Low-density lipoprotein cholesterol response to statins according to comorbidities and co-medications: A population-based study.

BACKGROUND: The response of low-density lipoprotein cholesterol (LDL-C) to statin therapy is variable, and may be affected by the presence of co-morbid conditions or the use of concomitant medications. Systematic variation in the response to statins based on these factors could affect the selection of the statin treatment regimen in population subgroups. We investigated whether common comorbidities and co-medications had clinically important effects on statin responses in individual patients. METHODS: This register-based cohort study included 89,006 simvastatin or atorvastatin initiators with measurements of pre-statin and on-statin LDL-C levels, in Denmark, 2008-2018. We defined statin response as the percentage reduction in LDL-C, and used linear regression to estimate percentage reduction differences (PRD) according to 175 chronic comorbidities and 99 co-medications. We evaluated both the statistical significance (P-values corrected for multiple testing) and the clinical importance (PRD of 5 percentage points or more) of the observed associations. RESULTS: Concomitant use of oral blood-glucose lowering drugs, which included metformin in 96% of treated individuals, was associated with a greater response to statin therapy that was both statistically significant and clinically important, with a PRD of 5.18 (95% confidence interval: 4.79 to 5.57). No other comorbidity or co-medication reached the prespecified thresholds for a significant, clinically important effect on statin response. Overall, comorbidities and co-medications had little effect on statin response, and altogether explained only 1.7% of the total observed population variance. CONCLUSION: Most of the studied comorbidities and co-medications did not have a clinically important effect on statin response, suggesting no need to modify treatment regimens. However, use of metformin was associated with a significantly enhanced LDL-C response to statins, suggesting that lower statin doses may be effective in patients taking metformin.

Effectiveness of low-density lipoprotein cholesterol reduction with lipid lowering therapy for secondary prevention amongst older individuals: a nationwide cohort study.

BACKGROUND: Data about the clinical benefit from initial low-density lipoprotein cholesterol (LDL-C) reduction with lipid lowering treatment for secondary prevention and risk of major vascular events amongst older as compared with younger individuals treated during routine clinical care are limited. We investigated this in a nationwide cohort. METHODS: Individuals aged ≥ 50 years with a first-time hospitalisation for a cardiovascular event (index event, including acute coronary syndrome, non-haemorrhagic stroke, transient ischaemic attack and coronary revascularisation), 1 January 2008 to 31 October 2018, who subsequently used lipid lowering treatment, and had an LDL-C measurement before and after the event were included. Hazard ratios (HRs) for major vascular events per 1 mmol/L reduction in LDL-C were estimated for the included 21,751 older and 22,681 younger individuals (≥/<70 years old) using Cox regression. RESULTS: LDL-C lowering was associated with a 12% lower risk of major vascular events in older individuals per 1 mmol/L reduction in LDL-C (HR 0.88, 95% confidence interval [CI] 0.84-0.93), with no significant difference compared with the risk reduction amongst younger individuals (HR 0.88, 95% CI 0.83-0.93; P-value for difference between age groups: 0.86). The risk reduction was more pronounced when post hoc restricting, as a proxy for compliance, to new users with an LDL-C reduction above the lowest decile for both older (0.81, 95% CI 0.73-0.90) and younger (0.81, 95% CI 0.72-0.91) individuals. CONCLUSIONS: This study strongly supports a similar relative clinical benefit of LDL-C reduction with lipid lowering treatment for secondary prevention of major vascular events amongst individuals aged ≥70 and <70 years.

Combined pH ratiometry and fluorescence lectin-binding analysis (pH-FLBA) for microscopy-based analyses of biofilm pH and matrix carbohydrates.

Bacterial biofilms have a complex and heterogeneous three-dimensional architecture that is characterized by chemically and structurally distinct microenvironments. Confocal microscopy-based pH ratiometry and fluorescence lectin-binding analysis (FLBA) are well-established methods to characterize pH developments and the carbohydrate matrix architecture of biofilms at the microscale. Here, we developed a combined analysis, pH-FLBA, to concomitantly map biofilm pH and the distribution of matrix carbohydrates in bacterial biofilms while preserving the biofilm microarchitecture. As a proof of principle, the relationship between pH and the presence of galactose- and fucose-containing matrix components was investigated in dental biofilms grown with and without sucrose. The pH response to a sucrose challenge was monitored in different areas at the biofilm base using the ratiometric pH-sensitive dye C-SNARF-4. Thereafter, the fucose- and galactose-specific fluorescently labeled lectins Aleuria aurantia lectin (AAL) and Morus nigra agglutinin G (MNA-G) were used to visualize carbohydrate matrix components in the same biofilm areas and their immediate surroundings. Sucrose during growth significantly decreased biofilm pH (P < 0.05) and increased the amounts of both MNA-G- and AAL-targeted matrix carbohydrates (P < 0.05). Moreover, it modulated the biofilm composition towards a less diverse community dominated by streptococci, as determined by 16S rRNA gene sequencing. Altogether, these results suggest that the production of galactose- and fucose-containing matrix carbohydrates is related to streptococcal metabolism and, thereby, pH profiles in dental biofilms. In conclusion, pH-FLBA using lectins with different carbohydrate specificities is a useful method to investigate the association between biofilm pH and the complex carbohydrate architecture of bacterial biofilms.IMPORTANCEBiofilm pH is a key regulating factor in several biological and biochemical processes in environmental, industrial, and medical biofilms. At the microscale, microbial biofilms are characterized by steep pH gradients and an extracellular matrix rich in carbohydrate components with diffusion-modifying properties that contribute to bacterial acid-base metabolism. Here, we propose a combined analysis of pH ratiometry and fluorescence lectin-binding analysis, pH-FLBA, to concomitantly investigate the matrix architecture and pH developments in microbial biofilms, using complex saliva-derived biofilms as an example. Spatiotemporal changes in biofilm pH are monitored non-invasively over time by pH ratiometry, while FLBA with lectins of different carbohydrate specificities allows mapping the distribution of multiple relevant matrix components in the same biofilm areas. As the biofilm structure is preserved, pH-FLBA can be used to investigate the in situ relationship between the biofilm matrix architecture and biofilm pH in complex multispecies biofilms.

Cumulative Incidence of Thiazide-Induced Hyponatremia : A Population-Based Cohort Study.

BACKGROUND: According to drug labels, the frequency of thiazide-induced hyponatremia is unknown or uncommon to very rare (that is, <1 in 10 000 to <1 in 100), but the exact burden remains unclear. OBJECTIVE: To estimate the increase in the cumulative incidence of hyponatremia using thiazide diuretics compared with nonthiazide antihypertensive drugs in routine clinical practice. DESIGN: Population and register-based cohort study using target trial emulation. SETTING: Denmark, 1 January 2014 to 31 October 2018. PARTICIPANTS: Two target trials were emulated among persons aged 40 years or older who had no recent prescription for any antihypertensive drug, had no previous hyponatremia, and were eligible for the studied antihypertensive treatments. The first target trial emulation compared new use of bendroflumethiazide (BFZ) versus a calcium-channel blocker (CCB). The second target trial emulation compared new use of hydrochlorothiazide plus a renin-angiotensin system inhibitor (HCTZ-RASi; that is, combination pill) versus a RASi alone. MEASUREMENTS: Two-year cumulative incidences of sodium levels less than 130 mmol/L using stabilized inverse probability of treatment-weighted survival curves. RESULTS: The study compared 37 786 new users of BFZ with 44 963 of a CCB and 11 943 new users of HCTZ-RASi with 85 784 of a RASi. The 2-year cumulative incidences of hyponatremia were 3.83% for BFZ and 3.51% for HCTZ-RASi. The risk differences were 1.35% (95% CI, 1.04% to 1.66%) between BFZ and CCB and 1.38% (CI, 1.01% to 1.75%) between HCTZ-RASi and RASi; risk differences were higher with older age and higher comorbidity burden. The respective hazard ratios were 3.56 (CI, 2.76 to 4.60) and 4.25 (CI, 3.23 to 5.59) during the first 30 days since treatment initiation and 1.26 (CI, 1.09 to 1.46) and 1.29 (CI, 1.05 to 1.58) after 1 year. LIMITATION: The study assumed that filled prescriptions equaled drug use, and residual confounding is likely. CONCLUSION: Treatment initiation with thiazide diuretics suggests a more substantial excess risk for hyponatremia, particularly during the first months of treatment, than indicated by drug labeling. PRIMARY FUNDING SOURCE: Independent Research Fund Denmark.

Does ecological drift explain variation in microbiome composition among groups in a social host species?

Within a given species, considerable inter-individual, spatial, and temporal variation in the composition of the host microbiome exists. In group-living animals, social interactions homogenize microbiome composition among group members, nevertheless divergence in microbiome composition among related groups arise. Such variation can result from deterministic and stochastic processes. Stochastic changes, or ecological drift, can occur among symbionts with potential for colonizing a host and within individual hosts, and drive divergence in microbiome composition among hosts or host groups. We tested whether ecological drift associated with dispersal and foundation of new groups cause divergence in microbiome composition between natal and newly formed groups in the social spider Stegodyphus dumicola. We simulated the initiation of new groups by splitting field-collected nests into groups of 1, 3, and 10 individuals respectively, and compared variation in microbiome composition among and within groups after 6 weeks using 16S rRNA gene sequencing. Theory predicts that ecological drift increases with decreasing group size. We found that microbiome composition among single founders was more dissimilar than among individuals kept in groups, supporting this prediction. Divergence in microbiome composition from the natal nest was mainly driven by a higher number of non-core symbionts. This suggests that stochastic divergence in host microbiomes can arise during the process of group formation by individual founders, which could explain the existence of among-group variation in microbiome composition in the wild. Individual founders appear to harbour higher relative abundances of non-core symbionts compared with founders in small groups, some of which are possible pathogens. These symbionts vary in occurrence with group size, indicating that group dynamics influence various core and non-core symbionts differently.

LDL-C Reduction With Lipid-Lowering Therapy for Primary Prevention of Major Vascular Events Among Older Individuals.

BACKGROUND: Reducing low-density lipoprotein (LDL) cholesterol with lipid-lowering therapy has consistently been shown to lower the risk of cardiovascular disease in primary prevention trials where the majority of individuals are aged <70 years. For older individuals, however, evidence is less clear. OBJECTIVES: In this study, the authors sought to compare the clinical effectiveness of lowering LDL cholesterol by means of lipid-lowering therapy for primary prevention of cardiovascular disease among older and younger individuals in a Danish nationwide cohort. METHODS: We included individuals aged ≥50 years who had initiated lipid-lowering therapy from January 1, 2008, to October 31, 2017, had no history of atherosclerotic cardiovascular disease, and had a baseline and a within-1-year LDL cholesterol measurement. We assessed the associated risk of major vascular events among older individuals (≥70 years) by HRs per 1 mmol/L reduction in LDL cholesterol compared with younger individuals (<70 years). RESULTS: For both the 16,035 older and the 49,155 younger individuals, the median LDL cholesterol reduction was 1.7 mmol/L. Each 1 mmol/L reduction in LDL cholesterol in older individuals was significantly associated with a 23% lower risk of major vascular events (HR: 0.77; 95% CI: 0.71-0.83), which was equal to that of younger individuals (HR: 0.76; 95% CI: 0.71-0.80; P value for difference = 0.79). Similar results were observed across all secondary analyses. CONCLUSIONS: Our study supports a relative clinical benefit of lowering LDL cholesterol for primary prevention of major vascular events in individuals aged ≥70 years similarly as in individuals aged <70 years.

Association Between Age and Low-Density Lipoprotein Cholesterol Response to Statins : A Danish Nationwide Cohort Study.

BACKGROUND: There is large patient-to-patient variability in the low-density lipoprotein cholesterol (LDL-C) response to statin treatment. The reduction in LDL-C may depend on the age of the patient treated-particularly in older adults, who have been substantially underrepresented in randomized controlled trials. OBJECTIVE: To investigate the association between age and the LDL-C reduction by statins. DESIGN: Nationwide, register-based cohort study. SETTING: Denmark, 2008 to 2018. PARTICIPANTS: 82 958 simvastatin or atorvastatin initiators with LDL-C measurements before and during statin use. MEASUREMENTS: Statin response, defined as percentage reduction in prestatin LDL-C level, and percentage reduction differences (PRDs) according to age and simvastatin or atorvastatin dose based on a longitudinal model for LDL-C. RESULTS: Among 82 958 statin initiators, 10 388 (13%) were aged 75 years or older. With low- to moderate-intensity statins, initiators aged 75 years or older had greater mean LDL-C percentage reductions than initiators younger than 50 years-for example, 39.0% versus 33.8% for simvastatin, 20 mg, and 44.2% versus 40.2% for atorvastatin, 20 mg. The adjusted PRD for initiators aged 75 years compared with initiators aged 50 years was 2.62 percentage points. This association was consistent for primary prevention (2.54 percentage points) and secondary prevention (2.32 percentage points) but smaller for initiators of high-intensity statins (atorvastatin, 40 mg: 1.36 percentage points; atorvastatin, 80 mg: -0.58 percentage point). LIMITATION: Use of administrative data, observational pre-post comparison with a moderately high proportion of missing data, lack of information on body mass index, and the mainly White study population may limit generalizability. CONCLUSION: Low- to moderate-intensity statins were associated with a greater reduction in LDL-C levels in older persons than younger persons and may be more appealing as initial treatment in older adults who are at increased risk for adverse events. PRIMARY FUNDING SOURCE: The Independent Research Fund Denmark, Brødrene Hartmanns Fond, and Fonden til Lægevidenskabens Fremme.

Social transmission of bacterial symbionts homogenizes the microbiome within and across generations of group-living spiders.

Disentangling modes and fidelity of symbiont transmission are key for understanding host-symbiont associations in wild populations. In group-living animals, social transmission may evolve to ensure high-fidelity transmission of symbionts, since non-reproducing helpers constitute a dead-end for vertical transmission. We investigated symbiont transmission in the social spider Stegodyphus dumicola, which lives in family groups where the majority of females are non-reproducing helpers, females feed offspring by regurgitation, and individuals feed communally on insect prey. Group members share temporally stable microbiomes across generations, while distinct variation in microbiome composition exists between groups. We hypothesized that horizontal transmission of symbionts is enhanced by social interactions, and investigated transmission routes within (horizontal) and across (vertical) generations using bacterial 16S rRNA gene amplicon sequencing in three experiments: (i) individuals were sampled at all life stages to assess at which life stage the microbiome is acquired. (ii) a cross-fostering design was employed to test whether offspring carry the microbiome from their natal nest, or acquire the microbiome of the foster nest via social transmission. (iii) adult spiders with different microbiome compositions were mixed to assess whether social transmission homogenizes microbiome composition among group members. We demonstrate that offspring hatch symbiont-free, and bacterial symbionts are transmitted vertically across generations by social interactions with the onset of regurgitation feeding by (foster)mothers in an early life stage. Social transmission governs horizontal inter-individual mixing and homogenization of microbiome composition among nest mates. We conclude that temporally stable host-symbiont associations in social species can be facilitated and maintained by high-fidelity social transmission.

Adapting to climate with limited genetic diversity: Nucleotide, DNA methylation and microbiome variation among populations of the social spider Stegodyphus dumicola.

Understanding the role of genetic and nongenetic variants in modulating phenotypes is central to our knowledge of adaptive responses to local conditions and environmental change, particularly in species with such low population genetic diversity that it is likely to limit their evolutionary potential. A first step towards uncovering the molecular mechanisms underlying population-specific responses to the environment is to carry out environmental association studies. We associated climatic variation with genetic, epigenetic and microbiome variation in populations of a social spider with extremely low standing genetic diversity. We identified genetic variants that are associated strongly with environmental variation, particularly with average temperature, a pattern consistent with local adaptation. Variation in DNA methylation in many genes was strongly correlated with a wide set of climate parameters, thereby revealing a different pattern of associations than that of genetic variants, which show strong correlations to a more restricted range of climate parameters. DNA methylation levels were largely independent of cis-genetic variation and of overall genetic population structure, suggesting that DNA methylation can work as an independent mechanism. Microbiome composition also correlated with environmental variation, but most strong associations were with precipitation-related climatic factors. Our results suggest a role for both genetic and nongenetic mechanisms in shaping phenotypic responses to local environments.

Fluorescence lectin binding analysis of carbohydrate components in dental biofilms grown in situ in the presence or absence of sucrose.

Carbohydrate components, such as glycoconjugates and polysaccharides, are constituents of the dental biofilm matrix that play an important role in biofilm stability and virulence. Exopolysaccharides in Streptococcus mutans biofilms have been characterized extensively, but comparably little is known about the matrix carbohydrates in complex, in situ-grown dental biofilms. The present study employed fluorescence lectin binding analysis (FLBA) to investigate the abundance and spatial distribution of glycoconjugates/polysaccharides in biofilms (n = 306) from 10 participants, grown in situ with (SUC) and without (H2O) exposure to sucrose. Biofilms were stained with 10 fluorescently labeled lectins with different carbohydrate specificities (AAL, ABA, ASA, HPA, LEA, MNA-G, MPA, PSA, VGA and WGA) and analyzed by confocal microscopy and digital image analysis. Microbial composition was determined by 16S rRNA gene sequencing. With the exception of ABA, all lectins targeted considerable matrix biovolumes, ranging from 19.3% to 194.0% of the microbial biovolume in the biofilms, which illustrates a remarkable variety of carbohydrate compounds in in situ-grown dental biofilms. MNA-G, AAL, and ASA, specific for galactose, fucose, and mannose, respectively, stained the largest biovolumes. AAL and ASA biovolumes were increased in SUC biofilms, but the difference was not significant due to considerable biological variation. SUC biofilms were enriched in streptococci and showed reduced abundances of Neisseria and Haemophilus spp., but no significant correlations between lectin-stained biovolumes and bacterial abundance were observed. In conclusion, FLBA demonstrates the presence of a voluminous biofilm matrix comprising a variety of different carbohydrate components in complex, in situ-grown dental biofilms.

Triculamin: An Unusual Lasso Peptide with Potent Antimycobacterial Activity.

Lasso peptides are ribosomally synthesized and post-translationally modified peptides (RiPPs) produced by microorganisms. Here we show that the two natural products triculamin and alboverticillin, originally isolated in 1967 and 1958, respectively, with potent and specific activity against mycobacteria are in fact the same lasso peptide. We solved the structure using 2D NMR spectroscopy and expanded on the previously reported bioactivity. Through genome sequencing, we identify the responsible biosynthetic gene clusters, which curiously revealed that, unlike any known lasso peptides, their precursor peptides appear to have a follower instead of a leader peptide.

Familial Resemblance in Low-Density Lipoprotein Cholesterol Response to Statins in the Danish Population.

Background Change in low-density lipoprotein cholesterol (LDL-C) level after statin initiation varies widely among individuals, and in part may be because of factors shared by family members. Methods and Results We used the Danish national registers to identify 89 006 individuals who initiated statins between 2008 and 2018 and had LDL-C measured immediately before and after the start of treatment. Among these, we identified 5148 first-degree relatives and 3198 spouses. We decomposed the variation in attained LDL-C level after statin initiation by applying a mixed-effect model with 5 variance components (inter-family and inter-individual variance in pre-statin LDL-C level, inter-family and inter-individual variance in statin response, and residual variance). Results were presented as a percentage of the total variance explained by the different variance components. We found that half of the variation in attained LDL-C level after statin initiation consisted of variance in statin response, approximately one third of variance in pre-statin LDL-C level, and the remaining 10% to 15% of residual variance. While the inter-individual variance in statin response accounted for almost half of the LDL-C variation in both cohorts, the inter-family variance in statin response accounted for 3.3% among first-degree relatives and for 6.0% among spouses. Conclusions Individual factors account for most of the variation in LDL-C level after statin initiation; factors affecting statin response common within spouses and first-degree relatives account for a similar share of variation. These results suggest a modest influence of shared genetics and shared familial environment on statin response.

Temporal and spatial microbiome dynamics across natural populations of the social spider Stegodyphus dumicola.

Host-symbiont interactions may form obligatory or facultative associations that are context dependent. Long-term studies on microbiome composition from wild populations should assess the temporal and spatial dynamics of host-microbe associations. We characterized the temporal and spatial variation in the bacterial microbiome composition in six populations of the social spider Stegodyphus dumicola for 2.5 years, using 16S rRNA gene amplicon sequencing of whole spiders. Individuals within a nest exhibit highly similar microbiomes, which remain stable over several generations and are not predictably affected by seasonal variation in temperature or humidity. This stability in nest microbiome is likely due to social transmission, whereas drift-like processes during new nest foundations explain variation in host microbiomes between nests. This is supported by the lack of obligate symbionts (i.e. no symbionts are present in all spider individuals). Quantitative PCR analyses showed that the bacterial load of individual spiders is stable in healthy nests but can increase dramatically in perishing nests. These increases are not driven by specific bacterial taxa but likely caused by loss of host immune control under deteriorating conditions. Spider nests show an annual survival rate of approximately 45%, but nest death is not correlated to microbiome composition, and the bacteria found in S. dumicola are not considered to be high virulence pathogens.

The myth of antibiotic spider silk.

Spider silk is frequently attributed antimicrobial properties. This notion is based on studies reporting antimicrobial activity (AMA) of spider silk; however, close inspection of these studies reveals that the evidence is conflicting, and at best anecdotal. We performed a systematic study of antimicrobial properties of different silk types from seven species across the spider phylogeny. We found no evidence of AMA of silk in direct contact and disc diffusion assays against Gram-negative Escherichia coli and Pseudomonas putida, and the Gram-positive Bacillus subtilis. Furthermore, staining experiments and fluorescence microscopy showed the presence of live bacteria on silk surfaces indicating no antimicrobial effect on direct contact. A critical evaluation of the literature reveals that published tests of AMA are scarce and that all the studies claiming positive results are compromised by methodological shortcomings. Our analysis demonstrates that the common notion that spider silk is antimicrobial is not supported by empirical data.

The bacterial and fungal nest microbiomes in populations of the social spider Stegodyphus dumicola.

Social spiders of the species Stegodyphus dumicola live in communal nests with hundreds of individuals and are characterized by extremely low species-wide genetic diversity. The lack of genetic diversity in combination with group living imposes a potential threat for infection by pathogens. We therefore proposed that specific microbial symbionts inhabiting the spider nests may provide antimicrobial defense. To compare the bacterial and fungal diversity in 17 nests from three different locations in Namibia, we used 16S rRNA gene and internal transcribed spacer (ITS2) sequencing. The nest microbiomes differed between geographically distinct spider populations and appeared largely determined by the local environment. Nevertheless, we identified a core microbiome consisting of four bacterial genera (Curtobacterium, Modestobacter, Sphingomonas, Massilia) and four fungal genera (Aureobasidium, Didymella, Alternaria, Ascochyta), which likely are selected from surrounding soil and plants by the nest environment. We did not find indications for a strain- or species-specific symbiosis in the nests. Isolation of bacteria and fungi from nest material retrieved a few bacterial strains with antimicrobial activity but a number of antimicrobial fungi, including members of the fungal core microbiome. The significance of antimicrobial taxa in the nest microbiome for host protection remains to be shown.

Prognostic factors of 90-day mortality in patients hospitalised with COVID-19.

INTRODUCTION: Mortality due to COVID-19 is higher among elderly patients with comorbidities. Even so, prognostication in COVID-19 remains limited. METHODS: We assessed 90-day mortality stratified by comorbidities, routine biochemical markers and oxygen need in a consecutive single-centre cohort from 2 March to 2 June 2020. RESULTS: We included 263 hospitalised patients with laboratory-confirmed COVID-19. On admission, fitness for intensive care was determined in 254 patients including 98 (39%) with a do-not-resuscitate order. Ninety-day overall mortality was 29%, whereas intensive care unit (ICU) mortality was 35% (14/40). Alcohol abuse, liver disease and elevated urea were strongly associated with mortality in univariable analyses. In a mutually adjusted multivariable analysis, we found an independent incremental increase in 90-day mortality with each increasing age by decade (hazard ratio (HR) = 1.5; 95% confidence interval (CI): 1.2-1.9), Charlson Comorbidity Index (CCI) score (HR = 1.2; 95% CI: 1.0-1.4), number of abnormal blood tests (HR = 1.2; 95% CI: 1.1-1.3) and l/min. of supplemental oxygen (HR = 1.1; 95% CI: 1.1-1.2). CONCLUSIONS: The overall mortality was similar to that of other hospitalised patients, whereas the ICU mortality was lower than expected. On admission, each additional age by decade, CCI score, number of abnormal blood tests and magnitude of supplemental oxygen were independently associated with increased mortality. FUNDING: none. TRIAL REGISTRATION: not relevant.

An antimicrobial Staphylococcus sciuri with broad temperature and salt spectrum isolated from the surface of the African social spider, Stegodyphus dumicola.

Some social arthropods engage in mutualistic symbiosis with antimicrobial compound-producing microorganisms that provide protection against pathogens. Social spiders live in communal nests and contain specific endosymbionts with unknown function. Bacteria are also found on the spiders' surface, including prevalent staphylococci, which may have protective potential. Here we present the genomic and phenotypic characterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 as novel strain of Staphylococcus sciuri within subgroup 2 of three newly defined genomic subgroups. Further phenotypic investigations showed that S. sciuri i1 is an extremophile that can grow at a broad range of temperatures (4 °C-45 °C), high salt concentrations (up to 27%), and has antimicrobial activity against closely related species. We identified a lactococcin 972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity, and found it conserved in two of the three subgroups of S. sciuri. These features indicate that S. sciuri i1, though not a specific symbiont, is well-adapted to survive on the surface of social spiders and may gain a competitive advantage by inhibiting closely related species.

How patients in Denmark acquire their medicines: overview, data sources and implications for pharmacoepidemiology.

The means by which patients acquire their medications differ between countries, and a knowledge of this is essential when conducting and interpreting pharmacoepidemiological studies. The aim of this paper is to provide an overview of how patients obtain medicines in Denmark, to relate these to nationwide registries available for research and to discuss the implications for research. Health services are predominantly tax-funded in Denmark, with dentistry and some medicine bought at community pharmacies being exceptions, involving partial reimbursement of charges. The paper gives an overview of prescription medicines acquired from community pharmacies (including magistral preparations), over-the-counter medicines, vaccinations and in-hospital medicine including so-called "free medicine" (in Danish: "vederlagsfri medicin"). "Free medicine" is medicines for a defined list of diseases and indications that is provided free of charge to patients in outpatient clinics. The paper also describes the content of the various Danish data sources about medicine use, summarizes their strengths and limitations, and exemplifies the ways of evaluating their completeness. An example is provided of the regional variation in the means by which medicines are acquired.

Microbiomes and Specific Symbionts of Social Spiders: Compositional Patterns in Host Species, Populations, and Nests.

Social spiders have remarkably low species-wide genetic diversities, potentially increasing the relative importance of microbial symbionts for host fitness. Here we explore the bacterial microbiomes of three species of social Stegodyphus (S. dumicola, S. mimosarum, and S. sarasinorum), within and between populations, using 16S rRNA gene amplicon sequencing. The microbiomes of the three spider species were distinct but shared similarities in membership and structure. This included low overall diversity (Shannon index 0.5-1.7), strong dominance of single symbionts in individual spiders (McNaughton's dominance index 0.68-0.93), and a core microbiome (>50% prevalence) consisting of 5-7 specific symbionts. The most abundant and prevalent symbionts were classified as Chlamydiales, Borrelia, and Mycoplasma, all representing novel, presumably Stegodyphus-specific lineages. Borrelia- and Mycoplasma-like symbionts were localized by fluorescence in situ hybridization (FISH) in the spider midgut. The microbiomes of individual spiders were highly similar within nests but often very different between nests from the same population, with only the microbiome of S. sarasinorum consistently reflecting host population structure. The weak population pattern in microbiome composition renders microbiome-facilitated local adaptation unlikely. However, the retention of specific symbionts across populations and species may indicate a recurrent acquisition from environmental vectors or an essential symbiotic contribution to spider phenotype.