title: Bactericidal effect of levofloxacin on strains with equal susceptibility in an in vitro urinary bladder model.
abstract: The in vitro bactericidal effects of therapeutic concentrations of levofloxacin (LVFX) on clinical isolates of Pseudomonas aeruginosa and Enterococcus faecalis were assessed. Starting from 10(7) CFU/ml, the bacterial count was determined serially during the exposure to LVFX present at concentrations automatically simulated to its clinically achievable urinary levels at the recommended dosage (100 mg 3 times daily). An isolate of P. aeruginosa for which the MIC of LVFX was 16 microgram/ml was completely eradicated after 10 h of exposure to LVFX. On the other hand, 40 h of exposure to LVFX were required for complete eradication of an isolate of E. faecalis with equal susceptibility, although the bacterial count was rapidly reduced to 10(2) CFU/ml in the early phase of the exposure. It was concluded that LVFX exerts a more potent bactericidal effect on P. aeruginosa than on E. faecalis despite a similar susceptibility of these organisms to LVFX.
authors.affiliation: Department of Urology, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Sano
authors.forename: M
authors.initials: M
authors.lastname: Nishimura
authors.forename: M
authors.initials: M
authors.lastname: Matsukawa
authors.forename: M
authors.initials: M
authors.lastname: Mikami
authors.forename: T
authors.initials: T
authors.lastname: Hirose
authors.forename: T
authors.initials: T
authors.lastname: Tsukamoto
mesh_terms: D000892:Anti-Infective Agents, Urinary / Q000494:pharmacology*; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000494:pharmacology*; D011552:Pseudomonas Infections / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D013997:Time Factors; D001743:Urinary Bladder / Q000382:microbiology; D014552:Urinary Tract Infections / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000892:Anti-Infective Agents, Urinary; D064704:Levofloxacin; D015242:Ofloxacin