1 Department of Otolaryngology. Complexo Hospitalario Universitario A Coruña, Xubias de Arriba, 84, 15006 A Coruña, Spain. Electronic address: nicolas.gonzalez.poggioli@sergas.es.
2 Department of Microbiology. Complexo Hospitalario Universitario Santiago de Compostela, Travesia Choupana s/n, 15706 Santiago de Compostela, Spain.