Layton, Blythe

Dr. Blythe Layton received her BA in Biology from Whitman College, and MS/PhD in Environmental Engineering and Science from Stanford University. Subsequently, she was a Microbiologist at the Southern California Coastal Water Research Project. In 2020, Dr. Layton joined Oregon State University as a Faculty Research Associate, working on sewer surveillance of the novel coronavirus. Currently she is a Research Program Manager at Clean Water Services, where she is applying genomic technologies to sewer surveillance, wastewater treatment, water reuse, and ambient water quality.

Titles from this speaker

Description: Genome-centric Insights into Full-scale EBPR Captured During a Biomonitoring...

Genome-centric Insights into Full-scale EBPR Captured During a Biomonitoring Campaign

Abstract

Phosphorus removal from wastewater remains a core component of modern wastewater treatment strategies critical for protecting aquatic ecosystems and capturing valuable nutrients. Enhanced biological phosphorus removal (EBPR) is attractive since it reduces the need for chemical precipitating agents and facilitates phosphorus recovery. However, instability can limit the reliable application of EBPR for meeting stringent effluent phosphorus limits. As part of an ongoing biomonitoring campaign, samples were collected before and during an EBPR process stability episode and sequenced for paired metagenomes and metatranscriptomes. Analysis revealed that shifts in carbon and phosphorus loads coupled with changes in the population sizes of non-fermenting polyphosphate accumulating organisms (PAOs; Candidatus Accumulibacter spp.), as identified in the metagenomic data, were associated with poor P-uptake. Metatranscriptomic data from these PAO populations revealed they were indeed substrate limited, as hypothesized from process data, with key genes related to carbon storage appearing down regulated during the instability event with respect to the stable control despite having a greater cell load during the instability period. Accordingly, several gene families related to carbon uptake, VFA metabolism, and PHA synthesis were found to be sensitive to the underlying carbon-limited conditions of the process instability. Our findings illustrate how combined metagenomic and metatranscriptomic sequencing can facilitate interpretation of process data and aid in evaluating the root cause of instability. These data also indicate potential gene targets suitable for developing EBPR performance markers as part of longer term or more frequent biomonitoring efforts.

As part of an ongoing biomonitoring campaign, samples were collected before and during an EBPR process stability episode and sequenced for paired metagenomes and metatranscriptomes. Analysis revealed that shifts in carbon and phosphorus loads coupled with changes in the population sizes and gene transcription of PAOs were associated with poor P-uptake. Our findings illustrate how sequence data can facilitate interpretation of process data and aid in evaluating the root cause of instability.

SpeakerLindner, Blake

Presentation time

14:00:00

14:30:00

Session time

13:30:00

15:00:00

SessionConnecting Molecular Biology Sensors to EBPR Performance

Session locationRoom S502 - Level 5

TopicAdvanced Level, Facility Operations and Maintenance, Municipal Wastewater Treatment Design, Nutrients

Author(s)

Lindner, Blake

Author(s)B. Lindner 1; B. Layton 2 ; B. Lindner 1; B. Layton 2; R. Golda 2; K. Lesnik 3; K. Konstantinidis 4; A. Menniti 2; P. Schauer 2;

Author affiliation(s)School of Civil and Environmental Engineering, Georgia Institute of Technology 1; Clean Water Services 2 ; School of Civil and Environmental Engineering, Georgia Institute of Technology 1; Clean Water Services 2; Clean Water Services 2; Maia Analytica 3; School of Civil and Environmental Engineering, Georgia Institute of Technology 4; Clean Water Services 2; Clean Water Services 2;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159085

Volume / Issue

Content sourceWEFTEC

Word count11

Spatial and Temporal Measurements of SARS-CoV-2 in a Sewershed

Abstract

The SARS-CoV-2 virus can be shed in the feces of persons infected with COVID-19. As a result, sewer surveillance can be used to identify the presence of COVID-19 infections in a particular sewershed. This study involved monitoring SARS-CoV-2 at strategic locations within a sewershed serving about 600,000 customers in Washington County, Oregon. Sampling was conducted at the four wastewater treatment plants (WWTPs) and at 25 manhole locations within this sewershed from spring 2020 to fall 2021. Samples were concentrated using electronegative filtration and analyzed using a ddPCR system. The 25 manholes were chosen to represent a range of characteristics in their micro-sewersheds including varying numbers of medical centers, industrial sectors, and residential demographics. The reported cases of COVID-19 from the Oregon Health Authority (by zip codes and outbreaks) were correlated with the wastewater virus concentrations. The virus concentrations in the influent to each of the four treatment plants correlated well with the reported COVID-19 cases in Washington County. All four treatment plants showed similar trends of a moderate peak of virus concentrations in summer 2020, followed by dramatic peaks over the holiday season and late summer and fall of 2021. SARS-CoV-2 concentrations at WWTPs appeared to be a leading indicator, with increases in wastewater observed two to three weeks before cases rose (Figure 1). At the manhole sites monitored during summer 2020, the frequency of high positive measurements was highest for several food-processing industrial sites where known outbreaks occurred. During the outbreaks, the virus concentrations in wastewater closely correlated with reported COVID-19 cases at the facilities. Sites with the highest virus concentrations also tended to occur in the zip codes with the highest prevalence of COVID-19. The demographics of residential areas have been shown to affect COVID-19 case prevalence, and a similar trend was also observed in virus concentrations in wastewater. Specifically, neighborhoods with high LatinX and high poverty populations also had higher SARS-CoV-2 concentrations. There was a surprising lack of detectable SARS-CoV-2 in the effluents of hospitals and health centers, even with a known presence of COVID-19 patients. The number of COVID-19 cases relative to the total number of patients in the hospital should have produced a clear signal, given previous positive signals detected from whole neighborhoods and industries with only a few documented cases. Quarternary ammonium compounds (QAC) disinfectants are commonly used to inactivate SARS-CoV-2 on surfaces in hospitals, and they are known to destroy DNA and RNA. These disinfectants may be entering the hospital wastewater via routine disinfection procedures and degrading the SARS-CoV-2 signal, leading to concentrations below the detection limit. Experiments conducted with a QAC disinfectant used in the hospitals in this study showed that there was nearly total decay in the RNA targets at 0.1% concentration, equivalent to 0.128 ounces of disinfectant per gallon of wastewater. It is feasible that disinfectants in the hospital environments are entering the wastewater at concentrations at or above this level and damaging the RNA, thus making it undetectable with the current analytical method. This surprising finding has serious implications for WBE monitoring at and downstream of hospitals and health centers. WWTP influent samples with at least 10,000 N gene copies per liter were also sequenced to determine the SARS-CoV-2 variants present in the samples. Each surge in reported cases corresponded to the dominance of a new variant, and several region-specific sub-variants were identified. The most recent surge in cases during summer and early fall 2021 was associated with the near-total dominance of the Delta variant and its sub-variants. Interestingly, wastewater concentrations during the Delta surge were much higher per reported case than during previous surges, which corresponds to the known increase in viral load in patients infected with the Delta variant. This study has demonstrated that SARS-CoV-2 can be successfully quantified at the micro-sewershed level by selection of appropriate key manholes and used as a surrogate or supplement to swab testing. Such a micro-sewershed approach can be used to identify hot spots of high infections such as industrial facilities and can correlate wastewater concentrations of the virus with community characteristics such as income levels. Such data may prove to be useful to the health care community to determine areas for increased testing or outreach and can be used to optimize data collection and reduce costs.

The following conference paper was presented at the Public Health and Water Conference & Wastewater Disease Surveillance Summit in Cincinnati, OH, March 21-24, 2022.

SpeakerLayton, Blythe

Presentation time

14:00:00

14:15:00

Session time

13:30:00

15:00:00

SessionExploring the Role of Various Models in Wastewater-Based Surveillance to Evaluate Epidemiological Control Strategies

Session number4

Session locationDuke Energy Convention Center, Cincinnati, Ohio

TopicModeling, Pathogens, Risk Management

Author(s)

Layton, Blythe

Author(s)B. Layton1; S. Mansell2; D. Kaya3; J. Cook4; H. Ferguson5; A. George6; M. Geniza7; D. Alegre8; A. Piemonti9; C. Kelly10; T. Radniecki11; K. Williamson12

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Mar 2022

DOI10.2175/193864718825158317

Volume / Issue

Content sourcePublic Health and Water Conference

Word count10