Surface-Patterned DNA Origami Rulers Reveal Nanoscale Distance Dependency of the Epidermal Growth Factor Receptor Activation.

The nanoscale arrangement of ligands can have a major effect on the activation of membrane receptor proteins and thus cellular communication mechanisms. Here we report on the technological development and use of tailored DNA origami-based molecular rulers to fabricate "Multiscale Origami Structures As Interface for Cells" (MOSAIC), to enable the systematic investigation of the effect of the nanoscale spacing of epidermal growth factor (EGF) ligands on the activation of the EGF receptor (EGFR). MOSAIC-based analyses revealed that EGF distances of about 30-40 nm led to the highest response in EGFR activation of adherent MCF7 and Hela cells. Our study emphasizes the significance of DNA-based platforms for the detailed investigation of the molecular mechanisms of cellular signaling cascades.

Chiral plasmonic metasurface assembled by DNA origami.

Chiral materials are essential to perceive photonic devices that control the helicity of light. However, the chirality of natural materials is rather weak, and relatively thick films are needed for noticeable effects. To overcome this limitation, artificial photonic materials were suggested to affect the chiral response in a much more substantial manner. Ideally, a single layer of such a material, a metasurface, should already be sufficient. While various structures fabricated with top-down nanofabrication technologies have already been reported, here we propose to utilize scaffolded DNA origami technology, a scalable bottom-up approach for metamolecule production, to fabricate a chiral metasurface. We introduce a chiral plasmonic metamolecule in the shape of a tripod and simulate its optical properties. By fixing the metamolecule to a rectangular planar origami, the tripods can be assembled into a 2D DNA origami crystal that forms a chiral metasurface. We simulate the optical properties but also fabricate selected devices to assess the experimental feasibility of the suggested approach critically.

Quantitative Characterization of RCA-based DNA Hydrogels - Towards Rational Design.

DNA hydrogels hold significant promise for biomedical applications and can be synthesized through enzymatic Rolling Circle Amplification (RCA). Due to the exploratory nature of this emerging field, standardized RCA protocols specifying the impact of reaction parameters are currently lacking. This study varied template sequences and reagent concentrations, evaluating RCA synthesis efficiency and hydrogel mechanical properties through quantitative PCR (qPCR) and indentation measurements, respectively. Primer concentration and stabilizing additives showed minimal impact on RCA efficiency, while changes in polymerase and nucleotide concentrations had a stronger effect. Concentration of the circular template exerted the greatest influence on RCA productivity. An exponential correlation between hydrogel viscosity and DNA amplicon concentration was observed, with nucleobase sequence significantly affecting both amplification efficiency and material properties, particularly through secondary structures. This study suggests that combining high-throughput experimental methods with structural folding prediction offers a viable approach for systematically establishing structure-property relationships, aiding the rational design of DNA hydrogel material systems.

Exploring the potential of horse amendment for the remediation of HCHs-polluted soils.

This study assessed for the first time the bioremediation potential of an organic horse amendment in soils contaminated with solid wastes of the obsolete pesticide lindane (α-hexachlorocyclohexane (α-HCH) = 80 mg kg-1, ß-HCH = 40 mg kg-1, γ,δ,ε-HCH≈10 mg kg-1) searching for a self-sufficient bio-based economy. Four treatments were implemented: polluted (PS, ΣHCHs = 130 mg kg-1) and control (CS, ΣHCHs = 1.24 mg kg-1) soils and the respective amended soils (APS and ACS). A commercial amendment, coming from organic wastes, was used for soil biostimulation (5% dry weight), and the temporal evolution of the enzymatic activity (dehydrogenase, ß-glucosidase activity, phenoloxidase, arylamidase, phosphatase, and urease) and HCHs concentration of the soils was evaluated over 55 days under controlled humidity and temperature conditions. The horse amendment positively influenced the physicochemical properties of the soil by reducing pH (from 8.3 to 8) and increasing the organic matter (TOC from 0.5 to 3.3%) and nutrient content (P and NH4+ from 24.1 to 13.7 to 142.1 and 41.2 mg kg-1, respectively). Consequently, there was a notable enhancement in the soil biological activity, specifically in the enzymatic activity of dehydrogenase, phenol-oxidase, phosphatase, and urease and, therefore, in HCH degradation, which increased from <1 to 75% after the incubation period. According to the chlorine position on the cyclohexane ring, the following ranking has been found for HCHs degradation: ß-HCH (46%) < Îµ-HCH (57%) < α-HCH (91%) ≈ Î´-HCH (91%) < Î³-HCH (100%). Pentachlorocyclohexene (PCCH) and 1,2,4-trichlorobenzene (1,2,4-TCB) were identified as HCHs degradation metabolites and disappeared at the end of the incubation time. Although further research is required, these preliminary findings suggest that organic amendments represent a sustainable, harmless, and cost-effective biostimulation approach for remediating soils contaminated with recalcitrant HCHs, boosting the circular economy.

Relationship Between Sexual Abuse and Substance Use Among Students from Caribbean Colombian.

Sexual abuse is a public health problem due to its negative impact on physical and mental health. This study aimed to determine the association between sexual abuse and the use of psychoactive substances among high-school adolescents in Colombia. A cross-sectional analytical study was designed in which tenth and eleventh-grade students were included. Overall, a history of sexual abuse was explored with the Trauma Symptom Checklist, and lifetime substance use was assessed with the United States Centers for Disease Control Youth Risk Behavior Questionnaire. The prevalence of sexual abuse was 17.4%, lifetime alcohol use was 77.4%, cigarette 22.4%, cannabis 11.6%, cocaine 2.7%, and other substances 5.1%. History of sexual abuse was associated with alcohol use (OR = 1.59, 95% CI 1.10-2.30), cigarette (OR = 2.08, 95% CI 1.51-2.85), cannabis (OR = 2.43, 95% CI 1.66-3.56), cocaine (OR = 2.51, 95% CI 1.25-5.04) and use of other substances (OR = 2.33, 95% CI 1.31-4.13). The history of sexual abuse is related to the use of substances in high school adolescents in the Caribbean Region of Colombia. More studies are needed to identify the impact of sexual abuse on short-term and lifelong mental health.

A Versatile Microfluidic Platform for Extravasation Studies Based on DNA Origami-Cell Interactions.

The adhesion of circulating tumor cells (CTCs) to the endothelial lumen and their extravasation to surrounding tissues are crucial in the seeding of metastases and remain the most complex events of the metastatic cascade to study. Integrins expressed on CTCs are major regulators of the extravasation process. This knowledge is primarily derived from animal models and biomimetic systems based on artificial endothelial layers, but these methods have ethical or technical limitations. We present a versatile microfluidic device to study cancer cell extravasation that mimics the endothelial barrier by using a porous membrane functionalized with DNA origami nanostructures (DONs) that display nanoscale patterns of adhesion peptides to circulating cancer cells. The device simulates physiological flow conditions and allows direct visualization of cell transmigration through microchannel pores using 3D confocal imaging. Using this system, we studied integrin-specific adhesion in the absence of other adhesive events. Specifically, we show that the transmigration ability of the metastatic cancer cell line MDA-MB-231 is influenced by the type, distance, and density of adhesion peptides present on the DONs. Furthermore, studies with mixed ligand systems indicate that integrins binding to RGD (arginine-glycine-aspartic acid) and IDS (isoleucine-aspartic acid-serine) did not synergistically enhance the extravasation process of MDA-MB-231 cells.

Reduced neutralizing antibody response to SARS-CoV-2 vaccine booster dose in people living with HIV with severe immunosuppression.

The aim of this study was to assess the immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among people living with HIV (PLWH) with severe immunosuppression, after a booster dose. The design was a case-control study nested in a prospective cohort of PLWH. All patients with CD4 cell count <200 cells/mm3 who had received additional dose of messenger RNA (mRNA) COVID-19 vaccine, after a standard immunization scheme were included. Control group: patients age- and sex-matched, with CD4 ≥ 200 cells/mm3 , in the ratio of 2:1. Antibody response to a booster dose (anti-S levels 33.8 ≥ BAU/mL) and neutralizing activity against SARS-CoV-2 B.1, B.1.617.2, and Omicron BA.1, BA.2, and BA.5 strains were assessed after the booster shot. Fifty-four PLWH were included, 18 with CD4 counts < 200 cells/mm3 . Fifty-one (94%) showed response to a booster dose. Response was less frequent in PLWH with CD4 < 200 cells/mm3 than in those with CD4 counts ≥ 200 cells/mm3 (15 [83%] vs. 36 [100%], p = 0.033). In the multivariate analysis, CD4 counts ≥ 200 cells/mm3 [incidence rate ratio (IRR) = 18.1 (95% confidence interval [CI]: 16.8-19.5), p < 0.001] was associated with a higher probability of showing antibody response. Neutralization activity against SARS-CoV-2 B.1, B.1.617, BA.1, and BA.2 strains was significantly inferior among individuals with CD4 counts < 200 cells/mm3 . In conclusion, among PLWH with CD4 counts < 200 cells/mm3 , the immune response elicited by mRNA additional vaccine dose is reduced.

Depression among COVID-19 survivors in Colombia.

The COVID-19 survivors are at high risk of meeting the criteria for depression. However, few studies have explored its prevalence and associated factors. The study aimed to know the frequency and variables associated with depression among COVID-19 survivors in Santa Marta, Colombia. A sample of COVID-19 survivors was included. Depression was quantified with the Patient Health Questionnaire (PHQ-9, α = 0.85). Three hundred and thirty survivors participated in the research. They were aged between 18 and 89 years, 61.5% were women, and 49.7% of participants scored above the cut-off point for depression. Depression was associated with female gender, younger age, COVID moderate or severe, and having presented symptoms for more than three weeks. In conclusion, depression occurs in half of the COVID-19 survivors and is higher in younger, women and who report more severe symptoms. Longitudinal studies can provide further information on the long-term impact on the mental health of COVID-19 survivors.

Linker Engineering of Ligand-Decorated DNA Origami Nanostructures Affects Biological Activity.

News from an old acquaintance: The streptavidin (STV)-biotin binding system is frequently used for the decoration of DNA origami nanostructures (DON) to study biological systems. Here, a surprisingly high dynamic of the STV/DON interaction is reported, which is affected by the structure of the DNA linker system. Analysis of different mono- or bi-dentate linker architectures on DON with a novel high-speed atomic force microscope (HS-AFM) enabling acquisition times as short as 50 ms per frame gave detailed insights into the dynamics of the DON/STV interaction, revealing dwell times in the sub-100 millisecond range. The linker systems are also used to present biotinylated epidermal growth factor on DON to study the activation of the epidermal growth factor receptor signaling cascade in HeLa cells. The studies confirm that cellular activation correlated with the binding properties of linker-specific STV/DON interactions observed by HS-AFM. This work sheds more light on the commonly used STV/DON system and will help to further standardize the use of DNA nanostructures for the study of biological processes.

SARS-CoV-2 surveillance strategy in essential workers of the Madrid City Council during the first epidemic wave in Spain, March-July 2020.

OBJECTIVES: To study prevalence of infection in essential workers of Madrid City Council by occupation, related characteristics, use of protective devices, risk perception, and main concerns about COVID-19 during lockdown. METHODS: A total of 30 231 workers were PCR tested for SARS-CoV-2 infection. Information was collected on COVID-19-related symptoms, risk factors, preventive equipment, and risk perception. The crude prevalence was calculated for infection, use of protective devices, perceived risk and main concerns. Additionally, adjusted prevalence and prevalence ratios (PR) were estimated for these variables using logistic regression models with age, gender, occupation, epidemiological week and laboratory as confounding factors. RESULTS: Overall prevalence of infection was 3.2% (95% CI 3.0% to 3.4%), being higher among policemen (4.4%) and bus drivers (4.2%), but lower among emergency healthcare personnel, firefighters, food market workers and burial services (<2%). Lower excess risk was observed in workers reporting occupational contact with COVID-19 cases only (PR=1.42; 95% CI 1.18 to 1.71) compared with household exposure only (PR=2.75; 95% CI 2.32 to 3.25). Infection was more frequent in symptomatic workers (PR=1.28; 95% CI 1.11 to 1.48), although 42% of detected infections were asymptomatic. Use of facial masks (78.7%) and disinfectants (86.3%) was common and associated with lower infection prevalence (PRmasks=0.68; 95% CI 0.58 to 0.79; PRdisinfectants=0.75; 95% CI 0.61 to 0.91). Over 50% of workers felt being at high risk of infection and worried about infecting others, yet only 2% considered quitting their work. CONCLUSIONS: This surveillance system allowed for detecting and isolating SARS-CoV-2 cases among essential workers, identifying characteristics related to infection and use of protective devices, and revealing specific needs for work-safety information and psychological support.

Suicide risk during the lockdown due to coronavirus disease (COVID-19) in Colombia.

The study aimed to estimate the high suicide risk during the COVID-19 lockdown in the Colombian population. A total of 700 adults aged between 18 and 76 years (M = 37.1, SD = 12.7; 68.0% women) completed an online questionnaire. Findings showed that 7.6% of participants reported a high suicide risk. High suicide risk was associated with high perceived stress related to COVID-19, risk of depressive episode, and insomnia. Our study suggests that 1 out of 13 Colombians in a non-probability sample reports a high suicide risk during COVID-19. Findings need to be corroborated in a representative sample of Colombians.

Acute Toxicity Evaluation of Lindane-Waste Contaminated Soils Treated by Surfactant-Enhanced ISCO.

The discharge of lindane wastes in unlined landfills causes groundwater and soil pollution worldwide. The liquid waste generated (a mixture of 28 chlorinated organic compounds, COCs) constitutes a dense non-aqueous phase liquid (DNAPL) that is highly persistent. Although in situ chemical oxidation (ISCO) is effective for degrading organic pollutants, the low COCs solubility requires high reaction times. Simultaneous injection of surfactants and oxidants (S-ISCO) is a promising technology to solve the limitation of ISCO treatment. The current work studies the remediation of highly polluted soil (COCs = 3682 mg/kg) obtained at the Sardas landfill (Sabiñáñigo, Spain) by ISCO and S-ISCO treatments. Special attention is paid to acute soil toxicity before and after the soil treatment. Microtox®, modified Basic Solid-Phase Test (mBSPT) and adapted Organic Solvent Sample Solubilization Test (aOSSST) were used for this scope. Persulfate (PS, 210 mM) activated by alkali (NaOH, 210 mM) was used in both ISCO and S-ISCO runs. A non-ionic and biodegradable surfactant selected in previous work, Emulse®3 (E3, 5, and 10 g/L), was applied in S-ISCO experiments. Runs were performed in soil columns filled with 50 g of polluted soil, with eight pore volumes (Pvs) of the reagents injected and 96 h between successive Pv injections. The total treatment time was 32 days. The results were compared with those corresponding without surfactant (ISCO). After remediation treatments, soils were water-washed, simulating the conditions of groundwater flux in the subsoil. The treatments applied highly reduced soil toxicity (final soil toxicity equivalent to that obtained for non-contaminated soil, mBSPT) and organic extract toxicity (reduction > 95%, aOSSST). Surfactant application did not cause an increase in the toxicity of the treated soil, highlighting its suitability for full-scale applications.

The influence of lifestyles to cope with stress over mental health in pregnant and postpartum women during the COVID-19 pandemic.

The COVID-19 pandemic affected daily life routines and lifestyles of pregnant and postpartum women and increased their stress and risk of suffering from mental health problems. The aim of this study was to analyse which sociodemographic variables, COVID-19 exposure variables and lifestyles to cope with stress variables predicted anxiety, depression, and PTSD symptoms in pregnant and postpartum women during the COVID-19 pandemic. A cross-sectional design was performed with a sample of 3356 Spanish women participating in the Riseup-PPD-COVID-19 study. These participants completed an online survey composed of measures of anxiety (GAD-7), depression (EPDS), and PTSD related to COVID-19 (Checklist DSM-5), as well as demographics, exposure to COVID-19, and lifestyles to cope with stress. Regarding results, 47.2% showed depression and a third reported anxiety, whereas moderate scores were observed in PTSD symptoms. The most commonly used strategies to cope with stress in the COVID-19 pandemic were talking with friends and family and increasing time with social networks. Better results in mental health were associated with coping strategies such as talking with family and friends or participating in family activities, physical activity, sleeping well at night, eating healthier, and increasing personal care. Furthermore, poor results in mental health were observed in those participants who increased time with screens, ate fast food, reported substance use, and talked more frequently with health professionals. More symptoms were also observed in younger women, primiparous women, and those who reported more exposure to COVID-19. The results underline the need to strengthen the mental health of pregnant and postpartum women. Trial registration: ClinicalTrials.gov Identifier: NCT04595123.

Prevalence and Factors Associated With Suicide Ideation in Colombian Caribbean Adolescent Students.

The study aimed to know the prevalence of and some factors associated with suicide ideation in high school adolescents from a Colombian Caribbean city. A cross-sectional analytical study was designed with probability sampling. An expected prevalence of 50% and an alpha error of 5% were estimated. High-school students from public and private institutions were invited to participate. One thousand four hundred sixty-two adolescents participated in, they were aged between 13 and 17 years, and 33.6% of students reported suicide ideation. Suicide ideation was associated with depression risk (OR = 4.54, 95% CI 2.35-8.77), family dysfunction (OR = 4.54, 95% CI 2.35-8.77), sexual violence (OR = 1.92 CI95% 1.33-2.76) and low academic achievement (OR = 1.97, 95% CI 1.42-2.73). It is concluded that 33.6% of adolescents enrolled in secondary education reported suicide ideation and was associated with depression risk, family dysfunction, sexual abuse, and poor academic achievement.

Characteristics of Citizens and Their Use of Teleconsultations in Primary Care in the Catalan Public Health System Before and During the COVID-19 Pandemic: Retrospective Descriptive Cross-sectional Study.

BACKGROUND: eConsulta-that is, asynchronous, two-way teleconsultation in primary care-is one of the most important telemedicine developments in the Catalan public health system, a service that has been heavily boosted by the onset of the COVID-19 pandemic. It is vital to know the characteristics of its users in order to be able to meet their needs and understand the coverage of this service in a context where there is reduced accessibility to the health system. OBJECTIVE: This study aims to analyze the profile of the citizens who use the eConsulta tool and the reasons for their use, as well as to gain an understanding of the elements that characterize their decision to use it while distinguishing between those who used it before and those who have used it since the onset of the COVID-19 pandemic. METHODS: A descriptive, observational study based on administrative data was performed. This study differentiates between the COVID-19 pandemic era and the period preceding it, considering the day the state of emergency was declared in Spain (ie, March 12, 2020) as the cut-off point. It also differentiates between eConsulta users who send messages and those who only receive them. RESULTS: During the pandemic, the number of unique users of this teleconsultation service had almost tripled, with up to 33.10 visits per 1000 inhabitants per month reported in the first three months. For the two user profiles analyzed, most users since the start of the COVID-19 outbreak were predominantly female, systematically younger, more actively employed, and with less complex pathologies. Furthermore, eConsulta users received more messages proactively from the health professionals. There was also a relative decrease in the number of conversations initiated by higher-income urban users and an increase in conversations initiated by users in rural areas. CONCLUSIONS: The COVID-19 pandemic has helped to generalize the use of telemedicine as a tool to compensate, to some extent, for the decline in face-to-face visits, especially among younger citizens in Catalonia. Telemedicine has made it possible to maintain contact between citizens and the health care system in the context of maximum complexity.

Healthcare workers' distress and perceived discrimination related to COVID-19 in Colombia.

This study examined the association of perceived discrimination related to COVID-19 with psychological distress in healthcare workers in the Colombian Caribbean region. The authors designed and conducted a cross-sectional study, recruiting a non-probabilistic sample by email or instant messaging. Participants filled out a questionnaire including scales for perceived discrimination, anxiety, depression, perceived stress related to COVID-19, and suicide risk. Healthcare workers (n = 150) aged 18 to 68 years participated; of these, 72% were women, and the breakdown by occupation was 39.3% nursing assistants, 18.0% nurses, and 42.7% physicians. Perceived discrimination scores showed positive correlations with depressive symptoms among nursing assistants and physicians (rs  = 0.34), and suicide risk in nursing assistants (rs  = 0.35) and physicians (rs  = 0.31). Among nurses, all measurements were independent of perceived discrimination. Nursing assistants scored highest in perceived discrimination. Physicians scored higher for COVID-19 perceived stress than nursing assistants, and nurses showed similar scores to physicians. In conclusion, perceived discrimination is related to depressive symptoms and suicide risk among nursing assistants and physicians. Nursing assistants report more perceived discrimination than nurses and physicians.

Social capital and psychological distress during Colombian coronavirus disease lockdown.

This study aimed to establish the association of low social capital (SC) with psychological distress indicators. A cross-sectional study was carried out using an online questionnaire that evaluated demographic variables, social capital, perceived stress related to coronavirus disease, depression risk, insomnia risk, and suicide risk. SC was taken as an independent variable, and symptoms indicating psychological distress were considered as dependent variables. A group of 700 adults aged between 18 and 76 years (M = 37, SD = 13) participated in the survey. Low SC was associated with depression risk (odds ratio [OR] = 2.00, 95% confidence interval [CI] = 1.34-2.97), elevated suicide risk (OR = 2.62, 95% CI = 1.40-4.91) high perceived stress related to coronavirus disease (OR = 2.08 95% CI, 1.15-3.76), and insomnia risk (OR = 2.42, 95% CI = 1.69-3.47). In conclusion, low CS was associated with indicators of psychological distress. SC is a community social resource that could help mitigate the quarantine impact of coronavirus disease amidst the Colombian population's psychological health.

Risk of a Major Depressive Episode in Asthma and COPD Patients Amidst Colombian SAR-CoV-2 Confinement.

BACKGROUND: Chronic non-communicable diseases, such as asthma (AS) and chronic obstructive pulmonary disease (COPD), are a public health problem that compromises patients' quality of life and is highly comorbid with medical and psychological conditions. The present study's objective was to know the variables associated with the risk of major depression during confinement due to SAR-CoV-2 in patients with AS and COPD in the Colombian Caribbean. SUBJECTS AND METHODS: An online cross-sectional observational study was done with the participation of patients diagnosed with AS or COPD. AS and COPD patients completed the Patient Health Questionnaire (PHQ-9) to identify a major depressive disorder risk. RESULTS: Two hundred seventy-seven patients diagnosed with AS or COPD aged 18 to 69 (M=60.4, SD=17.6) participated. The risk of major depression was assessed using the PHQ-9 sent online after telephone contact with the participants. 30.7% of the patients during the last month reported a risk of major depression, and it was associated with a history of major depressive disorder (OR=4.39, 95% CI 1.53-12.67) and medical comorbidity (OR=1.69, 95% CI 1.00-2.86). CONCLUSIONS: The depression risk is associated with a history of depressive disorder and medical comorbidity in patients with AS and COPD. Medical history is the leading risk factor for depression during confinement. It is recommended to carry out studies with many participants and study other variables that may mediate said associations during confinement by SAR-CoV-2 in the Colombian Caribbean.

Fatalism, Emotional Regulation, and Suicide Risk in Colombian Adults During the SAR-Cov-2 Disease Epidemic.

The current pandemic of Severe Acute Syndrome (SAR-CoV-2) is a public health problem with implications for mental health. The study aimed to determine the prevalence of suicide risk and its association with fatalism and emotional regulation during SARS-CoV-2 in Colombia's adult population. A cross-sectional study was designed, an online format was used, which evaluated sociodemographic variables, CES-D-SI, the Fatalism Questionnaire against COVID-19, and the Emotional Regulation Scale. 435 Colombian adults participated, aged between 18 and 79 years. A prevalence of suicide risk was found in 5.3%, and it was associated with the interaction between living in rural area and less education (OR = 5.60, 95%CI 1.28-24.53), emotional dysregulation (OR = 3.54, 95%CI 1.77-7.09), and fatalistic beliefs (OR = 3.09, 95%CI 1.53-6.27). 5.3% of the population presented an elevated suicide risk. It was associated with less education, rural areas, fatalistic beliefs, and emotional dysregulation in the Colombian population during mandatory confinement due to SAR-CoV-2.

Genome-based analyses reveal a synonymy among Halorubrum distributum Zvyagintseva and Tarasov 1989; Oren and Ventosa 1996, Halorubrum terrestre Ventosa et al. 2004, Halorubrum arcis Xu et al. 2007 and Halorubrum litoreum Cui et al. 2007. Emended description of Halorubrum distributum Zvyagintseva and Tarasov 1989; Oren and Ventosa 1996.

A comparative taxonomic study of Halorubrum distributum, Halorubrum terrestre, Halorubrum arcis and Halorubrum litoreum was carried out using different approaches, 16S rRNA gene sequence analysis, multilocus sequence analysis (MLSA), phylogenomic analysis based on the comparison of the core genome, orthologous average nucleotide identity (OrthoANI), Genome-to-Genome Distance Calculator (GGDC), synteny plots and polar lipid profile (PLP). The MLSA study, using the five concatenated housekeeping genes atpB, EF-2, glnA, ppsA and rpoB', and the phylogenomic analysis based on 1347 core translated gene sequences obtained from their genomes showed that Halorubrum distributum JCM 9100T, Halorubrum terrestre JCM 10247T, Halorubrum arcis JCM 13916T and Halorubrum litoreum JCM 13561T formed a robust cluster, clearly separated from the rest of species of the genus Halorubrum. The OrthoANI and digital DDH values, calculated by the GGDC, showed percentages among Hrr. distributum JCM 9100T, Hrr. terrestre JCM 10247T, Hrr. arcis JCM 13916T and Hrr. litoreum JCM 13561T that ranged from 98.1 to 97.5 %, and 84.0 to 78.0 %, respectively, while these values among those strains and the type strains of their most related species of Halorubrum were equal or lower than 90.8 and 41.2 %, respectively. Moreover, degree of synteny across the four genomes was very high, especially between the genomes of Halorubrum litoreum JCM 13561T and Halorubrum arcis JCM 13916T. In addition, the PLP is quite similar among the four strains studied, showing a common pattern typical of the neutrophilic species of the genus Halorubrum. Overall, these data show that Hrr. distributum, Hrr. terrestre, Hrr. arcis and Hrr. litoreum constitute a single species. Thus, the latter three should be considered as later, heterotypic synonyms of Hrr. distributum based on the rules for priority of names. We propose an emended description of Hrr. distributum, including the features of Hrr. terrestre, Hrr. arcis and Hrr. litoreum.