Microbiology: Pseudomonas Aeruginosa

Front 1

A 25 yo man has worsening chronic cough with green sputum, slight fever, fatigue, SOB and has longstanding cystic fibrosis. What type of infection might she have?

Back 1

Pseudomonas aeruginosa

Front 2

In someone with a P aeruginosa infection what would be seen on PE and blood work?

Back 2

fever, tachycardia, tachypnea, pallor, B/L rales and wheezes, distant heart sounds

Low Hct, leukocytosis, low pO2

Front 3

X ray in some with P aeruginosa would show what?

Back 3

hyperinflated lungs and patchy B/L infiltrates

Front 4

In general which 2 organisms can cause chronic pneumonia?

Back 4

burkholderia cepacia and P aeruginosa are good at persisting for a long time

Front 5

How is P aeruginosa characterized?

Back 5

gram - rod that is nonspore forming and actively motile with a single polar flagellum. They are strict aerobes

Front 6

What pathogens are in the family Pseudomonadaceae?

Back 6

P aeruginosa, burkholderia and stenotrophomonas

Front 7

Is P aeruginosa fermentative and oxidase positive?

Back 7

no it is nonfermentative but is oxidase +

Front 8

What bacteria has a blue pigment and what causes the pigment?

Back 8

P aeruginosa has a water soluble pigment called pyocyanin (blue pus)

Front 9

When grown blood agar what features characterized P aeruginosa?

Back 9

fruity odor and blue color

Front 10

A sample is taken from the lungs of a CF patient and the organism appears mucoid because of an alginate capsule. What is the isolate?

Back 10

P aeruginosa

Front 11

Where can P aeruginosa grow?

Back 11

ice, tap water, soil

Front 12

Is P aeruginosa an important nosicomial infection? Where are they found in a hospital setting?

Back 12

yes they occupy soaps, disinfectants, dialysis equipment and fluid

Front 13

How is P aeruginosa transmitted?

Back 13

inhalation or ingestion

Front 14

What food is P aeruginosa commonly found on?

Back 14

tomatoes

Front 15

How does P aeruginosa colonize the trachea?

Back 15

with flagella and pili when the pili binds sialic acid on epithelial cell surface

Front 16

What is exoenzyme S?

Back 16

P aeruginosa surface protein that is an adhesin for epithelial cell glycolipids

Front 17

Initially P aeruginosa starts in the trachea. What happens from here?

Back 17

migration down to the bronchi resulting in a phenotypic shift where they become MUCOID and develop an ALGINATE CAPSULE

Front 18

Once P aeruginosa is in the mucoid form can they be killed?

Back 18

they can evade complement, phagocytosis and antibodies

Front 19

What organism makes a biofilm in the lungs that prevents immune action?

Back 19

P aeruginosa

Front 20

What host factors promote P aeruginosa survival?

Back 20

1) impaired bronchial clearance
2) increased mucin production stimulated by LPS

Front 21

What is the primary response against P aeruginosa?

Back 21

neutrophilic

Front 22

What is a main cause of morbidity in patients with CF?

Back 22

inflammatory reaction induced by neutrophils

Front 23

What factors does P aeruginosa secrete to induce morbidity?

Back 23

elastase, exotoxin A, phospholipase

Front 24

What is the function of exotoxin A and what organism secretes it?

Back 24

P aeruginosa releases it. It causes ADP-ribosylation of EF-2 causing inhibition of protein synthesis

Front 25

How is P aeruginosa treated?

Back 25

extended spectrum penicillins like piperacillin, or cephalosporin like ceftazidime or a carbapenem like imipenem or tobramyocin

Front 26

What is P aeruginosa commonly resistant to?

Back 26

1st and 2nd gen penicillins and cephs, tetracyclines, chloramphenicol, macrolides

Front 27

What causes swimmers ear? where is the infection?

Back 27

1) P aeruginosa
2) otitis externa (external canal)

Front 28

folliculitis caused by P aeruginosa can be acquired where?

Back 28

HOT TUBS, swimming pools

Front 29

A nail that goes through a shoe puts you at risk for P aeruginosa infection called?

Back 29

puncture wound osteomyelitis

Front 30

Invasive otitis externa is a life threatening condition seen in people with what preexisting condition? What is a common organism that causes it and how does it spread to deeper structures?

Back 30

1) people with DM
2) P aeruginosa spreads via the ducts of Santorini and infects soft tissues below temporal bone

Front 31

What is one of the more common causes of UTIs in hospitalized patients?

Back 31

P aeruginosa. it is often seen with use of a Foley catheter

Front 32

Where do most septic infections with P aeruginosa occur?

Back 32

hospitals and nursing homes

Front 33

What causes ecthyma gangrenosum? What is it?

Back 33

1) systemic P aeruginosa
2) round skin lesions where organisms invaded blood vessels