Comparative analysis of phenol‐soluble modulin production andGalleria mellonellakilling by community‐associated and healthcare‐associated meticillin‐resistantStaphylococcusaureusstrains. Issue 12 (16th December 2016)

• Record Type: Journal Article
• Authors: Boakes, Eve; Marbach, Helene; Lynham, Steven; Ward, Malcolm; Edgeworth, Jonathan D.; Otter, Jonathan A.
• Is Part Of: Journal of medical microbiology. Volume 65:Issue 12(2016)
• Publication Date: 2016-12-16
• Subjects: MRSA -- community‐associated -- healthcare‐associated -- PSM -- Galleria melonella -- virulence; Medical microbiology -- Periodicals; 616.9041
• DOI: 10.1099/jmm.0.000379
• Languages: English
• ISSNs: 0022-2615

Abstract

Abstract : N/A: Community‐associated meticillin‐resistant Staphylococcus aureus (CA‐MRSA) have emerged globally and have been associated with more severe disease than healthcare‐associated MRSA (HA‐MRSA). The purpose of this study was to determine whether laboratory measures of virulence can distinguish dominant CA‐MRSA clones from HA‐MRSA clones. We compared the production of phenol‐soluble modulins (PSMs) and ability to kill Galleria mellonella caterpillars for a range of CA‐ and HA‐MRSA strains. Twenty‐two HA‐MRSA strains [ST22‐IV (EMRSA‐15), ST36‐II (EMRSA‐16) and ST239‐III] and 26 CA‐MRSA strains [ST1‐IV (PVL+ USA400), ST1‐IV (PVL‐), ST8‐IV (USA300), ST22‐IV (PVL+), ST30‐IV, ST59‐IV and ST80‐IV] were analysed. PSM production was measured using and compared using t ‐tests and ANOVA. A G mellonella (caterpillar) pathogenicity model was performed, and differences were compared using survival analysis and the log‐rank test. There was no significant difference in overall PSM production between HA and CA strains ( P =0.090), but there was significant variation between clones ( P =0.003). G. mellonella caterpillar killing varied significantly by clone ( P <0.001), and overall killing was greater for HA compared with CA clones ( P =0.007). The increased acute virulence phenotype of CA‐MRSA clones in humans is not associated with increased PSM production in vitro or increased killing in an in vivo caterpillar pathogenicity model.