Footnotes

• Handling editor Anna Maria Geretti

• BB and BR contributed equally.

• Correction notice The article has been corrected since it was published online first. The first author's name has been amended to Hervé Jacquier.

• Contributors Conception and design: HJ, BB, BR. Microbiological and molecular procedures: DH and SK. Analysis: HJ. Drafting and revising the article: HJ, GM, DH, OR, NN, SK, SB, GLP-Y, OB, BR, BB.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Ethics approval All of the procedures were performed in accordance with the ethical standard of the Helsinki declaration of 1975, revised in 2000. Demographical data (including geographical origin used in this study) were anonymized, and the database was approved and authorized at a national level (Commission Nationale Informatique et Liberté, no 718544).

• Provenance and peer review Not commissioned; internally peer reviewed.