Endophthalmitis after open globe injuries: changes in microbiological spectrum and isolate susceptibility patterns over 14 years

BACKGROUND The objective of this study was to evaluate the microbiologic spectrum and antimicrobial susceptibility of isolates in post-traumatic endophthalmitis and compare with our earlier published report. A retrospective review was conducted on 581 consecutive patients with culture-proven post-traumatic endophthalmitis at L. V. Prasad Eye Institute, India, from January 2006 to March 2013. FINDINGS A total of 620 isolates from 581 patients were identified (565 bacteria and 55 fungi). The most common isolate was Bacillus spp. (106/620, 17.1%) closely followed by Streptococcus pneumoniae (105/620, 16.9%), and coagulase-negative Staphylococci (97/620, 15.6%). In our earlier report, the commonest bacteria included Streptococcus spp. (30/139, 21.6%) and gram-positive coagulase-negative micrococci (26/139, 18.7%). Gram-positive isolates were usually susceptible to vancomycin (98.2%). Gram-negative isolates were generally susceptible to gatifloxacin (92.9%), ofloxacin (89.4%), chloramphenicol (88.6%, Pseudomonas isolates were often resistant), amikacin (83.5%), and ceftazidime (77.2%). Fourteen years ago, the most sensitive antibiotic was ciprofloxacin for both gram-positive bacteria (95.12%) and gram-negative bacteria (100%). CONCLUSIONS The microbiological spectrum of post-traumatic endophthalmitis has remained unchanged over the last 14 years, and Bacillus spp. continues as the most common infecting organism. Vancomycin is the drug of choice for empiric coverage of gram-positive bacteria. Susceptibility of gram-negative bacteria to commonly used antimicrobials (amikacin and ciprofloxacin) has decreased by 10% - 15% and to ceftazidime has increased by 10.5%.