Distribution and abundance of human‐specific Bacteroides and relation to traditional indicators in an urban tropical catchment

• Published in: Journal of applied microbiology Vol. 116; no. 5; pp. 1369 - 1383
• Main Authors: Nshimyimana, J. P, Ekklesia, E, Shanahan, P, Chua, L. H. C, Thompson, J. R
• Format: Journal Article
• Language: English
• Published: Oxford Published for the Society for Applied Bacteriology by Blackwell Science 01.05.2014; Blackwell; Oxford University Press; BlackWell Publishing Ltd
• Subjects: analysis of variance; aquaculture; Bacteria; Bacteroides; Bacteroides - classification; Bacteroides - genetics; Bacteroides - isolation & purification; Biological and medical sciences; coliform bacteria; environmental contamination; Escherichia coli; Escherichia coli - genetics; Escherichia coli - isolation & purification; Feces; Feces - microbiology; Fundamental and applied biological sciences. Psychology; Genetic diversity; Genetic Markers; horticulture; humans; indicator species; land use; Microbiology; Original; Phylogeny; Polymerase Chain Reaction; ponds; public health; risk; RNA, Ribosomal, 16S - genetics; sewage; Sewage - microbiology; Singapore; source tracking; surveys; Tropical Climate; wastewater treatment; Water Microbiology; Water Quality; Watersheds; Singapore; Human; Applied microbiology; Abundance; Contamination; Indicator; Source; Bacteroidaceae; Bacteroides; Surveillance; environmental contamination; Distribution; Water quality; source tracking; Bacteria; water quality
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.12455

AIMS: The study goals were to determine the relationship between faecal indicator bacteria (FIB), the HF183 marker and land use, and the phylogenetic diversity of HF183 marker sequences in a tropical urban watershed. METHODS AND RESULTS: Total coliforms, Escherichia coli, and HF183 were quantified in 81 samples categorized as undeveloped, residential and horticultural from the Kranji Reservoir and Catchment in Singapore. Quantitative‐PCR for HF183 followed by analysis of variance indicated that horticultural areas had significantly higher geometric means for marker levels (4·3 × 10⁴HF183‐GE 100 ml⁻¹) than nonhorticultural areas (3·07 × 10³HF183‐GE 100 ml⁻¹). E. coli and HF183 were moderately correlated in horticultural areas (R = 0·59, P = 0·0077), but not elsewhere in the catchment. Initial upstream surveys of candidate sources revealed elevated HF183 in a wastewater treatment effluent but not in aquaculture ponds. The HF183 marker was cloned, sequenced and determined by phylogenetic analysis to match the original marker description. CONCLUSION: We show that quantification of the HF183 marker is a useful tool for mapping the spatial distribution and potential sources of human sewage contamination in tropical environments such as Singapore. SIGNIFICANCE AND IMPACT: A major challenge for assessment of water quality in tropical environments is the natural occurrence and nonconservative behaviour of FIB. The HF183 marker has been employed in temperate environments as an alternative indicator for human sewage contamination. Our study supports the use of the HF183 marker as an indicator for human sewage in Singapore and motivates further work to determine HF183 marker levels that correspond to public health risk in tropical environments.