Exam 4: Pasteurella, Mannheimia, Actinobacillus

Question 1

What is Pasteurella pneumotropica a common commensal in?

Answer 1

Laboratory rodents

Question 2

What are primary carriers of Pasteurella pneumotropica?

Answer 2

Rats and mice

Question 3

How is Pasteurella pneumotropica transmitted?

Answer 3

By direct contact

It does not survive long in the environment

Question 4

What are the symptoms of Pasteurella pneumotropica?

Answer 4

Usually asymptomatic in immunocompetent hosts, but can cause disease in immunocompromised or stressed animals

Question 5

What can Pasteurella pneumotropica cause?

Answer 5

Conjunctivitis
Rhinitis
Otitis
Cervical lymphadenitis

Question 6

What was Mannheimia haemolytica formerly?

Answer 6

Pasteurella haemolytica biotype A

Question 7

What are the 12 different serotypes of M. haemolytica based on?

Answer 7

Capsular polysaccharides

Question 8

What does M. haemolytica grow on?

Answer 8

MacConkey agar

Question 9

What does M. haemolytica produce on MacConkey agar?

Answer 9

Beta hemolysis

Indole negative

Question 10

Describe lipopolysaccharide as a virulence factor of M. haemolytica

Answer 10

Long O side chains
Endotoxic
Complexes with leukotoxin to enhance and stabilize leukocytic activity

Question 11

Describe capsular polysaccharide as a virulence factor of M. haemolytica

Answer 11

Inhibits serum killing, phagocytosis, and intracellular killing, and enhances neutrophil recruitment and adhesion to alveolar epithelium

Question 12

Describe fimbriae as a virulence factor of M. haemolytica

Answer 12

May enhance colonization of URT

Question 13

Describe leukotoxin as a virulence factor of M. haemolytica

Answer 13

Poreforming cytolysin that affects ruminant leukocytes and platelets by altering function at low levels but causing lysis at high levels

Question 14

What is leukotoxin specific for?

Answer 14

Bovine peripheral leukocytes

Question 15

What does leukotoxin prefer?

Answer 15

Neutrophils over mononuclear cells

Question 16

What does leukotoxin bind to?

Answer 16

CD18 on surface of bovine leukocytes

Question 17

What happens with a low dose of leukotoxin?

Answer 17

Activates PMNs and stimulates degranulation

Question 18

What happens with a higher dose of leukotoxin?

Answer 18

Induces neutrophil apoptosis

Question 19

What happens with a high dose of leukotoxin?

Answer 19

Neutrophil lysis due to membrane disruption

Question 20

What does leukotoxin stimulate?

Answer 20

Release of IL-1 and TNF from mononuclear cells

Question 21

What do lymphocytes undergo with leukotoxin?

Answer 21

Apoptosis and necrosis

Question 22

What do platelets have with leukotoxin?

Answer 22

Increased adhesion

Question 23

What is the result of leukotoxins?

Answer 23

Massive inflammatory cell recruitment and inflammatory mediator release, tissue destruction

Question 24

In cattle, what is M. haemolytica the primary agent of?

Answer 24

Bovine respiratory disease or shipping fever

Question 25

What is the most common BRD agent?

Answer 25

Serotype A1, sometimes A2 which is the most common type in normal calves before shipment

Question 26

What are other tings that can be caused by M. haemolytica?

Answer 26

Mastitis in cows (A6) | Broncopneumonia and mastitis in sheep (A1, A6)

Question 27

Describe the treatment of M. haemolytica

Answer 27

Same as for P. multocida | M. haemolytica and P. multocida combination bacterins are inconsistent. Recombinant leukotoxin does not protect cattle

Question 28

What does Avibacterium paragallinarum require?

Answer 28

V factor (NAD)

Question 29

What will A. paragallinarum grow on?

Answer 29

Blood agar with Staphylococcous streak

Question 30

What does A. paragallinarum cause?

Answer 30

Infectious coryza, which is an acute contagious upper respiratory infection in chickens

Question 31

What can A. paragallinarum occur in?

Answer 31

Growing chickens or in layers

Question 32

What are clinical signs of A. paragallinarum?

Answer 32

``` Nasal discharge Sneezing Facial edema Conjunctivitis Lacrimation Anorexia Diarrhea ```

Question 33

What is the morbidity and mortality like with A. paragallinarum?

Answer 33

High morbidity | Low mortality

Question 34

What can A. paragallinarum be complicated by and what does that lead to?

Answer 34

Secondary bacteria and lead to septicemia and arthritis

Question 35

What is the result of A. paragallinarum?

Answer 35

Increased culls and decreased egg production

Question 36

Why is the diagnosis of A. paragallinarum by culture difficult?

Answer 36

It is slow growing and fastidious | It is easily overgrown

Question 37

How is A. paragallinarum diagnosed?

Answer 37

Serologic detection of serum antibodies by agglutination | PCR detection is effective

Question 38

What is A. gallinarum a commensal in?

Answer 38

URT of chickens

Question 39

What does A. gallinarum occasionally cause?

Answer 39

Low grade respiratory infections in chickens

Question 40

What are members of the genus Actinobacillus like?

Answer 40

Small GN, facultatively anaerobic, nonmotile rods

Question 41

What does Actinobacillus resemble morphologically and biochemically?

Answer 41

The genus Pasteurella

Question 42

What are the principle species of Actinobacillus and what do they cause?

Answer 42

``` A. pleuropneomoniae: swine pleuropneumonia A. suis: septicemia in young pigs A. lignierseii: bovine actinomycosis A. equuli: sleepy foal disease A. capsulatus: arthritis in rabbits ```

Question 43

What do all species of Actinobacillus occur as?

Answer 43

Commensals

Question 44

What is A. pleuropneomoniae associated with?

Answer 44

Respiratory tracts of sick or recovered animals

Question 45

What does A. pleuropneomoniae cause?

Answer 45

Acute, subacute, or chronic pleuropneumonia of swine

Question 46

What is A. pleuropneomoniae disease characterized by?

Answer 46

Serofibrinous pleuritis and fibrinous pneumonia

Question 47

What are the virulence factors of A. pleuropneomoniae?

Answer 47

LPS; long O side chains; adhesive properties Capsular polysaccharide: antiphagocytic, required for virulence Fimbriae RTX toxins

Question 48

What are the RTX toxins responsible for lung pathology with A. pleuropneomoniae?

Answer 48

ApxI, ApxII, ApxIII, and ApxIV

Question 49

Describe thee growth of A. pleuropneomoniae

Answer 49

Beta hemolytic | Requires NAD for growth

Question 50

What are the serotypes of A. pleuropneomoniae most common in North America? Europe?

Answer 50

Serotypes 1 and 5 | Serotype 2

Question 51

How are the capsular types of A. pleuropneomoniae identified?

Answer 51

Numbered 1-12

Question 52

What are the virulence factors of A. suis?

Answer 52

LPS Capsular polysaccharide 2 RTX toxins similar to Apx I and Apx II

Question 53

What kind of pathogen is A. suis?

Answer 53

Opportunistic

Question 54

What is A. lignieresii a commensal organism of?

Answer 54

The oral cavity and pharynx of ruminants

Question 55

What does A. lignieresii cause in cattle?

Answer 55

Sporadic endogenous disease

Question 56

Describe sporadic endogneous disease caused by A. lignieresii

Answer 56

Usually a result of direct inoculation into submucosal tissues Chronic granulomas form in SubQ tissues of head and neck Firm nodules develop with green pus Tongue protrudes from mouth Granulomatous lesions spread to lymph nodes and lungs

Question 57

What does A. lignieresii cause in sheep?

Answer 57

Suppurative infections around head and neck, sometimes mammary

Question 58

What is A. equuli a commesal organism of?

Answer 58

The GI tract and URT of normal horses | Reproductive tract of mares

Question 59

What does A. equuli cause?

Answer 59

Sleepy foal disease in neonatal horses

Question 60

What is the transmission of A. equuli though to be through?

Answer 60

In utero or ingestion, umbilicus, or respiratory tract during or immediately after birth