Bacterial keratitis: similar bacterial and clinical outcomes in female versus male New Zealand White rabbits infected with Serratia marcescens

Abstract

Females and males respond differently to a number of systemic viral infections. Differences between females and males with respect to the severity of keratitis caused by Gram-negative bacteria such as Serratia marcescens are less well established. In this study we injected female and male New Zealand White rabbit corneas with a keratitis isolate of S. marcescens and evaluated the eyes after 48 hours for a number of clinical and microbiological parameters. No statistical differences in bacterial burden and corneal scores were recorded between female and male rabbits although there was a non-significant trend toward a higher frequency of female rabbits demonstrating hypopyons. This data suggests that for experimental bacterial keratitis studies involving Gram-negative rods, a single sex or mixed group of rabbit is sufficient for evaluating pathology and bacterial burdens. This will reduce the number of animals used for subsequent studies.