title: Effect of primycin on growth-arrested cultures and cell integrity of Staphylococcus aureus.
abstract: Bactericidal effect against non-dividing bacteria is a very advantageous, but rare characteristic among antimicrobial agents, mostly possessed by those affecting the cell membrane. These kinds of agents can kill bacterial cells without lysis. We assessed these characteristics on primycin, a topical anti-staphylococcal agent highly effective against prevalent multiresistant strains, as it also acts on the cell membrane. In time-kill studies, primycin preserved its bactericidal activity against growth-arrested Staphylococcus aureus cultures. The bactericidal action was slower against growth-arrested cultures compared to the exponentially growing ones to different extents depending on the manner of arrest. The bactericidal effect was less influenced by stringent response and by protein synthesis inhibition, proving that it does not depend on metabolic activity. In contrast, uncoupling of the membrane potential predominantly slowed, and low temperature almost stopped killing of bacteria. In consideration of published data, these facts suggest that the antibacterial action of primycin involves disrupting of the membrane potential, and is predominantly influenced by the membrane fluidity. Optical density measurements and transmission electron microscopy verified that primycin kills bacterial cells without lysis. These results reveal favorable characteristics of primycin and point to, and broaden the knowledge on its membrane-targeted effect.
authors.affiliation: 1 PannonPharma Ltd. , Pécsvárad, Hungary.|2 Department of Medical Microbiology and Immunology, Medical School, University of Pécs , Pécs, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Feiszt
authors.affiliation: 2 Department of Medical Microbiology and Immunology, Medical School, University of Pécs , Pécs, Hungary.
authors.forename: György
authors.initials: G
authors.lastname: Schneider
authors.affiliation: 2 Department of Medical Microbiology and Immunology, Medical School, University of Pécs , Pécs, Hungary.|3 Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences , Budapest, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Emődy
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; C009041:primycin
keywords: Staphylococcus aureus; TEM; growth arrest; no bacteriolysis; primycin; time-kill