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Page No. : 92-97

ABSTRACT

Microbial source tracking (MST) portrays a suite of strategies and an analytical system for tracing faecal contamination sources in environmental waters. Based on the molecular techniques, MST can be library-de- pendent or library-independent. Library-independent techniques off er many advantages, particularly using viral DNA from enteric viruses (like adenoviruses) has shown promising results as MST marker. But due to their enormous diversity, low concentrations, and geographical and temporal fluctuation, viruses are difficult to detect, unless concentrated. Also, the upstream steps of apprehending viruses from environmental water sources alongside expelling PCR inhibitors from extracted genome remain forcing check to routine use. Thus, the aim of this study was to compare different molecular assays for detection of adenoviruses. Broad-range PCR assays which target conserved genomic motifs for post-amplification amplicon analysis permit detection of species-specific adenoviruses. In this study, conventional and real-time TaqMan quantitative PCR (RT-PCR) assays were compared for detection of human adenoviruses (HAdVs), bovine adenoviruses (BAdVs) and porcine adenoviruses (PAdVs) in surface water samples. HAdV were detected in 61.5% of surface water samples by TaqMan real-time qPCR while by conventional PCR only 38.4% samples were positive. Likewise, PAdV were detected in 21.2% of samples while by conventional PCR only 7.7% samples were positive. Thereby indicated that the odds of finding adenoviruses is almost twice by TaqMan real-time qPCR compared to conventional PCR. Thus, the use of qPCR for the detection of Human adenoviruses (HAdV) and Porcine Adenoviruses (PAdV) has clearly indicated that low viral loads are not an obstacle in the search for pathogens in environmental samples when used with high sensitivity detection methods.

Keywords: Adenoviruses, conventional PCR, MST, surface water, TaqMan qPCR