Infection And Immunity

Question 1

What is bacteraemia?

Answer 1

Presence of bacteria in blood, usually dealt with by immune system

Question 2

What is septicaemia?

Answer 2

Sepsis due to bacteria in the body, leading to systemic response

Question 3

What is meningococcal meningitis, what are the symptoms and how is it treated?

Answer 3

Caused by neissera meningitidis mainly in winter and is inflammation of spinal cord
Fever, neck stiffness, lower consciousness and rash
IV penicillin is preferred choice of antibiotics
Ceftriaxone penetrates CSF so is good in adults

Question 4

How can cytokines cause organ failure?

Answer 4

Initiates production of thrombin
Leads to coagulation cascade and in small vessels can cause blockage
Inhibits fibrinolysis and causes thrombus formation, leading to ischaemia and this organ failure

Question 5

List three urgent investigation in sepsis.

Answer 5

FBC, u&e, LFT, CRP, blood sugars

Question 6

List the sepsis six and understand that this is carried out within an hour.

Answer 6

Give three:
High flow oxygen
IV fluids 
IV antibiotics 
Take three:
Lactate measurement 
Urine sample
Blood cultures

Question 7

Give three life threatening complications of sepsis.

Answer 7

Irreversible hypotension 
Resp failure
Renal failure
High ICP
Necrosis of extremeties

Question 8

List the two methods that confirm an infection diagnosis.

Answer 8

Blood cultures

PCR

Question 9

How does sepsis lead to low BP?

Answer 9

Endotoxins in the form of lipopolysaccharides are released through bacterial cell lysis
LPS powerful activator of cytokines which promotes clotting cascade and vasodilation
Lowers BP

Question 10

What two antibiotics should be given for neissera meningitidis prophylaxis? What are the roles of these two antibiotics?

Answer 10

Ciprofloxacin
Rifampicin
Prevent bacterial DNA synthesis

Question 11

What three things determine a host-pathogen relationship?

Answer 11

Virulence factors
No. of microorganisms present
Hosts immune response

Question 12

Give an example of three physical barriers to infection and how they work.

Answer 12

Skin-loss of skin integrity (cannulation, trauma) is a site of entry for infection
Mucous membrane-in tracts open to outside environment-trap foreign particles and are then removed
Bronchial cilia-transports mucus to oropharynx for removal

Question 13

Give three examples of physiological barriers to infection.

Answer 13

-diarrhoea
Coughing
Sneezing
Vomiting

Question 14

Name three normal flora in the nasopharynx

Answer 14

Strep
Candida
Neissera
Haemophilus

Question 15

Name three normal flora in the skin

Answer 15

Staph
Strep
Yeast

Question 16

Name three normal flora in the upper bowel

Answer 16

Enterococcus
Enterobacteriaceae
Candida

Question 17

Name two normal flora in the lower bowel

Answer 17

Peptostreptocccus

Clostridium

Question 18

Name three normal flora in the vagina

Answer 18

Lactobacillus
Candida
Streptococci