CNS and STDs Flashcards
- What is the reservoir for Neisseria meningitidis?
- How is it spread?
- Nasopharynx of humans only
- Spread by respiratory transmission
What is the characteristic structure/physiology of Neisseria meningitidis?
Gram negative diplococci with a LipoOligoSaccharide capsule
- Does Neisseria meningitidis possess pili?
- What is the general process of a N. meningitidis infection?
- Yes
- Attach to non-cilia columnar epithelia → Internalized into phagocytic vacuoles → Transcytosis to subepithelial space → LOS induces vascular damage, vessel inflammation, thrombosis
- What does an acute *N. meningitidis *infection look like?
- What does infantile meningitis look like?
- How is N. meningitidis infection diagnosed?
- Abrupt and insidious onset w/ symptoms of a general meningitis (Nuchal rigidity etc.)
- Irritable, Decreased PO, Seizures, Disturbed tone, Coma
- Oxidase positive, Gram negative diplococci gram stain of CSF.
- What is the demographic with the highest incidence of N. meningitidis infection?
- School-age children and young adults
- How many and which serogroups does the N. meningitidis vaccine cover?
- What is added to make the vaccine effective?
- It is tetravalent for A, C, Y, W135
- It is a conjugate vaccine with Diptheria toxin.
What is the treatment for N. meningitidis infection?
Cefotaxime
Ceftriaxone
Penicillin G
What is used for prophylaxis if someone is exposed to the disease for >8 hours?
Rifampin
Cipro
Ceftriaxone
At what age are neonates most at risk/susceptible to N. meningitidis?
6 to 24 months
What two sugars does N. meningitidis metabolize?
Maltose and Glucose which can be remembered because meningitis has an M and a G in it.
- What is different about the structure of N. gonorrhea compared to N. meningitidis?
- How are they similar in structure?
- It has NO polysaccharide capsule
- They both possess pili
What does N. gonorrhea express that interferes with neutrophil degranulation and resists complement?
PorB
- What do Opa proteins do to promote N. gonorrhea virulence?
- What portion of N. gonorrhea causes cellular damage?
- They mediate binding to non-ciliated epithelial cells
- Core LOS damages urethral and vaginal epithelium
How does N. gonorrhea escape antibodies produced by the immune system?
- Pili frequently alter epitopes
- PorB has significant serological variation
What organism is responsible for the presence of Oxidase positive, gram negative diplococci within PMNLs?
Neisseria gonorrhea
What are the special needs of N. gonorrhea when attempting to culture?
It requires a complex medium (chocolate agar) and is sensitive to cold
Why isn’t there a vaccine for gonorrhea?
No capsule + High variability
- What age group is the peak incidence for gonorrhea?
- What is the major reservoir?
- Are symptoms more common in women or men?
- 15-24 year olds
- Asymptomatic individuals
- Men
- How is Chlamydia trachomatis structure similar/different than N. gonorrhea?
- What implication does this have on clinical treatment?
- It is gram negative but does not have a PDG cell wall
- Beta lactam antibiotics won’t work
There are two structural forms for Chlamydia trachomatis, the elementary body and the reticulate body. What is the purpose of each?
- Elementary body is the infectious form and is environment stable.
- Reticulate body is the replicative form, is metabolically active, and is NOT environment stable.
- Where does Chlamydia trachomatis replication take place?
- *Chlamydia trachomatis *is an obligate intracellular parasite. How does it manage to survive inside of inclusion body?
- Within an inclusion body.
- It interferes with normal endocytic trafficking.
- How is Chlamydia trachomatis acquired?
- It is acquired through abrasions or lesions at a sexual site. It attached to non-ciliated **columnar cuboidal ** or transitional epithelia cells.
- What is the more invasive form of Chlamydia trachomatis that can develop into proctitis in women?
- What happens with untreated Chlamydia trachomatis?
- Lymphogranuloma venereum
- It enters a chronic ulcerative phase.
- How/where is a specimen collected for women concerning for Chlamydia trachomatis?
* 2. Chlamydia trachomatis* cannot be grown in artificial media. What is the best way to test the specimen collected?
- Endocervical specimen
- Nucleic acid amplification test.