Browsing by Author "Staley, Christopher"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Beach sand and the potential for infectious disease transmission: observations and recommendationsPublication . Solo-Gabriele, Helena M.; Harwood, Valerie J.; Kay, David; Fujioka, Roger S.; Sadowsky, Michael J.; Whitman, Richard L.; Wither, Andrew; Caniça, Manuela; Carvalho da Fonseca, Rita; Duarte, Aida; Edge, Thomas A.; Gargaté, Maria J.; Gunde-Cimerman, Nina; Hagen, Ferry; McLellan, Sandra L.; Nogueira da Silva, Alexandra; Novak Babič, Monika; Prada, Susana; Rodrigues, Raquel; Romão, Daniela; Sabino, Raquel; Samson, Robert A.; Segal, Esther; Staley, Christopher; Taylor, Huw D.; Veríssimo, Cristina; Viegas, Carla; Barroso, Helena; Brandão, JoãoRecent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programs, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programs. First steps toward establishing a sand sampling program include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.
- Beach sand and the potential for infectious disease transmission: observations and recommendationsPublication . Solo-Gabriele, Helena; Harwood, Valerie J.; Kay, David; Fujioka, Roger; Sadowsky, Michael; Whitman, Richard; Wither, Andrew; Caniça, Manuela; Carvalho da Fonseca, Rita; Duarte, Aida; Edge, Thomas; Gargaté, Maria João; Gunde-cimerman, Nina; Hagen, Ferry; Mclellan, Sandra; Silva, Alexandra; Novak Babič, Monika; Prada, Susana; Rodrigues, Raquel; Romão, Daniela; Sabino, Raquel; Samson, Robert; Segal, Esther; Staley, Christopher; Taylor, Huw D.; Veríssimo, Cristina; Viegas, Carla; Barroso, Helena; Brandão, JoãoRecent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. In an effort to provide recommendations for sand sampling programmes in the original article, we outlined published guidelines for beach monitoring programmes, currently focused exclusively on measuring microbial levels in water. We also provided background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand.
- Impacts of a changing earth on microbial dynamics and human health risks in the continuum between beach water and sandPublication . Weiskerger, Chelsea J.; Brandão, João; Ahmed, Warish; Aslan, Asli; Avolio, Lindsay; Badgley, Brian D.; Boehm, Alexandria B.; Edge, Thomas A.; Fleisher, Jay M.; Heaney, Christopher D.; Jordao, Luisa; Kinzelman, Julie L.; Klaus, James S.; Kleinheinz, Gregory T.; Meriläinen, Päivi; Nshimyimana, Jean Pierre; Phanikumar, Mantha S.; Piggot, Alan M.; Pitkänen, Tarja; Robinson, Clare; Sadowsky, Michael J.; Staley, Christopher; Staley, Zachery R.; Symonds, Erin M.; Vogel, Laura J.; Yamahara, Kevan M.; Whitman, Richard L.; Solo-Gabriele, Helena M.; Harwood, Valerie J.Although infectious disease risk from recreational exposure to waterborne pathogens has been an active area of research for decades, beach sand is a relatively unexplored habitat for the persistence of pathogens and fecal indicator bacteria (FIB). Beach sand, biofilms, and water all present unique advantages and challenges to pathogen introduction, growth, and persistence. These dynamics are further complicated by continuous exchange between sand and water habitats. Models of FIB and pathogen fate and transport at beaches can help predict the risk of infectious disease from beach use, but knowledge gaps with respect to decay and growth rates of pathogens in beach habitats impede robust modeling. Climatic variability adds further complexity to predictive modeling because extreme weather events, warming water, and sea level change may increase human exposure to waterborne pathogens and alter relationships between FIB and pathogens. In addition, population growth and urbanization will exacerbate contamination events and increase the potential for human exposure. The cumulative effects of anthropogenic changes will alter microbial population dynamics in beach habitats and the assumptions and relationships used in quantitative microbial risk assessment (QMRA) and process-based models. Here, we review our current understanding of microbial populations and transport dynamics across the sand-water continuum at beaches, how these dynamics can be modeled, and how global change factors (e.g., climate and land use) should be integrated into more accurate beachscape-based models.
- Microbes in Beach Sands: Integrating Environment, Ecology and Public HealthPublication . Whitman, Richard; Harwood, Valerie; Edge, Thomas; Nevers, Meredith; Byappanahalli, Muruleedhara; Vijayavel, Kannappan; Brandão, João; Sadowsky, Michael; Wheeler Alm, Elizabeth; Crowe, Allan; Ferguson, Donna; Ge, Zhongfu; Halliday, Elizabeth; Kinzelman, Julie; Kleinheinz, Greg; Przybyla-Kelly, Kasia; Staley, Christopher; Staley, Zachery; Solo-Gabriele, HelenaBeach sand is a habitat that supports many microbes, including viruses, bacteria, fungi and protozoa (micropsammon). The apparently inhospitable conditions of beach sand environments belie the thriving communities found there. Physical factors, such as water availability and protection from insolation; biological factors, such as competition, predation, and biofilm formation; and nutrient availability all contribute to the characteristics of the micropsammon. Sand microbial communities include autochthonous species/phylotypes indigenous to the environment. Allochthonous microbes, including fecal indicator bacteria (FIB) and waterborne pathogens, are deposited via waves, runoff, air, or animals. The fate of these microbes ranges from death, to transient persistence and/or replication, to establishment of thriving populations (naturalization) and integration in the autochthonous community. Transport of the micropsammon within the habitat occurs both horizontally across the beach, and vertically from the sand surface and ground water table, as well as at various scales including interstitial flow within sand pores, sediment transport for particle-associated microbes, and the large-scale processes of wave action and terrestrial runoff. The concept of beach sand as a microbial habitat and reservoir of FIB and pathogens has begun to influence our thinking about human health effects associated with sand exposure and recreational water use. A variety of pathogens have been reported from beach sands, and recent epidemiology studies have found some evidence of health risks associated with sand exposure. Persistent or replicating populations of FIB and enteric pathogens have consequences for watershed/beach management strategies and regulatory standards for safe beaches. This review summarizes our understanding of the community structure, ecology, fate, transport, and public health implications of microbes in beach sand. It concludes with recommendations for future work in this vastly under-studied area.
- Next-generation sequencing and culture-based techniques offer complementary insights into fungi and prokaryotes in beach sandsPublication . Staley, Christopher; Romão, Daniela; Ferreira, Filipa; Rodrigues, Raquel; Sabino, Raquel; Veríssimo, Cristina; Wang, Ping; Brandão, João; Sadowsky, MichaelAn Illumina next-generation sequencing (NGS) approach, in conjunction with culture-based methods, was used to examine fungal and prokaryotic communities for the presence of potential pathogens in backshore sands at beaches throughout Portugal. We hypothesized that the same predominant taxa, present at high relative abundances, would be detected by both methods. Furthermore, traditional methods were anticipated to show greater sensitivity to specific low-abundance, potentially pathogenic taxa that may be missed by the NGS method. Culture-based fungal enumeration revealed low and variable concentrations of the species targeted (yeasts and dermatophytes), and these species, represented a minority of the community characterized by NGS targeting the ITS1 region. Furthermore, NGS indicated that the potentially pathogenic species Purpureocillium liliacinum comprised nearly the entire fungal community. Differences in culturable concentrations of species and NGS fungal community structure were not significantly different among the three regions tested (P > 0.05). Culturable fecal indicator bacterial concentrations were low or undetectable throughout the study and were not related to communities characterized by NGS targeting the V4 hypervariable region of the 16S rRNA gene. Prokaryotic communities were primarily comprised of the phyla Actinobacteria, Firmicutes, and α- and γ-Proteobacteria but differ from those previously described in beach sands at more specific taxonomic resolution and reveal a considerable abundance of archaea in sand communities. Few significant correlations were observed between taxonomic abundances of species characterized by culture-based and NGS methods. Taken together, these results indicate that there is a current need to leverage culture-based and NGS methods together, using a toolbox approach, to determine appropriate targets and metrics for beach sand monitoring in order to adequately protect public health. Results of this study highlight differences in methodology between sequencing and culture in beach sand monitoring and indicate that the techniques offer unique but complementary insights.
- Next-generation sequencing and culture-based techniques offer complementary insights into fungi and prokaryotes in beach sandsPublication . Romão, Daniela; Staley, Christopher; Ferreira, Filipa; Rodrigues, Raquel; Sabino, Raquel; Veríssimo, Cristina; Wang, Ping; Sadowsky, Michael; Brandão, JoãoA next-generation sequencing (NGS) approach, in conjunction with culture-based methods, was used to examine fungal and prokaryotic communities for the presence of potential pathogens in beach sands throughout Portugal. Culture-based fungal enumeration revealed low and variable concentrations of the species targeted (yeasts and dermatophytes), which were underrepresented in the community characterized by NGS targeting the ITS1 region. Conversely, NGS indicated that the potentially pathogenic species Purpureocillium liliacinum comprised nearly the entire fungal community. Culturable fecal indicator bacterial concentrations were low throughout the study and unrelated to communities characterized by NGS. Notably, the prokaryotic communities characterized revealed a considerable abundance of archaea. Results highlight differences in communities between methods in beach sand monitoring but indicate the techniques offer complementary insights. Thus, there is a need to leverage culture-based methods with NGS methods, using a toolbox approach, to determine appropriate targets and metrics for beach sand monitoring to adequately protect public health.