Microbiology

Question 1

What is the pathogenesis of a pathogen?

Answer 1

Adhere/colonise and invade
Evade host defences
Multiply/ complete life cycle
Exit host (host is damaged)

Question 2

What is virulence?

Answer 2

Capacity of a microbe to cause damage to the host

Question 3

What is the action of adhesin?

Answer 3

Enables binding of the organism to the host tissue

Question 4

What is the action of invasin?

Answer 4

Enables the organism to invade a host cell/tissue

Question 5

What is the action of impedin?

Answer 5

Enables the organism to avoid host defence mechanisms

Question 6

What is the action of aggressin?

Answer 6

Causes damage to the host directly

Question 7

What is the action of modulin?

Answer 7

Induces damage to the host indirectly

Question 8

What are virulence factors?

Answer 8

Molecules produced by bacteria, viruses, fungi, and protozoa that add to their effectiveness

Question 9

What microbes are found on the skin?

Answer 9

Staphylococci 
Staphylococcus aureus 
Diptheroids
Streptococci
Bacillus
Candida
Malessezia 
Mycobacterium

Question 10

What is coagulase?

Answer 10

The ability of a microbe to coagulase plasma, this helps with colonisation and allows a community of bacteria to grow

Question 11

Who is mostly affected by MRSA?

Answer 11

Eldery and immunocompromised
ICU
Burns patients
Surgical patients
IV lines 
Dialysis patients

Question 12

What superficial lesions can S.aureus cause?

Answer 12

Boil to abscesses

Question 13

What toxinoses can S.aureus cause?

Answer 13

Toxic shock

Scalded skin syndrome

Question 14

What are some important virulence factors of S.aureus?

Answer 14

Fibrinogen binding protein
TSSF-1 (toxin) 
Adhesin
Kills leukocytes
Shock, rahs, dequamation 
PVL

Question 15

What can PVL S.aureus cause?

Answer 15

Necrotising pneumonia
Recurrent furunclulosis
Sepsis
Necrotising fascitis

Question 16

What skin infections can staph auerus cause?

Answer 16

Rash
Folliculitis
Abscess
Carbuncle
Impetigo
Scalded skin syndrome

Question 17

What are the symptoms of TSST-1?

Answer 17

Rapid progression 
High fever
Vomiting
Diarrhoea
Sore throat
Muscle pain

Question 18

What are the symptoms of scalded skin syndrome?

Answer 18

Exfolatin toxins in the face, axillla and groin

Often neonatal

Question 19

What is the superantigen TSST-1 associated with?

Answer 19

Toxic shock syndrome

Question 20

What are the symptoms of necrotizing pneumonia?

Answer 20

Infleunza like syndrome
Necrotising haemorrhagic pneumonia
Rapid progression
Acute respiratory distress
Deterioration in pulmonary function 
Refractory hypoxeamia
Multi-organ failure despite antibiotic therapy

Question 21

How would you class streptococcus pyogenes?

Answer 21

Streptococci
Gram +ve cocci
Catalase nergative
Beta haemolysis

Question 22

What skin infections can S.pyogens cause?

Answer 22

Impetigo
Cellulitis
Necrotising fascitis

Question 23

What is cellulitis?

Answer 23

Deep skin infection that is not associated with necrosis

Question 24

What ks necrotizing fascitis?

Answer 24

Invasive strep A strains penetrate mucous membrane and develop in lesion
Rapidly destroys connective tissue

Question 25

What is a superantigen?

Answer 25

Class of antigens that cause non-specific activation of T cells resulting in polyclonal T cell activation and massive cytokine release

Question 26

What is a baceriophage?

Answer 26

A virus that parasitizes a bacterium by infecting it and reproducing inside it