Aerococcus is a genus in the phylum Firmicutes (Bacteria). The genus was first identified in 1953 from samples of air and dust as a catalase-negative, gram-positive coccus that grew in small clusters. They were subsequently found in hospital environments and meat-curing brines. It has been difficult to identify as it resembles alpha-hemolytic Streptococcus on blood agar plates and is difficult to identify by biochemical means. Sequencing of 16S rRNA has become the gold standard for identification, but other techniques such as MALDI-TOF have also been useful for identifying both the genus and species.