Pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma in vitro.

ABSTRACT

AIM: To understand the pathogen characteristics and its sensitivity against antimicrobial agents in fatal bacterial granuloma after eyelid trauma (FBGT) in vitro, and to provide laboratory evidence for diagnosis. METHODS: The FBGT pathogens were isolaated and cultured with reformed rabbit-brain anaerobic enriched broth (RRAB), and identified by ATB/API 20A system. The minimum inhibiting concentration (MIC) was determined by anaerobic broth dilution method. RESULTS: A total of 22 strains of pathogen were separated from 21 patients with FBGT and identified as Propionibacterium acnes (PA) by ATB/API 20A system. The MIC of ciprofloxacin for 22 PA strains was 0.0625-0.5mg/L, the MIC of penicillin, ampicillin, ampicillin/sulbactam, cefoperazone, lincomycin, and imipenem/cilastatin were 0.125-0.5mg/L, the MIC of ticarcillin/clavulanic acid was 0.250-1.000 mg/L, and the MIC of metronidazole was 64-256mg/L. The pathogen of FBGT was strictly anaerobic PA, which growed slowly and better in nutritious RRAB broth. All PA were resistant to metronidazole, but susceptive to other routine antimicrobial agents, such as penicillin, ampicillin and lincomycin. CONCLUSION: [corrected] FBGT should not be treated with metronidazole. Clinicians should choose combined use of drugs or operation to treat FBGT according to patients' individual condition and the results of drug sensitivity test.