Surface hydrophobicity of Staphylococcus intermedius and Staphylococcus hyicus

Surface hydrophobicity of 90 Staphylococcus intermedius and 55 S hyicus isolates was evaluated using the hexadecane adherence assay and the ammonium sulphate salt aggregation test. A strongly positive hydrocarbon adherence in the hexadecane adherence assay was demonstrated in 11 per cent of the S intermedius isolates and 7 per cent of the S hyicus isolates. Bacterial aggregation in 1.6 M, or less, ammonium sulphate was observed in 28 per cent of the S intermedius isolates and 37 per cent of the S hyicus isolates. There was no statistical correlation between the two assays. The adherence of both bacterial species to hexadecane was eliminated when the cells were first treated with pronase and trypsin, while it was mildly enhanced by prior heat treatment (60 degrees C and 95 degrees C for up to three hours). In contrast, aggregation of S intermedius in ammonium sulphate was not influenced by trypsin pretreatment, and aggregation of both bacterial species was diminished, or eliminated, with pronase or prior 95 degrees C heat treatment. Surface hydrophobicity, as measured in both assays, appeared to have no relationship with growth patterns in serum soft agar or production of slime. Similarly, the presence or absence of substantial surface receptor activity to fibrinogen, fibronectin or IgG did not appear to be related to surface hydrophobicity.