This document discusses differential diagnosis of brucellosis serologic reactions. It summarizes that Brucella species differ in their primary smooth lipopolysaccharide antigens, with B. melitensis and B. abortus expressing A and M antigens, and B. suis expressing primarily A antigens. Immune response to Brucella infection involves both cell-mediated and humoral antibody responses. Common serologic assays used for brucellosis diagnosis include detection of antibodies in serum or milk through rapid and inexpensive tests, though vaccination and environmental conditions can impact test sensitivity and specificity.

1. Differential Diagnosis of
Brucellosis Serologic Reactions
Steven G. Hennager
Bacterial and Hemoparasitic Serology Team
National Veterinary Services Laboratories
Workshop: An Integrated Approach to Controlling Brucellosis in Africa, Addis
Ababa, 29-31 January 2013
Safeguarding Animal Health

2. Dominant Brucella Antigens
Species
• Brucella melitensis
• Brucella abortus
• Brucella suis
• Brucella canis
• Brucella ovis
Primary Antigen
• M and A
• A and M
• A and M
• Rough
• Rough

3. Blue colonies = Smooth Brucella sp.
Crystal colonies = Rough Brucella sp.

4. Safeguarding Animal Health
Immune response to Brucella infection
• Cell mediated response
• Humoral or antibody production

5. Safeguarding Animal Health
Type: JPG
Website for this image
... and faster response - antibody titre is much higher, occurs much faster, ...
classes.midlandstech.edu
•Full-size image
•760 × 600 (1.2x larger), 66KB
•More sizes
•Search by image
•Similar images
Images may be subject to copyright.

6. Safeguarding Animal Health
Serologic Assays
 Antibody detection
 Serum
 Milk
 Rapid
 Inexpensive
 Sensitivity and Specificity
 Assays can be impacted by
 Vaccination
 Environmental conditions
Brucella card
test

7. Brucellosis Diagnostic Tests

8. Brucellosis Diagnostic Tests

9. Safeguarding Animal Health
Brucellosis Diagnostic Tests

10. Brucellosis Diagnostic Tests

11. Brucellosis Diagnostic Tests

12. Brucellosis Diagnostic Tests

13. Other Brucella Diagnostic Tests
• Polymerase Chain Reaction (PCR)
• Culture Identification
• Western Blot

14. Amount of Isotype (ng)
Test IgM IgG1 IgG2 IgA
Tube 20 ----- 125 650
Card ----- 600 7500 -----
Riv ----- 1550 2750 -----
CF 6500 290 ----- -----
ELISA 155 190 220 700

15. Brief History
 19th century – Bruce isolated organism
from human spleens
 Linked organism to raw goat’s milk
 Genus named after him
 19th century – Bang discovered
organism that caused abortions in
cattle
 Named organism Bacillus abortus
 20th century – Evans recognized the
relationship between Bruce’s organism
and Bang’s organism
 Advocated pasteurization of milk
 Re-named organism Brucella abortus
Sir David
Bruce
L.F. Bernhard
Bang
Alice C. Evans

16. Acknowledge Superior Laboratory
Support
• De Anne Wall, Diane Davis, Barb
Kesl, Molly Fritz
– Serology Laboratory Technicians
Questions?