Evaluation of digital droplet PCR (ddPCR) for improved Microbial Source Tracking

NSHIMYIMANA, JEAN PIERRE; CRUZ, MERCEDES CECILIA; WUERTZ, STEFAN; THOMPSON, JANELLE

Conferencia; UNC Water Microbiology Conference 2017. International Symposium on Health Related water microbiology; 2017

University of North Carolina

This study addressed whether digital droplet PCR (ddPCR) could improve sensitivity and specificity of human-associated Bacteroidales genetic markers and their quantification in environmental and fecal composite samples. BacHum and B. theta, previously validated for microbial source tracking in Singapore and Southeast Asia, were tested in 180 samples and quantified by qPCR and ddPCR (n = 35 human stool, n = 70 domestic and wild animal feces, n = 20 sewage, n = 20 environmental and n = 35 composite samples). Quantification of BacHum by ddPCR increased specificity (from 0.70 to 0.90) and accuracy (from 0.80 to 0.94) relative to qPCR, while the B. theta marker performed similarly on both platforms (specificity = 0.98 for qPCR and ddPCR). DdPCR and qPCR quantification of environmental and fecal composite samples were highly correlated (R > 0.87, p