streptococcus

American  

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

noun

Bacteriology.

streptococci plural

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 /

streptococci plural

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

"High numbers of scarlet fever, which is caused by group A streptococcus, also continue to be reported."

From BBC • Jan. 2, 2023

Some U.S. hospitals and European health authorities also report out-of-season increases in scarlet fever and Group A streptococcus infections.

From Washington Post • Dec. 15, 2022

The disease is due to a specific streptococcus—the streptococcus of Fehleisen.

From Essentials of Diseases of the Skin Including the Syphilodermata Arranged in the Form of Questions and Answers Prepared Especially for Students of Medicine by Stelwagon, Henry Weightman