Lab 3 Flashcards
Habitat of STAPHYLOCOCCUS
- skin,
- mucous membrane,
- food, plant,
- soil,
- water
Good resistance, can resist hyperosmotic conditions. Cannot tolerate heat.
Weeks, days
Culture STAPHYLOCOCCUS
Nutrient/blood agar
Golden/white pigment that doesnt solve in media (hydrophobic)
Som have beta haemolysis
Selective culture - has common habitat so often found together with other spp can tolerate hyperosmotic conditions
Gram+
Virulence factors of STAPHYLOCOCCUS
Ec enzymes: coagulase so immune cells dont disturbe the bacteria, fibrinolysin will lyse the clot after so the bacteria can spread
Toxin: hyaluronidase will damage the wbc for easy propegation (haemolysis in culture)
Pathogenicity of STAPHYLOCOCCUS
Local diseases like abcesses, arthritis Caused mostly bu S. aureus subsp. aureus.
Specis of STAPHYLOCOCCUS
Coagulase positive and negative spp
Coagulase positive species
S. aureus subsp. anaerobius. Causes Morel’s disease in sheep.
extracellular enzymes, toxins, mannitol + (can split it), haemolysis. More pathogenic.
Coagulase neg species of STAPHYLOCOCCUS
S. hyicus (parts is pos) - exudative epidermis/greasy pig disease in piglets.
Can produce only a few enzymes and less toxins.
Habitat and pathogenicity of micrococcus - importance
environment, mucous membrane, food, skin(same as staph)
Saprophytes - the imprtant thing of this genus is to differentiate it from the staphylococcus:
Glycose fermentation aerobic or missing. (For differentiation from S. which can be aerobic or anaerobic).
Streptococcus habitat and morphology
skin, mucous membrane, (different part; food, milk, digestive track)
Capsule can be a virulence factor as some spp prod hyaluridic acid and polysacchride -> ag in s. Suis and pneumonia, identification
Streptococcus staining and resistance
Gram positive
Good resistance - days
Culture of streptococcus
Festidious - blood/serum agar, some need co2
Selective - bc of blood and mucous membrane habitat its difficult to culture
Heamolytic alpha beta and gamma
traits of streptococcus that differentiates it from staphylococcus
Special traits
Form chains and not clusters, difference in catalase(-) and streptococcus are more fastidious.
(Some spp of streptococcus produce antibiotics. Some spp are found in natural flora of throat.)
Ags of streptococcus
Too complex to be used for identification, (lancefield) not specific enough - agglutination
Resistance and pathogenicity(diseases) of streptococcus
Medium
Local suppuration! Mastits, arthritis etc., septicaemia is imp on horses - strangles
Importance species and their diseases, streptococcus
S. pyogenes: capsule, scarlet fever in humans, rheumatic fever. Can cause ear and resp. infection and sore throat.
S. equi subsp. equi: strangles in Eq, can produce a hyaluronic acid capsule.
Culture of enterococcus: miljø
10-45 oC, pH 9,6 Lancefield D
Pathogenicity and habitat, enterococcus
Mainly saprophytes, sometimes cause encocarditis and abscesses. Found in the gut, mucous membranes (genital and resp.) Cause α-hemolysis.
- E. faecalis
- E. Faecium
Anaerobic cocci
Peptococcus, (metritis, arthritis, pneumonia)
- Peptostreptococcus, ( -“-)
- Ruminococcus, (saprophyte)
- Sarcina (saprophyte) In rumen or large intestine of monogastrics
Lactobacillus habitat and culture
Mucous membranes (GI, urogenital), gut, food, feed, plant.
Microaerophilic,
- Optimal temperature 30-40 oC (2-53 oC), - pH 5,5-6,2 (lower than usual, acidic)
Morph and staining of lactobacillus
Long, thin, sometimes curved rods.
Staining: Gram positive
Pathogenicity lactobacillus
Saprophytes
Erysipelothrix rhusiopathiae habitat
Alimentary tract (especially Su), mud, slime of fishes, water.
Morphology of Erysipelothrix
1-3 μm thin rods, S-R, form long chains. (Capsule very thin polysaccharide layer).
E. isolated from acute phases S colonies. And isolated from chronic phases R colonies.
Staining Erysipelothrix
Gram positive
Culture: Erysipelothrix
Nutrient agar, forms small colonies. Not very fastidious. On blood agar, some strains cause α-hemolysis. S-R colonies Broth: - S: uniform turbidity - R: sediment Selective: - NaN3 + crystal violet - Neomycin = antibiotic
Resistance of Erysipelothrix
Good, soil, halotolerance – can resist higher osmotic pressure. Good in environment and especially in water. Can resist salt
Pathogenicity of Erysipelothrix, important disease
Facultative pathogenic.
Su: Erysipelas
Chronic erysipelas (diamond skin disease in Su)
Listeria habitat
Soil, sewage, plants, silage, gut, food.
Differentiation from E which are primarily found in mucous membranes and L in soil and environment
Morphology of listeria
1-2 μm thick rods, flagella (only produced if its room-temp. 22 oC). The rods usually attach to each other
Staining of listeria
Gram +
Culture listeria
Simple (habitat is soil – demands are low) Forms white-grey colonies. β-haemolysis if cultured on blood agar.
4-45 oC
Selective:
- Cattle serum – trypaflavin – nalidixic acid (antibiotic) Selective enrichment:
In case you have isolations of bacteria of low number.
- Cold enrichment: 4°C, put the broth culture in the fridge. Normal bacteria don’t propagate at this temp.
- U-tube: Inoculation into a U-shaped tube. At the other end of the tube pure culture for reisolation can be obtained. This is due to the fact that Listeria produces flagella at room-temp. Other bacteria don’t move at this temp.
Antigens of listeria
Cell wall polysaccharide antigens.
- Flagellar protein antigens.
Both antigens are composite, and the antigens can combine.
Resistance listeria
Months in soil, propagate (!) since the temp. is advantagable. Can propagate in silage if the pH isn’t below 5.5.
Pathogenicity of listeria, imp diseases
Facultative pathogenic Sheep: Mainly CNS signs, listeriosis. Cattle: CNS signs, abortion. Rabbit: Abortion, septicaemia. Hu: Abortion, new born septicaemia, encephalitis.
