(F) Lesson 12: Haemophilus and Other Fastidious Bacteria (Part 1) Flashcards

1
Q

One major characteristic of how Haemophilus and other gram-negative bacteria are grouped depends on their ____

A

Gram staining results

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2
Q

Family of Haemophilus (including Actinobacillus, Pasteurella, and Aggregatibacter)

A

Pasteurellaceae

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3
Q
  • Are small, non-motile, pleomorphic gram-negative
  • Most are facultative anaerobes and obligate parasites
  • Inhabitants of the upper respiratory tract (URT) of humans and animals (except Haemophilus ducreyi)
  • 13 spp identified and 8 are associated with humans
A

Haemophilus

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4
Q
  • A key identifier for the members of the Pasteurellaceae family
A

Non-motility

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5
Q
  • Means varying morphology; can appear as coccobacilli
A

Pleomorphic

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6
Q
  • They do not require CO2, but its presence enhances the growth
A

Facultative Anaerobes

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7
Q
  • They require CO2 to grow
A

Obligate Anaerobes

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8
Q
  • This type of parasite depends on others for nutrition
A

Obligate parasites

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9
Q

T or F: All members of Haemophilus come from humans.

A

F (some come from animals)

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10
Q

Members of HACEK?

A
  • Haemophilus
  • Aggregatibacter
  • Cardiobacterium
  • Eikenella
  • Kingella
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11
Q
  • This is the key similarity of the members of HACEK.
A

Usual causes of bacterial endocarditis

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12
Q

T or F: All of the members of HACEK are normal biota.

A

F (most are normal biota but some are really common human pathogen)

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13
Q

T or F: Not all members of HACEK come out as bacilli since some come out as coccobacilli.

A

T

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14
Q
  • They tend to require a certain nutrition or supplement to grow in a media
A

Fastidious

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15
Q

Identify the species based on the description.

Fastidious, hemophilic?

Clue: 1 answer

A

Haemophilus spp.

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16
Q

Identify the species based on the description.

Fastidious fermenters and non-fermenters?

Clue: Three answers

A
  • Haemophilus aphrophilus
  • Eikenella spp.
  • Capnocytophaga spp.
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17
Q

Identify the species based on the description.

Fastidious anaerobes?

Clue: Three answers

A
  • Bacteroides spp.
  • Fusobacterium spp.
  • Prevotella spp.
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18
Q

Identify the species based on the description.

Non-fastidious fermenters of carbohydrates?

Clue: 1 answer

A

Enterobacteriaceae spp.

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19
Q

Identify the species based on the description.

Non-fastidious non-fermenter of carbohydrates?

Clue: Two answers

A
  • Pseudomonas spp.
  • Acinetobacter spp.
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20
Q

The 8 organisms of Haemophilus associated with humans.

A
  1. H. influenzae
  2. H. aegyptius
  3. H. ducreyi
  4. H. parainfluenzae
  5. H. haemolyticus
  6. H. parahaemolyticus
  7. H. paraphrohaemolyticus
  8. H. pittmaniae
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21
Q

What are the three (3) common human pathogens under Haemophilus?

A
  1. H. influenzae
  2. H. aegyptius
  3. H. ducreyi
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22
Q

What are the five (5) organisms under Haemophilus that are found in normal biota?

A
  1. H. parainfluenzae
  2. H. haemolyticus
  3. H. parahaemolyticus
  4. H. paraphrohaemolyticus
  5. H. pittmaniae
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23
Q

Haemophilus came from what two Greek words meaning?

A

Haemo (blood) + Philo (love)

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24
Q
  • Protoporphyrin IX or hemin or hematin
  • In BAP and CAP preparation, it uses the same procedures
  • However, in preparing BAP, the mixture is cooled down to a lukewarm temperature after autoclaving. Its red color is due to the intact RBCs
  • In CAP, blood is immediately added to the medium after autoclaving, lysing the RBCs causing the change in color from red to brown.
A

Factor X

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25
Q
  • NAD or NADP
  • Found in the blood
A

Factor V

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26
Q

Growth of Haemophilus is enhanced in?

A

5-10% CO2

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27
Q

They exhibit ____ around S. aureus.

A

Satellitism

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28
Q
  • Happens due to the beta-hemolytic property of S. aureus that lyses the RBC, allowing the growth of Haemophilus spp.
A

Satellitism

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29
Q

Haemophilus are (positive/negative) in catalse, oxidase, nitrate reduction, and hemolysis on 5% sheep/horse/rabbit blood agar (SBA, HBA, RBA).

A

Positive

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30
Q
  • This type of agar contains NADases that lyse NAD.
A

Sheep Blood Agar

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31
Q
  • Medium of choice for Haemophilus since it contains NAD, liberated Factor X from lysed RBCs in CAP
A

HCA or Horse Chocolate Agar Plate

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32
Q

Known with the common name of Pleiffer’s Bacillus

A

Haemophilus influenzae

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33
Q

Haemophilus influenzae

It was after the development of ____ that it became apparent that influenza was caused by a virus and the actual role of H. influenzae was that of a secondary/opportunistic invader.

A

Viral culture techniques

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34
Q

Haemophilus influenzae

It was after the development of viral culture techniques that it became apparent that influenza was caused by a virus and the actual role of H. influenzae was that of a ____.

A

Secondary or oppotunistic invader

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35
Q

Haemophilus influenzae

This makes the organism more pathogenic; mechanisms on how they can illicit diseases greatly.

A

Virulence Factor

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36
Q

Haemophilus influenzae

  • Used in serotyping, it has 6 antigenically distinct serologic groups: a, b, c, d, e, and f based on differences in the capsular polysaccharide
  • For its antiphagocytic property and anticomplementary activity
  • Not present in all H. influenzae
A

Capsule

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37
Q

Haemophilus influenzae

The six (6) antigenically distinct serologic groups are based on differences in their?

A

Capsular polysaccharide

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38
Q

Haemophilus influenzae

  • This the most invasive serotype since it contains a unique polymer: ribose, ribitol, and phosphate (polyribitol phosphate or polyribitol ribose phosphate).
A

Hib or serologic type B

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39
Q

Haemophilus influenzae

  • Protection from the phagocytic activity by phagocytes
A

Antiphagocytic

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40
Q

Haemophilus influenzae

  • Complements can’t attach to the organism, membrane attack complexes can’t be executed
A

Anticomplementary

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41
Q

Haemophilus influenzae

These types of Haemophilus do not contain capsules.

A

NTHi or non-typable H. influenzae

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42
Q

Haemophilus influenzae

This particular virulence factor is unique to Haemophilus influenzae.

A

Immunoglobulin A (IgA) Proteases

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43
Q

Haemophilus influenzae

  • Inhibits human secretory IgA found in body secretions
  • Since the Haemophilus spp. reside in the URT and there are a lot of secretions in the URT
A

Secretory IgA

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44
Q

Haemophilus influenzae

  • Sometimes organisms may contain pili for attachment
  • Significant in the type of infection produced by an organism
A

Adherence mechanisms

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45
Q

Haemophilus influenzae

  • ____ is non-adherent (no pili)
  • They tend to spread throughout the body, producing systemic infection
  • There is no organ of infection
A

Hib

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46
Q

Haemophilus influenzae

  • ____ are adherent
  • Produces localized infection (better compared to Hib)
A

NTHi

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47
Q

Haemophilus influenzae

T or F: The adherence mechanism of pili is not well-studied at the moment.

A

T

48
Q

Haemophilus influenzae

  • Similar to adherence mechanisms, these are not yet well-defined.
  • The cinical manifestation depends on whether an organism is capsulated or not.
A

Outer membrane components

49
Q

Haemophilus influenzae

  • Its content has something to do with the invasiveness, attachment, and antiphagocytic function
  • Paralyzing effect on the sweeping motion of ciliated respiratory epithelium
A

Lipopolysaccharide

50
Q

Haemophilus influenzae

  • Majority of the URT are ____, the LPS can have a ciliostatic effect on the wave-like motion of the cilia
A

Ciliated epithelium

51
Q

Haemophilus influenzae

T or F: The wave-like movement agitates the bacteria in the area.

A

F (removes them)

52
Q

Haemophilus influenzae

  • Tend to elicit systemic infections
  • Include: septicemia, meningitis, arthritis, tracheitis, pneumonia, and epiglottitis
A

Encapsulated strains

53
Q

Haemophilus influenzae

  • Causes more localized infections
  • Include: conjunctivitis, sinusitis, otitis media with effusion (luga)
A

NTHi strains

54
Q

Haemophilus influenzae

List the top three causes of Meningitis.

A
  1. S. pneumoniae
  2. N. meningitidis
  3. H. influenzae
55
Q

Haemophilus influenzae

List the top two causes of otitis media with effusion.

A
  1. S. pneumoniae
  2. H. influenzae
56
Q

Known with the common name of Koch-Week’s Bacillus

In honor of Robert Koch who discovered this organism

A

Haemophilus aegyptius

57
Q
  • Genetically related to H. influenzae, because of this it is difficult to differentiate H. influenzae from them
  • Observed in conjunctivitis (“pinkeye”) exudates from Egyptians by Koch in 1883
A

Haemophilus aegyptius

58
Q
  • A group separated because of the innovation in our molecular techniques
  • They are biochemically related but differ in DNA composition based on molecular testing
  • Non-encapsulated
  • Causes Brazilian purpuric fever (BPF) in Brazil in 1984
A

Haemophilus influenzae biogroup aegyptius

59
Q

Haemophilus influenzae biogroup aegyptius

T or F: They cause mostly localized infections.

A

F (systemic infections)

60
Q

Haemophilus influenzae biogroup aegyptius

  • Recurrent or concurrent conjunctivitis, high fever, vomiting, petechial or purpural rash, septicemia, shock, and vascular collapse
  • Mortality rate may reach 70% within 48 hours after onset
  • Would require hospitalization
A

Brazilian purpuric fever

61
Q
  • One of the species that can be really pathogenic
  • The only member of Haemophilus that does not reside in the URT, reside in the genitals
  • It infects mucosal epithelium, genital and nongenital skin, and regional lymph nodes within the genitals
  • Infected patients may produce chancroid, a genital ulcer disease (GUD)
A

Haemophilus ducreyi

62
Q

Haemophilus ducreyi

Soft chancre?

A

Haemophilus ducreyi

63
Q

Haemophilus ducreyi

Hard chancre?

A

Syphilis

64
Q

Haemophilus ducreyi

Incubation time?

A

4 to 14 days

65
Q

Haemophilus ducreyi

Initial stage of the disease?

A

Formation of painful lesions in the genitalia or perianal areas

66
Q

Haemophilus ducreyi

Once it spreads further to the lymph nodes (i.e., inguinal lymph nodes), it will form ____ which are suppurative inguinal lymph nodes.

A

Buboes

67
Q

Haemophilus

Familiarize yourself with the different specimens that can be used for laboratory diagnosis.

A
  • Blood
  • CSF
  • Middle ear exudate
  • Joint fluids
  • Upper and lower RT specimens
  • Conjunctival and vaginal swabs
  • Abscess drainage
68
Q

Haemophilus

T or F: H. influenzae can produce localized or systemic infections.

A

T

69
Q

Haemophilus

If localized infection is present, what are the best specimens to be collected?

A
  • Conjunctival
  • Vaginal swabs
  • Aspirates
70
Q

Haemophilus

If systemic infection is present, what is the best specimen to be collected?

A

Blood

71
Q

They die rapidly in clinical specimens, and prompt transportation and processing are vital for their isolation.

A

Haemophilus species

72
Q

This is a good medium for the isolation of Haemophilus spp. in respiratory specimens.

A

CHOC agar or CAP with bacitracin (300 mg/L)

73
Q

T or F: The addition of antibiotics to the medium makes it selective.

A

T

74
Q

What are the chosen mediums for isolation of Haemophilus influenzae?

A
  • CHOC agar
  • Levinthal’s agar
  • Fildes Enrichment
75
Q

What are the chosen mediums for isolation of Haemophilus aegyptius?

A

Enriched CHOC agar with
* 1% iso-Vitalex (BD Diagnostic Systems, Sparks, MD) or
* Vitoc (Oxoid, Basingstoke, UK)

76
Q

Haemophilus is mostly resistant to?

A

Vancomycin

77
Q

What are the chosen mediums for isolation of Haemophilus ducreyi?

A
  • Enriched CHOC medium
  • Nairobi plate split into two, aka biplate
  • GC agar containing 1% Hgb, 5%% fetal calf serum, 1% Iso-Vitalex, and 3mg/L vancomycin
  • MHA with chocolitized horse blood
78
Q

Identify the organism based on colonial morphology.

  • Translucent, tannish, moist, smooth, and convex with distinct mousy or bleach-like odor
A

Haemophilus influenzae

79
Q

T or F: Encapsulated strains grow larger and more mucoid than NTHi

A

T

80
Q

Identify the organism based on the colonial morphology.

  • Same colonial morphology as Haemophilus influenzae
A

Haemophilus influenza biogroup aegyptius

81
Q

Identify the organism based on the colonial morphology.

  • A normal biota
  • Tannish and drier with medium to large size
A

Haemophilus parainfluenzae

82
Q

Identify the organism based on the colonial morphology.

  • Has the same colonial morphology as Haemophilus parainfluenzae
A

Haemophilus parahemolyticus

83
Q

Identify the organism based on the colonial morphology.

  • Small, flat, smooth, nonmucoid, transparent to opaque colonies appearing tan or yellow
A

Haemophilus ducreyi

84
Q

T or F: Most members of the Haemophilus species have the same G/S outcome: small gram-positive coccobacilli to long filaments.

A

F (gram-negative)

85
Q

Identify the organism based on microscopic morphology.

  • Capsules are clear non-staining areas “halos” surrounding the organism
A

Haemophilus influenzae

86
Q

Identify the organism based on microscopic morphology.

  • School of fish, or railroad tracks or fingerprints
A

Haemophilus ducreyi

87
Q
  • Suspicion confirmed by laboratory identification methods
A

Presumptive

88
Q

Enumerate the three preliminaries for presumptive identification of Haemophilus species.

A
  1. Gram-negative pleomorphic coccobacilli
  2. (+) Growth on CHOC agar
  3. No growth in SBA (BAP) and MAC
89
Q
  • Impregnated strips of discs on MHA which uses three disks
  • Similar to AST
A

X and V Factor Requirement

90
Q

What are the three disks used for X and V Factor Requirement?

A
  • X Factor
  • V Factor
  • X + V Factor
91
Q

X and V Factor Requirement

  • This particular disk contains hemin protoporphyrin or hematin
A

X Factor

92
Q
  • Needing an x-factor means the organism is (independent/dependent) on others for an x-factor.
A

Dependent

93
Q

X and V Factor Requirement

T or F: Negative doesn’t necessarily mean an organism doesn’t need an x-factor, it means it is independent, it can produce its own.

A

T

94
Q

What does positive growth around X + V factor mean?

A

Needs both factors to grow

Characteristic of H. influenzae

95
Q
  • Used to differentiate heme-producing spp of Haemophilus
  • Similar to the X and V factor test
  • The disk contains delta-aminolevulinic acid (ALA) which is a precursor for porphyrins or porphobilinogen used in heme synthesis
A

Porphyrin Test

96
Q

Porphyrin Test

  • Positive Results: Red color
  • Used to visualize results
A

Addition of Kovac’s reagent or p-dimethylamino benzaldehyde

97
Q

Porphyrin Test

  • Used to visualize fluoroscence
  • Positive Result: Reddish orange fluorescence
A

Wood’s Lamp

98
Q

Porphyrin Test

T or F: Positive in Porphyrin test means also a positive in X Factor Test

A

F (negative X-factor)

99
Q

Identify the organisms.

  • (+) Factor X and V
  • (-) Porphyrin
A
  • H. influenzae
  • H. haemolyticus
100
Q

Identify the organisms.

  • (-) Factor X
  • (+) Factor V
  • (+) Porphyrin
A
  • H. parainfluenzae
  • H. parahaemolyticus
  • H. paraphrohaemolyticus
  • Aggregatibacter segnis
101
Q

Identify the organism.

  • (+) Factor X
  • (-) Factor V
  • (-) Porphyrin
A
  • H. ducreyi
102
Q

Identify the organisms.

  • (-) Factor X and V
  • (+) Porphyrin
A
  • Aggregatibacter aphrophilus
103
Q

Drug of choice for life-threatening H. influenzae?

A
  • Cefotaxime or ceftriaxone
104
Q

Alternative drugs for life-threatening of H. influenzae?

A
  • Trimethoprim-sulfamethoxazole
  • Imipenem
  • Ciprofloxacin
  • Chloramphenicol with ampicillin
105
Q

Drugs that may be used for non-life-threatening H. influenzae?

A
  • Amoxicillin-clavulanate
  • Trimethoprim-sulfamethoxazole
106
Q

Haemophilus influenzae (non-life-threatening drugs)

An oral second- or third-generation cephalosporin

A

Amoxicillin-clavulanate

107
Q

Drugs of choice for H. ducreyi?

A
  • Azithromycin
  • Ceftriaxone
  • Ciprofloxacin
  • Erythromycin
108
Q
  • This is not recommended as a first-line therapy because of the increased resistance to ampicillin.
A

Chloramphenicol with ampicillin

109
Q

T or F: Chloramphenicol with ampicilin may be used alone for initial therapy.

A

F (not be used alone)

110
Q
  • An enzyme that results in ampicillin-resistance in beta-lactam antibiotics
  • Antibiotics with beta-lactam rings
A

Beta-lactamase

111
Q
  • Detects the presence of the beta-lactamase enzyme
  • Uses disks impregnated with nitrocefin + water + bacterial colony
A

Chromogenic Cephalosporin Test

112
Q

Positive result for chromogenic cephalosporin test?

A

Red (organism has beta-lactamase)

113
Q

Chromogenic Cephalosporin Test

  • Contains beta-lactam, representing ampicillin and penicillin
A

Nitrocefin

114
Q
  • Detects the presence of the beta-lactamase enzyme
  • Uses strips impregnated with benzylpenicillin + bromocresol purple (pH indicator) +1-2 drops distilled water + bacterial colony
A

Acidometric Test

115
Q

Beta-lactamase neutralizes the beta-lactam ring in benzylpenicillin producing?

A

Penicilloic acid

116
Q

Positive result of Acidometric Test?

A

From purple to yellow (acidic)