Characterization of the relationship between polysaccharide intercellular adhesin and hemagglutination in Staphylococcus epidermidis

To determine whether a relationship exists between biofilm formation and hemagglutination in Staphylococcus epidermidis, 20 skin isolates and 19 prosthetic valve endocarditis isolates were characterized for biofilm formation, hemagglutination, and the presence of a 357-bp polymerase chain reaction product within icaA. A strong association existed between biofilm formation, which has been linked to strains that produce polysaccharide intercellular adhesin (PIA), and hemagglutination. Strains that produced biofilm were significantly (P<.001) more likely to mediate hemagglutination (16 biofilm-positive/hemagglutination-positive strains and 19 biofilm-negative/hemagglutination-negative strains) within the 39 clinical strains tested. In addition, Staphylococcus carnosus TM300, a biofilm-negative, hemagglutination-negative strain, carrying the ica operon-containing plasmid pCN27, produced significant biofilm on glass and mediated hemagglutination (>/=1/128). It was concluded that production of PIA and hemagglutination are strongly associated and that PIA, at least in part, mediates hemagglutination in S. epidermidis.