Lab 4 Flashcards
Corynebacterium habitat
Mucous membranes, skin, soil, milk (animal pathogens - saprophytes). There are some plant pathogenic
Corynebacterium Morphology
Polymorphism, very different shapes appear in one smear – Rods (typically curved), coccus. Chinese letters.
Metachromatic granules, stain strongly and contain stored materials.
Corynebacterium culture
Blood agar, haemolysis. Weak growth on nutrient agar
Corynebacterium, resistance
Average, short time in the environment.
Corynebacterium Pathogenicity
Local suppuration, arthritis, metritis, mastitis, abscesses.
Imp spp coryne
C. diphtheriae: Hu pathogene, diftery (inflammation of throat)
Nocardia habitat
Soil
Nocardia Morphology
Long, branched filaments, wrinckled colonies.
Culture Nocardia
Obligate aerobic, Carotenoid pigment, Filaments
- Nutrient agar (not fastidious), 3-5 days to form a colony.
Nocardia Pathogenicity
- Facultative pathogens, local lesions, - N. asteroides:
- Cattle chronic suppuration - Mastitis in cattle
Actinomyces habitat
Alimentary tract, mucous membranes
Morphology Actinomyces
Branching filaments, broken, sulphur granules in the pus but not on medium
Actinomyces Culture
Anaerobic or facultative anaerobic, blood agar.
Actinomyces Species and diseases
A. bovis: cattle actinomycosis - lumpy jaw, pig udder - actinomycosis
A. viscosus: caryes in human, dog – actinomycosis
A. israeli: obligate anaerobic human actinomycosis
A. hordeovulneris: dog actinomycosis
Dermatophilus
congolensis Habitat
Soil, skin
morph Dermatophilus
congolensis
Coccoid with branching filaments which can break into coccoids.
Dermatophilus
congolensis Culture
Obligate aerobic and capnophilic (need CO2), fastidious, blood agar. Form wrinckled yellow colonies. Hemolysis.
Life cycle: Flagellated coccus (zoospora) - filaments - branching - growth - cracking - zoospora
Dermatophilus
congolensis biochem
Proteolytic
Dermatophilus
congolensis pathogenicity
Exsudative dermatitis in mainly: Sheep, cattle
Renibacterium salmoninarum habitat
Water, fish
Renibacterium salmoninarum morph
1-1,5 μm rods, short chains
Renibacterium salmoninarum culture
Aerobic, 15-18 oC (since it affects fish) Fastidious (cistein, serum)
Renibacterium salmoninarum pathogenicity
Obligate pathogenic, intra cellular
Salmon, trout: abscesses in kidneys and other organs
Rhodococcus
R. (C.) equi habitat
Soil, plant, gut of horse
Rhodococcus
R. (C.) equi morph
Coccus-rod cycle. At the beginning of replication: rods and later
Capsule of polysaccharide.
Rhodococcus
R. (C.) equi culture
Simple Pigment (pink) Capsule
Rhodococcus
R. (C.) equi pathogenicity
Foal pneumonia Human pneumonia (immunosuppression, AIDS)
Mycobacterium habitat
Infected host, shed with faeces, milk etc. to the environment.
Mycobacterium morph
- Rods, coccoids
- Cell wall has lipids and waxes with mycolic acids. - No flagella, spores or capsule
- Species differences
Mycobacterium stain
- Ziehl-Neelsen positive (Acid fast)
- Theoretically: Gram positive but colorless since the dye can’t go through the cell wall. - Fluorescence dyes (auramin staining
Mycobacterium Culture
Obligate aerobic
- Broth: Henley, Sauton (cord formation is characteristic for virulent bacteria). Usage of tube instead of solid medium due to the long propagation time. Media goes dry after a couple of days.
- Solid:
- Egg (Kertai, Dorset, Petragnani and the most common Löwenstein-Jensen.) Egg enriched media for the pathogenic spp.
- Serum agar, glycerine potato.
- Selective: Petragnani, acid treatment (5% oxalic acid 10 min, neutralize with a base and then centrifuge and use the sediment for inoculation), animal trial.
- Incubation time, growth characteristics (species differences)
Mycobacterium antigens
Glycolipids, lipoproteins
- Shared antigens, immuno electrophoresis used to examine.
- Tuberculin (protein characteristic for M.) – PPD (purified protein derivate)
Mycobacterium resistance
Good against chemical disinfectants and environmental influences but not heat. Has the best resistance among the Gram + non-sporeforming bacteria.
Mycobacterium Pathogenicity
- Obligate pathogens
- Facultative pathogens
- Saprophytes (atypical)
Most common diseases are tuberculosis, paratuberculosis and Fe leprosy.
M. tuberculosis: human, swine, dog, cat, parrot, cattle
M. africanum: human
M. bovis: cattle, ruminants, swine, dog, cat, human, BCG (Bacillus Calmette-Guerin, 1
M. bovis strain as vaccine for Hu, not animals. Inoculation for 13 years on potato
media and strain lost its virulence.)
M. leprae: human
M. lepraemurium: mouse, cat (not culturable)
Mycobacterium groups
Groups – based on pigment production and growth
Mycobacterium: Photochromogens
pigment prod. in light: M. kansasii, M. marinum
Mycobacterium Scotochromogens
pigment prod. in light and dark: M. scrofulaceum, M. gordonae
Mycobacterium Non-chromogens
no pigment prod.: M. intracellulare, M. terrae
Rapid growers mycobacterium
form colonies after several days: M. phlei, M. fortuitum
