Project description:A total of 25 modifications were mapped to 16S and 23S RNA in B. subtilis ribosome, however most of the genes responsible for these modification sites remain unknown. In this work, bottom-up oligonucleotide LC-MS/MS was used to detect rRNA modifications in five single gene knock-out strains: yydA, yhcT, yjbO, ylyB, yqxC. By comparing oligonucleotide modification states between the background 168 strain (annotated as WT) and the mutants: ylyB was confirmed to be a pseudouridine synthase at positions 1940, 1944, 1946 of 23S; yydA is a N3-pseudouridine methyltransferase at 1944 of 23S; and yqxC is a dual 2’O-cytidine methyltransferase at 1417 of 16S and 1949 of 23S. Deletion of yhcT or yjbO does not change rRNA modification pattern.
Project description:Leptospirosis is a globally significant zoonotic disease caused by Leptospira spp. Iron is essential for growth of most bacterial species. Since availability of iron is low in the host, pathogens have evolved complex iron acquisition mechanisms to survive and establish infection. Virulence genes in some bacteria have been shown to be iron-regulated. In many bacteria, expression of iron-uptake and storage proteins is regulated by Fur. L. interrogans encodes four predicted Fur homologs; we have constructed a mutant in one of these, la1857. We conducted microarray analysis to identify differentially expressed genes in L. interrogans serovar Manilae grown under low iron compared with normal iron conditions found in EMJH medium. We also compared the transcriptional profile of the la1857 mutant versus wild-type Manilae under normal and low iron conditions. Analysis used RNA derived from L. interrogans serovar Manilae grown under low iron (EMJH medium + 40 µM 2,2-dipyridyl) and normal iron as experimental and control samples, respectively. We have a serovar Manilae mutant in la1857, one of four predicted fur homologs. The mutant was also grown under low iron and normal iron conditions and compared with wild-type Manilae grown under low and normal iron conditions respectively. Three independent RNA samples (biological replicates) from parent and mutant strains grown with or without 2,2-dipyridyl were compared in a loop design resulting in 12 arrays. The orientation of Cy3 to Cy5 labeling was the same for replicates 1 and 3, while replicate 2 was a dye swap. Direct comparisons were made between arrays of experimental and control samples using raw data pulled from two different channels for data analysis. Data from wild-type Manilae grown under low iron versus normal iron and mutant versus wild-type under normal iron conditions is reported in the manuscript.
Project description:RNA-seq analysis to assess the effect of different drugs (34503, 36009, 34503, 36018, Moxi) on Mycobacterium tuberculosis compared to untreated control cells (DMSO).
Project description:Leptospira, the causative agent of leptospirosis is known to have several proteases with potential to degrade extracellular matrix. However, a multipronged approach to identify, classify, characterize and elucidate their role has not been attempted. In this study, we carried out in-depth proteomic analysis of Triton X-114 fractions of Leptospirainterrogansusing high-resolution LC-MS/MS. Our analysis resulted in the identification of We have identified 2957 proteins that account 80.6% proteins of Leptospira and their subcellular distribution. The analysis showed differential enrichment of proteins in aqueous, detergent and pellet fractions with respect to the subcellular localization predicted by on CELLO v.2.5. It is found that highest number of OMP and pathogenic protein species were found in aqueous and pellet representing the cytoplasm and inner membranewhile the detergent fraction representing the OM contain highest amount of OMPs and pathogenic proteins even though the number of protein species were less. Thus the higher number of OMP and pathogenic proteins in the inner compartments of the cell carry the possibility of their deployment on the OM in abundance under pathogenic conditions.
Project description:Ribonucleases (RNases) are central actors in post-transcriptional regulation, a major level of regulation of gene expression in all cells. This control plays an important role in the bacterial pathogen Helicobacter pylori, although only the function of RNase J was characterized so far. Here, we studied the RNase R enzyme from H. pylori, a 3’-5’ exoribonuclease whose ortholog in Escherichia coli was reported to display, in addition, helicase activity and to be able to hydrolyze RNA substrates with double stranded structures. We observed that HpRNase R protein does not carry the domains responsible for helicase activity in E. coli and accordingly that the purified protein is unable to degrade in vitro RNA molecules with secondary structures. The RNase R helicase domain loss is widespread among the Campylobacterota and occurred gradually during their evolution. Furthermore, an in vivo interaction between HpRNase R and RhpA, the sole DEAD-box RNA helicase of H. pylori, was discovered. Phylogenomics suggests that this interaction might occur in other bacteria of the phylum Campylobacterota. Purified RhpA facilitates the degradation of double stranded RNA substrates by HpRNase R, showing that this complex is functional. HpRNase R has a minor role of in 5S rRNA maturation and, as shown by RNA-Seq, few targets in H. pylori all of them being included in the RhpA regulon. In conclusion, we describe a new type of RNase R that lacks some of the features that were considered as hallmarks of RNase R proteins, but that has co-opted another RNA helicase, which we hypothesize helps it accomplish some of its functions in vivo.
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.
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses.
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses.
Project description:Differential gene expression analysis of Leptospirillum ferriphilum DSM 14647 cells treated with quorum sensing singnal compounds. Briefly, Leptospirillum ferriphilum DSM 14647 cells were grown to early stationary phase in Mackintosh basal salt solution (Mac medium) pH 1.8 (Mackintosh 1978) with 71.6 mM Fe2+ (supplied as FeSO4•7H2O). Cultures were incubated under constant shaking at 140 rpm and 37 °C. Cells were harvested by centrifugation (7.000 g, 10 min). Subsequently cells were inoculated at 10^8 cells/mL in 100 mL Erlenmeyer flasks with 50 mL Mac medium (pH 1.8) and amended with combined DSF (cis-11-methyl-2-dodecenoic acid, CAS 677354-23-3; Sigma) and BDSF (cis-2-dodecenoic acid, CAS 55928-65-9; Sigma) at 2 µM per compound or with a mixture of N-acyl-homoserine-lactones, namely N-dodecanoyl-DL-homoserine lactone (C12-AHL, CAS 8627-38-8, Sigma), N-tetradecanoyl-DL-homoserine lactone (C14-AHL, CAS 98206-80-5, Sigma), N-(3-hydroxydodecanoyl)-DL-homoserine (3-OH-C12-AHL, CAS 182359-60-0), N-(3-hydroxytetradecanoyl)-DL-homoserine lactone (3-OH-C14-AHL, CAS 172670-99-4) at 5 µM per compound. Controls were supplemented with DMSO as used as solvent for signal compound stock solutions. After inoculation 32 mM iron(II) ions were added. The assay flasks were incubated for two hours at 37 °C and 140 rpm. Assays were periodically sampled for determination of Fe2+ concentrations using the phenantroline method (Harvey, Smart et al. 1955). Within this time the inhibitory effect of DSF/BDSF on Fe2+ oxidation was confirmed and subsequently the flasks were rapidly cooled on ice and by addition of 1 volume ice-cold Mac medium (pH 1.8). The cultures (n = 4 per condition) were centrifuged at 12,500 × g for 10 min at 4° C. The cell pellet was washed twice by re-suspending in 2 mL of sterile, ice-cold Mac medium (pH 1.8) and then flash frozen in liquid nitrogen and stored at -80 °C. The nucleic acid extraction was conducted as described by (Christel, Fridlund et al. 2016) with modifications. Briefly, the cells were re-suspended in lysis buffer (0.02 % sodium acetate, 2 % sodium dodecyl sulfate, 1 mM EDTA, pH 5.5) and lysed using Tri-reagent (Ambion) and the lysate was treated with bromo-chloro propane. Nucleic acids were precipitated with isopropanol, cleaned with 80% ethanol, dried at room temperature and subsequently treated with DNAse I (Thermo Fisher Scientific®). Ribosomal RNA depletion was conducted using the QIAseq® FastSelect™ −5S/16S/23S kit for bacterial RNA samples without fragmentation. Nucleic acid quantification and quality control were assessed by agarose gel electrophoresis, NanoDrop, Qubit™ RNA HS Assay kit (Invitrogen®) and the Agilent 2100 Bioanalyzer . Libraries (12 in total) were prepared by SciLifeLab, Stockholm, Sweden using the Illumina TruSeq stranded mRNA Kit. Paired-end sequencing (2 × 151 bp) was performed on one Illumina NovaSeq6000 lane using 'NovaSeqXp' workflow in 'S4' mode flowcell. Bioinformatics and statistics The Bcl to FastQ conversion was performed using bcl2fastq_v2.20.0.422 from the CASAVA software suite. The quality scale used is Sanger / phred33 / Illumina 1.8+. at SciLifeLab, Stockholm, Sweden. The quality of the raw sequencing reads was assessed with FastQC/MultiQC (Andrews 2010, Ewels, Magnusson et al. 2016). Subsequently adapter sequences were removed using Cutadapt/TrimGalore 0.6.1 (Martin 2011, Krueger 2019). Paired-end transcript reads were mapped against the reference genome with the accession number GCA_900198525 (Christel, Herold et al. 2017) using Bowtie2 (Langmead and Salzberg 2012), sorted by their genomic location using the samtools sort function (Liao, Smyth et al. 2019) and counted using feautureCounts of the Rsubreads package (Liao et al. 2019). Raw counts were then processed for assessment of statistically significant differential gene expression with DESeq2 (Love, Huber et al. 2014) by determination of Log2-fold changes (LFC) and corresponding p-values (padj, adjusted p-values).