High-resolution melting analysis of the spa locus reveals significant diversity within sequence type 93 methicillin-resistant Staphylococcus aureus from northern Australia

• Published in: Clinical microbiology and infection Vol. 15; no. 12; pp. 1126 - 1131
• Main Authors: Tong, S.Y.C., Lilliebridge, R.A., Holt, D.C., McDonald, M.I., Currie, B.J., Giffard, P.M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier Ltd 01.12.2009; Blackwell Publishing Ltd; Wiley-Blackwell
• Subjects: Anti-Bacterial Agents - pharmacology; Australia - epidemiology; Bacterial diseases; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Bacterial Typing Techniques; Biological and medical sciences; Exotoxins - genetics; Exotoxins - metabolism; Genetic Variation; Genotype; High resolution melting; Human bacterial diseases; Humans; Impetigo - epidemiology; Impetigo - microbiology; Infectious diseases; Leukocidins - genetics; Leukocidins - metabolism; Medical sciences; Methicillin - pharmacology; Methicillin-Resistant Staphylococcus aureus - classification; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbial Sensitivity Tests; Reproducibility of Results; SPA; ST93; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcal infections, streptococcal infections, pneumococcal infections; Staphylococcal Protein A - genetics; Staphylococcus aureus; Transition Temperature; Australia; Oceania; High resolution melting; SPA; ST93; Staphylococcus aureus; Infection; High resolution; Melting; Bacteriosis; Bacteria; Micrococcales; Micrococcaceae; Staphylococcal infection
• ISSN: 1198-743X; 1469-0691
• DOI: 10.1111/j.1469-0691.2009.02732.x

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.