Ampicillin was the aboriginal penicillin "broad spectrum" with action adjoin Gram - (+) bacteria, including Streptococcus pneumoniae, Streptococcus pyogenes, some isolates of Staphylococcus aureus (but not penicillin-resistant or aggressive strains of aureus), and some enterococci.
The action adjoin Gram - (-) contains Neisseria meningitidis bacteria, some Haemophilus influenzae, and some enteric bacteria. Spectrum of action is added by the accompanying administering of sulbactam, a biologic that inhibits the beta-lactamase, an agitator produced by bacilli that inactivate ampicillin and accompanying antibiotics.
