FRANCISELLA

Question 1

• Agent of tularemia, a zoonotic disease
- rabbit fever, deerfly fever, lemming fever, water rat trappers’ disease

Answer 1

Francisella

Question 2

• MOT:

Answer 2

ingestion, inhalation, arthropod bite (ticks, biting flies), contact with infected tissues

Question 3

• implicated in most human infections

Answer 3

F. tularensis

Question 4

• 4 subspecies:
  -: most severe disease

-: rarely fatal form

-: poorly studied as found only in Central Asia & Russia

-: present in North America, Australia, Southeast Asia, and almost avirulent in humans, few reports

Answer 4

subspecies tularensis (type A)

subsp. holarctica (type B)

subsp. mediasiatica

subsp. novicida

Question 5

Symptoms:
- Similar to plague - Lymph node involvement

Answer 5

Tularemia

Question 6

penetration site
Tularemia
• Clinical Disease
- (45%-80%) - contaminated bites
• Ulcer forms at the site of inoculation, followed by an enlargement of the regional lymph nodes

• (2-12%) - direct contact
• (1-2%) - direct contact
• (2-4%) - contaminated food
• (7-14%) - contaminated food

-: Peribronchial inflammation & Pneumonia (8-13%) -aerosols

Answer 6

Ulceroglandular

Glandular

Oculoglandular

Oropharyngeal

Typhoidal

Pneumonic

Question 7

TULAREMIA

CDC classifies it as category_____ biological agent, as it spreads from person to person contact, easily disseminated, & results in high mortality rates, a potentially great public health impact & public panic, same with Brucella, a reportable disease.

Answer 7

A

Question 8

: Laboratory Diagnosis

SPECIMENS:
• Blood, ulcer scrapings, lymph node biopsy, sputum, & serum
• Negative cultures during the early course of infection

Answer 8

Francisella

Question 9

: Laboratory Diagnosis

• MICROSCOPY:
o tiny, nomotile, GN coccobacillus, facultatively intracellular parasites

Answer 9

Francisella

Question 10

Francisella

CULTURE:
• strictly_____, fastidious, slow grower unless grown on special media
• Requires(3) for growth on successive passages
• CHOC with_____, MTM, modified BYCE agars may be used
•_____ not recommended due to aerosols
• DO NOT grow on (2)

Answer 10

aerobic

cysteine, cystine, or thiosulfate

Iso Vitalex

broths

MAC and EMB

Question 11

Francisella

• (bluish gray or metallic gray, smooth or slightly mucoid, with narrow alpha-hemolytic zone)

visible after 48H at 37C

check daily for 14 days

Answer 11

Blood-cysteine-glucose agar

Question 12

Francisella: Laboratory Diagnosis
• Biochemical:
oxidase
urease
X & V
weakly catalase and B-lactamase activity; ferments (3)

Answer 12

• -
  +
  glucose, maltose & mannose