25 – Histophilus and Glaesserella Flashcards
Microbiological Characteristics
- Gram negative COCCO-BACILLI
- Biocontainment level 2
- Facultative anaerobes
- Fastidious
- *Glaesserella is a new genus (2020)
What is the natural host or habitat of Histophilus somni?
- Respiratory and reproductive tract
What is the natural host or habitat of Glaesserella parasuis?
- Particularly pigs
- Early colonizer of respiratory tract
- Mucous membranes
- Lower genital tract
Taxonomy: requirement factors
- Factor X
o Haemin - Factor V
o NAD - *Used to figure out the species
Virulence factors of Glaesserela parasuis
- Capsule
- Fimbriae
- Lipooligosaccharide
- *induces cells to eat it (autophagy) to get in
- Strain variation in virulence is recognized
What does Histophilus somni in cattle cause?
- *more than one organ system
- Respiratory infection (shipping fever)
o Fever, tachypnea, cough, nasal discharge
o Can be FATAL
o Pain associated with pleuritis
o Congested lungs with multifocal areas of necrosis
What are other organ systems that can be involved with Histophilus somni in cattle?
- Thrombotic meningoencephalitis
- Septicemia
- Myocarditis: sudden death
- Arthritis
- Abortion
- Enzootic calf pneumonia
The lesions of Histophilus somni are related to vascular thrombosis?
- Tissue infarction and necrosis with haemorrhages
o Brain, heart, SC, kidney, intestine
What are the clinical signs related to site of thrombosis in cattle with Histophilus somni?
- Thrombotic meningoencephalitis in older calves and yearlings
o Depression, fever, blindness, coma and sudden death
How do you treat Histophilus somni in cattle?
- Antimicrobials
How do you control Histophilus somni in cattle?
- Vaccination
What is the disease and clinical signs of Histophilus somni in sheep?
- Similarly broad spectrum of pathologies
- Lameness
- Speticemia
- Epididymitis-orchitis
- Metritis
- Abortion
- Mastitis
What is the presentation of Glaesserella parasuis in pigs?
- Depends on site of infection
- *may play a role in porcine respiratory disease complex
- *usually in pigs 4-8 weeks old
- Short incubation: 1-5 days
What are the clinical signs seen in NAÏVE HERDS?
- RAPID ONSET OF DISEASE
- Pyrexia, inappetence, anorexia
- Aboriton in gilts
- Lameness chronically
- Rarely acute septicemic disease: rapid death
What are the symptoms of Glasser’s disease in pigs with Glaesserella parasuis?
- Fibrinous polyserositis=classical lesion
- Leptomeningitis: inflammation of subarachnoid space