Comparative Pan-Genomic Analysis Revealed an Improved Multi-Locus Sequence Typing Scheme for Staphylococcus aureus

Area of Science:

• Microbiology
• Genomics
• Epidemiology

Background:

• Antibiotic-resistant Staphylococcus aureus strains necessitate advanced typing methods for surveillance.
• Whole genome sequencing is accurate but not cost-effective for routine typing.
• Multi-Locus Sequence Typing (MLST) is an established bacterial typing technique.

Purpose of the Study:

• To analyze Staphylococcus aureus pangenome and phylogeny for species divergence.
• To evaluate and improve the existing Multi-Locus Sequence Typing (MLST) scheme.
• To develop a more efficient and higher-resolution typing strategy for S. aureus.

Main Methods:

• Comprehensive pangenome and phylogenetic analysis of 502/1279 S. aureus genomes.
• Evaluation of current MLST scheme, identifying genes for exclusion or substitution.
• Statistical analysis of candidate genes based on genomic data and scores.

Main Results:

• A revised MLST scheme was developed, integrating existing and new candidate genes.
• Genes yQil, aroE, and gmk were replaced by opuCC, aspS, and rpiB.
• The proposed MLST scheme achieved higher resolution, identifying 58 sequence types (STs) versus the prior 42 STs.

Conclusions:

• The revised MLST scheme offers improved discriminatory power for S. aureus typing.
• This enhanced method aids in more effective epidemiological investigations and surveillance.
• The updated scheme provides a more robust tool for characterizing S. aureus populations.