title: Induction of lysogenic bacteriophage and phage-associated toxin from group a streptococci during coculture with human pharyngeal cells.
abstract: We found that when group A streptococci are cocultured with human pharyngeal cells, they upregulate and secrete a 25-kDa toxin, determined to be the bacteriophage-encoded streptococcal pyrogenic exotoxin C (SpeC). This prompted us to determine if the bacteriophage themselves are induced during coculture conditions. We found that bacteriophage induction does occur, resulting in the release of approximately 10(5) phage particles during the 3-h coculture. Furthermore, we show that the bacteriophage induction event is mediated by a pharyngeal cell soluble factor for which we provide an initial characterization.
authors.affiliation: Department of Bacterial Pathogenesis and Immunology, Rockefeller University, New York, New York 10021, USA. broudyt@rockvax.rockefeller.edu
authors.forename: T B
authors.initials: TB
authors.lastname: Broudy
authors.forename: V
authors.initials: V
authors.lastname: Pancholi
authors.forename: V A
authors.initials: VA
authors.lastname: Fischetti
mesh_terms: D001426:Bacterial Proteins; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D005098:Exotoxins / Q000096:biosynthesis*; D015967:Gene Expression Regulation, Viral; D006801:Humans; D008242:Lysogeny; D008565:Membrane Proteins; D010614:Pharynx / Q000166:cytology / Q000382:microbiology*; D017108:Streptococcus Phages / Q000254:growth & development*; D013297:Streptococcus pyogenes / Q000821:virology*; D014764:Viral Proteins / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D017077:Culture Media, Conditioned; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; D014764:Viral Proteins; C027951:erythrogenic toxin