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Comparative analysis of current diagnostic PCR assays in detecting pathogenic Leptospira isolates from environmental samples


Yap, May Ling and Sekawi, Zamberi and Chee, Hui Yee and Ong, Alan Han Kiat and Vasantha Kumari, Neela (2019) Comparative analysis of current diagnostic PCR assays in detecting pathogenic Leptospira isolates from environmental samples. Asian Pacific Journal of Tropical Medicine, 12 (10). pp. 472-478. ISSN 1995-764


Objective: To compare the efficiency of routine diagnostic PCR assays in detecting pathogenic Leptospira isolated from water and soils. Methods: Seven routine assays targeting six genes (lipL32, flaB, gyrB, lfb1, secY and ligB) were evaluated and compared on the cultures of two groups of pathogenic Leptospira from different sources. One group included 19 described reference strains recovered from infected human or animals, and another group included 22 environmental isolates from recreational and residential sites in Malaysia. The latter have been confirmed for presence of pathogenic Leptospira DNA. PCR positivity or detection sensitivity of each assay was determined and compared between the two groups. Results: Validation on reference strains showed 100.0% PCR sensitivity for all assays except ligB-PCR (95.0%) that failed to amplify Leptospira interrogans serovar Pomona. In marked contrast, there was a notable decline in sensitivity in the environmental isolates (lipL32-PCR, 95.5%; flaB-PCR, 90.9%; gyrB-PCR, 77.3%; lfb1-PCR, 59.1%; secY-PCRs, 40.9% G1/G2-PCR, 36.4%; ligB-PCR, 13.6%), implying a large genetic distance between the two groups, as well as nucleotide polymorphism among environmental isolates. Conclusions: High proportion of false-negative PCR results suggests a need of prudent selection of primers in detecting environmental pathogenic Leptospira. These findings offer valuable insights on the extensive biodiversity of genus Leptospira and its impact on the efficacy and development of molecular detection tool.

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Additional Metadata

Item Type: Article
Divisions: Faculty of Medicine and Health Science
DOI Number: https://doi.org/10.4103/1995-7645.269908
Publisher: Wolters Kluwer - Medknow
Keywords: Leptospira; Pathogenic species; Environmental samples; PCR; Sensitivity
Depositing User: Ms. Nuraida Ibrahim
Date Deposited: 14 Oct 2020 20:41
Last Modified: 14 Oct 2020 20:41
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.4103/1995-7645.269908
URI: http://psasir.upm.edu.my/id/eprint/80964
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