Development of a DNA microarray for enterococcal species, virulence, and antibiotic resistance gene determinations among isolates from poultry

A DNA microarray (Enteroarray) was designed with probes targeting four species-specific taxonomic identifiers to discriminate among 18 different enterococcal species, while other probes were designed to identify 18 virulence factors and 174 antibiotic resistance genes. In total, 262 genes were utilized for rapid species identification of enterococcal isolates, while characterizing their virulence potential through the simultaneous identification of endogenous antibiotic resistance and virulence genes. Enterococcal isolates from broiler chicken farms were initially identified by using the API 20 Strep system, and the results were compared to those obtained with the taxonomic genes atpA, recA, pheS, and ddl represented on our microarray. Among the 171 isolates studied, five different enterococcal species were identified by using the API 20 Strep system: Enterococcus faecium, E. faecalis, E. durans, E. gallinarum, and E. avium. The Enteroarray detected the same species as API 20 Strep, as well as two more: E. casseliflavus and E. hirae. Species comparisons resulted in 15% (27 isolates) disagreement between the two methods among the five API 20 Strep identifiable species and 24% (42 isolates) disagreement when considering the seven Enteroarray identified species. The species specificity of key antibiotic and virulence genes identified by the Enteroarray were consistent with the literature adding further robustness to the redundant taxonomic probe data. Sequencing of the cpn60 gene further confirmed the complete accuracy of the microarray results. The new Enteroarray should prove to be a useful tool to accurately genotype strains of enterococci and assess their virulence potential.     

High-dose versus standard-dose vitamin D supplementation in older adults with COVID-19 (COVIT-TRIAL): A multicenter,open-label,randomized controlled superiority trial

BackgroundVitamin D supplementation has been proposed as a treatment for Coronavirus Disease 2019 (COVID-19) based on experimental data and data from small and uncontrolled observational studies. The COvid19 and VITamin d TRIAL (COVIT-TRIAL) study was conducted to test whether a single oral high dose of cholecalciferol (vitamin D3) administered within 72 hours after the diagnosis of COVID-19 improves, compared to standard-dose cholecalciferol, the 14-day overall survival among at-risk older adults infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2).Methods and findingsThis multicenter, randomized, controlled, open-label, superiority trial involved collaboration of 9 medical centers in France. Patients admitted to the hospital units or living in nursing homes adjacent to the investigator centers were eligible if they were ≥65 years, had SARS-CoV-2 infection of less than 3 days, and at least 1 COVID-19 worsening risk factor (among age ≥75 years, SpO2 ≤94%, or PaO₂/FiO₂ ≤300 mm Hg). Main noninclusion criteria were organ failure requiring ICU, SpO2 ≤92% despite 5 L/min oxygen, life expectancy <3 months, vitamin D supplementation >800 IU/day during the preceding month, and contraindications to vitamin D supplements. Eligible and consenting patients were randomly allocated to either a single oral high-dose (400,000 IU) or standard-dose (50,000 IU) cholecalciferol administered under medical supervision within 72 hours after the diagnosis of COVID-19. Participants and local study staff were not masked to the allocated treatment, but the Steering Committee and the Data and Safety Monitoring Board were masked to the randomization group and outcome data during the trial. The primary outcome was 14-day overall mortality. Between April 15 and December 17, 2020, of 1,207 patients who were assessed for eligibility in the COVIT-TRIAL study, 254 met eligibility criteria and formed the intention-to-treat population. The median age was 88 (IQR, 82 to 92) years, and 148 patients (58%) were women. Overall, 8 (6%) of 127 patients allocated to high-dose cholecalciferol, and 14 (11%) of 127 patients allocated to standard-dose cholecalciferol died within 14 days (adjusted hazard ratio = 0.39 [95% confidence interval [CI], 0.16 to 0.99], P = 0.049, after controlling for randomization strata [i.e., age, oxygen requirement, hospitalization, use of antibiotics, anti-infective drugs, and/or corticosteroids] and baseline imbalances in important prognostic factors [i.e., sex, ongoing cancers, profuse diarrhea, and delirium at baseline]). The number needed to treat for one person to benefit (NNTB) was 21 [NNTB 9 to ∞ to number needed to treat for one person to harm (NNTH) 46]. Apparent benefits were also found on 14-day mortality due to COVID-19 (7 (6%) deaths in high-dose group and 14 (11%) deaths in standard-dose group; adjusted hazard ratio = 0.33 [95% CI, 0.12 to 0.86], P = 0.02). The protective effect of the single oral high-dose administration was not sustained at 28 days (19 (15%) deaths in high-dose group and 21 (17%) deaths in standard-dose group; adjusted hazard ratio = 0.70 [95% CI, 0.36 to 1.36], P = 0.29). High-dose cholecalciferol did not result in more frequent adverse effects compared to the standard dose. The open-label design and limited study power are the main limitations of the study.ConclusionsIn this randomized controlled trial (RCT), we observed that the early administration of high-dose versus standard-dose vitamin D3 to at-risk older patients with COVID-19 improved overall mortality at day 14. The effect was no longer observed after 28 days.Trial registrationClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT04344041","term_id":"NCT04344041"}}NCT04344041.

In a randomized trial, Cedric Annweiler and colleagues evaluate whether a single high dose of vitamin D3 improves survival among older adults in France with SARS-CoV-2 infection.     

Longer Antennae for Romeo: Assessing Effect of Antennae Length on Courtship and Mating Success in Male Crickets, Acheta domesticus (Orthoptera, Gryllidae)

Animals use a variety of chemosensory functions to coordinate behavioral actions, such as sexual recognition and courtship. In particular, many insects use antennae as a vital chemosensory organ to transmit and receive sexual signals that are believed to be crucial in mate recognition and mating in various species of insects. Crickets provide a usable model to test the significance of antennae in insects. The general importance of antennae in male crickets to initiate courtship, ensure copulation, and post-copulatory mate guarding has been documented in studies that performed full antennectomy. Our study is the first to perform partial antennectomy to test the hypothesis that even partial loss due to injury has negative effects on sexual behaviors. We found that partially antennectomized males are not slower than control males in mate recognition and courtship initiation. However, we found that partially antennectomized males take longer to achieve copulation than control males with normal uncut antennae. Our results suggest that male crickets require long, undamaged antennae to efficiently engage in mating behavior and may already incur fitness costs when they lose half of their antennae.     

The Contribution of Occult Precipitation to Nutrient Deposition on the West Coast of South Africa

The Strandveld mediterranean-ecosystem of the west coast of South Africa supports floristically diverse vegetation growing on mostly nutrient-poor aeolian sands and extending from the Atlantic Ocean tens of kilometers inland. The cold Benguela current upwelling interacts with warm onshore southerly winds in summer causing coastal fogs in this region. We hypothesized that fog and other forms of occult precipitation contribute moisture and nutrients to the vegetation. We measured occult precipitation over one year along a transect running inland in the direction of the prevailing wind and compared the nutrient concentrations with those in rainwater. Occult deposition rates of P, N, K, Mg, Ca, Na, Al and Fe all decreased with distance from the ocean. Furthermore, ratios of cations to Na were similar to those of seawater, suggesting a marine origin for these. In contrast, N and P ratios in occult precipitation were higher than in seawater. We speculate that this is due to marine foam contributing to occult precipitation. Nutrient loss in leaf litter from dominant shrub species was measured to indicate nutrient demand. We estimated that occult precipitation could meet the demand of the dominant shrubby species for annual N, P, K and Ca. Of these species, those with small leaves intercepted more moisture and nutrients than those with larger leaves and could take up foliar deposits of glycine, NO₃-, NH₄⁺ and Li (as tracer for K) through leaf surfaces. We conclude that occult deposition together with rainfall deposition are potentially important nutrient and moisture sources for the Strandveld vegetation that contribute to this vegetation being floristically distinct from neighbouring nutrient-poor Fynbos vegetation.     

A putative vesicular transporter expressed in Drosophila mushroom bodies that mediates sexual behavior may define a neurotransmitter system

Vesicular transporters are required for the storage of?all classical and amino acid neurotransmitters in synaptic vesicles. Some neurons lack known vesicular transporters, suggesting additional neurotransmitter systems remain unidentified. Insect mushroom bodies (MBs) are critical for several behaviors, including learning, but the neurotransmitters released by the intrinsic Kenyon cells (KCs) remain unknown. Likewise, KCs do not express a known vesicular transporter. We report the identification of a novel Drosophila gene portabella (prt) that is structurally similar to known vesicular transporters. Both larval and adult brains express PRT in the KCs of the MBs. Additional PRT cells project to the central complex and optic ganglia. prt mutation causes an olfactory learning deficit and an unusual defect in the male's position during copulation that is rescued by expression in KCs. Because prt is expressed in neurons that lack other known vesicular transporters or neurotransmitters, it may define a previously unknown neurotransmitter system responsible for sexual behavior and a component of olfactory learning.     

Individual and Coupled Effects of Echinoderm Extracts and Surface Hydrophobicity on Spore Settlement and Germination in the Brown Alga Hincksia irregularis

Marine substrata possess cues that influence the behavior of fouling organisms. Initial adhesion of fouling algal zoospores to surfaces is also theorized to depend primarily upon interactions between substrata and spore cell bodies and flagellar membranes. In an effort to identify cues and surface characteristics that influence spore settlement and early development, the effects of bioactive echinoderm extracts, surface charge, and surface hydrophobicity were examined individually and in tandem on zoospore settlement and germination in Hincksia irregularis. Experiments utilizing 96-well plastic culture plates confirmed that spore settlement and germination were significantly affected by surface charge and hydrophobicity as well as by echinoderm metabolites, both individually and in tandem. Spore settlement rates in the dark over 30?min were >?400% higher on hydrophobic surfaces than on positively and negatively charged surfaces. Spore germling numbers were >?300% higher on hydrophobic surfaces than on positively and negatively charged surfaces when spores were allowed to settle in the light for 30?min and the settled spores allowed to subsequently germinate for 24?h. Spore germling numbers were consistently >?25% higher on hydrophobic surfaces than on positively and negatively charged surfaces when equal numbers of spores were allowed to completely settle in the light and subsequently germinate for 24?h. H. irregularis germ tube lengths were also significantly longer on positively charged plates than on negatively charged plates. All echinoderm extracts tested had significant effects on germination and settlement at levels below those of estimated ecological concentrations. Short-term (30?min) exposure and subsequent germination experiments indicated that higher concentrations of extracts had rapid toxic effects on algal spores. Synchronous effects of echinoderm extracts and plate charge upon spore settlement varied considerably and did not show a strong dose response relationship. Long-term (24?h) exposure of spores to echinoderm extracts had dosage dependent effects on germination and spore survival. The results of this study indicate that H. irregularis spores possess the capacity for complex responses to their environment, utilizing combined cues of surface charge, surface energy and biochemistry to determine where to settle and germinate. These responses may aid spores in the detection of suitable substrata and conditions for settlement in the marine environment.