Leptospira interrogans serovar Lai str. IPAV
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PROVIDER: PRJNA32553 | ENA |
REPOSITORIES: ENA
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Project description:Abstract Leptospirosis is one of the most important zoonoses. Leptospira interrogans serovar Lai is a pathogenic spirochete that is responsible for leptospirosis. Extracellular proteins play an important role in the pathogenicity of this bacterium. In this study, L. interrogans serovar Lai was grown in protein-free medium; the supernatant was collected and subsequently analyzed as the extracellular proteome. A total of 66 proteins with more than two unique peptides were detected by MS/MS, and 33 of these were predicted to be extracellular proteins by a combination of bioinformatics analyses, including Psortb, cello, SoSuiGramN and SignalP. Comparisons of the transcriptional levels of these 33 genes between in vivo and in vitro conditions revealed that 15 genes were upregulated and two genes were downregulated in vivo compared to in vitro. A BLAST search for the components of secretion system at the genomic and proteomic levels revealed the presence of the complete type I secretion system and type II secretion system in this strain. Moreover, this strain also exhibits complete Sec translocase and Tat translocase systems. The extracellular proteome analysis of L. interrogans will supplement the previously generated whole proteome data and provide more information for studying the functions of specific proteins in the infection process and for selecting candidate molecules for vaccines or diagnostic tools for leptospirosis.
| S-EPMC3783971 | biostudies-literature
Project description:Regulatory small RNAs (sRNA) are RNA transcripts that are not translated into proteins but act as functional RNAs. Pathogenic Leptospira cause an epidemic spirochaetal zoonosis, Leptospirosis. It is speculated that Leptospiral sRNAs are involved in orchestrating their pathogenicity. In this study, biocomputational approach was adopted to identify Leptospiral sRNAs. In this study, two sRNA prediction programs, i.e., RNAz and nocoRNAc, were employed to screen the reference genome of Leptospira interrogans serovar Lai. Out of 126 predicted sRNAs, there are 96 cis-antisense sRNAs, 28 trans-encoded sRNAs and 2 sRNAs that partially overlap with protein-coding genes in a sense orientation. To determine whether these candidates are expressed in the pathogen, they were compared with the coverage files generated from our RNA-seq datasets. It was found out that 7 predicted sRNAs are expressed in mid-log phase, stationary phase, serum stress, temperature stress and iron stress while 2 sRNAs are expressed in mid-log phase, stationary phase, serum stress, and temperature stress. Besides, their expressions were also confirmed experimentally via RT-PCR. These experimentally validated candidates were also subjected to mRNA target prediction using TargetRNA2. Taken together, our study demonstrated that biocomputational strategy can serve as an alternative or as a complementary strategy to the laborious and expensive deep sequencing methods not only to uncover putative sRNAs but also to predict their targets in bacteria. In fact, this is the first study that integrates computational approach to predict putative sRNAs in L. interrogans serovar Lai.Supplementary informationThe online version contains supplementary material available at 10.1007/s12088-022-01050-9.
| S-EPMC10172424 | biostudies-literature
Project description:Leptospira interrogans serovar Lai str. Lai Genome sequencing and assembly
| PRJNA74197 | ENA
Project description:Many microorganisms, as well as plants and fungi, synthesize thiamin, but vertebrates do not produce it. Phosphomethyl pyrimidine kinase is an enzyme involved in an intermediary step of thiamin biosynthesis from purine molecules. This enzyme is absent in humans. Thus, it is a potential chemotherapeutic target for antileptospiral treatment. Structure of this enzyme from Leptospira interrogans serovar lai strain 56601 has not yet been elucidated. We used the structural template of phosphomethyl pyrimidine kinase from Thermus thermophilus HB8 for modeling the phosphomethyl pyrimidine kinase structure from Leptospira interrogans serovar lai strain 56601 . The model is deposited in Protein Data Bank (PDB ID: 2G53) at RCSB. Thus, we analyse and propose the usefulness of the modeled phosphomethyl pyrimidine kinase for the design of suitable inhibitors towards the treatment of leptospirosis.
| S-EPMC1891682 | biostudies-literature
Project description:An examination of the two Leptospira interrogans genomes sequenced so far reveals few genetic differences, including an extra DNA region, 54 kb in length, in L. interrogans serovar Lai. This locus contains 103 predicted coding sequences that are absent from the genome of L. interrogans serovar Copenhageni, of which only 20% had significant BLASTP hits in GenBank. By analyzing the L. interrogans serovar Lai genome by pulsed-field gel electrophoresis, we also found that this 54-kb DNA fragment exists as a circular plasmid. This was confirmed by amplification of a DNA fragment corresponding to that of the predicted fragment if this region excised from the chromosome and its left and right ends joined together. In addition, cloning of the putative rep gene of this DNA region was responsible for autonomous replication in Leptospira spp., therefore generating a new Escherichia coli-Leptospira sp. shuttle vector. Taken together, our results show that this genomic island can excise from the chromosome and form a replicative plasmid. Analysis of the distribution of this genomic island revealed that highly related sequences exist in other L. interrogans virulent strains. This genomic island, containing a high proportion of novel genes, may have an important role in spreading genes, including virulence factors, among bacterial populations.
| S-EPMC1828511 | biostudies-literature
Project description:Causes leptospirosis
| PRJNA293 | ENA
Project description:Leptospira interrogans serovar Lai str. Langkawi Genome sequencing and assembly
| PRJNA74201 | ENA
Project description:In an earlier study, based on the ferric enterobactin receptor FepA of Escherichia coli, we identified and modeled a TonB-dependent outer membrane receptor protein (LB191) from the genome of Leptospira interrogans serovar Lai. Based on in silico analysis, we hypothesized that this protein was an iron-dependent hemin-binding protein. In this study, we provide experimental evidence to prove that this protein, termed HbpA (hemin-binding protein A), is indeed an iron-regulated hemin-binding protein. We cloned and expressed the full-length 81-kDa recombinant rHbpA protein and a truncated 55-kDa protein from L. interrogans serovar Lai, both of which bind hemin-agarose. Assay of hemin-associated peroxidase activity and spectrofluorimetric analysis provided confirmatory evidence of hemin binding by HbpA. Immunofluorescence studies by confocal microscopy and the microscopic agglutination test demonstrated the surface localization and the iron-regulated expression of HbpA in L. interrogans. Southern blot analysis confirmed our earlier observation that the hbpA gene was present only in some of the pathogenic serovars and was absent in Leptospira biflexa. Hemin-agarose affinity studies showed another hemin-binding protein with a molecular mass of approximately 44 kDa, whose expression was independent of iron levels. This protein was seen in several serovars, including nonpathogenic L. biflexa. Sequence analysis and immunoreactivity with specific antibodies showed this protein to be LipL41.
| S-EPMC1951163 | biostudies-literature
Project description:Leptospira interrogans serovar Lai str. Lai LPS mutant Genome sequencing and assembly
| PRJNA74199 | ENA
Project description:Leptospirosis is an important zoonosis of worldwide distribution. Humans become infected via exposure to pathogenic Leptospira spp. from infected animals or contaminated water or soil. The availability of genome sequences for Leptospira interrogans, serovars Lai and Copenhageni, has opened up opportunities to examine global transcription profiles using microarray technology. Temperature is a key environmental factor known to affect leptospiral protein expression. Leptospira spp. can grow in artificial media at a range of temperatures reflecting conditions found in the environment and the mammalian host. Therefore, transcriptional changes were compared between cultures grown at 20 degrees C, 30 degrees C, 37 degrees C, and 39 degrees C to represent ambient temperatures in the environment, growth under laboratory conditions, and temperatures in healthy and febrile hosts. Data from direct pairwise comparisons of the four temperatures were consolidated to examine transcriptional changes at two generalized biological conditions representing mammalian physiological temperatures (37 degrees C and 39 degrees C) versus environmental temperatures (20 degrees C and 30 degrees C). Additionally, cultures grown at 30 degrees C then shifted overnight to 37 degrees C were compared with those grown long-term at 30 degrees C and 37 degrees C to identify genes potentially expressed in the early stages of infection. Comparison of data sets from physiological versus environmental experiments with upshift experiments provided novel insights into possible transcriptional changes at different stages of infection. Changes included differential expression of chemotaxis and motility genes, signal transduction systems, and genes encoding proteins involved in alteration of the outer membrane. These findings indicate that temperature is an important factor regulating expression of proteins that facilitate invasion and establishment of disease.
| S-EPMC1594916 | biostudies-literature