Gram Neg Non-enteric Bacteria

Question 1

Family Pasteurellaceae

Answer 1

• facultative anaerobes
• ferment glucose
• catalase and cytochrone oxidase positive
• reduce nitrate to nitrite

Question 2

Normal sites of pasteruellaceae

Answer 2

• upper respiratory tract
• lower urogenital tract
• oral cavity

Question 3

Species of pasteurellaceae have ____ instead of LPS

Answer 3

LOS

• same thing as LPS, but short O chains
• still have toxic lipid A

Question 4

Pasteurella frequently show _______ staining

Answer 4

Bipolar

- stains darker on the ends

Question 5

P. multocida

Answer 5

Causes disease in multiple hosts

• opportunistic pathogen
• common commensal in URT of mammals and oral cavity of domestic animals

Question 6

Is P. multocida a common commensal of birds?

Answer 6

No

- when isolated from birds it is almost always associated with disease

Question 7

P. multocida is a _______ disease

Answer 7

Zoonotic

• one of the biggest hazards of small animal medicine
• all cats carry it in their mouths, most common cause of bite wound infections

Question 8

Antigenic types are based on ______

Answer 8

Capsular polysaccharides

- determined by capital letter

Question 9

Somatic types are identified by a ______

Answer 9

Number

- O antigens

Question 10

Type A

Answer 10

Fowl cholera
- most common type isolated from nondiseased or diseased cattle (BRD), swine (nontoxigenic procine pneumonic pasteurellosis), and rabbits (snuffles)

Question 11

Type B

Answer 11

Hemorrhagic septicemia

- cattle

Question 12

Type D

Answer 12

Atrophic rhinitis

• swine
• requires stress before infection

Question 13

Type E

Answer 13

Hemorrhagic septicemia

Question 14

Endotoxin

Answer 14

Lipopolysaccharide O side chains are shorter than Enterobacteriaceae
- cell surface is more hydrophobic and permeable

Question 15

________ is required for virulence

Answer 15

Capsular polysaccharide

• type A: hyaluronic acid (serves as adhesin)
• type D: made of heparin
• type F: chondroitin

Question 16

What is the result of capsules being identical to host tissues?

Answer 16

Poorly antigenic and bind complement poorly

- antiphagocytic

Question 17

What capsular type produces a thermolabile dermonecrotoxin?

Answer 17

Type D

- plays a role in atrophic rhinitis in swine (exotoxin)

Question 18

Hemorrhagic septicemia

Answer 18

Affects cattle and water buffalo in tropical/subtropical areas during rainy season

Question 19

Hemorrhagic septicemia transmisison

Answer 19

Ingestion or inhalation by direct contact or via fomites

• some animals become carriers in lymphatic tissues associated with upper respiratory tract
• shed in nasal secretions or induced by stress
• is not viable in environmental conditions, only survives for hrs to days in damp soil/water

Question 20

Hemorrhagic septicemia disease

Answer 20

3-5 incubation period with acute to peracute cases (no chronic cases)

• fever, dullness, reluctance to move
• salivation, profuse serous nasal discharge, edema
• calves: hemorrhagic gastroenteritis/dysentery
• respiratory distress frothing at the mouth
• death within 6-48 hrs

Question 21

Morbidity rate depends on _______

Answer 21

Environmental conditions, herd management, immune status

• all ages are affected where the disease is not endemic
• in endemic regions, outbreaks occur by introduction of asymptomatic carriers into a susceptible herd and young cattle 6 mo-2 yrs
• case mortality is 100%

Question 22

In the US, hemorrhagic septicemia is considered an _______

Answer 22

Exotic disease

- reportable to the state vet and USDA APHIS

Question 23

Fowl cholera

Answer 23

Highly contagious, affects both domestic and wild birds

• serotypes A:1, A: 3, A: 4
• turkeys tend to be more susceptible than chickens

Question 24

Fowl cholera transmission

Answer 24

Carrier birds maintain the pathogen

• transmission occurs by oral and respiratory routes
• wild birds may be a source of infection to commercial poultry

Question 25

Fowl cholera disease forms

Answer 25

- peracute: 60% mortalities without preceding signs - acute: depression, sleepiness, anorexia, diarrhea, death in a few hrs or 2-3 days, flock mortalities to 30% - subacute: respiratory, pneumonia in turkeys - chronic: localized caseous lesions in respiratory tract and conjunctiva, swollen wattles, joints, footpads swollen from fibrinosuppurative exudate

Question 26

Atrophic rhinitis

Answer 26

Caused by toxigenic P. multocida serotype D in association with bordetella - occurs in young pigs - ammonia act synergistically - dermonecrotoxin causes osteolysis of turbinates

Question 27

Atrophic rhinitis disease

Answer 27

- sneezing, tear-duct obstruction, serous-mucopurulent nasal discharge, epistaxis, lateral deviation of snout - less severe: turbinate atrophy caused by bordetella alone - both bordetella and multocida causes severe form - overstocking and poor management increases severity - secondary pneumonia due to loss of turbinate defenses, typically fibrinous

Question 28

Respiratory infections in multiple species due to serotype A

Answer 28

- secondary to stress or other bacterial or viral infections - cattle: shipping fever, BRD, fibrinous pleuropneumonia, bronchopneumonia, secondary to Pl-3, IBRV, BRSV - swine: porcine pneumonic pasteurellosis in grower-finishers, fibrinous pneumonia, stress associated - rabbits: snuffles, URT infection, mucopurulent exudates with occulsion of nares

Question 29

Secondary infections

Answer 29

- mastitis in cows and ewes | - bite wound infections in humans (dogs and cats)

Question 30

Diagnosis

Answer 30

- impression or blood smears may slow bipolar organisms - definitive diagnosis made by isolation and identification - media requires enrichment with blood or serum - colony growth requires 24-38 hrs at 37 C - colonies are round, gray, nonhemolytic, mucoid due to capsule

Question 31

Identification

Answer 31

Nonmotile, nonhemolytic, no growth on MacConkey agar - glucose fermented, no gas - oxidase and catalase positive - indole positive

Question 32

Treatment

Answer 32

Antibiotics: penicillin, streptomycin, tetracyclines, sulfonamides, chloramphenicol - fowl cholera: sulfaquinoxaline - antibiotic resistance is common

Question 33

Immunity

Answer 33

- adjuvant bacterins effective against hemorrhagic septicemia - bacterins for fowl cholera are inconsistent - combo M. haemolytica and P. multocida bacterins are inconsistent against BRD - P. multocida and B. bronchiseptica bacterins with toxoid are effective against atrophic rhinitis