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Grygiel-Górniak B, Folga BA. Chlamydia trachomatis-An Emerging Old Entity? Microorganisms 2023; 11:1283. [PMID: 37317257 DOI: 10.3390/microorganisms11051283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/04/2023] [Accepted: 05/12/2023] [Indexed: 06/16/2023] Open
Abstract
Chlamydia trachomatis is an evasive pathogen that can prompt severe clinical manifestations in humans such as vaginitis, epididymitis, lymphogranuloma venereum, trachoma, conjunctivitis and pneumonia. If left untreated, chronic infections with C. trachomatis can give rise to long-lasting and even permanent sequelae. To shed some light on its widespread nature, data from original research, systematic reviews and meta-analyses from three databases was collected and analyzed in the context of chlamydial infection, related symptoms and appropriate treatment modalities. This review describes the bacterium's pervasiveness on a global scale, especially in developing countries, and suggests ways to halt its transmission and spread. Infections with C. trachomatis often go unnoticed, as many individuals are asymptomatic and unaware of their diagnosis, contributing to a delay in diagnosis and treatment. The high prevalence of chlamydial infection highlights the need for a universal screening and detection method enabling immediate treatment at its onset. Prognosis is favorable with antibiotic therapy and education for high-risk groups and their sexual partners. In the future, a quick, easily accessible, and inexpensive test should be developed to diagnose and treat infected individuals early on. Along with a vaccine against C. trachomatis, it would halt the transmission and spread of the pathogen worldwide.
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Affiliation(s)
- Bogna Grygiel-Górniak
- Department of Rheumatology, Rehabilitation and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznań, Poland
| | - Barbara Anna Folga
- Department of Rheumatology, Rehabilitation and Internal Diseases, Poznan University of Medical Sciences, 61-701 Poznań, Poland
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Di Pietro M, Filardo S, Romano S, Sessa R. Chlamydia trachomatis and Chlamydia pneumoniae Interaction with the Host: Latest Advances and Future Prospective. Microorganisms 2019; 7:microorganisms7050140. [PMID: 31100923 PMCID: PMC6560445 DOI: 10.3390/microorganisms7050140] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/07/2019] [Accepted: 05/14/2019] [Indexed: 12/27/2022] Open
Abstract
Research in Chlamydia trachomatis and Chlamydia pneumoniae has gained new traction due to recent advances in molecular biology, namely the widespread use of the metagenomic analysis and the development of a stable genomic transformation system, resulting in a better understanding of Chlamydia pathogenesis. C. trachomatis, the leading cause of bacterial sexually transmitted diseases, is responsible of cervicitis and urethritis, and C. pneumoniae, a widespread respiratory pathogen, has long been associated with several chronic inflammatory diseases with great impact on public health. The present review summarizes the current evidence regarding the complex interplay between C. trachomatis and host defense factors in the genital micro-environment as well as the key findings in chronic inflammatory diseases associated to C. pneumoniae.
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Affiliation(s)
- Marisa Di Pietro
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome "Sapienza", 00185 Rome, Italy.
| | - Simone Filardo
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome "Sapienza", 00185 Rome, Italy.
| | - Silvio Romano
- Cardiology, Department of Life, Health and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy.
| | - Rosa Sessa
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome "Sapienza", 00185 Rome, Italy.
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Chiok KL, Paul NC, Adekanmbi EO, Srivastava SK, Shah DH. Dimethyl adenosine transferase (KsgA) contributes to cell-envelope fitness in Salmonella Enteritidis. Microbiol Res 2018; 216:108-119. [PMID: 30269850 DOI: 10.1016/j.micres.2018.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/17/2018] [Accepted: 08/21/2018] [Indexed: 01/02/2023]
Abstract
We previously reported that inactivation of a universally conserved dimethyl adenosine transferase (KsgA) attenuates virulence and increases sensitivity to oxidative and osmotic stress in Salmonella Enteritidis. Here, we show a role of KsgA in cell-envelope fitness as a potential mechanism underlying these phenotypes in Salmonella. We assessed structural integrity of the cell-envelope by transmission electron microscopy, permeability barrier function by determining intracellular accumulation of ethidium bromide and electrophysical properties by dielectrophoresis, an electrokinetic tool, in wild-type and ksgA knock-out mutants of S. Enteritidis. Deletion of ksgA resulted in disruption of the structural integrity, permeability barrier and distorted electrophysical properties of the cell-envelope. The cell-envelope fitness defects were alleviated by expression of wild-type KsgA (WT-ksgA) but not by its catalytically inactive form (ksgAE66A), suggesting that the dimethyl transferase activity of KsgA is important for cell-envelope fitness in S. Enteritidis. Upon expression of WT-ksgA and ksgAE66A in inherently permeable E. coli cells, the former strengthened and the latter weakened the permeability barrier, suggesting that KsgA also contributes to the cell-envelope fitness in E. coli. Lastly, expression of ksgAE66A exacerbated the cell-envelope fitness defects, resulting in impaired S. Enteritidis interactions with human intestinal epithelial cells, and human and avian phagocytes. This study shows that KsgA contributes to cell-envelope fitness and opens new avenues to modulate cell-envelopes via use of KsgA-antagonists.
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Affiliation(s)
- Kim Lam Chiok
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA
| | - Narayan C Paul
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA
| | - Ezekiel O Adekanmbi
- Department of Chemical and Materials Engineering, University of Idaho, Moscow, Idaho 83844-1021, USA
| | - Soumya K Srivastava
- Department of Chemical and Materials Engineering, University of Idaho, Moscow, Idaho 83844-1021, USA
| | - Devendra H Shah
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USA; Paul Allen School for Global Animal Health, Washington State University, Pullman, WA 99164-7040, USA.
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Hafner LM, Timms P. Development of a Chlamydia trachomatis vaccine for urogenital infections: novel tools and new strategies point to bright future prospects. Expert Rev Vaccines 2017; 17:57-69. [PMID: 29264970 DOI: 10.1080/14760584.2018.1417044] [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] [Indexed: 01/09/2023]
Abstract
INTRODUCTION The "cloaked" bacterial pathogen that is Chlamydia trachomatis continues to cause sexually transmitted infections (STIs) that adversely affect the health and well-being of children, adolescents and adults globally. The reproductive disease sequelae follow unresolved or untreated chronic or recurrent asymptomatic C.trachomatis infections of the lower female genital tract (FGT) and can include pelvic pain, pelvic inflammatory disease (PID) and ectopic pregnancy. Tubal Factor Infertility (TFI) can also occur since protective and long-term natural immunity to chlamydial infection is incomplete, allowing for ascension of the organism to the upper FGT. Developing countries including the WHO African (8.3 million cases) and South-East Asian regions (7.2 million cases) bear the highest burden of chlamydial STIs. AREAS COVERED Genetic advances for Chlamydia have provided tools for transformation (including dendrimer-enabled transformation), lateral gene transfer and chemical mutagenesis. Recent progress in these areas is reviewed with a focus on vaccine development for Chlamydia infections of the female genital tract. EXPERT COMMENTARY A vaccine that can elicit immuno-protective responses whilst avoiding adverse immuno-pathologic host responses is required. The current technological advances in chlamydial genetics and proteomics, as well as novel and improved adjuvants and delivery systems, provide new hope that the elusive chlamydial vaccine is an imminent and realistic goal.
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Affiliation(s)
- Louise M Hafner
- a School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Faculty of Health , Queensland University of Technology , Brisbane , Australia
| | - Peter Timms
- b Faculty of Science, Health, Education and Engineering , University of the Sunshine Coast , Maroochydore DC , Australia
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Seistrup KH, Rose S, Birkedal U, Nielsen H, Huber H, Douthwaite S. Bypassing rRNA methylation by RsmA/Dim1during ribosome maturation in the hyperthermophilic archaeon Nanoarchaeum equitans. Nucleic Acids Res 2017; 45:2007-2015. [PMID: 28204608 PMCID: PMC5389701 DOI: 10.1093/nar/gkw839] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 09/10/2016] [Indexed: 12/16/2022] Open
Abstract
In all free-living organisms a late-stage checkpoint in the biogenesis of the small ribosomal subunit involves rRNA modification by an RsmA/Dim1 methyltransferase. The hyperthermophilic archaeon Nanoarchaeum equitans, whose existence is confined to the surface of a second archaeon, Ignicoccus hospitalis, lacks an RsmA/Dim1 homolog. We demonstrate here that the I. hospitalis host possesses the homolog Igni_1059, which dimethylates the N6-positions of two invariant adenosines within helix 45 of 16S rRNA in a manner identical to other RsmA/Dim1 enzymes. However, Igni_1059 is not transferred from I. hospitalis to N. equitans across their fused cell membrane structures and the corresponding nucleotides in N. equitans 16S rRNA remain unmethylated. An alternative mechanism for ribosomal subunit maturation in N. equitans is suggested by sRNA interactions that span the redundant RsmA/Dim1 site to introduce 2΄-O-ribose methylations within helices 44 and 45 of the rRNA.
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Affiliation(s)
- Kenneth H. Seistrup
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Simon Rose
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Ulf Birkedal
- Department of Cellular & Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Henrik Nielsen
- Department of Cellular & Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Harald Huber
- Lehrstuhl für Mikrobiologie und Archaeenzentrum Universität Regensburg, Universitätsstraße 31, D-93053 Regensburg, Germany
| | - Stephen Douthwaite
- Department of Biochemistry & Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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Advances and Obstacles in the Genetic Dissection of Chlamydial Virulence. Curr Top Microbiol Immunol 2017; 412:133-158. [PMID: 29090367 DOI: 10.1007/82_2017_76] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Obligate intracellular pathogens in the family Chlamydiaceae infect taxonomically diverse eukaryotes ranging from amoebae to mammals. However, many fundamental aspects of chlamydial cell biology and pathogenesis remain poorly understood. Genetic dissection of chlamydial biology has historically been hampered by a lack of genetic tools. Exploitation of the ability of chlamydia to recombine genomic material by lateral gene transfer (LGT) ushered in a new era in chlamydia research. With methods to map mutations in place, genetic screens were able to assign functions and phenotypes to specific chlamydial genes. Development of an approach for stable transformation of chlamydia also provided a mechanism for gene delivery and platforms for disrupting chromosomal genes. Here, we explore how these and other tools have been used to test hypotheses concerning the functions of known chlamydial virulence factors and discover the functions of completely uncharacterized genes. Refinement and extension of the existing genetic tools to additional Chlamydia spp. will substantially advance understanding of the biology and pathogenesis of this important group of pathogens.
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Beyond Tryptophan Synthase: Identification of Genes That Contribute to Chlamydia trachomatis Survival during Gamma Interferon-Induced Persistence and Reactivation. Infect Immun 2016; 84:2791-801. [PMID: 27430273 DOI: 10.1128/iai.00356-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/15/2016] [Indexed: 12/31/2022] Open
Abstract
Chlamydia trachomatis can enter a viable but nonculturable state in vitro termed persistence. A common feature of C. trachomatis persistence models is that reticulate bodies fail to divide and make few infectious progeny until the persistence-inducing stressor is removed. One model of persistence that has relevance to human disease involves tryptophan limitation mediated by the host enzyme indoleamine 2,3-dioxygenase, which converts l-tryptophan to N-formylkynurenine. Genital C. trachomatis strains can counter tryptophan limitation because they encode a tryptophan-synthesizing enzyme. Tryptophan synthase is the only enzyme that has been confirmed to play a role in interferon gamma (IFN-γ)-induced persistence, although profound changes in chlamydial physiology and gene expression occur in the presence of persistence-inducing stressors. Thus, we screened a population of mutagenized C. trachomatis strains for mutants that failed to reactivate from IFN-γ-induced persistence. Six mutants were identified, and the mutations linked to the persistence phenotype in three of these were successfully mapped. One mutant had a missense mutation in tryptophan synthase; however, this mutant behaved differently from previously described synthase null mutants. Two hypothetical genes of unknown function, ctl0225 and ctl0694, were also identified and may be involved in amino acid transport and DNA damage repair, respectively. Our results indicate that C. trachomatis utilizes functionally diverse genes to mediate survival during and reactivation from persistence in HeLa cells.
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Edouard S, Raoult D. Use of the plaque assay for testing the antibiotic susceptibility of intracellular bacteria. Future Microbiol 2014; 8:1301-16. [PMID: 24059920 DOI: 10.2217/fmb.13.98] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The plaque assay was first described for titration of bacterial inoculums and clonal isolation, and was later adapted for testing antibiotics susceptibility and to study virulence factors and motility of bacteria. Over time, the sensitivity and reproducibility of the technique has been improved. Usually, the number of plaques is counted; however, the recent development of informatics tools has stimulated interest in the quantification of plaque size. Owing to this new approach, the plaque assay has been used to characterize the host cell response when infected cells are treated with antimicrobial agents. It was found that statins prevented cell lesions following rickettsial infection; in other studies, some antibiotics were found to cause apoptosis of host cells, suggesting a toxic activity. Here, we present an overview of the plaque assay as it has been used to investigate intracellular bacteria.
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Affiliation(s)
- Sophie Edouard
- Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD198, Inserm 1, 95, 13005 Marseille, France
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Porcel BM, Denoeud F, Opperdoes F, Noel B, Madoui MA, Hammarton TC, Field MC, Da Silva C, Couloux A, Poulain J, Katinka M, Jabbari K, Aury JM, Campbell DA, Cintron R, Dickens NJ, Docampo R, Sturm NR, Koumandou VL, Fabre S, Flegontov P, Lukeš J, Michaeli S, Mottram JC, Szöőr B, Zilberstein D, Bringaud F, Wincker P, Dollet M. The streamlined genome of Phytomonas spp. relative to human pathogenic kinetoplastids reveals a parasite tailored for plants. PLoS Genet 2014; 10:e1004007. [PMID: 24516393 PMCID: PMC3916237 DOI: 10.1371/journal.pgen.1004007] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 10/23/2013] [Indexed: 11/18/2022] Open
Abstract
Members of the family Trypanosomatidae infect many organisms, including animals, plants and humans. Plant-infecting trypanosomes are grouped under the single genus Phytomonas, failing to reflect the wide biological and pathological diversity of these protists. While some Phytomonas spp. multiply in the latex of plants, or in fruit or seeds without apparent pathogenicity, others colonize the phloem sap and afflict plants of substantial economic value, including the coffee tree, coconut and oil palms. Plant trypanosomes have not been studied extensively at the genome level, a major gap in understanding and controlling pathogenesis. We describe the genome sequences of two plant trypanosomatids, one pathogenic isolate from a Guianan coconut and one non-symptomatic isolate from Euphorbia collected in France. Although these parasites have extremely distinct pathogenic impacts, very few genes are unique to either, with the vast majority of genes shared by both isolates. Significantly, both Phytomonas spp. genomes consist essentially of single copy genes for the bulk of their metabolic enzymes, whereas other trypanosomatids e.g. Leishmania and Trypanosoma possess multiple paralogous genes or families. Indeed, comparison with other trypanosomatid genomes revealed a highly streamlined genome, encoding for a minimized metabolic system while conserving the major pathways, and with retention of a full complement of endomembrane organelles, but with no evidence for functional complexity. Identification of the metabolic genes of Phytomonas provides opportunities for establishing in vitro culturing of these fastidious parasites and new tools for the control of agricultural plant disease. Some plant trypanosomes, single-celled organisms living in phloem sap, are responsible for important palm diseases, inducing frequent expensive and toxic insecticide treatments against their insect vectors. Other trypanosomes multiply in latex tubes without detriment to their host. Despite the wide range of behaviors and impacts, these trypanosomes have been rather unceremoniously lumped into a single genus: Phytomonas. A battery of molecular probes has been used for their characterization but no clear phylogeny or classification has been established. We have sequenced the genomes of a pathogenic phloem-specific Phytomonas from a diseased South American coconut palm and a latex-specific isolate collected from an apparently healthy wild euphorb in the south of France. Upon comparison with each other and with human pathogenic trypanosomes, both Phytomonas revealed distinctive compact genomes, consisting essentially of single-copy genes, with the vast majority of genes shared by both isolates irrespective of their effect on the host. A strong cohort of enzymes in the sugar metabolism pathways was consistent with the nutritional environments found in plants. The genetic nuances may reveal the basis for the behavioral differences between these two unique plant parasites, and indicate the direction of our future studies in search of effective treatment of the crop disease parasites.
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Affiliation(s)
- Betina M. Porcel
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
- Université d'Evry, UMR 8030, Evry, France
- Centre National de Recherche Scientifique (CNRS), UMR 8030, Evry, France
- * E-mail: (BMP); (MD)
| | - France Denoeud
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
- Université d'Evry, UMR 8030, Evry, France
- Centre National de Recherche Scientifique (CNRS), UMR 8030, Evry, France
| | - Fred Opperdoes
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Benjamin Noel
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Mohammed-Amine Madoui
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Tansy C. Hammarton
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mark C. Field
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Corinne Da Silva
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Arnaud Couloux
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Julie Poulain
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Michael Katinka
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - Kamel Jabbari
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
- Université d'Evry, UMR 8030, Evry, France
- Centre National de Recherche Scientifique (CNRS), UMR 8030, Evry, France
| | - Jean-Marc Aury
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
| | - David A. Campbell
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | - Roxana Cintron
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Nicholas J. Dickens
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, United States of America
| | - Nancy R. Sturm
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States of America
| | | | - Sandrine Fabre
- CIRAD, TA A-98/F, Campus International de Baillarguet, Montpellier, France
| | - Pavel Flegontov
- Institute of Parasitology, Biology Centre and Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre and Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Shulamit Michaeli
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Jeremy C. Mottram
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Balázs Szöőr
- Centre for Immunity, Infection and Evolution, Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Dan Zilberstein
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Frédéric Bringaud
- Centre de Résonance Magnétique des Systèmes Biologiques, Université Bordeaux Segalen, CNRS UMR-5536, Bordeaux, France
| | - Patrick Wincker
- Commissariat à l'Energie Atomique (CEA), Institut de Génomique (IG), Genoscope, Evry, France
- Université d'Evry, UMR 8030, Evry, France
- Centre National de Recherche Scientifique (CNRS), UMR 8030, Evry, France
| | - Michel Dollet
- CIRAD, TA A-98/F, Campus International de Baillarguet, Montpellier, France
- * E-mail: (BMP); (MD)
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Dimethyl adenosine transferase (KsgA) deficiency in Salmonella enterica Serovar Enteritidis confers susceptibility to high osmolarity and virulence attenuation in chickens. Appl Environ Microbiol 2013; 79:7857-66. [PMID: 24123731 DOI: 10.1128/aem.03040-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dimethyl adenosine transferase (KsgA) performs diverse roles in bacteria, including ribosomal maturation and DNA mismatch repair, and synthesis of KsgA is responsive to antibiotics and cold temperature. We previously showed that a ksgA mutation in Salmonella enterica serovar Enteritidis results in impaired invasiveness in human and avian epithelial cells. In this study, we tested the virulence of a ksgA mutant (the ksgA::Tn5 mutant) of S. Enteritidis in orally challenged 1-day-old chickens. The ksgA::Tn5 mutant showed significantly reduced intestinal colonization and organ invasiveness in chickens compared to those of the wild-type (WT) parent. Phenotype microarray (PM) was employed to compare the ksgA::Tn5 mutant and its isogenic wild-type strain for 920 phenotypes at 28°C, 37°C, and 42°C. At chicken body temperature (42°C), the ksgA::Tn5 mutant showed significantly reduced respiratory activity with respect to a number of carbon, nitrogen, phosphate, sulfur, and peptide nitrogen nutrients. The greatest differences were observed in the osmolyte panel at concentrations of ≥6% NaCl at 37°C and 42°C. In contrast, no major differences were observed at 28°C. In independent growth assays, the ksgA::Tn5 mutant displayed a severe growth defect in high-osmolarity (6.5% NaCl) conditions in nutrient-rich (LB) and nutrient-limiting (M9 minimum salts) media at 42°C. Moreover, the ksgA::Tn5 mutant showed significantly reduced tolerance to oxidative stress, but its survival within macrophages was not impaired. Unlike Escherichia coli, the ksgA::Tn5 mutant did not display a cold-sensitivity phenotype; however, it showed resistance to kasugamycin and increased susceptibility to chloramphenicol. To the best of our knowledge, this is the first report showing the role of ksgA in S. Enteritidis virulence in chickens, tolerance to high osmolarity, and altered susceptibility to kasugamycin and chloramphenicol.
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Culver GM, Rife JP. Involvement of Ribosome Biogenesis in Antibiotic Function, Acquired Resistance, and Future Opportunities in Drug Discovery. Antibiotics (Basel) 2013. [DOI: 10.1002/9783527659685.ch15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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The endosymbiont Amoebophilus asiaticus encodes an S-adenosylmethionine carrier that compensates for its missing methylation cycle. J Bacteriol 2013; 195:3183-92. [PMID: 23667233 DOI: 10.1128/jb.00195-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
All organisms require S-adenosylmethionine (SAM) as a methyl group donor and cofactor for various biologically important processes. However, certain obligate intracellular parasitic bacteria and also the amoeba symbiont Amoebophilus asiaticus have lost the capacity to synthesize this cofactor and hence rely on its uptake from host cells. Genome analyses revealed that A. asiaticus encodes a putative SAM transporter. The corresponding protein was functionally characterized in Escherichia coli: import studies demonstrated that it is specific for SAM and S-adenosylhomocysteine (SAH), the end product of methylation. SAM transport activity was shown to be highly dependent on the presence of a membrane potential, and by targeted analyses, we obtained direct evidence for a proton-driven SAM/SAH antiport mechanism. Sequence analyses suggest that SAM carriers from Rickettsiales might operate in a similar way, in contrast to chlamydial SAM transporters. SAM/SAH antiport is of high physiological importance, as it allows for compensation for the missing methylation cycle. The identification of a SAM transporter in A. asiaticus belonging to the Bacteroidetes phylum demonstrates that SAM transport is more widely spread than previously assumed and occurs in bacteria belonging to three different phyla (Proteobacteria, Chlamydiae, and Bacteroidetes).
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O'Farrell HC, Rife JP. Staphylococcus aureus and Escherichia coli have disparate dependences on KsgA for growth and ribosome biogenesis. BMC Microbiol 2012; 12:244. [PMID: 23095113 PMCID: PMC3534330 DOI: 10.1186/1471-2180-12-244] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 10/11/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The KsgA methyltransferase has been conserved throughout evolution, methylating two adenosines in the small subunit rRNA in all three domains of life as well as in eukaryotic organelles that contain ribosomes. Understanding of KsgA's important role in ribosome biogenesis has been recently expanded in Escherichia coli; these studies help explain why KsgA is so highly conserved and also suggest KsgA's potential as an antimicrobial drug target. RESULTS We have analyzed KsgA's contribution to ribosome biogenesis and cell growth in Staphylococcus aureus. We found that deletion of ksgA in S. aureus led to a cold-sensitive growth phenotype, although KsgA was not as critical for ribosome biogenesis as it was shown to be in E. coli. Additionally, the ksgA knockout strain showed an increased sensitivity to aminoglycoside antibiotics. Overexpression of a catalytically inactive KsgA mutant was deleterious in the knockout strain but not the wild-type strain; this negative phenotype disappeared at low temperature. CONCLUSIONS This work extends the study of KsgA, allowing comparison of this aspect of ribosome biogenesis between a Gram-negative and a Gram-positive organism. Our results in S. aureus are in contrast to results previously described in E. coli, where the catalytically inactive protein showed a negative phenotype in the presence or absence of endogenous KsgA.
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Affiliation(s)
- Heather C O'Farrell
- Department of Physiology and Molecular Biophysics, Virginia Commonwealth University, Richmond, VA, USA
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The alternative translational profile that underlies the immune-evasive state of persistence in Chlamydiaceae exploits differential tryptophan contents of the protein repertoire. Microbiol Mol Biol Rev 2012; 76:405-43. [PMID: 22688818 DOI: 10.1128/mmbr.05013-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One form of immune evasion is a developmental state called "persistence" whereby chlamydial pathogens respond to the host-mediated withdrawal of L-tryptophan (Trp). A sophisticated survival mode of reversible quiescence is implemented. A mechanism has evolved which suppresses gene products necessary for rapid pathogen proliferation but allows expression of gene products that underlie the morphological and developmental characteristics of persistence. This switch from one translational profile to an alternative translational profile of newly synthesized proteins is proposed to be accomplished by maximizing the Trp content of some proteins needed for rapid proliferation (e.g., ADP/ATP translocase, hexose-phosphate transporter, phosphoenolpyruvate [PEP] carboxykinase, the Trp transporter, the Pmp protein superfamily for cell adhesion and antigenic variation, and components of the cell division pathway) while minimizing the Trp content of other proteins supporting the state of persistence. The Trp starvation mechanism is best understood in the human-Chlamydia trachomatis relationship, but the similarity of up-Trp and down-Trp proteomic profiles in all of the pathogenic Chlamydiaceae suggests that Trp availability is an underlying cue relied upon by this family of pathogens to trigger developmental transitions. The biochemically expensive pathogen strategy of selectively increased Trp usage to guide the translational profile can be leveraged significantly with minimal overall Trp usage by (i) regional concentration of Trp residue placements, (ii) amplified Trp content of a single protein that is required for expression or maturation of multiple proteins with low Trp content, and (iii) Achilles'-heel vulnerabilities of complex pathways to high Trp content of one or a few enzymes.
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15
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Transposon mutagenesis of Salmonella enterica serovar Enteritidis identifies genes that contribute to invasiveness in human and chicken cells and survival in egg albumen. Infect Immun 2012; 80:4203-15. [PMID: 22988017 DOI: 10.1128/iai.00790-12] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Enteritidis is an important food-borne pathogen, and chickens are a primary reservoir of human infection. While most knowledge about Salmonella pathogenesis is based on research conducted on Salmonella enterica serovar Typhimurium, S. Enteritidis is known to have pathobiology specific to chickens that impacts epidemiology in humans. Therefore, more information is needed about S. Enteritidis pathobiology in comparison to that of S. Typhimurium. We used transposon mutagenesis to identify S. Enteritidis virulence genes by assay of invasiveness in human intestinal epithelial (Caco-2) cells and chicken liver (LMH) cells and survival within chicken (HD-11) macrophages as a surrogate marker for virulence. A total of 4,330 transposon insertion mutants of an invasive G1 Nal(r) strain were screened using Caco-2 cells. This led to the identification of attenuating mutations in a total of 33 different loci, many of which include genes previously known to contribute to enteric infection (e.g., Salmonella pathogenicity island 1 [SPI-1], SPI-4, SPI-5, CS54, fliH, fljB, csgB, spvR, and rfbMN) in S. Enteritidis and other Salmonella serovars. Several genes or genomic islands that have not been reported previously (e.g., SPI-14, ksgA, SEN0034, SEN2278, and SEN3503) or that are absent in S. Typhimurium or in most other Salmonella serovars (e.g., pegD, SEN1152, SEN1393, and SEN1966) were also identified. Most mutants with reduced Caco-2 cell invasiveness also showed significantly reduced invasiveness in chicken liver cells and impaired survival in chicken macrophages and in egg albumen. Consequently, these genes may play an important role during infection of the chicken host and also contribute to successful egg contamination by S. Enteritidis.
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Resistance to a novel antichlamydial compound is mediated through mutations in Chlamydia trachomatis secY. Antimicrob Agents Chemother 2012; 56:4296-302. [PMID: 22644029 DOI: 10.1128/aac.00356-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel and quantitative high-throughput screening approach was explored as a tool for the identification of novel compounds that inhibit chlamydial growth in mammalian cells. The assay is based on accumulation of a fluorescent marker by intracellular chlamydiae. Its utility was demonstrated by screening 42,000 chemically defined compounds against Chlamydia caviae GPIC. This analysis led to the identification of 40 primary-hit compounds. Five of these compounds were nontoxic to host cells and had similar activities against both C. caviae GPIC and Chlamydia trachomatis. The inhibitory activity of one of the compounds, (3-methoxyphenyl)-(4,4,7-trimethyl-4,5-dihydro-1H-[1,2]dithiolo[3,4-C]quinolin-1-ylidene)amine (MDQA), was chlamydia specific and was selected for further study. Selection for resistance to MDQA led to the generation of three independent resistant clones of C. trachomatis. Amino acid changes in SecY, a protein involved in Sec-dependent secretion in Gram-negative bacteria, were associated with the resistance phenotype. The amino acids changed in each of the resistant mutants are located in the predicted central channel of a SecY crystal structure, based on the known structure of Thermus thermophilus SecY. These experiments model a process that can be used for the discovery of antichlamydial, anti-intracellular, or antibacterial compounds and has led to the identification of compounds that may have utility in both antibiotic discovery and furthering our understanding of chlamydial biology.
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Identification and characterization of the Chlamydia trachomatis L2 S-adenosylmethionine transporter. mBio 2011; 2:e00051-11. [PMID: 21558433 PMCID: PMC3104491 DOI: 10.1128/mbio.00051-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Methylation is essential to the physiology of all cells, including the obligate intracellular bacterium Chlamydia. Nevertheless, the methylation cycle is under strong reductive evolutionary pressure in Chlamydia. Only Parachlamydia acanthamoebae and Waddlia chondrophila genome sequences harbor homologs to metK, encoding the S-adenosylmethionine (SAM) synthetase required for synthesis of SAM, and to sahH, which encodes the S-adenosylhomocysteine (SAH) hydrolase required for detoxification of SAH formed after the transfer of the methyl group from SAM to the methylation substrate. Transformation of a conditional-lethal ΔmetK mutant of Escherichia coli with a genomic library of Chlamydia trachomatis L2 identified CTL843 as a putative SAM transporter based on its ability to allow the mutant to survive metK deficiency only in the presence of extracellular SAM. CTL843 belongs to the drug/metabolite superfamily of transporters and allowed E. coli to transport S-adenosyl-L-[methyl-(14)C]methionine with an apparent K(m) of 5.9 µM and a V(max) of 32 pmol min(-1) mg(-1). Moreover, CTL843 conferred a growth advantage to a Δpfs E. coli mutant that lost the ability to detoxify SAH, while competition and back-transport experiments further implied that SAH was an additional substrate for CTL843. We propose that CTL843 acts as a SAM/SAH transporter (SAMHT) serving a dual function by allowing Chlamydia to acquire SAM from the host cell and excrete the toxic by-product SAH. The demonstration of a functional SAMHT provides further insight into the reductive evolution associated with the obligate intracellular lifestyle of Chlamydia and identifies an excellent chemotherapeutic target. IMPORTANCE Obligate intracellular parasites like Chlamydia have followed a reductive evolutionary path that has made them almost totally dependent on their host cell for nutrients. In this work, we identify a unique transporter of a metabolite essential for all methylation reactions that potentially bypasses the need for two enzymatic reactions in Chlamydia. The transporter, CTL843, allows Chlamydia trachomatis L2 to steal S-adenosylmethionine (SAM) from the eukaryotic host cytosol and to likely remove the toxic S-adenosylhomocysteine (SAH) formed when SAM loses its methyl group, acting as a SAM/SAH transporter (SAMHT). In addition to reflecting the adaptation of Chlamydia to an obligate intracellular lifestyle, the specific and central roles of SAMHT in Chlamydia metabolism provide a target for the development of therapeutic agents for the treatment of chlamydial infections.
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Abstract
There are few documented reports of antibiotic resistance in Chlamydia and no examples of natural and stable antibiotic resistance in strains collected from humans. While there are several reports of clinical isolates exhibiting resistance to antibiotics, these strains either lost their resistance phenotype in vitro, or lost viability altogether. Differences in procedures for chlamydial culture in the laboratory, low recovery rates of clinical isolates and the unknown significance of heterotypic resistance observed in culture may interfere with the recognition and interpretation of antibiotic resistance. Although antibiotic resistance has not emerged in chlamydiae pathogenic to humans, several lines of evidence suggest they are capable of expressing significant resistant phenotypes. The adept ability of chlamydiae to evolve to antibiotic resistance in vitro is demonstrated by contemporary examples of mutagenesis, recombination and genetic transformation. The isolation of tetracycline-resistant Chlamydia suis strains from pigs also emphasizes their adaptive ability to acquire antibiotic resistance genes when exposed to significant selective pressure.
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Affiliation(s)
- Kelsi M Sandoz
- Molecular & Cellular Biology Program & the Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331–4804, USA
| | - Daniel D Rockey
- Molecular & Cellular Biology Program & the Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331–4804, USA
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