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1.
A parsimony analysis of parts of the mitochondrial genes 12S and 16S (722 base pairs) from 43 species of the advanced snakes (Caenophidia) resulted in two most parsimonious topologies. Based on a strict consensus of these the following objectives were addressed: (1) Which groupings of caenophidian taxa can be recognized? (2) Is Acrochordus sister group to, or included in, Caenophidia? (3) Are boigine snakes (sensu stricto) a monophyletic grouping and where do these taxa belong in a broader caenophidian context? (4) What are the systematic affinities of the African egg-eating genusDasypeltis ? The phylogeny was then used to discuss: (5) the evolution of the posterior maxillary dentition and the composition of the retinal visual cells. The results reveal that, when using Boa constrictor as outgroup,Acrochordus is the sistergroup to the remainder of the ingroup, and a further eight clades are defined. Five genera of elapids did not appear to be monophyletic and a number of colubrids (sensu lato) such as Mehelya,Lycodonomorphus , Lamprophis, Atractaspis, and Buhoma (formerly Geodipsas), which have traditionally been problematic to place systematically, did not group with any of the larger clades. These taxa are together with the elapids representatives of very early radiations in the evolution of the Advanced snakes. The homalopsine Enhydris enhydris appears as a sistergroup to the viperine clade (Clade 1). When plotted onto the topology the posterior maxillary dentition appear to express three, maybe four, independent origins of the Opistoglyph State. The retinal evolution also appeared very complex. The suggested very primitive placing of the Boigine snakes (sensu stricto) due to their lack of double cones in the retina of the eye was not supported here; instead the sequence data suggests this observation to be the result of a secondary loss.  相似文献   

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Background

Candida parapsilosis is recognized as a species complex: Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis are three distinct but closely related species.

Aims

To determine the species and antifungal susceptibility of members of the C. parapsilosis complex, isolated from clinical samples.

Methods

Isolates identified as C. parapsilosis complex by VITEK® 2 system were included. Antifungal susceptibility test was done using the VITEK® 2 semi-automated system. The distribution of the species in the complex was determined by multiplex PCR.

Results

Among the seventy-seven C. parapsilosis complex isolates, C. parapsilosis sensu stricto (57.1%) was the commonest species, followed by C. orthopsilosis (40.2%) and C. metapsilosis (2.5%). All three species were susceptible to amphotericin B, caspofungin and micafungin. Among C. parapsilosis sensu stricto isolates, 16% were resistant to fluconazole while 2.2% showed dose dependent susceptibility. Also, 18.2% of C. parapsilosis sensu stricto isolates showed dose dependent susceptibility to voriconazole.

Conclusions

C. parapsilosis sensu stricto was the most commonly isolated member of the C. parapsilosis complex and it showed high resistance to fluconazole. A high prevalence of C. orthopsilosis (40.2%) was also noted.  相似文献   

4.
Clostridium botulinum (group III), Clostridium novyi and Clostridium haemolyticum are well-known pathogens causing animal botulism, gas gangrene/black disease, and bacillary hemoglobinuria, respectively. A close genetic relationship exists between the species, which has resulted in the collective term C. novyi sensu lato. The pathogenic traits in these species, e.g., the botulinum neurotoxin and the novyi alpha toxin, are mainly linked to a large plasmidome consisting of plasmids and circular prophages. The plasmidome of C. novyi sensu lato has so far been poorly characterized. In this study we explored the genomic relationship of a wide range of strains of C. novyi sensu lato with a special focus on the dynamics of the plasmidome. Twenty-four genomes were sequenced from strains selected to represent as much as possible the genetic diversity in C. novyi sensu lato. Sixty-one plasmids were identified in these genomes and 28 of them were completed. The genomic comparisons revealed four separate lineages, which did not strictly correlate with the species designations. The plasmids were categorized into 13 different plasmid groups on the basis of their similarity and conservation of plasmid replication or partitioning genes. The plasmid groups, lineages and species were to a large extent entwined because plasmids and toxin genes had moved across the lineage boundaries. This dynamic process appears to be primarily driven by phages. We here present a comprehensive characterization of the complex species group C. novyi sensu lato, explaining the intermixed genetic properties. This study also provides examples how the reorganization of the botulinum toxin and the novyi alpha toxin genes within the plasmidome has affected the pathogenesis of the strains.  相似文献   

5.
We review the systematics of the Hypsiboas calcaratus species complex, a group of widely distributed Amazonian hylid frogs. A comprehensive analysis of genetic, morphological, and bioacoustic datasets uncovered the existence of eleven candidate species, six of which are confirmed. Two of them correspond to Hypsiboas fasciatus and Hypsiboas calcaratus and the remaining four are new species that we describe here. Hypsiboas fasciatus sensu stricto has a geographic range restricted to the eastern Andean foothills of southern Ecuador while Hypsiboas calcaratus sensu stricto has a wide distribution in the Amazon basin. Hypsiboas almendarizae sp. n. occurs at elevations between 500 and 1950 m in central and northern Ecuador; the other new species (H. maculateralis sp. n., H. alfaroi sp. n., and H. tetete sp. n.) occur at elevations below 500 m in Amazonian Ecuador and Peru. The new species differ from H. calcaratus and H. fasciatus in morphology, advertisement calls, and mitochondrial and nuclear DNA sequences. Five candidate species from the Guianan region, Peru, and Bolivia are left as unconfirmed. Examination of the type material of Hyla steinbachi, from Bolivia, shows that it is not conspecific with H. fasciatus and thus is removed from its synonymy.  相似文献   

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Orthoptera have been used for decades for numerous evolutionary questions but several of its constituent groups, notably crickets, still suffer from a lack of a robust phylogenetic hypothesis. We propose the first phylogenetic hypothesis for the evolution of crickets sensu lato, based on analysis of 205 species, representing 88% of the subfamilies and 71% tribes currently listed in the database Orthoptera Species File (OSF). We reconstructed parsimony, maximum likelihood and Bayesian phylogenies using fragments of 18S, 28SA, 28SD, H3, 12S, 16S, and cytb (~3600 bp). Our results support the monophyly of the cricket clade, and its subdivision into two clades: mole crickets and ant‐loving crickets on the one hand, and all the other crickets on the other (i.e. crickets sensu stricto). Crickets sensu stricto form seven monophyletic clades, which support part of the OSF families, “subfamily groups”, or subfamilies: the mole crickets (OSF Gryllotalpidae), the scaly crickets (OSF Mogoplistidae), and the true crickets (OSF Gryllidae) are recovered as monophyletic. Among the 22 sampled subfamilies, only six are monophyletic: Gryllotalpinae, Trigonidiinae, Pteroplistinae, Euscyrtinae, Oecanthinae, and Phaloriinae. Most of the 37 tribes sampled are para‐ or polyphyletic. We propose the best‐supported clades as backbones for future definitions of familial groups, validating some taxonomic hypotheses proposed in the past. These clades fit variously with the morphological characters used today to identify crickets. Our study emphasizes the utility of a classificatory system that accommodates diagnostic characters and monophyletic units of evolution. Moreover, the phylogenetic hypotheses proposed by the present study open new perspectives for further evolutionary research, especially on acoustic communication and biogeography.  相似文献   

9.
PCR amplification of 16S rRNA gene by universal primers followed by restriction fragment length polymorphism analysis using RsaI, CfoI and HinfI endonucleases, distinctly differentiated closely related Bacillus amyloliquefaciens, Bacillus licheniformis and Bacillus pumilus from Bacillus subtilis sensu stricto. This simple, economical, rapid and reliable protocol could be an alternative to misleading phenotype-based grouping of these closely related species.  相似文献   

10.
Yang, L., Mayden, R. L., Sado, T., He, S., Saitoh, K. & Miya, M. (2010). Molecular phylogeny of the fishes traditionally referred to Cyprinini sensu stricto (Teleostei: Cypriniformes). —Zoologica Scripta, 39, 527–550. Carps (e.g. Koi) of the genus Cyprinus and Crucian carps (e.g. Goldfish) of the genus Carassius are among the most popular freshwater fishes around the world. However, their phylogenetic positions within the subfamily Cyprininae, relationships with their allies (e.g. Procypris, Carassioides), and the monophyly of the group formed by them and their allies, which is referred as the tribe Cyprinini sensu stricto, are far from clear. Historically, the Cyprinini was defined by different people according to whether a cyprinine fish possessed a spinous anal‐fin ray (or anal spine), the spine was serrated or not, and occasionally, the number of branched dorsal‐fin rays. Some definitions were established without providing any diagnostic characters. In this study, we investigated the monophyly of the tribe Cyprinini sensu stricto, based on four different historical definitions, and explored the phylogenetic relationships of these members in the subfamily Cyprininae. Using five mitochondrial genes as markers, both maximum‐likelihood and Bayesian trees were constructed using the optimal partitioning strategy. Both analyses successfully resolved a monophyletic Cyprininae and recovered seven major clades from this subfamily. The diagnosis limiting the tribe Cyprinini sensu stricto to four genera, Cyprinus, Carassius, Carassioides and Procypris, received most support. We propose that only those cyprinines that possess a serrated anal spine and have no <10 branched dorsal‐fin rays should be considered members of this tribe. Cyprinini is sister to the Sinocyclocheilus clade, a group traditionally considered a barbin, and together they form the ‘Cyprinini‐Sinocyclocheilus’ clade. Procypris forms the basal clade of the Cyprinini, whereas species of Carassius and Carassioides locate at the top.  相似文献   

11.
This study was based on RAPD fingerprinting for species identification of the Saccharomyces sensu stricto complex. 40 random primers were used for RAPD analysis. The results showed that one of these primers, OPT-18, produced a 974 bp species-specific band, which was only found in the tested S. bayanus. Afterward this specific fragment was isolated from agarose gel and ligated into vector for DNA sequencing. A pair of primer SpeOPT18Sbay-F2 and SpeOPT18Sbay-R2 were designed according to the cloned species-specific sequence, which was employed for PCR with the template DNA of the S. sensu stricto strains, single 779 bp species-specific band was only found in S. bayanus. Therefore, we conclude that our novel species DNA marker could be used to rapidly and accurately identify the species of S. bayanus from S. sensu stricto complex by direct PCR.  相似文献   

12.
Increasing evidence suggests that perturbations in the intestinal microbiota composition of infants are implicated in the pathogenesis of food allergy (FA), while the actual structure and composition of the intestinal microbiota in human beings with FA remain unclear. Microbial diversity and composition were analyzed with parallel barcoded 454 pyrosequencing targeting the 16S rRNA gene hypervariable V1-V3 regions in the feces of 34 infants with FA (17 IgE mediated and 17 non-IgE mediated) and 45 healthy controls. Here, we showed that several key FA-associated bacterial phylotypes, but not the overall microbiota diversity, significantly changed in infancy fecal microbiota with FA and were associated with the development of FA. The proportion of abundant Bacteroidetes, Proteobacteria, and Actinobacteria phyla were significantly reduced, while the Firmicutes phylum was highly enriched in the FA group (P < 0.05). Abundant Clostridiaceae 1 organisms were prevalent in infants with FA at the family level (P = 0.016). FA-enriched phylotypes negatively correlated with interleukin-10, for example, the genera Enterococcus and Staphylococcus. Despite profound interindividual variability, levels of 20 predominant genera were significantly different between the FA and healthy control groups (P < 0.05). Infants with IgE-mediated FA had increased levels of Clostridium sensu stricto and Anaerobacter and decreased levels of Bacteroides and Clostridium XVIII (P < 0.05). A positive correlation was observed between Clostridium sensu stricto and serum-specific IgE (R = 0.655, P < 0.001). The specific microbiota signature could distinguish infants with IgE-mediated FA from non-IgE-mediated ones. Detailed microbiota analysis of a well-characterized cohort of infants with FA showed that dysbiosis of fecal microbiota with several FA-associated key phylotypes may play a pathogenic role in FA.  相似文献   

13.
Job Kuijt 《Brittonia》1968,20(2):136-147
The paper represents a reassessment of familial relationships within the Order Santalales. Rafflesiaceae, Hydnoraceae, and Balanophoraceae are excluded from the order, and their reproductive similarities with some Santalales regarded as evolutionary convergence. The exclusion of Grubbiaceae from Santalales sponsored by other workers is accepted, as is the reassignment to other families of the two only genera of Octoknemaceae. The remaining members of the order are placed into six families, viz. Olacaceae (possibly representing several smaller families); Santalaceae; Loranthaceae (sensu stricto); Viscaceae (sensu stricto); Myzodendraceae ; and Eremolepidaceae (containingEremolepis, Eubrachion, andAntidaphne). It is suggested thatLepidoceras, formerly placed near the above three genera, is more properly placed in Loranthaceae (sensu stricto) nearTupeia. The proposed scheme of affinities of the families of Santalales, as reconstituted, is based to a large extent on inflorescence structure, but is supported by floral morphology and other features. The thesis is defended that Loranthaceae (sensu stricto), Santalaceae, Myzodendraceae, and Eremolepidaceae represent four inde pendent lines of development from portions of the Olacacean complex. Viscaceae (sensu stricto) may be derived directly from Santalaceae.  相似文献   

14.
Oxidative modification of phospholipids generates a variety of oxidized phospholipid (Ox-PL) species which differ considerably in their chemical compositions and molecular structures. Recent results suggest that even closely related Ox-PL species can have considerably different biological effects. However, the molecular mechanism for this is not yet clear. In truncated Ox-PLs (tOx-PLs) the fatty acyl chain is shorter in length than the parent nonoxidized phospholipid molecules and contains a polar functional group(s). In a previous study we showed that two closely related tOx-PL species having a similar polar functional group and differing only in the length of the oxidized fatty acyl chain exerts significantly different effects on the physicochemical properties of the nonoxidized phospholipid particles containing these lipids (Kar et al., Chem Phys Lipids 164:54–61, 2011). In this study we have characterized the effect of polar functional groups of oxidized fatty acyl chain on the physicochemical properties of the nonoxidized phospholipid particles containing these lipids. Our results show that Ox-PL species differing only in the chemical nature of polar functional groups in their oxidized fatty acyl chain modify the properties of nonoxidized phospholipid particles containing them in a distinctive way. These results indicate that different species of Ox-PLs induce unique changes in the physicochemical properties of lipid particles/membranes containing them and that this may lead to their different biological effects.  相似文献   

15.
A Cylindrocarpon species with up to 10 μm wide, straight and predominantly 3-septate macroconidia, subglobose to ovoidal microconidia and chlamydospores, is described as Cyl. pauciseptatum. It is most similar to Cyl. austrodestructans but no chlamydospores and microconidia are formed in the latter. Similar macroconidia also occur in Cyl. theobromicola, which forms oval to ellipsoidal microconidia at least sparsely and has slightly curved macroconidia, and Cyl. destructans var. crassum, which forms abundant 1-celled microconidia. DNA sequence data of the internal transcribed spacer regions 1 and 2 plus the 5.8S rDNA and the partial beta-tubulin gene were used for phylogenetic inferences. Cylindrocarpon pauciseptatum and Cyl. macrodidymum are monophyletic and are closely related to other species of Cylindrocarpon sensu stricto including members of the Cyl. destructans (teleomorph, Neonectria radicicola) species complex, which accommodates Cyl. liriodendri (teleomorph, Neon. liriodendri), Cyl. destructans var. crassum and Cyl. austrodestructans (teleomorph, Neonectria austroradicicola comb. nov.). Cylindrocarpon theobromicola is distantly related to species of Cylindrocarpon sensu stricto or Neonectria sensu stricto. It clustered among cylindrocarpon-like species with curved macroconidia, of which some belong to the Neon. mammoidea group. Relatively voluminous cells in sporodochial conidiophores of Cyl. theobromicola resembled those described for Campylocarpon, which is closely related to members of the Neon. mammoidea group including Cyl. theobromicola. Cylindrocarpon pauciseptatum has been isolated from roots of Vitis spp. in South-eastern Europe (Slovenia) as well as New Zealand, where it also occurs on roots of Erica melanthera.  相似文献   

16.
Since the discovery of Paraburkholderia tuberum, an indigenous South African species and one of the first beta-rhizobia described, several other South African rhizobial Paraburkholderia species have been recognized. Here, we investigate the taxonomic status of 31 rhizobial isolates from the root nodules of diverse South African legume hosts in the Core Cape Subregion, which were initially identified as P. tuberum. These isolates originate from the root nodules of genera in the Papilionoideae as well as Vachellia karroo, from the subfamily Caesalpinioideae. Genealogical concordance analysis of five loci allowed delineation of the isolates into two putative species clusters (A and B). Cluster A included P. tuberum STM678T, suggesting that this monophyletic group represents P. tuberum sensu stricto. Cluster B grouped sister to P. tuberum and included isolates from the Paarl Rock Nature Reserve in the Western Cape Province. Average Nucleotide Identity (ANI) analysis further confirmed that isolates of Cluster A shared high genome similarity with P. tuberum STM678T compared to Cluster B and other Paraburkholderia species. The members of Cluster B associated with a single species of Podalyria, P. calyptrata. For this new taxon we accordingly propose the name Paraburkholderia podalyriae sp. nov., with the type strain WC7.3bT (= LMG 31413T; SARCC 750T). Based on our nodA and nifH phylogenies, P. podalyriae sp. nov. and strains of P. tuberum sensu stricto (including one from V. karroo) belong to symbiovar africana, the symbiotic loci of which have a separate evolutionary origin to those of Central and South American Paraburkholderia strains.  相似文献   

17.
Amniotes are rare in Late Carboniferous strata, especially in Europe, and despite a global diversification. They are generally more common in Lower Permian deposits. The French record around the Pennsylvanian-Cisuralian boundary is therefore re-examined. Each basin which yielded amniote remains is provided with general data on its sedimentology, stratigraphy, dating, and palaeontological content. Seven specimens are reported, of which five are synapsids and two are reptiles, each of them being a holotype. Their respective age is reassessed. The use of the regional Stephanian and Autunian stages is discussed, but their traditional sense is retained. There is currently no amniote in the Stephanian sensu stricto (= Early Gzhelian) of France. The Stephanian-Autunian Transitional Zone (= Late Gzhelian) contains the unique amniote Stereorachis blanziacensis. The Autunian sensu stricto (= Asselian) contains five, Stereorachis dominans, Haptodus baylei, Callibrachion gaudryi, Belebey augustodunensis, and Aphelosaurus lutevensis. Finally, Neosaurus cynodus can be assigned either to the Transitional Zone or to the Autunian sensu stricto. The amniote diversity increases through the Pennsylvanian-Cisuralian boundary. Despite the low number of specimens, the French record is representative of the global evolution of amniotes.  相似文献   

18.
The Sino-Himalayan Mountain Region is a major center of diversity of Heracleum (Apiaceae, Tordylieae, Tordyliinae), yet the phylogenetic relationships among its rich diversity of endemic taxa are largely unknown. In this study, we (1) investigate the monophyly of Heracleum and ascertain the phylogenetic placements of those species of Heracleum from China that fall outside of the group; (2) estimate phylogenetic relationships within Heracleum sensu stricto, particularly among those species occurring in the Hengduan Mountain Region of southwestern China; and (3) reconstruct the biogeographic history of Heracleum sensu stricto. To achieve these objectives, Bayesian inference and maximum-parsimony analyses of the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region and five noncoding chloroplast DNA (cpDNA) loci (rps16-trnK, rps16 intron, trnQ-rps16, rpl32-trnL, and psbA-trnH), separately and in combination, were carried out. Fruit morphology of the Chinese Heracleum species was examined. Statistical dispersal-vicariance analysis (S-DIVA) was used to reconstruct the biogeographic history. In total, 114 accessions were considered, which included 88 species representing eight genera of subtribe Tordyliinae, 28 of the 29 species of Heracleum occurring in China, and 4 species of Angelica as outgroups. The genus Heracleum is monophyletic upon the exclusion of nine species of Heracleum from China and the inclusion of the Caucasian monotypic genera Mandenovia and Symphyoloma. These nine excluded species show affinities to Tetrataenium, Semenovia, and Angelica. The species of Heracleum endemic to southwestern China form a moderately to strongly supported clade; however, major discordance between the ITS- and cpDNA-derived phylogenies, lack of resolution in the trees, and polyphyly of several species preclude unequivocal hypotheses of phylogenetic relationship. The distinctly clavate vittae, shorter than the length of the mericarp, is a diagnostic feature for Heracleum sensu stricto. Heracleum originated in the West Palearctic, with three possible migration routes leading to its present-day distribution. Major topological conflicts between the ITS and cpDNA trees may be due to interspecific hybridization and/or incomplete lineage sorting. The taxonomic limits of many Chinese Heracleum species remain unclear, possibly because of recent radiation in the Hengduan Mountains.  相似文献   

19.
We have examined the polar lipids of Clostridium psychrophilum, a recently characterized psychrophilic Clostridium isolated from an Antarctic microbial mat. Lipids were extracted from cells grown near the optimal growth temperature (+ 5 °C) and at − 5 °C, and analyzed by two-dimensional thin layer chromatography and liquid chromatography coupled with mass spectrometry. The major phospholipids of this species are: cardiolipin, phosphatidylethanolamine, and phosphatidylglycerol. Phosphatidylserine and lyso-phosphatidylethanolamine were found as minor components. The most abundant glycolipids are a monoglycosyldiradylglycerol (MGDRG) and a diglycosyldiradylglycerol (DGDRG). The latter was only seen in cells grown at − 5 °C. An ethanolamine-phosphate derivative of N-acetylglucosaminyldiradylglycerol was seen in cells grown at − 5 °C and an ethanolamine-phosphate derivative of MGDRG was found in cells grown at + 5 °C. All lipids were present in both the all acyl and plasmalogen (alk-1′-enyl acyl) forms with the exception of PS and MGDRG, which were predominantly in the diacyl form. The significance of lipid changes at the two growth temperatures is discussed.  相似文献   

20.
The C. parapsilosis sensu lato group involves three closely related species, C. parapsilosis sensu stricto, C . orthopsilosis and C . metapsilosis . Although their overall clinical importance is dramatically increasing, there are few studies regarding the virulence properties of the species of the psilosis complex. In this study, we tested 63 C. parapsilosis sensu stricto, 12 C . metapsilosis and 18 C . orthopsilosis isolates for the ability to produce extracellular proteases, secrete lipases and form pseudohyphae. Significant differences were noted between species, with the C . metapsilosis strains failing to secrete lipase or to produce pseudohyphae. Nine different clinical isolates each of C. parapsilosis sensu stricto, C . orthopsilosis and C . metapsilosis were co-cultured with immortalized murine or primary human macrophages. C. parapsilosis sensu stricto isolates showed a significantly higher resistance to killing by primary human macrophages compared to C . orthopsilosis and C . metapsilosis isolates. In contrast, the killing of isolates by J774.2 mouse macrophages did not differ significantly between species. However, C. parapsilosis sensu stricto isolates induced the most damage to murine and human macrophages, and C . metapsilosis strains were the least toxic. Furthermore, strains that produced lipase or pseudohyphae were most resistant to macrophage-mediated killing and produced the most cellular damage. Finally, we used 9 isolates of each of the C. parapsilosis sensus lato species to examine their impact on the survival of Galleria mellonella larvae. The mortality rate of G . mellonella larvae infected with C . metapsilosis isolates was significantly lower than those infected with C. parapsilosis sensu stricto or C . orthopsilosis strains. Taken together, our findings demonstrate that C . metapsilosis is indeed the least virulent member of the psilosis group, and also highlight the importance of pseudohyphae and secreted lipases during fungal-host interactions.  相似文献   

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