Ampicillin sulbactam microbiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Microbiology
Ampicillin is similar to benzyl penicillin in its bactericidal action against susceptible organisms during the stage of active multiplication. It acts through the inhibition of cell wall mucopeptide biosynthesis. Ampicillin has a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic andanaerobic bacteria. (Ampicillin is, however, degraded by beta-lactamases, and therefore the spectrum of activity does not normally include organisms which produce these enzymes.) A wide range of beta-lactamases found in microorganisms resistant to penicillins and cephalosporins have been shown in biochemical studies with cell-free bacterial systems to be irreversibly inhibited by sulbactam. Although sulbactam alone possesses little useful antibacterial activity except against the Neisseriaceae, whole organism studies have shown that sulbactam restores ampicillin activity against beta-lactamase producing strains. In particular, sulbactam has good inhibitory activity against the clinically important plasmid mediated beta-lactamases most frequently responsible for transferred drug resistance. Sulbactam has no effect on the activity of ampicillin against ampicillin susceptible strains. The presence of sulbactam in the ampicillin/sulbactam formulation effectively extends the antibiotic spectrum of ampicillin to include many bacteria normally resistant to it and to other beta-lactam antibiotics. Thus, ampicillin/sulbactam possesses the properties of a broad-spectrum antibiotic and a beta-lactamase inhibitor.[1]
References
- ↑ "http://www.accessdata.fda.gov/drugsatfda_docs/label/2012/050608s040lbl.pdf" (PDF). External link in
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Adapted from the FDA Package Insert.