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Updated: Apr 26, 2026
A Duplex Digital PCR Assay for Simultaneous Quantification of the Enterococcus spp. and the Human Fecal-associated HF183 Marker in Waters
Published on: March 9, 2016
Quantification of Salmonella Typhi in water and sediments by molecular-beacon based qPCR
Neetika Rani1, Poornima Vajpayee2, Saurabh Bhatti1
1Environmental Microbiology, Environmental Toxicology Group, CSIR-Indian Institute of Toxicology Research, Post Box 80, M.G. Marg, Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
Abstract:
A molecular-beacon based qPCR assay targeting staG gene was designed for specific detection and quantification of S. Typhi and validated against water and sediment samples collected from the river Ganga, Yamuna and their confluence on two days during Mahakumbha mela 2012-2013 (a) 18 December, 2012: before six major religious holy dips (Makar Sankranti, Paush Poornima, Mauni Amavasya, Basant Panchami, Maghi Poornima and Mahashivratri) (b) 10 February, 2013: after the holy dip was taken by over 3,00,00,000 devotees led by ascetics of Hindu sects at Sangam on 'Mauni Amavasya' (the most auspicious day of ritualistic mass bathing). The assay could detect linearly lowest 1 genomic equivalent per qPCR and is highly sensitive and selective for S. Typhi detection in presence of non specific DNA from other bacterial strains including S. Paratyphi A and S. Typhimurium. It has been observed that water and sediment samples exhibit S. Typhi. The mass holy dip by devotees significantly affected the water and sediment quality by enhancing the number of S. Typhi in the study area. The qPCR developed in the study might be helpful in planning the intervention and prevention strategies for control of enteric fever outbreaks in endemic regions.
