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1.
Microbiol Resour Announc ; : e0014124, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38967461

ABSTRACT

Papiliotrema laurentii 5307AH was isolated from an aircraft polymer-coated surface. The genome size is 19,510,785 bp with a G + C content of 56%. The genome harbors genes encoding oxygenases, cutinases, lipases, and enzymes for styrene degradation, all of which could play a critical role in survival on xenobiotic surfaces.

2.
J Clin Microbiol ; : e0070324, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38953652

ABSTRACT

The clinical microbiology laboratory is capable of identifying microorganisms in clinical specimens faster and more accurately than ever before. At face value, this should enable patient care providers to make better-informed decisions and target antimicrobial therapies to deliver individualized care. Ironically, more complete and specific reporting of microorganisms isolated from specimens may result in overtreatment based on the presence of a pathogen, even in the absence of clear signs of clinical infection. This conundrum calls into question the role of the laboratory in contributing to care through selective or "exception" reporting whereby some results are selectively withheld when there is a low probability that laboratory findings correlate with the clinical infection. In a recent article published in the Journal of Clinical Microbiology, Bloomfield et al. (J Clin Microbiol 62:e00342-24, 2024, https://doi.org/10.1128/jcm.00342-24) examine the impact and safety of an exception reporting strategy applied to wound swab specimens. Canonical pathogens associated with skin and soft tissue infections including S. aureus and beta-hemolytic streptococci are withheld from the laboratory report if certain patient criteria are met that would put them at low risk of adverse outcomes if untreated, or if treated with guideline-recommended empiric therapy. Their central finding was an approximately 50% reduction in post-laboratory report antibiotic initiation without adverse events or increased 30-day admission rate (indicative of infection-related complications, e.g., disseminated disease). While effectively achieving their goal, the premise of exception reporting and other modified reporting strategies raises questions about the potential risk of underreporting and how to ensure that the message is being interpreted, and acted upon, by care providers as was intended by the laboratory.

3.
Immunohorizons ; 8(5): 363-370, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38775688

ABSTRACT

Although the pathogenesis of choroidal neovascularization (CNV) is largely unknown in age-related macular degeneration (AMD), inflammasomes may contribute to CNV development and progression. To understand the role NLRP3 inflammasomes in CNV, we used Ccr2RFPCx3cr1GFP dual-reporter mice and immunostaining techniques to confirm localization of NLRP3 inflammasomes in the laser-induced CNV (LCNV) lesions. Confocal microscopy was used to image and quantify LCNV volumes. MCC950 was used as NLRP3 inhibitor. ELISA and quantitative RT-PCR were used to confirm the activation of NLRP3 by monitoring the expression of IL-1ß protein and mRNA in choroidal tissues from LCNV mice. In addition, NLRP3 (-/-) LCNV mice were used to investigate whether NLRP3 inflammasomes contribute to the development of LCNV lesions. We observed that red fluorescent protein (RFP)-positive monocyte-derived macrophages and GFP-positive microglia-derived macrophages, in addition to other cell types, were localized in LCNV lesions at day 7 post-laser injury. In addition, NLRP3 inflammasomes are associated with LCNV lesions. Inhibition of NLRP3 inflammasomes, using MCC950, caused an increased Ccr2RFP-positive macrophages, Cx3cr1GFP-positive microglia, and other cells, resulting in an increase in total lesion size. NLRP3 (-/-) LCNV mice showed significantly increased lesion size compared with age-matched controls. Inhibition of NLRP3 resulted in decreased IL-1ß mRNA and protein expression in the choroidal tissues, suggesting that increased lesion size may not be directly related to IL-1ß.


Subject(s)
Choroidal Neovascularization , Indenes , Inflammasomes , Interleukin-1beta , Microglia , Monocytes , NLR Family, Pyrin Domain-Containing 3 Protein , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Choroidal Neovascularization/metabolism , Choroidal Neovascularization/pathology , Mice , Inflammasomes/metabolism , Interleukin-1beta/metabolism , Microglia/metabolism , Monocytes/metabolism , Mice, Knockout , Sulfones/pharmacology , Mice, Inbred C57BL , Furans/pharmacology , Receptors, CCR2/metabolism , Receptors, CCR2/genetics , Macrophages/metabolism , Macrophages/immunology , Sulfonamides/pharmacology , Heterocyclic Compounds, 4 or More Rings/pharmacology , Carrier Proteins/metabolism , Carrier Proteins/genetics , Choroid/metabolism , Choroid/pathology , Disease Models, Animal , Lasers/adverse effects , Macular Degeneration/pathology , Macular Degeneration/metabolism , Macular Degeneration/genetics
4.
Sci Rep ; 14(1): 10040, 2024 05 02.
Article in English | MEDLINE | ID: mdl-38693189

ABSTRACT

Investigation of visual illusions helps us understand how we process visual information. For example, face pareidolia, the misperception of illusory faces in objects, could be used to understand how we process real faces. However, it remains unclear whether this illusion emerges from errors in face detection or from slower, cognitive processes. Here, our logic is straightforward; if examples of face pareidolia activate the mechanisms that rapidly detect faces in visual environments, then participants will look at objects more quickly when the objects also contain illusory faces. To test this hypothesis, we sampled continuous eye movements during a fast saccadic choice task-participants were required to select either faces or food items. During this task, pairs of stimuli were positioned close to the initial fixation point or further away, in the periphery. As expected, the participants were faster to look at face targets than food targets. Importantly, we also discovered an advantage for food items with illusory faces but, this advantage was limited to the peripheral condition. These findings are among the first to demonstrate that the face pareidolia illusion persists in the periphery and, thus, it is likely to be a consequence of erroneous face detection.


Subject(s)
Illusions , Humans , Female , Male , Adult , Illusions/physiology , Young Adult , Visual Perception/physiology , Photic Stimulation , Face/physiology , Facial Recognition/physiology , Eye Movements/physiology , Pattern Recognition, Visual/physiology
6.
Microbiol Spectr ; 12(4): e0416423, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38441465

ABSTRACT

We conducted a comparative evaluation of the FDA-cleared Simplexa GBS Direct and ARIES GBS molecular assays for the detection of Streptococcus agalactiae (Group B Streptococcus, GBS) in 386 prospectively collected, broth-enriched vaginal/rectal swab specimens. The sensitivity of each test was 96.2% and specificity was ≥98.7% when compared to a combined direct and enriched culture method using chromogenic culture medium. A total of four specimens were called positive by both molecular assays but negative by culture, likely representing specimens with a low burden of GBS in these specimens. Two specimens were reported positive by culture but negative by both molecular assays. One of these specimens demonstrated atypically colored colonies on chromogenic agar; the other yielded typically colored colonies only observed after broth enrichment. Our data demonstrate equivalent performance of Simplexa and ARIES molecular assays for the detection of GBS in clinical specimens.IMPORTANCEClinical laboratories often face decisions regarding which of the multiple available molecular platforms would best fit their needs based on cost, workflow, menu, and diagnostic performance. Therefore, objective clinical comparisons of similar molecular tests are valuable resources to aid these decisions. We provide a clinical comparison of two FDA-cleared tests to routine culture and to each other that can be used by clinical laboratories when determining which of the available molecular platforms would best fit their laboratory in terms of workflow, cost, and performance.


Subject(s)
Pregnancy Complications, Infectious , Streptococcal Infections , Pregnancy , Female , Humans , Pregnancy Complications, Infectious/diagnosis , Vagina , Sensitivity and Specificity , Streptococcal Infections/diagnosis , Rectum , Streptococcus agalactiae/genetics
7.
Microbiol Resour Announc ; 13(3): e0075623, 2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38376194

ABSTRACT

The Ascomycota yeast Aureobasidium melanogenum strain W12 was isolated from an aircraft polymer-coated surface. The genome size is 53,160,883 bp with a G + C content of 50.13%. The genome contains fatty acid transporters, cutinases, hydroxylases, and lipases potentially used for survival on polymer coatings on aircraft.

8.
Proc Biol Sci ; 291(2016): 20232908, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-38351803

ABSTRACT

Neural responses to sensory inputs can scale with the likelihood of encountering the input. This is consistent with the predictive coding framework, in that the human brain is expected to be less responsive to predicted inputs. Typically, however, prediction is not explicitly measured. It is inferred from the probability of encountering an event. When an input is explicitly predicted, responses to predicted inputs can be enhanced. Here, we ask if this effect can be ascribed to a generic priming effect, from pre-cogitating about one of two possible inputs. Consistent with this, we find that P300s (a relatively late event-related potential measured with electroencephalography) are greater for explicitly predicted audio and visual inputs, and that this effect cannot be distinguished from a priming effect from pre-imagining audio or visual presentations. Evidence indicates that participants engaged in pre-imagining presentations, as we were able to decode online what type of presentation (audio or visual) they were imagining with a high success rate (approx. 73%), and we encouraged compliance with neuro-feedback regarding this success rate. Our data confirm that human cortex can be more responsive to inputs that have been subject to pre-cogitation-including explicit predictions. This highlights that while anticipatory processes can reduce responding to likely inputs, they can also enhance responding to explicitly predicted inputs.


Subject(s)
Brain , Electroencephalography , Humans , Feedback , Brain/physiology , Brain Mapping , Probability
9.
Sci Rep ; 14(1): 836, 2024 01 08.
Article in English | MEDLINE | ID: mdl-38191506

ABSTRACT

Most people can conjure images and sounds that they experience in their minds. There are, however, marked individual differences. Some people report that they cannot generate imagined sensory experiences at all (aphantasics) and others report that they have unusually intense imagined experiences (hyper-phantasics). These individual differences have been linked to activity in sensory brain regions, driven by feedback. We would therefore expect imagined experiences to be associated with specific frequencies of oscillatory brain activity, as these can be a hallmark of neural interactions within and across regions of the brain. Replicating a number of other studies, relative to a Resting-State we find that the act of engaging in auditory or in visual imagery is linked to reductions in the power of oscillatory brain activity across a broad range of frequencies, with prominent peaks in the alpha band (8-12 Hz). This oscillatory activity, however, did not predict individual differences in the subjective intensity of imagined experiences. For audio imagery, these were rather predicted by reductions within the theta (6-9 Hz) and gamma (33-38 Hz) bands, and by increases in beta (15-17 Hz) band activity. For visual imagery these were predicted by reductions in lower (14-16 Hz) and upper (29-32 Hz) beta band activity, and by an increase in mid-beta band (24-26 Hz) activity. Our data suggest that there is sufficient ground truth in the subjective reports people use to describe the intensity of their imagined sensory experiences to allow these to be linked to the power of distinct rhythms of brain activity. In future, we hope to combine this approach with better measures of the subjective intensity of imagined sensory experiences to provide a clearer picture of individual differences in the subjective intensity of imagined experiences, and of why these eventuate.


Subject(s)
Brain , Gastropoda , Humans , Animals , Gamma Rays , Imagery, Psychotherapy , Individuality
10.
J Cogn Neurosci ; 36(1): 187-199, 2024 01 01.
Article in English | MEDLINE | ID: mdl-37902587

ABSTRACT

The oddball protocol has been used to study the neural and perceptual consequences of implicit predictions in the human brain. The protocol involves presenting a sequence of identical repeated events that are eventually broken by a novel "oddball" presentation. Oddball presentations have been linked to increased neural responding and to an exaggeration of perceived duration relative to repeated events. Because the number of repeated events in such protocols is circumscribed, as more repeats are encountered, the conditional probability of a further repeat decreases-whereas the conditional probability of an oddball increases. These facts have not been appreciated in many analyses of oddballs; repeats and oddballs have rather been treated as binary event categories. Here, we show that the human brain is sensitive to conditional event probabilities in an active, visual oddball paradigm. P300 responses (a relatively late component of visually evoked potentials measured with EEG) tended to be greater for less likely oddballs and repeats. By contrast, P1 responses (an earlier component) increased for repeats as a goal-relevant target presentation neared, but this effect occurred even when repeat probabilities were held constant, and oddball P1 responses were invariant. We also found that later, more likely oddballs seemed to last longer, and this effect was largely independent of the number of preceding repeats. These findings speak against a repetition suppression account of the temporal oddball effect. Overall, our data highlight an impact of event probability on later, rather than earlier, electroencephalographic measures previously related to predictive processes-and the importance of considering conditional probabilities in sequential presentation paradigms.


Subject(s)
Electroencephalography , Evoked Potentials , Humans , Acoustic Stimulation/methods , Electroencephalography/methods , Evoked Potentials/physiology , Probability , Brain/physiology
11.
ACS Appl Nano Mater ; 6(24): 22939-22946, 2023 Dec 22.
Article in English | MEDLINE | ID: mdl-38148985

ABSTRACT

Circulating monocytes migrate into the retina in response to inflammation and neovascularization. Furthermore, under inflammatory conditions such as diabetes, healthy monocytes become activated in the circulation. However, the contribution of activated monocytes to neovascularization is largely unknown. HIF-1α has been shown to contribute to the pathogenesis of neovascularization. We describe here the synthesis of a hybrid nanomaterial for targeted delivery and gene silencing in activated monocytes that are associated with pathological neovascularization. To test the gene silencing ability of AS-shRNA-lipids in vitro, we used the probe to inhibit HIF-1α mRNA induced in mouse monocytes by exposing them to hypoxia. In addition, we tested AS-shRNA-lipids for inhibition of neovascularization in vivo using the mouse model of oxygen-induced retinopathy (OIR). Significant reduction of neovascularization was achieved in mouse OIR by targeting activated monocytes using intraperitoneal injections of AS-shRNA-lipids. Expression of HIF-1α and CD14 mRNA were both inhibited in circulating cells, suggesting normalization of the activated monocytes in P17 OIR animals treated with AS-shRNA-lipids. We hypothesized that inhibition of HIF-1α mRNA in activated monocytes may have a direct impact on VEGF expression in the retinal tissues in vivo. We observed that VEGF mRNA expression was inhibited in P17 retinal tissues after systemic treatment with HIF-1α-targeted AS-shRNA-lipids. These findings may provide a framework for a strategy to inhibit retinal neovascularization by targeting circulating activated monocytes.

12.
N Z Med J ; 136(1586): 63-72, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38033241

ABSTRACT

AIMS: To evaluate the impact of a multifaceted intervention aimed at improving adherence to a list of preferred laxatives in two hospitals in New Zealand. METHODS: A constipation programme was developed at Capital & Coast District Health Board to improve adherence to safe and effective (preferred) laxatives over potentially dangerous and less effective (non-preferred) agents. The intervention included a new constipation guideline, a poster of preferred laxatives, a patient information leaflet, hospital formulary adjustments and staff education. The evaluation compared the number of dispensations of each laxative during two periods: a 12-month period prior to programme implementation and a 12-month period following programme implementation. Data were retrospectively gathered from multiple sources on all laxatives dispensed on 14 adult wards across two New Zealand hospitals. RESULTS: Prior to the programme, there were 111,771 laxatives dispensed, the majority of which (62%) were non-preferred agents. Following the programme, there were 91,005 laxatives dispensed, the majority of which (82%) were from the preferred list, indicating a large shift in prescribing habits. CONCLUSIONS: Inpatient laxative prescribing habits require attention and are amenable to quality improvement initiatives. This may reduce waste, prevent harm and improve patient outcomes.


Subject(s)
Constipation , Laxatives , Adult , Humans , Laxatives/therapeutic use , Retrospective Studies , New Zealand , Constipation/drug therapy , Hospitals
13.
J Appl Biomech ; 39(6): 432-439, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37739402

ABSTRACT

Chronic exposure to high tibiofemoral joint (TFJ) contact forces can be detrimental to knee joint health. Load carriage increases TFJ contact forces, but it is unclear whether medial and lateral tibiofemoral compartments respond similarly to incremental load carriage. The purpose of our study was to compare TFJ contact forces when walking with 15% and 30% added body weight. Young healthy adults (n = 24) walked for 5 minutes with no load, 15% load, and 30% load on an instrumented treadmill. Total, medial, and lateral TFJ contact peak forces and impulses were calculated via an inverse dynamics informed musculoskeletal model. Results of 1-way repeated measures analyses of variance (α = .05) demonstrated total, medial, and lateral TFJ first peak contact forces and impulses increased significantly with increasing load. Orthogonal polynomial trends demonstrated that the 30% loading condition led to a curvilinear increase in total and lateral TFJ impulses, whereas medial first peak TFJ contact forces and impulses responded linearly to increasing load. The total and lateral compartment impulse increased disproportionally with load carriage, while the medial did not. The medial and lateral compartments responded differently to increasing load during walking, warranting further investigation because it may relate to risk of osteoarthritis.


Subject(s)
Knee Joint , Walking , Adult , Humans , Biomechanical Phenomena , Body Weight , Gait
14.
Res Sq ; 2023 Sep 09.
Article in English | MEDLINE | ID: mdl-37720026

ABSTRACT

Though the pathogenesis of choroidal neovascularization (CNV) is largely unknown in age-related macular degeneration (AMD), inflammasomes may contribute to CNV development and progression. To understand the role NLRP3 inflammasomes in CNV, we used Ccr2RFPCx3cr1GFP dual-reporter mice to characterize migration of Ccr2RFP positive monocytes and Cx3cr1GFP positive microglial cells into CNV lesions after laser-induced rupture of Bruch's membrane. MCC950 was used as NLRP3 inhibitor. Immunostaining was used to confirm localization of NLRP3 inflammasomes in the LCNV lesions. Confocal microscopy was used to image and quantify LCNV volumes. ELISA and qRT-PCR were used to confirm the activation of NLRP3 by monitoring the expression of IL-1ß protein and mRNA in choroidal tissues from LCNV mice. In addition, NLRP3 (-/-) LCNV mice were used to investigate whether NLRP3 inflammasomes contribute to the development of LCNV lesions. We observed that RFP positive monocyte-derived macrophages and GFP positive microglia-derived macrophages, in addition to other cell types, were localized in LCNV lesions at day 7 post-laser injury. In addition, NLRP3 inflammasomes are associated with LCNV lesions. Inhibition of NLRP3 inflammasomes, using MCC950, caused an increased Ccr2RFP positive macrophages, Cx3cr1GFP positive microglia, and other cells resulting in an increase in total lesion size. NLRP3 (-/-) LCNV mice, showed significantly increased lesion size compared to age-matched controls. Inhibition of NLRP3, resulted in decreased IL-1ß mRNA and protein expression in the choroidal tissues, suggesting that increased lesion size may not be directly related to IL-1ß.

15.
Environ Microbiome ; 18(1): 66, 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37533117

ABSTRACT

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among DoD organizations and to facilitate resource, material and information sharing amongst consortium members, which includes collaborators in academia and industry. The 6th Annual TSMC Symposium was a hybrid meeting held in Fairlee, Vermont on 27-28 September 2022 with presentations and discussions centered on microbiome-related topics within seven broad thematic areas: (1) Human Microbiomes: Stress Response; (2) Microbiome Analysis & Surveillance; (3) Human Microbiomes Enablers & Engineering; (4) Human Microbiomes: Countermeasures; (5) Human Microbiomes Discovery - Earth & Space; (6) Environmental Micro & Myco-biome; and (7) Environmental Microbiome Analysis & Engineering. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted innovative research being done in academia and industry that can be leveraged by the DoD, and fostered collaborative opportunities. This report summarizes the activities and outcomes from the 6th annual TSMC symposium.

16.
MSMR ; 30(5): 9-14, 2023 May 20.
Article in English | MEDLINE | ID: mdl-37535262

ABSTRACT

In this study, wastewater samples collected from a participating sentinel site were initially screened for the presence or absence of SARS-CoV-2 RNA using portable RT-PCR, with positive samples sequenced using a handheld MinION nanopore sequencing device. Genomic biosurveillance of SARS-CoV-2 and its variants within wastewater has been established as an early warning system of infectious disease spread in a given catchment area, due to good correlation between spikes in viral levels detected in wastewater coincident with increases in COVID-19 incidence rates. Moreover, viral titers detected in a single wastewater sample are reflective of pre-symptomatic, asymptomatic, and post-symptomatic cases, making wastewater-based epidemiology (WBE) a cost-effective, non-invasive public health surveillance method complementary to clinical diagnostic testing. The results of this study demonstrate the utility of population-scale SARS-CoV-2 epidemiology for insights into the viral evolution and transmission dynamics associated with specific SARS-CoV-2 variants that are necessary for effective strategies of containment and timely deployment of appropriate countermeasures.


Subject(s)
Biosurveillance , COVID-19 , Military Personnel , Nanopore Sequencing , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Wastewater , COVID-19 Testing
17.
Atten Percept Psychophys ; 85(6): 1755-1760, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37415058

ABSTRACT

The oddball paradigm is commonly used to investigate human time perception. Trains of identical repeated events ('standards') are presented, only to be interrupted by a different 'oddball' that seems to have a relatively protracted duration. One theoretical account has been that this effect is driven by repetition suppression for repeated standards. The idea is that repeated events seem shorter as they incur a progressively reduced neural response, which is supported by the finding that oddball perceived duration increases linearly with the number of preceding repeated standards. However, typical oddball paradigms confound the probability of oddball presentations with variable numbers of standard repetitions on each trial, allowing people to increasingly anticipate an oddball presentation as more standards are presented. We eliminated this by making participants aware of what fixed number of standards they would encounter before a final test input and tested different numbers of standards in separate experimental sessions. The final event of sequences, the test event, was equally likely to be an oddball or another repeat. We found a positive linear relationship between the number of preceding repeated standards and the perceived duration of oddball test events. However, we also found this for repeat tests events, which speaks against the repetition suppression account of the temporal oddball effect.


Subject(s)
Awareness , Humans , Probability
18.
J Pediatr Psychol ; 48(9): 759-767, 2023 09 20.
Article in English | MEDLINE | ID: mdl-37500595

ABSTRACT

OBJECTIVE: Differences/disorders of sex development (DSDs) are rare, congenital conditions involving discordance between chromosomes, gonads, and phenotypic sex and are often diagnosed in infancy. A key subset of parents of children newly diagnosed with a DSD experience clinically elevated distress. The present study examines the relationship between perinatal factors (i.e., gestational age, delivery method) and trajectories of parental adjustment. METHODS: Parent participants (mothers = 37; fathers = 27) completed measures at baseline, 6- and 12-month follow-up. Multilevel linear regression controlled for clustering of the data at three levels (i.e., time point, parent, and family) and examined the relationship between perinatal factors and trajectories of depressive and anxious symptoms. Two-way interactions between perinatal factors and parent type were evaluated. RESULTS: Overall depressive and anxious symptoms decreased over time. There were significant interactions between gestational age and parent type for depressive and anxious symptoms, with younger gestational age having a stronger negative effect on mothers vs. fathers. There was a significant interaction between time and gestational age for depressive symptoms, with 36 weeks' gestational age demonstrating a higher overall trajectory of depressive symptoms across time compared to 38 and 40 weeks. Findings for the delivery method were not significant. CONCLUSIONS: Findings uniquely demonstrated younger gestational age was associated with increased depressive symptoms, particularly for mothers compared to fathers. Thus, a more premature birth may predispose parents of infants with DSD to distress. Psychosocial providers should contextualize early diagnosis-related discussions within stressful birth experiences when providing support.


Subject(s)
Mothers , Parents , Female , Infant , Child , Pregnancy , Humans , Male , Parents/psychology , Mothers/psychology , Gestational Age , Sexual Development , Genitalia , Fathers/psychology , Depression/psychology
19.
J Breath Res ; 17(3)2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37352843

ABSTRACT

Exhaled breath research has been hindered by a lack of standardization in collection and analysis methodologies. Recently, the Respiration Collector forIn VitroAnalysis (ReCIVA) sampling device has illustrated the potential to provide a consistent and convenient method for exhaled breath collection onto adsorbent media. However, the significant costs, compared to exhaled breath bags, associated with the standardized collector is believed to be the reason for limited widespread use by researchers in the exhaled breath field. For example, in addition to the sampling hardware, a single-use disposable silicon mask affixed with a filter is required for each exhaled breath collection. To reduce the financial burden, streamline device upkeep, reduce waste material, and ease the logistical burden associated with the single use masks, it is hypothesized that the consumable masks and filters could be sterilized by autoclaving for reuse. The masks were contaminated, autoclaved, and then tested for any surviving pathogens with spore strip standards and by measuring the optical density of cultures. The compound background collected when using the ReCIVA with new masks was compared to that collected with repeatedly autoclaved masks via thermal desorption gas chromatography mass spectrometry (TD-GC-MS). The capacity to block particulate matter of new filters was tested against that of autoclaved filters by introducing an aerosol and comparing pre-filter and post-filter particle counts. Finally, breath samplings were conducted with new masks and autoclaved masks to test for changes in measurements by TD-GC-MS of exogenous and endogenous compounds. The data illustrate the autoclave cycle sterilizes masks spiked with saliva to background levels (p= 0.2527). The results indicate that background levels of siloxane compounds are increased as masks are repetitively autoclaved. The data show that mask filters have significant breakthrough of 1µm particles after five repetitive autoclaving cycles compared to new filters (p= 0.0219). Finally, exhaled breath results utilizing a peppermint ingestion protocol indicate two compounds associated with peppermint, menthone and 1-Methyl-4-(1-methylethyl)-cyclohexanol, and an endogenous exhaled breath compound, isoprene, show no significant difference if sampled with a new mask or a mask autoclaved five times (p> 0.1063). Collectively, the data indicate that ReCIVA masks and filters can be sterilized via autoclave and reused. The results suggest ReCIVA mask and filter reuse should be limited to three times to limit potentially problematic background contaminants and filter dysfunction.


Subject(s)
Breath Tests , Sterilization , Humans , Breath Tests/methods , Gas Chromatography-Mass Spectrometry , Exhalation , Reference Standards
20.
Front Microbiol ; 14: 1172798, 2023.
Article in English | MEDLINE | ID: mdl-37206339

ABSTRACT

Steep Cone Geyser is a unique geothermal feature in Yellowstone National Park (YNP), Wyoming, actively gushing silicon-rich fluids along outflow channels possessing living and actively silicifying microbial biomats. To assess the geomicrobial dynamics occurring temporally and spatially at Steep Cone, samples were collected at discrete locations along one of Steep Cone's outflow channels for both microbial community composition and aqueous geochemistry analysis during field campaigns in 2010, 2018, 2019, and 2020. Geochemical analysis characterized Steep Cone as an oligotrophic, surface boiling, silicious, alkaline-chloride thermal feature with consistent dissolved inorganic carbon and total sulfur concentrations down the outflow channel ranging from 4.59 ± 0.11 to 4.26 ± 0.07 mM and 189.7 ± 7.2 to 204.7 ± 3.55 µM, respectively. Furthermore, geochemistry remained relatively stable temporally with consistently detectable analytes displaying a relative standard deviation <32%. A thermal gradient decrease of ~55°C was observed from the sampled hydrothermal source to the end of the sampled outflow transect (90.34°C ± 3.38 to 35.06°C ± 7.24). The thermal gradient led to temperature-driven divergence and stratification of the microbial community along the outflow channel. The hyperthermophile Thermocrinis dominates the hydrothermal source biofilm community, and the thermophiles Meiothermus and Leptococcus dominate along the outflow before finally giving way to more diverse and even microbial communities at the end of the transect. Beyond the hydrothermal source, phototrophic taxa such as Leptococcus, Chloroflexus, and Chloracidobacterium act as primary producers for the system, supporting heterotrophic growth of taxa such as Raineya, Tepidimonas, and Meiothermus. Community dynamics illustrate large changes yearly driven by abundance shifts of the dominant taxa in the system. Results indicate Steep Cone possesses dynamic outflow microbial communities despite stable geochemistry. These findings improve our understanding of thermal geomicrobiological dynamics and inform how we can interpret the silicified rock record.

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