Minimum Inhibitory Concentrations of Standard and Novel Antimicrobials for Isolates from Bacterial Keratitis -- Sueke et al. 51 (5): 2519 -- Investigative Ophthalmology & Visual Science.
Isolates (n = 772) were collected including coagulase negative Staphylococcus (CNS) (30%), Pseudomonas aeruginosa (23%), Staphylococcus aureus (14%), Enterobacteriaceae (14%), and streptococci (13%). Meropenem had low MICs for most isolates. All isolates except P. aeruginosa were susceptible to tigecycline. Linezolid was active against the majority of Gram-positive pathogens. Ten percent of S. aureus and 20% of CNS isolates were methicillin resistant. When systemic breakpoints were used, 84% of S. aureus isolates were susceptible to ciprofloxacin and 98% to moxifloxacin. Of the P. aeruginosa isolates, 99% were susceptible to ceftazidime, 96% to gentamicin, 99% to ciprofloxacin and 100% to moxifloxacin. More than 97% of Enterobacteriaceae isolates were susceptible to ceftazidime, gentamicin, ciprofloxacin, and moxifloxacin. Conclusions. Based on systemic breakpoint data, resistance to commonly used antimicrobials was apparent. Meropenem is a potentially effective agent for ophthalmic use, with low MICs throughout all the bacterial subgroups. Tigecycline and linezolid showed good activity against particular groups and may be useful for treating bacterial keratitis resistant to current antimicrobials. Of the fluoroquinolones, moxifloxacin showed the lowest MICs and resistance for both Gram-positive and -negative bacteria.