Clinical Microbiology and Antimicrobial Chemotherapy. 2013; 15(2):106-114
To determine bacterial pathogens causing ocular infections and their antimicrobial susceptibility patterns.
This prospective microbiological study included a total of 235 isolates of aerobic microorganisms obtained from 235 patients in 10 Russian regions. Susceptibility to the following antimicrobials (ampicillin, amoxicillin, amoxicillin/clavulanate, oxacillin, penicillin, ciprofloxacin, levofloxacin, moxifloxacin, ofloxacin, norfloxacin, tobramycin, gentamicin, chloramphenicol, polymyxin B, tetracycline, and erythromycin) was determined using serial dilution method.
The most predominant pathogens in ocular infections were S. aureus and Staphylococcus spp. (40.4% and 20.4% of isolates, respectively). They were followed by Streptococcus spp. (7.7%), S. pneumoniae (6.4%), H. influenzae (5.6%), and P. aeruginosa (4.3%). Aminoglycosides and third- and fourth-generation fluoroquinolones were the most active antimicrobials against isolates tested. Susceptibility of S. aureus isolates to oxacillin and erythromycin was 95.8% and 93.7%, respectively. S. epidermidis isolates had a higher antimicrobial resistance rate. No strains of H. influenzae were resistant to any of antimicrobials tested. Tetracycline and chloramphenicol non-susceptibility rates among Enterobacteriaceae were 39.1% and 63.5%, as well as 25.0% and 33.3% in coagulase-negative staphylococci, respectively.
Fluoroquinolones (mainly, third and fourth generation) and aminoglycosides may be considered as the drugs of choice for initial treatment of bacterial ocular infections. Given the high resistance rates to tetracycline and chloramphenicol, administration of these antimicrobials must be avoided.