title: Fluoroquinolone treatment and susceptibility of isolates from bacterial keratitis.
abstract: OBJECTIVE
  To analyze the relationship between fluoroquinolone use at presentation and minimum inhibitory concentration in bacterial keratitis.
  
  
  METHODS
  The Steroids for Corneal Ulcers Trial was a randomized, double-masked, placebo-controlled trial assessing the effect of adjunctive topical corticosteroid treatment on outcomes in bacterial keratitis. After presentation, all patients were treated with moxifloxacin hydrochloride, 0.5%. We compare antibiotic use at presentation with minimum inhibitory concentration against moxifloxacin for all isolates. Separate analyses accounted for organism species and fluoroquinolone generation.
  
  
  RESULTS
  Topical fluoroquinolone use at presentation was reported in 92 of 480 cases (19.2%). Causative organisms in the 480 cases included Streptococcus pneumoniae (247 cases [51.5%]), Pseudomonas aeruginosa (109 cases [22.7%]), and Nocardia species (55 cases [11.5%]). Isolates from patients who reported fluoroquinolone use at presentation had a 2.01-fold-higher minimum inhibitory concentration (95% CI, 1.39-fold to 2.91-fold; P < .001). Fourth-generation fluoroquinolones were associated with a 3.48-fold-higher minimum inhibitory concentration than those isolates that were not exposed to pretreatment at enrollment (95% CI, 1.99-fold to 6.06-fold; P < .001).
  
  
  CONCLUSIONS
  This study provides evidence that prior use of fluoroquinolones is associated with antibiotic resistance.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00324168.
authors.affiliation: Francis I. Proctor Foundation, University of California, San Francisco, CA 94143-0412, USA.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Ray
authors.forename: Lalitha
authors.initials: L
authors.lastname: Prajna
authors.forename: Muthiah
authors.initials: M
authors.lastname: Srinivasan
authors.forename: Manoharan
authors.initials: M
authors.lastname: Geetha
authors.forename: Rajarathinam
authors.initials: R
authors.lastname: Karpagam
authors.forename: David
authors.initials: D
authors.lastname: Glidden
authors.forename: Catherine E
authors.initials: CE
authors.lastname: Oldenburg
authors.forename: Catherine Q
authors.initials: CQ
authors.lastname: Sun
authors.forename: Stephen D
authors.initials: SD
authors.lastname: McLeod
authors.forename: Nisha R
authors.initials: NR
authors.lastname: Acharya
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lietman
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001372:Aza Compounds / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects*; D003320:Corneal Ulcer / Q000188:drug therapy / Q000382:microbiology*; D004311:Double-Blind Method; D024881:Drug Resistance, Bacterial; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000382:microbiology*; D005260:Female; D024841:Fluoroquinolones; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D000077266:Moxifloxacin; D009615:Nocardia / Q000187:drug effects; D009617:Nocardia Infections / Q000188:drug therapy / Q000382:microbiology; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology; D011239:Prednisolone / Q000031:analogs & derivatives / Q000627:therapeutic use; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D011804:Quinolines / Q000627:therapeutic use*; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D005938:Glucocorticoids; D011804:Quinolines; C009022:prednisolone phosphate; D011239:Prednisolone; D000077266:Moxifloxacin