16S rRNA Refseq V15.22 Genomic RefSeq V9.15
Human Oral Microbiome Taxon Description
Streptococcus mitis
Human Microbial Taxon ID:677Body Site:Nasal,Oral
Named - Cultured
Strain Information:
NCTC 12261
Check Global Catalogue of Microorganisms
NCBI Taxonomy ID:
16S rRNA Reference Sequences:
HOMD RefSeq ID: 677_3929

View in phylogenetic tree

Download latest 16S rRNA reference gene sequences
PubMed Search:965  [PubMed Link]
Nucleotide Search:6936  [Entrez Nucleotide Link]
Protein Search:92086  [Entrez Protein Link]
By molecular cloning:
Clones seen = 1973 / 34879 = 5.66%
Rank Abundance = 2
In other datasets:
Genome Sequence
134   View Genomes
View taxon in genome tree
View taxon in ribosome protein tree
View taxon in genomic 16S rRNA gene tree
Hierarchy Structure:    Hide or show the hierarchy structure
General Information:
Heterogenous group of viridans type of streptococci that has had taxonomic revisions.  Original type strain, NCTC 3165 (= SK51) clustered with Streptococcus gordonii strains.  Proposed NCTC 12261 be replacement type strain of S. mitis [2]. Closely related to S. pneumoniae by 16S rRNA comparisons.
Alpha-hemolytic colonies (0.7- 1.2 mm diameter) o­n blood agar and extensive greening o­n chocolate agar.
Phenotypic Characteristics:
Facultatively anaerobic, Gram positive cocci, approximately 1 um in diameter, that grow in short or long chains in broth cultures.   Carbohydrates are femented primarily to lactic acid and no gas. Catalase negative.  Cell wall contains riitol teichoic acid and minimal rhamnose. Peptidoglycan type is Lys-direct. G+C content is 41 mol%.[2,3]

2 biovars of S. mitis differ biochemically and serologically [2,3]

Prevalence and Source:
Commonly found o­n most surfaces in the human oral cavity and throat [1]. 
Disease Associations:
Not usually attributed to disease, especially oral infections.

May be involved in infective endocarditis, toxic shock-like syndrome, and neonatal infections.  Septicemias have been reported. 
PubMed database:
[1] Aas JA, Paster BJ, Stokes LN, Olsen I, Dewhirst FE. Defining the normal bacterial flora of the oral cavity. J Clin Microbiol. 2005 Nov;43(11):5721-32  [PubMed]
Non-PubMed database:
[2] Kilian M, Mikkelsen L, Henrichsen J. Taxonomic study of viridans Streptococci: Description of Streptococcus gordonii sp. nov. and emended descriptions of S. sanguis (White and Niven 1946), S. oralis .... Int J Syst Bacteriol. 1989 Oct;39(4):471-84.  
[3] Hardie RM. Genus Streptococcus. Bergey's Manual of Systematic Bacteriology 1986; Vol. 2, pp. 1043-1063.  
Creation Info:   Latest Modification:  bpaster,  2008-01-10 09:43:14
Copyright 2007-2022 The Forsyth Institute
Hosted on Amazon AWS EC2