Microbiology of Respiratory Infections Flashcards
What factor differentiates between harmless and virulent streptococci strains?
Alpha haemolytic and non haemolytic are often harmless. Beta haemolytic species are usually the ones that cause damage.
What strain of bordetella causes kennel cough?
Bronchoseptica
Describe bordetella bronchospetica
Strict aerobe gram negative rod
What other household species can bordetella bronchoseptica effect?
Cats
How effective is the kennel cough vaccine?
Not very, it only protects against one or two strains of the virus
Describe the pathogenic process of bordetella bronchoseptica
Adherence to the initial trauma of respiratory epithelium. Proliferation in the airways. Release of toxins causing irritation and coughing. Epithilial necrosis. Inflammation and interstitial pneumonia
Where is pasteurella multocida usually found?
In the oral cavity of dogs and other animals
Where does it commonly cause infection ?
secondary infection of upper respiratory tract and also in dog bite wound
What are the key features to identify pasteurella multocida?
Gram- negative rod, Oxidase positive, no growth on Mc-conkey
What is Rabbit ‘snuffles’?
P. Multocida infection of the upper respiratory tract
How does rabbit snuffles present?
Chronic nasal discharge and sneezing. Sometimes secondary skin disease on face due to being constantly moist
Where does p. multocida colonise in the rabbit?
Respiratory tract, middle ear, genitalia and occasionally lungs
If you see nodules in the lungs of rabbits but no URT symptoms what is the differential diagnosis excluding rabbit snuffles?
Uterine Adenoma carcinoma with metastatic spread
What B- haemolytic streptococci is highly virulent in the lungs?
s. zooepidemicus
How so streptococci respond to gram staining?
Gram positive
How does the M - protein contribute to stroptococcus pathogenicity ?
Halts the complement cascade and interferes with oppsonphagocytosis
How does actinomyces viscous appear under gram staining ?
gram positive
What disease does actinomyces viscosus cause in the dog?
granulomatous thoracic infection in dogs but also localised granulomatous abscesses of the skin
What gram positive soil bacteria can also cause chronic suppurating thoracic granulomas?
Nocardia
What pathology is associated with nocardiosis?
Copious red brown exudate in pleural cavity which may become chronic with adhesion formation.
How does chlamydophilia felis present ?
Conjunctivitis with nasal discharge that progresses to interstitial bronchopneumonia in cats
How does chlamydophilia felis reproduce?
Infect cells and builds reticulobodies which multiply by binary fission in fomites. They them shift back to elementary bodies and spread
What stain can you use to visulise chlamydophilia felis?
Kosters stain
What pathological findings are associated with Nasal aspergillosis?
Destruction of nasal turbinates, chronic granulomatous inflammation. Funghal hyphae
