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PHARM/MHD EXAM - 3 > L6 MHD: Pseudomonas/Gram - Rods > Flashcards

L6 MHD: Pseudomonas/Gram - Rods Flashcards

1
Q

What 6 gram negative Bacilli do not ferment glucose?

A
  1. PSEUDOMONAS Aureginosa
  2. Burkholderia pseudomallei
  3. Burkholderia cepacia
  4. Stenotrophomonas maltophilia
  5. Elizabethkingia meningoseptica
  6. Acinetobacter baumannii
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2
Q

Glucose Non-Fermenting Bacilli:

  1. Gram (+ or -)
  2. Spores?
  3. What 2 shapes?
  4. Aerobe/anaerobe? Facultative/obligate?
  5. Natural Habitat?
A
  1. Gram negative
  2. NOT spores
  3. Rods or Coccobacilli
  4. OBLIGATE AEROBES* (test)
    - good growth within 24hours
  5. Water, soil, plans

** exist in nature (unlike Enterobacteriaciae which is part of normal gut flora)

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3
Q

Pseudomonas Aeruginosa:

  1. Aerobic/Anaerobic?
  2. Rod or bacilli?
  3. What is unique to polysaccharide?
  4. What is on the cell surface?
A
  1. Aerobic Gram negative rod
  2. Motile with polar flagella
  3. Mucoid polysaccharide slime layer
  4. Pili on cell surface
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4
Q

EPIDEMIOLOGY of P AERUGINOSA:

  1. _____ organism
  2. Grows in ?
  3. What environment?
  4. Specifically what type of areas?
A
  1. ENVIRONMENTAL organism
  2. Grows in unsterile water, medications, disinfectants
  3. Hospital environment
  4. Moist areas:
Sinks
Toilets
Cut flowers
Floor mops
equipment

** be especially weary in the case of immunosuppressed patients**
(do not bring fresh flowers, salads etc because they may contain Non-fermenters)

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5
Q

P. aeruginosa is a _____pathogen

What 5 factors predispose to serious infections of P. Aeruginosa?

A

Oppotunistic

  1. Burn patients**
    - lose barrier of defense
  2. Cystic fibrosis patients
  3. Patients with hematologic malignancies
  4. Immunocompromised patients
  5. Can be part of the microbial flora in hospitalized patients and ambulatory, immunocompromised hosts
    - Infections occur at any site where moisture tends to accumulate, indwelling catheres, trach sites, burns, external ear
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6
Q

The following are examples of what:

  1. Burn wounds
  2. FOLLICULITIS
    - hot tubs, whirlpools, swimming pools, water slides
    - chlorine content may not be adequate to kill
    the bacteria
  3. NAIL infections
A

Pseudomonas Skin infections

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7
Q

Pseudomoas Pulmonary infection shows:

  1. ________ colonization
  2. What 3 main diseases?
  3. Most common cause of ______
A
  1. Asymptomatic
  2. a) Cystic fibrosis, b)chronic lung disease
    c) Severe necrotizing bronchopneumonia
  3. ventilator associated pneumonia (VAP)!!!!

** any question of a patient with ventilator = PSEUDOMONAS **

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8
Q

What are some other common pseudomonas infections not associated with skin or lungs? (6)

A
  1. Urinary tract infections
  2. Ear infections
    - “swimmers ear”
    - Malignant external otitis
    - Chronic otitis media
  3. Eye Infections
    pseudomonas is a
    contaminant in eye
    cosmetics
  4. Bacteremia
    - Ecthyma gangrenosum
  5. Endocarditis
    - IVDA and involves the tricuspid valve
  6. Osteomyelitis
PSEUDDO
P - pneumonia
S- sepsis 
E - otitis Externa 
U - UTI
D - diabetes
D - Drug use
O - osteomyolitis
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9
Q

What is Ecthyma Gangrenosum?

What is it associated with?

Which patients does it usually occur in?

A
  1. Uncommon cutaneous infection
  2. Bacteremic infection of P.Aeriginosa
  3. Critically ill & IMMUNOCOMPROMISED
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10
Q

What are the characteristics of Bactermia with Ecthyma Gangrenosum?

What does it evolve into?

How long would this take? (minimally)

A
  1. Hemorrhagic pustules
  2. Infarcted appearing areas w/ erythema
  3. Evolve into NECROTIC ULCERS surrounded by erythema
  4. **The transformation of an early lesion to a necrotic ulcer may occur in as little as 12 HOURS!!!

RAPID

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11
Q

What is the pneumonic PSEUDDO stand for?

What does the AERiginosa clue you in on?

A 
P = pneumonia
S = sepsis
E = otitis EXTERNA (swimmer's ear)
U = UTIs
D = drug use
D = diabetes
O = osteomyelitis

AERiginosa = AEROBIC

** think pseudomonas in burn victims

  • mucoid polysaccardie capsule may contribute to chronic pneumonia in cystic fibrosis patients due to BIOFILM formation
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12
Q

What color is the agar plate as a result of culturing P. Aeriginosa?

A

GREEN CAN ONLY BE THERE IF PRODUCING BOTH PYOCYANIN & PYOVERADIN

  • pyocyanin is a blue pigment
  • also produces Pyoveradin (yellow light on media)

(blue + yellow) = GREEN ON AGAR PLATE

green only present if both pyocyanin & pyoveradin produced

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13
Q

Describe the 4 main structural virulence factors of Pseudomonas aeruginosa.

A
  1. Capsule
  2. Pilli
  3. LPS
  4. Pyocyanin
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14
Q

What are the 3 Toxins and Enzymes that contribute to the virulence factors.

A
  1. Exotoxin A
  2. Exoenzyme S
  3. Elastase
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15
Q

The following describes Exotoxin A or Exoenzyme S?

  1. Correlates with virulence
  2. Blocks protein synthesis much like diphtheria toxin (inhibits E2F)
  3. Most likely contributes to DERMATONECROSIS in wounds and tissue damage in lungs
A

Exotoxin A

  • EF2 ribosylated by toxin
    = INHIBITION of protein synthesis & cell death
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16
Q

The following describes Exotoxin A or Exoenzyme S?

  1. ADP-ribosylating toxin
  2. Epithelial cell damage
    facilitates bacterial spread, tissue invasion and necrosis
A

Exoenzyme S

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17
Q

What toxin is specifically responsible for tissue destruction & hemorrhagic lesions?

What 2 enzymes are specifically responsible?

How does this toxin affect the innate & adaptive immune response? (2)

A
  1. ELASTASE
    - produces lung parenchymal damage
  2. LasA & LasB act synergistically to degrade ELASTIN
    • Degrades complement components
    • inhibits neutrophil chemotaxis and function
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18
Q

What kind of a media does P. Aeriginosa grow on?

- describe the way the colonies look

A
  1. Blood & MacConkey agar producing SPREADY colonies with a metallic sheen

(alligator skin appearance)

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19
Q

State the following for P.Aeriginosa (VERY IMPORTANT)

  1. Glucose (fermenter or non)
  2. Oxidase (+ or -)
  3. Characteristic odor?
  4. Produces ____ pigment
  5. Grows at ____ temp
  6. Obligate aerobe/anaerobe?

IT IS THE ONLY ORGANISM THAT PRODUCES _____

A
  1. Glucose NON fermenter
  2. Oxidase POSITIVE
  3. Grape odor
  4. produces PYOCYANIN & Pyoverdin
  5. grows at 42 celsius (warm)
  6. obligate AEROBE (air billow)

ONLY ORGANISM THAT PRODUCES PYOCYANIN!!

GRAM NEGATIVE ROD

-encapsulated!!!(thrives in aquativ envi/moist –> think of the tub from sketchy)

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20
Q

What accounts for the MUCOID appearance of P. Aeruginosa?

A
  1. Production of ALGINATE
    - all pseudomonas have a gene to produce alginate (normal pseudomonas as an inactive gene, and CF patients have conditions that are optimal for this gene and turn it “on”
    - high salt content
    - high humidity

Creates a mucoid colony which is difficult to resolve! Patients become chronically infected and eventually lung is destroyed and they need a lung transplant

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21
Q

How are pseudomonas infections treated?

Why is this bacteria resistant to so many antibiotics?

What are fluroroquinolones used to treat specifically?

A
  1. Combination therapy of
    - cell wall active agent
    - AMINOGLYCOSIDE

UREIDOPENICILLIN or CARBOXYPENICILLIN

  1. Resistant due to changes in PORINS
    - block the porins

TREAT WITH:
- pipercillin + tazobactam

less common: ahminoglycosides (w/B-lactam antibiotics) + fluoroquinolones

USED FOR UTIS!

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22
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
Community acquired urinary tract infection

C. Community acquired pneumoniae

D. Gastroenteritis following ingestion of contaminated water

A

1 cause Pneumonia = STREP PNEUMONIA!!!

A. Ear infection after swimming in a fresh water lake

Melioidosis is an infectious disease caused by a gram-negative bacterium, Burkholderia pseudomallei, found in soil and water. It is of public health importance in endemic areas, particularly in Thailand and northern Australia.

23
Q

If an organism is OXIDASE positive, which group of bacteria is automatically eliminated?

A

ENTEROBACTERIACAE

24
Q

Burkholderia Pseudomallei

  1. What do B. Mallei and B. Pseudomallei belong to?
A
  1. A single genomospecies
  • Originally named Pseudomonas
  • Changed to Burkholderia in 1992
25
Q

Burkholderia Pseudomallei

  1. Habitat?
  2. Found primarily where?
  3. What disease does it cause?
  4. What is a unique feature of this bacteria?
A
  1. Soil, water, vegetation of S.E. Asia, 20 north & south of equator
  2. Primarily found in India, Thailand, Vietnam, northern Australia. Also endemic in China, Taiwan, Laos
  3. CATEGORY B Biothreat

“burholderia can HOLD you hostage”

26
Q

What is the treatment for Burkholderia Pseudomallei?

A

Ceftriaxone & vancomycin

27
Q

Describe the symptoms of the 3 types of MELIOIDOSIS associated with Burkholderia Pseudomallei.

  1. Acute Disease
  2. Subacute Disease
  3. Chronic Disease
A
  1. Acute
    - SEPTICEMIA with metastatic lesions (95% mortality if untreated(
  2. Subacute
    * most common
    * TB LIKE PNEUMONIA w/ CEllulitis & Lymphangitis
  3. Chronic Disease:
  • LOCALIZED CHRONIC CELLULITIS
  • treat with antibiotics before draining otherwise become BACTEREMIC
28
Q

Burkholderi Cepacia COMPLEX

  1. Habitat?
    2.
A

Habitat:

  • water sources
  • wet surfaces
  • detergent solutions
  • (grows in iodine & hexochluorofene soap)
29
Q

What bacteria is a major clinical problem in patients with the following:

  1. CF
  2. Chronic Granulomatous Disease
  3. UTI
  4. Septicemia
  5. Other opportunistic infections
    & is a NON -LACTOSE FERMENTER
A

Burkholderia cepacia

30
Q
  1. Cystic fibrosis is (autosomal dom/recessive)?

2. What is it caused by?

A
  1. AUTOSOMAL RECESSIVE
    - in caucasians
  2. Mutation in CFTR transmembrane conductance regulator
    - Regulates components of sweat, digestive juices, mucus.
    - Persons without CF have two working copies of CFTR gene, only one is needed to prevent CF.
31
Q

Mutation in CFTR result in:

  1. Defects in ____ immunity & decreased ____ levels.
  2. Failure to do what?
  3. Increased _____ in CF airway
  4. Abnormal electrolyte transport resulting in _____

How does this abnormal electrolyte transport effect mucocilliary clearance?

A
  1. defects in INNATE immunity including decreased NITRIC OXIDE levels
  2. failure to internalize bacteria in bronchial epithelial cells
  3. increased INFLAMMATION in CF airway
  4. abnormal electrolyte transport causing THICK, DRY, STICKY mucus

Abnormal mucus adversely effects mucocilliary clearance providing an ideal niche for CHRONIC lung infection

32
Q

85% of premature deaths in CF are due to ____ secondary to chronic lung infection.

A
  1. Cardiopulmonary failure

In US median life expectancy is 37 yrs.

**Lung transplant is often necessary as CF worsens

CF may be Dx by many different methods including newborn screening, sweat testing, and genetic testing.

33
Q

What is PULMONARY EXACERBATION?

Result of this?

A

Cellular defect results in THICKENED viscous mucus layer in resp tract and impaired innate immunity

  • Results in impaired mucocillary transport and chronic infection with limited number of bacterial species

Chronic infection leads to INTERMITTENT PULMONARY EXACERBATIOn

34
Q

What is Pulmonary Exacerbation characterized by? (3)

  1. What is recruited?
  2. What is released?
  3. High levels of what?
A
  1. Recruitment of neutrophils
  2. Cytokine release
  3. High level of neutrophil derived ELASTASES causing significant lung pathology
35
Q

What are the 3 main CF pathogens of CHRONIC LUNG DISEASE?

A
  1. Staph Aureus
  2. P. Auriginosa
  3. B. Cepacia

ALSO:

  1. Aspergillus
  2. Scedosporium
  3. Mycobacterium abscessus

AND RHINOVIRUS IS THE MOST COMMON VIRUS in CLD

36
Q

Burkholderia Cepacia Complex:

  1. Glucose (fermenter or non?
  2. Pigment?
  3. Oxidase + or - ?

KNOW THESE

A
  1. Glucose NON - fermenter
  2. YELLOW pigment
  3. Slow oxidase positive
    - resistant to most antibiotics
37
Q

Stenotrophomonas Maltophilia

WHat 5 opportunistic infections is it associated with?

A

First called Pseudomonas then Xanthomonas

  1. Bacteremia
  2. Pneumonia
  3. Meningitis
  4. Wound Infections
  5. Urinary Tract

Treatment complicated by resistance to many commonly used antibiotics

38
Q

What is the habitat of
Stenotrophomonas maltophilia? (4)

What is the most common? Area

A
  1. Worldwide distribution
  2. SOIL, WATER, animals, vegetation, crops
  3. Not part of normal skin or GI flora
    (but can be recovered from almost any clinical site)
  4. RESPIRATORY TRACT MOST COMMON
39
Q

Stenotrophomonas maltophilia

  1. > 95% of all clinical infections are ____ acquired
  2. 2nd leading cause of what?
  3. Hallmark is _______
A
  1. Hospital acquired!
  2. 2nd leading cause of gram-negative
    non-fermentative bacillary infections
  3. Hallmark: LIFE - THREATENIN SYSTEMIC INFECTIONS in DEBILITATED PATIENTS

(usually malignancy)

40
Q

Stenotrophomonas maltophilia

  1. Shows good growth on ____
  2. Oxidase + or -? (TEST TEST TEST)
  3. Similar to B. Cepacia in that its pigment is _____
A
  1. BAP & MacConkey
  2. Oxidase NEGATIVE
    - usually non-fermenters are oxidase negative like Enterobacteriacae, but so is S. Maltophila!
  3. YELLOW pigment
41
Q

True or False: Stenotrophomonas Maltophilia is very resistant to beta lactam agents.

A

TRUE

  • Inherently resistant to beta lactam agents including imipenem and aminoglycosides
42
Q

What is the drug of choice for S. Maltophilia?

What is the exception to this?

A

trimethoprim-sulfamethoxazole (SXT)” = BACTRAM

  1. SULFA ALLERGY
    - do not use this

instead use:

ticarcillin/clavulanate (discontinued - timentin), 
ceftazidime,
 levofloxacin, 
minocycline,
 tigecycline
43
Q

Which bacteria is often found in the following habitat:

  1. Soil, water, plants food stuffs
  2. Water systems & wet surfaces
  3. Nocosomial outbreaks traced to BREAST PUMPS
A

Elizabethkingia meningoseptica

** REMEMBER Breast pumps = Elizabethkingia Meningoseptica

44
Q

What are the 5 bacteria that cause neonatal meningitis?

test

A

NEONATAL MENINGITIS

  1. Ecoli
  2. Citrobacter koseri
  3. E.Meningoseptica
  4. GROUP B strep (+)
  5. Listeria (+)
45
Q

Elizabethkingia Meningoseptica

  1. Pathogenic for _____
  2. Associated with what neonatal disease?
  3. Where do epidemics occur?
  4. Nocosomial outbreaks linked to _____
  5. May cause pneumonia in what type of adults?
A
  1. PREMATURE infants
  2. Neonatal Meningitis
  3. Epidemics in NURSERIES
  4. Breast pumps!!!
  5. Immunocompromised adults are likely to get Elizabethkingia Meningoseptica
46
Q

Elizabethkingia Meningoseptica

  1. Oxidase + or -?
  2. Pigment on BAP?
  3. Growth on MacConkey?
    * different from other gram -
A
  1. Oxidase POSITIVE
  2. Yellow pale pigment on BAP
  3. INHIBITED ON MacConkey
47
Q

Elizabethkingia Meningoseptica

  1. Susceptibility?
  2. Resistant to? (2)
A
  1. VERY RESISTANT

2.

  • resistant to beta lactam agents
  • aminoglycosides
48
Q

Drug of choice for Elizabethkingia Meningoseptica (4)

A

Drug of choice:

  1. Minocycline
  2. Rifampin
  3. SXT
  4. Quinolones
49
Q

Acinetobacter Baumannii

Habitat?

Most common organism carried on _____

A
  1. Free living in water and soil
  2. Isolated foods, hospital air, inanimate objects, numerous human sources
  3. Most common gram-negative organism carried on skin of hospital personnel
50
Q

Acinetobacter Baumannii:

  1. Low ____ but implicated in community acquired & nosocomial infections
  2. Recovered from what human sources? (5)
  3. Found to colonize 45% of inpatient_____
A
  1. LOW VIRULENCE
2. blood
sputum
urine
feces
vagina
  1. Found to colonize 45% of inpatient tracheostomy

WHY?
- tracheostomies need a lot of daily care
most common org. on hands of hospital employees

fortunately = LOW VIRULENCE (may just be colonized –> but no infection )

51
Q

Acinetobacter baumannii

  1. Shape on gram stain?
  2. Growth on BAP & MacConkey?
  3. Oxidase + or -
  4. Motile?
A
  1. COCCOBACILLI on gram stain
  2. GOOD growth on BAP and MacConkey (unlike E. meningoseptica )
  3. Oxidase NEGATIVE!!!
  4. Non-motile
52
Q

What is Acinetobacter Baumannii commonly treated with? (5 total, 2 most important)

A
  1. Imipenem
  2. Meropenem

** broadest spectrum CARBEPENAMS**

  1. Fluoroquinolone + amikacin or ceftazidime
  2. Ampicillin-sulbactam
  3. Colistin

***Resistance rates increasing

If something is carbepenam resistant = RESISTANT TO EVERYTHING! (but fortunately A. Baumannii is LOW VIRULENCE!)

53
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. Elizabethkingia meningoseptica

  • BREAST PUMP

PHARM/MHD EXAM - 3 (21 decks)

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