Tuberculosis Aerobiology – Antonio Rothfuchs group

We use air sampling to study the survival and infectiousness of M. tuberculosis in aerosols, and to detect M. tuberculosis in cough and indoor air.

Lab picture Tony Rotfuchs

Research focus

Survival and infectiousness of Mycobacterium tuberculosis after aerosolization

Tuberculosis (TB) is transmitted when aerosols carrying Mycobacterium tuberculosis are inhaled into the lung and infect macrophages lining the alveoli. A caveat for the success of this cascade is that the bacilli can cope with aerosol stress and survive long enough in open air before they can be inhaled. Extended time in aerosol also stands to impact the infection potental of the bacilli in macrophages. The ability of M. tuberculosis to remain viable and infectious in aerosol is therefore a key determinant for its transmission.

We are investigating if there are specific environmental conditions that support or mitigate the cultureability and infectiousness of M. tuberculosis in aerosols. We are also investigating if extended aerosol dwelling reduces survival and infectivity of M. tuberculosis; if aerosol transpor triggers specific gene-expression in M. tuberculosis, and finally, if the success of highly-transmissible community isolates of M. tuberculosis is linked to their ability to endure aerosol transport.

We have set up a unique aerobiology platform in BSL3 to address these important knowledge gaps in tuberculosis transmission. This platform and its trained personnel also support Swedish pandemic laboratory preparedness with capabilities to study the aerobiology of new and emerging pathogens.

Results from this research will contribute important new information on conditions that mitigate transmission of airborne M. tuberculosis, and provide novel insights on mycobacteria-macrophages interactions.

Two images showing test chamber
Test chamber for aerosol experiments in Biosafety Level 3. Photo: Antonio Rothfuchs
THOR electrostatic air sampler.
THOR electrostatic air sampler. The device discharges ionization from the red ports causing ionized, airborne microbes to precipitate onto the collector rod on the center of the unit, which is removed for downstream analysis. Photo: Nuno Rufino de Sousa.

Detection of M. tuberculosis in cough aerosols

Aerosols carrying M. tuberculosis are released during coughing by persons with active pulmonary TB. These infectious aerosols can remain airborne for extensive periods of time. Detection of M. tuberculosis in aerosols can help break the chain of transmission by identifying infectious persons and community hotspots of transmission. Tools that are easy-to-use and scalable in low-income, high-burden countries are however lacking.

With this in mind we have developed a small, low-cost electrostatic air sampler that can be used together with nucleic acid amplification tests to detect M. tuberculosis in aerosols. We are investigating the performance of this device at collecting aerosolized M. tuberculosis from TB patients in Sweden and South Africa. By comparing M. tuberculosis detection in cough with routine sputum diagnostics we can discern the feasibility of using cough as a diagnostic for TB. In a clinical aerobiology platform at Stellenbosch University, South Africa, we are stratifying detection on our low-cost sampler with validated readouts for TB infectioussness in patients.

Our air sampler has recently been used to demonstrate infectious SARS-CoV-2 in the air from hospital rooms housing COVID-19 patients. It is currently being tested as a monitoring device for respiratory viruses in sheltered housing for the elderly.

Results from this research will inform on the use of cough as a novel TB diagnostic specimen, and detection of M. tuberculosis in cough as an estimation of transmission risk.

Support our research

Publications

Selected publications

Funding

Research Funding

Our research has received funding from various sources over the years. We acknowledge the generous support from the following bodies that have funded research in the group or enabled researchers to come and work with us:

  • Bill and Melinda Gates Foundation, USA
  • CAPES, Brazil
  • China Scholarship Council CSC
  • European Research Council
  • Karolinska Institutet
  • Karolinska Innovations AB
  • SciLifeLab
  • STINT
  • Swedish Heart-Lung Foundation
  • Swedish Research Council VR
  • Swedish Society for Medicine
  • Åke Wiberg Stiftelse

Collaboration with companies

In addition to academic collaborations we also work with companies and research institutes in different projects related to tuberculosis, aerobiology or infection control. Some of our current and previous private sector partnerships include:

  • Cepheid, USA
  • Semair Diagnostics, Sweden
  • Sarepta Therapeutics, USA
  • S3I, USA
  • Zeteo Tech, USA

Staff and contact

Group leader

All members of the group

Other people connected to the group

  • Achar, Jay

Former group members

  • Lei Shen, postdoc, 2017-2019. Now Shanghai Pulmonary Hospital, China
  • Juliana Aggio, visiting PhD student from ICC/Fiocruz Brazil, 2018-2019. Now postdoc Cambridge University, UK.
  • Pryscilla Wowk, postdoc/visiting researcher from ICC/Fiocruz Brazil, 2017-2018
  • Niklas Sandström, postdoc, 2015-2017. Now SciLifeLab, Stockholm
  • Vishnu Priya Bollampalli, PhD student. Defended in 2017. Now Cepheid, Stockholm.
  • Jintao Guo, postdoc, 2016-2017. Now Legend Biotech, Nanjing, China.
  • Sara Fernández León, research assistant, 2016-2017. Now Annoca AB, Södertälje.
  • Livia Yamashiro, visiting PhD student from UFSC Brazil, 2014. Now Arcus Biosciences, USA.

Contact and visit us

Contact information for the Antonio Rothfuchs research group at the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet.

Postal address

Karolinska Institutet
Department of Microbiology, Tumor and Cell Biology
171 77 Stockholm

Visiting address (visitors, couriers, etc.)

Karolinska Institutet
Biomedicum, C9
Solnavägen 9
171 65 Solna

Delivery address (goods, parcels, etc.)

Tomtebodavägen 16
171 65 Solna

Where to find us

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