Abstract
Abstract: :
Purpose: To evaluate the in vitro anti–infective activity of newer and established topical antibiotics using isolates recovered from bacterial keratitis patients. Methods: 1015 corneal isolates (824 Gram–positive and 191 Gram–negative) were collected from bacterial keratitis patients referred to the Quinze–Vingts National Center of Ophthalmology, Paris, France, between January 2001 and September 2003. Bacteria were identified to the species–level and the antibiotic susceptibility profiles were determined using the National Committee for Clinical Laboratory Standards–approved reference disk diffusion method. Isolates were tested for their susceptibility to ticarcillin (TIC), cefalotin (C1G), ceftazidime (C3G), gentamicin (GEN), tobramycin (TOB), tetracycline (TET), chloramphenicol (CHL), bacitracin (BAC), ofloxacin (OFL), ciprofloxacin (CIP), moxifloxacin (MOX), rifamycin (RIF), vancomycin (VAN). Results: The three most frequent Gram–positive bacteria were Staphylococcus epidermidis (589 isolates), Staphylococcus aureus (n = 116) and Streptococcus sp. (n = 87). The overall percentage of Staphylococcus isolates susceptible to selected antibiotics was: C1G 88%, GEN 92%, TOB 71%, TET 72%, CHL 79%, BAC 96%, OFL 100%, RIF 91%, VAN 100%. The percentages of susceptibility were: C1G 96%, TET 56%, CHL 83%, BAC 99%, MOX 100%, RIF 98%, VAN 100%, for Streptococcus sp. Pseudomonas sp. (103 isolates), Serratia sp. (n = 26) were the most frequently recovered Gram–negative bacteria. The overall percentage of Gram–negative isolates susceptible to selected antibiotics was: C3G 96%, GEN 81%, TOB 88%, TET 12%, CHL 19%, CIP 97%, RIF 13%, TIC 80%. Conclusions: The results of this in vitro study suggest that second generation fluoroquinolones (OFL, CIP) still offer broad spectrum coverage. However, older anti–infective agents (GEN, RIF) and narrow spectrum antibiotics (BAC) remain useful namely when combination therapy and/or fortified antibiotics are required.
Keywords: bacterial disease • keratitis • cornea: clinical science