A Novel Topical Combination Ointment with Antimicrobial Activity against Methicillin-Resistant Streptococcus aureus, Gram-Negative Superbugs, Yeasts, and Dermatophytic Fungi.
BACKGROUND
The use of topical antimicrobial agents for management of minor skin infections is a clinical strategy that is commonly practiced in the community. Coupled with the use of topical antimicrobial agents is the emergence of antibiotic-resistant strains of pathogens leading to the need for alternative treatments.


OBJECTIVE
A novel topical combination ointment consisting of salicylic acid, oak bark extract, benzoic acid, and polyethylene glycol (Bensal HP, Sonar products Inc., Carlstadt, NJ) with antimicrobial properties was assessed to determine its spectrum of activity.


METHODS
One hundred eighty-four bacterial and fungal isolates from culture collections that included multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter spp, and gram-negative so-called superbugs, as well as yeasts and filamentous fungi, were investigated by cylinder diffusion and agar dilution assays.


RESULTS
All 184 bacterial and fungal isolates were susceptible to the combination ointment at the clinically applied concentration and there was no evidence of cross-resistance between Bensal HP and other classes of antimicrobials. In time-kill tests, Bensal HP was rapidly bactericidal against P aeruginosa ATCC 27853 and methicillin-resistant S aureus SA179 at 4 × the MIC, a concentration that is applied clinically.


CONCLUSIONS
The results of this study suggest that this combination ointment has a broad in vitro spectrum of antimicrobial activity against both more common bacterial and fungal pathogens and may be particularly useful for treatment of infections by multidrug-resistant organisms. Additional studies are warranted to investigate the full clinical utility as a therapeutic agent and also for possible infection control interventions.
Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska; Department of Pathology and Laboratory Medicine, University of Louisville School of Medicine, Louisville, Kentucky; Current affiliation: Department of Pathology and Laboratory Medicine, University of Louisville School of Medicine, Louisville, Kentucky.
Kenneth S
KS
Thomson
Department of Microbiology, University of Louisville Hospital, Louisville, Kentucky.
Gina K
GK
Thomson
Department of Microbiology, Creighton Alegent Hospital, Omaha, Nebraska.
John
J
Biehle
Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska.
Andrew
A
Deeb
Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska.
Jamaal
J
Crawford
Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, Nebraska.
R
R
Herrera
methicillin-resistant Staphylococcus aureus; multiple-drug resistant organisms; topical antibiotics
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