A metalloprotease is common to swine, avian and bovine isolates of Staphylococcus hyicus

Staphylococcus hyicus is considered to be an etiological agent of exudative epidermitis in young pigs, but is frequently isolated from chickens and cows. In the present study, the proteases of 58 S. hyicus isolates from pigs, chickens and cows were examined by skim milk agar plate culture, gelatinolytic zymogram and polymerase chain reaction (PCR). These isolates showed proteolytic activity on skim milk agar plate, but activity differed amongst the isolates. In the gelatinolytic zymogram, one main band was observed in all the porcine, avian and bovine isolates, while one to two other bands were recognized in some isolates. The formation of the main band was inhibited by EDTA, suggesting that this protease is a metalloprotease. When the Shp1 gene, which codes for one the metalloproteases of S. hyicus as reported previously, was examined by PCR, one band arising from an open reading frame (ORF) was detected in all of 58 isolates tested. In addition, upstream nucleotides containing the promoter region of Shp1 gene were amplified and sequenced. From these results, it seems likely that the metalloprotease is common to porcine, avian and bovine isolates of S. hyicus.