Lab 3

Question 1

Habitat of STAPHYLOCOCCUS

Answer 1

• skin,
• mucous membrane,
• food, plant,
• soil,
• water

Good resistance, can resist hyperosmotic conditions. Cannot tolerate heat.

Weeks, days

Question 2

Culture STAPHYLOCOCCUS

Answer 2

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+

Question 3

Virulence factors of STAPHYLOCOCCUS

Answer 3

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)

Question 4

Pathogenicity of STAPHYLOCOCCUS

Answer 4

Local diseases like abcesses, arthritis Caused mostly bu S. aureus subsp. aureus.

Question 5

Specis of STAPHYLOCOCCUS

Answer 5

Coagulase positive and negative spp

Question 6

Coagulase positive species

Answer 6

S. aureus subsp. anaerobius. Causes Morel’s disease in sheep.

extracellular enzymes, toxins, mannitol + (can split it), haemolysis. More pathogenic.

Question 7

Coagulase neg species of STAPHYLOCOCCUS

Answer 7

S. hyicus (parts is pos) - exudative epidermis/greasy pig disease in piglets.

Can produce only a few enzymes and less toxins.

Question 8

Habitat and pathogenicity of micrococcus - importance

Answer 8

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).

Question 9

Streptococcus habitat and morphology

Answer 9

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

Question 10

Streptococcus staining and resistance

Answer 10

Gram positive

Good resistance - days

Question 11

Culture of streptococcus

Answer 11

Festidious - blood/serum agar, some need co2

Selective - bc of blood and mucous membrane habitat its difficult to culture

Heamolytic alpha beta and gamma

Question 12

traits of streptococcus that differentiates it from staphylococcus

Special traits

Answer 12

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.)

Question 13

Ags of streptococcus

Answer 13

Too complex to be used for identification, (lancefield) not specific enough - agglutination

Question 14

Resistance and pathogenicity(diseases) of streptococcus

Answer 14

Medium

Local suppuration! Mastits, arthritis etc., septicaemia is imp on horses - strangles

Question 15

Importance species and their diseases, streptococcus

Answer 15

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.

Question 16

Culture of enterococcus: miljø

Answer 16

10-45 oC, pH 9,6 Lancefield D

Question 17

Pathogenicity and habitat, enterococcus

Answer 17

Mainly saprophytes, sometimes cause encocarditis and abscesses. Found in the gut, mucous membranes (genital and resp.) Cause α-hemolysis.

• E. faecalis
• E. Faecium

Question 18

Anaerobic cocci

Answer 18

Peptococcus, (metritis, arthritis, pneumonia)

• Peptostreptococcus, ( -“-)
• Ruminococcus, (saprophyte)
• Sarcina (saprophyte) In rumen or large intestine of monogastrics

Question 19

Lactobacillus habitat and culture

Answer 19

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)

Question 20

Morph and staining of lactobacillus

Answer 20

Long, thin, sometimes curved rods.

Staining: Gram positive

Question 21

Pathogenicity lactobacillus

Answer 21

Saprophytes

Question 22

Erysipelothrix rhusiopathiae habitat

Answer 22

Alimentary tract (especially Su), mud, slime of fishes, water.

Question 23

Morphology of Erysipelothrix

Answer 23

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.

Question 24

Staining Erysipelothrix

Answer 24

Gram positive

Question 25

Culture: Erysipelothrix

Answer 25

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

Question 26

Resistance of Erysipelothrix

Answer 26

Good, soil, halotolerance – can resist higher osmotic pressure. Good in environment and especially in water. Can resist salt

Question 27

Pathogenicity of Erysipelothrix, important disease

Answer 27

Facultative pathogenic.
Su: Erysipelas
Chronic erysipelas (diamond skin disease in Su)

Question 28

Listeria habitat

Answer 28

Soil, sewage, plants, silage, gut, food.

Differentiation from E which are primarily found in mucous membranes and L in soil and environment

Question 29

Morphology of listeria

Answer 29

1-2 μm thick rods, flagella (only produced if its room-temp. 22 oC). The rods usually attach to each other

Question 30

Staining of listeria

Answer 30

Gram +

Question 31

Culture listeria

Answer 31

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.

Question 32

Antigens of listeria

Answer 32

Cell wall polysaccharide antigens.
- Flagellar protein antigens.
Both antigens are composite, and the antigens can combine.

Question 33

Resistance listeria

Answer 33

Months in soil, propagate (!) since the temp. is advantagable. Can propagate in silage if the pH isn’t below 5.5.

Question 34

Pathogenicity of listeria, imp diseases

Answer 34

Facultative pathogenic
Sheep: Mainly CNS signs, listeriosis.
Cattle: CNS signs, abortion.
Rabbit: Abortion, septicaemia.
Hu: Abortion, new born septicaemia, encephalitis.