1
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Hallenbeck M, Chua M, Collins J. The role of the universal sugar transport system components PtsI (EI) and PtsH (HPr) in Enterococcus faecium. FEMS MICROBES 2024; 5:xtae018. [PMID: 38988831 PMCID: PMC11234649 DOI: 10.1093/femsmc/xtae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/31/2024] [Indexed: 07/12/2024] Open
Abstract
Vancomycin-resistant enterococci (VRE) pose a serious threat to public health because of their limited treatment options. Therefore, there is an increasing need to identify novel targets to develop new drugs. Here, we examined the roles of the universal PTS components, PtsI and PtsH, in Enterococcus faecium to determine their roles in carbon metabolism, biofilm formation, stress response, and the ability to compete in the gastrointestinal tract. Clean deletion of ptsHI resulted in a significant reduction in the ability to import and metabolize simple sugars, attenuated growth rate, reduced biofilm formation, and decreased competitive fitness both in vitro and in vivo. However, no significant difference in stress survival was observed when compared with the wild type. These results suggest that targeting universal or specific PTS may provide a novel treatment strategy by reducing the fitness of E. faecium.
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Affiliation(s)
- Michelle Hallenbeck
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - Michelle Chua
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - James Collins
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
- Center for Microbiomics, Inflammation and Pathogenicity, University of Louisville, Louisville, KY 40202, United States
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2
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Potter AD, Criss AK. Dinner date: Neisseria gonorrhoeae central carbon metabolism and pathogenesis. Emerg Top Life Sci 2024; 8:15-28. [PMID: 37144661 PMCID: PMC10625648 DOI: 10.1042/etls20220111] [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: 03/03/2023] [Revised: 04/10/2023] [Accepted: 04/14/2023] [Indexed: 05/06/2023]
Abstract
Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, is a human-adapted pathogen that does not productively infect other organisms. The ongoing relationship between N. gonorrhoeae and the human host is facilitated by the exchange of nutrient resources that allow for N. gonorrhoeae growth in the human genital tract. What N. gonorrhoeae 'eats' and the pathways used to consume these nutrients have been a topic of investigation over the last 50 years. More recent investigations are uncovering the impact of N. gonorrhoeae metabolism on infection and inflammatory responses, the environmental influences driving N. gonorrhoeae metabolism, and the metabolic adaptations enabling antimicrobial resistance. This mini-review is an introduction to the field of N. gonorrhoeae central carbon metabolism in the context of pathogenesis. It summarizes the foundational work used to characterize N. gonorrhoeae central metabolic pathways and the effects of these pathways on disease outcomes, and highlights some of the most recent advances and themes under current investigation. This review ends with a brief description of the current outlook and technologies under development to increase understanding of how the pathogenic potential of N. gonorrhoeae is enabled by metabolic adaptation.
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Affiliation(s)
- Aimee D. Potter
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA USA
| | - Alison K. Criss
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, VA USA
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3
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Kumar S, Narayan KS, Shandilya S, Sood SK, Kapila S. Role of non-PTS dependent glucose permease (GlcU) in maintaining the fitness cost during acquisition of nisin resistance by Enterococcus faecalis. FEMS Microbiol Lett 2020; 366:5628326. [PMID: 31738414 DOI: 10.1093/femsle/fnz230] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/15/2019] [Indexed: 11/13/2022] Open
Abstract
Nisin is used for food preservation due to its antibacterial activity. However, some bacteria survive under the prevailing conditions owing to the acquisition of resistance. This study aimed to characterize nisin-resistant Enterococcus faecalis isolated from raw buffalo milk and investigate their fitness cost. FE-SEM, biofilm and cytochrome c assay were used for characterization. Growth kinetics, HPLC, qPCR and western blotting were performed to confer their fitness cost. Results revealed that nisin-resistant E. faecalis were morphologically different from sensitive strain and internalize more glucose. However, no significant difference was observed in the growth pattern of the resistant strain compared to that of the sensitive strain. A non-phosphotransferase glucose permease (GlcU) was found to be associated with enhanced glucose uptake. Conversely, Mpt, a major phosphotransferase system responsible for glucose uptake, did not play any role, as confirmed by gene expression studies and western blot analysis of HPr protein. The phosphorylation of His-15 residue of HPr phosphoprotein was reduced, while that of the Ser-46 residue increased with progression in nisin resistance, indicating that it may be involved in the regulation of pathogenicity. In conclusion, resistance imposes a significant fitness cost and GlcU plays a key role in maintaining the fitness cost in nisin-resistant variants.
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Affiliation(s)
- Sandeep Kumar
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Kapil Singh Narayan
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Shruti Shandilya
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Shiv Kumar Sood
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
| | - Suman Kapila
- Animal Biochemistry Division, National Dairy Research Institute, Karnal 132001, Haryana, India
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4
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Guo P, Zhu B, Liang H, Gao W, Zhou G, Xu L, Gao Y, Yu J, Zhang M, Shao Z. Comparison of Pathogenicity of Invasive and Carried Meningococcal Isolates of ST-4821 Complex in China. Infect Immun 2019; 87:e00584-19. [PMID: 31570554 PMCID: PMC6867847 DOI: 10.1128/iai.00584-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/26/2019] [Indexed: 11/20/2022] Open
Abstract
Serotype 4821 (ST-4821) clonal complex (cc4821) Neisseria meningitidis strains are divided into two groups (groups I and II) according to the core genome-based phylogenetic analysis. Group I contains the greater number of invasive disease isolates. However, the differences in pathogenicity between the two groups are unclear. In this study, the pathogenicity of cc4821 isolates (n = 28) belonging to group I and group II (each containing eight invasive isolates and six isolates from healthy carriers) was investigated, including adhesion, invasion, and induction of interleukin-6 (IL-6) and interleukin-8 (IL-8) release from host cells (Hep2 and A549). The invasive isolates had higher adhesion and invasion capabilities than the carried isolates in both groups. The carried cc4821 isolates in group I had stronger invasion capability than those in group II. Invasive isolates induced more IL-6 and IL-8 secretion than carried isolates in both groups. The carried cc4821 isolates stimulated higher levels of IL-8 in group I than in group II. The isolates were defined as hyperadherent and hypoadherent groups according to their adhesion ability and as hyperinvasive and hypoinvasive groups based on their invasion ability. The hyperadherent and hyperinvasive isolates mediated more IL-6 and IL-8 release than the hypoadherent and hypoinvasive isolates. There was no difference in the level of cytokine release when cc4821 isolates lost their adhesion and invasion capability after lysis. The results revealed that differences in pathogenicity existed between the two groups and that the differences were mainly determined by differences in adhesion and invasion capabilities.
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Affiliation(s)
- Pengbo Guo
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Bingqing Zhu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hao Liang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wanying Gao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Guilan Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Li Xu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuan Gao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jianxing Yu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Maojun Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhujun Shao
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
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5
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Ji N, Wang X, Yin C, Peng W, Liang R. CrgA Protein Represses AlkB2 Monooxygenase and Regulates the Degradation of Medium-to-Long-Chain n-Alkanes in Pseudomonas aeruginosa SJTD-1. Front Microbiol 2019; 10:400. [PMID: 30915046 PMCID: PMC6422896 DOI: 10.3389/fmicb.2019.00400] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/15/2019] [Indexed: 11/13/2022] Open
Abstract
AlkB monooxygenases in bacteria are responsible for the hydroxylation of medium- and long-chain n-alkanes. In this study, one CrgA protein of Pseudomonas aeruginosa SJTD-1, a member of LysR family, was proved to regulate AlkB2 monooxygenase and the degradation of medium-to-long-chain n-alkanes (C14-C20) by directly binding to the upstream of alkB2 gene. Two specific sites for CrgA binding were found in the promoter region of alkB2 gene, and the imperfect mirror repeat (IIR) structure was proved critical for CrgA recognition and binding. Hexadecyl CoA and octadecyl CoA could effectively release the CrgA binding and start the transcription of alkB2 gene, implying a positive regulation of metabolic intermediate. In the presence of medium-to-long-chain n-alkanes (C14-C20), deletion of crgA gene could enhance the transcription and expression of AlkB2 monooxygenase significantly; and in n-octadecane culture, strain S1ΔalkB1&crgA grew more vigorously than strain S1 ΔalkB1 &crgA . Almost no regulation of CrgA protein was observed to alkB1 gene in vitro and in vivo. Therefore, CrgA acted as a negative regulator for the medium-to-long-chain n-alkane utilization in P. aeruginosa SJTD-1. The work will promote the regulation mechanism study of n-alkane degradation in bacteria and help the bioremediation method development for petroleum pollution.
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Affiliation(s)
- Nannan Ji
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiuli Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Chong Yin
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Wanli Peng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Rubing Liang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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6
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Pajarillo EAB, Kim SH, Valeriano VD, Lee JY, Kang DK. Proteomic View of the Crosstalk between Lactobacillus mucosae and Intestinal Epithelial Cells in Co-culture Revealed by Q Exactive-Based Quantitative Proteomics. Front Microbiol 2017; 8:2459. [PMID: 29312173 PMCID: PMC5732961 DOI: 10.3389/fmicb.2017.02459] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 11/27/2017] [Indexed: 01/28/2023] Open
Abstract
Lactobacilli are bacteria that are beneficial to host health, but information on communication between Lactobacilli and host cells in the intestine is lacking. In this study, we examined the proteomes of the Lactobacillus mucosae strain LM1, as a model of beneficial bacteria, and the intestinal porcine epithelial cell line (IPEC-J2) after co-culture. Label-free proteomics demonstrated the high-throughput capability of the technique, and robust characterization of the functional profiles and changes in the bacteria and intestinal cells was achieved in pure and mixed cultures. After co-culture, we identified totals of 376 and 653 differentially expressed proteins in the LM1 and IPEC-J2 proteomes, respectively. The major proteomic changes in the LM1 strain occurred in the functional categories of transcription, general function, and translation, whereas those in IPEC-J2 cells involved metabolic and cellular processes, and cellular component organization/biogenesis. Among them, elongation factor Tu, glyceraldehyde 3-phosphate dehydrogenase, and phosphocarrier protein HPr, which are known to be involved in bacterial adhesion, were upregulated in LM1. In contrast, proteins involved in tight junction assembly, actin organization, and genetic information processing (i.e., histones and signaling pathways) were significantly upregulated in IPEC-J2 cells. Furthermore, we identified functional pathways that are possibly involved in host–microbe crosstalk and response. These findings will provide novel insights into host–bacteria communication and the molecular mechanism of probiotic establishment in the intestine.
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Affiliation(s)
| | - Sang Hoon Kim
- Department of Animal Resources Science, Dankook University, Cheonan, South Korea
| | | | - Ji Yoon Lee
- National Instrumentation Center for Environmental Management, Seoul National University, Seoul, South Korea
| | - Dae-Kyung Kang
- Department of Animal Resources Science, Dankook University, Cheonan, South Korea
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7
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Privett BR, Pellegrini M, Kovacikova G, Taylor RK, Skorupski K, Mierke D, Jon Kull F. Identification of a Small Molecule Activator for AphB, a LysR-Type Virulence Transcriptional Regulator in Vibrio cholerae. Biochemistry 2017; 56:3840-3849. [PMID: 28640592 PMCID: PMC5963692 DOI: 10.1021/acs.biochem.7b00337] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AphB is a LysR-type transcriptional regulator (LTTR) that cooperates with a second transcriptional activator, AphA, at the tcpPH promoter to initiate expression of the virulence cascade in Vibrio cholerae. Because it is not yet known whether AphB responds to a natural ligand in V. cholerae that influences its ability to activate transcription, we used a computational approach to identify small molecules that influence its activity. In silico docking was used to identify potential ligands for AphB, and saturation transfer difference nuclear magnetic resonance was subsequently employed to access the validity of promising targets. We identified a small molecule, BP-15, that specifically binds the C-terminal regulatory domain of AphB and increases its activity. Interestingly, molecular docking predicts that BP-15 does not bind in the putative primary effector-binding pocket located at the interface of RD-I and RD-II as in other LTTRs, but rather at the dimerization interface. The information gained in this study helps us to further understand the mechanism by which transcriptional activation by AphB is regulated by suggesting that AphB has a secondary ligand binding site, as observed in other LTTRs. This study also lays the groundwork for the future design of inhibitory molecules to block the V. cholerae virulence cascade, thereby preventing the devastating symptoms of cholera infection.
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Affiliation(s)
| | - Maria Pellegrini
- Department of Chemistry, Dartmouth College, Hanover NH 03755, USA
| | - Gabriela Kovacikova
- Department of Microbiology and Immunology, Geisel School of Medicine, Hanover NH 03755, USA
| | - Ronald K. Taylor
- Department of Microbiology and Immunology, Geisel School of Medicine, Hanover NH 03755, USA
| | - Karen Skorupski
- Department of Microbiology and Immunology, Geisel School of Medicine, Hanover NH 03755, USA
| | - Dale Mierke
- Department of Chemistry, Dartmouth College, Hanover NH 03755, USA
| | - F. Jon Kull
- Department of Chemistry, Dartmouth College, Hanover NH 03755, USA
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8
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The Legionella pneumophila Incomplete Phosphotransferase System Is Required for Optimal Intracellular Growth and Maximal Expression of PmrA-Regulated Effectors. Infect Immun 2017; 85:IAI.00121-17. [PMID: 28373357 DOI: 10.1128/iai.00121-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/30/2017] [Indexed: 11/20/2022] Open
Abstract
The nitrogen phosphotransferase system (PTSNtr) is a regulatory cascade present in many bacteria, where it controls different functions. This system is usually composed of three basic components: enzyme INtr (EINtr), NPr, and EIIANtr (encoded by the ptsP, ptsO, and ptsN genes, respectively). In Legionella pneumophila, as well as in many other Legionella species, the EIIANtr component is missing. However, we found that deletion mutations in both ptsP and ptsO are partially attenuated for intracellular growth. Furthermore, these two PTSNtr components were found to be required for maximal expression of effector-encoding genes regulated by the transcriptional activator PmrA. Genetic analyses which include the construction of single and double deletion mutants and overexpression of wild-type and mutated forms of EINtr, NPr, and PmrA indicated that the PTSNtr components affect the expression of PmrA-regulated genes via PmrA and independently from PmrB and that EINtr and NPr are part of the same cascade and require their conserved histidine residues in order to function. Furthermore, expression of the Legionella micdadei EIINtr component in L. pneumophila resulted in a reduction in the levels of expression of PmrA-regulated genes which was completely dependent on the L. pneumophila PTS components and the L. micdadei EIINtr conserved histidine residue. Moreover, reconstruction of the L. pneumophila PTS in vitro indicated that EINtr is phosphorylated by phosphoenolpyruvate (PEP) and transfers its phosphate to NPr. Our results demonstrate that the L. pneumophila incomplete PTSNtr is functional and involved in the expression of effector-encoding genes regulated by PmrA.
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9
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Ma F, Yi L, Yu N, Wang G, Ma Z, Lin H, Fan H. Streptococcus suis Serotype 2 Biofilms Inhibit the Formation of Neutrophil Extracellular Traps. Front Cell Infect Microbiol 2017; 7:86. [PMID: 28373968 PMCID: PMC5357632 DOI: 10.3389/fcimb.2017.00086] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 03/06/2017] [Indexed: 12/11/2022] Open
Abstract
Invasive infections caused by Streptococcus suis serotype 2 (SS2) has emerged as a clinical problem in recent years. Neutrophil extracellular traps (NETs) are an important mechanism for the trapping and killing of pathogens that are resistant to phagocytosis. Biofilm formation can protect bacteria from being killed by phagocytes. Until now, there have only been a few studies that focused on the interactions between bacterial biofilms and NETs. SS2 in both a biofilm state and a planktonic cell state were incubated with phagocytes and NETs, and bacterial survival was assessed. DNase I and cytochalasin B were used to degrade NET DNA or suppress phagocytosis, respectively. Extracellular DNA was stained with impermeable fluorescent dye to quantify NET formation. Biofilm formation increased up to 6-fold in the presence of neutrophils, and biofilms were identified in murine tissue. Both planktonic and biofilm cells induced neutrophils chemotaxis to the infection site, with neutrophils increasing by 85.1 and 73.8%, respectively. The bacteria in biofilms were not phagocytized. The bactericidal efficacy of NETs on the biofilms and planktonic cells were equal; however, the biofilm extracellular matrix can inhibit NET release. Although biofilms inhibit NETs release, NETs appear to be an important mechanism to eliminate SS2 biofilms. This knowledge advances the understanding of biofilms and may aid in the development of treatments for persistent infections with a biofilm component.
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Affiliation(s)
- Fang Ma
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Li Yi
- College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China; College of Life Science, Luoyang Normal UniversityLuoyang, China
| | - Ningwei Yu
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Guangyu Wang
- National Center of Meat Quality and Safety Control, Nanjing Agriculture University Nanjing, China
| | - Zhe Ma
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Huixing Lin
- College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural UniversityNanjing, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and ZoonosesYangzhou, China
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10
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Galinier A, Deutscher J. Sophisticated Regulation of Transcriptional Factors by the Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System. J Mol Biol 2017; 429:773-789. [PMID: 28202392 DOI: 10.1016/j.jmb.2017.02.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/01/2017] [Accepted: 02/04/2017] [Indexed: 11/16/2022]
Abstract
The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is a carbohydrate transport and phosphorylation system present in bacteria of all different phyla and in archaea. It is usually composed of three proteins or protein complexes, enzyme I, HPr, and enzyme II, which are phosphorylated at histidine or cysteine residues. However, in many bacteria, HPr can also be phosphorylated at a serine residue. The PTS not only functions as a carbohydrate transporter but also regulates numerous cellular processes either by phosphorylating its target proteins or by interacting with them in a phosphorylation-dependent manner. The target proteins can be catabolic enzymes, transporters, and signal transduction proteins but are most frequently transcriptional regulators. In this review, we will describe how PTS components interact with or phosphorylate proteins to regulate directly or indirectly the activity of transcriptional repressors, activators, or antiterminators. We will briefly summarize the well-studied mechanism of carbon catabolite repression in firmicutes, where the transcriptional regulator catabolite control protein A needs to interact with seryl-phosphorylated HPr in order to be functional. We will present new results related to transcriptional activators and antiterminators containing specific PTS regulation domains, which are the phosphorylation targets for three different types of PTS components. Moreover, we will discuss how the phosphorylation level of the PTS components precisely regulates the activity of target transcriptional regulators or antiterminators, with or without PTS regulation domain, and how the availability of PTS substrates and thus the metabolic status of the cell are connected with various cellular processes, such as biofilm formation or virulence of certain pathogens.
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Affiliation(s)
- Anne Galinier
- Laboratoire de Chimie Bactérienne, UPR 9043, CNRS, Aix Marseille Université, IMM, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; Centre National de la Recherche Scientifique, UMR8261 (affiliated with the Univ. Paris Diderot, Sorbonne, Paris Cité), Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, 75005 Paris, France.
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11
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Vacca I, Del Tordello E, Gasperini G, Pezzicoli A, Di Fede M, Rossi Paccani S, Marchi S, Mubaiwa TD, Hartley-Tassell LE, Jennings MP, Seib KL, Masignani V, Pizza M, Serruto D, Aricò B, Delany I. Neisserial Heparin Binding Antigen (NHBA) Contributes to the Adhesion of Neisseria meningitidis to Human Epithelial Cells. PLoS One 2016; 11:e0162878. [PMID: 27780200 PMCID: PMC5079597 DOI: 10.1371/journal.pone.0162878] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 08/30/2016] [Indexed: 11/19/2022] Open
Abstract
Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein ubiquitously expressed by Neisseria meningitidis strains and an antigen of the Bexsero® vaccine. NHBA binds heparin through a conserved Arg-rich region that is the target of two proteases, the meningococcal NalP and human lactoferrin (hLf). In this work, in vitro studies showed that recombinant NHBA protein was able to bind epithelial cells and mutations of the Arg-rich tract abrogated this binding. All N-terminal and C-terminal fragments generated by NalP or hLf cleavage, regardless of the presence or absence of the Arg-rich region, did not bind to cells, indicating that a correct positioning of the Arg-rich region within the full length protein is crucial. Moreover, binding was abolished when cells were treated with heparinase III, suggesting that this interaction is mediated by heparan sulfate proteoglycans (HSPGs). N. meningitidis nhba knockout strains showed a significant reduction in adhesion to epithelial cells with respect to isogenic wild-type strains and adhesion of the wild-type strain was inhibited by anti-NHBA antibodies in a dose-dependent manner. Overall, the results demonstrate that NHBA contributes to meningococcal adhesion to epithelial cells through binding to HSPGs and suggest a possible role of anti-Bexsero® antibodies in the prevention of colonization.
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Affiliation(s)
| | | | | | | | | | | | | | - Tsisti D. Mubaiwa
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | | | - Michael P. Jennings
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Kate L. Seib
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
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12
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Antunes A, Derkaoui M, Terrade A, Denizon M, Deghmane AE, Deutscher J, Delany I, Taha MK. The Phosphocarrier Protein HPr Contributes to Meningococcal Survival during Infection. PLoS One 2016; 11:e0162434. [PMID: 27655040 PMCID: PMC5031443 DOI: 10.1371/journal.pone.0162434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/23/2016] [Indexed: 12/27/2022] Open
Abstract
Neisseria meningitidis is an exclusively human pathogen frequently carried asymptomatically in the nasopharynx but it can also provoke invasive infections such as meningitis and septicemia. N. meningitidis uses a limited range of carbon sources during infection, such as glucose, that is usually transported into bacteria via the phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS), in which the phosphocarrier protein HPr (encoded by the ptsH gene) plays a central role. Although N. meningitidis possesses an incomplete PTS, HPr was found to be required for its virulence. We explored the role of HPr using bioluminescent wild-type and ΔptsH strains in experimental infection in transgenic mice expressing the human transferrin. The wild-type MC58 strain was recovered at higher levels from the peritoneal cavity and particularly from blood compared to the ΔptsH strain. The ΔptsH strain provoked lower levels of septicemia in mice and was more susceptible to complement-mediated killing than the wild-type strain. We tested whether meningococcal structures impacted complement resistance and observed that only the capsule level was decreased in the ΔptsH mutant. We therefore compared the transcriptomic profiles of wild-type and ΔptsH strains and identified 49 differentially expressed genes. The HPr regulon contains mainly hypothetical proteins (43%) and several membrane-associated proteins that could play a role during host interaction. Some other genes of the HPr regulon are involved in stress response. Indeed, the ΔptsH strain showed increased susceptibility to environmental stress conditions. Our data suggest that HPr plays a pleiotropic role in host-bacteria interactions most likely through the innate immune response that may be responsible for the enhanced clearance of the ΔptsH strain from blood.
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Affiliation(s)
- Ana Antunes
- Institut Pasteur, Unité des Infections Bactériennes Invasives, Paris, France, 75724 Paris Cedex 15, France
- * E-mail: (AA); (MKT)
| | - Meriem Derkaoui
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Aude Terrade
- Institut Pasteur, Unité des Infections Bactériennes Invasives, Paris, France, 75724 Paris Cedex 15, France
| | - Mélanie Denizon
- Institut Pasteur, Unité des Infections Bactériennes Invasives, Paris, France, 75724 Paris Cedex 15, France
| | - Ala-Eddine Deghmane
- Institut Pasteur, Unité des Infections Bactériennes Invasives, Paris, France, 75724 Paris Cedex 15, France
| | - Josef Deutscher
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
- Centre National de la Recherche Scientifique, UMR8261 (affiliated with Univ. Paris Diderot, Sorbonne Paris Cité), Expression Génétique Microbienne, Institut de Biologie Physico-Chimique, 75005, Paris, France
| | - Isabel Delany
- Novartis Vaccines and Diagnostics s.r.l. (a GSK company), Via Fiorentina 1, 53100, Siena, Italy
| | - Muhamed-Kheir Taha
- Institut Pasteur, Unité des Infections Bactériennes Invasives, Paris, France, 75724 Paris Cedex 15, France
- * E-mail: (AA); (MKT)
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Derkaoui M, Antunes A, Nait Abdallah J, Poncet S, Mazé A, Ma Pham QM, Mokhtari A, Deghmane AE, Joyet P, Taha MK, Deutscher J. Transport and Catabolism of Carbohydrates by Neisseria meningitidis. J Mol Microbiol Biotechnol 2016; 26:320-32. [DOI: 10.1159/000447093] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/25/2016] [Indexed: 11/19/2022] Open
Abstract
We identified the genes encoding the proteins for the transport of glucose and maltose in <i>Neisseria meningitidis</i> strain 2C4-3. A mutant deleted for <i>NMV_1892</i><i>(glcP)</i> no longer grew on glucose and deletion of <i>NMV_0424</i><i>(malY)</i> prevented the utilization of maltose. We also purified and characterized glucokinase and α-phosphoglucomutase, which catalyze early catabolic steps of the two carbohydrates. <i>N. meningitidis</i> catabolizes the two carbohydrates either via the Entner-Doudoroff (ED) pathway or the pentose phosphate pathway, thereby forming glyceraldehyde-3-P and either pyruvate or fructose-6-P, respectively. We purified and characterized several key enzymes of the two pathways. The genes required for the transformation of glucose into gluconate-6-P and its further catabolism via the ED pathway are organized in two adjacent operons. <i>N. meningitidis</i> also contains genes encoding proteins which exhibit similarity to the gluconate transporter <i>(NMV_2230)</i> and gluconate kinase <i>(NMV_2231)</i> of Enterobacteriaceae and Firmicutes. However, gluconate might not be the real substrate of <i>NMV_2230</i> because <i>N. meningitidi</i>s was not able to grow on gluconate as the sole carbon source. Surprisingly, deletion of <i>NMV_2230</i> stimulated growth in minimal medium in the presence and absence of glucose and drastically slowed the clearance of <i>N. meningitidis</i> cells from transgenic mice after intraperitoneal challenge.
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