title: Comparative analysis of phenol-soluble modulin production and Galleria mellonella killing by community-associated and healthcare-associated meticillin-resistant Staphylococcusaureus strains.
abstract: 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.
authors.affiliation: Centre for Clinical Infection and Diagnostics Research (CIDR), Department of Infectious Diseases, King's College London & Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Eve
authors.initials: E
authors.lastname: Boakes
authors.affiliation: Centre for Clinical Infection and Diagnostics Research (CIDR), Department of Infectious Diseases, King's College London & Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Helene
authors.initials: H
authors.lastname: Marbach
authors.affiliation: Centre of Excellence for Mass Spectrometry, King's College London, London, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Lynham
authors.affiliation: Centre of Excellence for Mass Spectrometry, King's College London, London, UK.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Ward
authors.affiliation: Centre for Clinical Infection and Diagnostics Research (CIDR), Department of Infectious Diseases, King's College London & Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Edgeworth
authors.affiliation: Centre for Clinical Infection and Diagnostics Research (CIDR), Department of Infectious Diseases, King's College London & Guy's and St Thomas' NHS Foundation Trust, London, UK.|Imperial College Healthcare NHS Trust, St Mary's Hospital, Praed Street, London W2 1NY, UK.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Otter
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000378:metabolism; D017714:Community-Acquired Infections / Q000382:microbiology*; D003428:Cross Infection / Q000382:microbiology*; D004195:Disease Models, Animal; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology*; D009036:Moths / Q000382:microbiology*; D019800:Phenol; D012995:Solubility; D013203:Staphylococcal Infections / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis / Q000235:genetics
chemical_list: D001427:Bacterial Toxins; D037521:Virulence Factors; C025971:staphylococcal delta toxin; D019800:Phenol