Application of mitochondrial DNA analysis for microbial source tracking purposes in shellfish harvesting waters

摘要

We present a method for the reliable detection and source characterisation of faecal pollution innwater and shellfish matrices, utilising real-time PCR analysis of mitochondrial DNA targets. In thisnstudy we designed real-time PCR (TaqMan) probes to target human, bovine, ovine and swinenmtDNA. PCR amplification using species-specific TaqMan probes on faecal matter and mixedneffluent slurries revealed no cross-reactions between species of interest and other vertebratenfaecal matter. Performed as a single blind experiment we were able to correctly identify faecalnmaterial in 17/20 effluents (85% correct). mtDNA degrades relatively quickly in faecally-spikednwater samples (,2 weeks), a similar timeframe of environmental persistence to several bacterialnfaecal indictors, highlighting its applicability. The procedure described here is specific, rapidn(,5 hours) and sensitive. These results confirm the suitability of using species-specific mtDNA asnan indicator in source tracking studies in surface waters, shellfish harvesting areas and shellfishnmatrices.