Family Corynebacteriaceae Flashcards
Genus Corynebacterium species
C.bovis
C.pseudotuberculosis
C.renale
Key points Corynebacterium
Gram + Pleomorphic Fastidious Enriched media Pyogenic infections Non-motile Facultative anaerobes Catalase positive Oxidase negative Commensals on mucous membranes
C.bovis
Facultative anaerobes Blood agar, no haemolysis? Catalase positive Oxidase negative No suppurative conditions Part of normal flora in teat canal of cow Mastitis in cows
C.pseudotuberculosis
Fastidious
Enriched media
Facultative anaerobes
Catalase positive
Oxidase negative
Lymphadenitis, pseudotuberculosis in small ruminants
Abscesses in lymphnodes and internal organs (onion ring)
Survives inside macrophages
CAMP negative (but show r.equi positivity)
Very contagious
C.renale
Fastidious Facultative anaerobes Produce urease=enzyme destroying Blood agar Catalase positive Oxidase negative No growth on MacConkey agar Fimbriae Cystitis and pyelonephritis in small ruminants
Genus Rhodococcus species
R.equi
“Corynebacterium equi”
Key points Rhodococcus
Gram+ Rods or cocci Non-enriched media Salmon pink, mucoid colonies Non haemolytic Aerobic Non motile CAMP test positive (with c.pseudotuberculosis, shovel shape) Soil saprophyte Respiratory pathogen in foals
R.equi
Gram+, but staining not so useful
Aerobes
Non enriched media
Pinkish mucoid colonies
Spread from inhalation (faeces, dust)
Ag production depending on temperature (encoded in plasmids)
Suppurative bronchopneumonia, abcessation in foals
Catalase positive
Oxidase negative
No haemolysis no oxidation-fermentation/API negative
Class Actinobacteria
Bacteria similar to fungi
Key points Actinobacteria
Gram+ Branching filaments in many species Opportunistic pathogens Inflammatory responses MZN staining for differentiation
Family Actinomycetaceae species
Arcanobacterium pyogenes Actinomyces bovis Actinomyces viscous Actinobaculum suis Truperella pyogenes
Key points Actinomyces
Anaerobic or facultative anaerobic Capnophilic Granules in pus Haemolytic exotoxins, protease, neuraminidases Produce filament formations Non-spore forming Non-motile MZN staining Colonize mucus membranes
