Microbiology worksheet with answers

What does "endemic" mean in epidemiology?

1. AOccurring as a sudden outbreak well above the expected level in an area
2. BConstantly present in a population or region at a usual level
3. CFound only in animals
4. DSpreading quickly across the whole world

Which of these is caused by a virus?

1. AMalaria
2. BInfluenza
3. CTuberculosis
4. DTetanus

Who discovered penicillin in 1928?

1. ALouis Pasteur
2. BRobert Koch
3. CAlexander Fleming
4. DJoseph Lister

Which organism is a common cause of infection in burns and in people with cystic fibrosis, and can produce a green pigment?

1. AHelicobacter pylori
2. BClostridium tetani
3. CPseudomonas aeruginosa
4. DStreptococcus pyogenes

Which bacterium is the most common cause of stomach ulcers?

1. AHelicobacter pylori
2. BClostridioides difficile
3. CStaphylococcus aureus
4. DEscherichia coli

Which statement is one of Koch's postulates?

1. AThe organism must be visible with the naked eye
2. BThe disease must respond to antibiotics
3. CThe organism must be found in healthy people as well
4. DThe organism must cause the same disease when introduced into a healthy susceptible host

Gram-positive cocci are found. Which test quickly separates staphylococci from streptococci?

1. AGrowth on MacConkey agar
2. BThe catalase test
3. CThe acid-fast stain
4. DThe coagulase test

On MacConkey agar, pink colonies grow from a urine sample. What does this tell you?

1. AThe organism does not ferment lactose, so it is probably Salmonella
2. BThe organism is a Gram-positive coccus
3. CThe organism is a fungus
4. DThe organism is probably a Gram-negative rod that ferments lactose