- Key Characteristics
- Grows slowly at 35-37°C, on sheep blood, chocolate or
Thayer-Martin agar, does not require CO2
- Does not grow on MacConkey or EMB agar
- Very tiny coccobacillus, Gram-negative
- Catalase negative, or weakly positive
- Non-motile
- Oxidase negative
- Urease negative
- X and V factors are not required
ISOLATES WITH THE ABOVE CHARACTERISTICS SHOULD BE REPORTED TO THE
PATIENT'S PHYSICIAN AS FRANCISELLA SPECIES, UNABLE TO RULE-OUT
TULARENSIS. CONTACT YOUR STATE PUBLIC HEALTH LABORATORY FOR INSTRUCTIONS
ABOUT REFERRING THE ISOLATE OR SPECIMEN.
- Colony Characteristics
- Grows poorly on sheep blood agar: 1-2mm, gray-white,
non-hemolytic at 48-72 hours
- On chocolate or Thayer-Martin agar: 1-3 mm, gray-white to
bluish-gray with entire border and smooth flat surface at 48-72 hours.
Growth in thioglycollate broth is slow, with denser band near top,
diffusing with age
- Ability to grow on sheep blood agar usually lost on subculture
- Microscopic Characteristics
- Faintly staining, very tiny Gram-negative coccobacillus
(0.2-0.7 x 0.7-1.0 um), seen mostly as single cells. Bipolar staining is
not a distinctive feature. Cells are smaller than those of Brucella
spp.
- Safety
- F. tularensis is highly infectious. Once this organism is
suspected on the basis of clinical and/or laboratory information,
additional testing MUST be performed within a certified biosafety
cabinet.
- Biosafety Level 2 for processing clinical specimens
- Biosafety Level 3 practices for culture manipulations that
might produce aerosols
- Contact
- If you suspect the above agent, immediately contact (in the order presented):
- Drs. Lucy DesJardin and Mike Pentella at the University
Hygienic Laboratory. If they aren't readily available, ask for someone in
the Bacteriology, Virology, Serology, or Molecular laboratory.
319.335.4500 or 1.800.421.IOWA(4692)
- University Hygienic Laboratory Duty Officer
319.335.4500 or 319.530.5981
- As a final resort, the following 24-hour emergency hotlines
have been established:
Iowa Public Health Emergency Terrorism/Disaster Notification Hotline
1.866.834.9671
Environmental Protection Agency Region 7 Spill Hotline
913.281.0991
CDC Hotline 404.639.2540 or 777.488.7100
National Response Center (oil and chemical spills) 800.424.8802
Warning: Automated identification systems may key out as
non-F.tularensis (e.g., Haemophilus influenzae and Actibibacillus
spp.)
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