Collection and Extraction of Occupational Air Samples for Analysis of Fungal DNA
May 2nd, 2018
12.2K views
Determining the fungal diversity within an environment is a method utilized in occupational health studies to identify health hazards. This protocol describes DNA extraction from occupational air samples for amplification and sequencing of fungal ITS regions. This approach detects many fungal species that can be overlooked by traditional assessment methods.
Overview
This protocol outlines a method for extracting DNA from occupational air samples to amplify and sequence fungal ITS regions. It aims to identify fungal diversity in environments, which is crucial for assessing potential health hazards in occupational settings.
Key Study Components
Area of Science
- Occupational health
- Environmental microbiology
- Fungal diversity assessment
Background
- Fungal exposure can lead to negative health effects in workers.
- Traditional methods may overlook certain fungal species.
- DNA sequencing offers a more comprehensive detection approach.
- This method enhances occupational exposure assessments.
Purpose of Study
- To identify potential fungal hazards in occupational environments.
- To improve detection of fungal species using DNA sequencing.
- To address key questions regarding worker exposure to fungi.
Methods Used
- Air sampling using a NIOSH aerosol sampler.
- Assembly of air-sampling filter cassettes.
- DNA extraction from collected air samples.
- Amplification and sequencing of fungal ITS regions.
Main Results
- Identification of fungal species not detected by traditional methods.
- Enhanced understanding of fungal diversity in occupational settings.
- Potential health risks associated with specific fungal exposures.
- Methodology validated for occupational health studies.
Conclusions
- The protocol effectively identifies fungal hazards in work environments.
- Sequencing-based methods provide a comprehensive assessment of fungal diversity.
- This approach can inform health risk assessments and preventive measures.
Frequently Asked Questions
What is the main goal of this study?
The main goal is to identify potential fungal hazards in occupational settings through DNA extraction and sequencing.
How does this method improve fungal detection?
It allows for the identification of fungal species that traditional culture or microscopy methods may miss.
What are the key components of the air sampling method?
The method involves assembling filter cassettes, air sampling, and subsequent DNA extraction and sequencing.
Why is fungal diversity important in occupational health?
Understanding fungal diversity helps assess health risks associated with exposure to various fungal species.
What are the advantages of using DNA sequencing in this context?
DNA sequencing provides a more comprehensive view of fungal diversity compared to traditional methods.
Can this method be applied to other environments?
Yes, while focused on occupational settings, the method can be adapted for other environments to assess fungal diversity.
Executive Industry Relevance
This method enables comprehensive fungal hazard identification in occupational environments by overcoming limitations of culture-based detection. Molecular analysis of ITS regions provides species-level resolution critical for exposure risk assessment in biopharma manufacturing and research facilities. The approach supports predictive confidence in environmental monitoring programs by revealing hidden fungal diversity that may impact product safety or worker health.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of fungal exposure hypotheses in occupational settings through unbiased detection of diverse taxa.
- Operational Value: Provides standardized workflow for air sample processing that supports reproducible hazard identification across facilities.
Screening & Assay Development
- Scientific Value: Generates quantitative diversity indices (Chao-1, Shannon) that enable comparative assessment of fungal burden between environments.
- Operational Value: Produces sequencing-ready DNA extracts compatible with downstream ITS amplicon analysis for high-throughput screening.
Translational & Preclinical Research
- Scientific Value: Establishes disease-relevant exposure characterization by linking specific fungal taxa to potential health outcomes in worker populations.
- Operational Value: Supports continuity from environmental sampling to mechanistic studies through standardized DNA extraction yielding amplifiable fungal ITS regions.
Pipeline & Workflow Integration
The method integrates into environmental monitoring workflows from sample collection through data generation, enabling risk-informed decisions in facility management and occupational health programs.
- Discovery Biology: Supports hypothesis testing regarding fungal exposure sources and worker health impacts through culture-independent detection.
- Screening: Delivers assay-ready nucleic acid extracts with inhibitor removal ensuring reliable downstream PCR and sequencing performance.
- Analytics: Generates taxonomic profiles and diversity metrics that allow quantitative comparison of fungal communities across occupational settings.
- Translational Research: Connects environmental exposure data to health risk assessment through species-level identification relevant to toxicological studies.
- Enterprise Reuse: Provides a standardized molecular approach applicable across multiple sites for consistent fungal surveillance in GMP-adjacent environments.
Operational & Enterprise Impact
- Scientific Value: Reduces false negatives in fungal detection by capturing species missed by microscopy and culture methods.
- Operational Value: Enables scalable processing of multiple air samples through bead-beating lysis and column-based purification.
- Strategic Value: Informs risk-based prioritization of environmental controls by revealing true fungal diversity in occupational spaces.
- Portfolio Impact: Supports evidence-based decisions on facility hygiene and worker protection programs through comprehensive hazard profiling.
Implementation Considerations
- Requires expertise in molecular biology techniques including PCR setup and agarose gel electrophoresis for amplicon validation.
- Depends on access to bead mill homogenizers, centrifuges, and thermocyclers for DNA extraction and amplification steps.
- Necessitates standardized protocols across teams to ensure comparable diversity metrics between sampling events and locations.
- Involves adaptation considerations for different air sampler types while maintaining filter-based collection and extraction consistency.
- Includes practical limitations such as absence of quantitative burden measurements, focusing instead on presence/absence and diversity assessment.
Biopharma FAQs
Why does ITS region amplification matter for fungal target validation?
Amplification of fungal internal transcribed spacer (ITS) regions enables species-level identification critical for validating exposure hypotheses in occupational settings. This approach detects taxa missed by culture methods, providing mechanistic clarity on potential health hazards. The resulting sequences support taxonomic placement that informs risk assessment in biopharma environments.
How does air sample collection using NIOSH cyclone samplers fit the discovery pipeline?
Personal aerosol sampling in the worker breathing zone captures real-time fungal exposure relevant to occupational health studies. The method integrates with downstream DNA extraction to generate samples for diversity analysis. This positions air sampling as an early discovery step for identifying environmental hazards before mechanistic follow-up.
What quantitative dependent variable measurements enable comparative fungal diversity assessment?
Chao-1 Richness and Shannon Diversity indices derived from ITS sequencing data provide quantitative measures of fungal species richness and evenness. These metrics allow comparison between different occupational environments or intervention conditions. Bray-Curtis dissimilarity coefficients further enable assessment of community compositional differences across samples.
Why do replication requirements matter for cross-functional collaboration in environmental monitoring?
Triplicate PCR reactions and consistent extraction protocols ensure technical reproducibility essential for reliable data sharing between occupational health and environmental teams. Standardized lysis buffer volumes and bead-beating conditions minimize variability across sampling events. This supports collaborative interpretation of diversity trends in facility risk assessments.
What statistical analysis capabilities are required before implementing fungal ITS sequencing in occupational settings?
Ability to calculate diversity indices (Chao-1, Shannon) and dissimilarity metrics (Bray-Curtis) from sequencing data is essential for meaningful interpretation. Familiarity with rarefaction curves and taxonomic classification pipelines supports accurate diversity assessment. These capabilities enable teams to move beyond presence/absence to quantitative comparisons of fungal communities.
Chapters in this video
0:04
Title
0:48
Preparing the NIOSH Aerosol Sampler
2:00
Personal Aerosol Sampling
2:47
Extraction of Genomic DNA from Air Samples
7:46
Amplification of Fungal Ribosomal DNA
9:37
Verification of Fungal ITS Amplification Using Agarose Gel Electrophoresis
10:12
Results: Sequence-based Approach to Analyze Fungal Diversity in an Occupational Environment Using Bioaerosols
11:31
Conclusion
