Aims: To provide comparative genome sequence data for two related model strains of Staphylococcus aureus (SH1000 and 8325-4) that are used extensively in laboratory research.
Methods and results: Comparative genome sequencing was used to identify genetic differences between Staph. aureus SH1000 and the fully genome-sequenced ancestral strain, Staph. aureus NCTC 8325. PCR amplification and DNA sequencing were employed to determine which of the genetic polymorphisms identified were also present in Staph. aureus 8325-4, a direct derivative of 8325 and the parent strain of SH1000. Aside from known genetic differences between these strains, Staph. aureus SH1000 harboured 15 single-nucleotide polymorphisms compared with 8325 (of which 12 were also found in 8325-4), and a 63-bp deletion upstream of the spa gene not present in either 8325 or 8325-4.
Conclusions: Staphylococcus aureus SH1000 and 8325-4 contain a number of genetic polymorphisms relative to the progenitor strain of the lineage (8325) and to each other.
Significance and impact of the study: The comparative genome sequences of SH1000 and 8325-4 presented here define the genotypes of two key strains in staphylococcal laboratory research and reveal genetic polymorphisms that may impact their phenotypic properties.