Detection by PCR and analysis of the distribution of a fibronectin-binding protein gene (fbn) among staphylococcal isolates.

The fibronectin-binding proteins of Staphylococcus aureus are considered to be important virulence factors for colonisation and infection. The polymerase chain reaction (PCR) was used to detect part of a gene equivalent to the fbnA gene of S. aureus in 120 isolates of staphylococci (S. aureus, S. epidermidis, S. haemolyticus, S. simulans, S. hominis, S. warneri, S. cohnii and S. lugdunensis). Primers specific for the binding domain region of the fbnA gene of S. aureus produced PCR products of the predicted sizes (93 and 207 bp). The identity of the PCR products was confirmed by digestion with DdeI and nucleic acid hybridisation. The fibronectin-binding activity of the staphylococci was determined with a particle agglutination assay (PAA). The fbn gene was found to be present by PCR in 107 of the 120 staphylococci tested, irrespective of their site of isolation, and expression of the gene was detected by PAA in 101 of the 120 strains.