Bacterial Disease - Diagnosis and Control

Question 1

Clinical signs of Bacterial Disease

Answer 1

• Pyrexia
  
  • Depressed demeanour
  • Off food
  • Purulent discharge
  • Swelling
  • Changes to white blood cell/neutrophil count
  • Acute phase proteins
    ○ Fibrinogen
    ○ C Reactive Protein - dogs
    ○ Serum Amyloid A - horses/cats
    ○ Haptoglobin - cattle

Question 2

Examples of a disease with specific presentation

Answer 2

Greasy pig disease
* Staphylococcus Hyicus
Raised circular lesions

Strangles
* Streptococcus equi equi
Purulent nasal discharge
Dull, depressed, off food
Open abscesses under jaw

Question 3

Treatment of Staphylococcus Hyicus

Answer 3

Antibiotics sensitive against staphylococci and licensed in pigs

Question 4

Treatment of Streptococcus equi equi

Answer 4

Drain abscesses
Lavage
isolate individual
Antibiotics are not commonly used

Question 5

Why do we use culture and sensitivity?

Answer 5

Gold standard
* Confirms bacterial presence and identifies species
* Identifies which antibiotic will be most effective

Question 6

Limitations of culture and sensitivity

Answer 6

• May not change treatment plan
• Client may have financial restrictions
• May need to make immediate decision in emergency (foal sepsis, pleuropneumonia)
  Takes 48h for culture, 72h+ for sensitivity

Question 7

Gram Stain colours

Answer 7

Purple - Gram +ve
Pink - Gram -ve

Question 8

Gram stain method

Answer 8

1. Drop of sample on slide to make a smear
2. Apply crystal violet which binds to peptidoglycan staining cells purple
3. Iodine forms complex with gram +ve bacteria
4. Gram -ve bacteria decolourised by alcohol/acetone
5. Counter stain applied which stains gram -ve pink