title: Survey of the bp/tee genes from clinical group A streptococcus isolates in New Zealand - implications for vaccine development.
abstract: Group A streptococcus (GAS) is responsible for a wide range of diseases ranging from superficial infections, such as pharyngitis and impetigo, to life-threatening diseases, such as toxic shock syndrome and acute rheumatic fever (ARF). GAS pili are hair-like extensions protruding from the cell surface and consist of highly immunogenic structural proteins: the backbone pilin (BP) and one or two accessory pilins (AP1 and AP2). The protease-resistant BP builds the pilus shaft and has been recognized as the T-antigen, which forms the basis of a major serological typing scheme that is often used as a supplement to M typing. A previous sequence analysis of the bp gene (tee gene) in 39 GAS isolates revealed 15 different bp/tee types. In this study, we sequenced the bp/tee gene from 100 GAS isolates obtained from patients with pharyngitis, ARF or invasive disease in New Zealand. We found 20 new bp/tee alleles and four new bp/tee types/subtypes. No association between bp/tee type and clinical outcome was observed. We confirmed earlier reports that the emm type and tee type are associated strongly, but we also found exceptions, where multiple tee types could be found in certain M/emm type strains, such as M/emm89. We also reported, for the first time, the existence of a chimeric bp/tee allele, which was assigned into a new subclade (bp/tee3.1). A strong sequence conservation of the bp/tee gene was observed within the individual bp/tee types/subtypes (>97 % sequence identity), as well as between historical and contemporary New Zealand and international GAS strains. This temporal and geographical sequence stability provided further evidence for the potential use of the BP/T-antigen as a vaccine target.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand.|School of Medical Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: John D
authors.initials: JD
authors.lastname: Steemson
authors.affiliation: Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand.|School of Biological Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Moreland
authors.affiliation: Institute of Environmental Science and Research, Wellington, New Zealand.|Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand.|School of Medical Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Deborah
authors.initials: D
authors.lastname: Williamson
authors.affiliation: Institute of Environmental Science and Research, Wellington, New Zealand.
authors.forename: Julie
authors.initials: J
authors.lastname: Morgan
authors.affiliation: Institute of Environmental Science and Research, Wellington, New Zealand.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Carter
authors.affiliation: Maurice Wilkins Centre, University of Auckland, Auckland, New Zealand.|School of Medical Sciences, University of Auckland, Auckland, New Zealand.
authors.forename: Thomas
authors.initials: T
authors.lastname: Proft
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D036781:Fimbriae Proteins / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009520:New Zealand / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000942:Antigens, Bacterial; D004269:DNA, Bacterial; D036781:Fimbriae Proteins