Researchers from Jet Propulsion Laboratory studied stains of bacterium Enterobacter on ISS for pathogenic potential
Strains of the bacterium Enterobacter that are similar to opportunistic infectious organisms found in a few hospital settings have been identified on the International Space Station (ISS). Although the strains identified in space were not pathogenic to humans, researchers at the Jet Propulsion Laboratory, California Institute of Technology suggested that they should be studied for potential health implications that may occur in future missions. The research was published in the journal BMC Microbiology on November 23, 2018.
The team studied five strains of Enterobacter that were isolated from the space toilet and the exercise platform on the ISS in March 2015. The study was a part of a wider effort to characterize the bacterial communities that reside on surfaces inside ISS. The team compared the ISS strains to all publicly available genomes of 1,291 Enterobacter strains collected on Earth in order to identify the species of Enterobacter collected on the ISS. The study also focused on demonstrating detailed genetic make-up of the individual strains. According to Dr. Kasthuri Venkateswaran, Senior Research Scientist at the Jet Propulsion Laboratory Biotechnology and Planetary Protection Group and the corresponding author of the study, various methods were used to characterize the strain genomes in detail in order to show which species of the bacteria were present on the ISS.
The team found that genomes of the five ISS Enterobacter strains were genetically most similar to three strains newly identified on Earth. These three strains belonged to one species of the bacteria, known as Enterobacter bugandensis. The strains were found to cause disease in neonates and a compromised patient that were hospitalized in three different healthcare centers in east Africa, Washington state, and Colorado. The team compared the genomes of the five ISS strains to the three clinical Earth strains to get a better understanding of whether the ISS strains had antimicrobial resistance. The study also helped to determine whether the ISS strains had gene profiles similar to those found in known multi-drug resistant bacteria. Moreover, the caparison also helped to identify genes related to their ability to cause disease.