Microbial Diversity of Source and Point-of-Use Water in Rural Haiti – A Pyrosequencing-Based Metagenomic Survey

Abstract

Haiti endures the poorest water and sanitation infrastructure in the Western Hemisphere, where waterborne diseases cause significant morbidity and mortality. Most of these diseases are reported to be caused by waterborne pathogens. In this study, we examined the overall bacterial diversity of selected source and point-of-use water from rural areas in Central Plateau, Haiti using pyrosequencing of 16s rRNA genes. Taxonomic composition of water samples revealed an abundance of Firmicutes phyla, followed by Proteobacteria and Bacteroidetes. A total of 38 bacterial families and 60 genera were identified. The presence of several Klebsiella spp. (tentatively, K. pneumoniae, K. variicola and other Klebsiella spp.) was detected in most water samples. Several other human pathogens such as Aeromonas, Bacillus, Clostridium, and Yersinia constituted significantly higher proportion of bacterial communities in the point-of-use water samples compared to source water. Bacterial genera traditionally associated with biofilm formation, such as Chryseobacterium, Fusobacterium, Prevotella, Pseudomonas were found in the point-of-use waters obtained from water filters or domestic water storage containers. Although the pyrosequencing method utilized in this study did not reveal the viability status of these pathogens, the abundance of genetic footprints of the pathogens in water samples indicate the probable risk of bacterial transmission to humans. Therefore, the importance of appropriate handling, purification, and treatment of the source water needed to be clearly communicated to the communities in rural Haiti to ensure the water is safe for their daily use and intake.

Microbial Dynamics of Biosand Filters and Contributions of the Microbial Food Web to Effective Treatment of Wastewater-Impacted Water Sources

“…reduction in the relative abundance of Flavobacteriia and Bacteroidetes spp. has also been seen in other studies of sand filtration (8,26). Bacteria from groups commonly associated with fecal matter that appear to be preferentially removed (higher relative abundance in the influent than the effluent) include Epsilonproteobacteria (the most abundant genus was Arcobacter) (42,56), Fusobacteriia (57,58), Bacilli (most abundant groups include Streptococcaceae and Carnobacteriaceae) (59,60), and Verruco-5 (61).…”

“…The diversity and composition of the microorganisms in biosand filters have been characterized across a broad range of operating conditions. Most previous work on the microbial communities in biosand filters has focused on continuously operated systems representative of municipal-scale systems (5,8,13,(21)(22)(23)(24)(25), while only limited work focused on intermittently operated filters, typical of household-scale systems (26)(27)(28). This gap in our knowledge of the microbial communities in intermittently operated biosand filters is important given that many intermittently operated filters are implemented in conditions with less monitoring and often without posttreatment disinfection steps (2).…”

Analysis of a Tropical Warm Spring Microbiota Using 16S rRNA Metabarcoding

“…at very low prevalence. These organisms which can form biofilms normally form an association with humans or other animals and could indicate use of these spring sources for recreational use [40]. Worthy of note is that the phylum Fusobacteria, a group of gram-negative non spore formers, were found but not exclusively in the Ikogosi Warm Spring.…”

A Metagenomic Approach to Evaluating Surface Water Quality in Haiti

“…Although the focus of most prior studies has been on V. cholerae , one metagenomic study has been conducted to the southwest of Hinche, primarily in the region of the Rivière Hinquitte, a tributary of the Rivière Guayamouc [ 42 ]. This study examined bacterial diversity in source and point-of-use water.…”

“…For example, dominance of Sphingobium yanoikuyae ( Figure S3 ), often associated with PAH-contaminated soils [ 43 ], at the Mirebalais Rivière La Thème site, as well as the presence of predatory Bacteriovorax spp. [ 44 ], will change the bacterial community structure in our study compared to the pathogen-dominated genera in the source and point-of-use study [ 42 ].…”