Performance of Five Commercial Identification Platforms for Identification of Staphylococcus delphini

Area of Science:

• Veterinary Microbiology
• Clinical Microbiology
• Bacterial Taxonomy

Background:

• The Staphylococcus intermedius group (SIG) comprises four species: S. cornubiensis, S. delphini, S. intermedius, and S. pseudintermedius.
• SIG members are primarily animal pathogens with infrequent human infections.
• Accurate identification is crucial for S. pseudintermedius due to antimicrobial susceptibility testing implications.

Purpose of the Study:

• To evaluate the performance of five commercial identification platforms in identifying S. delphini isolates.
• To compare the efficacy of automated biochemical methods versus MALDI-TOF MS for SIG species differentiation.

Main Methods:

• Analysis of 21 Staphylococcus delphini isolates from diverse animal and geographic origins.
• Testing against five commercially available bacterial identification platforms, including automated biochemical analyzers and MALDI-TOF MS.

Main Results:

• Automated biochemical platforms failed to identify S. delphini to the species level, often misidentifying isolates as Staphylococcus aureus.
• These platforms could identify isolates to the SIG level with varying accuracy.
• One MALDI-TOF MS system successfully identified S. delphini to the species level.

Conclusions:

• MALDI-TOF MS is the preferred method for accurate species-level identification within the SIG.
• Current automated systems are inadequate for differentiating S. delphini.
• Further research is needed to determine the necessity of routine species-level identification for other SIG members as their pathogenic roles evolve.