Community-Scale Wastewater Surveillance of Candida auris during an Ongoing Outbreak in Southern Nevada.

Candida auris is an opportunistic fungal pathogen and an emerging global public health threat, given its high mortality among infected individuals, antifungal resistance, and persistence in healthcare environments. This study explored the applicability of wastewater surveillance for C. auris in a metropolitan area with reported outbreaks across multiple healthcare facilities. Influent or primary effluent samples were collected over 10 weeks from seven sewersheds in Southern Nevada. Pelleted solids were analyzed using an adapted quantitative polymerase chain reaction (qPCR) assay targeting the ITS2 region of the C. auris genome. Positive detection was observed in 72 of 91 samples (79%), with higher detection frequencies in sewersheds serving healthcare facilities involved in the outbreak (94 vs 20% sample positivity). Influent wastewater concentrations ranged from 2.8 to 5.7 log10 gene copies per liter (gc/L), and primary clarification achieved an average log reduction value (LRV) of 1.24 ± 0.34. Presumptive negative surface water and wastewater controls were non-detect. These results demonstrate that wastewater surveillance may assist in tracking the spread of C. auris and serve as an early warning tool for public health action. These findings provide the foundation for future application of wastewater-based epidemiology (WBE) to community- or facility-level surveillance of C. auris and other high consequence, healthcare-associated infectious agents.

Pre-treatment chest X-ray stability duration and tuberculosis disease in San Diego, California, 2012-2017.

Background: Overseas screening for tuberculosis (TB) has sought to reduce the burden of active TB in the United States. The duration of time between two unchanged, or stable, chest X-rays (CXRs) taken four to six months apart has been considered clinically useful in the evaluation of suspected pulmonary TB disease, but this relationship has not been previously quantified. Objective: To investigate the association between pre-treatment CXR stability duration and future clinical or culture-confirmed (Class 3) diagnosis of pulmonary TB in San Diego, California, USA. Methods: This retrospective record review included County of San Diego TB clinic patients with abnormal CXR results who were started on treatment between 2012 and 2017; multivariable logistic regression was used to analyze the clinical data. Results: Pre-treatment CXR stability duration of at least four months was not significantly associated with a Class 3 pulmonary TB diagnosis (adjusted odds ratio [AOR], 0.83; 95 % confidence interval [CI], 0.20-3.48), nor was pre-treatment CXR stability duration of at least six months (AOR, 0.97; 95 % CI, 0.30-3.10). Similar results were obtained when four-to-six-month stability was considered (AOR, 0.78; 95 % CI, 0.16-3.89). Patients screened overseas (B1 notification) were less likely to develop Class 3 TB (unadjusted OR, 0.15; 95 % CI 0.05-0.44). Conclusion: Pre-treatment chest X-ray stability duration was not associated with excluding Class 3 pulmonary TB in this setting, and CXR stability duration cut points may not be as clinically informative as previously understood, but overseas screening is likely an important step in reducing active TB disease burden in the U.S.

Differential expression patterns of phospholipase D isoforms 1 and 2 in the mammalian brain and retina.

Phosphatidic acid is a key signaling molecule heavily implicated in exocytosis due to its protein-binding partners and propensity to induce negative membrane curvature. One phosphatidic acid-producing enzyme, phospholipase D (PLD), has also been implicated in neurotransmission. Unfortunately, due to the unreliability of reagents, there has been confusion in the literature regarding the expression of PLD isoforms in the mammalian brain which has hampered our understanding of their functional roles in neurons. To address this, we generated epitope-tagged PLD1 and PLD2 knockin mice using CRISPR/Cas9. Using these mice, we show that PLD1 and PLD2 are both localized at synapses by adulthood, with PLD2 expression being considerably higher in glial cells and PLD1 expression predominating in neurons. Interestingly, we observed that only PLD1 is expressed in the mouse retina, where it is found in the synaptic plexiform layers. These data provide critical information regarding the localization and potential role of PLDs in the central nervous system.

Identification of Synaptic DGKθ Interactors That Stimulate DGKθ Activity.

Lipids and their metabolic enzymes are a critical point of regulation for the membrane curvature required to induce membrane fusion during synaptic vesicle recycling. One such enzyme is diacylglycerol kinase θ (DGKθ), which produces phosphatidic acid (PtdOH) that generates negative membrane curvature. Synapses lacking DGKθ have significantly slower rates of endocytosis, implicating DGKθ as an endocytic regulator. Importantly, DGKθ kinase activity is required for this function. However, protein regulators of DGKθ's kinase activity in neurons have never been identified. In this study, we employed APEX2 proximity labeling and mass spectrometry to identify endogenous interactors of DGKθ in neurons and assayed their ability to modulate its kinase activity. Seven endogenous DGKθ interactors were identified and notably, synaptotagmin-1 (Syt1) increased DGKθ kinase activity 10-fold. This study is the first to validate endogenous DGKθ interactors at the mammalian synapse and suggests a coordinated role between DGKθ-produced PtdOH and Syt1 in synaptic vesicle recycling.

The U.S. Department of Housing and Urban Development BUILD Las Vegas 2019 Event: Lessons Learned in Public Health Community Engagement.

The U.S. Department of Housing and Urban Development (HUD) BUILD Las Vegas 2019 event brought together Las Vegas Lead Hazard Control and Healthy Homes Program (LVLHCHHP) staff, community leaders, and volunteers from multiple organizations for a neighborhood clean-up and community resource fair in a low-income, historic west Las Vegas neighborhood. In preparation for the event, LVLHCHHP staff encountered a lack of published guidance regarding past BUILD events or planning of community-based public health events. To address this gap in the literature, this brief report offers lessons learned from the process of planning and evaluating the HUD BUILD Las Vegas 2019 event. These include taking early planning measures, centering the focus on community needs, and forming strategic partnerships, which can provide a valuable foundation for future events that want to integrate community engagement with public health.

Naturalistic Topography Assessment in a Randomized Clinical Trial of Smoking Unfiltered Cigarettes: Challenges, Opportunities, and Recommendations.

Smoking topography (ST) is a set of measures profiling the behavioral characteristics of smoking in various settings. The CReSS portable device can measure ST in the natural environment. No standard protocol exists for measuring ST longitudinally with the CReSS. This study examined the utilization of the CReSS to measure ST and highlights challenges and opportunities in a naturalistic setting. This study is part of a randomized cross-over clinical trial of smoking filtered or unfiltered cigarettes. Participants (n = 43) smoked in each study condition for two weeks using the CReSS device for five days in their naturalistic smoking setting. The devices were calibrated and cleaned during the washout period, and data were downloaded every visit. Five test puffs were administered to calibrate each device. Moderate compliance rates (74.1%) were found with device usage, and the issues encountered were overheating/clogging, incorrectly registered date/time-stamped data, and device repair/replacement. Routine inspection/cleaning and training in device usage were instrumental in mitigating device malfunctioning. The CReSS device proved to be a feasible tool to examine naturalistic smoking topography and the potential impact of changes in tobacco product design on smoking unfiltered cigarettes. This is the first study to examine ST variables longitudinally, measured at multiple time points, and using unfiltered cigarettes.

Effects of Unfiltered Cigarettes on Smoking Behavior and Toxicant Exposure: Protocol for a Randomized Crossover Clinical Trial.

BACKGROUND: Plastic filters on cigarette butts are a widespread source of nonbiodegradable, toxic environmental waste. State and local legislation to ban the sale of single-use cigarettes may be considered to prevent this waste, but scientific evidence on the impact of switching smokers to unfiltered cigarettes on smoking behavior and toxicant exposures is needed to inform this policy. We have designed an open-label, randomized, 9-week, crossover clinical trial of adult filtered-cigarette smokers who switch to unfiltered cigarettes. OBJECTIVE: Our objective is to understand the impact of switching smokers of filtered cigarettes to unfiltered cigarettes on smoking behavior and toxic exposures. METHODS: This trial involves a 1-week baseline period; a 2-week period of smoking filtered or unfiltered cigarettes, where groups are randomly assigned; a 3-week washout period; another 1-week baseline period; and a 2-week crossover period of smoking the opposite condition (ie, filtered or unfiltered cigarettes) for a sufficient sample size of 40 participants. We will determine changes in (1) observed topography (ie, puff count, interpuff interval, and puff volume) and cigarettes smoked per day, via butt counts and self-report, (2) expired carbon monoxide and excretion of urinary cotinine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, and volatile organic compounds, and (3) participants' knowledge and attitudes toward unfiltered cigarettes, satisfaction with smoking, and intention to quit if they were not able to smoke filtered cigarettes. RESULTS: This study was funded in June 2018 and approved by the relevant Institutional Review Boards in July 2018. This study has enrolled 37 participants as of October 2020. Data analysis is currently underway, and trial results are expected to be published in spring 2021. CONCLUSIONS: This pilot proof-of-principle study will inform the design of a larger, future research project that can provide robust scientific evidence on our research question. Such a large study could inform possible state or local legislation to ban the sale of single-use filtered cigarettes in order to mitigate the environmental impact of discarded single-use plastic filters. TRIAL REGISTRATION: ClinicalTrials.gov NCT03749876; https://clinicaltrials.gov/ct2/show/NCT03749876. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/19603.

Roles of DGKs in neurons: Postsynaptic functions?

Diacylglycerol kinases (DGKs) contribute to an important part of intracellular signaling because, in addition to reducing diacylglycerol levels, they generate phosphatidic acid (PtdOH) Recent research has led to the discovery of ten mammalian DGK isoforms, all of which are found in the mammalian brain. Many of these isoforms have studied functions within the brain, while others lack such understanding in regards to neuronal roles, regulation, and structural dynamics. However, while previously a neuronal function for DGKθ was unknown, it was recently found that DGKθ is required for the regulation of synaptic vesicle endocytosis and work is currently being conducted to elucidate the mechanism behind this regulation. Here we will review some of the roles of all mammalian DGKs and hypothesize additional roles. We will address the topic of redundancy among the ten DGK isoforms and discuss the possibility that DGKθ, among other DGKs, may have unstudied postsynaptic functions. We also hypothesize that in addition to DGKθ's presynaptic endocytic role, DGKθ might also regulate the endocytosis of AMPA receptors and other postsynaptic membrane proteins.

Lipid Metabolism Crosstalk in the Brain: Glia and Neurons.

Until recently, glial cells have been considered mainly support cells for neurons in the mammalian brain. However, many studies have unveiled a variety of glial functions including electrolyte homeostasis, inflammation, synapse formation, metabolism, and the regulation of neurotransmission. The importance of these functions illuminates significant crosstalk between glial and neuronal cells. Importantly, it is known that astrocytes secrete signals that can modulate both presynaptic and postsynaptic function. It is also known that the lipid compositions of the pre- and post-synaptic membranes of neurons greatly impact functions such as vesicle fusion and receptor mobility. These data suggest an essential lipid-mediated communication between glial cells and neurons. Little is known, however, about how the lipid metabolism of both cell types may interact. In this review, we discuss neuronal and glial lipid metabolism and suggest how they might interact to impact neurotransmission.

Phosphatidic acid-producing enzymes regulating the synaptic vesicle cycle: Role for PLD?

In cortical and hippocampal neurons of the mammalian brain, the synaptic vesicle cycle is a series of steps that tightly regulate exo- and endocytosis of vesicles. Many proteins contribute to this regulation, but lipids have recently emerged as critical regulators as well. Of all the many lipid signaling molecules, phosphatidic acid is important to the physical processes of membrane fusion. Therefore, the lipid-metabolizing enzymes that produce phosphatidic acid are vital to the regulation of the cycle. Our lab is particularly interested in the potential regulatory mechanisms and neuronal roles of two phosphatidic acid-producing enzymes: diacylglycerol kinase theta (DGKθ) and phospholipase D (PLD). We recently discovered a regulatory role of DGKθ on evoked endocytosis (Goldschmidt et al., 2016). In addition to this enzyme, studies implicate PLD1 in neurotransmission, although its precise role is of some debate. Altogether, the production of phosphatidic acid by these enzymes offer an interesting and novel pathway for the regulation of the synaptic vesicle cycle.

Health Hazards in the Home: An Assessment of a Southern Nevada Community.

As a sub-grantee of a Department of Housing and Urban Development (HUD) Lead Hazard Control and Healthy Homes Program, the University of Nevada, Las Vegas' Department of Environmental and Occupational Health performed lead and Healthy Homes investigations and collected data regarding conditions in the home environment in Henderson, Nevada. The purpose of this research is to characterize housing conditions in southern Nevada, compare data to census data, and to highlight the health outcomes associated with adverse housing conditions. Visual home assessments were conducted in 106 homes in southern Nevada, and specific hazards were characterized using the Healthy Homes Rating System. The results were then compared, when possible, to American Housing Survey (AHS) data for the Las Vegas metropolitan area. Lead, domestic hygiene, carbon monoxide, damp and mold, excess cold and heat, and structural collapse were the most frequently identified hazards, found in at least 101 (90%) of participant households. Median household income of program participants was half (50%) that of the surrounding zip code, which was expected, as classification as "low-income" by HUD standards was a requirement for participation. Our data indicated that the AHS data may not be representative of very low income housing in southern Nevada and may underreport actual conditions. In-home inspections performed by trained personnel provide a more accurate picture of conditions than the self-report method used by the AHS. In addition, we recommend the development of a standardized Healthy Homes visual assessment tool to allow for the comparison of housing conditions between communities.

Phosphatidic acid and neurotransmission.

Lipids play a vital role in the health and functioning of neurons and interest in the physiological role of neuronal lipids is certainly increasing. One neuronal function in which neuronal lipids appears to play key roles in neurotransmission. Our understanding of the role of lipids in the synaptic vesicle cycle and neurotransmitter release is becoming increasingly more important. Much of the initial research in this area has highlighted the major roles played by the phosphoinositides (PtdIns), diacylglycerol (DAG), and phosphatidic acid (PtdOH). Of these, PtdOH has not received as much attention as the other lipids although its role and metabolism appears to be extremely important. This lipid has been shown to play a role in modulating both exocytosis and endocytosis although its precise role in either process is not well defined. The currently evidence suggest this lipid likely participates in key processes by altering membrane architecture necessary for membrane fusion, mediating the penetration of membrane proteins, serving as a precursor for other important SV cycling lipids, or activating essential enzymes. In this review, we address the sources of PtdOH, the enzymes involved in its production, the regulation of these enzymes, and its potential roles in neurotransmission in the central nervous system.

Compensatory plasticity in the olfactory epithelium: age, timing, and reversibility.

Like other biological systems, olfaction responds "homeostatically" to enduring change in the stimulus environment. This adaptive mechanism, referred to as compensatory plasticity, has been studied almost exclusively in developing animals. Thus it is unknown if this phenomenon is limited to ontogenesis and irreversible, characteristics common to some other forms of plasticity. Here we explore the effects of odor deprivation on the adult mouse olfactory epithelium (OE) using nasal plugs to eliminate nasal airflow unilaterally. Plugs were in place for 2-6 wk after which electroolfactograms (EOGs) were recorded from the occluded and open sides of the nasal cavity. Mean EOG amplitudes were significantly greater on the occluded than on the open side. The duration of plugging did not affect the results, suggesting that maximal compensation occurs within 2 wk or less. The magnitude of the EOG difference between the open and occluded side in plugged mice was comparable to adults that had undergone surgical naris occlusion as neonates. When plugs were removed after 4 wk followed by 2 wk of recovery, mean EOG amplitudes were not significantly different between the always-open and previously plugged sides of the nasal cavity suggesting that this form of plasticity is reversible. Taken together, these results suggest that compensatory plasticity is a constitutive mechanism of olfactory receptor neurons that allows these cells to recalibrate their stimulus-response relationship to fit the statistics of their current odor environment.