Whole-genome sequencing of Staphylococcus pseudintermedius isolated from nasal swabs of healthy dogs in Pennsylvania
Open Access
- Author:
- Kolar, Janel
- Area of Honors:
- Veterinary and Biomedical Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Bhushan M Jayarao, Thesis Supervisor
Robert John Vansaun, Thesis Honors Advisor - Keywords:
- Staphylococcus pseudintermedius
Pennsylvania
Dogs
Whole-genome sequencing
Antimicrobial resistance genes
Biofilms
Canine nasal passages
MRSP
Virulence genes - Abstract:
- In this study, a genomic investigation of Staphylococcus pseudintermedius isolated from the nasal passages of healthy dogs was conducted to identify the presence of virulence and antimicrobial resistance genes and to study the ability of S. pseudintermedius to form biofilms. Eighteen isolates regrown from stock cultures maintained by the Bacteriology Section of the Penn State Animal Diagnostic Laboratory were characterized using whole-genome sequencing. Biofilm production was examined using a crystal violet staining method. Identified sequence types included MLST188, MLST241, MLST527, MLST764, and MLST1296, along with several unknown sequence types, reflecting diversity in the collection. Similar ranges of virulence genes, encoding enzymes, toxins, adhesions, and regulatory systems, that influence the ability of S. pseudintermedius to cause opportunistic infection were detected in the isolates. Particularly, great diversity in frequency was observed in S. pseudintermedius surface protein genes, markedly: spsF, spsO, spsP, spsQ, and spsR. A wide array of antimicrobial resistance genes was detected in this study that correlated with the phenotypic resistance of isolates, highlighting the concern of S. pseudintermedius in human and veterinary health. The most predominant antimicrobial resistance gene was the blaZ gene. In addition, four isolates were methicillin-resistant and encoded the mecA gene. In terms of biofilms, the ica operon was observed in most isolates; however, the relationship between the amount of biofilm formation and the presence of the ica operon is unclear. Staphylococcus pseudintermedius isolates from the nasal passages encoded for similar virulence and antimicrobial genes as isolates collected from healthy dogs and dogs with atopic dermatitis. This suggests that in addition to the skin, the nasal passages could be an important source for the transmission of S. pseudintermedius.