chapter 8: Neisseria

Question 1

species of neisseria

Answer 1

meningitidis

gonorrheae

Question 2

virulance factors of neisseria meningitidis

Answer 2

capsule: antiphagocytic, it is antigenic, usually serogroups ABC

endotoxin (LPS): blood vessel destruction and sepsis, petechiae on the skin

IgA1 protease: only on pathogenic species of neisseria, cleaves IgA in half

N meningitidis can extractr iron from human transferrin

pili: allow attachment to human nasopharyngeal cells and undergo antigenic variation to avoid attack by immune system

Question 3

carrier state

Answer 3

often Neisseria meningitidis blends in and becomes part of normal flora of nasopharynx

• these indiciduals are carriers and are asymptomatic
• asymptomatic nasopharyngeal infection allows them to develop anti-meningococcal Abs

Question 4

high risk groups for neisseria

Answer 4

infants aged 6 months to 2 years

army recruites
college freshmen

Question 5

classic clue to invasive meningococcal infection is

Answer 5

appearance of petechial rash

Question 6

meningococcemia

Answer 6

intravascular multiplication of Neisseria meningitidis results in abrupt onset of spiking fevers, chills, joint and muscle pain and petechial rash

-once in bloodstream they disseminate throughout body, can lead to meningitis or fulminant meningococcemia

Question 7

fulminant meningococcemia (waterhouse friderichsen syndrome

Answer 7

septic shock
bilateral hemorrhage into adrenal glands occurs = adrenal insufficiency
abrupt hypotension and tachycardia, enlarging petechial skin lesions

DIC and coma may develop

death can occur rapidly (6-8 hours)

Question 8

meningitis

Answer 8

this is the most common form of menigococcal disease, usually striking infants under the age of 1

bulging open anterior fontanelle

Question 9

classic pethechial skin rash may occur when

Answer 9

meningococcemia occurs in conjuction with meningitis

-physician can make diagnosiss beforfe spinal tap

Question 10

two bacteria cause meningitis later in life after maternal Abs are gone

Answer 10

neisseria meningitidis- most common now that H influenza treated better

haemophilus influenzae

Question 11

classic medium for culturing neisseria is called

Answer 11

thayer-martin VCN

V stands for vancomycin (kills gram + bacteria)

C is colistin (kills all gram negative organisms except neisseria)

N nystatin: eliminates fungi

Question 12

virulence factors neisseria gonorrhoeae

Answer 12

pili: changing often, protect bacteria from our Abs as well as vaccines, also adhere bacteria to host cells
- prevent phagocytosis

outer membrane protein porins
-PorA and PorB promote invasion of epithelial cells

Opa proteins: adherence and invasion into epithelial cells

Question 13

gonorrhea in men

Answer 13

most men syptomatic, purulent urethral discharge, possible epididymitis, prostatitis, urethral strictures

Question 14

men having sex with men

Answer 14

MSM results in rectal gonococcal infection

-often asymptomatic but can cause anal pruritis, tenesmus, and or rectal bleeding

Question 15

gonococcal disease in women

Answer 15

more asymptomatic
can progress to pelvic inflammatory disease
-infection of uterus (endometritis), fallopian tubes (salpingitis) and or ovaries (oophoritis)

Question 16

gonococcal disease in women, menstruation

-IUD

Answer 16

allows bacteria to spread from cervix to upper gi tract

-presenceof IUD increasesd risk of cervical gonoccocal infection progressing to PID

Question 17

complications of PID

Answer 17

sterility: damaged fallopian tubes

ectopic pregnancy: dilated fallopian tubes

abscesses (rare)

peritonitis (rare)

peri-hepatitis: infects liver, pain in right upper quadrant

Question 18

is bactermia common in gonnarea infections

Answer 18

no

Question 19

septic artritis in men and women gonoccocal disease

Answer 19

most common kind of septic arthritis in young ,sexually active individuals

Question 20

gonococcal disease in infants

Answer 20

transferred during pregnancy can result in ophthalmia neonatorum (eye infection that can damage cornea, causing blindness)

erythromycin eye drops given to newborns which treatrs gonorrhoease and chlamydia

Question 21

chromosomally mediated antibitotic resistance

Answer 21

mtr gene locus encodes efflux pump that prevents accumulation of antibiotics in cells

penA locus alteras penicillin binding protein 2

gyrA and gyrB mutations that encode DNA gyrases

Question 22

moraxella catarrhalis caues what

Answer 22

otitis media and URI in pts with COPD or emphysema or in elderly

Question 23

otitis media caused by what 3 main bacteria

Answer 23

stretococus pneumoniae
haemophilus influenza
moraxella catarrhalis

Question 24

kingella kingae

Answer 24

colonizes throats of young children and can cause septic arthritis and osteomyelitis in children

-in children and adulss it can cause endocarditis of native prostettic valves

Question 25

kingella kingae is commonly grouped with several slow growing gram negative pathogens known as

Answer 25

HACEK

haemophilus 
actinobacillus
cardiobacterium
eikenella
kingella