12) Gram Neg Respiratory Pathogens

What are the 3 main genus that belong to the gram negative respiratory pathogens?

-Neisseria

-Haemophilus

-Bordetella

What is the relationship with oxygen for the following?

-Neisseria

-Haemophilus

-Bordetella

-Neisseria: obligate aerobe

-Haemophilus

-Bordetella

What are the 2 main species of Neisseria genus?

-N. Meningitis (can spread through blood stream with a capsule avoiding phagocytosis!)

-N. Gonorrhoeae (RARELY spreads through blood stream)

True or false

Humans are the only known reservoir for the bacteria Neisseria

True

-woman can be asymptomatic with N. gonorrhoeae

-other species of Neisseria (besides meningitidis and gonorrhea can live naturally in the upper respiratory tract and mucosal surfaces(

What gram positive bacteria has a diplococcus shape?

What gram negative bacteria has a diplococcus shape?

Gram positive diplococcus: Streptococcus pneumonia

Gram negative diplococcus: Neisseria and Moraxella

____________% of people die from Neisseria Meningitidis even with antibiotics

10-15%

-Endotoxin shock!

Neisseria meningitidis infection can lead to meningococcemia which can spread to the meninges via the __________ plexus

choroid plexus

Meningitis is ________% fatal when untreated, but if it is treated how fatal? Why are very young babies not affected by it?

untreated: 80% fatal

treated:5-15% fatal

-neurological damage, hearing loss

babies get maternal antibodies from breast milk

What are the virulence factors of Neisseria meningitidis?

-LPA (LOS)....no O-antigen!! (Haemophilus too)

-endotoxin (causes macrophage to release cytokines and inflammation)

-capsule allowing it to travel through blood

There are meningitis vaccines for types that express capsule _____ (A / B)

Vaccine made for capsule type A

-for type B meningitis capsule vaccines don't work... surface protein vaccines new to target it

-in US where most people are vaccinated we have type B capsules present but not really type A

True or false

N. Meningitidis exhibits exotoxins

False!

But does have 1 exo-enzyme (IgA1 protease which is also expressed by Strep pneumoniae)

What 2 bacterias have a modified LPS (LOS) with no o-antigen?

Neisseria Meningitidis

Haemophilus Influenzae

*very inflammatory

What 3 bacteria have the exoenzyme IgA protease?

-Strep pneumoniae

-Neisseria meningitidis

-Haemophilus influenzae

What bacteria attaches to the cilia of cells opposed to the epithelial cell itself?

Bordetella pertussis (whopping cough)

-not a systemic thing, only affects the throat

What are the 3 extracellular toxins that Bordetella pertussis makes ?

pertussis toxin (PT)

-causes you to make cAMP

-similar to cholera toxin

adenylate cyclase toxin

-causes bacteria cells to make cAMP

tracheal cytotoxin

-kills tracheal cells as it attaches to cilia

What antibiotivs do you use to treat Neisseria meningitidus? But why is antibiotics alone not enough to treat it?

Penicillin G (IV) is effective, also ceftriaxone (IV)

Endotoxins (cytotoxins) are still present

Are the following located in normal human flora?

-Neisseria

-Haemophilus

-Bordetella

Neisseria: yes (but NOT pathogens meningitidis and gonorrhea)

Haemophilus: yes (non capsulated upper respiratory tract)

Bordetella: no

What are the "triplets" or respiratory and encapsulated pathogens that can lead to meningitis?

Neisseria meningitidis

Haemophilus influenzae

Streptococcus pneumoniae (gram positive)