title: Postantibiotic effect of various antibiotics on Legionella pneumophila strains isolated from water systems.
abstract: The postantibiotic effects (PAE) of azithromycin, clarithromycin, ciprofloxacin, and levofloxacin were investigated against Legionella pneumophila (L. pneumophila) strains isolated from several hot water systems of different buildings in Istanbul. Each strain in logarithmic phase of growth was exposed to concentrations of antibiotics equal to minimum inhibitory concentration (MIC) and 4× MIC for 1 h. Recovery periods of test cultures were evaluated after centrifugation using the viable counting method. The mean values of PAEs for the strains of L. pneumophila, azithromycin at a concentration equal to and 4 times of MIC values were found 1.75 ± 0.28 h and 4.06 ± 0.44 h, for clarithromycin 2.98 ± 0.70 h and 4.18 ± 0.95 h, for ciprofloxacin 2.97 ± 0.63 h and 4.70 ± 0.63 h, for levofloxacin 2.05 ± 0.33 h and 3.78 ± 0.46 h, respectively. All of the antibiotics showed increased PAE values in a concentration-dependent manner. The findings of our study may play useful role in selecting the appropriate timing of doses during therapy with antimicrobials to treat patients infected with L. pneumophila.
authors.affiliation: Department of Pharmaceutical Microbiology, Faculty of Pharmacy, İstanbul University, Istanbul, Turkey. seherbirteksoz@hotmail.com
authors.forename: Ayşe Seher
authors.initials: AS
authors.lastname: Birteksöz-Tan
authors.forename: Zuhal
authors.initials: Z
authors.lastname: Zeybek
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D006801:Humans; D016952:Legionella pneumophila / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D013997:Time Factors; D014421:Turkey; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents