Erratum to: 'Identification and characterization of the bacterial etiology of clinically problematic acute otitis media after tympanocentesis or spontaneous otorrhea in German children'. Issue 1 (December 2016) - Grevers, Gerhard; Wiedemann, Susanne; Bohn, Jan-Christof; Blasius, Rolf-Werner; Harder, Thomas; Kroeniger, Werner; Vetter, Volker; Pirçon, Jean-Yves; Marano, Cinzia