Penicillins kill bacteria by:

Blocking bacterial cell wall synthesis

Blocking bacterial folic acid synthesis

Blocking bacterial protein synthesis

Paracetamol lowers fever mainly by:

Blocking prostaglandin synthesis in the brain

Blocking histamine release from mast cells

Increasing sweating through cholinergic action

Killing the organisms that cause the fever

On day 3 of a 7-day amoxicillin course, a patient says his fever has gone and he plans to stop the tablets. What is the nurse's best response?

Advise him to finish the course as prescribed

Advise him to take half doses from now on

Advise him to stop and keep the rest for later

Advise him to stop and restart if fever returns

Microbiology and applied pharmacology

35 Staff nurse recruitment practice questions on Microbiology and applied pharmacology, part of Basic Sciences. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
In a patient on long-term morphine, tolerance develops to most effects but does not develop to:
1. ARespiratory depression
2. BConstipation
3. CSedation
4. DNausea
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Answer: B · Constipation
With regular opioid use, tolerance develops to sedation, nausea, euphoria and respiratory depression. Little or no tolerance develops to constipation and miosis. So constipation persists for as long as the drug is taken. A regular laxative is therefore started with the first regular dose.
- A: Tolerance to respiratory depression does develop over time.
- C: Sedation usually wears off after the first days.
- D: Nausea usually settles with continued use.
Question 2 · Easy
Penicillins kill bacteria by:
1. ABlocking bacterial folic acid synthesis
2. BBlocking bacterial cell wall synthesis
3. CBlocking bacterial protein synthesis
4. DBlocking bacterial DNA gyrase
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Answer: B · Blocking bacterial cell wall synthesis
Penicillins are beta-lactams that bind penicillin-binding proteins and stop the cross-linking of peptidoglycan. The weakened wall bursts as the bacterium grows, so they are bactericidal. Human cells have no cell wall, which makes penicillins safe apart from allergy. Cephalosporins act in the same way.
- A: Folate synthesis is blocked by sulfonamides and trimethoprim.
- C: Protein synthesis is blocked by aminoglycosides and tetracyclines.
- D: DNA gyrase is the target of fluoroquinolones.
Question 3 · Easy
Which antibiotic is bacteriostatic rather than bactericidal?
1. AGentamicin
2. BPenicillin
3. CCiprofloxacin
4. DTetracycline
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Answer: D · Tetracycline
Bacteriostatic drugs stop bacteria multiplying and rely on host defences to clear the infection. Tetracyclines, sulfonamides, chloramphenicol and macrolides are mainly bacteriostatic. Penicillins, aminoglycosides and fluoroquinolones kill bacteria directly. Bactericidal drugs are preferred in endocarditis and in immunosuppressed patients.
- A: Gentamicin is bactericidal by faulty protein synthesis.
- B: Penicillin is bactericidal by breaking the cell wall.
- C: Ciprofloxacin is bactericidal by blocking DNA gyrase.
Question 4 · Easy
Paracetamol lowers fever mainly by:
1. ABlocking histamine release from mast cells
2. BIncreasing sweating through cholinergic action
3. CBlocking prostaglandin synthesis in the brain
4. DKilling the organisms that cause the fever
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Answer: C · Blocking prostaglandin synthesis in the brain
Fever is driven by prostaglandin E2 acting on the hypothalamic temperature centre. Paracetamol inhibits cyclo-oxygenase mainly in the brain, resetting the set point towards normal. It has little anti-inflammatory action in the tissues and does not irritate the stomach. It does not treat the cause of the fever.
- A: Blocking histamine is the action of antihistamines.
- B: Paracetamol has no cholinergic action.
- D: Paracetamol has no antimicrobial effect.
Question 5 · Medium
On day 3 of a 7-day amoxicillin course, a patient says his fever has gone and he plans to stop the tablets. What is the nurse's best response?
1. AAdvise him to take half doses from now on
2. BAdvise him to stop and keep the rest for later
3. CAdvise him to stop and restart if fever returns
4. DAdvise him to finish the course as prescribed
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Answer: D · Advise him to finish the course as prescribed
Feeling better does not mean all the bacteria have been cleared. Stopping early can allow relapse and favours the survival of resistant organisms. The patient should take the course as prescribed unless the doctor changes it. Saved tablets also lead to unsupervised self-treatment later.
- A: Half doses give low levels that select resistant bacteria.
- B: Leftover antibiotics encourage self-medication and resistance.
- C: Stopping and restarting risks relapse and resistance.
Question 6 · Easy
Codeine relieves pain mainly after the liver converts part of it into:
1. AMorphine
2. BNaloxone
3. CPethidine
4. DParacetamol
Answer and explanation in LearnFree account
Question 7 · Hard
A urine sample for culture was left on the ward bench for 5 hours before dispatch. The report reads: mixed growth of three organisms, each about 10^4 CFU/mL. The patient is afebrile. What should the nurse do?
1. AStart antibiotics against all three organisms
2. BSend a fresh midstream sample promptly
3. CReport a severe mixed urinary infection
4. DAsk the laboratory to re-culture the same sample
Answer and explanation in LearnFree account
Question 8 · Hard
A patient's drug chart reads 'Allergy: penicillin, anaphylaxis'. New orders: ampicillin 1 g IV 6-hourly, metronidazole 500 mg IV 8-hourly, paracetamol 1 g IV 6-hourly, pantoprazole 40 mg IV daily. Which order should the nurse withhold and clarify first?
1. AParacetamol
2. BPantoprazole
3. CAmpicillin
4. DMetronidazole
Answer and explanation in LearnFree account
Question 9 · Medium
A boy with a deep, bleeding dog bite on the leg gets rabies vaccine and rabies immunoglobulin into the wound on the same day. Why is the immunoglobulin needed?
1. AIt gives lifelong active immunity against rabies
2. BIt neutralises virus before vaccine antibodies form
3. CIt kills the bacteria that usually infect bite wounds
4. DIt makes the later vaccine doses unnecessary
Answer and explanation in LearnFree account
Question 10 · Medium
A patient on co-trimoxazole is told to drink plenty of fluids mainly to prevent:
1. AConstipation
2. BOral thrush
3. CCrystals forming in the urine
4. DLow serum potassium
Answer and explanation in LearnFree account
Question 11 · Easy
Ringworm (tinea) of the skin is caused by:
1. AA spirochaete bacterium
2. BA herpes group virus
3. CA dermatophyte fungus
4. DA parasitic roundworm
Answer and explanation in LearnFree account
Question 12 · Easy
Ondansetron is mainly given to:
1. APrevent nausea and vomiting
2. BTreat constipation
3. CRelieve severe pain
4. DReduce gastric acid secretion
Answer and explanation in LearnFree account
Question 13 · Easy
Pantoprazole and omeprazole reduce gastric acid by blocking the:
1. AMuscarinic receptor
2. BHistamine H2 receptor on parietal cells
3. CGastrin receptor
4. DProton pump (H+/K+ ATPase)
Answer and explanation in LearnFree account
Question 14 · Hard
Vancomycin 1 g in 250 mL of normal saline is ordered to run over 2 hours by infusion pump. At what rate should the pump be set?
1. A83 mL/hour
2. B500 mL/hour
3. C125 mL/hour
4. D250 mL/hour
Answer and explanation in LearnFree account
Question 15 · Medium
Gentamicin is given by injection rather than by mouth for systemic infections because it:
1. AIs too bitter to swallow
2. BCauses severe vomiting orally
3. CIs poorly absorbed from the gut
4. DIs destroyed by stomach acid
Answer and explanation in LearnFree account
Question 16 · Medium
A patient prescribed oral ciprofloxacin also takes an aluminium-magnesium antacid for heartburn. What should the nurse advise?
1. ATake both together so the stomach is protected
2. BTake ciprofloxacin with a glass of milk instead
3. CTake ciprofloxacin 2 hours before the antacid
4. DStop ciprofloxacin whenever heartburn occurs
Answer and explanation in LearnFree account
Question 17 · Easy
Atropine is sometimes given before general anaesthesia to:
1. AProduce amnesia for the whole operation
2. BReduce salivary and airway secretions
3. CRelax the skeletal muscles
4. DRelieve postoperative pain
Answer and explanation in LearnFree account
Question 18 · Medium
For a stool culture in suspected bacillary dysentery, the nurse should send:
1. AStool taken from the bedpan after disinfectant was added
2. BStool from a nappy collected and kept since the morning
3. CStool mixed with urine to give a larger amount
4. DFresh stool with any mucus, in a sterile pot
Answer and explanation in LearnFree account
Question 19 · Easy
Tetanus toxoid used for immunisation is:
1. AA live, weakened strain of the bacterium
2. BReady-made antibodies against the tetanus toxin
3. CKilled whole bacteria in a suspension
4. DA toxin made harmless but still antigenic
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Question 20 · Medium
When should a blood smear for malaria parasites be collected from a patient with fever?
1. AOnly after the fever has fully settled
2. BAt once, before any antimalarial is given
3. CAfter the first dose of antimalarial is given
4. DOnly after fever has persisted for three days
Answer and explanation in LearnFree account
Question 21 · Medium
Repeated doses of pethidine are avoided, especially in renal failure, because its metabolite norpethidine can cause:
1. AHearing loss
2. BYellow-tinted vision
3. CTremors and seizures
4. DLow blood glucose levels
Answer and explanation in LearnFree account
Question 22 · Medium
When the surgeon advises stopping low-dose aspirin about a week before an elective operation, why must it be stopped that early?
1. AIt prolongs the INR for several days
2. BIt lowers the platelet count for a week
3. CIt irreversibly blocks platelet COX
4. DIt inactivates vitamin K in the liver
Answer and explanation in LearnFree account
Question 23 · Medium
After ten days of a broad-spectrum antibiotic, a patient develops white, curd-like patches in the mouth. Why does this happen?
1. AIt is an allergic reaction to the drug
2. BThe drug directly burns the oral mucosa
3. CInfection has spread from another patient
4. DNormal flora is suppressed and Candida overgrows
Answer and explanation in LearnFree account
Question 24 · Medium
A serious wound infection is caused by methicillin-resistant Staphylococcus aureus (MRSA). The drug most often used IV for it is:
1. AAmoxicillin-clavulanate
2. BCloxacillin
3. CVancomycin
4. DCeftriaxone
Answer and explanation in LearnFree account
Question 25 · Medium
A young adult with fever, sore throat and enlarged neck nodes is given amoxicillin and two days later has a widespread maculopapular rash. This reaction is most typical of infection with:
1. AEpstein-Barr virus
2. BStreptococcus pyogenes
3. CMeasles virus
4. DVaricella-zoster virus
Answer and explanation in LearnFree account

10 more Microbiology and applied pharmacology questions

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Microbiology and applied pharmacology

In a patient on long-term morphine, tolerance develops to most effects but does not develop to:

Penicillins kill bacteria by:

Which antibiotic is bacteriostatic rather than bactericidal?

Paracetamol lowers fever mainly by:

On day 3 of a 7-day amoxicillin course, a patient says his fever has gone and he plans to stop the tablets. What is the nurse's best response?

Codeine relieves pain mainly after the liver converts part of it into:

A urine sample for culture was left on the ward bench for 5 hours before dispatch. The report reads: mixed growth of three organisms, each about 10^4 CFU/mL. The patient is afebrile. What should the nurse do?

A patient's drug chart reads 'Allergy: penicillin, anaphylaxis'. New orders: ampicillin 1 g IV 6-hourly, metronidazole 500 mg IV 8-hourly, paracetamol 1 g IV 6-hourly, pantoprazole 40 mg IV daily. Which order should the nurse withhold and clarify first?

A boy with a deep, bleeding dog bite on the leg gets rabies vaccine and rabies immunoglobulin into the wound on the same day. Why is the immunoglobulin needed?

A patient on co-trimoxazole is told to drink plenty of fluids mainly to prevent:

Ringworm (tinea) of the skin is caused by:

Ondansetron is mainly given to:

Pantoprazole and omeprazole reduce gastric acid by blocking the:

Vancomycin 1 g in 250 mL of normal saline is ordered to run over 2 hours by infusion pump. At what rate should the pump be set?

Gentamicin is given by injection rather than by mouth for systemic infections because it:

A patient prescribed oral ciprofloxacin also takes an aluminium-magnesium antacid for heartburn. What should the nurse advise?

Atropine is sometimes given before general anaesthesia to:

For a stool culture in suspected bacillary dysentery, the nurse should send:

Tetanus toxoid used for immunisation is:

When should a blood smear for malaria parasites be collected from a patient with fever?

Repeated doses of pethidine are avoided, especially in renal failure, because its metabolite norpethidine can cause:

When the surgeon advises stopping low-dose aspirin about a week before an elective operation, why must it be stopped that early?

After ten days of a broad-spectrum antibiotic, a patient develops white, curd-like patches in the mouth. Why does this happen?

A serious wound infection is caused by methicillin-resistant Staphylococcus aureus (MRSA). The drug most often used IV for it is:

A young adult with fever, sore throat and enlarged neck nodes is given amoxicillin and two days later has a widespread maculopapular rash. This reaction is most typical of infection with: