AUTHOR=Pato Catarina , Melo-Cristino José , Ramirez Mario , Friães Ana , The Portuguese Group for the Study of Streptococcal Infections , Vaz Teresa , Gião Marília , Ferreira Rui , Silva Ana Cristina , Costa Hermínia , Silva Maria Fátima , Afonso Maria Amélia , Domingos Ana , Marrão Gina , Grossinho José , Lopes Paulo , Lameirão Angelina , Abreu Gabriela , Selaru Aurélia , Marques Hermínia , Tomaz Margarida , Mota Paula , Ramos Maria Helena , Castro Ana Paula , Fonseca Fernando , Canhoto Nuno , Afonso Teresa , Pina Teresa , Peres Helena , Chantre Odete , Marques João , Marcelo Cristina , Peres Isabel , Lourenço Isabel , Pinto Margarida , Monteiro Lurdes , Lito Luís Marques , Toscano Cristina , Ana Pessanha Maria , Ramalheira Elmano , Diaz Raquel , Ferreira Sónia , Roxo Inês Cravo , Castro Ana Paula , Ribeiro Graça , Tomé Rui , Pontes Celeste , Boaventura Luísa , Chaves Catarina , Reis Teresa , Fonseca Ana Buschy , Ribeiro Manuela , Gonçalves Helena , Faustino Alberta , Alves Adelaide , Iglesias Maria Cármen , Fontes Ilse , Martinho Paulo , Gonçalves Maria Luísa , Neto Olga , Sancho Luísa , Coutinho Adriana , Diogo José , Rodrigues Ana , Read Maria Antónia , Alves Valquíria , Monteiro Margarida , Bento Rosa TITLE=Streptococcus pyogenes Causing Skin and Soft Tissue Infections Are Enriched in the Recently Emerged emm89 Clade 3 and Are Not Associated With Abrogation of CovRS JOURNAL=Frontiers in Microbiology VOLUME=9 YEAR=2018 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.02372 DOI=10.3389/fmicb.2018.02372 ISSN=1664-302X ABSTRACT=

Although skin and soft tissue infections (SSTI) are the most common focal infections associated with invasive disease caused by Streptococcus pyogenes (Lancefield Group A streptococci - GAS), there is scarce information on the characteristics of isolates recovered from SSTI in temperate-climate regions. In this study, 320 GAS isolated from SSTI in Portugal were characterized by multiple typing methods and tested for antimicrobial susceptibility and SpeB activity. The covRS and ropB genes of isolates with no detectable SpeB activity were sequenced. The antimicrobial susceptibility profile was similar to that of previously characterized isolates from invasive infections (iGAS), presenting a decreasing trend in macrolide resistance. However, the clonal composition of SSTI between 2005 and 2009 was significantly different from that of contemporary iGAS. Overall, iGAS were associated with emm1 and emm3, while SSTI were associated with emm89, the dominant emm type among SSTI (19%). Within emm89, SSTI were only significantly associated with isolates lacking the hasABC locus, suggesting that the recently emerged emm89 clade 3 may have an increased potential to cause SSTI. Reflecting these associations between emm type and disease presentation, there were also differences in the distribution of emm clusters, sequence types, and superantigen gene profiles between SSTI and iGAS. According to the predicted ability of each emm cluster to interact with host proteins, iGAS were associated with the ability to bind fibrinogen and albumin, whereas SSTI isolates were associated with the ability to bind C4BP, IgA, and IgG. SpeB activity was absent in 79 isolates (25%), in line with the proportion previously observed among iGAS. Null covS and ropB alleles (predicted to eliminate protein function) were detected in 10 (3%) and 12 (4%) isolates, corresponding to an underrepresentation of mutations impairing CovRS function in SSTI relative to iGAS. Overall, these results indicate that the isolates responsible for SSTI are genetically distinct from those recovered from normally sterile sites, supporting a role for mutations impairing CovRS activity specifically in invasive infection and suggesting that this role relies on a differential regulation of other virulence factors besides SpeB.