Evaluation of bacterial pathogen diversity, abundance and health risks in urban recreational water by amplicon next-generation sequencing and quantitative PCR
Qijia Cui , Tingting Fang , Yong Huang , Peiyan Dong , Hui Wang
DOI:10.1016/j.jes.2016.11.008
Received July 04, 2016,Revised September 26, 2016, Accepted November 10, 2016, Available online November 29, 2016
Volume 29,2017,Pages 137-149
The microbial quality of urban recreational water is of great concern to public health. The
monitoring of indicator organisms and several pathogens alone is not sufficient to
accurately and comprehensively identify microbial risks. To assess the levels of bacterial
pathogens and health risks in urban recreational water, we analyzed pathogen diversity
and quantified four pathogens in 46 water samples collected from waterbodies in Beijing
Olympic Forest Park in one year. The pathogen diversity revealed by 16S rRNA gene targeted
next-generation sequencing (NGS) showed that 16 of 40 genera and 13 of 76 reference
species were present. The most abundant species were Acinetobacter johnsonii, Mycobacterium
avium and Aeromonas spp. Quantitative polymerase chain reaction (qPCR) of Escherichia coli
(uidA), Aeromonas (aerA), M. avium (16S rRNA), Pseudomonas aeruginosa (oaa) and Salmonella
(invA) showed that the aerA genes were the most abundant, occurring in all samples with
concentrations of 10 4–6 genome copies/100 mL, followed by oaa, invA and M. avium. In total,
34.8% of the samples harbored all genes, indicating the prevalence of these pathogens in
this recreational waterbody. Based on the qPCR results, a quantitative microbial risk
assessment (QMRA) showed that the annual infection risks of Salmonella, M. avium and P.
aeruginosa in five activities were mostly greater than the U.S. EPA risk limit for recreational
contacts, and children playing with water may be exposed to the greatest infection risk. Our
findings provide a comprehensive understanding of bacterial pathogen diversity and
pathogen abundance in urban recreational water by applying both NGS and qPCR.
