Haemophilus Flashcards by EJ Kharl Alcovilla

Gram (-) fastidious bacilli.

Haemophilus
HACEK group
Capnocytophaga
Pasteurella
Brucella
Francisella

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Which is/are not characteristics of Haemophilus?
A. Pleomorphic
B. Nonmotile
C. Blood loving
D. Facultative aerobes

D.
They are facultative anaerobes

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Which is/are not characteristics of Haemophilus?
A. Reduce nitrate-nitrite
B. Reduce nitrite-nitrate
C. Obligate parasites in human
D.part of normal flora

B and D
They are not normal flora but a true pathogens

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Major spp. Of haemophilus that are pathogenic to humans.

H. influenzae
H. aegyptius
H. ducreyi

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Growth factors req. By haemophilus in blood.

X factor
V. factor

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T or F
The prefix “para” only requires X factors

False-V factor

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T or F
Haemophilus are mostly hemolytic in 10% horse/rabbit blood agar.

False: 5%

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X factor contains:____
V. facto contains:____

X= hemin/hematin
V= NAD(nicotinamide adenine dinucleotide)

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Which statement is true
1.Both X and V factos found in blood
2.Both grows in pure culture media (SBA)

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What media is good for haemophilus?

CHOC (THE LYSIS OF RBC produce X and V factors)

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What media is good for haemophilus?

CHOC (THE LYSIS OF RBC produce X and V factors)

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Spp. That requires V factors.

S. aureus
S. pneumoniae
Neisseria spp.
Haemophilus spp.

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The Haemophilus X factor obtain from ___.

SBA

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The haemophilus obtain V factor from ___.

S. aureus
S. pneumoniae
Neisseria

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A phenomenon that helps in the recognition of Haemophilus.

Satellitism

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They don’t req. V factors and don’t produce satellitism.

H. ducreyi
A. aphrophilus

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Significant virulence factor of H. influenzae.

Capsule

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How many serotypes of capsule does H. influenzae have? What are they?

6 serotypes (A-F)

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Encapsulated strain of H. influenzae belongs to ____ occured primarily in young children.

Serotype B (Hib)

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Serotype capsule of H. influenzae composed of what?

Ribose
Ribitol
Phosphate
(Polyribitol phosphate)

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T or F
All strain of H. influenzae is encapsulated.

False - some are not, and they are called non-typable H. influenzae (NTHi).

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The only sp. Of Haemophilus that has IgA protease.

H. influenzae

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What is the adherence mechanism of H. influenzae?

Fimbriae

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T or F
Encapsulated strain of H. influenzae has the adherence mechanism.

False- nonencapsulated strain (NTHi)

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Absent of adherence mechanism of most serotype b of H. influenzae cause ____.

Systemic infections

The presence of an adherence mechanism of NTHi strain cause ___.

Localized infections (acute conjunctivitis)

Two patterns of disease attributed by H. influenzae.

Invasive disease Localized infection

Example of invasive disease.

Septicemia Meningitis arthritis epiglottitis tracheitis Pneumonia

Example of localized infections.

Conjunctivitis Sinusitis Otitis media

Arrange from the most-least prevalent cause of otitis media.

S. pneumoniae H. influenzae M. catarrhalis

Other name of H. aegyptius

Koch-Weeks bacillus

It was observed in conjunctivitis exudates from Egyptian.

H. aegyptius

H. aegyptius is associated with acute, contagious conjunctivitis AKA as___.

Pink eye.

It causes conjunctivitis primarily in pediatric populations.

Haemophilus influenzae Biogroup aegyptius

Whay severe systemic disease cause by Haemophilus influenzae Biogroup aegyptius.

Brazilian purpuric fever

T or F Haemophilus influenzae Biogroup aegyptius is encasulared.

False (unencapsulated)

Causative agent of chancroid.

H. ducreyi

A highly communicable sexual transmitted genital ulcer disease (GUD) cause by H. ducreyi.

Chancroid

T or F Soft chancre = syphilis Hard chancre= chancroid

False Soft chancre = chancroid Hard chancre= syphilis

Common site of H. ducreyi.

Penis Labia of vagina

Common symptoms of chancroid.

Suppurative Enlarged,draining, inguinal lymph nodes (buboes).

2 Miscellaneous species of Haemophilus.

H. parainfluenzae H. paraharmolyticus

Miscellaneous sp. Of H. that rarely cause endocarditis and the primary site is mitral valve.

H. parainfluenzae

Miscellaneous sp that can cause pharyngitis.

H. parahaemlyticus

Common source of Haemophilus spp.

- Blood – CSF – Middle-ear exudate – Joint fluids – URT and LRT (bronchial washing) specimens – Conjunctival swabs – Vaginal swabs – Abscess drainage

Specimen and its infections Blood:(septicemia) CSF: Middle-ear exudate: Joint fluids: URT and LRT (bronchial washing) specimens: Conjunctival swabs: Abscess drainage:

Specimen and its infections Blood:(septicemia) CSF: (meningitis) Middle-ear exudate: (otitis) Joint fluids:(arthritis) URT and LRT (bronchial washing) specimens: (pneumonia) Conjunctival swabs:(conjunctivitis) Abscess drainage:(mucous)

In collection of Haemophilus spp., The following are correct except: A. First cleaned with sterile gauze moistened with sterile saline B. Direct plating on selective media is preferred C. Susceptible to drying D. Used of 70% isopropyl alcohol

The swab is pre moistened with ___.

Phosphate-buffered saline

Media used for isolation of Haemophilus from respiratory specimen.

CHOC+Bacitracin

Media for H. aegyptius.

CHOC supplemented with 1% IsoVitaleX or Vitox (4days)

Special media for H. ducreyi.

Nairobi biplate medium (GC agar base with 2% bovine Hb and 5% fetal calf serum + MH agar with 5% chocolatized horse blood)

Haemophilus influen Are incubated at what temp and % of CO2?

Incubated at 33°C to 37°C under 5% to 10% CO2.

T or F - Incubated under 5% to 10% CO2 with high humidity. - Grows best at 35°C (held for 7 days)

True False (33°C)

Stain used to detect Haemophilus spp.

Acridine orange Methylene blue

Haemophilus spp. Resembles what?

Amorphous serous material (serum-like/ proteinaceous material)

Pale staining gram-negative coccobacilli arranged singly or in clusters

H. ducreyi

The clusters of H. ducreyi are AKA

-school of fish -railroad tracks -fingerprints

Colony of H. Influenzae can grow in what media?

CHOC, MAC, SBA

All are characteristics of H. influenzae in choc Except: A. tannish B. moist, C.rough D. convex

C. (They are smooth)

Odor of H. influenzae in CHOC.

Mousy/bleach-like odor

T or F Encapsulated strains of H. influenzae grow smaller and more mucoid

False (larger)

Appearance of H. influenzae in MAC agar plate.

N/A (they don't grow in MAC)

ALL are Characteristics of Colonies of H. parainfluenzae in CHOC except: A. tannish B.drier C. medium to large size compared to H. influenzae D. Convex

They resemble H. parainfluenzae and on horse or rabbit blood agar, it is β-hemolytic.

H. parahaemolyticus

H. ducreyi appear ___ in CHOC A. small B. flat C. smooth D. nonmucoid, E. transparent - opaque

All of the above

Color of H. ducreyi in CHOC.

tan or yellow

T or F H. ducreyi can be pushed intact.

True

Which statement is not true about H. ducreyi colonies? A. They can perform satellitism B. It's difficult to pick up C. produce a “clumpy” nonhomogeneous appearance (saline) D. Can be pushed intact

ALL are First clue for the genus of Haemophilus spp.except. A. Gram (-) pleomorphic coccobacilli B. (Gram (+)pleomorphic coccobacilli C. No growth in SBA and MAC D. Present in CHOC

Test for identification of Haemophilus spp.

- Testing for X and V factors - Traditional biochemicals - Hemolysis on media containing rabbit or horse blood - Oxidase and catalase tests

T or F Care must be taken not to transfer X factor-containing medium to agar plates used for X factor requirement.

True

What happened if the X factor was carried over to the plate for X factor testing?

It produces erroneous or inconclusive results, causing misidentified H. influenzae into H. parainfluenzae.

T or F When Haemophilus spp. Grows anaerobically, they don't need V. Factor.

False - X factor

In all spp. That need V. Factor, ___ is the only oxidase (-).

Aggregatibacter segnis

The an alternative method for differentiating the heme-producing spp. Of Haemophilus.

Porphyrin test

The principle of porphyrin test is the ability of the microorganism to convert deltaaminolevulinic acid (ALA) into ____.

porphyrins or porphobilinogen (intermediates in synthesis of X factor)

Porphobilinogen is detected by adding ___.

Kovacs reagent

If porphobilinogen is present in porphyrin test what is the color?

Pink/red

Porphyrins can be detected by using __.

UV light

Prophyrins fluoresce ___ in uv test.

Reddish orange

Main advantage of porphyrin test.

X factor is not required and prevents carry over.

Treatment for life threatening H. influenzae except: A. Cefotaxime or ceftriaxone B. Amoxicillin-clavulanate C. Chloramphenicol D. Imipenem

Treatment for not life threatening H. Influenzae.

- Amoxicillin-clavulanate - Trimethoprim-SXT

Treatment for H. ducreyi

Erythromycin

Haemophilus Flashcards

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