Emergence of the same successful clade among distinct populations of emm89 Streptococcus pyogenes in multiple geographic regions

• Author(s): Friães, Ana ; Machado, Miguel P. ; Pato, Catarina ; Carrico, Joao Andre ; Cristino, José Melo ; Ramirez, Mário
• Date: 2015
• Persistent ID: http://hdl.handle.net/10451/51234
• Origin: Repositório da Universidade de Lisboa
• Document Type: Journal article
• Language: English
• Contributor(s): Repositório Científico de Acesso Aberto da ULisboa

Description

The emergence of clades within emm89 Streptococcus pyogenes isolates that rapidly became the dominant lineages expressing this emm type was recently reported in the United Kingdom and in a study that included isolates from the United States, Finland, and Iceland (United States/FI/IC). In the United Kingdom, the emerging clade was associated with the absence of the hasABC locus, responsible for the synthesis of the hyaluronic acid capsule. The study from the United States/FI/IC highlighted the strict association of the emerging clade with an nga promoter variant, also found in contemporary emm1 isolates, which results in increased expression of the nga locus. The study from the United Kingdom also examined this region and found that the nga-ifs-slo locus and surrounding sequences of the emerging clade shared 99% DNA identity with that of contemporary emm1 and emm12 strains, but the authors do not offer any information on the nga promoter (1). The acquisition of this region by emm1 isolates is currently considered the major molecular event triggering the success and enhanced virulence of this clone.