Importance of Whole Genome Sequencing for the assessment of outbreaks in Diagnostic Laboratories: analysis of multiple samples taken from patients with severe pediatric and adult Streptococcus pyogenes infections. Investigation of several clinical cases of severe Streptococcus pyogenes infection by whole genome sequencing in Switzerland

After noticing an increase of invasive Streptococcus pyogenes infections in Switzerland, we performed a whole genome sequence (WGS) analysis of 11 isolates withdrawn between the 13.12.2015 and the 12.03.2016. Compared with emm-typing, MLST, only WGS allowed a good discrimination between the isolates and could rule out an outbreak of a hypervirulent clone. Characterization of the genes involved in the virulence and antibiotic resistances was also performed. Results were given to the clinicians in less than 10 days after the start of the analysis and had a positive impact on public health.