Brainscape's Knowledge GenomeTM

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


See full index

MHD Block 3:: Gram Negative Cocci and Bacilli > Pseudomonas and Other Non fermenters of Glucose > Flashcards

Pseudomonas and Other Non fermenters of Glucose Flashcards

1
Q

What are the characterisitics of glucose non-fermenting gram neg bacilli?

A 
Gram neg
Nonspore forming
Rods/Coccobacilli
Obligate Aerobes
Good growth in 24h
No glucose fermentation
Found in nature in water, soil, plants (Not part of normal gut flora)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Characteristics of Pseudomonas Aeruginosa?

A 
Aerobic Gram Neg Rod
Motile wit polar flagella
Mucoid polysaccharide slime layer
Pili
Oxidase Positive
Pyocyanin
Grape like odor
Opportunistic Pathogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where is pseudomonas found?

A

Environment
Grows in unsterile water, medications
Hospital
Moist areas

*Dont bring stuff fresh from outside like flowers when seeing immunosuppressed patients -> can get resistant organisms in

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

What factors predispose patients to serious pseudomonas infections?

A

Burns
Cystic Fibrosis
Hematologic Malignancies
Immunocompromised

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

How can you get pseudomonas skin infections?

A

Burn wounds
Folliculitis (hot tubs, whirlpools, water slides, swimming pools)
Nail infections

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

What are the types of pseudomonas pulmonary infections?

A

Asymptomatic colonization

Cystic fibrosis or chronic lung disease

Severe Necrotizing bronchopneumonia

VAP: ventilator associated penumonia

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

What are other pseudomnal infections?

A 
UTI
Ear infections : swimmer's ear; chronic otitis media
Eye infections
Bacteremia: Ecthyma Gangrenosum
Endocarditis: Tricuspid valve
Osteomyelitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is ecthyma gangrenosum

A

Happens in bacteremia due to P.Aeruginosa infections

Occurs in patients who are critically ill and immunocompromised => signals pseudomonal sepsis

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

What do ecthyma gangrenosum look like?

A

Hemorrhagic pustules or infarcted looking areas with surrounding erythema -> evolves into necrotic ulcers surrounded by erythema

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

What are hte virulence factors of P.Aeruginosa?

A

Structural: Capsule, Pili, LPS, Pyocyanin
Exotoxin A
Exoenzyme S
Elastase

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

What color is produced by the colonies of Pseudomonas on agar plate?

A

Greenish color due to pyocyanin + pyoveridin

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

What does Exotoxin A do in Pseudomonas?

A

Virulence factor

Blocks protein synthesis similar ot diptheria toxin

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

What does Exoenzyme S do in Pseudomonas?

A

ADP Ribosylation toxin -> damage epithelial cells -> promote bacterial spread, tissue invasion and necrosis

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

What does Elastase do in Pseudomonas?

A

Destroy elastin -> tissue destruction -> lung parenchymal damage and hemorrhagic lesions (Ecthyma Gangrenosum)

Also degrades complement components and prevent neutrophil chemotaxis and funciton

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

How is P.Aeruginosa infections diagnosed?

A

Culture: Grown on blood and MacConkey -> spready colonies with metallic sheen/offwhite color

ID: Glucose non fermenter, Oxidase Positive, Grape like odor, produce pyocyanin, Grows at 42deg C

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

What does Pseudomonoas look like on MacConkey Agar compared to E.Coli?

A

P.Aeruginosa: blue-grey colonies with lactose negative with green pigmentation
Ecoli: Purple colonies

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

How is Pseudomonas Infections treated?

A

REistant to many common abx for gram neg infections due to porins

Combination Therapy: Cell wall active agent + Aminoglycosides

18
Q

A gram‐negative rod grows as a colorless colony on a
MacConkey agar plate.Further laboratory testing
shows the organism is oxidase positive, does not
ferment glucose, produces a sweet grape‐like odor and
grows at 420C.Which of the following clinical
infections is most likely to be caused by this organism?
A. Ear infection after swimming in a fresh water
lake
B. Melioidosis
C. Community acquired urinary tract infection
D. Community acquired pneumoniae
E. Gastroenteritis following ingestion of
contaminated water

A

A

19
Q

What is important about Burkholderia Pseudomallei?

A

Causes melioidosis
Cat B Biothreat Agent
High Fatality rate associated with Bacteremia caused by B.Pseudomallei

20
Q

What are the different kinds of Melioidosis caused by B.Pseudomallei?

A

Acute: Septicemia with metastatic lesions -> 95% mortality if untreated

Subacute: Most common; TB like pneumonia wiht cellulitis and lymphangitis

Chronic: Localized chronic cellulitis; Treat with abx before draining or will become bacteremic

Can show latency and come out later as late infection

21
Q

How is B.Pseudomallei treated?

A

Ceftriaxone and Vanco

22
Q

What are some complicaitons prsent with CF patients?

A

Mutation in CFTR -> defective innate immunity -> cannot internalize bacteria in bronchial epithelial cells -> increased inflmmation in airway + abnormal electrolyte transport -> thick dry sticky mucus => ideal niche for lung infection

23
Q

How are pulmonary exacerbations and CF related?

A

Pts with CF have impaired mucocilliary transport with chronic infections leading to pulmonary exacerbations

This leads to impaired innate immunity and lung pathology due to neutrophil acitons

24
Q

Which known pathogens cause chronic lung disease in CF patients?

A

S.Aureus
P.Aeruginosa
B.Cepacia Complex

25
Q

What is important about Burkholderia Cepacia Complex?

A

60% isolated in resp tract infections
Major problem in patients with CF and CGD
Causes UTI, septicemia, and othe ropportunistic infections

26
Q

How does B.Cepacia complex look on culture?

A

Blood Culture: Yellow pigmented colonies
Slowly positive Oxidase

REsistant to most abx => difficult to treat

27
Q

What does Steotrophomonas Maltophilia cause?

A

Opportunistic Infection: Bacteremia, Pneumonia, Meningitis, Wound infections, UTI

resistant to many abx

28
Q

Where is STenotrophomonas Maltophilia found?

A

Environment
Not part of normal skin or GI flora
Found in clincal sites

29
Q

What are key characteristics of Stenotrophomonas Maltophilia

A

> 95% are hospital acquired

2nd leading cause of gram neg nonfermentative bacillary infections

30
Q

What is the hallmark of S.Maltophilia infection?

A

Life threatening systemic infections in debilitated patients

31
Q

How does S.Maltophilia look on blood agar?

A

Good growht on BAP and MacConkey
Oxidase Negative
Grayish Tint
Nonfermenter

32
Q

How is S.Maltophilia infection treated?

A

SXT: Trimethoprim-sulfamethoxazole/ Bactrim
Alternative: Ticarcillin/Clavulanate, Ceftazidime, Levofloxacin, Minocycline, Tigecycline

resistant to b-lactam agents like imipenem and aminoglycosides

33
Q

Where is Elizabethkingia Meningoseptica found?

A

Environment, water systems,wet surfaces in hospital

34
Q

Where are nosocomial outbreaks of E.Meningospetica traced to?

A

Breast Pumps in Hospital nurseries

35
Q

What is Elizabethkingia Meningoseptica associated wiht ?

A 
Neonatal Meningitis (along with E.coli, GBS, listeria, etc)
Pneumonia in adults in IC
36
Q

How does Elizabethkingia Meningoseptica appear on culture?

A

Oxidase Positive
Pale Yellow Pigment on BAP

Poor growth on MacConkey
Gram Neg

37
Q

How is Elizabethkingia Meningoseptica treated?

A

Currently: Minocycline, Rifampin, SXT, Quinolones

Inherently resistant to B-lactam agents and aminoglycosides

38
Q

Where is Acinetobacter Baumannnii found?

A

Water and soil

Skin of hospital personnel commonly

39
Q

What kind of diseases is Acinetobacter Baumanni associated with?

A

Low virulence community acquired and nosocomial infections

40
Q

How is acinetobacter baumannii identified?

A

Gram Neg coccobacilli
Good growth on BAP and MacConkey
Oxidase Neg
Non-motile

41
Q

How is Acinetobacter Baumannii treated?

A

Imipenem/Meropenem
Fluoroquinolone + Amikacin or Ceftadzidime
Ampicillin-sulbactam

But low virulence so back off and not treat if possible as resistance rates are increasing

42
Q

A gram-negative rod was recovered from the CSF of a
newborn with meningitis. It was an oxidase-positive,
glucose non-fermenting rod, that failed to grow on
MacConkey agar and was indole-positive. An
epidemiologic investigation revealed that the mother was
using a breast pump that belong to the hospital nursery
and may have been the source of the causative agent.
What is the likely agent of meningitis in this case.
A. Elizabethkingia meningoseptica
B. Citrobacter koseri
C. E. coli
D. Listeria monocytogenes
E. Neisseria meningitidis

A

A

MHD Block 3:: Gram Negative Cocci and Bacilli (6 decks)

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