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16S rRNA RefSeq: V15.22    Genomic RefSeq: V9.15
Genus: Schaalia
Lineage: Bacteria;Actinobacteria;Actinomycetia;Actinomycetales;Actinomycetaceae;Schaalia
Overview: Bacteria of the genus Schaalia are abundant in the healthy mouth, particularly on the tongue dorsum, tonsils, and throat where they make up 3 to 6% of the oral microbial community. They were formerly considered to be in genus Actinomyces and were reclassified into genus Schaalia in 2018 (Nouioui et al. 2018).

Ecological role/importance in health and disease: There are 9 species of Schaalia in the mouth, including 5 named species (S. cardiffensis, S. georgiae, S. lingnae [Not Validly Published], S. meyeri, and S. odontolytica, as well as 4 taxa that are currently unnamed (Schaalia spp. HMT 172, 178, 180, and 877). Most of the Schaalia spp. detected in the healthy mouth in Human Microbiome Project data are members of the unnamed taxa S. sp. HMT 172 and S. sp. HMT 180 (Eren et al. 2014). S. odontolytica (formerly A. odontolyticus) is a member of the "purple complex" in subgingival plaque together with Veillonella parvula (Socransky et al. 1998).

Schaalia Image
A bacterial consortium scraped from the top surface of a human tongue. The colors represent different kinds of bacteria: Schaalia in red, Rothia mucilaginosa in blue, Veillonella in magenta, Streptococcus in green, Neisseriaceae in yellow.
Image credit: Steven Wilbert.
eHOMD Taxonomy
LifeCellular Organisms
 DomainBacteria (788) Abundance
  PhylumActinobacteria (119) Abundance
   ClassActinomycetia (104) Abundance
    OrderActinomycetales (34) Abundance
     FamilyActinomycetaceae (34) Abundance
      GenusSchaalia (9) Abundance
       Species       Schaalia cardiffensis (HMT-850) Abundance
       Schaalia georgiae (HMT-617) Abundance
       Schaalia lingnae (HMT-181) Abundance
       Schaalia meyeri (HMT-671) Abundance
       Schaalia odontolytica (HMT-701) Abundance
       Schaalia sp._HMT_172 (HMT-172) Abundance
       Schaalia sp._HMT_178 (HMT-178) Abundance
       Schaalia sp._HMT_180 (HMT-180) Abundance
       Schaalia sp._HMT_877 (HMT-877) Abundance