【摘 要】
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Various hemolysis-related methods were utilized to explore how Klebsiella pneumoniae acquired hemolytic properties after the Shenzhou Ⅷ spaceflight mission.K.pneumoniae was carried into space by the S
【机 构】
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Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
【出 处】
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中国空间科学学会空间生命专业委员会第二十届学术研讨会暨中国宇航学会航天医学工程与空间生物学专业委员会第四届学术研讨会
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Various hemolysis-related methods were utilized to explore how Klebsiella pneumoniae acquired hemolytic properties after the Shenzhou Ⅷ spaceflight mission.K.pneumoniae was carried into space by the Shenzhou Ⅷ spacecraft for approximately398 hours.After spaceflight, a mutant strain with hemolytic properties was observed.Genomic and transcriptomic analyses were performed to identify variations;these analyses included comparative genomics, gene expression comparison, dN/dS calculation, and detection of promoters, transcription factor-binding sites and inserted sequences.After spaceflight on the Shenzhou Ⅷ spacecraft, the K.pneumoniae strain LCT-KP182 exhibited significantly higher hemolytic activity compared to the K.pneumoniae strain LCT-KP214, which was cultured on earth and subjected to spaceflight simulation.Alignment of the genome sequences of both strains revealed that most genomic regions were conserved in the strain LCT-KP182;however, in this strain, there were variations in four genes related to hemolysin transport and hemolytic ability.Analysis of gene expression and selection pressure revealed that the toxin TisB was expressed at a higher level in the strain LCT-KP182: therefore, this strain could withstand higher concentrations of hemolysin.dN/dS analysis revealed that the sequence of the gene encoding the hemolysin activator HlyB was conserved in the strain LCT-KP182.Analysis of transcription factor-binding sites revealed that binding site of the transcriptional repressor AbrB upstream of the phospholipase synthesis gene was mutated in strain LCT-KP182, which potentially enhanced hemolysis in this strain.Furthermore, an inserted sequence (IS) in the strain LCT-KP182introduced a gene island related to the Fe3+-siderophore transport system, potentially increasing hemolytic activity in this strain.This study provides various tools for the study of hemolysis in K.pneumoniae and establishes a valuable foundation for research on microorganisms subjected to spaceflight, paving the way for future in vivo simulation studies.
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