The microbiome of the habitat-forming brown alga Fucus vesiculosus (Phaeophyceae) has similar cross-Atlantic structure that reflects past and present drivers1.

Latitudinal diversity gradients have provided many insights into species differentiation and community processes. In the well-studied intertidal zone, however, little is known about latitudinal diversity in microbiomes associated with habitat-forming hosts. We investigated microbiomes of Fucus vesiculosus because of deep understanding of this model system and its latitudinally large, cross-Atlantic range. Given multiple effects of photoperiod, we predicted that cross-Atlantic microbiomes of the Fucus microbiome would be similar at similar latitudes and correlate with environmental factors. We found that community structure and individual amplicon sequencing variants (ASVs) showed distinctive latitudinal distributions, but alpha diversity did not. Latitudinal differentiation was mostly driven by ASVs that were more abundant in cold temperate to subarctic (e.g., Granulosicoccus_t3260, Burkholderia/Caballeronia/Paraburkholderia_t8371) or warm temperate (Pleurocapsa_t10392) latitudes. Their latitudinal distributions correlated with different humidity, tidal heights, and air/sea temperatures, but rarely with irradiance or photoperiod. Many ASVs in potentially symbiotic genera displayed novel phylogenetic biodiversity with differential distributions among tissues and regions, including closely related ASVs with differing north-south distributions that correlated with Fucus phylogeography. An apparent southern range contraction of F. vesiculosus in the NW Atlantic on the North Carolina coast mimics that recently observed in the NE Atlantic. We suggest cross-Atlantic microbial structure of F. vesiculosus is related to a combination of past (glacial-cycle) and contemporary environmental drivers.

The fatty acid signaling molecule cis-2-decenoic acid increases metabolic activity and reverts persister cells to an antimicrobial-susceptible state.

Persister cells, which are tolerant to antimicrobials, contribute to biofilm recalcitrance to therapeutic agents. In turn, the ability to kill persister cells is believed to significantly improve efforts in eradicating biofilm-related, chronic infections. While much research has focused on elucidating the mechanism(s) by which persister cells form, little is known about the mechanism or factors that enable persister cells to revert to an active and susceptible state. Here, we demonstrate that cis-2-decenoic acid (cis-DA), a fatty acid signaling molecule, is able to change the status of Pseudomonas aeruginosa and Escherichia coli persister cells from a dormant to a metabolically active state without an increase in cell number. This cell awakening is supported by an increase of the persister cells' respiratory activity together with changes in protein abundance and increases of the transcript expression levels of several metabolic markers, including acpP, 16S rRNA, atpH, and ppx. Given that most antimicrobials target actively growing cells, we also explored the effect of cis-DA on enhancing antibiotic efficacy in killing persister cells due to their inability to keep a persister cell state. Compared to antimicrobial treatment alone, combinational treatments of persister cell subpopulations with antimicrobials and cis-DA resulted in a significantly greater decrease in cell viability. In addition, the presence of cis-DA led to a decrease in the number of persister cells isolated. We thus demonstrate the ability of a fatty acid signaling molecule to revert bacterial cells from a tolerant phenotype to a metabolically active, antimicrobial-sensitive state.

SSU rRNA sequencing data for bacterial communities associated with Vibrio-infected rainbow trout (Oncorhynchus mykiss).

Vibrio anguillarum infection in aquacultured trout, besides its own harmful effects, can also make the fish more susceptible to other infections, both by swamping the host's immune system and by creating the skin lesions that serve as a direct gateway for opportunistic bacteria. Tissue samples were taken from the intestines, spleen and skin lesions of cage-grown rainbow trout suffering from natural Vibrio infections of varying severity. In addition, a water sample was taken to document the planktonic bacteria inhabiting the fish farm at the time of the study. Total DNA was isolated from these samples and used to produce v3-v4 SSU rRNA amplicons, which were then sequenced on Illumina MiSeq (2 × 300 bp) and assembled into 97% identity OTUs. This dataset allows analysis of bacteria co-colonizing the skin and intestines of infected fish along with the pathogenic Vibrio anguillarum, as well as provides information on the spread of bacteria between various bodily compartments of trout.

Bacterial Communities Show Algal Host (Fucus spp.)/Zone Differentiation Across the Stress Gradient of the Intertidal Zone.

The intertidal zone often has varying levels of environmental stresses (desiccation, temperature, light) that result in highly stress-tolerant macrobiota occupying the upper zone while less tolerant species occupy the lower zone, but little comparative information is available for intertidal bacteria. Here we describe natural (unmanipulated) bacterial communities of three Fucus congeners (F. spiralis, high zone; F. vesiculosus, mid zone; F. distichus, low zone) as well as those of F. vesiculosus transplanted to the high zone (Dry and Watered treatments) and to the mid zone (Procedural Control) during summer in Maine (United States). We predicted that bacterial communities would be different among the differently zoned natural congeners, and that higher levels of desiccation stress in the high zone would cause bacterial communities of Dry transplants to become similar to F. spiralis, whereas relieving desiccation stress on Watered transplants would maintain the mid-zone F. vesiculosus bacterial community. Bacteria were identified as amplicon sequence variants (ASVs) after sequencing the V4 hypervariable region of the 16S rRNA gene. Microbiome composition and structure were significantly different between the differently zoned congeners at each tissue type (holdfasts, receptacles, vegetative tips). ASVs significantly associated with the mid-zone congener were frequently also present on the high-zone or low-zone congener, whereas overlap in ASVs between the high-zone and low-zone congeners was rare. Only 7 of 6,320 total ASVs were shared among tissues over all congeners and transplant treatments. Holdfast bacterial community composition of Dry transplants was not significantly different from that of F. spiralis, but Watered holdfast communities were significantly different from those of F. spiralis and not significantly different from those of procedural controls. Additional stressor(s) appeared important, because bacterial communities of Dry and Watered transplants were only marginally different from each other (p = 0.059). The relative abundance of Rhodobacteraceae associated with holdfasts generally correlated with environmental stress with highest abundance associated with F. spiralis and the two high-zone transplant treatments. These findings suggest that the abiotic stressors that shape distributional patterns of host species also affect their bacterial communities.

New approach for evaluating the effectiveness of whole-body magnetic field therapy in the rehabilitation of patients with lumbar discectomy.

OBJECTIVE: Magnetic field therapy involves the application of low-intensity magnetic fields (1-3.5 mT) to a patient's whole body. The purpose of this study was to assess the effectiveness of whole-body magnetic field (WBMF) therapy in the early rehabilitation of patients after lumbar discectomy. METHODS: A convenience sample of 73 patients who underwent lumbar discectomy within 1 month previously participated in the study. All patients were randomly assigned to one of two groups and received either a course of conventional rehabilitation (control group) or conventional rehabilitation together with 10 sessions of WBMF therapy (WBMF group). Participants were evaluated before and after the rehabilitation course by using the Visual Analog Scale for Pain (VAS) and thermal infrared imaging. The latter was used to detect pathological changes in temperature (hyperthermia and thermal asymmetry) of the surface of the skin overlying the lumbar spine and lower extremities. RESULTS: The VAS score of the WBMF group decreased from 6.2 ± 0.3 cm before to 3.2 ± 0.2 cm after rehabilitation (p< 0.01), compared to 6.1 ± 0.4 cm before to 4.3 ± 0.2 cm after rehabilitation for the control group (p< 0.05). Reduction of the area of lumbar hyperthermia was observed in 88% of WBMF and 35% of control group patients. CONCLUSIONS: When combined with conventional rehabilitation, WBMF therapy was effective in reducing lumbar pain, temperature, and, possibly, inflammation. Results of this study will be used for designing a large-scale clinical trial.