SYNERGISTIC EFFECT BETWEEN CLOXACILLIN AND ESSENTIAL OIL OF Melaleuca armillaris AGAINST Staphylococcus aureus

MARCHETTI L; BUCHAMER A; MESTORINO N; BULDAIN D; ALIVERTI F

Ciudad Autónoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencia; 2017

The increasing antibiotic-resistance impulse us to investigate newtherapeutic alternatives.Cloxacillin (CLOX) is an antibiotic widely used in veterinary medicineagainst S. aureus. Our objective was to evaluate the effect ofthe combination CLOX with Melaleuca armillaris?s essential oil (EO)as an alternative. EO was obtained by steam distillation. Three wild type S. aureusstrains were isolated from Holstein cows. S. aureus ATCC 29213strain was used as reference.The Minimum Inhibitory Concentration (MIC) of CLOX and EO incombination was determined by microdilution in broth at pH 7.4; 6.5and 5. The checkerboard technique evaluated the interaction betweenCLOX and EO, the Fractional Inhibitory Concentration Index(FIC) was calculated:(A): CLOX MIC in combination with EO; (B): EO MIC in the mixturewith CLOX, (MIC)a and (MIC)b: MIC of the antimicrobial and EOalone, respectively. Synergism was considered if FIC ≤ 0.5; Partialsynergism if 0.5