Infections of the heart and circulatory system

Question 1

Bacteraemia

Answer 1

Bacteria in blood

Question 2

Septicaemia

Answer 2

Bacteria in blood causing clinical symptoms

Question 3

Causative agents of septicaemia, preWW2, after antibiotics, and today

Answer 3

Before WW2: Pyogenic cocci
After antibiotics: Gram-ve rods
Today: Gram+ve and Gram-ve bacteria and C. albicans

Question 4

Gram stain and shape of Y. pestis and also the family is belongs to

Answer 4

Caused by Y. pestis. Pleomorphic and G-ve bacillus. Member of Enterobacteriaceae.

Question 5

How is plague transmitted

Answer 5

Can be transmitted by droplets, contact, faecal-oral and vector

Question 6

In plague how does septicaemia spread

Answer 6

Septicaemia migrates to lymph node  inflammation  necrosis (bubonic). Can go to the lungs and getting inflammation.

Question 7

Immunosupression

Answer 7

Immunosuppression = predisposing factor for development of septicaemia

Question 8

Infections of heart+Circ system: opportunistic pathogens

Answer 8

• Pseudomonas aeruginosa
• Stenotrophomonas maltophilia
• Acinetobacter spp. (e.g. baumannii)

Question 9

Newborn babies are vulnerable to serpticaemia caused by?

Answer 9

• Listeria monocytogenes
• Group B streptococcus (e.g. S. agalactiae)

Question 10

What causes endotoxic shock. Warm shock and cold shock

Answer 10

Typical cause of symptoms found in G-ve septicaemia. Lipid A causes vasodilation and hypotension –> warm shock. Early stages, blood pressure plummets.
Peripheral blood vessels constrict to counteract –> cold shock.

Question 11

What is DIC

Answer 11

Disseminated intravascular coagulation

Question 12

What does DIC cause

Answer 12

coagulopathy, profuse bleeding from orifices, endotoxin induced coagulation, clotting in blood but not on any surface, all coagulation factors are used up, -> bleeding -> multisystem organ failure.

Question 13

What is toxic shock syndrome caused by (TSS)

Answer 13

Staph or Strep

Question 14

TSS1

Answer 14

Toxin shock syndrome - toxin

Question 15

TSLS

Answer 15

Toxic shock like syndrome

Question 16

N. meningitis mode of infection

Answer 16

endotoxin mediated increase in vascular permeability causes loss of protein, fluid and plasma into the tissue with pathological compensatory vasoconstriction.

Question 17

What is TSS caused by

Answer 17

TSST-1 toxin of S.aureus

Question 18

TSST-1 toxin mode of action

Answer 18

• Nonspecific binding of MHC II with T-cell receptors by TSST-1, it is a superantigen.
• There is polyclonal activation leading to a cytokine storm, uncontrolled inflammation.

Question 19

How many draws are taken for lab diagnosis of septicaemia

Answer 19

Three

Question 20

Antimicobial treamtnet of septicaemia

Answer 20

Emperical therapy: Aminoglycoside, b-lactam, metronidazole (AnO2 effective)
Therapy modified post susceptibility testing

Question 21

Endocarditis definition

Answer 21

Infection of the lining of the heart, not the muscle, usually refering to endocardial surface (valves)

Question 22

Frequency of endocarditis based on values (list) and reason

Answer 22

Frequency: Mitral, aortic, tricuspid and pulmonic (based on SA).

Question 23

What is endocarditis typified by

Answer 23

Vegetation

Question 24

Native heart endocarditis steps (5)

Answer 24

1. Damaged valves/prosthetic valves  disturbances in blood flow
2. Development of microcolonies and so fibrin is deposited in an immune response which in a hypocritical way it shields the microcolonies
3. Growing vegetations are friable (fragile so bits break off)  septic emboli.  blockage if a large part breaks off and contains pathogens, which then can grow.
4. Vegetation is a biofilm- cidal antibiotics are required.
5. Can remove valve via surgery

Question 25

Early prosthertic value endocaridits occurs how long after valve replacement

Answer 25

Before a year

Question 26

Early prosthertic value endocaridits is caused by contamination of what

Answer 26

Valve

Question 27

Early prosthertic value endocaridits is caused by what organisms

Answer 27

CoNS S. aureus Dipetheroids, e.g Corynebacterium spp.

Question 28

Late prosthertic value endocaridits occurs how long after post replacement

Answer 28

Post a year

Question 29

Late prosthertic value endocaridits is caused by

Answer 29

Viridians streptococci Enterococci CoNS transient bacteriaemia from mouth

Question 30

How often is native valve endocaridits caused by S. aureus seen, common group and what valvue and why

Answer 30

Rare, IV drug users, tricupsid valve as it is for venous return

Question 31

Duke criteria is for what

Answer 31

Score likelihood of endocaridits

Question 32

Major duke criteria

Answer 32

* 2x Blood cultures positive for organisms known to cause IE * Echocardiogram positive for IE  visualise any vegetations.

Question 33

Minor duke criteria

Answer 33

* Predisposing factors (IV drug use, heart condition) * Fever * Vascular phenomena (emboli, conjunctival haemorrhage, Janeway lesions)

Question 34

Definitive diagnosis following Duke criteria of endocardiatis (number of major and minors scored)

Answer 34

2 major 1 major, 3 minor 5 minor

Question 35

Mycotic aneurysm

Answer 35

Infected aneurysm, arteritis. Inflammatory damage and weaking of arterial wall leading to buldging (aneurysm)

Question 36

Suppurative thrombophelbitis

Answer 36

Inflammation of vein wall, clot formation, microbial colonisation. common in IV catheters