Studies of the taxonomic significance and function of Staphylococcal polypeptides from human sources
Human staphylococcal polypeptides were analysed using four techniques; Polyacrylamide Gel Electrophoresis (PAGE), Western Blot, Silver Strain and Plasmid Analysis. Whole-cell profiles of S. aureus, S. capitis, S. epidermidis and S. saprophyticus showed minor variations between strains of one species and each species produced a characteristic protein profile. Data generated here was not suitable for the development of a typing method. Western Blot analysis of whole-cell extracts of S. epidermidis and S. capitis also produced species distinct profiles with only minor variations between strains of one species. However similar analysis of exported protein extracts showed enough heterogeneity for this technique to be of value as a typing method for both S. epidermidis and S. capitis. Silver staining of exported protein extacts was found to be of little taxonomic value. Plasmids were found in a small percentage of strains of S. epidermidis, and restriction enzyme digests of both plasmid and chromosomal DNA of these strains require further technical modifications to yield reproducible results. Of the techniques used, therefore, only Western Blot of exported proteins yields data suitable for the development of a typing scheme.