Dataset Information

Mycobiome: Approaches to analysis of intestinal fungi.

ABSTRACT: Massively parallel sequencing (MPSS) of bacterial 16S rDNA has been widely used to characterize the microbial makeup of the human and mouse gastrointestinal tract. However, techniques for fungal microbiota (mycobiota) profiling remain relatively under-developed. Compared to 16S profiling, the size and sequence context of the fungal Internal Transcribed Spacer 1 (ITS1), the most common target for mycobiota profiling, are highly variable. Using representative gastrointestinal tract fungi to build a known "mock" library, we examine how this sequence variability affects data quality derived from Illumina Miseq and Ion Torrent PGM sequencing pipelines. Also, while analysis of bacterial 16S profiles is facilitated by the presence of high-quality well-accepted databases of bacterial 16S sequences, such an accepted database has not yet emerged to facilitate fungal ITS sequence characterization, and we observe that redundant and inconsistent ITS1 sequence representation in publically available fungal reference databases affect quantitation and annotation of species in the gut. To address this problem, we have constructed a manually curated reference database optimized for annotation of gastrointestinal fungi. This targeted host-associated fungi (THF) database contains 1817 ITS1 sequences representing sequence diversity in genera previously identified in human and mouse gut. We observe that this database consistently outperforms three common ITS database alternatives on comprehensiveness, taxonomy assignment accuracy and computational efficiency in analyzing sequencing data from the mouse gastrointestinal tract.

SUBMITTER: Tang J

PROVIDER: S-EPMC4451377 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Mycobiome: Approaches to analysis of intestinal fungi.

Tang Jie J Iliev Iliyan D ID Brown Jordan J Underhill David M DM Funari Vincent A VA

Journal of immunological methods 20150417

Massively parallel sequencing (MPSS) of bacterial 16S rDNA has been widely used to characterize the microbial makeup of the human and mouse gastrointestinal tract. However, techniques for fungal microbiota (mycobiota) profiling remain relatively under-developed. Compared to 16S profiling, the size and sequence context of the fungal Internal Transcribed Spacer 1 (ITS1), the most common target for mycobiota profiling, are highly variable. Using representative gastrointestinal tract fungi to build ...[more]

PMID: 25891793

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Project description:The gastrointestinal (GI) tract harbors a diverse population of microorganisms. While much work has been focused on the characterization of the bacterial community, very little is known about the fungal community, or mycobiota, in different animal species and chickens in particular. Here, we characterized the biogeography of the mycobiota along the GI tract of day 28 broiler chicks and further examined its possible shift in response to bacitracin methylene disalicylate (BMD), a commonly used in-feed antibiotic, through Illumina sequencing of the internal transcribed spacer 2 (ITS2) region of fungal rRNA genes. Out of 124 samples sequenced, we identified a total of 468 unique fungal features that belong to four phyla and 125 genera in the GI tract. Ascomycota and Basidiomycota represented 90% to 99% of the intestinal mycobiota, with three genera, i.e., Microascus, Trichosporon, and Aspergillus, accounting for over 80% of the total fungal population in most GI segments. Furthermore, these fungal genera were dominated by Scopulariopsis brevicaulis (Scopulariopsis is the anamorph form of Microascus), Trichosporon asahii, and two Aspergillus species. We also revealed that the mycobiota are more diverse in the upper than lower GI tract. The cecal mycobiota transitioned from being S. brevicaulis dominant on day 14 to T. asahii dominant on day 28. Furthermore, 2-week feeding of 55?mg/kg BMD tended to reduce the cecal mycobiota ?-diversity. Taken together, we provided a comprehensive biogeographic view and succession pattern of the chicken intestinal mycobiota and its influence by BMD. A better understanding of intestinal mycobiota may lead to the development of novel strategies to improve animal health and productivity.IMPORTANCE The intestinal microbiota is critical to host physiology, metabolism, and health. However, the fungal community has been often overlooked. Recent studies in humans have highlighted the importance of the mycobiota in obesity and disease, making it imperative that we increase our understanding of the fungal community. The significance of this study is that we revealed the spatial and temporal changes of the mycobiota in the GI tract of the chicken, a nonmammalian species. To our surprise, the chicken intestinal mycobiota is dominated by a limited number of fungal species, in contrast to the presence of hundreds of bacterial taxa in the bacteriome. Additionally, the chicken intestinal fungal community is more diverse in the upper than the lower GI tract, while the bacterial community shows an opposite pattern. Collectively, this study lays an important foundation for future work on the chicken intestinal mycobiome and its possible manipulation to enhance animal performance and disease resistance.

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Project description:Identifying microbial indicators of damp and moldy buildings remains a challenge at the intersection of microbiology, building science, and public health. Sixty homes in New York City were assessed for moisture-related damage, and three types of dust samples were collected for microbiological analysis. We applied four approaches for detecting fungal signatures of moisture damage in these buildings. Two novel targeted approaches selected specific taxa, identified by a priori hypotheses, from the broad mycobiome as detected with amplicon sequencing. We investigated whether (i) hydrophilic fungi (i.e., requiring high moisture) or (ii) fungi previously reported as indicating damp homes would be more abundant in water-damaged rooms/homes than in nondamaged rooms/homes. Two untargeted approaches compared water-damaged to non-water-damaged homes for (i) differences between indoor and outdoor fungal populations or (ii) differences in the presence or relative abundance of particular fungal taxa. Strong relationships with damage indicators were found for some targeted fungal groups in some sampling types, although not always in the hypothesized direction. For example, for vacuum samples, hydrophilic fungi had significantly higher relative abundance in water-damaged homes, but mesophilic fungi, unexpectedly, had significantly lower relative abundance in homes with visible mold. Untargeted approaches identified no microbial community metrics correlated with water damage variables but did identify specific taxa with at least weak positive links to water-damaged homes. These results, although showing a complex relationship between moisture damage and microbial communities, suggest that targeting particular fungi offers a potential route toward identifying a fungal signature of moisture damage in buildings.IMPORTANCE Living or working in damp or moldy buildings increases the risk of many adverse health effects, including asthma and other respiratory diseases. To date, however, the particular environmental exposure(s) from water-damaged buildings that causes the health effects have not been identified. Likewise, a consistent quantitative measurement that would indicate whether a building is water damaged or poses a health risk to occupants has not been found. In this work, we tried to develop analytical tools that would find a microbial signal of moisture damage amid the noisy background of microorganisms in buildings. The most successful approach taken here focused on particular groups of fungi-those considered likely to grow in damp indoor environments-and their associations with observed moisture damage. With further replication and refinement, this hypothesis-based strategy may be effective in finding still-elusive relationships between building damage and microbiomes.

Dataset Information

Mycobiome: Approaches to analysis of intestinal fungi.

Publications

Mycobiome: Approaches to analysis of intestinal fungi.

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