L7 - Gram Positive Rods (pt. 2)

Question 1

Which of the following statement is incorrect regarding antimicrobial susceptibility testing?

A. MIC is the lowest concentration of antimicrobial agent that can inhibit the growth of bacteria
B. Published break points are required for interpretation of AST results
C. MIC can be measured in E-Test
D. MIC can be accurately measured in Disk diffusion test (Kirby Bauer tests)

Answer 1

D. MIC can be accurately measured in Disk diffusion test (Kirby Bauer tests)

Question 2

A bacteria which uses host actin filaments to travel through cells;

A. Listeria monocytogenes
B. Erysipelothrix rhusiopathiae
C. Bacillus anthracis
D. Streptococcus iniae

Answer 2

A. Listeria monocytogenes

Note: Erysipelothrix rhusiopathiae(is an extracellular bacteria); Listeria is intracellular

Question 3

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 lesion in adult ruminants

Answer 3

D. Hepatic necrosis is the main lesion in adult ruminants

Note: Seen in winter because there is no grass so people start feeding the ruminants silage; see hepatic necrosis in young animals and monogastric animals as a result of septicemia

Question 4

This pig will most likely have an infection caused by:

A. Erysipelothrix rhusiopathiae
B. Listeria monocytogenes
C. Staphylococcus hyicus
D. Streptococcus suis

Answer 4

A. Erysipelothrix rhusiopathiae