Lecture 15: Pseudomonas and Burkholderia

What are the characteristics of Pseudomonas aeruginosa?

• Gram _

• Motility?

• Respiratory pattern?

• Oxidase _

• Catalase _

• Gram - rods

• Motile

• Obligate aerobe

• Oxidase +

• Catalase +

T/F: P. aeruginosa has an inherent resistant to antimicrobials

True, (ESKAPE)

P. aeruginosa is a notorious opportunist, it is able to escape being killedby drugs/cleaners by hiding itself in what?

Biofilm

How does Biofilm facilitate the survival of P. aeruginosa in and outside the host?

• Inside Host

  • Prevents phagocytosis

  • Protection from antimicrobials

  • Facilitates colonization and long-term persistence

• Outside Host

  • Survival under environmental stressors and low nutrition

What is the key virulence factor of P. aeruginosa?

Biofilm

Biofilm is just one way that P. aeruginosa can be resistant to antibiotics, what are the other 2?

1. Intrinsic resistance

2. Acquired Resistance

3. Biofilm

P. aeruginosa is a common cause of what disease in…

1. Companion animals

2. Horses

3. Sheep

4. Cattle

5. Mink

6. Poultry

7. Reptiles

1. Skin infections (Otitis externa/pyoderma)

2. Corneal ulcer

3. Fleece rot 

4. Mastitis

5. Hemorrhagic pneumoniae

6. Embryo mortality and omphalitis (bacterial infection of the umbilical stump)

7. Necrotic stomatitis

   1. Mouth rot/canker mouth

What predisposes sheep to disease by P. aeruginosa?

• P. aeruginosa causes fleece rot in sheep

• Prevent it by shearing them before rainy season 

What type of environment do P. aeruginosa prefer?

Aqueous 

T/F: Some strains of Pseudomonas aeruginosa produce pigment

True

Which bacteria produces an aromatic compound that smells grape-like or fruity?

Pseudomonas aeruginosa

What are the 2 species of Burkholderia do we discuss?

1. Burkholderia mallei

2. Burkholderia pseudomallei

What bacteria causes Glanders in Equidae? Describe the infection

• Burkholderia mallei

• Serial development of nodules in the upper respiratory tract, lungs, and skin.

What is the concern regarding Burkholderia mallei for equestrians?

Burkholderia mallei is a zoonotic disease

What are the characteristics of Burkholderia mallei?

• Gram _

• Shape?

• Motility?

• Intracellular/Extracellular?

• Unique features

• Gram -

• Rods

• Non-motile

• Facultative intracellular

• Bipolar (More stain at either end of the rod)

Glanders (Burkholderia mallei) is primarily a disease of the _________ _____ and ______

Respiratory system and Skin

What is the incubation period of Burkholderia mallei (Glanders)?

3 days → 2 weeks

An important characteristic of Burkholderia mallei (Glanders) is that it causes acute __________, what does this mean for the C.S?

• Burkholderia mallei causes acute septicemia

• The C.S presents quickly due to the bacterias’s swiftness in entering the blood stream

Burkholderia mallei (Glanders) can present as a cutaneous or pulmonary infection, describe the difference in presentation of each

1. Pulmonary

   1. Pyogranulomas with caseous centers

   2. Fatal in donkeys

   3. Chronic/Subclinical in horses

2. Cutaneous

   1. aka “Farcy“

   2. Nodules/Subcutaneous abscesses along the lymphatic vessels

   3. Discharge yellow honey-like pus

What are the general C.S of a Burkholderia mallei (Glanders) infection in horses?

• Fever, mucopurulent/blood-tinged nasal discharge, respiratory distress (See image)

• Lymphadenitis of the head/neck region

  • Similar to Equine strangles (SEE)

• Nodules/ulcers in the upper airway, nasal septum, and skin

T/F: Local or generalized lymphadenopathy (swollen lymph nodes) is typically in all types of glanders

True

T/F: Human glanders is fatal in 95% of cases if left untreated after septicemia

True

What is Burkholderia pseudomallei commonly known as?

Meliodiosis (Pseudoglanders)

What are the characteristics of Burkholderia pseudomallei? What is the main difference between Burkholderia pseudomallei and Burkholderia mallei?

• Gram _

• Shape?

• Motility?

• Intracellular/Extracellular?

• Gram -

• Rods

• Motile

• Facultative intracellular

• Bipolar

Burkholderia pseudomallei is Motile and Burkholderia mallei is non-motile

Burkholderia pseudomallei, unlike B mallei, is a __________ (soil bacterium)

Saprophyte, it is an endosymbiote of Amoebae (just need to know it’s a saprophyte)

What is the gross presentation of meliodiosis (pseudoglanders) caused by Burkholderia pseudomallei?

Sepsis, pneumonia, and visceral abscesses (abscesses on organs)

What is Whitmore’s Disease?

• Human Meliodiosis (pseudoglanders)

• Asymptomatic to acute spesis

• Often fatal 

Burkholderia pseudomallei grows at __°C

42°C (107°F), this is likely why the bacteria is only found in hotter/moist climates (Asia and Australia)

Pseudomonas aeruginosa is a Gram-negative, _____ (resp. pattern) rod

Aerobic

Pseudomonas infections are commonly nosocomial, they occur as the result of __________ of medical devices and solutions

Contamination

T/F: Pseudomonas aeruginosa is a facultative anaerobe

False, it is an obligate aerobe

T/F: P. aeruginosa is a commensal of dog’s skin

False, P. aueruginosa is a transient bacteria, meaning they are temporarily present on or in the body and do not permanently colonize

List 2 mechanisms that contribute to Pseudomonas resistance to antibiotics

1. Intrinsic resistance

   1. Efflux Pump (pumps out antibiotics)

2. Acquired resistance

   1. Gene mutation, horizontal gene transfer

1. Biofilm

List two characteristics that aid in the diagnosis of Pseudomonas

1. Fruity odor

2. Non-lactose fermenter on MacConkey

3. Pigment

4. Oxidase +

List 3 disease conditions in livestock/ and or large animals caused by pseudomonas

1. Ocular infections in horses

2. Fleece rot in sheep

3. Mastitis in Cattle

P. aeruginosa causes __________ in mink?

Hemorrhagic pneumoniae

T/F: Burkolderia mallei is a host-adapted pathogen

True, it is specific to Equidae

T/F: B. mallei and B. pseudomallei are categorized as foreign animal diseases in Canada

True

Gram staining of an ear swab of a dog shows a moderate number of Gram-negative rods. Which organism will you highly suspect?

Pseudomonas aeruginoas