Three cases of Actinomyces isolation from the eye lesions of patients with a chronic and recurrent ophthalmic infection

Abstract

Actinomycosis is an indolent, slowly progressive infection caused by Gram-positive facultative anaerobic bacteria from the genus Actinomyces. These bacteria have been reported as a cause of ophthalmic infections such as endophthalmitis, keratitis, and canaliculitis. The objective of the present study was to investigate the pattern and antibiotic sensitivity profile of anaerobes isolated from lesions in the medial canthus of the eye. Three pus aspirate samples (from eye) were delivered to a microbiology laboratory in a strict anaerobic condition in Robertson Cooked Meat media (RCM). The samples were inoculated on Blood Agar and incubated anaerobically in a Gas Pack Jar incubator at 5%-10% CO2 and in aerobic condition at 37°C. Pure colonies isolated on anaerobically incubated plates were identified by the VITEK® 2 COMPACT system. Antibiotic sensitivity testing was conducted using an Epsilometer-strip test. Three isolates identified and confirmed with the help of VITEK® 2 were Actinomyces israelii, Actinomyces odontolyticus, and Actinomyces meyeri. All three species of Actinomyces were sensitive to Vancomycin, Moxifloxacin, and Imipenem, but they were resistant to Metronidazole. Since there have been several cases of anaerobic ophthalmic infections reported to date, samples from patients with chronic eye infections should be analyzed for anaerobic culture for correct diagnosis and proper treatment. Moxifloxacin but not Metronidazole is a suitable drug for the treatment of anaerobic eye infection.