Evaluation of a monoclonal antibody-based dot-blot ELISA for detection of Leptospira spp in bovine urine samples.
OBJECTIVE
To evaluate the efficacy of a novel monoclonal antibody (MAb)-based dot-blot ELISA for detection of Leptospira antigens in urine samples of cattle.


METHODS
Blood and urine samples of 45 test cattle from 5 farms in Chonburi province and 20 control cattle from 2 farms in Khon Kaen province in Thailand.


METHODS
Blood and urine samples were assayed (microscopic agglutination test and urine antigen test) for Leptospira infection by use of an MAb-based dot-blot ELISA, and results for the ELISA were compared with those for dark-field microscopy (DFM), microbial culture, and a polymerase chain reaction (PCR) assay.


RESULTS
All urine samples with positive results for DFM, microbial culture, PCR assay, or > 1 of these tests also had positive results when tested by use of the MAb-based dot-blot ELISA, except for 1 sample that had positive results only for the PCR assay. Detection limits of the dot-blot ELISA were 10(3) leptospires/mL of urine and 9.3 ng of Leptospira homogenate. Comparison revealed that the diagnostic sensitivity, specificity, efficacy (accuracy), positive predictive value, and negative predictive value for the ELISA were in agreement with results for DFM (100%, 72.72%, 80%, 57.14%, and 100%, respectively), microbial culture (100%, 61.54%, 66.62%, 28.57%, and 100%, respectively), and PCR assay (95.45%, 100%, 91.77%, 100%, and 95.83%, respectively).


CONCLUSIONS
The MAb-based dot-blot ELISA is suitable as a tool for detecting leptospires in urine samples of cattle.
Suwimonteerabutr
Junpen
J
Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
Chaicumpa
Wanpen
W
Saengjaruk
Patcharin
P
Tapchaisri
Pramuan
P
Chongsa-nguan
Manas
M
Kalambaheti
Thareerat
T
Ramasoota
Pongrama
P
Sakolvaree
Yuwaporn
Y
Virakul
Prachin
P
D000818:Animals; D000911:Antibodies, Monoclonal; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000662:veterinary; D005260:Female; D015151:Immunoblotting / Q000379:methods* / Q000662:veterinary; D007919:Leptospira / Q000302:isolation & purification*; D007922:Leptospirosis / Q000097:blood / Q000652:urine / Q000662:veterinary*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal