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Compositional guideline: Streptococcus salivarius M18

19 August 2019

Name of the ingredient

Streptococcus salivarius

Synonym

Streptococcus salivarius M18, BLIS M18™

Definition of the ingredient

Streptococcus salivarius is a bacterium found as part of the normal human oral microflora, predominately colonising the oral cavity (teeth, tongue). They are Gram positive, cocci which grow in chains or pairs, are catalase negative and nonmotile. On blood agar they form non-haemolytic colonies. They form distinctive mucoid colonies when grown on sucrose agar, due to the production of extracellular polysaccharides.

BLIS M18™ is a freeze-dried culture of Streptococcus salivarius M18 (NLT 1 x 1011 CFU/g) in a protective matrix of food-grade Maltodextrin, Trehalose Dihydrate and Lactitol.

S. salivarius M18 has been deposited in the American Type Culture Collection (ATCC) as ATCC BAA 2593. It also has been lodged with the German Collection of Microorganisms and Cell Cultures Deutsche Sammlung von Mikroorganismen und Zellkuturen GmbH) under the accession number DSM 14685. The strain is also patented for the prevention of dental caries (Patent number: US 7,226,590 B2) in the following territories: New Zealand, United States, European Union, Canada, Australia, China, India, Denmark, Finland, France, Germany, Italy, Netherlands, Spain, Sweden, Switzerland and the United Kingdom.

Table 1. Ingredient specific requirements
Test Method reference Acceptance criteria
Description
Appearance Visual evaluation Free flowing off-white powder
Odour/taste Organoleptic evaluation Proteinaceuous taste
Characteristics
Particle size Sieve analysis 90% NMT 500µm
Water activity (aw) USP <1112> NMT 0.25
Identification
Microscopic morphology USP <1113> Gram staining

Gram reaction: positive

Cellular shape: cocci in chains or pairs

Macroscopic morphology Visual examination of growth on Mitis salivarius agar at 37°C in 5% CO2 in air after 24-48 hr

Colony size: 1-2 mm in diameter

Colony shape:

  • Form: round
  • Margin: entire
  • Elevation: convex

Colony colour: blue

Colony texture: mucoid

Visual examination of growth on Blood agar [Columbia Agar Base with 5% human blood] at 37°C in 5% CO2 in air after 24-48 hr

Colony size: NMT 1 mm in diameter

Colony shape:

  • Form: round
  • Margin: entire
  • Elevation: convex

Colony Colour: white

Colony Texture: butyrous

Haemolysis: None

Biochemical profile

USP <1113> biochemical tests

and/ or

Automated microbial identification test (e.g. API 20 Strep test system)

Negative for: catalase

Positive for: acetoin production, β-glucosidase, α-galactosidase, β-galactosidase leucine aminopeptidase, D-lactose, D-trehalose, inulin, and D-raffinose.

Molecular identification of strain Heng NC (2011)[1] Matches the sequence for S. salivarius M18
Deferred antagonism, P- typing producer Tagg and Bannister (1979)[2], Burton (2013)[3]

Matches the fingerprint for S. salivarius M18 (677)

Assay
Streptococcus salivarius M18 Viable plate count on CAB K12 agar cultured at 37°C in 5% CO2 in air after 24-48 hr per Ishijama (2012)[4], Burton (2011)[5] modified to enumerate M18 NLT 1 x 1011 CFU/g
Table 2. Incidental constituents
Test Method reference Acceptance criteria
Microbiology
Total aerobic microbial count @ 35˚C Compendium 5th Edition 2015, Chapter 8 (excluding S. salivarius M18) NMT 10,000 CFU/g
Coliforms Compendium 5th Edition 2015 chapter 9 modified Not detected/g
E. coli Compendium 5th Edition 2015 chapter 9 modified Not detected/g
Salmonella ISO 6579:2002 (E) Not detected/25g
Mesophilic aerobic spore count @ 35°C Compendium 5th Edition 2015 chapter 23 NMT 200 CFU/g
Coagulase producing Staphylococcus aureus ISO 6888-3:2003 Not detected/g
Moulds BP NMT 50 CFU/g
Yeasts BP NMT 50 CFU/g
Notes
While ingredient manufacturers are encouraged to include limits for incidental metals and non-metals, it is the product into which those substances are formulated that contains the ingredient, alone or in combination with other ingredients, which must comply with the acceptance criteria set in the United States Pharmacopoeia - National Formulary (USP-NF) general chapter '<2232> Elemental Contaminants in Dietary Supplements'.

Key to abbreviations

BP = British Pharmacopoeia

CFU = Colony forming units

NLT = Not less than

NMT = Not more than

Ph Eur = European Pharmacopoeia

USP = United States Pharmacopoeia

Footnotes