Actinobacteria & Actinomycetes in Water-Damaged Buildings: Research
104 papers · Curated by Lauren Lowenstein, The Biotoxin Lady
If you've remediated the mold, your HERTSMI-2 looks good, and you still aren't improving, it's time to talk about actinobacteria.
Actinobacteria (older papers often call them actinomycetes) are gram-positive, filamentous bacteria. They live in soil and water, grow in water-damaged buildings, and some live on human skin. Many species make potent metabolites, and they've been studied for decades in occupational lung disease such as hypersensitivity pneumonitis. More recently, CIRS researchers have looked at them as a trigger in their own right, separate from mold.
All too often I see people working with a Shoemaker-aware provider who still haven't addressed actinos. Standard mold testing like ERMI won't pick them up. You have to test for them specifically.
This hub collects about 104 research papers on actinobacteria and CIRS: indoor exposure, identification methods (including 16S sequencing), Streptomyces, Nocardia and related genera, immune and inflammatory effects, and building-related illness.
For the practical side, including how actino dust and skin testing works and what the scores mean, read my full Actinobacteria guide.
Educational only, not medical advice.
— Lauren Lowenstein, The Biotoxin Lady · Last reviewed October 19, 2026
Key facts
- Actinobacteria are gram-positive, filamentous bacteria found in soil, water-damaged buildings and on human skin.
- They can drive inflammation even when mold has been addressed.
- ERMI and HERTSMI-2 measure mold DNA and don't detect actinobacteria. Separate testing is needed.
- Actinomycetes have long been studied as a cause of hypersensitivity pneumonitis.
Key research papers
- Identification of environmental Actinobacteria in buildings by means of chemotaxonomy, 16S rRNA sequencing, and MALDI-TOF MS.
Anna Chudzik et al. · Microbiology spectrum · 2024
- The biocontaminants and complexity of damp indoor spaces: more than what meets the eyes
Thrasher J et al. · Toxicology and Industrial Health · 2009
- Exposure to bacterial and fungal bioaerosols in facilities processing biodegradable waste
Merja H. Kontro et al. · Frontiers in Public Health · 2022
- Bacteria in a water-damaged building: associations of actinomycetes and non-tuberculous mycobacteria with respiratory health in occupants
Ju‐Hyeong Park et al. · Indoor Air · 2017
- Microbiological analyses and inflammatory effects of settled dusts from rice and hay
Shen Y et al. · Biomedical and environmental sciences · 1990
- The Genome Analysis of the Human Lung-Associated Streptomyces sp. TR1341 Revealed the Presence of Beneficial Genes for Opportunistic Colonization of Human Tissues
Ana Lara et al. · Microorganisms · 2021
- Streptomyces cheonanensis sp. nov., a novel streptomycete with antifungal activity
Kim HJ et al. · INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY · 2006
- Actinobacteria: Boon or Bane?
Aeshna Nigam et al. · Microsphere · 2025
- Synergistic interaction in simultaneous exposure to Streptomyces californicus and Stachybotrys chartarum
Kati Huttunen et al. · Environmental Health Perspectives · 2004
- Detection of streptomycetes in house dust - comparison of culture and PCR methods
Helena Rintala et al. · Indoor Air · 2004
- Release of Streptomyces albus propagules from contaminated surfaces
Górny RL et al. · Environmental Research · 2003
- Species of Fungi and Pollen in the PM1 and the Inhalable Fraction of Indoor Air in Homes
Rui Lü et al. · Atmosphere · 2021
- The Proportions ofStreptomyces californicusandStachybotrys chartarumin Simultaneous Exposure Affect Inflammatory Responses in Mouse RAW264.7 Macrophages
Penttinen P et al. · Inhalation Toxicology · 2005
- Isolation and identification of environmental microorganisms from the Tumbas Reales de Sipan museum
Rocío Farro-Barbaran et al. · Revista U D C A Actualidad & Divulgación Científica · 2021
- Systematic review of Pulmonary Manifestations by Thermophilic Actinomycetes: A Biological, Clinical and Pathological Analysis.
Anlly Añez et al. · SAP Multidisciplinary Open · 2025
- Exposure to Actinobacteria resident in water-damaged buildings and resultant immune injury in Chronic Inflammatory Response Syndrome
Ritchie C. Shoemaker et al. · Medical Research Archives · 2021
- Streptomyces albireticuli lung infection managed as a pulmonary air cyst: a case report and literature review
Jiajiao Liu et al. · Frontiers in Cellular and Infection Microbiology · 2024
- Systemic Immunoresponses in Mice after Repeated Exposure of Lungs to Spores of Streptomyces californicus
Jussila J et al. · Clinical and Vaccine Immunology · 2003
- TUBB1, TUBA4A and MAPK as Indicators of Die-Back Degenerative Central Nervous System Disease in Patients Sickened by Specific Exposure to the Interior Environment of Water- Damaged Buildings
Ritchie C. Shoemaker et al. · Medical Research Archives · 2023
- Screening for Biomarkers of Actinobacteria Associated with Water-Damaged Buildings – Part 1
Ritchie C. Shoemaker et al. · Medical Research Archives · 2022
- Newer Molecular Methods Bring New Insights into Human- And Building-Health Risk Assessments from Water-Damaged Buildings: Defining Exposure and Reactivity, the Two Sides of Causation of CIRS-WDB Illness
R. L. Shoemaker et al. · Medical Research Archives · 2021
- EFFECT OF LINER AND CORE MATERIALS OF PLASTERBOARD ON MICROBIAL GROWTH, SPORE-INDUCED INFLAMMATORY RESPONSES, AND CYTOTOXICITY IN MACROPHAGES
Murtoniemi T et al. · Inhalation Toxicology · 2002
- Induction of Cytotoxicity and Production of Inflammatory Mediators in RAW264.7 Macrophages by Spores Grown on Six Different Plasterboards
Murtoniemi T et al. · Inhalation Toxicology · 2001
- Divergent TLR2 and TLR4 Activation by Fungal Spores and Species Diversity in Dust from Waste Sorting Plants
Anani Komlavi Afanou et al. · Applied and Environmental Microbiology · 2023
- Induced Production of Nitric Oxide, Tumor Necrosis Factor, and Interleukin-6 in RAW 264.7 Macrophages by Streptomycetes from Indoor Air of Moldy Houses
Hirvonen MR et al. · Archives of Environmental Health An International Journal · 1997
- Co-cultivation of Streptomyces californicus and Stachybotrys chartarum stimulates the production of cytostatic compound(s) with immunotoxic properties
Penttinen P et al. · Toxicology and Applied Pharmacology · 2006
- Filamentous microorganisms and their fragments in indoor air- a review
Gorny RL · Annals of agricultural and environmental medicine · 2004
- Inflammatory Responses in Mice after Intratracheal Instillation of Spores of Streptomyces californicus Isolated from Indoor Air of a Moldy Building
Juha Jussila et al. · Toxicology and Applied Pharmacology · 2001
- Co-occurrence of toxic bacterial and fungal secondary metabolites in moisture-damaged indoor environments
Taubel M et al. · Indoor Air · 2011
- The relation between growth of four microbes on six different plasterboards and biological activity of spores
Murtoniemi T et al. · Indoor Air · 2003
- Indoor microbiome and allergic diseases: From theoretical advances to prevention strategies
Xi Fu et al. · Eco-Environment & Health · 2022
- Interactions between and can induce apoptosis and cell cycle arrest in mouse RAW264.7 macrophages
Penttinen P et al. · Toxicology and Applied Pharmacology · 2005
- Introduction to Chronic Inflammatory Response Syndrome (CIRS)
Andrew Heyman et al. · 2023
- Treatable metabolic and inflammatory abnormalities in Post COVID Syndrome (PCS) define the transcriptomic basis for persistent symptoms: Lessons from CIRS
Ritchie C. Shoemaker et al. · Medical Research Archives · 2021
- Bacterial strains from moldy buildings are highly potent inducers of inflammatory and cytotoxic effects
Hirvonen MR et al. · Indoor Air · 2005
- Relationship between secondary metabolism and fungal development
Calvo AM et al. · Microbiology and Molecular Biology Reviews · 2002
- A Novel Therapeutic Approach to Parkinson's Disease: Using Transcriptomics to Identify Unique Patterns of Gene Expression including 'Triple Positives,' Toll receptors, and Endotoxin Exposure
R Shoemaker et al. · Medical Research Archives · 2025
- Timber-colonizing gram-negative bacteria as potential causative agents of respiratory diseases in woodworkers
Angelina Wójcik-Fatla et al. · International Archives of Occupational and Environmental Health · 2022
- The Evolution of Chronic Inflammatory Response Syndrome (CIRS) and the Biotoxin Pathway
Ritchie C. Shoemaker et al. · 2023
- Characterizing bioaerosols in PM2.5 in a semi-arid region experiencing desert dust events
Hossein Karimi et al. · Frontiers in Environmental Science · 2024
- Characterization and decontamination of deposited dust: a management regime at a museum
A. A. Abdel Hameed et al. · Aerobiologia · 2024
- a novel inhibitor of alfatoxin production by aflatoxigenic fungi
Ono M et al. · The Journal of Antibiotics · 1997
- Production of proinflammatory mediators by indoor air bacteria and fungal spores in mouse and human cell lines
Kati Huttunen et al. · Environmental Health Perspectives · 2002
- Vasoactive intestinal polypeptide (VIP) corrects chronic inflammatory response syndrome (CIRS) acquired following exposure to water-damaged buildings
Ritchie C. Shoemaker et al. · Health · 2013
- Bioactive products from streptomyces
Behal V · Advances in applied microbiology · 2000
- Effects of microbial cocultivation on inflammatory and cytotoxic potential of spores
Timo Murtoniemi et al. · Inhalation Toxicology · 2005
- Exposure to airborne microbes during the repair of moldy buildings
Rautiala S et al. · American Industrial Hygiene Association Journal · 1996
- Suppression of Fusarium Wilt of Watermelon by NonpathogenicFusarium oxysporumand Other Microorganisms Recovered from a Disease-Suppressive Soil
Larkin RP et al. · Phytopathology · 1996
- EFFECT OF GROWTH MEDIUM ON POTENTIAL OFStreptomyces AnulatusSPORES TO INDUCE INFLAMMATORY RESPONSES AND CYTOTOXICITY IN RAW264.7 MACROPHAGES
Hirvonen MR et al. · Inhalation Toxicology · 2001
- Regulation of secondary metabolism in streptomycetes
Bibb MJ · Current Opinion in Microbiology · 2005
- Hypersensitivity pneumonitis: a historical, clinical, and radiologic review
Hirschmann J et al. · Radiographics · 2009
- Detection of AirborneStachybotrys chartarumMacrocyclic Trichothecene Mycotoxins on Particulates Smaller than Conidia
Brasel TL et al. · Applied and Environmental Microbiology · 2005
- VEGF delivery with retrogradely transported lentivector prolongs survival in a mouse ALS model
Azzouz Mimoun et al. · Nature · 2004
- Targeting melanocortin receptors as a novel strategy to control inflammation
Catania A et al. · Pharmacological Reviews · 2004
- Leptin regulates proinflammatory immune responses
S. Loffreda et al. · The FASEB Journal · 1998
- Hypoxia-Inducible Factor 1α in the Glaucomatous Retina and OpticNerve Head
Texel G et al. · Archives of Ophthalmology · 2004
- Differential Cytokine Production and Toll-Like Receptor Signaling Pathways by Candida albicans Blastoconidia and Hyphae
Chantal A. A. van der Graaf et al. · Infection and Immunity · 2005
- The von Hippel–Lindau Protein, Vascular Endothelial Growth Factor, and Kidney Cancer
Daniel J. George et al. · New England Journal of Medicine · 2003
- Occurrence of Toxigenic Aspergillus versicolor Isolates and Sterigmatocystin in Carpet Dust from Damp Indoor Environments
Engelhart S et al. · Applied and Environmental Microbiology · 2002
- The Leptin Receptor Activates Janus Kinase 2 and Signals for Proliferation in a Factor-Dependent Cell Line
Nico Ghilardi et al. · Molecular Endocrinology · 1997