Investigating the association between nitrate dosing and nitrite generation by the human oral microbiota in continuous culture.

The generation of nitrite by the oral microbiota is believed to contribute to healthy cardiovascular function, with oral nitrate reduction to nitrite associated with systemic blood pressure regulation. There is the potential to manipulate the composition or activities of the oral microbiota to a higher nitrate-reducing state through nitrate supplementation. The current study examined microbial community composition and enzymatic responses to nitrate supplementation in sessile oral microbiota grown in continuous culture. Nitrate reductase (NaR) activity and nitrite concentrations were not significantly different to tongue-derived inocula in model biofilms. These were generally dominated by Streptococcus spp., initially, and a single nitrate supplementation resulted in the increased relative abundance of the nitrate-reducing genera Veillonella, Neisseria, and Proteus spp. Nitrite concentrations increased concomitantly and continued to increase throughout oral microbiota development. Continuous nitrate supplementation, over a 7-day period, was similarly associated with an elevated abundance of nitrate-reducing taxa and increased nitrite concentration in the perfusate. In experiments in which the models were established in continuous low or high nitrate environments, there was an initial elevation in nitrate reductase, and nitrite concentrations reached a relatively constant concentration over time similar to the acute nitrate challenge with a similar expansion of Veillonella and Neisseria. In summary, we have investigated nitrate metabolism in continuous culture oral biofilms, showing that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of putatively NaR-producing taxa.IMPORTANCEClinical evidence suggests that blood pressure regulation can be promoted by nitrite generated through the reduction of supplemental dietary nitrate by the oral microbiota. We have utilized oral microbiota models to investigate the mechanisms responsible, demonstrating that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of nitrate-reducing taxa.

Molecular characterisation of a novel sadwavirus infecting cattleya orchids in Australia.

The complete genome sequence of a novel sadwavirus infecting cattleya orchids in South East Queensland is described. Isometric virions of c. 27 nm diameter were observed in sap extracts viewed under a transmission electron microscope, and the genome sequence of this virus was determined by high-throughput sequencing. The viral genome consists of two RNA components, 5,910 and 4,435 nucleotides (nt) in length, each encoding a long polyprotein, with predicted cleavage sites at H/Y, E/G, Q/S, and Q/G for the RNA1 and T/G for the RNA2 translation products, respectively. RNA2 has an additional small ORF of 684 nt near the 3' untranslated region. Phylogenetic analysis based on an amino acid sequence alignment of the Pro-Pol region suggested that this virus is most closely related to pineapple secovirus A, a member of the subgenus Cholivirus, but warrants classification as a member of a new species because it exhibited no more than 64% amino acid identity in pairwise sequence comparisons. Because of the prominent purple ringspots that were observed on the leaves of some of the plants, we propose the name "cattleya purple ringspot virus" for this virus (suggested species name: "Sadwavirus cattleyacola").

"We have to change our mindsets": a qualitative study of barriers and facilitators in research collaboration across integrated care system organisations.

The introduction of Integrated Care Systems (ICS) in England aimed to increase joint planning and delivery of health and social care, and other services, to better meet the needs of local communities. There is an associated duty to undertake collaborative research across ICS partners to inform this new integrated approach, which might be challenging given that organisations span health, local authority, voluntary and community sector, and research. This study aimed to explore the appetite for collaborative Research and Innovation (R&I) across ICSs, potential barriers and solutions. This qualitative study involved semi-structured interviews with 24 stakeholders who held senior positions within organisations across two ICS areas (Staffordshire and Stoke-on-Trent; Shropshire, Telford and Wrekin). Interview transcripts were analysed using inductive and deductive analysis, first mapping to the Theoretical Domains Framework (TDF), then considering key influences on organisational behaviour in terms of Capability, Opportunity and Motivation from the COM-B Behaviour Change Wheel. There were fundamental limitations on organisational opportunities for collaborative R&I: a historical culture of competition (rather than collaboration), a lack of research culture and prioritisation, compounded by a challenging adverse economic environment. However, organisations were motivated to undertake collaborative R&I. They recognised the potential benefits (e.g., skill-sharing, staff development, attracting large studies and funding), the need for collaborative research that mirrors integrated care, and subsequent benefits for care recipients. Related barriers included negative experiences of collaboration, fear of failing and low confidence. Capability varied across organisations in terms of research skills and confidence, which reflected the range of partners (from local authorities to NHS Trusts, primary care, and academic institutions). These findings indicate a need to shift from a culture of competition to collaboration, and to help organisations across ICS to prioritise research, and share resources and skills to mitigate the limiting effects of a constrained economic environment. This could be further explored using a systems change approach, to develop the collaborative research efforts alongside the overarching move towards integrated care.

Transcription Factors with Broad Expression in the Zebrafish Spinal Cord.

Background: The spinal cord is a crucial part of the vertebrate central nervous system, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 22 transcription factor genes in the zebrafish spinal cord. Results: We analyzed the spinal cord expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in the spinal cord, they have distinct expression patterns from one another. Some are predominanatly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors that regulate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. Conclusions: Our data identify 22 different transcription factors that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.

Genomic variation in pepper vein yellows viruses in Australia, including a new putative variant, PeVYV-10.

Since the first identification and full sequence of the polerovirus pepper vein yellows virus in Australia in 2016, virus surveys of crops and weeds have sporadically identified PeVYV in different hosts and locations. Genomic comparisons of 14 PeVYV-like isolates using RT-PCR products spanning the 3' end of the RdRp region (ORF 2), the intergenic region, ORF 3a, ORF 4, and ORF 3 (1388 nt) showed that four of the PeVYV isolates might be a new variant or PeVYV-like virus. From six PeVYV-positive plants, eight PeVYV-like sequences were obtained by high-throughput sequencing, as two hosts, 5352 and 5634, contained two slightly different PeVYV-like isolates. Three of the PeVYV-like isolates were most closely related to PeVYV-6 and PeVYV-5, and two isolates were closely related to PeVYV-9 and PeVYV-2. The other three isolates shared only 69-74% nucleotide sequence identity across the whole genome with any of the other PeVYVs, despite sharing 73-98%, 87-91%, and 84-87% amino acid sequence identity in ORF 3a, ORF 3, and the RdRp (ORF 2), respectively, suggesting that this virus is a new PeVYV-like virus, which we have tentatively called PeVYV-10. This is also the first report of a PeVYV-like virus infecting garlic.

One and done: Feasibility and Safety of Primary Ureteroscopy in a Pediatric Population.

BACKGROUND: Pediatric urolithiasis has been increasing at rate of 4-10 % annually in the United States, most notably within adolescents and females. A significant number of patients will require surgical management of their stones. Primary ureteroscopy (URS) affords the opportunity to treat stones under a single anesthetic with lower re-treatment rates or anatomical and stone characteristic limitations compared to shockwave lithotripsy. Previous studies evaluating primary URS have been largely underpowered, are limited by stone location, and/or are not representative of the stone population in the United States. OBJECTIVES: Primary study outcomes were the success of primary URS and patient characteristics associated with success. Secondary outcomes were the stone-free rate (SFR), 30-day emergency department (ED) visits, 30-day readmissions, and complications. METHODS: We performed a retrospective cohort study of patients less than 18 years of age from 2011 to 2023 who underwent primary URS. Patients were excluded if a ureteral stent was placed prior to URS or diagnostic URS was performed. A successful primary URS was considered if access to the ureter was obtained and treatment of the stone(s) completed. In failed primary URS, a ureteral stent was placed for staged management. RESULTS: A total of 196 patients were included and primary URS was performed or attempted on 224 renal units. The median age was 15.8 (IQR 13.4-16.9) years and median follow up 8.4 (IQR 1.1-24.6) months. The success rate of primary URS was 79 %. No significant characteristics were appreciated for successful primary URS based on: overall age, <14 vs > 14 years of age, sex, body mass index, history of stones, history of endourologic procedures, preoperative alpha blockade, location of stone(s), multiple stones, type of URS, or acute treatment. In successful primary URS, the SFR was 88 % with stone size (p = 0.0001) the only predictor of having residual stones. The 30-day ED rate was 21.4 %, 30-day unplanned readmission rate was 12.5 %, and complication rate was 7.5 %. No long-term complications were appreciated. DISCUSSION: Our success of primary URS compares favorably to previously published literature. Our SFR rate, 30-day ED visits, 30-day unplanned readmission, and complication rates are similar to other studies. Limitations of the study are its retrospective design, selection bias, and intermediate follow-up. CONCLUSIONS: Primary URS can be completed safely in the majority of pediatric patients without any patient characteristics associated with success. We advocate for primary URS when possible due to the excellent SFR and potential of treating stones under a single anesthetic.

Morphogenesis in Trypanosoma cruzi epimastigotes proceeds via a highly asymmetric cell division.

Trypanosoma cruzi is a protist parasite that is the causative agent of Chagas disease, a neglected tropical disease endemic to the Americas. T. cruzi cells are highly polarized and undergo morphological changes as they cycle within their insect and mammalian hosts. Work on related trypanosomatids has described cell division mechanisms in several life-cycle stages and identified a set of essential morphogenic proteins that serve as markers for key events during trypanosomatid division. Here, we use Cas9-based tagging of morphogenic genes, live-cell imaging, and expansion microscopy to study the cell division mechanism of the insect-resident epimastigote form of T. cruzi, which represents an understudied trypanosomatid morphotype. We find that T. cruzi epimastigote cell division is highly asymmetric, producing one daughter cell that is significantly smaller than the other. Daughter cell division rates differ by 4.9 h, which may be a consequence of this size disparity. Many of the morphogenic proteins identified in T. brucei have altered localization patterns in T. cruzi epimastigotes, which may reflect fundamental differences in the cell division mechanism of this life cycle stage, which widens and shortens the cell body to accommodate the duplicated organelles and cleavage furrow rather than elongating the cell body along the long axis of the cell, as is the case in life-cycle stages that have been studied in T. brucei. This work provides a foundation for further investigations of T. cruzi cell division and shows that subtle differences in trypanosomatid cell morphology can alter how these parasites divide.

Rapid Weight Loss Practices Within Olympic Weightlifters.

ABSTRACT: Gee, TI, Campbell, P, Bargh, MJ, and Martin, D. Rapid weight loss practices within Olympic weightlifters. J Strength Cond Res 37(10): 2046-2051, 2023-Rapid weight loss (RWL) practices are common among athletes to "make weight" for a chosen bodyweight class. This study's purpose was to investigate RWL prevalence, magnitude, and methods within Olympic weightlifters from Great Britain. Subjects (n = 39, male = 22, female = 17) were recruited from International Weightlifting Federation lifting populations (mandatory two-hour competition weigh-in). Subjects were categorized into competitive groups based on Sinclair coefficient total (high, mid, low) and also gender (male, female). The validated Rapid Weight Loss Questionnaire was used to establish RWL magnitude and practices. Of respondents, 33 of 39 (84.6%) had purposely acutely reduced body mass to compete, a higher proportion present within females (94.1%) than males (77.3%). The cohort's mean habitual precompetition acute body mass loss was 3.8 ± 1.7% and the "rapid weight loss score" (RWLS) was 23.6 ± 9.5. Across competitive groups there were no significant differences in habitual or highest precompetition body mass loss, postcompetition body mass gain or RWLS (p > 0.05). However, females attributed a significantly greater "highest" relative precompetition body mass loss compared with males (7.4 vs 4.9%, p = 0.045). For RWL methods used, frequencies of "always" and "sometimes" were reported highest for "restricting fluid ingestion" (81.8%), "gradual dieting" (81.8%), and "water loading" (54.5%). The prevalence of RWL is high among competitive Olympic weightlifters, and especially within the sampled female athletes. Magnitude of RWL was similar across different standards of athlete; however, female lifters demonstrated a higher maximum precompetition RWL.

A comparison of rapid weight loss practices within international, national and regional powerlifters.

Background: Rapid weight loss (RWL) practices are common amongst strength-sport athletes to 'make weight' for a chosen weight class. Aim: This study compared the RWL practices of International Powerlifting Federation (IPF) powerlifters from Great Britain. Methods: Participants (n = 69, male = 36, female = 33) were recruited from IPF lifting populations (mandatory <2-hour competition weigh-in). Participants were categorised based on highest level of competition (regional, national and international) and also sex (male and female). The previously validated 'Rapid Weight Loss Questionnaire' established RWL practices, however also included an open-ended question regarding thoughts, feeling and mood during RWL. Results: Nearly all participants (97%) had purposely acutely reduced body mass to compete, with an average typical pre-competition loss of 4.2%. Regional competitors reported a higher 'typical' body mass loss compared to international competitors (5.5% vs 3.3%, p = 0.004). Females reported a greater 'highest' body mass loss than males (6.7% vs 5.3%, p = 0.028). Fluid restriction (86.5%), water loading (67.2%) and increased exercise (49.2%) were the RWL methods most commonly used 'always' or 'sometimes'. Content analysis revealed a predominance of negative perceptions during RWL with the emergence of codes; fatigue, sensations, anxiety, low mood and irritation, accounting for ∼70% of responses. Conclusion: Prevalence of RWL is high amongst competitive powerlifters, with many competitors attributing negative perceptions during the weight-cutting process. The magnitude of reported acute RWL within regional lifters was beyond where performance decrements are commonly seen (>5%), this should be cautioned against given the IPF's mandatory <2-hour competition weigh-in.

Behaviour and sun exposure in holidaymakers alters skin microbiota composition and diversity.

Introduction: The skin microbiota plays a crucial role in maintaining epidermal homeostasis. Ultraviolet radiation (UVR) and other environmental challenges can impact the skin microbiota through direct and indirect mechanisms. This study aimed to investigate the effects of sun exposure on the skin microbiota and its relationship with individual skin phototypes. Methods: Healthy volunteers (n = 21 [4M, 17 F], mean age 33.2 years) holidayed in a sunny destination for a minimum of 7 days with swabs taken pre-holiday and up to 84 days post-holiday. Participant group was categorised by individual typology angle (ITA) classification and the composition of the skin microbiota was examined using 16S rRNA gene sequencing. Results: In the entire cohort and at all time points, the major bacterial phyla were Actinobacteria, Proteobacteria and Firmicutes. There was a significant change in microbial beta diversity at day 28 post-holiday, compared to baseline, for all participants. However, when participants were segregated into three cohorts dependent on the degree of skin tanning response between baseline (pre-holiday) and immediately one-day post-holiday, there was a reduction in Proteobacteria in the sun-seeking participants 1 day after the holiday, which recovered over time. Discussion: These findings suggest that sun exposure can affect the diversity and composition of the skin microbiota, which may have downstream effects on skin health.

Morphogenesis in Trypanosoma cruzi epimastigotes proceeds via a highly asymmetric cell division.

Trypanosoma cruzi is a protist parasite that is the causative agent of Chagas' disease, a neglected tropical disease endemic to the Americas. T. cruzi cells are highly polarized and undergo morphological changes as they cycle within their insect and mammalian hosts. Work on related trypanosomatids has described cell division mechanisms in several life-cycle stages and identified a set of essential morphogenic proteins that serve as markers for key events during trypanosomatid division. Here, we use Cas9-based tagging of morphogenic genes, live-cell imaging, and expansion microscopy to study the cell division mechanism of the insect-resident epimastigote form of T. cruzi, which represents an understudied trypanosomatid morphotype. We find that T. cruzi epimastigote cell division is highly asymmetric, producing one daughter cell that is significantly smaller than the other. Daughter cell division rates differ by 4.9 h, which may be a consequence of this size disparity. Many of the morphogenic proteins identified in T. brucei have altered localization patterns in T. cruzi epimastigoes, which may reflect fundamental differences in the cell division mechanism of this life cycle stage, which widens and shortens the cell body to accommodate the duplicated organelles and cleavage furrow rather than elongating the cell body along the long axis of the cell, as is the case in life-cycle stages that have been studied in T. brucei. This work provides a foundation for further investigations of T. cruzi cell division and shows that subtle differences in trypansomatid cell morphology can alter how these parasites divide.

Genome Characterisation of the CGMMV Virus Population in Australia-Informing Plant Biosecurity Policy.

The detection of cucumber green mottle mosaic (CGMMV) in the Northern Territory (NT), Australia, in 2014 led to the introduction of strict quarantine measures for the importation of cucurbit seeds by the Australian federal government. Further detections in Queensland, Western Australia (WA), New South Wales and South Australia occurred in the period 2015-2020. To explore the diversity of the current Australian CGMMV population, 35 new coding sequence complete genomes for CGMMV isolates from Australian incursions and surveys were prepared for this study. In conjunction with published genomes from the NT and WA, sequence, phylogenetic, and genetic variation and variant analyses were performed, and the data were compared with those for international CGMMV isolates. Based on these analyses, it can be inferred that the Australian CGMMV population resulted from a single virus source via multiple introductions.

Cytokinesis in Trypanosoma brucei relies on an orphan kinesin that dynamically crosslinks microtubules.

Many single-celled eukaryotes have complex cell morphologies defined by microtubules arranged into higher-order structures. The auger-like shape of the parasitic protist Trypanosoma brucei (T. brucei) is mediated by a parallel array of microtubules that underlies the plasma membrane. The subpellicular array must be partitioned and segregated using a microtubule-based mechanism during cell division. We previously identified an orphan kinesin, KLIF, that localizes to the ingressing cleavage furrow and is essential for the completion of cytokinesis. We have characterized the biophysical properties of a truncated KLIF construct in vitro to gain mechanistic insight into the function of this novel kinesin. We find that KLIF is a non-processive dimeric kinesin that dynamically crosslinks microtubules. Microtubules crosslinked by KLIF in an antiparallel orientation are translocated relative to one another, while microtubules crosslinked parallel to one another remain static, resulting in the formation of organized parallel bundles. In addition, we find that KLIF stabilizes the alignment of microtubule plus ends. These features provide a mechanistic understanding for how KLIF functions to form a new pole of aligned microtubule plus ends that defines the shape of the new cell posterior, which is an essential requirement for the completion of cytokinesis in T. brucei.

Distinct microbiome profiles in convergent wisdom tooth impactions.

AIMS: Long-term retention of impacted third molars (wisdom teeth) is associated with plaque stagnation and the development of caries on the adjacent surface of the neighboring second molar. While caries and tooth loss are common outcomes of impaction, there is currently insufficient evidence to support the pre-emptive removal of asymptomatic wisdom teeth. Emerging evidence suggests that convergently growing impactions are associated with caries. We have therefore investigated the composition of dental plaque on the distal surface of the mandibular second molar at various impaction angles. METHODS AND RESULTS: We have compared the microbiome of these surfaces at four impaction angulations using short-read sequencing of the bacterial 16S rRNA gene: two convergent (horizontal and mesial) and two divergent (distal and vertical) angulations, and in cases where the wisdom tooth is missing. Horizontal angulations exhibited lower microbial diversity than mesial impactions. Amplicon Sequence Variants (ASVs) associated with Veillonella were significantly more abundant at impactions with angulations toward the midline. Using machine learning, a random forest classifier trained to distinguish microbiome profiles was used to predict the native angulations for a subset of samples, with samples from the two convergent impactions estimated with the greatest accuracy. CONCLUSIONS: Differences in microbial diversity were apparent between caries-associated convergent (horizontal and mesial) impacted wisdom teeth, as well as greater abundances of Veillonella ASVs at horizontal impactions.

Adjuvant Intravesical Chemohyperthermia Versus Passive Chemotherapy in Patients with Intermediate-risk Non-muscle-invasive Bladder Cancer (HIVEC-II): A Phase 2, Open-label, Randomised Controlled Trial.

BACKGROUND: Adjuvant intravesical chemotherapy following tumour resection is recommended for intermediate-risk non-muscle-invasive bladder cancer (NMIBC). OBJECTIVE: To assess the efficacy and safety of adjuvant intravesical chemohyperthermia (CHT) for intermediate-risk NMIBC. DESIGN, SETTING, AND PARTICIPANTS: HIVEC-II is an open-label, phase 2 randomised controlled trial of CHT versus chemotherapy alone in patients with intermediate-risk NMIBC recruited at 15 centres between May 2014 and December 2017 (ISRCTN 23639415). Randomisation was stratified by treating hospital. INTERVENTIONS: Patients were randomly assigned (1:1) to adjuvant CHT with mitomycin C at 43°C or to room-temperature mitomycin C (control). Both treatment arms received six weekly instillations of 40 mg of mitomycin C lasting for 60 min. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was 24-mo disease-free survival as determined via cystoscopy and urinary cytology. Analysis was by intention to treat. RESULTS: A total of 259 patients (131 CHT vs 128 control) were randomised. At 24 mo, 42 patients (32%) in the CHT group and 49 (38%) in the control group had experienced recurrence. Disease-free survival at 24 mo was 61% (95% confidence interval [CI] 51-69%) in the CHT arm and 60% (95% CI 50-68%) in the control arm (hazard ratio [HR] 0.92, 95% CI 0.62-1.37; log-rank p = 0.8). Progression-free survival was higher in the control arm (HR 3.44, 95% CI 1.09-10.82; log-rank p = 0.02) on intention-to-treat analysis but was not significantly higher on per-protocol analysis (HR 2.87, 95% CI 0.83-9.98; log-rank p = 0.06). Overall survival was similar (HR 2.55, 95% CI 0.77-8.40; log-rank p = 0.09). Patients undergoing CHT were less likely to complete their treatment (n =75, 59% vs n = 111, 89%). Adverse events were reported by 164 patients (87 CHT vs 77 control). Major (grade III) adverse events were rare (13 CHT vs 7 control). CONCLUSIONS: CHT cannot be recommended over chemotherapy alone for intermediate-risk NMIBC. Adverse events following CHT were of low grade and short-lived, although patients were less likely to complete their treatment. PATIENT SUMMARY: The HIVEC-II trial investigated the role of heated chemotherapy instillations in the bladder for treatment of intermediate-risk non-muscle-invasive bladder cancer. We found no cancer control benefit from heated chemotherapy instillations over room-temperature chemotherapy. Adverse events following heated chemotherapy were low grade and short-lived, although these patients were less likely to complete their treatment.

Comparison of health-care utilization, costs and health-related quality of life across the subgroups defined by the Keele STarT MSK Tool.

OBJECTIVES: The aim of this study was to describe and compare health economic outcomes [health-care utilization and costs, work outcomes, and health-related quality of life (EQ-5D-5L)] in patients classified into different levels-of-risk subgroups by the Keele STarT MSK Tool. METHODS: Data on health-care utilization, costs and EQ-5D-5L were collected from a health-care perspective within a primary care prospective observational cohort study. Patients presenting with one (or more) of the five most common musculoskeletal pain presentations were included: back, neck, shoulder, knee or multi-site pain. Participants at low, medium and high risk of persistent disabling pain were compared in relation to mean health-care utilization and costs, health-related quality of life, and employment status. Regression analysis was used to estimate costs. RESULTS: Over 6 months, the mean (s.d.) total health-care (National Health Service and private) costs associated with the low, medium, and high-risk subgroups were £132.92 (167.88), £279.32 (462.98) and £476.07 (716.44), respectively. Mean health-related quality of life over the 6-month period was lower and more people changed their employment status in the high-risk subgroup compared with the medium- and low-risk subgroups. CONCLUSIONS: This study demonstrates that subgroups of people with different levels of risk for poor musculoskeletal pain outcomes also have different levels of health-care utilization, health-care costs, health-related quality of life, and work outcomes. The findings show that the STarT MSK Tool not only identifies those at risk of a poorer outcome, but also those who will have more health-care visits and incur higher costs.

Comparative genomics and genomic diversity of Pseudomonas syringae clade 2b-a in Australia.

BACKGROUND: A zucchini disease outbreak with unusual symptoms associated with Pseudomonas syringae clade 2b was identified in Bundaberg, Australia during autumn 2016. To investigate the genetic diversity of the 11 Australian isolates obtained from the outbreak, the genomes were compared to the publicly available P. syringae strains in phylogroup 2. RESULTS: Average nucleotide identity refined the P. syringae clade 2b-a into four clusters (Cluster A, B, C1 and C2), an expansion from the previously identified A, B and C. Australian isolates were in Cluster A, C1 and C2. Genomic analyses highlighted several key factors that may contribute to the virulence of these isolates. Six orthologous groups, including three virulence factors, were associated with P. syringae phylogroup 2 cucurbit-infecting strains. A region of genome plasticity analysis identified a type VI secretion system pathway in clade 2b-a strains which could also contribute to virulence. Pathogenicity assays on isolates KL004-k1, KFR003-1 and 77-4C, as representative isolates of Cluster A, C1 and C2, respectively, determined that all three isolates can infect pumpkin, squash, watermelon and zucchini var. Eva with different levels of disease severity. Subsequently, type III effectors were investigated and four type III effectors (avrRpt2, hopZ5, hopC1 and hopH1) were associated with host range. The hopZ effector family was also predicted to be associated with disease severity. CONCLUSIONS: This study refined the taxonomy of the P. syringae clade 2b-a, supported the association between effector profile and pathogenicity in cucurbits established in a previous study and provides new insight into important genomic features of these strains. This study also provided a detailed and comprehensive resource for future genomic and functional studies of these strains.

Targeted Whole Genome Sequencing (TWG-Seq) of Cucumber Green Mottle Mosaic Virus Using Tiled Amplicon Multiplex PCR and Nanopore Sequencing.

Rapid and reliable detection tools are essential for disease surveillance and outbreak management, and genomic data is essential to determining pathogen origin and monitoring of transmission pathways. Low virus copy number and poor RNA quality can present challenges for genomic sequencing of plant viruses, but this can be overcome by enrichment of target nucleic acid. A targeted whole genome sequencing (TWG-Seq) approach for the detection of cucumber green mottle mosaic virus (CGMMV) has been developed where overlapping amplicons generated using two multiplex RT-PCR assays are then sequenced using the Oxford Nanopore MinION. Near complete coding region sequences were assembled with ≥100× coverage for infected leaf tissue dilution samples with RT-qPCR cycle quantification (Cq) values from 11.8 to 38 and in seed dilution samples with Cq values 13.8 to 27. Consensus sequences assembled using this approach showed greater than 99% nucleotide similarity when compared to genomes produced using metagenomic sequencing. CGMMV could be confidently detected in historical seed isolates with degraded RNA. Whilst limited access to, and costs associated with second-generation sequencing platforms can influence diagnostic outputs, the portable Nanopore technology offers an affordable high throughput sequencing alternative when combined with TWG-Seq for low copy or degraded samples.

Magnetotransport in Graphene/Pb0.24Sn0.76Te Heterostructures: Finding a Way to Avoid Catastrophe.

While heterostructures are ubiquitous tools enabling new physics and device functionalities, the palette of available materials has never been richer. Combinations of two emerging material classes, two-dimensional materials and topological materials, are particularly promising because of the wide range of possible permutations that are easily accessible. Individually, both graphene and Pb1-xSnxTe (PST) are widely investigated for spintronic applications because graphene's high carrier mobility and PST's topologically protected surface states are attractive platforms for spin transport. Here, we combine monolayer graphene with PST and demonstrate a hybrid system with properties enhanced relative to the constituent parts. Using magnetotransport measurements, we find carrier mobilities up to 20 000 cm2/(V s) and a magnetoresistance approaching 100%, greater than either material prior to stacking. We also establish that there are two distinct transport channels and determine a lower bound on the spin relaxation time of 4.5 ps. The results can be explained using the polar catastrophe model, whereby a high mobility interface state results from a reconfiguration of charge due to a polar/nonpolar interface interaction. Our results suggest that proximity induced interface states with hybrid properties can be added to the still growing list of behaviors in these materials.

NetrinG1+ cancer-associated fibroblasts generate unique extracellular vesicles that support the survival of pancreatic cancer cells under nutritional stress.

It is projected that in 5 years, pancreatic cancer will become the second deadliest cancer in the United States. A unique aspect of pancreatic ductal adenocarcinoma (PDAC) is its stroma; rich in cancer-associated fibroblasts (CAFs) and a dense CAF-generated extracellular matrix (ECM). These pathogenic stroma CAF/ECM units cause the collapse of local blood vessels rendering the tumor microenvironment nutrient-poor. PDAC cells are able to survive this state of nutrient stress via support from CAF-secreted material, which includes small extracellular vesicles (sEVs). The tumor-supportive CAFs possess a distinct phenotypic profile, compared to normal-like fibroblasts, expressing NetrinG1 (NetG1) at the plasma membrane, and active Integrin α5ß1 localized to the multivesicular bodies; traits indicative of poor patient survival. We herein report that NetG1+ CAFs secrete sEVs that stimulate Akt-mediated survival in nutrient-deprived PDAC cells, protecting them from undergoing apoptosis. Further, we show that NetG1 expression in CAFs is required for the pro-survival properties of sEVs. Additionally, we report that the above-mentioned CAF markers are secreted in distinct subpopulations of EVs; with NetG1 being enriched in exomeres, and Integrin α5ß1 being enriched in exosomes. Finally, we found that NetG1 and Integrin α5ß1 were detected in sEVs collected from plasma of PDAC patients, while their levels were significantly lower in plasma-derived sEVs of sex/age-matched healthy donors. The discovery of these tumor-supporting CAF-EVs elucidates novel avenues in tumor-stroma interactions and pathogenic stroma detection.