scholarly journals Assessment of a microplate method for determining the post-antibiotic effect in Staphylococcus aureus and Escherichia coli

2004 ◽  
Vol 54 (1) ◽  
pp. 139-143 ◽  
Author(s):  
W. J. Stubbings
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibiotic Effect ◽  
Post Antibiotic Effect

scholarly journals Antisense PNA Accumulates in Escherichia coli and Mediates a Long Post-antibiotic Effect

2007 ◽  
Vol 15 (8) ◽  
pp. 1537-1542 ◽  
Author(s):  
Abbas Nikravesh ◽  
Rikard Dryselius ◽  
Omid R Faridani ◽  
Shan Goh ◽  
Majid Sadeghizadeh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Effect ◽  
Post Antibiotic Effect

Synergistic effect of antimicrobial peptide LL-37 and colistin combination against multidrug-resistant Escherichia coli isolates

2021 ◽  
Author(s):  
Gianluca Morroni ◽  
Laura Di Sante ◽  
Oriana Simonetti ◽  
Lucia Brescini ◽  
Wojciech Kamysz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Antimicrobial Peptide ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
E Coli ◽  
Antibiotic Effect ◽  
Global Spread ◽  
Time Kill ◽  
Post Antibiotic Effect

Overview: The global spread of antibiotic resistance represents a serious threat for public health. Aim: We evaluated the efficacy of the antimicrobial peptide LL-37 as antimicrobial agent against multidrug-resistant Escherichia coli. Results: LL-37 showed good activity against mcr-1 carrying, extended spectrum β-lactamase- and carbapenemase-producing E. coli (minimum inhibitory concentration, MIC, from 16 to 64 mg/l). Checkerboard assays demonstrated synergistic effect of LL-37/colistin combination against all tested strains, further confirmed by time–kill and post antibiotic effect assays. MIC and sub-MIC concentrations of LL-37 were able to reduce biofilm formation. Conclusion: Our preliminary data indicated that LL-37/colistin combination was effective against multidrug resistant E. coli strains and suggested a new possible clinical application.

Synergic interaction between pomegranate extract and antibiotics against Staphylococcus aureus

2005 ◽  
Vol 51 (7) ◽  
pp. 541-547 ◽  
Author(s):  
L C Braga ◽  
A A.M Leite ◽  
K G.S Xavier ◽  
J A Takahashi ◽  
M P Bemquerer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Efflux Pump ◽  
Punica Granatum ◽  
Dilution Method ◽  
Antibiotic Effect ◽  
Time Kill ◽  
Useful Lifetime ◽  
Broth Dilution ◽  
Post Antibiotic Effect

We evaluated the interaction between Punica granatum (pomegranate) methanolic extract (PGME) and antibiotics against 30 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). Susceptibility testing of the isolates to PGME and antibiotics was performed by the broth dilution method. Synergic activity was detected between PGME and the 5 antibiotics tested, chloramphenicol, gentamicin, ampicillin, tetracycline, and oxacillin, ranging from 38% to 73%. For some isolates, PGME did not interfere with the action of any of the antibiotics tested. The bactericidal activity of PGME (0.1 × MIC) in combination with ampicillin (0.5 × MIC) was assessed using chosen isolates by time-kill assays, and they confirmed the synergic activity. Using this combination, cell viability was reduced by 99.9% and 72.5% in MSSA and MRSA populations, respectively. PGME increased the post-antibiotic effect (PAE) of ampicillin from 3 to 7 h. In addition, PGME demonstrated the potential to either inhibit the efflux pump NorA or to enhance the influx of the drug. The detection of in vitro variant colonies of S. aureus resistant to PGME was low and they did not survive. In conclusion, PGME dramatically enhanced the activity of all antibiotics tested, and thus, offers an alternative for the extension of the useful lifetime of these antibiotics.Key words: Staphylococcus aureus, antibiotic-resistance, synergy, NorA, Punica granatum.

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