Lab 3

Question 1

What is the most common bacteria recovered from healthy bovine teat apex

Answer 1

1. Actinobacteria
2. Bacteriodetes
3. Firmicutes
4. Proteobacteria

Question 2

what bacteria makes up significant portion of teat canal

Answer 2

Staphylococcus

Question 3

what is often the first clue of mastitis problem

Answer 3

High somatic cell count in bulk reports

Question 4

bulk tanks with >___somatic cell counts indicate mastitis

Answer 4

300k

Question 5

what form of mastitis often affects a large number of cows in short period

Answer 5

Contagious

Question 6

What form of mastitis affects a smaller number of cows, sporadically

Answer 6

Environmental

Question 7

what organisms are included in contagious mastitis

Answer 7

S. Aureus, Streptococcus alagactiae, mycoplasm spp

Question 8

Out of the organisms that cause contagious mastitis which is most contagious/ severe

Answer 8

Mycoplasma Bovis

Question 9

What organisms are included in environmental mastitis

Answer 9

E. Coli, Klebsiella, Enterobacter spp, Streptococcus uberis and dysgalactiae

Question 10

what is cut off for somatic cell count in grade A milk

Answer 10

750k

Question 11

how does CMT work and what does it test for

Answer 11

Add milk from each quadrant mixed with reagents, watch for clumping and color changes

Testing somatic cell counts

Question 12

what does a negative CMT look like

Answer 12

No thickening, homogenous

Question 13

What does trace on CMT look like

Answer 13

Slight thickening, reaction disappears after 10 seconds

Question 14

what does a mild mastitis show on CMT

Answer 14

Distinct thickening, no gel formation

Question 15

What does a moderate mastitis show on CMT

Answer 15

Quick to thicken up, begins to gel, levels at bottom of cup

Question 16

what does a severe mastitis show on CMT

Answer 16

Gels immediately, surface elevates with a central peak above the mass

Question 17

what is the tri-plate selective for

Answer 17

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

Question 18

What is the CAMP test used for

Answer 18

differentiate streptococcus alagatiae an important organism in mastitis vs other streptococcus species

Question 19

how do you know if CAMP test is positive for streptococcus alagatiae

Answer 19

Production of B-hemolysis

Question 20

what are the steps in performing CAMP test

Answer 20

1. TSA agar plate with 5% sheep blood and streak of staphylococcus
2. Then streak streptoccocus species and don’t let them intersect

Question 21

If we have an anaerobic gram negative bacilli what API strip do we use

Answer 21

API 20A

Question 22

If we have an aerobic gram negative bacilli what do we need to do first before API and what API strip do we use

Answer 22

1. Oxidase test
2. Oxidase negative use API 20E
   2a. Oxidase positive use API 20NE

Question 23

If we have a gram positive anaerobic bacilli what API strip

Answer 23

API 20A