Spatial-temporal targeted and non-targeted surveys to assess microbiological composition of drinking water in Puerto Rico following Hurricane Maria

Abstract

Loss of basic utilities, such as drinking water and electricity distribution, were sustained for months in the aftermath of Hurricane Maria's (HM) landfall in Puerto Rico (PR) in September 2017. The goal of this study was to assess if there was deterioration in biological quality of drinking water due to these disruptions. This study characterized the microbial composition of drinking water following HM across nine drinking water systems (DWSs) in PR and utilized an extended temporal sampling campaign to determine if changes in the drinking water microbiome were indicative of HM associated disturbance followed by recovery. In addition to monitoring water chemistry, the samples were subjected to culture independent targeted and non-targeted microbial analysis including quantitative PCR (qPCR) and genome-resolved metagenomics. The qPCR results showed that residual disinfectant was the major driver of bacterial concentrations in tap water with marked decrease in concentrations from early to late sampling timepoints. While Mycobacterium avium and Pseudomonas aeruginosa were not detected in any sampling locations and timepoints, genetic material from Leptospira and Legionella pneumophila were transiently detected in a few sampling locations. The majority of metagenome assembled genomes (MAGs) recovered from these samples were not associated with pathogens and were consistent with bacterial community members routinely detected in DWSs. Further, whole metagenome-level comparisons between drinking water samples collected in this study with samples from other full-scale DWS indicated no significant deviation from expected community membership of the drinking water microbiome. Overall, our results suggest that disruptions due to HM did not result in significant and sustained deterioration of biological quality of drinking water at our study sites.

A Snapshot of the Global Drinking Water Virome: Diversity and Metabolic Potential Vary with Residual Disinfectant Use

“…To produce a snapshot of the virome in drinking water distribution systems, we mined publicly available drinking water metagenomes (Chao et al, 2013; Dai et al, 2020; Douterelo et al, 2018; Garner et al, 2018; Jia et al, 2015; Ma et al, 2019, 2017; Potgieter et al, 2020; Sevillano et al, 2021; Shi et al, 2012; Zhang et al, 2019). Table 1 summarizes the metadata for each study.…”

“…To investigate the influence of water quality parameters independently from study-specific effects, we focused on the Dai et al (2020) samples, collected from the UK and Netherlands, and the Sevillano et al (2021) samples, collected from Puerto Rico. Both studies found that chlorine was a major determinant of the differences in the microbial community composition (Dai et al, 2020; Sevillano et al, 2021).…”

“…To investigate the influence of water quality parameters independently from study-specific effects, we focused on the Dai et al (2020) samples, collected from the UK and Netherlands, and the Sevillano et al (2021) samples, collected from Puerto Rico. Both studies found that chlorine was a major determinant of the differences in the microbial community composition (Dai et al, 2020; Sevillano et al, 2021). Dai et al (2020) additionally found that DO and conductivity were correlated with the microbial community structure of these samples; Sevillano et al (2021) found that DO, temperature, and TOC were each significantly associated with changes in microbial composition at specific sites.…”

“…Both studies found that chlorine was a major determinant of the differences in the microbial community composition (Dai et al, 2020; Sevillano et al, 2021). Dai et al (2020) additionally found that DO and conductivity were correlated with the microbial community structure of these samples; Sevillano et al (2021) found that DO, temperature, and TOC were each significantly associated with changes in microbial composition at specific sites. As bacterial community structure is a critical driver of bacteriophage community structure (Gregory et al, 2019; Jonge et al, 2018), we hypothesized that these parameters would also be correlated with the viral community relatedness (Bray Curtis dissimilarities).…”

“…Additionally, both the Sevillano et al (2021) and Dai et al (2020) samples were used to investigate the effects of water quality parameters, including residual disinfectant, on the viral community. These two studies were chosen as the only two to include both samples with and without residual disinfectant.…”