BacT Clicker questions

Question 1

What are the issues associated with PCR in diagnosing Staphylococcal skin infections?

Answer 1

Samples collected for PCR can be easily contaminated during collection thus throwing off PCR results

Question 2

What is the best treatment for a mature staphylococcal abscess?

Answer 2

Open it –> clean it –> flush it

Often more effective than antibiotics

Question 3

Humoral immune response is measured by screening for?

Answer 3

Antibodies!

Question 4

Ability of a test to accurately identify an infected animal as positive is known as?

Answer 4

Sensitivity

Question 5

Ability of a test to accurately identify a non-infected animal as negative is known as?

Answer 5

Specificity

Question 6

An ELISA was used to screen two cattle herds for the presence of Johne’s disease. Herd A has a prevalence of 80% and hred B has a prevalence of 15%. The positive predictive value of this test is much higher in?

Answer 6

Herd A - the higher the prevalence the higher the predictive value

Question 7

Which of the following is not an appropriate practice in sample collection and transport?
A. Urine collected by free catch shipped over night in ice
B. Urine collected by catheterization
C. Urine collected by cystocentesis in a red top tube
D. Urine collected and shipped to the lab in a syringe with needle still attached

Answer 7

D - why would you leave the needle attached?!

Question 8

What bacteria uses host actin filaments to travel between cells?

Answer 8

Listeria monocytogenes

Question 9

Which of the following is incorrect about listeriosis in ruminants?
A. Outbreaks occurs after feeding soiled silage
B. Encephalitis and neurological signs occurs after the organism enter through the wounds in the buccal mucosa
C. Generally disease occurs in the winter months
D. Hepatic necrosis is the main lesions in adult animals

Answer 9

D

Question 10

Toxin and capsule are both required for the virulence of Bacillus anthracis. True or False?

Answer 10

TRUE

Question 11

Capsule of anthrax bacilli is composed of a polysaccharide

Answer 11

False, it is made up of polyD-glutamic acid

Question 12

McFadyean straining reaction is used for detecting…?

Answer 12

Capsule of anthrax bacilli

appears as a pink shadow around bacteria

Question 13

In avirulent forms of Bacillus anthracis presence of toxin is essential for protective immune response. True or False?

Answer 13

TRUE!

Question 14

Positive antibody titres to phospholipase D exotoxin of C. pseudotuberculosis is diagnosti for caseous lymphadenitis. True or False?

Answer 14

False

Question 15

Rhodococcus equi is an obligate intracellular pathogen. True or False?

Answer 15

False, it is a faculative intracellular pathogen

Question 16

MIC can be accurately measured in Disk diffusion test (Kirby Bauer Test)

Answer 16

False

Question 17

Which one of the following processes is the least virulent mechanism in a bacteria?
A. Bacterial movement using flagella
B. Bacterial attachment using frimbriae
C. biofilm production and attachment to surfaces
D. Bacterial protein production by ribosomes

Answer 17

D

Question 18

Anthrax is a contagious disease. True or False?

Answer 18

FALSE FALSE FALSE! it is an infectious disease, but not a contagious one. The bacteria must first be expelled from the host and exposed to air in order to sporulate. only then can it infect a new host!