Evaluation of antifungal combination against Cryptococcus spp.

The second cause of death among systemic mycoses, cryptococcosis treatment represents a challenge since that 5‐flucytosine is not currently available in Brazil. Looking for alternatives, this study evaluated antifungal agents, alone and combined, correlating susceptibility to genotypes. Eighty Cryptococcus clinical isolates were genotyped by URA5 gene restriction fragment length polymorphism. Antifungal susceptibility was assessed following CLSI‐M27A3 for amphotericin (AMB), 5‐flucytosine (5FC), fluconazole (FCZ), voriconazole (VRZ), itraconazole (ITZ) and terbinafine (TRB). Drug interaction chequerboard assay evaluated: AMB + 5FC, AMB + FCZ, AMB + TRB and FCZ + TRB. Molecular typing divided isolates into 14 C. deuterogattii (VGII) and C. neoformans isolates were found to belong to genotype VNI (n = 62) and VNII (n = 4). C. neoformans VNII was significantly less susceptible than VNI (P = 0.0407) to AMB; C. deuterogattii was significantly less susceptible than VNI and VNII to VRZ (P < 0.0001). C. deuterogattii was less susceptible than C. neoformans VNI for FCZ (P = 0.0170), ITZ (P < 0.0001) and TRB (P = 0.0090). The combination FCZ + TRB showed 95.16% of synergistic effect against C. neoformans genotype VNI isolates and all combinations showed 100% of synergism against genotype VNII isolates, suggesting the relevance of cryptococcal genotyping as it is widely known that the various genotypes (now species) have significant impact in antifungal susceptibilities and clinical outcome. In difficult‐to‐treat cryptococcosis, terbinafine and different antifungal combinations might be alternatives to 5FC.     

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.     

Genotypic diversity of environmental Cryptococcus neoformans isolates from Northern Portugal

The Cryptococcus neoformans/C. gattii species complex members are the main agents of systemic cryptococcosis. This disease is believed to be acquired from the environment via fungal cell inhalation. Often, isolates recovered from environmental and clinical sources have proven to be genotypically similar. We assessed the occurrence of C. neoformans and C. gattii in environmental substrates collected in a Portuguese region. Twenty‐eight isolates were identified as C. neoformans – five from decaying Eucalyptus leaves and 23 from domestic pigeon droppings. The isolates were genotyped using a URA5‐RFLP approach. The C. neoformans VNIV (53.6%, n = 15) and VNI (32.1%, n = 9) genotypes were abundantly present among environmental isolates. The hybrid VNIII (14.3%, n = 4) genotype was underrepresented and the VNII was not found. Cryptococcus gattii was also not found although some isolates yielded a positive canavanine–glycine–bromothymol blue test.     

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 characterisation of clinical Cryptococcus neoformans and Cryptococcus gattii isolates from Sichuan province,China

Previous reports on the molecular characteristics of clinical isolates of Cryptococcus species in China have focused on isolates from southeast China. To obtain a more detailed molecular epidemiology, a total of 92 cryptococcal isolates were collected from Sichuan province. A total of 24 isolates from 12 other provinces were collected for comparative study. Genotypes and mating types of 116 Cryptococcus isolates were determined. Among the 116 isolates, 43 isolates (19 isolates from Sichuan and 24 isolates outside of Sichuan) were analysed by multi‐locus sequence typing (MLST). All 116 clinical isolates were mating type α. Most isolates (114/116) were molecular type VNI and the remaining two isolates were VGI and VGII respectively. MLST results revealed five sequence types (STs) of C. neoformans including two novel STs, with most isolates identified as ST5. The two C. gattii isolates identified in our study were ST44 and ST159. Based on our report and previous studies, there are 15 C. neoformans STs in China which can be divided into three subgroups. The C. gattii isolate from Sichuan could be a scattered subtype of VGII (ST44). Our findings demonstrated that C. neoformans isolates in Sichuan are genetically homogeneous, and ST5 is the epidemic clone of C. neoformans in China.     

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.     

Infective capacity of Cryptococcus neoformans and Cryptococcus gattii in a human astrocytoma cell line

Pathogenesis of cryptococcosis in the central nervous system (CNS) is a topic of ongoing research, including the mechanisms by which this fungus invades and infects the brain. Astrocytes, the most common CNS cells, play a fundamental role in the local immune response. Astrocytes might participate in cryptococcosis either as a host or by responding to fungal antigens. To determine the infectivity of Cryptococcus neoformans var. grubii and Cryptococcus gattii in a human astrocytoma cell line and the induction of major histocompatibility complex (MHC) molecules. A glioblastoma cell line was infected with C. neoformans var. grubii and C. gattii blastoconidia labelled with FUN‐1 fluorescent stain. The percentage of infection and expression of HLA class I and II molecules were determined by flow cytometry. The interactions between the fungi and cells were observed by fluorescence microscopy. There was no difference between C. neoformans var. grubii and C. gattii in the percentage infection, but C. neoformans var. grubii induced higher expression of HLA class II than C. gattii. More blastoconidia were recovered from C. neoformans‐infected cells than from C. gattii infected cells. Cryptococcus neoformans var. grubii may have different virulence mechanisms that allow its survival in human glia‐derived cells.     

Central nervous system infection due to Cryptococcus gattii sensu lato in India: Analysis of clinical features,molecular profile and antifungal susceptibility

Cryptococcus gattii species complex has evolved as a pathogen in the last two decades causing infection among both immunocompetent and immunocompromised hosts. We aimed to analyse the clinical features of CNS infection caused by C. gattii sensu lato, molecular and antifungal susceptibility profile of this pathogen. Cases diagnosed to have CNS cryptococcosis were included in the study. Cryptococcus recovered from patient's specimen was identified by standard protocol. Species confirmation, mating type and molecular type determination were performed by PCR based methods. Antifungal susceptibility was tested in VITEK2C to amphotericin B, 5‐flucytosine, fluconazole and voriconazole. Among 199 cases, 20 (10%) were due to C. gattii, comprising of 75% cryptococcal meningitis and 25% cryptococcoma cases. Young adult males were commonly affected. Headache and vomiting were prominent symptoms and 50% were immunocompromised. Among the isolates, 75%, 20% and 5% were C. tetragattii, C. gattii sensu stricto and C. bacillisporus respectively and all had mating type α. Four (20%) isolates of C. tetragattii and the only isolate of C. bacillisporus were resistant to fluconazole. The most common species isolated from south India is C. tetragattii. The study contributes to the epidemiology of C. gattii and reiterates the need for genotyping and antifungal susceptibility testing.     

Molecular typing of environmental Cryptococcus neoformans/C. gattii species complex isolates from Manaus,Amazonas, Brazil

Cryptococcus neoformans and Cryptococcus gattii are the main causative agents of cryptococcosis, a systemic fungal disease that affects internal organs and skin, and which is acquired by inhalation of spores or encapsulated yeasts. It is currently known that the C. neoformans/C. gattii species complex has a worldwide distribution, however, some molecular types seem to prevail in certain regions. Few environmental studies of Cryptococcus have been conducted in the Brazilian Amazon. This is the first ecological study of the pathogenic fungi C. neoformans/C. gattii species complex in the urban area of Manaus, Amazonas, Brazil. A total of 506 samples from pigeon droppings (n = 191), captive bird droppings (n = 60) and tree hollows (n = 255) were collected from June 2012 to January 2014 at schools and public buildings, squares, pet shops, households, the zoo and the bus station. Samples were plated on niger seed agar (NSA) medium supplemented with chloramphenicol and incubated at 25°C for 5 days. Dark‐brown colonies were isolated and tested for thermotolerance at 37°C, cycloheximide resistance and growth on canavanine‐glycine‐bromothymol blue agar. Molecular typing was done by PCR‐RFLP. Susceptibility to the antifungal drugs amphotericin B, fluconazole, itraconazole and ketoconazole was tested using Etest^® strips. In total, 13 positive samples were obtained: one tree hollow (C. gattiiVGII), nine pigeon droppings (C. neoformansVNI) and three captive bird droppings (C. neoformansVNI). The environmental cryptococcal isolates found in this study were of the same molecular types as those responsible for infections in Manaus.     

In vitro susceptibility testing of amphotericin B for Cryptococcus neoformans variety grubii AFLP1/VNI and Cryptococcus gattii AFLP6/VGII by CLSI and flow cytometry

Cryptococcus neoformans var. grubii AFLP1/VNI is the main causative agent of cryptococcosis associated with AIDS in the world. Cryptococcus gattii AFLP6/VGII causes mainly endemic primary infection in immunocompetent hosts. To determine the minimum inhibitory concentrations (MICs) of C. neoformans var. grubii AFLP1/VNI and C. gattii AFLP6/VGII against amphotericin B (AMB) in a short period of time, flow cytometry (FCM) with FUN‐1 fluorochrome was used to compare with broth microdilution method (CLSI M27‐A3). The minimum incubation period was evaluated by minimum fungicidal concentration procedure. Seventeen clinical isolates of C. neoformans var. grubii AFLP1/VNI and 18 of C. gattii AFLP6/VGII were analysed. The time for the determination of MICs by FCM was 2 h against 72 h by CLSI M27‐A3 and the comparison of MIC showed a positive significant correlation (P = 0.048). It is important to highlight the role of the FCM as an alternative method to determine the MICs for AMB in within a day, with positive cost‐benefit.     

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.     

Five‐year profile of candidaemia at an Indian trauma centre: High rates of Candida auris blood stream infections

Candidaemia is a potentially fatal infection with varied distribution of Candida species and their antifungal susceptibility profiles. The recent emergence of Candida auris in invasive candidiasis is a cause for concern. This study describes the profile of candidaemia at an Indian tertiary care hospital and reports the emergence of C. auris. All patients diagnosed with candidaemia between 2012 and 2017 were studied. The isolates were identified using conventional methods, VITEK 2 and MALDI‐TOF MS. The isolates not identified by MALDI‐TOF were sequenced. Antifungal susceptibility testing was done by the CLSI broth microdilution method and VITEK 2. A total of 114 isolates of Candida species were analysed. Candida tropicalis (39.4%) was the most common species, followed by C. auris (17.5%), C. albicans (14%) and C. parapsilosis (11.4%). Notably, Diutina mesorugosa isolates (n = 10) were not identified by MALDI‐TOF and were confirmed by sequencing. Furthermore, 45% (n = 9) C. auris strains exhibited low MICs of FLU (0.05‐4 μg/mL) and the remaining 55% (n = 11) isolates had high MICs ≥ 64 μg/mL. Also, D. mesorugosa exhibited high MICs of FLU (32 μg/mL) in 2 isolates. A high rate of errors in antifungal susceptibility was noted with the VITEK 2 as compared to the CLSI method. Candida auris was the second most prevalent species causing candidaemia warranting infection control practices to be strengthened to prevent its spread.     

Isolation of Rhodotorula mucilaginosa from blood cultures in a tertiary care hospital

Rhodotorula species have traditionally been considered as one of common non‐virulent environmental inhabitant. They have emerged as an opportunistic pathogen, particularly in immunocompromised hosts and most infections have been associated with intravenous catheters in these patients. We review the isolates in blood cultures of Rhodotorula mucilaginosa in our Hospital. We describe the demographic and clinical features of the cases and the antifungal susceptibility profiles of the isolates. Selected patients had an isolation of R. mucilaginosa in blood cultures in our tertiary care Hospital. All data were collected retrospectively from clinical records during 5 years. We report 8 isolates in blood, two of them were considered contaminants. Immunosuppression, surgery, previous antibiotic therapy were common clinical features. For all the isolates, minimum inhibitory concentration (MIC) values were high for echinocandins and azoles and low for amphotericin B and 5‐flucytosine. One strain showed atypical susceptibility profile. Rhodotorula mucilaginosa may be present on the skin and blood cultures can be contaminated. Fungaemia due to R. mucilaginosa is a rare clinical entity which requires risk factors but clinically relevant because of the multiresistant profile. Rhodotorula mucilaginosa shows high MIC values for azoles and echinocandins, therefore amphotericin B and flucytosine must be administered as antifungal therapy.     

Cryptococcosis in patients with diabetes mellitus II in mainland China: 1993‐2015

Diabetes mellitus II (DM II) is a newly defined independent factor contributing to the morbidity and mortality of cryptococcosis. This retrospective case analysis aims to explore the epidemiology, clinical profile and strain characteristics of cryptococcosis in Chinese DM II patients. This study included 30 cases of cryptococcosis with DM II occurring from 1993 to 2015 in mainland China. The hospital‐based prevalence of cryptococcosis in DM II was 0.21%. The mean age of the patients was 56.1 years (95% confidence interval: 51.5, 60.6), and 93% of the patients were older than 40 years. Sixty‐two per cent of the patients experienced untreated or poorly controlled blood glucose before infection. Multilocus sequence typing analysis categorised all cultured strains as Cryptococcus neoformans and sequence type 5. Sixty‐nine per cent of pulmonary cryptococcosis patients experienced misdiagnoses and treatment delays. Sixty per cent of cryptococcal meningitis patients received substandard antifungal therapy. The overall death rate was 33%. Considering the large population size of DM II patients in China, improved attention should be paid to the high prevalence of cryptococcosis as revealed by us. We also emphasised the importance of blood glucose control for infection prevention, especially among the elderly.     

Evaluation of virulence factors and antifungal susceptibility patterns of different Candida species isolated from the female camel (Camelus dromedarius) genital tract

The purposes of this study were to investigate the enzymatic activity of different Candida species and their antifungal susceptibility patterns. The study involved a total of 83 isolates of Candida from the genital tract of the female Camelus dromedarius. After species identification, the isolates were analysed for the production/activity of phospholipase, proteinase and haemolysin. In addition, the agar disc diffusion method was performed on the basis of CLSI guidelines M44‐A2 protocol for antifungal susceptibility testing. All the isolates were able to produce phospholipase, proteinase and haemolysin. A total of 35.48%, 87.09% and 64.51% of C. albicans isolates exhibited very high phospholipase, proteinase and haemolytic activities, respectively, whereas very high phospholipase, proteinase and haemolytic activities were determined in 5.76%, 23.07% and 45.16% of non‐C. albicans isolates respectively. Overall, 61 (73.5%) of Candida isolates were susceptible to fluconazole, 70 (84.3%) susceptible to clotrimazole, 82 (98.8%) susceptible to voriconazole, 76 (91.6%) susceptible to itraconazole, 75 (90.4%) susceptible to ketoconazole, 83 (100%) susceptible to amphotericin B, 81 (97.6%) susceptible to nystatin and 36 (43.4%) susceptible to flucytosine. Candida isolates showed higher haemolytic activity than that of other secreted hydrolases among vaginal Candida species. In addition, amphotericin B was the most in vitro effective antifungal drug and flucytosine had the poorest activity under such conditions.     

In vitro postantifungal effect,adhesion traits and haemolysin production of Candida dubliniensis isolates following exposure to 5‐fluorocytosine

The phenomenon of postantifungal effect (PAFE), which is the suppression of candidal growth following brief exposure to antifungal agents, is linked with candidal pathogenicity. Adhesion to buccal epithelial cells (BEC), germ tube (GT) formation and relative cell surface hydrophobicity (CSH) are all adhesion traits of candidal pathogenicity. Ability to produce haemolysin by Candida species is also a determinant of its pathogenicity. There is no information on either the PAFE or its impact on adhesion traits and haemolysin production of oral Candida dubliniensis isolates following exposure to 5‐fluorocytosine (5‐FC). Hence, the focus of this investigation was to research the in vitro PAFE, adhesion to BEC, GT formation, relative CSH and haemolysin production on 20 C. dubliniensis isolates following exposure to 5‐FC. Following obtaining the minimum inhibitory concentration (MIC) of 5‐FC, isolates of C. dubliniensis were exposed to sub‐lethal concentrations (×3 MIC) of 5‐FC for 1 h. After this brief exposure, the antimycotic was removed and PAFE, adhesion to BEC, GT formation, relative CSH and haemolysin production was determined by formerly described in vitro methods. MIC (μg/ml) of C. dubliniensis isolates to 5‐FC ranged from 0.002 to 0.125. The mean PAFE (hours) elicited by 5‐FC on C. dubliniensis isolates was approximately 1 h. Exposure to 5‐FC suppressed the ability of C. dubliniensis isolates to adhere BEC, GT formation, relative CSH and haemolysin activity by a mean percentage reduction in 50.98%, 29.51%, 36.79% and 12.75% (P < 0.001 for all) respectively. Therefore, brief exposure of C. dubliniensis isolates to 5‐FC appears to exert an antifungal effect by subduing its growth, adhesion traits as well as haemolysin production.     

Molecular types of Cryptococcus gattii/Cryptococcus neoformans species complex from clinical and environmental sources in Nairobi,Kenya

Cryptococcal meningitis infections cause high mortality rates among HIV‐infected patients in Sub‐Saharan Africa. The high incidences of cryptococcal infections may be attributed to common environmental sources which, if identified, could lead to institution of appropriate control strategies. To determine the genotypes of Cryptococcus gattii/C. neoformans‐ species complex from Nairobi, Kenya, 123 clinical and environmental isolates were characterised. Typing was done using orotidine monophosphate pyrophosphorylase (URA5) gene restriction fragment length polymorphism (URA5‐RFLP). The majority of the isolates [105/123; 85.4%] were C. neoformans genotype (AFLPI/VNI) and 1.6% AFLP1A/VNB/VNII, whereas (13%) were C. gattii (AFLP4/VGI). This is the first report on the genotypes of C. gattii/C. neoformans species complex from clinical and environmental sources in Nairobi, Kenya and the isolation of C. gattii genotype AFLP4/VGI from the environment in Kenya.     

Cryptococcus neoformans infection in malignancy

Cryptococcosis is an opportunistic invasive fungal infection that is well described and easily recognised when it occurs as meningitis in HIV‐infected persons. Malignancy and its treatment may also confer a higher risk of infection with Cryptococcus neoformans, but this association has not been as well described. A case of cryptococcosis in a cancer patient is presented, and all cases of coincident C. neoformans infection and malignancy in adults published in the literature in English between 1970 and 2014 are reviewed. Data from these cases were aggregated in order to describe the demographics, type of malignancy, site of infection, clinical manifestations, treatment and outcomes of cryptococcosis in patients with cancer. Haematologic malignancies accounted for 82% of cases, with lymphomas over‐represented compared to US population data (66% vs. 53% respectively). Cryptococcosis was reported rarely in patients with solid tumours. Haematologic malignancy patients were more likely to have central nervous system (P < 0.001) or disseminated disease (P < 0.001), receive Amphotericin B as part of initial therapy (P = 0.023), and had higher reported mortality rates than those with solid tumours (P = 0.222). Providers should have heightened awareness of the possibility of cryptococcosis in patients with haematologic malignancy presenting with infection.     

Molecular identification,antifungal resistance and virulence of Cryptococcus neoformans and Cryptococcus deneoformans isolated in Seville,Spain

Cryptococcal meningitis is one of the leading causes of death in HIV/AIDS patients. Our aim was to in order to characterise the epidemiology, antifungal susceptibility pattern and virulence of 28 Cyptococcus sp. strains recovered from 12 AIDS patients during two years in a Spanish single institution. Antifungal susceptibility testing was performed according to the CLSI protocols. Clinical strains were molecularly characterised by serotyping, mating type, PCR fingerprinting (M13 and GACA₄ microsatellites) and analysis of two rDNA regions (IGS1 and ITS). Sequencing of the ERG11 gene was used to explore mechanisms of fluconazole resistance. Differences in virulence between species were studied in a Galleria mellonella infection model. Cryptococcus deneoformans and C. deneoformans x Cryptococcus neoformans hybrids were the most frequent variety (65%) followed by C. neoformans (35%). Strains were categorised according to 13 microsatellite genotypes and mixed infections could be detected in three patients. Twenty‐nine per cent of the strains were fluconazole resistant. In one of the patients, the fluconazole resistance phenotype was associated with a point mutation in the ERG11 gene responsible for the amino acid substitution G470R. C. neoformans strains were able to kill G. mellonella larvae more efficiently than C. deneoformans and hybrids between both species. Precisely molecular characterisation of C. neoformans species is important for an accurate patient's management.     

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.