Haemophilus Aggregatibacter Cardiobacterium Eikenella Kingella

(F) Lesson 12: Haemophilus and Other Fastidious Bacteria (Part 1) Flashcards by Kchianna Lauren Coronel

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

Gram staining results

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

Pasteurellaceae

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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

Haemophilus

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A key identifier for the members of the Pasteurellaceae family

Non-motility

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Means varying morphology; can appear as coccobacilli

Pleomorphic

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They do not require CO2, but its presence enhances the growth

Facultative Anaerobes

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They require CO2 to grow

Obligate Anaerobes

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This type of parasite depends on others for nutrition

Obligate parasites

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

F (some come from animals)

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Members of HACEK?

Haemophilus
Aggregatibacter
Cardiobacterium
Eikenella
Kingella

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This is the key similarity of the members of HACEK.

Usual causes of bacterial endocarditis

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

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

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

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They tend to require a certain nutrition or supplement to grow in a media

Fastidious

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Identify the species based on the description.

Fastidious, hemophilic?

Clue: 1 answer

Haemophilus spp.

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Identify the species based on the description.

Fastidious fermenters and non-fermenters?

Clue: Three answers

Haemophilus aphrophilus
Eikenella spp.
Capnocytophaga spp.

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Identify the species based on the description.

Fastidious anaerobes?

Clue: Three answers

Bacteroides spp.
Fusobacterium spp.
Prevotella spp.

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Identify the species based on the description.

Non-fastidious fermenters of carbohydrates?

Clue: 1 answer

Enterobacteriaceae spp.

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Identify the species based on the description.

Non-fastidious non-fermenter of carbohydrates?

Clue: Two answers

Pseudomonas spp.
Acinetobacter spp.

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The 8 organisms of Haemophilus associated with humans.

H. influenzae
H. aegyptius
H. ducreyi
H. parainfluenzae
H. haemolyticus
H. parahaemolyticus
H. paraphrohaemolyticus
H. pittmaniae

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

H. influenzae
H. aegyptius
H. ducreyi

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

H. parainfluenzae
H. haemolyticus
H. parahaemolyticus
H. paraphrohaemolyticus
H. pittmaniae

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Haemophilus came from what two Greek words meaning?

Haemo (blood) + Philo (love)

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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.

Factor X

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* NAD or NADP * Found in the blood

Factor V

Growth of Haemophilus is enhanced in?

5-10% CO2

They exhibit ____ around S. aureus.

Satellitism

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

Satellitism

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

Positive

* This type of agar contains NADases that lyse NAD.

Sheep Blood Agar

* Medium of choice for Haemophilus since it contains NAD, liberated Factor X from lysed RBCs in CAP

HCA or Horse Chocolate Agar Plate

Known with the common name of **Pleiffer's Bacillus**

Haemophilus influenzae

# 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.

Viral culture techniques

# 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 ____.

Secondary or oppotunistic invader

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

Virulence Factor

# 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

Capsule

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

Capsular polysaccharide

# Haemophilus influenzae * This the **most invasive serotype** since it contains a unique polymer: ribose, ribitol, and phosphate (polyribitol phosphate or polyribitol ribose phosphate).

Hib or serologic type B

# Haemophilus influenzae * Protection from the phagocytic activity by phagocytes

Antiphagocytic

# Haemophilus influenzae * Complements can’t attach to the organism, membrane attack complexes can’t be executed

Anticomplementary

# Haemophilus influenzae These types of Haemophilus do not contain capsules.

NTHi or non-typable H. influenzae

# Haemophilus influenzae This particular virulence factor is unique to Haemophilus influenzae.

Immunoglobulin A (IgA) Proteases

# 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

Secretory IgA

# Haemophilus influenzae * Sometimes organisms may contain pili for attachment * Significant in the type of infection produced by an organism

Adherence mechanisms

# Haemophilus influenzae * ____ is non-adherent *(no pili)* * They tend to spread throughout the body, producing **systemic infection** * There is **no organ of infection**

Hib

# Haemophilus influenzae * ____ are adherent * Produces **localized infection** *(better compared to Hib)*

NTHi

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

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

Outer membrane components

# 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

Lipopolysaccharide

# Haemophilus influenzae * Majority of the URT are ____, the LPS can have a **ciliostatic effect** on the wave-like motion of the cilia

Ciliated epithelium

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

F *(removes them)*

# Haemophilus influenzae * Tend to elicit **systemic infections** * Include: septicemia, meningitis, arthritis, tracheitis, pneumonia, and epiglottitis

Encapsulated strains

# Haemophilus influenzae * Causes more **localized infections** * Include: conjunctivitis, sinusitis, otitis media with effusion *(luga)*

NTHi strains

# Haemophilus influenzae List the top three causes of Meningitis.

1. S. pneumoniae 2. N. meningitidis 3. H. influenzae

# Haemophilus influenzae List the top two causes of otitis media with effusion.

1. S. pneumoniae 2. H. influenzae

Known with the common name of **Koch-Week's Bacillus** | In honor of Robert Koch who discovered this organism

Haemophilus aegyptius

* 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

Haemophilus aegyptius

* 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

Haemophilus influenzae biogroup aegyptius

# Haemophilus influenzae biogroup aegyptius T or F: They cause mostly localized infections.

F *(systemic infections)*

# 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

Brazilian purpuric fever

* 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)

Haemophilus ducreyi

# Haemophilus ducreyi Soft chancre?

Haemophilus ducreyi

# Haemophilus ducreyi Hard chancre?

Syphilis

# Haemophilus ducreyi Incubation time?

4 to 14 days

# Haemophilus ducreyi Initial stage of the disease?

Formation of painful lesions in the genitalia or perianal areas

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

Buboes

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

* Blood * CSF * Middle ear exudate * Joint fluids * Upper and lower RT specimens * Conjunctival and vaginal swabs * Abscess drainage

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

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

* Conjunctival * Vaginal swabs * Aspirates

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

Blood

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

Haemophilus species

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

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

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

What are the chosen mediums for isolation of Haemophilus influenzae?

* CHOC agar * Levinthal’s agar * Fildes Enrichment

What are the chosen mediums for isolation of Haemophilus aegyptius?

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

Haemophilus is mostly resistant to?

Vancomycin

What are the chosen mediums for isolation of Haemophilus ducreyi?

* 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

# Identify the organism based on colonial morphology. * Translucent, tannish, moist, smooth, and convex with **distinct mousy or bleach-like odor**

Haemophilus influenzae

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

# Identify the organism based on the colonial morphology. * Same colonial morphology as Haemophilus influenzae

Haemophilus influenza biogroup aegyptius

# Identify the organism based on the colonial morphology. * A normal biota * Tannish and drier with medium to large size

Haemophilus parainfluenzae

# Identify the organism based on the colonial morphology. * Has the same colonial morphology as Haemophilus parainfluenzae

Haemophilus parahemolyticus

# Identify the organism based on the colonial morphology. * Small, flat, smooth, nonmucoid, transparent to opaque colonies appearing tan or yellow

Haemophilus ducreyi

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

F *(gram-negative)*

# Identify the organism based on microscopic morphology. * Capsules are clear non-staining areas **“halos”** surrounding the organism

Haemophilus influenzae

# Identify the organism based on microscopic morphology. * School of fish, or railroad tracks or fingerprints

Haemophilus ducreyi

* Suspicion confirmed by laboratory identification methods

Presumptive

Enumerate the three preliminaries for presumptive identification of Haemophilus species.

1. Gram-negative pleomorphic coccobacilli 2. (+) Growth on CHOC agar 3. No growth in SBA (BAP) and MAC

* Impregnated strips of discs on MHA which uses three disks * Similar to AST

X and V Factor Requirement

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

* X Factor * V Factor * X + V Factor

# X and V Factor Requirement * This particular disk contains **hemin protoporphyrin or hematin**

X Factor

* Needing an x-factor means the organism is (**independent/dependent**) on others for an x-factor.

Dependent

# 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.

What does positive growth around X + V factor mean?

Needs both factors to grow ## Footnote Characteristic of **H. influenzae**

* 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

Porphyrin Test

# Porphyrin Test * **Positive Results:** Red color * Used to **visualize results**

Addition of Kovac's reagent or p-dimethylamino benzaldehyde

# Porphyrin Test * Used to **visualize fluoroscence** * **Positive Result:** Reddish orange fluorescence

Wood's Lamp

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

F *(negative X-factor)*

# Identify the organisms. * (+) Factor X and V * (-) Porphyrin

* H. influenzae * H. haemolyticus

# Identify the organisms. * (-) Factor X * (+) Factor V * (+) Porphyrin

* H. parainfluenzae * H. parahaemolyticus * H. paraphrohaemolyticus * Aggregatibacter segnis

# Identify the organism. * (+) Factor X * (-) Factor V * (-) Porphyrin

* H. ducreyi

# Identify the organisms. * (-) Factor X and V * (+) Porphyrin

* Aggregatibacter aphrophilus

Drug of choice for **life-threatening H. influenzae**?

* Cefotaxime or ceftriaxone

Alternative drugs for **life-threatening of H. influenzae**?

* Trimethoprim-sulfamethoxazole * Imipenem * Ciprofloxacin * Chloramphenicol with ampicillin

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

* Amoxicillin-clavulanate * Trimethoprim-sulfamethoxazole

# Haemophilus influenzae (non-life-threatening drugs) An oral second- or third-generation cephalosporin

Amoxicillin-clavulanate

Drugs of choice for **H. ducreyi**?

* Azithromycin * Ceftriaxone * Ciprofloxacin * Erythromycin

* This is not recommended as a first-line therapy because of the increased resistance to ampicillin.

Chloramphenicol with ampicillin

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

F *(not be used alone)*

* An enzyme that results in ampicillin-resistance in beta-lactam antibiotics * Antibiotics with beta-lactam rings

Beta-lactamase

* Detects the presence of the beta-lactamase enzyme * Uses disks impregnated with **nitrocefin + water + bacterial colony**

Chromogenic Cephalosporin Test

Positive result for chromogenic cephalosporin test?

Red *(organism has beta-lactamase)*

# Chromogenic Cephalosporin Test * Contains beta-lactam, representing ampicillin and penicillin

Nitrocefin

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

Acidometric Test

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

Penicilloic acid

Positive result of Acidometric Test?

From purple to yellow *(acidic)*

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

(116 cards)