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RUSVM Bacteriology Gram Negatives > Pseudomonas > Flashcards

Flashcards in Pseudomonas Deck (46):
1

Pseudomonas: Gram ________? Shape?

Gram Negative, Rods

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2

Pseudomonas: Aerobic/Non-aerobic?

Obligate aerobe

3

Pseudomonas: Motile/Non-motile?

Motile

4

Pseudomonas: Distribution? Opportunist?

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

5

Pseudomonas: What is the strain of veterinary importance?

P. aeruginosa - Secondary agent

6

Pseudomonas: Does it exhibit antimicrobial sensitivity?

**Significant antimicrobial resistance** R plasmids!

7

Pseudomonas: Places it can be found in the environment?

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

8

Pseudomonas: Virulence Factors

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

9

Pseudomonas: Types of Adhesins

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

10

Pseudomonas: Types of Siderophores

Pyochelin & Pyoverdin

11

Pseudomonas: Types of Exotoxins

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

12

Pseudomonas: Exotoxin A function

Inhibits protein synthesis

13

Pseudomonas: Exotoxin S & T function

Affect actin cytoskeleton, interfere with phagocytosis

14

Pseudomonas: Exotoxin U function

Cytotoxic effect

15

Pseudomonas: Exotoxin Y function

Increases intracellular cAMP to cytopathic levels

16

Pseudomonas: Miscellaneous products

Bacteriocins & Pigments -Toxic to bacteria and eukaryotic cells

17

Pseudomonas: Bacteriocins (Pyocins)

Useful epidemiologically

18

Pseudomonas: Pigments (Pyocyanins)

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

19

Pseudomonas: Catalase and Superoxide dismutase function

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

20

Pseudomonas: Reservoir

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

21

Pseudomonas: Transmission

Secondary to compromised host (environmental or endogenous)

22

Pseudomonas: Pathogenesis

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

23

Pseudomonas: Disease Patterns: Dog & Cat

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

24

Pseudomonas: Disease Patterns: Horse

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

25

Pseudomonas: Case Report:

 

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Boxer dog, multifocal papular deep bacterial pyoderma

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26

Pseudomonas: Disease Pattern: Farmed Mink

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

27

Pseudomonas: Disease Pattern: Bovine

Mastitis (Contaminated intramammary infusion / teat-dipping solution)

28

Pseudomonas: Disease Pattern: Reptiles

Necrotic stomatitis, pneumonia, septicemia -Poor husbandry

29

Pseudomonal botryomycosis Presentation

Chronic granulomatous inflammation of skin, subcutis, viscera.

30

DDx of Pseudomonal botryomycosis

Fungal infections, Staphylococcal botryomycosis

31

Pseudomonas: Case Study Disease Pattern: Sheep

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

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32

Pseudomonas: Disease pattern: Humans

Septicemia -Immunocompromised individuals -Burns, leukemia, cystic fibrosis

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33

Pseudomonas: Immunology

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

34

Pseudomonas: Vaccine?

Possible with extracts of organisms or exotoxin A

35

What Media should be used to grow Pseudomonas?

Grows on all common media, 4-42C

36

Does Pseudomonas exhibit hemolysis?

Beta-hemolytic & grows quickly

37

What do Pseudomonas cultures often smell like?

Corn tortillas, grapes, flowers

38

Are Pseudomonas spp. Oxidase positive or negative?

Oxidase Positive -Different from enterics!

39

What are the results of the TSI test with Pseudomonas?

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

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40

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

Pigments give darker appearance in areas of confluent growth

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41

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

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That it is Lactose Negative

42

Pseudomonas: Lab Dx: Trypticase soy agar results

Pyocyanin production

43

What do these cultures reveal about Pseudomonas spp. pigments?

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-Left: Pyocanin pigment production by P. aeruginosa on trypticase soy agar

-Right: Green pigmentation from two water-soluble dyes: blue pyocins & yellow fluorescein

44

Pseudomonas: Treatment & Control

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

45

Pseudomonas: Antimicrobial Therapy

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

46

Pseudomonas: Resistance Factors

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