Heterologous Production of 1-Tuberculosinyladenosine in Mycobacterium kansasii Models Pathoevolution towards the Transcellular Lifestyle of Mycobacterium tuberculosis

ABSTRACT Mycobacterium kansasii is an environmental nontuberculous mycobacterium that causes opportunistic tuberculosis-like disease. It is one of the most closely related species to the Mycobacterium tuberculosis complex. Using M. kansasii as a proxy for the M. kansasii-M. tuberculosis common ancestor, we asked whether introducing the M. tuberculosis-specific gene pair Rv3377c-Rv3378c into M. kansasii affects the course of experimental infection. Expression of these genes resulted in the production of an adenosine-linked lipid species, known as 1-tuberculosinyladenosine (1-TbAd), but did not alter growth in vitro under standard conditions. Production of 1-TbAd enhanced growth of M. kansasii under acidic conditions through a bacterial cell-intrinsic mechanism independent of controlling pH in the bulk extracellular and intracellular spaces. Production of 1-TbAd led to greater burden of M. kansasii in the lungs of C57BL/6 mice during the first 24 h after infection, and ex vivo infections of alveolar macrophages recapitulated this phenotype within the same time frame. However, in long-term infections, production of 1-TbAd resulted in impaired bacterial survival in both C57BL/6 mice and Ccr2−/− mice. We have demonstrated that M. kansasii is a valid surrogate of M. tuberculosis to study virulence factors acquired by the latter organism, yet shown the challenge inherent to studying the complex evolution of mycobacterial pathogenicity with isolated gene complementation. IMPORTANCE This work sheds light on the role of the lipid 1-tuberculosinyladenosine in the evolution of an environmental ancestor to M. tuberculosis. On a larger scale, it reinforces the importance of horizontal gene transfer in bacterial evolution and examines novel models and methods to provide a better understanding of the subtle effects of individual M. tuberculosis-specific virulence factors in infection settings that are relevant to the pathogen

Comparative analysis of mycobacterium and related actinomycetes yields insight into the evolution of mycobacterium tuberculosis pathogenesis

<p>Abstract</p> <p>Background</p> <p>The sequence of the pathogen <it>Mycobacterium tuberculosis </it>(<it>Mtb</it>) strain <it>H37Rv </it>has been available for over a decade, but the biology of the pathogen remains poorly understood. Genome sequences from other <it>Mtb </it>strains and closely related bacteria present an opportunity to apply the power of comparative genomics to understand the evolution of <it>Mtb </it>pathogenesis. We conducted a comparative analysis using 31 genomes from the Tuberculosis Database (TBDB.org), including 8 strains of <it>Mtb </it>and <it>M. bovis</it>, 11 additional Mycobacteria, 4 Corynebacteria, 2 Streptomyces, <it>Rhodococcus jostii RHA1, Nocardia farcinia, Acidothermus cellulolyticus, Rhodobacter sphaeroides, Propionibacterium acnes</it>, and <it>Bifidobacterium longum</it>.</p> <p>Results</p> <p>Our results highlight the functional importance of lipid metabolism and its regulation, and reveal variation between the evolutionary profiles of genes implicated in saturated and unsaturated fatty acid metabolism. It also suggests that DNA repair and molybdopterin cofactors are important in pathogenic Mycobacteria. By analyzing sequence conservation and gene expression data, we identify nearly 400 conserved noncoding regions. These include 37 predicted promoter regulatory motifs, of which 14 correspond to previously validated motifs, as well as 50 potential noncoding RNAs, of which we experimentally confirm the expression of four.</p> <p>Conclusions</p> <p>Our analysis of protein evolution highlights gene families that are associated with the adaptation of environmental Mycobacteria to obligate pathogenesis. These families include fatty acid metabolism, DNA repair, and molybdopterin biosynthesis. Our analysis reinforces recent findings suggesting that small noncoding RNAs are more common in Mycobacteria than previously expected. Our data provide a foundation for understanding the genome and biology of <it>Mtb </it>in a comparative context, and are available online and through TBDB.org.</p

Mycobacterium tuberculosis releases an antacid that remodels phagosomes

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<span style="font-size: 20.5pt;mso-bidi-font-size:13.5pt;font-family:"Times New Roman","serif"">Growth of AM fungion <i><span style="font-size:21.0pt;mso-bidi-font-size:14.0pt; font-family:"Times New Roman","serif"">in vitro </span></i><span style="font-size:20.5pt;mso-bidi-font-size:13.5pt;font-family:"Times New Roman","serif"">root organ culture of <i><span style="font-size:21.0pt;mso-bidi-font-size: 14.0pt;font-family:"Times New Roman","serif"">Sorghum vulgare </span></i><span style="font-size:20.5pt;mso-bidi-font-size:13.5pt;font-family:"Times New Roman","serif"">and <i><span style="font-size:21.0pt;mso-bidi-font-size:14.0pt;font-family: "Times New Roman","serif"">Saccharum, officinarum</span></i> </span></span></span>

1293-1298<span style="font-size: 15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""="">Spores of Gl mosseae and Gig gigantea germinated on minimal medium produced extraradical mycelium. Gl. Mosseae infected roots of S. officinarum in <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">in <span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;font-family: " times="" new="" roman","serif""="">vitro <span style="font-size:15.5pt; mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif""="">condition were inoculated in M medium with in vitro cultured roots of Sorghum vulgare (test roots). From the infected root of <span style="font-size:15.5pt; mso-bidi-font-size:8.5pt;font-family:" arial","sans-serif""="">S. officinarum , <span style="font-size:15.5pt;mso-bidi-font-size:8.5pt;font-family: " times="" new="" roman","serif""="">the mycelium developed and it infected the test roots. The roots developed new mycelia and further the mycelia produced a few hyaline spores. In MS medium combined with soil extract, root exudate, thiamine HCI and inositol combination, spore germination and germ tube growth were higher when compared with other media. </span

Influence of Ni and Sn Perovskite NiSn(OH)₆ Nanoparticles on Energy Storage Applications

New NiSn(OH)6 hexahydroxide nanoparticles were synthesised through a co-precipitation method using various concentrations of Ni2+ and Sn4+ ions (e.g., 1:0, 0:1, 1:2, 1:1, and 2:1; namely, N, S, NS-3, NS-2, and NS-1) with an ammonia solution. The perovskite NiSn(OH)6 was confirmed from powder X-ray diffraction and molecule interactions due to different binding environments of Ni, Sn, O, and water molecules observed from an FT-IR analysis. An electronic transition was detected from tin (Sn 3d) and nickel (Ni 2p) to oxygen (O 2p) from UV-Vis/IR spectroscopy. Photo luminescence spectroscopy (PL) identified that the emission observed at 400–800 nm in the visible region was caused by oxygen vacancies due to various oxidation states of Ni and Sn metals. A spherical nanoparticle morphology was observed from FE-SEM; this was due to the combination of Ni2+ and Sn4+ increasing the size and porosity of the nanoparticle. The elemental (Ni and Sn) distribution and binding energy of the nanoparticle were confirmed by EDAX and XPS analyses. Among the prepared various nanoparticles, NS-2 showed a maximum specific capacitance of 607 Fg−1 at 1 Ag−1 and 56% capacitance retention (338 Fg−1 and 5 Ag−1), even when increasing the current density five times, and excellent cycle stability due to combining Ni2+ with Sn4+, which improved the ionic and electrical conductivity. EIS provided evidence for NS-2’s low charge transfer resistance compared with other prepared samples. Moreover, the NS-2//AC (activated carbon) asymmetric supercapacitor exhibited the highest energy density and high-power density along with excellent cycle stability, making it the ideal material for real-time applications

Mycobacterium tuberculosis SigM Positively Regulates Esx Secreted Protein and Nonribosomal Peptide Synthetase Genes and Down Regulates Virulence-Associated Surface Lipid Synthesis

The Mycobacterium tuberculosis genome encodes 12 alternative sigma factors, several of which regulate stress responses and are required for virulence in animal models of acute infection. In this work we investigated M. tuberculosis SigM, a member of the extracytoplasmic function subfamily of alternative sigma factors. This sigma factor is expressed at low levels in vitro and does not appear to function in stress response regulation. Instead, SigM positively regulates genes required for the synthesis of surface or secreted molecules. Among these are genes encoding two pairs of Esx secreted proteins, a multisubunit nonribosomal peptide synthetase operon, and genes encoding two members of the proline-proline-glutamate (PPE) family of proteins. Genes up regulated in a sigM mutant strain include a different PPE gene, as well as several genes involved in surface lipid synthesis. Among these are genes involved in synthesis of phthiocerol dimycocerosate (PDIM), a surface lipid critical for virulence during acute infection, and the kasA-kasB operon, which is required for mycolic acid synthesis. Analysis of surface lipids showed that PDIM synthesis is increased in a sigM-disrupted strain and is undetectable in a sigM overexpression strain. These findings demonstrate that SigM positively and negatively regulates cell surface and secreted molecules that are likely to function in host-pathogen interactions