Evaluation of sampling and concentration methods for Salmonella enterica serovar typhi detection from wastewater
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Salmonella enterica serovar (Salmonella Typhi) is the causative bacterial agent of typhoid fever. Environmental surveillance of wastewater and wastewater-impacted surface waters has proven effective in monitoring various pathogens and has recently been applied to Salmonella Typhi. This study evaluated eight sample collection and concentration methods with 12 variations currently being developed and used for Salmonella Typhi surveillance globally to better understand the performance of each method based on its ability to detect Salmonella Typhi and its feasibility. Salmonella Typhi strains Ty21a and Ty2 were seeded to influent wastewater at known concentrations to evaluate the following methods: grab sampling using electropositive filters, centrifugation, direct enrichment, or membrane filtration and trap sampling using Moore swabs. Concentrated samples underwent nucleic acid extraction and were detected and/or quantified via quantitative polymerase chain reaction (qPCR). Results suggest that all methods tested can be successful at concentrating Salmonella Typhi for subsequent detection by qPCR, although each method has its own strengths and weaknesses, including the Salmonella Typhi concentration it is best suited for, with a range of positive detections observed as low as 0.1–0.001 colony-forming units (CFU) Ty21a/mL and 0.01 CFU Ty2/mL. These factors should be considered when identifying a method for environmental surveillance and will greatly depend on the use case planned.
Date Issued
2023-03-01
Date Acceptance
2022-10-13
Citation
American Journal of Tropical Medicine and Hygiene, 2023, 108 (3), pp.482-491
ISSN
0002-9637
Publisher
American Society of Tropical Medicine and Hygiene
Start Page
482
End Page
491
Journal / Book Title
American Journal of Tropical Medicine and Hygiene
Volume
108
Issue
3
Copyright Statement
Copyright © 2023 The author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
License URL
Publication Status
Published
Date Publish Online
2023-02-06