streptococcus

American  

[strep-tuh-kok-uhs] / ˌstrɛp təˈkɒk əs /

noun

Bacteriology.

plural

streptococci

1. any of several spherical or oval bacteria of the genus Streptococcus, occurring in pairs or chains, certain species of which are pathogenic for humans, causing scarlet fever, tonsillitis, etc.

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streptococcus British  

/ ˌstrɛptəʊˈkɒkəl, -ˈkɒksɪk, ˌstrɛptəʊˈkɒkəs, ˌstrɛptəʊˈkɒkɪk /

noun

1. Often shortened to: strep.  any Gram-positive spherical bacterium of the genus Streptococcus, typically occurring in chains and including many pathogenic species, such as S. pyogenes, which causes scarlet fever, sore throat, etc: family Lactobacillaceae

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streptococcus Scientific  

/ strĕp′tə-kŏk′əs /

plural

streptococci

1. Any of various bacteria of the genus Streptococcus that are gram-positive cocci and are normally found on the skin and mucous membranes and in the digestive tract of mammals. One type of streptococcus, Group A, is a common pathogen in humans and causes various infections, including strep throat, scarlet fever, pneumonia, and some types of impetigo.

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streptococcus Cultural  

1. A category of bacteria that can cause various infections in humans, including scarlet fever and strep throat.

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Other Word Forms

• streptococcal
  adjective
• streptococcic
  adjective

Etymology

Origin of streptococcus

From New Latin, dating back to 1875–80; see origin at strepto-, coccus

Example Sentences

A jury inquest which concluded on 8 October 2025 found the medical cause of death to be an "invasive streptococcus pyogenes infection following male circumcision".

From BBC • Jan. 2, 2026

And she decides that the bacteria she’s going to target with her vaccine is hemolytic streptococcus, which had been showing up again and again in flu patients.

From Scientific American • Oct. 19, 2023

Deliveries of antibiotics for the treatment of group A streptococcus infection are being sped up to reach wholesalers and pharmacies across Northern Ireland in the coming days.

From BBC • Dec. 11, 2022

Group A streptococcus is highly contagious and spreads through close contact with an infected person.

From New York Times • Dec. 6, 2022

Contrary to what one would expect in an organism existing in keffir grains, this streptococcus is as little able to withstand desiccation as the above-mentioned yeast.

From The Bacillus of Long Life a manual of the preparation and souring of milk for dietary purposes, together with and historical account of the use of fermente by Douglas, Loudon