Lecture 4 Part 2: Neisseria Flashcards
TRUE or FALSE
N. gonorrhoeae is a non commensal organism.
TRUE
TRUE or FALSE
N. meningitidis is NOT found colonizing the nasopharynx
FALSE
N. meningitidis is found colonizing the nasopharynx
What is the shape and gram-staining characteristics of Neisseria?
Neisseria is a Gram-negative, flat-sided, diplococcus
What type of environment do Neisseria bacteria require for growth?
Neisseria bacteria are aerobic
What enzymes are produced by Neisseria bacteria?
Neisseria bacteria are oxidase-positive and most are catalase-positive
How do Neisseria bacteria produce acid?
Neisseria bacteria produce acid by oxidation, not fermentation
What sugars does N. gonorrhoeae utilize for acid production?
N. gonorrhoeae utilizes glucose for acid production
What sugars does N. meningitidis utilize for acid production?
N. meningitidis utilizes glucose and maltose for acid production
Does N. gonorrhoeae have a true capsule?
N. gonorrhoeae does not have a true capsule
Which Neisseria species has 13 serogroups?
N. meningitidis has 13 serogroups
Which serogroups of N. meningitidis are the most infectious?
The most infectious serogroups of N. meningitidis are A, B, C, Y, and W135
What are pili composed of in Neisseria species?
Pili are composed of pilin subunits
3 What functions do pili serve in Neisseria species?
1.regulate attachment,
2. transfer of genetic material
3. motility
How is the expression of pili in Neisseria species regulated?
The expression of pili is regulated by the pil gene complex
What is the role of pili in Neisseria species regarding antigenic diversity?
Pili establish antigenic diversity in Neisseria species.
look at slide 20
What are porin proteins in Neisseria species?
Porin proteins are
- outer membrane channel proteins
- interfere with neutrophil degranulation
- facilitate invasion into epithelial cells
What is the role of transferrin-, lactoferrin-, and hemoglobin-binding proteins in Neisseria species?
These proteins compete with the host cell for essential metabolic iron
What is LOS (lipooligosaccharide) in Neisseria species?
LOS is composed of lipid A and core oligosaccharide of LPS, with endotoxin activity
What is the function of IgA1 protease in Neisseria species?
IgA1 protease cleaves the hinge region of IgA1
What do β-lactamases do in Neisseria species?
β-lactamases degrade penicillin and other β-lactams
know difference between LOS and LAM
What is the first step in the pathogenesis of Neisseria species?
The first step is attach and penetrate host mucosal cells using pili and PorB
How do Neisseria species multiply during infection?
intracellularly
Where do Neisseria species establish infection?
They establish infection in the sub-epithelial space
What role does LOS play in the pathogenesis of Neisseria species? CLARFY THIS LATERRRRRRR
LOS promotes inflammation via TNFα (a major cytokine in gonococcal disease)
slide 24 what am i suppsoe to retain?
What disease does Neisseria gonorrhoeae cause in the urethra?
Gonorrhea
What is gonococcemia?
Gonococcemia is a disseminated infection caused by Neisseria gonorrhoeae
leading to septicemia and skin and joint infections (purulent arthritis)
What is ophthalmia neonatorum caused by?
Ophthalmia neonatorum is caused by Neisseria gonorrhoeae and leads to eye infections in newborns
What are the 4 clinical diseases caused by Neisseria meningitidis?
Meningitis
Meningococcemia (septicemia)
Pneumonia
Arthritis
