Interactions between tear defences and Staphylococcus epidermidis [thesis]

E. Carol McWilliam Leitch
1998
Purpose. Staphylococcus epidermidis is rarely associated with contact lens infections but is the predominant causative agent of prosthetic infections. Aims. To determine the extent of in vivo contact lens colonisation by S. epidermidis, explore its interactions with the tear defences and apply this knowledge to help prevent infections of prosthetic devices. Hypothesis. Tear proteins prevent growth of S. epidermidis in vivo and reduce the viability of S. epidermidis biof1lms in vitro. Methods.
more » ... aphylococci isolated from contact lenses were identified and enumerated. Adsorption of lactoferrin, lysozyme, complement and vitronectin to S. epidermidis isolates and viability in the presence of these proteins was determined. The effect of lactoferrin, in combination with lysozyme or vancomycin on the viability of suspended and biofilrn cells was also assessed and the antistaphylococcal mechanism of lactoferrin and lysozyme determined. The efficacy of lactoferrin on the vancomycin susceptibility of resistant enterococci and the mechanism of action was determined. Results. S. epidermidis was the predominant staphylococcal species isolated from the contact lenses of asymptomatic subjects but was present in low numbers. Of the tear proteins examined, only lactoferrin and lysozyme, in combination, exhibited anti-staphylococcal properties. These proteins I would also like to acknowledge Profs Brien Holden and Debbie Sweeney for their management of CRCERT. The generosity of the microbiology department and antibiotic research centre of the
doi:10.26190/unsworks/13274 fatcat:pr572iyrnzhbrf5fzhur7uwetq