Postantibiotic effect of various antibiotics on Legionella pneumophila strains isolated from water systems

• Published in: Folia microbiologica Vol. 57; no. 6; pp. 495 - 499
• Main Authors: Birteksöz-Tan, Ayşe Seher, Zeybek, Zuhal
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01-11-2012; Springer Netherlands; Springer Nature B.V
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotics; Antimicrobial agents; Applied Microbiology; Azithromycin; Bacteria; Bacteriology; Biomedical and Life Sciences; buildings; Centrifugation; Ciprofloxacin; Clarithromycin; Colony Count, Microbial; Counting methods; Environmental Engineering/Biotechnology; Humans; Immunology; Legionella pneumophila; Legionella pneumophila - drug effects; Legionella pneumophila - isolation & purification; Legionella pneumophila - physiology; Levofloxacin; Life Sciences; Microbial Sensitivity Tests; Microbial Viability - drug effects; Microbiology; Minimum inhibitory concentration; patients; therapeutics; Time Factors; Turkey; Water heaters; Water Microbiology; Turkey; Istanbul Turkey; Minimum Inhibitory Concentration; Levofloxacin; Clarithromycin; Postantibiotic Effect; Azithromycin
• ISSN: 0015-5632; 1874-9356
• DOI: 10.1007/s12223-012-0161-2

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.