Lecture 11. Neisseria Species and Moraxella catarrhalis

What is the correct description of the Neisseria Genus?

• Gram-negative diplococci

• Found in human mucosal surfaces

What species causes gonorrhea; common sexually transmitted infection (STI)

Neisseria

Gonorrhea is also known as:

Gonococcus (GC)

Gram-negative diplococi found inside polymorphonuclear leukocytes (PMNS) (or granulocytes)

Neisseria gonorrhoeae

Neisseria gonorrhoeae is often described as having what kind of shape?

Kidney or coffee bean

Neisseria gonorrhoeae is grown on:

Chocolate agar or Thayer-Martin selective medium due to being highly fastidius

What kind of environment does Neisseria gonorrhoeae need for optimal growth?

CO2-enriched environment and nutrient rich

Neisseria gonorrhoeae is oxidase:

Positive (purple)

Which gram-negative diplococcus is the leading cause of bacterial meningitis & septicemia worldwide?

Neisseria meningitidis (also known as meningococcus)

Meningitis

Fever, severe headache, stiff neck, photophobia & altered mental status caused by Neisseria meningitidis

Meningococcemia (bloodstream infection)

Rapidly proggressive disease caused by Neisseria meningitidis; symptoms like fever, chills, fatigue, and a characteristic petechial or purpuric rash

Waterhouse-Friderichsen syndrome

Adrenal gland failure due to bleeding, a rare but severe complication of meningococcemia

What specimens are required when testing for Neisseria meningitidis?

• Cerebrospinal fluid (CSF)

• Blood

• Nasopharyngeal swabs (for carriers)

Latex agglutination test

Detects meningococcal antigens in CSF for rapid diagnosis but have varying sensitivity

What species shares similarities with Neisseria but is a normal respiratory flora in the upper respiratory tract?

Moraxella catarrhalis

On media, Moraxells catarrhalis have distinct colonies with a characteristic ____ ____ consistency, colonies can be pushed across an agar plate without losing shape

Hockey puck