However, during our 10-year (2006–2016) prospective, longitudinal clinical, and translational studies of AOM, only since 2013 have we observed cases of severe AOM symptoms and TM rupture caused by Mcat (Pichichero et al., unpublished observations), suggesting that the virulence of Mcat as an otopathogen may be increasing. This evidence concerns the gene MCAT and infectious otitis media.