Chapter 33: Brucella species Flashcards
Size of Brucella
Small (0.6 x 0.6 to 1.5 um)
Motility
Non-motile
Shape
Coccobacilliary
Type of bacteria
Gram-negative
Environement
Aerobic and capnophilic (high CO2)
Test for:
-Catalase
-Oxidase
-Positive
-Positive (some are negative)
Oxidase positive except
-B. ovis
-B. neotomae
Urease positive except
B. ovis
Requirement (fastidious)
-5 to 10% CO2 for primary isolation
- enriched media with blood or serum for culturing
Require 5 to 10% CO2 for primary isolation
-Brucella bovis
- some biotypes of B. abortus
-growth of other Brucella spp is enhanced in this atmosphere
Requires enriched media with blood or serum for culturing:
-B. abortus biotype 2
- B. ovis
Referred to as MZN-psotive because
They are not decolorized by 0.5% acetic acid in the modified Ziehl-Neelsen (MZN) staining technique
MZN-stained smears of body fluids or tissues, characteristically appear as
Clusters of red coccobacilli
Brucella genome is unusual because
It is composed of two circular chromosomes
(except: B. suis biovar 3- single chromosome)
Predilection for
Both female and male reproductive organs in sexually mature animals
Remain viable in
moist environment for many months
Transmission
Direct contact (infected animals/fluids and tissues associated with abortion)
Stain ____ using MZN method
Red
Some species cause ____ in humans
Undulant fever
Site of replication and dependence on host cells
They are intracellular pathogens
Usual Host: Cattle
Clinical significance: Abortion, orchitis
B. abortus
Usual Host: Goats, sheep
Clinical significance:Abortion, orchitis, arthtritis
B. melitensis
Usual Host: Pigs
Clinical significance:
-abortion
-orchitis
-spondylitis
-infertility
B. suis
Usual Host: Sheep
Clinical significance:
-Epididymitis in rams
-sporadic abortion in ewes
B. ovis
Usual Host: Dogs
Clinical significance:
-Abortion
-Epididymitis
-Discospondylitis
-Sterility in male dogs
B. canis
Usual Host: Dessert wood rat
Clinical significance:
-not isolated from domestic animals
B. neotomae
Usual Host: Cetaceans
Clinical significance:
B. ceti
Usual Host: Pinnipeds
Clinical significance:
B. pinnipedialis
Species occasionally infected:
-Sheep
-Goats
-Pigs
Clinical significance:
-Sporadic abortion
B. abortus
Species occasionally infected:
-Horses
Clinical significance:
-Bursitis
B. abortus
Species occasionally infected:
-cattle
Clinical significance:
-sporadic abortion
-brucellae in milk
B. melitensis
Species occasionally infected:
-Humans
Clinical significance:
-Malta fever
-severe systemic disease
B. melitensis
Species occasionally infected:
-Humans
Clinical significance:
-intermittent fever
-systemic disease
B. suis
Species occasionally infected:
-Humans
Clinical significance:
-Mild systemic disease
B. canis
Species occasionally infected:
-Dolphins
Clinical significance:
-May cause abortion
-Neurological disease has been described
B. ceti
Species occasionally infected:
-Humans
Clinical significance:
-little evidence of disease
B. ceti
Species occasionally infected:
-Humans
Clinical significance:
-little evidence of disease
B. pinnipedalis
B. abortus:
-Number of biotypes
-Requirement for CO2
-7
-v