Evaluation of the impact of tromethamine edetate disodium dihydrate on antimicrobial susceptibility of Pseudomonas aeruginosa in biofilm in vitro

作者：Pye Charlotte C^*; Singh Ameet; Weese J Scott

来源：Veterinary Dermatology, 2014, 25(2): 120-+.

DOI：10.1111/vde.12115

image %26lt;br%26gt;image %26lt;br%26gt;Background %26lt;br%26gt;Biofilm formation by Pseudomonas aeruginosa has been documented in canine otic isolates. An increase in minimal inhibitory concentration (MIC) for specific antibiotics has been noted for biofilm-embedded bacteria. Tromethamine edetate disodium dihydrate buffered to pH 8 with tromethamine hydrochloride and deionized water (Triz-EDTA((R))) has been documented to potentiate bactericidal activity when used in combination with topical antibiotics, but the impact on biofilm-embedded bacteria is unknown. Hypothesis/Objectives %26lt;br%26gt;The objective of this study was to evaluate the impact of Triz-EDTA((R)) use on in vitro antimicrobial susceptibility of biofilm-embedded P. aeruginosa. Methods %26lt;br%26gt;Biofilm formation was documented using a microtitre plate assay. Broth microdilution was used to assess the MIC of neomycin, polymyxin B, enrofloxacin and gentamicin for the biofilm-embedded bacteria. The microtitre plate assay was again used to assess the MIC of neomycin, polymyxin B, enrofloxacin and gentamicin for biofilm-embedded bacteria with added Triz-EDTA((R)). Results %26lt;br%26gt;Thirty-one isolates from dogs with otitis were tested. Addition of Triz-EDTA((R)) significantly reduced MICs for neomycin (P %26lt; 0.003) and gentamicin (P %26lt; 0.02) but not for polymyxin B (P = 0.3). Enrofloxacin MICs increased in the presence of Triz-EDTA (P %26lt; 0.036). Conclusions and clinical importance %26lt;br%26gt;Triz-EDTA((R)) may be a useful adjunctive treatment for chronic cases of Pseudomonas otitis where biofilms may have developed, if gentamicin or neomycin is to be used as a topical treatment. In vivo study is required to confirm this effect.

• 出版日期2014-4