title: Review of resistance of ocular isolates of Pseudomonas aeruginosa and staphylococci from keratitis to ciprofloxacin, gentamicin and cephalosporins.
abstract: BACKGROUND
  Microbial keratitis is a rare disease but most commonly caused by bacterial infection. Two of the most common bacteria to cause microbial keratitis are Pseudomonas aeruginosa and Staphylococcus aureus. Antibiotic therapy to treat keratitis caused by these bacteria is either monotherapy with a fluoroquinolone or combination therapy with fortified gentamicin.
  
  
  METHODS
  Literature searches were made in Medline and Pubmed using the search terms [Pseudomonas] or [Staphylococcus] and [fluoroquinolone] or [cephalosporin] or [gentamicin] and [keratitis] or [cornea]. Rates of resistance to ciprofloxacin, gentamicin or cephalosporins were then compared for isolates from different geographic regions.
  
  
  RESULTS
  There are low resistance rates of P. aeruginosa and S. aureus to ciprofloxacin in isolates from Australia. Isolates from the Indian subcontinent are more commonly resistant to ciprofloxacin, with resistance rates of greater than 20 per cent being reported. Data from USA and Europe indicate that if the S. aureus is a methicillin resistant strain, then resistance to ciprofloxacin increases, often to greater than 80 per cent of isolates. Resistance to gentamicin and cephalosporins is also generally low in isolates from Australia. Again resistance is increased in isolates from the Indian subcontinent, as well as from South America.
  
  
  CONCLUSIONS
  In Australia, the major ocular pathogens are generally sensitive to the most commonly used antibiotics to treat microbial keratitis. The prescription of fluoroquinolones, aminoglycosides and cephalosporins is generally reserved for treatment of significant or sight-threatening conditions such as microbial keratitis. This approach is not likely to contribute to an increase in resistance rates.
authors.affiliation: School of Optometry and Vision Science, University of New South Wales, Sydney NSW 2052, Australia. m.willcox@unsw.edu.au
authors.forename: Mark D P
authors.initials: MD
authors.lastname: Willcox
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002511:Cephalosporins / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005839:Gentamicins / Q000627:therapeutic use; D006801:Humans; D007634:Keratitis / Q000188:drug therapy*; D011552:Pseudomonas Infections / Q000188:drug therapy*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013203:Staphylococcal Infections / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D002511:Cephalosporins; D005839:Gentamicins; D002939:Ciprofloxacin