Corynebacterium spp as causative agents of microbial keratitis

Purpose To report the clinical and microbiological profile of keratitis caused by Corynebacterium spp. Methods The medical and microbiology records of 22 patients, who had presented at the L V Prasad Eye Institute, Bhubaneswar, between June 2009 and December 2012, and whose corneal scrapings had yielded significant growth of Corynebacterium spp, were retrospectively reviewed. A detailed ocular examination was performed before the respective corneal scraping was sent for a microbiological work-up. The data collected from each record included age, gender, predisposing factors (ocular and systemic), clinical presentation, management and outcome of treatment. Results The mean age of the patients was 43.8 +/-24.4 years. Ocular predisposing factor was present in 14 (63.6%) eyes. Surgical intervention was required in 12 (54.5%) patients. In vitro susceptibility (Kirby-Bauer disc diffusion method) results of Corynebacterium spp to vancomycin (17/19, 89.5%), cefazolin (16/20, 80%), chloramphenicol (11/20, 55%), ofloxacin (13/19, 68.4%), ciprofloxacin (10/20, 50%) and gatifloxacin (10/19, 52.6%) were variable. Drug resistance (more than one drug) was seen in nine (40.9%) Corynebacterium isolates, of which, two (22.2%) showed multidrug resistance to three or more classes of antibiotics. Conclusions Corynebacteria can cause severe corneal infection requiring surgical intervention.