Key Characteristics

• Grows slowly at 35-37°C. CO2 enhances growth of some biovars of B. abortus
• Gram-negative, coccobacillus
• Catalase positive
• Non-motile
• Oxidase positive (B. canis is variable)
• Urease positive; strong, typically <2h, some within 5 minutes
• X and V factors not required

ISOLATES WITH THE ABOVE CHARACTERISTICS SHOULD BE REPORTED TO THE PATIENT'S PHYSICIAN AS UNABLE TO RULE-OUT BRUCELLA SPECIES. CONTACT YOUR STATE PUBLIC HEALTH LABORATORY FOR INSTRUCTIONS ABOUT REFERRING THE ISOLATE OR SPECIMEN.

Colony Characteristics

• Usually not visible or pinpoint at 24 hours
• Grows slowly on most standard media (e.g. sheep blood, chocolate and tryptic soy agars). Pinpoint, smooth, with an entire border, translucent, non-hemolytic at 48 hours
• Some strains grow on MacConkey agar
• Grows on Martin-Lewis and Thayer-Martin agars

Microscopic Characteristics

• Faintly-staining, small Gram-negative coccobacilllus (0.5-0.7 x 0.6-1.5 um), seen mostly as single cells and appearing like fine sand. Bipolar staining is not a distinctive feature. Although a small Gram-negative coccobacillus, cells are typically larger than those of F. tularensis

Safety

Brucella species are 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 all 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

Note: If you have isolated an organism that resembles Clostridium botulinum, contact your state public health laboratory for appropriate action.