Streptococcus
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40 free Streptococcus trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Strep A is the everyday name for group A Streptococcus, the bacterium behind strep throat and a surprising list of other illnesses, some mild and some life-threatening. Its wider family is just as interesting: some relatives live quietly in the mouth and gut, some trouble farm animals, and a few help make the food in your fridge. This quiz covers the whole genus. You will meet the symptoms doctors look for in a sore throat, the complications that can follow an untreated infection, the lab tests that tell these bacteria from their look-alikes, and the scientists who named and classified them. A few famous patients and classic novels turn up along the way. It is written for curious players, students revising microbiology or nursing, and anyone who has ever waited on a throat swab result. Every answer comes with a short explanation, so you will leave knowing more than when you started.
30 of 40 questions with answers and explanations. Play the quiz
Q 01Which group A strep disease strikes Beth March in Little Women and the boy in The Velveteen Rabbit?
Scarlet fever
Scarlet fever was a leading cause of death in children in the early 20th century, which is why it haunts so many classic stories.
Q 02Group A strep is one cause of necrotizing fasciitis, a rare infection better known by which grim nickname?
Flesh-eating disease
Flesh-eating disease is a misnomer: the bacteria do not eat tissue but release toxins that kill it, making it a surgical emergency.
Q 03Which entertainer died in May 1990 of toxic shock syndrome caused by a group A streptococcal infection?
Jim Henson
Jim Henson, creator of the Muppets, was 53; his doctor said he might have been saved had he reached hospital a few hours sooner.
Q 04Streptococcus mutans, a bacterium that thrives in the mouth, is a major contributor to which common health problem?
Tooth decay
Tooth decay sets in because the bacterium turns sucrose into acid that erodes the enamel.
Q 05Streptococcus thermophilus, a harmless cousin of the strep throat germ, is a standard starter culture for which food?
Yogurt
Yogurt is made by keeping warm milk for hours with this species and Lactobacillus bulgaricus, which sour and thicken it together.
Q 06Group A strep has never developed resistance to which antibiotic, still a first-choice treatment for strep throat?
Penicillin
Penicillin still works against every strain, whereas some have become resistant to macrolides, tetracyclines and clindamycin.
Q 07A defence system that Streptococcus pyogenes uses against invaders was adapted in 2012 into which laboratory tool?
CRISPR gene editing
CRISPR gene editing relies on the bacterium's Cas9 protein as programmable scissors, work that won the 2020 Nobel Prize in Chemistry.
Q 08A group A strep infection can leave a child's tongue red and bumpy, a sign doctors name after which fruit?
Strawberry
Strawberry tongue begins with a white coating that sheds after four or five days, leaving the swollen red surface behind.
Q 09Which symptom, typical of an ordinary cold, usually points away from strep throat when a doctor checks a sore throat?
Cough
Cough is so unusual in strep throat that its absence scores a point on the Centor criteria doctors use to decide who needs a test.
Q 10Staphylococci, the cluster-forming look-alikes of streptococci, are named after the Greek for a bunch of which fruit?
Grapes
Grapes inspired the name because these bacteria pile up in bunches; the Scottish surgeon Alexander Ogston coined it after finding them in abscess pus.
Q 11Which inflammatory disease can follow untreated strep throat by a few weeks and permanently damage the heart valves?
Rheumatic fever
Rheumatic fever is the immune system's doing, not the bacteria's: antibodies made against strep mistakenly attack the body's own tissue.
Q 12Which contagious skin infection of young children, known for its honey-coloured crusts, can be caused by group A strep?
Impetigo
Impetigo is most common between the ages of two and five and spreads easily through schools and day care.
Q 13Group B strep, carried harmlessly by many healthy women, is a leading cause of serious infection in which group?
Newborn babies
Q 21The 'strepto' in Streptococcus, a name coined in 1877, comes from an Ancient Greek word with which meaning?
Twisted
Twisted was joined to kokkos, the Greek for grain, to describe how the growing cells looked under the microscope.
Q 22The 'pyogenes' in Streptococcus pyogenes comes from Greek words meaning that the bacterium forms which substance?
Pus
Pus gave the species its name because so many of its infections, from sore throats to skin sores, produce it.
Q 23In 1944, Oswald Avery's team used pneumococcus bacteria to show which molecule carries hereditary information?
DNA
DNA was a surprise: most scientists of the day believed that proteins carried genetic information.
Newborn babies can pick it up during birth, so US guidelines call for testing late in pregnancy and antibiotics during labour for carriers.
Q 14Strep throat typically brings a fever, a sore throat and which red, swollen structures at the back of the mouth?
Tonsils
Tonsils often carry white patches in strep throat, and the lymph nodes at the front of the neck usually swell as well.
Q 15Under the microscope, the round cells of streptococci are typically arranged in which pattern?
Chains
Chains form because each cell divides along a single axis and the daughters stay attached, like beads on a necklace.
Q 16Strep throat, which peaks in late winter and early spring, spreads between people mainly by which route?
Respiratory droplets
Respiratory droplets from talking or sneezing carry the bacteria, and touching a contaminated surface and then the mouth, nose or eyes can spread them too.
Q 17Strep throat is the best-known bacterial sore throat, but most sore throats are caused by what?
Viruses
Viruses are behind most sore throats; group A strep accounts for only 5–15% of them in adults, which is why doctors test before prescribing.
Q 18Strangles, a streptococcal disease named for the swollen glands that can block the airway, affects which animals?
Horses
Horses pass it on through shared troughs, brushes and tack, and a recovered animal can remain a long-term carrier.
Q 19Streptococci are gram-positive bacteria, which means they hold which colour after the Gram stain is applied?
Purple
Purple comes from crystal violet dye trapped in the thick cell wall; gram-negative bacteria lose it and are counterstained pink.
Q 20Besides pneumonia, Streptococcus pneumoniae is a leading bacterial cause of which common childhood complaint?
Middle ear infection
Middle ear infection, or otitis media, is among the milder illnesses this bacterium causes, alongside pink eye and sinusitis.
Q 24Which 19th-century doctor cut deaths from childbed fever, often a strep infection, by making staff wash their hands?
Ignaz Semmelweis
Ignaz Semmelweis cut maternal deaths in his clinic from 18% to under 2%, yet some doctors mocked the idea that their hands were to blame.
Q 25Post-streptococcal glomerulonephritis, a delayed complication of strep infections, is an inflammation of which organs?
Kidneys
Kidneys become inflamed a week or more after the infection, the time the body needs to raise the antibodies involved.
Q 26Viridans streptococci take their name from the Latin for which colour, the tint that appears around their colonies?
Green
Green gave these mouth-dwelling bacteria their name; they are mostly harmless but can infect heart valves if they reach the bloodstream.
Q 27Streptococci are classed as alpha, beta or gamma by how fully they destroy which ingredient of their growth medium?
Red blood cells
Red blood cells are burst completely by beta types such as group A strep, leaving a clear ring around each colony.
Q 28Streptokinase, an enzyme first obtained from streptococci, is given as an emergency medicine to do what?
Dissolve clots
To dissolve clots, it switches on the body's own clot-busting system, and it is used after some heart attacks and pulmonary embolisms.
Q 29Which American microbiologist sorted streptococci into the lettered groups, such as A and B, that doctors still use?
Rebecca Lancefield
Rebecca Lancefield's lab was nicknamed the Scotland Yard of streptococcal mysteries because she so willingly answered other scientists' questions.
Q 30Sydenham's chorea, a nervous disorder that can follow a group A strep infection, has which historical name?
St. Vitus' dance
St. Vitus' dance recalls the patron saint of dancers, before whose statue crowds once danced wildly on his feast day.