Test 2- Haemophilus Flashcards
Haemophilus General
- NAD dependent (staphylococcus necessary for culture)
- Obligate symbiotic
- Little resistant in environment
- Host specific
- Facultative pathogenic
———-Commensals of mucosae: respiratory system and genital tract
- Differences in virulence (serotype dependent)
- Rare, but worldwide
- Age: 2wks-4mths (mainly at weaning)
Haemophilus Virulence factors
- Endotoxins (LPS)
- Fimbriae (role?)
- Neuramidase (?)
- Transferrin binding proteins
Haemophilus parasuis (Glässer disease) Pathogenesis
- Endogenic-exogenic infection
- Septicaemiae General symptoms, acute mortality
- Meningitis CNS symptoms
- Polyserositis, polyarthritis Peritonitis, pericarditis Pleuritis
pic- swollen joints- typical
Haemophilus parasuis (Glässer disease) Treatment and prevention
Treatment
• Antimicrobials
——————-At onset of outbreak: all piglets of litter IM injection
Prevention
• Vaccination (not always successful, sometimes farm specific bacterin/auto- vaccin)
Haemophilus felis
In cats
———– Pneumonia, chronic
———–conjunctivitis
- Also present in health cats
- Rare
Histophilus somnei General
- Formerly Haemophilus somnus- sleepy
- 2 days incubation with 5-10% CO2 (thus frequently overgrowth)
———–Difficult diagnosis
- Colonizes the mucosal surfaces of ruminants (urogenital)
- Obligate symbiotic
Histophilus somnei Symptoms
- Septicaemia
- CNS (TEME: trombo embolic meningo-encephalitis: sleepers disease)
- Arthritis
- Retinitis, conjunctivitis
- Myocarditis
- Pneumonia, tracheitis
- Mastitis
- Abortion
- Otitis
Histophilus somnei Virulence factors
• Lipooligosaccharides (LOS):
———–immune evasion and complement resistance
• OMPs
———–Transferrin binding proteins
———– Ig binding proteins (less opsonisation)
• Host cell interaction
———– Activation of caspases & induction of apoptosis: intravascular coagulation
———– Activation of thrombocytes: intravascular coagulation
• Biofilms
Histophilus somnei dx, vaccine, treatment
• Diagnosis
———–Bacterial culture
• Treatment
———– Antibiotics
———– Little successful in: septicemic, TEME, myocarditis, polyarthritis, mastitis
• Vaccine is available
Avibacterium paragallinarum Infectious coryza
- Formerly haemophilus paragallinarum
- Obligate symbiotic
- Little resistant in the environment
- NAD dependent
- Obligate pathogen for chickens
- Coryza: rhinitis & sinusitis
- Mainly hobby chickens
Avibacterium paragallinarum Virulence factors
- Capsule (polysaccharides)
- anti-phagocytosis
- Anti-complement
- Adhesins
- Endotoxin
- Iron acquisition
Avibacterium paragallinarum pathogenesis and symptoms
• Pathogenesis
————-Carriers
————-Transmission via drinking water or aerosol
————-Stress
• Symptoms
————-Acute
———————- General symptoms and anorexia
———————-Conjunctivitis
————-Subacute
————————Sinusitis and pus
————————- Oedema head and neck
• Can become chronic
Avibacterium paragallinarum diagnosis, treatment and prevention
Diagnosis
• Bacterial culture
Treatment
- Important: be fast
- Antibiotics
Prevention
• Eliminate carriers
