title: An Enterotoxin-Bearing Pathogenicity Island in Staphylococcus epidermidis.
abstract: Cocolonization of human mucosal surfaces causes frequent encounters between various staphylococcal species, creating opportunities for the horizontal acquisition of mobile genetic elements. The majority of Staphylococcus aureus toxins and virulence factors are encoded on S. aureus pathogenicity islands (SaPIs). Horizontal movement of SaPIs between S. aureus strains plays a role in the evolution of virulent clinical isolates. Although there have been reports of the production of toxic shock syndrome toxin 1 (TSST-1), enterotoxin, and other superantigens by coagulase-negative staphylococci, no associated pathogenicity islands have been found in the genome of Staphylococcus epidermidis, a generally less virulent relative of S. aureus. We show here the first evidence of a composite S. epidermidis pathogenicity island (SePI), the product of multiple insertions in the genome of a clinical isolate. The taxonomic placement of S. epidermidis strain FRI909 was confirmed by a number of biochemical tests and multilocus sequence typing. The genome sequence of this strain was analyzed for other unique gene clusters and their locations. This pathogenicity island encodes and expresses staphylococcal enterotoxin C3 (SEC3) and staphylococcal enterotoxin-like toxin L (SElL), as confirmed by quantitative reverse transcription-PCR (qRT-PCR) and immunoblotting. We present here an initial characterization of this novel pathogenicity island, and we establish that it is stable, expresses enterotoxins, and is not obviously transmissible by phage transduction. We also describe the genome sequence, excision, replication, and packaging of a novel bacteriophage in S. epidermidis FRI909, as well as attempts to mobilize the SePI element by this phage.
authors.affiliation: Department of Oral Biology, NYS Center of Excellence in Bioinformatics and Life Sciences, The State University of New York, NY, USA.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Madhusoodanan
authors.forename: Keun Seok
authors.initials: KS
authors.lastname: Seo
authors.forename: Brian
authors.initials: B
authors.lastname: Remortel
authors.forename: Joo Youn
authors.initials: JY
authors.lastname: Park
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Hwang
authors.forename: Lawrence K
authors.initials: LK
authors.lastname: Fox
authors.forename: Yong Ho
authors.initials: YH
authors.lastname: Park
authors.forename: Claudia F
authors.initials: CF
authors.lastname: Deobald
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.forename: Sean C
authors.initials: SC
authors.lastname: Daugherty
authors.forename: Ann Lindley
authors.initials: AL
authors.lastname: Gill
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Bohach
authors.forename: Steven R
authors.initials: SR
authors.lastname: Gill
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004768:Enterotoxins / Q000235:genetics*; D020869:Gene Expression Profiling; D044404:Genomic Islands; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D016254:Mutagenesis, Insertional; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004768:Enterotoxins; D037521:Virulence Factors