Pseudomonas

Question 1

Pseudomonas: Gram ________? Shape?

Answer 1

Gram Negative, Rods

Question 2

Pseudomonas: Aerobic/Non-aerobic?

Answer 2

Obligate aerobe

Question 3

Pseudomonas: Motile/Non-motile?

Answer 3

Motile

Question 4

Pseudomonas: Distribution? Opportunist?

Answer 4

Ubiquitous - Worldwide - Remarkable capacity to adapt & thrive in diverse ecological niches **Opportunistic Pathogen**

Question 5

Pseudomonas: What is the strain of veterinary importance?

Answer 5

P. aeruginosa - Secondary agent

Question 6

Pseudomonas: Does it exhibit antimicrobial sensitivity?

Answer 6

**Significant antimicrobial resistance** R plasmids!

Question 7

Pseudomonas: Places it can be found in the environment?

Answer 7

Wet, poorly aerated environments -Surgery areas w/support bags -Hoses in anesthetic machine -Mastitis preparations/infusions -Semen extenders -Irrigation Fluids -Hydrotherapy baths -***Endotracheal tubes

Question 8

Pseudomonas: Virulence Factors

Answer 8

-Adhesins (different types) -Capsule -Cell Wall LPS -Extracellular Slime/Biofilm -Siderophores (types) -Exotoxins -Others: Elastase, Proteases, Phospholipase C (hemolysin)

Question 9

Pseudomonas: Types of Adhesins

Answer 9

-Fimbrial, Type IV pili, bind glycoproteins on epithelial cells -Non-Fimbrial (OMPs) -Affinity for mucin -Flagella & LPS - Affinity for Cl- channels

Question 10

Pseudomonas: Types of Siderophores

Answer 10

Pyochelin & Pyoverdin

Question 11

Pseudomonas: Types of Exotoxins

Answer 11

T3SS - **Exotoxin A** -Exotoxin S, T, U & Y

Question 12

Pseudomonas: Exotoxin A function

Answer 12

Inhibits protein synthesis

Question 13

Pseudomonas: Exotoxin S & T function

Answer 13

Affect actin cytoskeleton, interfere with phagocytosis

Question 14

Pseudomonas: Exotoxin U function

Answer 14

Cytotoxic effect

Question 15

Pseudomonas: Exotoxin Y function

Answer 15

Increases intracellular cAMP to cytopathic levels

Question 16

Pseudomonas: Miscellaneous products

Answer 16

Bacteriocins & Pigments -Toxic to bacteria and eukaryotic cells

Question 17

Pseudomonas: Bacteriocins (Pyocins)

Answer 17

Useful epidemiologically

Question 18

Pseudomonas: Pigments (Pyocyanins)

Answer 18

Use Diagnostically -Produce O2 radicals toxic to eukaryotes & prokaryotes -Self-protected by catalase & superoxide dismutase

Question 19

Pseudomonas: Catalase and Superoxide dismutase function

Answer 19

Protect from O2 radicals produced by pigments/pyocyanins to kill host cells

Question 20

Pseudomonas: Reservoir

Answer 20

Soil, water, feces of normal animals (NOT normal flora)

Question 21

Pseudomonas: Transmission

Answer 21

Secondary to compromised host (environmental or endogenous)

Question 22

Pseudomonas: Pathogenesis

Answer 22

Reduced normal flora / antimicrobial use –> Pseudomonas colonization, highly resistant, strong adherence –> Tissue destruction, inflammation, exotoxins, pyocyanin

Question 23

Pseudomonas: Disease Patterns: Dog & Cat

Answer 23

*Otitis Externa (swimmers, long droopy ears, hair in ear canal) *Lower UTI Pyoderma

Question 24

Pseudomonas: Disease Patterns: Horse

Answer 24

Metritis/Vaginitis (secondary or contaminated semen) Keratitis & conjunctivitis (after topical steroid-antibiotic mixtures)

Question 25

Pseudomonas: Case Report:

Answer 25

Boxer dog, multifocal papular deep bacterial pyoderma

Question 26

Pseudomonas: Disease Pattern: Farmed Mink

Answer 26

Particularly susceptible Hemorrhagic pneumonia & septicemia with high mortalities ~50%

Question 27

Pseudomonas: Disease Pattern: Bovine

Answer 27

Mastitis (Contaminated intramammary infusion / teat-dipping solution)

Question 28

Pseudomonas: Disease Pattern: Reptiles

Answer 28

Necrotic stomatitis, pneumonia, septicemia -Poor husbandry

Question 29

Pseudomonal botryomycosis Presentation

Answer 29

Chronic granulomatous inflammation of skin, subcutis, viscera.

Question 30

DDx of Pseudomonal botryomycosis

Answer 30

Fungal infections, Staphylococcal botryomycosis

Question 31

Pseudomonas: Case Study Disease Pattern: Sheep

Answer 31

Fleece Rot -Purulent rhinitis & otitis after showered with contaminated "shower wash"

Question 32

Pseudomonas: Disease pattern: Humans

Answer 32

Septicemia -Immunocompromised individuals -Burns, leukemia, cystic fibrosis

Question 33

Pseudomonas: Immunology

Answer 33

No significant specific immune response -Need to decrease risk of secondary infection (hygiene, husbandry)

Question 34

Pseudomonas: Vaccine?

Answer 34

Possible with extracts of organisms or exotoxin A

Question 35

What Media should be used to grow Pseudomonas?

Answer 35

Grows on all common media, 4-42C

Question 36

Does Pseudomonas exhibit hemolysis?

Answer 36

Beta-hemolytic & grows quickly

Question 37

What do Pseudomonas cultures often smell like?

Answer 37

Corn tortillas, grapes, flowers

Question 38

Are Pseudomonas spp. Oxidase positive or negative?

Answer 38

Oxidase Positive -Different from enterics!

Question 39

What are the results of the TSI test with Pseudomonas?

Answer 39

-Red butt & slant (K/K) -Non-fermenter of all three sugars -No Gas Production

Question 40

What do Pseudomonas spp. pigments do to the appearance of the colonies?

Answer 40

Pigments give darker appearance in areas of confluent growth

Question 41

What does this image indicate about Pseudomonas grown on MacConkey agar?

Answer 41

That it is Lactose Negative

Question 42

Pseudomonas: Lab Dx: Trypticase soy agar results

Answer 42

Pyocyanin production

Question 43

What do these cultures reveal about Pseudomonas spp. pigments?

Answer 43

- Left: Pyocanin pigment production by P. aeruginosa on trypticase soy agar - Right: Green pigmentation from two water-soluble dyes: blue pyocins & yellow fluorescein

Question 44

Pseudomonas: Treatment & Control

Answer 44

\*\*ID predisposing factor, eliminate source of organism\*\* -Antimicrobial Therapy (other slide) -Hygeinic Practices -Vaccines may reduce disease severity

Question 45

Pseudomonas: Antimicrobial Therapy

Answer 45

Very resistant so difficult -Often aids colonization of pseudomonads by eliminating other bacteria -Tetracycline for dog UTI -Gentamicin or tobramycin with cabenicllinin or potentiated ticarcillin

Question 46

Pseudomonas: Resistance Factors

Answer 46

--Low outer membrane permeability --Multidrug efflux pumps --Production of chromosomally-encoded B-lactamases --Biofilms/Slimes