N. meningitidis - A. baumanii Flashcards
This is a Gram (-), non-motile, capsulated diplococci that ferments both maltose and glucose and grows on chocolate agar
N. meningitidis
note: test can include CSF sample
Is N. meningitidis oxidase positive or negative?
positive
What are the outer surface antigens of N. meningitidis?
capsule, pili, LOS
Where does N. meningitidis colonize? How is it spread?
pharynx and nasopharynx; respiratory droplets in close contact
What serogroups of N. meningitidis are most common in Europe/US?
B, C, Y
N. meningitidis is the #1 cause of what in kids?
bacterial meningitis
This disease caused by N. meningitidis is the most rapid, lethal cause of septic shock.
Meningococcemia
How does meningococcemia progress?
bacterial products damage walls of blood vessels, blood leaks into skin and organs -> hemorrhagic skin lesions! There is also decreased cerebral perfusion and this may lead to confusion.
Meningoccemia can be associated with Waterhouse-Friderichsen Syndrome. Describe how this disease presents?
infection leads to massive hemorrhage into adrenal glands; characterized by overwhelming bacterial infection, low BP, and shock, DIC
This disease caused by N. meningitidis is common in kids and those with complement deficiency, abrupt onset with typical meningeal signs (HA, stiff neck, drowsy rash, phophobia, fever, and vomiting). There is also purpura fulminans (large lesions that become necrotic) which is due to IL-6/IL-1
meningococcal meningitis
The virulence of N. meningitidis is mostly due to what?
outer surface components of the capsule - allows it to survive in blood and CSF, anti-phagocytic
PorA/PorB are virulence factors of N. meningitids. What do they do?
form pores; trigger endocytosis
How does LOS help in virulence of N. meningitids?
antigenic variability
What is the role of the pili in virulence of N. meningitidis?
antigenic variability, assist in mucosal adherence
This bacterium is a Gram (-) diplococcus that ferments glucose but NOT maltose.
N. gonorrhoeae
note: test may include PMN’s with Gram (-) intracellular diplococci
Is N. gonorrhoeae oxidase positive or negative?
positive
When sampling for N. gonorrhoeae, one should look at discharge or take rectal swab and see round, gray colonies on a ____ ____ Agar plate
Thayer Martin
N. gonorrhoeae is considered a ____, and therefore puts 15-24 yo’s with complement def. at high risk.
STD
Are males or females more likely to contract N. gonorrhoeae?
females
Anatomically, where is the N. gonorrhoeae infection located in males and females?
males: urethra
females: cervix
Describe the urethritis (males) caused by N. gonorrhoeae - Onset and presentation.
2-6 days after contraction; dysuria, purulent discharge, itching, testicular pain
Describe the cervicitis (females) caused by N. gonorrhoeae. Can it be passed to baby?
purulent discharge, edema, pain, redness, gram stain shows lots of bacteria and inflammatory cells; yes, can be passed to baby
This bacterium is the #1 cause of septic arthritis in 16-45 yo’s
N. gonorrhoeae
What is the main virulence factor of N. gonorrhoeae?
iron binding proteins allow N. gonorrhoeae to steal our iron
This bacterium is a Gram (-), aerobic, diploccocus that cannot ferment sucrose, glucose, maltose, or lactose.
M. catarrhalis
Is M. catarrhalis oxidase positive or negative?
positive
M. catarrhalis is the #3 most common cause of ___ ___
otitis media
In regards to disease, what does a M. catarrhalis infection entail?
OM and sinusitis - kids
LRTI - adults
This bacterium is an aerobic Gram(-), rod, coccobacilli (while sationary) that can survive in variable pH and temp.
A. baumanii
What do A. baumanii colonies look like?
colorless, mucoid
Is A. baumanii oxidase positive or negative?
negative
note: this distinguishes it from Neisseria or Maraxella
A. baumanii can survive on fomites for weeks and is commonly seen in what individuals?
US troops in Iraq
A. baumanii is the only Gram (-) bacterium that can be part of normal ___ ___
skin flora
What disease does A. baumanii produce?
pneumonia - mostly those on ventilators
note: may also cause bacteremia, septic shock, or meningitis
What are the main virulence factors of A. baumanii?
biofilm, outer membrane proteins/LPS
