In vitro susceptibility patterns of clinically important Trichophyton and Epidermophyton species against nine antifungal drugs

Despite the common, worldwide, occurrence of dermatophytes, little information is available regarding susceptibility profiles against currently available and novel antifungal agents. A collection of sixty‐eight clinical Trichophyton species and Epidermophyton floccosum were previously identified and verified to the species level by sequencing the internal transcribed spacer (ITS) regions of rDNA. MICs of amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole, terbinafine and MECs of caspofungin and anidulafungin were performed based on CLSI M38‐A2. The resulting MIC₉₀s of all strains were, in increasing order, as follows: terbinafine (0.063 mg l^?1); posaconazole (1 mg l^?1); isavuconazole and anidulafungin (2 mg l^?1); itraconazole, voriconazole, amphotericin B, and caspofungin (4 mg l^?1) and fluconazole (>64 mg l^?1). These results confirm that terbinafine is an excellent agent for treatment of dermatophytosis due to T. rubrum, T. mentagrophytes, T. verrucosum, T. schoenleinii and E. floccosum. In addition, the new azoles POS and ISA are potentially useful antifungals to treat dermatophytosis. However, the clinical effectiveness of these novel antifungals remains to be determined.     

Poststernotomy sternal osteomyelitis and mediastinitis by Trichosporon asahii: a rare occurrence with a grave prognosis

Post‐sternotomy infectious complications, including superficial and deep wound infections, sternal osteomyelitis and mediastinitis, are rarely caused by fungi. Trichosporon asahii is the main Trichosporon species that causes systemic infection in humans. Most cases involved neutropenic patients with hematologic malignancies. We report a unique case of a non‐cancer, non‐neutropenic but severely ill patient who developed an ultimately lethal T. asahii infection after sternotomy. We speculate that our patient had been colonized with the fungus and his surgical site infection may have been related to his emergency revascularization surgery. Therapy with liposomal amphotericin failed to sterilize the bloodstream despite in vitro susceptibility results. The addition of voriconazole helped sterilizing the bloodstream without changing the outcome. Physicians must be aware of the continuously expanding spectrum of infections with this emerging difficult‐to‐treat fungal pathogen.     

Tintelnotia,a new genus in Phaeosphaeriaceae harbouring agents of cornea and nail infections in humans

Phaeosphaeriaceae is a family in the order Pleosporales containing numerous plant pathogens, endophytes, lichenised fungi, and environmental saprobes. A novel genus, Tintelnotia is introduced containing two species, one of which caused an eye infection and several nail infections in humans. All species of Tintelnotia produce conidia in soft pycnidia with a wide ostiole. The generic type species is T. opuntiae causing necrotic spots on cactus plants. The isolates of the human opportunist T. destructans showed variable susceptibility pattern to a panel of common antifungal agents. The MICs of amphotericin B, voriconazole, posaconazole and itraconazole were 1 μg/mL, complemented by an in vitro MEC of 16 μg/mL against caspofungin; the MIC of terbinafine was 0.125 μg/mL. The latter compound contributed to the successful therapy in the ocular mycosis refractory to standard antifungal therapy, the benefit of terbinafine should be highlighted as a therapeutic option especially in difficult‐to‐treat fungal keratitis.     

In vitro antifungal susceptibilities of isolates of Candida spp. and Aspergillus spp. from China to nine systemically active antifungal agents: data from the SENTRY antifungal surveillance program, 2010 through 2012

We report the in vitro activity of nine systemically active antifungal agents against 237 contemporary clinical isolates of yeast and moulds obtained from 13 laboratories in China during 2010 through 2012. Susceptibility testing was performed using CLSI methods. Sequencing of fks hot spots was performed for echinocandin non‐wild‐type (WT) strains. Isolates included 220 from eight species of Candida, 15 from four species of Aspergillus and one isolate each of Rhodotorula mucilaginosa and Trichosporon asahii. Resistance to amphotericin B (0.0%), flucytosine (0.0–1.7%) and the echinocandins (0.0–3.4%) was distinctly uncommon among C. albicans, C. parapsilosis, C. tropicalis, C. glabrata and C. pelliculosa. Three C. albicans isolates showed resistance to echinocandins and one harboured a mutation in HS1 of fks1. Resistance to the azoles was much more common with resistance to fluconazole, voriconazole and posaconazole detected among isolates of C. glabrata and C. tropicalis. Both C. parapsilosis and C. pelliculosa exhibited decreased susceptibility to fluconazole. Amphotericin B, the mould‐active azoles and the echinocandins were all quite active against isolates of A. fumigatus and A. flavus. Consistent with previous studies from China, resistance to fluconazole is prominent among Candida spp. isolates in this country.     

Phenotypic and molecular identification of Fonsecaea pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela

Chromoblastomycosis is a chronic granulomatous disease caused frequently by fungi of the Fonsecaea genus. The objective of this study was the phenotypic and molecular identification of F. pedrosoi strains isolated from chromoblastomycosis patients in Mexico and Venezuela. Ten strains were included in this study. For phenotypic identification, we used macroscopic and microscopic morphologies, carbohydrate assimilation test, urea hydrolysis, cixcloheximide tolerance, proteolitic activity and the thermotolerance test. The antifungal activity of five drugs was evaluated against the isolates. Molecular identification was performed by sequencing the internal transcribed spacer (ITS) ribosomal DNA regions of the isolated strains. The physiological analysis and morphological features were variable and the precise identification was not possible. All isolates were susceptible to itraconazole, terbinafine, voriconazole and posaconazole. Amphotericin B was the least effective drug. The alignment of the 559‐nucleotide ITS sequences from our strains compared with sequences of GenBank revealed high homology with F. pedrosoi ( EU285266.1 ). In this study, all patients were from rural areas, six from Mexico and four from Venezuela. Ten isolates were identified by phenotypic and molecular analysis, using ITS sequence and demonstrated that nine isolates from Mexico and Venezuela were 100% homologous and one isolate showed a small genetic distance.     

Susceptibility profile and epidemiological cut‐off values of Cryptococcus neoformans species complex from Argentina

Epidemiological cut‐off values (ECVs) based on minimal inhibitory concentration (MIC) distribution have been recently proposed for some antifungal drug/Cryptococcus neoformans combinations. However, these ECVs vary according to the species studied, being serotypes and the geographical origin of strains, variables to be considered. The aims were to define the wild‐type (WT) population of the C. neoformans species complex (C. neoformans) isolated from patients living in Argentina, and to propose ECVs for six antifungal drugs. A total of 707 unique C. neoformans isolates obtained from HIV patients suffering cryptococcal meningitis were studied. The MIC of amphotericin B, flucytosine, fluconazole, itraconazole, voriconazole and posaconazole was determined according to the EDef 7.2 (EUCAST) reference document. The MIC distribution, MIC₅₀, MIC₉₀ and ECV for each of these drugs were calculated. The highest ECV, which included ≥95% of the WT population modelled, was observed for flucytosine and fluconazole (32 μg ml^?1 each). For amphotericin B, itraconazole, voriconazole and posaconazole, the ECVs were: 0.5, 0.5, 0.5 and 0.06 μg ml^?1 respectively. The ECVs determined in this study may aid in identifying the C. neoformans strains circulating in Argentina with decreased susceptibility to the antifungal drugs tested.     

Molecular epidemiology and antifungal susceptibility of Serbian Cryptococcus neoformans isolates

Molecular typing and antifungal susceptibility testing of 34 clinical Serbian Cryptococcus neoformans isolates from 25 patients was retrospectively performed. Amplified fragment length polymorphism (AFLP) fingerprinting was used for genotyping, whereas a novel real‐time PCR was used to determine the mating‐ and serotype. The antifungals amphotericin B, 5‐fluorocytosine, fluconazole, voriconazole, itraconazole and posaconazole were used to determine the antifungal susceptibility profiles. The majority of isolates belonged to genotype AFLP1/VNI (n = 20; 58.8%), followed by AFLP2/VNIV (n = 10; 29.4%), AFLP3/VNIII (n = 3; 8.8%) and AFLP1B/VNII (n = 1; 2.9%). All AFLP1/VNI isolates were mating–serotype αA, the sole AFLP1B/VNII isolate was found to be a A, whereas AFLP2/VNIV harboured serotype D isolates with either the a (n = 2; 5.9%) or α (n = 8; 23.5%) mating‐type allele. The isolates (n = 3; 8.8%) that were found to be genotype AFLP3/VNIII had the hybrid mating‐ and serotype combination a A‐αD. In vitro antifungal susceptibility testing showed that all isolates were susceptible to amphotericin B, voriconazole and posaconazole. Low resistance level was observed for fluconazole (n = 1; 2.9%) and 5‐fluorocytosine. (n = 2; 5.8%). A large percentage of isolates was found to be susceptible dose dependent to itraconazole (n = 16; 47.1%). AFLP1/VNI was the most common genotype among clinical C. neoformans isolates from immunocompromised patients in Serbia. C. neoformans from HIV‐negative patients were significantly less susceptible to 5‐fluorocytosine (P < 0.01). Correlation between genotypes and antifungal susceptibility was not observed.     

Major variations in Aspergillus fumigatus arising within aspergillomas in chronic pulmonary aspergillosis

Aspergillomas develop from progressive layers of mycelial growth on the walls of pulmonary cavities over months. Aspergillomas are characteristic of chronic pulmonary aspergillosis and are a risk factor for azole resistance. We investigated genotypic and phenotypic alterations in Aspergillus fumigatus recovered from aspergillomas. Aspergillomas were removed from three patients (two at surgery, one at autopsy) and dissected. Overall 92 colonies of A. fumigatus were isolated. Microsatellite typing was conducted to determine genetic type. Itraconazole, voriconazole and posaconazole susceptibilities were performed. The cyp51A gene was sequenced in 22 isolates. Isolates from Patient 1 (n = 25) were azole susceptible and resistant, although all cyp51A sequences were wild type, the isolates split into two distinct clades. In Patient 2, isolates were less variable (n = 10), all were azole susceptible. In Patient 3 only azole‐resistant strains (n = 57) were isolated, with M220K or M220T Cyp51A alterations, and microevolution was indicated. Marked diversity was observed in isolates from these patients; revealing differences in azole susceptibility, mechanism of resistance and genetic type. Importantly, routine sampling from respiratory specimens proved suboptimal in all cases; azole resistance was missed (Patient 1), cultures were negative (Patient 2) and high‐level posaconazole resistance was not detected (Patient 3).     

Trichosporon asahii infection presenting as chronic meningo‐ventriculitis and intra ventricular fungal ball: a case report and literature review

Central nervous system trichosporonosis is a rare clinical entity and so far only six cases including three each of brain abscess and meningitis has been on record. We report a rare case of chronic meningo‐ventriculitis and intraventricular fungal ball due to Trichosporon asahii in an 18‐year‐old immunocompetent male from Burundi, east Africa. Neuroendoscopy showed multiple nodules and a fungal ball within the ventricle, which on culture grew T. asahii. He was initially empirically treated with liposomal amphotericin B. However, the antifungal susceptibility testing of T. asahii isolate revealed high minimum inhibitory concentration for amphotericin B (2 μg ml^?1), flucytosine (16 μg ml^?1) and caspofungin (2 μg ml^?1) but exhibited potent activity for voriconazole, posaconazole, itraconazole and fluconazole. The patient rapidly succumbed to cardiac arrest before antifungal therapy could be changed. Although disseminated trichosporonosis has been increasingly reported the diagnosis represents a challenge especially in rare clinical settings such as intraventricular fungal ball in the present case, which has not been described previously.     

Detection of some new Trichosporon species from the dystrophied nails of three female members of a family from North Indian State of Jammu and Kashmir

Dermatophytes are considered as the main pathogens responsible for onychomycosis, but recently successive isolations of yeast‐like fungi from the infected nails has led to consider these also as primary agents of nail infections. Trichosporon species which are non‐candidal, basidiomycetous, yeast‐like, anamorphic fungi are commonly isolated from soil but they are also emerging as important etiological agents of onychomycosis. Three species of Trichosporon viz., T. asahii, T. asteroides and T. faecale were isolated from the infected nails of three female members of a family from district Doda of Jammu and Kashmir State. Among the isolated species of Trichosporon, T. asahii was recovered from the nail samples of all the three members, thus confirming its recognition as a main pathogenic species of onychomycosis. So far, there is no report of T. asteroides and T. faecale causing onychomycosis and hence they constitute new additions to the list of onychomycotic fungi. Some of the predisposing factors like low socio‐economic condition, poor hygiene, frequent exposure of finger nails to water and dirt, climatic conditions and nail trauma were observed to be the main causes of nail infection in these patients. However, a link between the pathogenic genus and the genetic makeup of the patients is also probable.     

Species diversity,antifungal susceptibility and phenotypic and genotypic characterisation of Exophiala spp. infecting patients in different medical centres in Brazil

The Exophiala genus is responsible for many superficial and invasive infections resulting from black fungi. Identification of Exophiala at the species level is based on morphological observations complemented by molecular tests. The aim of this study was to identify 23 clinical isolates of Exophiala spp. and evaluate the antifungal susceptibility to seven different agents. Molecular identification was based on an analysis of ITS region of rDNA using genomic databases. The micromorphology was evaluated by microculture and scanning electron microscopy. The susceptibility tests were performed using the antifungal agents 5‐fluorocytosine (5‐FC), amphotericin B (AMB), itraconazole (ITC), voriconazole (VRC), posaconazole (PSC), caspofungin (CFG) and terbinafine (TRB). The ITS analysis identified 100% of the following isolates as: E. dermatitidis (8), E. xenobiotica (6), E. bergeri (4), E. oligosperma (3), E. spinifera (1) and E. mesophila (1). The antifungal susceptibility tests showed that the triazoles compounds were in vitro the most active agents against Exophiala. ITS sequencing enabled the accurate identification of the 23 tested isolates. The triazoles, particularly itraconazole and posaconazole, exhibited MIC values lower than AMB, CAS and 5‐FC. Although the guidelines do not indicate AMB for treatment against Exophiala spp., this study showed activity for all of the tested species, except E. mesophila.     

Multi‐triazole‐resistant Aspergillus fumigatus infections in Australia

The emergence of triazole resistance, including multi‐triazole‐resistant Aspergillus fumigatus is being reported around the world, but there has been little evidence of this problem to date in Australia. Here we describe a retrospective search of antifungal susceptibility results of all Australian clinical A. fumigatus isolates referred to the National Mycology Reference Centre, Adelaide, Australia between 2000 and 2013, yielding 13 isolates with elevated minimum inhibitory concentrations to itraconazole, posaconazole and/or voriconazole. Four isolates were found to be Aspergillus lentulus, a closely related, morphologically similar species known to have reduced susceptibility to triazoles. Analysis of the cyp51A gene of nine confirmed A. fumigatus isolates revealed two carrying the TR₃₄/L98H mutation, one apparently locally acquired in 2004, and the other probably acquired abroad in 2012. Four isolates possessed the G54R, F46Y, Y431S and G448S mutations, respectively, whereas three isolates did not possess known cyp51A resistance mutations, raising the possibility of other, undetected resistance mechanisms. Routine antifungal susceptibility testing is definitively recommended in patients on long term and sub‐therapeutic triazole therapy with breakthrough Aspergillus infection and recommended for all clinically relevant A. fumigatus isolates.     

Molecular epidemiology and in vitro antifungal susceptibility testing of 108 clinical Cryptococcus neoformans sensu lato and Cryptococcus gattii sensu lato isolates from Denmark

Cryptococcosis is mainly caused by members of the Cryptococcus gattii/Cryptococcus neoformans species complexes. Here, we report the molecular characterisation and in vitro antifungal susceptibility of Danish clinical cryptococcal isolates. Species, genotype, serotype and mating type were determined by amplified fragment length polymorphism (AFLP) fingerprinting and qPCR. EUCAST E.Def 7.2 MICs were determined for amphotericin B, flucytosine, fluconazole, voriconazole and isavuconazole. Most isolates were C. neoformans (serotype A; n = 66) and belonged to genotype AFLP1/VNI (n = 61) or AFLP1B/VNII (n = 5) followed by Cryptococcus deneoformans (serotype D; genotype AFLP2, n = 20), C. neoformans × C. deneoformans hybrids (serotype AD; genotype AFLP3, n = 13) and Cryptococcus curvatus (n = 2). Six isolates were C. gattii sensu lato, and one isolate was a C. deneoformans × C. gattii hybrid (genotype AFLP8). All isolates were amphotericin B susceptible. Flucytosine susceptibility was uniform MIC₅₀ of 4–8 mg l^?1 except for C. curvatus (MICs >32 mg l^?1). Cryptococcus gattii sensu lato isolates were somewhat less susceptible to the azoles. MICs of fluconazole (>32 mg l^?1), voriconazole (≥0.5 mg l^?1) and isavuconazole (0.06 and 0.25 mg l^?1 respectively) were elevated compared to the wild‐type population for 1/19 C. deneoformans and 1/2 C. curvatus isolates. Flucytosine MIC was elevated for 1/61 C. neoformans (>32 mg l^?1). Antifungal susceptibility revealed species‐specific differential susceptibility, but suggested acquired resistance was an infrequent phenomenon.     

Clinical characteristics,rapid identification,molecular epidemiology and antifungal susceptibilities of Talaromyces marneffei infections in Shenzhen,China

Although case series of talaromycosis have been reported in China, their detailed clinical and microbiological characteristics have never been systematically profiled. In this study, we report the clinical characteristics, molecular epidemiology, rapid identification and antifungal susceptibilities of talaromycosis in The University of Hong Kong‐Shenzhen Hospital in Shenzhen. Seven cases of talaromycosis were observed since commencement of hospital service in 2012. Three patients were local Shenzhen residents, whereas the other four were immigrants from other parts of China. Two patients were HIV‐negative, but with underlying diseases requiring immunosuppressive therapy. Two of the seven patients succumbed. All the seven isolates were successfully identified as T. marneffei by MALDI–TOF MS using Bruker database expanded with in‐house generated T. marneffei mass spectra. MLST showed that the seven strains belonged to six different, novel sequences types. Phylogenetic analyses of the concatenated five‐locus sequence revealed that the seven strains were scattered amongst other T. marneffei strains. The MICs of itraconazole, isavuconazole, posaconazole and voriconazole against the seven clinical isolates were low but MICs of anidulafungin were high. Underlying diseases other than HIV infection are increasingly important risk factors of talaromycosis. MALDI–TOF MS is useful for rapid identification. Highly diverse T. marneffei sequence types were observed.     

Cryptococcal meningitis due to Cryptococcus neoformans genotype AFLP1/VNI in Iran: a review of the literature

Cryptococcal meningitis is the most important opportunistic fungal infection with a high mortality in HIV‐patients in less developed regions. Here, we report a case of cryptococcal meningitis in a 49‐year‐old HIV‐positive female due to Cryptococcus neoformans (serotype A, mating‐type alpha, genotype AFLP1/VNI) in Sari, Iran. In vitro antifungal susceptibility tests showed MICs of isavuconazole (0.016 μg ml^?1), voriconazole (0.031 μg ml^?1), posaconazole (0.031 μg ml^?1), itraconazole (0.063 μg ml^?1), amphotericin B (0.125 μg ml^?1) and fluconazole (8 μg ml^?1). Despite immediate antifungal therapy, the patient died 4 days later due to respiratory failure. Cryptococcal infections have been infrequently reported from Iran and therefore we analysed all published cases of cryptococcosis in Iran since the first reported case from 1969.     

Molecular identification and antifungal susceptibility of Curvularia australiensis,C. hawaiiensis and C. spicifera isolated from human eye infections

A reliable identification method was developed for three closely related Curvularia species, which are frequently isolated from human keratomycoses. Since the traditionally used morphological method and the increasingly used internal transcribed spacer (ITS)‐based molecular method proved to be insufficient to discern C. australiensis, C. hawaiiensis and C. spicifera, other molecular targets, such as β‐tubulin, translation elongation factor 1‐α and the nuclear ribosomal intergenic spacer (IGS), were tested. Among them, the use of the highly divergent IGS sequence is suggested and the species‐specific discriminating characters were determined in appropriate reference strains. It was also concluded that C. hawaiiensis and C. spicifera can be predominantly isolated from eye infections among the three species. The in vitro antifungal susceptibility of 10 currently used antifungal agents against 32 Curvularia isolates was also investigated. MICs were determined in each case. Isolates of C. spicifera proved to be less susceptible to the tested antifungals than those of C. hawaiiensis, which underline the importance of the correct identification of these species.     

In vitro antifungal susceptibility of clinical isolates of Arthrographis kalrae,a poorly known opportunistic fungus

The in vitro antifungal activity of amphotericin B (AMB), itraconazole, voriconazole, posaconazole, terbinafine (TRB), caspofungin, anidulafungin and micafungin were evaluated by a broth microdilution technique against 22 isolates of Arthrographis kalrae of clinical origin. TRB showed the highest activity, followed by the azoles, particularly posaconazole. AMB exerted low activity whereas the echinocandins showed almost no antifungal activity.     

Polymorphisms in the ITS rDNA regions for differentiating strains of the Trichophyton mentagrophytes complex in Sfax‐Tunisia

The Trichophyton mentagrophytes complex is the main cause of superficial mycoses in humans and animals. Molecular research has provided useful insights into the taxonomy of this complex to overcome the challenges with conventional diagnostics. The aim of this study was to identify, type and differentiate anthropophilic and zoophilic species of the T. mentagrophytes complex. Sixty clinical samples identified as T. mentagrophytes by morphological characteristics were isolated using polymerase chain reaction‐restriction fragment length polymorphism and sequence analysis of the internal transcribed spacer (ITS) regions. The identification of our strains by conventional methods was confirmed using polymerase chain reaction (PCR) sequencing in 93.34% of the cases. The strains under investigation were recategorised as T. rubrum (Tr2711). In addition, PCR products were independently digested with the restriction endonucleases, MvaI and HinfI, to produce a single dominant profile for T. interdigitale. ITS sequence analysis revealed a polymorphism in the ITS1 and 5.8S regions. Analysis of the consensus sequences distinguished four types of genotypes among our T. interdigitale species. Moreover, ITS type I was the dominant genotype characterising the anthropophilic variant of T. interdigitale. The phylogenetic study showed that only 5% of our strains were zoophilic. PCR sequencing was useful for distinguishing anthropophilic and zoophilic species of T. interdigitale, in which the differentiation is relevant because it helps to prescribe the correct treatment and to identify the surrounding source of infection.     

Invasive pulmonary infection caused by Chrysosporium articulatum: the first case report

Chrysosporium species, saprobic soil fungi, comprise more than 60 species. There is some confusion regarding the taxonomy and nomenclature between Chrysosporium and Emmonsia since the causative agents of adiaspiromycosis, the development of big thick‐walled spores (adiaspores) in humans or animals, were previously thought to be Chrysosporium. Chrysosporium articulatum has never been reported to cause invasive infection in humans. We report herein the first case of invasive pulmonary infection caused by Chrysosporium articulatum in a 16‐year‐old man with acute T‐cell lymphoblastic leukaemia. He was successfully treated with voriconazole.     

Molecular identification and classification of Trichophyton mentagrophytes complex strains isolated from humans and selected animal species

Species differentiation within Trichophyton mentagrophytes complex group currently poses a major diagnostic challenge, with molecular methods increasingly supplementing classical identification based on the morphological and physiological properties of the fungi. Diagnostic and epidemiological research aimed at determining the source and means of transmission of dermatophytoses in both humans and animals requires not only species differentiation of isolates but also differentiation within species. The study was conducted on 24 isolates originating in humans and various animal species with clinical symptoms of dermatophytosis. The analysis included phenotypical identification methods and molecular methods: internal transcribed spacer sequencing and ITS‐restriction fragment length polymorphism (RFLP) with multi‐enzyme restriction. ITS sequence analysis identified the isolates to species – Trichophyton interdigitale, Arthroderma benhamiae and A. vanbreuseghemii, and ITS‐RFLP detected six different genotypes. Genotypes I, II and III characterised strains belonging to A. benhamiae, genotype IV characterised the A. vanbreuseghemii strain, and genotypes V and VI occurred only within the species T. interdigitale. Strains isolated from guinea pigs were dominant within genotype I, while genotype II was found mainly in strains from foxes. Multi‐enzyme restriction analysis of this region enables intraspecific differentiation, which may be useful in epidemiological research, particularly in determining the source of infections.