Chromoblastomycosis in the Amazon region, Brazil, caused by Fonsecaea pedrosoi, Fonsecaea nubica, and Rhinocladiella similis: Clinicopathology, susceptibility, and molecular identification.

Chromoblastomycosis is a chronic subcutaneous disease caused by human contact with melanized fungi occurring mainly in tropical and subtropical zones worldwide. This study assessed 12 patients with chromoblastomycosis from Rondônia, Brazil, Amazon region. In sum, 83.3% were men, 41.6% were from Monte Negro city, median age was 52.9 years, and median time to disease progression was 12.2 years. Lesions were located on the lower limbs (75%), and verruciform was prevalent form (66.6%). After 3 years of treatment with itraconazole, two patients were considered cured. The etiological agents were identified by the molecular sequence of the ribosomal internal transcribed spacer ITS1, 5.8S, and ITS2 region and ß-tubulin genes. Eight strains were identified as Fonsecaea pedrosoi, two were F. nubica, and two were Rhinocladiella similis. The antifungal activity of five drugs was evaluated, and the most active drug was terbinafine (range minimal inhibitory concentration [MIC] 0.015-0.12 µg/ml), itraconazole (range MIC 0.03-0.5 µg/ml) and voriconazole (range MIC 0.06-0.5 µg/ml). The highest MIC was 5-fluorocytosine (range MIC 2-32 µg/ml), and amphotericin B (range MIC 0.25-2 µg/ml). In conclusion, the present study expanded the epidemiological disease database and described for the first time F. nubica and R. similis as chromoblastomycosis agents in the Brazilian Amazon region. Our results confirmed the importance of using molecular methods to identify the melanized fungi and stimulate the recognition of the disease in other places where no cases have been reported.

Antifungal Resistance in Cryptococcal Infections.

Antifungal therapy, especially with the azoles, could promote the incidence of less susceptible isolates of Cryptococcus neoformans and C. gattii species complexes (SC), mostly in developing countries. Given that these species affect mostly the immunocompromised host, the infections are severe and difficult to treat. This review encompasses the following topics: 1. infecting species and their virulence, 2. treatment, 3. antifungal susceptibility methods and available categorical endpoints, 4. genetic mechanisms of resistance, 5. clinical resistance, 6. fluconazole minimal inhibitory concentrations (MICs), clinical outcome, 7. environmental influences, and 8. the relevance of host factors, including pharmacokinetic/pharmacodynamic (PK/PD) parameters, in predicting the clinical outcome to therapy. As of now, epidemiologic cutoff endpoints (ECVs/ECOFFs) are the most reliable antifungal resistance detectors for these species, as only one clinical breakpoint (amphotericin B and C. neoformans VNI) is available.

Comparison of the broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing and the Clinical Laboratory Standards Institute BMD method for non-Candida albicans and non-C. tropicalis bloodstream isolates from eleven tertiary hospitals in São Paulo state, Brazil.

We aim in this study to provide levels of susceptibility of 162 bloodstream isolates of non-Candida albicans and non-C. tropicalis species from a sentinel program conducted in 11 hospitals in Brazil. Additionally, we compared the broth microdilution (BMD) method of the European Committee of Susceptibility Testing (EUCAST) with Clinical Laboratory Standards Institute (CLSI) BMD method for fluconazole, itraconazole, voriconazole, and amphotericin B. The study included 103 C. parapsilosis, 38 C. glabrata, 8 C. orthopsilosis, and 7 C. krusei isolates, and single isolates of Pichia anomala, C. famata, C. lusitaniae, C. kefyr, C. guilliermondii, and C. metapsilosis. Of note, we observed cross-resistance between fluconazole and voriconazole for two isolates being one C. parapsilosis and one C. glabrata. Good essential agreement (EA) was observed between the EUCAST and the CLSI results for C. parapsilosis and for fluconazole, itraconazole, voriconazole, and amphotericin B, respectively: 98%, 99%, 98%, and 97%. Otherwise, for C. glabrata, the EA for fluconazole was 84.2% and for voriconazole 89.4%. Because data from Brazil are scarce, our results contribute to the consolidation of the database of candidemia agents and monitoring of trends in the profile of drug resistance.

Evaluation of the Sensititre YeastOne and Etest in Comparison with CLSI M38-A2 for Antifungal Susceptibility Testing of Three Azoles, Amphotericin B, Caspofungin, and Anidulafungin, against Aspergillusfumigatus and Other Species, Using New Clinical Breakpoints and Epidemiological Cutoff Values.

Aspergillosis is an invasive fungal disease associated with high mortality. Antifungal susceptibility testing (AFST) is receiving increasing consideration for managing patients, as well as for surveilling emerging drug resistance, despite having time-consuming and technically complex reference methodologies. The Sensititre YeastOne (SYO) and Etest methods are widely utilized for yeasts but have not been extensively evaluated for Aspergillus isolates. We obtained Posaconazole (POS), Voriconazole (VCZ), Itraconazole (ITC), Amphotericin B (AMB), Caspofungin (CAS), and Anidulafungin (AND) minimum inhibitory concentrations (MICs) for both the Etest (n = 330) and SYO (n = 339) methods for 106 sequenced clinical strains. For 84 A. fumigatus, we analyzed the performance of both commercial methods in comparison with the CLSI-AFST, using available cutoff values. An excellent correlation could be demonstrated for Etest-AMB and Etest-VCZ (p < 0.01). SYO-MICs of AMB, VCZ, and POS resulted in excellent essential agreement (>93%), and >80% for AMB, VCZ, and ITC Etest-MICs. High categoric agreement was found for AMB, ITC, and CAS Etest-MICs (>85%) and AMB SYO-MICs (>90%). The considerable number of major/very major errors found using Etest and SYO, possibly related to the proposed cutoffs and associated with the less time-consuming processes, support the need for the improvement of commercial methods for Aspergillus strains.

Five-year evaluation of bloodstream yeast infections in a tertiary hospital: the predominance of non-C. albicans Candida species.

This is a retrospective observational study of clinical and epidemiologic data from bloodstream yeast infections over 5 years (2004-2008) in a tertiary-care hospital. During this period, there were 52 such infections, at a rate of 2.4 per 1,000 hospital admissions. Non-C. albicans Candida species and other genera were responsible for 82% of infections, with C. tropicalis and C. parapsilosis being the most common. In 2008 no C. albicans infections occurred. Several uncommon fungal pathogens were observed, including Trichosporon asahii, Rhodotorula spp. and Candida zeylanoides. Of 16 isolates tested, 3 (19%) were resistant to fluconazole, including one C. zeylanoides (MIC 8 microg/ml) and one C. tropicalis (MIC 16 microg/ml) isolate, as well as intrinsically resistant C. krusei. All isolates tested were susceptible to itraconazole (n = 7) and amphotericin B (n = 8). Yeast infections were associated with severe underlying diseases, mainly hematological/solid cancers (71%), hospitalization in the ICU (41%), central venous catheters (80%), and use of antimicrobials (94%). The overall mortality rate was 50%. Our finding of a predominance of non-C. albicans Candida species infection with uncommon yeasts, and fluconazole resistance, suggests the need for continuous surveillance of fungemia and of antibiotic susceptibility trends, in order to adopt treatment strategies applicable to particular healthcare institutions.

Coumaric acid analogues inhibit growth and melanin biosynthesis in Cryptococcus neoformans and potentialize amphotericin B antifungal activity.

Fungal infections are on the rise, since the imunocompromised population is increasing due to AIDS/HIV, organ transplant and chemotherapy. Many environmental and pathogenic fungi are able to accomplish melanin biosynthesis as a virulence factor to promote host invasion. Melanized cells are more resistant to radiation, oxidative and osmotic stresses; also melanin confers an advantage in vivo, since melanized cells are more resistant to phagocytic engulfment and oxidative stress caused by the host defense cells and by some antifungal drugs, such as fluconazole (FCZ) and amphotericin B (AmB). Brown, red or black melanin pigments can be produced by the polyketide pathway (DHN-melanin) or from dihydroxyphenols, such as L-DOPA (L-3,4-dihydroxyphenylalanine) and L-tyrosine by polyphenoloxidases. Among several pathogenic fungi, Cryptococcus neoformans is a melanized yeast that causes pneumonia and meningoencephalitis in immunocompromised patients. The knockout of the laccase genes or other interruptions on melanin biosynthetic pathway generates cryptococcal strains with attenuated virulence in an animal model. In this study 16 analogues of coumaric and cinnamic acid were evaluated as possible tyrosinase inhibitors. We have identified some valuable inhibitors of C. neoformans growth and melanin biosynthesis disruption agents. The results showed that coumaric acid derivatives (1a-c), the ketones (3a-b) and 2-allylphenol (7c) are significant inhibitors of tyrosinase and melanization of the fungus. Two analogues (1b and 3b) were selected as promising antimelanogenic agents to be combined with AmB, showing to promote 16-fold reduction in the AmB fungicidal concentration with no appreciable cytotoxicity to mammalian cells. The data suggest that inhibition of the melanin biosynthesis by these compounds may increase the susceptibility of the cells to the oxidative stress generated by AmB. In summary, our data show that C. neoformans can be a suitable model system to test novel inhibitors that target melanin biosynthesis, and novel compounds for adjunct therapy against C. neoformans were identified.

Brazilian flora extracts as source of novel antileishmanial and antifungal compounds.

Natural products have long been providing important drug leads for infectious diseases. Leishmaniasis is a protozoan parasitic disease found mainly in developing countries, and it has toxic therapies with few alternatives. Fungal infections have been the main cause of death in immunocompromised patients and new drugs are urgently needed. In this work, a total of 16 plant species belonging to 11 families, selected on an ethnopharmacological basis, were analyzed in vitro against Leishmania (L.) chagasi, Leishmania (L.) amazonensis, Candida krusei, and C. parapsilosis. Of these plant species, seven showed antifungal activity against C. krusei, five showed antileishmanial activity against L. chagasi and four against L. amazonensis, among them species of genus Plectranthus. Our findings confirm the traditional therapeutic use of these plants in the treatment of infectious and inflammatory disorders and also offer insights into the isolation of active and novel drug prototypes, especially those used against neglected diseases as Leishmaniasis.

AIDS-associated central nervous system cryptococcosis: a Brazilian case study.

In recent years the effect of HAART in patients with AIDS has been great at decreasing the incidence of opportunistic infections. Nonetheless, patients with AIDS living in developing countries still present with severe central nervous system cryptococcosis, with high mortality rates. The study of the clinical-epidemiological-laboratory aspects of the patients treated before the HAART era might be useful in an assessment of the impact of these drugs in the prognosis of cases.

Gas Chromatography-Triple Quadrupole Mass Spectrometry Analysis and Vasorelaxant Effect of Essential Oil from Protium heptaphyllum (Aubl.) March.

The Protium heptaphyllum species, also known as Almécega, produces an oily resin, used in folk medicine as an analgesic and anti-inflammatory agent, in healing, and as an expectorant, which is rich in pentacyclic triterpenes and essential oils. In this study, the essential oil obtained by hydrodistillation of Almécega's resin was analyzed by gas chromatography-triple quadrupole mass spectrometry and evaluated for chemical composition and vasorelaxant activity in rat superior mesenteric artery. The main constituents determined by gas chromatography-triple quadrupole mass spectrometry were limonene, p-cineole, and o-cymene. In intact rings precontracted with phenylephrine (Phe 1 µM), EOPh (3-750 µg/mL) induced relaxation, and the essential oil had a concentration-dependent vasorelaxant effect, without involvement of endothelial mediators.

Antifungal Activity of the Biphosphinic Cyclopalladate C7a against Candida albicans Yeast Forms In Vitro and In Vivo.

Vulvovaginal and invasive candidiasis are frequent conditions in immunosuppressed individuals caused by Candida albicans and non-albicans Candida spp. Fluconazole and Amphotericin B are the main drugs used to fight the infection. However, resistance to fluconazole and other azole antifungal drugs is an important clinical problem that encourages the search for new therapeutic alternatives. In this work, we evaluate the antifungal activity of the biphosphinic cyclopalladate C7a in the in vitro and in vivo model. Our results showed fungicidal activity, with low values of minimal inhibitory concentrations and minimum fungicidal concentrations, even for fluconazole and/or miconazole resistant Candida isolates. Fluorescence microscopy and transmission electron microscopy revealed that the compound was able to inhibit the formation of hyphae/pseudohyphae and, moreover, promoted morphological alterations in cellular organelles and structures, such as disruption of cell wall, apparent mitochondrial swelling, chromatin marginalization into the nuclei and increased numbers of electron-lucent vacuoles. C7a significantly decreased the biofilm formation and reduced the viability of yeast cells in mature biofilms when tested against a virulent C. albicans strain. In vivo assays demonstrated a significant decrease of fungal burden in local (vaginal canal) and disseminated (kidneys) infection. In addition, we observed a significant increase in the survival of the systemically infected animals treated with C7a. Our results suggest C7a as a novel therapeutic agent for vaginal and disseminated candidiasis, and an alternative for conventional drug-resistant Candida.

Endocarditis due to Rhodotorula mucilaginosa in a kidney transplanted patient: case report and review of medical literature.

Introduction. Endocarditis caused by yeasts is currently an emerging cause of infective endocarditis and, when accompanied byfever of unknown origin, is more severe since interferes with proper diagnosis and endocarditis treatment. Case presentation. The Rio de Janeiro Infective Endocarditis Study Group reports a case of infectious endocarditis (IE) with negative blood cultures in a 45-year-old white female resident in Rio de Janeiro, Brazil, previously submitted to kidney transplantation. After diagnosis and intervention, the valve culture revealed Rhodotorula mucilaginosa. The clinical aspects and overview of endocarditis caused by Rhodotorula spp. demonstrated that R. muscilaginosa have been isolated from the last IE cases from kidney transplanted patients. Conclusion. Though most of the patients (in literature) recovered well from endocarditis caused by Rhodotorula spp., physicians must be aware for diagnosis of fungemia and fungal treatment in kidney transplanted patients suffering of fever of unknown origin in the modern immunosuppressive treatment.

Comparative analysis of Etest and broth microdilution method (AFST-EUCAST) for trends in antifungal drug susceptibility testing of Brazilian Cryptococcus neoformans isolates.

A prospective study was performed to evaluate the correlation between the proposed standard of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST-EUCAST) (document 7.1) and the commercial system Etest for determining the MICs of flucytosine, amphotericin B, fluconazole, itraconazole and voriconazole for a collection of 100 clinical and environmental isolates of Cryptococcus neoformans. The agreements among Etest MICs within +/-2 log2 dilutions of AFST-EUCAST standard MICs were greater for flucytosine, fluconazole and voriconazole (76, 78 and 88 %, respectively) than for amphotericin B (5 %), the lowest agreement, and itraconazole (67 %). Overall, the correlation coefficients were statistically significant (P<0.05), and it is suggested that the Etest and AFST-EUCAST method are reliable alternatives and present good correlation for all drugs evaluated except amphotericin B. However, the observed differences related to MICs for susceptible, susceptible dose dependent and resistant strains between the methods suggest that it will be necessary to carry out further studies, including assessment of interlaboratory agreement and correlation of MICs by different methods with in vivo response.

Population Genetic Analysis Reveals a High Genetic Diversity in the Brazilian Cryptococcus gattii VGII Population and Shifts the Global Origin from the Amazon Rainforest to the Semi-arid Desert in the Northeast of Brazil.

Cryptococcus neoformans and Cryptococcus gattii are responsible globally for almost one million cryptococcosis cases yearly, mostly in immunocompromised patients, such as those living with HIV. Infections due to C. gattii have mainly been described in tropical and subtropical regions, but its adaptation to temperate regions was crucial in the species evolution and highlighted the importance of this pathogenic yeast in the context of disease. Cryptococcus gattii molecular type VGII has come to the forefront in connection with an on-going emergence in the Pacific North West of North America. Taking into account that previous work pointed towards South America as an origin of this species, the present work aimed to assess the genetic diversity within the Brazilian C. gattii VGII population in order to gain new insights into its origin and global dispersal from the South American continent using the ISHAM consensus MLST typing scheme. Our results corroborate the finding that the Brazilian C. gattii VGII population is highly diverse. The diversity is likely due to recombination generated from sexual reproduction, as evidenced by the presence of both mating types in clinical and environmental samples. The data presented herein strongly supports the emergence of highly virulent strains from ancestors in the Northern regions of Brazil, Amazonia and the Northeast. Numerous genotypes represent a link between Brazil and other parts of the world reinforcing South America as the most likely origin of the C. gattii VGII subtypes and their subsequent global spread, including their dispersal into North America, where they caused a major emergence.

Cerebral aspergillosis due to Aspergillus fumigatus in AIDS patient: first culture-proven case reported in Brazil.

Cerebral aspergillosis is a rare cause of brain expansive lesion in AIDS patients. We report the first culture-proven case of brain abscess due to Aspergillus fumigatus in a Brazilian AIDS patient. The patient, a 26 year-old male with human immunodeficiency virus (HIV) infection and history of pulmonary tuberculosis and cerebral toxoplasmosis, had fever, cough, dyspnea, and two episodes of seizures. The brain computerized tomography (CT) showed a bi-parietal and parasagittal hypodense lesion with peripheral enhancement, and significant mass effect. There was started anti-Toxoplasma treatment. Three weeks later, the patient presented mental confusion, and a new brain CT evidenced increase in the lesion. He underwent brain biopsy, draining 10 mL of purulent material. The direct mycological examination revealed septated and hyaline hyphae. There was started amphotericin B deoxycholate. The culture of the material demonstrated presence of the Aspergillus fumigatus. The following two months, the patient was submitted to three surgeries, with insertion of drainage catheter and administration of amphotericin B intralesional. Three months after hospital admission, his neurological condition suffered discrete changes. However, he died due to intrahospital pneumonia. Brain abscess caused by Aspergillus fumigatus must be considered in the differential diagnosis of the brain expansive lesions in AIDS patients in Brazil.

SUSCEPTIBILITY TEST FOR FUNGI: CLINICAL AND LABORATORIAL CORRELATIONS IN MEDICAL MYCOLOGY.

During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.

A new culture medium for recovering the agents of Cryptococcosis from environmental sources.

The isolation of Cryptococcosis agents from environmental samples may be difficult due to the presence of groups of fast-growing fungi. We propose a new culture medium based on a modification of Dichloran Rose-Bengal Chloramphenicol Medium (DRBCm) to detect colonies of Cryptococcus neoformans. Our results indicate that DRBCm is superior to the classical Bird Seed Agar in its ability to detect colonies of C. neoformans.

Cryptococcosis: a review of the Brazilian experience for the disease.

Cryptococcosis is a systemic mycosis caused by Cryptococcus neoformans. The disease occurs in patients with cellular immunodeficiency. The incidence of cryptococcosis arises with aids, and mycosis is one of the opportunistic infections that defines AIDS. After the HAART era the occurrence of cryptococcosis decreased all over the world, but it still continues to be a prevalent disease in Brazil. Thus, we consider this paper to be very important as a result of our reviewing of Brazilian literature regarding some relevant aspects of that disease.

Cryptococcus gattii in North American Pacific Northwest: whole-population genome analysis provides insights into species evolution and dispersal.

The emergence of distinct populations of Cryptococcus gattii in the temperate North American Pacific Northwest (PNW) was surprising, as this species was previously thought to be confined to tropical and semitropical regions. Beyond a new habitat niche, the dominant emergent population displayed increased virulence and caused primary pulmonary disease, as opposed to the predominantly neurologic disease seen previously elsewhere. Whole-genome sequencing was performed on 118 C. gattii isolates, including the PNW subtypes and the global diversity of molecular type VGII, to better ascertain the natural source and genomic adaptations leading to the emergence of infection in the PNW. Overall, the VGII population was highly diverse, demonstrating large numbers of mutational and recombinational events; however, the three dominant subtypes from the PNW were of low diversity and were completely clonal. Although strains of VGII were found on at least five continents, all genetic subpopulations were represented or were most closely related to strains from South America. The phylogenetic data are consistent with multiple dispersal events from South America to North America and elsewhere. Numerous gene content differences were identified between the emergent clones and other VGII lineages, including genes potentially related to habitat adaptation, virulence, and pathology. Evidence was also found for possible gene introgression from Cryptococcus neoformans var. grubii that is rarely seen in global C. gattii but that was present in all PNW populations. These findings provide greater understanding of C. gattii evolution in North America and support extensive evolution in, and dispersal from, South America. Importance: Cryptococcus gattii emerged in the temperate North American Pacific Northwest (PNW) in the late 1990s. Beyond a new environmental niche, these emergent populations displayed increased virulence and resulted in a different pattern of clinical disease. In particular, severe pulmonary infections predominated in contrast to presentation with neurologic disease as seen previously elsewhere. We employed population-level whole-genome sequencing and analysis to explore the genetic relationships and gene content of the PNW C. gattii populations. We provide evidence that the PNW strains originated from South America and identified numerous genes potentially related to habitat adaptation, virulence expression, and clinical presentation. Characterization of these genetic features may lead to improved diagnostics and therapies for such fungal infections. The data indicate that there were multiple recent introductions of C. gattii into the PNW. Public health vigilance is warranted for emergence in regions where C. gattii is not thought to be endemic.

The new mutation L321F in Candida albicans ERG11 gene may be associated with fluconazole resistance.

BACKGROUND: For many years fluconazole has been commonly used to treat Candida infections. However, the indiscriminate use of this antimycotic therapy has favored the emergence of resistant isolates. Mutations in the ERG11 gene have been described as one of the primary mechanisms of resistance in Candida species. AIMS: In this study we investigated missense mutations in ERG11 genes of Candida albicans, Candida glabrata and Candida tropicalis isolates previously evaluated by susceptibility testing to fluconazole. METHODS: Screening for these mutations was performed on 19 Candida clinical isolates (eight C. albicans, five C. glabrata and six C. tropicalis) resistant and susceptible to fluconazole. The ERG11 gene was amplified by PCR with specific primers for each Candida species and analyzed by automated sequencing. RESULTS: We identified 14 different missense mutations, five of which had not been described previously. Among them, a new mutation L321F was identified in a fluconazole resistant C. albicans isolate and it was analyzed by a theoretical three-dimensional structure of the ERG11p. CONCLUSION: The L321F mutation in C. albicans ERG11 gene may be associated with fluconazole resistance.

Susceptibility to antifungal agents and genotypes of Brazilian clinical and environmental Cryptococcus gattii strains.

There are few reports concerning the in vitro antifungal susceptibility of clinical and environmental Cryptococcus gattii isolates. In this study, we performed polymerase chain reaction-restriction fragment length polymorphism to investigate the molecular subtypes of 50 clinical and 4 environmental Brazilian isolates of C. gattii and assessed their antifungal susceptibility for fluconazole (FLU) and amphotericin B (Amb) according to recent recommendations proposed for antifungal susceptibility testing of nonfermentative yeasts. Time-kill curve studies were performed using RPMI 1640 medium to analyze the fungicidal effect of AmB. We found 47 VGII (94%) molecular types and 3 VGI (6%) types among the clinical isolates. The environmental isolates were VGII (75%) subtype and VGI (25%) subtype. The FLU-MIC ranged from 1 to 64 mg L(-1), and MIC(50)/MIC(90) values were, respectively, 8/16 mg L(-1). For AmB, the MICs were low and homogeneous, ranging from 0.12 to 0.5 mg L(-1), for VGI or VGII. The time required to reach the fungicidal end point (99.9% killing) was 6 h for the majority of strains (64%), but viable cells of VGII were still present after 48 h of exposition. We pointed out the occurrence of high FLU-MICs for C. gattii isolates with highest values for VGII. Our data also suggest that the rate of killing of C. gattii by AmB is strain dependent, and viable cells of VGII genotype strains were still observed after an extended incubation time, addressing future studies to determine whether the in vitro fungicidal activity could be clinically relevant.