Enterobacteriaceae & Pseudomonas

Front 1

What are the main Yersinia species of concern in vet med?

Back 1

1. Yersinia pestis = plague

2. Y. enterocolitica

3. Y. pseudotuberculosis = enteric disease, septicaemia

4. Y. ruckeri = perioral haemorrhagic inflammation in fish

Front 2

What are the common characteristics of the Yersinia spp?

Back 2

1. Gram negative, Rods

2. Non-lactose fermenters

3. Demonstrate bipolar staining in Giemsa stained smears from animal tissue

4. Motile (except Y. pestis)

Front 3

___________ & ______________ used to discriminate between strains.

Back 3

SEROTYPING & BIOTYPING

Front 4

What two yersinia species are found in the intestinal tract of wild mammals, birds, & domestic animals and spread in feces?

Back 4

Y. pseudotuberculosis & Y. enterocolitica

* Both grow in wide temperature range (4-43 C)

Front 5

In endemic areas, wild rodent are important reservoirs of ___________. Fleas transmit the infection to man and other animals.

Back 5

Yersinia pestis

Front 6

How do the enteric, pathogenic yersinia species (pseudotuberculosis & enterocolitica) avoid uptake by phagocytes in the host?

Back 6

They invade some cells (M cells) of Peyers patches & hijack host cell signaling systems to avoid phagocytosis and sometimes result in killing macrophages.

Front 7

Virulence factors required for survival & inhibition of phagocytosis by Yersinia species is ____________ & ____________ encoded.

Back 7

PLASMA & CHROMOSOMAL ENCODED virulence factors

Front 8

Survival of Y. enterocolitica & pseudotuberculosis is enhanced by __________________ secreted by the organism (via a type III secretion system), which interfere with normal function of neutrophils & macrophages in the host.

Back 8

PHAGOCYTIC PROTEINS (Yops)

- secreted into the cytosol of the target cell = disables or alters their function

Front 9

In GI mucosa, Yersinia bacteria prevent phagocytosis by replicating in _______________________________ with the development of necrotic lesions & neutrophil infiltration.

Back 9

MESENTERIC LYMPH NODES

Front 10

Treatment of clinical infections with Yersinia is seldom feasible.

True or False?

Back 10

TRUE - due to the acute nature of the disease

Front 11

General clinical signs of infection with Yersinia?

Back 11

1. Diarrhea

2. Weight loss/emaciation

3. Sudden death = septicaemia (common w/ rats & birds)

Front 12

The pig is a natural reservoir for Y. ________________, which is an important zoonotic pathogen in humans.

Back 12

Yersinia enterocolitica - more common in other EU countries, not so much in UK because meat is often cooked well here.

Front 13

Diagnosis of Yersinia?

Back 13

1. Histological examination of intestinal lesions

2. Culture of Y. enterocolitica & pseudotuberculosis from feces, pus or tissue

3. Plated on MacConkey agar for growth

4. Cold enrichment (grows at cooler temps than most)

5. Serotyping

Front 14

Zoonotic infection in rodents, transferred by fleas.

Back 14

PLAGUE = Yersinia Pestis

Organism in blood of rodents -> Blood taken up by fleas -> Flea bites & transmits to human

Front 15

Yersinia pestis (plague) is endemic to what regions?

Back 15

Africa

Asia

SW/Pacific Coast USA

Front 16

The susceptibilities of different wild rodent species to plague-related mortality vary greatly.

True or false?

Back 16

TRUE

- Prairie dogs of N. America are extremely susceptible

- Kangaroo rats can be infected, but are relatively resistant & suffer few ill effects.

Front 17

Differentiate the following plague syndromes in humans: Bubonic vs pneumonic vs septicemic plague?

Back 17

Bubonic - bacteria travels to lymph nodes, where they form large swollen balls of pus

Pneumonic - exists within the lungs

Septicemic - infection within the blood

Front 18

Virulence factors specific to Y. pestis?

Back 18

1. Fraction 1 (F1) antigen = plasma-encoded capsule

2. HPI = iron acquisition (also Ye & Yp)

3. Ymt protein (phospholipase D) required for survival in flea midgut

4. Hms locus = required for transmission of Y. pestis to subcut sites

5. Pla = plasma-encoded & is essential for dissemination from subcut site of bite to lymph nodes or blood stream.

Front 19

Diagnosis of Y. pestis?

Back 19

1. Specimens (pus, blood, lymph node aspirate) sent to specialized labs

2. Giemsa stained smears - bipolar rods = Y. pestis

3. Culture

4. DFA (direct fluorescent antibody) = ab coupled to specific proteins, which glow when positive

5. Passive haemagglutination on paired samples from infected cats

Front 20

Treatment of Y. pestis?

Back 20

Animal kept in isolation & treated with IV tetracycline or chloramphenicol for bubonic plague

Front 21

Control of Y. pestis?

Back 21

1. Endemic areas routinely treat for fleas

2. Rodent control

3. Surveillance

4. Avoiding sick/dead animals & areas of outbreak

5. Vaccination

6. Insect repellents

Front 22

Pseudomonas auruginosa & Burkholderia spp share similar characteristics. What are they?

Back 22

1. Gram negative rods

2. OBLIGATE AEROBES (req oxygen)

3. Non-fermenters (oxidize carbs)

4. Oxidase, catalase positive

5. Grow well on MacConkey agar

Front 23

Describe the clinical conditions arising from infection with pseudomonas aeruginosa for the following animals:

1. Cattle

2. Sheep

3. Horses

4. Dogs/cats

Back 23

1. Cattle = mastitis superinfections; typically antibiotic resistant

2. Sheep = fleece rot

3. Horses = keratitis

4. Dogs, cats = otitis externa

Front 24

_______________ are environmental organisms occurring worldwide in water, soil & vegetation.

Back 24

PSEUDOMONADS

Front 25

Which pseudomonas spp causes a wide range of opportunistic infections, such as bovine mastitis, fleece rot in sheep, necrotic stomatitis in reptiles & haemorrhagic pneumonia in mink?

Back 25

PSEUDOMONAS AERUGINOSA

Front 26

List the many virulence factors of P. aeruginosa:

Back 26

1. Binding proteins & capsules

2. Fimbriae

3. Alginate

4. Pyochelin

5. Toxins & pigments (Endos- & exos-)

6. Enzymes & proteases

Front 27

Diagnosis of pseudomonas?

Back 27

1. Lab diagnosis of specimens (pus, respiratory aspirates, mastitic milk, ear swabs)

2. Blood agar & MacConkey inoculated & identified by colonial morphology

- Pyocyanin (dark grey/black pigment on agar) production

3. Non-lactose fermenter

4. Oxidase positive

5. TSI -ve

6. API 20 NE

Front 28

Treatment of pseudomonas spp infection?

Back 28

* NATURALLY VERY RESISTANT TO MANY ANTIBIOTICS, so lab testing on isolates to determine effectivity.

Front 29

Control of pseudomonas spp?

Back 29

1. Predisposing causes & sources of infection identified and eliminated

2. Vaccines for farmed mink & chinchillas.

Front 30

Glanders is caused by ____________________.

Back 30

BURKHOLDERIA MALLEI

Front 31

Rare, contagious disease of equidae characterized by formation of nodules and ulcers in the respiratory tract and skin.

Back 31

GLANDERS = caused by burkholderia mallei.

Front 32

Humans are not susceptible to bulkholderia mallei.

True or False?

Back 32

FALSE - Humans & carnivores also susceptible to bulkholderia mallei; potential bioterrorism agent

* Transmission by ingestion of food/water contaminated by nasal discharge of infected horses or inhalation/skin abrasions.

Front 33

Clinical features of Glanders (bulkholderia mallei)?

Back 33

1. Acute septicaemia with fever

2. Mucopurulent nasal discharge

3. Respiratory signs

4. Chronic disease more common presenting as nasal, pulmonary and cutaneous forms

5. Ulcerative nodules develop on the mucosa of the nasal turbinates & septum

Front 34

Diagnosis of bulkholderia mallei?

Back 34

1. Clinical signs

2. Lab diagnosis (pus, lesion discharge, blood)

3. Serology

Front 35

Treatment of bulkholderia mallei?

Back 35

Slaughter :(

* Recovered animals can still shed the bacteria.

Front 36

Melioidosis?

Back 36

Caused by Burkholderia pseudomallei

- Endemic in soil & water in SE Asia

- "Vietnam timebomb"

- Oppotunistic pathogen!

- Many species, including humans, susceptible

- Acute or chronic infections = septicaemic, respiratory, disseminated

- Characterized by abcess formation

- Infected zoo in France in 70s, resulting in entire zoo being euthanized and sterolized

Front 37

Describe Aeromona bacteria.

Back 37

Primarily pathogens of reptiles & fish, although some can infect mammals & birds

- Gram neg rods

- Non-lactose fermenting

- Oxidase positive

- A. hydrophila = food poisoning in man; B-hemolytic

- A. salmonicida = furunculosis in salmon

Front 38

What bacteria causes FURUNCULOSIS (soft tissue abscesses) in salmon?

Back 38

AEROMONA SALMONICIDA