Typical Host Research Articles

The Effect of Cytomegalovirus on Pediatric Acute Lymphoblastic Leukemia

Background: Recent evidence supports the role of cytomegalovirus (CMV) in the development of childhood ALL. The underlying mechanism and CMV's role in the leukemic cell phenotype is unknown, but CMV typically interacts with the host immune system allowing the virus to survive in a latent state; it may be that this immune dysregulation affects the risk of ALL. This study aims to explore the association of CMV and ALL at the time of leukemia diagnosis, using AML cases as a control and further, to determine whether CMV affects certain subgroups of ALL patients such as specific ethnicities, age groups, or cytogenetic subtypes.Methods: Pediatric diagnostic leukemia bone marrow samples obtained from the California Childhood Leukemia Study were screened for the presence of CMV DNA using a custom-designed droplet digital PCR assay. A total of 869 cases were analyzed including 125 AML cases and 744 ALL cases. Demographic and clinical features were compared between patients found to be CMV positive (cases with any detectable CMV positive droplets) and those who were CMV negative (cases with no detectable CMV positive droplets). The effect of the level of CMV viral DNA load was also assessed. For a subset of cases (n=61), Affymetrix Array gene expression data were available and differential gene expression performed to compare CMV positive cases with high viral load to CMV negative cases. Odds ratios and confidence intervals were estimated using logistic regression.Results: ALL cases were more likely to be CMV positive compared to AML (OR: 2.50; CI 1.00, 5.47, p = 0.039 for CMV highest quintile vs. CMV negative). Within ALL cases, B-cell ALL (B-ALL) was significantly associated with CMV positivity compared to T-cell ALL (T-ALL) (OR: 2.93; CI: 1.01, 8.52, p = 0.048 for CMV highest tertile vs. CMV negative). Further subtype analysis of B-ALL cases revealed CMV positivity to be significantly associated with high hyperdiploidy, one of the most common ALL subtypes, when compared to ETV6-RUNX1 (OR: 2.52; CI:1.34, 4.73, p = 0.004 for highest CMV tertile vs. CMV negative). CMV positive B-ALL cases were also more likely to harbor deletions of EBF1, a B-cell development gene, compared to CMV negative cases (OR: 6.10; CI: 1.09, 34.06, p = 0.04 for CMV 2 nd tertile vs. CMV negative; OR: 5.54; CI: 1.13, 27.18, p = 0.03 for CMV highest tertile vs. CMV negative). Differential gene expression analysis revealed 830 genes to be significantly differentially expressed between the highest quintile of CMV positive cases and CMV negative cases, and gene ontology analysis revealed upregulation of processes involved in viral infection and replication. Specifically, cytokine signaling pathways including IL-1, IL-8, and IL-7 were upregulated in CMV positive cases while Th1 and the pathway facilitating crosstalk between dendritic cells and natural killer cells were downregulated. Interestingly, B-cell receptor signaling was also upregulated in CMV positive cases.Conclusion: Our results support the hypothesis that CMV plays an enhanced role in leukemia development in specific subtypes of ALL, and not in AML development. The ability of CMV to interact with the host immune system, highlights immune dysregulation as a potential mechanism by which CMV contributes to risk of ALL. Gene expression analysis on a subset of cases revealed differentially expressed genes to be enriched in pathways involved in immune response, suggesting a potential role for active CMV infection in the leukemic phenotype. The patterns of up- and downregulation in these pathways were consistent with the host response to CMV. Additionally, acute CMV infection has been shown to promote B-cell activation and proliferation. Further, CMV seropositive individuals have been reported to have altered immune responses even with the virus in a latent state highlighting the virus's effect on B-cells. In our study we also found B-cell receptor signaling to be upregulated in CMV positive cases. This is consistent with the known effects of CMV in a typical host, but in patients with leukemia it provides an interesting potential link between CMV infection and development of pediatric ALL. These intriguing results require validation and warrant continued investigation of the role of CMV in pediatric leukemia development. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Molecular Characterization of Staphylococcus aureus Isolated from Human and Food Samples in Northern Algeria.

Staphylococcus aureus is a commensal resident of the skin and nasal cavities of humans and can cause various infections. Some toxigenic strains can contaminate food matrices and cause foodborne intoxications. The present study aimed to provide relevant information (clonal complex lineages, agr types, virulence and antimicrobial resistance-associated genes) based on DNA microarray analyses as well as the origins and dissemination of several circulating clones of 60 Staphylococcus aureus isolated from food matrices (n = 24), clinical samples (n = 20), and nasal carriers (n = 16) in northern Algeria. Staphylococcus aureus were genotyped into 14 different clonal complexes. Out of 60 S. aureus, 13 and 10 isolates belonged to CC1-MSSA and CC97-MSSA, respectively. The CC 80-MRSA-IV was the predominant S. aureus strain in clinical isolates. The accessory gene regulator allele agr group III was mainly found among clinical isolates (70.4%). Panton–Valentine leukocidin genes lukF/lukS-PV were detected in 13.3% of isolates that all belonged to CC80-MRSA. The lukF/S-hlg, hlgA, and hla genes encoding for hemolysins and leucocidin components were detected in all Staphylococcus aureus isolates. Clinical and food isolates harbored more often the antibiotic resistance genes markers. Seventeen (28.3%) methicillin-resistant Staphylococcus aureus carrying the mecA gene localized on a SCCmec type IV element were identified. The penicillinase operon (blaZ/I/R) was found in 71.7% (43/60) of isolates. Food isolates belonging to CC97-MSSA carried several antibiotic resistance genes (blaZ, ermB, aphA3, sat, tetM, and tetK). The results of this study showed that all clones were found in their typical host, but interestingly, some nasal carriers had isolates assigned to CC705 thought to be absent in humans. The detection of MRSA strains among food isolates should be considered as a potential public health risk. Therefore, controlling the antibiotics prescription for a rational use in human and animal infections is mandatory.

RNA-Sequencing in Resistant (QL3) and Susceptible (Theis) Sorghum Cultivars Inoculated With Johnsongrass Isolates of Colletotrichum sublineola.

Gene expression was analyzed at 0- and 24-h post-inoculation of two inbred sorghum cultivars known to differ in response to inoculation with Colletotrichum sublineola, the fungal pathogen that causes anthracnose. QL3 is reported to have quantitative resistance, while Theis is susceptible to most pathotypes of the pathogen; RNASeq identified over 3,000 specific genes in both cultivars as showing significant changes in expression following inoculation; in all but one gene, the changes in QL3 and Thies were in the same direction. Many other genes showed significant changes in only one of the two cultivars. Overall, more genes were downregulated than upregulated. Differences in changes in expression levels of a few genes suggested potential roles for the difference in disease response between QL3 and Theis, but did not identify known resistance genes. Gene ontology (GO) and pathway enrichment analysis identified upregulation of 23 transcription factor encoding genes as well as genes involved in the production of secondary metabolites, which are part of a typical host defense reaction.

The Risk of Wheat Blast in Rice-Wheat Co-Planting Regions in China: MoO Strains of Pyricularia oryzae Cause Typical Symptom and Host Reaction on Both Wheat Leaves and Spikes.

The Triticum pathotype of Magnaporthe oryzae (syn. Pyricularia oryzae) causes wheat blast, which has recently spread to Asia. To assess the potential risk of wheat blast in rice-wheat growing regions, we investigated the pathogenicity of 14 isolates of P. oryzae on 32 wheat cultivars, among which Oryzae pathotype of P. oryzae (MoO) isolates were completely avirulent on the wheat cultivars at 22°C but caused various degrees of infection 25°C. These reactions at 25°C were isolate and cultivar dependent, like race-cultivar specificity, which was also recognized at the heading stage and caused typical blast symptoms on spikes. Microscopic analyses indicated that a compatible MoO isolate produced appressoria and infection hyphae on wheat as on rice. When we compared transcriptomes in wheat-MoO interactions, the bulk of pathogen-related genes were upregulated or downregulated in compatible and incompatible patterns, but changes in gene transcription were more significant in a compatible pattern. These results indicate that temperature could influence the infection ratio of wheat with MoO, and some MoO strains could be potential pathogens that increase the risk of wheat blast outbreaks in wheat-rice growing regions with global warming. In addition, certain wheat cultivars exhibited resistance and are assumed to carry resistance-promoting genes to the MoO strains.

The role of cardiac rehabilitation after Streptococcus agalactiae Infective Endocarditis with Septic Embolic Complication in an Elderly Patient: Case Report

Introduction. In the past, Streptococcus agalactiae was known to be associated with invasive infections in pregnant women and newborns. More recently, given a more appropriate antibiotic prophylaxis and treatment, the incidence among pregnant women and infants diminished. However, an increasing number of cases with infective endocarditis with Streptococcus agalactiae has been reported in the recent years in older patients with underlying comorbidities. Case report. An 80-year-old female patient presented with dyspnea, weight loss, fever, fatigue, chills, dry cough and bilateral lower limb edema. The work-up revealed complicated infective endocarditis with Streptococcus agalactiae on the native aortic valve with severe aortic regurgitation as a result of the valvular destruction and a metastatic spleen abscess. Antibiotic treatment was started with resolution of the fever and chills. The patient however developed congestive heart failure due to the valvular regurgitation. A decision was made to proceed urgently with aortic valve replacement and splenectomy, which were performed at the same time, followed by a good recovery. Results and discussion. An increasing number of cases with IE with GBS in elderly patients has been reported in the recent years, with high rate of complications and mortality. The underlying comorbidities are important risk factors for S. agalactiae IE. Considering our case, a patient in her eighties with significant abdominal surgical history and multiple medical conditions could be a typical host. Recovery after cardiac surgery is one of the most important indications of physical training. This includes patients post-coronary artery bypass grafting, after valve prosthetic replacement, after surgery for congenital diseases and after heart transplantation. Early mobilization is particularly important in avoiding immobility and cardiac deconditioning. Conclusions. Despite the fact that mortality in Group B Streptococcus endocarditis is 40%, a combined medical and surgical strategy individualized to the specific situation of each patient have led to a positive outcome in a number of cases. We present such a combined treatment approach in a case of complicated infective endocarditis with metastatic spleen abscess in an elderly patient. The aortic valve replacement and splenectomy were performed at the same time. Keywords: endocarditis, septic emboli, valve replacement, splenectomy

Advances of polymer-monomer production by cyanobacterial cell factory

Cyanobacteria is one of the promising microbial chassis in synthetic biology, which serves as a typical host for light-driven production. With the gradual depletion of fossil resources and intensification of global warming, the research on cyanobacterial cell factory using CO2 as carbon resource is ushering in a new wave. For a long time, research focus on cyanobacterial cell factory has mainly been the production of energy products, such as liquid fuels and hydrogen. One of the critical bottlenecks occurring in cyanobacterial cell factory is the poor economic performance, which is mainly caused by the inherent inefficiency of cyanobacteria. The problem is particularly prominent for these extremely cost-sensitive energy products. As an indispensable basis for modern industry, polymer monomers belong to the bulk chemicals with high added value. Therefore, increasing attention has been focused on polymer monomers which are superior in overcoming the economic barrier in commercialization of cyanobacterial cell factories. Here, we systematically review the progress on the production of polymer monomers using cyanobacteria, including the strategies for improving production, and the related technologies for the application of this important microbial cell factory. Finally, we summarize several issues in cyanobacterial synthetic biology and proposed future developing trends in this field.

Forming massive seed black holes in high-redshift quasar host progenitors

ABSTRACT The presence of massive black holes (BHs) with masses of the order of $10^9\, {\rm M_\odot }$, powering bright quasars when the Universe was less than 1 Gyr old, poses strong constraints on their formation mechanism. Several scenarios have been proposed to date to explain massive BH formation, from the low-mass seed BH remnants of the first generation of stars to the massive seed BHs resulting from the rapid collapse of massive gas clouds. However, the plausibility of some of these scenarios to occur within the progenitors of high-z quasars has not yet been thoroughly explored. In this work, we investigate, by combining dark-matter only N-body simulations with a semi-analytic framework, whether the conditions for the formation of massive seed BHs from synchronized atomic-cooling halo pairs and/or dynamically heated (DH) mini-haloes are fulfilled in the overdense regions where the progenitors of a typical high-redshift quasar host form and evolve. Our analysis shows that the peculiar conditions in such regions, i.e. strong halo clustering and high star formation rates, are crucial to produce a non-negligible number of massive seed BH host candidates: we find ≈1400 DH metal-free mini-haloes, including one of these which evolves to a synchronized pair and ends up in the massive quasar-host halo by z = 6. This demonstrates that the progenitors of high-redshift quasar host haloes can harbour early massive seed BHs. Our results further suggest that multiple massive seed BHs may form in or near the quasar host’s progenitors, potentially merging at lower redshifts and yielding gravitational wave events.

Tidal Disruption Event Hosts Are Green and Centrally Concentrated: Signatures of a Post-merger System

Abstract We study the properties of the galaxies hosting the first 19 tidal disruption events (TDEs) detected with the Zwicky Transient Facility (ZTF) within the context of a carefully constructed, representative host galaxy sample. We find that the ZTF sample of TDE hosts is dominated by compact “green valley” galaxies. After we restrict the comparison sample to galaxies with a similar concentration, as measured by the Sérsic index, we find this green valley overrepresentation is even larger. That is, concentrated red sequence galaxies are not producing TDEs at elevated levels. We present host galaxy spectra that show that E + A galaxies are overrepresented in the ZTF sample by a factor of ≈22, which is lower than previous TDE host galaxy studies have found. We find that this overrepresentation can be fully accounted for when taking into account the masses, colors, and Sérsic indices of the ZTF TDE hosts. The combination of both green colors and high Sérsic index of the typical TDE host galaxy could be explained if the TDE rate is temporarily enhanced following a merger that leads to a higher central concentration of stars.

Coronavirus Envelope Protein: Lipid Sensitivity and Membrane Bending

The Coronavirus envelope (E) protein is a pentameric viroporin that is implicated in numerous viral processes including but not limited to assembly, budding, envelope formation, and pathogenesis. While much work has recently been done to characterize this protein's structure, function, and interactions with other proteins, its interactions with and effects on surrounding membranes are less well understood. It is known that the viroporin loses ion-selectivity in an exclusively neutral lipid environment, but it is not clear what drives this behavior. In the present study we use coarse-grain molecular dynamics (CG-MD) simulations to identify stable binding sites for anionic lipid headgroups. We then use all-atomistic molecular dynamics (AA-MD) simulations to investigate the effect of lipid charge on viroporin structure using the sites identified from CG-MD. Incorporation of anionic lipid species into the existing protein structure may explain the change in selectivity observed in previous studies, and could prove useful for groups pursuing drug development projects. The E protein is also required for membrane curvature – giving the virus its characteristic shape in the process – although the precise mechanism is unknown. Using CG-MD, we observe that the E protein bends the membrane in simulations with lipid species that have long acyl chains. We find this effect is limited when shorter lipid species are used, which suggests it results from asymmetric mismatch between the viroporin transmembrane domain (TMD) and the thickness of a typical host membrane. This result has implications for viral pathogenesis, as induction of membrane curvature is one of the important viral processes that leads to budding and further viral spread.

A population of galaxy-scale jets discovered using LOFAR

ABSTRACT The effects of feedback from high luminosity radio-loud active galactic nuclei (AGN) have been extensively discussed in the literature, but feedback from low-luminosity radio-loud AGN is less well understood. The advent of high sensitivity, high angular resolution, large field-of-view telescopes such as LOFAR is now allowing wide-area studies of such faint sources for the first time. Using the first data release of the LOFAR Two Metre Sky Survey (LoTSS) we report on our discovery of a population of 195 radio galaxies with 150-MHz luminosities between 3 × 1022 and 1.5 × 1025 WHz−1 and total radio emission no larger than 80 kpc. These objects, which we term galaxy-scale jets (GSJ), are small enough to be directly influencing the evolution of the host on galaxy scales. We report upon the typical host properties of our sample, finding that 9 per cent are hosted by spirals with the remainder being hosted by elliptical galaxies. Two of the spiral-hosted GSJ are highly unusual with low radio luminosities and FRII-like morphology. The host properties of our GSJ show that they are ordinary AGN observed at a stage in their life shortly after the radio emission has expanded beyond the central regions of the host. Based on our estimates, we find that about half of our GSJ have internal radio lobe energy within an order of magnitude of the ISM energy so that, even ignoring any possible shocks, GSJ are energetically capable of affecting the evolution of the host. The current sample of GSJ will grow in size with future releases of LoTSS and can also form the basis for further studies of feedback from low-luminosity radio sources.

Morphological, histological, and molecular evidence of Myxobolusspinacurvatura(Cnidaria: Myxosporea) from Mugilcephalus in the Turkish Black Sea coast

In the present study, a total of 30 M. cephalus captured from the Samsun coast of the Black Sea, Turkey were examined for myxozoa infections. Different sizes of whitish and rounded cyst-like plasmodia were macroscopically detected in the liver and intestine wall of M. cephalus. Morphological and histological examinations were performed. The SSU rDNA was amplified using nested PCR and myxosporean-specific primers. The present Myxobolus species was identified as M. spinacurvatura based on the spore morphology and host/organ specificity. In the present study, morphological, histological, and molecular data on M. spinacurvatura were presented. Furthermore, BLASTn research showed that SSU rDNA sequences of M. spinacurvatura (accession number MH374629) were identical to that of the reference sequence of M. spinacurvatura (accession from AF378341) recorded previously. The current study includes the first record and molecular evidence of M. spinacurvatura infecting M. cephalus from the Turkish waters. To date, there is no report on comprehensive morphological, histopathological, and molecular data of M. spinacurvatura in M. cephalus as a typical host. Moreover, the new valid SSU rDNA sequence of M. spinacurvatura (accession number MH374629) was the second record in the GenBank. The present SSU rDNA sequence can also be used to construct a phylogenetic tree with other mugiliform-infecting Myxobolus species worldwide.

The Massive and Distant Clusters of WISE Survey. IX. High Radio Activity in a Merging Cluster

Abstract We present a multiwavelength investigation of the radio galaxy population in the galaxy cluster MOO J1506+5137 at z = 1.09 ± 0.03, which in previous work we identified as having multiple complex radio sources. The combined data set used in this work includes data from the Low-Frequency Array Two-meter Sky Survey, NSF’s Karl G. Jansky Very Large Array, the Robert C. Byrd Green Bank Telescope, the Spitzer Space Telescope, and the Dark Energy Camera Legacy Survey. We find that there are five radio sources, which are all located within 500 kpc (∼1′) of the cluster center and have radio luminosities P 1.4 GHz > 1.6 × 1024 W Hz−1. The typical host galaxies are among the highest stellar mass galaxies in the cluster. The exceptional radio activity among the massive galaxy population appears to be linked to the dynamical state of the cluster. The galaxy distribution suggests an ongoing merger, with a subgroup found to the northwest of the main cluster. Furthermore, two of the five sources are classified as bent-tail sources, with one being a potential wide-angle tail/hybrid morphology radio source, indicating a dynamic environment. The cluster also lies in a region of the mass–richness plane occupied by other merging clusters in the Massive and Distant Clusters of WISE Survey. The data suggest that during the merger phase, radio activity can be dramatically enhanced, which would contribute to the observed trend of increased radio activity in clusters with increasing redshift.

Damped Ly α absorbers and atomic hydrogen in galaxies: the view of the GAEA model

ABSTRACT Using the GAEA semi-analytic model, we analyse the connection between Damped Ly α systems (DLAs) and H i in galaxies. Our state-of-the-art semi-analytic model is tuned to reproduce the local galaxy H i mass function, and that also reproduces other important galaxy properties, including the galaxy mass–gas metallicity relation. To produce catalogues of simulated DLAs we throw 105 random lines of sight in a composite simulated volume: dark matter haloes with log$(\frac{M_{200}}{ {\rm M}_{\odot }}) \ge 11.5$ are extracted from the Millennium Simulation, while for $9.2 \le \log (\frac{M_{200}}{ \mathrm{M}_{\odot }})\lt 11.5$ we use the Millennium II, and for $8 \le \log (\frac{M_{200}}{\mathrm{M}_{\odot }}) \lt 9.2$ a halo occupation distribution model. At 2 < z < 3, where observational data are more accurate, our fiducial model predicts the correct shape of the column density distribution function, but its normalization falls short of the observations, with the discrepancy increasing at higher redshift. The agreement with observations is significantly improved increasing both the H i masses and the disc radii of model galaxies by a factor of 2, as implemented ‘a posteriori’ in our 2M−2R model. In the redshift range of interest, haloes with $M_{200} \ge {10}^{11} \, \mathrm{M}_{\odot }$ give the major contribution to ΩDLA, and the typical DLA host halo mass is $\sim \!{10}^{11} \, \mathrm{M}_{\odot }$. The simulated DLA metallicity distribution is in relatively good agreement with observations, but our model predicts an excess of DLAs at low metallicities. Our results suggest possible improvements for the adopted modelling of the filtering mass and metal ejection in low-mass haloes.

Simulating kilonovae in the ΛCDM universe

ABSTRACT Kilonovae are optical flashes produced in the aftermath of neutron star–neutron star mergers or neutron star–black hole mergers. In this work, we use the Millennium Simulation, combined with semi-analytic galaxy formation model gabe (Galaxy Assembly with Binary Evolution) to explore the cosmic event rate of kilonovae, and the properties of their host galaxies in a cosmological context. We find that model with supernova kick velocity of $V_{\rm kick}=0\, \, {\rm km}\, \, {\rm s}^{-1}$ fits the observation best, satisfying the preference for low kick velocity binary system in theoretical models. With $V_{\rm kick}=0\, \, {\rm km}\, \, {\rm s}^{-1}$, the cosmic event rate of NNMs and NBMs at z = 0 are 283 and $91\, \, {\rm Gpc}^{-3}\, \, {\rm yr}^{-1}$, respectively, marginally consistent with the constraint from LVC GWTC-1. For Milky Way-mass galaxies, we predict the NNM rate is $25.7^{+59.6}_{-7.1}\, {\rm Myr}^{-1}$, which is also in good agreement with the observed properties of binary neutron stars in the Milky Way. Taking all the kilonovae into account in the history of Milky Way-mass galaxies, we find that the averaged r-process elements yield (A > 79) in an NNM/NBM event should be $0.01\, {\rm M}_\odot$ to be consistent with observation. We conclude that NGC 4993, the host galaxy of GW170817, is a typical host galaxy for NNMs. However, generally, NNMs and NBMs tend to reside in young, blue, star-forming, late-type galaxies, with stellar mass, and gaseous metallicity distribution peaking at $M_{\rm *}=10^{10.65}\, {\rm M}_\odot$ and 12 + log (O/H) = 8.72 − 8.85, respectively. By exploring the connection between kilonovae and their host galaxies in the cosmological background, it is promising to constrain model better when we have more events in the forthcoming future.

Semi-analytic modelling of AGNs: autocorrelation function and halo occupation

ABSTRACT The spatial clustering of active galactic nuclei (AGNs) is considered to be one of the important diagnostics for the understanding of the underlying processes behind their activities complementary to measurements of the luminosity function (LF). We analyse the AGN clustering from a recent semi-analytic model performed on a large cosmological N-body simulation covering a cubic gigaparsec comoving volume. We have introduced a new time-scale of gas accretion on to the supermassive black holes to account for the loss of the angular momentum on small scales, which is required to match the faint end of the observed X-ray LF. The large simulation box allows us accurate determination of the autocorrelation function of the AGNs. The model prediction indicates that this time-scale plays a significant role in allowing massive haloes to host relatively faint population of AGNs, leading to a higher bias factor for those AGNs. The model predictions are in agreement with observations of X-ray selected AGNs in the luminosity range $10^{41.5}~\mathrm{erg} \ \mathrm{s}^{-1} \le L_{2{-}10\mathrm{keV}} \le 10^{44.5}~\mathrm{erg} \ \mathrm{s}^{-1}$, with the typical host halo mass of $10^{12.5-13.5} h^{-1}\, {\rm M}_{\odot }$ at $z \lesssim 1$. This result shows that the observational clustering measurements impose an independent constraint on the accretion time-scale complementary to the LF measurements. Moreover, we find that not only the effective halo mass corresponding to the overall bias factor, but the extended shape of the predicted AGN correlation function shows remarkable agreement with those from observations. Further observational efforts towards the low-luminosity end at $z$ ∼ 1 would give us stronger constraints on the triggering mechanisms of AGN activities through their clustering.

Transcriptome analysis of Lactobacillus paracasei SMN-LBK under ethanol stress

Lactobacillus paracasei SMN-LBK (serial number: CCTCC M 2017429) is an ethanol-resistant lactic acid bacteria (LAB) in kumiss. However, the anti-ethanol stress mechanism of L. paracasei SMN-LBK remains unclear. Hence, we performed a transcriptome analysis between L. paracasei SX10 (L. paracasei SMN-LBK under 10% ethanol stress strain, abbreviated as SX10) and L. paracasei SMN-LBK (abbreviated as S10) by RNA sequencing. We performed real-time quantitative PCR (RT-qPCR) to verify the accuracy of the transcription data. The transcriptome data revealed that 315 genes exhibited upregulated expression, and 332 genes were downregulated in the SX10 compared with the S10 group. The PFK, LDH, GPDH, and GK genes were upregulated, with a log2-fold change of 1.10, 0.30, 0.56, and 1.512, respectively. A gene ontology enrichment analysis revealed significant enrichment of ribosomes, ribonucleoprotein complex, non-membrane-bounded organelles, and intracellular non-membrane-bound organelles. Analysis using the Kyoto Encyclopedia of Genes and Genomes database revealed differential genes associated with ribosome function, pyruvate metabolism, biosynthesis of amino acids, fatty acid biosynthesis, fatty acid metabolism, ATP-binding cassette (ABC) transporter, glycolysis, and glycerophospholipid metabolism. The RT-qPCR results were consistent with the transcriptome results. Lactococcus lactis NZ9000 is a typical host bacterium. We performed PFK and GK overexpression to verify the function of the L. paracaseiSX10 resistance gene in Lactococcus lactis NZ9000. Using sodium dodecyl sulfate (SDS)-PAGE electrophoresis, these resistance genes were successfully expressed in Lactococcus lactis NZ9000. The survival rate and key enzyme activity of the recombinant strains were determined under ethanol stress. The survival rate of Lactococcus lactis NZ9000-pNZ8148-PFK and Lactococcus lactis NZ9000-pNZ8148-GK under 10% ethanol stress were 3.43- and 3.80-fold higher compared with the Lactococcus lactis NZ9000-pNZ8148 control, respectively. These results indicate that PFK and GK are important for the ethanol tolerance of LAB and can increase the ethanol tolerance of Lactococcus lactis NZ9000. Hence, PFK and GK were identified as key genes of L. paracasei SX10 with a high ethanol tolerance. Our results provide novel insight for further studies to perform a systematic analysis of the differentially expressed genes and to determine their potential functions in the ethanol tolerance mechanism of LAB.

Isolation of Leptospira serovar Pomona from a crested porcupine (Hystrix cristata, L., 1758).

Pathogenic Leptospira is widespread in rodents, the most studied reservoir and the main hosts involved in its transmission. In Italy, among rodents, Hystrix cristata (crested porcupine) is the largest species and it is distributed all over the country. In this paper, the isolation and characterization of pathogenic Leptospira spp. from the kidney of H. cristata is reported for the first time. During Autumn 2018, Leptospira detection by real‐time PCR and isolation were performed from kidneys of two died female porcupines (an adult and a porcupette). Only for porcupette kidney sample, real‐time PCR for pathogenic Leptospira tested positive. The isolated strain was identified as Leptospira interrogans serogroup Pomona serovar Pomona, using the three schemes of multilocus sequence typing. The results show that H. cristata could be a Leptospira host. The infection of serovars Pomona could be related to the habitat shared with wild boar, a typical reservoir host for this serovar.

Examining supernova events in Type 1 active galactic nuclei

ABSTRACT A statistical study of intermediate Palomar Transient Factory supernovae (SNe) in Type 1 active galactic nuclei (AGNs) has shown a major deficit of supernovae around Type 1 AGN host galaxies, with respect to Type 2 AGN hosts. The aim of this work is to test whether there is any preference for Type 1 AGNs to host SN of a specific kind. Through the analysis of SN occurrence and their type (thermonuclear versus core-collapse), we can directly link the type of stars producing the SN events, thus this is an indirect way to study host galaxies in Type 1 AGNs. We examine the detection fractions of SNe, the host galaxies and compare the sample properties to typical host galaxies in the Open Supernova Catalog (OSC). The majority of the host galaxies in the AGN sample are late type, similar to typical galaxies hosting SN within the OSC. The findings are supportive of a deficiency of SNe near Type 1 AGNs, although we cannot with certainty assess the overall detection fractions of SNe in Type 1 AGNs relative to other SN host galaxies. We can state that Type 1 AGN has equal detection fractions of thermonuclear versus core-collapse SNe. However, we note the possibility of a higher detection rate of core-collapse supernovae in Type 1 AGN with insecure AGN classifications.

No significant correlation between radial velocity planet presence and debris disc properties

ABSTRACT We investigate whether the tentative correlation between planets and debris discs which has been previously identified can be confirmed at high significance. We compile a sample of 201 stars with known planets and existing far-infrared observations. The sample is larger than those studied previously since we include targets from an unpublished Herschel survey of planet hosts. We use spectral energy distribution modelling to characterize Kuiper belt analogue debris discs within the sample, then compare the properties of the discs against a control sample of 294 stars without known planets. Survival analysis suggests that there is a significant (p ∼ 0.002) difference between the disc fractional luminosity distributions of the two samples. However, this is largely a result of the fact that the control sample contains a higher proportion of close binaries and of later-type stars; both of these factors are known to reduce disc detection rates. Considering only Sun-like stars without close binary companions in each sample greatly reduces the significance of the difference (p ∼ 0.3). We also find no evidence for a difference in the disc fractional luminosities of stars hosting planets more or less massive than Saturn (p ∼ 0.9). Finally, we find that the planet hosts have cooler discs than the control stars, but this is likely a detection bias, since the warmest discs in the control sample are also the faintest, and would thus be undetectable around the more distant planet hosts. Considering only discs in each sample that could have been detected around a typical planet host, we find p ∼ 0.07 for the temperatures.

Site-specific glycan analysis of the SARS-CoV-2 spike.

The emergence of the betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), represents a considerable threat to global human health. Vaccine development is focused on the principal target of the humoral immune response, the spike (S) glycoprotein, which mediates cell entry and membrane fusion. The SARS-CoV-2 S gene encodes 22 N-linked glycan sequons per protomer, which likely play a role in protein folding and immune evasion. Here, using a site-specific mass spectrometric approach, we reveal the glycan structures on a recombinant SARS-CoV-2 S immunogen. This analysis enables mapping of the glycan-processing states across the trimeric viral spike. We show how SARS-CoV-2 S glycans differ from typical host glycan processing, which may have implications in viral pathobiology and vaccine design.