title: [Antibiotic susceptibility of blood-borne Streptococcus pneumoniae and efficacy assessment of respiratory quinolones using Monte Carlo simulation].
abstract: We analyzed Streptococcus pneumoniae isolates from the bloodstream between April 2005 and February 2007. We analyzed isolates of 28 strains from medical facilities in Gifu prefecture to determine antibiotic susceptibility, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes. We also assessed the efficacy of respiratory quinolones using Monte Carlo simulation. Garenoxacin (GRNX) and moxifloxacin (MFLX) showed the lowest MIC90 value of 0.125 microg/mL, followed by MIC90 of imipenem (IPM) of 0.25 microg/mL and tosufloxacin (TFLX), MIC90 of meropenem (MEPM) and vancomycin (VCM) of 0.5 microg/mL. Twenty-two strains possessed at least one mutation in PBP-encoding genes pbp1a, pbp2x or pbp2b and seven strains possessed all three mutant alleles. Twenty-two strains possessed either of macrolide resistant genes ermB or mefA, and one strain possessed both. On efficacy assessment, we calculated the probability of target attainment for free-drug area under the curve (fAUC)/MIC ratio (fAUC/MIC). GRNX and MFLX showed a probability of 90% or more at fAUC/MIC of 30 and 125, each considered effective against Gram-positive bacteria and suppression of resistance development, furthermore, GRNX showed a probability of 89.7% at fAUC/MIC of 250.
authors.affiliation: Research Laboratories of Toyama Chemical Co., Ltd.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawamoto
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nomura
authors.forename: Junichi
authors.initials: J
authors.lastname: Mitsuyama
authors.forename: Kazukiyo
authors.initials: K
authors.lastname: Yamaoka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Asano
authors.forename: Haruki
authors.initials: H
authors.lastname: Sawamura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suematsu
authors.forename: Mayumi
authors.initials: M
authors.lastname: Teraji
authors.forename: Hikonori
authors.initials: H
authors.lastname: Hashido
authors.forename: Yoko
authors.initials: Y
authors.lastname: Matsukawa
authors.forename: Shigenori
authors.initials: S
authors.lastname: Matsubara
authors.forename: Takanori
authors.initials: T
authors.lastname: Miyabe
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Mikamo
authors.forename: Kunitomo
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001769:Blood / Q000382:microbiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024841:Fluoroquinolones / Q000493:pharmacokinetics* / Q000494:pharmacology*; D005838:Genotype; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D000077731:Meropenem; D009010:Monte Carlo Method; D009154:Mutation; D046915:Penicillin-Binding Proteins / Q000235:genetics; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D013845:Thienamycins / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D046915:Penicillin-Binding Proteins; D013845:Thienamycins; D014640:Vancomycin; D015378:Imipenem; D000077731:Meropenem