Abstract:
To obtain the information of virulence factors associated with Staphylococcus pseudintermedius pathogenicity, host survival and adaptation, the study of staphylococcal enterotoxin (SE) genes and cell wall-associated (CWA) protein genes in S. pseudintermedius isolates from dogs, humans, and environment were performed. Human methicillin-resistant Staphylococcus pseudintermedius (MRSP) harbored the hightes number of SE genes at 12 out of 17 genes compared to those from dogs at 5 and environmental isolates at 3 gene types. For CWA protein genes or S. pseudintermedius surface proteins (sps), there was no an easy and fast method to detect them. Therefore, this study develop the multiplex PCR assays (mPCRs) for detection of 18 sps genes. spsP and spsQ were more frequently detected in the canine isolates from infected sites than from carriage sites with statistically significant. The positive amplicons of spsR gene in three human isolates showed partial gene deletions. Adherence assays were performed to assess the ability of 5 MRSP isolates from different origins and to find the relation with CWA protein gene profiles. Three MRSP-ST45 from dog, human, and environment had the greatest ability to adhere to both canine and human corneocytes without the association to sps gene profiles. This study successfully developed the novel mPCR for sps genes detection. The association between sources and enterotoxin genes were hightlighted in the isolates from humans. The diversity of virulence genes in human isolates are assumed to transfer by mobile genetic elements and might associate with higher pathogenicity than dog, and environmental isolates. Moreover, the diversity of sps may be responsible for host adaptation.
