Unit 3: Mannheimia and Bibersteinia

Question 1

Is Mannheimia haemolytica trehalose negative or positive?

Answer 1

it is trehalose negative

Question 2

What other species belong to the Mannheimia genus but are of minor importance as causes of disease?

Answer 2

M. glucosida, M. granulomatis, M. ruminalis, and M. verigena

Question 3

Mannheimia haemolytica is considered to be the most important bacterial cause of _____ _____ in _____ and ______ and also causes ______ in sheep.

Answer 3

respiratory disease; cattle; sheep; mastitis

Question 4

On gram stain, what does Mannheimia haemolytica look like?

Answer 4

gram negative, small coccobacillus

Question 5

How does Mannheimia haemolytica grow on MacConkey’s?

Answer 5

it is supposed to grow but isolates frequently do not grow or grow only poorly

Question 6

What do colonies of Mannheimia haemolytica look like?

Answer 6

it forms a smaller colony than P. multocida, lacks the musty odor and is hemolytic but often with a very narrow zone of complete hemolysis

Question 7

Is Mannheimia haemolytica lactose positive or negative?

Answer 7

positive

Question 8

Is Mannheimia haemolytica indole positive or negative?

Answer 8

negative

Question 9

What main type of toxin does Mannheimia haemolytica produce and what does it do?

Answer 9

a RTX toxin which is toxic for leukocytes and platelets of ruminants by forming pores into the leukocyte

Question 10

What other virulence factors does Mannheimia haemolytica produce that are involved in induction of pneumonia?

Answer 10

lipopolysaccharide, capsular polysaccharide, fimbriae, glycoprotease, neuraminidase, and membrane proteins

Question 11

What is the natural habitat of Mannheimia haemolytica?

Answer 11

upper respiratory tract of cattle and sheep

Question 12

How is Mannheimia haemolytica transmitted?

Answer 12

ingestion or inhalation

Question 13

What does Biotype A serotype 1 of Mannheimia haemolytica cause in cattle?

Answer 13

acute fibrinous pleuropneumonia involved in the shipping fever complex (which is the leading cause of loss to the feeder cattle industry)

Question 14

What does Mannheimia haemolytica cause in sheep and goats?

Answer 14

septicemia in newborn lambs and pneumonia in adults

Question 15

Aside from pneumonia, what does Mannheimia haemolytica cause in sheep?

Answer 15

‘blue bag’ - gangrenous mastitis

Question 16

What products have been used to stimulate an immune response against Mannheimia haemolytica in cattle?

Answer 16

killed bacterins and modified live vaccines

Question 17

What cells are important in the defense of the lower respiratory tract?

Answer 17

phagocytic cells - alveolar macrophages and neutrophils

Question 18

At low levels, what is the function of the Mannheimia haemolytica cytotoxin?

Answer 18

it inhibits the function of alveolar macrophages and neutrophils

Question 19

At high levels, what is the function of the Mannheimia haemolytica cytotoxin?

Answer 19

the cytotoxin is able to kill these same cells

Question 20

What is the pathogenesis of disease caused by the Mannheimia haemolytica cytotoxin?

Answer 20

When the neutrophils and alveolar macrophages in the lungs are killed they release their lysosomal enzymes onto the surface of the cells in the alveolar space causing inflammation. The inflammation causes the pulmonary tissue to be non-functional. If the area of inflammation is large enough then the animal can go into respiratory distress. The organism manipulates the immune system so that the inflammatory mediators and activated immune-effector cells end up being a major contributor to the disease process

Question 21

Some believe a successful humoral immune response to a Mannheimia haemolytica infection requires antibody against the ____ and ____ ____ _______.

Answer 21

cytotoxin and cell surface components

Question 22

Is Bibersteinia trehalosi trehalose positive or negative?

Answer 22

positive

Question 23

Bibersteinia trehalosi produces a toxin almost identical to what other bacteria?

Answer 23

Mannheimia haemolytica

Question 24

In cattle, what does Bibersteinia trehalosi cause?

Answer 24

severe respiratory disease in dairy cattle and more recently associated with feedlot pneumonias

Question 25

What does Bibersteinia trehalosi cause in sheep?

Answer 25

septicemia in feeder lambs via the esophagus

Question 26

What does Bibersteinia trehalosi cause in goats?

Answer 26

respiratory disease