Difference between revisions of "Haemophilus species"
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**Mortality up to 50% insome outbreaks | **Mortality up to 50% insome outbreaks | ||
**Chronic arthritis, meningitis and intestinal obstruction due to adhesions in surviving pigs | **Chronic arthritis, meningitis and intestinal obstruction due to adhesions in surviving pigs | ||
| − | *Fibrinous pneumonia secondary to enzootic pneumonia or virus infection | + | *Fibrinous pneumonia secondary to enzootic pneumonia or virus infection e.g. swine influenza |
Revision as of 15:50, 17 December 2007
Overview
- Inhabit mucosal epithelium of upper respiratory and lower genital tract
- Suppurative infections due to release of pro-inflammatory cytokines released from macrophages
- Serofibrinous to fibrinopurative infections of lungs, body cavities and joints
- Colonisation of meningeal vessels causes a thrombotic vasculitis leading to encephalitis and meningitis
Haemophilus characteristics
- Morphologically variable Gram-negative bacilli, ranging from short rods to long filaments
- Facultative anaerobes
- Typically oxidase positive
- Depend on beta-nicotinamide adenine dinucleotide (NAD) (V factor) and/or Haemin (X fector) for growth
- Heated blood agar (Chocolate Agar) required for growth of NAD-dependent strains
- Haemin-dependent strains grow on Blood Agar
- Do not grow on MacConkey agar
Haemophilus parasuis
- Inhabits nasopharynx of normal swine
- Serotype B causes Glasser's disease in pigs
- Glasser's disease
- Due to transport, environmental stresses, dietary and managemental factors
- Acute septicaemia
- Causes a polyserositis - pericarditis, peritonitis, pleurisy and meningitis - in pigs 3-10 weeks old
- Also causes suppurative bronchopneumonia, pleuritis, polyarthritis (also H. suis)
- Expressed lesions vary between animals - meningitis is most consistent, arthritis in 20% of cases
- Sporadic outbreaks in the UK
- Can be fatal in 2-5 days
- Mortality up to 50% insome outbreaks
- Chronic arthritis, meningitis and intestinal obstruction due to adhesions in surviving pigs
- Fibrinous pneumonia secondary to enzootic pneumonia or virus infection e.g. swine influenza
Haemophilus somnus
- Haemophilus sommus in Enzootic pneumonia of calves
- Causes infectious thromboencephalitis in cattle 1-3 years old
- Found in the USA and Europe, including UK
- Causes a meningoencephalitis with fibrinous arterial thrombosis and necrosis
- Causes fever, staggering and dyspnoea, progressing to somnolence, paralysis and death
- Mortality can be high
Haemophilus pleuopneumonia
- H. pleuropneumonia in Contagious porcine pleuropneumonia
Haemophilus paragalinarum
- Infectious coryza of poultry
- Resistant to complement-mediated lysis and phagocytosis
Haemophilus influenzae
- Human meningitis, septicaemia, bronchopneumonia, conjunctivitis, epiglottitis, and otitis