Label - Free Quantitative Proteomics Analysis to Study the Effect of Triclosan on Delta-Haemolysin: A Haemolytic Factor of Methicillin - Resistant Staphylococcus Aureus
Triclosan is a widely used biocide to prevent Methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in hospitals. Lately, long term exposure to triclosan has resulted in certain strains showing susceptibility and thereby resistance and even enhancement of colonisation has been reported. Adhesion to host tissue is achieved by a large family of staphylococcal surface proteins that bind with varying degrees of specificity to host matrix proteins. The aim of this study was to investigate at the proteome level, the effect of triclosan by examining the role of the proteins secreted by MRSA in the presence of triclosan.
Mass spectrometric analysis of the secretome of the MRSA strain showed the presence of delta haemolysin when compared to the Methicillin-sensitive Staphylococcus aureus (MSSA) strain. On conducting a haemolytic assay, clearance zones were observed for MRSA while it was absent in the MSSA plates. A similar assay was conducted with MRSA in the presence and absence of triclosan after determining a suitable MIC. The untreated MRSA showed clearance zones while the treated lacked any. To investigate further, an MS assisted proteomics analysis was conducted and this confirmed the presence of delta — haemolysin in the untreated MRSA cultures.
On the basis of the experiments conducted, triclosan can be considered as a potential anti — haemolytic agent due to its deleterious effect on delta haemolysin.