Test 2- Haemophilus Flashcards Preview

Bact > Test 2- Haemophilus > Flashcards

Flashcards in Test 2- Haemophilus Deck (13):
1

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)

2

Haemophilus Virulence factors

• Endotoxins (LPS)

• Fimbriae (role?)

• Neuramidase (?)

• Transferrin binding proteins

3

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

4

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)

5

Haemophilus felis

 In cats

----------- Pneumonia, chronic

-----------conjunctivitis

• Also present in health cats

• Rare

6

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

7

Histophilus somnei Symptoms

• Septicaemia

• CNS (TEME: trombo embolic meningo-encephalitis: sleepers disease)

• Arthritis

• Retinitis, conjunctivitis

• Myocarditis

 • Pneumonia, tracheitis

• Mastitis

• Abortion

• Otitis

8

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

9

Histophilus somnei dx, vaccine, treatment

• Diagnosis

-----------Bacterial culture

• Treatment

----------- Antibiotics

----------- Little successful in: septicemic, TEME, myocarditis, polyarthritis, mastitis

• Vaccine is available

10

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

11

Avibacterium paragallinarum Virulence factors

• Capsule (polysaccharides)

• anti-phagocytosis

• Anti-complement

• Adhesins

• Endotoxin

• Iron acquisition

12

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

13

Avibacterium paragallinarum diagnosis, treatment and prevention

Diagnosis

• Bacterial culture

Treatment

• Important: be fast

• Antibiotics

 Prevention

• Eliminate carriers