Sampling Locations Research Articles

Spatial and temporal variation of Antarctic microbial interactions: a study around the west Antarctic Peninsula

BackgroundThe west Antarctic Peninsula (WAP) is a region of rapid environmental changes, with regional differences in climate warming along the north–south axis of the peninsula. Along the WAP, Palmer corresponds to a warmer region with lesser sea ice extent in the north compared to Rothera ~ 400 km to the south. Comprehensive and comparative, year-round assessments of the WAP microbial community dynamics in coastal surface waters at these two locations are imperative to understand the effects of regional climate warming variations on microbial community dynamics, but this is still lacking.ResultsWe report on the seasonal diversity, taxonomic overview, as well as predicted inter-and intra-domain causal effects (interactions) of the bacterial and microbial eukaryotic communities close to the Palmer station and at the Rothera time-series site between July 2013 and April 2014. Our 16S- and 18S-rRNA gene amplicon sequencing data showed that across all seasons, both bacteria and microbial eukaryotic communities were considerably different between the two sites which could be attributed to seawater temperature, and sea ice coverage in combination with sea ice type differences. Overall, in terms of biotic drivers, causal-effect modelling suggests that bacteria were stronger drivers of ecosystem dynamics at Palmer, while microbial eukaryotes played a stronger role at Rothera. The parasitic taxa Syndiniales persevered at both sites across the seasons, with Palmer and Rothera harbouring different key groups. Up to 62.3% of the negative causal effects were driven by Syndiniales at Rothera compared to only 13.5% at Palmer, suggesting that parasitism drives community dynamics at Rothera more strongly than at Palmer. Conversely, SAR11 Clade II, which was less abundant but persistent year-round at both sites, was the dominant driver at Palmer, evidenced by many (28.2% and 37.4% of positive and negative effects respectively) strong causal effects. Article note: Kindly check first page article notes are correct.ConclusionsOur research has shed light on the dynamics of microbial community composition and correlative interactions at two sampling locations that represent different climate regimes along the WAP.

Relationship of bioelectrical impedance to organoleptic sensory data of farm-raised olive flounder, paralichthys olivaceus

There exists a need for simple, objective, noninvasive digital testing methods to ensure the quality of seafood products as they move from harvest sites to consumers. In this study, Paralichthys olivaceus sourced from a land-based aquaculture tank were harvested and bioelectrical impedance analysis (BIA) scores and organoleptic sensory data were recorded for each fish. The Certified Quality Reader 3.0 BIA device (“CQR®;” CQ Foods Inc.) used BIA data to generate a certified quality number (CQN) that was used to objectively quantify results. Organoleptic scores were obtained by Safe Quality Seafood Associates (SQSA) using standard methods. Mean CQN increased from day 1 to day 5 post-harvest and then decreased from day 5 to day 20 post-harvest. There was strong correlation between BIA data and organoleptic data, indicating the usefulness of BIA for objectively quantifying levels of degradation in this species of fish. Mean CQN and mean organoleptic scores were inversely related in post rigor mortis fish. Notably, BIA was able to differentiate objectively between fresh versus frozen fish samples. This study suggests that BIA can be used for rapid, noninvasive quality assurance of the degradation state of fish, though individual variability is high for measurements which may be controlled by the development of a standardized sample location.

Exposure to perchlorate via drinking water from eight major water basins in China and its health risks across different age groups

Perchlorate is widely used in various industrial fields and has been widely detected in aquatic environments because of its high solubility and stability. Considering the endocrine-disrupting properties of perchlorate, the possibility of perchlorate exposure to humans through drinking water has become a public health concern. To examine whether perchlorate pollution in source water causes a risk to populations of different age groups exposed to residues in drinking water, the spatial distribution of perchlorate levels in source water and drinking water from eight major water basins in China in 2019 was quantified with ion chromatography. The average daily potential dose (ADD) of perchlorate from drinking water intake was estimated for different age groups in the Chinese population. The health risks were quantified by dividing the ADD by the reference dose corresponding to 50% inhibition of iodide uptake. The results revealed that source water contamination was the main factor in population exposure to perchlorate via drinking water. A significant difference in perchlorate contamination was observed, ranging from 5.03 µg/L to 1.80 mg/L, and high perchlorate contamination levels were detected in industrial areas with a high concentration of firework production. In contrast to previously inferred possible sources of perchlorate, i.e., emissions from the production of rockets and missiles, firework production was identified as the dominant source of perchlorate exposure via drinking water in this study. This investigation was conducted five years ago; however, the identification of sampling locations with a health risk quotient above 1 provides quantitative evidence that exposure to perchlorate in drinking water poses a risk to residents in areas affected by source pollution, and the results are helpful for identifying priority risk control areas.

Desiccation as a suitable alternative to cold-storage of phyllosphere samples for DNA-based microbial community analyses.

The study of microbial communities of the plant phyllosphere in remote locations using DNA-based approaches is limited by the challenges associated with their preservation in the field and during transportation. Freezing is a common DNA preservation strategy, but it may be unsuitable for leaf samples, or inaccessible in some locations. Other methods such as desiccation, ethanol or commercial preservatives are potential alternative DNA preservation methods for ambient temperature storage. In this study, we assessed the efficacy of desiccation (with silica gel packs), and of three preservation solutions (95% ethanol, RNAlater, LifeGuard) for the preservation of epiphytic phyllosphere communities of Populus tremuloides and Picea glauca at ambient indoor temperature (21°C) for up to three weeks. We assessed effects on DNA concentration and quality and used metabarcoding to detect changes in bacterial and fungal communities between treatments over time. A secondary study was conducted on leaves of Populus grandidentata to further test the ability of the desiccation treatment to resolve differences between sampling sites. Silica gel packs were identified as effective ambient temperature preservative of phyllosphere bacterial and fungal communities. There were some changes in the communities compared to immediate extraction due to this treatment, but these changes did not affect the ability to distinguish tree species and sampling locations. Overall, our study supports the use of silica gel pack short term preservation at ambient temperature for phyllosphere samples intended for DNA-based microbial community analyses.

Left-right-alternating theta sweeps in entorhinal-hippocampal maps of space.

Place cells in the hippocampus and grid cells in the entorhinal cortex are elements of a neural map of self position1-5. For these cells to benefit navigation, their representation must be dynamically related to the surrounding locations2. A candidate mechanism for linking places along an animal's path has been described for place cells, in which the sequence of spikes in each cycle of the hippocampal theta oscillation encodes a trajectory from the animal's current location towards upcoming locations6-8. In mazes that bifurcate, such trajectories alternately traverse the two upcoming arms when the animal approaches the choice point9,10, raising the possibility that the trajectories express available forward paths encoded on previous trials10. However, to bridge the animal's path with the wider environment, beyond places previously or subsequently visited, an experience-independent spatial sampling mechanism might be required. Here we show in freely moving rats that in individual theta cycles, ensembles of grid cells and place cells encode a position signal that sweeps linearly outwards from the animal's location into the ambient environment, with sweep direction alternating stereotypically between left and right across successive theta cycles. These sweeps are accompanied by, and aligned with, a similarly alternating directional signal in a discrete population of parasubiculum cells that have putative connections to grid cells via conjunctive grid × direction cells. Sweeps extend into never-visited locations thatare inaccessible to the animal. Sweeps persist during REM sleep. The sweep directions can be explained by an algorithm that maximizes the cumulative coverage of the surrounding manifold space. The sustained and unconditional expression of theta-patterned left-right-alternating sweeps in the entorhinal-hippocampal positioning system provides an efficient 'look around' mechanism for sampling locations beyond the travelled path.

Identification of Somatic Genetic Variants in Superficial Vascular Malformations by Liquid Biopsy in a Cohort of 88 Patients from a French Hospital.

Superficial vascular anomalies are complex disorders characterized by abnormal vascular growth. Next-generation sequencing has recently identified somatic genetic alterations associated with these malformations, offering new insights for targeted treatments. However, tissue biopsies for genetic testing can be invasive and difficult to obtain, especially in arteriovenous malformations (AVM) with hemorrhagic risks. A liquid biopsy, a non-invasive approach, offers a promising solution by detecting genetic mutations in cell-free DNA. This pilot study aimed to evaluate the feasibility of using a liquid biopsy for the genetic analysis of patients with superficial vascular anomalies through cell-free DNA sampling. Additionally, it explored whether specific sampling sites, such as the afferent artery, nidus, and efferent vein, could enhance the sensitivity of detecting pathogenic variants in patients with AVM. A total of 88 patients were enrolled, including 55 with AVM and 33 with lymphatic malformations. For patients with AVM, cell-free DNA samples were collected from peripheral blood, efferent veins, afferent arteries, and the AVM nidus. In patients with lymphatic malformations, cystic lymphatic fluid was collected by a direct puncture during diagnostic procedures. A molecular analysis was performed using a targeted gene panel relevant to somatic alterations in solid tumors. Pathogenic variants were validated by digital polymerase chain reaction for patients with lymphatic malformations. Pathogenic variants were identified in 23.6% of patients with AVM, predominantly in MAP2K1 and KRAS genes, with higher sensitivity near the AVM nidus. In addition, pathogenic variants were identified in 27.3% of patients with lymphatic malformations, all involving the PIK3CA gene. Despite the lower sensitivity of a cell-free DNA analysis compared with a tissue biopsy, especially in patients with AVM, the detection rate suggests the utility for a cell-free DNA analysis, particularly when a tissue biopsy is not feasible. This study confirms the feasibility of using a cell-free DNA liquid biopsy for genotyping patients with superficial vascular anomalies, although a tissue biopsy remains the gold standard for comprehensive genetic profiling because of its higher sensitivity. A liquid biopsy offers a non-invasive option for molecular analysis that is useful as a preliminary or alternative approach when direct tissue sampling is not possible. Importantly, the sensitivity of cell-free DNA sampling in AVM appeared highest when obtained close to the nidus, indicating an optimal sampling location for future studies. Further research is needed to improve detection sensitivity, especially for samples taken near the nidus, to validate and strengthen these findings.Although our study focused on superficial/extra-cranial AVM, further research should assess the applicability of this approach to cerebral AVM, where a tissue biopsy is particularly risky.

Real-time monitoring of small changes in powder blends and ejected tablets in a low-dose formulation with 1 %w/w of active pharmaceutical ingredient using Raman and near-infrared spatially resolved spectroscopy within a tablet press.

This study used Raman and near-infrared (NIR) spectroscopy to monitor small real-time changes in powder blends and tablets in low-dose pharmaceutical formulations. The research aims to enhance process analytical technology (PAT) in pharmaceutical manufacturing, ensuring high-quality and uniform products with applications to produce drugs with narrow therapeutic indices (NTI). The study utilizes Raman and NIR spatially resolved spectroscopy (SRS) techniques to monitor a moderate cohesive material's active pharmaceutical ingredient (API) concentrations during manufacturing. The sampling locations were a bin blender for the batch blending procedure where the powder heterogeneity plays a significant role in product homogeneity, a feed frame of a tablet press where powder blend dynamics is critical to final product quality, and the outlet port of the tablet press where tablets immediately after ejection can be monitored in real-time. The study used semifine acetaminophen (APAP) as the API. Results indicated that Raman and NIR SRS could detect small API concentration changes as low as 0.50%w/w, demonstrating their sensitivity and utility in real-time monitoring. The findings support the feasibility of these techniques in ensuring tight process control and highlight the performance of reducing waste and optimizing manufacturing processes in line with quality by design principles. The results highlight the importance of residence time distribution (RTD) in understanding the flow of the materials and powder behavior within the tablet press feed frame. RTD analyses showed that both Raman and NIR SRS techniques could effectively track concentration changes and ensure uniformity in the powder blends and tablets with signal-to-noise ratios higher than 3, demonstrating the sensitivity of the methods to small API changes. The %RSD during a steady state of 250s (corresponding to 1.04kg of material at 15kg/h) for the step changes presented values of 6.74% at 0.50%w/w, 5.39% at 1.00%w/w, and 2.99% at 1.50%w/w for Raman predictions in powder blends within the feed frame and 15.46% at 0.50%w/w, 9.64% at 1.00%w/w, and 5.68% at 1.50%w/w for NIR SRS predictions of tablets ejected at the outlet port of the tablet press. In conclusion, this research demonstrates the potential of advanced spectroscopic techniques and data analysis in pharmaceutical manufacturing. By enabling precise real-time monitoring and control, these techniques contribute to higher-quality drug products, particularly NTI drugs, aligning with modern regulatory expectations and advancing pharmaceutical production technology.

Investigating the respiratory and systemic effects of exposure to BTEX among municipal solid waste workers.

Workers at municipal solid waste (MSW) facilities may be exposed to a range of volatile organic compounds (VOCs). This study aimed to evaluate the potential systemic and respiratory effects, as well as to conduct cancer and non-cancer health risk assessments, associated with exposure to an important group of VOCs-Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX)-among MSW workers. For this purpose, 48 air samples were collected from an MSW facility (36 samples from the landfill and 12 samples from the transfer station) and from a green space serving as the control area (n=6), located in Hamedan, in the west of Iran, during the spring and summer of 2019. Additionally, 60 individuals (30 in the exposure group and 30 in the control group) underwent testing for inflammatory markers, blood factors, and respiratory function. The highest levels of all BTEX compounds were detected at the transfer station, while the lowest concentrations were found at the green space. The mean concentrations of total BTEX compounds were 127μg/m³, 42μg/m³, and 4μg/m³ for air samples collected from the transfer station, the landfill, and the green space, respectively, with Toluene being the dominant pollutant at all sampling sites. While all BTEX compound concentrations remained below the Reference Concentration (RfC) and Threshold Limit Value (TLV), high lifetime cancer risks (LCRs) for Benzene and Ethylbenzene were observed at certain sampling locations, particularly at the transfer station and the active zone of landfill, with LCR values exceeding acceptable thresholds. Biological monitoring of workers indicated that working at sites with higher concentrations of BTEX adversely impacted blood biomarkers and respiratory function. This emphasizes the need for more effective protective strategies to minimize exposure and address associated occupational hazards.

EuPPollNet: A European Database of Plant‐Pollinator Networks

ABSTRACTMotivationPollinators play a crucial role in maintaining Earth's terrestrial biodiversity. However, rapid human‐induced environmental changes are compromising the long‐term persistence of plant‐pollinator interactions. Unfortunately, we lack robust, generalisable data capturing how plant‐pollinator communities are structured across space and time. Here, we present the EuPPollNet (European Plant‐Pollinator Networks) database, a fully open European‐level database containing harmonised taxonomic data on plant‐pollinator interactions referenced in both space and time, along with other ecological variables of interest. In addition, we evaluate the taxonomic and sampling coverage of EuPPollNet, and summarise key structural properties in plant‐pollinator networks. We believe EuPPollNet will stimulate research to address data gaps in plant‐pollinator interactions and guide future efforts in conservation planning.Main Types of Variables IncludedEuPPollNet contains 1,162,109 interactions between plants and pollinators from 1864 distinct networks, which belong to 52 different studies distributed across 23 European countries. Information about sampling methodology, habitat type, biogeographic region and additional taxonomic rank information (i.e. order, family, genus and species) is also provided.Spatial Location and GrainThe database contains 1214 different sampling locations from 13 different natural and anthropogenic habitats that fall in 7 different biogeographic regions. All records are geo‐referenced and presented in the World Geodetic System 1984 (WGS84).Time Period and GrainSpecies interaction data was collected between 2004 and 2021.Major Taxa and Level of MeasurementThe database contains interaction data at the species level for 94% of the records, including a total of 1411 plant and 2223 pollinator species. The database includes data on 6% of the European species of flowering plants, 34% of bees, 26% of butterflies and 33% of syrphid species at the European level.Software FormatThe database was built with R and is stored in ‘.rds’ and ‘.csv’ formats. Its construction is fully reproducible and can be accessed at: https://doi.org/10.5281/zenodo.14747448.

Sensitivity of pteropod calcification to multi stressor variability in coastal habitats.

Comprehensive understanding of environmental multiple stressors on calcification in marine calcifiers remains an important topic of study, especially under ocean global change associated with multiple stressors. We explore the impact of multiple stressor on pteropod calcification in the southern Salish Sea (Washington, U.S.), a coastal estuarine system that exhibits a high degree of spatial and temporal variability in multiple environmental parameters across sampling locations. We hypothesized that such variability is associated with differences in pteropod calcification. Shell thickness and shell density across pteropod life history stages was compared with high-resolution outputs from a realistic model of regional circulation and biogeochemistry to explore how the mean and variability of multiple stressors (aragonite saturation state (Ωar), temperature, food availability) influence calcification. We found that both the mean and variability in multiple stressors play a major role in calcification in pteropods, with a generalized linear model explaining more than 60% of the variance. We suggest two different modes of shell building: stable conditions of lower mean Ωar trigger the loss of shell thickness and density. In the more variable habitats, i.e., where the variability occurs over diel and seasonal scales, shell thickness increases at higher Ωar variability and greater food availability, which might partially compensate for the loss of shell density. This plastic response appears to be consistent across life stages and could represent a response mechanism that allows some compensatory calcification under less favourable conditions. However, compensation is very limited, as evident by lower shell growth resulting in shell sizes comparable to early life stages. These results substantially improve the understanding of the variability in multiple stressors on the calcification process under multiple stressors and provide a foundation for the development of two new proxies for calcification monitoring, and with implications for marine carbon dioxide removal strategies.

On progressive failure of sand considering fabric evolution with micropolar hypoplastic model

To study the progressive failure of sand considering the multi-scale and its fabric evolution, the fabric is used as the quantitative link from micro to macro, then the influence of fabric on the anisotropic critical state is adopted to establish a hypoplastic model, and the fabric evolution and micropolar theory are employed to describe the mesoscopic mechanism of local deformation, finally, the simulations of discrete element methods (DEM) and finite element methods (FEM) is coordinated to reproduce the progressive failure. In the DEM biaxial simulations, the distribution of the contact normal is quantitatively determined by the novel orthotropic fabric tensor, and the difference in particle shapes and sample position showed that the fabric evolution is obvious, especially inside and outside the shear band, and before or after the shear band penetration. The fabric evolution of DEM is implanted into the corresponding location of the FEM sample, the results indicate that the macro-meso incorporation hypoplastic model can effectively describe strain localization evolution and progressive failure. The internal length of micropolar theory and particle size are identified as the main factors influencing the shear band thickness. The anisotropic fabric influences the shear band patterns, with circular and elliptical particles tending to form an "X-shape" shear band, while square and triangular particles tend to form a "L-shape" shear band.

Klasifikasi dan Autentifikasi Tanaman Seurapoh (Chromolaena odorata Linn) Menggunakan Metode Kombinasi Spektroskopi Inframerah dan Kemometrik

This study classifies the Seurapoh plant (Chromolaena odorata Linn) collected from various locations across Aceh Province. The analysis aims to determine the influence of geographic differences on the origin of Seurapoh plants by performing classification and authentication. Seurapoh leaf samples in this study were obtained from several locations, including Aceh Besar, Sabang, Southwest Aceh, South Aceh, Aceh Jaya, Bireun, Bener Meriah, and Central Aceh. Classification of Seurapoh leaf extracts was carried out using Principal Component Analysis (PCA), while authentication was conducted using Linear Discriminant Analysis (LDA). The PCA score plot analysis results indicate that it can explain a total data variance of 62%. Based on the PCA score plot, samples generally form three distinct groups: Group 1 consists of samples from the highland region of Gayo, specifically Central Aceh (TA) and Bener Meriah (BM); Group 2 consists of samples from the coastal areas of Aceh, namely Southwest Aceh (ABD), South Aceh (AS), Aceh Jaya (AJ), and Bireun (Br); and Group 3 comprises samples from geothermal manifestation areas of Seulawah Agam and Jaboi. The classifications derived from PCA analysis were subsequently authenticated using LDA. The LDA analysis results indicate that the LDA model, based on cross-validation, accurately predicts the origin locations of Seurapoh leaf samples with a 100% accuracy rate.

Genetic structure of invasive ctenophore Mnemiopsis leidyi populations in temperate northern European waters is consistent with a southern North Sea overwintering refuge

The ctenophore Mnemiopsis leidyi is native to the Atlantic coasts of the Americas and is considered a threat to biodiversity and food webs in recipient ecosystems. Most of these invasive ctenophores perish during the cold winter in temperate northern European waters (North and Baltic Seas) but spread again every summer/autumn. We collected ctenophores from the southern North Sea, inner Danish waters, and western Baltic Sea in 2017 and 2018, and sequenced genomic DNA obtained from tissue samples. We obtained sequences of internal transcribed spacer (ITS) 1 and 2, and the intervening 5.8S fragment and partial fragments of the flanking 18S rRNA and 28S rRNA genes from nuclear DNA. Excluding the rRNA regions and focussing on only the two ITS sequences, we compared with ITS sequences archived in databases from specimens in its native (Northwest Atlantic) and other invaded habitats (Caspian Sea, Mediterranean Sea, central-western Atlantic Ocean). The comparison revealed no significant difference in genetic variation among temperate northern European sampling locations but showed variation when compared with native and other invaded habitats. No significant genetic difference was identified between specimens collected in the temperate northern European waters for two consecutive years. The very low interregional and interannual genetic variations in M. leidyi specimens in the Northeast Atlantic are consistent with the presence of one single panmictic population in northern European waters and with the hypothesis, also suggested in previous studies, that annual dispersal from the southeastern North Sea into the western Baltic Sea can be traced back to the same population, which most likely originates every spring from the Dutch Wadden Sea and the English Channel.

Scant Evidence for Long-Range Atmospheric Transport of Particle-Bound Benzotriazole Ultraviolet Stabilizers.

Despite benzotriazole UV stabilizers (BT-UVs) being widely used since the 1960s, few empirical data on their atmospheric presence exist. UV-328 was added to the Stockholm Convention on Persistent Organic Pollutants, based in part on model calculations indicating atmospheric long-range transport potential. We investigated the atmospheric occurrence of BT-UVs at multiple sites that differ greatly in their proximity to potential sources. UV-P, UV-328, UV-234, UV-326, UV-329, and UV-327 were quantified in active air samples collected in suburban Toronto, on Saturna Island in the Salish Sea, at Point Petre on Lake Ontario, and in Alert, Nunavut, as well as in XAD-resin based passive air samplers deployed at sites in British Columbia and Quebec. As the most volatile BT-UV, UV-P was present in the gas phase across all sampling locations, with higher concentrations in urban areas. The five less volatile BT-UVs were present only in active air samples from suburban Toronto and were not found above detection limits (0.03-1.7 pg·m-3) anywhere else. Empirical evidence thus does not support model predictions of long-range atmospheric transport of particle-bound BT-UVs. Predictions based on simple model calculations should be supported by empirical data if they are to be used as the basis for regulatory decisions.

P-1848. Reduction of microbial burden on environmental floor samples through advanced photohydrolysis technology and its impact on Candida auris, fungi, and aerobic bacteria

Abstract Background The continued rise of antimicrobial resistance (AMR) and reduction of pharmacological options has created an urgent need for new treatments or countermeasures to combat the spread of multi-drug resistant organisms (MDROs). Focus on MDROs has become paramount with the rise of Candida auris (C. auris) infections that are associated with high mortality and AMR. Attention must be given to pathogen reservoirs such as the surfaces of floors, which have an underappreciated potential to transfer pathogens to hands from objects in contact with the floor. Mean CFUs of Aerobic Bacteria from Baseline to Post-Activation #4. Methods An experimental study to explore the impact of advanced photohydrolysis (AP) technology inside a high acuity hospital unit with active C. auris infections was performed from September 2023 to January 2024 and investigated the effect of the AP system on floor colony forming units (CFUs) of aerobic bacteria, fungi, and C. auris. Baseline pre-activation samples were compared to post-activation samples, which occurred every four weeks on Tuesday mornings prior to shift change and daily environmental services (EVS) cleaning. Mean CFUs of Fungi from Baseline to Post-Activation #4. Results Pairwise comparisons with a Bonferroni correction found median floor fungal CFUs achieved a statistically significant reduction of 99% (p=.011) from Baseline to Post-Activation #4. Aerobic bacteria decreased 98%; C. auris by 66% but did not achieve statistical significance. The mean CFUs on high-touch surfaces were reduced for aerobic bacteria by 82% and fungi by 99%. C. auris was reduced by 100% from Baseline to Post-Activation #3 (41 CFUs to 0 CFUs) but increased in Post-Activation #4 due to two positive sample locations in a patient room with an active C. auris infection. Although the locations were positive for C. auris, they both tested under 500 CFU/cm2, which is associated with a reduced level of infection risk from environmental bioburden. Mean CFUs of Candida Auris from Baseline to Post-Activation #4. Conclusion This study clearly demonstrates that despite intensive efforts by EVS, serious microbes remain on floors; however, application of the AP technology provided a continual and persistent decline in floor microbial burden all without the need for additional skilled labor or increases in cleaning and disinfection practices. A forthcoming study will analyze how these demonstrated environmental changes affected patient outcomes. Disclosures Kimberly Trosch, RN, BSN, ActivePure Technologies: Full time employee Amy Carenza, BBA, ActivePure Technologies: Full time employee Deborah Birx, MD, ActivePure Technologies: Advisor/Consultant

P-1282. Saving Lives and Costs: Respiratory Syncytial Virus Wastewater Surveillance to Guide all infant prophylaxis in Ontario, Canada

Abstract Background Wastewater-based surveillance (WBS) of respiratory syncytial virus (RSV) detected seasonal activity up to one month earlier than clinical surveillance (CS) during the 2022 RSV season in two Ontario cities, Canada. The associated cost-consequence analysis comparing the use of WBS vs CS to guide the start of provincial immunoprophylaxis programs showed WBS-guided prophylaxis realized savings of CAD $2.1-3.5m in the first year and $13.7-16.6m over 1-3 years due to early RSV detection. Further investigation is needed to explore the reproducibility and scalability of WBS for RSV in a provincial surveillance initiative. Geospatial distribution of the 12 sentinel sampling locations across Ontario, Canada Methods In collaboration with the Ontario Ministry of Health (MOH), 12 locations in the province were selected as sentinel WBS sites based on population density, socio-economic strata, and their significance as primary pediatric centres where palivizumab is administered (Figure 1). City-wide, 24-hour composite wastewater samples were collected and screened for RSV by RT-qPCR three to seven times a week. We monitored RSV-WBS data and pediatric RSV-related hospitalizations (RSVH) between September 1, 2023, to March 15, 2024. Cumulative fraction of locations for the onset of the 2023 RSV season in Ontario, Canada Date of onset of regional RSV activity as identify by wastewater surveillance at each of the 12 sentinel locations during the 2023 RSV season, represented as a cumulative fraction. Results During the study period, RSV was detected in 76% (1092/1440) of all wastewater samples collected, with detection at all locations. WBS effectively tracked the geographical variation in viral activity across the province. There was a 73-day variation in the RSV season onset across locations, with northern sites lagging southern locations by 62 ± 11 days (Figure 2). WBS detected regional RSV activity up to 15 days prior to the provincial start date of October 30, 2023, as determined by CS. Considering the estimated WBS cost of $0.50 per eligible infant compared to an average of $5,000 per RSVH, and an estimated fewer RSVHs per year, provincial WBS-guided prophylaxis could significantly reduce healthcare costs and the burden of RSV associated illness. Conclusion RSV WBS could be a highly cost-effective strategy that identifies the early onset of the RSV season, thereby optimizing immunoprophylaxis timing. Additionally, it is scalable to communities of varying sizes and socioeconomic strata and reflects geospatial variation in regional RSV activity supporting its use in a provincial-wide WBS initiative. Disclosures Bosco Paes, MD, Professor Emeritus, AstraZeneca: advisor/lecturer outside the scope of this study|Sanofi: advisor/lecturer outside the scope of this study John Fullarton, n/a, AstraZeneca: Employer has received payment from AstraZeneca for work on various projects outside the scope of this study|Sanofi: Employer has received payment from Sanofi for work on various projects outside the scope of this study Barry Rodgers-Gray, n/a, AstraZeneca: Employer has received payment from AstraZeneca for work on various projects outside the scope of this study|Sanofi: Employer has received payment from Sanofi for work on various projects outside the scope of this study

P-1954. Wastewater-Based Surveillance More Accurately Describes Disease Burden Of COVID-19 In Communities with Less Than 60,000 Inhabitants – An Ontario-Wide Study

Abstract Background The emergence of COVID-19 in Canada prompted extensive efforts in population-wide surveillance, including wastewater-based surveillance (WBS). WBS offers insights into the prevalence of infectious disease burden, however, reasons for poor correlation between hospital admissions and wastewater viral signal in some locations across Ontario remain unclear, while others demonstrate remarkable correlations. This study aims to elucidate the parameters influencing hospitalization-WBS correlation quality to guide infectious disease research and surveillance.Figure 1:Geographic overview of sampling locations in Ontario, Canada Methods Wastewater viral signals and daily hospital admissions geospatially linked with the surveyed sewersheds, were obtained from the Ontario Wastewater Surveillance Initiative. The study included 94 sampling sites (Figure 1), excluding those with inadequate sampling frequency. Spearman’s rank correlation coefficient (ρ) was calculated between hospital admissions and wastewater signals for all included sites during the Omicron BA.1 and BA.2 waves from Nov. 1st,2021 to Jun. 30th, 2022. Regression trees were constructed using the R packages “rpart” and “rpart.plot” to identify factors influencing hospitalization-WBS ρ, including population size, hospital admissions range, proportion of zero admissions, and site isolation status.Figure 2:Regression trees representing a classification model for evaluating the correlation quality between hospitalizations and wastewater signal during the Omicron BA.1 wave – coinciding with a period of waned vaccination immunity (A) and the Omicron BA.2 wave – coinciding with a period of significant vaccination immunity (B). Results Regression tree analysis identified critical population size thresholds influencing hospitalization-WBS ρ: populations under 66,000 exhibited weaker ρ (ρ > 0.650) during Omicron BA.1, and under 187,000 during the BA.2 wave (Figure 3). Larger population areas exhibited stronger hospitalization-WBS ρ, suggesting both are reliable infectious disease burden indicators, influenced by differences in community immunity dynamics between the two waves. Conclusion Populations under 66,000 during a period of waned vaccine immunity and under 187,000 during a period of significant vaccine immunity exhibit distinct relationship between hospital admissions and wastewater signals. These thresholds mark key sizes of communities where the efficacy of wastewater surveillance becomes more pronounced, emphasizing its utility in smaller populations where clinical surveillance of infectious diseases may be limited. Disclosures All Authors: No reported disclosures

P-356. Reduction of high-touch surface aerobic bacteria and fungi colony counts with the implementation of ActivePure continuous disinfection technology

Abstract Background As hospitals nationwide rebound from the effects of the COVID pandemic, reduced staffing and increased hospital-acquired infections (HAIs) are still challenges. Surface disinfection plays a pivotal role in the prevention of HAIs. To improve high-touch surface disinfection and remove the dependence on the human factor, ActivePure continuous disinfection technology devices were installed in the Medical Intensive Care Unit (MICU) HVAC system at Ochsner LSU Health Shreveport in October 2023. ActivePure is a novel technique that kills microbes in the environment by using an advanced photocatalytic oxidation particle. Methods A prospective study was conducted in the 19-bed MICU. Two weeks before device activation, 50 high-touch surface samples and 10 reservoir samples were collected by sterile sponge in situ and plated onto Nutritive (tryptic soy) agar for total aerobic microbial counts, Selective (Sabouraud dextrose) agar for total fungal counts, selective (MeReSa) agar for total MRSA counts, and CHROMagar selective for Carbapenem-Resistant Acinetobacter baumannii (CRAB). All agar plates were incubated at 30°C or 37°C (as applicable) for 48-96 hours. For evaluation, serial dilution plate counts were used to calculate the CFU per sponge for each media type. The detection limit was 10 CFU/sponge for each evaluation. After 4 weeks post-activation, 50 high-touch surface samples and 10 reservoir samples from the same pre-activation sample locations were collected and evaluated via the same methods, and the same was repeated at 9 weeks post-activation. Routine cleaning and disinfection protocols were unchanged during the entire study period. Figure 2 Results The mean aerobic bacterial and fungi surface CFUs were reduced over 99.78% (Fig 1). The mean MRSA surface CFUs were reduced by 99.99% and the mean CRAB surface CFUs were reduced by 99.75% (Fig 2). There was a 94% reduction in surfaces with greater than 500 CFUs/100cm2 of MRSA. There was a 100% reduction in reservoirs with greater than 500 CFUs/100cm2 of CRAB and 80% reduction in reservoirs with greater than 10 CFUs/100cm2 of CRAB. Conclusion The ActivePure continuous disinfection technology devices significantly reduced total aerobic bacteria, including MRSA, difficult-to-treat CRAB, and fungi surface colony counts on high-touch surfaces. Disclosures Kimberly Trosch, RN, BSN, ActivePure Technologies: Full time employee Daniel Marsh, n/a, ActivePure Medical: Advisor/Consultant

The southern house mosquito Culex quinquefasciatus in Abu Dhabi, UAE, is developing resistance to deltamethrin insecticide

Culex quinquefasciatus is a widely spread mosquito species that poses a significant public health threat in many countries. This insect vector is present in the United Arab Emirates (UAE), yet no studies have been conducted on its resistance to any insecticide group. Research shows that controlling mosquitoes is crucial to eliminating mosquito-borne diseases, but when these vectors develop insecticide resistance, the situation can escalate dangerously out of control. This study aimed to identify a knockdown resistance (kdr) mutation L1014F using molecular tools. Additionally, it aimed to assess deltamethrin resistance using the Centers for Disease Control and Prevention (CDC) bottle bioassay. We screened Cx. quinquefasciatus adults (N = 174) for the presence of the mutation using allele-specific PCR (AS-PCR) and DNA sequencing. We detected the mutation and found the kdr allele in all the sampled locations. Furthermore, the CDC bottle bioassay revealed deltamethrin resistance from only one sampling location. To our knowledge, this is the first report of insecticide resistance in Cx. quinquefasciatus in the UAE. Our findings show the need for continued insecticide resistance monitoring for effective mosquito control in the UAE.

A serosurvey study of hand, foot and mouth disease in healthy children aged 6 to 71 months old in West Bandung and Bandung Region, Indonesia

BackgroundHand, foot, and mouth disease (HFMD) is an infectious disease that often affects children under 5 years of age. Over the past 20 years, enterovirus 71 (EV71) has become a major concern among children, especially in the Asia-Pacific region. Currently, there are no data showing the seroprevalence of HMFDs in Indonesia. This study aimed to determine the seroprevalence of antibodies to EV71 infection in rural and urban areas.MethodsThis study was an observational analysis and cross-sectional seroprevalence survey of HFMD in children aged 6 to 71 months. The sampling locations were the Padalarang health centre, which is rural, and the Garuda health centre, which is urban. The total sample included 600 children aged 6–71 months from these two locations. Blood sample testing uses enzyme-linked immunosorbent assays (ELISAs) to identify subjects who are positive for IgG EV71 and the risk factors that may influence it.ResultsIn total, 596 subjects (99.3%) were positive for the seroprevalence of EV71 IgG in rural and urban areas. Child age, sex, nutritional status, height/age, immunisation status, parental income, and father’s and mother’s educations were not statistically related in rural and urban areas (p > 0.05) because the rate of IgG EV71 seropositivity was very high.ConclusionThis study revealed that the rate of IgG EV71 HFMD seropositivity in Indonesia, especially in the Padalarang health centre and Garuda health centre, was very high. Further research is needed to investigate HFMD cases because of the lack of attention given to this disease and the need to consider whether immunisation is necessary to prevent HFMD.Trial registrationThis study is registered at clinicaltrials.gov, National Clinical Trial (NCT) No. NCT05637229.