NEW LOWER PRICES - ACT FAST
Medicine (MD/DO)
/
Courses
/
Microbiology
/
Gram Negative Coccobacilli
/
Haemophilus influenzae Characteristics

Master Haemophilus influenzae Characteristics with Picmonic for Medicine

With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing.

DOWNLOAD PDF
Haemophilus influenzae Characteristics

Recommended Picmonics

picmonic thumbnail
Haemophilus Influenzae Disease
picmonic thumbnail
Brucella
picmonic thumbnail
Bordetella pertussis
picmonic thumbnail
Pasteurella multocida

Haemophilus influenzae Characteristics

He-man In-flute
Picmonic
Haemophilus influenzae is a gram-negative coccbacilli that can cause several diseases, including meningitis, pneumonia, otitis media and epiglottitis. There are two major categories of H. influenzae, including the encapsulated strains and the unencapsulated strains. Encapsulated strains are classified based on their distinct capsular antigen: A,B,C,D,E,G,. Type B is known to cause the most severe disease including meningitis and epiglottitis. H. influenzae organisms require nutrient supplementation to grow in laboratory cultures. Specifically, they grow on chocolate agar, which is an enriched growth medium containing red blood cells that have been lysed, providing growth factors like NAD (factor V) and hematin (factor X). Virulence mechanisms include an antiphagocytic PRP capsule and IgA protease.
9 KEY FACTS
CHARACTERISTICS
Gram-Negative
Graham-cracker Negative-devil

This organism stains Gram negative due to relatively thin peptidoglycan layer in the cell wall.

Coccobacilli
Cockeyed-rod

Coccobacilli are a type of rod-shaped bacteria that are short and wide, so they resemble spherical cocci.

PRP Capsule in Type B
PRP Capsule with a B

The polyribosyl ribitol phosphate (PRP) capsule is the most important virulence factor of type B Haemophilus influenzae infections, because it plays a role in resisting phagocytosis.

Positive Quellung Reaction
Positive Quail-lungs

A Quellung reaction is a biochemical reaction in which antibodies bind to a bacterial capsule, allowing species with a positive Quellung reaction to be visualized under a microscope. Haemophilus influenza has a positive Quellung reaction.

IgA Protease
(IgA) Apple Globulin-Goblin with Propeller-ace

An IgA protease is an enzyme that cleaves certain amino acid sequences of proteins including immunoglobulin A. Haemophilus influenzae releases IgA proteases which destroy IgA, leading to increased pathogenicity. Other IgA protease producers include Neisseria gonorrhoeae and Streptococcus pneumoniae.

Chocolate Agar
Chocolate-bar

Haemophilus influenzae organisms require nutrient supplementation to grow in laboratory cultures. Specifically, they grow on chocolate agar, which is an enriched growth medium containing red blood cells that have been lysed, providing growth factors like NAD and hematin. The agar is named for the chocolate color of the medium and does not actually contain chocolate.

Factor V is NAD
(NAD) Nicotine Character giving (5) Hand high five

Haemophilus influenzae requires two accessory growth factors when cultured, including factor X and factor V. Factor V is NAD (nicotinamide adenine dinucleotide).

Factor X is Hematin
(10) X-factor sign held by 10 He-men

Haemophilus influenzae requires two accessory growth factors when cultured, including factor X and factor V. Factor X is hematin.

Staph Aureus Provides Factor V
Staff-of-Oreos with NAD factor V

H. influenzae can grow in the hemolytic zone of Staph aureus on blood agar plates, because hemolysis of cells by Staph aureus releases factor V, which is needed for growth.

DOWNLOAD PDF

Take the Haemophilus influenzae Characteristics Quiz

Picmonic's rapid review multiple-choice quiz allows you to assess your knowledge.

It's worth every penny

Our Story Mnemonics Increase Mastery and Retention

Memorize facts with phonetic mnemonics

Unforgettable characters with concise but impactful videos (2-4 min each)

Memorize facts with phonetic mnemonics

Ace Your Medicine (MD/DO) Classes & Exams with Picmonic:

Over 1,870,000 students use Picmonic’s picture mnemonics to improve knowledge, retention, and exam performance.

Choose the #1 Medicine (MD/DO) student study app.

Picmonic for Medicine (MD/DO) covers information that is relevant to your entire Medicine (MD/DO) education. Whether you’re studying for your classes or getting ready to conquer the USMLE Step 1, USMLE Step 2 CK, COMLEX Level 1, or COMLEX Level 2, we’re here to help.

Works better than traditional Medicine (MD/DO) flashcards.

Research shows that students who use Picmonic see a 331% improvement in memory retention and a 50% improvement in test scores.