Fungal-derived xenobiotic exhibits antibacterial and antibiofilm activity against Staphylococcus aureus

Abstract

Staphylococcus aureus is an opportunistic pathogen, responsible for superficial and invasive infections both in nosocomial and community-acquired settings. The incidences of infection have become more problematic attributable to emerging drug resistance and biofilm formation. These challenges suggest the need for new antimicrobial agents against S. aureus. In present work, we purified a fungal xenobiotic (FI3) which elicits a potent antimicrobial activity against a list of tested microbes including methicillin sensitive (MSSA) and methicillin resistance (MRSA) S. aureus. The cell growth of MSSA and MRSA were completely ceased with the 1x minimum inhibitory concentration (MIC); 32 microg/mL and 128 microg/mL, respectively. The cell viability severely decreased within 90 min, due to disturbance of membrane homeostasis. This bactericidal effect was enhanced at lower pH (pH 4) with a speculation to retain positive charge. The FI3 potently disrupts biofilm adherence at 64 microg/mL and found to be a safe with no toxic effect on mammalian tissue. FI3 also leads to increase the potency of tested antibiotics. Taken together, we established that FI3 has a potent antimicrobial activity against tested microbes and safer to human tissue. It may be proven a leading molecule for the treatment of bacterial infections.