Antibiotic susceptibility pattern of bacterial isolates from microbial keratitis in North and Central India: A multi centric study.

Purpose: This study was conducted to examine microbiological profile with their antibiotic sensitivity in cases of bacterial keratitis in north and central India to ensure appropriate use of antibiotics.

Methods: The microbiology laboratory records of 228 patients with culture-proven bacterial keratitis from 1 January to 31 December 2019 were analyzed. Cultured bacterial isolates were subjected to antimicrobial susceptibility testing to antibiotics commonly used in the treatment of corneal ulcer. Chi-squared or Fisher's exact test were applied to check the significance of difference between the susceptibility levels of antibiotics.

Results: The prevalence of Staphylococcus aureus and Pseudomonas aeruginosa-induced keratitis was higher in northern India, whereas that by Streptococcus pneumoniae was more prevalent in central India. In central India, 100% of S. pneumoniae isolates were found to be sensitive to ceftriaxone compared to 79% in northern India (P = 0.017). In comparison to 67% of isolates from north India, 15% of S. aureus isolates from central India were found to be sensitive to ofloxacin (P = 0.009). Similarly, 23% of isolates from central India were found sensitive to amikacin compared to 65% of isolates from north India (P = 0.012). P. aeruginosa isolates from central India were found to be sensitive to ceftazidime in 63% of cases compared to 21% of isolates from north India (P = 0.034).

Conclusion: Prevalence of bacteria and their susceptibility to antibiotics are not uniform across geography. Vancomycin remained the most effective drug in all gram-positive coccal infections. S. aureus susceptibility to amikacin was significantly greater in north India. P. aeruginosa showed less susceptibility as compared to previous reports.