10. Spectrum of microbial keratitis and antimicrobial susceptibility at tertiary care teaching hospital in north Karnataka

To aim of the present study is to determine the incidence and microbiological profile of keratitis and antimicrobial susceptibility pattern seen at a tertiary care eye hospitals. A prospective study of all clinically diagnosed infective keratitis presenting between August 2009 and September 2011 was performed. A standardised proforma was filled out for each patient, documenting socio-demographic features and information pertaining to risk factors. Corneal scrapes were collected and subjected to culture and microscopy. Antimicrobial susceptibility testing was done for all the bacterial isolates. A total of 200 consecutive patients with infective keratitis were evaluated, of which 32.5% were found to be of bacterial aetiology, 41.0% were fungal, and the remaining (26.5%) were found to be culture negative. The predominant bacterial and fungal pathogens isolated were Pseudomonas aeruginosa (29.6%) and Fusarium spp. (38.5%), respectively. Most of the patients (66.84%) with fungal keratitis were between 31 and 50 years old, and 60.21% of the patients with bacterial keratitis were older than 45 years and rural residents have shown the higher incidence (83.1%) of fungal keratitis that is associated with the farm work. Mixed infections due to fungal and bacterial pathogens were seen in 6 patients. Antibiotic sensitivity pattern revealed that 69% of the Pseudomonas aeruginosa and 49% Staphylococcus aureus were multi drug resistant. 24% of Pseudomonas aeruginosa were extended spectrum beta lactamases producers and 7% were metallo beta lactamase producers. 14% of Staphylococcus aureus were resistances to methicillin. The management of mycotic keratitis in instituting an empirical therapy, especially when facilities for microscopy, cultures and antifungal susceptibility are not readily available. The baseline information presented will also be helpful in the planning of a corneal ulcer management strategy and for future studies on mycotic keratitis.