Association between cytotoxic and invasive Pseudomonas aeruginosa and clinical outcomes in bacterial keratitis

JAMA Ophthalmol. 2013 Feb;131(2):147-53. doi: 10.1001/jamaophthalmol.2013.778.


Objectives: To determine whether cytotoxic and invasive Pseudomonas aeruginosa strains differentially influence clinical presentation, outcomes, or therapeutic response in bacterial keratitis.

Methods: Pseudomonas aeruginosa isolates from the National Eye Institute-funded Steroids for Corneal Ulcers Trial were subtyped as cytotoxic or invasive strains. The main outcome measure compared between the 2 subtypes was change in visual acuity at 3 months using Huber robust regression, adjusting for topical corticosteroid treatment.

Results: Of 101 confirmed P aeruginosa isolates from the Steroids for Corneal Ulcers Trial, 74 had a classically cytotoxic or invasive genotype. While corneal ulcers caused by genotypically invasive P aeruginosa strains were associated at presentation with significantly better visual acuity than corneal ulcers caused by genotypically cytotoxic P aeruginosa strains when adjusting for the effect of ulcer location (P= .008), invasive ulcers had improved significantly less than cytotoxic ulcers at 3 months (0.35; 95% CI, 0.04-0.66 logMAR; P= .03 [3.5-line difference]). Compared with topical moxifloxacin alone, adjunctive treatment with topical corticosteroids was associated with significantly more improvement in visual acuity in the invasive subgroup (P= .04) but was associated with less improvement in visual acuity in the cytotoxic subgroup (P= .07).

Conclusions: Rational profiling of differentially expressed virulence determinants (eg, cytotoxicity and invasiveness for P aeruginosa) could be used as a tool for decision making in the management of infections to optimize outcomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / therapeutic use
  • Aza Compounds / therapeutic use
  • Bacterial Toxins / genetics
  • Bacterial Typing Techniques
  • Corneal Ulcer / diagnosis
  • Corneal Ulcer / drug therapy
  • Corneal Ulcer / microbiology*
  • DNA, Bacterial / analysis
  • Exotoxins / physiology
  • Eye Infections, Bacterial / diagnosis
  • Eye Infections, Bacterial / drug therapy
  • Eye Infections, Bacterial / microbiology*
  • Fluoroquinolones
  • Genotype
  • Glucocorticoids / therapeutic use
  • Humans
  • L-Lactate Dehydrogenase / metabolism
  • Middle Aged
  • Moxifloxacin
  • Polymerase Chain Reaction
  • Pseudomonas Infections / diagnosis
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / isolation & purification
  • Pseudomonas aeruginosa / pathogenicity*
  • Pseudomonas aeruginosa / physiology
  • Quinolines / therapeutic use
  • Virulence / physiology
  • Visual Acuity / physiology


  • Anti-Infective Agents
  • Aza Compounds
  • Bacterial Toxins
  • DNA, Bacterial
  • Exotoxins
  • Fluoroquinolones
  • Glucocorticoids
  • Quinolines
  • L-Lactate Dehydrogenase
  • Moxifloxacin