Abstract
A multiplex rapid detection system, based on a PCR-lateral flow biosensor (mPCR-LFB) was developed to identify Salmonella Typhi and Salmonella Paratyphi A from suspected carriers. The lower detection limit for S. Typhi and S. Paratyphi A was 0.16 and 0.08 ng DNA equivalent to 10 and 102 CFU/mL, respectively. Lateral flow biosensor was used for visual detection of mPCR amplicons (stgA, SPAint, ompC, internal amplification control) by labeling forward primers with fluorescein-isothiocyanate (FITC), Texas Red, dinitrophenol (DNP) and digoxigenin (DIG) and reverse primers with biotin. Binding of streptavidin-colloidal gold conjugate with the amplicons resulted in formation of a red color dots on the strip after 15–20 min of sample exposure. The nucleic acid lateral flow analysis of the mPCR-LFB was better in sensitivity and more rapid than the conventional agarose gel electrophoresis. Moreover, the mPCR-LFB showed 100% sensitivity and specificity when evaluated with stools spiked with 100 isolates of Salmonella genus and other bacteria. A prospective cohort study on stool samples of 1176 food handlers in outbreak areas (suspected carriers) resulted in 23 (2%) positive for S. Typhi. The developed assay has potential to be used for rapid detection of typhoid carriers in surveillance program.
Highlights
Published: 14 April 2021Enteric fever is a public health problem in many developing and underdeveloped countries
The present study describes a multiplex PCR-lateral flow biosensor for the detection of S
All primers used in this study were designed using Primer Explorer V4 software, targeting the specific regions of Salmonella Typhi genome retrieved from the GenBank (Table 1)
Summary
Enteric fever is a public health problem in many developing and underdeveloped countries. Typhoid fever has become relatively rare in developed countries [1]. The majority of cases are caused by Salmonella Typhi, followed by Salmonella Paratyphi A. According to the World Health Organization (WHO), a carrier is defined as a person who has fully recovered but continues the fecal excretion of. S. Typhi intermittently for up to a year thereafter [3]. 1 to 5% of typhoid patients have been confirmed to be carriers when their stools were tested one-year postinfection [3]. They showed no clinical symptoms but have the potential to cause outbreaks in communities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
