Pseudomonas Flashcards Preview

RUSVM Bacteriology Gram Negatives > Pseudomonas > Flashcards

Flashcards in Pseudomonas Deck (46):
1

Pseudomonas: Gram ________? Shape?

Gram Negative, Rods

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:

 

Boxer dog, multifocal papular deep bacterial pyoderma

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

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

32

Pseudomonas: Disease pattern: Humans

Septicemia -Immunocompromised individuals -Burns, leukemia, cystic fibrosis

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

40

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

Pigments give darker appearance in areas of confluent growth

41

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

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?

-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