title: Staphylococcal chromosomal cassette mec type I, spa type, and expression of Pls are determinants of reduced cellular invasiveness of methicillin-resistant Staphylococcus aureus isolates.
abstract: We have shown previously that pls, which codes for the surface protein Pls of methicillin-resistant Staphylococcus aureus (MRSA), reduces adhesion to immobilized fibronectin, fibrinogen, laminin, and immunoglobulin G as well as invasion of host cells. Here, we tested a collection of 66 clinical MRSA isolates--48 negative for pls/Pls (pls(-)/Pls(-)), 15 positive for pls/Pls (pls(+)/Pls(+)), and 3 harboring the pls gene but not expressing Pls (pls(+)/Pls(-))--for cellular invasiveness. Invasion of 293 cells by pls(+)/Pls(+) strains was lower than that by the pls(-)/Pls(-) strains (median [range], 36% [22%-70%] vs. 93% [25%-162%]). The 3 pls(+)/Pls(-) strains (median [range], 95% [63%-103%]) were as invasive as the pls(-)/Pls(-) strains. In addition, we identified a pls(+)/Pls(+) staphylococcal chromosomal cassette mec (SCCmec) IV strain. In conclusion, 3 properties--pls/Pls, SCCmec type, and spa type--strongly predicted the cellular invasiveness of MRSA strains, as indicated by good clustering. In contrast, the spa type-deduced multilocus sequence typing clonal complex (MLST-CC) was not able to predict the invasiveness of MRSA strains equally well. The underlying mechanism remains to be elucidated.
authors.affiliation: Institute of Medical Microbiology, University Hospital of Munster, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Werbick
authors.forename: Karsten
authors.initials: K
authors.lastname: Becker
authors.forename: Alexander
authors.initials: A
authors.lastname: Mellmann
authors.forename: Katri M
authors.initials: KM
authors.lastname: Juuti
authors.forename: Christof
authors.initials: C
authors.lastname: von Eiff
authors.forename: Georg
authors.initials: G
authors.lastname: Peters
authors.forename: Pentti I
authors.initials: PI
authors.lastname: Kuusela
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Friedrich
authors.forename: Bhanu
authors.initials: B
authors.lastname: Sinha
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002876:Chromosomes, Bacterial / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008712:Methicillin; D016106:Methicillin Resistance; D046915:Penicillin-Binding Proteins; D013205:Staphylococcal Protein A / Q000235:genetics* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D046915:Penicillin-Binding Proteins; D013205:Staphylococcal Protein A; C487789:mecA protein, Staphylococcus aureus; D008712:Methicillin