Corynebacterium, Rhodococcus, Nocardia Flashcards
What are the characteristics of Corynebacterium?
Gram +, pleomorphic, aerobic rods
Short mycolic acid chain in cell wall
Usually commensals
Opportunistic
What kind of infections do Corynebacterium cause?
Mostly pyogenic infections
Chronic, granulomatous infections
What does Corynebacterium diphtheriae cause?
Human childhood disease, diphtheria
What does Corynebacterium pseudotuberculosis cause?
Caseous lymphadenitis in sheep and goats
Chronic pyogranulomatous infection of lymph nodes
Local lymphadenitis
What kind of pathogen is Corynebacterium pseudotuberculosis?
Facultative intracellular pathogen
What is a clinical sign of Corynebacterium pseudotuberculosis?
Abscess/chronic weight loss
What do positive titers of Corynebacterium pseudotuberculosis indicate?
Indicate past resolved infections, recent exposure, recent vaccination, or active lesions
Treatment options for Corynebacterium pseudotuberculosis include what?
Lancing and draining, surgical excision
What does Corynebacterium pseudotuberculosis cause in horses?
Pigeon fever, ulcerative lymphangitis of lower extremities
What does Corynebacterium pseudotuberculosis cause in cattle?
Bovine ulcerative lymphangitis
What does Corynebacterium renale group cause?
Contagious bovine pyelonephritis - Disease of adult cows
What is the reservoir for Corynebacterium renale?
Clinically normal carrier cows, lives in the urogenital tract
What are the risk factors for Corynebacterium renale?
Trauma to bladder and urethra during parturition
How is Corynebacterium renale transmitted?
Contaminated bedding, venereal transmission non-sterile OB instruments
What does Corynobacterium kutscheri cause?
Murine pseudotuberculosis
What does Corynobacterium kutscheri cause in the lungs?
Suppurative pneumonia
What does Corynobacterium kutscheri cause in kidney, liver and heart?
Similar nodular lesions
What does Corynobacterium kutscheri cause in joints?
Arthritic lesions of pedal extremities
What does Corynobacterium kutscheri cause in lymph nodes?
Lymphoid hyperplasia of regional nodes
What does Corynobacterium bovis cause?
Dermatitis, hyperkeratosis in mice
What is Rhodococcus equi the main cause of?
Foal pneumonia
Most serious cause of pneumonia in 1-4 month old foals
What kind of pathogen is Rhodococcus equi?
Facultative intracellular pathogen
What is the possible reason for foal susceptibility to Rhodococcus equi?
Appears to be the result of a bacterial-directed inappropriate Th2, rather than Th1 based immune response
Where does Rhodococcus equi target itself?
The macrophages
What is the standard empirical treatment for Rhodococcus equi?
Combo of macrolide and rifampin
What kind of bacteria are Nocardia?
Facultative intracellular bacterium
What is a key point about pathogenic Nocardia spp?
They are saprophytes and live in soil, water and on plants
Infections often follow wounds or are nosocomial
What can be observed in the exudate to diagnose myocardial or actinomycotic infections?
Sulphur granules
What is the most common isolated species of Nocardia in dogs and cats?
N. asteroides
What animal is N. mastitis seen in?
Cattle
What is the best choice for Nocardia treatment?
Aminoglycoside and a carbapenem
