title: Genetic and phenotypic diversity among isolates of Streptococcus pyogenes from invasive infections.
abstract: To determine if recent cases of invasive group A streptococcal disease were caused by strains with a unique characteristic, 117 isolates Streptococcus pyogenes from patients with a variety of diseases, including necrotizing fasciitis and toxic shock syndrome, were analyzed. Significant genomic heterogeneity was observed among selected isolates, as determined using pulsed-field gel electrophoresis. The frequency of the bacteriophage-associated streptococcal erythrogenic toxin genes A and C (speA and speC) among the isolates was 44% (49/112) and 34% (38/112), respectively. Forty-three percent of speA-positive isolates produced streptococcal erythrogenic toxin (SPE) A in vitro. Seventy-six percent (85/112) of isolates produced SPE B in vitro, and in contrast to SPE A, little variation in the concentration of SPE B in broth culture supernatants was detected. The genetic and phenotypic heterogeneity observed among isolates from recent cases of severe infection does not support a clonal basis for the resurgence of invasive streptococcal infections.
authors.affiliation: Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Chaussee
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: D L
authors.initials: DL
authors.lastname: Stevens
authors.forename: J J
authors.initials: JJ
authors.lastname: Ferretti
mesh_terms: D001426:Bacterial Proteins; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004269:DNA, Bacterial / Q000235:genetics; D005098:Exotoxins / Q000235:genetics*; D005208:Fasciitis / Q000382:microbiology; D005838:Genotype; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D012772:Shock, Septic / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D005098:Exotoxins; D008565:Membrane Proteins; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin