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Wright MJ, Bai G. Bacterial second messenger cyclic di-AMP in streptococci. Mol Microbiol 2023; 120:791-804. [PMID: 37898560 DOI: 10.1111/mmi.15187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/10/2023] [Accepted: 10/15/2023] [Indexed: 10/30/2023]
Abstract
Cyclic dimeric adenosine monophosphate (c-di-AMP) has been well studied in bacteria, including those of the genus Streptococcus, since the first recognition of this dinucleotide in 2008. Streptococci possess a sole diadenylate cyclase, CdaA, and distinct c-di-AMP phosphodiesterases. Interestingly, cdaA is required for viability of some streptococcal species but not all when streptococci are grown in standard laboratory media. Bacteria of this genus also have distinct c-di-AMP effector proteins, diverse c-di-AMP-signaling pathways, and subsequent biological outcomes. In streptococci, c-di-AMP may influence bacterial growth, morphology, biofilm formation, competence program, drug resistance, and bacterial pathogenesis. c-di-AMP secreted by streptococci has also been shown to interact with the mammalian host and induces immune responses including type I interferon production. In this review, we summarize the reported c-di-AMP networks in seven species of the genus Streptococcus, which cause diverse clinical manifestations, and propose future perspectives to investigate the signaling molecule in these streptococcal pathogens.
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Affiliation(s)
- Michael J Wright
- Department of Internal Medicine, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Guangchun Bai
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
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2
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Zhu X, Baranowski E, Hao Z, Li X, Zhao G, Dong Y, Chen Y, Hu C, Chen H, Citti C, Wang A, Guo A. An atypical GdpP enzyme linking cyclic nucleotide metabolism to osmotic tolerance and gene regulation in Mycoplasma bovis. Front Microbiol 2023; 14:1250368. [PMID: 38098652 PMCID: PMC10720645 DOI: 10.3389/fmicb.2023.1250368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/10/2023] [Indexed: 12/17/2023] Open
Abstract
Nucleotide second messengers play an important role in bacterial adaptation to environmental changes. Recent evidence suggests that some of these regulatory molecular pathways were conserved upon the degenerative evolution of the wall-less mycoplasmas. We have recently reported the occurrence of a phosphodiesterase (PDE) in the ruminant pathogen Mycoplasma bovis, which was involved in c-di-AMP metabolism. In the present study, we demonstrate that the genome of this mycoplasma species encodes a PDE of the GdpP family with atypical DHH domains. Characterization of M. bovis GdpP (MbovGdpP) revealed a multifunctional PDE with unusual nanoRNase and single-stranded DNase activities. The alarmone ppGpp was found unable to inhibit c-di-NMP degradation by MbovGdpP but efficiently blocked its nanoRNase activity. Remarkably, MbovGdpP was found critical for the osmotic tolerance of M. bovis under K+ and Na+ conditions. Transcriptomic analyses further revealed the biological importance of MbovGdpP in tRNA biosynthesis, pyruvate metabolism, and several steps in genetic information processing. This study is an important step in understanding the role of PDE and nucleotide second messengers in the biology of a minimal bacterial pathogen.
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Affiliation(s)
- Xifang Zhu
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou, China
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | | | - Zhiyu Hao
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Xixi Li
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Gang Zhao
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yaqi Dong
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Yingyu Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Changmin Hu
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Huanchun Chen
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
| | | | - Aiping Wang
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
- Longhu Laboratory of Advanced Immunology, Zhengzhou, China
| | - Aizhen Guo
- The State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture of the People’s Republic of China, Wuhan, China
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, International Research Center for Animal Disease, Ministry of Science and Technology of the People’s Republic of China, Wuhan, China
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3
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Acciarri G, Gizzi FO, Torres Manno MA, Stülke J, Espariz M, Blancato VS, Magni C. Redundant potassium transporter systems guarantee the survival of Enterococcus faecalis under stress conditions. Front Microbiol 2023; 14:1117684. [PMID: 36846772 PMCID: PMC9945522 DOI: 10.3389/fmicb.2023.1117684] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/17/2023] [Indexed: 02/10/2023] Open
Abstract
Enterococcus is able to grow in media at pH from 5.0 to 9.0 and a high concentration of NaCl (8%). The ability to respond to these extreme conditions requires the rapid movement of three critical ions: proton (H+), sodium (Na+), and potassium (K+). The activity of the proton F0F1 ATPase and the sodium Na+ V0V1 type ATPase under acidic or alkaline conditions, respectively, is well established in these microorganisms. The potassium uptake transporters KtrI and KtrII were described in Enterococcus hirae, which were associated with growth in acidic and alkaline conditions, respectively. In Enterococcus faecalis, the presence of the Kdp (potassium ATPase) system was early established. However, the homeostasis of potassium in this microorganism is not completely explored. In this study, we demonstrate that Kup and KimA are high-affinity potassium transporters, and the inactivation of these genes in E. faecalis JH2-2 (a Kdp laboratory natural deficient strain) had no effect on the growth parameters. However, in KtrA defective strains (ΔktrA, ΔkupΔktrA) an impaired growth was observed under stress conditions, which was restored to wild type levels by external addition of K+ ions. Among the multiplicity of potassium transporters identify in the genus Enterococcus, Ktr channels (KtrAB and KtrAD), and Kup family symporters (Kup and KimA) are present and may contribute to the particular resistance of these microorganisms to different stress conditions. In addition, we found that the presence of the Kdp system in E. faecalis is strain-dependent, and this transporter is enriched in strains of clinical origin as compared to environmental, commensal, or food isolates.
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Affiliation(s)
- Giuliana Acciarri
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Fernán O. Gizzi
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina
| | - Mariano A. Torres Manno
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Jörg Stülke
- Department of General Microbiology, Georg August University, Göttingen, Germany
| | - Martín Espariz
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Área Bioinformática, Departamento de Matemática y Estadística, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Víctor S. Blancato
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina
| | - Christian Magni
- Laboratorio de Fisiología y Genética de Bacterias Lácticas, Instituto de Biología Molecular y Celular de Rosario (IBR), Sede Facultad de Ciencias Bioquímicas y Farmacéuticas (FBioyF), Universidad Nacional de Rosario (UNR), Consejo Nacional de Ciencia y Tecnología (CONICET), Rosario, Argentina,Laboratorio de Biotecnología e Inocuidad de los Alimentos, Área de Biotecnología de los Alimentos, FBioyF, UNR–Municipalidad de Granadero Baigorria, Rosario, Argentina,*Correspondence: Christian Magni, ✉
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Electrochemical Control of Biofilm Formation and Approaches to Biofilm Removal. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12136320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review deals with microbial adhesion to metal-based surfaces and the subsequent biofilm formation, showing that both processes are a serious problem in the food industry, where pathogenic microorganisms released from the biofilm structure may pollute food and related material during their production. Biofilm exhibits an increased resistance toward sanitizers and disinfectants, which complicates the removal or inactivation of microorganisms in these products. In the existing traditional techniques and modern approaches for clean-in-place, electrochemical biofilm control offers promising technology, where surface properties or the reactions taking place on the surface are controlled to delay or prevent cell attachment or to remove microbial cells from the surface. In this overview, biofilm characterization, the classification of bacteria-forming biofilms, the influence of environmental conditions for bacterial attachment to material surfaces, and the evaluation of the role of biofilm morphology are described in detail. Health aspects, biofilm control methods in the food industry, and conventional approaches to biofilm removal are included as well, in order to consider the possibilities and limitations of various electrochemical approaches to biofilm control with respect to potential applications in the food industry.
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5
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The PTS
Ntr
-KdpDE-KdpFABC Pathway Contributes to Low Potassium Stress Adaptation and Competitive Nodulation of Sinorhizobium fredii. mBio 2022; 13:e0372121. [PMID: 35491828 PMCID: PMC9239096 DOI: 10.1128/mbio.03721-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In all ecological niches, potassium is actively consumed by diverse prokaryotes and their interacting eukaryote hosts. It is only just emerging that potassium is a key player in host-pathogen interactions, and the role of potassium in mutualistic interactions remains largely unknown.
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6
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Dunkers JP, Iyer H, Jones B, Camp CH, Stranick SJ, Lin NJ. Toward absolute viability measurements for bacteria. JOURNAL OF BIOPHOTONICS 2021; 14:e202100175. [PMID: 34510771 DOI: 10.1002/jbio.202100175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/13/2021] [Accepted: 09/05/2021] [Indexed: 06/13/2023]
Abstract
We aim to develop a quantitative viability method that distinguishes individual quiescent from dead cells and is measured in time (ns) as a referenceable, comparable quantity. We demonstrate that fluorescence lifetime imaging of an anionic, fluorescent membrane voltage probe fulfills these requirements for Streptococcus mutans. A random forest machine-learning model assesses whether individual S. mutans can be correctly classified into their original populations: stationary phase (quiescent), heat killed and inactivated via chemical fixation. We compare the results to intensity using three models: lifetime variables (τ1 , τ2 and p1 ), phasor variables (G, S) or all five variables, with the five variable models having the most accurate classification. This initial work affirms the potential for using fluorescence lifetime of a membrane voltage probe as a viability marker for quiescent bacteria, and future efforts on other bacterial species and fluorophores will help refine this approach.
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Affiliation(s)
- Joy P Dunkers
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Hariharan Iyer
- Statistical Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Brynna Jones
- Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
- Department of Chemistry, University of North Florida, Jacksonville, Florida, USA
| | - Charles H Camp
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Stephan J Stranick
- Materials Measurement Science Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Nancy J Lin
- Biosystems and Biomaterials Division, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
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7
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Abstract
Potassium is an essential mineral nutrient required by all living cells for normal physiological function. Therefore, maintaining intracellular potassium homeostasis during bacterial infection is a requirement for the survival of both host and pathogen. However, pathogenic bacteria require potassium transport to fulfill nutritional and chemiosmotic requirements, and potassium has been shown to directly modulate virulence gene expression, antimicrobial resistance, and biofilm formation. Host cells also require potassium to maintain fundamental biological processes, such as renal function, muscle contraction, and neuronal transmission; however, potassium flux also contributes to critical immunological and antimicrobial processes, such as cytokine production and inflammasome activation. Here, we review the role and regulation of potassium transport and signaling during infection in both mammalian and bacterial cells and highlight the importance of potassium to the success and survival of each organism.
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8
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Abundant Monovalent Ions as Environmental Signposts for Pathogens during Host Colonization. Infect Immun 2021; 89:IAI.00641-20. [PMID: 33526568 DOI: 10.1128/iai.00641-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Host colonization by a pathogen requires proper sensing and response to local environmental cues, to ensure adaptation and continued survival within the host. The ionic milieu represents a critical potential source of environmental cues, and indeed, there has been extensive study of the interplay between host and pathogen in the context of metals such as iron, zinc, and manganese, vital ions that are actively sequestered by the host. The inherent non-uniformity of the ionic milieu also extends, however, to "abundant" ions such as chloride and potassium, whose concentrations vary greatly between tissue and cellular locations, and with the immune response. Despite this, the concept of abundant ions as environmental cues and key players in host-pathogen interactions is only just emerging. Focusing on chloride and potassium, this review brings together studies across multiple bacterial and parasitic species that have begun to define both how these abundant ions are exploited as cues during host infection, and how they can be actively manipulated by pathogens during host colonization. The close links between ion homeostasis and sensing/response to different ionic signals, and the importance of studying pathogen response to cues in combination, are also discussed, while considering the fundamental insight still to be uncovered from further studies in this nascent area of inquiry.
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9
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Turner ME, Huynh K, Carroll RK, Ahn SJ, Rice KC. Characterization of the Streptococcus mutans SMU.1703c-SMU.1702c Operon Reveals Its Role in Riboflavin Import and Response to Acid Stress. J Bacteriol 2020; 203:e00293-20. [PMID: 33077636 PMCID: PMC7950412 DOI: 10.1128/jb.00293-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans utilizes numerous metabolite transporters to obtain essential nutrients in the "feast or famine" environment of the human mouth. S. mutans and most other streptococci are considered auxotrophic for several essential vitamins including riboflavin (vitamin B2), which is used to generate key cofactors and to perform numerous cellular redox reactions. Despite the well-known contributions of this vitamin to central metabolism, little is known about how S. mutans obtains and metabolizes B2 The uncharacterized protein SMU.1703c displays high sequence homology to the riboflavin transporter RibU. Deletion of SMU.1703c hindered S. mutans growth in complex and defined medium in the absence of saturating levels of exogenous riboflavin, whereas deletion of cotranscribed SMU.1702c alone had no apparent effect on growth. Expression of SMU.1703c in a Bacillus subtilis riboflavin auxotroph functionally complemented growth in nonsaturating riboflavin conditions. S. mutans was also able to grow on flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN) in an SMU.1703c-dependent manner. Deletion of SMU.1703c and/or SMU.1702c impacted S. mutans acid stress tolerance, as all mutants showed improved growth at pH 5.5 compared to that of the wild type when medium was supplemented with saturating riboflavin. Cooccurrence of SMU.1703c and SMU.1702c, a hypothetical PAP2 family acid phosphatase gene, appears unique to the streptococci and may suggest a connection of SMU.1702c to the acquisition or metabolism of flavins within this genus. Identification of SMU.1703c as a RibU-like riboflavin transporter furthers our understanding of how S. mutans acquires essential micronutrients within the oral cavity and how this pathogen successfully competes within nutrient-starved oral biofilms.IMPORTANCE Dental caries form when acid produced by oral bacteria erodes tooth enamel. This process is driven by the fermentative metabolism of cariogenic bacteria, most notably Streptococcus mutans Nutrient acquisition is key in the competitive oral cavity, and many organisms have evolved various strategies to procure carbon sources or necessary biomolecules. B vitamins, such as riboflavin, which many oral streptococci must scavenge from the oral environment, are necessary for survival within the competitive oral cavity. However, the primary mechanism and proteins involved in this process remain uncharacterized. This study is important because it identifies a key step in S. mutans riboflavin acquisition and cofactor generation, which may enable the development of novel anticaries treatment strategies via selective targeting of metabolite transporters.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
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10
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Golla RM, Mishra B, Dang X, Lakshmaiah Narayana J, Li A, Xu L, Wang G. Resistome of Staphylococcus aureus in Response to Human Cathelicidin LL-37 and Its Engineered Antimicrobial Peptides. ACS Infect Dis 2020; 6:1866-1881. [PMID: 32343547 DOI: 10.1021/acsinfecdis.0c00112] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Staphylococcus aureus is notoriously known for its rapid development of resistance to conventional antibiotics. S. aureus can alter its membrane composition to reduce the killing effect of antibiotics and antimicrobial peptides (AMPs). To obtain a more complete picture, this study identified the resistance genes of S. aureus in response to human cathelicidin LL-37 peptides by screening the Nebraska Transposon Mutant Library. In total, 24 resistant genes were identified. Among them, six mutants, including the one with the known membrane-modifying gene (mprF) disabled, became more membrane permeable to the LL-37 engineered peptide 17BIPHE2 than the wild type. Mass spectrometry analysis detected minimal lysyl-phosphatidylglycerol (lysylPG) from the mprF mutant of S. aureus JE2, confirming loss-of-function of this gene. Moreover, multiple mutants showed reduced surface adhesion and biofilm formation. In addition, four S. aureus mutants were unable to infect wax moth Galleria mellonella. There appears to be a connection between the ability of bacterial attachment/biofilm formation and infection. These results underscore the multiple functional roles of the identified peptide-response genes in bacterial growth, infection, and biofilm formation. Therefore, S. aureus utilizes a set of resistant genes to weave a complex molecular network to handle the danger posed by cationic LL-37. It appears that different genes are involved depending on the nature of antimicrobials. These resistant genes may offer a novel avenue to designing more potent antibiotics that target the Achilles heels of S. aureus USA300, a community-associated pathogen of great threat.
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Affiliation(s)
- Radha M. Golla
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198-5900, United States
| | - Biswajit Mishra
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198-5900, United States
| | - Xiangli Dang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198-5900, United States
| | - Jayaram Lakshmaiah Narayana
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198-5900, United States
| | - Amy Li
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Libin Xu
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Guangshun Wang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, Nebraska 68198-5900, United States
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11
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Abstract
Ceramic water filters (CWFs) are point-of-use drinking water treatment systems that are manufactured and used in under-served communities around the world. The clayey material (CM) used to manufacture CWFs is a locally sourced mixture of clay, sand, slit and amorphous material (usually dug near the CWF factory). CM varies in composition and purity depending on the geographical location and geological setting. In this study, a set of 13 CM samples collected from around the world were analyzed using grain size analysis, as well as liquid and plastic limit tests. Mineralogical composition was determined using X-ray diffraction. A selection of three CM samples (Guatemala, Canada, and Guinea Bissau) with a range of compositions were used to study biofilm growth on CM before and after firing. Biofilm coverage was studied on CM (before firing) and CWF material (after firing) using Pseudomonas fluorescens Migula. The average biofilm coverages for Guatemala, Canada, and Guinea Bissau CM were 20.03 ± 2.80%, 19.28 ± 0.91%, and 9.88 ± 4.02%, respectively. The average biofilm formation coverages for Guatemala, Canada, and Guinea Bissau CWF were 13.08 ± 1.74%, 10.36 ± 3.41%, and 8.66 ± 0.13%, respectively. The results presented here suggest that CM can be manipulated to manufacture better performing CWFs by engineering the soil characteristics, such as grain size, liquid and plastic limits, and mineralogy. This could improve the durability and biofilm resistance of CWFs.
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12
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Ahn SJ, Desai S, Blanco L, Lin M, Rice KC. Acetate and Potassium Modulate the Stationary-Phase Activation of lrgAB in Streptococcus mutans. Front Microbiol 2020; 11:401. [PMID: 32231651 PMCID: PMC7082836 DOI: 10.3389/fmicb.2020.00401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/26/2020] [Indexed: 12/28/2022] Open
Abstract
Fluctuating environments force bacteria to constantly adapt and optimize the uptake of substrates to maintain cellular and nutritional homeostasis. Our recent findings revealed that LrgAB functions as a pyruvate uptake system in Streptococcus mutans, and its activity is modulated in response to glucose and oxygen levels. Here, we show that the composition of the growth medium dramatically influences the magnitude and pattern of lrgAB activation. Specifically, tryptone (T) medium does not provide a preferred environment for stationary phase lrgAB activation, which is independent of external pyruvate concentration. The addition of pyruvate to T medium can elicit PlrgA activation during exponential growth, enabling the cell to utilize external pyruvate for improvement of cell growth. Through comparison of the medium composition and a series of GFP quantification assays for measurement of PlrgA activation, we found that acetate and potassium (K+) play important roles in eliciting PlrgA activation at stationary phase. Of note, supplementation of pooled human saliva to T medium induced lrgAB expression at stationary phase and in response to pyruvate, suggesting that LrgAB is likely functional in the oral cavity. High concentrations of acetate inhibit cell growth, while high concentrations of K+ negatively regulate lrgAB activation. qPCR analysis also revealed that growth in T medium (acetate/K+ limited) significantly affects the expression of genes related to the catabolic pathways of pyruvate, including the Pta/AckA pathway (acetate metabolism). Lastly, stationary phase lrgAB expression is not activated when S. mutans is cultured in T medium, even in a strain that overexpresses lytST. Taken together, these data suggest that lrgAB activation and pyruvate uptake in S. mutans are connected to acetate metabolism and potassium uptake systems, important for cellular and energy homeostasis. They also suggest that these factors need to be implemented when planning metabolic experiments and analyzing data in S. mutans studies that may be sensitive to stationary growth phase.
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Affiliation(s)
- Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Shailja Desai
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Loraine Blanco
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, United States
| | - Min Lin
- Department of Chemistry, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, United States
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
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13
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Chen X, Liu C, Peng X, He Y, Liu H, Song Y, Xiong K, Zou L. Sortase A‐mediated modification of the
Streptococcus mutans
transcriptome and virulence traits. Mol Oral Microbiol 2019; 34:219-233. [PMID: 31342653 DOI: 10.1111/omi.12266] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 07/16/2019] [Accepted: 07/18/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Xuan Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
| | - Chengcheng Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
- Department of Periodontics West China Hospital of Stomatology, Sichuan University Chengdu China
| | - Xian Peng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
| | - Yuanli He
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
| | - Haixia Liu
- Stomatological Hospital of Chongqing Medical University Chongqing China
| | - Ying Song
- Stomatological Hospital of Chongqing Medical University Chongqing China
| | - Kaixin Xiong
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
| | - Ling Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases Sichuan University Chengdu China
- Department of Conservation Dentistry and Endodontics West China Hospital of Stomatology, Sichuan University Chengdu China
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14
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Ng ZY, Fang BZ, Li WJ, Tan GYA. Marinitenerispora sediminis gen. nov., sp. nov., a member of the family Nocardiopsaceae isolated from marine sediment. Int J Syst Evol Microbiol 2019; 69:3031-3040. [PMID: 31310190 DOI: 10.1099/ijsem.0.003587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three novel actinobacterial strains, designated as TPS16T, TPS81 and TPS83, were isolated from a sample of marine sediment collected from Tioman Island, Malaysia. The strains formed abundant branched substrate mycelia without fragmentation along with production of blue spores and blue diffusible pigment on soybean meal agar. The strains could grow at pH ranging from pH 6 to 12 and in 0-8 % (w/v) NaCl. Cell-wall hydrolysis showed the presence of meso-diaminopimelic acid. The strains were closely related to Marinactinospora thermotolerans SCSIO 00652T (97.60 %) and Marinactinospora endophytica YIM 690053T (96.87 %) based on phylogenetic analysis of 16S rRNA gene sequences. Multilocus sequence analysis including gyrB, recA and rpoB genes further confirmed that strain TPS16T represented a distinct branch within the family Nocardiopsaceae. The predominant menaquinones were MK-11(H2), MK-10(H2), MK-11(H4) and MK-10(H4), while the major fatty acids were found to be iso-C16 : 0, anteiso-C17 : 0, iso-C15 : 0 and C18 : 1ω9c. Genome sequencing revealed genome sizes of approximately 6 Mb and G+C contents of 73.8 mol%. A new genus, Marinitenerispora gen. nov., is proposed within the family Nocardiopsaceae based on polyphasic data and the type species is Marinitenerispora sediminis gen. nov., sp. nov. The type strain is TPS16T (=DSM 46825T=TBRC 5138T).
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Affiliation(s)
- Zoe Yi Ng
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Bao-Zhu Fang
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat Sen University, Guangzhou 510275, PR China.,Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), 51900 Zhuhai, PR China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat Sen University, Guangzhou 510275, PR China.,Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), 51900 Zhuhai, PR China
| | - Geok Yuan Annie Tan
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
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15
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Kajala I, Bergsveinson J, Friesen V, Redekop A, Juvonen R, Storgårds E, Ziola B. Lactobacillus backii and Pediococcus damnosus isolated from 170-year-old beer recovered from a shipwreck lack the metabolic activities required to grow in modern lager beer. FEMS Microbiol Ecol 2019; 94:4604776. [PMID: 29126241 DOI: 10.1093/femsec/fix152] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 11/07/2017] [Indexed: 12/21/2022] Open
Abstract
In 2010, bottles of beer containing viable bacteria of the common beer-spoilage species Lactobacillus backii and Pediococcus damnosus were recovered from a shipwreck near the Åland Islands, Finland. The 170-year quiescent state maintained by the shipwreck bacteria presented a unique opportunity to study lactic acid bacteria (LAB) evolution vis-a-vis growth and survival in the beer environment. Three shipwreck bacteria (one L. backii strain and two P. damnosus strains) and modern-day beer-spoilage isolates of the same two species were genome sequenced, characterized for hop iso-α-acid tolerance, and growth in degassed lager and wheat beer. In addition, plasmid variants of the modern-day P. damnosus strain were analyzed for the effect of plasmid-encoded genes on growth in lager beer. Coding content on two plasmids was identified as essential for LAB growth in modern lager beer. Three chromosomal regions containing genes related to sugar transport and cell wall polysaccharides were shared by pediococci able to grow in beer. Our results show that the three shipwreck bacteria lack the necessary plasmid-located genetic content to grow in modern lager beer, but carry additional genes related to acid tolerance and biofilm formation compared to their modern counterparts.
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Affiliation(s)
- Ilkka Kajala
- VTT Technical Research Centre of Finland Ltd, PL 1000, 02044 VTT, Espoo, Finland
| | - Jordyn Bergsveinson
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Royal University Hospital, Box 17, 103 Hospital Drive, Saskatoon, SK S7N 0W8, Canada
| | - Vanessa Friesen
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Royal University Hospital, Box 17, 103 Hospital Drive, Saskatoon, SK S7N 0W8, Canada
| | - Anna Redekop
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Royal University Hospital, Box 17, 103 Hospital Drive, Saskatoon, SK S7N 0W8, Canada
| | - Riikka Juvonen
- VTT Technical Research Centre of Finland Ltd, PL 1000, 02044 VTT, Espoo, Finland
| | - Erna Storgårds
- VTT Technical Research Centre of Finland Ltd, PL 1000, 02044 VTT, Espoo, Finland
| | - Barry Ziola
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Royal University Hospital, Box 17, 103 Hospital Drive, Saskatoon, SK S7N 0W8, Canada
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16
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Parsons C, Lee S, Kathariou S. Heavy Metal Resistance Determinants of the Foodborne Pathogen Listeria monocytogenes. Genes (Basel) 2018; 10:genes10010011. [PMID: 30586907 PMCID: PMC6356457 DOI: 10.3390/genes10010011] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 12/18/2022] Open
Abstract
Listeria monocytogenes is ubiquitous in the environment and causes the disease listeriosis. Metal homeostasis is one of the key processes utilized by L. monocytogenes in its role as either a saprophyte or pathogen. In the environment, as well as within an animal host, L. monocytogenes needs to both acquire essential metals and mitigate toxic levels of metals. While the mechanisms associated with acquisition and detoxification of essential metals such as copper, iron, and zinc have been extensively studied and recently reviewed, a review of the mechanisms associated with non-essential heavy metals such as arsenic and cadmium is lacking. Resistance to both cadmium and arsenic is frequently encountered in L. monocytogenes, including isolates from human listeriosis. In addition, a growing body of work indicates the association of these determinants with other cellular functions such as virulence, suggesting the importance of further study in this area.
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Affiliation(s)
- Cameron Parsons
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695-7624, USA.
| | - Sangmi Lee
- Seoul National University, Seoul 08826, Korea.
| | - Sophia Kathariou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695-7624, USA.
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17
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Jacquiod S, Nunes I, Brejnrod A, Hansen MA, Holm PE, Johansen A, Brandt KK, Priemé A, Sørensen SJ. Long-term soil metal exposure impaired temporal variation in microbial metatranscriptomes and enriched active phages. MICROBIOME 2018; 6:223. [PMID: 30545417 PMCID: PMC6292020 DOI: 10.1186/s40168-018-0606-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/25/2018] [Indexed: 05/13/2023]
Abstract
BACKGROUND It remains unclear whether adaptation and changes in diversity associated to a long-term perturbation are sufficient to ensure functional resilience of soil microbial communities. We used RNA-based approaches (16S rRNA gene transcript amplicon coupled to shotgun mRNA sequencing) to study the legacy effects of a century-long soil copper (Cu) pollution on microbial activity and composition, as well as its effect on the capacity of the microbial community to react to temporal fluctuations. RESULTS Despite evidence of microbial adaptation (e.g., iron homeostasis and avoidance/resistance strategies), increased heterogeneity and richness loss in transcribed gene pools were observed with increasing soil Cu, together with an unexpected predominance of phage mRNA signatures. Apparently, phage activation was either triggered directly by Cu, or indirectly via enhanced expression of DNA repair/SOS response systems in Cu-exposed bacteria. Even though total soil carbon and nitrogen had accumulated with increasing Cu, a reduction in temporally induced mRNA functions was observed. Microbial temporal response groups (TRGs, groups of microbes with a specific temporal response) were heavily affected by Cu, both in abundance and phylogenetic composition. CONCLUSION Altogether, results point toward a Cu-mediated "decoupling" between environmental fluctuations and microbial activity, where Cu-exposed microbes stopped fulfilling their expected contributions to soil functioning relative to the control. Nevertheless, some functions remained active in February despite Cu, concomitant with an increase in phage mRNA signatures, highlighting that somehow, microbial activity is still happening under these adverse conditions.
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Affiliation(s)
- Samuel Jacquiod
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Agroécologie, AgroSup Dijon, INRA, Univ Bourgogne Franche-Comté, 17 rue Sully, 21000, Dijon, France
| | - Inês Nunes
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Present address: Microbe Technology Department, Novozymes A/S, Krogshoejvej 36, 2880, Bagsværd, Denmark
| | - Asker Brejnrod
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
- Present address: Center for Basic Metabolic Research, University of Copenhagen, Blegdamsvej 3A, 2200, Copenhagen, Denmark
| | - Martin A Hansen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Peter E Holm
- Present address: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Anders Johansen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark
| | - Kristian K Brandt
- Present address: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg C, Denmark
| | - Anders Priemé
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark
| | - Søren J Sørensen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100, Copenhagen, Denmark.
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18
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Nomura R, Morita Y, Matayoshi S, Nakano K. Inhibitory effect of surface pre-reacted glass-ionomer (S-PRG) eluate against adhesion and colonization by Streptococcus mutans. Sci Rep 2018; 8:5056. [PMID: 29568011 PMCID: PMC5864963 DOI: 10.1038/s41598-018-23354-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/08/2018] [Indexed: 12/17/2022] Open
Abstract
Surface Pre-reacted Glass-ionomer (S-PRG) filler is a bioactive filler produced by PRG technology, which has been applied to various dental materials. A S-PRG filler can release multiple ions from a glass-ionomer phase formed in the filler. In the present study, detailed inhibitory effects induced by S-PRG eluate (prepared with S-PRG filler) against Streptococcus mutans, a major pathogen of dental caries, were investigated. S-PRG eluate effectively inhibited S. mutans growth especially in the bacterium before the logarithmic growth phase. Microarray analysis was performed to identify changes in S. mutans gene expression in the presence of the S-PRG eluate. The S-PRG eluate prominently downregulated operons related to S. mutans sugar metabolism, such as the pdh operon encoding the pyruvate dehydrogenase complex and the glg operon encoding a putative glycogen synthase. The S-PRG eluate inhibited several in vitro properties of S. mutans relative to the development of dental caries especially prior to active growth. These results suggest that the S-PRG eluate may effectively inhibit the bacterial growth of S. mutans following downregulation of operons involved in sugar metabolism resulting in attenuation of the cariogenicity of S. mutans, especially before the active growth phase.
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Affiliation(s)
- Ryota Nomura
- Department of Pediatric Dentistry, Division of Oral Infections and Disease Control, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
| | - Yumiko Morita
- Department of Pediatric Dentistry, Division of Oral Infections and Disease Control, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Saaya Matayoshi
- Department of Pediatric Dentistry, Division of Oral Infections and Disease Control, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Kazuhiko Nakano
- Department of Pediatric Dentistry, Division of Oral Infections and Disease Control, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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19
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First description of novel arginine catabolic mobile elements (ACMEs) types IV and V harboring a kdp operon in Staphylococcus epidermidis characterized by whole genome sequencing. INFECTION GENETICS AND EVOLUTION 2018; 61:60-66. [PMID: 29567304 DOI: 10.1016/j.meegid.2018.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/09/2018] [Accepted: 03/16/2018] [Indexed: 11/23/2022]
Abstract
The arginine catabolic mobile element (ACME) was first described in the methicillin-resistant Staphylococcus aureus strain USA300 and is thought to facilitate survival on skin. To date three distinct ACME types have been characterized comprehensively in S. aureus and/or Staphylococcus epidermidis. Type I harbors the arc and opp3 operons encoding an arginine deaminase pathway and an oligopeptide permease ABC transporter, respectively, type II harbors the arc operon only, and type III harbors the opp3 operon only. To investigate the diversity and detailed genetic organization of ACME, whole genome sequencing (WGS) was performed on 32 ACME-harboring oro-nasal S. epidermidis isolates using MiSeq- and PacBio-based WGS platforms. In nine isolates the ACMEs lacked the opp3 operon, but harbored a complete kdp operon (kdpE/D/A/B/C) located a maximum of 2.8 kb upstream of the arc operon. The kdp operon exhibited 63% DNA sequence identity to the native S. aureus kdp operon. These findings identified a novel, previously undescribed ACME type (designated ACME IV), which could be subtyped (IVa and IVb) based on distinct 5' flanking direct repeat sequences (DRs). Multilocus sequence typing (MLST) sequences extracted from the WGS data identified the sequence types (STs) of the isolates investigated. Four of the nine ACME IV isolates belonged to ST153, and one to ST17, a single locus variant of ST153. A tenth isolate, identified as ST5, harbored another novel ACME type (designated ACME V) containing the kdp, arc and opp3 operons and flanked by DR_F, and DR_B but lacked any internal DRs. ACME V was colocated with a staphylococcal chromosome cassette mec (SCCmec) IV element and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) in a 116.9 kb composite island. The extensive genetic diversity of ACME in S. epidermidis has been further elucidated by WGS, revealing two novel ACME types IV and V for the first time.
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20
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Binepal G, Wenderska IB, Crowley P, Besingi RN, Senadheera DB, Jeannine Brady L, Cvitkovitch DG. K+ modulates genetic competence and the stress regulon of Streptococcus mutans. MICROBIOLOGY-SGM 2017; 163:719-730. [PMID: 28530170 DOI: 10.1099/mic.0.000458] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Potassium (K+) is the most abundant cation in dental plaque fluid. Previously, we reported the link between K+ transport via Trk2 in Streptococcus mutans and its two critical virulence attributes: acid tolerance and surface adhesion. Herein, we build further on the intimate link between K+ levels and S. mutans biology. High (>25 mM) versus low (≤5 mM) K+ concentrations in the growth medium affected conformational epitopes of cell surface-localized adhesin P1. At low K+, the expression of stress response elements gcrR and codY, cell-adhesion-associated genes such as spaP and metabolism-associated genes such as bglP was induced at stationary phase (P<0.05), suggesting that K+-mediated regulation is growth phase-dependent and stress-sensitive. Production of the newly discovered secretory protein encoded by SMU_63c was strongly dependent on the availability of K+ and growth phase. This protein is a newly discovered regulator of genetic competence and biofilm cell density. Thus, the influence of K+ on DNA transformation efficiency was also examined. Compared with 25 mM K+ concentration, the presence of low K+ reduced the transformation frequency by 100-fold. Genetic transformation was abolished in a strain lacking a Trk2 system under all K+ concentrations tested. Consistent with these findings, repression of competence-associated genes, comS and comX, was observed under low environmental K+ conditions and in the strain lacking Trk2. Taken together, these results highlight a pivotal role for environmental K+ as a regulatory cation that modulates stress responses and genetic transformation in S. mutans.
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Affiliation(s)
- Gursonika Binepal
- Department of Oral Microbiology, Faculty of Dentistry, University of Toronto, ON M5G 1G6, Toronto, Canada
| | - Iwona B Wenderska
- Department of Oral Microbiology, Faculty of Dentistry, University of Toronto, ON M5G 1G6, Toronto, Canada
| | - Paula Crowley
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
| | - Richard N Besingi
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
| | - Dilani B Senadheera
- Department of Oral Microbiology, Faculty of Dentistry, University of Toronto, ON M5G 1G6, Toronto, Canada
| | - L Jeannine Brady
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
| | - Dennis G Cvitkovitch
- Department of Oral Microbiology, Faculty of Dentistry, University of Toronto, ON M5G 1G6, Toronto, Canada
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21
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Baker JL, Faustoferri RC, Quivey RG. Acid-adaptive mechanisms of Streptococcus mutans-the more we know, the more we don't. Mol Oral Microbiol 2016; 32:107-117. [PMID: 27115703 DOI: 10.1111/omi.12162] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2016] [Indexed: 01/19/2023]
Affiliation(s)
- J L Baker
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - R C Faustoferri
- Center for Oral Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - R G Quivey
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.,Center for Oral Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
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