Chapter 11

Question 1

Bacillus: General Characteristics

Answer 1

large
aerobic
gram +
long chains

Question 2

Bacillus: Typical Morphology

Answer 2

3-4*1
square ends
centeral spores

Question 3

Bacillus: Culture

Answer 3

round
“cut glass” apearence
common hemolysis in B. cereus + saprophytics
gelatin liquefier

Question 4

B. anthracis: Pathogenesis

Answer 4

cutaneous
inhalation (woolsorters' disease)
gastrointestinal
injection
gelatinous edema, spread via lymphatics

Question 5

B. anthracis: Virulence Factors

Answer 5

poly-gamma-D-glutamic acid capsule (plasmid: pXO2) (no disease without capsule)
PA (protective factor , membrane channel)
EF (edema factor , adenylate cyclase)
LF (lethal factor , impairing immunity)
(pXO1)

Question 6

Bacillus in immunocompromised

Answer 6

meningitis
endocarditis
endophthamitis
conjunctivitis
acute gastroenteritis

Question 7

B. anthracis: Clinical Findings (Cutaneous Anthrax)

Answer 7

pruritic papule 1-7 days , vesicle , necrotic ulcer (centeral black eschar)
lymphangitis
lymphadenopathy
fever
malaise
headache
20% sepsis –> meningitis
no antibiotic therapy (only prevents dissemination)
after 7-10 days eschar fully developed and heals by granulation with scar

Question 8

B. anthracis: Clinical Findings (Inhalation Anthrax)

Answer 8

spores phagocytosed in lungs , mediastinal lymph nodes , hemorrhagic mediastinitis , sepsis
up to 6 week incubation
marked hemorrhagic necrosis
mediastinal edema (visible widening on radiographs)
substernal pain
hemorrhagic pleural effusion
cough
sepsis –> hemorrhagic meningitis/hematogenous spread to GI tract –> bowel ulcer

Question 9

B. anthracis: Clinical Findings (Gastrointestinal Anthrax)

Answer 9

abdominal pain
vomiting
bloody diarrhea

Question 10

B. anthracis: Clinical Findings (Injection Anthrax)

Answer 10

extensive , painless , subcutaneous edema (no eschar)

hemodynamic instability

Question 11

B. anthracis: Diagnostic Lab Tests

Answer 11

immunofluorscent
blood agar: nonhemolytic , white-gray , tenacious , rough , ground-glass appearance , medusa head
capsule: bicarbonate with 5-7% CO2 medium
always nonmotile (B cereus: swarming)
definitive: lysis with anthrax gamma-bacteriophage , fluorscent Ab , PCR
ELISA not + in early disease

Question 12

B. anthracis: Immunity

Answer 12

vaccine: cultures grown in 42-52 c for several months , AVA BioThrax (unencapsulated toxigenic with PA absorbed to AlOH3)

Question 13

B. anthracis: Treament

Answer 13

ciprofloxacin
penicillin G
doxycycline
erythromycin
vancomycin
Bioterorrism: prophylaxis + ciprofluxacin / doxycycline for 60 days
Raxibacumab: PA inhibitor
AIGIV: PA inhibitor , polyclonal antiserum

Question 14

B. cereus: Emetic Food Poisoning

Answer 14

fried rice , milk , pasta
nausea
vomiting
abdominal cramps
diarrhea
self-limiting (within 24 hours)
emetic toxin: plasmid-encoded preformed cyclic peptide

Question 15

B. cereus: Diarrhael Food Poisoning

Answer 15

meat , dishes , sauces
1-24 hours incubation
profuse diarrhea
abdominal pain and cramps
vomiting (uncommon)
fever (uncommon)
eterotoxin: fluid accumulation in small intestine

Question 16

B. cereus: Pathogenesis

Answer 16

eye infections: severe keratitis , endophthalmitis

systemic: endocarditis, catheter-associated bacteremia , CNS infection , osteomyelitis , pneumonia

Question 17

B. cereus: Treatment

Answer 17

non-food borne infections: vancomycin , clindamycin + aminoglycoside
wound infecrion: ciprofloxacin

Question 18

B. cereus: Resistance

Answer 18

penicillins , cephalosporins