RAPID: Microbiome Analysis of Household Biofilm Specimens in Flint, Michigan

Wayne State University, Detroit MI

Investigators

Abstract

1639066 Kilgore In April 2014, the city of Flint switched its water supply from Detroit's system (Lake Huron) to the Flint River as a cost-saving measure. The increased corrosiveness resulted in the release of heavy metals (e.g., lead and iron) into the water supply. This RAPID grant addresses a critical gap in our knowledge and offers a timely, yet unique opportunity to advance our fundamental understanding of bacterial communities that make up biofilms in the Flint potable water distribution systems. Biofilm and amoebic hosts are an important habitat for pathogens and protect them from disinfectants such as chlorine. Individuals may be exposed to aerosolized Legionella spp., Mycobacterium spp., and Pseudomonas spp in contaminated water from shower heads, shower plumbing, and water heaters. Despite recognition that contaminated water exposure is an important risk factor for Legionellosis, there is currently limited information on bacterial populations that coexist with Legionella spp. within biofilm microbiomes. In this project, the PIs proposed research will characterize bacterial biofilm communities and their distribution within potable water distribution systems supplying Flint households. Using metagenomic analysis targeting 16S rDNA, the PIs hypothesize that biofilm bacterial populations may vary by household distance from water treatment sites as well as by physico-chemical characteristics of water collected concurrent with biofilm sampling. Currently, household sampling of potable water and biofilm swabs from household shower pipes and humidifiers are being analyzed using standard culture and molecular methods for the presence of Legionella spp. The aim of this study is to compare microbiome found in biofilm specimens with and without Legionella spp. The study will utilize quantitative PCR and DNA sequencing methods to identify bacterial pathogens biofilm microbiomes. The proposed project will provide novel characterization of bacterial species in biofilm microbiomes of Flint households. These data will be used to compare potable water chlorine levels among specimens with and without Legionella spp. Results from microbiome analysis will used to guide future environmental sampling and surveillance for Legionella and other bacterial pathogens. Moreover, available Legionella spp. isolated from case-patients in the epidemic of 2015 will be genetically compared with those identified among biofilm specimens in Flint households. The results of this work will help guide the development of important intervention strategies to reduce OPPP exposure and protect susceptible individuals from these potential pathogens.