These European Society for Clinical Microbiology and Infectious Diseases and European Confederation of Medical Mycology Joint Clinical Guidelines focus on the diagnosis and management of mucormycosis. Only a few of the numerous recommendations can be summarized here. To diagnose mucormycosis, direct microscopy preferably using optical brighteners, histopathology and culture are strongly recommended. Pathogen identification to species level by molecular methods and susceptibility testing are strongly recommended to establish epidemiological knowledge. The recommendation for guiding treatment based on MICs is supported only marginally. Imaging is strongly recommended to determine the extent of disease. To differentiate mucormycosis from aspergillosis in haematological malignancy and stem cell transplantation recipients, identification of the reverse halo sign on computed tomography is advised with moderate strength. For adults and children we strongly recommend surgical debridement in addition to immediate first-line antifungal treatment with liposomal or lipid-complex amphotericin B with a minimum dose of 5 mg/kg/day. Amphotericin B deoxycholate is better avoided because of severe adverse effects. For salvage treatment we strongly recommend posaconazole 4×200 mg/day. Reversal of predisposing conditions is strongly recommended, i.e. using granulocyte colony-stimulating factor in haematological patients with ongoing neutropenia, controlling hyperglycaemia and ketoacidosis in diabetic patients, and limiting glucocorticosteroids to the minimum dose required. We recommend against using deferasirox in haematological patients outside clinical trials, and marginally support a recommendation for deferasirox in diabetic patients. Hyperbaric oxygen is supported with marginal strength only. Finally, we strongly recommend continuing treatment until complete response demonstrated on imaging and permanent reversal of predisposing factors.
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°C, and the assimilation of sucrose, raffinose, and ribitol.Sporothrix schenckii is a dimorphic fungus causing sporotrichosis, a severe infection usually acquired by the traumatic inoculation of colonized materials or by inhalation of spores through the respiratory tract (3, 6). Cutaneous lymphatic disease is the most common clinical manifestation, although other types of disease including disseminated infection are also produced. Sporotrichosis has a worldwide distribution, especially in tropical and subtropical areas. The natural habitat of S. schenckii is soil and plants. The teleomorph of this fungus has not yet been discovered, although a close genetic relationship between S. schenckii and the ascomycetous genus Ophiostoma has been demonstrated (2, 3). Contrary to previously reported suggestions, Ophiostoma stenoceras appears (5) not to be the teleomorph (4,8,27,30). In recent years, numerous molecular studies involving S. schenckii have been carried out (13,15,22,23,25,32,34) and have clearly demonstrated the existence of several groups that are genetically different. In a recent multilocus study, we investigated the population structure of S. schenckii and showed the existence of at least six putative phylogenetic species prevalent in different geographical regions (20). In several in vitro antifungal susceptibility studies of clinical isolates of S. schenckii, a wide range of susceptibility to different drugs has been demonstrated (16,21,31). This suggests that these isolates could represent different species. If true, knowledge of their various responses to antifungal agents would be critical for appropriate patient management.The aim of the present study was to phenotypically characterize the different phylogenetic species of the S. schenckii complex in order to find key morphological and/or physiological ...
Mycoses summarized in the hyalohyphomycosis group are heterogeneous, defined by the presence of hyaline (non-dematiaceous) hyphae. The number of organisms implicated in hyalohyphomycosis is increasing and the most clinically important species belong to the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces. Severely immunocompromised patients are particularly vulnerable to infection, and clinical manifestations range from colonization to chronic localized lesions to acute invasive and/or disseminated diseases. Diagnosis usually requires isolation and identification of the infecting pathogen. A poor prognosis is associated with fusariosis and early therapy of localized disease is important to prevent progression to a more aggressive or disseminated infection. Therapy should include voriconazole and surgical debridement where possible or posaconazole as salvage treatment. Voriconazole represents the first-line treatment of infections due to members of the genus Scedosporium. For Acremonium spp., Scopulariopsis spp., Purpureocillium spp. and Paecilomyces spp. the optimal antifungal treatment has not been established. Management usually consists of surgery and antifungal treatment, depending on the clinical presentation.
Current knowledge on the opportunist Scedosporium apiospermum (teleomorph: Pseudallescheria boydii), generated over a period of more than 120 years, is reviewed. The natural environmental habitat of the fungus is unknown; nutrient-rich, brackish waters like river estuaria have been suggested. The fungus is strongly promoted by agricultural and particularly by industrial pollution.
Scedosporium prolificans is a truly emerging fungal pathogen. It has only been recognized as a human pathogen for 22 years and has been related with numerous infections in immunocompromised and immunocompetent patients. A search for cases in the literature was performed and a database was constructed. Cases were reviewed in order to analyse the epidemiology and outcome of infection. A total of 162 cases were included. The median age of patients was 45 years (ranging from a few months to 81 years), and 102 (63%) infections were diagnosed in males. Risk factors for scedosporiosis were malignancy, 74/162 (45.7%), cystic fibrosis, 19/172 (11.7%), and solid organ transplantation 14/162 (8.6%). The most common clinical presentations were disseminated infection, 72/162 cases (44.4%), pulmonary mycosis, 47/162 (29%), and bone and joint infections, 17/162 (10.4%). All disseminated infections afflicted patents with underlying diseases, primarily haematological malignancies (57/72 [80%]). Blood cultures were positive in 70% of patients suffering from disseminated mycosis. Neutropenia, fever and cerebral symptoms were independently related to the development of disseminated infection whereas recovery from aplasia was associated with a reduced risk. The overall mortality was 46.9% but mortality rate was 87.5% in patients with disseminated disease. Survival was independently associated with surgical excision and recovery from aplasia. Antifungal treatments were not related to a reduced risk of death. Infections caused by S. prolificans are life threatening in susceptible patients, and can be considered a truly emerging disease. Infections are difficult to treat since it is a multi-resistant species. Multicenter studies are essential with the aim of developing and disseminating appropriate techniques and protocols to treat this mycosis.
The aetiological agents of many invasive fungal infections are saprobes and opportunistic pathogens. Some of these fungi are darkly pigmented due to melanin production and traditionally have been named 'dematiaceous'. The melanized fungi cause a wide array of clinical syndromes ranging from superficial to deep-seated infections. Diagnosis relies on histopathological examination of clinical specimens and on examination of cultures. Sequencing is recommended for accurate species identification, especially for unusual or newly described pathogens. In cases of mycetoma and chromoblastomycosis, pathognomonic histological findings are useful and the Fontana-Masson stain, specific for melanin, usually confirms the diagnosis. There are no standardized therapies but voriconazole, posaconazole and itraconazole demonstrate the most consistent in vitro activity against this group of fungi. Oral itraconazole has been considered the drug of choice, given the extensive clinical experience with this drug. However, voriconazole may presumably be superior for central nervous system infections because of its ability to achieve good levels in the cerebrospinal fluid. Posaconazole is a well-tolerated alternative drug, backed by less clinical experience but with excellent salvage treatment results after failure of other antifungals. Amphotericin B has been useful as alternative therapy in some cases. Combination antifungal therapy is recommended for cerebral abscesses when surgery is not possible and for disseminated infections in immunocompromised patients.
Pseudallescheria boydii (anamorph Scedosporium apiospermum) is the species responsible for human scedosporiosis, a fungal infection with a high mortality rate and which is difficult to treat. Recently, it has been demonstrated that high genetic variation exists within this species. We have performed a morphological and molecular study involving numerous strains of clinical or environmental origins and from different countries. The analysis of partial sequences of the -tubulin (two loci) and calmodulin genes and the internal transcribed spacer region of the rRNA gene has demonstrated that P. boydii is a species complex. The combined analysis of the sequences of the four loci of 60 strains has showed the presence of 44 haplotypes in the ingroup. Three species morphologically related to P. boydii sensu stricto, i.e., Pseudallescheria angusta, Pseudallescheria ellipsoidea, and Pseudallescheria fusoidea, which had previously been considered synonyms, could be differentiated genetically from P. boydii in our study. It is relevant that two of the three strains now included in P. ellipsoidea have caused invasive infections. The species Pseudallescheria minutispora and Scedosporium aurantiacum are clearly phylogenetically separated from the other species studied and are here proposed as new. Morphological features support this proposal. All the strains included in S. aurantiacum species have a clinical origin, while those included in P. minutispora are environmental. Further studies are needed to demonstrate whether all the species included in the P. boydii complex have different clinical spectra and antifungal susceptibility.Pseudallescheria boydii (anamorph Scedosporium apiospermum) is a ubiquitous ascomycetous fungus that causes a wide array of human infections that can affect practically all the organs of the body (8). These infections have been known for a long time, but in recent years, a marked increase in severe invasive infections has been noticed, mainly in immunocompromised hosts. The treatment of these infections has not yet been resolved, and the mortality rate is very high (3, 17). One of the most typical features of this species, which is very rare in other pathogenic fungi, is its ability to develop sexual structures on routine culture media. The presence of spherical ascomata (cleistothecia) and fusiform or ellipsoidal ascospores allows easy identification of this species and its differentiation from the other species of Scedosporium, Scedosporium prolificans, whose sexual state still remains unknown.On the basis of nuclear DNA-DNA reassociation, some studies have proved that important genetic variation exists in P. boydii. Gueho and de Hoog (10) found three infraspecific ecological and clinical groups. Rainer et al. (16) reported the existence of five different small-subunit rRNA gene sequence lengths. Random amplified polymorphic DNA studies also demonstrated that numerous and very different genotypes can be found (7). Other authors have reported considerable differences with respect to growth and sp...
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.
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