Abstract
Therapy of S. aureus keratitis is increasingly challenging due to emerging resistant strains. Staphylolysin (LasA protease) is a staphylolytic endopeptidase secreted by Pseudomonas aeruginosa. The purpose of the current study was to study the effect of treatment with staphylolysin on experimental keratitis caused by various Staphylococcus aureus strains. The therapeutic effect was studied in a keratitis model induced in rabbits by intrastromal injections of 10(3) S. aureus cells of three different methicillin-resistant S. aureus (MRSA) strains and one methicillin-susceptible S. aureus strain (MSSA). Topical treatment with either staphylolysin or bovine serum albumin (BSA; control) was applied every half hour for 5h, starting at 4h after infection. Corneas were removed for bacterial quantification. Histopathological analysis was performed on MSSA-infected rabbits, killed at either one or 84h after completion of treatment and on uninfected eyes 1h after treatment termination. The number of bacteria in the staphylolysin-treated corneas was significantly reduced in all infections with the four S. aureus strains studied as compared to controls: the staphylolysin-treated eyes infected with MRSA strains were either completely sterilized or showed a 3-4 orders of magnitude decrease in the number of cfu/cornea (p = 0.004 to 0.005); all of the staphylolysin-treated MSSA-infected eyes were sterile. Histopathological analysis of the methicillin-sensitive (MSSA) strain-infected eyes at 84h after completion of treatment showed moderate inflammation in the staphylolysin-treated eyes as compared with extensive abscess formation in the control group. The uninfected corneas showed only mild stromal edema in both the staphylolysin and BSA-treated groups. Staphylolysin provided long-lasting protection against several strains of S. aureus, evident by both its strong anti-bacterial activity and beneficial histopathological results of treatment.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Graefe's Archive for Clinical and Experimental Ophthalmology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
