Simple jQuery Dropdowns
Please use this identifier to cite or link to this item: http://repository.li.mahidol.ac.th/dspace/handle/123456789/40922
Title: Utility of a Lateral Flow Immunoassay (LFI) to Detect Burkholderia pseudomallei in Soil Samples
Authors: Patpong Rongkard
Viriya Hantrakun
Sabine Dittrich
Prapaporn Srilohasin
Premjit Amornchai
Sayan Langla
Cherry Lim
Nicholas P.J. Day
David AuCoin
Vanaporn Wuthiekanun
Direk Limmathurotsakul
Mahidol University
Mahosot Hospital
Nuffield Department of Clinical Medicine
Foundation for Innovative New Diagnostics, Switzerland
University of Nevada School of Medicine
Keywords: Medicine
Issue Date: 14-Dec-2016
Citation: PLoS Neglected Tropical Diseases. Vol.10, No.12 (2016)
Abstract: © 2016 Rongkard et al. Background: Culture is the gold standard for the detection of environmental B. pseudomallei. In general, soil specimens are cultured in enrichment broth for 2 days, and then the culture broth is streaked on an agar plate and incubated further for 7 days. However, identifying B. pseudomallei on the agar plates among other soil microbes requires expertise and experience. Here, we evaluate a lateral flow immunoassay (LFI) developed to detect B. pseudomallei capsular polysaccharide (CPS) in clinical samples as a tool to detect B. pseudomallei in environmental samples. Methodology/Principal Findings: First, we determined the limit of detection (LOD) of LFI for enrichment broth of the soil specimens. Soil specimens (10 grams/specimen) culture negative for B. pseudomallei were spiked with B. pseudomallei ranging from 10 to 105CFU, and incubated in 10 ml of enrichment broth in air at 40°C. Then, on day 2, 4 and 7 of incubation, 50 μL of the upper layer of the broth were tested on the LFI, and colony counts to determine quantity of B. pseudomallei in the broth were performed. We found that all five soil specimens inoculated at 10 CFU were negative by LFI on day 2, but four of those five specimens were LFI positive on day 7. The LOD of the LFI was estimated to be roughly 3.8x106CFU/ml, and culture broth on day 7 was selected as the optimal sample for LFI testing. Second, we evaluated the utility of the LFI by testing 105 soil samples from Northeast Thailand. All samples were also tested by standard culture and quantitative PCR (qPCR) targeting orf2. Of 105 soil samples, 35 (33%) were LFI positive, 25 (24%) were culture positive for B. pseudomallei, and 79 (75%) were qPCR positive. Of 11 LFI positive but standard culture negative specimens, six were confirmed by having the enrichment broth on day 7 culture positive for B. pseudomallei, and an additional three by qPCR. The LFI had 97% (30/31) sensitivity to detect soil specimens culture positive for B. pseudomallei. Conclusions/Significance: The LFI can be used to detect B. pseudomallei in soil samples, and to select which samples should be sent to reference laboratories or proceed further for bacterial isolation and confirmation. This could considerably decrease laboratory workload and assist the development of a risk map for melioidosis in resource-limited settings.
URI: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85008699109&origin=inward
http://repository.li.mahidol.ac.th/dspace/handle/123456789/40922
ISSN: 19352735
19352727
Appears in Collections:Scopus 2016-2017

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.