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ABSTRACT:
PROVIDER: PRJNA1311539 | ENA |
REPOSITORIES: ENA
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Project description:Pathogen: clinical or host-associated sample
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Project description:Our data demonstrate the suitability of target capture technology for purifying very low quantities of Leptospira DNA from biological samples where the human genome is in vast excess. This enables deep sequencing of partial Leptospira genomes directly from clinical samples using next generation technologies and genotyping.
2022-05-23 | E-MTAB-11667 | biostudies-arrayexpress
Project description:Pathogenic Leptospira spp. are the causative agents of the zoonotic disease leptospirosis. During infection, Leptospira are confronted with deadly reactive oxygen species (ROS). Withstanding ROS produced by the host innate immunity is an important strategy evolved by pathogenic Leptospira for persisting in and colonizing hosts. The peroxide stress regulator, PerRA, represses genes involved in ROS defenses in L. interrogans. We have identified an ORF encoding a putative second PerR in pathogenic Leptospira that we named PerRB. We have determined the transcriptomic profil of a single perRB and a double perRAperRB mutants. The concomitant inactivation of perRA and perRB has a pleiotropic effect on the transcriptomic profil of L. interrogans. The lack of both PerRA and PerRB regulators led to the differential expression of several virulence-associated genes and a loss of virulence. Our findings provide new insights into a new regulatory network that controls virulence and host colonization.
2021-10-07 | GSE158051 | GEO
Project description:Leptospira are emerging zoonotic pathogens transmitted from animals to humans typically through contaminated environmental sources of water and soil. Transcriptional regulation 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° (optimal in vitro temperature) and 37°C (host temperature) and selectively enriched for 5' ends of native transcripts. Primary TSS (pTSS) was identified for 2,865 genes, accounting for 67% of the total genome. The majority of the TSSs were located between 0 to 10 nucleotides from the translational start site. Comparative 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 E. coli model. RNA sequencing also identified 277 and 226 putative small regulatory RNAs (sRNAs) at 30°C and 37°C, respectively, including 8 validated sRNAs by Northern blots. These results provide the first global view of transcriptional start sites and the repertoire of sRNAs in L. interrogans, and will establish a foundation for future experimental work on gene regulation under various environmental conditions including those in the host.
2017-01-23 | GSE92976 | GEO
Project description:Transmission of leptospirosis requires that the spirochete pathogen adapts rapidly to the mammalian host milieu during infection and the external environment upon shedding from the renal tubules of animal reservoirs. The pathogenic Leptospira genomes encode a notably large number (≥76) of putative two-component system (TCS) proteins, which presumably play a key role in switching the ecological niches. Yet to date, the regulatory networks that govern virulence and environmental adaptation have not been elucidated in Leptospira. We identified seven ORFs encoding putative TCS proteins that are exclusively conserved in all the pathogenic Leptospira species. Two of these ORFs (LMANv2_670020, LMANv2_670019), juxtaposed in an operon, are predicted to encode a cytoplasmic hybrid histidine kinase and response regulator. Corresponding transposon mutants ΔlvrA/B and ΔlvrB demonstrated a loss-of-virulence in a hamster model of leptospirosis and aberrant motility phenotype. RNA sequencing revealed the differential expression of transcripts on a global scale in ΔlvrA/B (8.13%), ΔlvrB (5.06%) and ΔlvrA/B∩ΔlvrB (8.24%). In vitro transcriptomes provided insights into the role of Lvr dyad in regulating virulence, motility, signal transduction and metabolism related genes. Phosphotransfer assays indicated that LvrA interacts with LvrB in a branched signaling pathway. Phylogenetic analyses indicated that Our findings suggest that a novel, hybrid two-component system Lvr plays a key role in governing virulence and mediating global regulation in pathogenic Leptospira.
2018-04-04 | GSE79107 | GEO
Project description:Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with .10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil’s) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of ‘‘core’’ housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaption, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants. Transcriptome analysis of L. interrogans Copenhageni FIOCRUZ L1-130 using RNA from 2 different conditions using RNA-seq. Also, the reproducibility and robustness of data is ensured by three biological replicates from each condition.
2014-03-20 | E-GEOD-53818 | biostudies-arrayexpress
Project description:Pathogenic Leptospira spp. are the causative agents of the zoonotic disease leptospirosis. During infection, Leptospira are confronted with deadly reactive oxygen species (ROS). Withstanding ROS produced by the host innate immunity is an important strategy evolved by pathogenic Leptospira for persisting in and colonizing hosts. The peroxide stress regulator, PerR, represses genes involved in ROS defenses in L. interrogans. We have performed RNA sequencing in WT and perR mutant strains to characterize the L. interrogans adaptive response to hydrogen peroxide. We showed that Leptospira solicit three main peroxidase machineries (catalase, cytochrome C peroxidase and peroxiredoxin) and heme to adapt to peroxide stress as well as canonical chaperones of the heat shock response, and DNA repair. Determining the PerR regulon allowed to identify the PerR-dependent mechanisms of the peroxide adaptive response and has revealed a regulatory network involving other transcriptional regulators, two-component systems and sigma factors as well as non-coding RNAs that putatively orchestrate, in concert with PerR, this adaptive response. Our findings provide comprehensive insight into the mechanisms required by pathogenic Leptospira to overcome infection-related oxidants. This will participate in framing future hypothesis-driven studies to identify and decipher novel virulence mechanisms.
2020-09-22 | GSE140019 | GEO
Project description:Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with .10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil’s) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of ‘‘core’’ housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaption, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants.
2014-03-20 | GSE53818 | GEO