Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: In vitro antimicrobial activity of narasin and monensin in combination with adjuvants against pathogens associated with canine otitis externa
Author: Chan, W.Y.
Hickey, E.E.
Khazandi, M.
Page, S.W.
Trott, D.J.
Hill, P.B.
Citation: Veterinary Dermatology: an international journal, 2019; 31(2):138-145
Publisher: Wiley
Issue Date: 2019
ISSN: 0959-4493
Statement of
Wei Yee Chan, Elizabeth E. Hickey, Manouchehr Khazandi, Stephen W. Page, Darren J. Trott, Peter B. Hill
Abstract: BACKGROUND:The emergence of antimicrobial resistance represents a serious human and animal health risk. Good antimicrobial stewardship is essential to prolong the lifespan of existing antibiotics, and new strategies are required to combat infections in man and animals. HYPOTHESIS/OBJECTIVES:To determine the in vitro interaction of ionophores (narasin or monensin) with antimicrobial adjuvants (N-acetylcysteine (NAC), Tris-EDTA or disodium EDTA) against bacterial strains representing pathogens associated with canine otitis externa (OE). ANIMAL/ISOLATES:American Type Culture Collection (ATCC) strains Staphylococcus aureus 29213, Pseudomonas aeruginosa 27853 and P. aeruginosa biofilm producer PAO1, and a clinical isolate of Proteus mirabilis from a case of canine OE were tested. METHODS AND MATERIALS:A 2D microdilution checkerboard method was used, allowing calculation of fractional inhibitory concentration index (FICI), dose reduction index (DRI) and plotting of isobolograms. RESULTS:The combination of narasin with either Tris-EDTA or disodium EDTA produced additive effects (FICI = 0.75) against P. aeruginosa ATCC 27853 and P. aeruginosa biofilm producer ATCC PAO1. An additive effect (FICI = 0.53-0.75) was found against S. aureus ATCC 29213 when narasin or monensin were combined with NAC. The highest DRI (32-fold) was found with monensin/NAC where the MIC of monensin was reduced from 4 to 0.125 μg/mL. CONCLUSIONS AND CLINICAL IMPORTANCE:The combination of narasin with Tris-EDTA or disodium EDTA is a promising strategy to inhibit the intrinsic resistance elements of Gram-negative bacteria. These novel combinations potentially could be useful as a multimodal approach to treat mixed infections in canine OE.
Keywords: Animals
Pseudomonas aeruginosa
Proteus mirabilis
Staphylococcus aureus
Otitis Externa
Dog Diseases
Adjuvants, Pharmaceutic
Anti-Bacterial Agents
Microbial Sensitivity Tests
Drug Synergism
Rights: © 2019 ESVD and ACVD, Veterinary Dermatology
DOI: 10.1111/vde.12803
Grant ID:
Appears in Collections:Animal and Veterinary Sciences publications
Aurora harvest 8

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.