title: A new closed-tube multiplex real-time PCR to detect eleven superantigens of Streptococcus pyogenes identifies a strain without superantigen activity.
abstract: Superantigens (SAgs) are very potent microbial toxins that are involved in severe diseases such as necrotizing fasciitis and toxic shock syndrome. There are currently 11 different SAgs that have been identified from Streptococcus pyogenes. In the present study, two sets of multiplex PCRs were developed for detection of these 11 SAg genes. The first group comprises spea1-3+5, spec, speg, spej, spek, and spel. The second group consists of spea1-4, speh, spei, spem, ssa, and smez. The presence of Streptococcus pyogenes SAg genes can be immediately identified using a real-time method with SYBR-Green, thus providing an excellent tool in clinical diagnostics. After testing more than 300 clinical isolates, we identified one strain without any SAg gene. This finding contrasts with previous reports describing SAg genes located on every Streptococcus pyogenes genome. This SAg gene-negative strain also did not show any mitogenic activity. It is hypothesized that clinical isolates from patients may overrepresent bacterial strains with pathogenic factors, such as SAgs.
authors.affiliation: Institute of Immunology, RWTH Aachen University Hospital, Pauwelsstrasse 30, D-52074 Aachen, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Lintges
authors.forename: Sabine
authors.initials: S
authors.lastname: Arlt
authors.forename: Peter
authors.initials: P
authors.lastname: Uciechowski
authors.forename: Birgit
authors.initials: B
authors.lastname: Plümäkers
authors.forename: Ralf R
authors.initials: RR
authors.lastname: Reinert
authors.forename: Adnan
authors.initials: A
authors.lastname: Al-Lahham
authors.forename: Rudolf
authors.initials: R
authors.lastname: Lütticken
authors.forename: Lothar
authors.initials: L
authors.lastname: Rink
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D052160:Benzothiazoles; D003959:Diamines; D006801:Humans; D009930:Organic Chemicals / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods*; D011804:Quinolines; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D018089:Superantigens / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D052160:Benzothiazoles; D003959:Diamines; D009930:Organic Chemicals; D011804:Quinolines; D018089:Superantigens; C098022:SYBR Green I