Microbiology worksheet with answers

What is an antigen?

1. AA type of white blood cell
2. BA molecule that the immune system recognises
3. CA protein made by plasma cells to fight infection
4. DA drug that blocks bacterial growth

Which bacterium is the most common cause of urinary tract infections?

1. AStreptococcus pyogenes
2. BEscherichia coli
3. CStaphylococcus aureus
4. DMycobacterium tuberculosis

Which disease has been eradicated worldwide through vaccination?

1. AMeasles
2. BTuberculosis
3. CSmallpox
4. DMalaria

Which infection is a typical complication of broad-spectrum antibiotic use, causing severe diarrhoea?

1. ASalmonella infection
2. BHepatitis A
3. CClostridioides difficile infection
4. DHelicobacter pylori infection

Which laboratory test separates Staphylococcus aureus from most other staphylococci?

1. AThe coagulase test
2. BThe acid-fast stain
3. CThe catalase test
4. DThe Gram stain

Why does high vaccination coverage also protect babies too young to be vaccinated?

1. AFewer people can pass on the infection, so it spreads less
2. BVaccinated people pass antibodies to everyone they meet
3. CBabies are naturally immune to all vaccine-preventable diseases
4. DVaccines kill the pathogen in the environment

Why is Chlamydia trachomatis usually diagnosed with nucleic acid amplification tests instead of routine culture on agar?

1. AIt is an obligate intracellular bacterium that cannot grow on ordinary media
2. BIt dies immediately in the presence of oxygen
3. CIt is too large to grow on agar plates
4. DIt is a virus and has no DNA

What is the key difference between bactericidal and bacteriostatic antibiotics?

1. ABacteriostatic drugs always work faster than bactericidal drugs
2. BBactericidal drugs work only on viruses; bacteriostatic drugs work on bacteria
3. CBactericidal drugs kill bacteria; bacteriostatic drugs stop growth and rely on the immune system to clear them
4. DBactericidal drugs work only outside the body