A quantitative PCR (TaqMan) assay for pathogenic Leptospira spp.
BACKGROUND
Leptospirosis is an emerging infectious disease. The differential diagnosis of leptospirosis is difficult due to the varied and often "flu like" symptoms which may result in a missed or delayed diagnosis. There are over 230 known serovars in the genus Leptospira. Confirmatory serological diagnosis of leptospirosis is usually made using the microscopic agglutination test (MAT) which relies on the use of live cultures as the source of antigen, often performed using a panel of antigens representative of local serovars. Other techniques, such as the enzyme linked immunosorbent assay (ELISA) and slide agglutination test (SAT), can detect different classes of antibody but may be subject to false positive reactions and require confirmation of these results by the MAT.


METHODS
The polymerase chain reaction (PCR) has been used to detect a large number of microorganisms, including those of clinical significance. The sensitivity of PCR often precludes the need for isolation and culture, thus making it ideal for the rapid detection of organisms involved in acute infections. We employed real-time (quantitative) PCR using TaqMan chemistry to detect leptospires in clinical and environmental samples.


CONCLUSIONS
The PCR assay can be applied to either blood or urine samples and does not rely on the isolation and culture of the organism. Capability exists for automation and high throughput testing in a clinical laboratory. It is specific for Leptospira and may discriminate pathogenic and non-pathogenic species. The limit of detection is as low as two cells.
Smythe
Lee D
LD
WHO/FAO/OIE Collaborating Centre for Reference & Research on Leptospirosis, Centre for Public Health Sciences, Queensland Health Scientific Services, Brisbane, Australia. lee_smythe@health.qld.gov.au
Smith
Ina L
IL
Smith
Greg A
GA
Dohnt
Michael F
MF
Symonds
Meegan L
ML
Barnett
Leonie J
LJ
McKay
David B
DB
D001800:Blood Specimen Collection / Q000009:adverse effects / Q000379:methods; D004269:DNA, Bacterial / Q000097:blood / Q000652:urine; D006493:Heparin / Q000009:adverse effects / Q000031:analogs & derivatives; D006801:Humans; D007919:Leptospira / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D007922:Leptospirosis / Q000175:diagnosis / Q000235:genetics; D008094:Lithium / Q000009:adverse effects; D016133:Polymerase Chain Reaction / Q000187:drug effects / Q000379:methods*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D019914:Taq Polymerase
D004269:DNA, Bacterial; D006493:Heparin; D008094:Lithium; D019914:Taq Polymerase