title: Streptococcus pneumoniae: susceptibility to penicillin and moxifloxacin.
abstract: OBJECTIVE
  To determine the minimum inhibitory concentrations (MICs) of parenteral penicillin and moxifloxacin against Streptococcus pneumoniae strains isolated at a hospital center.
  
  
  METHODS
  In-vitro, prospective study involving 100 S. pneumoniae isolates collected from patients who had been treated, between October of 2008 and July of 2010, at the Hospital das Clínicas complex of the University of São Paulo School of Medicine, located in the city of São Paulo, Brazil. The isolates were obtained from respiratory tract cultures or blood samples unrelated to meningeal infections, and they were tested for penicillin and moxifloxacin susceptibility by E-test. The MIC category interpretations were based on updated standards.
  
  
  RESULTS
  All isolates were fully susceptible to parenteral penicillin (MIC < 2 µg/mL), and, consequently, they were also susceptible to amoxicillin, ampicillin, third/fourth generation cephalosporins, and ertapenem. Of the S. pneumoniae strains, 99% were also susceptible to moxifloxacin, and only one strain showed an MIC = 1.5 µg/mL (intermediate).
  
  
  CONCLUSIONS
  Our results showed high susceptibility rates to parenteral penicillin and moxifloxacin among S. pneumoniae isolates unrelated to meningitis, which differs from international reports. Reports on penicillin resistance should be based on updated breakpoints for non-meningitis isolates in order to guide the selection of an antimicrobial therapy and to improve the prediction of the clinical outcomes.
authors.affiliation: Laboratório de Microbiologia, Hospital das Clinicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil. frossi@hcnet.usp.br
authors.forename: Flávia
authors.initials: F
authors.lastname: Rossi
authors.forename: Maria Renata Gomes
authors.initials: MR
authors.lastname: Franco
authors.forename: Heleni Mota de Pina
authors.initials: HM
authors.lastname: Rodrigues
authors.forename: Denise
authors.initials: D
authors.lastname: Andreazzi
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D024841:Fluoroquinolones; D006801:Humans; D008297:Male; D000077266:Moxifloxacin; D010403:Penicillin Resistance / Q000187:drug effects*; D010406:Penicillins / Q000494:pharmacology*; D011446:Prospective Studies; D011804:Quinolines / Q000494:pharmacology*; D012141:Respiratory Tract Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D010406:Penicillins; D011804:Quinolines; D000077266:Moxifloxacin