Impact of pH and cationic supplementation on in vitro postantibiotic effect

• DOI: 10.1128/aac.35.12.2617
• Publication Date: 2012-06-28T00:05:50Z
• Authors: A Gudmundsson; H Erlendsdottir; M Gottfredsson; S Gudmundsson
• Keywords: Dicloxacillin

Most studies on pharmacodynamic variables in vitro, including the postantibiotic effect (PAE), are performed at pH 7.4 noncationic-supplemented media, a situation which may differ significantly from true microenvironment most infected foci. We studied impact of five different levels (pH 5, 6, 7, 7.4, and 8) duration PAE, MIC, bactericidal activity. Acid was found to have general deleterious activity aminoglycosides ciprofloxacin against Escherichia coli Pseudomonas aeruginosa, with MIC being higher, rate lower, PAE shorter 5 (and lesser extent 6) than more alkaline levels. Similar results were observed for imipenem P. aeruginosa. The PAEs induced by ampicillin E. dicloxacillin Staphylococcus aureus not predictably dependent pH, whereas S. longest either end spectrum. these agents was, however, dependent, slower acid pHs. addition 50 mg Ca2+ 20 Mg2+ per liter liquid medium did affect PAE. Since abscess cavities be close observations importance employment closed or poorly drained infections.