Microbiology

Question 1

Why is microbiology important in pharmacy?

Answer 1

It underpins understanding of infections, medication safety, antibiotic use, vaccine development, and contamination prevention in healthcare and pharmaceutical practice.

Question 2

Give examples of positive uses of microbes in pharmacy.

Answer 2

Production of antibiotics (e.g. penicillin), insulin, vaccines, and their role in mutagenicity testing (e.g. Ames test).

Question 3

What were the earliest theories of disease?

Answer 3

Demonic theory, punitive theory (by gods), and miasma theory (bad air).

Question 4

Who disproved spontaneous generation and how?

Answer 4

Louis Pasteur, using the swan-neck flask experiment.

Question 5

What are Koch’s postulates?

Answer 5

Criteria proving a specific microbe causes a specific disease.

Question 6

How are microorganisms classified?

Answer 6

Non-cellular (prions, viruses), prokaryotes (bacteria), eukaryotes (fungi, protozoa).

Question 7

What are prions?

Answer 7

Infectious misfolded proteins that induce misfolding in others; cause neurodegenerative diseases and are heat-stable.

Question 8

What are viruses composed of?

Answer 8

DNA or RNA enclosed in a protein capsid; sometimes an envelope.

Question 9

List the steps of the viral infection cycle.

Answer 9

Attachment, entry, replication, assembly, and release.

Question 10

What are the three patterns of viral infection?

Answer 10

Acute, latent/reactivating, and chronic.

Question 11

Define viral tropism.

Answer 11

Specificity of a virus for a particular host, tissue, or cell type.

Question 12

What distinguishes Gram-positive and Gram-negative bacteria?

Answer 12

Gram-positive have thick PGN and retain crystal violet; Gram-negative have thin PGN, outer membrane, and LPS.

Question 13

What are the functions of bacterial capsules?

Answer 13

Prevent phagocytosis and desiccation.

Question 14

What are endospores?

Answer 14

Dormant, resistant bacterial forms that survive harsh conditions (e.g., Clostridium).

Question 15

What is the composition of peptidoglycan?

Answer 15

Alternating NAG-NAM sugars crosslinked by peptides, with β-1,4 linkages.

Question 16

What are the components of LPS?

Answer 16

Lipid A (toxic), core polysaccharide, and variable O-antigen.

Question 17

Why is LPS clinically significant?

Answer 17

It acts as an endotoxin, triggering immune responses like fever and inflammation.

Question 18

What is the role of bacterial flagella?

Answer 18

Motility.

Question 19

What is the role of pili and fimbriae?

Answer 19

Pili: gene transfer (conjugation); fimbriae: adherence to surfaces.

Question 20

What are key features of Mycobacteria?

Answer 20

Waxy mycolic acid-rich walls, acid-fast, cause TB and leprosy.

Question 21

Describe the Chlamydia life cycle.

Answer 21

Infectious elementary bodies enter cells, become reticulate bodies to replicate.

Question 22

What is unique about Mycoplasma?

Answer 22

No cell wall, highly pleomorphic.

Question 23

What is characteristic of Rickettsia?

Answer 23

Gram-negative intracellular bacteria with peptidoglycan.

Question 24

What are the two main forms of fungi?

Answer 24

Yeasts (unicellular) and moulds (filamentous).

Question 25

What is the fungal cell wall made of?

Answer 25

Chitin.

Question 26

What are protozoa?

Answer 26

Single-celled eukaryotes without a cell wall, classified by movement type.

Question 27

Give examples of protozoa in the oral cavity.

Answer 27

Entamoeba gingivalis, Trichomonas tenax.

Question 28

What size range are bacteria and viruses?

Answer 28

Bacteria: 0.2–8 µm; Viruses: 20–300 nm.

Question 29

What is the resolution limit of a light microscope?

Answer 29

Approximately 0.2 µm.

Question 30

List benefits of the normal microbiota.

Answer 30

Colonisation resistance, vitamin production, immune stimulation.

Question 31

What is the impact of antibiotics on microbiota?

Answer 31

Can lead to dysbiosis, e.g. C. difficile overgrowth.

Question 32

Where is Staphylococcus epidermidis commonly found?

Answer 32

Skin.

Question 33

Which microbe dominates the vaginal microbiota?

Answer 33

Lactobacillus.

Question 34

Name common gut microbiota.

Answer 34

Bacteroides, E. coli, Clostridium spp.

Question 35

What is colonisation?

Answer 35

Presence of microbes without tissue damage or symptoms.

Question 36

What is infection?

Answer 36

Invasion and multiplication of microbes causing tissue damage and symptoms.

Question 37

What are the key stages of infection?

Answer 37

Reservoir → transmission → adherence → immune evasion → replication → damage → exit.

Question 38

How do microbes evade immune responses?

Answer 38

Capsule formation, antigenic variation, intracellular hiding.

Question 39

What bacterial feature allows evasion from phagocytosis?

Answer 39

Capsule.

Question 40

Why are bacterial spores clinically significant?

Answer 40

They are highly resistant and can contaminate medical equipment.

Question 41

Name two genera that produce endospores.

Answer 41

Bacillus and Clostridium.