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Clinical Bacteriology > (F) Lesson 13: Non-fermenters and Miscellaneous Gram-Negative Bacilli (Part 2) > Flashcards

(F) Lesson 13: Non-fermenters and Miscellaneous Gram-Negative Bacilli (Part 2) Flashcards

1
Q

General Characteristics

  • 12 species: 2 species most commonly seen in clinical specimens
  • Environment: soil, water, and food stuffs
  • Hospital environment: ventilators, humidifiers, catheters, and other devices
  • Insignificant or as contaminants when isolated from nonsterile sites
  • Increased isolates indicate resistance
  • Are opportunists (#2 in nosocomial infections)
A

Acinetobacter spp.

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2
Q
  • Formerly Herella vaginocola
  • Glucose-oxidizing nonhemolytic strain
  • Has high potential for resistance, like P. aeruginosa
  • Causes ventilator-associated pneumonia and sepsis that have high mortality rates
  • Causes UTIs, pneumonia, tracheobronchitis, or both, endocarditis, septicemia, meningitis, and cellulitis, endophthalmitis, conjunctivitis, and corneal ulcerations
A

Acinetobacter baumannii

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3
Q

Acinetobacter baumanii

Resistant/Susceptible?

  • Penicillin
  • First and second-generation cephalosporins
  • Fluoroquinolones
A

Resistant

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4
Q

Acinetobacter baumanii

Resistant/Susceptible?

  • Aminoglycosides
  • B-lactam + B-lactamase inhibitor combinations
A

Susceptible

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5
Q

Acinetobacter baumanii

  • Contain carbapenemases
  • Susceptible to colistin and tigecycline
A

CRAB or Carbapenem-Resistant Acinetobacter baumanii

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6
Q
  • Formerly Mima polymorpha
  • Glucose-negative, nonhemolytic strain
  • Less virulent and less severe
  • Susceptible to most antibiotics
A

Acinetobacter lwoffii

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7
Q
  • Strictly aerobic
  • G(-) coccobacilli or even G(-) cocci from blood culture
  • (+) catalase,
  • (-) oxidase, non-motile
  • Can resist decolorization and retain crystal violet, leading to mis-ID
A

Acinetobacter spp.

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8
Q

Acinetobacter spp.

Saccharolytic in MAC (purplish)?

A

Acinetobacter baumannii

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9
Q

Acinetobacter spp.

Asaccharolytic in MAC?

A

Acinetobacter lwoffii

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10
Q

Clinical Infections

  • 3rd most common non-fermentative, G(-) bacillus isolated in the clinical laboratory.
  • Former genus: Pseudomonas → Xanthomonas (plant pathogen) → Stenotrophomonas
  • Usually found as a saprophyte or a colonizer
  • Environment: water, sewage, and plant materials
  • Hospital environment: contaminating blood drawing equipment, disinfectants, transducers, and other equipment
A

Stenotrophomonas maltophilia

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11
Q
  • Risk factors: immunosuppression, hospitalization, especially in an ICU, and the presence of a central venous catheter.
  • Endocarditis, especially in a setting of prior intravenous (IV) drug abuse or heart surgery, wound infections, including cellulitis and ecthyma gangrenosum, bacteremia and, rarely; meningitis and UTIs
A

Clinical Infection of Stenotrophomonas maltophilia

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12
Q

What is the rank of Stenotrophomas maltophilia in lower respiratory tract infections in CF patients?

A

Third

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13
Q
  • G(-) bacilli
  • (+) catalase, DNase, esculin and gelatin hydrolysis, and lysine decarboxylase
  • (-) oxidase
  • Colonies: bluish on MAC, ammonia-like odor
A

Stenotrophomonas maltophilia

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14
Q

Stenotrophomonas maltophilia

Resistant/Susceptible?

  • Cephalosporins
  • Penicillins
  • Carbapenems
  • Aminoglycosides
A

Resistant

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15
Q

Stenotrophomonas maltophilia

Resistant/Susceptibility?

  • Trimethoprim-sulfamethoxazole (SXT) (DOC)
  • Ticarcillin-clavulanate
  • Fluoroquinolone levofloxacin
  • Tetracyclines, including tigecycline
A

Susceptible

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16
Q
  • Mortality in patients with S. maltophilia infections are associated with inappropriate antimicrobial treatment
  • They were initially given ____
A

Carbapenem

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17
Q

Stenotrophomonas maltophilia

  • ____ and ____ can be performed
A

Broth microdilution and Etest or agar dilution

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18
Q
  • All have been isolated from humans
  • Former member of the Pseudomonas
  • From irrigation fluids, anesthetics, nebulizers, detergents, and disinfectants.
  • Part of the non-fluorescent group
  • Contains plant pathogens that have arisen as opportunistic organisms, associated with pneumonia in patients with CF or chronic granulomatous disease
  • Colonies: non-wrinkled
A

Burkholderia Cepacia Complex

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19
Q
  • (+) oxidase, glucose, maltose, lactose, and mannitol, lysine decarboxylase (LDC) and ONPG, motile (polar tufts of flagella)
  • (-) ornithine decarboxylase (ODC), nitrate → nitrite
  • (+) MAC
A

Burkholderia spp.

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20
Q
  • Increased recovery in ____ that reduce growth of P. aeruginosa and other G(-) bacilli
A

Selective media with antimicrobials

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21
Q
  • Most effective
  • Selective agar has additional antibiotics to inhibit the growth of normal flora
A

BCSA (Burkholderia cepacia selective agar)

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22
Q
  • Crystal violet, bile salts, polymyxin B, ticarcillin, phenol red
A

Pseudomonas cepacia

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23
Q

What rank is Burkholderia spp. in terms of causing of pneumonia in patients with CF or chronic granulomatous disease?

A

Second

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24
Q

Identify the organism.

  • Endocarditis (specifically in IV drug abusers)
  • Pneumonitis, UTIs, osteomyelitis, dermatitis
  • Other wound infections resulting from the use of contaminated water
A

Burkholderia spp.

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25
Q

Burkholderia spp.

Resistant/Susceptible?

  • Aminoglycosides
  • Polymyxins
  • β-lactam antibiotics
A

Resistant

26
Q

Burkholderia spp.

Resistant/Susceptible?

  • Chloramphenicol
  • Ceftazidime
  • Piperacillin
  • Minocylcine
  • Some fluoroquinolones
  • SXT
  • Carbapenems (variable)
A

Susceptible

27
Q
  • Usually in very immunocompromised patients because it is a plant pathogen
  • Resembles B. cepacia complex (molecular tools for confirmation)
  • Differentiate from P. aeruginosa using oxidase test
  • Clinical Infections: In patients with CF (lung transplant) and CGD, immunocompromised patients
A

Burkholderia gladioli

28
Q
  • Colonies: yellow
  • (+) motile (one or two polar flagella), catalase, urease, glucose, mannitol, MAC
  • (-) decarboxylase, oxidase (some are weakly positive)
A

Burkholderia gladioli

29
Q

Burkholderia gladioli

Resistant/Susceptible?

  • Polymyxin B
  • Aztreonam
  • Cephalosporins
A

Resistant

30
Q

Burkholderia gladioli

Resistant/Susceptible?

  • Aminoglycosides
  • Carbapenems
  • Ciprofloxacin
  • SXT
A

Susceptible

31
Q

T or F: B. gladioli isolates are more susceptible to antimicrobials than B. cepacia.

A

T

32
Q
  • Potential bioterrorism agent
  • Can be weaponized
  • Since it causes a respiratory infection, it spreads easily
  • A zoonotic disease
A

Burkholderia mallei

33
Q

Identify the organisms.

  • Rare in humans: severe local suppurative or acute pulmonary infections
  • e.g. Glanders Disease
A

Burkholderia mallei

34
Q
  • G(-) coccobacillus
  • Colonies: non-pigmented in 2 days, non-motile
  • Only non-fermenter that is non-pigmented
  • (+) MAC, oxidase (variable), glucose, nitrate to nitrite, ADH
  • (-) decarboxylase, oxidase (some are weakly positive), non motile
A

Burkholderia mallei

35
Q

Burkholderia mallei

A respiratory tract zoonosis primarily affecting livestock such as horses, mules, and donkeys

A

Glanders Disease

36
Q

Burkholderia mallei

The only drug resistant with Burkholderia mallei?

A

Polymyxin B

37
Q
  • CLSI recommends ____ with ____ to consider
A

Broth microdilution with Brucella broth

38
Q
  • Also called Vietnamese Time Bomb
  • Potential agents of bioterrorism
  • Found in water and muddy soils in Southeast Asia (including Vietnam and Thailand), Northern Australia, and Mexico
A

Burkholderia pseudomallei

39
Q
  • Also produces a respiratory infection
  • Like rabies, the incubation period may be prolonged, with reactivation occurring long after exposure
  • Unusual for bacteria which usually takes only weeks before the onset of an infection
  • Its latency is common among viruses
A

Burkholderia pseudomallei

40
Q

Identify the organism.

  • Meliodosis
  • Overwhelming septicemia
  • Local infections such as orbital cellulitis, dacryocystitis, and draining abscesses, sometimes with with pneumonia
A

Burkholderia pseudomallei

41
Q

Burkholderia pseudomallei

Aggressive, granulomatous, pulmonary disease
By ingestion, inhalation, or inoculation of the organisms, with metastatic abscess formation in lungs and other viscera

A

Meliodosis

42
Q
  • (+) Bipolar staining
  • Colonies: wrinkled
  • MALDI-TOF for rapid confirmation
  • Multiplex polymerase chain reaction (PCR) assays for the identification
A

Burkholderia pseudomallei

43
Q
  • Selective for B. pseudomallei
  • Contains colistin (antibiotic)
  • Results in deep pink colonies from the absorption of neutral red from the medium + earthy odor
A

Ashdown Medium

44
Q

Burkholderia pseudomallei

Resistant/Susceptible?

  • SXT
  • Chloramphenicol
  • Tetracycline
  • Semisynthetic
  • Penicillin
  • Ceftazidime
A

Susceptible

45
Q
  • Grouped due to similar biochemical reactions
  • An unusual group of non-fermenters, though they are obligate aerobes, they are susceptible to penicillin
  • G(-) coccobacillary to bacillary
  • (+) oxidase,
  • (-) motility, asaccharolytic
  • Are opportunists that reside on the mucous membranes of humans and lower animals
  • Rarely cause disease in humans, except M. catarrhalis
A

Moraxella, Oligella, and Psychrobacter

46
Q
  • Resistance is due to continued exposure
  • Resistance to ____ is found in the plasmid that can be shared via pili
A

Penicillin

47
Q

What are the most commonly encountered species of Moraxella?

A
  • M. catarrhalis
  • M. nonliquefaciens
  • M. lacunata
  • M. osloensis
  • M. lincolnii
  • M. atlantae
48
Q

Moraxella spp.

Reclassified as Psychrobacter phenylpyruvicus

A

M. phenylpyruvica

49
Q
  • Most frequent isolate in the genus Moraxella from clinical specimens
  • Especially from the ear and respiratory specimens
  • Resembles the Neisseria due to G(-) coccal morphology
A

Moraxella catarrhalis

50
Q
  • Second most commonly isolated member of the genus.
  • Can cause rare cases of bacteremia, keratitis, and endophthalmitis
  • Normal biota in the respiratory tract
  • Morphologically and biochemically similar to M. osloensis
A

Moraxella nonliquefaciens

51
Q

Osloensis and Nonliquefaciens?

Found in the genitourinary tract?

A

Moraxella osloensis

52
Q

Osloensis and Nonliquefaciens?

Found in the respiratory tract?

A

Moraxella nonliquefaciens

53
Q
  • Its 2 species can be differentiated by motility
  • Use a Sulfide, Indole, Motility (SIM) medium to observe motility
A

Oligella spp.

54
Q

Oligella spp.

The motile species of Oligella

A

Oligella ureolytica

55
Q

Oligella spp.

The non-motile species of Oligella

A

Oligella urethralis

56
Q
  • (+) MAC, phenylalanine deaminase (PDA), oxidase, and nitrate to nitrite w/ gas formation
  • (-) non-oxidative, non-motile
  • Commensal of the genitourinary tract
  • Report of a case of infectious arthritis that was mistaken for gonococcal arthritis
  • Susceptible: penicillin
A

Oligella urethralis

57
Q
  • (+) MAC, phenylalanine deaminase (PDA), oxidase and nitrate to nitrite w/ gas formation, motile (peritrichous flagella)
  • (-) non-oxidative
  • Bacteremia in a patient with AIDS and in an 18-month-old child with pneumonia
  • Susceptible: penicillin
A

Oligella ureolytica

58
Q
  • Are weird organisms since these grow well at low temperatures, 5-250C, rarely at 35 deg C
  • It thrives in high temperatures
A

Psychrobacter

59
Q
  • Psychrotrophic: optimal growth at 20°C (5-25°C)
  • Modified Thayer-Martin Medium
  • Isolated from fish, processed meat, and poultry.
  • (+) oxidase, oxidative, nitrate to nitrite
  • (-) non-motile
  • Not susceptible to penicillin, but susceptible to other antimicrobial agents
A

Psychroabcter immobilis

60
Q

Psychrobacter immobilis

  • Modified by adding Tween 80
  • Growth has odor of roses like phenyl ethyl alcohol, isolates resemble Moraxella
  • Commonly used for isolating Neisseria spp.
A

Modified Thayer-Martin

61
Q

Associate the organism with the odor.

  1. Pseudomonas aeruginosa
  2. Stenotrophomonas maltophilia
  3. Burkholderia pseudomallei

A. Ammonia-like
B. Earthy odor
C. Grape-like

A
  1. C
  2. A
  3. B
62
Q
  • Isolated from urine, blood, CSF, and the genitourinary tract
  • (+) urease, phenylalanine deaminase (PDA)
A

Psychrobacter phenylpyruvicus

Clinical Bacteriology (33 decks)

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