adhesiomeR: a tool for Escherichia coli adhesin classification and analysis.

Adhesins are crucial factors in the virulence of bacterial pathogens such as Escherichia coli. However, to date no resources have been dedicated to the detailed analysis of E. coli adhesins. Here, we provide adhesiomeR software that enables characterization of the complete adhesin repertoire, termed the adhesiome. AdhesiomeR incorporates the most comprehensive database of E. coli adhesins and facilitates an extensive analysis of adhesiome. We demonstrate that adhesiomeR achieves 98% accuracy when compared with experimental analyses. Based on analysis of 15,000 E. coli genomes, we define novel adhesiome profiles and clusters, providing a nomenclature for a unified comparison of E. coli adhesiomes.

Pervasive associations between dark septate endophytic fungi with tree root and soil microbiomes across Europe.

Trees interact with a multitude of microbes through their roots and root symbionts such as mycorrhizal fungi and root endophytes. Here, we explore the role of fungal root symbionts as predictors of the soil and root-associated microbiomes of widespread broad-leaved trees across a European latitudinal gradient. Our results suggest that, alongside factors such as climate, soil, and vegetation properties, root colonization by ectomycorrhizal, arbuscular mycorrhizal, and dark septate endophytic fungi also shapes tree-associated microbiomes. Notably, the structure of root and soil microbiomes across our sites is more strongly and consistently associated with dark septate endophyte colonization than with mycorrhizal colonization and many abiotic factors. Root colonization by dark septate endophytes also has a consistent negative association with the relative abundance and diversity of nutrient cycling genes. Our study not only indicates that root-symbiotic interactions are an important factor structuring soil communities and functions in forest ecosystems, but also that the hitherto less studied dark septate endophytes are likely to be central players in these interactions.

Enterosignatures define common bacterial guilds in the human gut microbiome.

The human gut microbiome composition is generally in a stable dynamic equilibrium, but it can deteriorate into dysbiotic states detrimental to host health. To disentangle the inherent complexity and capture the ecological spectrum of microbiome variability, we used 5,230 gut metagenomes to characterize signatures of bacteria commonly co-occurring, termed enterosignatures (ESs). We find five generalizable ESs dominated by either Bacteroides, Firmicutes, Prevotella, Bifidobacterium, or Escherichia. This model confirms key ecological characteristics known from previous enterotype concepts, while enabling the detection of gradual shifts in community structures. Temporal analysis implies that the Bacteroides-associated ES is "core" in the resilience of westernized gut microbiomes, while combinations with other ESs often complement the functional spectrum. The model reliably detects atypical gut microbiomes correlated with adverse host health conditions and/or the presence of pathobionts. ESs provide an interpretable and generic model that enables an intuitive characterization of gut microbiome composition in health and disease.

LotuS2: an ultrafast and highly accurate tool for amplicon sequencing analysis.

BACKGROUND: Amplicon sequencing is an established and cost-efficient method for profiling microbiomes. However, many available tools to process this data require both bioinformatics skills and high computational power to process big datasets. Furthermore, there are only few tools that allow for long read amplicon data analysis. To bridge this gap, we developed the LotuS2 (less OTU scripts 2) pipeline, enabling user-friendly, resource friendly, and versatile analysis of raw amplicon sequences. RESULTS: In LotuS2, six different sequence clustering algorithms as well as extensive pre- and post-processing options allow for flexible data analysis by both experts, where parameters can be fully adjusted, and novices, where defaults are provided for different scenarios. We benchmarked three independent gut and soil datasets, where LotuS2 was on average 29 times faster compared to other pipelines, yet could better reproduce the alpha- and beta-diversity of technical replicate samples. Further benchmarking a mock community with known taxon composition showed that, compared to the other pipelines, LotuS2 recovered a higher fraction of correctly identified taxa and a higher fraction of reads assigned to true taxa (48% and 57% at species; 83% and 98% at genus level, respectively). At ASV/OTU level, precision and F-score were highest for LotuS2, as was the fraction of correctly reported 16S sequences. CONCLUSION: LotuS2 is a lightweight and user-friendly pipeline that is fast, precise, and streamlined, using extensive pre- and post-ASV/OTU clustering steps to further increase data quality. High data usage rates and reliability enable high-throughput microbiome analysis in minutes. AVAILABILITY: LotuS2 is available from GitHub, conda, or via a Galaxy web interface, documented at http://lotus2.earlham.ac.uk/ . Video Abstract.

Efficacy and ease of use of an intravenous catheter designed to prevent blood leakage: a prospective observational trial.

PURPOSE: Conventional safety intravenous (IV) catheters prevent blood exposure during catheter placement but blood leakage from the unconnected catheter still frequently occurs. In the current study a new safety IV catheter equipped with a blood leakage control septum was assessed under routine clinical conditions. METHODS: This prospective observational trial was conducted at the KKRN (Katholisches Klinikum Ruhrgebiet Nord), Germany, September/October 2012. Peripheral IV access was established in presurgical patients using either the investigational ("IS3") or a conventional safety IV catheter ("IS"). Incidence of blood leakage during placement and subsequent (dis-)connection procedures, duration of placement as well as handling conditions were compared. RESULTS: A total of 200 IV accesses were established (n(IS3) = 102 and n(IS) = 98). Blood leakage during catheter placement (4.9% (IS3) vs. 61.2% (IS); p<0.001) and blood contaminations (3.9% (IS3) vs. 14.3% (IS); p = 0.01) were significantly reduced for IS3. All blood leakages observed with IS3 were due to improper technique. No blood leakage occurred during repeated (dis-)connections of IS3 (blood leakage IS: 74%). Using IS3, vein compression was not required (no compression: 98%) and duration of catheter placement was significantly shorter (t(IS3) = 69.6 ± 22.4 s vs. t(IS) = 85.2 ± 28.2 s; p<0.001). CONCLUSIONS: The investigational IV catheter effectively prevented blood leakage, thereby reducing contamination risk and workload associated with cleaning. Omission of vein compression facilitated and shortened IV catheter placement.