Ciprofloxacin-resistant Pseudomonas keratitis.
OBJECTIVE
To determine ciprofloxacin resistance of corneal isolates of Pseudomonas and to review the clinical response to topical therapy in cases of ciprofloxacin-resistant Pseudomonas keratitis, where medical therapy was begun with 0.3% ciprofloxacin.


METHODS
Retrospective noncomparative case series.


METHODS
Medical and microbiology records of 141 culture-proven cases of Pseudomonas keratitis, examined between January 1991 and June 1998, were reviewed retrospectively.


METHODS
All isolates of the Pseudomonas species from corneal scrapings were tested for their susceptibility to routinely used antibiotics by the Kirby-Bauer disc-diffusion method. The minimum inhibitory concentration of ciprofloxacin was determined by the agar-dilution method for most of the isolates found resistant to ciprofloxacin. Clinical response to initial therapy with 0.3% ciprofloxacin was determined in cases of keratitis caused by ciprofloxacin-resistant Pseudomonas.


METHODS
Resistance of Pseudomonas isolates to ciprofloxacin and clinical response to initial therapy with 0.3% ciprofloxacin.


RESULTS
By use of the in vitro antimicrobial susceptibility test, 22 cases of keratitis caused by ciprofloxacin-resistant Pseudomonas were identified. The minimum inhibitory concentration of ciprofloxacin for these isolates was > or =16 microg/ml (mean = 43 microg/ml). Gentamicin resistance occurred in 63.6% of isolates also, but 90.9% ciprofloxacin-resistant isolates were susceptible to amikacin. Fifteen (76.7%) of 19 patients who initially received ciprofloxacin did not show any clinical improvement even after 3 days of intensive medical therapy. The infiltrate resolved in all 8 cases where the antibiotic therapy was modified on the basis of susceptibility test. Four eyes were subjected to penetrating keratoplasty, and three were eviscerated following failure of treatment with ciprofloxacin.


CONCLUSIONS
True resistance to ciprofloxacin is emerging in ophthalmology even among Pseudomonas isolates; therefore, the empiric treatment of infectious keratitis with ciprofloxacin monotherapy must be critically reviewed at this time.
Sight Savers' Corneal Training Centre, Hyderabad, India. prashant@lvpeye.stph.net
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P
Garg
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S
Sharma
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Rao
D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002648:Child; D002939:Ciprofloxacin / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination / Q000627:therapeutic use; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000382:microbiology*; D005260:Female; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D007634:Keratitis / Q000188:drug therapy / Q000382:microbiology*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009883:Ophthalmic Solutions; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies
D000890:Anti-Infective Agents; D005839:Gentamicins; D009883:Ophthalmic Solutions; D002939:Ciprofloxacin