BRUCELLA INTRODUCTION
Brucella
Sir David Bruce isolated
Micrococcus melitensis from a
British soldier who died from
Maltese fever in Malta.
The Micrococcus of Malta Fever.
Practitioner, 1888, 40: 241-249.
Sir David Bruce
(1855 - 1931)
Classification of Brucella
Bacteria, Proteobacteria, a-Proteobacteria, Rhizobiales, Brucellaceae
Species Host
B. abortus cattle, human
B. canis dogs, foxes,
coyotes, human
B. melitensis sheep, goats,
human
B. neotomae desert wood rats
B. ovis rams
B. suis pigs, human
Gram negative, cocco-bacillus;
facultative intracellular bacterium
Brucella listed as CDC and NIH priority category B pathogen
Acquisition of Brucella Infection
Infects Regional
Entry Systemic
Lymph Spread
phagocytic Nodes
cells
Liver, spleen,
other lymph
Abortion Infection
nodes; uterus
in ungulates
Secretions, tissues, Milk, cheese
fetus & secretions
Transmission to other vertebrates = Zoonosis
Brucellosis in Vertebrates
Animals:
• Chronic infection leading to abortion and
infertility
• Clinical signs & symptoms vary with species
- metritis, spondylitis, lameness, paralysis
- testicular swelling, lympadenitis, splenitis
Humans:
• Clinical signs & symptoms: fever (Undulant Fever)
anorexia, back pain, fatigue, malaise, myalgia,
sweats, weight loss.
• Mortality rate is low; abortions NOT common
• Clinical manifestations - a lot, including reactive
arthritis (a type of spondylitis)
Brucellosis in livestock
Global Livestock Production and Health Atlas,
Animal Production and Health Division, 2006, FAO
Brucella Genomes
Highly similar
Large - B. melitensis, B. abortus & B. suis
chromosome I genomes are completely
~ 2.1 Mb sequenced; B. ovis is pending
- have 2 chromosomes
- contain about 3200 ORFs
- more than 90% of annotated
Small genes share 95-100% homology
chromosome II
~ 1.2 Mb
- most of the differentiating genes
are located in 6 large islands
Brucella can be intentionally
released for bioterrorism
Brucella organisms could be released in aerosol form, by accidental spills of culture suspensions
or live vaccines, or in liquids such as dairy products or water. Brucellosis has fairly low
fatality rate, but could be used as an incapacitating agent, as the disease tends to be
chronic, requiring prolonged treatment
2. Emergency Contact: Local health departments and local law enforcement agencies
should be contacted in the event of accidental or intentional release of Brucella
species(Website 3).
3. Delivery Mechanism: Brucella organisms could be aerosolized and released at infectious
doses. 10-500 organisms in aerosol form constitute an infectious dose.
4. Containment: Most commercial disinfectants are effective at killing or neutralizing
Brucella organisms.
http://www.nigms.nih.gov/News/Reports/biodefense.htm
Brucella intentional release modeling
Goal: See how is used, and how to possibly prevent and contain it.
Create new terms:
Planned process: Brucella intentional release; Brucella aerosolization; Brucella infectious dose
(means: a dose that can induce brucellosis in a host.)
Input: aerosolized Brucella
Output:
Planned objective:
Term: Brucella containment
Term: Brucella intentional release route ??
2. Emergency Contact: Local health departments and local law enforcement agencies should
be contacted in the event of accidental or intentional release of Brucella species(Website 3).
3. Delivery Mechanism: Brucella organisms could be aerosolized and released at infectious
doses. 10-500 organisms in aerosol form constitute an infectious dose.
4. Containment: Most commercial disinfectants are effective at killing or neutralizing
Brucella organisms.
http://www.nigms.nih.gov/News/Reports/biodefense.htm
bearer_of has_part
is_realized_by abortion
B.abortus cattle brucellosis pathogen role cattle brucellosis
process
disease course
is_realized_by
brucellosis patient Brucella-contaminated milk
bearer_of is_a
resides_in
Drink… cattle brucellosis disposition
milk producing function Brucella-infected cow
bearer_of
is_a
B. abortus infection Brucella infection
is_realized_by
bearer_of bearer_of
human Brucellosis host Cow
Brucella-contaminated milk
NOTES:
• We don’t have ‘resides_in’ relation.
• Focus: brucellosis is a zoonotic disease, it can infect both human and animals.