Susceptibility profile of echinocandins,azoles and amphotericin B against yeast phase of <Emphasis Type="Italic">Talaromyces marneffei</Emphasis> isolated from HIV-infected patients in Guangdong,China

Talaromyces marneffei (T. marneffei) can cause talaromycosis, a fatal systemic mycosis, in patients with AIDS. With the increasing number of talaromycosis cases in Guangdong, China, we aimed to investigate the susceptibility of 189 T. marneffei clinical strains to eight antifungal agents, including three echinocandins (anidulafungin, micafungin, and caspofungin), four azoles (posaconazole, itraconazole, voriconazole, and fluconazole), and amphotericin B, with determining minimal inhibition concentrations (MIC) by Sensititre YeastOne? YO10 assay in the yeast phase. The MICs of anidulafungin, micafungin, caspofungin, posaconazole, itraconazole, voriconazole, fluconazole, and amphotericin B were 2 to >?8 μg/ml, >8 μg/ml, 2 to >?8 μg/ml, ≤?0.008 to 0.06 μg/ml, ≤?0.015 to 0.03 μg/ml, ≤?0.008 to 0.06 μg/ml, 1 to 32 μg/ml, and ≤?0.12 to 1 μg/ml, respectively. The MICs of all echinocandins were very high, while the MICs of posaconazole, itraconazole, and voriconazole, as well as amphotericin B were comparatively low. Notably, fluconazole was found to have a higher MIC than other azoles, and exhibited particularly weak activity against some isolates with MICs over 8 μg/ml. Our data in vitro support the use of amphotericin B, itraconazole, voriconazole, and posaconazole in management of talaromycosis and suggest potential resistance to fluconazole.     

Comparing Etest and Broth Microdilution for Antifungal Susceptibility Testing of the Most-Relevant Pathogenic Molds

Invasive mold infections are life-threatening diseases for which appropriate antifungal therapy is crucial. Their epidemiology is evolving, with the emergence of triazole-resistant Aspergillus spp. and multidrug-resistant non-Aspergillus molds. Despite the lack of interpretive criteria, antifungal susceptibility testing of molds may be useful in guiding antifungal therapy. The standard broth microdilution method (BMD) is demanding and requires expertise. We assessed the performance of a commercialized gradient diffusion method (Etest method) as an alternative to BMD. The MICs or minimal effective concentrations (MECs) of amphotericin B, voriconazole, posaconazole, caspofungin, and micafungin were assessed for 290 clinical isolates of the most representative pathogenic molds (154 Aspergillus and 136 non-Aspergillus isolates) with the BMD and Etest methods. Essential agreements (EAs) within ±2 dilutions of ≥90% between the two methods were considered acceptable. EAs for amphotericin B and voriconazole were >90% for most potentially susceptible species. For posaconazole, the correlation was acceptable for Mucoromycotina but Etest MIC values were consistently lower for Aspergillus spp. (EAs of <90%). Excellent EAs were found for echinocandins with highly susceptible (MECs of <0.015 μg/ml) or intrinsically resistant (MECs of >16 μg/ml) strains. However, MEC determinations lacked consistency between methods for strains exhibiting mid-range MECs for echinocandins. We concluded that the Etest method is an appropriate alternative to BMD for antifungal susceptibility testing of molds under specific circumstances, including testing with amphotericin B or triazoles for non-Aspergillus molds (Mucoromycotina and Fusarium spp.). Additional study of molecularly characterized triazole-resistant Aspergillus isolates is required to confirm the ability of the Etest method to detect voriconazole and posaconazole resistance among Aspergillus spp.     

First report of human infection caused by Curvularia warraberensis,manifesting as invasive sinusitis with intracranial involvement

Curvularia species are saprophytic dematiaceous fungi commonly isolated from environmental sources. Most often, they are responsible for allergic fungal rhinosinusitis, an intense, allergic inflammatory sinus disease in immunocompetent individuals. Though invasive infections are rare and more commonly observed in immunocompromised patients, recent reports indicate an increasing trend of invasive sinusitis caused by Curvularia species in immunocompetent hosts. Over the past few years, new species of the genus Curvularia are increasingly being recognized as human pathogens. Here, we report the first human infection caused by Curvularia warraberensis, a cryptic species of Curvularia primarily described as an endophyte in Australian grasses. The 33-year-old female presented with chronic invasive sinusitis of the sphenoid and ethmoid sinuses that progressed to involve the pituitary gland, mid-brain, the facial-vestibulocochlear nerve complex, and basilar artery. The patient underwent endoscopic sinus surgery. Histopathology, microscopic examination and culture of biopsy tissues revealed a dematiaceous fungus that was identified as C. warraberensis, based on sequencing the internal transcribed spacer (ITS) and large subunit (LSU) regions of ribosomal DNA. Antifungal susceptibility testing (AFST) showed low minimum inhibitory concentrations (MICs) for amphotericin B (1 µg/mL), itraconazole (0.25 µg/mL) and posaconazole (0.125 µg/mL). Accurate identification and AFST are crucial for making treatment decisions as some Curvularia species demonstrate variable susceptibility to antifungal agents. The patient died despite combined surgical and medical intervention owing to late presentation and delay in initiating antifungal therapy. A high index of suspicion together with an early diagnosis and aggressive treatment may improve the outcome in such cases.     

In vitro synergistic effect of minocycline combined with antifungals against Cryptococcus neoformans

BackgroundCryptococcus neoformans infections occur in immunocompromised patients, especially those with HIV infection, chemoradiotherapy after cancer, and organ transplantation. Infection can cause pneumonia and meningoencephalitis in severe cases with a high mortality rate if not treated. Although fluconazole and amphotericin B are the first-line treatments for cryptococcosis, the rate of fluconazole resistance has increased significantly due to long-term use. Minocycline is a derivative of tetracycline that exerts its antibacterial effect through inhibition of bacterial protein synthesis. It is also able to pass the blood-brain barrier to act on the central nervous system. The present study investigates the effects of minocycline in combination with antifungals in treating C. neoformans.ObjectiveTo determine in vitro interactions of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole and amphotericin B against C. neoformans.MethodsThe minimum inhibitory concentrations (MIC) of the antifungals were determined by the CLSI Clinical and Laboratory Standards Institute M27-A3 microdilution method. The in vitro synergistic effects of minocycline combined with itraconazole, voriconazole, posaconazole, fluconazole, and amphotericin B on C. neoformans were detected by the broth microdilution checkerboard technique and disk diffusion testing.Results and ConclusionThe working concentration ranges were 0.125–4 µg/mL for itraconazole, 0.03–0.125 µg/ml for voriconazole, 0.03–1 µg/ml for posaconazole, 0.25–16 µg/ml for fluconazole, and 0.125–2 µg/ml for amphotericin B. The synergistic rates of minocycline combinations against C. neoformans were 55% with itraconazole, 10% with voriconazole, 85% with posaconazole, 20% with fluconazole, and 70% with amphotericin B. The effective MIC value of minocycline in the synergistic combination decreased to 2–32 µg/ml, while the MIC of itraconazole decreased to 0.03–0.125 µg/ml, voriconazole 0.03–0.125 µg/ml, posaconazole 0.03–0.125 µg/ml, 0.125–4 µg/ml fluconazole, and 0.06–0.50 µg/ml amphotericin B. The disk diffusion assay showed that the plates containing minocycline and antifungal drugs produced inhibition zones with diameters larger than the single drug plates. Minocycline showed no antagonistic effect in the combinations. In conclusion, the combination of minocycline and azoles or amphotericin B has synergistic effects against C. neoformans in vitro.     

Bone and joint infections by Mucorales,Scedosporium, Fusarium and even rarer fungi

Abstract

Mucorales, Scedosporium and Fusarium species are rarely considered as cause for bone and joint infections. However, these moulds are emerging as important fungal pathogens in immunocompromised and immunocompetent patients. Typical pre-disposing host conditions are immunosuppression and diabetes. Most common causative pathogens are Mucorales followed by Scedosporium and Fusarium. Acremonium and Phialemonium species are rare but some case reports exist. MRI is the gold standard imaging technique. Tissue specimens obtained as aspirates, imaging guided biopsy or open surgery need mycological and histopathological work-up for genus and species identification. Multimodal treatment strategies combine surgical debridement, drainage of joints or abscesses, removal of infected prosthetic joints and systemic antifungals. The treatment of mucormycosis is polyene based and may be combined with either posaconazole or – in rare cases – caspofungin. As Scedosporium species are intrinsically resistant to polyenes and azoles show absence of in vitro activity, voriconazole plus synergistic treatment regimens become the therapeutic standard. In fusariosis, fungal susceptibility is virtually impossible to predict, so that combination treatment of voriconazole and lipid-based amphotericin B should be the first-line strategy while susceptibility results are pending. In the absence of randomized controlled trials, infections due to the above moulds should be registered, e.g. in the registries of the European Confederation of Medical Mycology (ECMM).     

Allergic fungal rhinosinusitis caused by Neoscytalidium dimidiatum: A case report: Allergic fungal rhinosinusitis due to Neoscytalidium dimidiatum

Neoscytalidium dimidiatum is a rare dematiaceous fungus that was first described in 1916 as Dothiorella mangiferae. From the standpoint of epidemiology and therapy, early detection of fungal rhinosinusitis (FRS), the causative agents, and their associated risk factors can improve the therapeutic outcome and decrease the mortality rates among patients. In this study, we report a 34-year-old Iranian female patient with allergic bronchopulmonary aspergillosis (ABPA), who presented to our facility with an 8-year history of chronic fungal sinusitis, drug-resistant asthma, pneumonia, bronchitis, post-nasal discharge, nasal obstruction, nasal polyposis, and anemia. The patient was subjected to diagnostic nasal endoscopy and computed tomography (CT) scan of paranasal sinuses, as well as routine, complementary mycological, and molecular methods, which confirmed the diagnosis of allergic fungal rhinosinusitis in patients with ABPA. Neoscytalidium dimidiatum was isolated from the sinus of the patient. Results of in vitro susceptibility tests indicated that the case isolate was susceptible to amphotericin B and itraconazole at concentrations which are commonly achieved in patients receiving recommended dosages for invasive mycoses (0.25 to 0.75 mg/kg of body weight daily for amphotericin B and 100 to 400 mg daily for itraconazole) and resistant in vitro to caspofungin, voriconazole, and posaconazole. The patient was successfully treated with amphotericin B / itraconazole + postoperative oral corticosteroids (OCS). Neoscytalidium dimidiatum infection should be considered as a possible additional factor in the etiology of AFRS, especially in immunocompromised patients.     

Isothermal microcalorimetry: a novel method for real-time determination of antifungal susceptibility of Aspergillus species

We evaluated microcalorimetry for real-time susceptibility testing of Aspergillus spp. based on growth-related heat production. The minimal heat inhibitory concentration (MHIC) for A. fumigatus ATCC 204305 was 1 mg/L for amphotericin B, 0.25 mg/L for voriconazole, 0.06 mg/L for posaconazole, 0.125 mg/L for caspofungin and 0.03 mg/L for anidulafungin. Agreement within two 2-fold dilutions between MHIC (determined by microcalorimetry) and MIC or MEC (determined by CLSI M38A) was 90% for amphotericin B, 100% for voriconazole, 90% for posaconazole and 70% for caspofungin. This proof-of-concept study demonstrated the potential of isothermal microcalorimetry for growth evaluation of Asperg llus spp. and real-time antifungal susceptibility testing.     

Breakthrough infection of Trichosporon asahii during posaconazole treatment in a patient with acute myeloid leukaemia

A neutropenic patient with acute myeloid leukaemia experienced a breakthrough infection of Trichosporon asahii during posaconazole treatment. After treatment was changed to a combination therapy with voriconazole and liposomal amphotericin B, the infection resolved. Posaconazole works effectively as an antifungal prophylaxis and salvage therapy in rare invasive fungal infections. This case however illustrates that breakthrough infections with T. asahii may occur during posaconazole treatment.     

Candida nivariensis isolated from an Indonesian human immunodeficiency virus-infected patient suffering from oropharyngeal candidiasis

Candida nivariensis was isolated from an Indonesian human immunodeficiency virus-infected patient who suffered from oropharyngeal candidiasis and was identified with molecular tools. Our isolate demonstrated low MICs to amphotericin B, flucytosine, posaconazole, caspofungin, and isavuconazole and was susceptible to fluconazole, itraconazole, and voriconazole.     

Bloodstream infections due to Trichosporon species in paediatric patients: Results from the first national study from Turkey

BackgroundInvasive Trichosporon infections are rarely seen opportunistic fungal infections in children and mainly affect immunocompromised patients. This multicenter retrospective study has rewieved the characteristics, risk factors, treatment modalities and outcomes of bloodstream infections caused by Trichosporon species in children diagnosed over the past ten years in Turkey.MethodsThe study was performed with the participation of 12 of 55 hospitals invited from Turkey. In each center, the patients with bloodstream infections caused by Trichosporon spp. between January 2010 and December 2020 were retrospectively ascertained and the results were reported to the study coordinator by means of a simple case report. Data were collected on patient demographics, underlying condition(s), treatment of.infections caused by Trichosporon spp, and 7 and 30- day mortality rates.ResultsA total of 28 cases with fungemia caused by Trichosporon spp. were included in the study. The most common underlying disease was paediatric cancers (39.3%). T. asahii infections were detected in 78.5 % (n=22) of patients. A various spectrum of antifungal treatment regimens were used including intravenous amphotericin B monotherapy in 35.7%, intravenous amphotericin B and voriconazole combination in 32.1% and intravenous voriconazole monotherapy in 28.6% of the patients. The overall mortality rate was 28.5 %. The mortality rates were 12.5% in the voricanozole, 30% in the amphotericin B and 33.3% in combined voriconazole -amphotericin B armsConclusionsInvasive Trichosporon infections with an important impact of patients quality of life are almost related to underlying diseases with an overall mortality rate of 28.5%. Voriconazole was found to be associated with lower mortality rates when compared with other treatment regimens.     

A prospective survey of Aspergillus spp. in respiratory tract samples: prevalence, clinical impact and antifungal susceptibility

A three-month laboratory-based prospective survey was conducted at four major university hospitals covering one-third of the Danish population in order to determine the prevalence, significance, and susceptibility pattern of aspergilli in airway samples. Samples received in January–March 2007 for routine microbiologic investigation were examined for Aspergillus following routine procedures and with extended incubation (5 days). Identification was done by morphologic criteria and susceptibility testing using EUCAST method for azoles and amphotericin B E-test. Invasive aspergillosis (IA) was evaluated using modified EORTC/MSG criteria. A total of 11,368 airway samples were received. Growth of Aspergillus spp. was found in 129 and 151 patients using routine and extended incubation, respectively. Three patients had proven IA (2%), 11 probable (7%), four had allergic bronchopulmonary aspergillosis (ABPA) (3%), but the majority was colonised (88%). Underlying conditions were cystic fibrosis in 82 patients (55%), chronic obstructive pulmonary disease in 19 (13%) and haematological disorder in 11 (7%). Twenty-six patients (18%) were at intensive care unit and 69 (47%) received steroid treatment. Azole MICs were elevated for five isolates as follows (itraconazole, posaconazole, voriconazole MICs [mg/L]): two A. fumigatus isolates (>4; >4; 2 and >4; 0.125; 1), one A. lentulus isolate (2; 2; 0.5) and two A. terreus isolates (2; 2; 2 and 2; 0.125; 1). For four isolates the amphotericin B MIC was >1 μg/ml (3/112 A. fumigatus, 1/2 A. terreus). In conclusion, Aspergillus appears to be an important pathogen in Denmark. Elevated itraconazole MICs were detected in 4% of the isolates including a multi-azole resistant isolate.     

Molecular identification,phylogenetic analysis and antifungal susceptibility patterns of Aspergillus nidulans complex and Aspergillus terreus complex isolated from clinical specimens

ObjectiveAspergillus sections Terrei and Nidulantes are the less common causes of invasive aspergillosis and pulmonary aspergillosis (PA) in immunocompromised patients when compared to A. fumigatus and A. flavus. Identifying these fungi as the infectious agent is crucial because of the resistance to amphotericin B (AMB) and increased lethality. The aim of this study was to identify the molecular status, evaluate the genetic diversity and examine the antifungal susceptibility profile of the uncommon Aspergillus species. Forty-five uncommon Aspergillus species were identified based on the microscopic and macroscopic criteria. Then, the molecular identification was performed using the sequencing beta tubulin (benA) gene. In vitro antifungal susceptibility to amphotericin B (AMB), itraconazole (ITC), ravuconazole (RAV), voriconazole (VRC), caspofungin (CFG) isavuconazole (ISA) and posaconazole (POS) test was performed according to the CLSI M38-A2 guidelines.ResultsA. terreus was the most species detected, followed by A. nidulans, A. latus, A. ochraceus, and A. citrinoterreus, respectively. The analysis of the benA gene showed the presence of 12 distinct genotypes among the A. terreus isolates. The other species did not show any intraspecies variation. CFG exhibited the lowest MEC₅₀/MIC₅₀ (0.007 μg/mL), followed by POS (0.125 μg/mL), VRC, ITC, ISA (0.25 μg/mL), RAV (0.5 μg/mL), and AMB (8 μg/mL). Among all the isolates, only 15.5% (7/45) were susceptible to AMB.ConclusionAntifungal susceptibility pattern of the uncommon Aspergillus species is useful to improve patient management and increase knowledge concerning the local epidemiology. Moreover, this information is necessary when an outbreak dealing with drug-resistant infections occurs.     

Comparative in vitro activities of seven antifungal drugs against clinical isolates of Candida parapsilosis complex

ObjectiveCandida parapsilosis species complex, an important set of non-albicans Candida species, is known to cause candidaemia particularly in neonates and infants. However, the incidence has increased in recent years, owing to higher numbers of at individuals at risk for these infections. Our objective was to evaluate the in vitro susceptibility of clinical isolates of C. parapsilosis complex isolates from Iran to seven antifungal drugs.Material and methodsOne hundred-one clinical isolates of C. parapsilosis species complex cultured from humans were included. Species identification had been previously confirmed by combined phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry-based assay and reconfirmed by DNA sequence analysis of the ITS rDNA region and D1/D2 gene. Minimum inhibitory concentrations (MICs) for amphotericin B, fluconazole, itraconazole, voriconazole, posaconazole, micafungin and anidulafungin were determined against well-characterized isolates by broth microdilution susceptibility testing according to the CLSI M27-A3 guideline.ResultsSpecies identifications were performed on 101 isolates, of which 88 (87.2%) C. parapsilosis sensu stricto and 13 (12.8%) C. orthopsilosis. Amphotericin B and posaconazole were the most active drugs with 100% of isolates being wild-type (WT). Voriconazole and micafungin, 99% of isolates were WT. The low activity was recorded for fluconazole and itraconazole with 93.1% and 89.1% of isolates being WT, respectively. At the species level, all Candida parapsilosis sensu stricto isolates were WT to amphotericin B and posaconazole and all Candida orthopsilosis isolates were WT to amphotericin B, voriconazole, posaconazole, anidulafungin and micafungin. In contrast, the highest rate of non-WT was observed in C. orthopsilosis to itraconazole (4 of 13, 30.8%).ConclusionsAlthough almost all of the tested drugs demonstrated potent activity against C. parapsilosis species complex, it seems that more especially C. orthopsilosis isolates had decreased susceptibility to itraconazole. Further studies are needed to determine how these findings may switch into in vivo efficacy.     

Sequence-based identification,genotyping and EUCAST antifungal susceptibilities of Trichosporon clinical isolates from Greece

Trichosporon yeasts constitute emerging pathogens, implicated in organ-specific and systemic infections. In this first, comprehensive study of Trichosporon clinical isolates in Greece, 42 isolates were identified by sequencing the hypervariable D1/D2 domain of the Large Subunit (LSU) rDNA gene, while Trichosporon asahii were genotyped by sequencing the Intergenic Spacer 1 region, and antifungal susceptibilities were determined by the EDef 7.2 (EUCAST) method, in parallel with the CLSI standard. Trichosporon asahii was the primary species (37 isolates) followed by Trichosporon coremiiforme, Trichosporon dermatis, Trichosporon loubieri and Trichosporon mycotoxinivorans. One strain remained unidentified. Seven T. asahii genotypes were recorded. The major genotypes were: genotypes 4 (29%) and 3 (26%) followed by 1, 5 and 7 (9.5% each). Two novel genotypes were identified designated as 10 and 11. EUCAST MIC ≥2 mg/L was recorded in 58% of the isolates (amphotericin B), 41% (itraconazole), 41% (posaconazole) and 38% (voriconazole). Fluconazole MICs of ≥32 mg/L were recorded in 23.8% of the isolates. Analysis of variance performed on absolute values showed that the amphotericin B, itraconazole, posaconazole and voriconazole MICs of T. asahii were equivalent. Typically higher MIC values were displayed by fluconazole. Antifungal susceptibilities of the seven different genotypes were homogeneous. Agreements between EUCAST and CLSI ranged from 88.1 to 97.62%. Overall, the high MICs recorded among the Trichosporon isolates for all tested drugs justify routine susceptibility testing of clinical isolates.     

Performances of disk diffusion method for determining triazole susceptibility of Aspergillus species: Systematic review

The therapeutic management of invasive aspergillosis should be guided by antifungal susceptibility testing (AFST). The disk diffusion (DD) method due to its simplicity and low cost could be an appropriate alternative to the reference methods (CLSI, EUCAST) which are not suitable for AFST in routine clinical microbiology laboratories, particularly in resource-constrained settings. This review summarizes the available data on the performance of the DD method in determining triazole susceptibility profile of Aspergillus species. The published articles on the performance of DD method for determining triazole susceptibility of Aspergillus spp. were systematically searched on major medical databases and Google Scholar. We identified 2725 articles of which 13 met the inclusion criteria. The overall average agreement value obtained between DD and CLSI broth microdilution (CLSI-BMD) methods for the itraconazole 10 µg disk (70.75%) was low especially when the medium used was not Mueller-Hinton (MH) agar. In contrast average agreement for the voriconazole 1 µg disk and the posaconazole 5 µg disk were > 94% regardless of media used. The correlation coefficient values between the DD and CLSI-BMD methods on MH agar were acceptable (≥ 0.71) for the itraconazole 10 µg disk and posaconazole 5 µg disk and good (≥ 0.80) for the voriconazole 1 and 10 µg disk. The reproducibility of the DD method regardless to the medium used was ≥ 82%. This systematic review shows that the disk diffusion method could be a real alternative for triazole antifungals susceptibility testing of Aspergillus spp.     

Intensive care management of influenza-associated pulmonary aspergillosis

BackgroundSevere pulmonary infections are among the most common reasons for admission to intensive care units (ICU). Within the last decade, increasing reports of severe influenza pneumonia resulting in acute respiratory distress syndrome (ARDS) complicated by Aspergillus infection were published.ObjectivesTo provide a comprehensive review of management of influenza-associated pulmonary aspergillosis in patients with ARDS.SourcesReview of the literature pertaining to severe influenza-associated pulmonary aspergillosis. PubMed database was searched for publications from the database inception to January 2019.ContentIn patients with lower respiratory symptoms, development of respiratory insufficiency should trigger rapid and thorough clinical evaluation, in particular in cases of suspected ARDS, including electrocardiography and echocardiography to exclude cardiac dysfunction, arrhythmias and ischaemia. Bronchoalveolar lavage should obtain lower respiratory tract samples for galactomannan assay, direct microscopy, culture, and bacterial, fungal and viral PCR. In case of positive Aspergillus testing, chest CT is the imaging modality of choice. If influenza pneumonia is diagnosed, neuraminidase inhibitors are the preferred approved drugs. When invasive aspergillosis is confirmed, first-line therapy consists of isavuconazole or voriconazole. Isavuconazole is an alternative in case of intolerance to voriconazole, drug–drug interactions, renal impairment, or if a spectrum of activity including the majority of Mucorales is desired. Primary anti-mould prophylaxis with posaconazole is recommended in haematology patients at high-risk. It may be considered in newly diagnosed influenza and ARDS, but ideally in clinical trials.ImplicationsThe rising reports of influenza-associated pulmonary aspergillosis in patients with ARDS, who are otherwise not considered at risk for fungal pneumonia demands heightened clinical awareness. Tracheobronchitis and Aspergillus in respiratory tract samples should prompt suspicion of invasive fungal infection and further work-up. The management algorithm should comprise bronchoalveolar lavage, CT imaging, sophisticated ventilator-management, rescue extracorporeal membrane oxygenation, and antifungal and antiviral therapy. To decrease the burden of influenza-related illness, vaccination is of utmost importance, specifically in patients with co-morbidities.     

European Confederation of Medical Mycology (ECMM) epidemiological survey on invasive infections due to Fusarium species in Europe

In order to better understand the epidemiology of fusariosis in Europe, a survey collecting information on the clinical characteristics of the patients infected by Fusarium as well as on the infecting isolates was launched. A total of 76 cases of invasive fusariosis occurring from January 2007 to June 2012 were collected and Fusarium isolates were identified by sequencing the translation elongation factor 1α (TEF) gene. Also, antifungal susceptibility was tested by broth microdilution according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Etest. Disseminated disease was considered proven in 46 cases and probable in 17 cases. Localised infection was seen in 13 cases. Gibberella fujikuroi species complex (SC), including Fusarium verticillioides and F. proliferatum, and F. solani SC were the most frequent aetiology of disseminated and localised infections, respectively. The crude mortality rate was 46 %, the highest associated with F. solani SC (67 %) and F. proliferatum (62.5 %). A wide range of antifungal susceptibilities was observed. Amphotericin B was the most potent antifungal in vitro, and itraconazole the least effective. The azoles exhibited lower minimum inhibitory concentrations (MICs) against F. verticillioides strains, with posaconazole having a slightly better performance, while F. solani SC isolates were resistant to all three azoles tested. The essential agreement between the Etest and the EUCAST method was 100 % for itraconazole and voriconazole, and 96 % for amphotericin B and posaconazole. In conclusion, we confirm that fusariosis is a rare but severe event in Europe, that G. fujikuroi SC is the predominant cause of deep infections and that different species have different antifungal in vitro susceptibility patterns.     

Comparative Evaluation of the Vitek 2 Yeast Susceptibility Test and CLSI Broth Microdilution Reference Method for Testing Antifungal Susceptibility of Invasive Fungal Isolates in Italy: the GISIA3 Study

The newly available AST-YS01 Vitek 2 cards were evaluated, and the results were compared with those obtained by the CLSI M27-A2 microdilution reference method. Clinical fungal isolates, including 614 isolates of Candida spp., 10 Cryptococcus neoformans isolates, 1 Geotrichum capitatum isolate, and 2 quality control strains, were tested for their susceptibilities to amphotericin B, fluconazole, and voriconazole using both methods. The majority of fungal isolates were susceptible to all antifungal agents tested: the MIC₉₀ values determined by the Vitek 2 and CLSI methods were 0.5 and 1 μg/ml, respectively, for amphotericin B; 8 and 16 μg/ml, respectively, for fluconazole; and <0.12 and 0.25 μg/ml, respectively, for voriconazole. Overall there was excellent categorical agreement (CA) between the methods (99.5% for amphotericin B, 92% for fluconazole, 98.2% for voriconazole), but discrepancies were observed within species. The CAs for fluconazole were low for Candida glabrata and Candida krusei when the results of the CLSI method at 48 h were considered. Moreover, the fully automated commercial system did not detect the susceptibility of Cryptococcus neoformans to voriconazole. The Vitek 2 system can be considered a valid support for antifungal susceptibility testing of fungi, but testing of susceptibility to agents not included in the system (e.g., echinocandins and posaconazole) should be performed with other methods.Antifungal susceptibility testing (AFST) has become increasingly common in clinical practice in recent years. This is a result of both the improved performance of antifungal susceptibility testing methods and the introduction of antifungal drugs with various mechanisms of action, such as the echinocandins and triazoles (7, 9, 10). It is generally considered that the outcome of invasive fungal infections, in particular, candidemia, is improved by prompt initiation of appropriate antifungal therapy (13). Treatment of invasive Candida infections is currently based on the updated IDSA guidelines (15), but knowledge of the susceptibilities of local clinical isolates to antifungal agents can further guide physicians'' choice of appropriate and safe antifungal agents, which is especially important for long-term treatment (9).AFST reference methods for fungi have been available since 1997 from the Clinical and Laboratory Standards Institute (CLSI; formerly the National Committee for Clinical Laboratory Standards) and, more recently, from the subcommittee on AFST of the European Committee for Antimicrobial Susceptibility Testing (EUCAST). However, both of these methods are time-consuming and clinical microbiological laboratory personnel may be unfamiliar with the methodologies (3, 6, 11, 12, 14, 20). Commercially available methods demonstrate variable performance compared with the performance of reference methods; two commercial assays have been approved by the U.S. Food and Drug Administration (FDA) for AFST of fungi with several antifungal agents: Etest (bioMérieux SA, Marcy l''Etoile, France) and the Sensititre YeastOne system (Trek Diagnostic Systems Ltd., East Grinstead, England). Recently, bioMérieux expanded its role in this area with a yeast susceptibility test that determines Candida growth spectrophotometrically using the Vitek 2 microbiology systems, performing fully automated testing of susceptibility to flucytosine, amphotericin B, fluconazole, and voriconazole (1, 16-18).To investigate the reliability of the new AST-YS01 Vitek 2 cards, the susceptibilities of clinical fungal isolates to amphotericin B, fluconazole, and voriconazole, as determined by the Vitek 2 system, were compared with those obtained with the reference CLSI (M27-A2) broth microdilution method (14).     

A difficult-to-treat pleuropulmonary histoplasmosis in a patient with rheumatoid arthritis in Taiwan

Amphotericin B and itraconazole are the primary agents for treating histoplasmosis. Newer azoles are alternatives for patients refractory to or intolerant of standard therapy. We report an 83-year-old woman with rheumatoid arthritis complicated with pleuropulmonary histoplasmosis who responded to liposomal amphotericin B, but progressed under voriconazole and posaconazole maintenance therapy.     

Caspofungine et mycoses à champignons rares : activité in vitro et in vivo chez l’animal et chez l’homme

Caspofungine belongs to the echinocandin family. It is a large lipopeptide molecule that inihibits the β-(1,3)-glucan synthesis, a cell wall component. No drug target is present in mammalian cells. In vitro data and experimental studies have demonstrated that caspofungin displays antifungal activity against most Candida spp. (including isolates resistant to azoles and amphotericin B), several species of filamentous fungi, including Aspergillus and certain dimorphic fungi, such as Histoplasma, Blastomyces and Coccidioïdes. However, the molecule displays no activity in vitro against Fusarium spp., Zygomycetes (Mucor circinelloides, Absidia corymbifera, Rhizomucor pusillus, Cunninghamella bertholletiae, etc.), Rhizopus spp. and Pseudoallescheria spp. Caspofungin generated low Minimum Inhibitory Concentrations (MICs) and Minimum Effective Concentrations (MECs) against Aspergillus but not against Fusarium. Studies were conducted using several experimental models of fungal infection. They were not active at clinically relevant concentrations against Zygomycetes, Cryptococcus neoformans or Fusarium spp. Absence of antagonism in combination with other antifungal drugs suggests that combination antifungal therapy could become a general feature of echinocandins, particularly in the case of invasive aspergillosis. The results of these first clinical trials are promising but further studies are required to define the exact role of caspofungin in the arsenal of antifungal agents. New trials using caspofungin alone or in combination are necessary to demonstrate its efficacy in the treatment of mycoses due to uncommon fungi.