Journal Article

Antimicrobial synergy between mRNA- and protein-level inhibitors

Rikard Dryselius, Natalia Nekhotiaeva and Liam Good

in Journal of Antimicrobial Chemotherapy

Published on behalf of British Society for Antimicrobial Chemotherapy

Volume 56, issue 1, pages 97-103
Published in print July 2005 | ISSN: 0305-7453
Published online May 2005 | e-ISSN: 1460-2091 | DOI:
Antimicrobial synergy between mRNA- and protein-level inhibitors

Show Summary Details


Background: The few available distinct classes of antimicrobials limits the scope for single and combination drug treatment of resistant infections.

Objective: To evaluate antimicrobial effectiveness from combinations of protein-specific drugs and mRNA-specific antisense inhibitors.

Methods: Interactions between conventional antimicrobial drugs and mRNA-specific translation inhibiting antisense peptide nucleic acids were assessed in Escherichia coli and Staphylococcus aureus cultures using pairwise combinations in a chequerboard arrangement. Fractional inhibitory concentration indices (FICIs) were calculated and grouped according to the functional relationship between the inhibitor targets. Antisense specificity controls included different antisense sequences targeting the same mRNA, as well as biochemical quantification of active protein expressed from the essential fabI gene and from the lacZ reporter gene after single and combined inhibitor treatment.

Results: FICIs were higher for inhibitor combinations with unrelated targets than for combinations with functionally related targets. Inhibitor combinations with shared genetic targets displayed the lowest FICIs, with several qualifying for the conservative definition of antimicrobial synergy (FICI ≤ 0.5). Furthermore, low FICIs arise as the hyperbolic dose–response curves for each separate inhibitor are maintained in combination.

Conclusion: Interactions between mRNA- and protein-level inhibitors with the same genetic target can be synergistic and may provide a strategy to improve antimicrobial efficacy, facilitate drug mechanism of action studies and aid the search for new antimicrobials.

Keywords: antimicrobial treatment; antisense; chequerboard; inhibitor combinations; PNA

Journal Article.  4173 words.  Illustrated.

Subjects: Medical Oncology ; Critical Care

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.