Infectious Diseases - Enterococcus and Meningococcal Disease

Question 1

What do enterococci look like under the microscope?

Answer 1

Gram positive diplococci

Question 2

What Clinical presentations are caused by enterococcus?

Answer 2

UTI and prostatitis

Bacteraemia and endocarditis

Meningitis usually associated with neurosurgery interventions

Intra-abdominal

• SBP in cirrhosis
• IP dialysis

Question 3

What are the atypical features seen in enterococcus endocarditis?

Answer 3

Subacute

Splenic abscesses

Hiccups

Pleural effusions

Spondylodiscitis

Often with heart failure

Question 4

What do meningococcal look like under the microscope?

Answer 4

Gram negative diplococci

Usually encapsulated

Question 5

What mucosal enzyme is involved in meningococcal infections?

Answer 5

N. Meningitidis produces IgA1 protease which reduces interruption of colonisation by mucosal IgA

Question 6

How do meningococcal infections cause endothelial injury?

Answer 6

Endothelial injury from:

LPS

Endotoxin binding to CD14 with assoc TLR4

Question 7

Effect on coagulation of meningococcal infection?

Answer 7

Intravascular thrombosis due to UPREGULATION OF TISSUE FACTOR

Downregulation of anticoagulant pathway from:

• loss of endothelial THROMBOMODULIN
• loss of endothelial PROTEIN C RECEPTORS
• decreases levels of protein C, S And antithrombin III

Question 8

Immune associations with developing meningococcal infections?

Answer 8

• complement deficiency of C5-9, or PROPERDIN or FACTOR D
• hyposplenism
• hypogammaglobulinaemia
• deficiency of mannose binding protein
• TLR4 mutation

Question 9

Clinics risk factors for developing meningococcal infections?

Answer 9

Smoking hx

Recent viral LRTI

Recent mycoplasma

Question 10

What rash do you get In meningococcal infections?

Answer 10

Nonblanching petechial

Later you get purpura fulminans

Question 11

Which serotypes of meningococcal cause pneumonia?

Answer 11

Serotypes Y, W and Z

Question 12

What vital sign abnormality is associated in particular with meningococcal infections?

Answer 12

Relative bradycardia with Hypertension

Question 13

Poor prognostic Factors in meningococcal septicaemia?

Answer 13

• ABSENCE of meningism
• young
• coma
• hypotension
• febrile >38
• leukopenia
• thrombocytopenia
• Metabolic Acidosis
• high serum PAI-1
• low antithrombin, and proteins C and S
• DIC
• LOW ESR and CRP

Question 14

What is Post Meningococcal Reactive Disease?

Answer 14

= immune complex develops 4-10 days post onset (due to meningococcal polysaccharide antigen) morning

Arthritis
Vasculitic rash
Iritis
Pericarditis

Self resolves

Question 15

Long term complications of meningococcal infections?

Answer 15

• post necrotic scarring of skin and/or amputations
• hearing loss
• neuro complications
• psychological disturbances and ADHD