var. attenuata (MECA) and their antimicrobial activity was tested against various clinical pathogens, namely, Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and Candida albicans. Methods: Methanol extract of these plant extract was prepared by the Soxhlet method. We analyzed phytochemical nature of theses plant, and subsequently, a cream was formulated cold-cream C. adscendens var. attenuata (FCA) different concentration such as FCA 50 mg, FCA 100 mg, and FCA 200 mg. In the present study, aimed to the antimicrobial activity of cold cream was measured by agar well diffusion method, and standard antibiotic Neosporin (market available) cream was used as positive control and dummy cold cream (without-MECA) were used as the negative control. Results: Phytochemical screening showed that the plant extracts were found a rich source of secondary metabolites. For more, the efficacy of cold cream from MECA extracts to against the clinical pathogen. Positive control Neosporin and 200 mg FCA cream was a highly significant difference in the zone of inhibition when compared to dummy cream. The 200 mg FCA was activity against Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant E. faecium, and C. albicans highly significantly difference (p<0.05) compared FCA 50 mg and FAC 100 mg creams. Conclusion: The results from this study suggested that the cold cream form base of MECA crude had antimicrobial activity in the different clinical pathogen. They could be used as an alternative source to conventional antimicrobial agents for the treatment of pathological infection.


2016 ◽  
Vol 60 (7) ◽  
pp. 4342-4345 ◽  
Author(s):  
Adam Belley ◽  
David Lalonde Seguin ◽  
Francis Arhin ◽  
Greg Moeck

ABSTRACTAntibacterial agents that kill nondividing bacteria may be of utility in treating persistent infections. Oritavancin and dalbavancin are bactericidal lipoglycopeptides that are approved for acute bacterial skin and skin structure infections in adults caused by susceptible Gram-positive pathogens. Using time-kill methodology, we demonstrate that oritavancin exerts bactericidal activity against methicillin-resistantStaphylococcus aureus(MRSA) isolates that are maintained in a nondividing statein vitro, whereas dalbavancin and the glycopeptide vancomycin do not.


2009 ◽  
Vol 53 (10) ◽  
pp. 4495-4497 ◽  
Author(s):  
Shveta Rani Singh ◽  
Alfred E. Bacon ◽  
David C. Young ◽  
Kimberly A. Couch

ABSTRACT Many clinicians are trying unique strategies, including vancomycin and linezolid in combination, for treatment of patients who do not respond to conventional therapy against methicillin (meticillin)-resistant Staphylococcus aureus. In our study, which illustrated in vitro activity only, no synergistic activity was seen when the two agents were combined. Conversely, antagonistic activity occurred in three of five strains when linezolid was added to vancomycin. Our results indicate that vancomycin and linezolid in combination should be avoided.


1994 ◽  
Vol 302 (2) ◽  
pp. 535-538 ◽  
Author(s):  
J Alvarez-Bravo ◽  
S Kurata ◽  
S Natori

Previously, we identified a core undecapeptide of sapecin B having antimicrobial activity. Based on the structure of this peptide, we systematically synthesized peptides consisting of terminal basic motifs and internal oligo-leucine sequences and examined their antimicrobial activities. Of these peptides, RLKLLLLLRLK-NH2 and KLKLLLLLKLK-NH2 were found to have potent microbicidal activity against Staphylococcus aureus, Escherichia coli, methicillin-resistant S. aureus and Candida albicans in liquid medium. We also synthesized the D-enantiomer of KLKLLLLLKLK-NH2. This enantiomer was resistant to tryptic digestion and persisted longer in the culture medium, showing greater antimicrobial activity than the original peptide.


2012 ◽  
Vol 56 (5) ◽  
pp. 2753-2755 ◽  
Author(s):  
Louisa D'Lima ◽  
Lisa Friedman ◽  
Lu Wang ◽  
Ping Xu ◽  
Mark Anderson ◽  
...  

ABSTRACTTwenty-five serial passages ofEscherichia coli,Pseudomonas aeruginosa, andStaphylococcus aureusand 50 passages of methicillin-resistantStaphylococcus aureusresulted in no significant increase in NVC-422 MICs, while ciprofloxacin MICs increased 256-fold forE. coliand 32-fold forP. aeruginosaandS. aureus. Mupirocin, fusidic acid, and retapamulin MICs for MRSA increased 64-, 256-, and 16-fold, respectively. No cross-resistance to NVC-422 was observed with mupirocin-, fusidic acid-, and retapamulin-resistant strains.


Author(s):  
Mariana Ferreira ◽  
Lucinda J. Bessa ◽  
Carla F. Sousa ◽  
Peter Eaton ◽  
Dafne Bongiorno ◽  
...  

Fluoroquinolones (FQs) are antibiotics commonly used in clinical practice, although nowadays they are becoming ineffective due to the emergence of several mechanisms of resistance in most bacteria. The complexation of FQs with divalent metal ions and phenanthroline (phen) is a possible approach to circumvent antimicrobial resistance, since it forms very stable complexes known as metalloantibiotics. This work is aimed at determining the antimicrobial activity of metalloantibiotics of Cu(II)FQphen against a panel of multidrug-resistant (MDR) clinical isolates and to clarify their mechanism of action. Minimum inhibitory concentrations (MICs) were determined against MDR isolates of Escherichia coli, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA). Metalloantibiotics showed improved antimicrobial activity against several clinical isolates, especially MRSA. Synergistic activity was evaluated in combination with ciprofloxacin and ampicillin by the disk diffusion and checkerboard methods. Synergistic and additive effects were shown against MRSA isolates. The mechanism of action was studied though enzymatic assays and atomic force microscopy (AFM) experiments. The results indicate a similar mechanism of action for FQs and metalloantibiotics. In summary, metalloantibiotics seem to be an effective alternative to pure FQs against MRSA. The results obtained in this work open the way to the screening of metalloantibiotics against other Gram-positive bacteria.


2007 ◽  
Vol 2 (9) ◽  
pp. 1934578X0700200 ◽  
Author(s):  
Mohamed M. Radwan ◽  
Susan P. Manly ◽  
Samir A. Ross

Two new sulfated steroids, 3β, 5α, 6β- trihydroxy-24-methylene-cholesta-7-ene-3-sodium sulfate (1) and 3β, 5α, 6β-trihydroxy-23 E-24-methyl-cholesta-7,23-diene-3-sodium sulfate (2) have been isolated from the sponge, Lendenfeldia dendyi. Their structures were determined on the basis of extensive spectroscopic data (IR, HRMS, 1H and 13C NMR, HMQC, HMBC, COSY and ROESY). The two metabolites lacked antimicrobial activity against Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Cryptococcus neoformans, Mycobacterium intracellulare, Aspergillus fumigatus, and methicillin-resistant Staphylococcus aureus (MRSa).


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