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1.
C.subbracteata var.tolucensis (sect.Ovales) andC. distentiformis (sect.Extensae) from Mexico,C. guatemalensis (sect.Longicaules) andC. caxinensis (sect.Viridiflorae) from Guatemala, andC. volcanica (sect.Ovales) from Mexico and Guatemala are described as new.  相似文献   

2.
Carex sect. Spirostachyae comprises 25 species displaying the centre of diversity in Eurasia, while sect. Elatae comprises 22 species displaying the centre of diversity in tropical African mountainous regions. Phylogenetic analysis of the 136 ITS and 108 5′trnK intron sequences of 23 species of sect. Spirostachyae and 20 species of sect. Elatae revealed that neither section is monophyletic. With the exclusion of C. montis-eeka (sect. Spirostachyae) and C. insularis, C. iynx and C. longibrachiata (sect. Elatae), the sects. Spirostachyae and Elatae constitute a monophyletic group of 38 species, 22 of which were previously included in sect. Spirostachyae and 16 of which were in sect. Elatae (considering C. thomasii as C. mannii ssp. thomasii). Two main groups with different edaphic preferences were identified in the core Spirostachyae, in congruence with some morphological features. One group comprises primarily acidophilus species including 11 species of sect. Spirostachyae and 16 species of sect. Elatae. The other group includes 11 basophilic species of sect. Spirostachyae. Incongruence between nuclear and plastid genomes was detected, suggesting hybridization or lineage sorting processes in the evolution of the core Spirostachyae.  相似文献   

3.
4.
Five new Conocybe species are described from Russia based on collections made in different parts of the country. One species (C. olivaceopileata) belongs to sect. Conocybe, two species (C. praticola and C. coniferarum) to sect. Mixtae. The ornamented basidiospores of C. confundens and C. incerta is characteristic for sect. Ochromarasmius. All new species are described based on morphology and, in some cases, on DNA sequencing (ITS rDNA). Photos of basidiocarps, illustrations of microstructures and a comparison with similar taxa are given.  相似文献   

5.

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   

6.
Based on the study of herbarium material, a critical taxonomic account has been provided onCardamine sect.Macrophyllum (Cruciferae) from the Asian territory of the Soviet Union. Different morphological characters were examined but special attention was paid to flowers, nectar glands, pollen grains, fruits and seeds, followed by the anatomical studies of fruits and seeds. 8 species have been recognized which are arranged in 2 subsections underCardamine sect.Macrophyllum viz. 1.Macrophyllae (C. leucantha, C. tomentella, C. macrophylla andC densiflora) and 2.Prorepentae (C. schinziana, C. yezoensis, C. amareaformis andC. prorepens). Phylogenetic trend also has been traced out suggesting preliminary centres of divergency and polymorphism of the treated taxa.  相似文献   

7.

Background

Candida auris and Candida haemulonii are emerging and multiresistant pathogens. C. auris has produced hospital outbreaks and is misidentified by phenotypic-based methods. The only reliable identification methods are DNA sequencing and MALDI-TOF.

Aims

To develop a classical-PCR method capable of rapidly and accurately identify C. auris and C. haemulonii.

Methods

A multiplex PCR was carried out in one tube that included an internal control and oligonucleotides that specifically hybridize to the ITS2 region of C. auris and C. haemulonii. The usefulness of the new method was verified by testing a collection of 50 strains of 20 different species (previously identified by ITS sequencing). The selection of species was made in order to emulate the C. auris panel used by the CDC to validate diagnostic tools. In addition, other yeast species not included in the aforementioned panel were incorporated based on reported identification errors.

Results

The results obtained with the proposed protocol were in total agreement with those obtained by ITS sequencing.

Conclusions

We present a PCR method able to unequivocally identify C. auris and differentiate it from C. haemulonii. It is inexpensive, fast and it could be a useful tool to reduce the chances of a C. auris outbreak.  相似文献   

8.
Columnea chrysotricha, C. cuspidata (bothColumnea sect.Collandra), andGasteranthus recurvatus are described from Colombia;C. sulcata (Columnea sect.Collandra) from Ecuador and Colombia; andDrymonia anisophylla from the Amazonian lowland rain forests of Brazil, Colombia, Ecuador, and Peru.  相似文献   

9.
10.
Five new species are described, three of which, C. crassiflora, C. paucipetala, and C. trochilus, belong to sect. Heterodon, a group of predominantly annual, western Mexican species. The perennial C. rasilis is a new member of sect. Melvilla and the perennial C. spectabilis is new to sect. Diploptychia. Chromosome numbers for the annual species and two additional ones, C. procumbens and C. koehneana, closely related to the novelties, are reported for the first time.  相似文献   

11.
Nuclear DNA content was estimated using flow cytometry in 13 sections represented by 18 species of the genusTaraxacum using propidium iodide as the DNA stain. Investigated plants represented diploid, triploid and tetraploid species from sections considered both primitive and advanced, i.e.,T. sect.Dioszegia, Piesis, Glacialia, Mongolica, Scariosa, Obovata, T. pyrenaicum group,T. sect.Coronata, Palustria, Taraxacum (=Crocea),Kashmirana, Ruderalia andErythrosperma. Estimated nuclear 2C DNA content ranged from 1.74 pg in diploidT. linearisquameum (T. sect.Ruderalia) to 6.91 pg in tetraploidT. albidum (T. sect.Mongolica), demonstrating 3.97-fold variation. The lowest monoploid genome size 1Cx=0.87 pg was recorded inT. linearisquameum (T. sect.Ruderalia) together withT. brachyglossum (T. sect.Erythrosperma), and the highest one (1.73 pg) was recorded inT. albidum (T. sect.Mongolica), giving a 1.99-fold difference in the genus. No significant differences in genome size were observed withinT. sect.Ruderalia, similarly no intraspecific variation was observed inT. paludosum (T. sect.Palustria) andT. serotinum (T. sect.Dioszegia). These results indicate a high intraspecific stability of the trait. Preliminary comparisons of genome size in species/sections considered to be close relatives were made. These data give tentative additional evidence for the close phylogenetic relationship between sectionsPalustria andPiesis and against the close relationship between sectionsPiesis andDioszegia.  相似文献   

12.
13.

Background

Invasive fungal infections are increasing, and Candida yeasts are the main cause. Species other than Candida albicans are becoming more frequent, and some of them may have variable patterns of susceptibility to antifungal agents, making it important to identify them correctly. Conventional identification methods used by most laboratories may present with drawbacks. Mass spectrometry (MALDI-TOF MS) has emerged as an alternative method.

Aims

The aim of this study was to evaluate the concordance of the identification, at species level, by conventional methods (API) and MALDI-TOF MS.

Methods

The following species and number of isolates were studied: Candida parapsilosis (28), Candida glabrata (34), Candida krusei (24), Candida tropicalis (45), Candida guilliermondii (30), C. albicans (28), Candida dubliniensis (6), Candida kefyr (1), and Candida lipolytica (1) from the strain collection of Autonomous City of Buenos Aires Mycology Network (RMCABA). The strains C. parapsilosis 22019, C. glabrata 90030, C. krusei 6258 and C. albicans 68548 from the American Type Culture Collection (ATCC) were also included. Discrepancies were resolved by genotyping.

Results and conclusions

The direct concordance between the conventional identification method and MALDI-TOF MS was 92.5% (186/201).  相似文献   

14.

Background

Candida parapsilosis, Candida metapsilosis and Candida orthopsilosis are emerging as relevant causes of candidemia. Moreover, they show differences in their antifungal susceptibility and virulence. The echinocandins are different in terms of in vitro antifungal activity against Candida. Time-kill (TK) curves represent an excellent approach to evaluate the fungicidal activity of antifungal drugs.

Aims

To compare the fungicidal activities of anidulafungin, caspofungin and micafungin against C. parapsilosis species complex by TK curves.

Methods

Antifungal activities of three echinocandins against C. parapsilosis, C. metapsilosis and C. orthopsilosis were studied by TK curves. Drug concentrations assayed were 0.25, 2 and 8 μg/ml. CFU/ml were determined at 0, 2, 4, 6, 24 and 48 h.

Results

Killing activities of echinocandins were species-, isolates- and concentration-dependent. Anidulafungin reached the fungicidad endpoint for 6 out of 7 isolates (86%); it required between 13.34 and 29.67 h to reach this endpoint for the three species studied, but more than 48 h were needed against one isolate of C. orthopsilosis (8 μg/ml). Caspofungin fungicidal endpoint was only achieved with 8 μg/ml against one isolate of C. metapsilosis after 30.12 h (1 out of 7 isolates; 14%). Micafungin fungicidal endpoint was reached in 12.74–28.38 h (8 μg/ml) against one isolate each of C. parapsilosis and C. orthopsilosis, and against both C. metapsilosis isolates (4 out of 7 isolates; 57%).

Conclusions

C. metapsilosis was the most susceptible species to echinocandins, followed by C. orthopsilosis and C. parapsilosis. Anidulafungin was the most active echinocandin against C. parapsilosis complex.  相似文献   

15.

Background

An increased incidence of fungal infections caused by Candida species, especially Candida glabrata and Candida krusei, which are less susceptible to azoles, has been observed. Standardized susceptibility testing is essential for clinical management and for monitoring the epidemiology of resistance.

Aims

We evaluated the performance of two different susceptibility testing commercial methods, Vitek 2® and Sensititre YeastOne®, and compared them with the standard broth microdilution method (CLSI).

Methods

A total of 80 isolates of several Candida species (Candida albicans, Candida parapsilosis complex, Candida tropicalis, C. glabrata and C. krusei) were selected for this study.

Results

We analyzed the categorical agreement (CA) between the methods, stratifying the disagreements. The average CA between the methods was 96.3% for Vitek 2® and 84% for Sensititre YeastOne®. No very major errors were observed. Major errors and minor errors were found for all the isolates tested. With the azoles, both Vitek 2® and Sensititre YeastOne® had good and similar performance levels, except for C. tropicalis and C. krusei (Sensititre YeastOne® showed low CA, 56.2%). With the echinocandins, both methods showed good performance for C. albicans, C. parapsilosis and C. tropicalis. However, we observed important discrepancies for C. krusei with caspofungin: Vitek 2® had 100% CA while Sensititre YeastOne® had only 25%. With amphotericin B, both Vitek 2® and Sensititre YeastOne® had good performance with high CA.

Conclusions

Despite the limited isolates tested, we concluded that both methods have good performance and are reliable for antifungal susceptibility testing. However, caspofungin activity against C. krusei and C. glabrata should be interpreted carefully when using Sensititre YeastOne® because we observed a low CA.  相似文献   

16.

Background

Cryptococcosis is a systemic opportunistic mycosis, caused by Cryptococcus neoformans and Cryptococcus gattii, which affects mainly the central nervous system of immunocompromised patients; no reports have been made on the isolation of the fungus from the environment of Popayán, Colombia.

Aims

The main objective of this investigation was to determinate the incidence of C. neoformans in the urban perimeter in the City of Popayán, Colombia.

Methods

A total of 303 samples from droppings of Columba livia and Bubulcus ibis were collected between September 2012 and June 2013. The samples were processed by conventional techniques; identification of colonies was performed by biochemical tests, and molecular patterns were determined by PCR fingerprinting with the primer (GTG)5 and restriction fragment length polymorphism (RFLP) of the gene URA5.

Results

A total of 118 (38.94%) samples were positive for Cryptococcus in excreta of C. livia, and 361 strains belonging to Cryptococcus neoformans var. grubii were isolated. From the latter, 99.2% corresponded to the molecular pattern VNI and 0.8% to VNII, with an increased occurrence (24.4%) at a temperature of 22.5 °C and a humidity of 60.8%. The excreta of B. ibis did not show the presence of the fungus.

Conclusions

C. livia excreta is a key environmental niche for C. neoformans var. grubii, type VNI, supporting growth and reproduction, and serving as a major source of infection for susceptible populations in Popayán. This represents the first report on the isolation of the agent of cryptococcosis from the environment in this region, with a significant prevalence in bird excreta.  相似文献   

17.

Background and Aims

Corymbia species from different sections hybridize readily, with some of increasing economic importance to plantation forestry. This study explores the locations of reproductive barriers between interspecific Corymbia hybrids and investigates the reproductive success of a wide taxonomic range of C. torelliana hybrid crosses.

Methods

Pollen, pistil and embryo development were investigated for four C. torelliana crosses (×C. torelliana, ×C. citriodora subsp. citriodora, ×C. tessellaris and ×C. intermedia) using fluorescent and standard microscopy to identify the locations of interspecific reproductive isolating barriers. Corymbia torelliana was also crossed with 16 taxa, representing six of the seven Corymbia sections, both Corymbia subgenera and one species each from the related genera, Angophora and Eucalyptus. All crosses were assessed for capsule and seed yields.

Key Results

Interspecific C. torelliana hybridization was controlled by pre-zygotic reproductive isolating barriers inhibiting pollen adhesion to the stigma, pollen germination, pollen tube growth in the style and pollen tube penetration of the micropyle. Corymbia torelliana (subgenus Blakella, sect. Torellianae) was successfully hybridized with Corymbia species from subgenus Blakella, particularly C. citriodora subsp. citriodora, C. citriodora subsp. variegata, C. henryi (sect. Maculatae) and C. tessellaris (sect. Abbreviatae), and subgenus Corymbia, particularly C. clarksoniana and C. erythrophloia (sect. Septentrionales). Attempted intergeneric hybrids between C. torelliana and either Angophora floribunda or Eucalyptus pellita were unsuccessful.

Conclusions

Corymbia hybrids were formed between species from different sections and subgenera, but not with species from the related genera Angophora or Eucalyptus. Reproductive isolation between the interspecific Corymbia hybrid crosses was controlled by early- and late-acting pre-zygotic isolating barriers, with reproductive success generally decreasing with increasing taxonomic distance between parent species. These findings support the monophyly of Corymbia and the close relationships of infrageneric clades. The hybridizing propensity of Corymbia species provides opportunities for breeding but suggests risks of environmental gene flow.  相似文献   

18.
19.
Acer sect. and ser.Macrophylla were not validly published until 1962 by Momotani.Acer sect. and ser.Spicata Pax are synonyms of sect. and ser.Acer respectively since they include the generic lectotype;Acer sect.Parviflora Koidz. and ser.Caudata Pax are adopted here for the taxa which includeAcer spicatum Lam. and its close relatives.Acer sect.Integrifolia Pax becomes a synonym of sect.Palmata following the lectotypification of Fang, not Murray; sect. Oblonga (Hu & Cheng) Delendick is proposed as a new combination to replace sect.Integrifolia sensu Murray.  相似文献   

20.
Cyanea kuhihewa (Campanulaceae: Lobelioideae) is described from Kaua'i in the Hawaiian Islands and assigned to sect.Hirtellae. Because of its leaves, it was first identified asC. linearifolia, a member of sect.Delisseoideae presumed extinct. However, the new species differs by its flat or slightly revolute (vs. strongly revolute) leaf margins, fewer-flowered pubescent inflorescences with shorter peduncles and bracts longer than wide (vs. wider than long), and larger pubescent flowers.  相似文献   

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