Bacterial CNS I Flashcards
What are the predisposing factors for those potentially infected by pneumococcal meningitis?
Pneumonia and chronic otitis media.
What are the predisposing factors for those potentially infected by meningococcal meningitis?
History of recent URTI (viral)
Complement deficiencies
Outbreaks in winter within schools and barracks.
What are the three common symptoms of meningitis?
Fever
Headache
Stiff Neck
What attributes are typically seen in bacterial meningitis?
Decreased PMNs
Decreased Glucose
Increased Protein
Increased Pressure
What attributes are typically seen in viral meningitis?
Mono/lymphos
Rare PMNs
Normal Glucose
Normal or slightly elevated protein.
This gram positive, alpha hemolytic, lance shaped bacterium most often causes what two symptoms upon infection?
Strep pneumo typically causes otitis media as well as Bacteremia
Less commonly it causes pneumonia and meningitis.
What age demographic dause pneumoccoccal meningitis typically infect?
The very old and the very young
What are the virulence factors of a pneumococcal infection?
Binds the oropharynx via choline binding proteins.
Pneumolysin and IgA protease
Capsule aids in dissemination
Pneumolysin interferes with macrophage uptake.
How is an acute bacterial pneumococcal infection treated?
It is treated as a medical emergency with vancomycin and cephalosporin immediately for 10-14 days.
Up to 1/3 are immune to Penicillin and thus shouldn’t be used.
Describe the PPV:PPV23 pneumococcal vaccine.
This is a purified capsular polysaccharide antigen from 23 types of pneumococcus.
Not effective in
What age grouping should the pneumococcal PPV23 vaccine be used for?
Reccomended to be used for
> 65 yrs
or persons >2 years if immunocompromised or experiencing other medical risks.
Describe the PCV13 pneumococcal vaccine.
This is a conjugated vaccine in which a polysaccharide is connected to a nontoxic diptheria toxin.
What population should the pneumococcal vaccinations PCV7;PCV13 be used in treating?
This vaccine should be used when treating the younger population and is very useful in infants and young children,
What are the recommended dosages for the PCV13 vaccination?
Routine vaccination for children with dosages given at 2, 4, 6 months and a booster dose at 12-15 months of age.
What characteristics are unique to N. Meningititis?
Coffee bean shaped
Gram negative
Encapsulated with Lipooligosaccharide (similar to LPS)
Oxidase and Catalase positive
Ferments Glucose and maltose (This is the only species that ferments glucose)
Requires CO2 to culture.
What are the symptoms most often seen following a N. Meningitis infection?
Meningitis and Bacterimia.
Less likely to cause pneumonia compared to strep pneumo.
Transmitted through aerosol commonly in areas of close locations.
Which serotype of N. Meningitides is most commonly seen in children
This is serotype B.
What virulence factors are commonly associated with N. Meningitides infections?
Pilli for nasopharynx.
Capsule protects from compliment and macrophage.
LOS immune system stimulation
Crosses blood brain barier by using neutrophils.
How is N. Meningitides typically treated?
It is treated emperically with vancomycin and cephalosporin at first until diagnosed, at which point it can be treated with penicillin (unlike pneumococcal meningitis)
Is there a vaccination available for N. Meningitides?
Yes there is a tetravalent polysaccharide vaccine available but is innefective for children
What age grouping is N. Meningitides polysaccharide vaccines used in?
Typically most used in patients that are above 55 years of age.
What age grouping is the MCV4 N meningitides conjugatged vaccine used in?
This is licinsed for used between ages of 11 and 55 and is approved for ages 1-55 with increased risk populations.
It contains the same 4 serotypes as the MPV4 vaccine but is more effective due to conjugation to a diptheria toxin.
Recommended that those age 11-12 recieve the vaccinations prior to entering highschool and college freshmen.
What is Streptococcus agalactiae (GBS) identified by?
It is Beta hemolytic
Resistant to bacitracin
Gram positive.
What are the virulence factors of GBS (Streptococcus agalactiae)
Just the polysaccharide capsule. Antibody responses are typically effective at removing these organisms but in newborns that lack maternal antibodies infection is possible.
(2% chance of early onset sepsis, pneumonia, and meningitis).
What are the symptoms involved in early onset GBS infections in neonates?
Bacteremia*** Also seen in gram negative N. Meningitides
Meningitis
Pneumonia
Mortality rate of 10%
What is the drug of choice for GBS infections?
Penicillin is the drug of choice for treating GBS infections. (Ampicillin is an effective alternative)
It can be administered intravenously for pregnant mothers to prevent early onset disease in newborns.
What is unique about Haemophilus influenzae?
It is gram negative encapsulated bacterium requiring Hemin X and NAD V for growth on chocolate agar containing 6 serotypes a thru f.
Prior to vaccination, which serotype of H influenzae caused most cases of invasive disease?
Serotype B.
What are the symptoms of encapsulated vs non encapsulatged H. Influenzae infections?
Encapsulated: Meningitis and Epiglottits
Unencapsulated: Pinkeye, otitis media, synusitis.
What vaccinations are available for H. Influenzae?
Both a conjugated and non conjugated are available though, the conjugated is far more efficient.
It is reccomended that the conjugated be given beginning at two months of age.
If you see the words “Drumstick shaped Spore” you should immediately think what?
You should immediately think of Tetanus bacteria, gram positive anaerobe.
What sort of toxin is Tetanus toxin and how does it work?
It is an AB toxin that is internalized and brought to the spinal cord where it inactivates the release of inhibitory neurotransmitters causing spastic paralysis.
What is the treatment for Tetanus?
Immunoglobulin (Passive immunity)
or
Tetanus toxoid treatment (Active immunity)
The goal is to simply remove as much toxin as possible.
What preventitive measures are available for tetanus?
Preventable measures can be taken by administration of the Tetanus toxoid vaccination via the DTaP at 2 months and boosters every 10 years.
How does the Botulinim toxin work?
The botulinim toxin is an AB toxin that works by binding and entering motor neurons leading to the blocking of acetylcholine release.
This results in a flaccid paralysis.
Meningitis with mycobacterium tuberculosis is typically seen following what event?
Typically seen following a pulmonary infection.
S. Aureus meningitis is most often seen following what sort of event?
This is typically seen following a bacteremia infection resulting in brain abscesses.
