Reconsider the burn: The transient effect of a chlorine burn on controlling opportunistic pathogens in a full-scale chloraminated engineered water system.

Nitrification is a serious water-quality issue in chloraminated engineered water systems (EWSs). Nitrification is often remediated by a chlorine burn (i.e.

Periodic Addition of Glucose Suppressed Cyanobacterial Abundance in Additive Lake Water Samples during the Entire Bloom Season.

Previously, we showed that prophylactic addition of glucose to Harsha Lake water samples could inhibit cyanobacteria growth, at least for a short period of time. The current study tested cyanobacterial control with glucose for the entire Harsha Lake bloom season. Water samples (1000 ml) were collected weekly from Harsha Lake during the algal-bloom season starting June 9 and lasting until August 24, 2022.

Spatial and Temporal Variability of Saxitoxin-Producing Cyanobacteria in U.S. Urban Lakes.

Harmful cyanobacterial blooms (HCBs) are of growing global concern due to their production of toxic compounds, which threaten ecosystems and human health. Saxitoxins (STXs), commonly known as paralytic shellfish poison, are a neurotoxic alkaloid produced by some cyanobacteria. Although many field studies indicate a widespread distribution of STX, it is understudied relative to other cyanotoxins such as microcystins (MCs).

Genomic Characterization and Wetland Occurrence of a Novel Isolate from Canada Geese.

Populations of resident, non-migratory Canada geese are rapidly increasing. Canada geese are known to transmit viral and bacterial diseases, posing a possible threat to human health. The most prevalent pathogens vectored by geese are species, yet the current understanding of the identity and virulence of these pathogens is limited.

Metagenomic mapping of cyanobacteria and potential cyanotoxin producing taxa in large rivers of the United States.

Cyanobacteria and cyanotoxin producing cyanobacterial blooms are a trending focus of current research. Many studies focus on bloom events in lentic environments such as lakes or ponds. Comparatively few studies have explored lotic environments and fewer still have examined the cyanobacterial communities and potential cyanotoxin producers during ambient, non-bloom conditions.

Effective Early Treatment of Exponential Growth and Microcystin Production with Hydrogen Peroxide and Hydroxyapatite.

Mitigating cyanotoxin production is essential to protecting aquatic ecosystems and public health. However, current harmful cyanobacterial bloom (HCB) control strategies have significant shortcomings. Because predicting HCBs is difficult, current HCB control strategies are employed when heavy HCBs have already occurred.

Possible Antagonism between and in a Freshwater Lake during Bloom Seasons.

To ensure drinking-water safety, it is necessary to understand the factors that regulate harmful cyanobacterial blooms (HCBs) and the toxins they produce. One controlling factor might be any relationship between fungi and the cyanobacteria. To test this possibility, water samples were obtained from Harsha Lake in southwestern Ohio during the 2015, 2016, and 2017 bloom seasons, i.

Prophylactic Addition of Glucose Suppresses Cyanobacterial Abundance in Lake Water.

To mitigate harmful cyanobacterial blooms (HCBs), toxic algicides have been used, but alternative methods of HCB prevention are needed. Our goal was to test the prophylactic addition of glucose to inhibit HCB development, using and the toxin microcystin as the HCB model. Water samples were collected weekly, from 4 June to 2 July, from Harsha Lake in southwestern Ohio during the 2021 algal bloom season.

Cyanotoxin-encoding genes as powerful predictors of cyanotoxin production during harmful cyanobacterial blooms in an inland freshwater lake: Evaluating a novel early-warning system.

Freshwater harmful cyanobacterial blooms (HCBs) potentially produce excessive cyanotoxins, mainly microcystins (MCs), significantly threatening aquatic ecosystems and public health. Accurately predicting HCBs is thus essential to developing effective HCB mitigation and prevention strategies. We previously developed a novel early-warning system that uses cyanotoxin-encoding genes to predict cyanotoxin production in Harsha Lake, Ohio, USA, in 2015.

Legionella and other opportunistic pathogens in full-scale chloraminated municipal drinking water distribution systems.

Water-based opportunistic pathogens (OPs) are a leading cause of drinking-water-related disease outbreaks, especially in developed countries such as the United States (US). Physicochemical water quality parameters, especially disinfectant residuals, control the (re)growth, presence, colonization, and concentrations of OPs in drinking water distribution systems (DWDSs), while the relationship between OPs and those parameters remain unclear. This study aimed to quantify how physicochemical parameters, mainly monochloramine residual concentration, hydraulic residence time (HRT), and seasonality, affected the occurrence and concentrations of four common OPs (Legionella, Mycobacterium, Pseudomonas, and Vermamoeba vermiformis) in four full-scale DWDSs in the US.

Co-occurring microorganisms regulate the succession of cyanobacterial harmful algal blooms.

Cyanobacterial harmful algal blooms (CyanoHABs) have been found to transmit from N fixer-dominated to non-N fixer-dominated in many freshwater environments when the supply of N decreases. To elucidate the mechanisms underlying such "counter-intuitive" CyanoHAB species succession, metatranscriptomes (biotic data) and water quality-related variables (abiotic data) were analyzed weekly during a bloom season in Harsha Lake, a multipurpose lake that serves as a drinking water source and recreational ground. Our results showed that CyanoHABs in Harsha Lake started with N-fixing Anabaena in June (ANA stage) when N was high, and transitioned to non-N-fixing Microcystis- and Planktothrix-dominated in July (MIC-PLA stage) when N became limited (low TN/TP).

The Bacterial Community Diversity of Bathroom Hot Tap Water Was Significantly Lower Than That of Cold Tap and Shower Water.

Microbial drinking water quality in premise plumbing systems (PPSs) strongly affects public health. Bacterial community structure is the essential aspect of microbial water quality. Studies have elucidated the microbial community structure in cold tap water, while the microbial community structures in hot tap and shower water are poorly understood.

A comprehensive evaluation of monochloramine disinfection on water quality, Legionella and other important microorganisms in a hospital.

Opportunistic pathogens such as Legionella are of significant public health concern in hospitals. Microbiological and water chemistry parameters in hot water throughout an Ohio hospital were monitored monthly before and after the installation of a monochloramine disinfection system over 16 months. Water samples from fifteen hot water sampling sites as well as the municipal water supply entering the hospital were analyzed using both culture and qPCR assays for specific microbial pathogens including Legionella, Pseudomonas spp.

Use of qPCR and RT-qPCR for monitoring variations of microcystin producers and as an early warning system to predict toxin production in an Ohio inland lake.

Public concern over cyanobacterial blooms has increased due to their higher frequency of occurrence and their potential ecological and health impacts. Detection of microcystin (MC) producers (MCPs) using qPCR and RT-qPCR allows for the rapid identification of blooms by combining specificity and sensitivity with a relatively high throughput capability. Investigation of MCP population composition (correlation, dominance), toxin gene expression, and relationship to MC concentration was conducted using a panel of qPCR assays targeting mcyA, E and G on weekly and daily water samples collected from an Ohio inland reservoir lake.

A Model for Determining Infectivity of Zoonotic .

To better understand public health implications of waterfowl as reservoirs for zoonotic sources of in recreational waters, we developed a (chick) model of infection to assess the pathogenicity of environmental isolates of . This method involved exposure of 1-day-old chicks through ingestion of water, the natural route of infection. Viable from laboratory-infected animals were monitored by using a modified non-invasive sampling of fresh chick excreta followed by a passive polycarbonate-filter migration culture assay.

Nitrogen-phosphorus-associated metabolic activities during the development of a cyanobacterial bloom revealed by metatranscriptomics.

The efforts towards reduction of nutrient contamination of surface waters have greatly gained attention to mitigate increasing incidences of harmful cyanobacterial blooms (CyanoHABs), but little attention has been paid on the roles and importance of cyanobacterial N-fixation and phosphorus (P) scavenging pathways during cyanoHABs. Meta-transcriptomic analyses revealed that expressions of genes involved in N-fixation (nifDKH) and P-scavenging were significantly upregulated during the bloom compared to pre-bloom in Harsha Lake. The activities of N-fixation occurred during early summer after a late spring phytoplankton bloom, and were associated with high phosphorus and low nitrogen.

Chlorine and Monochloramine Disinfection of Colonizing Copper and Polyvinyl Chloride Drinking Water Biofilms.

Building water systems promote the regrowth and survival of opportunistic pathogens, such as , especially within biofilms, where most drinking water microbes reside. However, compared to their planktonic form, disinfection efficacy for the biofilm-associated forms of water-based pathogens is unclear. The aim of this study was to determine the effectiveness of free chlorine and monochloramine in the inactivation of biofilm-associated strain Philadelphia-1 serogroup 1 (LpP1s1).

Opportunistic Pathogens and Microbial Communities and Their Associations with Sediment Physical Parameters in Drinking Water Storage Tank Sediments.

The occurrence and densities of opportunistic pathogens (OPs), the microbial community structure, and their associations with sediment elements from eight water storage tanks in Ohio, West Virginia, and Texas were investigated. The elemental composition of sediments was measured through X-ray fluorescence (XRF) spectra. The occurrence and densities of OPs and amoeba hosts (i.

Annual variations and effects of temperature on Legionella spp. and other potential opportunistic pathogens in a bathroom.

Opportunistic pathogens (OPs) in drinking water, like Legionella spp., mycobacteria, Pseudomonas aeruginosa, and free-living amobae (FLA) are a risk to human health, due to their post-treatment growth in water systems. To assess and manage these risks, it is necessary to understand their variations and environmental conditions for the water routinely used.

Preferential colonization and release of Legionella pneumophila from mature drinking water biofilms grown on copper versus unplasticized polyvinylchloride coupons.

Legionella occurrence in premise drinking water (DW) systems contributes to legionellosis outbreaks, especially in the presence of suitable protozoan hosts. This study examined L. pneumophila behavior within DW biofilms grown on copper (Cu) and unplasticized polyvinylchloride (uPVC) surfaces in the presence of Acanthamoeba polyphaga.

Eukaryotic diversity in premise drinking water using 18S rDNA sequencing: implications for health risks.

The goal of this study was to characterize microbial eukaryotes over a 12-month period to provide insight into the occurrence of potential bacterial predators and hosts in premise plumbing. Nearly 6,300 partial 18S rRNA gene sequences from 24 hot (36.9-39.

Legionella pneumophila transcriptional response following exposure to CuO nanoparticles.

Copper ions are an effective antimicrobial agent used to control Legionnaires' disease and Pontiac fever arising from institutional drinking water systems. Here, we present data on an alternative bactericidal agent, copper oxide nanoparticles (CuO-NPs), and its efficacy on Legionella pneumophila. In broth cultures, the CuO-NPs caused growth inhibition, which appeared to be concentration and exposure time dependent.

The balance of TCF7L2 variants with differential activities in Wnt-signaling is regulated by lithium in a GSK3beta-independent manner.

TCF7L2 transcription factor is a downstream effector of the canonical Wnt/beta-catenin signaling, which controls cell fate and homeostasis. However, the complexity of TCF7L2 expression with numerous mRNA isoforms coding for proteins with distinct N- and C-termini allows variability in TCF7L2 functions and regulations. Here, we show that although TCF7L2 mRNA isoforms distinguish fetal, immortalized and adult differentiated endothelial cells (EC), they cannot explain the lack of significant beta-catenin/TCF7 activities in ECs.

Enhanced endothelial cell senescence by lithium-induced matrix metalloproteinase-1 expression.

Endothelial cell (EC) senescence and dysfunction occurring after chronic injury and inflammation are highly associated with the development and progression of cardiovascular diseases. However, the factors involved in the establishment of EC senescence remain poorly understood. We have previously shown that lithium, an inhibitor of glycogen synthase kinase (GSK)-3beta and activator of the Wnt/beta-catenin signaling pathway, induces an EC senescent-like phenotype.