Indications for Vancomycin Vancomycin is active against Most gram-positive cocci and bacilli, including almost all Staphylococcus aureus and coagulase-negative staphylococcal strains that are resistant to penicillins and cephalosporins Many strains of enterococci (mostly Enterococcus faecalis) However, many strains of enterococci and some strains of S aureus are resistant.