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Brauer AL, Learman BS, Taddei SM, Deka N, Hunt BC, Armbruster CE. Preferential catabolism of l- vs d-serine by Proteus mirabilis contributes to pathogenesis and catheter-associated urinary tract infection. Mol Microbiol 2022; 118:125-144. [PMID: 35970717 PMCID: PMC9486832 DOI: 10.1111/mmi.14968] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/24/2022] [Accepted: 07/30/2022] [Indexed: 11/29/2022]
Abstract
Proteus mirabilis is a common cause of urinary tract infection, especially in catheterized individuals. Amino acids are the predominant nutrient for bacteria during growth in urine, and our prior studies identified several amino acid import and catabolism genes as fitness factors for P. mirabilis catheter-associated urinary tract infection (CAUTI), particularly those for d- and l-serine. In this study, we sought to determine the hierarchy of amino acid utilization by P. mirabilis and to examine the relative importance of d- vs l-serine catabolism for critical steps in CAUTI development and progression. Herein, we show that P. mirabilis preferentially catabolizes l-serine during growth in human urine, followed by d-serine, threonine, tyrosine, glutamine, tryptophan, and phenylalanine. Independently disrupting catabolism of either d- or l-serine has minimal impact on in vitro phenotypes while completely disrupting both pathways decreases motility, biofilm formation, and fitness due to perturbation of membrane potential and cell wall biosynthesis. In a mouse model of CAUTI, loss of either serine catabolism system decreased fitness, but disrupting l-serine catabolism caused a greater fitness defect than disrupting d-serine catabolism. We, therefore, conclude that the hierarchical utilization of amino acids may be a critical component of P. mirabilis colonization and pathogenesis within the urinary tract.
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Affiliation(s)
- Aimee L. Brauer
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Brian S. Learman
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Steven M. Taddei
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Namrata Deka
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Benjamin C. Hunt
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Chelsie E. Armbruster
- Department of Microbiology and Immunology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
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Lawal OU, Barata M, Fraqueza MJ, Worning P, Bartels MD, Goncalves L, Paixão P, Goncalves E, Toscano C, Empel J, Urbaś M, Domiìnguez MA, Westh H, de Lencastre H, Miragaia M. Staphylococcus saprophyticus From Clinical and Environmental Origins Have Distinct Biofilm Composition. Front Microbiol 2021; 12:663768. [PMID: 34163443 PMCID: PMC8216562 DOI: 10.3389/fmicb.2021.663768] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
Biofilm formation has been shown to be critical to the success of uropathogens. Although Staphylococcus saprophyticus is a common cause of urinary tract infections, its biofilm production capacity, composition, genetic basis, and origin are poorly understood. We investigated biofilm formation in a large and diverse collection of S. saprophyticus (n = 422). Biofilm matrix composition was assessed in representative strains (n = 63) belonging to two main S. saprophyticus lineages (G and S) recovered from human infection, colonization, and food-related environment using biofilm detachment approach. To identify factors that could be associated with biofilm formation and structure variation, we used a pangenome-wide association study approach. Almost all the isolates (91%; n = 384/422) produced biofilm. Among the 63 representative strains, we identified eight biofilm matrix phenotypes, but the most common were composed of protein or protein-extracellular DNA (eDNA)-polysaccharides (38%, 24/63 each). Biofilms containing protein-eDNA-polysaccharides were linked to lineage G and environmental isolates, whereas protein-based biofilms were produced by lineage S and infection isolates (p < 0.05). Putative biofilm-associated genes, namely, aas, atl, ebpS, uafA, sasF, sasD, sdrH, splE, sdrE, sdrC, sraP, and ica genes, were found with different frequencies (3-100%), but there was no correlation between their presence and biofilm production or matrix types. Notably, icaC_1 was ubiquitous in the collection, while icaR was lineage G-associated, and only four strains carried a complete ica gene cluster (icaADBCR) except one that was without icaR. We provided evidence, using a comparative genomic approach, that the complete icaADBCR cluster was acquired multiple times by S. saprophyticus and originated from other coagulase-negative staphylococci. Overall, the composition of S. saprophyticus biofilms was distinct in environmental and clinical isolates, suggesting that modulation of biofilm structure could be a key step in the pathogenicity of these bacteria. Moreover, biofilm production in S. saprophyticus is ica-independent, and the complete icaADBCR was acquired from other staphylococci.
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Affiliation(s)
- Opeyemi U. Lawal
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Marta Barata
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Maria J. Fraqueza
- Centre for Interdisciplinary Research in Animal Health, Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisbon, Portugal
| | - Peder Worning
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Mette D. Bartels
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | | | | | | | | | - Joanna Empel
- Department of Epidemiology and Clinical Microbiology, Narodowy Instytut Leków, Warszawa, Poland
| | - Malgorzata Urbaś
- Department of Epidemiology and Clinical Microbiology, Narodowy Instytut Leków, Warszawa, Poland
| | | | - Henrik Westh
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
- Institute of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hermínia de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- The Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, NY, United States
| | - Maria Miragaia
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
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Gene Expression of Putative Pathogenicity-Related Genes in Verticillium dahliae in Response to Elicitation with Potato Extracts and during Infection Using Quantitative Real-Time PCR. Pathogens 2021; 10:pathogens10050510. [PMID: 33922492 PMCID: PMC8146963 DOI: 10.3390/pathogens10050510] [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: 03/18/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Quantitative real-time PCR was used to monitor the expression of 15 Verticillium dahliae's genes, putatively involved in pathogenicity, highly (HAV) and weakly aggressive (WAV) V. dahliae isolates after either (i) elicitation with potato leaf, stem, or root extracts, or (ii) inoculation of potato detached petioles. These genes, i.e., coding for Ras-GAP-like protein, serine/threonine protein kinase, Ubiquitin-conjugating enzyme variant-MMS2, NADH-ubiquinone oxidoreductase, Thioredoxin, Pyruvate dehydrogenase E1 VdPDHB, myo-inositol 2-dehydrogenase, and HAD-superfamily hydrolase, showed differential upregulation in the HAV versus WAV isolate in response to plant extracts or after inoculation of potato leaf petioles. This suggests their potential involvement in the observed differential aggressiveness between isolates. However, other genes like glucan endo-1,3-alpha-glucosidase and nuc-1 negative regulatory protein VdPREG showed higher activity in the WAV than in the HAV in response to potato extracts and/or during infection. This, in contrast, may suggest a role in their lower aggressiveness. These findings, along with future functional analysis of selected genes, will contribute to improving our understanding of V. dahliae's pathogenesis. For example, expression of VdPREG negatively regulates phosphorus-acquisition enzymes, which may indicate a lower phosphorus acquisition activity in the WAV. Therefore, integrating the knowledge about the activity of both genes enhancing pathogenicity and those restraining it will provide a guild line for further functional characterization of the most critical genes, thus driving new ideas towards better Verticillium wilt management.
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Prevalence of virulence genes in Staphylococcus saprophyticus isolated from women with urinary tract infections in Lagos State. SCIENTIFIC AFRICAN 2020. [DOI: 10.1016/j.sciaf.2020.e00626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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The Gene Expression Profile of Uropathogenic Escherichia coli in Women with Uncomplicated Urinary Tract Infections Is Recapitulated in the Mouse Model. mBio 2020; 11:mBio.01412-20. [PMID: 32788379 PMCID: PMC7439467 DOI: 10.1128/mbio.01412-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Different experimental models have been used to study UPEC pathogenesis, including in vitro cultures in different media, tissue culture, and mouse models of infection. The last is especially important since it allows evaluation of mechanisms of pathogenesis and potential therapeutic strategies against UPEC. Bacterial physiology is greatly shaped by environment, and it is therefore critical to understand how closely bacterial physiology in any experimental model relates to human infection. In this study, we found strong correlation in bacterial gene expression between the mouse model and human UTI using identical strains, suggesting that the mouse model accurately mimics human infection, definitively supporting its continued use in UTI research. Uropathogenic Escherichia coli (UPEC) is the primary causative agent of uncomplicated urinary tract infections (UTIs). UPEC fitness and virulence determinants have been evaluated in a variety of laboratory settings, including a well-established mouse model of UTI. However, the extent to which bacterial physiologies differ between experimental models and human infections remains largely understudied. To address this important issue, we compared the transcriptomes of three different UPEC isolates in human infection and under a variety of laboratory conditions, including LB culture, filter-sterilized urine culture, and the UTI mouse model. We observed high correlation in gene expression between the mouse model and human infection in all three strains examined (Pearson correlation coefficients of 0.86 to 0.87). Only 175 of 3,266 (5.4%) genes shared by all three strains had significantly different expression levels, with the majority of them (145 genes) downregulated in patients. Importantly, gene expression levels of both canonical virulence factors and metabolic machinery were highly similar between the mouse model and human infection, while the in vitro conditions displayed more substantial differences. Interestingly, comparison of gene expression between the mouse model and human infection hinted at differences in bladder oxygenation as well as nutrient composition. In summary, our work strongly validates the continued use of this mouse model for the study of the pathogenesis of human UTI.
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Silva KCS, Silva LOS, Silva GAA, Borges CL, Novaes E, Paccez JD, Fontes W, Giambiagi-deMarval M, Soares CMDA, Parente-Rocha JA. Staphylococcus saprophyticus Proteomic Analyses Elucidate Differences in the Protein Repertories among Clinical Strains Related to Virulence and Persistence. Pathogens 2020; 9:pathogens9010069. [PMID: 31963821 PMCID: PMC7169411 DOI: 10.3390/pathogens9010069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/06/2020] [Accepted: 01/10/2020] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus saprophyticus is a Gram-positive and coagulase negative cocci that composes the skin microbiota and can act as an opportunistic agent causing urinary tract infections, being more frequent in sexually active young women. The ability of a pathogen to cause infection in the host is associated to its ability to adhere to host cells and to survive host immune defenses. In this work, we presented the comparative proteomic profile of three S. saprophyticus strains. It was possible to characterize differences in the proteome content, specially related to expression of virulence factors. We compiled this data and previous data and we detected one strain (9325) possessing higher production and secretion of proteins related to virulence. Our results show that phenotypic, genotypic, and proteomic differences reflect in the ability to survive during interaction with host cells, since the 9325 strain presented a higher survival rate after macrophage interaction. In counterpart, the 7108 strain that possesses lower content of proteins related to virulence presented higher ability to form biofilm suggesting that this strain can be better adapted to persist in the host and in the environment. Our work describes, for the first time, proteomic flexibility among S. saprophyticus strains, reflecting in virulence and persistence.
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Affiliation(s)
- Karla Christina Sousa Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Lana O’Hara Souza Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Guilherme Algusto Alves Silva
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Evandro Novaes
- Departamento de Biologia, Universidade Federal de Lavras, Lavras 37200-900, Brazil;
| | - Juliano Domiraci Paccez
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Wagner Fontes
- Laboratório de Química de Proteínas, Instituto de Biologia, Universidade de Brasília, UnB-Brasilia 70910-900, Brazil;
| | - Marcia Giambiagi-deMarval
- Laboratório de Microbiologia Molecular, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro-RJ 21941-902, Brazil;
| | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
| | - Juliana Alves Parente-Rocha
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia-GO 74690-900, Brazil; (K.C.S.S.); (L.O.S.S.); (G.A.A.S.); (C.L.B.); (J.D.P.); (C.M.d.A.S.)
- Correspondence:
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Yu Y, Yang J, Zheng LY, Sheng Q, Li CY, Wang M, Zhang XY, McMinn A, Zhang YZ, Song XY, Chen XL. Diversity of D-Amino Acid Utilizing Bacteria From Kongsfjorden, Arctic and the Metabolic Pathways for Seven D-Amino Acids. Front Microbiol 2020; 10:2983. [PMID: 31998270 PMCID: PMC6965332 DOI: 10.3389/fmicb.2019.02983] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/10/2019] [Indexed: 12/20/2022] Open
Abstract
D-amino acids (DAAs) are an important component of the refractory dissolved organic matter pool in the ocean. Microbes play a vital role in promoting the recycling of DAAs in the ocean. However, the diversity of marine DAA-utilizing bacteria and how they metabolize DAAs are seldom studied. Here, by enrichment culture with DAAs as the sole nitrogen source, bacteria of 12 families from three phyla were recovered from surface seawater and sediment from Kongsfjorden, Arctic, and seven DAA-utilizing bacterial strains were isolated. These strains have different DAA-utilizing abilities. Of the seven DAAs used, Halomonas titanicae SM1922 and Pseudoalteromonas neustonica SM1927 were able to utilize seven and five of them, respectively, while the other strains were able to utilize only one or two. Based on genomic, transcriptional and biochemical analyses, the key genes involved in DAA metabolism in each strain were identified and the metabolic pathways for the seven DAAs in these marine bacteria were identified. Conversion of DAAs into α-keto acids is generally the main pathway in marine DAA-utilizing bacteria, which is performed by several key enzymes, including DAA oxidoreductases/dehydrogenases, D-serine ammonia-lyases, D-serine ammonia-lyase DSD1s and DAA transaminases. In addition, conversion of DAAs into LAAs is another pathway, which is performed by amino acid racemases. Among the identified key enzymes, D-serine ammonia-lyase DSD1 and Asp racemase are first found to be employed by bacteria for DAA utilization. These results shed light on marine DAA-utilizing bacteria and the involved DAA metabolism pathways, offering a better understanding of the DAA recycling in the ocean.
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Affiliation(s)
- Yang Yu
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Jie Yang
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Li-Yuan Zheng
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Qi Sheng
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Chun-Yang Li
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, China
| | - Min Wang
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, China
| | - Xi-Ying Zhang
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Andrew McMinn
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, China.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Institute of Marine Science and Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
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d-Serine Degradation by Proteus mirabilis Contributes to Fitness during Single-Species and Polymicrobial Catheter-Associated Urinary Tract Infection. mSphere 2019; 4:4/1/e00020-19. [PMID: 30814316 PMCID: PMC6393727 DOI: 10.1128/msphere.00020-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Urinary tract infections are among the most common health care-associated infections worldwide, the majority of which involve a urinary catheter (CAUTI). Our recent investigation of CAUTIs in nursing home residents identified Proteus mirabilis, Enterococcus species, and Escherichia coli as the three most common organisms. These infections are also often polymicrobial, and we identified Morganella morganii, Enterococcus species, and Providencia stuartii as being more prevalent during polymicrobial CAUTI than single-species infection. Our research therefore focuses on identifying “core” fitness factors that are highly conserved in P. mirabilis and that contribute to infection regardless of the presence of these other organisms. In this study, we determined that the ability to degrade d-serine, the most abundant d-amino acid in urine and serum, strongly contributes to P. mirabilis fitness within the urinary tract, even when competing for nutrients with another organism. d-Serine uptake and degradation therefore represent potential targets for disruption of P. mirabilis infections. Proteus mirabilis is a common cause of catheter-associated urinary tract infection (CAUTI) and secondary bacteremia, which are frequently polymicrobial. We previously utilized transposon insertion-site sequencing (Tn-Seq) to identify novel fitness factors for colonization of the catheterized urinary tract during single-species and polymicrobial infection, revealing numerous metabolic pathways that may contribute to P. mirabilis fitness regardless of the presence of other cocolonizing organisms. One such “core” fitness factor was d-serine utilization. In this study, we generated isogenic mutants in d-serine dehydratase (dsdA), d-serine permease (dsdX), and the divergently transcribed activator of the operon (dsdC) to characterize d-serine utilization in P. mirabilis and explore the contribution of this pathway to fitness during single-species and polymicrobial infection. P. mirabilis was capable of utilizing either d- or l-serine as a sole carbon or nitrogen source, and dsdA, dsdX, and dsdC were each specifically required for d-serine degradation. This capability was highly conserved among P. mirabilis isolates, although not universal among uropathogens: Escherichia coli and Morganella morganii utilized d-serine, while Providencia stuartii and Enterococcus faecalis did not. d-Serine utilization did not contribute to P. mirabilis growth in urine ex vivo during a 6-h time course but significantly contributed to fitness during single-species and polymicrobial CAUTI during a 96-h time course, regardless of d-serine utilization by the coinfecting isolate. d-Serine utilization also contributed to secondary bacteremia during CAUTI as well as survival in a direct bacteremia model. Thus, we propose d-serine utilization as a core fitness factor in P. mirabilis and a possible target for disruption of infection. IMPORTANCE Urinary tract infections are among the most common health care-associated infections worldwide, the majority of which involve a urinary catheter (CAUTI). Our recent investigation of CAUTIs in nursing home residents identified Proteus mirabilis, Enterococcus species, and Escherichia coli as the three most common organisms. These infections are also often polymicrobial, and we identified Morganella morganii, Enterococcus species, and Providencia stuartii as being more prevalent during polymicrobial CAUTI than single-species infection. Our research therefore focuses on identifying “core” fitness factors that are highly conserved in P. mirabilis and that contribute to infection regardless of the presence of these other organisms. In this study, we determined that the ability to degrade d-serine, the most abundant d-amino acid in urine and serum, strongly contributes to P. mirabilis fitness within the urinary tract, even when competing for nutrients with another organism. d-Serine uptake and degradation therefore represent potential targets for disruption of P. mirabilis infections.
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Deka G, Bharath SR, Savithri HS, Murthy MRN. Structural and biochemical studies on the role of active site Thr166 and Asp236 in the catalytic function of D-Serine deaminase from Salmonella typhimurium. Biochem Biophys Res Commun 2018; 504:40-45. [PMID: 30173889 DOI: 10.1016/j.bbrc.2018.08.116] [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: 08/07/2018] [Accepted: 08/17/2018] [Indexed: 11/18/2022]
Abstract
D-Serine deaminase (DSD) degrades D-Ser to pyruvate and ammonia. Uropathogenic bacteria survive in the toxic D-Ser containing mammalian urine because of DSD activity. The crystal structure of the apo form of Salmonella typhimurium DSD (StDSD) has been reported earlier. In the present work, we have investigated the role of two active site residues, Thr166 and Asp236 by site directed mutagenesis (T166A and D236L). The enzyme activity is lost upon mutation of these residues. The 2.7 Å resolution crystal structure of T166A DSD with bound PLP reported here represents the first structure of the holo form of StDSD. PLP binding induces small changes in the relative dispositions of the minor and major domains of the protein and this inter-domain movement becomes substantial upon interaction with the substrate. The conformational changes bring Thr166 to a position at the active site favorable for the degradation of D-Ser. Examination of the different forms of the enzyme and comparison with structures of homologous enzymes suggests that Thr166 is the most probable base abstracting proton from the Cα atom of the substrate and Asp236 is crucial for binding of the cofactor.
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Affiliation(s)
- Geeta Deka
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India
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Oliveira ASD, Rosa IIR, Novaes E, Oliveira LSD, Baeza LC, Borges CL, Marlinghaus L, Soares CMDA, Giambiagi-deMarval M, Parente-Rocha JA. The exoproteome profiles of three Staphylococcus saprophyticus strains reveal diversity in protein secretion contents. Microbiol Res 2018; 216:85-96. [PMID: 30269860 DOI: 10.1016/j.micres.2018.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/07/2018] [Accepted: 08/21/2018] [Indexed: 12/24/2022]
Abstract
Staphylococcus saprophyticus is a gram-positive microorganism responsible for urinary tract infections (UTIs). Although some virulence factors are characterized, such as urease, autolysins, adhesins and hemagglutinins, large-scale proteomic studies have not been performed within this species. We performed the characterization of the exoproteome from three S. saprophyticus strains: the reference strain ATCC 15,305, a non-capsular strain 7108 and the 9325 strain containing a thick capsule which were cultured in BHI medium and culture supernatants were analysed by using mass spectrometry approach. We observed a core of 72 secreted proteins. In addition, it was possible to detect diversity in the protein profiles of the exoproteomes. Interestingly, strain 7108 presented no secretion of three antigenic proteins, including the classical SsaA antigen. In addition, the level of antigenic proteins secreted by strain 9325 was higher than in ATCC 15,305. This result was confirmed by Western blot analysis using anti-SsaA polyclonal antibodies, and no production/ secretion of SsaA was detected in strain 7108. Transcriptional data shows that 7108 strain produces transcripts encoding SsaA, suggesting post-transcriptional regulation occurs in this strain. Moreover, when compared with the other strains that were analyzed, it was possible to detect higher levels of proteases secreted by strain 7108 and higher levels of antigenic proteins and transglycosylases secreted by 9325 strain. The results reveal diversity in protein secretion among strains. This research is an important first step towards understanding the variability in S. saprophyticus exoproteome profile and could be significant in explaining differences among strains.
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Affiliation(s)
- Andrea Santana de Oliveira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Isabella Inês Rodrigues Rosa
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Evandro Novaes
- Escola de Agronomia, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Lucas Silva de Oliveira
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Lilian Cristiane Baeza
- Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Cascavel, Brazil
| | - Clayton Luiz Borges
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | | | - Célia Maria de Almeida Soares
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil
| | - Marcia Giambiagi-deMarval
- Laboratório de Microbiologia Molecular, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro - Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana Alves Parente-Rocha
- Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
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11
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Sasabe J, Suzuki M. Emerging Role of D-Amino Acid Metabolism in the Innate Defense. Front Microbiol 2018; 9:933. [PMID: 29867842 PMCID: PMC5954117 DOI: 10.3389/fmicb.2018.00933] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/23/2018] [Indexed: 12/30/2022] Open
Abstract
Mammalian innate and adaptive immune systems use the pattern recognition receptors, such as toll-like receptors, to detect conserved bacterial and viral components. Bacteria synthesize diverse D-amino acids while eukaryotes and archaea generally produce two D-amino acids, raising the possibility that many of bacterial D-amino acids are bacteria-specific metabolites. Although D-amino acids have not been identified to bind to any known pattern recognition receptors, D-amino acids are enantioselectively recognized by some other receptors and enzymes including a flavoenzyme D-amino acid oxidase (DAO) in mammals. At host-microbe interfaces in the neutrophils and intestinal mucosa, DAO catalyzes oxidation of bacterial D-amino acids, such as D-alanine, and generates H2O2, which is linked to antimicrobial activity. Intestinal DAO also modifies the composition of microbiota through modulation of growth for some bacteria that are dependent on host nutrition. Furthermore, regulation and recognition of D-amino acids in mammals have additional meanings at various host-microbe interfaces; D-phenylalanine and D-tryptophan regulate chemotaxis of neutrophils through a G-coupled protein receptor, D-serine has a bacteriostatic role in the urinary tract, D-phenylalanine and D-leucine inhibit innate immunity through the sweet taste receptor in the upper airway, and D-tryptophan modulates immune tolerance in the lower airway. This mini-review highlights recent evidence supporting the hypothesis that D-amino acids are utilized as inter-kingdom communication at host-microbe interface to modulate bacterial colonization and host defense.
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Affiliation(s)
- Jumpei Sasabe
- Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan
| | - Masataka Suzuki
- Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan
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12
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de Paiva-Santos W, de Sousa VS, Giambiagi-deMarval M. Occurrence of virulence-associated genes among Staphylococcus saprophyticus isolated from different sources. Microb Pathog 2018; 119:9-11. [PMID: 29604423 DOI: 10.1016/j.micpath.2018.03.054] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 03/09/2018] [Accepted: 03/28/2018] [Indexed: 11/27/2022]
Abstract
Staphylococcus saprophyticus is an important pathogen responsible for community urinary tract infections (UTI). Besides composing the human microbiota, this species is widely distributed in the environment and the origins of this organism for human infection is not fully characterized. Although some virulence determinants are known, such as d-serine deaminase (DsdA), urease and cell-wall associated proteins, few studies investigated the distribution of virulence-associated genes and analyzed the pathogenic potential of S. saprophyticus strains from different sources. The aim of the present study was to detect the presence of S. saprophyticus genes encoding surface proteins UafA, Aas, Ssp, SdrI, SssF as well as the DsdA and urease enzymes. A total of 142 S. saprophyticus strains were obtained from four sources: UTI, colonization, water and food. It was found, in every tested strain, the presence of genes encoding the surface proteins UafA, Aas, Ssp and SssF and the DsdA and urease enzymes. In contrast, the gene encoding SdrI surface protein was not detected in any of the strains of S. saprophyticus. These results provide a better understanding of the characteristics of S. saprophyticus strains and suggest that isolates from non-human sources have a potential to colonize the urinary tract.
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Affiliation(s)
- Weslley de Paiva-Santos
- Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde (CCS), Av. Carlos Chagas Filho, 373, Bloco I, Cidade Universitária, 21941-920, Rio de Janeiro, RJ, Brazil
| | - Viviane Santos de Sousa
- Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde (CCS), Av. Carlos Chagas Filho, 373, Bloco I, Cidade Universitária, 21941-920, Rio de Janeiro, RJ, Brazil
| | - Marcia Giambiagi-deMarval
- Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Centro de Ciências da Saúde (CCS), Av. Carlos Chagas Filho, 373, Bloco I, Cidade Universitária, 21941-920, Rio de Janeiro, RJ, Brazil.
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13
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Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract. Microbiol Spectr 2017; 4. [PMID: 27227294 DOI: 10.1128/microbiolspec.uti-0012-2012] [Citation(s) in RCA: 198] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.
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14
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Deutch CE. Limited effectiveness of over-the-counter plant preparations used for the treatment of urinary tract infections as inhibitors of the urease activity from Staphylococcus saprophyticus. J Appl Microbiol 2017; 122:1380-1388. [PMID: 28245081 DOI: 10.1111/jam.13430] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/08/2017] [Accepted: 02/16/2017] [Indexed: 12/24/2022]
Abstract
AIMS Urease is a key virulence factor for the Gram-positive urinary tract pathogen Staphylococcus saprophyticus and a potential target for antimicrobial therapy. The enzyme from S. saprophyticus is unusual in that it does not contain cysteine at the active site. The aims of this study were to test 14 over-the-counter plant preparations as inhibitors of this urease and to determine whether they can prevent the increase in pH that normally occurs in bacterial cultures containing urea. METHODS AND RESULTS Urease activity was measured colorimetrically by the formation of ammonium ions. The green tea and Uva-Ursi preparations reduced urease activity in a soluble extract of S. saprophyticus by more than 75%. Two herbal mixtures were weakly inhibitory and reduced activity by about 25%, but the other products had little or no effect. The green tea and Uva-Ursi extracts also inhibited urease activity in whole cells by more than 75%. One of the herbal products (WishGarden UTI) showed some inhibition of urease activity but the other (UTI Clear) did not. The green tea and Uva-Ursi preparations prevented the increase in pH that normally occurs when S. saprophyticus is grown in an artificial urine medium, but this was due primarily to bacterial death. The WishGarden UTI preparation could partially delay the pH increase while allowing some cells to remain viable. CONCLUSION These results indicate that only a few of the commercially available over-the-counter plant preparations commonly used for the treatment of urinary tract infections (UTIs) can inhibit the urease activity from S. saprophyticus. SIGNIFICANCE AND IMPACT OF THE STUDY While over-the-counter plant preparations may be considered an alternative to traditional antibiotics for the treatment of UTIs, they should be used with caution and a product should be matched to the properties of the virulence factors of the bacterial pathogen involved.
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Affiliation(s)
- C E Deutch
- Department of Biology, Creighton University, Omaha, NE, USA
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15
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Xie Y, Qiu N, Wang G. Toward a better guard of coastal water safety-Microbial distribution in coastal water and their facile detection. MARINE POLLUTION BULLETIN 2017; 118:5-16. [PMID: 28215556 DOI: 10.1016/j.marpolbul.2017.02.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 01/19/2017] [Accepted: 02/09/2017] [Indexed: 06/06/2023]
Abstract
Prosperous development in marine-based tourism has raised increasing concerns over the sanitary quality of coastal waters with potential microbial contamination. The World Health Organization has set stringent standards over a list of pathogenic microorganisms posing potential threats to people with frequent coastal water exposure and has asked for efficient detection procedures for pathogen facile identification. Inspection of survey events regarding the occurrence of marine pathogens in recreational beaches in recent years has reinforced the need for the development of a rapid identification procedure. In this review, we examine the possibility of recruiting uniform molecular assays to identify different marine pathogens and the feasibility of appropriate biomarkers, including enterochelin biosynthetic genes, for general toxicity assays. The focus is not only on bacterial pathogens but also on other groups of infectious pathogens. The ultimate goal is the development of a handy method to more efficiently and rapidly detect marine pathogens.
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Affiliation(s)
- Yunxuan Xie
- Tianjin University Center for Marine Environmental Ecology, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China
| | - Ning Qiu
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
| | - Guangyi Wang
- Tianjin University Center for Marine Environmental Ecology, School of Environmental Science & Engineering, Tianjin University, Tianjin 300072, China.
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16
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Shea AA, Bernhards RC, Cote CK, Chase CJ, Koehler JW, Klimko CP, Ladner JT, Rozak DA, Wolcott MJ, Fetterer DP, Kern SJ, Koroleva GI, Lovett SP, Palacios GF, Toothman RG, Bozue JA, Worsham PL, Welkos SL. Two stable variants of Burkholderia pseudomallei strain MSHR5848 express broadly divergent in vitro phenotypes associated with their virulence differences. PLoS One 2017; 12:e0171363. [PMID: 28187198 PMCID: PMC5302386 DOI: 10.1371/journal.pone.0171363] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/18/2017] [Indexed: 12/12/2022] Open
Abstract
Burkholderia pseudomallei (Bp), the agent of melioidosis, causes disease ranging from acute and rapidly fatal to protracted and chronic. Bp is highly infectious by aerosol, can cause severe disease with nonspecific symptoms, and is naturally resistant to multiple antibiotics. However, no vaccine exists. Unlike many Bp strains, which exhibit random variability in traits such as colony morphology, Bp strain MSHR5848 exhibited two distinct and relatively stable colony morphologies on sheep blood agar plates: a smooth, glossy, pale yellow colony and a flat, rough, white colony. Passage of the two variants, designated "Smooth" and "Rough", under standard laboratory conditions produced cultures composed of > 99.9% of the single corresponding type; however, both could switch to the other type at different frequencies when incubated in certain nutritionally stringent or stressful growth conditions. These MSHR5848 derivatives were extensively characterized to identify variant-associated differences. Microscopic and colony morphology differences on six differential media were observed and only the Rough variant metabolized sugars in selective agar. Antimicrobial susceptibilities and lipopolysaccharide (LPS) features were characterized and phenotype microarray profiles revealed distinct metabolic and susceptibility disparities between the variants. Results using the phenotype microarray system narrowed the 1,920 substrates to a subset which differentiated the two variants. Smooth grew more rapidly in vitro than Rough, yet the latter exhibited a nearly 10-fold lower lethal dose for mice than Smooth. Finally, the Smooth variant was phagocytosed and replicated to a greater extent and was more cytotoxic than Rough in macrophages. In contrast, multiple locus sequence type (MLST) analysis, ribotyping, and whole genome sequence analysis demonstrated the variants' genetic conservation; only a single consistent genetic difference between the two was identified for further study. These distinct differences shown by two variants of a Bp strain will be leveraged to better understand the mechanism of Bp phenotypic variability and to possibly identify in vitro markers of infection.
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Affiliation(s)
- A. A. Shea
- Diagnostic Systems Division, USAMRIID, Frederick, Maryland, United States of America
| | - R. C. Bernhards
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - C. K. Cote
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - C. J. Chase
- Diagnostic Systems Division, USAMRIID, Frederick, Maryland, United States of America
| | - J. W. Koehler
- Diagnostic Systems Division, USAMRIID, Frederick, Maryland, United States of America
| | - C. P. Klimko
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - J. T. Ladner
- Center for Genome Sciences, USAMRIID, Frederick, Maryland, United States of America
| | - D. A. Rozak
- Diagnostic Systems Division, USAMRIID, Frederick, Maryland, United States of America
| | - M. J. Wolcott
- Diagnostic Systems Division, USAMRIID, Frederick, Maryland, United States of America
| | - D. P. Fetterer
- Biostatistical Services Division, USAMRIID, Frederick, Maryland, United States of America
| | - S. J. Kern
- Biostatistical Services Division, USAMRIID, Frederick, Maryland, United States of America
| | - G. I. Koroleva
- Center for Genome Sciences, USAMRIID, Frederick, Maryland, United States of America
| | - S. P. Lovett
- Center for Genome Sciences, USAMRIID, Frederick, Maryland, United States of America
| | - G. F. Palacios
- Center for Genome Sciences, USAMRIID, Frederick, Maryland, United States of America
| | - R. G. Toothman
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - J. A. Bozue
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - P. L. Worsham
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
| | - S. L. Welkos
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, Maryland, United States of America
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17
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Marlinghaus L, Huß M, Korte-Berwanger M, Sakinc-Güler T, Gatermann SG. D-serine transporter in Staphylococcus saprophyticus identified. FEMS Microbiol Lett 2016; 363:fnw143. [PMID: 27252156 DOI: 10.1093/femsle/fnw143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2016] [Indexed: 11/13/2022] Open
Abstract
Among staphylococci Staphylococcus saprophyticus is the only species that is typically uropathogenic and an important cause of urinary tract infections in young women. The amino acid D-serine occurs in relatively high concentrations in human urine and has a bacteriostatic or toxic effect on many bacteria. In uropathogenic Escherichia coli and S. saprophyticus, the amino acid regulates the expression of virulence factors and can be used as a nutrient. The ability of uropathogens to respond to or to metabolize D-serine has been suggested as a factor that enables colonization of the urinary tract. Until now nothing is known about D-serine transport in S. saprophyticus We generated mutants of putative transporter genes in S. saprophyticus 7108 that show homology to the D-serine transporter cycA of E. coli and tested them in a D-serine depletion assay to analyze the D-serine uptake rate of the cells. The mutant of SPP1070 showed a strong decrease in D-serine uptake. Therefore, SSP1070 was identified as a major D-serine transporter in S. saprophyticus 7108 and was named D-serine transporter A (DstA). D-serine caused a prolonged lag phase of S. saprophyticus in a chemically defined medium. This negative effect was dependent on the presence of DstA.
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Affiliation(s)
- Lennart Marlinghaus
- Department of Medical Microbiology, Institute for Hygiene and Microbiologie, Ruhr-University Bochum, Universitätsstraße 150, 44892 Bochum, Germany
| | - Melanie Huß
- Department of Medical Microbiology, Institute for Hygiene and Microbiologie, Ruhr-University Bochum, Universitätsstraße 150, 44892 Bochum, Germany
| | - Miriam Korte-Berwanger
- Department of Medical Microbiology, Institute for Hygiene and Microbiologie, Ruhr-University Bochum, Universitätsstraße 150, 44892 Bochum, Germany
| | - Türkan Sakinc-Güler
- Division of Infectious Diseases, Department of Internal Medicine II, University Hospital Freiburg, Breisacherstr 115b, 79106 Freiburg, Germany
| | - Sören G Gatermann
- Department of Medical Microbiology, Institute for Hygiene and Microbiologie, Ruhr-University Bochum, Universitätsstraße 150, 44892 Bochum, Germany
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18
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Siderophore biosynthesis coordinately modulated the virulence-associated interactive metabolome of uropathogenic Escherichia coli and human urine. Sci Rep 2016; 6:24099. [PMID: 27076285 PMCID: PMC4831015 DOI: 10.1038/srep24099] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/22/2016] [Indexed: 02/06/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) growth in women’s bladders during urinary tract infection (UTI) incurs substantial chemical exchange, termed the “interactive metabolome”, which primarily accounts for the metabolic costs (utilized metabolome) and metabolic donations (excreted metabolome) between UPEC and human urine. Here, we attempted to identify the individualized interactive metabolome between UPEC and human urine. We were able to distinguish UPEC from non-UPEC by employing a combination of metabolomics and genetics. Our results revealed that the interactive metabolome between UPEC and human urine was markedly different from that between non-UPEC and human urine, and that UPEC triggered much stronger perturbations in the interactive metabolome in human urine. Furthermore, siderophore biosynthesis coordinately modulated the individualized interactive metabolome, which we found to be a critical component of UPEC virulence. The individualized virulence-associated interactive metabolome contained 31 different metabolites and 17 central metabolic pathways that were annotated to host these different metabolites, including energetic metabolism, amino acid metabolism, and gut microbe metabolism. Changes in the activities of these pathways mechanistically pinpointed the virulent capability of siderophore biosynthesis. Together, our findings provide novel insights into UPEC virulence, and we propose that siderophores are potential targets for further discovery of drugs to treat UPEC-induced UTI.
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19
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A Highly Conserved Bacterial D-Serine Uptake System Links Host Metabolism and Virulence. PLoS Pathog 2016; 12:e1005359. [PMID: 26727373 PMCID: PMC4699771 DOI: 10.1371/journal.ppat.1005359] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/03/2015] [Indexed: 01/22/2023] Open
Abstract
The ability of any organism to sense and respond to challenges presented in the environment is critically important for promoting or restricting colonization of specific sites. Recent work has demonstrated that the host metabolite D-serine has the ability to markedly influence the outcome of infection by repressing the type III secretion system of enterohaemorrhagic Escherichia coli (EHEC) in a concentration-dependent manner. However, exactly how EHEC monitors environmental D-serine is not understood. In this work, we have identified two highly conserved members of the E. coli core genome, encoding an inner membrane transporter and a transcriptional regulator, which collectively help to "sense" levels of D-serine by regulating its uptake from the environment and in turn influencing global gene expression. Both proteins are required for full expression of the type III secretion system and diversely regulated prophage-encoded effector proteins demonstrating an important infection-relevant adaptation of the core genome. We propose that this system acts as a key safety net, sampling the environment for this metabolite, thereby promoting colonization of EHEC to favorable sites within the host.
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20
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dsdA Does Not Affect Colonization of the Murine Urinary Tract by Escherichia coli CFT073. PLoS One 2015; 10:e0138121. [PMID: 26366567 PMCID: PMC4569052 DOI: 10.1371/journal.pone.0138121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/25/2015] [Indexed: 12/16/2022] Open
Abstract
The urinary tract environment provides many conditions that deter colonization by microorganisms. D-serine is thought to be one of these stressors and is present at high concentrations in urine. D-serine interferes with L-serine and pantothenate metabolism and is bacteriostatic to many species. Uropathogenic Escherichia coli commonly possess the dsdCXA genetic locus, which allows them to use D-serine as a sole carbon, nitrogen, and energy source. It was previously reported that in the model UPEC strain CFT073, a dsdA mutant outcompetes wild type in the murine model of urinary tract infection. This “hypercolonization” was used to propose a model whereby UPEC strains sense D-serine in the urinary tract and subsequently up-regulate genes necessary for pathogenesis. Here, we show that inactivation of dsdA does not lead to hypercolonization. We suggest that this previously observed effect is due to an unrecognized secondary mutation in rpoS and that some D-serine specific effects described in other studies may be affected by the rpoS status of the strains used. Inactivation of dsdA in the original clinical isolate of CFT073 gives CFT073 ΔdsdA a growth defect in human urine and renders it unable to grow on minimal medium containing D-serine as the sole carbon source. However, CFT073 ΔdsdA is able to colonize the urinary tracts of CBA/J mice indistinguishably from wild type. These findings indicate that D-serine catabolism, though it may play role(s) during urinary tract infection, does not affect the ability of uropathogenic E. coli to colonize the murine urinary tract.
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21
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Dessì A, Liori B, Caboni P, Corsello G, Giuffrè M, Noto A, Serraino F, Stronati M, Zaffanello M, Fanos V. Monitoring neonatal fungal infection with metabolomics. J Matern Fetal Neonatal Med 2015; 27 Suppl 2:34-8. [PMID: 25284175 DOI: 10.3109/14767058.2014.954787] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The objective of our study was to evaluate the capability of the metabolomics approach to identify the variations of urine metabolites over time related to the neonatal fungal septic condition. The study population included a clinical case of a preterm neonate with invasive fungal infection and 13 healthy preterm controls. This study showed a unique urine metabolic profile of the patient affected by fungal sepsis compared to urine of controls and it was also possible to evaluate the efficacy of therapy in improving patient health.
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Affiliation(s)
- Angelica Dessì
- Neonatal Intensive Care Unit, Puericulture Institute and Neonatal Section, Azienda Ospedaliera Universitaria, University of Cagliari , Cagliari , Italy
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22
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Connolly JPR, Finlay BB, Roe AJ. From ingestion to colonization: the influence of the host environment on regulation of the LEE encoded type III secretion system in enterohaemorrhagic Escherichia coli. Front Microbiol 2015; 6:568. [PMID: 26097473 PMCID: PMC4456613 DOI: 10.3389/fmicb.2015.00568] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 05/24/2015] [Indexed: 12/21/2022] Open
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) binds to host tissue and intimately attaches to intestinal cells using a dedicated type III secretion system (T3SS). This complex multi-protein organelle is encoded within a large pathogenicity island called the locus of enterocyte effacement (LEE), which is subject to extensive regulatory control. Over the past 15 years we have gained a wealth of knowledge concerning how the LEE is regulated transcriptionally by specific, global and phage encoded regulators. More recently, significant advances have been made in our understanding of how specific signals, including host or microbiota derived metabolic products and various nutrient sources, can affect how the LEE-encoded T3SS is regulated. In this review we discuss regulation of the LEE, focusing on how these physiologically relevant signals are sensed and how they affect the expression of this major virulence factor. The implications for understanding the disease process by specific regulatory mechanisms are also discussed.
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Affiliation(s)
- James P R Connolly
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow, UK
| | - B Brett Finlay
- Michael Smith Laboratories, University of British Columbia , Vancouver, BC, Canada
| | - Andrew J Roe
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow , Glasgow, UK
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