title: Microbial profile and antibiotic susceptibility of culture-positive bacterial endophthalmitis.
abstract: OBJECTIVE
  To assess the distribution of microorganisms isolated from patients with bacterial endophthalmitis and their antimicrobial susceptibility.
  
  
  METHODS
  Retrospective analysis of medical and microbiological records of patients with suspected diagnosis of endophthalmitis. The following information was assessed: number of presumed and culture-positive endophthalmitis cases, source of infection, microbiological result (aqueous and/or vitreous culture and Gram staining), microbial characterization and distribution, and antimicrobial susceptibility.
  
  
  RESULTS
  A total of 107 (46%) of 231 patients with bacterial endophthalmitis showed positive results by gram stain or culture. Of these, 97 (42%) patients were positive for culture only. Most of them (62%) were secondary to a surgical procedure (postoperative), 12% were posttraumatic and 26% were secondary to an unknown source or the data were unavailable. A total of 100 microorganisms were isolated (38 aqueous and 67 vitreous samples) from the 97 culture-positive cases (91% were gram-positive and 9% were gram-negative). Coagulase-negative Staphylococcus(CoNS) (48%) were the most frequently isolated, followed by Stretococcus viridans(18%), and Staphylococcus aureus(13%). The antimicrobial susceptibility for CoNS was as follows: amikacin-91.6%, cephalothin-97.9%, ceftriaxone-50%, ciprofloxacin-62.5%, chloramphenicol-91.8%, gatifloxacin-79.5%, gentamicin-72.9%, moxifloxacin-89.5%, ofloxacin-70.8%, oxacillin-58.3%, penicillin-33.3%, tobramycin-85.4%, and vancomycin-100%.
  
  
  CONCLUSIONS
  Gram-positive bacteria were the major causes of infectious endophthalmitis in this large series, usually following surgery. CoNS was the most common isolate. Of interest, susceptibility to oxacillin and fourth-generation quinolones was lower than previously published.
authors.affiliation: Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil. gustavobmelo@oftalmo.epm.br
authors.forename: G B
authors.initials: GB
authors.lastname: Melo
authors.forename: P J M
authors.initials: PJ
authors.lastname: Bispo
authors.forename: M C Z
authors.initials: MC
authors.lastname: Yu
authors.forename: A C C
authors.initials: AC
authors.lastname: Pignatari
authors.forename: A L
authors.initials: AL
authors.lastname: Höfling-Lima
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D009877:Endophthalmitis / Q000188:drug therapy / Q000382:microbiology*; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D008826:Microbial Sensitivity Tests; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents