Streptococcus mitis, previously known as Streptococcus mitior, is a mesophilic alpha-hemolytic species of Streptococcus that inhabits the human mouth. It is most commonly found in the throat, nasopharynx, and mouth. It is a Gram-positive coccus, facultative anaerobe and catalase negative. It can cause infective endocarditis. It has been widely reported that this organism survived for over two years on the Surveyor 3 probe on the moon; but some NASA scientists suggest this may be a result of contamination during or after return of Surveyor parts to Earth.
- Lamas, C. C.; Eykyn, S. J. (2003). "Blood culture negative endocarditis: Analysis of 63 cases presenting over 25 years". Heart (British Cardiac Society). 89 (3): 258–262. doi:10.1136/heart.89.3.258. PMC . PMID 12591823..
- http://lsda.jsc.nasa.gov/scripts/experiment/exper.cfm?exp_index=1651. NASA
- "Surveyor 3 Streptococcus Mitis (APSTREPMIT)". NASA. Retrieved 27 December 2015.