Streptococcus salivarius

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Streptococcus salivarius
Streptococcus salivarius.tif
Colony of Streptococcus salivarius on blood agar
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Bacteria
Phylum: Bacillota
Class: Bacilli
Order: Lactobacillales
Family: Streptococcaceae
Genus: Streptococcus
Species:
S. salivarius
Binomial name
Streptococcus salivarius
Andrewes & Horder 1906
Synonyms

Streptococcus salivarius subsp. thermophilus Andrewes & Horder 1906

Contents

Streptococcus salivarius is a species of spherical, gram-positive, facultative anaerobic lactic acid bacteria [1] that is both catalase and oxidase negative. S. salivarius colonizes (usually in chains) the oral cavity and upper respiratory tract of humans just a few hours after birth, making further exposure to the bacteria harmless in most circumstances. The bacteria is considered an opportunistic pathogen, rarely finding its way into the bloodstream, where it has been implicated in cases of sepsis in people with neutropenia, (a deficiency in white blood cells).

S. salivarius has distinct characteristics when exposed to different environmental nutrients. For example, in the laboratory, if a growth medium is used that includes sucrose then S. salivarius is able to use the sucrose to produce a capsule around itself. However, if sucrose is replaced by glucose as on a GYC (glucose, yeast extract, calcium carbonate) plate, S. salivarius is unable to make a capsule from the glucose.

More importantly, in the laboratory, S. salivarius can show a distinct clearing on GYC plates. This is because S. salivarius can ferment the glucose yielding lactic acid. Next, the lactic acid actually reacts with the calcium carbonate in the GYC plate, resulting in zones of clearings on the plate.

Role as a probiotic

Some strains of S. salivarius are being trialed for their use as a probiotic in the prevention of oral infections. Some strains of S. salivarius are found to produce BLIS (Bacteriocin-like Inhibitory Substances) which are antimicrobial peptides. These peptides display interspecies inhibition, and inhibit Streptococcus pyogenes (which causes strep throat infections). Lozenges containing S. salivarius are marketed to support immunity against more virulent Streptococcus strains. People with this strain of naturally occurring S. salivarius on their tongue have been shown to have fewer Strep throat infections. [2] This is also being investigated for its potential to prevent rheumatic heart disease which is also caused by S. pyogenes.[ citation needed ]

Agglutination of Streptococcus salivarius is often used in the diagnosis of atypical pneumonia caused by Haemophilus influenzae [ citation needed ]

Subspecies

Streptococcus thermophilus was originally described as a subspecies of this entry, Streptococcus salivarius subsp. thermophilus. It has since been promoted to the species rank. [3] The FastANI metric used by GTDB concurs with this decision. [4]

Related Research Articles

<i>Streptococcus</i> Genus of bacteria

Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes.

<span class="mw-page-title-main">Lactic acid</span> Group of stereoisomers

Lactic acid is an organic acid. It has a molecular formula CH3CH(OH)COOH. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a hydroxyl group adjacent to the carboxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate. The name of the derived acyl group is lactoyl.

<i>Lactobacillus</i> Genus of bacteria

Lactobacillus is a genus of gram-positive, aerotolerant anaerobes or microaerophilic, rod-shaped, non-spore-forming bacteria. Until 2020, the genus Lactobacillus comprised over 260 phylogenetically, ecologically, and metabolically diverse species; a taxonomic revision of the genus assigned lactobacilli to 25 genera.

<i>Lactobacillus delbrueckii <span style="font-style:normal;">subsp.</span> bulgaricus</i> Subspecies of bacteria, used in yogurt

Lactobacillus bulgaricus is one of over 200 published species in the Lactobacillus genome complex (LGC) and is the main bacterium used for the production of yogurt. It also plays a crucial role in the ripening of some cheeses, as well as in other processes involving naturally fermented products. It is defined as homofermentive lactic acid bacteria due to lactic acid being the single end product of its carbohydrate digestion. It is also considered a probiotic.

<i>Lactococcus lactis</i> Species of bacterium

Lactococcus lactis is a gram-positive bacterium used extensively in the production of buttermilk and cheese, but has also become famous as the first genetically modified organism to be used alive for the treatment of human disease. L. lactis cells are cocci that group in pairs and short chains, and, depending on growth conditions, appear ovoid with a typical length of 0.5 - 1.5 µm. L. lactis does not produce spores (nonsporulating) and are not motile (nonmotile). They have a homofermentative metabolism, meaning they produce lactic acid from sugars. They've also been reported to produce exclusive L-(+)-lactic acid. However, reported D-(−)-lactic acid can be produced when cultured at low pH. The capability to produce lactic acid is one of the reasons why L. lactis is one of the most important microorganisms in the dairy industry. Based on its history in food fermentation, L. lactis has generally recognized as safe (GRAS) status, with few case reports of it being an opportunistic pathogen.

<span class="mw-page-title-main">Probiotic</span> Microorganisms said to provide health benefits when consumed

Probiotics are live microorganisms promoted with claims that they provide health benefits when consumed, generally by improving or restoring the gut microbiota. Probiotics are considered generally safe to consume, but may cause bacteria-host interactions and unwanted side effects in rare cases. There is some evidence that probiotics are beneficial for some conditions, but there is little evidence for many of the health benefits claimed for them.

<i>Lactobacillus acidophilus</i> Species of bacterium

Lactobacillus acidophilus is a rod-shaped, Gram-positive, homofermentative, anaerobic microbe first isolated from infant feces in the year 1900. The species is most commonly found in humans, specifically the gastrointestinal tract, oral cavity, and vagina, as well as various fermented foods such as fermented milk or yogurt. The species most readily grows at low pH levels, and has an optimum growth temperature of 37 °C. Certain strains of L. acidophilus show strong probiotic effects, and are commercially used in dairy production. The genome of L. acidophilus has been sequenced.

<i>Streptococcus mutans</i> Species of bacterium

Streptococcus mutans is a facultatively anaerobic, gram-positive coccus commonly found in the human oral cavity and is a significant contributor to tooth decay. It is part of the "streptococci", an informal general name for all species in the genus Streptococcus. The microbe was first described by James Kilian Clarke in 1924.

The dental pellicle, or acquired pellicle, is a protein film that forms on the surface enamel, dentin, artificial crowns, and bridges by selective binding of glycoproteins from saliva that prevents continuous deposition of salivary calcium phosphate. It forms in seconds after a tooth is cleaned, or after chewing. It protects the tooth from the acids produced by oral microorganisms after consuming carbohydrates.

<span class="mw-page-title-main">Lactic acid bacteria</span> Order of bacteria

Lactobacillales are an order of gram-positive, low-GC, acid-tolerant, generally nonsporulating, nonrespiring, either rod-shaped (bacilli) or spherical (cocci) bacteria that share common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation, giving them the common name lactic acid bacteria (LAB).

<span class="mw-page-title-main">Food microbiology</span> Study of the microorganisms that inhibit, create, or contaminate food

Food microbiology is the study of the microorganisms that inhabit, create, or contaminate food. This includes the study of microorganisms causing food spoilage; pathogens that may cause disease ; microbes used to produce fermented foods such as cheese, yogurt, bread, beer, and wine; and microbes with other useful roles, such as producing probiotics.

<i>Streptococcus thermophilus</i> Species of bacterium

Streptococcus thermophilus formerly known as Streptococcus salivarius subsp. thermophilus is a gram-positive bacterium, and a fermentative facultative anaerobe, of the viridans group. It tests negative for cytochrome, oxidase, and catalase, and positive for alpha-hemolytic activity. It is non-motile and does not form endospores. S. thermophilus is fimbriated.

<span class="mw-page-title-main">Class II bacteriocin</span>

Class II bacteriocins are a class of small peptides that inhibit the growth of various bacteria.

<i>Streptococcus anginosus</i> Species of bacterium

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 after the previously assumed but later refuted idea of a single species Streptococcus milleri. Phylogenetic relatedness of S. anginosus, S. constellatus, and S. intermedius has been confirmed by rRNA sequence analysis.

<i>Pediococcus acidilactici</i> Species of bacterium

Pediococcus acidilactici is a species of Gram-positive cocci that is often found in pairs or tetrads. P. acidilactici is a homofermentative bacterium that can grow in a wide range of pH, temperature, and osmotic pressure, therefore being able to colonize the digestive tract. It has emerged as a potential probiotic that has shown promising results in animal and human experiments, though some of the results are limited. They are commonly found in fermented vegetables, fermented dairy products, and meat.

<i>Latilactobacillus sakei</i> Species of bacterium

Latilactobacillus sakei is the type species of the genus Latilactobacillus that was previously classified in the genus Lactobacillus. It is homofermentative; hexoses are metabolized via glycolysis to lactic acid as main metabolite; pentoses are fermented via the Phosphoketolase pathway to lactic and acetic acids.

Lactobacillus gasseri is a species in the genus Lactobacillus identified in 1980 by François Gasser and his associates. It is part of the vaginal flora. Its genome has been sequenced. L. gasseri is a normal inhabitant of the lower reproductive tract in healthy women. It also produces Lactocillin.

<i>Lactobacillus bulgaricus</i> GLB44 Subspecies of bacterium

Lactobacillus delbrueckii subsp. bulgaricus is a bacterial subspecies traditionally isolated from European yogurts. Lactobacillus bulgaricusGLB44 differs from the rest of the L. bulgaricus strains because it was isolated from the leaves of Galanthus nivalis in Bulgaria.

Proteobiotics are natural metabolites which are produced by fermentation process of specific probiotic strains. These small oligopeptides were originally discovered in and isolated from culture media used to grow probiotic bacteria and may account for some of the health benefits of probiotics.

RopB transcriptional regulator, also known as RopB/Rgg transcriptional regulator is a transcriptional regulator protein that regulates expression of the extracellularly secreted cysteine protease streptococcal pyrogenic exotoxin B (speB) [See Also: erythrogenic toxins] which is an important virulence factor of Streptococcus pyogenes and is responsible for the dissemination of a host of infectious diseases including strep throat, impetigo, streptococcal toxic shock syndrome, necrotizing fasciitis, and scarlet fever. Functional studies suggest that the ropB multigene regulon is responsible for not only global regulation of virulence but also a wide range of functions from stress response, metabolic function, and two-component signaling. Structural studies implicate ropB's regulatory action being reliant on a complex interaction involving quorum sensing with the leaderless peptide signal speB-inducing peptide (SIP) acting in conjunction with a pH sensitive histidine switch.

References

  1. Roger, P.; Delettre, J.; Bouix, M.; Béal, C. (September 2011). "Characterization of Streptococcus salivarius growth and maintenance in artificial saliva: Growth of S. salivarius in saliva". Journal of Applied Microbiology. 111 (3): 631–641. doi:10.1111/j.1365-2672.2011.05077.x. PMID   21672100. S2CID   22232278.
  2. Wescombe, P. A.; Heng, N. C. K.; et al. (2009). "Streptococcal bacteriocins and the case for Streptococcus salivarius as model oral probiotics". Future Microbiology. 4 (7): 819–835. doi:10.2217/fmb.09.61. PMID   19722837.
  3. "Validation of the Publication of New Names and New Combinations Previously Effectively Published Outside the IJSB: List No. 54". International Journal of Systematic Bacteriology. 45 (3): 619–620. July 1995. doi: 10.1099/00207713-45-3-619 .
  4. "GTDB - Tree at s__Streptococcus thermophilus". gtdb.ecogenomic.org. Retrieved 30 January 2023.

Further reading