Hormones Can Influence Antibiotic Susceptibilities Even in Mono- and Co-Culture Conditions

Abstract Pseudomonas aeruginosa and Staphylococcus aureus are known as important nosocomial infectious agents also their co-infections commonly seen in some patient groups. It is well that host factors such hormones have roles modulation of growth, pathogenesis susceptibilities to antimicrobials. In our study, the influences norepinephrine (NE) melatonin (MEL) on antibiotic were examined mono co-culture conditions. Methicilin resistant (MRSA) ATCC 43300 27853 investigated determine minimum inhibitory concentrations (MIC) bactericidal (MBC) ciprofloxacin gentamicin absence/presence NE (0.0017 0.04μg/mL) MEL (6 60 pg/mL) by microdilution method co-culture. was found decreased (among 2-64 fold) MIC MBC values both antibiotics for MRSA. However, it shown had no effect P. aeruginosa. be reduced compared monoculture MRSA; increased Whereas, Our results suggest seems could influence a strain-dependent manner.