Antibiotic treatment of orbital cellulitis: an analysis of pathogenic bacteria and bacterial susceptibility.

The proper choice of effective antibiotics is a mainstay for the treatment of orbital cellulitis. The lack of native data regarding the microorganism causing the infection and its antibiotic sensitivity prompted us to conduct this study. We retrospectively collected 29 cases of orbital cellulitis admitted to Chung-Ho Memorial Hospital of Kaohsiung Medical College from January 1994 to September 1998. The effectiveness of antibiotics with bacterial susceptibility was analyzed. Of the 29 cases, fifteen were male and fourteen female. The patients ranged in age from 7 months to 79 years (mean, 37.6 years). Sinusitis (9 cases, 31.0%) is the most common etiology. Fourteen cases received both medical and surgical treatments. Eighteen cases had purulent discharge from the infection areas sent for culture isolation of the microorganism. The culture positive rate was 50% (9 in 18 cases). The Staphylococcus aureus (5 cases) was the most common pathogen. The bacterial susceptibility test showed drug resistance of 100% for penicillin G (seven out of seven cases; 7/7), 100% for ampicillin (10/10), and 0% for amikacin (0/3) and vancomycin (0/7). Penicillin and ampicillin are not effective for those isolated bacteria. Oxacillin and gentamicin, frequently used in first line treatment, might encounter drug resistance in some cases. Amikacin and vancomycin, without any resistance in bacterial susceptibility tests, could be used in vision-threatening, critical, and intractable cases.