vpm 2010 lab 6b bovine mastitis demo 1 unknown...
TRANSCRIPT
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Sample A is Staphylococcus aureus
Media Key colony characteristics Gram stain Additional Tests
BA Moderate size (1.0 mm), circular, convex, cream-to-light yellow, opaqueDouble-zone (target) hemolysis
Gram +ve cocciClumps, pairs,
Catalase +ve
Coagulase +ve
MAC No growth - -
Ed No growth - -
Exercise 1. Bovine mastitic milk sample A. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown A
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Staph. aureus on BA
Staph. aureus iscoagulase positive
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown A
4 uM
Gram stain
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Sample B is Streptococcus uberis
Media Key colony characteristics Gram stain Additional Tests
BA Pinpoint to small (<0.5 mm), circular, translucent at 24 hours.Opaque, ~ 1mm at 48 hoursStrains are (weak) alpha or nonhemolyticRecall - hemolysis shows “zone of greening” around colonies
Gram +veChains of cocci
Catalase -veCAMP -ve
MAC No growth - -
Ed Growth - grey to brown coloniesDue to hydrolysis of Esculin and formation of Fe precipitate
- Esculin +ve
Exercise 1. Bovine mastitic milk sample B. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown B
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Streptococcus uberis at 48 hrs, BA
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown B
Gram stain 5 uM
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Sample C is Escherichia coli
Media Key colony characteristics Gram stain Additional Tests
BA 2-3 mm greyish, single narrow zone of hemolysis
Gram-negativerods, singly and in pairs
Oxidase –veIndole +ve Citrate & Urease -ve
MAC Growth, Lactose Fermentor (LF) –intensely pink with pink in agar around colonies
-
Ed No growth -
Exercise 1. Bovine mastitic milk sample C. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown C
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Urease Citrate
E. coliNeg.
E. coliNeg.
E. coli Pos.
E. coli on MAC
E. coli showing hemolysis on BA
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown C
Gram stain
5 uM
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Sample D is Corynebacterium bovis
Media Key colony characteristics Gram stain Additional Tests
BA Small, white, dry coloniesnonhemolytic
Gram +ve “Coryneform”- rods & coccobacilli- “L” & “V” formsPalisades
Catalase +veUrease -ve
MAC No growth -
Ed No growth
Exercise 1. Bovine mastitic milk sample D. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown D
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Catalase test
Note: we don’t have a good picture of C. bovis- This is a high mag shot of C. pseudotuberculosis- C. bovis is more off-white, less glossy & no hemolysis
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown D
Gram stain
6 uM
Appreciate the “coryneform” microscopic morphology “acute-angles “L’s” & “V’s” are evident
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Sample E is a Coagulase Negative Staphylococcus spp. (CoNS or CNS)
Media Key colony characteristics Gram stain Additional Tests
BA Moderate size (1.0 mm), circular, convex, off-white, opaqueNon- or single-zone hemolysis
Gram +ve cocciClumps, pairs, occasional short (3-4) chains
Catalase +veCoagulase -ve
MAC No growth -
Ed No growth -
Exercise 1. Bovine mastitic milk sample E. NOTE – there are no images for CoNS
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown E
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Sample F is Streptococcus dysgalactiae subsp. dysgalactiae
Media Key colony characteristics Gram stain Additional Tests
BA Small translucent colonies,Strains are typically alpha-hemolytic Recall - hemolysis shows “zone of greening” around colonies
Gram +ve cocciShort chains - Smears from milk sample tend to show chaining better
Catalase –veCAMP -ve
Esculin -ve
MAC No growth -
Ed Growth – hemolytic zone is oftenVisible
-
Exercise 1. Bovine mastitic milk sample F. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown F
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Close-up of a Streptococcus -hemolysis– note the “zone-of-greening” around colonies
Streptococcus dysgalactiae– 48 hour BA plate
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown F
Gram stain 5 uM
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Sample G is Klebsiella pneumoniae
Media Key colony characteristics Gram stain Additional Tests
BA Large (5-10 mm), light grey, coalescing, mucoid coloniesNonhemolytic
Gram-negativeShort, plump rods occurring singly or in pairs. A large, unstained “halo” may be evident particularly with Fuchsincounterstain – this is the capsule
Oxidase –veIndole –veCitrate & Urease +ve
MAC Large, mucoid, LF- pale pink -
Ed No growth -
Exercise 1. Bovine mastitic milk sample G. Note – relevant images are on next page
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown G
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Urease Citrate
K. p
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iae
K. p
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iae
K. p
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iae
Klebsiella pneumoniae on BA
Klebsiella pneumoniae on MAC
VPM 2010 Lab 6b Bovine Mastitis – Demo 1 Unknown G
Gram stain6 uM