Publication: Development of a magnetic bead fluorescence microscopy immunoassay to detect and quantify Leptospira in environmental water samples
Issued Date
2012-04-01
Resource Type
ISSN
18736254
0001706X
0001706X
Other identifier(s)
2-s2.0-84857110052
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Mahidol University
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SCOPUS
Bibliographic Citation
Acta Tropica. Vol.122, No.1 (2012), 119-125
Suggested Citation
Stefan Schreier, Galayanee Doungchawee, Darapond Triampo, Piyada Wangroongsarb, Rudi A. Hartskeerl, Wannapong Triampo Development of a magnetic bead fluorescence microscopy immunoassay to detect and quantify Leptospira in environmental water samples. Acta Tropica. Vol.122, No.1 (2012), 119-125. doi:10.1016/j.actatropica.2011.12.011 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/13472
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Title
Development of a magnetic bead fluorescence microscopy immunoassay to detect and quantify Leptospira in environmental water samples
Abstract
Climate change, world population growth, and poverty have led to an increase in the incidence of leptospirosis. Leptospirosis is caused by pathogenic spirochaete bacteria that belong to the genus Leptospira. The bacteria are maintained in the renal tubules of the reservoir hosts (typically a rodent), then shed into the environment via the urine. Water is key for environmental survival and transmission, as leptospires can survive for several weeks in a moist environment. Therefore, environmental epidemiological studies are needed to study the contamination of environmental water sources. However, few such studies have been performed using cultivation of the isolates and PCR assays. But, leptospira cultivation can be easily contaminated by other organisms and takes usually several weeks. Moreover, PCR is a complex and costly analysis for the underdeveloped countries that have the highest incidence of leptospirosis. In this study, we describe two modifications of a fluorescence microscopy assay based on immuno-magnetic separation (IMS) to detect leptospires in environmental water samples that mainly differ in fluorescent dye staining. The first type uses acridine orange fluorescent dye staining combined with multiplexed IMS for sample screening. The detection limit ranged from 10 2 to 10 3 organisms per mL and largely depended on the capture efficiency (CE) of the immuno-magnetic particles. The second type uses serogroup-specific immuno-particles and direct fluorescence antibody staining (DFA) to detect leptospires; the detection limit of this second assay was approximately 10 1 cells per mL. Both assay types were applied to natural and experimentally infected water samples, which were also analysed with DFM and real-time PCR. Our data show that the fluorescent microscopy immunoassay successfully identified experimental leptospire contamination and was as sensitive as PCR. This modified immune-fluorescence assay may therefore enable epidemiological studies of leptospirosis. © 2012 Elsevier B.V.