Micro 4

Question 1

What are common virulence factors?

Answer 1

Diverse secretion systems
Flagella
Pili
Capsule
Endospores
Biofilms

Question 2

What is a neurotoxin?

Answer 2

An exotoxin that work on nerves or motor end plates.

E.g. tetanus toxin, botulinum toxin

Question 3

What is an enterotoxin?

Answer 3

Exotoxin that works on the GI tract and stimulates diarrhoea.
Infectious diarrhoea; e.g. E. coli, Shigella, Campylobacter jejuni, Vibrio cholera

Food poisoning; Staph aureus, Bacillus cereus

Question 4

What is pyrogenic exotoxin?

Answer 4

Exotoxin that stimulates release of cytokines

e.g. Staph aureus, Strep pyogenes

Question 5

What is a tissue invasive exotoxin?

Answer 5

Exotoxin which destroys and tunnels through tissue. Breaks down DNA, collagen, fibrin etc.
e.g. Staph aureus, Strep pyogenes, Clostridium perfingens

Question 6

What is a miscellaneous exotoxin?

Answer 6

Specific to a certain bacterium/mechanism is poorly understood.
e.g. Bacillus anthracis and Corynebacterium diphtheriae

Question 7

What is meant by an endotoxin?

Answer 7

Produced by gram-negative bacteria.

Lipid A moiety of LPS is shed, when bacteria is lysed, it sheds the LPS/endotoxin -> septic shock.

Question 8

What is meant by septic shock?

Answer 8

It is when there is a dangerous drop in BP and/or organ dysfunction.
Treated by eradicating the microbe.

Question 9

What is the action of shiga toxin?

Answer 9

AB5 subunit contains StxA enzyme active component and pentamer StxB binding component.
StxA enzymes cleave 28s ribosomal RNA in eukaryotic cells -> inhibition of protein synthesis
Bacterial ribosomes are substrates for StxA so there will be less bacterial proliferation.

Question 10

What is the mechanism of virulence of Enteroagreggative E. coli (EAEC)?

Answer 10

Gene encoding aggregative adherence fibrin (AAF) is located on the plasmid.
Allows attachment to enterocytes.
Stimulates a strong IL-8 response which can create biofilms.

Question 11

What are the communicable diseases in Europe?

Answer 11

Respiratory tract infections
STIs
Food and waterborne diseases, zoonoses
Emerging and vector borne diseases
Vaccine preventable diseases
Antimicrobial resistance and healthcare-associated diseases

Question 12

Which are the two respiratory tract infections caused by bacteria?

Answer 12

Legionnaire’s disease- Legionella pneumophila

Tuberculosis-mycobacterium tuberculosis

Question 13

What is the virulence factor of Legionella pneumophilia?

Answer 13

Type IV secretion system so effector proteins can be secreted

Question 14

Which are the STIs caused by bacteria?

Answer 14

Chlamydia trachomatis
Gonorrhoea
Syphilis

Question 15

What is the virulence factor of neisseria gonorrhoea?

Answer 15

Pili and antigenic variation

Question 16

What are the emerging and vector-borne diseases caused by bacteria?

Answer 16

Plague (Yersinia pestis)
Q fever (Coxiella burnetti)

Question 17

What are the vaccine preventable diseases caused by bacteria?

Answer 17

Diptheria
Haemophilus influenzae
Neisseria meningitidis
Streptococcus pnemoniae
Bordatella pertussis
Clostridium tetani