Pneumococcus, meningococcus, GBS

Question 1

Not all Neisseria are; what makes the difference?

Answer 1

pathogenic (aside: meningitidis is facultative intracellular);
VIRULENCE FACTORS
1. LOS (aside for quieter inflamm response)
2. IgA protease
3. Meningococcus capsule (gonococcus has pili, porins, Opa!!)

Question 2

N meningitidis as a pathogen is a

Answer 2

gram neg diplococcus, aerobic/facultative, human-restricted, oxidase-positive, catalase-positive; FERMENTS MALTOSE!!
(aside: airborne droplet transmission and infection resolves without symptoms usually with IgG raised and individuals with natural immunity often by 20)

Question 3

Growth of N meningitidis is; so use

Answer 3

inhibited on blood agar and overgrown by normal flora on nonselective media;
Thayer-Martin if sampling from mucus membrane (genital, nasopharyngeal), chocolate if NORMALLY-STERILE site (CSF, blood)

Question 4

Host defends meningitidis with; what can cause complications?

Answer 4

IgG-enhanced complement and PMNs: often effective against meningococcus, usually contains gonococcus;

complement deficiency

Question 5

_____ gonococcus in women leads to

Answer 5

Asympatomatic/untreated;

PID

Question 6

What can follow DGI/meningococcemia:

Answer 6

septic arthritis (aside is draw joint fluid with gram negatives and culture on chocolate agar), meningitis (aside is draw CSF, maybe gram stain and culture on chocolate), endocarditis

Question 7

Neonates are protected

Answer 7

from meningococcus by maternal passive, must be protected by prophylactic eye ointment from gonococcus

Question 8

Test for N meningitidis with

Answer 8

culture and gram stain of appropriate samples; DNA testing is also available

(aside: you can have petechial rash and lead to gangrene; also Waterhouse-Friderichen syndrome with destruction of adrenals, DIC, purpura

Question 9

What is available to prevent meningo/gonococcus?

Answer 9

Vaccine for former, condoms for latter!!!

Question 10

How can you treat N meningitidis?

Answer 10

(aside: Penicillin G unless allergic)

Ceftriaxone, cefixime, NOT STEROIDS; admit if complications!!! (aside: give prophylactic rifampin)

Question 11

For GBS (S agalactiae), give the key features:

Answer 11

1. Encapsulated gram +
2. beta-hemolytic cocci
3. often normal flora
4. seldom pathogenic in previously-healthy adults
   (think normal vaginal flora or in GI and upper respiratory tract)

Question 12

_____ pathogen in neonates regarding GBS, and what do we see?

Answer 12

Opportunistic;

sepsis with pneumonia early or meningitis late; early disease prevented by INTRAPARTUM IV antibiotics!!

Question 13

______ pathogen in elderly with ______ regarding GBS; what are some issues?

Answer 13

Opportunistic; predispositions like diabetes and CHF;
think MECA (meningitis, endocarditis, cellulitis, abscess)

Question 14

Test for GBS by; treat with

Answer 14

gram stain, cAMP factor (S aureus beta-hemolysin can be activated when secreted by GBS), hippurate;
penicillin, amoxicillin, vancomycin (if allergic), surgery!! (PAVS)

Question 15

For strep pneumoniae, what’s the key feature?

Answer 15

Gram +, catalase - diplococci, form chains in culture (aside: form diplococci in chains)

Question 16

Pneumococcus is the most common cause of; important cause of

Answer 16

community-acquired pneumonia, bacterial meningitis, bacteremia, otitis media; (BOB)
sinusitis, septic arthritis, osteomyelitis, peritonitis, endocarditis (SOPES)

Question 17

Pneumococcus carriage common in

Answer 17

upper respiratory tract: healthy adult, or vaccinated immunity contains it there

Question 18

In non-invasive disease of pneumococcus, what is the pathogenesis and how do you diagnose and treat?

Answer 18

Pathogenesis by direct extension into sinuses, eustachian tubes, bronchi (SEB): can cause sinusitis, otitis media, mild pneumonia (diagnose by otoscope and stethoscope, outpatient amoxicillin or cephalosporin), severe pneumonia (diagnose by stethoscope and Xray for lobar consolidation, admit for amoxicillin, fluroquinolones, and/or vancomycin, so do antibiotic sens testing) FAV

Question 19

Invasive disease pathogenesis for pneumococcus is

Answer 19

hematogenous spread to meninges, joints, heart valves and strong inflammatory response (aside: bimodal distribution, patients 65, immunosuppressed)

Question 20

Spinal tap findings typical of bacterial meningitis with pneumococcus:

Answer 20

1. Elevated opening pressure
2. Elevated WBC count and neutrophil level
3. Elevated protein
4. Decreased glucose
5. Highly elevated lactic acid
6. Gram stain and culture are POSITIVE unless antibiotic treatment began >4 hrs prior to tap

Question 21

Initial antibiotics (for invasive disease of pneumococcus) are

Answer 21

vancomycin plus ceftriaxome or cefotaxime (CVC); if antibiotic testing comes back resistant (toxic MIC), add RIFAMPIN, meropenem, or chloramphenicol (MCR)

Question 22

Steroids may be used for _______

Answer 22

pneumococcus; sparingly early in the antibiotic course, surgical care for septic joints, cellulitis, endocarditis (SEC)

Question 23

Invasive disease regarding pneumococcus is prevented by

Answer 23

VACCINATION: Prevnar7 recently increased to Prevnar13 and may have to step up again (“replacement disease”)

Question 24

Classic tetrad of meningitis:

Answer 24

Headache, fever, stiff neck, photophobia