Spectrum of bacterial keratitis at a tertiary eye care centre in India.

Aim: To report the aetiological spectrum and susceptibility patterns of bacteria isolated from patients with corneal ulceration.

Method: The microbiological data of all patients with suspected infectious corneal ulceration who presented to the ocular microbiology service at this centre between 2005 and 2012 were reviewed retrospectively.

Result: Microorganisms were recovered from 1665 (77%) of the 2170 ulcers. Bacterial isolates accounted for 1205 of the organisms isolated. The most common bacterial pathogens isolated were various species of Staphylococcus, representing 777 (64.5%), followed by Staphylococcus spp. (148; 12.3%) and Pseudomonas aeruginosa (117; 9.7%). High percentages of Gram-positive bacteria were susceptible to gatifloxacin (>94%), followed by ofloxacin and moxifloxacin. Almost 90% of Pseudomonas aeruginosa isolates were susceptible to ciprofloxacin and moxifloxacin. Sixty-two (44%) of 140 isolates of Streptococcus pneumoniae, 79 (14.8%) of 534 isolates of Staphylococcus epidermidis, and 33 (14%) of 234 isolates of Staphylococcus aureus were resistant to three or more antibiotics.

Conclusion: Staphylococcus spp. were the most common bacterial pathogens isolated from patients with keratitis in this setting. High percentages of Gram-positive and Gram-negative bacteria were susceptible to gatifloxacin and moxifloxacin, respectively. Interestingly, a high percentage of Streptococcus pneumoniae isolates were found to be resistant to three or more antibiotics.