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Kędzierska-Mieszkowska S. Sigma factors of RNA polymerase in the pathogenic spirochaete Leptospira interrogans, the causative agent of leptospirosis. FASEB J 2023; 37:e23163. [PMID: 37688587 DOI: 10.1096/fj.202300252rrr] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 07/13/2023] [Accepted: 08/14/2023] [Indexed: 09/11/2023]
Abstract
The aim of this review is to summarize the current knowledge on the role of σ factors in a highly invasive spirochaete Leptospira interrogans responsible for leptospirosis that affects many mammals, including humans. This disease has a significant impact on public health and the economy worldwide. In bacteria, σ factors are the key regulators of gene expression at the transcriptional level and therefore play an important role in bacterial adaptative response to different environmental stimuli. These factors form a holoenzyme with the RNA polymerase core enzyme and then direct it to specific promoters, which results in turning on selected genes. Most bacteria possess several different σ factors that enable them to maintain basal gene expression, as well as to regulate gene expression in response to specific environmental signals. Recent comparative genomics and in silico genome-wide analyses have revealed that the L. interrogans genome, consisting of two circular chromosomes, encodes a total of 14 σ factors. Among them, there is one putative housekeeping σ70 -like factor, and three types of alternative σ factors, i.e., one σ54 , one σ28 and 11 putative ECF (extracytoplasmic function) σE -type factors. Here, characteristics of these putative σ factors and their possible role in the L. interrogans gene regulation (especially in this pathogen's adaptive response to various environmental conditions, an important determinant of leptospiral virulence), are presented.
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Hsu SH, Wu CT, Sun YJ, Chang MY, Li C, Ko YC, Chou LF, Yang CW. Crystal structure of Leptospira LSS_01692 reveals a dimeric structure and induces inflammatory responses through Toll-like receptor 2-dependent NF-κB and MAPK signal transduction pathways. FEBS J 2023; 290:4513-4532. [PMID: 37243454 DOI: 10.1111/febs.16874] [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: 02/23/2023] [Revised: 05/12/2023] [Accepted: 05/25/2023] [Indexed: 05/28/2023]
Abstract
Leptospirosis is a commonly overlooked zoonotic disease that occurs in tropical and subtropical regions. Recent studies have divided the Leptospira spp. into three groups based on virulence, including pathogenic, intermediate, and saprophytic species. Pathogenic species express a protein family with leucine-rich repeat (LRR) domains, which are less expressed or absent in nonpathogenic species, highlighting the importance of this protein family in leptospirosis. However, the role of LRR domain proteins in the pathogenesis of leptospirosis is still unknown and requires further investigation. In this study, the 3D structure of LSS_01692 (rLRR38) was obtained using X-ray crystallography at a resolution of 3.2 Å. The results showed that rLRR38 forms a typical horseshoe structure with 11 α-helices and 11 β-sheets and an antiparallel dimeric structure. The interactions of rLRR38 with extracellular matrix and cell surface receptors were evaluated using ELISA and single-molecule atomic force microscopy. The results showed that rLRR38 interacted with fibronectin, collagen IV, and Toll-like receptor 2 (TLR2). Incubating HK2 cells with rLRR38 induced two downstream inflammation responses (IL-6 and MCP-1) in the TLR2 signal transduction pathway. The TLR2-TLR1 complex showed the most significant upregulation effects under rLRR38 treatment. Inhibitors also significantly inhibited nuclear factor κB and mitogen-activated protein kinases signals transduction under rLRR38 stimulation. In conclusion, rLRR38 was determined to be a novel LRR domain protein in 3D structure and demonstrated as a TLR2-binding protein that induces inflammatory responses. These structural and functional studies provide a deeper understanding of the pathogenesis of leptospirosis.
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Affiliation(s)
- Shen-Hsing Hsu
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Che-Ting Wu
- Department of Life Science and Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsin Chu, Taiwan
| | - Yuh-Ju Sun
- Department of Life Science and Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsin Chu, Taiwan
| | - Ming-Yang Chang
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chien Li
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yi-Ching Ko
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Li-Fang Chou
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chih-Wei Yang
- Kidney Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Department of Nephrology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Phoka T, Fule L, Da Fonseca JP, Cokelaer T, Picardeau M, Patarakul K. Investigating the role of the carbon storage regulator A (CsrA) in Leptospira spp. PLoS One 2021; 16:e0260981. [PMID: 34898610 PMCID: PMC8668096 DOI: 10.1371/journal.pone.0260981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 11/20/2021] [Indexed: 01/08/2023] Open
Abstract
Carbon Storage Regulator A (CsrA) is a well-characterized post-transcriptional global regulator that plays a critical role in response to environmental changes in many bacteria. CsrA has been reported to regulate several metabolic pathways, motility, biofilm formation, and virulence-associated genes. The role of csrA in Leptospira spp., which are able to survive in different environmental niches and infect a wide variety of reservoir hosts, has not been characterized. To investigate the role of csrA as a gene regulator in Leptospira, we generated a L. biflexa csrA deletion mutant (ΔcsrA) and csrA overexpressing Leptospira strains. The ΔcsrA L. biflexa displayed poor growth under starvation conditions. RNA sequencing revealed that in rich medium only a few genes, including the gene encoding the flagellar filament protein FlaB3, were differentially expressed in the ΔcsrA mutant. In contrast, 575 transcripts were differentially expressed when csrA was overexpressed in L. biflexa. Electrophoretic mobility shift assay (EMSA) confirmed the RNA-seq data in the ΔcsrA mutant, showing direct binding of recombinant CsrA to flaB3 mRNA. In the pathogen L. interrogans, we were not able to generate a csrA mutant. We therefore decided to overexpress csrA in L. interrogans. In contrast to the overexpressing strain of L. biflexa, the overexpressing L. interrogans strain had poor motility on soft agar. The overexpressing strain of L. interrogans also showed significant upregulation of the flagellin flaB1, flaB2, and flaB4. The interaction of L. interrogans rCsrA and flaB4 was confirmed by EMSA. Our results demonstrated that CsrA may function as a global regulator in Leptospira spp. under certain conditions that cause csrA overexpression. Interestingly, the mechanisms of action and gene targets of CsrA may be different between non-pathogenic and pathogenic Leptospira strains.
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Affiliation(s)
- Theerapat Phoka
- Medical Microbiology, Interdisciplinary and International Program, Graduate School, Chulalongkorn University, Bangkok, Thailand
| | - Lenka Fule
- Institut Pasteur, Biology of Spirochetes Unit, French National Reference Centre for Leptospirosis, Paris, France
| | - Juliana Pipoli Da Fonseca
- Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
| | - Thomas Cokelaer
- Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, Paris, France
- Hub de Bioinformatique et Biostatistique – Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Mathieu Picardeau
- Institut Pasteur, Biology of Spirochetes Unit, French National Reference Centre for Leptospirosis, Paris, France
| | - Kanitha Patarakul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- Chula Vaccine Research Center (Chula VRC), Center of Excellence in Vaccine Research and Development, Chulalongkorn University, Bangkok, Thailand
- * E-mail: ,
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Grassmann AA, Zavala-Alvarado C, Bettin EB, Picardeau M, Benaroudj N, Caimano MJ. The FUR-like regulators PerRA and PerRB integrate a complex regulatory network that promotes mammalian host-adaptation and virulence of Leptospira interrogans. PLoS Pathog 2021; 17:e1009078. [PMID: 34855918 PMCID: PMC8638967 DOI: 10.1371/journal.ppat.1009078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/18/2021] [Indexed: 11/18/2022] Open
Abstract
Leptospira interrogans, the causative agent of most cases of human leptospirosis, must respond to myriad environmental signals during its free-living and pathogenic lifestyles. Previously, we compared L. interrogans cultivated in vitro and in vivo using a dialysis membrane chamber (DMC) peritoneal implant model. From these studies emerged the importance of genes encoding the Peroxide responsive regulators PerRA and PerRB. First described in in Bacillus subtilis, PerRs are widespread in Gram-negative and -positive bacteria, where regulate the expression of gene products involved in detoxification of reactive oxygen species and virulence. Using perRA and perRB single and double mutants, we establish that L. interrogans requires at least one functional PerR for infectivity and renal colonization in a reservoir host. Our finding that the perRA/B double mutant survives at wild-type levels in DMCs is noteworthy as it demonstrates that the loss of virulence is not due to a metabolic lesion (i.e., metal starvation) but instead reflects dysregulation of virulence-related gene products. Comparative RNA-Seq analyses of perRA, perRB and perRA/B mutants cultivated within DMCs identified 106 genes that are dysregulated in the double mutant, including ligA, ligB and lvrA/B sensory histidine kinases. Decreased expression of LigA and LigB in the perRA/B mutant was not due to loss of LvrAB signaling. The majority of genes in the perRA and perRB single and double mutant DMC regulons were differentially expressed only in vivo, highlighting the importance of host signals for regulating gene expression in L. interrogans. Importantly, the PerRA, PerRB and PerRA/B DMC regulons each contain multiple genes related to environmental sensing and/or transcriptional regulation. Collectively, our data suggest that PerRA and PerRB are part of a complex regulatory network that promotes host adaptation by L. interrogans within mammals.
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Affiliation(s)
- André A. Grassmann
- Department of Medicine, University of Connecticut Health, Farmington, Connecticut, United States of America
| | - Crispin Zavala-Alvarado
- Unité de Biologie des Spirochètes, Department of Microbiology, Institut Pasteur, Paris, France
- Université de Paris, Sorbonne Paris Cité, Communauté d’universités et d’établissements (COMUE), Bio Sorbonne Paris Cité (BioSPC), Paris, France
| | - Everton B. Bettin
- Department of Medicine, University of Connecticut Health, Farmington, Connecticut, United States of America
- Programa de Pós-Graduação em Biotecnologia, Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sol, Brazil
| | - Mathieu Picardeau
- Unité de Biologie des Spirochètes, Department of Microbiology, Institut Pasteur, Paris, France
| | - Nadia Benaroudj
- Unité de Biologie des Spirochètes, Department of Microbiology, Institut Pasteur, Paris, France
| | - Melissa J. Caimano
- Department of Medicine, University of Connecticut Health, Farmington, Connecticut, United States of America
- Department of Pediatrics, University of Connecticut Health, Farmington, Connecticut, United States of America
- Department of Molecular Biology and Biophysics, University of Connecticut Health, Farmington, Connecticut, United States of America
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Bierque E, Thibeaux R, Girault D, Soupé-Gilbert ME, Goarant C. A systematic review of Leptospira in water and soil environments. PLoS One 2020; 15:e0227055. [PMID: 31986154 PMCID: PMC6984726 DOI: 10.1371/journal.pone.0227055] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/10/2019] [Indexed: 01/02/2023] Open
Abstract
Background Leptospirosis, caused by pathogenic Leptospira, is a zoonosis of global distribution. This infectious disease is mainly transmitted by indirect exposure to urine of asymptomatic animals via the environment. As human cases generally occur after heavy rain, an emerging hypothesis suggests that rainfall re-suspend leptospires together with soil particles. Bacteria are then carried to surface water, where humans get exposed. It is currently assumed that pathogenic leptospires can survive in the environment but do not multiply. However, little is known on their capacity to survive in a soil and freshwater environment. Methods We conducted a systematic review on Leptospira and leptospirosis in the environment in order to collect current knowledge on the lifestyle of Leptospira in soil and water. In total, 86 scientific articles retrieved from online databases or institutional libraries were included in this study. Principals findings/significance This work identified evidence of survival of Leptospira in the environment but major gaps remain about the survival of virulent species associated with human and animal diseases. Studies providing quantitative data on Leptospira in soil and water are a very recent trend, but must be interpreted with caution because of the uncertainty in the species identification. Several studies mentioned the presence of Leptospira in soils more frequently than in waters, supporting the hypothesis of the soil habitat and dispersion of Leptospira with re-suspended soil particles during heavy rain. In a near future, the growing use of high throughput sequencing will offer new opportunities to improve our understanding of the habitat of Leptospira in the environment. This better insight into the risk of leptospirosis will allow implementing efficient control measures and prevention for the human and animal populations exposed.
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Affiliation(s)
- Emilie Bierque
- Leptospirosis Research and Expertise Unit, Institut Pasteur in New Caledonia, Institut Pasteur International Network, Noumea, New Caledonia
| | - Roman Thibeaux
- Leptospirosis Research and Expertise Unit, Institut Pasteur in New Caledonia, Institut Pasteur International Network, Noumea, New Caledonia
| | - Dominique Girault
- Leptospirosis Research and Expertise Unit, Institut Pasteur in New Caledonia, Institut Pasteur International Network, Noumea, New Caledonia
| | - Marie-Estelle Soupé-Gilbert
- Leptospirosis Research and Expertise Unit, Institut Pasteur in New Caledonia, Institut Pasteur International Network, Noumea, New Caledonia
| | - Cyrille Goarant
- Leptospirosis Research and Expertise Unit, Institut Pasteur in New Caledonia, Institut Pasteur International Network, Noumea, New Caledonia
- * E-mail:
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cis-Acting Determinant Limiting Expression of Sphingomyelinase Gene sph2 in Leptospira interrogans, Identified with a gfp Reporter Plasmid. Appl Environ Microbiol 2018; 84:AEM.02068-18. [PMID: 30266732 DOI: 10.1128/aem.02068-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 09/25/2018] [Indexed: 12/29/2022] Open
Abstract
Many strains of the spirochete Leptospira interrogans serovar Pomona express the osmotically inducible sphingomyelinase gene sph2 at much higher levels than strains from other serovars. We developed a new green fluorescent protein (GFP) reporter plasmid to examine sph2 gene expression determinants. The vector enables the fusion of the test promoter to the ribosome-binding site and coding region of gfp We fused the sph2 promoters from the L. interrogans serovar Lai strain 56601 and from the L. interrogans serovar Pomona strain LC82-25 to gfp to examine the molecular determinants of differential sph2 expression between the two strains. Similar to what was observed with the native sph2 genes, the introduction of the plasmids into the Lai 56601 strain resulted in near background levels of gfp expression from the Lai sph2 promoter, while the expression from the Pomona sph2 promoter was high. The expression of both fusions increased at physiologic levels of osmolarity achieved by adding sodium chloride to the culture medium. We examined the role of a 17-bp upstream element found in all L. interrogans strains expressing low basal levels of sph2 and missing from Pomona strains that express sph2 at high levels. When the 17-bp sequence present upstream of the Lai sph2 promoter was deleted or scrambled, the fusion expression increased substantially. Conversely, the insertion of the 17-bp sequence upstream of the Pomona sph2 promoter diminished fusion expression. In contrast, the removal of an insertion sequence-like element that is found only in the Pomona sph2 upstream sequence had no effect on the expression from the Pomona sph2 fusion in the Lai strain. These findings demonstrate the utility of the gfp reporter plasmid in analyzing gene expression in L. interrogans IMPORTANCE Genetic tools are needed to examine gene expression in the pathogen Leptospira interrogans We developed a reporter plasmid that replicates in L. interrogans with green fluorescent protein (GFP) as the readout of promoter activity. We demonstrated an application of the new reporter plasmid by identifying an upstream element responsible for the poor basal expression of the sph2 sphingomyelinase gene in an L. interrogans serovar Lai strain. This new tool is useful for the discovery of the molecular determinants of L. interrogans gene expression.
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Quantification of Leptospira interrogans Survival in Soil and Water Microcosms. Appl Environ Microbiol 2018; 84:AEM.00507-18. [PMID: 29703737 DOI: 10.1128/aem.00507-18] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/21/2018] [Indexed: 12/22/2022] Open
Abstract
Leptospira interrogans is the etiological agent of leptospirosis, a globally distributed zoonotic disease. Human infection usually occurs through skin exposure with water and soil contaminated with the urine of chronically infected animals. In this study, we aimed to quantitatively characterize the survival of Leptospira interrogans serovar Copenhageni in environmental matrices. We constructed laboratory microcosms to simulate natural conditions and determined the persistence of DNA markers in soil, mud, spring water and sewage using a quantitative PCR (qPCR) and a propidium monoazide (PMA)-qPCR assay. We found that L. interrogans does not survive at high concentrations in the tested matrices. No net growth was detected in any of the experimental conditions and in all cases the concentration of the DNA markers targeted decreased from the beginning of the experiment following an exponential decay with a decreasing decay rate over time. After 12 and 21 days of incubation the spiked concentration of 106L. interrogans cells/ml or g decreased to approximately 100 cells/ml or g in soil and spring water microcosms, respectively. Furthermore, culturable L. interrogans persisted at concentrations under the limit of detection by PMA-qPCR or qPCR for at least 16 days in soil and 28 days in spring water. Altogether, our findings suggest that the environment is not a multiplication reservoir but a temporary carrier of L. interrogans Copenhageni, although the observed prolonged persistence at low concentrations may still enable the transmission of the disease.IMPORTANCE Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira that primarily affects impoverished populations worldwide. Although leptospirosis is transmitted by contact with water and soil, little is known about the ability of the pathogen to survive in the environment. In this study, we quantitatively characterized the survival of L. interrogans in environmental microcosms and found that although it cannot multiply in water, soil or sewage, it survives for extended time periods (days to weeks depending on the matrix). The survival parameters obtained here may help to better understand the distribution of pathogenic Leptospira in the environment and improve the predictions of human infection risks in areas where such infections are endemic.
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Long-term preservation of Leptospira spp.: challenges and prospects. Appl Microbiol Biotechnol 2018; 102:5427-5435. [PMID: 29736823 DOI: 10.1007/s00253-018-9047-9] [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: 01/27/2018] [Revised: 04/18/2018] [Accepted: 04/19/2018] [Indexed: 10/17/2022]
Abstract
Preservation of leptospiral cultures is tantamount to success in leptospiral diagnostics, research, and development of preventive strategies. Each Leptospira isolate has imperative value not only in disease diagnosis but also in epidemiology, virulence, pathogenesis, and drug development studies. As the number of circulating leptospires is continuously increasing and congruent with the importance to retain their original characteristics and properties, an efficient long-term preservation is critically needed to be well-established. However, the preservation of Leptospira is currently characterized by difficulties and conflicting results mainly due to the biological nature of this organism. Hence, this review seeks to describe the efforts in developing efficient preservation methods, to discover the challenges in preserving this organism and to identify the factors that can contribute to an effective long-term preservation of Leptospira. Through the enlightenment of the previous studies, a potentially effective method has been suggested. The article also attempts to evaluate novel strategies used in other industrial and biotechnological preservation efforts and consider their potential application to the conservation of Leptospira spp.
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Zhang JJ, Hu WL, Yang Y, Li H, Picardeau M, Yan J, Yang XF. The sigma factor σ 54 is required for the long-term survival of Leptospira biflexa in water. Mol Microbiol 2018; 109:10.1111/mmi.13967. [PMID: 29633391 PMCID: PMC6174002 DOI: 10.1111/mmi.13967] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2018] [Indexed: 12/21/2022]
Abstract
Leptospira spp. comprise both pathogenic and free-living saprophytic species. Little is known about the environmental adaptation and survival mechanisms of Leptospira. Alternative sigma factor, σ54 (RpoN) is known to play an important role in environmental and host adaptation in many bacteria. In this study, we constructed an rpoN mutant by allele exchange, and the complemented strain in saprophytic L. biflexa. Transcriptome analysis revealed that expression of several genes involved in nitrogen uptake and metabolism, including amtB1, glnB-amtB2, ntrX and narK, were controlled by σ54 . While wild-type L. biflexa could not grow under nitrogen-limiting conditions but was able to survive under such conditions and recover rapidly, the rpoN mutant was not. The rpoN mutant also had dramatically reduced ability to survive long-term in water. σ54 appears to regulate expression of amtB1, glnK-amtB2, ntrX and narK in an indirect manner. However, we identified a novel nitrogen-related gene, LEPBI_I1011, whose expression was directly under the control of σ54 (herein renamed as rcfA for RpoN-controlled factor A). Taken together, our data reveal that the σ54 regulatory network plays an important role in the long-term environmental survival of Leptospira spp.
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Affiliation(s)
- Jun-Jie Zhang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Wei-Lin Hu
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Youyun Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Hongxia Li
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | - Jie Yan
- Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - X. Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Critical Knowledge Gaps in Our Understanding of Environmental Cycling and Transmission of Leptospira spp. Appl Environ Microbiol 2017; 83:AEM.01190-17. [PMID: 28754706 PMCID: PMC5601346 DOI: 10.1128/aem.01190-17] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Exposure to soil or water contaminated with the urine of Leptospira-infected animals is the most common way in which humans contract leptospirosis. Entire populations can be at high risk of leptospirosis while working in inundated fields, when engaging in aquatic sports, or after periods of heavy rainfall. The risk of infection after contact with these environmental sources depends on the ability of Leptospira bacteria to survive, persist, and infect new hosts. Multiple variables such as soil and water pH, temperature, and even environmental microbial communities are likely to shape the environmental conditions needed by the pathogen to persist. Here we review what is known about the environmental phase of the infectious Leptospira transmission cycle and identify knowledge gaps that will serve as a guide for future research.
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Zhukova A, Fernandes LG, Hugon P, Pappas CJ, Sismeiro O, Coppée JY, Becavin C, Malabat C, Eshghi A, Zhang JJ, Yang FX, Picardeau M. Genome-Wide Transcriptional Start Site Mapping and sRNA Identification in the Pathogen Leptospira interrogans. Front Cell Infect Microbiol 2017; 7:10. [PMID: 28154810 PMCID: PMC5243855 DOI: 10.3389/fcimb.2017.00010] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/06/2017] [Indexed: 12/13/2022] Open
Abstract
Leptospira are emerging zoonotic pathogens transmitted from animals to humans typically through contaminated environmental sources of water and soil. Regulatory pathways of pathogenic Leptospira spp. underlying the adaptive response to different hosts and environmental conditions remains elusive. In this study, we provide the first global Transcriptional Start Site (TSS) map of a Leptospira species. RNA was obtained from the pathogen Leptospira interrogans grown at 30°C (optimal in vitro temperature) and 37°C (host temperature) and selectively enriched for 5′ ends of native transcripts. A total of 2865 and 2866 primary TSS (pTSS) were predicted in the genome of L. interrogans at 30 and 37°C, respectively. The majority of the pTSSs were located between 0 and 10 nucleotides from the translational start site, suggesting that leaderless transcripts are a common feature of the leptospiral translational landscape. Comparative differential RNA-sequencing (dRNA-seq) analysis revealed conservation of most pTSS at 30 and 37°C. Promoter prediction algorithms allow the identification of the binding sites of the alternative sigma factor sigma 54. However, other motifs were not identified indicating that Leptospira consensus promoter sequences are inherently different from the Escherichia coli model. RNA sequencing also identified 277 and 226 putative small regulatory RNAs (sRNAs) at 30 and 37°C, respectively, including eight validated sRNAs by Northern blots. These results provide the first global view of TSS and the repertoire of sRNAs in L. interrogans. These data will establish a foundation for future experimental work on gene regulation under various environmental conditions including those in the host.
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Affiliation(s)
- Anna Zhukova
- Bioinformatics and Biostatistics Hub, Institut Pasteur, C3BI Paris, France
| | | | - Perrine Hugon
- Biology of Spirochetes Unit, Institut PasteurParis, France; Mutualized Microbiology Platform, Institut Pasteur, Pasteur International Bioresources NetworkParis, France
| | - Christopher J Pappas
- Biology of Spirochetes Unit, Institut PasteurParis, France; Department of Biology, Manhattanville CollegePurchase, NY, USA
| | - Odile Sismeiro
- CITECH, Institut Pasteur, Plate-forme Transcriptome et Epigenome, Pole Biomics - CITECH Paris, France
| | - Jean-Yves Coppée
- CITECH, Institut Pasteur, Plate-forme Transcriptome et Epigenome, Pole Biomics - CITECH Paris, France
| | - Christophe Becavin
- Bioinformatics and Biostatistics Hub, Institut Pasteur, C3BI Paris, France
| | - Christophe Malabat
- Bioinformatics and Biostatistics Hub, Institut Pasteur, C3BI Paris, France
| | - Azad Eshghi
- Biology of Spirochetes Unit, Institut Pasteur Paris, France
| | - Jun-Jie Zhang
- Department of Microbiology and Immunology, Indiana University School of Medicine Indianapolis, IN, USA
| | - Frank X Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine Indianapolis, IN, USA
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