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− | <big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>
| + | #REDIRECT[[:Category:Haemophilus species]] |
− | <big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
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− | ===Overview===
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− | *Inhabit mucosal epithelium of upper respiratory and lower genital tract
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− | *Suppurative infections due to release of pro-inflammatory cytokines released from macrophages
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− | *Serofibrinous to fibrinopurative infections of lungs, body cavities and joints
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− | *Colonisation of meningeal vessels causes a thrombotic vasculitis leading to encephalitis and meningitis
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− | ===''Haemophilus'' characteristics===
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− | *Morphologically variable Gram-negative bacilli, ranging from short rods to long filaments
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− | *Facultative anaerobes
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− | *Typically oxidase positive
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− | *Depend on beta-nicotinamide adenine dinucleotide (NAD) (V factor) and/or Haemin (X fector) for growth
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− | *Heated blood agar (Chocolate Agar) required for growth of NAD-dependent strains
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− | *Haemin-dependent strains grow on Blood Agar
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− | *Do not grow on MacConkey agar
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− | ===''Haemophilus parasuis''===
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− | *Inhabits nasopharynx of normal swine
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− | *Serotype B causes Glasser's disease in pigs
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− | *Glasser's disease
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− | **Septicaemia
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− | **Acute inflammation affecting pleua, peritoneum, mediastinum, pericardium, joints and meninges
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− | **Causes a polyserositis - pericarditis, [[Peritoneal cavity - inflammatory#Peritonitis|peritonitis]], pleurisy and meningitis - in pigs 3-10 weeks old
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− | **Also causes suppurative [[Respiratory Bacterial Infections - Pathology#Glasser's disease|bronchopneumonia, pleuritis]], [[Joints - inflammatory#In Pigs|polyarthritis]] (also ''H. suis)
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− | **Expressed lesions vary between animals - meningitis is most consistent, arthritis in 20% of cases
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− | **Fever, general malaise, repsiratory and abdominal signs, lameness, paralysis or convulsions
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− | **Sporadic outbreaks in the UK
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− | **Morbidity and mortality often low due to widespread acquired resistance
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− | **Mortality up to 50% in some outbreaks e.g. specific pathogen-free herds
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− | **Can be fatal in 2-5 days
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− | **Chronic arthritis, meningitis and intestinal obstruction due to adhesions in some surviving pigs
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− | **Due to transport, environmental stresses, dietary and managemental factors
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− | *Fibrinous pneumonia secondary to enzootic pneumonia or virus infection e.g. swine influenza
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− | ===''Haemophilus somnus''===
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− | *Cattle
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− | **''Haemophilus sommus'' in [[Respiratory Bacterial Infections - Pathology#Enzootic pneumonia of calves|Enzootic pneumonia of calves]]
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− | **Septicaemia
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− | **Causes infectious thromboencephalitis, bronchopneumonia and sporadic reproductive tract infections in cattle 1-3 years old
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− | **Found in the USA and Europe, including UK
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− | **Causes a meningoencephalitis with fibrinous arterial thrombosis and necrosis
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− | **Causes fever, staggering and dyspnoea, progressing to somnolence, paralysis and death
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− | **Mortality can be high
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− | *Sheep
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− | **Epididymitis in young rams
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− | **Vulvitis, mastitis and reduced reproductive performance in ewes
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− | **Septicaemia, arthritis, meningitis and pneumonia in lambs
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− | ===''Haemophilus pleuopneumonia''===
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− | *''H. pleuropneumonia'' in [[Respiratory Bacterial Infections - Pathology#Contagious porcine pleuropneumonia|Contagious porcine pleuropneumonia]]
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− | ===''Haemophilus paragalinarum''===
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− | *Infectious coryza of poultry - accute upper-respiratory tract infection
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− | *Nasal discharge, swollen sinuses, facial oedema and conjunctivitis
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− | *Resistant to complement-mediated lysis and phagocytosis
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− | ===''Haemophilus haemoglobinophilus''===
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− | *Commensal of canine lower genital tract
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− | *Causes cystitis and neonatal infections
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− | ===''Haemophilus felis''===
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− | *Associated with feline conjunctivitis
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− | ===''Haemophilus influenzae''===
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− | *Human meningitis, septicaemia, bronchopneumonia, conjunctivitis, epiglottitis, and otitis
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