Publications by authors named "Rachel C Williams"
Evaluation of wastewater surveillance for SARS-CoV-2 in a prison population: a mixed-methods approach.
Front Public Health
December 2024
Background: Prisons are high-risk settings for the transmission of communicable disease. Robust surveillance systems are required to identify and control outbreaks. Wastewater surveillance for SARS-CoV-2 was introduced in four prisons in Wales in March 2022.
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- Wastewater-based epidemiology (WBE) is a valuable tool for monitoring community infections, including silent cases of SARS-CoV-2 and other pathogens.
- Next-generation sequencing (NGS) allows for more detailed analyses of viruses, but many facilities still don't use these advanced methods in their routine surveillance.
- The review discusses how to better incorporate NGS into WBE programs to improve detection of emerging viruses and enhance global health response strategies.
Wastewater-based monitoring has been widely implemented worldwide for the tracking of SARS-CoV-2 outbreaks and other viral diseases. In many surveillance programmes, unprocessed and processed wastewater samples are often frozen and stored for long periods of time in case the identification and tracing of an emerging health threat becomes necessary. However, extensive sample bioarchives may be difficult to maintain due to limitations in ultra-freezer capacity and associated cost.
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- * The study examined how well different types of wastewater samples preserve the genetic material of various viruses under various storage conditions, finding that certain genes, like the Spike (S) gene of SARS-CoV-2, are less stable during freeze-thaw cycles compared to others.
- * Results indicated that storing raw wastewater samples at 4 °C optimally preserves SARS-CoV-2, while a laboratory comparison showed that Phi6 phage serves well as a stable surrogate for studying SARS-CoV-2, with minimal degradation
Article Synopsis
- Genomic surveillance of SARS-CoV-2 has revealed important information about the virus's evolution and variant lineages, and expanding this method to other respiratory pathogens can enhance public health preparedness for future outbreaks.
- The study involved sequencing 38 respiratory pathogens in urban wastewater from multiple treatment plants, effectively detecting common viruses like SARS-CoV-2 and influenza, and highlighting seasonal variations in pathogen presence and diversity.
- The research showed that while RT-qPCR is great for quantifying pathogens, next-generation sequencing is better for detecting low abundance viruses; combining both methods improves the overall monitoring of respiratory pathogens in communities, aiding in timely public health interventions.
Wastewater-based epidemiology is now widely used in many countries for the routine monitoring of SARS-CoV-2 and other viruses at a community level. However, efficient sample processing technologies are still under investigation. In this study, we compared the performance of the novel Nanotrap® Microbiome Particles (NMP) concentration method to the commonly used polyethylene glycol (PEG) precipitation method for concentrating viruses from wastewater and their subsequent quantification and sequencing.
View Article and Find Full Text PDFNear-source passive sampling for monitoring viral outbreaks within a university residential setting.
Epidemiol Infect
February 2024
Wastewater-based epidemiology (WBE) has proven to be a powerful tool for the population-level monitoring of pathogens, particularly severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). For assessment, several wastewater sampling regimes and methods of viral concentration have been investigated, mainly targeting SARS-CoV-2. However, the use of passive samplers in near-source environments for a range of viruses in wastewater is still under-investigated.
View Article and Find Full Text PDFDiurnal changes in pathogenic and indicator virus concentrations in wastewater.
Environ Sci Pollut Res Int
December 2023
Wastewater-based epidemiology (WBE) has been commonly used for monitoring SARS-CoV-2 outbreaks. As sampling times and methods (i.e.
View Article and Find Full Text PDFRetinal oxygen saturation is influenced by systemic and local vasculature, intraocular pressure (IOP), and individual cellular function. In numerous retinal pathologies, early changes take place at the level of the microvasculature, thereby affecting retinal oxygenation. The purpose of this study was to investigate diurnal variations in retinal oximetry measures and evaluate the relationship with other ocular and systemic physiological processes.
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- Mouse lemurs, a diverse group of tiny primates in Madagascar, have seen a rapid increase in recognized species over the last 20 years, raising concerns about the oversplitting of this group.
- In a study focusing on an area in northeastern Madagascar, researchers used genetic data to examine two pairs of mouse lemur lineages, discovering significant differences in their populations and genetic structures.
- The findings support classifying one previously undescribed lineage as a separate species, while questioning the distinction of two other recognized species, indicating rapid evolution and reproductive isolation within these primates.
Article Synopsis
- The study focuses on the evolution of vomeronasal type-1 receptors (V1Rs), which are believed to influence species boundaries and mate choice, particularly in nocturnal mammals.
- It explores V1R evolution in Madagascar's small-bodied nocturnal mouse and dwarf lemurs using a comparative genomic approach, doubling the genetic data for strepsirrhine primates.
- The findings show that nocturnal lemurs have more diverse V1R repertoires compared to diurnal ones, with specific V1R subfamilies exhibiting signs of positive selection linked to their evolutionary response to different stimuli.
Article Synopsis
- - Madagascar's biodiversity, particularly its unique dwarf lemurs, faces severe threats from deforestation and climate change, leading to the need for genetic research due to their rarity.
- - Researchers conducted a comparative genomic study, producing the first comprehensive genome-wide genetic diversity estimates for various dwarf lemur species, including generating a reference genome for the fat-tailed dwarf lemur (Cheirogaleus medius).
- - The analysis revealed strong evolutionary relationships among species, identified areas of ancient genetic mixing possibly related to hibernation, and found low genetic diversity in isolated populations, emphasizing the importance of genomic studies for conservation efforts.
Article Synopsis
- Kimura's neutral theory of molecular evolution is crucial for advances in evolutionary and conservation genetics, helping identify species at risk of losing evolutionary potential due to inbreeding and small populations.
- Conservation genetics can be categorized into three types: inventorial, functional, and a new "process-driven" category that focuses on historical patterns and data, especially from genomic studies.
- Understanding these categories allows for a comprehensive approach to collecting data, analyzing it, and forming hypotheses that can aid in the development of informed conservation policies.
Introduction: Gingival fibroblast-mediated extracellular matrix remodelling is implicated in the pathogenesis of periodontitis, yet the stimuli that regulate this response are not fully understood. The immunoregulatory adipokine leptin is detectable in the gingiva, human gingival fibroblasts express functional leptin receptor mRNA and leptin is known to regulate extracellular matrix remodelling responses in cardiac fibroblasts. We therefore hypothesised that leptin would enhance matrix metalloproteinase secretion in human gingival fibroblasts.
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- Understanding genetic diversity in species is crucial for effective conservation strategies to prevent loss of unique populations.
- The study on Nautilus pompilius reveals significant genetic isolation among nearby reefs in Australia, while showing minimal genetic structure between distant populations in the Philippines and west Australia.
- Findings suggest that if Philippine populations go extinct due to overfishing, they may not be naturally recolonized by individuals from west Australia, highlighting the importance of understanding population structure for sustainable management and conservation efforts.
The recently published genome sequence of Bacillus anthracis Ames has facilitated the prediction of proteins associated with the virulence of this bacterium. The aim of this study was to define reference maps for the extracellular and cytoplasmic proteomes of the avirulent B. anthracis strain UM23C1-2 that are useful for physiological studies and the development of improved vaccines.
View Article and Find Full Text PDFProtective antigen (PA) is a component of the Bacillus anthracis lethal and edema toxins and the basis of the current anthrax vaccine. In its heptameric form, PA targets host cells and internalizes the enzymatically active components of the toxins, namely lethal and edema factors. PA and other toxin components are secreted from B.
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