[Skip to Content](https://www.sigmaaldrich.com#main-content) [![MilliporeSigma](https://www.sigmaaldrich.com/static/logos/purple/millipore_sigma.svg)](https://www.sigmaaldrich.com/US/en) Products Cart0 USEN Products [Login / Register](https://www.sigmaaldrich.com/oidc-sign-in) [Order Lookup](https://www.sigmaaldrich.com/US/en/order-lookup) [Quick Order](https://www.sigmaaldrich.com/US/en/quick-order) Cart0 [Home](https://www.sigmaaldrich.com/US/en)[Microbial Cell Culture](https://www.sigmaaldrich.com/US/en/applications/cell-culture-and-cell-culture-analysis/cell-culture-by-cell-type/microbial-cell-culture)Streptococci - Overview of Detection, Identification, Differentiation and Cultivation Techniques # Streptococci - Overview of Detection, Identification, Differentiation and Cultivation Techniques __Jvo Siegrist__ *AnalytiX Volume 7 Article 3* [[email protected]](mailto:[email protected]) *Streptococci* are non-motile, microaerophilic, Grampositive spherical bacteria (cocci). They often occur as chains or pairs and are facultative or strict anaerobes. *Streptococci* give a negative catalase test, while staphylococci are catalase-positive. The cell division of *Streptococci* species involves two separate biosynthetic events: peripheral cell-wall elongation and septal-wall synthesis.1 Because they are unable to synthesize cytochromes, *Streptococci* cannot carry out oxidative phosphorylation. They are able to ferment sugars, but the end product is always lactic acid. Therefore, *Streptococci* are very acid tolerant and count among the lactic acid bacteria order. There are many natural sources of *Streptococci*, including humans and diverse animals where they often colonize the mucosal surfaces of mouth, intestinal tract, nasal passages and pharynx. The presence of *Streptococci*  in drinking water indicates fecal contamination. Food sources with high risk of *Streptococcal* contamination include milk and dairy products, eggs, steamed lobster, ground ham, potato salad, custard, rice pudding and shrimp salad. In most Streptococcal food poisoning cases, the food was allowed to stand at room temperature for several hours between preparation and consumption. The contamination of the food is most often the result of poor hygiene, handling of the food by infected people, or the use of raw (unpasteurized) milk. Although they can be potent pathogens, some *Streptococci* are commercially important for the production of cheese and yogurt. These include *S. lactis, S. cremoris, S. diacelillactis and S. thermophilus,* the latter being the most well-known. For detection, identification, differentiation, enumeration and cultivation of *Streptococci*, we provide a broad range of specific agars and broths (__Table 1__), *Streptococci* Diagnostic Tests (__Table 2__) and a Gram staining kit and component solutions (__Table 3__). ![Streptococci](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/cell-culture-and-analysis/mammalian-cell-culture/streptococci-1.jpg "Streptococci") ## Scientific classification of *Streptococcus* Kingdom: Eubacteria Phylum: Firmicutes Class: Bacilli Order: Lactobacillales Family: Streptococcaceae Genus: *Streptococcus* ## Grouping of *Streptococci* based on hemolytic activity *Streptococci* are divided into three groups based on their hemolytic (red blood cell lysing) activity. The hemolytic reaction can be visualized on blood agar plates, such as the non-selective Agars for Differentiation that are listed in __Table 1.__ #### Non-selective Enrichment Broths | | | | |----------------------------------------------------------------|---------------|---------------------------------------------| | Cat. No. | Brand | Description | | [53286](https://www.sigmaaldrich.com/US/en/product/sial/53286) | Sigma-Aldrich | Brain Heart Broth | | [B2551](https://www.sigmaaldrich.com/US/en/product/sial/b2551) | Sigma-Aldrich | Brewer thioglycollate medium | | [22089](https://www.sigmaaldrich.com/US/en/product/sial/22089) | Sigma-Aldrich | Casein peptone Lecithin Polysorbate Broth | | [22098](https://www.sigmaaldrich.com/US/en/product/sial/22098) | Sigma-Aldrich | CASO Broth | | [60865](https://www.sigmaaldrich.com/US/en/product/sial/60865) | Sigma-Aldrich | Cooked Meat Broth | | [17123](https://www.sigmaaldrich.com/US/en/product/sial/17123) | Sigma-Aldrich | Elliker Broth | | [5121](https://www.sigmaaldrich.com/US/en/product/sial/05121) | Sigma-Aldrich | Heart Infusion Broth | | [70122](https://www.sigmaaldrich.com/US/en/product/sial/70122) | Sigma-Aldrich | Nutrient Broth No. 1 | | [70149](https://www.sigmaaldrich.com/US/en/product/sial/70149) | Sigma-Aldrich | Nutrient Broth No. 3 | | [40893](https://www.sigmaaldrich.com/US/en/product/sial/40893) | Sigma-Aldrich | Peptone Water, phosphate-buffered, Vegitone | | [70179](https://www.sigmaaldrich.com/US/en/product/sial/70179) | Sigma-Aldrich | Peptone Water | | [77187](https://www.sigmaaldrich.com/US/en/product/sial/77187) | Sigma-Aldrich | Peptone Water, phosphate-buffered | | [S4681](https://www.sigmaaldrich.com/US/en/product/sial/S4681) | Sigma-Aldrich | Standard Nutrient Broth No. 1 | | [85905](https://www.sigmaaldrich.com/US/en/product/sial/85905) | Sigma-Aldrich | Stuart Ringertz Medium | | [90404](https://www.sigmaaldrich.com/US/en/product/sial/90404) | Sigma-Aldrich | Thioglycolate Broth with Resazurine | | [T1438](https://www.sigmaaldrich.com/US/en/product/sial/T1438) | Sigma-Aldrich | Todd Hewitt Broth | | [22092](https://www.sigmaaldrich.com/US/en/product/sial/22092) | Sigma-Aldrich | Tryptic Soy Broth | | [51228](https://www.sigmaaldrich.com/US/en/product/sial/51228) | Sigma-Aldrich | Tryptic Soy Broth No. 2 | | [41298](https://www.sigmaaldrich.com/US/en/product/sial/41298) | Sigma-Aldrich | Tryptic Soy Broth, Vegitone | | [T3938](https://www.sigmaaldrich.com/US/en/product/sial/T3938) | Sigma-Aldrich | Tryptone Soya Broth without Dextrose | | [T4407](https://www.sigmaaldrich.com/US/en/product/sial/T4407) | Sigma-Aldrich | Tryptose Broth | | [V5262](https://www.sigmaaldrich.com/US/en/product/sial/V5262) | Sigma-Aldrich | Veal Infusion Broth | #### Selective Enrichment Broths | | | | |----------------------------------------------------------------|---------------|---------------------| | Cat. No. | Brand | Description | | [17157](https://www.sigmaaldrich.com/US/en/product/sial/17157) | Sigma-Aldrich | Glucose Azide Broth | ### Non-selective Agars for Cultivation, Enumeration and Isolation | | | | |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------|----------------------------------------------------| | Cat. No. | Brand | Description | | [A3340](https://www.sigmaaldrich.com/US/en/product/sial/A3340) | Sigma-Aldrich | AC Agar | | [70138](https://www.sigmaaldrich.com/US/en/product/sial/70138) | Sigma-Aldrich | Brain Heart Infusion Agar | | [22095](https://www.sigmaaldrich.com/US/en/product/sial/22095) | Sigma-Aldrich | CASO Agar | | [27688](https://www.sigmaaldrich.com/US/en/product/sial/27688) | Sigma-Aldrich | Columbia Agar | | [D3060](https://www.sigmaaldrich.com/US/en/product/sial/D3060) | Sigma-Aldrich | Dextrose starch agar | | [D8184](https://www.sigmaaldrich.com/US/en/product/sial/D8184) | Sigma-Aldrich | Diagnostic sensitivity test agar | | [70147](https://www.sigmaaldrich.com/US/en/product/sial/70147) | Sigma-Aldrich | Milk Agar | | [70148](https://www.sigmaaldrich.com/US/en/product/sial/70148) | Sigma-Aldrich | Nutrient Agar | | [17197](https://www.sigmaaldrich.com/US/en/product/sial/17197) | Sigma-Aldrich | Peptonized Milk Agar | | [70152](https://www.sigmaaldrich.com/US/en/product/sial/70152) | Sigma-Aldrich | Plate Count Agar | | [88588](https://www.sigmaaldrich.com/US/en/product/sial/88588) | Sigma-Aldrich | Plate Count Agar according to Buchbinder et al. | | [19718](https://www.sigmaaldrich.com/US/en/product/sial/19718) | Sigma-Aldrich | Plate Count Agar, Vegitone | | [17257](https://www.sigmaaldrich.com/US/en/product/sial/17257) | Sigma-Aldrich | Streptococcus thermophilus Isolation Agar | | [22091](https://www.sigmaaldrich.com/US/en/product/sial/22091) | Sigma-Aldrich | Tryptic Soy Agar | | [14432](https://www.sigmaaldrich.com/US/en/product/sial/14432) | Sigma-Aldrich | Tryptic Soy Agar, Vegitone | | [51414](https://www.sigmaaldrich.com/US/en/product/sial/T1438) | Sigma-Aldrich | Tryptic Soya Agar with Polysorbate 80 and Lecithin | | [70159](https://www.sigmaaldrich.com/product/sial/70159%20/product/sial/70179%20/product/sial/74042%20/product/sial/75482%20/product/sial/77187%20/product/sial/77730%20/product/sial/85905%20/product/sial/87794%20/product/sial/88597%20/product/sial/90107%20/product/sial/90404%20/product/sial/94448%20/product/sial/94635%20/product/sial/97580%20/US/en/product/sial/A3340%20/product/sial/B1676%20/product/sigma/B2551%20/product/sial/D2560%20/US/en/product/sial/D3060%20/US/en/product/sial/D8184%20/product/sial/S4681%20/US/en/product/sial/T1438%20/US/en/product/sial/T1438) | Sigma-Aldrich | Tryptone Glucose Extract Agar | | [T2313](https://www.sigmaaldrich.com/US/en/product/sial/T2313) | Sigma-Aldrich | Tryptose Agar | #### Non-selective Agars for Differentiation | | | | |----------------------------------------------------------------|---------------|-------------------------------------| | Cat. No. | Brand | Description | | [70133](https://www.sigmaaldrich.com/US/en/product/sial/70133) | Sigma-Aldrich | Blood Agar (Base) | | [B1676](https://www.sigmaaldrich.com/US/en/product/sial/B1676) | Sigma-Aldrich | Blood Agar Base No. 2 | | [55420](https://www.sigmaaldrich.com/US/en/product/sial/55420) | Sigma-Aldrich | CLED Agar | | [70136](https://www.sigmaaldrich.com/US/en/product/sial/70136) | Sigma-Aldrich | Deoxyribonuclease Test Agar | | [D2560](https://www.sigmaaldrich.com/US/en/product/sial/D2560) | Sigma-Aldrich | DNase Test Agar with Toluidine Blue | | [17153](https://www.sigmaaldrich.com/US/en/product/sial/17153) | Sigma-Aldrich | LS Differential Agar | #### Selective Agars with Differential System for Differentiation, Detection and Isolation | | | | |----------------------------------------------------------------|---------------|------------------------------| | Cat. No. | Brand | Description | | [06105](https://www.sigmaaldrich.com/US/en/product/sial/06105) | Sigma-Aldrich | Bile Esculin Azide Agar | | [17151](https://www.sigmaaldrich.com/US/en/product/sial/17151) | Sigma-Aldrich | Kanamycin Esculin Azide Agar | | [01337](https://www.sigmaaldrich.com/US/en/product/sial/01337) | Sigma-Aldrich | Mitis Salivarius Agar | #### Media for Sensitivity Testing | | | | |----------------------------------------------------------------|---------------|-----------------------| | Cat. No. | Brand | Description | | [97580](https://www.sigmaaldrich.com/US/en/product/sial/97580) | Sigma-Aldrich | Mueller-Hinton Agar 2 | Table 1Media for Streptococci ## Alpha-Hemolytic *Streptococci* In alpha hemolysis, the red blood cells remain intact, but the hemoglobin is converted to biliverdin. This causes dark greening of the blood agar plate around the colonies. - *Pneumococci* *S. pneumoniae*: Causes bacterial pneumonia, otitis media and meningitis. *S. pneumoniae* sensitivity to optochin (ethyl hydrocupreine hydrochloride) is the basis of a diagnostic test (__Figure 1, Table 2__). ![Pneumococci](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/technical-documents/articles/cell-culture-and-analysis/mammalian-cell-culture/alpha-hemolytic-streptococci.jpg "Pneumococci") __Figure 1.__Differentiation and identification flow chart of Gram-positive cocci | | | | |----------------------------------------------------------------|---------------|------------------| | Cat. No. | Brand | Description | | [88597](https://www.sigmaaldrich.com/US/en/product/sial/88597) | Sigma-Aldrich | Catalase Test | | [08382](https://www.sigmaaldrich.com/US/en/product/sial/08382) | Sigma-Aldrich | Bacitracin Disks | | [74042](https://www.sigmaaldrich.com/US/en/product/sial/74042) | Sigma-Aldrich | Optochin Disks | | [67886](https://www.sigmaaldrich.com/US/en/product/sial/67886) | Sigma-Aldrich | PYRase Strips | Table 2Diagnostic tests for identification and differentiation of streptococci - Viridans and Others *S. mutans:* Associated with dental caries. *S. viridans:* Causative agent for endocarditis and dental abscesses. *S. salivarius:* Considered to be an opportunistic pathogen. *S. salivarius subsp. thermophilus:* Used in the production of cheese and yogurt. ## Beta-Hemolytic *Streptococci* Beta hemolysis is a complete hemolysis of erythrocytes by the enzyme hemolysin. Clear zones will appear around the colonies on the blood agar plate. Beta-hemolytic *Streptococci* are further divided into serological groups using specific antibodies that recognize surface carbohydrate antigens (e.g. A, B, etc.). - Group A *S. pyogenes:* Causes infections like strep throat, acute rheumatic fever, scarlet fever, acute glomerulonephritis and necrotizing fasciitis. It is sensitive to bacitracin (Fig. 1), a fact that is employed in a *Streptococcus* diagnostic test (Table 2). Other *Streptococci* species may also possess the Group A antigen but are not human pathogens. These include *S. dysgalactiae subsp. equisimilis* and *S. anginosus strains.* - Group B *S. agalactiae:* Causes meningitis in neonates and the elderly. Occasionally colonizing the female reproductive tract, they increase the risk for premature rupture of membranes and transmission of the infection to the child. - Group C *S. equi:* Causes strangles infection in horses. *S. zooepidemicus:* Causes infections in cattle, horses and other mammals. - Group D (Enterococci) Many former Group D *Streptococci* have been reclassified to the genus Enterococcus (*e.g. S. faecalis, S. faciem, S. durans, S avium*). *S. bovis and S. suis:* Still in the Group D *streptococci*. ## Non-Hemolytic or Gamma-Hemolytic *Streptococci* Gamma hemolysis is a misnomer as there is actually no hemolysis. Non-hemolytic or gamma-hemolytic *Streptococci* rarely cause disease. | | | | |----------------------------------------------------------------|---------------|--------------------------------| | Cat. No. | Brand | Description | | [77730](https://www.sigmaaldrich.com/US/en/product/sial/77730) | Sigma-Aldrich | Gram Staining Kit | | [94448](https://www.sigmaaldrich.com/US/en/product/sial/94448) | Sigma-Aldrich | Gram‘s Crystal violet Solution | | [75482](https://www.sigmaaldrich.com/US/en/product/sial/75482) | Sigma-Aldrich | Gram‘s Decolorizer Solution | | [87794](https://www.sigmaaldrich.com/US/en/product/sial/87794) | Sigma-Aldrich | Gram’s Fuchsin Solution | | [90107](https://www.sigmaaldrich.com/US/en/product/sial/90107) | Sigma-Aldrich | Gram‘s Iodine Solution | | [94635](https://www.sigmaaldrich.com/US/en/product/sial/94635) | Sigma-Aldrich | Gram‘s Safranin Solution | Table 3Gram staining kit and component solutions ## Materials Sorry, an unexpected error has occurred Response not successful: Received status code 500 ### References 1\. Beilharz K, Novakova L, Fadda D, Branny P, Massidda O, Veening J. 2012. Control of cell division in Streptococcus pneumoniae by the conserved Ser/Thr protein kinase StkP. Proceedings of the National Academy of Sciences. 109(15):E905-E913. [https://doi.org/10.1073/pnas.1119172109](https://doi.org/10.1073/pnas.1119172109) __Related Articles__ - [Introduction to Microbial Media](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/cell-culture-and-cell-culture-analysis/microbial-cell-culture/microbial-media) - [Virus Cultivation](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/cell-culture-and-cell-culture-analysis/microbial-cell-culture/virus-cultivation) - [Yeast and Molds in Food and Beverages](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/cell-culture-and-cell-culture-analysis/microbial-cell-culture/yeasts) - [Microbial Detection Using Chromogenic and Fluorogenic Culture Media](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/clinical-testing-and-diagnostics-manufacturing/bacteriology/overview-chromogenic-media) - [Media for Staphylococcus Aureus Detection](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/clinical-testing-and-diagnostics-manufacturing/bacteriology/staphylococcus-aureus) - [Identification of Microorganisms Based on Color](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/clinical-testing-and-diagnostics-manufacturing/cytology-and-microscopy/color-identification-microorganisms) - [EN ISO 11133 Microbiological Culture Media](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/food-and-beverage-testing-and-manufacturing/microbiological-analysis-for-food-and-beverage/en-iso-11133-water-for-the-preparation-and-performance-testing) - [ISO 11133:2014 Quality Culture Media for Food and Water Testing](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/food-and-beverage-testing-and-manufacturing/regulatory-compliance-for-food-and-beverage/iso-11133-culture-media-food-and-water-testing) - [View More](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) __Related Product Categories__ - [Microbial Culture Media](https://www.sigmaaldrich.com/US/en/products/industrial-microbiology/microbial-culture-media) - [Molecular Cloning & Protein Expression](https://www.sigmaaldrich.com/US/en/products/molecular-biology-and-functional-genomics/cloning-and-expression/molecular-cloning-and-protein-expression) Top __Sign In To Continue__ To continue reading please sign in or create an account. Sign In__Don't Have An Account?__Register An unknown error has occured. - English - EN - Español - ES [Learn More](https://www.sigmaaldrich.com)