title: High-resolution melting analysis of the spa locus reveals significant diversity within sequence type 93 methicillin-resistant Staphylococcus aureus from northern Australia.
abstract: High-resolution melting analysis is an inherently robust, easy and inexpensive approach to the examination of genomic regions containing single-nucleotide polymorphisms and hypervariable loci. Staphylococcus aureus sequence type (ST) 93 is a singleton, Panton-Valentine leukocidin-positive clone unique to Australia. A high-resolution melting-based method for the identification of ST93 was developed, and a similar approach was used to reveal diversity within the spa locus of this lineage. Statistical and graphical methods that account for instrumental and operator-dependent variation in high-resolution melting curves were developed, to allow greater confidence and reproducibility in deciding whether another curve is truly different from the baseline curve of an amplicon with known sequence. The data support a very early acquisition, or multiple independent acquisitions, of SCCmec by ST93 methicillin-susceptible S. aureus (MSSA), and the coexistence of MSSA and methicillin-resistant S. aureus versions of the same lineage within northern Australia.
authors.affiliation: Menzies School of Health Research, Institute of Advanced Studies, Charles Darwin University, Darwin, NT, Australia.
authors.forename: S Y C
authors.initials: SY
authors.lastname: Tong
authors.forename: R A
authors.initials: RA
authors.lastname: Lilliebridge
authors.forename: D C
authors.initials: DC
authors.lastname: Holt
authors.forename: M I
authors.initials: MI
authors.lastname: McDonald
authors.forename: B J
authors.initials: BJ
authors.lastname: Currie
authors.forename: P M
authors.initials: PM
authors.lastname: Giffard
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001315:Australia / Q000453:epidemiology; D001427:Bacterial Toxins / Q000235:genetics / Q000378:metabolism; D015373:Bacterial Typing Techniques; D005098:Exotoxins / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007169:Impetigo / Q000453:epidemiology / Q000382:microbiology; D007956:Leukocidins / Q000235:genetics / Q000378:metabolism; D008712:Methicillin / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D015203:Reproducibility of Results; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013205:Staphylococcal Protein A / Q000235:genetics*; D044366:Transition Temperature
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D013205:Staphylococcal Protein A; D008712:Methicillin