Abstract
Abstract: :
Purpose: This study describes the spectrum and frequency of bacteria recovered during clinical studies of conjunctivitis conducted from 1999 through 2003 in the United States, various regions of Europe, and India. The susceptibility profile to selected antibiotics was determined to benchmark antibiotic resistance rates in this community–acquired infection. Methods: Bacteria were identified to the species level by a combination of phenotypic and DNA–based methods. Susceptibility testing was performed to obtain end–point MICs for >20 antibiotics. Results: The percentage of the 2312 unique isolates recovered in US, Europe, and India, respectively, grouped into three bacterial phyla: Firmicutes (67,80,60); Actinobacteria (5.4, 2.4, 9.5); Proteobacteria (27,17,30). The MIC range, MIC50 and MIC90 data for all species with >10 isolates are summarized. The percentage of resistant isolates in the 4 major species by geographical region were: Streptococcus pneumoniae: penicillin (14,6,0), erythromycin (32,19,0), tetracycline (22,16,18), trimethoprim (43,27,3). Haemophilus influenzae: ampicillin (35,20,nd), trimethoprim (32,48,nd). Staphylococcus aureus: oxacillin (18,4,2), erythromycin (31,9,5), tobramycin (18,4,7), gentamicin (2,3,12), trimethoprim (4,7,54), ciprofloxacin (20,6,10). Staphylococcus epidermidis: oxacillin (49,17,17), erythromycin (35,37,5), tobramycin (19,28,31), gentamicin (8,13,29), trimethoprim (12,8,51), ciprofloxacin (8,7,14). Conclusions: Although the conjunctivitis pathogens have not changed over the recent decades, the percentage of resistant isolates to various antibiotics has increased and differs significantly in various parts of the world. The extremely high rate of resistance to certain older antibiotics raises questions about the appropriateness of therapies based upon these agents.