Lab 3 Flashcards
What is the most common bacteria recovered from healthy bovine teat apex
- Actinobacteria
- Bacteriodetes
- Firmicutes
- Proteobacteria
what bacteria makes up significant portion of teat canal
Staphylococcus
what is often the first clue of mastitis problem
High somatic cell count in bulk reports
bulk tanks with >___somatic cell counts indicate mastitis
300k
what form of mastitis often affects a large number of cows in short period
Contagious
What form of mastitis affects a smaller number of cows, sporadically
Environmental
what organisms are included in contagious mastitis
S. Aureus, Streptococcus alagactiae, mycoplasm spp
Out of the organisms that cause contagious mastitis which is most contagious/ severe
Mycoplasma Bovis
What organisms are included in environmental mastitis
E. Coli, Klebsiella, Enterobacter spp, Streptococcus uberis and dysgalactiae
what is cut off for somatic cell count in grade A milk
750k
how does CMT work and what does it test for
Add milk from each quadrant mixed with reagents, watch for clumping and color changes
Testing somatic cell counts
what does a negative CMT look like
No thickening, homogenous
What does trace on CMT look like
Slight thickening, reaction disappears after 10 seconds
what does a mild mastitis show on CMT
Distinct thickening, no gel formation
What does a moderate mastitis show on CMT
Quick to thicken up, begins to gel, levels at bottom of cup
what does a severe mastitis show on CMT
Gels immediately, surface elevates with a central peak above the mass
what is the tri-plate selective for
Factor media: gram positive and differential for hemolytic staphylococcus
Modified TKT media: selective for streptococcus species and differential for hemolytic strains
MacConkey media: gram negative organisms and differential for lactose fermenters
What is the CAMP test used for
differentiate streptococcus alagatiae an important organism in mastitis vs other streptococcus species
how do you know if CAMP test is positive for streptococcus alagatiae
Production of B-hemolysis
what are the steps in performing CAMP test
- TSA agar plate with 5% sheep blood and streak of staphylococcus
- Then streak streptoccocus species and don’t let them intersect
If we have an anaerobic gram negative bacilli what API strip do we use
API 20A
If we have an aerobic gram negative bacilli what do we need to do first before API and what API strip do we use
- Oxidase test
- Oxidase negative use API 20E
2a. Oxidase positive use API 20NE
If we have a gram positive anaerobic bacilli what API strip
API 20A
