In vitro activity of micafungin combined with itraconazole against Candida spp

The in vitro activity of the combination micafungin + itraconazole was evaluated against 105 strains of six species of Candida. The highest percentage of synergy was obtained against Candida albicans (50%) and the lowest against Candida tropicalis (0%).

El papel del voriconazol en el tratamiento de las micosis emergentes

Voriconazole is a broad-spectrum antifungal drug belonging to triazoles class. Recently, it has been recommended for the treatment of invasive candidiasis in non neutropenic patients. In addition, this drug has showed clinical efficacy in the treatment of fungal infections caused by Candida species other than Candida albicans, and also in several other infections caused by less common fungi, such as Aspergillus terreus, Fusarium and Scedosporium.

Acrophialophora fusispora: an emerging agent of human mycoses. A report of 3 new clinical cases

Acrophialophora fusispora is a soil-borne fungus, which is emerging as a human pathogen. Only four cases of human infection had been described previously. We describe three more cases, two from Europe and one from India. Since this fungus has been misidentified in several other cases, it is probably more frequent than first thought.

Reclassification of Graphium tectonae as Parascedosporium tectonae gen. nov., comb. nov., Pseudallescheria africana as Petriellopsis africana gen. nov., comb. nov. and Pseudallescheria fimeti as Lophotrichus fimeti comb. nov

During a biodiversity survey of Argentinian soil fungi, we recovered a rare Scedosporium-like fungus which was proven to be genetically and morphologically different from known species of Scedosporium (anamorph of Pseudallescheria) and relatives and is proposed here as representing a new genus. This genus is mainly characterized by producing sympodial conidia from denticulate conidiogenous cells. This isolate was morphologically identical to Graphium tectonae and thus the new combination Parascedosporium tectonae gen. nov., comb. nov. is proposed. Sequence analysis of four regions of three genes, i.e. β-tubulin (two loci), calmodulin and the internal transcribed spacer region of the 5.8S rRNA, confirmed our proposal. Both the phylogenetic analysis and morphological studies excluded Pseudallescheria africana and Pseudallescheria fimeti from the genus Pseudallescheria. The former is proposed as a member of the new genus Petriellopsis, and the latter has been accommodated in Lophotrichus. The type strains of Parascedosporium tectonae gen. nov., comb. nov., Petriellopsis africana gen. nov., comb. nov. and Lophotrichus fimeti comb. nov. are respectively CBS 127.84T, CBS 311.72T and CBS 129.78T.

Sporothrix brasiliensis, S. globosa, and S. mexicana, three new Sporothrix species of clinical interest

Sporothrix schenckii is the species responsible for sporotrichosis, a fungal infection caused by the traumatic implantation of this dimorphic fungus. Recent molecular studies have demonstrated that this species constitutes a complex of numerous phylogenetic species. Since the delineation of such species could be of extreme importance from a clinical point of view, we have studied a total of 127 isolates, most of which were received as S. schenckii, including the available type strains of species currently considered synonyms, and also some close morphological species. We have phenotypically characterized all these isolates using different culture media, growth rates at different temperatures, and numerous nutritional tests and compared their calmodulin gene sequences. The molecular analysis revealed that Sporothrix albicans, S. inflata, and S. schenckii var. luriei are species that are clearly different from S. schenckii. The combination of these phenetic and genetic approaches allowed us to propose the new species Sporothrix brasiliensis, S. globosa, and S. mexicana. The key phenotypic features for recognizing these species are the morphology of the sessile pigmented conidia, growth at 30, 35, and 37 degrees C, and the assimilation of sucrose, raffinose, and ribitol.

In vitro activity of voriconazole against dermatophytes, Scopulariopsis brevicaulis and other opportunistic fungi as agents of onychomycosis

Using a reference microdilution method, we studied the antifungal susceptibility to voriconazole and fluconazole of 304 clinical isolates from four species of onychomycosis-causing dermatophytes, 196 isolates of dermatophytes not related to nail infection as well as Scopulariopsis brevicaulis, Fusarium spp. and Scytalidium dimidiatum. Results showed a high antifungal activity of voriconazole against dermatophytes (geometric mean minimal inhibitory concentration (MIC)=1.14 microg/mL; MIC for 50% of the organisms (MIC(50))=0.062 miccrog/mL; MIC for 90% of the organisms (MIC(90))=0.25 microg/mL). For S. brevicaulis, the in vitro activity of voriconazole was considerably lower (geometric mean MIC=8.52 microg/mL; MIC(50) and MIC(90)=16 microg/mL). Although voriconazole is not among the drugs recommended for the management of onychomycosis, it can be a useful alternative for recalcitrant infections.

Efficacy of voriconazole in a murine model of cryptococcal central nervous system infection

OBJECTIVES

We studied the efficacy of voriconazole compared with amphotericin B in a murine model of central nervous system infection by Cryptococcus neoformans. Infection was established intracerebrally.

METHODS

Mice were treated with voriconazole at 10, 40 or 60 mg/kg/day orally or with amphotericin B at 1.5 mg/kg/day intraperitoneally. Treatment began 1 day after infection and continued for 10 days post-infection. Tissue burden studies were performed on day 7 and 1 day after the treatment finished.

RESULTS

Both drugs were able to significantly prolong survival with respect to the control group. The highest tissue burden reduction was achieved with voriconazole at 60 mg/kg/day.

CONCLUSIONS

We have developed a murine model of cryptococcal central nervous system infection and demonstrated that voriconazole has a potential for the treatment of cryptococcosis.

Combined therapies in a murine model of blastoschizomycosis

In a murine model of blastoschizomycosis, amphotericin B combined with micafungin, flucytosine or voriconazole did not improve the efficacy of fluconazole. However, such combinations can constitute therapeutic options for those cases where fluconazole fails.

A reassessment of cleistothecia as a taxonomic character

The morphology of sexual fruit bodies has been historically regarded as a key character in fungal taxonomy. In the 1970s the class Plectomycetes was recognized in order to classify the cleistothecial ascomycetes. However, recent analysis of DNA sequencing data concerning the phylogeny of numerous cleistothecial ascomycetes confirmed that the criterion of the production of closed ascomata without a predefined opening and with an irregular arrangement of the asci at the centrum is of little systematic value, as pointed out by different authors on the basis of morphological studies.

Aeromonas hemolytic uremic syndrome. A case and a review of the literature

Although rarely, hemolytic uremic syndrome can be induced by Aeromonas. We report a case in a 40-year-old Spanish female produced by Aeromonas veronii bv. sobria and review the previous cases described in the literature. This is the 2nd case described in adults.

Two new ascomycetes from rainforest litter in Costa Rica

Two new ascomycetes, Boerlagiomyces costaricensis (Pleosporales) and Scopinella musciformis (Sordariales sensu lato), from litter samples collected in rainforests of Costa Rica, are described and illustrated. Boerlagiomyces costaricensis has globose, ostiolate ascomata covered by numerous setae-like hairs; cylindrical, fissitunicate asci without apical structures; and large, fusiform, muriform, hyaline to pale brown ascospores. Scopinella musciformis is characterized by ostiolate ascomata with a few compact clusters of hypha-like hairs distributed on the peridial surface and a long neck; ovate to ellipsoidal unitunicate asci; and small quadrangular ascospores with diagonal germ slits.

Universal in vitro antifungal resistance of genetic clades of the Fusarium solani species complex

Eleven antifungal drugs were tested against representative isolates of the four phylogenetic clades of the Fusarium solani species complex obtained in a multilocus sequence analysis. They all showed very poor activity, with no differences among the clades. Amphotericin B was the most active drug.

Saksenaea vasiformis infections: case report and literature review

Since the first human infection by Saksenaea vasiformis in 1976 another 26 cases have been reported. Here is a report of a new case which involved an Ecuadorian adolescent who suffered serious burns after a car accident. It developed as a localized cutaneous infection which was successfully treated with surgical debridement and amphotericin B. This is the second report of this infection from South America and the third involving a burn patient. The previously reported 27 cases are reviewed.

Effect of antifungal treatment in a murine model of blastoschizomycosis

Blastoschizomyces capitatus is an emerging pathogenic fungus that can cause deep invasive diseases in neutropenic patients. We developed a model of disseminated blastoschizomycosis in immunosuppressed mice to evaluate the effectiveness of amphotericin B, flucytosine, fluconazole and voriconazole. High-dose fluconazole was the most effective drug at prolonging the survival of mice and at reducing fungal burden in the kidneys, spleen and liver.

A quick and cost-effective method for diagnosing disseminated histoplasmosis in children

The examination of fecal mucus for detecting yeast cells of Histoplasma capsulatum has proved to be a useful tool for diagnosing disseminated histoplasmosis in paediatric patients in a study of 13 cases carried out in Ecuador.

Distinct signalling pathways coordinately contribute to virulence of Fusarium oxysporum on mammalian hosts

The filamentous fungus Fusarium oxysporum causes vascular wilt on a wide range of plant species and is an emerging pathogen of humans. A mitogen-activated protein kinase, Fmk1, and a G protein beta subunit, Fgb1, control pathogenicity of F. oxysporum on plants through distinct signalling pathways. In the present report, we studied the genetic interaction between fmk1 and fgb1 and their role in virulence on a mammalian host. The delta fmk1 or delta fgb1 single mutants exhibited similar virulence patterns as the wild type strain in an immunodepressed mouse model. By contrast, double mutants lacking both genes had dramatically reduced virulence. All mutants showed similar in vitro growth or tolerance to temperature and osmotic stress as the wild type strain. However, the delta fgb1 and delta fmk1 strains were reduced in specific extracellular protease activity or adhesion to fibronectin, respectively, two factors previously associated with fungal virulence. Thus, Fmk1 and Fgb1 are components of distinct signalling pathways which collectively control virulence of F. oxysporum on mammalian hosts.

Molecular phylogeny of Coniochaetales

Although the taxonomy of ascomycetes has changed dramatically, generic delimitation within the recently proposed order Coniochaetales has not been resolved. In order to clarify the phylogenetic relationships of genera in the Coniochaetaceae, we performed a molecular study based on the analyses of the sequences of the partial SSU and of the variable domains of the LSU rDNA genes. The phylogenetic trees obtained do not support the monophyly of the genera Coniochaeta, Coniochaetidium, Ephemeroascus, and Poroconiochaeta. A morphological study confirmed that there were not enough differences to distinguish these genera, and the latter three are treated as synonyms of Coniochaeta. The phialidic anamorph proved to be an informative phylogenetic character in Coniochaetales, while that the type of ascomata (cleistothecial or perithecial) and the ornamentation of the ascospore walls were of little taxonomic value at the generic level. The circumscription of the genus Coniochaeta is revised. The genera Coniocessia and Coniolariella are proposed as new within the order Xylariales to accommodate Coniochaeta nodulisporioides, and C. gamsii, respectively. The taxonomic position of Synaptospora and Wallrothiella subiculosa are also discussed.

Corylomyces: a new genus of Sordariales from plant debris in France

The new genus Corylomyces, isolated from the surface of a hazelnut (Corylus avellana) in the French Pyrenees, is described, illustrated and compared with morphologically similar taxa. It is characterised by tomentose, ostiolate ascomata possessing long necks composed of erect to sinuose hairs, and one- or two-celled, opaque, lunate to reniform ascospores. Analyses of the SSU and LSU fragments rDNA gene sequences support its placement in the Lasiosphaeriaceae (Sordariales).

Molecular phylogeny of Sporothrix schenckii

The pathogenic dimorphic fungus Sporothrix schenckii is the agent responsible for sporotrichosis, an important fungal infection with a worldwide distribution. Little is known about the population structure of S. schenckii, although recent molecular and phenotypic data seem to demonstrate that different genetic lineages exist within this species. The aim of this study was to determine, by sequence analysis of three protein coding loci (chitin synthase, beta-tubulin, and calmodulin), whether this variability is due to species divergence or intraspecific diversity in S. schenckii. We included in the analysis 60 isolates (59 of clinical and 1 of environmental origin) of this species from a wide geographical range. DNA sequence data from the three nuclear regions were used in a phylogenetic analysis. The combined analysis of the three loci revealed the presence of three major clades, one grouping all of the European isolates, another with only Brazilian isolates, and the third with isolates from other South American countries and Africa. A total of 14 100% bootstrap-supported nodes were shown, 6 of them representing putative phylogenetic species. Our data also demonstrated that most of these species prevail in different geographical regions.

Antifungal susceptibilities of the species of the Pseudallescheria boydii complex

Eighty-four isolates belonging to eight species that constitute the Pseudallescheria boydii complex were tested against 11 antifungal agents by using the microdilution method. There were significant differences among the species, with Scedosporium aurantiacum being the most resistant. In general, voriconazole was the most active drug, followed by posaconazole.

Clinical manifestations, treatment and outcome of Paecilomyces lilacinus infections

The fungus Paecilomyces lilacinus is an emerging pathogen that causes severe human infections, including devastating oculomycosis. Usually, it shows low susceptibility to conventional antifungal drugs in vitro, and variable susceptibility to novel triazoles. A review of the published literature identified 119 reported cases of human infection by P. lilacinus between 1964 and 2004. Most were cases of oculomycosis (51.3%), followed by cutaneous and sub-cutaneous infections (35.3%), and a smaller group of miscellaneous infections (13.4%). Lens implantation is the most frequent predisposing factor for oculomycosis. Cutaneous and sub-cutaneous infections occur mainly in solid organ and bone marrow transplant recipients, although surgery and primary or acquired immunodeficiency are also relevant predisposing factors. Infections in apparently immunocompetent patients have also been reported. Surgical debridement combined with antifungal drug therapy, or the correction of predisposing factors, such as neutropenia, are usually required to obtain improvement. Treatment with traditional antifungal drugs often fails. Voriconazole has demonstrated good activity in both cutaneous and ocular infections in the few cases in which this drug has been used. The new triazoles ravuconazole and posaconazole show good in-vitro activity against P. lilacinus and could be promising therapeutic alternatives.