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

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Space Station ◽  
Biological Characteristics ◽  
Microgravity Environment ◽  
Short Term ◽  
Future Space ◽  
Short Term Exposure

Background: Microbes threaten human health in space exploration. Studies have shown that P. 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. Objective: This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm and its related mechanism. Methods: The strange deformable rods were cultured continuously for 14 days under the microgravity simulated by (HARVs) in a high- aspect ratio vessels. 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. Results: The 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 down-regulation of related genes (pstS,sodB and fumC). Conclusion: It provides a certain reference for the prevention and treatment of P. mirabilis infection in the future space station by exploring the effect of simulated microgravity exposure on P. mirabilis.

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

2021 ◽  
Author(s):  
Dapeng Wang ◽  
Po Bai ◽  
Bin Zhang ◽  
Xiaolei Su ◽  
Xuege Jiang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Condition ◽  
Biological Characteristics ◽  
Space Environment ◽  
Microgravity Environment ◽  
Constructive Method ◽  
Short Term Exposure

Abstract Background Microbes 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. Objective This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm, and its related mechanism. Methods The 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. Results The 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). Conclusion The 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.

scholarly journals Increased biofilm formation ability in Klebsiella pneumoniae after short‐term exposure to a simulated microgravity environment

2016 ◽  
Vol 5 (5) ◽  
pp. 793-801 ◽  
Author(s):  
Haili Wang ◽  
Yanfeng Yan ◽  
Dan Rong ◽  
Jing Wang ◽  
Hongduo Wang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Microgravity Environment ◽  
Short Term ◽  
Short Term Exposure

scholarly journals Effects of Simulated Microgravity on the Physiology of Stenotrophomonas maltophilia and Multiomic Analysis

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaolei Su ◽  
Yinghua Guo ◽  
Tingzheng Fang ◽  
Xuege Jiang ◽  
Dapeng Wang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Differentially Expressed Genes ◽  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Differentially Expressed ◽  
Space Environment ◽  
Biological Adhesion ◽  
Proteomic Analyses

Many studies have shown that the space environment plays a pivotal role in changing the characteristics of conditional pathogens, especially their pathogenicity and virulence. However, Stenotrophomonas maltophilia, a type of conditional pathogen that has shown to a gradual increase in clinical morbidity in recent years, has rarely been reported for its impact in space. In this study, S. maltophilia was exposed to a simulated microgravity (SMG) environment in high-aspect ratio rotating-wall vessel bioreactors for 14days, while the control group was exposed to the same bioreactors in a normal gravity (NG) environment. Then, combined phenotypic, genomic, transcriptomic, and proteomic analyses were conducted to compare the influence of the SMG and NG on S. maltophilia. The results showed that S. maltophilia in simulated microgravity displayed an increased growth rate, enhanced biofilm formation ability, increased swimming motility, and metabolic alterations compared with those of S. maltophilia in normal gravity and the original strain of S. maltophilia. Clusters of Orthologous Groups (COG) annotation analysis indicated that the increased growth rate might be related to the upregulation of differentially expressed genes (DEGs) involved in energy metabolism and conversion, secondary metabolite biosynthesis, transport and catabolism, intracellular trafficking, secretion, and vesicular transport. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the increased motility might be associated the upregulation of differentially expressed proteins (DEPs) involved in locomotion, localization, biological adhesion, and binding, in accordance with the upregulated DEGs in cell motility according to COG classification, including pilP, pilM, flgE, flgG, and ronN. Additionally, the increased biofilm formation ability might be associated with the upregulation of DEPs involved in biofilm formation, the bacterial secretion system, biological adhesion, and cell adhesion, which were shown to be regulated by the differentially expressed genes (chpB, chpC, rpoN, pilA, pilG, pilH, and pilJ) through the integration of transcriptomic and proteomic analyses. These results suggested that simulated microgravity might increase the level of corresponding functional proteins by upregulating related genes to alter physiological characteristics and modulate growth rate, motility, biofilm formation, and metabolism. In conclusion, this study is the first general analysis of the phenotypic, genomic, transcriptomic, and proteomic changes in S. maltophilia under simulated microgravity and provides some suggestions for future studies of space microbiology.

scholarly journals Evaluation of pathogenesis and biofilm formation ability of Yersinia pestis after 40-day exposure to simulated microgravity

2021 ◽  
Author(s):  
Ye Li ◽  
Yulu Chen ◽  
Lei Wang ◽  
Yixuan Li ◽  
Ruifu Yang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Simulated Microgravity ◽  
Normal Gravity ◽  
Microgravity Condition ◽  
Microgravity Environment ◽  
Crystal Violet Staining ◽  
Rna Seq ◽  
Manned Space ◽  
Manned Space Missions

Abstract Background: With the increase of manned space missions and the rise of space microbiology, the research of microbes grown under microgravity environment attracts more attentions. The research scope in space microbiology has been extended beyond pathogens directly related to spaceflight Y. pestis, the causative agent of plague, is also of interest to researchers. Results: After Y. pestis strain 201 cultivated for 40 consecutive passages in either simulated microgravity and normal gravity (NG) conditions, the cultures were used to observe the main phenotypic features of Y. pestis. By using crystal violet staining assays, increased biofilm amount was detected in Y. pestis grown under SMG condition. Besides that, the damage degrees of Hela cell caused by SMG-grown Y. pestis were found diminished in relative to those NG condition. Consistent with this observation, death course was delayed in mice infected with SMG-grown Y. pestis, suggesting that microgravity condition could contribute the attenuated virulence. RNA-seq-based transcriptomics analysis showed a total of 219 genes were differentially regulated, of which 92 upregulated and 127 downregulated. We found dozens of virulence-associated genes were downregulated, which partially explained the reduced virulence of Y. pestis under SMG condition. Our study demonstrated that long-term exposure to simulated microgravity influence the pathogenesis and biofilm formation ability of Y. pestis in a different way, which provides a novel avenue to study the mechanism of physiology and virulence in this pathogen.Conclusions: Microgravity enhanced the ability of biofilm formation of Y. pestis. The virulence and cytotoxicity of Y. pestis were reduced under the microgravity environment. The expressions of many virulence-associated genes of Y. pestis were differentially regulated in response to the stimulated microgravity.

scholarly journals The effects of real and simulated microgravity on cellular mitochondrial function

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hong Phuong Nguyen ◽  
Phuong Hoa Tran ◽  
Kyu-Sung Kim ◽  
Su-Geun Yang
Keyword(s):  
Oxidative Stress ◽  
Respiratory Chain ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Simulated Microgravity ◽  
Space Shuttle ◽  
Parabolic Flight ◽  
Space Station ◽  
Microgravity Environment ◽  
Mitochondrial Stress

AbstractAstronauts returning from space shuttle missions or the International Space Station have been diagnosed with various health problems such as bone demineralization, muscle atrophy, cardiovascular deconditioning, and vestibular and sensory imbalance including visual acuity, altered metabolic and nutritional status, and immune system dysregulation. These health issues are associated with oxidative stress caused by a microgravity environment. Mitochondria are a source of reactive oxygen species (ROS). However, the molecular mechanisms through which mitochondria produce ROS in a microgravity environment remain unclear. Therefore, this review aimed to explore the mechanism through which microgravity induces oxidative damage in mitochondria by evaluating the expression of genes and proteins, as well as relevant metabolic pathways. In general, microgravity-induced ROS reduce mitochondrial volume by mainly affecting the efficiency of the respiratory chain and metabolic pathways. The impaired respiratory chain is thought to generate ROS through premature electron leakage in the electron transport chain. The imbalance between ROS production and antioxidant defense in mitochondria is the main cause of mitochondrial stress and damage, which leads to mitochondrial dysfunction. Moreover, we discuss the effects of antioxidants against oxidative stress caused by the microgravity environment space microgravity in together with simulated microgravity (i.e., spaceflight or ground-based spaceflight analogs: parabolic flight, centrifugal force, drop towers, etc.). Further studies should be taken to explore the effects of microgravity on mitochondrial stress-related diseases, especially for the development of new therapeutic drugs that can help increase the health of astronauts on long space missions.

Integrating Microgravity Test Data with a Human Computer Reach Model

1992 ◽  
Vol 36 (16) ◽  
pp. 1249-1253
Author(s):  
Mihriban Whitmore ◽  
Ann M. Aldridge ◽  
Randy B. Morris ◽  
Abhilash K. Pandya ◽  
Robert P. Wilmington ◽  
...  
Keyword(s):  
Space Station ◽  
Three Dimensional ◽  
Microgravity Environment ◽  
Space Vehicles ◽  
Interactive Graphics ◽  
Workstation Design ◽  
Future Space ◽  
Wide Range ◽  
Series Of Experiments ◽  
Extract Information

Future space vehicles such as the Space Station Freedom will be equipped with computers that have direct manipulation capabilities. The human factors challenge is to provide an optimal human-systems interface which will accommodate a wide range of users and tasks in a microgravity environment. A series of experiments have been conducted by the Man-Systems Division at Johnson Space Center to resolve anthropometric issues related to human reach capabilities and limitations impacting workstation design. To facilitate this goal, two approaches, “Performance-based” and “Model-based” analyses, were integrated to investigate the human reach mapped onto the workstation display panels. Microgravity maximum reach sweep data were collected onboard NASA's KC-135 Reduced Gravity Aircraft. A three-dimensional (3-D) interactive graphics system, PLAID, was used to generate anthropometrically correct human computer models. Video tapes recorded during the flights were used to extract information for positioning each human representation in the computer model relative to the workstation. The approach, findings and implications of the evaluations are discussed in the paper.

Heart Rate and Blood Pressure Response to Short-Term Head-Down Bed Rest: A Nonlinear Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 157-159 ◽  
Author(s):  
R. Balocchi ◽  
A. Di Garbo ◽  
C. Michelassi ◽  
S. Chillemi ◽  
M. Varanini ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Blood Pressure ◽  
Prolonged Exposure ◽  
Orthostatic Intolerance ◽  
Bed Rest ◽  
Microgravity Environment ◽  
Short Term ◽  
Short Term Exposure ◽  
Recurrence Quantification

Abstract:Although it is well-known that prolonged exposure to microgravity environment such as in space travel results in derangements of orthostasis, recent evidence suggests that even short-term exposure may have similar effects and parallels such common examples as prolonged bed rest. Whereas spectral analysis of heart rate and systolic blood pressure have been unable to detect changes, we hypothesized that nonlinear indexes may be better able to uncover such perturbations. Eighteen healthy subjects were exposed to 4-hour head-down tilt, and of these, 4 exhibited fainting. Two nonlinear indexes, mutual information and recurrence quantification were used to analyze the data. Only recurrence quantification was able to detect a “decoupling” of heart rate and systolic blood pressure at rest using discriminant analysis (p < 0.05). These results suggest that orthostatic intolerance may be due to a decoupling of heart rate from systolic blood pressure reflexive activity occurring at rest.

scholarly journals Effect of short-term exposure to red and blue light on dill plants growth

2013 ◽  
Vol 40 (No. 4.) ◽  
pp. 177-185 ◽  
Author(s):  
B. Frąszczak
Keyword(s):  
Growth Rate ◽  
Blue Light ◽  
Plant Development ◽  
Red Light ◽  
Fresh Mass ◽  
Anethum Graveolens ◽  
Short Term ◽  
Controlled Conditions ◽  
Short Term Exposure

Effect of the end-of-day and the end-of-night red and blue light in dill growth was investigated. Ambrozja dill (Anethum graveolens L.) cvs were grown in vegetation chambers in completely controlled conditions exposed to white diode light. Red and blue light was employed for 30 min before the initiation or after the end of the lighting period. The values of plant fresh mass, area and height parameters were the highest for plants treated with red light at the end of night. The application of red light at the end of day exerted a similar effect on plants as the exposure of plants to blue light at the end of night. Plants treated with blue light at the end of the lighting period were characterised by the poorest growth rate. Plants additionally lighted with blue light were found to have both distinctly smaller mass as well as area in comparison with plants exposed to red light. Both methods are useful to control the plants growth depending on the phase of plant development and growers&rsquo; requirements.

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