Micro U3 L1.

Question 1

Neisseria meningitidis bacteriology

Answer 1

gram - diplococci, encapsulated, oxidase +, catalase +, ferments glucose and maltose, grows on choclate agar or Thayer-Martin, facultative intracellular

Question 2

What is the difference between chocolate agar and Thayer-Martin?

Answer 2

chocolate agar is for sterile and Thayer-Martin might have normal flora

Question 3

What are the virulence factors for neisseria meningitidis

Answer 3

1. IgA protease to colonize nasopharnyx 2. encapsulated 3. endotoxin LOS

Question 4

How is neisseria meningitidis transmitted?

Answer 4

airborne droplets

Question 5

What are differences between neisseria meningitidis and gonorrhea?

Answer 5

gonorrhea not encapsulated and needs close contact to be transmitted

Question 6

What deficiency predisposes spread of neisseria meningitidis beyond respiratory system?

Answer 6

deficiency in late-acting complement C5-C9

Question 7

Where does neisseria meningitidis colonize?

Answer 7

joints (septic arthritis) and meninges

Question 8

Where is neisseria meningitidis typically found?

Answer 8

young adults living in close quarters (age 2-18) - natural immunity typically by age 20

Question 9

Symptoms of meningitis in adults

Answer 9

classic fever/headache, stiff neck, photophobia

Question 10

Symptoms of meningitis in children

Answer 10

irritiability, convulsions, lassitude, fever, abdominal discomfort/vomiting

Question 11

How is diagnosis of neisseria meningitidis made?

Answer 11

draw CSF for meningitis; draw joint fluid for septic arthritis

Question 12

Prevention of neisseria meningitidis

Answer 12

vaccine - Ab to capsule is protective

Question 13

Meningococcemia symptoms

Answer 13

fever and hourly-spreading rash

Question 14

Waterhouse-Friedrichen syndrome

Answer 14

high fever, shock, widespread purpura, DIC, thrombocytopenia, destruction of adrenal glands, 50% fatal

Question 15

Labs for meningococcemia

Answer 15

gram stain, culture on chocolate agar, blood tests for DIC

Question 16

Treatment for meningococcemia

Answer 16

penicillin G - NO STEROIDS

Question 17

Prevention of meningococcemia

Answer 17

vaccine and antibiotic prophylaxis for close contacts

Question 18

GBS bacteriology

Answer 18

gram + cocci, beta-hemolytic, encapsulated, polysaccharide toxin virulence factor, serotype-specific antibody-mediated immunity, normal vaginal flor (15-45%)

Question 19

Pathogenesis GBS

Answer 19

most common cause of neonatal sepsis

Question 20

Early disease vs Late disease neonatal sepsis

Answer 20

early disease: pneumonia w/ bacteria, 1-7 days postpartum, more common in US. late disease: bacteremia with meningitis, 1-12 wk postpartum, serotype 3

Question 21

What are risk factors for neonatal sepsis?

Answer 21

prematurity and prolonged rupture of membranes

Question 22

What are the predisposing risk factors for GBS disease in geriatrics?

Answer 22

diabetes, malignancy, CHF

Question 23

Diagnosis of GBS

Answer 23

gram stain and culture, CT/MRI for abscesses, echocardiogram for endocarditis

Question 24

Treatment for GBS

Answer 24

penicillin or amoxicillin (vancomycin if allergic) - sometimes surgical intervention needed esp in geriatric

Question 25

Prevention of GBS

Answer 25

test term-pregnant patients - if positive then intrapartum IV administration of penicillin during delivery

Question 26

CAMP Test for GBS

Answer 26

The CAMP test is a test to identify Group B β-streptococci based on their formation of a substance (CAMP factor) that enlarges the area of hemolysis formed by β-hemolysin from Staphylococcus aureus

Question 27

Pneumococcus

Answer 27

strep pneumoniae, gram +, catalase -, facultative anaerobe, form diplococci in chain

Question 28

What is the most common cause of community-acquired pneumonia, bacterial meningitis, bacteremia, and otitis media?

Answer 28

pneumococcus

Question 29

What are the virulence factors for pneumococcus?

Answer 29

1. encapsulated 2. IgA protease

Question 30

What do pathogenic strains of pneumococcus produce?

Answer 30

pneumolysin

Question 31

What is protective against pneumococcus?

Answer 31

anti-caupsule IgG

Question 32

What unless most of the clinical disease symptoms in pneumococcus?

Answer 32

strong inflammatory response

Question 33

When are the infection peaks for pneumococcus?

Answer 33

fall and winter (carriers congregate more closely)

Question 34

Pathogenesis pneumococcus

Answer 34

easily colonizes upper respiratory tract using adhesion virulence factors - contained by innate immunity in healthy adults - can spread in young children, patients with pre-existing asthma, allergies, bronchitis, smoking, COPD

Question 35

Exam for pneumococcus

Answer 35

diseases of direct extension (non-invasive) - sinusitis, otitis media, bronchitis, pneumonia. diseases of hematogenous spread (invasive) - meningitis, septic arthritis, pericarditis, endocarditis, osteomyelitis (bimodal distribution)

Question 36

What is shown on radiology findings of pneumococcus

Answer 36

lobar consolidation

Question 37

Signs of meningitis with pneumococcus

Answer 37

FAST (hours/days) - mental status changes, lethargy, delirium, + Brudzinski, cranial nerve palsies, focal neurologic defects

Question 38

What are you looking for on spinal tap for bacterial meningitis?

Answer 38

decreased glucose, elevated lactic acid (fermenting), gram stain and culture are positive (unless antibiotic treatment was begun more than 4 hours before tap)

Question 39

Treatment for pneumococcus

Answer 39

noninvasive: outpatient amoxicillin or cephalosporin invasive: admit with vancomycin plus ceftriaxome or cefotaxime

Question 40

Pneumococcus antibiotic resistance

Answer 40

increase in dosage can sometimes overcome resistance but has a transposon so resistance to multiple antibiotics

Question 41

Prevention of pneumococcus

Answer 41

Prevnar7 vaccine - raises protective IgG against the capsules in 7 serotypes (universal childhood vaccine). Prevnar 13 has protection for an additional 6 serotypes