Nervous System Infections (Exam 5)

meningitis

an infection of the connective tissue coverings of the brain (meninges)

cerebrospinal fluid or the tissues of the meninges

where does the growth of the pathogen occur with meningitis?

True

True or False: any kind of microbial pathogen can potentially cause meningitis

bacteria

the most serious cases of meningitis are caused by…

spread to the brain from other places

all meningitis is caused by infections that…

blood and CSF

two sterile fluids in the body

barriers to infection

these prevent the spread of microbes to the blood

blood-brain barrier

the brain is sealed off from the rest of the body by the _______

glial cells

these cells of the NS surround and seal the capillaries of the brain to prevent pathogens from entering

False; same pattern

True or False: all types of pathogens that cause meningitis follow different pattern of spread

cause primary infection in one of the mucous membranes of the body (typically lungs)

what is the first step in the pattern of spread for meningitis pathogens?

they break down the mucosal barrier and spread into the blood

what is the second step in the pattern of spread for meningitis pathogens?

from the blood they are able to break down the blood-brain barrier

what is the third step in the pattern of spread for meningitis pathogens?

invasive pathogens

pathogens that can spread from their initial sites of infection

True

True or False: all pathogens that cause meningitis must be invasive pathogens?

all can be carried in normal microbiota

what is one common feature of all the bacteria that cause meningitis?

Group B Streptococci

this is an invasive strain of bacteria that causes UTIs and pneumonia; it can cause meningitis

Streptococcus pneumoniae and Haemophilus influenzae

these two invasive strains cause bacterial pneumonia; they can cause meningitis

Neisseria meningitidis

most common cause of meningitis in teenagers and young adults. approximately 20-30% of college age students will carry this bacteria in the microbiota of their nose

negative

is Neisseria meningitidis gram + or -?

coccus

shape of Neisseria meningitidis

endotoxin, type 4 pili, capsule

what virulence factors does Neisseria meningitidis have?

type 4 pili

this virulence factor for Neisseria meningitidis allows the cell to adhere to body tissue

capsule

this virulence factor for Neisseria meningitidis allows the cell to evade the immune system

antigen mimicry

the Neisseria capsule allows it to avoid the immune system by _______

polysialic acid

what is the capsule for Neisseria made of? (sugar)

epithelial cells of blood vessels and mucous membranes

where can polysialic acid be found?

colonization and invasion

two infect the meninges, Neisseria must perform two rounds of _______

epithelium; nasal cavity

the first round occurs in the _____ of the _________

type 4 pili

how do the Neisseria bacteria attach to the nasal epithelium during the first round of colonization and invasion?

trick the cells of the nose to open a pathway for invasion

once attached, Neisseria grows slowly in the microbiota of the nose, eventually _________________________ therefore allowing the bacteria to invade the blood

blood vessels in the brain

the second round of colonization and invasion for Neisseria happens in the ______

type 4 pili

during the second round of colonization and invasion, Neisseria attaches to the cells of the blood vessels using _____

trick the cells of the blood vessel to break down the blood brain barrier

as they grow slowly on the surface of the blood vessel, Neisseria is able to ____________, allowing invasion of the meninges

cortical plaque

the growth of the bacteria attached to epithelial cells creates a structure called a ________

activate signaling receptors on the epithelial cells

the newly grown cells in the cortical plaque can…

break down the proteins that hold together the epithelial layer

activating the signaling receptors on the epithelial cell causes the cell to…

True

True or False: the breakdown of the proteins holding cells together with cortical plaque happens in both the nasal epithelium and blood vessel endothelium

release of lipopolysaccharide (LPS)

the symtoms of the infection are caused by ______ once Neisseria is in the blood and meninges

destroyed by phagocytosis; innate defenses

the release of LPS happens either when the bacteria are ______ or when they are destroyed by _______

sepsis-like

in the blood, the inflammatory response caused by LPS can cause _____ symptoms

increased intracranial pressure

in the meninges, the inflammatory response caused by LPS causes _________

True

True or False: nearly all invasive Neisseria infections cause symptoms of sepsis

meningococcemia

infection of the blood by Neisseria bacteria is called ____

pale skin with red/purple spotted rash, severe fever and body aches, unusually cold hands and feet

symptoms of Neisseria sepsis

70

___% of invasive Neisseria infections cause symptoms of meningitis

inflammation and swelling in the meninges causes the squeezing of the brain, reducing blood flow and eventually causes nerve cells to malfunction and die

dangers of meningitis

severe headache, sensitivity to light, neck stiffness with an inability to flex the neck forward

symptoms of Neisseria meningitis and increased pressure:

nuchal rigidity

neck stiffness with an inability to flex the neck forward is called _____

seizures and loss of consciousness

severe symtoms of Neisseria meningitis are:

human carriers and infected human hosts

reservoir for Neisseria meningitidis

10; 20-40

____% o the general population are carriers of Neisseria meningitidis; in populations that are in close quarters it is as high as ___%

respiratory droplets or saliva

portal of exit for Neisseria meningitidis

prolonged direct person to person contact (respiratory droplets or kissing) and vehicle transmission (things contaminated with saliva)

modes of transmission for Neisseria meningitidis

eyes, nose, mouth

portal of entry for Neisseria meningitidis

opportunistic

is Neisseria meningitidis a primary pathogen or an opportunistic pathogen?

young children, immunocompromised adults, smokers/vapers

susceptible groups for Neisseria meningitidis

untreated HIV, transplant patients, people with autoimmune diseases

examples of imunocompromised adults

subunit vaccine

what type of vaccine is available for Neisseria meningitidis?

4-6 years

how long is the vaccine for Neisseria meningitidis effective?