Bacterial communities in termite fungus combs are comprised of consistent gut deposits and contributions from the environment

Fungus-growing termites (subfamily Macrotermitinae) mix plant forage with asexual spores of their plant-degrading fungal symbiont Termitomyces in their guts and deposit this blend in fungus comb structures, within which the plant matter is degraded. As Termitomyces grows, it produces nodules with asexual spores, which the termites feed on. Since all comb material passes through termite guts, it is inevitable that gut bacteria are also deposited in the comb, but it has remained unknown which bacteria are deposited and whether distinct comb bacterial communities are sustained. Using high-throughput sequencing of the 16S rRNA gene, we explored the bacterial community compositions of 33 fungus comb samples from four termite species (three genera) collected at four South African geographic locations in 2011 and 2013. We identified 33 bacterial phyla, with Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Candidate division TM7 jointly accounting for 92 % of the reads. Analyses of gut microbiotas from 25 of the 33 colonies showed that dominant fungus comb taxa originate from the termite gut. While gut communities were consistent between 2011 and 2013, comb community compositions shifted over time. These shifts did not appear to be due to changes in the taxa present, but rather due to differences in the relative abundances of primarily gut-derived bacteria within fungus combs. This indicates that fungus comb microbiotas are largely termite species-specific due to major contributions from gut deposits and also that environment affects which gut bacteria dominate comb communities at a given point in time. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00248-015-0692-6) contains supplementary material, which is available to authorized users

The murine lung microbiome in relation to the intestinal and vaginal bacterial communities

BACKGROUND: This work provides the first description of the bacterial population of the lung microbiota in mice. The aim of this study was to examine the lung microbiome in mice, the most used animal model for inflammatory lung diseases such as COPD, cystic fibrosis and asthma. Bacterial communities from broncho-alveolar lavage fluids and lung tissue were compared to samples taken from fecal matter (caecum) and vaginal lavage fluid from female BALB/cJ mice. RESULTS: Using a customized 16S rRNA sequencing protocol amplifying the V3-V4 region our study shows that the mice have a lung microbiome that cluster separately from mouse intestinal microbiome (caecum). The mouse lung microbiome is dominated by Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria overlapping the vaginal microbiome. We also show that removal of host tissue or cells from lung fluid during the DNA extraction step has an impact on the resulting bacterial community profile. Sample preparation needs to be considered when choosing an extraction method and interpreting data. CONCLUSIONS: We have consistently amplified bacterial DNA from mouse lungs that is distinct from the intestinal microbiome in these mice. The gut microbiome has been extensively studied for its links to development of disease. Here we suggest that also the lung microbiome could be important in relation to inflammatory lung diseases. Further research is needed to understand the contribution of the lung microbiome and the gut-lung axis to the development of lung diseases such as COPD and asthma

Optimal pressure for mimicking clinical breath holding inspiratory CT in the deceased for VPMCT

Introduction Ventilated PMCT (VPMCT) has been reported to provide better quality of pulmonary structures in PMCT in adults and children. However, there are no consensus regarding optimal inflation pressure, and the practical use of VPMCT is still limited by cost of ventilation equipment. Here, we describe a simple and cost-efficient inflation-device for VPMCT and investigate optimal inflation pressure. Aim To elucidate the effect of different ventilation pressures on total lung volume and the volume of ground glass opacities (GGO), air-filled tissue, consolidations, and bronchi in VPMCT. Materials and method A precise inflation device was assembled using standard components: a back-pressure regulator, a water manometer and silicone tubing. Each case had PMCT performed at 0, 10, 20, 30 and 40 cmH2O pressure. Volumes were measured using stereology. Results 14 cases were enrolled in the study. The total lung volume increased significantly by 3612 mL (median) from 0 to 30 cmH2O (p = 0.001). The volume of consolidations was significantly reduced by 455.86 mL (median) between 0 and 30 cmH2O (p = 0.001). A significant reduction of GGO-volume of 133 mL (median) was observed at the pressure interval 30–40 cmH2O (p = 0.031), but not at lower pressures. Conclusion The constructed inflation device allowed precise and reproducible inflation of the lungs in deceased humans. We found a maximum effect of inflation at 30 cmH2O. At further inflation pressure, only the volume of GGOs decreased , but the effect was minor. For mimicking an in vivo breath-hold scan in PMCT we recommend inflation pressure of 30 cmH2O. + Graphical abstrac