1
|
Hoggard M, Vesty A, Wong G, Montgomery JM, Fourie C, Douglas RG, Biswas K, Taylor MW. Characterizing the Human Mycobiota: A Comparison of Small Subunit rRNA, ITS1, ITS2, and Large Subunit rRNA Genomic Targets. Front Microbiol 2018; 9:2208. [PMID: 30283425 PMCID: PMC6157398 DOI: 10.3389/fmicb.2018.02208] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 08/29/2018] [Indexed: 12/28/2022] Open
Abstract
Interest in the human microbiome has increased dramatically in the last decade. However, much of this research has focused on bacteria, while the composition and roles of their fungal counterparts remain less understood. Furthermore, a variety of methodological approaches have been applied, and the comparability between studies is unclear. This study compared four primer pairs targeting the small subunit (SSU) rRNA (18S), ITS1, ITS2, and large subunit (LSU) rRNA (26S) genomic regions for their ability to accurately characterize fungal communities typical of the human mycobiota. All four target regions of 21 individual fungal mock community taxa were capable of being amplified adequately and sequenced. Mixed mock community analyses revealed marked variability in the ability of each primer pair to accurately characterize a complex community. ITS target regions outperformed LSU and SSU. Of the ITS regions, ITS1 failed to generate sequences for Yarrowia lipolytica and all three Malassezia species when in a mixed community. These findings were further supported in studies of human sinonasal and mouse fecal samples. Based on these analyses, previous studies using ITS1, SSU, or LSU markers may omit key taxa that are identified by the ITS2 marker. Of methods commonly used in human mycobiota studies to date, we recommend selection of the ITS2 marker. Further investigation of more recently developed fungal primer options will be essential to ultimately determine the optimal methodological approach by which future human mycobiota studies ought to be standardized.
Collapse
Affiliation(s)
- Michael Hoggard
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Anna Vesty
- School of Medicine, The University of Auckland, Auckland, New Zealand.,Microbiology Laboratory, LabPLUS, Auckland City Hospital, Auckland, New Zealand
| | - Giselle Wong
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Johanna M Montgomery
- Department of Physiology, Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Chantelle Fourie
- Department of Physiology, Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Richard G Douglas
- School of Medicine, The University of Auckland, Auckland, New Zealand
| | - Kristi Biswas
- School of Medicine, The University of Auckland, Auckland, New Zealand
| | - Michael W Taylor
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
2
|
Singer E, Wagner M, Woyke T. Capturing the genetic makeup of the active microbiome in situ. THE ISME JOURNAL 2017; 11:1949-1963. [PMID: 28574490 PMCID: PMC5563950 DOI: 10.1038/ismej.2017.59] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/02/2017] [Accepted: 03/10/2017] [Indexed: 12/21/2022]
Abstract
More than any other technology, nucleic acid sequencing has enabled microbial ecology studies to be complemented with the data volumes necessary to capture the extent of microbial diversity and dynamics in a wide range of environments. In order to truly understand and predict environmental processes, however, the distinction between active, inactive and dead microbial cells is critical. Also, experimental designs need to be sensitive toward varying population complexity and activity, and temporal as well as spatial scales of process rates. There are a number of approaches, including single-cell techniques, which were designed to study in situ microbial activity and that have been successively coupled to nucleic acid sequencing. The exciting new discoveries regarding in situ microbial activity provide evidence that future microbial ecology studies will indispensably rely on techniques that specifically capture members of the microbiome active in the environment. Herein, we review those currently used activity-based approaches that can be directly linked to shotgun nucleic acid sequencing, evaluate their relevance to ecology studies, and discuss future directions.
Collapse
Affiliation(s)
- Esther Singer
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Michael Wagner
- University of Vienna, Department of Microbial Ecology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Tanja Woyke
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| |
Collapse
|