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Horng YT, Panjaitan NSD, Tsai YJ, Su PW, Yang HC, Soo PC. The role of EII complex in the bacterial responses to the glucose-survey in clinical Klebsiella pneumoniae isolates. PLoS One 2023; 18:e0289759. [PMID: 37549172 PMCID: PMC10406186 DOI: 10.1371/journal.pone.0289759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/24/2023] [Indexed: 08/09/2023] Open
Abstract
Type 3 fimbriae in Klebsiella pneumoniae are important for bacterial colonization on abiotic and biotic surfaces. The major subunit of type 3 fimbriae (MrkA) is increased by overexpression of EtcABC, an EII complex of phosphoenolpyruvate:carbohydrate phosphotransferase systems (PTSs), through cAMP-cAMP receptor protein (cAMP-CRP) in K. pneumoniae STU1. Here, we further characterized the relations between the amount of etcABC mRNA and MrkA in 78 clinical K. pneumoniae isolates incubated in high levels of glucose. By Western blotting, we observed that MrkA of 29 isolates were not decreased much by high levels of glucose (Group A) but MrkA of other 49 isolates were significantly reduced (Group B) in the same condition. The bacterial biofilms on abiotic surfaces and colonization in the Caenorhabditis elegans of representative isolates in the Group A were not affected by high levels of glucose. However, the biofilm and colonization in the worm of clinical isolates in the Group B were much reduced by high levels of glucose. After quantification by real time RT-PCR, 76% of Group A but just 10% of Group B showed high amount of etcA mRNA. In summary, our results suggested that for most of K. pneumoniae clinical isolates, the amount of etcABC mRNA was positively related to their type 3 fimbriae production in a high level of glucose, thereby to their biofilm formation and colonization in the worm.
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Affiliation(s)
- Yu-Tze Horng
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Novaria Sari Dewi Panjaitan
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
- Center for Biomedical Research, Research Organization for Health, National Research and Innovation Agency (BRIN), Cibinong Science Center, Cibinong, Bogor, West Java, Indonesia
| | - Yi-Jhen Tsai
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Pin-Wei Su
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Hung-Chi Yang
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan, R.O.C
| | - Po-Chi Soo
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
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Zhang Y, Yang M, Bao Y, Tao W, Tuo J, Liu B, Gan L, Fu S, Gong H. A genome-scale metabolic model of the effect of dissolved oxygen on 1,3-propanediol fermentation by Klebsiella pneumoniae. Bioprocess Biosyst Eng 2023:10.1007/s00449-023-02899-w. [PMID: 37403004 DOI: 10.1007/s00449-023-02899-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023]
Abstract
Although 1,3-propanediol (1,3-PD) is usually considered an anaerobic fermentation product from glycerol by Klebsiella pneumoniae, microaerobic conditions proved to be more conducive to 1,3-PD production. In this study, a genome-scale metabolic model (GSMM) specific to K. pneumoniae KG2, a high 1.3-PD producer, was constructed. The iZY1242 model contains 2090 reactions, 1242 genes and 1433 metabolites. The model was not only able to accurately characterise cell growth, but also accurately simulate the fed-batch 1,3-PD fermentation process. Flux balance analyses by iZY1242 was performed to dissect the mechanism of stimulated 1,3-PD production under microaerobic conditions, and the maximum yield of 1,3-PD on glycerol was 0.83 mol/mol under optimal microaerobic conditions. Combined with experimental data, the iZY1242 model is a useful tool for establishing the best conditions for microaeration fermentation to produce 1,3-PD from glycerol in K. pneumoniae.
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Affiliation(s)
- Yang Zhang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Menglei Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Yangyang Bao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Weihua Tao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Jinyou Tuo
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Boya Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Luxi Gan
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Shuilin Fu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China
| | - Heng Gong
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, People's Republic of China.
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Krieger MC, Merritt J, Raghavan R. Genome-Wide Identification of Novel sRNAs in Streptococcus mutans. J Bacteriol 2022; 204:e0057721. [PMID: 35285723 PMCID: PMC9017351 DOI: 10.1128/jb.00577-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/10/2022] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans is a major pathobiont involved in the development of dental caries. Its ability to utilize numerous sugars and to effectively respond to environmental stress promotes S. mutans proliferation in oral biofilms. Because of their quick action and low energetic cost, noncoding small RNAs (sRNAs) represent an ideal mode of gene regulation in stress response networks, yet their roles in oral pathogens have remained largely unexplored. We identified 15 novel sRNAs in S. mutans and show that they respond to four stress-inducing conditions commonly encountered by the pathogen in human mouth: sugar-phosphate stress, hydrogen peroxide exposure, high temperature, and low pH. To better understand the role of sRNAs in S. mutans, we further explored the function of the novel sRNA SmsR4. Our data demonstrate that SmsR4 regulates the enzyme IIA (EIIA) component of the sorbitol phosphotransferase system, which transports and phosphorylates the sugar alcohol sorbitol. The fine-tuning of EIIA availability by SmsR4 likely promotes S. mutans growth while using sorbitol as the main carbon source. Our work lays a foundation for understanding the role of sRNAs in regulating gene expression in stress response networks in S. mutans and highlights the importance of the underexplored phenomenon of posttranscriptional gene regulation in oral bacteria. IMPORTANCE Small RNAs (sRNAs) are important gene regulators in bacteria, but the identities and functions of sRNAs in Streptococcus mutans, the principal bacterium involved in the formation of dental caries, are unknown. In this study, we identified 15 putative sRNAs in S. mutans and show that they respond to four common stress-inducing conditions present in human mouth: sugar-phosphate stress, hydrogen peroxide exposure, high temperature, and low pH. We further show that the novel sRNA SmsR4 likely modulates sorbitol transport into the cell by regulating SMU_313 mRNA, which encodes the EIIA subunit of the sorbitol phosphotransferase system. Gaining a better understanding of sRNA-based gene regulation may provide new opportunities to develop specific inhibitors of S. mutans growth, thereby improving oral health.
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Affiliation(s)
- Madeline C Krieger
- Department of Biology, Portland State University, Portland, Oregon, USA
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Justin Merritt
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, Oregon, USA
| | - Rahul Raghavan
- Department of Biology, Portland State University, Portland, Oregon, USA
- Department of Molecular Microbiology and Immunology, The University of Texas at San Antoniogrid.215352.2, San Antonio, Texas, USA
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The PTS Components in Klebsiella pneumoniae Affect Bacterial Capsular Polysaccharide Production and Macrophage Phagocytosis Resistance. Microorganisms 2021; 9:microorganisms9020335. [PMID: 33567595 PMCID: PMC7914778 DOI: 10.3390/microorganisms9020335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/04/2022] Open
Abstract
Capsular polysaccharide (CPS) is a crucial virulence factor for Klebsiella pneumoniae infection. We demonstrated an association of CPS production with two phosphoenolpyruvate:carbohydrate phosphotransferase systems (PTSs). Deficiency of crr, encoding enzyme IIA of PTS, in K. pneumoniae enhanced the transcriptional activities of galF, wzi and gnd, which are in the cps gene cluster, leading to high CPS production. A crr mutant exhibited a higher survival rate in 1% hydrogen peroxide than the wild-type. The crr mutant showed less sensitivity to engulfment by macrophage (RAW 264.7) than the wild-type by observing the intracellular bacteria using confocal laser scanning microscopy (CLSM) and by calculating the colony-forming units (CFU) of intracellular bacteria. After long-term incubation, the survival rate of the intracellular crr mutant was higher than that of the wild-type. Deficiency of crr enhanced the transcriptional activities of etcABC which encodes another putative enzyme II complex of a PTS. Deletion of etcABC in the crr mutant reduced CPS production and the transcriptional activities of galF compared to those of the crr mutant. These results indicated that one PTS component, Crr, represses CPS production by repressing another PTS component, EtcABC, in K. pneumoniae. In addition, PTS plays a role in bacterial resistance to macrophage phagocytosis.
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Regulation of Pyruvate Formate Lyase-Deficient Klebsiella pneumoniae for Efficient 1,3-Propanediol Bioproduction. Curr Microbiol 2019; 77:55-61. [PMID: 31705389 DOI: 10.1007/s00284-019-01795-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 10/16/2019] [Indexed: 10/25/2022]
Abstract
Anaerobic growth defect of pyruvate formate lyase (PFL)-deficient Klebsiella pneumoniae limits its industrial application, and the reason for this growth defect was analyzed in this study. The obtained evidences, combined with normal intracellular redox status and no further inhibition by adhE deletion, strongly suggested that growth defect in PFL-deficient K. pneumoniae was probably caused by lack of carbon flux from pyruvate to acetyl-CoA (AcCoA). Correspondingly, the anaerobic growth of PFL-deficient K. pneumoniae was promoted by deletion of pdhR, a negative transcriptional regulator gene for AcCoA generation. Through the regulation of pdhR deletion, the PFL-deficient K. pneumoniae exhibited highly efficient 1,3-propanediol production. Besides, in a 2-L fed-batch fermentation process, the cell growth of PFL-deficient K. pneumoniae strain almost recovered, when compared with that of the normal strain, and the 1,3-propanediol yield increased by 14%, while the byproducts acetate and 2,3-butanediol contents decreased by 29% and 24%, respectively.
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Panjaitan NSD, Horng YT, Cheng SW, Chung WT, Soo PC. EtcABC, a Putative EII Complex, Regulates Type 3 Fimbriae via CRP-cAMP Signaling in Klebsiella pneumoniae. Front Microbiol 2019; 10:1558. [PMID: 31354661 PMCID: PMC6629953 DOI: 10.3389/fmicb.2019.01558] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/21/2019] [Indexed: 01/09/2023] Open
Abstract
Biofilm formation by Klebsiella pneumoniae on indwelling medical devices increases the risk of infection. Both type 1 and type 3 fimbriae are important factors in biofilm formation by K. pneumoniae. We found that a putative enzyme II (EII) complex of the phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS), etcA (EIIA)-etcB (EIIB)-etcC (EIIC), regulated biofilm and type 3 fimbriae formation by K. pneumoniae STU1. In this study, the regulatory mechanism of etcABC in K. pneumoniae type 3 fimbriae formation was investigated. We found via quantitative RT-PCR that overexpression of etcABC enhanced the transcription level of the mrk operon, which is involved in type 3 fimbriae synthesis, and reduced the transcription level of the fim operon, which is involved in type 1 fimbriae synthesis. To gain further insight into the role of etcABC in type 3 fimbriae synthesis, we analyzed the region upstream of the mrk operon and found the potential cyclic 3′5′-adenosine monophosphate (cAMP) receptor protein (CRP) binding site. After crp was deleted in K. pneumoniae STU1 and two clinical isolates, these three crp mutant strains could not express MrkA, the major subunit of the fimbrial shaft, indicating that CRP positively regulated type 3 fimbriae synthesis. Moreover, a crp mutant overexpressing etcABC could not express MrkA, indicating that the regulation of type 3 fimbriae by etcABC was dependent on CRP. In addition, deletion of cyaA, which encodes the adenylyl cyclase that synthesizes cAMP, and deletion of crr, which encodes the glucose-specific EIIA, led to a reduction in lac operon regulation and therefore bacterial lactose uptake in K. pneumoniae. Exogenous cAMP but not etcABC overexpression compensated for the role of cyaA in bacterial lactose uptake. However, either etcABC overexpression or exogenous cAMP compensated for the role of crr in bacterial lac operon regulation that would eventually restore lactose uptake. We also found via ELISA and the luxCDABE reporter system that overexpression of etcABC increased intracellular cAMP levels and the transcription level of crp, respectively, in K. pneumoniae. In conclusion, overexpression of etcABC positively regulated cAMP production and cAMP-CRP activity to activate the mrk operon, resulting in increased type 3 fimbriae synthesis in K. pneumoniae.
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Affiliation(s)
| | - Yu-Tze Horng
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien City, Taiwan
| | - Shih-Wen Cheng
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien City, Taiwan
| | - Wen-Ting Chung
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien City, Taiwan
| | - Po-Chi Soo
- Institute of Medical Sciences, College of Medicine, Tzu Chi University, Hualien City, Taiwan.,Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien City, Taiwan
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