title: Genetic diversity of staphylocoagulase genes (coa): insight into the evolution of variable chromosomal virulence factors in Staphylococcus aureus.
abstract: BACKGROUND
  The production of staphylocoagulase (SC) causing the plasma coagulation is one of the important characteristics of Staphylococcus aureus. Although SCs have been classified into 10 serotypes based on the differences in the antigenicity, genetic bases for their diversities and relatedness to chromosome types are poorly understood.
  
  
  RESULTS
  We compared the nucleotide sequences of 105 SC genes (coa), 59 of which were determined in this study. D1 regions, which contain prothrombin-activating and -binding domains and are presumed to be the binding site of each type-specific antiserum, were classified into twelve clusters having more than 90% nucleotide identities, resulting to create two novel SC types, XI and XII, in addition to extant 10 types. Nine of the twelve SC types were further subdivided into subtypes based on the differences of the D2 or the central regions. The phylogenetical relations of the D1 regions did not correlate exactly with either one of agr types and multilocus sequence types (STs). In addition, genetic analysis showed that recombination events have occurred in and around coa. So far tested, STs of 126 S. aureus strains correspond to the combination of SC type and agr type except for the cases of CC1 and CC8, which contained two and three different SC types, respectively.
  
  
  CONCLUSIONS
  The data suggested that the evolution of coa was not monophyletic in the species. Chromosomal recombination had occurred at coa and agr loci, resulting in the carriage of the combinations of allotypically different important virulence determinants in staphylococcal chromosome.
authors.affiliation: Department of Infection Control Science, Graduate School of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.forename: Teruyo
authors.initials: T
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasaki
authors.forename: Shanshuang
authors.initials: S
authors.lastname: Li
authors.forename: Ikuo
authors.initials: I
authors.lastname: Uchiyama
authors.forename: Kozue
authors.initials: K
authors.lastname: Kishii
authors.forename: Ken
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Robert Leo
authors.initials: RL
authors.lastname: Skov
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hiramatsu
mesh_terms: D000483:Alleles; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003030:Coagulase / Q000737:chemistry / Q000235:genetics*; D044708:DNA, Concatenated / Q000235:genetics; D021901:DNA, Intergenic / Q000235:genetics; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D003030:Coagulase; D044708:DNA, Concatenated; D021901:DNA, Intergenic; D037521:Virulence Factors