Slime production and expression of the slime-associated antigen by staphylococcal clinical isolates

Abstract

The ability to produce slime and to express a slime-associated antigen was examined in a collection of staphylococcal clinical isolates. Slime-producing strains were found among coagulase-negative staphylococci in percentages comparable to those reported in other studies; surprisingly, a high percentage of Staphylococcus aureus strains also were able to produce this extracellular material. In the latter case, this ability was strongly dependent on the presence of an additional carbohydrate source in the growth medium. Expression of the slime-associated antigen appeared to be species specific and confined to the Staphylococcus epidermidis sensu stricto isolates; its strong association with the ability of these strains to produce thicker biofilms indicated slime-associated antigen as a possible virulence marker for S. epidermidis.

FIG. 1

Slime production of SAA-positive and SAA-negative S. epidermidis clinical isolates. Dots indicate the average OD of triplicate determinations of the biofilm produced by each strain. Bars indicate the medians of the plotted values.

FIG. 2

Slime production of S. aureus strains in the presence of glucose (a) or without glucose addition (b). Dots indicate the average OD of triplicate determinations. Bars indicate the medians of the plotted values.