An Insight Into Intestinal Microbiota of Spontaneously Hypertensive Rats After Valsartan Administration

It has been proven a close relationship between intestinal microbiota and hypertension. Valsartan is a widely used ARB antihypertensive drug; so far, the effect of valsartan on intestinal microbiota remains largely unexplored. Herein, we evaluated the composition, structure and metabolites of intestinal microbiota of spontaneously hypertensive rats (SHRs) after valsartan administration. In the present study, valsartan administration decreased intestinal microbiota diversity, altered gut microbiota composition, leading to 192 unique OTUs deficiency ( vs WKY rats) and 10 unique OTUs deficiency ( vs SHRs) and did not prove impaired intestinal mucosal barriers. Valsartan decreased the production of isobutyric acid and isovaleric acid in SCFAs. Our findings revealed valsartan administration induced far-reaching and robust changes to the intestinal microbiota of SHRs and provided a better understanding of the relationship between efficacy of valsartan and gastrointestinal tract reaction.

Not That Close to Mommy: Horizontal Transmission Seeds the Microbiome Associated with the Marine Sponge Plakina cyanorosea

Marine sponges are excellent examples of invertebrate–microbe symbioses. In this holobiont, the partnership has elegantly evolved by either transmitting key microbial associates through the host germline and/or capturing microorganisms from the surrounding seawater. We report here on the prokaryotic microbiota during different developmental stages of Plakina cyanorosea and their surrounding environmental samples by a 16S rRNA metabarcoding approach. In comparison with their source adults, larvae housed slightly richer and more diverse microbial communities, which are structurally more related to the environmental microbiota. In addition to the thaumarchaeal Nitrosopumilus, parental sponges were broadly dominated by Alpha- and Gamma-proteobacteria, while the offspring were particularly enriched in the Vibrionales, Alteromonodales, Enterobacterales orders and the Clostridia and Bacteroidia classes. An enterobacterial operational taxonomic unit (OTU) was the dominant member of the strict core microbiota. The most abundant and unique OTUs were not significantly enriched amongst the microbiomes from host specimens included in the sponge microbiome project. In a wider context, Oscarella and Plakina are the sponge genera with higher divergence in their associated microbiota compared to their Homoscleromorpha counterparts. Our results indicate that P. cyanorosea is a low microbial abundance sponge (LMA), which appears to heavily depend on the horizontal transmission of its microbial partners that likely help the sponge host in the adaptation to its habitat.

Long-term effects of mixed planting on arbuscular mycorrhizal fungal communities in the roots and soils of Juglans mandshurica plantations

Background Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management. Results Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil. Conclusions Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

Long-term Effects of Mixed Planting on Arbuscular Mycorrhizal Fungal Communities in the Roots and Soils of Juglans mandshurica Plantations

Background: Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management.Results: Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil.Conclusions: Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

Untapped sponge microbiomes: structure specificity at host order and family levels

ABSTRACT Sponges are complex holobionts in which the structure of the microbiome has seldom been characterized above the host species level. The hypothesis tested in this study is that the structure of the sponge microbiomes is specific to the host at the order and family levels. This was done by using 33 sponge species belonging to 19 families representing five orders. A combination of three primer sets covering the V1-V8 regions of the 16S rRNA gene provided a more comprehensive coverage of the microbiomes. Both the diversity and structure of sponge microbiomes were demonstrated to be highly specific to the host phylogeny at the order and family levels. There are always dominant operational taxonomic units (OTUs) (relative abundance >1%) shared between microbial communities of sponges within the same family or order, but these shared OTUs showed high levels of dissimilarity between different sponge families and orders. The unique OTUs for a particular sponge family or order could be regarded as their ‘signature identity’. 70%–87% of these unique OTUs (class level) are unaffiliated and represent a vast resource of untapped microbiota. This study contributes to a deeper understanding on the concept of host-specificity of sponge microbiomes and highlights a hidden reservoir of sponge-associated microbial resources.

High similarity in the microbiota of cold-water sponges of the Genus Mycale from two different geographical areas

Sponges belonging to genus Mycale are common and widely distributed across the oceans and represent a significant component of benthic communities in term of their biomass, which in many species is largely composed by bacteria. However, the microbial communities associated with Mycale species inhabiting different geographical areas have not been previously compared. Here, we provide the first detailed description of the microbiota of two Mycale species inhabiting the sub-Antarctic Magellan region (53°S) and the Western Antarctic Peninsula (62–64°S), two geographically distant areas (>1,300 km) with contrasting environmental conditions. The sponges Mycale (Aegogropila) magellanica and Mycale (Oxymycale) acerata are both abundant members of benthic communities in the Magellan region and in Antarctica, respectively. High throughput sequencing revealed a remarkable similarity in the microbiota of both sponge species, dominated by Proteobacteria and Bacteroidetes, with both species sharing more than 74% of the OTUs. In contrast, 16% and 10% of the OTUs were found only in either M. magellanica or M. acerata, respectively. Interestingly, despite slight differences in the relative abundance, the most dominant OTUs were present in both species, whereas the unique OTUs had very low abundances (less than 1% of the total abundance). These results show a significant overlap among the microbiota of both Mycale species and also suggest the existence of a low level of specificity of the most dominant symbiont groups.

Increased culturability of soil bacteria from Marcellus shale temperate forest in Pennsylvania

Soil bacteria comprise a largely untapped resource with only 1-10% of bacterial species predicted to live in soil being culturable in the laboratory. Establishing culture-dependent protocols that identify unique operational taxonomic units (OTUs) is an important research topic in soil bacterial ecology. The culturability of soil bacteria may be improved by employing different culture media due to inherent preferences of growth substrate utilization. Soil-extract agar, R-2A agar, and 1% nutrient agar were used in this study to isolate bacteria obtained from soil samples collected in winter months to increase the understanding of bacterial diversity in Abernathy Field Station, a Marcellus shale temperate forest in Washington, Pennsylvania. Changes in bacterial diversity can be used to assess the early impact of anthropological factors, such as hydraulic fracturing in the Marcellus shale region, which may lead to severe environmental problems. For the purpose of long term ecological monitoring, data obtained from this year’s sample collection were analyzed in conjunction with previous years’ assessments. Bacterial isolates were analyzed taxonomically and phylogenetically. Unique OTUs were identified through comparative analysis of 16S rDNA. The Shannon-Weaver and Simpson’s diversity indices ranked isolates on soil-extract agar highest for species richness, and rarefaction analysis suggests that sampling saturation of OTUs identified on soil-extract agar has not yet been reached. Each culture medium studied supported isolates of four common phyla: Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Soil-extract agar supported the greatest proportion of pigmented colonies including a Cyanobacterium which exhibited intra-16S rDNA polymorphism. Each culture medium supported the growth of unique OTUs and genera with Bacillus, Flavobacterium, Pseudomonas, Rhizobium, and Streptomyces found on each. This study suggests that utilizing different culture media can increase the culturability of soil bacteria.

Fecal Microbiota Diversity in Survivors of Adolescent/Young Adult Hodgkin Lymphoma

Abstract 1533 Survivors of adolescent/young adult Hodgkin lymphoma (AYAHL) report fewer exposures to infections during childhood compared to controls. They also have persistent genomic and functional aberrations in their lymphocytes that are partially attributable to chemotherapy or radiotherapy. Recent studies have shown that the gut microbiome can affect both the innate and adaptive immune response, and can suppress or exacerbate an inflammatory response. Given the central role of the gut microbiota in immune function, we investigated whether AYAHL survivors, who were members of 13 mono- and dizygotic twin pairs discordant for this disease, have differences in the diversity or phylogenetic configurations of their fecal microbiota compared to their unaffected co-twins. Twin pairs discordant for AYAHL are an ideal study population because they are at least partially matched on genetic and early life factors, both of which influence the composition of the gut microbiome. Pyrosequencing of bacterial 16S rRNA amplicons generated from single fecal samples obtained from each individual yielded 253,182 filtered and de-noised reads translated into species-level operational taxonomic units (OTUs). Standardized across individuals by random sampling, reads were assigned to 2513 OTUs to compare microbiome diversity and relative abundance of taxa. The number of OTU's was compared between twins using a paired student's t-test and a one-way analysis of variance was performed to determine whether such measures differed across twin pairs by comparing the measures between twins to those of randomly paired individuals. AYAHL survivors had less diverse fecal microbial communities compared to their unaffected co-twin controls by all measures of alpha diversity (Table 1). Measures that weighted the relative abundance of the bacteria were not statistically significantly different (Shannon Index, p= 0.270; Chao index, p= 0.066, PD Whole Tree Index, p= 0.051). However, when the unweighted number of unique OTUs was considered, the difference was significant (338 in cases vs. 369 in unaffected co-twin controls, p= 0.015). When the analysis was restricted to OTUs that were present at an abundance of > 0.1% in at least 2 of the 23 samples analyzed, the differences were attenuated, with only the PD Whole Tree index difference in diversity remaining marginally significant (p= 0.045). Only one bacterial taxon was associated with AYAHL, probably due to chance. Phylogenetic measurements indicated that the bacterial component of the microbiota of co-twins were more similar with respect to one another than unrelated individuals, although no differences by zygosity were observed. These results provide evidence that AYAHL survivors have reduced diversity of the gut microbiota, perhaps as a consequence the disease, its treatment, or a particularly hygienic environment. Table 1. Comparisons of alpha diversity measurements between Hodgkin lymphoma cases and co-twin controls. Measurements of Alpha Diversity Mean (Cases) Mean (Unaffected Co-twins) Mean Difference (Unaffected co-twin-case difference) P-value1 Initial analysis No. unique OTUs 338 369 31 0.015 Shannon index 5.6 5.8 0.2 0.27 Chao1 533 574 41 0.066 PD_whole tree 21.2 22.8 1.6 0.051 Conservative analysis No. unique OTUs 183 196 13 0.10 Shannon index 5.2 5.4 0.2 0.40 Chao1 230 237 7 0.47 PD_whole tree 13.7 14.6 0.9 0.045 1 P-value by paired t-tests. Disclosures: No relevant conflicts of interest to declare.