<abstract xmlns="http://www.w3.org/1999/xhtml"><p>To evaluate effects of microgravity on virulence, we studied the ability of four common clinical pathogens—<italic>Klebsiella</italic>, <italic>Streptococcus</italic>, <italic>Proteus</italic>, and <italic>Pseudomonas</italic>—to kill wild type <italic>Caenorhabditis elegans</italic> (<italic>C. elegans)</italic> nematodes at the larval and adult stages. Simultaneous studies were performed utilizing spaceflight, rotation in a 2D clinorotation device, and static ground controls. Nematodes, microbes, and growth media were separated until exposed to true or modeled microgravity, then mixed and grown for 48 hours. Experiments were terminated by paraformaldehyde fixation, and optical density measurements were used to assay residual microorganisms. Spaceflight was associated with reduced virulence for <italic>Klebsiella</italic> and <italic>Streptococcus</italic>, but had negligible effect on <italic>Enterococcus</italic> and <italic>Pseudomonas.</italic> Clinorotation generated very different results with all four organisms showing significantly reduced virulence. We conclude that clinorotation is not a consistent model of the changes that actually occur under microgravity conditions. Further, bacteria virulence is unchanged or reduced, not increased during spaceflight.</p></abstract>

To evaluate effects of microgravity on virulence, we studied the ability of four common clinical pathogens—Klebsiella, Streptococcus, Proteus, and Pseudomonas—to kill wild type Caenorhabditis elegans (C. elegans) nematodes at the larval and adult stages. Simultaneous studies were performed utilizing spaceflight, rotation in a 2D clinorotation device, and static ground controls. Nematodes, microbes, and growth media were separated until exposed to true or modeled microgravity, then mixed and grown for 48 hours. Experiments were terminated by paraformaldehyde fixation, and optical density measurements were used to assay residual microorganisms. Spaceflight was associated with reduced virulence for Klebsiella and Streptococcus, but had negligible effect on Enterococcus and Pseudomonas. Clinorotation generated very different results with all four organisms showing significantly reduced virulence. We conclude that clinorotation is not a consistent model of the changes that actually occur under microgravity conditions. Further, bacteria virulence is unchanged or reduced, not increased during spaceflight.

Effects of Microgravity and Clinorotation on the Virulence of <italic>Klebsiella</italic>, <italic>Streptococcus</italic>, <italic>Proteus</italic>, and <italic>Pseudomonas</italic>

Durham VA Medical Center, Medicine and Research and Development Services

Nephrology Division, Department of Internal Medicine

Department of Veterans Affairs Office of Research and Development

Departments of Otorhinolaryngology, Immunology and Psychiatry, Baylor College of Medicine

Gravitational and Space Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effects of Microgravity and Clinorotation on the Virulence of , , , and 

To evaluate effects of microgravity on virulence, we studied the ability of four common clinical pathogens—Klebsiella, Streptococcus, Proteus, and...

Effects of Microgravity and Clinorotation on the Virulence of Klebsiella, Streptococcus, Proteus, and Pseudomonas

Article Category: Research Article

Published Online: Jul 17, 2020

Page range: 39 - 50

DOI: https://doi.org/10.2478/gsr-2016-0004

Keywords
Virulence, Spaceflight, Nematodes, Clinorotation, Microgravity, Microorganism

© 2016 Timothy G. Hammond et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Effects of Microgravity and Clinorotation on the Virulence of Klebsiella, Streptococcus, Proteus, and Pseudomonas

Article Category: Research Article

Published Online: Jul 17, 2020

Page range: 39 - 50

DOI: https://doi.org/10.2478/gsr-2016-0004

KeywordsVirulence, Spaceflight, Nematodes, Clinorotation, Microgravity, Microorganism

© 2016 Timothy G. Hammond et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Virulence, Spaceflight, Nematodes, Clinorotation, Microgravity, Microorganism