Evaluation of disc diffusion and MIC testing for determining susceptibility of <i>Pseudomonas aeruginosa</i> isolates to topical enrofloxacin/silver sulfadiazine

Section: Discussionmentioning

confidence: 90%

Tris–EDTAsignificantly enhances antibiotic efficacy against multidrug‐resistantPseudomonas aeruginosa in vitro

Buckley

McEwan

Nuttall

2013

“…Silver sulfadiazine is a topical sulfonamide/silver antibacterial agent that is commonly used for burn wounds in humans . It has shown excellent activity against P. aeruginosa , alone as well as combined with enrofloxacin in an otic solution approved for the treatment of canine otitis externa in the USA . Although silver sulfadiazine is already being used by some clinicians for the treatment of MDPA infections with promising results, its MIC as a single agent against isolates from canine otitis externa has not been established.…”

Section: Introductionmentioning

confidence: 99%

Determination of minimum inhibitory concentrations for silver sulfadiazine and other topical antimicrobial agents against strains of Pseudomonas aeruginosa isolated from canine otitis externa

Silva-Tarouca

Wolf

Mueller

2019

Background -Otitis externa is a common presenting complaint in practice. Ear infections by Pseudomonas aeruginosa are particularly problematic due to the organism's high level of resistance and ability to damage the tympanum. Treatment should be based on susceptibility testing although minimum inhibitory concentrations (MICs) are not available for all treatment options. Silver sulfadiazine has been used in cases of recurrent P. aeruginosa otitis, although a MIC for silver sulfadiazine as a single agent has not been established.Objectives -To describe susceptibility patterns of P. aeruginosa isolated from canine otitis externa and determine the MIC for silver sulfadiazine and other topical antimicrobials.Animals -Thirty-six P. aeruginosa isolates were collected from client-owned dogs, suffering from otitis externa.Methods and materials -Susceptibility patterns were established using disc diffusion susceptibility testing against 17 antimicrobial agents. For determination of the MIC, selected strains were tested against increasing concentrations of marbofloxacin, enrofloxacin, gentamicin, polymyxin B and silver sulfadiazine using broth microdilution.Results -For nine of 17 antimicrobial agents, complete resistance was seen in all isolates tested via disk diffusion susceptibility testing. Approximately 94% and 96% of isolates were susceptible to gentamicin and imipenem, respectively. These findings were consistent with broth dilution, where all strains were susceptible to gentamicin. Resistance was higher against polymyxin B and the fluoroquinolones. Silver sulfadiazine was effective in vitro with a MIC ranging from 1 to 64 lg/mL. Conclusions and clinical significance -As the MIC of silver sulfadiazine was lower than the concentration in a 1% preparation, such a product potentially represents a treatment option for dogs with P. aeruginosa otitis.

“…Silver sulfadiazine binds to the DNA helix and inhibits transcription 55 . A topical cream formulation is used for burn wounds in humans, 88 and its antimicrobial effects have been documented in vitro 89,90 …”

Section: Resultsmentioning

confidence: 99%

“…In some countries, a combination of silver sulfadiazine and enrofloxacin is available as a combination product for topical treatment of otitis externa. Synergy between these two agents has been reported 90 . Based on the published information, silver sulfadiazine can be recommended for treatment of localized infections (COE III).…”

Section: Resultsmentioning

confidence: 99%

A review of topical therapy for skin infections with bacteria and yeast

Mueller

Bergvall

Bensignor³

et al. 2012