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Nanomaterials composed of non-nutritive elements are gaining momentum in agriculture. In view of these advances, this study aimed to synthesize and assess the effects of silver (Ag) and cobalt (Co) nanoparticles as seed treatment in maize crops. Nanoparticles were synthesized by coprecipitation and characterized by X-ray diffractometry, transmission electron microscopy, surface area analysis, and Fourier-transform infrared spectroscopy. An experiment was carried out according to a completely randomized design with a 3 × 5 factorial arrangement. The factors were Ag and Co source (soluble, microparticle, and nanoparticle) and concentration (0, 20, 40, 80, and 160 mg L−1). A total of 50 maize seeds were used per treatment. Seeds were placed on germination paper moistened with distilled water. Germination, biometric parameters (root and shoot lengths), and biomass production were evaluated. Characterization analyses showed that particles ranged from 20 to 100 nm in size and were composed of oxides, such as Ag2O and Co3O4. Nanoparticle treatment improved germination and reduced the incidence of defects. The best results were achieved with 98–106 mg L−1 Ag2O and 75–80 mg L−1 Co3O4. There was no significant change in biometric parameters between treatments.

Abstract The SHiP-charm project was proposed to measure the associated charm production induced by 400 GeV/c protons in a thick target, including the contribution from cascade production. An optimisation run was performed in July 2018 at CERN SPS using a hybrid setup. The high resolution of nuclear emulsions acting as vertex detector was complemented by electronic detectors for kinematic measurements and muon identification. Here we present first results on the analysis of nuclear emulsions exposed in the 2018 run, which prove the capability of reconstructing proton interaction vertices in a harsh environment, where the signal is largely dominated by secondary particles produced in hadronic and electromagnetic showers within the lead target.

ABSTRACT Staphylococcus aureus produces a plethora of virulence factors critical to its ability to establish an infection and cause disease. We have previously characterized a small membrane protein, MspA, which has pleiotropic effects on virulence and contributes to S. aureus pathogenicity in vivo. Here we report that mspA inactivation triggers overaccumulation of the essential cell wall component, lipoteichoic acid (LTA), which, in turn, decreases autolytic activity and leads to increased cell size due to a delay in cell separation. We show that MspA directly interacts with the enzymes involved in LTA biosynthesis (LtaA, LtaS, UgtP, and SpsB), interfering with their normal activities. MspA, in particular, interacts with the type I signal peptidase SpsB, limiting its cleavage of LtaS into its active form. These findings suggest that MspA contributes to maintaining a physiological level of LTA in the cell wall by interacting with and inhibiting the activity of SpsB, thereby uncovering a critical role for the MspA protein in regulating cell envelope biosynthesis and pathogenicity.IMPORTANCEThe S. aureus cell envelope, comprising the cytoplasmic membrane, a thick peptidoglycan layer, and the anionic polymers lipoteichoic acid and wall teichoic acids, is fundamental for bacterial growth and division, as well as being the main interface between the pathogen and the host. It has become increasingly apparent that the synthesis and turnover of cell envelope components also affect the virulence of S. aureus. In this study, we show that MspA, an effector of S. aureus virulence, contributes to the maintenance of normal levels of lipoteichoic acid in the cell wall, with implications on cell cycle and size. These findings further our understanding of the connections between envelope synthesis and pathogenicity and suggest that MspA represents a promising target for the development of future therapeutic strategies.

The Hyphomicrobiales (Rhizobiales) order contains soil bacteria with an irregular distribution of the Calvin–Benson–Bassham cycle (CBB). Key enzymes in the CBB cycle are ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), whose large and small subunits are encoded in cbbL and cbbS, and phosphoribulokinase (PRK), encoded by cbbP. These genes are often found in cbb operons, regulated by the LysR-type regulator CbbR. In Bradyrhizobium, pertaining to this order and bearing photosynthetic and non-photosynthetic species, the number of cbbL and cbbS copies varies, for example: zero in B. manausense, one in B. diazoefficiens, two in B. japonicum, and three in Bradyrhizobium sp. BTAi. Few studies addressed the role of CBB in Bradyrhizobium spp. symbiosis with leguminous plants. To investigate the horizontal transfer of the cbb operon among Hyphomicrobiales, we compared phylogenetic trees for concatenated cbbL-cbbP-cbbR and housekeeping genes (atpD-gyrB-recA-rpoB-rpoD). The distribution was consistent, indicating no horizontal transfer of the cbb operon in Hyphomicrobiales. We constructed a ΔcbbLS mutant in B. diazoefficiens, which lost most of the coding sequence of cbbL and has a frameshift creating a stop codon at the N-terminus of cbbS. This mutant nodulated normally but had reduced competitiveness for nodulation and long-term adhesion to soybean (Glycine max (L.) Merr.) roots, indicating a CBB requirement for colonizing soybean rhizosphere.

We report on a clinical case of capecitabine-induced acute ileitis in a patient treated with pre-operative concurrent chemoradiation with capecitabine for locally advanced rectal cancer and provide a comprehensive literature review. This a rare, but life-threatening, clinical situation, that clinicians should be aware of. Severe persistent diarrhea is the most frequent clinical feature and computed tomography is a valid tool for diagnosis. Conservative management includes capecitabine withdrawal, antidiarrheal therapy and endovenous hydration, together with dietary modifications and broad-spectrum antibiotics. Pelvic irradiation represents an adjunctive risk factor, which may increase the likelihood of occurrence of terminal ileitis. Early recognition and prompt intervention are crucial for successful clinical management.

Greenhouse gas emissions, such as N2O from excessive N-fertilizer use, are of concern. Symbiotic N2-fixation by pulses such as soybean might mitigate this issue, for which inoculants carrying locally adapted Bradyrhizobium strains are recommended. In the frame of this goal, enhancing the quality control of these inoculants is required on two key aspects: determining the presence of nosZ, for the strains being able to reduce N2O, and assessing N2-fixation potential. Previously it was demonstrated that, in soybean leaves, N-contents are well correlated with chlorophyll contents. However, no such correlations were made with either N obtained from N2-fixation or with nodules mass, which is an indicator of nodular activity. Here we aimed to leverage the correlation between N and chlorophyll levels to develop a simple and non-destructive laboratory method to be applied in quality control of inoculants, able to assess the N2-fixing capacity of rhizobial strains. To establish such correlations, we cultivated soybeans in vermiculite with N-free nutrient solution, and inoculated them with various Bradyrhizobium field isolates that displayed a range of symbiotic N2-fixing capacities. Subsequently, we measured chlorophyll with a portable chlorophyllometer, and correlated these measures with symbiotic parameters. Moreover, we tested for the presence of nosZ by PCR. We observed significant correlations between chlorophyll and shoot nitrogen obtained from N2-fixation and, in addition, we corroborated that chlorophyll contents were significantly correlated also with nodules mass. Two B. diazoefficiens strains stood out and possessed nosZ. In contrast, B. elkanii and B. japonicum isolates displayed lower chlorophyll and symbiotic performance, and lacked nosZ. Our findings highlight the potential of measuring chlorophyll contents and testing for the presence of nosZ as two straightforward techniques that may enhance laboratory tests for quality control, enabling selection of superior and safe locally isolated strains for soybean inoculants without increased production costs.

The bloodstream represents a hostile environment that bacteria must overcome to cause bacteraemia. To understand how the major human pathogen Staphylococcus aureus manages this we have utilised a functional genomics approach to identify a number of new loci that affect the ability of the bacteria to survive exposure to serum, the critical first step in the development of bacteraemia. The expression of one of these genes, tcaA, was found to be induced upon exposure to serum, and we show that it is involved in the elaboration of a critical virulence factor, the wall teichoic acids (WTA), within the cell envelope. The activity of the TcaA protein alters the sensitivity of the bacteria to cell wall attacking agents, including antimicrobial peptides, human defence fatty acids, and several antibiotics. This protein also affects the autolytic activity and lysostaphin sensitivity of the bacteria, suggesting that in addition to changing WTA abundance in the cell envelope, it also plays a role in peptidoglycan crosslinking. With TcaA rendering the bacteria more susceptible to serum killing, while simultaneously increasing the abundance of WTA in the cell envelope, it was unclear what effect this protein may have during infection. To explore this, we examined human data and performed murine experimental infections. Collectively, our data suggests that whilst mutations in tcaA are selected for during bacteraemia, this protein positively contributes to the virulence of S. aureus through its involvement in altering the cell wall architecture of the bacteria, a process that appears to play a key role in the development of bacteraemia.

Hundreds of different species of small RNAs can populate a bacterial cell. This small transcriptome contains important information for the adaptation of cellular physiology to environmental changes. Underlying cellular networks involving small RNAs are RNA–RNA and RNA-protein interactions, which are often intertwined. In addition, small RNAs can function as mRNAs. In general, small RNAs are referred to as noncoding because very few are known to contain translated open reading frames. In this article, we intend to highlight that the number of small RNAs that fall within the set of translated RNAs is bound to increase. In addition, we aim to emphasize that the dynamics of the small transcriptome involve different functional codes, not just the genetic code. Therefore, since the role of small RNAs is always code-driven, we believe that there is little reason to continue calling them small noncoding RNAs.

Abstract The Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50 $$\mathrm { \,m}$$ m long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400 $$\,\mathrm {GeV}$$ GeV protons, the experiment aims at profiting from the $$4\times 10^{19}$$ 4 × 10 19 protons per year that are currently unexploited at the SPS, over a period of 5–10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few $${\mathrm {\,MeV\!/}c^2}$$ MeV / c 2 up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end.

Nanoparticles of silicon (Si) and titanium (Ti), typically considered non-essential elements, show promise in enhancing fertilizer efficiency and crop performance. This study aimed to synthesize these nanoparticles and evaluate their potential as seed treatments for maize. Using the sol-gel method, Si and Ti nanoparticles were produced and extensively characterized through techniques like X-ray diffractometry, transmission electron microscopy, surface area analysis, and Fourier-transform infrared spectroscopy. Their effects on maize were assessed in a randomized experiment with a 2 × 5 factorial design, testing two sources (microparticles and nanoparticles) of Si and Ti at concentrations ranging from 0 to 160 mg L−1. SiO2 and TiO2 nanoparticles, with particle sizes below 50 nm and specific surface areas of 282.3 and 134.8 m2 g−1, respectively, were utilized. Mathematical models did not adequately explain variations in germination rate, abnormal seedlings, non-viable seeds, or biometric parameters in response to these nanoparticles. However, concentrations of 20 or 40 mg L−1 of Si and Ti nanoparticles notably improved maize germination rates, reduced abnormalities and non-viability in seedlings, and enhanced overall plant biometrics. These findings underscore the potential of SiO2 and TiO2 nanoparticles to enhance maize seed germination and growth metrics. [ABSTRACT FROM AUTHOR]

ABSTRACT Staphylococcus aureus is a clinically important bacterial pathogen that has become resistant to treatment with most routinely used antibiotics. Alternative strategies, such as vaccination and phage therapy, are therefore actively being investigated to prevent or combat staphylococcal infections. Vaccination requires that vaccine targets are expressed at sufficient quantities during infection so that they can be targeted by the host’s immune system. While our knowledge of in vitro expression levels of putative vaccine candidates is comprehensive, crucial in vivo expression data are scarce and promising vaccine candidates during in vitro assessment often prove ineffective in preventing S. aureus infection. Here, we show how a newly developed high-throughput quantitative reverse transcription-PCR (qRT-PCR) assay monitoring the expression of 84 staphylococcal genes encoding mostly virulence factors can inform the selection and design of effective vaccine candidates against staphylococcal infections. We show that this assay can accurately quantify mRNA expression levels of these genes in several host organs relying only on very limited amounts of bacterial mRNA in each sample. We selected two highly expressed genes, lukE and lukD, encoding pore-forming leukotoxins, to inform the design of detoxified recombinant proteins and showed that immunization with recombinant genetically detoxified LukED antigens conferred protection against staphylococcal skin infection in mice. Consequently, knowledge of in vivo-expressed virulence determinants can be successfully deployed to identify and select promising candidates for optimized design of effective vaccine antigens against S. aureus. Notably, this approach should be broadly applicable to numerous other pathogens. IMPORTANCE Vaccination is an attractive strategy for preventing bacterial infections in an age of increased antimicrobial resistance. However, vaccine development frequently suffers significant setbacks when candidate antigens that show promising results in in vitro experimentation fail to protect from disease. An alluring strategy is to focus resources on developing bacterial virulence factors that are expressed during disease establishment or maintenance and are critical for bacterial in-host survival as vaccine targets. While expression profiles of many virulence factors have been characterized in detail in vitro, our knowledge of their in vivo expression profiles is still scarce. Here, using a high-throughput qRT-PCR approach, we identified two highly expressed leukotoxins in a murine infection model and showed that genetically detoxified derivatives of these elicited a protective immune response in a murine skin infection model. Therefore, in vivo gene expression can inform the selection of promising candidates for the design of effective vaccine antigens.

ABSTRACT Behind the pathogenic lifestyle of Pseudomonas aeruginosa exists a complex regulatory network of intertwined switches at both the transcriptional and posttranscriptional levels. Major players that mediate translation regulation of several genes involved in host-P. aeruginosa interaction are small RNAs (sRNAs) and the Hfq protein. The canonical role of Hfq in sRNA-driven regulation is to act as a matchmaker between sRNAs and target mRNAs. Besides, the sRNA CrcZ is known to sequester Hfq and abrogate its function of translation repression of target mRNAs. In this study, we describe the novel sRNA GssA in the strain PA14 and its multifaceted interplay with Hfq. We show that GssA is multiresponsive to environmental and physiological signals and acts as an apical repressor of key bacterial functions in the human host such as the production of pyocyanin, utilization of glucose, and secretion of exotoxin A. We suggest that the main role of Hfq is not to directly assist GssA in its regulatory role but to repress GssA expression. In the case of pyocyanin production, we suggest that Hfq interplays with GssA also by converging a positive effect on this pathway. Furthermore, our results indicate that both Hfq and GssA play a positive role in anaerobic growth, possibly by regulating the respiratory chain. On the other hand, we show that GssA can modulate not only Hfq expression at both transcriptional and posttranscriptional levels but also that of CrcZ, thus potentially influencing the pleiotropic role of Hfq. IMPORTANCE The pathogenic lifestyle of the bacterium Pseudomonas aeruginosa, a leading cause of life-threatening infections in the airways of cystic fibrosis patients, is based on the fine regulation of virulence-associated factors. Regulatory small RNAs (sRNAs) and the RNA-binding protein Hfq are recognized key components within the P. aeruginosa regulatory networks involved in host-pathogen interaction. In this study, we characterized in the highly virulent P. aeruginosa strain PA14 the novel sRNA GssA. We found that it can establish a many-sided reciprocal interplay with Hfq which goes beyond the canonical mechanism of direct physical interaction that had previously been characterized for other sRNAs. Given that the Hfq-driven regulatory network of virulence factors is very broad and important for the progression of infection, we consider GssA as a new RNA target that can potentially be used to develop new antibacterial drugs.

ABSTRACT A major feature of the pathogenicity of Staphylococcus aureus is its ability to secrete cytolytic toxins. This process involves the translocation of the toxins from the cytoplasm through the bacterial membrane and the cell wall to the external environment. The process of their movement through the membrane is relatively well defined, involving both general and toxin-specific secretory systems. Movement of the toxins through the cell wall was considered to involve the passive diffusion of the proteins through the porous cell wall structures; however, recent work suggests that this is more complex, and here we demonstrate a role for the wall teichoic acids (WTA) in this process. Utilizing a genome-wide association approach, we identified a polymorphism in the locus encoding the WTA biosynthetic machinery as associated with the cytolytic activity of the bacteria. We verified this association using an isogenic mutant set and found that WTA are required for the release of several cytolytic toxins from the bacterial cells. We show that this effect is mediated by a change in the electrostatic charge across the cell envelope that results from the loss of WTA. As a major target for the development of novel therapeutics, it is important that we fully understand the entire process of cytolytic toxin production and release. These findings open up a new aspect to the process of toxin release by a major human pathogen while also demonstrating that clinical isolates can utilize WTA production to vary their cytotoxicity, thereby altering their pathogenic capabilities. IMPORTANCE The production and release of cytolytic toxins is a critical aspect for the pathogenicity of many bacterial pathogens. In this study, we demonstrate a role for wall teichoic acids, molecules that are anchored to the peptidoglycan of the bacterial cell wall, in the release of toxins from S. aureus cells into the extracellular environment. Our findings suggest that this effect is mediated by a gradient of electrostatic charge which the presence of the negatively charged WTA molecules create across the cell envelope. This work brings an entirely new aspect to our understanding of the cytotoxicity of S. aureus and demonstrates a further means by which this major human pathogen can adapt its pathogenic capabilities.

The Hyphomicrobiales (Rhizobiales) order contains soil bacteria with an irregular distribution of the Calvin–Benson–Bassham cycle (CBB). Key enzymes in the CBB cycle are ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), whose large and small subunits are encoded in cbbL and cbbS, and phosphoribulokinase (PRK), encoded by cbbP. These genes are often found in cbb operons, regulated by the LysR-type regulator CbbR. In Bradyrhizobium, pertaining to this order and bearing photosynthetic and non-photosynthetic species, the number of cbbL and cbbS copies varies, for example: zero in B. manausense, one in B. diazoefficiens, two in B. japonicum, and three in Bradyrhizobium sp. BTAi. Few studies addressed the role of CBB in Bradyrhizobium spp. symbiosis with leguminous plants. To investigate the horizontal transfer of the cbb operon among Hyphomicrobiales, we compared phylogenetic trees for concatenated cbbL-cbbP-cbbR and housekeeping genes (atpD-gyrB-recA-rpoB-rpoD). The distribution was consistent, indicating no horizontal transfer of the cbb operon in Hyphomicrobiales. We constructed a ΔcbbLS mutant in B. diazoefficiens, which lost most of the coding sequence of cbbL and has a frameshift creating a stop codon at the N-terminus of cbbS. This mutant nodulated normally but had reduced competitiveness for nodulation and long-term adhesion to soybean (Glycine max (L.) Merr.) roots, indicating a CBB requirement for colonizing soybean rhizosphere. [ABSTRACT FROM AUTHOR]

Background We aimed to determine the diagnostic yield of transthoracic (TTE) and transesophageal echocardiography (TEE) in patients with ischemic stroke and transient ischemic attack with established indications for direct oral anticoagulants before the index event. Methods and Results This was a retrospective cohort study of consecutive patients with preceding established indications for long‐term therapeutic direct oral anticoagulants presenting to a single comprehensive stroke center with ischemic stroke or transient ischemic attack. Choice of echocardiography modality was based on expert recommendations. The primary outcome was a composite of prespecified management‐relevant high‐risk findings adjudicated by an expert panel, based on TTE and TEE reports according to evidence‐based recommendations. Explorative analyses were performed to identify biomarkers associated with the primary outcome. Of 424 patients included (median [interquartile range] age, 78 [70–84] years; 175 [41%] women; National Institutes of Health Stroke Scale, 4 [1–12]; 67% atrial fibrillation), 292 (69%) underwent echocardiography, while 132 (31%) did not. Modality was TTE in 191 (45%) and TEE in 101 (24%). Median time from index event to echocardiography was 2 (1–3) days. TTE identified 26 of 191 (14%) patients with 35 management‐relevant pathologies. TEE identified 16 of 101(16%) patients with 20 management‐relevant pathologies. Most management‐relevant findings represented indicated coronary artery disease and valvular pathologies. In a further 3 of 191 (2%) patients with TTE and 4 of 101 (4%) patients with TEE, other relevant findings were identified. Variables associated with management‐relevant high‐risk pathologies included more severe stroke, diabetes, and laboratory biomarkers (NT‐proBNP [N‐terminal pro‐B‐type natriuretic peptide], C‐reactive protein, d‐dimer, and troponin levels). Conclusions In patients with established indications for long‐term direct oral anticoagulant therapy and stroke who received echocardiography, both TTE and TEE identified a relevant and similar proportion of management‐relevant high‐risk pathologies and predictive biomarkers could help to guide diagnostic workup in such patients.

The multidimensional prognostic index (MPI) is a comprehensive geriatric assessment (CGA) tool exploring the multiple domains of older subject. The knowledge and the diffusion of self-assessment tools for identifying frailty in general medicine is still limited. The aim of our study is to determine the prevalence of frailty using a multidimensional frailty screening tool (SELFY-MPI) in a cohort of older adults, belonging to the general practitioner’s (GPs) experience. In the frame of a national educational program organized by the Italian Geriatric Hospital and Community Society (SIGOT), expert geriatricians carried-out local courses addressed to GPs, focused on multidimensional approach in primary care. A cross-sectional study of the SELFY-MPI, based on eight different domains, in the general practitioners’ outpatient clinic was performed among 50 GPs. SELFY-MPI risk score was used for dividing the participants in robust, pre-frail, or frail. A total of 526 participants (mean age: 77.7 years; females=55.3%) fulfilled the SELFY-MPI. The participants were, on average, independent in the activities of daily living, had a good mobility, but they reported some cognitive difficulties, and they can be considered at risk of malnutrition. A high prevalence of comorbidities and polypharmacotherapy was also present. The 20.2% of the sample lived alone, suggesting a potential social frailty. The mean SELFY-MPI score was 0.26 0.17: therefore, 21.67% of the participants were categorized as pre-frail, and 3.99% as frail. Pre-frailty and frailty are common in GPs experience. SELFY-MPI is a feasible screening tool for multidimensional frailty in the GPs clinical practice.