Bacteriophage phi297--the new species of temperate phages Pseudomonas aeruginosa with a mosaic genome: potential use in phagotherapy

The genome of halo-forming temperate Pseudomonas aeruginosa phage phi297 and lytic activity of its virulent mutant were studied. A mosaic structure was revealed for phi297 genome by its complete sequencing. The phi97 genome was partly homologous to the genomes of phages D3 and F116. High lytic activity was assumed for temperate P. aeruginosa bacteriophage phi297 on the basis of morphological features of negative colonies. Virulent mutant phi297vir, which was capable oflysing bacteria, while the wild-type phage induced lysogeny, was isolated. Lytic activity was compared for phi297 and the phages from commercial mixtures of two manufacturers (facilities of Nizhnii Novgorod and Perm'). Phage phi297 caused lysis of the mutant PAO1 bacteria that were resistant to the phages from commercial preparations, but the lystic activity spectrum of phi297 was narrower that the spectra of the commercial phages. The use of nonreverting virulent mutants of certain temperate bacteriophages was proposed for the treatment of P. aeruginosa infections.     

<Emphasis Type=Italic>Pseudomonas aeruginosa</Emphasis> inhibits <Emphasis Type=Italic>in-vitro Candida</Emphasis> biofilm development

Background  

Elucidation of the communal behavior of microbes in mixed species biofilms may have a major impact on understanding infectious diseases and for the therapeutics. Although, the structure and the properties of monospecies biofilms and their role in disease have been extensively studied during the last decade, the interactions within mixed biofilms consisting of bacteria and fungi such as Candida spp. have not been illustrated in depth. Hence, the aim of this study was to evaluate the interspecies interactions of Pseudomonas aeruginosa and six different species of Candida comprising C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis, and C. dubliniensis in dual species biofilm development.     

Submolecular unfolding units of <Emphasis Type=Italic>Pseudomonas aeruginosa</Emphasis> cytochrome <Emphasis Type=Italic>c</Emphasis>-551

Hydrogen exchange rates for backbone amide protons of oxidized Pseudomonas aeruginosa cytochrome c-551 (P. aeruginosa cytochrome c) have been measured in the presence of low concentrations of the denaturant guanidine hydrochloride. Analysis of the data has allowed identification of submolecular unfolding units known as foldons. The highest-energy foldon bears similarity to the proposed folding intermediate for P. aeruginosa cytochrome c. Parallels are seen to the foldons of the structurally homologous horse cytochrome c, although the heme axial methionine-bearing loop has greater local stability in P. aeruginosa cytochrome c, in accord with previous folding studies. Regions of low local stability are observed to correspond with regions that interact with redox partners, providing a link between foldon properties and function. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Genome instability of <Emphasis Type=Italic>Pseudomonas aeruginosa</Emphasis> phages of the EL species: Examination of virulent mutants

The article continues a study of pseudolysogeny in Pseudominas aeruginosa infected with phiKZ-like phages of the EL species. Analysis was performed for several newly isolated vir mutants of EL phages (EL and RU) that were virulent (capable of causing lysis of bacteria infected with the wild-type phage) and a lower extent of opalescence of negative colonies (NCs). Wile-type recombinants were detected in crosses of virulent mutants of phages EL and RU to confirm the polygenic control of virulence. Since a deletion mutation was found in one of the virulent EL mutants and high genetic instability was characteristic of another mutant, a mobile genetic element was assumed to play a role in mutagenesis. Pseudolysogeny of bacteria provides for horizontal gene transfer between different bacterial strains. Hence, sequencing of the phage genome and demonstration of the lack of toxic gene products are insufficient for the phage to be included into a therapeutic mixture. To use live phages, it is essential to study in detail the possible consequences of their interaction with host bacteria.     

<Emphasis Type=Italic>Boletus kermesinus</Emphasis>, a new species of <Emphasis Type=Italic>Boletus</Emphasis> section <Emphasis Type=Italic>Luridi</Emphasis> from central Honshu,Japan

Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of dark-red basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely lacerate-rimose with age.     

<Emphasis Type=Italic>Chrysosporium speluncarum</Emphasis>, a new species resembling <Emphasis Type=Italic>Ajellomyces capsulatus,</Emphasis> obtained from bat guano in caves of temperate Europe

A new species, Chrysosporium speluncarum, obtained from bat guano in caves in the Czech Republic, Slovakia, and Romania, is described, based on phenotype and rDNA sequences. It possesses tuberculate conidia similar to the Histoplasma anamorph of Ajellomyces capsulatus, but it is not dimorphic, does not grow at 37°C, lacks microconidia, and is nonpathogenic and nonkeratinolytic. All studied characteristics suggest a close relationship with Renispora flavissima. The morphologically similar C. chiropterorum, another species known from the bat environment, is a relative of C. lobatum and Polytolypa hystricis, but is distinct from A. capsulatus and C. speluncarum. The affinity for bats and the presence of conidia with prominent tuberculations has originated convergently in several groups of onygenalean fungi. In addition, the occurrence of fungi mimicking A. capsulatus in caves of temperate Europe is reviewed.     

<Emphasis Type=Italic>Cantharellus pseudoformosus</Emphasis>, a new species associated with <Emphasis Type=Italic>Cedrus deodara</Emphasis> from India

The genus Cantharellus is known to have a global distribution and to form ectomycorrhizal associations with a diverse set of host plants. Here we describe Cantharellus pseudoformosus as a species new to science with a possible association with Cedrus deodara. ITS and LSU data demonstrated that the material from India is distinct from Cantharellus formosus and other closely related species.     

<Emphasis Type=Italic>Eriocaulon epedunculatum</Emphasis>, a new species of <Emphasis Type=Italic>Eriocaulaceae</Emphasis> from the Western Ghats,India

Summary  A new species of Eriocaulon, E. epedunculatum (Eriocaulaceae) is described and illustrated from the Western Ghats, India.     

A new species of <Emphasis Type=Italic>Cortinarius</Emphasis> sect. <Emphasis Type=Italic>Orellani</Emphasis> from Japan

Cortinarius breviradicatus sp. nov., found in deciduous forests, is described and illustrated from Niigata, Japan. It is characterized by its medium-sized to large dark brown basidiocarp, acutely conical pileus, and rooting stipe, and by subglobose to broadly ellipsoid basidiospores. In addition, the extracting solution from its basidiocarps exhibits a strong fluorescence around 400–430 nm in ultraviolet radiation (250 nm), which was observed in a species of Cortinarius sect. Orellani. The new species belongs to the section Orellani. The differences between the new taxon and similar species are briefly discussed.     

<Emphasis Type=Italic>Barleria compacta</Emphasis>: a new species in <Emphasis Type=Italic>Barleria</Emphasis> sect. <Emphasis Type=Italic>Prionitis</Emphasis> (Acanthaceae) from Somalia

Following a re-examination of the material treated under Barleria brevispina (Fiori) Hedrén in the recent Flora of Somalia account of the Acanthaceae, it is concluded that two distinct species are involved and Barleria compacta Malombe & I. Darbysh. is described here from north-eastern Somalia. Its affinities and conservation status are discussed.     

Mineralization of metanilic acid by <Emphasis Type=Italic>Pseudomonas aeruginosa</Emphasis> CLRI BL22

Pseudomonas aeruginosa CLRI BL22 was able to degrade metanilic acid, a sulfonated aromatic amine upto a concentration of 1,500 mg l⁻¹. The degradation of metanilic acid started when the organism reached its exponential growth phase. Chromatographic and spectrophotometric analyses confirmed the presence of aniline and β-keto adipic acid indicating the ortho pathway reaction. Further proof for this pathway was provided by dioxygenase activity of the strain grown in the medium containing metanilic acid and glucose.     

Manipulating the <Emphasis Type=Italic>Caenorhabditis elegans</Emphasis> genome using <Emphasis Type=Italic>mariner</Emphasis> transposons

Tc1, one of the founding members of the Tc1/mariner transposon superfamily, was identified in the nematode Caenorhabditis elegans more than 25 years ago. Over the years, Tc1 and other endogenous mariner transposons became valuable tools for mutagenesis and targeted gene inactivation in C. elegans. However, transposition is naturally repressed in the C. elegans germline by an RNAi-like mechanism, necessitating the use of mutant strains in which transposition was globally derepressed, which causes drawbacks such as uncontrolled proliferation of the transposons in the genome and accumulation of background mutations. The more recent mobilization of the Drosophila mariner transposon Mos1 in the C. elegans germline circumvented the problems inherent to endogenous transposons. Mos1 transposition strictly depends on the expression of the Mos transposase, which can be controlled in the germline using inducible promoters. First, Mos1 can be used for insertional mutagenesis. The mobilization of Mos1 copies present on an extrachromosomal array results in the generation of a small number of Mos1 genomic insertions that can be rapidly cloned by inverse PCR. Second, Mos1 insertions can be used for genome engineering. Triggering the excision of a genomic Mos1 insertion causes a chromosomal break, which can be repaired by transgene-instructed gene conversion. This process is used to introduce specific changes in a given gene, such as point mutations, deletions or insertions of a tag, and to create single-copy transgenes.     

<Emphasis Type=Italic>Gagea robusta</Emphasis> (Liliaceae), a new species from <Emphasis Type=Italic>Flora Iranica</Emphasis> area

A new species, endemic to the Flora Iranica area, Gagea robusta (Liliaceae) is described and illustrated. It differs from G. reticulata (Pall.) Schult. & Schult. f. in having a puberulent indumentum on the basal leaf and from G. setifolia Baker ex Aitch. in having a long neck (up to 12 cm long). Its ecology, distribution and conservation status are discussed.     

<Emphasis Type=Italic>Psychotria kupensis</Emphasis> (<Emphasis Type=Italic>Rubiaceae</Emphasis>) a new dwarf,litter-gathering species from western Cameroon

Summary   Psychotria kupensis Cheek is described as a new species in Psychotria sect. Confertiflorae Hiern. Attention is drawn to its monopodial, dwarf, litter-gathering and adventitious root-forming habit and to its anomalous stipules. The species appears to be endemic to the submontane evergeen forest of Mt Kupe in Cameroon. Its conservation status is assessed.     

<Emphasis Type=Italic>Hyptis maya</Emphasis>, a new species of <Emphasis Type=Italic>Lamiaceae</Emphasis> from Belize,Central America,and the closely related <Emphasis Type=Italic>H. lanceolata</Emphasis>

A new species of Lamiaceae from Belize: Hyptis maya is described and illustrated. It is closely related to the more widespread H. lanceolata Poir., with which it is compared.