Identifications of hordeolum pathogens and its susceptibility to antimicrobial agents in topical and oral medications

Background: Unnecessary use of antibiotics can be a problem in the treatment of hordeolum since the providers prescriptions, pathogens and their susceptibilies are peculiar to local situations.

Objectives: We identified current pathogenic organisms in hordeolum and its susceptibilities to antimicrobial agents in topical eye medications in Thai patients.

Methods: Seventy-nine patients from the King Chulalongkorn Memorial Hospital who never received any treatment for hordeolum participated in the study. Pus specimens were collected from incision and curettage. The bacteria was stained by Gram stain and grown on aerobic and anaerobic culture agars. If there was bacterial growth, drug susceptibility test was conducted utilizing Ciprofloxacin, Fusidic acid, Oxytetracycline, Polymyxin, Neomycin, and Chloramphenicol.

Results: Bacterial growth was detected in 54 isolates from 50 patients (63.3%). These isolates were identified to be Staphylococcus epidermidis (19 isolates, 35.2%), Proprionibacterium acnes (13 isolates, 24.1%), Staphylococcus aureus (10 isolates, 18.5%), Corynebacterium spp. (10 isolates, 18.5%), Aerococcus viridans (1.85%), and Prevotella intermedia (1.85%). Susceptabilty test of P. acne to Tobramycin and Polymyxin showed MIC₉₀ (Minimal Inhibitory Concentration) was more than 10 times lower compared to other antibiotics tested.

Conclusion: Most of the pathogens were from the normal skin flora. The most common organism continues to be the Staphylococcus species. All eye medications tested had antibiotic concentrations more than 10 times higher than the values of MIC₉₀ except for Tobramycin and Polymyxin which indicated that there was an emergence of drug resistant P. acne.