title: Presence of streptococcal pyrogenic exotoxin A and C genes in human isolates of group G streptococci.
abstract: The bacteriophage-associated genes speA and speC encode streptococcal pyrogenic exotoxins of group A streptococci (GAS). Human isolates of group C and G streptococci (GCS and GGS) are commensals and the closest known genetic relatives of GAS; on occasion, GCS-GGS can cause infection that is clinically similar to GAS disease. Thirty-four human isolates of GCS-GGS were tested for speA and speC. Two GGS isolates harbored speA only, whereas a third GGS had both genes. All spe alleles found in GGS were identical to known spe alleles of GAS, except for one speA allele, which was unique. The presence of shared speA and speC alleles in GAS and GGS is highly suggestive of recent interspecies transfer. Acquisition of GAS-like virulence genes by GGS may lead to enhanced pathogenicity in this usually commensal-like organism.
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, Box 208106, 06520, New Haven, CT, USA.
authors.forename: Awdhesh
authors.initials: A
authors.lastname: Kalia
authors.forename: Debra E
authors.initials: DE
authors.lastname: Bessen
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D005098:Exotoxins / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D005798:Genes, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010802:Phylogeny; D011749:Pyrogens / Q000235:genetics*; D016415:Sequence Alignment; D013290:Streptococcal Infections / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D005098:Exotoxins; D008565:Membrane Proteins; D011749:Pyrogens; C117980:SpeA protein, Streptococcus pyogenes; C027951:erythrogenic toxin