Figure 1Differentiation of Brucella abortus and Brucella melitensis visualized in 10% acrylamide gel electrophoresis using the silver staining method. Lane M: 50-bp DNA ladder (Fermentase); lane 1: B. abortus 544 (99 bp); lanes 2–4: B. abortus biovar 3 strains; lane 5: B. melitensis 16M (84 bp); lanes 6–7: B. melitensis biovar 1 isolates.
Figure 2(A) Sensitivity of polymerase chain reaction assay for the detection of Brucella abortus 544 DNA. Lane M: 50-bp DNA ladder; lanes 2–5: 10-fold serial dilution of template DNA as follows: 500 ng/μL, 50 ng/μL, 5 ng/μL, 0.5 ng/μL, 0.05 ng/μL. (B) Sensitivity of the polymerase chain reaction assay for the detection of Brucella melitensis 16M DNA. Lane M: 50-bp DNA ladder (Fermentase); lanes 1–5: 10-fold serial dilution of template DNA as follows: 650 ng/μL, 65 ng/μL, 6.5 ng/μL, 0.065 ng/μL.
Table 1Bacterial strains used in specificity assay
Bacterial strain |
Origin |
No. |
Brucella abortus biovar 1 (544) |
ATCC 23448 |
1 |
Brucella abortus biovar 2 |
Field isolate |
1 |
Brucella abortus biovar 3 |
Field isolate |
1 |
Brucella abortus biovar 5 |
Field isolate |
1 |
Brucella abortus biovar 9 |
Field isolate |
1 |
Brucella melitensis biovar 1 (16M) |
ATCC 23456 |
1 |
Brucella melitensis biovar 2 |
Field isolate |
1 |
Brucella melitensis biovar 3 |
Field isolate |
1 |
Brucella suis biovar 1 (1330) |
ATCC 23444 |
1 |
Escherichia coli O:157 |
Human |
1 |
Vibrio cholera O:1 |
Human |
1 |
Yersinia enterocolitica O:9 |
Human |
1 |
Table 2Bacteriological test results
Year |
Host |
Sample |
No |
Ring test |
RBT |
Bacterial isolation |
Phage typing |
2013 |
Bovine |
Lymph node |
+30 |
|
|
+ |
B. abortus biotype 3 |
2013 |
Bovine |
Lymph node |
−8 |
|
|
− |
|
2013 |
Bovine |
Blood |
+9 |
|
+ |
+ |
B. abortus biotype 3 |
2013 |
Bovine |
Blood |
−31 |
|
− |
− |
|
2013 |
Bovine |
Milk |
+6 |
+ |
|
+ |
B. abortus biotype 3 |
2013 |
Bovine |
Milk |
−13 |
− |
|
− |
|
2013 |
Human |
Blood |
+27 |
|
+ |
+ |
B. melitensis biotype 1 |
2014 |
Bovine |
Lymph node |
+28 |
|
|
+ |
B. abortus biotype 3 |
2014 |
Bovine |
Lymph node |
−2 |
|
|
− |
|
2014 |
Bovine |
Blood |
+8 |
|
+ |
+ |
B. abortus biotype 3 |
2014 |
Bovine |
Blood |
−6 |
|
− |
− |
|
2014 |
Bovine |
Milk |
+7 |
+ |
|
+ |
B. abortus biotype 3 |
2014 |
Bovine |
Milk |
−9 |
− |
|
− |
|
2014 |
Human |
Blood |
+21 |
|
+ |
+ |
B. melitensis biotype 1 |
Table 3Frequencies of Brucella species isolated from bovine and human samples in 2013 and 2014 were estimated by GenALEx 6.41 software
Year |
Samples |
No. of Brucella-positive samples |
Species frequencies |
B. abortus 3 |
B. melitensis 1 |
2013 |
Bovine |
45 |
0.978 |
0.022 |
|
Human |
27 |
0.00 |
1.00 |
2014 |
Bovine |
43 |
1.00 |
0.00 |
|
Human |
21 |
0.00 |
1.00 |