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[9c] MODULE 6 UNIT 3: Non-fermentative Gram-negative Bacilli > LECTURE > Flashcards

LECTURE Flashcards

1
Q

are those that catabolize carbohydrates anaerobically in which inorganic ions other than oxygen can serve as the final electron acceptor, or by both aerobic and anaerobic pathways.

A

Fermentative organisms (fermenters)

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2
Q

are those that do NOT ferment carbohydrates

A

Nonfermentative organisms (nonfermenters)

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3
Q

use carbohydrates aerobically to derive energy for their metabolism

A

oxidizers

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4
Q

do not break down carbohydrates at all

A

nonoxidizers or asaccharolytic.

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5
Q

are ubiquitous and found in moist environments, typically in soil and water, on plants and decaying vegetation, and in many foodstuffs

A

nonfermentative gram-negative bacilli (NFGNB )

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6
Q

isolated from nebulizers, dialysate fluids, saline, catheters, and other devices

A

nonfermentative gram-negative bacilli (NFGNB )

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7
Q

rarely, if ever, part of the normal host microbiota but can easily colonize hospitalized patients, especially those who are immunocompromised; have become clinically significant because of the increasing numbers of immunocompromised patients

A

nonfermentative gram-negative bacilli (NFGNB )

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8
Q

account for about 15% of all gram-negative bacilli isolated from clinical specimens

A

nonfermenters

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9
Q

Four groups of nonfermenters make up most isolates routinely seen in clinical laboratories:

A

Pseudomonas aeruginosa, Burkholderia spp., Acinetobacter spp., and Stenotrophomonas maltophilia.

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10
Q

accounts for the largest percentage of all nonfermenters isolated from clinical specimens.

A

Pseudomonas

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11
Q

The pseudomonads have been classified based on

A

rRNA/DNA homology and common culture characteristics.

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12
Q

It is now known that each of the five rRNA groups represents taxonomically distinct genetic groups, and as a result different genus names have been assigned to each of the [?].

A

rRNA groups

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13
Q

Only the members of [?] retain the genus designation of Pseudomonas.

A

rRNA group I

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14
Q

produce pyoverdin

A

P. aeruginosa, P. fluorescens, P. putida

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15
Q

occurs widely in soil, water, plants, and animals, and grows to very high numbers in moist environments.

A

P. aeruginosa

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16
Q

• It is an uncommon part of the normal flora of the colon in about 10% of humans, and gets in on the skin from fecal organisms

A

P. aeruginosa

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17
Q

• Sources of infections include:

  • contaminated catheters, humidifiers, ventilators, intravenous solutions, anesthesia and resuscitation equipment in hospitals;
  • raw vegetables, and cut and potted flowers;
  • in sink drains, and if not properly maintained, in pools, and hot tubs
A

P. aeruginosa

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18
Q

• P. aeruginosa is primarily an

A

opportunist

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19
Q

P. aeruginosa is unlikely to cause infections in healthy people with

A

intact anatomical barriers.

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20
Q

Severe infections occur in people with [?] (e.g., when mucous membranes and skin are disrupted by direct tissue damage as in the case of burn wounds; or when neutropenia is present, as in cancer chemotherapy)

A

weakened host defenses

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21
Q

P. aeruginosa is primarily a [?] (accounting for 5% to 15% of all hospital-acquired infections) causing infections after invasive medical procedures (e.g., when intravenous or urinary catheters are used).

A

nosocomial pathogen

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22
Q

P. aeruginosa is notorious for its resistance to many [?] therefore becomes dominant and important when more susceptible bacteria of the normal flora are suppressed.

A

antimicrobial agents

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23
Q

Is the third most common cause of gram-negative bacillary bacteremia, after E. coli and Klebsiella pneumoniae

A

Bacteremia/ septicemia

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24
Q

Poor prognostic factors associated with P. aeruginosa
bacteremia include septic shock, granulocytopenia,
inappropriate antimicrobial therapy, and the presence of septic metastatic lesions.

A

Bacteremia/ septicemia

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25
Q

can give rise to grave conditions such as endocarditis, meningitis, and bronchopneumonia.

A

Pseudomonas septicemia

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26
Q

are cutaneous papules which progress to black, necrotic ulcers that are surrounded by erythema and often do not contain pus. This result from direct invasion and destruction of blood vessel walls by the P.aeruginosa and is uncommon in bacteremia caused by organisms other than P. aeruginosa.

A

Ecthyma gangrenosum

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27
Q

P. aeruginosa is the leading cause of nosocomial respiratory infections

A

Pneumonia/ventilator-associated pneumonia

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28
Q

Respiratory tract infections are often linked with contaminated respirators and results in necrotizing pneumonia.

A

Pneumonia

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29
Q

Since P. aeruginosa can colonize mucosal surfaces, such as the oropharynx, patients in the intensive care unit (ICU) who are mechanically ventilated may quickly become colonized.

A

Pneumonia

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30
Q

P.aeruginosa is a major threat to hospitalized patients with

A

cystic fibrosis

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31
Q

an inherited defect in chloride ion transport that causes severe damage to the lungs, digestive system and other organs of the body. It affects the cells that produce mucus, digestive juices, and sweat. The
defective gene responsible for CF leads to the creation of thicker and stickier mucus than is usual. The colonization of the bronchi then becomes
a biofilm with microcolonies of bacteria and debris imbedded in the alginate. Instead of acting as a lubricant, the secretions plug up the ducts and passageways leading to severe lung infections

A

Cystic Fibrosis (CF)

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32
Q

For P. aeruginosa, the selective advantages of the biofilm include [?] (complement, antibody, phagocytes)
and [?].

A

inaccessibility of the immune system

antimicrobial agents

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33
Q

resulting to exudation of “blue-green pus (associated to pyocyanin production) with a “grapelike odor”.

A

Infection of wounds and burns

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34
Q

detected in infected wounds, or burns by ultraviolet fluorescence

A

pyoverdin

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35
Q

occurs when P. aeruginosa is introduced by contaminated catheters and instruments or in irrigating solutions.

A

Urinary tract infection

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36
Q

results when the organism is introduced by lumbar puncture or during a neurosurgical procedure through contaminated instrumentation

A

Meningitis

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37
Q

an inflammation of the external ear canal, is
often found in a less severe form (mild otitis external) in swimmers (“swimmer’s ear”) and in invasive form (malignant otitis externa) in patients with diabetes

A

Otitis externa

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38
Q

occurs most commonly after injury or surgical procedures that can be fulminant and threaten permanent loss of vision

A

Eye infections

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39
Q

P. aeruginosa attaches to and colonizes the mucous membranes or skin, invades locally, and produces

A

systemic disease

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40
Q

Capsular polysaccharide that allows infecting bacteria to adhere to lung epithelial cell surfaces and form biofilms which, in turn, protect the bacteria from antibiotics and the body’s immune system.

A

Alginate

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41
Q

Surface appendages that allow adherence of organism to GM-1 ganglioside receptors on host epithelial cell surfaces

A

Pili

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42
Q

Removes the sialic acid residues from GM-1 ganglioside receptors on host epithelial cells, facilitating binding of pili

A

Neuraminidase

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43
Q

Responsible for many of the endotoxic properties of the organism that plays a direct role in causing fever, shock, oliguria, leukocytosis and leukopenia, disseminated intravascular coagulation, and adult respiratory distress syndrome

A

Lipopolysaccharide

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44
Q

Inhibits protein synthesis and causes tissue necrosis by a mechanism of action identical to that of diphtheria toxin, although the structures of the two toxins are not identical

A

Exotoxin A (ExoA)

45
Q

Interrupts normal gastrointestinal activity, resulting to

diarrhea

A

Enterotoxin

46
Q
  • Inhibits protein synthesis
A

Exoenzyme S (ExoS)

47
Q
  • Entry into the cytoplasm of the host cell is facilitated by a Type III secretion system of the organism
A

Exoenzyme S (ExoS)

48
Q

A heat-labile hemolysin that degrades lipids thereby
destroying the host cell cytoplasmic membrane; which
favors spread of the organism to contiguous tissues

A

Phospholipase C

49
Q

Destroys pulmonary surfactant and inactivates opsonins

A

Phospholipase C

50
Q

Cleaves immunoglobulins and complement components, and disrupts neutrophil activity

A

Elastase

51
Q

Degrades proteins that allow the organism to acquire nutrients from the host and disseminate from the local site

A

Elastase

52
Q

Inhibits neutrophil and lymphocyte function

A

Leukocidin

53
Q

Suppress other bacteria and disrupt respiratory ciliary activity

A

Pyocyanins

54
Q

Cause oxidative damage to tissues, particularly oxygenated tissues such as that of the lungs

A

Pyocyanins

55
Q

P. aeruginosa binds and secretes the [?], which acts on protein synthesis by the same mechanism as diphtheria toxin

A

Exotoxin A (ExoA)

56
Q

a type III injection secretion system delivers [?] to the cell cytoplasm.

A

Exoenzyme S (ExoS)

57
Q

is secreted extracellularly. All toxins act to destroy the cell and the bacteria may enter the blood.

A

Elastase

58
Q

Since most common nosocomial Pseudomonas infection occur in compromised hosts, scrupulous attention to [?], especially among health care workers, is necessary to prevent infections caused by this ubiquitous pathogen.

A

disinfection and hand washing

59
Q

Because pseudomonas thrives in [?], special attention should be paid to sinks, water baths, showers, hot tubs, and other wet areas.

A

moist environments

60
Q

Vaccines incorporating [?] from multiple P. aeruginosa serotypes have been developed and proved immunogenic in humans. The primary candidates for such preparations are [?]. Although some protection has been demonstrated, these preparations are still experimental.

A

somatic antigens

patients with burn injuries, CF, or immunosuppression

61
Q

These include other gram-negative bacilli that are either asaccharolytic or oxidative in their metabolism.

A

Other Nonfermentative Gram-Negative Bacilli (NFGNB)

62
Q

includes species that were formerly placed in the genus Pseudomonas.

A

Genus Burkholderia

63
Q

is an obligate parasite of animals (primarily horses, mules, and donkeys) causing a respiratory tract infection known as glanders or farcy

A

B. mallei

64
Q

manifests with prominent pulmonary involvement, subcutaneous ulcerative lesions, and lymphatic thickening with nodules; systemic disease also occurs.

A

Glanders in horses

65
Q

Human disease is extremely rare; from an animal source, it can be transmitted to humans either by entry of the organism through an abrasion or break on the skin, or by inhalation of the organisms.

A

B. mallei

66
Q

Human infections can be fatal which usually begins as an ulcer of the skin or mucous membranes followed by lymphangitis and sepsis. Inhalation of the organisms may lead to primary pneumonia.

A

B. mallei

67
Q

is an environmental organism found in soil, streams, surface water, such as rice paddies.

A

B. pseudomallei

68
Q

It causes infection in sheep, goats, swine, horses, and other animals, although animals do not appear to be a primary reservoir for the organism.

A

B. pseudomallei

69
Q

Human infections can occur by inhalation of dust, ingestion of contaminated water, and contact with contaminated materials (e.g., soil).

A

B. pseudomallei

70
Q

a disease that is clinically and pathologically similar to glanders

A

melioidosis

71
Q

It is endemic in areas with tropical climates such as that of Southeast Asia (including Vietnam and Thailand), northern Australia, and Mexico.

A

B. pseudomallei

72
Q

Incubation period is not clearly defined but may range from 2 days to many years.

A

B. pseudomallei

73
Q

An important feature is its ability to produce latent infection that can reactivate many years after primary exposure.

A

B. pseudomallei

74
Q

most common form of melioidosis; primary pneumonitis

A

pulmonary infection

75
Q

clinical manifestations of melioidosis

A

(a) acute, localized infection
(b) acute bloodstream infection
(c. ) chronic suppurative infection involving various organs of the body

76
Q

are considered potential agents for biologic warfare and biologic terrorism

A

B. pseudomallei and B. mallei

77
Q

has been dubbed as “Vietnamese time bomb” as American veterans who aided in the Vietnam conflict has acquired the disease but may still be incubating at the time of their return in their homeland. Symptoms only became apparent several days up to years.

A

Melioidosis

78
Q

consists of the prototypic species Burkholderia cepacia plus at least 18 other genomospecies which have been isolated in humans

A

B. cepacia complex

79
Q

an environmental organism able to grow in water, soil, plants, animals, and decaying vegetable materials

A

B. cepacia complex

80
Q

Human transmission is by exposure of medical

devices and solutions contaminated from the environment

A

B. cepacia complex

81
Q

People with [?] and those patients with [?] are particularly vulnerable to infection with bacteria in B. cepacia complex.

A

cystic fibrosis (CF)

chronic granulomatous disease

82
Q

They may have asymptomatic carriage, progressive deterioration over a period of months, or rapidly progressive deterioration with necrotizing pneumonia and bacteremia.

A

B. cepacia complex

83
Q

It is likely that B. cepacia can be transmitted from one CF patient to another by

A

close contact

84
Q

members have been reported to cause endocarditis (specifically in intravenous drug abusers), pneumonitis, UTIs, osteomyelitis, dermatitis, and other wound infections resulting from the use of
contaminated water

A

B. cepacia complex

85
Q

are opportunists, and they are second to P. aeruginosa in frequency of isolation of all nonfermenters in the clinical microbiology laboratory.

A

Acinetobacter species

86
Q

is the species most commonly isolated in the • Genus Acinetobacter

A

A. baumannii

87
Q

They are widely distributed in soil and water and can occasionally on the skin and mucous membranes (.e.g, pharynx) of healthy people.

A

Acinetobacter species

88
Q

They are widely distributed in soil and water and can occasionally on the skin and mucous membranes (.e.g, pharynx) of healthy people.

A

Acinetobacter species

89
Q

In the hospital environment, they have been associated with ventilators, humidifiers, catheters, and other devices

A

Acinetobacter species

90
Q

Transmission in health care settings is usually aided by instrumentation.

A

Acinetobacter species

91
Q

Infections primarily affect patients with weakened immune systems and coexisting diseases. These infections usually occur in areas with a high fluid content such as the urinary tract and respiratory tract, and in peritoneal fluids.

A

Acinetobacter species

92
Q

Diseases with which they have been associated include UTIs; pneumonia, tracheobronchitis, or both; endocarditis; septicemia; meningitis, often as a complication chemotherapy; and cellulitis, usually as a result of contaminated indwelling catheters, trauma, burns, or introduction of a foreign body.

A

Acinetobacter species

93
Q

They can be isolated from blood, sputum, skin, pleural fluid, and urine.

A

Acinetobacter species

94
Q

Acinetobacter species are usually [?] in appearance.

A

coccobacillary or coccal

95
Q

Acinetobacter species resemble [?] on smears, because diplococcal forms predominate in body fluids and on solid media.

A

neisseriae

96
Q

also occur, and occasionally the bacteria may appear to be gram-positive as they can resist decolonization and retain the crystal violet stain, leading to misidentification.

A

Rod-shaped forms

97
Q

is the third most common nonfermentative, gram negative bacillus isolated in the clinical laboratory.

A

S. maltophila

98
Q

Before 1983, S. maltophila was a member of the genus Pseudomonas; it was later reclassified as a member of the plant pathogen genus [?].

After DNA homology and sequencing analysis, it was classified as a member of the genus [?], where it remains today.

A

Xanthomonas

Stenotrophomonas

99
Q

is ubiquitous in the environment, being found in water, sewage, and plant materials.

A

S. maltophilia

100
Q

It is a significant nosocomial pathogen; it is very common in the hospital environment, where they can be found contaminating blooddrawing equipment, disinfectants, transducers, and other equipment.

A

S. maltophilia

101
Q

Risk factors for colonization or infection with this organism are mechanical ventilation, use of broad spectrum antibiotics, catheterization, and neutropenia.

A

S. maltophilia

102
Q

Diseases attributed to this organism includes endocarditis, especially in a setting of prior intravenous drug abuse or heart surgery; wound infections, including cellulitis and ecthyma gangrenosum; bacteremia; and, rarely, meningitis, cholangitis, and UTIs.

A

S. maltophilia

103
Q

BAM: No distinctive appearance.
MAC: NLF

A

Burkholderia mallei

104
Q

BAM: Smooth and slightly raised; dirt-like odor.
MAC: NLF; colonies become dark pink to red because of oxidation of lactose after 4-7 days. Burkholderia cepacia selective agar (BCSA), Pseudomonas cepacia (PC) agar, or oxidativefermentative base-polymyxin Bbacitracin-lactose (OFPBL) agar: Smooth.

A

Burkholderia cepacia complex

105
Q

BAM: Smooth, opaque, raised, creamy, and smaller than Enterobacteriaceae; some genospecies are beta-hemolytic.
MAC: NLF, but colonies exhibit a purplish hue that may cause the organism to be mistaken for LF.

A

Acinetobacter baumannii

Acinetobacter lwoffi

106
Q

BAM: Large, smooth, glistening colonies with uneven edges and lavender-green to light purple pigment; greenish discoloration underneath growth; ammonia smell.
MAC: NLF

A

Stenotrophomonas maltophila

107
Q

Acid production (yellow) is seen only in the open tube, indicating that the organism is capable of oxidizing glucose but incapable of fermenting glucose.

A

OXIDATIVE UTILIZATION OF GLUCOSE by: Pseudomonas species, Burkholderia species, A. baumannii, or S. maltophila.

108
Q

does not produce acids from glucose either fermentatively or oxidatively

A

Acinetobacter lwoffi

[9c] MODULE 6 UNIT 3: Non-fermentative Gram-negative Bacilli (2 decks)

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