<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Bacteria of the genera <italic>Bacillus</italic> and <italic>Staphylococcus</italic> are frequent inhabitants of the International Space Station (ISS) and represent possible opportunistic pathogens. The effect of simulated microgravity on growth and the frequency of mutation to antibiotic resistance in the model surrogate organisms <italic>Bacillus subtilis</italic> (<italic>B. subtilis</italic>) and <italic>Staphylococcus epidermidis</italic> (<italic>S. epidermidis</italic>) were investigated. The test organisms were cultivated for six days in Rotating Wall Vessel (RWV) clinostats either in the vertical (simulated microgravity) or horizontal (1 <italic>g</italic> control) orientation. Parameters measured were: optical densities (ODs); viable counts; frequencies of resistance to rifampicin (RFM); and frequencies of double resistance to RFM and trimethoprim (TMP). The results indicated that the response to simulated microgravity differed in the two microorganisms. Both <italic>B. subtilis</italic> and <italic>S. epidermidis</italic> grew to higher ODs and cell numbers in simulated microgravity. However, the frequencies of mutation, both to RFM resistance and double resistance to RFM and TMP, were observed to increase significantly in simulated microgravity-grown <italic>B. subtilis</italic> but not in <italic>S. epidermidis</italic>.</p></abstract>

Bacteria of the genera Bacillus and Staphylococcus are frequent inhabitants of the International Space Station (ISS) and represent possible opportunistic pathogens. The effect of simulated microgravity on growth and the frequency of mutation to antibiotic resistance in the model surrogate organisms Bacillus subtilis (B. subtilis) and Staphylococcus epidermidis (S. epidermidis) were investigated. The test organisms were cultivated for six days in Rotating Wall Vessel (RWV) clinostats either in the vertical (simulated microgravity) or horizontal (1 g control) orientation. Parameters measured were: optical densities (ODs); viable counts; frequencies of resistance to rifampicin (RFM); and frequencies of double resistance to RFM and trimethoprim (TMP). The results indicated that the response to simulated microgravity differed in the two microorganisms. Both B. subtilis and S. epidermidis grew to higher ODs and cell numbers in simulated microgravity. However, the frequencies of mutation, both to RFM resistance and double resistance to RFM and TMP, were observed to increase significantly in simulated microgravity-grown B. subtilis but not in S. epidermidis.

Differing Responses in Growth and Spontaneous Mutation to Antibiotic Resistance in <italic>Bacillus subtilis</italic> and <italic>Staphylococcus epidermidis</italic> Cells Exposed to Simulated Microgravity

Gravitational and Space Research

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

Differing Responses in Growth and Spontaneous Mutation to Antibiotic Resistance in  and  Cells Exposed to Simulated Microgravity

Bacteria of the genera Bacillus and Staphylococcus are frequent inhabitants of the International Space Station (ISS) and represent possible opportunistic...

Differing Responses in Growth and Spontaneous Mutation to Antibiotic Resistance in Bacillus subtilis and Staphylococcus epidermidis Cells Exposed to Simulated Microgravity

Article Category: Research Article

Published Online: Jan 18, 2022

Page range: 34 - 45

DOI: https://doi.org/10.2478/gsr-2014-0011

© 2014 Patricia Fajardo-Cavazos et al., published by Sciendo

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