BACKGROUND: Previous investigations of community-associated methicillin-resistant Staphylococcus aureus(CA-MRSA) isolates have revealed a wide diversity of genetic backgrounds, with only sporadic occurrence of ST8-USA300, in Geneva, Switzerland. We conducted a molecular epidemiologic analysis to identify the origin of a sudden increase of ST8 PVL-positive isolates in Geneva during 2013. METHODS: On the basis of prospective CA-MRSA surveillance, we collected colonizing and infecting ST8-USA300 isolates and compared them to non-ST8 CA-MRSA isolates. Whole-genome sequencing (WGS) was performed for each isolate of this collection, and discriminating molecular features were linked to patient data. RESULTS: In 2013, 22 isolates with the ST8-USA300 profile were identified among 46 cases of CA-MRSA. WGS revealed 2 groups of strains that differed by the type of the SCCmec IV element encoded and whether they harbored an arginine catabolism mobile element (ACME) locus. ACME-negative strains were mainly isolated from patients traveling in or originating from South America. Single-nucleotide polymorphism positions in isolate groups were used to infer their common ancestor, determine their geographical origin, and trace their relatedness. CONCLUSIONS: WGS allowed the identification of transmission events and revealed that the increased prevalence of USA300 CA-MRSA isolates resulted from multiple importation events from the Americas but not from local clonal expansion of a successful clone.
BACKGROUND: Previous investigations of community-associated methicillin-resistant Staphylococcus aureus(CA-MRSA) isolates have revealed a wide diversity of genetic backgrounds, with only sporadic occurrence of ST8-USA300, in Geneva, Switzerland. We conducted a molecular epidemiologic analysis to identify the origin of a sudden increase of ST8 PVL-positive isolates in Geneva during 2013. METHODS: On the basis of prospective CA-MRSA surveillance, we collected colonizing and infecting ST8-USA300 isolates and compared them to non-ST8 CA-MRSA isolates. Whole-genome sequencing (WGS) was performed for each isolate of this collection, and discriminating molecular features were linked to patient data. RESULTS: In 2013, 22 isolates with the ST8-USA300 profile were identified among 46 cases of CA-MRSA. WGS revealed 2 groups of strains that differed by the type of the SCCmec IV element encoded and whether they harbored an arginine catabolism mobile element (ACME) locus. ACME-negative strains were mainly isolated from patients traveling in or originating from South America. Single-nucleotide polymorphism positions in isolate groups were used to infer their common ancestor, determine their geographical origin, and trace their relatedness. CONCLUSIONS: WGS allowed the identification of transmission events and revealed that the increased prevalence of USA300 CA-MRSA isolates resulted from multiple importation events from the Americas but not from local clonal expansion of a successful clone.
Authors: M Sassi; B Felden; M Revest; P Tattevin; Y Augagneur; P-Y Donnio Journal: Eur J Clin Microbiol Infect Dis Date: 2017-09-02 Impact factor: 3.267
Authors: D O Andrey; P François; C Manzano; E J Bonetti; S Harbarth; J Schrenzel; W L Kelley; A Renzoni Journal: Eur J Clin Microbiol Infect Dis Date: 2016-10-15 Impact factor: 3.267
Authors: Lavanya Challagundla; Xiao Luo; Isabella A Tickler; Xavier Didelot; David C Coleman; Anna C Shore; Geoffrey W Coombs; Daniel O Sordelli; Eric L Brown; Robert Skov; Anders Rhod Larsen; Jinnethe Reyes; Iraida E Robledo; Guillermo J Vazquez; Raul Rivera; Paul D Fey; Kurt Stevenson; Shu-Hua Wang; Barry N Kreiswirth; Jose R Mediavilla; Cesar A Arias; Paul J Planet; Rathel L Nolan; Fred C Tenover; Richard V Goering; D Ashley Robinson Journal: mBio Date: 2018-01-02 Impact factor: 7.867
Authors: Lena Strauß; Marc Stegger; Patrick Eberechi Akpaka; Abraham Alabi; Sebastien Breurec; Geoffrey Coombs; Beverly Egyir; Anders Rhod Larsen; Frederic Laurent; Stefan Monecke; Georg Peters; Robert Skov; Birgit Strommenger; François Vandenesch; Frieder Schaumburg; Alexander Mellmann Journal: Proc Natl Acad Sci U S A Date: 2017-11-20 Impact factor: 11.205