Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment

Dapeng Wang,Tingzheng Fang,Bin Zhang,Po Bai,Changting Liu,Xiaolei Su,Xuege Jiang,Junfeng Wang

doi:10.1007/s42770-021-00588-y

Abstract

BackgroundMicrobes threaten human health in space exploration. Studies have shown that Proteus mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis.ObjectiveThis study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm, and its related mechanism.MethodsThe strange deformable rods were cultured continuously for 14 days under microgravity simulated in high-aspect rotating vessels (HARVs). The morphology, growth rate, metabolism, and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype.ResultsThe growth rate, metabolic ability, and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability, and biofilm forming ability may be caused by the downregulation of related genes (pstS, sodB, and fumC).ConclusionThe simulated microgravity condition enables us to explore the potential relationship between bacterial phenotype and molecular biology, thus opening up a suitable and constructive method for medical fields that have not been explored before. It provides a certain strategy for the treatment of P. mirabilis infectious diseases in space environment by exploring the microgravity of P. mirabilis.

Highlights

IntroductionAstronauts and cabin equipment inevitably bring microbes, including bacteria, fungi, and viruses, into space in the process of manned spaceflight
It is speculated that P. mirabilis adapts to a new environment by changing the characteristics of its metabolism, as seen in the simulated microgravity environment
The study provided data showing a decline in growth rate, metabolism, and biofilm formation of P. mirabilis after 14 days of exposure to simulated microgravity

Summary

Introduction

Astronauts and cabin equipment inevitably bring microbes, including bacteria, fungi, and viruses, into space in the process of manned spaceflight. The space environment is characterized by a series of prominent features more than 100 km above the earth’s surface, including strong ionizing radiation, high. Various factors in the space environment can induce genetic changes of microorganisms, and affect the phenotypic characteristics of microorganisms, including morphology, growth rate, biofilm forming ability, virulence, and drug resistance, which may induce infectious diseases and affect the health of resident personnel. It is of great significance to study the phenotypic characteristics of microorganisms in space environment. Studies have shown that Proteus mirabilis has been found in human space habitats. The biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis

Methods

Results

Conclusion