1. Intro to microbes

Question 1

What is commonly reported on an FCB in relation to infection?

Answer 1

WBC and neutrophils. Lymphocytes also relevant

Question 2

What type of infection would neutrophils be increased or decreased in?

Answer 2

Bacterial

Question 3

What type of infection would lymphocytes be increased or decreased in?

Answer 3

Viral

Question 4

What are the 4 main structural components of a virus?

Answer 4

Spikes
Envelope (not present in all)
Protein coat
Nucleic acid (single or double stranded DNA or RNA)

Question 5

What is a bacteriophage?

Answer 5

A virus that infects and replicated in a bacterium

Question 6

What are bacteriophages composed of?

Answer 6

Composed of proteins that encapsulate DNA or RNA. Made of a head, collar, and tail with long tail fibres and a base plate

Question 7

What are the main structural components of a bacterium?

Answer 7

Pili
Flagellum
Polysaccharide capsule
Peptidoglycan cell wall
Plasma membrane
Cytoplasm
Ribosomes
Plasmids
Nucleoid (circular DNA)

Question 8

what are the 3 main bacterial shapes?

Answer 8

Coccus
Spirillus
Bacillus (rods)

Question 9

What are the two arrangements of cocci?

Answer 9

Clusters

Chains

Question 10

What colour is gram positive bacteria, and what layer retains some of the stain?

Answer 10

Purple

The thick peptidoglycan cell wall

Question 11

What colour does gram negative bacteria stain? What causes the stain to wash off?

Answer 11

Pink
Thin peptidoglycan cell wall, due to presence of a second outer lipid membrane, this is an outer membrane with a lipopolysaccharide layer

Question 12

What does obligate mean? Eg obligate aerobes or anaerobes?

Answer 12

Requires. So requires oxygen or oxygen-free environment for survival

Question 13

What is a spore?

Answer 13

Bacteria in an inactive form. Can survive very high temperatures, pressures and disinfection

Question 14

How are bacteria, fungi and parasites named?

Answer 14

Linnaean taxonomy (Genus and species)
May be supplemented by adjectives (eg describing growth, typing, antimicrobial susceptibility characteristics)

Question 15

Name two gram positive cocci?

Answer 15

Staph aureus (MRSA)
Staph epidermidis

Streps

Question 16

Name one gram negative cocci

Answer 16

Neisseria meningitidis

Question 17

Name one gram negative bacilli

Answer 17

Escherichia coli

Question 18

What are virulence factors? Give some examples

Answer 18

Ways in which a microbe is adapted to aid survival.
Eg in bacteria polysaccharide capsule can protect cells from being phagocytosed. Synthesis of collagenase, which is released by bacteria and breaks down the collagen in connective tissue.

Question 19

Why are toxins produced by bacteria?

Answer 19

Exo and endotoxins are produced by bacteria in order to damage host tissues and disable the immune system.

Question 20

Are fungi eukaryotes or prokaryotes? Why is this important?

Answer 20

Eukaryotes, so more difficult to kill than prokaryotes eg with an anti-fungal without killing the hosts own cells

Question 21

What are the two classes of fungi?

Answer 21

Yeasts - single-celled

Moods - multicellular

Question 22

What are the two main groups of parasites?

Answer 22

Protozoa - single-celled

Helminths - worms, multicellular

Question 23

What are the four main types of pathogen? Are the prokaryotes or eukaryotes?

Answer 23

Virus
Bacterium - prokaryote
Fungus - eukaryote
Parasite - eukaryote

Question 24

What are the different factors what can affect the whether a patient becomes infected? Give an example for each

Answer 24

Person - eg age - elderly
Time - eg calendar time - winter
Place - eg current - hospital

Question 25

What are the 7 mechanisms of infection?

Answer 25

``` Contiguous spread - direct Inoculation - needle stick injury Haematogenous - via blood Ingestion - food borne Inhalation - droplet or aerosol Vector - intermediates eg insects Verticals transmission - mother to child ```

Question 26

How do infections cause host damage?

Answer 26

Via attachment then interaction with host defences or toxin production. Inflammation can also occur after interaction with host defences before host damage

Question 27

What are the 3 main things to do as part of management of infection?

Answer 27

Diagnosis Treatment Infection prevention

Question 28

What two pathways can treatment take? Give examples

Answer 28

Specific - antimicrobials, surgery | Supportive - symptom relief, physiological restoration

Question 29

What are the two ends of the spectrum with outcome of infection?

Answer 29

Cure to death, with or without disability

Question 30

Name one gram positive bacilli

Answer 30

Clostridium difficile

Question 31

Name 4 types of infections that adenoviruses can cause

Answer 31

Ocular Respiratory GI Urinary tract

Question 32

What are the observed disease symptoms caused by adenoviruses related to?

Answer 32

Killing of epithelial cells

Question 33

Give adenoviruses structure and mechanism of infection

Answer 33

Non-enveloped, icosahedral, dslDNA | Gene that income proteins that lead to the sitting off of host cellular DNA, RNA and protein synthesis

Question 34

How is the spread of adenoviruses prevented?

Answer 34

Vaccine for military personnel Proper sterilisation of ophthalmologic instruments Don't hare towels or go swimming when infected with ocular disease