''Streptococcus constellatus'' is a species of ''

Streptococcus ''Streptococcus'' is a genus of gram-positive spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a sing ...

'' bacteria that is part of the normal flora in the oral cavity, urogenital region, and intestinal tract. However, it can frequently cause purulent infections in other parts of the body. DNA homology studies and 16S rRNA sequence analysis demonstrate ''S. constellatus'' belongs to the Streptococcus anginosus group (milleri group) along with ''

Streptococcus intermedius ''Streptococcus intermedius'' is an aerotolerant anaerobic commensal bacterium and a member of the ''Streptococcus anginosus'' group. The ''S. anginosus'' group, occasionally termed “''Streptococcus milleri'' group” (SMG) display hemolytic a ...

'' and ''

Streptococcus anginosus ''Streptococcus anginosus'' is a species of ''Streptococcus''. This species, '' Streptococcus intermedius'', and '' Streptococcus constellatus'' constitute the ''anginosus'' group, which is sometimes also referred to as the ''milleri'' group af ...

.''

Morphology

''S. constellatus'' are gram positive, non-sporing, non-motile, catalase negative cocci. The cells are small, normally 0.5-1μm in diameter and form short chains. Their cell wall peptidoglycan is composed of Lys-Ala_1-3 and has a DNA G+C content of 37-38%.Whiley, R. A., Hall, L. M. C., Hardie, J. M., Beighton, D. A study of small-colony, -haemolytic, Lancefield group C streptococci within the anginosus group: description of Streptococcus constellatus subsp. pharyngis subsp. nov., associated with the human throat and pharyngitis Int J Syst Bacteriol 1999 49: 1443-1449

Metabolism and growth

In the presence of CO₂ growth is enhanced, under

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

conditions growth is reduced, and some strains require

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic ad ...

conditions to grow. ''S. constellatus'' produces major amounts of lactic acid, fermented glucose, maltose and sucrose, but not lactose and hydrolyzed aesculin.

Biochemical characteristics

The typical species is

Lancefield Lancefield is a town in the Shire of Macedon Ranges local government area in Victoria, Australia north of the state capital, Melbourne, 33.6km south of Puckapunyal and had a population of at least 2,743 at the 2021 census. History The are ...

Groups A,C, G, and F, with the remaining NG (non-groupable) and haemolysis on blood agar is β-haemolytic and NH (non-haemolytic).

Disease

Clinically it is associated with abscess formation in the upper body and respiratory tract. It has also been found to be involved with pulmonary exacerbations in

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

patients and can lead to toxic shock and limb amputation.

Subspecies

Evidence supports the further subdivision of ''S. constellatus'' into three subspecies, ''S. constellatus'' subsp. ''constellatus'' and ''S. constellatus'' subsp. ''pharyngis'' and ''Streptococcus constellatus'' subsp. ''viborgensis''.

''S. constellatus subsp. constellatus''

Normally found in the oral cavities and upper respiratory tracts and isolated from purulent human infections, including appendicitis. Strains are frequently β-haemolyic and belong to

Group F or are nonhaemolytic (α and γ) and serologically ungroupable. However, a few strains react with

Group A, C, and G

antisera In immunology, antiserum is a blood serum containing antibodies (either monoclonal or polyclonal) that is used to spread passive immunity to many diseases via blood donation (plasmapheresis). For example, convalescent serum, or passive antibod ...

.Whiley, R. A., Hall, L. M. C., Hardie, J. M., Beighton, D. A study of small-colony, -haemolytic, Lancefield group C streptococci within the anginosus group: description of Streptococcus constellatus subsp. pharyngis subsp. nov., associated with the human throat and pharyngitis Int J Syst Bacteriol 1999 49: 1443-1449 Most strains produce: * α-glucosidase, but very few produce: β-galactosidase and β-glucosidase Most strains do NOT produce: * β-N-acetylglucosaminidase * β-D-fucosidase * α-galactosidase * β-glucuronidase * pyrrolidonylarylamidase * sialidase

''S. constellatus subsp. pharyngis''

Normally found in infections of the human throat, patients with pharyngitis. Strains frequency are β-haemolytic and belong to

C. Most strains produce: * β-N-acetylgalactosaminidase * β-D-fucosidase * α-galactosidase * α-glucosidase * β-glucosdiase * β-N-acetylglucosaminidase Most strains do NOT produce: * α-galactosidase * β-glucuronidase * pyrrolidonylarylamidase * sialidase

References

External links

Type strain of ''Streptococcus constellatus'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q7623346 Streptococcaceae