Purpose
To compare prevalence and distribution of ocular pathogens encountered during recent (2009-2011) versus older (2004-2007) bacterial conjunctivitis clinical studies of besifloxacin ophthalmic suspension, 0.6%.
Methods
Pathogens recovered across five multicenter, randomized, double-masked, clinical studies evaluating besifloxacin were evaluated. A total of 2,348 baseline isolates from 3,379 patients were collected, of which 1,324 isolates were recovered in 2004-2007 and 1,024 in 2009-2011. Recovered isolates across all treatment groups were evaluated for baseline frequency, microbial eradication, and antimicrobial susceptibility profiles.
Results
Of interest, 15 new bacterial conjunctivitis pathogens, not recovered from study eyes between 2004-2007, were isolated in the later studies, including the potentially emerging pathogens Dolosigranulum pigrum (n=26) and Corynebacterium accolens (n=5). The 5 most frequently isolated species or taxomic groups remained the predominant bacterial conjunctivitis pathogens across all five besifloxacin studies. Microbial eradication rates of pathogens isolated in besifloxacin treated subjects in the more recent studies included 100% eradication of D. pigrum (14/14), Acinetobacter calcoaceticus/baumannii complex (3/3), and Elizabethkingia meningoseptica (2/2).
Conclusions
The most prevalent bacterial conjunctivitis pathogens have remained consistent across clinical trials over a seven year period; however, additional pathogens have emerged as causative agents of bacterial conjunctivitis. This may be due to improved methods for the identification of bacterial isolates or changes in human or bacterial ecology that promote the spreading of these species to the ocular surface. Eye care practitioners should be aware of these atypical pathogens when considering appropriate options for empiric treatment of bacterial conjunctivitis.
Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
475 conjunctivitis •
593 microbial pathogenesis: clinical studies