Sequencing the Genomes of the First Terrestrial Fungal Lineages: What Have We Learned?

The first genome sequenced of a eukaryotic organism was for Saccharomyces cerevisiae, as reported in 1996, but it was more than 10 years before any of the zygomycete fungi, which are the early-diverging terrestrial fungi currently placed in the phyla Mucoromycota and Zoopagomycota, were sequenced. The genome for Rhizopus delemar was completed in 2008; currently, more than 1000 zygomycete genomes have been sequenced. Genomic data from these early-diverging terrestrial fungi revealed deep phylogenetic separation of the two major clades-primarily plant-associated saprotrophic and mycorrhizal Mucoromycota versus the primarily mycoparasitic or animal-associated parasites and commensals in the Zoopagomycota. Genomic studies provide many valuable insights into how these fungi evolved in response to the challenges of living on land, including adaptations to sensing light and gravity, development of hyphal growth, and co-existence with the first terrestrial plants. Genome sequence data have facilitated studies of genome architecture, including a history of genome duplications and horizontal gene transfer events, distribution and organization of mating type loci, rDNA genes and transposable elements, methylation processes, and genes useful for various industrial applications. Pathogenicity genes and specialized secondary metabolites have also been detected in soil saprobes and pathogenic fungi. Novel endosymbiotic bacteria and viruses have been discovered during several zygomycete genome projects. Overall, genomic information has helped to resolve a plethora of research questions, from the placement of zygomycetes on the evolutionary tree of life and in natural ecosystems, to the applied biotechnological and medical questions.

A study on the fungal rhinosinusitis: Causative agents, symptoms, and predisposing factors.

Background: In natural conditions, inhaled fungi are considered a part of the microflora of nasal cavities and sinuses. However, subsequent to the protracted use of corticosteroids and antibacterial agents, suppression of the immune system by chemotherapy, and poor ventilation, these fungi can become pathogens. Fungal colonization in the nose and paranasal sinuses is a prevalent medical issue in immunocompetent and immunosuppressed patients. In this study, we aimed to categorize fungal rhinosinusitis (FRS) among immunocompetent and immunosuppressed patients and identified the etiologic agents of disease by molecular methods. Materials and Methods: A total of 74 cases were evaluated for FRS. Functional endoscopic sinus surgery was performed for sampling. The clinical samples were examined by direct microscopy with potassium hydroxide 20% and subcultured on Sabouraud Dextrose Agar with chloramphenicol. Polymerase chain reaction sequencing was applied to identify causative agents. Results: Thirty-three patients (44.6%) had FRS. Principal predisposing factors were antibiotic consumption (n = 31, 93.9%), corticosteroid therapy (n = 22, 66.6%), and diabetes mellitus (n = 21, 63.6%). Eyesore (n = 22, 66.6%), proptosis (n = 16, 48.5%), and headache (n = 15, 45.4%) were the most common clinical manifestations among patients. Rhizopus oryzae (n = 15, 45.4%) and Aspergillus flavus (n = 10, 30.3%) were the most prevalent fungal species. Conclusion: Diagnosis and classification of FRS are crucial, and a lack of early precise diagnosis can lead to a delay in any surgical or medical management. Since there are a variety of treatments for FRS, accurate identification of etiologic agents should be performed based on phenotypic and molecular methods.

Phaeohyphomycosis caused by Neoscytalidiumdimidiatum in a COVID-19 patient.

BACKGROUND: Neoscytalidiumdimidiatum is an opportunistic dematiaceous fungus belonging to the class Dothideomycetes. CASE REPORT: We report a case of N. dimidiatum cerebral phaeohyphomycosis post COVID-19 infection in a 32-year-old male from Iran. The causative agent was identified by cytopathology, routine mycological methods, and DNA sequencing of the internal transcribed spacer (ITS) region of rDNA. Apart from COVID-19 complications and the corticosteroid therapy, no underlying condition was diagnosed. The symptoms suggesting the fungal infection were shown two weeks after being discharged from COVID-19 hospital stay. Magnetic resonance of the brain showed a multi-focal central nervous system infection. The delayed identification of the fungus and, thus, a late starting of the antifungal treatment with amphotericin B, might have affected the patient outcome as he finally died. CONCLUSIONS: Considering the rare incidence of N. dimidiatum infections, this case should aware us about them, leading to a timely antifungal management.

Marginal lands and fungi - linking the type of soil contamination with fungal community composition.

Fungi can be found in almost all ecosystems. Some of them can even survive in harsh, anthropogenically transformed environments, such as post-industrial soils. In order to verify how the soil fungal diversity may be changed by pollution, two soil samples from each of the 28 post-industrial sites were collected. Each soil sample was characterized in terms of concentration of heavy metals and petroleum derivatives. To identify soil fungal communities, fungal internal transcribed spacer 2 (ITS2) amplicon was sequenced for each sample using Illumina MiSeq platform. There were significant differences in the community structure and taxonomic diversity among the analysed samples. The highest taxon richness and evenness were observed in the non-polluted sites, and lower numbers of taxa were identified in multi-polluted soils. The presence of monocyclic aromatic hydrocarbons, gasoline and mineral oil was determined as the factors driving the differences in the mycobiome. Furthermore, in the culture-based selection experiment, two main groups of fungi growing on polluted media were identified - generalists able to live in the presence of pollution, and specialists adapted to the usage of BTEX as a sole source of energy. Our selection experiment proved that it is long-term soil contamination that shapes the community, rather than temporary addition of pollutant.

In vitro activity of eight antifungal drugs against Chaetomiaceae.

The incidence of infections caused by uncommon Chaetomiaceae (Chaetomium and related species) in humans has increased in the recent years. The in vitro activity of eight antifungal drugs (amphotericin B, five azoles, two echinocandins) against 42 morphologically identified Chaetomium strains was determined according to the Clinical and Laboratory Standards Institute (CLSI) guideline. The strains were subsequently identified based on sequences of the internal transcribed spacer 1 and 2 including the intervening 5.8S nrDNA region (ITS) and the partial ß tubulin gene (tub2). Chaetomium globosum (n = 24), was the most frequently isolated species, followed by Amesia atrobrunnea (syn. Chaetomium atrobrunnea, n = 6), Dichotomopilus dolichotrichus (syn. Chaetomium dolichotrichum, n = 2) and Acrophialophora jodhpurensis, Chaetomium coarctatum, C. elatum, C. gracile, C. subaffine, C. tarraconense, C. unguicola, Dichotomopilus sp., Dichotomopilus variostiolatus, Ovatospora brasiliensis (all represented by a single strain). The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all strains were (in increasing order): micafungin 0.12 µg/ml, itraconazole and posaconazole 0.21 µg/ml, amphotericin B 0.25 µg/ml, voriconazole 0.45 µg/ml, isavuconazole 0.54 µg/ml, caspofungin 2.57 µg/ml, and fluconazole 45.25 µg/ml. Micafungin had the lowest geometric mean followed by amphotericin B which had the largest range against tested isolates. All examined C. globosum strains had similar antifungal susceptibility patterns. Fluconazole and caspofungin could not be considered as an option for treatment of infections caused by Chaetomium and chaetomium-like species. LAY SUMMARY: Infections caused by uncommon fungi such as Chaetomium have increased in the recent years. Chaetomium globosum has been reported from onychomycosis and phaeohyphomycosis. This species often induces superficial infections in immunocompetent patients. The taxonomy of Chaetomium spp. has changed dramatically in the last years. Antifungal treatment is a crucial step for managing these kinds of infections. Therefore, the in vitro activity of eight antifungal drugs against Chaetomium strains was determined and ß-tubulin (tub2) sequencing was applied to identify the strains. Chaetomium globosum was the most frequent species in our dataset. Based on the results of susceptibility testing, micafungin had the lowest geometric mean followed by amphotericin B. Fluconazole and caspofungin cannot be considered a proper treatment option for infections caused by Chaetomium and chaetomium-like species.

In vitro activities of 8 antifungal drugs against 126 clinical and environmental Exophiala isolates.

BACKGROUND: Exophiala is the main genus of black fungi comprising numerous opportunistic species. Data on antifungal susceptibility of Exophiala isolates are limited, while infections are potentially fatal. MATERIALS AND METHODS: In vitro activities of eight antifungal drugs (AMB, five azoles, two echinocandins) against 126 clinical (n = 76) and environmental (n = 47) isolates from around the world were investigated. E. oligosperma (n = 58), E. spinifera (n = 33), E. jeanselmei (n = 14) and E. xenobiotica (n = 21) were included in our dataset. RESULTS: The resulting MIC90 s of all strains were as follows, in increasing order: posaconazole 0.063 µg/ml, itraconazole 0.125 µg/ml, voriconazole and amphotericin B 1 µg/ml, isavuconazole 2 µg/ml, micafungin and caspofungin 4 µg/ml, and fluconazole 64 µg/ml. Posaconazole, itraconazole and micafungin were the drugs with the best overall activity against Exophiala species. Fluconazole could not be considered as a treatment choice. No significant difference could be found among antifungal drug activities between these four species, neither in clinical nor in environmental isolates. CONCLUSION: Antifungal susceptibility data for Exophiala spp. are crucial to improve the management of this occasionally fatal infection and the outcome of its treatment.

Molecular Diversity of Aspergilli in Two Iranian Hospitals.

The Aspergillus species are main causative agents of various infections such as invasive aspergillosis (IA) in immunocompromised patients and these infections have high mortality rates. In this study, we provide insight in the species causing aspergillosis in Iran based on morphology and sequence data. Clinical (n = 117) and environmental isolates (n = 54) collected during 2010-2016 from University hospitals in Mashhad and Tehran (Iran) were identified both morphologically and molecularly using partial calmodulin (CaM) gene sequences. Clinical cases were identified based on EORTC/MSG criteria. Aspergillus flavus (n = 96, 55%) was the most prevalent species among the clinical and environmental isolates while A. fumigatus (n = 13, 7.5%) ranked fourth after A. tubingensis (n = 23, 13%) and A. welwitchiae (n = 18, 10%). Species such as A. tubingensis, A. welwitschiae, A. fumigatus, A. sydowii, A. neoniger and A. terreus were present in both clinical and environmental samples indicating the possible environmental source of infections. Interestingly, A. niger was isolated only once. Furthermore, 13 other rare and cryptic Aspergillus species were detected. Pulmonary and respiratory disorders (n = 33), followed by transplantation (n = 23), invasive fungal rhinosinusitis (n = 14), and haematological malignancies (n = 12) were major predisposing factors. According to EORTC/MSG criteria, there were 43 probable cases identified followed by 36 cases for each of proven and possible ones. Correct molecular identification will be useful for further epidemiological studies.

Phylogenetic Analysis of Clinically Relevant Fusarium Species in Iran.

Fungi of the genus Fusarium are well known as major plant pathogens but also cause a broad spectrum of human infections. Sixty-three clinical isolates, collected during 2014-2017, were identified using a part of the TEF1 gene as barcoding marker. Fusarium fujikuroi species complex (FFSC, n = 41, 65%) showed to be the dominant etiological agent, followed by F. solani species complex (FSSC, n = 14, 22%) and F. oxysporum species complex (FOSC, n = 7, 11%). There was one strain belonging to F. lateritium species complex (FLSC, n = 1, 1.5%). For final identification, a phylogenetic tree was constructed including the type strains of each species complex. Most cases of fusariosis were due to nail infection (n = 38, 60.3%), followed by keratitis (n = 22, 34%). Fusarium infections are difficult to be treated due to their intrinsic resistance to different azoles; however, accurate and fast identification of etiological agents may enhance management of the infection. We present the first phylogenetic study on clinical Fusarium spp. from Iran.

Molecular Identification, Genotypic Diversity, Antifungal Susceptibility, and Clinical Outcomes of Infections Caused by Clinically Underrated Yeasts, Candida orthopsilosis, and Candida metapsilosis: An Iranian Multicenter Study (2014-2019).

Despite the increasing occurrence of Candida orthopsilosis and Candida metapsilosis in clinical settings, little is known about their microbiological and clinical properties. Herein, we conducted a national retrospective study (2014-2019) from multiple centers in Iran. Among the 1,770 Candida isolates collected, we identified 600 Candida parapsilosis species complex isolates. Isolate identification was performed by 9-plex PCR, matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS), and rDNA sequencing, and antifungal susceptibility testing (AFST) followed CLSI M27-A3/S4; genotyping was performed by amplified fragment length polymorphism (AFLP) analysis; and clinical information was mined. Thirty-one isolates of C. orthopsilosis from various clinical sources, one mixed sample (blood) concurrently containing C. orthopsilosis and C. parapsilosis and one isolate of C. metapsilosis from a nail sample were identified. Although both 9-plex PCR and MALDI-TOF successfully identified all isolates, only 9-plex PCR could identify the agents in a mixed sample. For the C. orthopsilosis isolates, resistance (non-wild type) was noted only for itraconazole (n = 4; 12.5%). Anidulafungin and fluconazole showed the highest and voriconazole had the lowest geometric mean values. AFLP analysis showed three main and four minor genotypes. Interestingly, 90% of nail isolates clustered with 80% of the blood isolates within two clusters, and four blood isolates recovered from four patients admitted to a hospital clustered into two genotypes and showed a high degree of similarity (>99.2%), which suggests that C. orthopsilosis disseminates horizontally. Supported by our data and published case studies, C. orthopsilosis and C. metapsilosis can be linked to challenging clinical failures, and successful outcomes are not always mirrored by in vitro susceptibility. Accordingly, conducting nationwide studies may provide more comprehensive data, which is required for a better prognosis and clinical management of patients.

Carbon assimilation profiles of mucoralean fungi show their metabolic versatility.

Most mucoralean fungi are common soil saprotrophs and were probably among the first land colonisers. Although Mucoromycotina representatives grow well on simple sugar media and are thought to be unable to assimilate more complex organic compounds, they are often isolated from plant substrates. The main goal of the study was to explore the effects of isolation origin and phylogenetic placement on the carbon assimilation capacities of a large group of saprotrophic Mucoromycotina representatives (i.e. Umbelopsidales and Mucorales). Fifty two strains representing different Mucoromycotina families and isolated from different substrates were tested for their capacity to grow on 99 different carbon sources using the Biolog phenotypic microarray system and agar plates containing selected biopolymers (i.e. cellulose, xylan, pectin, and starch) as a sole carbon source. Although our results did not reveal a correlation between phylogenetic distance and carbon assimilation capacities, we observed 20 significant differences in growth capacity on specific carbon sources between representatives of different families. Our results also suggest that isolation origin cannot be considered as a main predictor of the carbon assimilation capacities of a particular strain. We conclude that saprotrophic Mucoromycotina representatives are, contrary to common belief, metabolically versatile and able to use a wide variety of carbon sources.

First case of fungal keratitis due to Aspergillus minisclerotigenes in Iran.

BACKGROUND AND PURPOSE: Herein, we report the first case of fungal keratitis due to Aspergillus minisclerotigenes in a 68-year-old rural woman admitted to the Ophthalmology Center of Khatam-Al-Anbia Hospital in Mashhad, northeast of Iran. CASE REPORT: The patient presented with severe pain, burning, foreign body sensation, and reduced vision in her right eye. She had long-term uncontrolled diabetes and was not able to close her eye due to an anatomical problem with the eyelid. The cornea smear sample was cultured, and the fungus was initially identified as Aspergillus flavus. The isolated strain was further identified by sequencing a part of the calmodulin gene as A. minisclerotigenes. The patient did not respond to any antifungal treatments (e.g., amphotericin B and voriconazole drops, and fluconazole 300 mg/day); therefore, she was eventually subjected to corneal transplantation surgery. CONCLUSION: Fungal keratitis can be caused by the less common species. The reliable identification of the causative agents can be accomplished by the implementation of molecular methods.

Comparative pathogenicity of opportunistic black yeasts in Aureobasidium.

Aureobasidium pullulans and A. melanogenum are black-yeast-like surface colonisers and are commonly encountered as contaminants in the hospital. The species are able to produce melanin which play a role in protection against environmental stress and irradiation. Aureobasidium melanogenum shows higher frequency in opportunistic infections compared to A. pullulans. Comparative pathogenicity of opportunistic black yeasts between Aureobasidium pullulans and A. melanogenum to explain the observed differences in frequency in infection. Degrees of melanisation and thermotolerance were measured, and virulence of strains from different sources was examined in Galleria mellonela and murine infection models. Aureobasidium melanogenum responds with increased melanisation to temperature stress and generally survives at 37°C, A. pullulans on average scored less on these parameters. In the murine model, differences between species were not significant, but the melanised A. melanogenum group showed the highest virulence. This result was not reproducible in Galleria mellonella larvae at 25°C. The A. melanogenum black group showed higher pathogenicity in murine model, indicating that the combination of melanisation and thermotolerance rather than species affiliation is instrumental. Galleria larvae did not survive very well at 37°C, and hence, this model is judged insufficient to detect the small virulence differences observed in Aureobasidium.

Phylogenetic and Phylogenomic Definition of Rhizopus Species.

Phylogenomic approaches have the potential to improve confidence about the inter-relationships of species in the order Mucorales within the fungal tree of life. Rhizopus species are especially important as plant and animal pathogens and bioindustrial fermenters for food and metabolite production. A dataset of 192 orthologous genes was used to construct a phylogenetic tree of 21 Rhizopus strains, classified into four species isolated from habitats of industrial, medical and environmental importance. The phylogeny indicates that the genus Rhizopus consists of three major clades, with R. microsporus as the basal species and the sister lineage to R. stolonifer and two closely related species R. arrhizus and R. delemar A comparative analysis of the mating type locus across Rhizopus reveals that its structure is flexible even between different species in the same genus, but shows similarities between Rhizopus and other mucoralean fungi. The topology of single-gene phylogenies built for two genes involved in mating is similar to the phylogenomic tree. Comparison of the total length of the genome assemblies showed that genome size varies by as much as threefold within a species and is driven by changes in transposable element copy numbers and genome duplications.

Origin and distribution of Sporothrix globosa causing sapronoses in Asia.

PURPOSE: The aim of the study was to evaluate the main sources and epidemiological patterns and speculate on the evolutionary origin of Sporothrix globosa in Asia. METHODOLOGY: Case and case series literature on sporotrichosis in Asia from January 2007 onwards were reviewed using meta-analysis. Phylogenetic analysis of relevant S. globosa was carried out on the basis of concatenated sequences of ITS, TEF3 and CAL. A haplotype network of CAL sequences of 281 Sporothrix isolates was analysed to determine the population structure of S. globosa. RESULTS: Nearly all cases of sporotrichosis caused by S. globosa in Asia were human. In contrast to the remaining pathogenic Sporothrix species, feline transmission was exceptional; nearly all regional cat-associated cases were caused by Sporothrix schenckii. While the latter species was highly variable and showed recombination, S. globosa seemed to be a clonal offshoot, as was Sporothrix brasiliensis. The origin of the segregants was located in an area of high variability in S. schenckii with a relatively high frequency of Asian strains. CONCLUSION: In Asia, S. globosa was the prevalent species. The low diversity of S. globosa suggested a recent divergence with a founder effect of low variability from the variable ancestral species, S. schenckii.

The genus Anthopsis and its phylogenetic position in Chaetothyriales.

The genus Anthopsis was introduced for a black fungus with peculiar, inverted phialides and triangular conidia. The genus accommodates, in addition to the type species Anthopsis deltoidea, which once was reported as a cause of human phaeohyphomycosis, two further taxa: A. catenata and A. microspora. Current taxonomy is mainly based on microscopic structures of phialides. To assess the phylogenetic position of the genus, sequences of the internal transcribed spacer region and partial LSU rDNA were obtained for Anthopsis spp. and compared with sequences from public databases. Phylogenetic analyses based on both loci were used to assess the evolutionary relationships of Anthopsis spp. at the family and ordinal levels. Anthopsis s.str. was found to cluster in Chaetothyriales, while A. catenata proved to be of helotialean affinity. Thermotolerance and morphology of each species were recorded.

Identification of Candida species isolated from vulvovaginitis using matrix assisted laser desorption ionization-time of flight mass spectrometry.

BACKGROUND AND PURPOSE: Vulvovaginal candidiasis (VVC) is a common problem in women. The purpose of this study was to identify Candida isolates by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from women with vulvovaginitis that were referred to Ghaem Hospital, Mashhad, Iran. MATERIALS AND METHODS: This study was conducted on 65 clinical samples isolated from women that were referred to Ghaem Hospital. All specimens were identified using phenotyping techniques, such as microscopy and culture on Sabouraud dextrose agar and corn meal agar. In addition, all isolates were processed for MALDI-TOF MS identification. RESULTS: Out of the 65 analyzed isolates, 61 (94%) samples were recognized by MALDI-TOF MS. However, the remaining four isolates (6%) had no reliable identification. According to the results, C. albicans (58.5%) was the most frequently isolated species, followed by C. tropicalis (16.9%), C. glabrata (7.7%), C. parapsilosis (7.7%), and guilliermondii (3.1%). CONCLUSION: As the findings indicated, MALDI TOF MS was successful in the identification of clinical Candida species. C. albicans was identified as the most common Candida species isolated from the women with VVC. Moreover, C. tropicalis was the most common species among the non-albicans Candida species.

Rapid detection of Candida species in bronchoalveolar lavage fluid from patients with pulmonary symptoms

Abstract Candida species, especially C. albicans, are commensals on human mucosal surfaces, but are increasingly becoming one of the important invasive pathogens as seen by a rise in its prevalence in immunocompromised patients and in antibiotic consumption. Thus, an accurate identification of Candida species in patients with pulmonary symptoms can provide important information for effective treatment. A total of 75 clinical isolates of Candida species were obtained from the bronchoalveolar lavage fluid of both immunocompromised and immunocompetent patients with pulmonary symptoms. Candida cultures were identified based on nuclear ribosomal Internal Transcribed Spacer (ITS1-ITS2 rDNA) sequence analysis by polymerase chain reaction–restriction fragment length polymorphisms (PCR-RFLP). Molecular identification indicated that the isolates belonged predominantly to C. albicans (52%), followed by C. tropicalis (24%), C. glabrata (14.7%), C. krusei (5.3%), C. parapsilosis (1.3%), C. kefyr (1.3%) and C. guilliermondii (1.3%). Given the increasing complexity of disease profiles and their management regimens in diverse patients, rapid and accurate identification of Candida species can lead to timely and appropriate antifungal therapy.

Rapid detection of Candida species in bronchoalveolar lavage fluid from patients with pulmonary symptoms.

Candida species, especially C. albicans, are commensals on human mucosal surfaces, but are increasingly becoming one of the important invasive pathogens as seen by a rise in its prevalence in immunocompromised patients and in antibiotic consumption. Thus, an accurate identification of Candida species in patients with pulmonary symptoms can provide important information for effective treatment. A total of 75 clinical isolates of Candida species were obtained from the bronchoalveolar lavage fluid of both immunocompromised and immunocompetent patients with pulmonary symptoms. Candida cultures were identified based on nuclear ribosomal Internal Transcribed Spacer (ITS1-ITS2 rDNA) sequence analysis by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Molecular identification indicated that the isolates belonged predominantly to C. albicans (52%), followed by C. tropicalis (24%), C. glabrata (14.7%), C. krusei (5.3%), C. parapsilosis (1.3%), C. kefyr (1.3%) and C. guilliermondii (1.3%). Given the increasing complexity of disease profiles and their management regimens in diverse patients, rapid and accurate identification of Candida species can lead to timely and appropriate antifungal therapy.

Food preparation with mucoralean fungi: A potential biosafety issue?

Mucorales have been used for production of fermented food in Asia and Africa since time immemorial. Particularly Rhizopus species are rapidly growing, active producers of lipases and proteases and occur naturally during the first stages of soybean fermentation. Two biosafety issues have been raised in recent literature: (1) pathogenicity, Rhizopus species being prevalent opportunists causing erosive infections in severely compromised patients, and (2) toxicity, strains harbouring endosymbiotic Burkholderia producing toxic secondary metabolites. At the molecular level, based on different gene markers, species identity was found between strains used for food processing and clinical strains. In this study, we screened for bacterial symbionts in 64 Rhizopus strains by light microscopy, 16S rRNA sequencing, and HPLC. Seven strains (11 %) carried bacteria identified as Burkholderia rhizoxinica and Burkholderia endofungorum, and an unknown Burkholderia species. The Burkholderia isolates proved to be able to produce toxic rhizoxins. Strains with endosymbionts originated from food, soil, and a clinical source, and thus their presence could not be linked to particular habitats. The presence of Burkholderia in Rhizopus producing toxins could not be excluded as a potential risk for human health. In contrast, given the type of diseases caused by Rhizopus species, we regard the practical risk of infection via the food industry as negligible.

In Vitro Activities of Five Antifungal Drugs Against Opportunistic Agents of Aspergillus Nigri Complex.

Black aspergilli, particularly Aspergillus niger and A. tubingensis, are the most common etiological agents of otomycosis followed by onychomycosis, pulmonary aspergillosis and aspergilloma. However, so far there is no systematic study on their antifungal susceptibility profiles. A collection of 124 clinical and environmental species of black aspergilli consisted of A. niger, A. tubingensis, A. uvarum. A. acidus and A. sydowii were verified by DNA sequencing of the partial ß-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MECs of caspofungin were performed based on CLSI M38-A2. Posaconazole and caspofungin had the lowest MIC range (0.016-0.125 µg/ml and 0.008-0.031 µg/ml, respectively), followed by amphotericin B (0.25-4 µg/ml), voriconazole (0.125-16 µg/ml) and itraconazole (0.25 to >16) in an increasing order. Some strains of A. niger showed high MIC value for itraconazole and voriconazole (>16 µg/ml), in contrast only environmental isolates of A. tubingensis had high itraconazole MICs (>16 µg/ml). These results confirm that posaconazole and caspofungin are potential drugs for treatment of aspergillosis due to opportunistic agents of Aspergillus Nigri complex. However, in vivo efficacy remains to be determined.