Neisseria

Question 1

what is the best agar to grow neisseria on

Answer 1

chocolate agar

Question 2

neisseria - overview

Answer 2

*gram negative diplococci
*require chocolate agar to grow
*oxidase positive
*catalase positive
*humans are the only reservoir
*can survive intracellular and extracellular

Question 3

neisseria - virulence factors

Answer 3

*pilin
*por protein
*opa protein
*LOS (lipooligosaccharide)

Question 4

does neisseria meningitidis have a capsule

Answer 4

YES

Question 5

does neisseria gonorrhoeae have a capsule

Answer 5

NO

Question 6

neisseria meningitidis - pathophysiology

Answer 6

*acquired through respiratory droplets or close contact
*colonizes nasopharynx and then attaches to epithelial cells
*crosses the epithelium into the blood and translocates through endothelium
*travels into other tissues (esp the meninges)
*does NOT kill the epithelial cells

Question 7

neisseria gonnorhoeae - pathophysiology

Answer 7

*enters genitourinary tract and crosses epithelium by KILLING the cells

Question 8

major host defense against neisseria

Answer 8

complement & terminal membrane attack complex (MAC)
*deficiencies in the MAC is a major risk factor for severe disseminated infection and meningitis

Question 9

most common serotype of sporadic infections from neisseria meningitidis

Answer 9

strain B

Question 10

at risk populations for neisseria meningitidis

Answer 10

*sickle cell/splenectomy patients
*children, teens, young adults
*immunocompromised ppl
*elderly
*those who live in close contact (military barracks, prisons, etc)

Question 11

what 3 encapsulated organisms are splenectomy patients at high risk for

Answer 11

1. strep pneumo
2. haemophilus
3. neisseria meningitidis

Question 12

neisseria meningitidis - clinical presentation: meningococcemia

Answer 12

-disseminated life threatening infection
-early: petechial rash, progresses to purpura
-profound hypotension (septic shock)
*DIC
*severe organ system dysfunction
*Waterhouse-Frederickson syndrome

Question 13

Waterhouse-Frederickson syndrome

Answer 13

*associated with N. meningitidis (meningococcemia)
*bilateral adrenal hemorrhage
*loss of ability to make adrenal hormones to regulate blood pressure

Question 14

neisseria meningitidis - diagnosis

Answer 14

1. PCR of blood or CSF (quick)
2. gram staining of CSF (intra- and extra-cellular gram negative diplococci)

Question 15

neisseria gonnorhoeae - ranking in STDs

Answer 15

2 cause of STDs in the US

Question 16

neisseria gonnorhoeae

Answer 16

*transmitted primarily by sexual contact
*often asymptomatic in women

Question 17

neisseria gonnorhoeae - clinical aspects

Answer 17

MALES:
-urethritis (usually symptomatic b/c painful)
FEMALE:
-cervicitis (not painful so often asymptomatic)
-urethritis
-ascending genital infections (PID)

Question 18

Fitz/Hugh Curtis

Answer 18

*complication of neisseria gonnorhoeae from pelvic inflammatory disease
*adhesions and inflammation around the liver and subdiaphragmatic space
*RUQ pain

Question 19

disseminated gonococcal infection (DGI)

Answer 19

*if gonorrhea gets into bloodstream and lands into soft tissue
*women>men
*risk increases during MENSTRUATION in females (cervix more friable)
*small pustules on extremities, esp hands and feet

Question 20

neisseria gonnorhoeae - diagnosis

Answer 20

*nucleic acid amplification assay (NAAT) of urethral swab, cervical swab, or urine