Phylogeny of the Ophiostoma stenoceras-Sporothrix schenckii complex

Ophiostoma stenoceras is a well-known sapwood-colonizing fungus occurring on some coniferous and hardwood hosts in the Northern Hemisphere. In the Southern Hemisphere, the fungus has been reported only from New Zealand. The human pathogen, Sporothrix schenckii, has been suggested to be the anamorph of O. stenoceras. The aim of this study was to gain a better understanding of the phylogenetic relationship between these two species. The study also provided the opportunity to confirm the identity of some Sporothrix and O. stenoceras-like isolates recently collected from wood and soil around the world. For this purpose, the DNA sequence of internal transcribed spacer (ITS) regions of the ribosomal RNA operon was determined. Isolates of O. nigrocarpum, O. albidum, O. abietinum, O. narcissi and O. ponderosae, all morphologically similar to O. stenoceras, were included in the study. From phylogenetic analyses of the sequence data, four main clades were observed. These represented O. stenoceras, O. nigrocarpum and two separate groups containing isolates of S. schenckii. Our results confirm earlier suggestions that S. schenckii should be classified within the teleomorph genus Ophiostoma but support studies separating O. stenoceras and S. schenckii. Ophiostoma albidum and O. ponderosae should be considered synonyms of O. stenoceras. The status of O. narcissi and O. abietinum needs further clarification. The two groups within S. schenckii might represent two species, but this needs to be confirmed. This study represents the first reports of O. stenoceras from Colombia, Kenya, Uruguay and South Africa.     

Two new Ophiostoma species with Sporothrix anamorphs from Austria and Azerbaijan

The genus Ophiostoma includes numerous species of primarily insect-vectored, wood-staining fungi. Several anamorph genera that differ in their micronematous or macronematous conidiogenous cells have been associated with Ophiostoma species. Among the former group, Sporothrix is associated with many species and is characterized by conidiogenous cells that arise laterally or terminally from any place on the hyphae and produce nonseptate conidia on sympodially developing denticles. The purpose of this study was to characterize ophiostomatoid isolates with Sporothrix anamorphs recently collected in Austria and Azerbaijan. The isolates were characterized based on comparisons of rDNA and β-tubulin sequence data. Morphology, growth in culture, and sexual reproductive mode were also considered. Phylogenetic analyses of the combined sequence data showed that the isolates formed two distinct groups, one including isolates from Austria and the other isolates from Austria and Azerbaijan. Growth at 25 C and morphology revealed some differences between the two groups, and supported the view that they represent two new species, which we describe here as Ophiostoma fusiforme sp. nov. and Ophiostoma lunatum sp. nov. Both these groups phylogenetically were related to, but distinct from, Ophiostoma stenoceras.     

Ecology of Sporothrix schenckii and of Ceratocystis stenoceras in Corsica and Alsace, French provinces free of sporotrichosis]

The study was conducted in 2 French Provinces free of sporotrichosis. Of 40 samples (soil, plant fragments, . . .) taken from Corsica, 59 isolations were obtained. All of these contained S. schenckii type of growth. Of 30 retained for further study, 14 were later identified as Ceratocystis stenoceras. All 14 needed pyrimidine as a growth factor. They developed well at 37 degrees and gave a yeast-like growth in shaken medium at 35 degrees and 25 degrees. One of the strains was pathogenic to mice. From 422 small mammals trapped in Alsace 37 isolations were made which morphologically were identified as S. schenckii. From these 31 were identified as C. stenoceras. Six isolations were considered as S. schenckii. The presence of nature of C. stenoceras and S. scheckii is discussed. Both fungi were isolated from various materials collected in tropical areas where sporotrichosis is endemic but also in such temperate areas as Corsica and Alsace where the mycosis is non-existent.     

鼻部固定型孢子丝菌病1例

报道1例猫抓后引起的固定型孢子丝菌病.患者男,16岁,皮损表现为鼻翼部位的增生物,其上覆有脓痂.临床上易与细菌感染混淆,但根据患者的病史、临床表现、病理、真菌镜检及培养诊断为申克孢子丝菌引起的孢子丝菌病.患者在应用7个月的碘化钾结合特比萘芬软膏外用治疗后,皮损完全消失.     

Sporothrix brunneoviolacea and Sporothrix dimorphospora, two new members of the Ophiostoma stenoceras-Sporothrix schenckii complex

Sporothrix inflata is a saprobic member of the Ophiostoma stenoceras-Sporothrix schenckii species complex, reported mainly from soil. Ophiostoma bragantinum, an ascomycete described from Brazil, has been proposed as its possible teleomorph. Previous studies revealed that Sporothrix inflata is phenotypically and genetically variable, suggesting the existence of cryptic species. During a continued survey on the biodiversity of microfungi from different countries, seven isolates morphologically similar to S. inflata were obtained from soil samples collected in Spain and USA. In this study their phenotypic features and phylogenetic relationships were assessed. DNA sequence data of two nuclear loci revealed that these isolates correspond to two unnamed clades in S. inflata s.l., one of which also included the type strain of Humicola dimorphospora, a species that traditionally has been considered a synonym of S. inflata. These two groups are proposed herein as Sporothrix brunneoviolacea sp. nov. and Sporothrix dimorphospora comb. nov. S. brunneoviolacea is characterized phenotypically by the production of a diffusible violet-brown pigment in culture and mostly globose, pigmented, lateral blastoconidia. On the other hand S. dimorphospora lacks diffusible pigments and shows mostly subglobose to obovoid pigmented lateral blastoconidia. In contrast to the type strain of S. inflata S. brunneoviolacea and S. dimorphospora assimilate raffinose. The phylogenetic analysis suggested that the proposed anamorph-teleomorph connection between S. inflata and O. bragantinum might not be correct.     

An endemic area of sporotrichosis in Guatemala]

An endemic area of sporotrichosis is described in the Lake of Ayarza District, South Guatemala, where 53 patients have been observed within 3 years. In 45.3% of the cases, the infection appeared after handling fish. The disease was more frequently observed in man (83%) and in patients less than 30 years of age. The most frequent clinical type was the ascending lymphocutaneous sporotrichosis of the limbs. Some cases of ulcerative or verrucous lesions were seen. Almost all the patients cured rapidly either by potassium iodide (46 patients) or spontaneously, or after application of local heat (4 patients). Intradermal tests were performed in healthy population in the endemic area and, for comparison, in Guatemala City. Whole yeast cell antigens of Sporothrix schenckii and Ceratocystis stenoceras were used in these tests. Skin tests to both antigens were more frequently positive in the endemic area; the highest frequency was obtained with the antigen of C. stenoceras. A serological study was performed in 26 patients. The fluorescent antibody staining technique was more sensitive than yeast cell and latex particles agglutinations. C. stenoceras was isolated from bark of some trees, especially Eucalyptus, in the environment, but not S. schenckii.     

Fatty acid composition of polar and neutral lipids of Sporothrix schenckii and Ceratocystis stenoceras]

The fatty acids contained in the neutral and polar lipids from Sprorthrix schenckii and Ceratocystis stenoceras and 3 mutants of the latter fungus were found to be identical. The major fatty acids were palmitic, oleic and linoleic. The fungi had similar quantitative composition especially the mutant strains and S. schenckii. This observation provides more data regarding the possible relationship between Ceratocystis and sporothrix.     

Isolation of Gemmata-like and Isosphaera-like planctomycete bacteria from soil and freshwater.

New cultured strains of the planctomycete division (order Planctomycetales) of the domain Bacteria related to species in the genera Gemmata and Isosphaera were isolated from soil, freshwater, and a laboratory ampicillin solution. Phylogenetic analysis of the 16S rRNA gene from eight representative isolates showed that all the isolates were members of the planctomycete division. Six isolates clustered with Gemmata obscuriglobus and related strains, while two isolates clustered with Isosphaera pallida. A double-membrane-bounded nucleoid was observed in Gemmata-related isolates but not in Isosphaera-related isolates, consistent with the ultrastructures of existing species of each genus. Two isolates from this study represent the first planctomycetes successfully cultivated from soil.     

申克孢子丝菌菌丝相至酵母相转化的实验研究

目的观察申克孢子丝菌菌丝相向酵母相转化的形态学变化并初步研究连续传代后菌株转化为酵母相的百分率。方法将95株申克孢子丝菌临床株于脑心浸液琼脂培养基上连续传代至酵母相,利用显微镜及血细胞计数板计数菌丝和孢子比例并记录显微镜下形态。结果 95株申克孢子丝菌中,经1次传代即成功转化有23株,经2次传代有14株,经3次传代有10株,经4次传代有6株,4次传代后总计55.8%实验菌株转化为酵母相。结论部分申克孢子丝菌由菌丝相向酵母相转化需经过连续多次传代,连续传代增加了菌丝相至酵母相的转化率。     

Sporothrix globosa,a pathogenic fungus with widespread geographical distribution

Sporothrix globosa, reported from the USA, Europe, and Asia, is a recently described pathogenic species morphologically similar to Sporothrix schenckii. In this study, the phylogenetic affinities of 32 clinical and environmental isolates morphologically identified as S. schenckii, from Mexico, Guatemala, and Colombia, were assessed by cladistic analysis of partial sequences of the calmodulin gene using the maximum parsimony and neighbor-joining methods. The study revealed that one out of 25 isolates from Mexico (4%), one out of three isolates from Guatemala (33.3%), and two out of four isolates from Colombia (50%) belonged to S. globosa, while the other isolates belonged to S. schenckii sensu stricto. This is the first record of S. globosa from Mexico, and Central and South America.     

Viability, morphological characteristics and dimorphic ability of fungi preserved by different methods

The viability, morphological characteristics and dimorphic ability of fungi were evaluated. Strain subcultures were maintained under mineral oil and in soil for different periods of time, ranging from 49 to eight years. Of the 16 Blastomyces dermatitidis strains, four maintained viability and were able to complete the dimorphic process to the M phase producing a large amount of conidia, but were unable to form Y cells at 36 degrees C. Of the 15 Histoplasma capsulatum var. capsulatum strains, only one was viable but it was impossible to check its identity because it lost sporulating and dimorphic ability. Of the 53 Sporothrix schenckii strains, 37 were viable, 28 able to sporulate and 12 of them completed the whole M <=> Y dimorphic process. All subcultures in soil became inviable. The results demonstrate that the preservation methods used here affected the morphology and sporulating and dimorphic ability of the strains. B. dermatitidis and S. schenckii were considered to be species that survive better than H. capsulatum var. capsulatum under mineral oil. Thus, it is necessary to establish routine monitoring and appropriate environmental and culture conditions, using less widely spaced transplants and choosing the exact time of intervention to induce growth and development restriction in each strain.     

Chromosomal Polymorphism in the Sporothrix schenckii Complex

Sporotrichosis is a polymorphic disease caused by a complex of thermodimorphic fungi including S. brasiliensis, S. schenckii sensu stricto (s. str.), S. globosa and S. luriei. Humans and animals can acquire the disease through traumatic inoculation of propagules into the subcutaneous tissue. Despite the importance of sporotrichosis as a disease that can take epidemic proportions there are just a few studies dealing with genetic polymorphisms and genomic architecture of these pathogens. The main objective of this study was to investigate chromosomal polymorphisms and genomic organization among different isolates in the S. schenckii complex. We used pulsed field gel electrophoresis (PFGE) to separate chromosomal fragments of isolated DNA, followed by probe hybridization. Nine loci (β-tubulin, calmodulin, catalase, chitin synthase 1, Internal Transcribed Spacer, Pho85 cyclin-dependent kinase, protein kinase C Ss-2, G protein α subunit and topoisomerase II) were mapped onto chromosomal bands of Brazilian isolates of S. schenckii s. str. and S. brasiliensis. Our results revealed the presence of intra and interspecies polymorphisms in chromosome number and size. The gene hybridization analysis showed that closely related species in phylogenetic analysis had similar genetic organizations, mostly due to identification of synteny groups in chromosomal bands of similar sizes. Our results bring new insights into the genetic diversity and genome organization among pathogenic species in the Sporothrix schenckii complex.     

Phenotypic and Molecular Identification of <Emphasis Type="Italic">Sporothrix</Emphasis> Isolates from an Epidemic Area of Sporotrichosis in Brazil

Sporotrichosis has significantly increased in Brazil in the last decade, particularly in the state of Rio de Janeiro, with the occurrence of an epidemic related to zoonotic transmission from cats to humans. Recently, four new phylogenetic species were incorporated into the Sporothrix species complex based on the phenotypic and molecular characteristics, and a new species name (Sporothrix brasiliensis) was proposed for some of the Sporothrix isolates from this epidemic. This study describes the characterization of 246 isolates obtained from patients attending the Laboratory of Infectious Dermatology, IPEC-FIOCRUZ, between 1998 and 2008, together with one environmental sample. Two hundred and six of the isolates (83.4%) were characterized as S. brasiliensis, 15 (6.0%) as S. schenckii, and one (0.5%) as S. mexicana. Twenty-five isolates (10.1%) could not be identified according to their phenotype and were classified as Sporothrix spp. The calmodulin gene was sequenced to confirm the identity of these isolates. The molecular analysis demonstrated that 24 of the isolates were S. brasiliensis, with the remainder being a S. globosa isolate. The isolate characterized phenotypically as S. mexicana was clustered on the S. schenckii clade. The correlation between molecular data and phenotypic characteristics described in this study is fundamental to the identification of the Sporothrix complex.     

Humoral immune response against soluble and fractionate antigens in experimental sporotrichosis

Sporotrichosis is a chronic granulomatous mycosis caused by the dimorphic fungus Sporothrix schenckii, which is widely distributed in nature, and presents a saprophytic mycelial form on plant debris and soil. The immunological mechanisms involved in the prevention and control of sporotrichosis are not yet fully understood. In this study, mice were studied after infection with Sporothrix schenckii. In the first week after infection, fungal loading increased and thence decreased drastically 14 days after infection. Analysis by immunoblotting showed that the sera of all mice tested had antibodies reacting only with a 70 kDa antigen, with predominance of IgG1 and IgG3. Taken together, our results show that antigens from S. schenckii induced a specific humoral response in infected mice.     

Evolutionary Relationships of the Dutch Elm Disease Fungus Ophiostoma novo-ulmi to Other Ophiostoma Species Investigated by Restriction Fragment Length Polymorphism Analysis of the rDNA Region

Restriction fragment length polymorphisms (RFLPs) in the ribosomal RNA gene (rDNA) region were used to assess relationships between the Dutch elm disease fungi Ophiostoma novo-ulmi and Ophiostoma ulmi , the recently described Himalayan Dutch elm disease pathogen, Ophiostoma himal-ulmi , the morphologically similar sapstain fungi, Ophiostoma piceae and Ophiostoma quercus , and several Ophiostoma species from hardwood trees, including Ophiostoma stenoceras and Ophiostoma proliferum . A distance matrix and cluster analysis indicated that the rDNA region of O. himal-ulmi is more closely related to those of O. novo-ulmi and O. ulmi than to those of O. piceae and O. quercus and is more distantly related to O. stenoceras and the other Ophiostoma species, which formed a separate clade. The rDNA region of O. quercus was found to be at least as closely related to that of O. novo-ulmi and O. ulmi as it is to that of O. piceae . The implications of these results for the evolution of the Dutch elm disease fungi are discussed.     

Multilocus genotyping and molecular phylogenetics resolve a novel head blight pathogen within the Fusarium graminearum species complex from Ethiopia

A survey of Fusarium head blight (FHB)-contaminated wheat in Ethiopia recovered 31 isolates resembling members of the Fusarium graminearum species complex. Results of a multilocus genotyping (MLGT) assay for FHB species and trichothecene chemotype determination suggested that 22 of these isolates might represent a new species within the Fg complex. Phylogenetic analyses of multilocus DNA sequence data resolved the 22 Ethiopian isolates as a novel, phylogenetically distinct species. The new species also appears to be novel in that MLGT probe data and sequence analysis of both ends of the TRI-cluster identified 15ADON and NIV recombination blocks, documenting inter-chemotype recombination involving the chemotype-determining genes near the ends of the TRI-cluster. Results of pathogenicity experiments and analyses of trichothecene mycotoxins demonstrated that this novel Fg complex species could induce FHB on wheat and elaborate 15ADON in planta. Herein the FHB pathogen from Ethiopia is formally described as a novel species.     

发簇孢属的一个新种

不规则分枝发簇孢Sporothrix inusitatiramosa Kong分离于湖北省神农架的木头上,它的某些形态特征不同于该属已发表的各个种。