1000 resultados para Listeria sp
Resumo:
Hypoechinorhynchus robustus sp. n. is described from Notolabrus parilus (Richardson) (Labridae) from Pt Peron, Western Australia. It has a proboscis with 30 hooks arranged in ten longitudinal rows: 5 rows of a small apical spine, a large anterior hook and a small posterior spine, 5 rows of a large anterior hook, a middle spine and a posterior spine. The new species is distinguished from other species of the genus by having a set of 5 small apical spines anterior to the large hooks on the proboscis, by having lemnisci that barely extend beyond the proboscis receptacle and testes which are more adjacent than tandem. H. robustus also has robust trunk spines anteriorly. Re-examination of Hypoechinorhynchus alaeopis Yamaguti, 1939 (type species) revealed trunk spines that had been overlooked previously. The Hypoechinorhynchidae is made a junior synonym of Arhythmacanthidae because there is considerable overlap between the two family diagnoses, particularly in that both families have a proboscis armature that changes abruptly from small basal spines to large apical (or subapical if present) hooks. The genus Hypoechinorhynchus is placed in the subfamily Arhythmacanthinae because it has trunk spines and a spherical proboscis with few hooks (relative to other arhythmacanthid genera). It is also proposed that Heterosentis magellanicus (Szidat, 1950) be returned to the genus Hypoechinorhynchus since it was transferred to Heterosentis primarily because it had trunk spines. The other hypoechinorhynchid genus contained only Bolborhynchoides exiguus (Achmerov et Dombrowskaja-Achmerova, 1941) Achmerov, 1959 and is relegated to incertae sedis.
Resumo:
A diagnosis is given for the lecithasterid genus Hysterolecithoides Yamaguti, 1934, which is now found to have two to six (possibly seven) vitelline masses. The species H. frontilatus (Manter, 1969) is returned to the genus, having been considered a member of the bunocotylid genus Neotheletrum by recent authors. It is redescribed from Siganus nebulosus, Moreton Bay, and S. doliatus, Lizard Island, Great Barrier Reef and New Caledonia, with emphasis on the presence of Juel's organ, a uterine seminal receptacle and the blind sac associated with the genital atrium. It differs from its congeners in the trajectory of the pars prostatica which recurves dorsally to the sinus-sac. Oligolecithoides Shen, 1982 is synonymised with Hysterolecithoides and O. trilobatus Shen, 1982 is synomised with H. epinepheli Yamaguti, 1934. Machidatrema Leon-Regagnon, 1998 is diagnosed, and found to be close to Hysterolecithoides, but differs in the lack of a blind-sac projecting from the dorsal genital atrium, by its tandem testes, the coiling of the uterus between the testes and the ovary, and the ventral excretory pore. M. leonae n. sp. is described from Siganus fuscescens, S. lineatus, S. doliatus, S. corallinus, S. vulpinus and Scarus globiceps at Heron Island, Queensland. It differs from its closest congener, M. akeh, in the muscular and tegumental flap over the genital pore and details of the terminal genitalia. M. chilostoma (Machida, 1980) and M. kyphosi (Yamaguti, 1970) are redescribed from Kyphosus vaigiensis from Heron Island. Neotheletrum Gibson & Bray, 1979 is diagnosed: it differs from Hysterolecithoides in its confluent excretory arms, blind seminal receptacle (no Juel's organ) and uniformly tripartite vitellarium. A cladistic analysis suggests that M. chilostoma and M. kyphosi are not best accommodated in Machidatrema, that Machidatrema (sensu stricto) is monophyletic and that Hysterolecithoides is paraphyletic. Hysterolecithoides and Machidatrema are considered hysterolecithine lecithasterids, whilst Neotheletrum is retained as an opisthadenine bunocotylid.
Resumo:
Three species of Trifoliovarium are described from marine fishes from Moreton Bay, Queensland: T. triacanthi (Parukhin, 1964) n. comb. (syns Hysterolecitha triacanthi Parukhin, 1964; T. triacanthi Bilqees, 1973; T. triacanthusi Gupta & Ahmad, 1976) from Tripodichthys angustifrons; T. ovarilobulus (Wang, 1989) n. comb. (syn. Hysterolecithia[sic]ovarilobulus) from Paramonacanthus japonicus and Pelates quadrilineatus; and T. draconis n. sp. from Callionymus sublaevis and C. belcheri. A list of the species of the subfamily Trifoliovariinae is given along with a key. A cladistic study of the subfamily based on 23 characters is presented, the results of which indicate the monophyly of the genus Assitrema and the paraphyly of Trifoliovarium.
Resumo:
Genetic variation among Australian isolates of the fungus Fusarium oxysporum f. sp. cubense (Foc), which causes Fusarium wilt in banana, was examined using DNA amplification fingerprinting (DAF). Ninety-four isolates which represented Races 1, 2, 3, and 4, and vegetative compatibility groups (VCGs) 0120, 0124, 0125, 0128, 0129, 01211, 01213/16, and 01220 were analysed. The genetic relatedness among isolates within each VCG, and between the 8 different VCGs of Foc present in Australia was determined. The DNA fingerprint patterns were VCG-specific, with each VCG representing a unique genotype. The genetic similarity among isolates within each VCG ranged from 97% to 100%. Among the different VCGs of Foc, 3 major clusters were distinguished which corresponded with race. All Race 1 and 2 isolates (VCGs 0124, 0125, 0128, and 01220) were closely related and clustered together, the Race 3 isolates from Heliconia clustered separately, and all Race 4 isolates (VCGs 0120, 0129, 01211, and 01213/16) clustered together. Fifteen isolates from Alstonville, NSW, were characterised because although they were classified as Race 2 based on their recovery from cooking banana cultivars, they belonged in VCG 0124, which had previously contained only Race 1 isolates. The occurrence of more than one race within a VCG means that vegetative compatibility grouping cannot be used to assign pathotype to pathogenic race as previously thought. It was possible to distinguish the Race 1 and Race 2 isolates within VCG 0124 using DNA fingerprinting, as each race produced a unique DNA fingerprint pattern. Among the Australian isolates, DNA fingerprinting analysis identified 9 different VCGs and genotypes of Foc.
Resumo:
The new acanthocolpid genus Venusicola is erected for V. inusitatus sp, n. from the marine tuskfish Choerodon venustus from Heron Island on the southern Great Barrier Reef. This genus is unique in the family in having a greatly elongated ventral sucker with lateral apertural lips and a pavement of blunt spines lining the aperture.
Resumo:
Two sponge's belonging to the family Latrunculiidae (Negombata and Latrunculia sp.) collected during scientific trawling operations in Prydz Bay, Antarctica, and by scuba off Port Campbell, Victoria, have yielded a new antibacterial pyrroloiminoquinone, discorhabdin R (2). The structure was assigned as 2 on the basis of detailed, spectroscopic analysis and comparison with the known co-metabolite discorhabdin B (3).
Resumo:
Bioassay-directed fractionation of the EtOH extract of an Oceanapia sp. collected off the northern Rottnest Shelf, Australia, has yielded three novel dithiocyanates, thiocyanatins A (1), B (2a), and C (2b). The structures were determined by detailed spectroscopic analysis and confirmed by total synthesis. In addition to featuring an unprecedented dithiocyanate functionality, thiocyanatins possess an unusual 1,16-difunctionalized n-hexadecane carbon skeleton and are revealed as a hitherto unknown class of nematocidal agents
Resumo:
A synthetic Synechocystis sp. PCC6803 DnaB split mini-intein gene was constructed for the in vivo cyclization of recombinant proteins expressed in Escherichia coli. The system was used to cyclize the NH2-terminal domain of E. coli DnaB, the structure of which had been determined previously by NMR spectroscopy. Cyclization was found to proceed efficiently, with little accumulation of precursor, and the product was purified in high yield. The solution structure of cyclic DnaB-N is not significantly different from that of linear DnaB-N and it unfolds reversibly at temperatures similar to14 degreesC higher. Improved hydrogen bonding was observed in the first and last helices, and the length of the last helix was increased, while the 9-amino acid linker used to join the NH2 and COOH termini was found to be highly mobile. The measured thermodynamic stabilization of the structure (DeltaDeltaG approximate to 2 kcal/mol) agrees well with the value estimated from the reduced conformational entropy in the unfolded form. Simple polymer theory can be used to predict likely free energy changes resulting from protein cyclization and how the stabilization depends on the size of the protein and the length of the linker used to connect the termini.
Resumo:
Bioassay-directed fractionation of two southern Australian sponges, Phoriospongia sp. and Callyspongia bilamellata, yielded two new nematocidal depsipeptides, identified as phoriospongins A (1) and B (2). The structures of the phoriospongins were determined by detailed spectroscopic analysis and comparison with the previously reported sponge depsipeptide cyclolithistide A (3), as well as ESIMS and HPLC analysis of acid hydrolysates. It is noteworthy that the unique and yet structurally related metabolites 1-3 are found in sponges spanning three taxonomic orders, Poescilosclerida, Haplosclerida, and Lithistida.
Resumo:
Bioassay-directed fractionation of a Hymeniacidon sp. yielded as nematocidal agents the equilibrating E/Z bromoindole ethyl esters 1 and 2 and corresponding methyl esters 3 and 4. Also isolated for the first time as a natural product was an equilibrating mixture of seco-xanthine formamides, attributed the trivial name hymeniacidin (5). The structure for 5 was assigned on the basis of detailed spectroscopic analysis and total synthesis.
Resumo:
in December 1997,196 soil and snow samples were collected from Vestvold Hills, Davis Base, Antarctica. Two isolates, CBS 8804 T (pink colonies) and CBS 8805 (yellow colonies), were shown by proteome analysis and DNA sequencing to represent the same species. Results from the sequencing of the D1/D2 region of the large rDNA subunit placed this species in the hymenomycetous tree in a unique sister clade to the Trichosporonalles and the Tremellalles. The clade consists of Holtermannia corniformis CBS 6979 and CBS strains 8804(T) 8805, 8016, 7712, 7713 and 7743. Morphological and physiological characteristics placed this species in the genus Cryptococcus, with characteristics including the assimilation Of D-glucuronate and myo-inositol, no fermentation, positive Diazonium blue B and urease reactions, absence of sexual reproduction and production of starch-like compounds. Fatty acid analysis identified large proportions of polyunsaturated lipids, mainly linolleic (C-18.2) and, to a lesser extent, linolenic (C-18.3) acids. On the basis of the physiological and phylogenetic data, isolates CBS 8804(T) and CBS 8805 are described as Cryptococcus nyarrowii sp. nov.
Resumo:
A morphological and physiological characterization of yeast strains CBS 8908, CBS 8915, CBS 8920, CBS 8925(T) and CBS 8926, isolated from Antarctic soils, was performed. Phylogenetic analyses of the sequences of the D1/D2 regions and the adjacent internal transcribed spacer (ITS) regions of the large-subunit rDNA of these strains placed them into the Tremellales clade of the Hymenomycetes. The sequence data identified strains CBS 8908, CBS 8915 and CBS 8920 as belonging to the species Cryptococcus victoriae. Strains CBS 8925(T) and CBS 8926 were found to represent an unique clade within the Hymenomycetes, with Dioszegia crocea CBS 6714(T) being their closest phylogenetic relative. Fatty acid composition and proteome fingerprint data for these novel strains were also obtained. No sexual state was observed. A novel basidiomycetous species, Cryptococcus statzelliae, is proposed for strains CBS 8925(T) and CBS 8926.
Resumo:
Scorpidotrema longistipes n. g., n. sp. is described from the intestine of Scorpis georgiana Valenciennes (Scorpididae) from off Point Peron, Western Australia. The new genus is distinguished by the combination of a remarkably long and retractable ventral sucker peduncle, a possible uroproct, well-developed cirrus-sac and a uterine seminal receptacle. The subfamilial relationships of the new genus are troublesome. It incorporates features of the Opecoelinae, Stenakrinae and Plagioporinae. The absence of a canalicular seminal receptacle suggests a relationship with the Opecoelinae and Stenakrinae, whereas the well-developed cirrus-sac suggests a relationship with the Plagioporinae and Stenakrinae. The overall arrangement of the gonads is not similar to that of existing genera of Stenakrinae. It is concluded that the genus is best placed in the Stenakrinae although that subfamily may now be an artificial assemblage. This new genus forms part of a distinctive fauna of trematodes restricted to Australian southern temperate fishes.
Resumo:
An unusual new species of the gall-inducing scale insect genus Apiomorpha Rubsaamen is described from Queensland. The adult female, its gall, and the first-instar nymph (crawler) are illustrated, and relationships of the new species are estimated using mitochondrial COII data. Adult females induce cigar-shaped galls on leaves of several eucalypts in section Adnataria of subgenus Symphyomyrtus. The bilobed anal lobes of the adult female differ from those of all other Apiomorpha species (single lobe) and the first-instar nymph possesses features, such as broad frontal tubercles and dorsal stripes, that are not present in crawlers of other Apiomorpha species. However, DNA sequence data confirm that the new species falls within Apiomorpha, rather than representing a sister group, and indicate that the new species is not closely related to the A. pharetrata (Schrader) species-group, the only other group within Apiomorpha that induces cigar-shaped galls on leaves. The systematic affiliations of A. gullanae sp. n. are currently not known. Females only are known and there is some indication that reproduction in the new taxon is parthenogenetic. This represents the first putative case of parthenogenesis in Apiomorpha.
Resumo:
Soil, snow and organic material, collected in November 1997 from the Vestvold Hills, Davis Base, Antarctica, were screened for yeasts. Two isolates, which were shown to be indistinguishable by rDNA sequencing and protein analysis by SIDS-PAGE, are described in this communication as a novel species, Cryptococcus watticus sp. nov. (type culture, CBS 9496(T) = NRRL Y-27556(T)). Sequence analyses of the 26S rDNA D1/D2 region placed C. watticus in the hymenomycetous yeasts in a cluster with Holtermannia corniformis and Cryptococcus nyarrowii. This species has been allocated to the genus Cryptococcus on the basis of physiological and morphological characteristics.