Pseudomonas & Burkholderia

Question 1

What species of Pseudomonas and Burkholderia are of most importance? What respiration do they all undergo?

Answer 1

P. aeruginosa, P. fluorescens = opportunistic

B. mallei, B. pseudomallei = pathogen, bioterrorism

aerobic!

Question 2

What is Pseudomonas aeruginosa?

Answer 2

Gram-negative, aerobic rod with polar flagella for motility and attachment

Question 3

What is commonly associated with Pseudomonas aeruginosa wounds and cultures?

Answer 3

fruity, grape-like smell caused by aminoacetophenone

Question 4

Pseudomonas are able to produce pigments. Which one is characteristic to P. aeruginosa?

Answer 4

pyocyanin
(others are pyoverdine, pyorubin, and pyomelanin)

Question 5

Where is Pseudomonas aeruginosa typically found? What is its host range like?

Answer 5

in the environment
- water
- soil/plants
- hospitals, especially moist and plastic
- home

humans/animals –> broad, most common in immunocompromised (opportunistic)

Question 6

What 5 factors of Pseudomonas aeruginosa contribute to its multidrug resistance?

Answer 6

1. impermeability
2. multidrug efflux pumps
3. aminoglycoside-modifying enzymes
4. β-lactamases
5. biofilm (alginate) - slime, viscous gel

Question 7

What 5 toxins are produced by Pseudomonas aeruginosa? How does it attach to its targets?

Answer 7

1. exotoxin A - blocks endocytosis and protein synthesis
2. phospholipase C - hemolysin breaks cell membrane
3. pyocyanin - ROS
4. pyoverdine - siderophore
5. degradive enzymes

pili, flagella, LPS endotoxin

Question 8

What is the point of Pseudomonas aeruginosa producing alginate and using T3SS?

Answer 8

ALGINATE - mucoid EPS used for biofilm formation, which blocks antibiotics

T3SS - translocates exoenzyme S into host cells to cause apoptosis and blocks immune response

Question 9

What are common symptoms of skin and ear infections caused by Pseudomonas aeruginosa?

Answer 9

SKIN - fleece rot in sheep, pyoderma in dogs

EAR - otitis externa in dogs and cats, otitis media/interna in chinchillas

Question 10

What are common symptoms of eye and respiratory infections caused by Pseudomonas aeruginosa?

Answer 10

EYE - ulcerative keratitis in dogs, cats, and horses

RESP - pneumonia in dogs, cats, and chinchillas

Question 11

What are common symptoms of blood infections caused by Pseudomonas aeruginosa? What are 2 other common types of infection?

Answer 11

BLOOD - bacteremia and septicemia in chinchillas

1. mastitis in sheep and cattle
2. necrotic stomatitis in snakes

Question 12

What specimen can be collected for Pseudomonas aeruginosa isolation? How does it grow on nutrient agar, MacConkey agar, and blood agar?

Answer 12

pus, respiratory aspirates, milk samples, ear swabs

NUTRIENT: fruity grape-like odor, produces pyocyanin
MACCONKEY: non-lactose fermenter (white/colorless)
BLOOD: β-hemolytic

Question 13

How does Pseudomonas aeruginosa respond to oxidase and catalase tests?

Answer 13

oxidase +
catalase +

Question 14

How is Pseudomonas aeruginosa treated/controlled?

Answer 14

• antibiotic therapy is difficult —> MDR
• vaccines for farmed mink and chinchillas

Question 15

What is Pseudomonas fluorescens? What are 2 unique properties it contains?

Answer 15

Gram-negatice, motile, aerobic rod

1. unable to ferment glucose
2. produces a fluorescent pigment (pyoverdine) under UV light

Question 16

Where is Pseudomonas fluorescens commonly found? What symptoms does it cause?

Answer 16

soil and water

skin ulcers and septicemia in freshwater fish and reptiles

Question 17

What is Burkholderia mallei? Where is it most commonly found?

Answer 17

Gram-negative, non-motile, aerobic coccobacillus

facultative intracellular pathogen - cannot live outside of their host

Question 18

What is Burkholderia mallei the causative agent of? Why must it be handled very carefully?

Answer 18

Glanders in horses, donkeys, and mules

it is a category B bioterrorism agent

Question 19

What 5 virulence factors does Burkholderia mallei contain?

Answer 19

1. capsule
2. LPS
3. multiple secretion systems
4. quorum sensing mechanism
5. adhesion proteins and fimbriae

Question 20

What is Glanders? How is it transmitted from horses to humans?

Answer 20

contagious, sporadic, endemic, zoonotic disease common in horses and caused by Burkholderia mallei characterized by the formation of nodules and ulcers on the skin and in the respiratory tract

contact, ingestion, inhalation

Question 21

What is the difference betwen acute and chronic forms of Glanders?

Answer 21

ACUTE: fever, septicemia, pneumonia

CHRONIC: more common, develops in several months

Question 22

What are the 3 forms of Glanders based on presentation?

Answer 22

1. PULOMARY: tubercle like lesions (nodules)
2. CUTANEOUS (farcy): nodules, ulcers, yellowish pus
3. NASAL: ulcerative nodules, nasal discharge (mucopurulent, bloody)

Question 23

Glanders, pulmonary form:

Answer 23

nodules in lung —> black, miliated

Question 24

Glanders, cutaneous form (farcy):

Answer 24

Question 25

Glanders, nasal form:

Answer 25

Question 26

In what media does Burkholderia mallei grow the best? What is it unable to grow in?

Answer 26

enriched blood agar containing 1% glycerol MacConkey (unlike Pseudomonas)

Question 27

What is the only test approved for Glanders diagnosis?

Answer 27

serological tests detecting antibodies in the blood - complement fixation test

Question 28

What test was created to diagnose Glanders in the field?

Answer 28

Mallein test ---> glycoprotein from B. mallei culture used as an antigen and applied to the skin of lower eyelid or neck - no longer really recommended due to animal welfare

Question 29

How is Burkholderia mallei specimens processed? How can infection be treated and controlled?

Answer 29

must be processed within biohazard cabinet - effective cleaning and disinfection with a contact time of 6 hours (formalin, iodophor, sodium hydrochloride, 70% ethanol) - antibiotic therapy in endemic areas - euthanasia in US - no vaccine

Question 30

What is Burkholderia pseudomallei? How does it characteristically stain? Where is it naturally found?

Answer 30

Gram-negative, aerobic, motile bacillus bipolar stain, giving it a safety pin appearance - facultative intracellular pathogen - soil and water where it can lay dormant for years

Question 31

What is Burkholderia pseudomallei the causative agent of?What does this cause?

Answer 31

melioidosis via contact in the environment, aka Whitmore's disease or pseudoglanders (category B bioterrorism agent) abscess formation in multiple organs

Question 32

What 7 virulence factors do Burkholderia pseudomalleia contain?

Answer 32

1. capsule 2. LPS 3. multiple secretion systems 4. quorum sensing 5. type IV pili 6. exotoxins 7. protease

Question 33

How does Burkholderia pseudomallei typically present clinically? In sheep, goats, pigs, horses, dogs/cats, cows, and humans?

Answer 33

- local skin ulcers - chronic abscess formation - granuloma formation - chronic pneumonia - acute septicemia SHEEP: lung abscesses, pneumnia GOATS: mastitis PIGS: asymptomatic lesions on the spleen HORSE: pseudoglanders DOG/CAT: abscess formation on multiple organs COWS: pneumonia, CNS disease HUMANS: pneumonia, subclinical abscessed

Question 34

On what 2 media can Burkholderia pseudomallei grow?

Answer 34

1. blood agar - greyish-white, non-hemolytic with musty odor 2. MacConkey agar

Question 35

How is it recommended to treat Burkholderia pseudomallei infection? What are 2 common interventions?

Answer 35

antibiotic therapy ---> be careful with resistance and relapse 1. surgical drainage of large abscesses 2. enucleation in the case of eye infection

Question 36

Pseudomonas and Burkholderia summary:

Answer 36