Staphylococcus epidermidis Prevails Staphylococcus aureus in Multispecies Biofilm under Gentamicin Stress

Out of 60 staphylococcal isolates isolated form different sources, the results revealed that 20 and 10 were identified as S. aureus and S. epidermidis, respectively. These results were confirmed by detecting 16sRNA gene. Remarkably, 80 % of S. aureus and 80 % of S. epidrmidis isolates developed Methicillinresistance. Findings of the current work demonstrated that most of methicillin resistant S. aureus (MRSA) and methicillin resistant S. epidermidis (MRSE) formed weak biofilm. The competition between S. aureus and S. epidermidis in multispecies biofilm were tested at several conditions encompassed temperature, pH, and starvation. Results showed that the numbers of biofilm cells have intensely decrease to undetectable limits in the presence of Gentamicin, approximately, at all tested conditions. With few exceptions, S. epidermidis showed a noticeable dominance in all species combinations.