In vitro antimicrobial activity of narasin and monensin in combination with adjuvants against pathogens associated with canine otitis externa.

Autor: Chan WY; Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, South Australia, 5371, Australia.; Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Malaysia., Hickey EE; Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, South Australia, 5371, Australia., Khazandi M; Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, South Australia, 5371, Australia., Page SW; Luoda Pharma Pty Ltd., 1/304-318, The Kingsway, Caringbah, New South Wales, 2229, Australia., Trott DJ; Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, South Australia, 5371, Australia., Hill PB; Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, South Australia, 5371, Australia.
Jazyk: angličtina
Zdroj: Veterinary dermatology [Vet Dermatol] 2020 Apr; Vol. 31 (2), pp. 138-145. Date of Electronic Publication: 2019 Nov 11.
DOI: 10.1111/vde.12803
Abstrakt: 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.
(© 2019 ESVD and ACVD.)
Databáze: MEDLINE
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