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Flores P, McBride SA, Galazka JM, Varanasi KK, Zea L. Biofilm formation of Pseudomonas aeruginosa in spaceflight is minimized on lubricant impregnated surfaces. NPJ Microgravity 2023; 9:66. [PMID: 37587131 PMCID: PMC10432549 DOI: 10.1038/s41526-023-00316-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 08/02/2023] [Indexed: 08/18/2023] Open
Abstract
The undesirable, yet inevitable, presence of bacterial biofilms in spacecraft poses a risk to the proper functioning of systems and to astronauts' health. To mitigate the risks that arise from them, it is important to understand biofilms' behavior in microgravity. As part of the Space Biofilms project, biofilms of Pseudomonas aeruginosa were grown in spaceflight over material surfaces. Stainless Steel 316 (SS316) and passivated SS316 were tested for their relevance as spaceflight hardware components, while a lubricant impregnated surface (LIS) was tested as potential biofilm control strategy. The morphology and gene expression of biofilms were characterized. Biofilms in microgravity are less robust than on Earth. LIS strongly inhibits biofilm formation compared to SS. Furthermore, this effect is even greater in spaceflight than on Earth, making LIS a promising option for spacecraft use. Transcriptomic profiles for the different conditions are presented, and potential mechanisms of biofilm reduction on LIS are discussed.
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Affiliation(s)
- Pamela Flores
- BioServe Space Technologies, Aerospace Engineering Sciences Department, University of Colorado Boulder, Boulder, CO, 80309, USA.
- Molecular, Cellular, and Developmental Biology Department, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | | | - Jonathan M Galazka
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Kripa K Varanasi
- Massachusetts Institute of Technology (MIT), Cambridge, MA, 02139, USA.
| | - Luis Zea
- BioServe Space Technologies, Aerospace Engineering Sciences Department, University of Colorado Boulder, Boulder, CO, 80309, USA.
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Zeng S, Shi Q, Liu Y, Li M, Lin D, Zhang S, Li Q, Pu J, Shen C, Huang B, Chen C, Zeng J. The small RNA PrrH of Pseudomonas aeruginosa regulates hemolysis and oxidative resistance in bloodstream infection. Microb Pathog 2023; 180:106124. [PMID: 37105322 DOI: 10.1016/j.micpath.2023.106124] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023]
Abstract
Small regulatory RNAs (sRNAs) regulate multiple physiological functions in bacteria, and sRNA PrrH can regulate iron homeostasis and virulence. However, the function of PrrH in Pseudomonas aeruginosa (P. aeruginosa) bloodstream infection (BSI) is largely unknown. The aim of this study was to investigate the role of PrrH in P. aeruginosa BSI model. First, P. aeruginosa PAO1 was co-cultured with peripheral blood cells for 6 h qRT-PCR results showed a transient up-regulation of PrrH expression at 1 h. Simultaneously, the expression of iron uptake genes fpvA, pvdS and phuR was upregulated. In addition, the use of iron chelator 2,2'-dipyridyl to create low-iron conditions caused up-regulation of PrrH expression, a result similar to the BSI model. Furthermore, the addition of FeCl3 was found to decrease PrrH expression. These results support the hypothesis that the expression of PrrH is regulated by iron in BSI model. Then, to clarify the effect of PrrH on major cells in the blood, we used PrrH mutant, overexpressing and wild-type strains to act separately on erythrocytes and neutrophils. On one hand, the hemolysis assay revealed that PrrH contributes to the hemolytic activity of PAO1, and its effect was dependent on the T3SS system master regulator gene exsA, yet had no association with the hemolytic phospholipase C (plcH), pldA, and lasB elastase genes. On the other hand, PrrH mutant enhanced the oxidative resistance of PAO1 in the neutrophils co-culture assay, H2O2-treated growth curve and conventional plate spotting assays. Furthermore, the katA was predicted to be a target gene of PrrH by bioinformatics software, and then verified by qPCR and GFP reporter system. In summary, dynamic changes in the expression of prrH are iron-regulated during PAO1 bloodstream infection. In addition, PrrH promotes the hemolytic activity of P. aeruginosa in an exsA-dependent manner and negatively regulates katA to reduce the oxidative tolerance of P. aeruginosa.
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Affiliation(s)
- Shenghe Zeng
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China; The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China
| | - Qixuan Shi
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China; The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China
| | - YinZhen Liu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China; The Second Clinical College of Guangzhou University of Chinese Medicine, Guangzhou, 510000, China
| | - Mo Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Dongling Lin
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Shebin Zhang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Qiwei Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Jieying Pu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Cong Shen
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China
| | - Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510000, China.
| | - Cha Chen
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China.
| | - Jianming Zeng
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou, 510000, China.
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Yu X, Meng C, Tan X, Su Y, Cao Z, Hwang TS, Li L. RsmA3 modulates RpoS through the RetS-Gac-Rsm signaling pathway in response to H 2 O 2 stress in the phytopathogen Pseudomonas syringae. Environ Microbiol 2022; 24:4755-4770. [PMID: 35837862 DOI: 10.1111/1462-2920.16132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 05/27/2022] [Accepted: 07/06/2022] [Indexed: 11/28/2022]
Abstract
Reactive oxygen species are a fatal challenge to the plant pathogenic bacterium Pseudomonas syringae. In this study, we reveal that the global regulatory protein RsmA3 from the RetS-Gac/Rsm signaling pathway modulates RpoS in the early-log growth phase in the P. syringae wild-type strain MB03, thereby regulating oxidative tolerance to H2 O2 and ultimately affecting pathogenicity to the host plant. Following increased H2 O2 by external addition or endogenous induction by menadione, the resistance of the mutant strain ΔretS to H2 O2 is significantly enhanced due to rapid increases in the transcription of Rsm-related non-coding small RNAs (nc sRNAs), a sigma factor RpoS, and H2 O2 -detoxifying enzymes. Moreover, the ΔretS mutant is significantly less pathogenic in cucumber leaves. Seven Rsm-related nc sRNAs (namely, rsmZ, rsmY, and rsmX1-5 ) show functional redundancy in the RetS-Gac-Rsm signaling pathway. External addition of H2 O2 stimulates increases in the transcription of both rsmY and rsmZ. Thus, we propose a regulatory model of the RetS-Gac-Rsm signaling pathway in P. syringae MB03 for the regulation of H2 O2 tolerance and phytopathogenicity in the host plant.
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Affiliation(s)
- Xun Yu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
| | - Cui Meng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
| | - Xiaocheng Tan
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
| | - Yuwei Su
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
| | - Zhiping Cao
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
| | - Tzann-Shun Hwang
- Graduate Institute of Biotechnology, Chinese Culture University, Taipei, Taiwan
| | - Lin Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agriculture University, Wuhan, PR China
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