Lab 3 Streptococci, Staphylococci Flashcards
Staphylococci habitat and morphology
Habitat: skin, mm, food/plant, soil, water
Morphology: coccus, bunch of grapes
Staphylococci culture and pigment
Simple culture: nutrient agar and nutrient broth
Pigment: caroteinoid (gold-ish)
Give two selective cultures used for Staphylococci and what they detect
- Mannitol-salt agar (with pH indicator: phenol)
Detects s. aureus (and micrococci) colour change! - Baird-Parker agar (with Na-tellurite, glycine, pyruvic acid and egg)
Can detect staph coagulase positive!
Staphylococci catalase and oxidase
Catalase +
Oxidase -
What EC enzymes do staphylococci produce?
Coagulase
Fibrinolysin
Hyaluronidase
What surface proteins and toxins do staphylococci have?
Surface proteins: protein-A:
can bind immunoglobulins and hide from immune system of host
Toxins: haemolysins, leucosidins (WBC damage), enterotoxins toxic shock syndrome toxins!
Do staphylococci produce spores? What resistance do they have?
No spores
Good resistance
Give pathogenicity of staphylococci (7)
Local suppuration Abcesses Arthritis Mastitis Metritis Dermatitis Septicaemia
Give some characteristics of coagulase POS species of staphylococci
Many extracellular enzymes Hemolysis Mannitol fermentation Toxin production Facultative pathogenicity
Give some characteristics of coagulase NEG species of staphylococci
Few extracellular enzymes No hemolysis or mannitol fermentation No or little toxin production No or subclinical pathogenicity Generally saprophytes
S. aureus subsp. aureus
Staph
Biotypes A-E (different hosts)
MRSA: methicillin resistant s. aureus
Coag+
S. aureus subsp. anaerobius
Staph
Morel-disease in sheep (lymphadenitis)
Coag+
S. pseudointermedius
Staph
Dermatitis/otitis externa in Ca and Fe
Coag+
S. intermedius
Staph
Ca, Eq, Av: mucous membranes
Saprophyte
Coag+
S. epidermidis
Staph
Frequent wound infection in Ca and Eq
Coag-
S. haemolyticus
Staph
Milk
Coag-
S. hyicus
Staph
Some strains are coag pos!
Porcine exudative epidermitis (greasy pig disease)
Coag-
S. gallinarum
S. equorum
S. felis
Staph
Dermatitis
Coag-
Micrococcus habitat and morphology
Habitat: environment, mm, food, skin
Morphology: cocci, clusters
Micrococcus biochemistry and pathogenicity
Biochem: decomposition of glucose is aerobic or missing
Pathogenicity: saprophyte
Catalase and oxidase pos
M. luteus
Yellow colonies, grape clusters
Streptococci habitat and morphology
Habitat: skin, mm, food, milk, digestive tract
Morphology: coccus, in chains (NOT CLUSTERS) diplococci
Some species have a capsule (hyaluronic acid or polysaccharide)
Streptococci cultures
Fastidious: blood/serum agar (some need CO2)
Selective culture: Crystal Violet, Thallium-SO4, esculin, blood (Edwards)
What type of haemolysis do you see in Streptococci compared to Staphylococci
Strep: alpha, beta and gamma hemolysis
Staph: only beta and gamma hemolysis
What streptococci is detected with CAMP test
S. agalactiae (in presence of s. aureus)
Streptococci catalase and oxidase
Catalase neg and oxidase neg
Streptococci utilization of glycosides
Esculin, salicin
Streptococci antigens
Complex
Lancefield A-W
Other type specific antigens
Capsule antigens (S. suis, S. pneumoniae)
Streptococci resistance and pathogenicity
Resistance: good Local suppuration Metritis, mastitis, arthritis Septicaemia Strangles (!) Pneumonic diseases
S. pyogenes:
Strep
capsule
toxin,
Hu: scarlet fever, rheumatic fever, glomerulonephritis
S. agalactiae, S. dysgalactiae (subsp. equismilis), S. uberis
Strep
Ruminants
Mastitis
Subsp. equismilis: lymphadenitis, abortion in Eq
S. equi
Strep
Subsp. equi: horse strangles
Subsps. zooepidemicus: suppuration, septicaemia, mastitis, abortion
S. suis S. porcinus S. canis S. bovis S. salivarius, sanguis, mutans S. pneumoniae
Strep Suis: septicaemia, arthritis, meningitis Porcinus: lymphadenitis, abcesses Canis: metritis, neonatal septicaemia Bovis: septicaemia (pigeon) SSM: oral streptococci Pneumoniae: calf, foal, human: pneumonia, meningitis
Enterococcus culture and Lancefield category
Culture: 10-45 C, pH 9,6, Lancefield D
Forms chains
Enterococcus species
E. faecalis (hemolysis)
E. faecium
E. avium
E. gallinarum
Enterococcus habitat, pathogenicity
Gut, mainly saprophytes
Sometimes endocarditis, abscesses
Lactococcus fermenters and Lancefield category
Fast lactose fermenters
Found in gut flora (Probiotic)
Lancefield N
Lactococci species and subspecies
L. lactis subsp. lactis
L. lactis subsp. cremoris
L. plantarum (silage)
Anaerobic cocci habitat and species
Habitat: mucous membranes, mainly saprophytes1 Peptococcus Peptostreptococcus Peptoniphilus Ruminococcus Sarcina
Lactobacillus habitat and morphology
Habitat: mm, gut, feed, plants
Morphology: long, thin (sometimes curved) rods
Lactobacillus culture (temp and pH)
Microaerophilic
Temp. 30-40C (2-53)
pH 5.5-6.2
Lactobacillus production and use
Produces lactate from lactose (pH 4)
Used in dairy industry (yogurt etc)
Erysipelothrix habitat and morphology
Habitat: alimentary tract, mid, slime of fish, water
Morphology: small thin rods (s) filaments (r)
Erysipelothrix culture
Nutrient agar
Nutrient broth: S: uniform, R: sediment
NaN3 + Crystal violet, neomycin
Erysipelothrix catalase and oxidase
Catalase -
Oxidase -
Erysipelothrix extracellular enzymes
Neuroaminidase
Hyaluronidase
Erysipelothrix resistance
Good, halotolerance, soil
Alpha hemolysis
Erysipelothrix pathogenicity
Facultative pathogenic Su: erysipelas Ov: wound infection Av: septicaemia Hu: wound inf
E. tonsillarum
Present in tonsils of Su
Endocarditis in dogs
Listeria habitat and morphology
Habitat: soil, sewage, plants, silage, gut, food
Morph: thick rods, flagella (in room temp)
Listeria culture
Simple: nutrient agar/broth
Wide temp range
pH 5.5-9.6
Selective: cattle serum - trypaflavin, nalidixic acid (U-tube)
Listeria catalase and oxidase
Catalase +
Oxidase -
Listeria virulence factors and antigens
Listeriolysin (haemolysin) IC replication Monocytosis factor (cell wall, lipoid)
Antigens: cell wall polysaccharide
flagellar protein
13 serotypes
Listeria resistance and pathogenicity
Good: propagation in soil
Facultative pathogenic: haemolysis, lipolysis, monocytosis Sheep: encephalitis, abortion Cattle: encephalitis, abortion Rabbit: septicaemia, abortion Humans: abortion, neonatal septicaemia, encephalitis Birds: septicaemia
