title: Evolutionary origin and emergence of a highly successful clone of serotype M1 group a Streptococcus involved multiple horizontal gene transfer events.
abstract: To better understand the molecular events involved in the origin of new pathogenic bacteria, we studied the evolution of a highly virulent clone of serotype M1 group A Streptococcus (GAS). Genomic, DNA-DNA microarray, and single-nucleotide polymorphism analyses indicated that this clone evolved through a series of horizontal gene transfer events that involved (1) the acquisition of prophages encoding streptococcal pyrogenic exotoxin A and extracellular DNases and (2) the reciprocal recombination of a 36-kb chromosomal region encoding the extracellular toxins NAD+-glycohydrolase (NADase) and streptolysin O (SLO). These gene transfer events were associated with significantly increased production of SLO and NADase. Virtual identity in the 36-kb region present in contemporary serotype M1 and M12 isolates suggests that a serotype M12 strain served as the donor of this region. Multiple horizontal gene transfer events were a crucial factor in the evolutionary origin and emergence of a very abundant contemporary clone of serotype M1 GAS.
authors.affiliation: Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Sumby
authors.forename: Steve F
authors.initials: SF
authors.lastname: Porcella
authors.forename: Andres G
authors.initials: AG
authors.lastname: Madrigal
authors.forename: Kent D
authors.initials: KD
authors.lastname: Barbian
authors.forename: Kimmo
authors.initials: K
authors.lastname: Virtaneva
authors.forename: Stacy M
authors.initials: SM
authors.lastname: Ricklefs
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Sturdevant
authors.forename: Morag R
authors.initials: MR
authors.lastname: Graham
authors.forename: Jaana
authors.initials: J
authors.lastname: Vuopio-Varkila
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Hoe
authors.forename: James M
authors.initials: JM
authors.lastname: Musser
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D002999:Clone Cells; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D022761:Gene Transfer, Horizontal / Q000235:genetics*; D016680:Genome, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D009244:NAD+ Nucleosidase / Q000235:genetics / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000235:genetics / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000201:enzymology / Q000235:genetics*; D013301:Streptolysins / Q000235:genetics / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D013301:Streptolysins; C014689:streptococcal M protein; C025964:streptolysin O; D009244:NAD+ Nucleosidase