Brucella Flashcards
Brucella
Reportable
False positive serology with Yersinia enterocolitica 09
High genetic homology (similarities in sequence of protein or nucleic acid between organisms of the same species) -> Diagnosis and identification
Brucella abortus Pathogenesis
Infection via mucosae, oral, wounds (upon handling contaminated meat)
Spread to lymphonodus
During this time there is no symptoms = spread is intracellular in macrophages
Target organs:
reproductive organs = uterus-fetus, udder, male repro organs
articulations
tendon sheath
synovial bursa
Brucella abortus
Pathogenesis in Uterus + Fetus
Placentoma & multiplicaiton -> excetion and spread to bovines, humans
Fetus & multiplication -> abortion, premature birth, normal partus but calf is carrier
Brucella abortus Pathogenesis in Udder
Subclinical mastitis
Excretion and spread
Diagnosis on milk samples - antibodies and antigens
Brucella abortus
Virulence Factors
No capsule
No flagella
Cell wall:
Smooth colonies
=high virulence; zoonotic species (B. melitesis, B. abortus, B. suis)
Rough colonies
=low virulence; B. ovis, B. canis; lack O-polysaccharide
Thicker PG than other Gram-
Erythritol - responsible for preferential location (repro organs, mammary gland)
Brucella abortus Immunity
Antibodies come late
-Facultative intracellular, spread intracellular -only when in organs Abs are formed
Cellular immunity early
Brucella abortus Vaccination
Need for both humoral and cellular immunity
AroC mutants and DnaK mutants
Brucella abortus Diagnosis
SAW or SAT - Slow Agglutination of Wright/Test
1st blood sample = ELISA+
2nd blood sample = ELISA+
Skin test et/ou IFN+ = Brucellose
Brucella suis
General
Reportable
Needs enriched media for growth
Resistant in the environment but does not withstand direct sunlight
5 Biovars: biovar 1-3 are the most pathogenic for pigs
Brucella suis
Symptoms
Reproduction system = abortion,orchitis, infertility Arthritis Tendovaginitis Bursitis Osteomyelitis
Swine can be infected with B. abortus, B. melitensis, and B. canis but these infections do not result in clinical symptoms
Brucella suis
Pathogenesis
Introduction via skin, mucosae
Replication:
regional lymph nodes, bacteremia, location with abscess formation
Brucella suis
Immunity
Strong cellular immunity (facultatvie intracellular)
Carriers (in macrophages)
Brucella melitensis
Brucella ovis
Sheep and goat
B. melitensis - zoonotic
B. ovis - not zoonotic
Brucella canis
Need enriched media for growth Do not have O antigens Resistant in the environment Zoonotic STD
