Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2.2 Microbiology > Denise - Pseudomonas > Flashcards

Denise - Pseudomonas Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the reservoirs for Pseudomonas

A

Free-living bacterium
Found in the environment (soil, water, sewage, moist surfaces, hot tubs)
Found on plants and animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When can pseudomonas cause problems
(3)

A

Plant pathogens
Food spoilage organisms
Bioremediation - present in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How would pseudomonas be transmissed
(4)

A

Direct contact with water - ingestion or bathing

Inhalation of aerosols

Medical Devices rinsed with contaminated water

Indirect contact from contaminated surfaces via the hands of health care workers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How common is pseudomonas in the lab?
(4)

A

15% of clinical bacterial isolates in the lab

Very common hospital acquired infection

Often multi drug resistance

An ESKAPE Pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What percentage of HCAI are pseudomonas species?

A

4% of HCAI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Comment on P. aeruginosa and immunocompromised patients
(4)

A

Pseudomonas increasingly recognised as an opportunistic pathogen

Pseudomonas is common in present in moist environments in hospitals especially in respiratory therapy equipment, Dialysis tubing catheters

It is pathogenic when introduced into areas devoid of normal defences or the immunocompromised

Dysfunctional Immune System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Who is at risk of P. aeruginosa infections due to dysfunctional immune system?
(6)

A

Neonates
Cystic fibrosis
AIDA
Neutropenia
Complement Deficiency
Hypogammaglobulinemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Who is at risk of Pseudomonas infections due to disruption of physical barriers?
(5)

A

Burn injuries

Intravenous IV lines

Urinary catheters

Dialysis catheters

Endotracheal tubes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Pseudomonas infects what areas of the body

A

Respiratory tract
Ear
GI tract
Urinary tract
Eye
Bones and joints

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What infections does Pseudomonas cause in the respiratory tract?

A

Pneumonia
Cystic fibrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What infections does Pseudomonas cause in the ear

A

Otitis externa
Otitis media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What infections does Pseudomonas cause in the eye

A

Bacterial keratitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What infections does Pseudomonas cause in the Bones and joints

A

Osteomyelitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What infections does Pseudomonas cause in the GIT?

A

Diarrhoea, enteritis, enterocolitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the five types of systemic infections that Pseudomonas can cause

A

Blood stream infections
Secondary pneumonia, bone and joint infections
Endocarditis
CNS
Skin and soft Tissue infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Comment on the invasiveness of Pseudomonas
(2)

A

Invasive P.aeruginosa infections are on the increase

MDR strains have fluctuated between 4-9% since 2014

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the first step in P. aeruginosa infection

A

Colonisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Comment on the colonisation of P. aeruginosa

A

Break in first line defence
Cell associated virulence factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Comment on the P. aeruginosa in an acute infection
(4)

A

Virulence factors increased

Protease toxins

Invasion

Tissue damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Comment on P. aeruginosa in chronic infections
(3)

A

Persistent pulmonary infection in Cystic Fibrosis

Formation of biofilm

Virulence factors lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

List the cell associated factors that promote colonisation in P. aeruginosa infections
(2)

A

Pili
Capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What virulence factors cause systemic infections in P. aeruginosa?
(2)

A

Exotoxin A
Endotoxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What extracellular factors degrade tissue and promote invasion?
(4)

A

Proteases
Elastases
Phospholipase C
Exotoxin A

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Comment on the LPS of P. aeruginosa

A

There is some structural variability of LPS
It differs between mucoid to nonmucoid transition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the two secreted components of P. aeruginosa?

A

Pyocyanin

Alginate slime

26
Q

What does pyocyanin do?
(2)

A

Interferes with the antioxidant defences in the lung

Facilitates oxidative damage to the lung epithelium

27
Q

What does alginate slime do?
(2)

A

Matrix of biofilm formation

Impairs cillary function

28
Q

List the exotoxins and exoenzymes of P. aeruginosa
(4)

A

Leukocidin

Elastase

Alkaline Protease

Phospholipase C

29
Q

What does elastase do?
(3)

A

Destruction of elastin

Cleaves IgG, IgA, Complement

Degrades surfactant proteins A and D

30
Q

What does alkaline protease do?

A

Lyses fibrin

31
Q

What does phospholipase C do?

A

A class of membrane-associated enzymes that cleave phospholipids

32
Q

What does leukocidin do?
(2)

A

A type of cytotoxin or exotoxin

A pore-forming toxin that kills or destroys white blood cells by creating holes in their membranes

33
Q

Write about exotoxin A

A

ADP ribosylation
Inactivation of elongation factor 2
Inhibits protein synthesis
Regulated by environmental iron availability

34
Q

What does exotoxin S do?

A

It impairs the function of phagocytic cells

35
Q

What type of secretion system does Pseudomonas aeruginosa employ

A

The type III secretion system

36
Q

What four effector proteins make up the type III secretion system of Pseudomonas?

A

ExoS
ExoT
ExoU
ExoY

37
Q

What does ExoU do?

A

Rapid destruction of host cell membranes
Is greater in P. aeruginosa isolated in hospital ICUs and burn units

38
Q

What does ExoS do

A

Relevant in patients with CF

39
Q

Which protein effectors of the type 3 secretion system are mutually exclusive

A

ExoU and ExoS

40
Q

What does Pseudomonas produce in chronic infections?

A

Bacterial biofilms

41
Q

What biofilm is produced by Pseudomonas

A

Exopolysaccharide alginate

Produced in vitro and in vivo

42
Q

What is the function of biofilm
(5)

A

Its a survival mechanism for bacteria - it’s a form of protection

Protects against:
- host immune cells
- host antibodies
- disinfectant
- antibodies

43
Q

Describe sessile vs planktonic
(2)

A

Sessile bacteria grow more slowly and have restricted mobility

Planktonic forms in culture media and have unnatural access to nutrients, they multiply rapidly and are often highly motile

44
Q

Comment on P. aeruginosa and cystic fibrosis

A

Infection with P. aeruginosa and development of chronic infection is directly related to the loss of lung fucntion in cystic fibrosis

45
Q

Comment on biofilms in the health care setting
(3)

A

Biofilms form on instruments and implants

Equipment (catheters, prosthetic heart valves, prosthetic joints, shunts)

Healthcare setting (water systems and air conditioning units)

46
Q

How is Pseudomonas infections treated?
(3)

A

There is increased resistance during therapy

Pseudomonas may acquire resistance during therapy

Dual therapy is recommended to avoid resistance that develops rapidly when single antimicrobials are used

47
Q

Comment on the dual therapy approach to treating Pseudomonas and give two examples of treatment
(3)

A

Two agents from different classes should be used

Beta-lactams such as cephalosporin and an aminoglycoside such as tobramycin

Carbapenems such as meropenem with a fluroquinolone such as ciprofloxacin

48
Q

What mechanisms of antimicrobial resistance does P. aeruginosa have?
(5)

A

Permeability barrier

Biofilm formation

Resistance plasmids

Efflux pumps

Resistant to disinfectants

49
Q

Comment on the permeability barrier of the P. aeruginosa

A

P. aeruginosa is naturally resistant to many antibiotics due to the permeability barrier gram-negative outer membrane

50
Q

What is the point of biofilm formation

A

This makes the cells impervious to therapeutic concentrations antibiotics

51
Q

What is the main method of antimicrobial resistance in P. aeruginosa?

A

Porins -> pump out the antibiotic

52
Q

What specimens can be put up for Pseudomonas

A

Urine
Sputum
Blood
Pus

53
Q

Psueomonas is usually put up on what media
(5)

A

Blood agar
Chocolate agar
Moderately selective media - MacConkey media
Selective agar - Cetramide agar

Incubate aerobically at 37 degrees Celsius for 24-48 hours

54
Q

How does Pseudomonas look on blood agar
(2)

A

Metallic sheen
Sweet odour

55
Q

How does Pseudomonas look on MacConkey agar?

A

Non lactose Fermenter (yellow colonies)

56
Q

How does Pseudomonas look on cetrimide agar?

A

Enhanced pigment of pseudomonas aeruginosa => bright green colour produced

57
Q

How does cetrimide agar work

A

It enhances the production of Pseudomonas pigments such as pyocyanin and pyoverdine which show a characteristic blue-green and yellow-green colour

58
Q

How can you classify Pseudomonas aeruginosa based on colonial morphology

A

Non-mucoid to mucoid transition

59
Q

What are the results of P. aeruginosa basic characteristic tests
(3)

A

GNBs
Oxidase positive
Weak catalase positive

+ distinctive morphology e.g. metallic sheen and mucoid colonies

60
Q

How would you identify Pseudomonas in the lab
(4)

A

Growth on selective media
Growth at 42 degrees Celsius
Failure to grow at 4 degrees Celsius
Biochemical Identification

61
Q

Can the Maldi/Vitek be used to identify Pseudomonas?

A

No as there are issues with the Maldi/Vitek especially for the mucoid strains

2.2 Microbiology (60 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions