The human gastrointestinal tract contains a complex community of microbes, fulfilling important health-promoting functions. However, this vast complexity of species hampers the assignment of ...responsible organisms to these functions. Recently, Akkermansia muciniphila, a new species from the deeply branched phylum Verrucomicrobia, was isolated from the human intestinal tract based on its capacity to efficiently use mucus as a carbon and nitrogen source. This anaerobic resident is associated with the protective mucus lining of the intestines.
In order to uncover the functional potential of A. muciniphila, its genome was sequenced and annotated. It was found to contain numerous candidate mucinase-encoding genes, but lacking genes encoding canonical mucus-binding domains. Numerous phage-associated sequences found throughout the genome indicate that viruses have played an important part in the evolution of this species. Furthermore, we mined 37 GI tract metagenomes for the presence, and genetic diversity of Akkermansia sequences. Out of 37, eleven contained 16S ribosomal RNA gene sequences that are >95% identical to that of A. muciniphila. In addition, these libraries were found to contain large amounts of Akkermansia DNA based on average nucleotide identity scores, which indicated in one subject co-colonization by different Akkermansia phylotypes. An additional 12 libraries also contained Akkermansia sequences, making a total of ∼16 Mbp of new Akkermansia pangenomic DNA. The relative abundance of Akkermansia DNA varied between <0.01% to nearly 4% of the assembled metagenomic reads. Finally, by testing a large collection of full length 16S sequences, we find at least eight different representative species in the genus Akkermansia.
These large repositories allow us to further mine for genetic heterogeneity and species diversity in the genus Akkermansia, providing novel insight towards the functionality of this abundant inhabitant of the human intestinal tract.
Human intestinal bacteria produce butyrate, which has signalling properties and can be used as energy source by enterocytes thus influencing colonic health. However, the pathways and the identity of ...bacteria involved in this process remain unclear. Here we describe the isolation from the human intestine of Intestinimonas strain AF211, a bacterium that can convert lysine stoichiometrically into butyrate and acetate when grown in a synthetic medium. Intestinimonas AF211 also converts the Amadori product fructoselysine, which is abundantly formed in heated foods via the Maillard reaction, into butyrate. The butyrogenic pathway includes a specific CoA transferase that is overproduced during growth on lysine. Bacteria related to Intestinimonas AF211 as well as the genetic coding capacity for fructoselysine conversion are abundantly present in colonic samples from some healthy human subjects. Our results indicate that protein can serve as a source of butyrate in the human colon, and its conversion by Intestinimonas AF211 and related butyrogens may protect the host from the undesired side effects of Amadori reaction products.
This review presents the current state of the art regarding multiparametric magnetic resonance (MR) imaging of prostate cancer. Technical requirements and clinical indications for the use of ...multiparametric MR imaging in detection, localization, characterization, staging, biopsy guidance, and active surveillance of prostate cancer are discussed. Although reported accuracies of the separate and combined multiparametric MR imaging techniques vary for diverse clinical prostate cancer indications, multiparametric MR imaging of the prostate has shown promising results and may be of additional value in prostate cancer localization and local staging. Consensus on which technical approaches (field strengths, sequences, use of an endorectal coil) and combination of multiparametric MR imaging techniques should be used for specific clinical indications remains a challenge. Because guidelines are currently lacking, suggestions for a general minimal protocol for multiparametric MR imaging of the prostate based on the literature and the authors' experience are presented. Computer programs that allow evaluation of the various components of a multiparametric MR imaging examination in one view should be developed. In this way, an integrated interpretation of anatomic and functional MR imaging techniques in a multiparametric MR imaging examination is possible. Education and experience of specialist radiologists are essential for correct interpretation of multiparametric prostate MR imaging findings. Supportive techniques, such as computer-aided diagnosis are needed to obtain a fast, cost-effective, easy, and more reproducible prostate cancer diagnosis out of more and more complex multiparametric MR imaging data.
The diversity of mucin-degrading bacteria in the human intestine was investigated by combining culture and 16S rRNA-dependent approaches. A dominant bacterium, strain MucT, was isolated by dilution ...to extinction of faeces in anaerobic medium containing gastric mucin as the sole carbon and nitrogen source. A pure culture was obtained using the anaerobic soft agar technique. Strain MucT was a Gram-negative, strictly anaerobic, non-motile, non-spore-forming, oval-shaped bacterium that could grow singly and in pairs. When grown on mucin medium, cells produced a capsule and were found to aggregate. Strain MucT could grow on a limited number of sugars, including N-acetylglucosamine, N-acetylgalactosamine and glucose, but only when a protein source was provided and with a lower growth rate and final density than on mucin. The G + C content of DNA from strain MucT was 47.6 mol%. 16S rRNA gene sequence analysis revealed that the isolate was part of the division Verrucomicrobia. The closest described relative of strain MucT was Verrucomicrobium spinosum (92 % sequence similarity). Remarkably, the 16S rRNA gene sequence of strain MucT showed 99 % similarity to three uncultured colonic bacteria. According to the data obtained in this work, strain MucT represents a novel bacterium belonging to a new genus in subdivision 1 of the Verrucomicrobia; the name Akkermansia muciniphila gen. nov., sp. nov. is proposed; the type strain is MucT (= ATCC BAA-835T = CIP 107961T).
Abstract Objective This study assessed the prevalence and risk factors of chemotherapy-induced peripheral neuropathy, and its impact on health-related quality of life among ovarian cancer survivors, ...2–12 years after diagnosis. Methods Women (n = 348) diagnosed with ovarian cancer between 2000 and 2010, as registered by the Dutch population-based Eindhoven Cancer Registry, were eligible for participation. A questionnaire, including the EORTC QLQ-C30 and EORTC QLQ-OV28 measures, containing 3 items about neuropathy, was returned by 191 women (55%). Recurrence and chemotherapy data were obtained from medical records. Results Of all 191 women, the 129 women who received chemotherapy more often reported having tingling hands/feet and feeling numbness in fingers/toes, specifically 51% reported “a little” to “very much” of these symptoms vs. about 27% who did not receive chemotherapy. Women reporting more neuropathy symptoms reported lower levels of functioning and overall quality of life. They also reported more symptoms of fatigue, nausea/vomiting, pain, dyspnea, insomnia, appetite loss, and financial problems. Moreover, women reporting more neuropathy symptoms had experienced the disease and treatment more often as being a burden and were more worried about their health, had more gastrointestinal and hormonal symptoms, hair loss and more other chemotherapy side effects. Linear regression analyses showed that more cycles of chemotherapy, more recurrences and a shorter period since last treatment were associated with a higher neuropathy score. Conclusion Neuropathy symptoms were experienced by 51% of women with ovarian cancer who received chemotherapy even up to 12 years after the end of treatment, and this seriously affected their HRQoL.
The human intestinal tract harbors diverse and complex microbial communities that have a vast metabolic capacity including the breakdown of complex carbohydrates into short chain fatty acids, ...acetate, propionate, and butyrate. As butyrate is beneficial for gut health there is much attention on butyrogenic bacteria and their role in the colonic anaerobic food chain. However, our understanding how production of butyrate by gut microorganisms is controlled by interactions between different species and environmental nutrient availability is very limited. To address this, we set up experimental
in vitro
co-culture systems to study the metabolic interactions of
Anaerostipes rhamnosivorans
, a butyrate producer with each of its partners;
Blautia hydrogenotrophica
, an acetogen;
Methanobrevibacter smithii
, a methanogen and
Bacteroides thetaiotaomicron
, a versatile degrader of plant cell wall pectins; through corresponding specific cross-feeding. In all co-cultures,
A. rhamnosivorans
was able to benefit from its partner for enhanced butyrate formation compared to monocultures. Interspecies transfer of hydrogen or formate from
A. rhamnosivorans
to the acetogen
B. hydrogenotrophica
and in turn of acetate from the acetogen to the butyrogen were essential for butyrate formation.
A. rhamnosivorans
grown on glucose supported growth of
M. smithii
via interspecies formate/hydrogen transfer enhancing butyrate formation. In the co-culture with pectin, lactate was released by
B. thetaiotaomicron
which was concomitantly used by
A. rhamnosivorans
for the production of butyrate. Our findings indicate enhanced butyrate formation through microbe-microbe interactions between
A. rhamnosivorans
and an acetogen, a methanogen or a pectin-degrader. Such microbial interactions enhancing butyrate formation may be beneficial for colonic health.
Summary
Intestinimonas is a newly described bacterial genus with representative strains present in the intestinal tract of human and other animals. Despite unique metabolic features including the ...production of butyrate from both sugars and amino acids, there is to date no data on their diversity, ecology, and physiology. Using a comprehensive phylogenetic approach, Intestinimomas was found to include at least three species that colonize primarily the human and mouse intestine. We focused on the most common and cultivable species of the genus, Intestinimonas butyriciproducens, and performed detailed genomic and physiological comparison of strains SRB521T and AF211, isolated from the mouse and human gut respectively. The complete 3.3‐Mb genomic sequences of both strains were highly similar with 98.8% average nucleotide identity, testifying to their assignment to one single species. However, thorough analysis revealed significant genomic rearrangements, variations in phage‐derived sequences, and the presence of new CRISPR sequences in both strains. Moreover, strain AF211 appeared to be more efficient than strain SRB521T in the conversion of the sugars arabinose and galactose. In conclusion, this study provides genomic and physiological insight into Intestinimonas butyriciproducens, a prevalent butyrate‐producing species, differentiating strains that originate from the mouse and human gut.
A novel butyrate-producing bacterium, strain 1y-2T, was isolated from a stool sample of a 1-year-old, healthy Dutch infant. The isolate was obtained by using lactate and acetate as sources of carbon ...and energy. The strain was Gram-variable, strictly anaerobic and spore-forming and formed curly rod-shaped cells that fermented glucose into butyrate, lactate, formate and acetate as main products. The DNA G+C content of the strain was 44.5 mol% and its major cellular fatty acids were C12 : 0, iso-C19 : 1 I and C16 : 0. Strain 1y-2T was related to Anaerostipes caccae DSM 14662T based on 16S rRNA gene sequence analysis, with 3 % divergence, but hybridization studies of their genomic DNA revealed only 33 % relatedness. Moreover, strain 1y-2T showed marked physiological and biochemical differences from known species of the genus Anaerostipes. Based on phylogenetic, chemotypic and phenotypic criteria, we propose that strain 1y-2T should be classified in the genus Anaerostipes within a novel species, Anaerostipes rhamnosivorans sp. nov. The type strain is 1y-2T ( = DSM 26241T = KCTC 15316T).
Purpose
It is unknown whether positive psychological changes (e.g., in life perspective, self-perception, and social relationships) after being diagnosed with ovarian cancer can reduce anxiety and ...depression in patients and their partners. The first aim of the present study was to assess differences in anxiety and depression between patients diagnosed with an ovarian tumor and their partners. The second aim was to explore the mutual associations of patients’ and partners’ posttraumatic growth and their anxiety and depressive symptoms.
Methods
Participants included 130 Dutch couples of which one partner was diagnosed with a borderline ovarian tumor or ovarian cancer between 2000 and 2010, as registered by the Netherlands Cancer Registry. In September 2011, a questionnaire was sent including the Hospital Anxiety and Depression Scale (anxiety and depression) and Cancer Survivors (Partners) Unmet Needs measure (positive psychological changes).
Results
A one-way multivariate analysis of variance showed that patients reported higher anxiety than partners, without differences in depression. Contrasting to our expectations, an actor-partner interdependence model revealed no mutual dyadic associations between positive psychological changes and anxiety or depressive symptoms.
Conclusions
Based on these findings, positive psychological change seems to be an independent construct unrelated to anxiety or depression in couples diagnosed with ovarian tumors. Still, as ovarian tumor patients and partners suffer from high anxiety and depression, further research investigating how these feelings can be reduced in couples dealing with an ovarian tumor is necessary.
Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their ...study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies.
Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP.
This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.
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