39 results on '"Melhem MSC"'
Search Results
2. Identification of Trichosporon yeast isolates from superficial infections in male patients from Central Brazil: an approach to the diversity of infections caused by this basidiomycete fungus.
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Leite Júnior DP, Oliveira EC, Vasconcelos KR, Vivi-Oliveira VK, Maia MLDS, Oliboni GM, Macioni MB, Oliveira ID, Takahashi JPF, Bonfietti LX, and Melhem MSC
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- Male, Humans, Brazil, Adult, Young Adult, Adolescent, Middle Aged, Aged, Child, Phenotype, Mycological Typing Techniques, Trichosporon genetics, Trichosporon isolation & purification, Trichosporon classification, Trichosporonosis microbiology
- Abstract
The genus Trichosporon are currently recognized as opportunistic pathogens capable of causing superficial "white piedra" infections and potentially fatal invasive diseases (Trichosporonosis). In this work, determine the agent Trichosporon spp. isolated from the skin and appendages of a male population group in the Central-West region of Brazil. The isolates were analyzed by phenotypic, biochemical and molecular methods. Twenty-five strains of Trichosporon were isolated: T. asahii (18; 72%), followed by T. inkin (4; 16%) and T. faecale (3; 12%). Skin infections were the most affected (16; 64%) and the genitocrural region (13; 52%) was the most affected. The highest rate of isolation occurred between the ages of 21 and 30 years (9; 36%), with black men (African descent) (13; 52%) being the most affected by this type of superficial infection. After the advent of molecular techniques, more than 50 subspecies and about 16 different strains have been reported to cause human disease. In this series, three species of the genus Trichosporon of medical importance were highlighted, colonizing the genital and perigenital region of the studied population. For the identifications, classical phenotypic methods associated with genotypic identification were carried out, using molecular techniques based on the study of DNA; using sequence analysis of the DNA intergenic spacer region 1 (IGS1).
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- 2024
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3. Aspergillus in the Indoor Air of Critical Areas of a Tertiary Hospital in Brazil.
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Lemos MSC, Higa Junior MG, Paniago AMM, Melhem MSC, Takahashi JPF, Fava WS, Venancio FA, Martins NM, and Chang MR
- Abstract
Airborne Aspergillus spp. are critical pathogens that cause nosocomial infections in hospitals. Despite their importance, little is known about the distribution of Aspergillus species in the indoor air of hospitals in Brazil. We investigated Aspergillus spp. in the indoor air of critical areas in a tertiary hospital in Brazil. Air samples (n = 238) were collected from the intensive care unit (ICU), medical clinic unit (MCU), and urgency and emergency unit (UEU) using an air sampler (100 L/min). Of the 324 Aspergillus isolates, 322 were identified using phenotypic methods, and 37 were identified using DNA sequencing. Aspergillus spp. was grouped into five sections: Fumigati (29.3%), Nidulantes (27.8%), Nigri (27.5%), Flavi (11.7%), and Terrei (3.1%). The predominant species identified via sequencing were Aspergillus sydowii (n = 9), Aspergillus flavus (n = 7), and Aspergilus fumigatus (n = 6). The number of Aspergillus spp. and their sections varied according to the collection day. A. fumigatus was isolated more frequently during winter and in the ICU. This study is the first to demonstrate the diversity of airborne Aspergillus (saprophytic, allergenic, toxigenic, and potentially pathogenic) strains in a hospital located in the Midwest region of Brazil. It contributes to the knowledge of the diversity of cryptic species in the hospital environment.
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- 2024
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4. Neonatal innate immunity response in invasive candidiasis.
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Suárez JAG, Calumby RJN, Silva DP, Barbosa VT, Maranhão FCA, Moreira IF, Melhem MSC, and Moreira RTF
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- Humans, Infant, Newborn, Immunity, Innate immunology, Candidiasis, Invasive immunology
- Abstract
Infections caused by Candida spp. are frequent in critically hospitalized patients, especially among premature neonates, representing one of the most common healthcare-related infections. Although there is considerable production of current knowledge about the mechanisms of immune response, aspects involved in the newborn's innate defense are not fully understood. The aim of this study was to describe the innate immune mechanisms involved in the defense of neonates against invasive candidiasis. This is an integrative literature review from the Scopus, Scifinder, Medline, Web of Science databases and the electronic libraries ScienceDirect and Scielo, in the period between 2002 and 2020, with rescue based on primary descriptor Immunity Innate plus secondary descriptors Candidiasis Invasive AND Infant Newborn. We have observed the involvement of various mechanisms in the neonatal response against invasive candidiasis, including the recognition, signaling, recruitment, and initiation of an effective immune response. These mechanisms encompass the presence of antimicrobial peptides, phagocytosis, synthesis of reactive oxygen species, inflammatory mediators, and complex cell signaling systems mediated by Pattern Recognition Receptors (PRRs). With this study, it is expected to contribute to the expansion of knowledge about the immunological mechanisms involved in the innate immune response of the newborn against disseminated infections caused by Candida species, and in the same sense, highlight the importance of this knowledge as a reflex in the decrease in mortality in the neonatal period.
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- 2024
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5. Standardization of Semi-Quantitative Dot Blotting Assay-Application in the Diagnosis, Follow-Up, and Relapse of Paracoccidioidomycosis.
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Pereira BAS, Cavalcante RS, Pereira-Chioccola VL, Melhem MSC, de Carvalho LR, and Mendes RP
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Introduction: This study standardized a semi-quantitative dot blotting assay (DB) and a quantitative real-time polymerase chain reaction (qPCR) to detect specific antibodies for Paracoccidioides brasiliensis and its DNA in PCM patients., Methodology: We evaluated 42 confirmed PCM patients upon admission using a serological double agar gel immunodiffusion test (DID), DB, and molecular tests (qPCR in total blood). The control groups included 42 healthy individuals and 37 patients with other infectious diseases. The serological progress during treatment was evaluated in eight patients, and there was a relapse diagnosis in ten patients using the Pb B.339 strain antigen. The cut-off points for the serological tests were determined by a receiver operator characteristic curve., Results: The DB and DID tests showed similar accuracy, but the DB identified lower antibody concentrations. Cross-reactions were absent in the DB assay. In the relapse diagnoses, DB exhibited much higher sensitivity (90%) than DID (30%)., Conclusions: A DB assay is easier and faster than a DID test to be performed; DB and DID tests show the same accuracy, while blood qPCR is not recommended in the diagnosis at the time of admission; cross-reactions were not observed with other systemic diseases; DB and DID tests are useful for treatment monitoring PCM patients; and a DB assay is the choice for diagnosing relapse. These findings support the introduction of semi-quantitative DB assays in clinical laboratories.
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- 2024
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6. Antifungal Resistance in Cryptococcal Infections.
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Melhem MSC, Leite Júnior DP, Takahashi JPF, Macioni MB, Oliveira L, de Araújo LS, Fava WS, Bonfietti LX, Paniago AMM, Venturini J, and Espinel-Ingroff A
- Abstract
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.
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- 2024
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7. Genotyping Analysis of Cryptococcus deuterogattii and Correlation with Virulence Factors and Antifungal Susceptibility by the Clinical and Laboratory Standards Institute and the European Committee on Antifungal Susceptibility Testing Methods.
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Andrade-Silva LE, Vilas-Boas A, Ferreira-Paim K, Andrade-Silva J, Santos DA, Ferreira TB, Borges AS, Mora DJ, Melhem MSC, and Silva-Vergara ML
- Abstract
Data about the relationship between their molecular types, virulence factors, clinical presentation, antifungal susceptibility profile, and outcome are still limited for Cryptococcus deuterogattii . This study aimed to evaluate the molecular and phenotypic characteristics of 24 C . deuterogattii isolates from the southeast region of Brazil. The molecular characterization was performed by multilocus sequence typing (MLST). The antifungal susceptibility profile was obtained according to CLSI-M27-A3 and EUCAST-EDef 7.1 methods. The virulence factors were evaluated using classic techniques. The isolates were divided into four populations. The molecular analysis suggests recombinant events in most of the groups evaluated. Resistance and susceptibility dose-dependent to fluconazole were evidenced in four isolates (16%) by EUCAST and in four isolates (16%) by CLSI methods. The agreement at ±two dilutions for both methods was 100% for itraconazole, ketoconazole, and voriconazole, 96% for amphotericin B, and 92% for fluconazole. Significant differences in virulence factor expression and antifungal susceptibility to itraconazole and amphotericin B were found. The mixed infection could be suggested by the presence of variable sequence types, differences in virulence factor production, and decreased antifungal susceptibility in two isolates from the same patient. The data presented herein corroborate previous reports about the molecular diversity of C . deuterogattii around the world.
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- 2023
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8. CRYPTOCOCCOSIS: A bibliographic narrative review on antifungal resistance.
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Kakizaki MIT and Melhem MSC
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- Humans, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Voriconazole pharmacology, Triazoles pharmacology, Microbial Sensitivity Tests, Drug Resistance, Fungal, Cryptococcosis drug therapy, Cryptococcosis epidemiology, Cryptococcosis microbiology, Cryptococcus neoformans
- Abstract
Cryptococcosis is an infectious fungal disease widely studied for its epidemiological importance in the context of public health, given the high morbidity and mortality associated with this invasive fungal infection. Many cases of the disease present clinical resistance and progress to death, even in the presence of antifungal therapy. The prolonged use of triazole drugs to maintain the treatment of cryptococcosis in AIDS patients, can lead to selective pressure from mutant strains, among other resistance mechanisms, justifying the poor clinical evolution of some cases. In this study, a narrative review of the literature on the occurrence of antifungal resistance in cryptococcosis agents was performed. Publications from 2010 to 2022 that address this topic were selected using Google Scholars and Scopus website. Data from the studies were analyzed for the values of minimum inhibitory concentration (MIC) of drugs used in the management of cryptococcosis. The review showed that the highest MIC values occurred for voriconazole, especially against C. neoformans. It is concluded that there is a lack of studies with statistical analysis of the data obtained, in order to provide a better dimensioning of the resistance rates of cryptococcosis agents to different antifungal agents, both in geographical and temporal context.
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- 2023
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9. Aspects related to biofilm production and antifungal susceptibility of clinically relevant yeasts of the genus Trichosporon.
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Lara BR, de Camargo BB, Paula CR, Monari GPM, Garces HG, Arnoni MV, Silveira M, Gimenes VMF, Leite Junior DP, Bonfietti LX, Oliveira L, Melhem MSC, Auler M, Ramos RTB, Dias ALT, Silva NC, Moreira D, Richini-Pereira VB, Anversa L, and Ruiz LDS
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- Humans, Animals, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Fluconazole pharmacology, Caspofungin, Itraconazole, Amphotericin B pharmacology, Biofilms, Microbial Sensitivity Tests veterinary, Trichosporon, Trichosporonosis microbiology, Trichosporonosis veterinary
- Abstract
Trichosporonosis corresponds to a systemic fungal disease that leads to high mortality rates and is frequently associated with medical devices. It affects immunosuppressed patients in particular and is strongly linked to acquired human immunodeficiency, organ and tissue transplants, and malignant hematologic diseases such as leukemia and lymphomas. Trichosporon infections have been increasingly reported worldwide; however, little information is available either about their characteristics or the causative microorganism. Thus, the aims of the present study were: to investigate 59 yeasts of the genus Trichosporon by verifying the biofilm formation capacity of isolates; to analyze the susceptibility patterns of planktonic cells against the antifungals fluconazole, itraconazole, amphotericin-B, voriconazole, and caspofungin by comparing European Committee for Antimicrobial Susceptibility Testing (EUCAST) broth microdilution technique with the commercial method Etest; and to assess the susceptibility patterns of biofilm cells (sessile) against the same antifungals through broth microdilution. The ability to form biofilm on the surface of polystyrene plates was noted for all isolates, and 54.3% of samples were considered strong producers. Comparison between the antifungal susceptibility techniques evidenced that Etest showed higher and discordant minimum inhibitory concentrations (MICs) from those obtained by the microdilution method, especially for fluconazole, itraconazole, and caspofungin. Considering the susceptibility of biofilms, most species had high MIC50 and MIC90 against the tested antifungals, showing 4-to-66-fold higher concentrations for amphotericin B and 2-to-33-fold greater concentrations for caspofungin. These results highlight the importance of further studies with Trichosporon spp. for comparison between laboratory findings and in vivo response, considering both the susceptibility tests and the behavior of biofilm cells against drugs., (© The Author(s) 2023. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
- Published
- 2023
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10. Species and antifungal susceptibility profile of agents causing vulvovaginal candidiasis in a military population: a cross-sectional study.
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Trajano DTM, Melhem MSC, Takahashi JPF, Bonfietti LX, de Araújo MR, Corrêa VB, Araújo KBO, Barnabé V, and Fernandes CG
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- Female, Animals, Cross-Sectional Studies, Proteomics, Brazil epidemiology, Candida albicans, Candida parapsilosis, Microbial Sensitivity Tests veterinary, Drug Resistance, Fungal, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Candidiasis, Vulvovaginal microbiology, Candidiasis, Vulvovaginal veterinary
- Abstract
Military women on active duty are exposed to constant physical and mental demands, which may predispose them to some infection risks, including vulvovaginal candidiasis (VVC), a pathology considered a global public health problem. To monitor the prevalent and emerging pathogens in VVC, this study aimed to evaluate the distribution of yeast species and their in vitro antifungal susceptibility profile. We studied 104 vaginal yeast specimens obtained during routine clinical examinations. The population was attended at the Medical Center of the Military Police, São Paulo, Brazil, and was divided into two groups: infected patients (VVC) and colonised patients. Species were identified by phenotypic and proteomic methods (MALDI-TOF MS) and susceptibility to eight antifungal drugs, including azoles, polyenes, and echinocandins, was determined using microdilution broth. Candida albicans stricto sensu was found to be the most frequently isolated species (55%), but we observed a considerable rate of other Candida species isolates (30%), including Candida orthopsilosis stricto sensu only in the infected group. There were also other rare genera such as Rhodotorula, Yarrowia, and Trichosporon (15%), of which Rhodotorula mucilaginosa was the most prevalent in both groups. Fluconazole and voriconazole had the highest activity against all species in both groups. Candida parapsilosis was the most susceptible species, except for amphotericin-B in the infected group. Of note, we observed unusual resistance in C. albicans. Our results have allowed us to compile an epidemiological database on the etiology of VVC to support the empirical treatment and improve the health care of military women., (© The Author(s) 2023. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
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- 2023
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11. 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 Aspergillus fumigatus and Other Species, Using New Clinical Breakpoints and Epidemiological Cutoff Values.
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Melhem MSC, Coelho VC, Fonseca CA, Oliveira L, Bonfietti LX, Szeszs MW, Magri MMC, Dorneles FS, Taguchi H, Moreira DVS, Motta AL, Batista MV, Kamei K, and Shikanai-Yasuda MA
- Abstract
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.
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- 2022
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12. Antifungal activity of liriodenine on clinical strains of Cryptococcus neoformans and Cryptococcus gattii species complexes.
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Levorato-Vinche AD, Melhem MSC, Bonfietti LX, de-la-Cruz-Chacón I, Boaro CSF, Fabro AT, Ferreira G, da Silva JF, Dos Santos DC, Pereira BAS, Marçon C, Maza L, de Carvalho LR, and Mendes RP
- Abstract
Background: Cryptoccocal meningitis continues to present high incidence among AIDS patients. The treatment of choice is the synergistic combination of flucytosine (5-FC) with amphotericin B deoxycholate (AmBd) or its lipid formulations. However, 5-FC is unavailable in many countries and AmB demands hospitalization. The combination of AmB with the fungistatic fluconazole (FLC) or the use of high FLC daily doses alone became the choice. Nonetheless, sterilization of cerebrospinal fluid is delayed with FLC monotherapy, mainly with high fungal burden. These findings suggest the search for new antifungal compounds, such as liriodenine., Methods: Liriodenine antifungal activity was evaluated by three procedures: determining the minimum inhibitory concentration (MIC) on 30 strains of the Cryptococcus neoformans ( C. neoformans ) complex and 30 of the Cryptococcus gattii ( C. gattii ) complex, using EUCAST methodology and amphotericin B deoxycholate as control; performing the time-kill methodology in two strains of the C. neoformans complex and one of the C. gattii complex; and injury to cryptococcal cells, evaluated by transmission electron microscopy (TEM). Liriodenine absorption and safety at 0.75 and 1.50 mg.kg
-1 doses were evaluated in BALB/c mice., Results: Liriodenine MICs ranged from 3.9 to 62.5 μg.mL-1 for both species complexes, with no differences between them. Time-kill methodology confirmed its concentration-dependent fungicidal effect, killing all the strains below the limit of detection (33 CFU.mL-1 ) at the highest liriodenine concentration (32-fold MIC), with predominant activity during the first 48 hours. Liriodenine induced severe Cryptococcus alterations - cytoplasm with intense rarefaction and/or degradation, injury of organelles, and presence of vacuoles. Liriodenine was better absorbed at lower doses, with no histopathological alterations on the digestive tract., Conclusion: The fungicidal activity confirmed by time-kill methodology, the intense Cryptococcus injury observed by TEM, the absorption after gavage administration, and the safety at the tested doses indicate that the liriodenine molecule is a promising drug lead for development of anticryptococcal agents., Competing Interests: Competing interests: The authors declare that they have no competing interests.- Published
- 2022
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13. Investigation of fluconazole heteroresistance in clinical and environmental isolates of Cryptococcus neoformans complex and Cryptococcus gattii complex in the state of Amazonas, Brazil.
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Moreira IMB, Cortez ACA, de Souza ÉS, Pinheiro SB, de Souza Oliveira JG, Sadahiro A, Cruz KS, Matsuura ABJ, Melhem MSC, Frickmann H, and de Souza JVB
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- Animals, Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Brazil, Drug Resistance, Fungal, Fluconazole pharmacology, Microbial Sensitivity Tests, Cryptococcosis drug therapy, Cryptococcosis microbiology, Cryptococcus gattii, Cryptococcus neoformans
- Abstract
Heteroresistance, defined as the occurrence of apparently homogeneous subpopulations of microbial cells showing different levels of antimicrobial susceptibility is a problem that has been associated with therapeutical failure in cryptococcosis. The purpose of the study was an investigation on the level of heteroresistance to fluconazole (LHF) as observed in clinical and environmental C. neoformans/C. gattii complex species isolates from Amazonas State (AM), Brazil. A total of 45 isolates and 9 type strains were analyzed. The assessments comprised testing for minimal inhibitory concentrations (MICs), for LHFs, for the strains' capacity of adaptation to high fluconazole (FLC) concentrations above the LHF, and for the stability of the heteroresistance phenomenon. The mean MICs for clinical isolates of C. gattii (6.4 µg/ml) were higher than those observed for environmental C. gattii strains (1.7 µg/ml) and clinical (3.7 µg/ml) as well as environmental (1.5 µg/ml) C. neoformans isolates. The phenomenon of heteroresistance to FLC was recorded for all isolates. On average, the LHF (8-256 µg/ml) of the isolates was 16 times higher than the FLC MICs (0.5-16 µg/ml) and a proportion of 85% isolates showed LHFs ≥ 16 µg/ml, 40% even ≥ 32 µg/ml. According to the adaptation assay, a considerable number of isolates (58%) showed the capacity of adaptation to MICs even higher than the initially recorded LHF. After the adaptation experiment, the adaptative-LHF values (8-512 µg/ml) were about 60 times higher than the original MIC values. After nine subsequent passages in drug-free broth, the isolates had their adaptative-LHF reduced. However, the LHF did not revert to the initially measured level. Our findings challenge the clinical interpretation of the antifungal MIC testing and motivate future studies correlating the levels of heteroresistance and parameters like LHF and adaptative-LHF with cryptococcosis-associated morbidity and mortality., Lay Summary: Cryptococcosis affects many people and is caused by fungi of the Cryptococcus neoformans/Cryptococcus gattii complexes. These agents appear to become more resistant to antifungals when exposed to increasing concentrations of antifungals due to a phenomenon called heteroresistance., (© The Author(s) 2022. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
- Published
- 2022
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14. Early clinical and microbiological predictors of outcome in hospitalized patients with cryptococcal meningitis.
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de Oliveira L, Melhem MSC, Buccheri R, Chagas OJ, Vidal JE, and Diaz-Quijano FA
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- Antifungal Agents therapeutic use, Brazil epidemiology, Humans, Cryptococcus, Meningitis, Cryptococcal drug therapy
- Abstract
Background: Cryptococcal meningitis causes high mortality in immunocompromised and immunocompetent patients. The objective of this study was to identify early predictors of clinical outcome, available at the first days of hospitalization, in patients with cryptococcal meningitis in a tertiary center in Brazil., Methods: Ninety-six cases of cryptococcal meningitis with clinical, epidemiological and laboratory data, and identification and antifungal susceptibility of the strains were analyzed. Quantitative CSF yeast counts were performed by direct microscopic exam with a Fuchs-Rosenthal cell counting chamber using an institutional protocol. Univariable and multiple analyses using logistic regression were performed to identify predictors, available at the beginning of hospitalization, of in-hospital mortality. Moreover, we performed a secondary analysis for a composite outcome defined by hospital mortality and intensive care unit transfer., Results: The species and the antifungal susceptibility were not associated with the outcomes evaluated. The variables significantly associated with the mortality were age (OR = 1.08, 95% CI 1.02-1.15), the cerebrospinal fluid (CSF) yeasts count (OR = 1.65, 95% CI 1.20-2.27), systemic arterial hypertension (OR = 22.63, 95% CI 1.64-312.91) and neurological impairment identified by computed tomography (OR = 41.73, 95% CI 3.10-561.65). At the secondary analysis, CSF yeast count was also associated with the composite outcome, in addition to the culture of Cryptococcus spp. from bloodstream and cerebral toxoplasmosis. The associations were consistent with survival models evaluated., Conclusions: Age and CSF yeast count were independently associated with in-hospital mortality of patients with cryptococcal meningitis but Cryptococcus species identification and antifungal susceptibility were not associated with the outcomes. Quantitative CSF yeast counts used in this study can be evaluated and implemented in other low and middle-income settings., (© 2022. The Author(s).)
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- 2022
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15. A Rare Case of Aspergillus Mediastinitis After Coronary Artery Bypass Surgery: A Case Report and Literature Review.
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Monteiro OMC, Higa Júnior MG, Palhares MA, Nunes MO, Melhem MSC, and Chang MR
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- Aged, Aspergillus fumigatus, Coronary Artery Bypass adverse effects, Humans, Male, Staphylococcus aureus, Surgical Wound Infection diagnosis, Surgical Wound Infection etiology, Mediastinitis diagnosis, Mediastinitis etiology
- Abstract
BACKGROUND Mediastinitis is a serious complication after cardiac surgery; it is a deep sternal wound infection following sternotomy, with clinical evidence and/or microbiological involvement and sternal osteomyelitis. The most common pathogens are Staphylococcus spp (S. aureus), followed by gram-negative organisms. Establishing an etiological diagnosis of fungal mediastinitis is often a challenging issue, given the nonspecific clinical presentation. CASE REPORT A 74-year-old man was diagnosed with a three-vessel coronary artery disease in a university hospital. The patient had as clinical background hypertension, a body mass index (BMI) of 29.78 kg/m², and no diabetes mellitus. After an uneventful coronary artery bypass surgery, he presented clinical and radiological mediastinitis manifestations on the 9th postoperative day. He was treated with a range of antibiotics, with no clinical improvement until the 33rd postoperative day. Then, mediastinal fluid and biopsied tissue were collected and he was started on voriconazole due to growing Aspergillus spp. On the 93rd postoperative day, he had clinical improvement and, after several exams, was released from the hospital. We present the first report of Aspergillus fumigatus mediastinitis after cardiac surgery in Brazil, successfully treated with voriconazole. CONCLUSIONS Aspergillus infection should be considered in the differential diagnosis of mediastinitis after coronary surgery, especially in a clinical case of unexplained sepsis, negative blood culture, and no clinical improvement despite antibiotic therapy. This case report highlights that the mediastinal fluid and biopsy tissue culture can be useful for the diagnosis of fungal mediastinitis.
- Published
- 2021
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16. Comparing the phenotypic, genotypic, and proteomic identification of Trichosporon species: A globally emerging yeast of medical importance.
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Lara BR, de Camargo BB, Paula CR, Junior DPL, Garces HG, Arnoni MV, Silveira M, Gimenes VMF, Siqueira LPM, Takahashi JPF, Melhem MSC, Richini-Pereira VB, Anversa L, and Ruiz LDS
- Subjects
- Animals, Proteomics, Saccharomyces cerevisiae, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization veterinary, Trichosporon genetics
- Abstract
Trichosporon spp. are widely distributed in the nature, comprising species that inhabit different ecological niches and can be found in the water, soil, and body surface of animals and humans. Such microorganisms have been classically associated with superficial infections; however, in the last decades, they have also been related to disseminated infections in immunocompromised patients, behaving as opportunistic agents, which demands rapid and accurate species identification for efficient therapy. Concordance level between the traditional phenotypic method and the molecular technique (gold standard) in the identification of all 59 Trichosporon samples was 59.3%. Identification concordance between MALDI-TOF spectrometry and the molecular technique was 71.2%. No isolate of environmental origin was identifiable by MALDI-TOF mass spectrometry (MS), and 100% of such environmental isolates were discordant for IGS region sequencing and phenotypic characterization. Both comparisons evidenced greatest concordance in the identification of T. asahii. The species T. debeurmannianum, T. dermatis, T. venhuisii and T. insectorum were not properly identified by both MALDI-TOF MS and the phenotypic technique. MALDI-TOF MS, in particular, seems to be appropriate to investigate yeasts of the genus Trichosporon; however, database updates are still necessary, especially for species that are not common in the clinical routine. With the aim of helping understand the aspects involved in early and accurate diagnosis of infections caused by this opportunistic agent, the present study compared the phenotypic, molecular (IGS region) and mass-spectrometry (MALDI-TOF) identification of 59 yeasts of the genus Trichosporon which had clinical and environmental origin and were kept in a mycology collection., (© The Author(s) 2021. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
- Published
- 2021
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17. Modifications of antifungal sensibility testing as suggested by CLSI document M27-A4: proposal for using different culture medium and buffer.
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de Sousa ESO, Pinheiro SB, Cortez ACA, Cruz KS, de Souza ÉS, Melhem MSC, Frickmann H, and de Souza JVB
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- Buffers, Clinical Laboratory Services, Fungi classification, Humans, Laboratories, Clinical standards, Microbial Sensitivity Tests methods, Reproducibility of Results, Antifungal Agents pharmacology, Culture Media chemistry, Fungi drug effects, Microbial Sensitivity Tests standards
- Abstract
A common strategy in antifungal susceptibility testing is the utilization of the standardized protocol based on the microbroth dilution assay approach as described by the Clinical Laboratory Standards Institute (CLSI) (M27-A4). One major problem for laboratories in resource-limited countries with this protocol arises from the use of expensive culture media like RPMI-1640 and 3-N-morpholinopropanesulfonic acid (MOPS) buffer. One approach of circumventing this problem in cases of economic need is the evaluation of alternative culture media and buffers. The overall goal of this work was to investigate the influence of modifications in the protocol M27-A4 on diagnostic reliability. We performed univariate analyses evaluating (1) 2 different culture media (YNB and modified SAB); (2) three different buffers (sodium bicarbonate, Tris-HCL, and phosphate), as well as the influence of inoculum concentration (10
2 , 103 , 104 , 105 cells/mL), the influence of incubation time, and the influence of the assessment mode (visual, biological dye, and spectrophotometer). Our results suggested that (1) RPMI-1640 may be substituted by modified SAB and (2) MOPS buffer may be substituted by Tris-HCl buffer for defined analyses. By comparing the CLSI protocol and the alternative protocol proposed in the present study (modified SAB and Tris-HCl buffer) for the assessment of fluconazole susceptibility of eighteen yeasts (clinical isolates), similar results with both methodologies were recorded. We feel that this study should stimulate a discussion on the feasibility and evolution of the M27-A4 protocol in order to include pragmatic alternatives for resource-limited settings., (Copyright © 2021 Elsevier Inc. All rights reserved.)- Published
- 2021
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18. Fungi in dialysis water and dialysate: occurrence, susceptibility to antifungal agents and biofilm production capacity.
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Anversa L, Lara BR, Romani CD, Saeki EK, Nogueira Nascentes GA, Bonfietti LX, Melhem MSC, da Silva Ruiz L, Camargo CH, and Pereira VBR
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- Biofilms, Dialysis, Fungi, Microbial Sensitivity Tests, Renal Dialysis, Water, Antifungal Agents pharmacology, Dialysis Solutions
- Abstract
The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017-June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10-40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested.
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- 2021
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19. Antifungal susceptibility profile of Candida clinical isolates from 22 hospitals of São Paulo State, Brazil.
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Rodrigues DKB, Bonfietti LX, Garcia RA, Araujo MR, Rodrigues JS, Gimenes VMF, and Melhem MSC
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- Brazil, Drug Resistance, Fungal, Hospitals, Microbial Sensitivity Tests, Antifungal Agents pharmacology, Candida
- Abstract
This study aimed to evaluate the frequency of cryptic Candida species from candidemia cases in 22 public hospitals in São Paulo State, Brazil, and their antifungal susceptibility profiles. During 2017 and 2018, 144 isolates were molecularly identified as 14 species; C. parapsilosis (32.6%), C. albicans (27.7%), C. tropicalis (14.6%), C. glabrata (9.7%), C. krusei (2.8%), C. orthopsilosis (2.8%), C. haemulonii var. vulnera (2.1%), C. haemulonii (1.4%), C. metapsilosis (1.4%), C. dubliniensis (1.4%), C. guilliermondii (1.4%), C. duobushaemulonii (0.7%), C. kefyr (0.7%), and C. pelliculosa (0.7%). Poor susceptibility to fluconazole was identified in 6.4% of C. parapsilosis isolates (0.12 to >64 µg/mL), 50% of C. guilliermondii (64 µg/mL), 66.6% of C. haemulonii var. vulnera (16-32 µg/mL), and C. duobushaemulonii strain (MIC 64 µg/mL). Our results corroborated the emergence of C. glabrata in Brazilian cases of candidemia as previously reported. Importantly, we observed a large proportion of non-wild type C. glabrata isolates to voriconazole (28.6%; <0.015 to 4 µg/mL) all of which were also resistant to fluconazole (28.6%). Of note, C. haemulonii, a multidrug resistant species, has emerged in the Southeast region of Brazil. Our findings suggested a possible epidemiologic change in the region with an increase in fluconazole-resistant species causing candidemia. We stress the relevance of routine accurate identification to properly manage therapy and monitor epidemiologic trends.
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- 2021
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20. Difference Between the Profiles Presented by Yeasts that Colonize the Vaginal Mucosa or Cause Primary or Recurrent Candidiasis.
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Moreira D, Ruiz LS, Leite-Jr DP, Auler ME, Ramos RTB, Costa VT, Lara BR, Gasparetto A, Gandra RF, Melhem MSC, and Paula CR
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- Antifungal Agents therapeutic use, Candida albicans, Female, Humans, Mucous Membrane, Rhodotorula, Candidiasis drug therapy, Candidiasis, Vulvovaginal drug therapy
- Abstract
Candida yeasts are the most frequent in the vaginal content. This yeast may be a normal microbiota but also causes candidiasis. In symptomatic cases, primary candidiasis (VVC) or recurrence (RVVC) can be considered. This study aims to compare the frequency and in vitro sensitivity profile of Candida species isolated in the vaginal content with the different stages of the presence of yeasts. A total of 258 non-pregnant patients with/without VVC were prospectively screened at a teaching Health Centre of the Faculty of Medicine, in the University of Sao Paulo. The vaginal isolates were identified by traditional and molecular methods. Yeasts were isolated in 160 women. 34% were asymptomatic, 34% with vulvovaginal candidiasis (VVC), and 32% recurrent vulvovaginal candidiasis (RVVC). C. albicans was the most frequent species with 50.1% (82/160), followed by C. parapsilosis 13.7%(22/160), C. glabrata 12.5% (20/160), and C. tropicalis (6.2%). Analysis by the group showed that, in the asymptomatic group, eight yeast species were isolated, C. albicans 44.5% (24/54), C. glabrata 20% (11/54), C. parapsilosis and Rhodotorula rubra being the most frequent. In the VVC group, 11 yeast species were identified. Most isolates were C. albicans 68.5% (37/54), C. tropicalis 7.5% (4/54), and C. parapsilosis 5.5% (3/54). In the RVVC group, ten species were identified, the most frequent being C. albicans 38.5% (20/52), C. parapsilosis 17% (9/52), C. glabrata 4% (8/52), and C. tropicalis 6% (3/52). Less frequent species, such as C. haemulonii and Trichosporon spp, were isolated in the VVC and RVVC groups, C. kefyr was isolated in the three groups studied, and Rhodotorula spp was isolated in the control and RVVC groups. Candida metapsilosis was present in two isolates from the RVVC group. Most isolates were considered sensitive to the tested antifungals. Less sensitivity was seen for caspofungin. In this study, we were able to verify that the most common species of yeasts found in vaginal secretion were isolated in the three groups studied; however, there was the diversity of species in VVC and RVVC. Cryptic species C. haemulonii and were isolated in symptomatic patients. High levels of MICs, some of the antifungals tested, in the control group, draw attention in the group of asymptomatic women. We would like to emphasize that this research aims to assist clinicians and gynecologists, as well as assist in the epidemiological studies of candidiasis, in our country, how to draw attention to the profile of sensitivity/resistance to antifungals.
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- 2021
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21. High genetic variability of clinical and environmental Cryptococcus gattii isolates from Brazil.
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Vilas-Bôas AM, Andrade-Silva LE, Ferreira-Paim K, Mora DJ, Ferreira TB, Santos DA, Borges AS, Melhem MSC, and Silva-Vergara ML
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- Animals, Brazil epidemiology, Cryptococcosis epidemiology, Cryptococcus gattii classification, Cryptococcus gattii isolation & purification, Genetic Variation, Genetics, Population, Genotype, Humans, Phylogeny, Cryptococcosis microbiology, Cryptococcus gattii genetics, Environmental Microbiology
- Abstract
Among Cryptococcus gattii genotypes, VGII has gained pivotal relevance in epidemiological, clinical and genetic contexts due to its association with several outbreaks in temperate regions and due to the high variability of this genotype. The aim of this study was to compare 25 isolates of C. gattii from the Southeast region of Brazil with previously described isolates from other regions of the country and around the world. Among the 25 isolates, 24 were VGII and one was VGI. All of them were newly identified. Three new allele types (AT) (AT47 for the URA5 locus, AT56 for the LAC1 locus, and AT96 for the IGS1 region) were also described. Compared with other Brazilian isolates, those from the Southeast region presented the greatest haplotype diversity. In general, the regions presented different sequence types (STs), and only nine STs were found in more than one location. GoeBURST analysis showed two large groups among the Brazilian isolates. The largest group consists of 59 STs predominantly from the North and Northeast regions; the other large group includes 57 STs from the Southeast and Midwest regions. In a global context the South American isolates presented the highest genetic diversity (STs = 145, haplotype diversity (Hd) = 0.999 and π = 0.00464), while the African populations showed the lowest genetic diversity (STs = 3, Hd = 0.667 and π = 0.00225). These results confirm that the Brazilian C. gattii VGII population is highly diverse and reinforce the hypothesis of dispersion of this genotype from South America., (© The Author(s) 2020. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
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- 2020
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22. Visible DNA microarray and loop-mediated isothermal amplification (LAMP) for the identification of Cryptococcus species recovered from culture medium and cerebrospinal fluid of patients with meningitis.
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Stivanelli P, Tararam CA, Trabasso P, Levy LO, Melhem MSC, Schreiber AZ, and Moretti ML
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- Humans, Nucleic Acid Amplification Techniques, Oligonucleotide Array Sequence Analysis, Sequence Analysis, DNA, Cryptococcus neoformans genetics, Meningitis, Cryptococcal diagnosis
- Abstract
Cryptococcal meningitis affects normal hosts and immunocompromised patients exhibiting high mortality rates. The objective of this study was to design two molecular assays, visible microarray platforms and loop-mediated isothermal amplification (LAMP), to identify Cryptococcus spp. and the species neoformans and gattii from the cerebral spinal fluid (CSF). To identify Cryptococcus and the two species, we designed two microarrays DNA platforms based on the internal transcribed spacer (ITS) region and CAP59 gene and LAMP assays specific for Cryptococcus species. The assays were tested using CSF from patients with cryptococcal meningitis. CSF from patients with cryptococcal meningitis was cultured in Sabouraud culture medium, and the Cryptococcus spp. grown in the culture medium were also tested for LAMP and microarray platforms. The results were compared to DNA sequencing of the same genetic regions. A total of 133 CSF samples were studied. Eleven CSFs were positive for Cryptococcus (9 C. neoformans and 2 C. gattii), 15 were positive for bacteria, and 107 were negative. The CAP59 platform correctly identified 73% of the CSF samples, while the ITS platform identified 45.5%. CAP59 platform correctly identified 100% of the Cryptococcus isolates, and ITS platform identified 70%. The two sets of LAMP primers correctly identified 100% of the Cryptococcus isolates. However, for CSF samples, the amplification occurred only in 55.5% of C. neoformans. The methodologies were reliable in the identification of Cryptococcus species, mainly for isolates from culture medium, and they might be applied as adjunctive tests to identify Cryptococcus species.
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- 2020
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23. Coumaric acid analogues inhibit growth and melanin biosynthesis in Cryptococcus neoformans and potentialize amphotericin B antifungal activity.
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Oliveira L, Ferrarini M, Dos Santos AP, Varela MT, Corrêa ITS, Tempone AG, Melhem MSC, Vallim MA, Fernandes JPS, and Pascon RC
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- Amphotericin B pharmacology, Animals, Antifungal Agents pharmacology, Coumaric Acids, Humans, Melanins, Cryptococcosis drug therapy, Cryptococcus neoformans
- Abstract
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., Competing Interests: Declarations of Competing Interest The authors declare no competing interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
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- 2020
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24. Lack of efficacy of echinocandins against high metabolic activity biofilms of Candida parapsilosis clinical isolates.
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Thomaz DY, Melhem MSC, de Almeida Júnior JN, Benard G, and Del Negro GMB
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- Amphotericin B pharmacology, Candida parapsilosis physiology, Candidemia drug therapy, Candidemia microbiology, Candidiasis drug therapy, Candidiasis microbiology, Catheter-Related Infections drug therapy, Catheter-Related Infections microbiology, Deoxycholic Acid pharmacology, Drug Combinations, Drug Evaluation, Preclinical, Humans, Microbial Sensitivity Tests, Antifungal Agents pharmacology, Biofilms drug effects, Candida parapsilosis drug effects, Echinocandins pharmacology
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Candida parapsilosis produces biofilm, which colonizes catheters and other invasive medical devices that are manipulated by health care workers. In previous studies, C. parapsilosis in vitro biofilms have exhibited high resistance rates against conventional antifungals, but susceptibility to both echinocandins and lipid formulations of amphotericin B (lipid complex and liposomal). However, a recent study showed good activity of amphotericin B deoxycholate on the biomass of C. parapsilosis biofilms. Although moderate activity of echinocandins has been demonstrated against low metabolic activity biofilms of C. parapsilosis, few studies have analyzed the action of these drugs on high metabolic activity biofilms. Moreover, high biofilm-forming isolates have been associated with central venous catheter-related fungemia outbreaks and higher mortality rates. Therefore, it is relevant to verify the activity of the main antifungal drugs against high metabolic activity biofilms of C. parapsilosis. Our study aimed to evaluate the in vitro activity of amphotericin B deoxycholate, anidulafungin, caspofungin, and micafungin against high biofilm-forming and high metabolic activity clinical isolates of C. parapsilosis. Our results showed good activity of amphotericin B against C. parapsilosis biofilms, but none of the echinocandin drugs was effective. This suggests that amphotericin B deoxycholate may be a better choice than echinocandins for the treatment of biofilm-associated infections by C. parapsilosis, mainly in countries with insufficient health care resources to purchase lipid formulations of amphotericin B. These results warn of the possibility of persistent catheter-related candidemia caused by high biofilm-forming C. parapsilosis strains when treated with echinocandin drugs.
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- 2020
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25. Chromoblastomycosis in the Amazon region, Brazil, caused by Fonsecaea pedrosoi, Fonsecaea nubica, and Rhinocladiella similis: Clinicopathology, susceptibility, and molecular identification.
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de Andrade TS, de Almeida AMZ, Basano SA, Takagi EH, Szeszs MW, Melhem MSC, Albuquerque M, Camargo JSAA, Gambale W, and Camargo LMA
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- Adult, Aged, Antifungal Agents therapeutic use, Brazil epidemiology, Chromoblastomycosis diagnosis, Chromoblastomycosis drug therapy, Chromoblastomycosis microbiology, DNA, Fungal genetics, DNA, Ribosomal Spacer genetics, Female, Humans, Itraconazole pharmacology, Itraconazole therapeutic use, Male, Microbial Sensitivity Tests, Middle Aged, Mitosporic Fungi drug effects, Phylogeny, Sequence Analysis, DNA, Antifungal Agents pharmacology, Ascomycota drug effects, Ascomycota genetics, Chromoblastomycosis epidemiology, Mitosporic Fungi genetics
- Abstract
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 β-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., (© The Author(s) 2019. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology.)
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- 2020
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26. Evaluation of Vitek MS for Differentiation of Cryptococcus neoformans and Cryptococcus gattii Genotypes.
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Siqueira LPM, Gimenes VMF, de Freitas RS, Melhem MSC, Bonfietti LX, da Silva AR Jr, Souza Santos LB, Motta AL, Rossi F, Benard G, and de Almeida JN Jr
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- Cryptococcus gattii chemistry, Cryptococcus gattii classification, Cryptococcus gattii isolation & purification, Cryptococcus neoformans chemistry, Cryptococcus neoformans classification, Cryptococcus neoformans isolation & purification, Databases, Genetic, Genotype, Humans, Cryptococcosis microbiology, Cryptococcus gattii genetics, Cryptococcus neoformans genetics, Mycological Typing Techniques methods, Mycological Typing Techniques standards, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization standards
- Abstract
Cryptococcus neoformans and Cryptococcus gattii are the main pathogenic species of invasive cryptococcosis among the Cryptococcus species. Taxonomic studies have shown that these two taxa have different genotypes or molecular types with biological and ecoepidemiological peculiarities. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been proposed as an alternative method for labor-intensive methods for C. neoformans and C. gattii genotype differentiation. However, Vitek MS, one of the commercial MALDI-TOF MS instruments, has not been yet been evaluated for this purpose. Thus, we constructed an in-house database with reference strains belonging to the different C. neoformans (VNI, VNII, VNIII, and VNIV) and C. gattii (VGI, VGII, VGIII, and VGIV) major molecular types by using the software Saramis Premium (bioMérieux, Marcy-l'Etoile, France). Then, this new database was evaluated for discrimination of the different genotypes. Our in-house database provided correct identification for all C. neoformans and C. gattii genotypes; however, due to the intergenotypic mass spectral similarities, a careful postanalytic evaluation is necessary to provide correct genotype identification., (Copyright © 2019 American Society for Microbiology.)
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- 2019
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27. Antifungal Susceptibility of Candida Species Isolated from Horticulturists with Onychomycosis in Piauí, Brazil.
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Mobin M, Szeszs MW, Takahashi JP, Martins M, de Hippólito DDC, Porto JCS, Teles JB, de Lima SG, and Melhem MSC
- Abstract
Background: We aimed to assess susceptibility pattern of Candida species isolated from horticulturists with onychomycosis to four antifungal drugs and to compare the effectiveness of conventional identification methods with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS)., Methods: This study was conducted in a community garden located in Teresina, State of Piauí, Brazil, in the year 2014. The samples were identified through phenotypic methods and per MALDI-TOF MS, being used PCR as definitive identification test. The susceptibility pattern to four antifungal drugs was determined according to Clinical and Laboratory Standards Institute (CLSI)., Results: Fourteen clinical isolates from seven different species were identified by the phenotypic method and by MALDI-TOF MS, with an observed concordance of 71.4% between the two methods. C. albicans (28.6%), C. parapsilosis (21.4%), C. guilliermondii and C. metapsilosis (both with 14.3%) were the most frequent species. With the exception of C. krusei , all species were sensitive to the tested antifungal., Conclusion: This is the first study of antifungal susceptibility of Candida in Piauí, Brazil. With the exception of C. krusei , no species showed resistance to the antifungal drugs used. This study suggests constants updates from the public databases used in MALDI-TOF MS to provide a rapid and accurate mycological diagnosis., Competing Interests: Conflict of interest The authors declare that they have no conflict of interest.
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- 2018
28. Infections Caused by Fusarium Species in Pediatric Cancer Patients and Review of Published Literature.
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Arnoni MV, Paula CR, Auler ME, Simões CCN, Nakano S, Szeszs MW, Melhem MSC, Pereira VBR, Garces HG, Bagagli E, Silva EG, de Macêdo MF, and Ruiz LDS
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- Antifungal Agents pharmacology, Antifungal Agents therapeutic use, Brazil, Child, Cross Infection drug therapy, Female, Fusariosis drug therapy, Fusarium classification, Fusarium drug effects, Fusarium genetics, Genotype, Hospitals, Pediatric, Humans, Male, Microbial Sensitivity Tests, Cross Infection diagnosis, Cross Infection pathology, Fusariosis diagnosis, Fusariosis pathology, Fusarium isolation & purification, Leukemia, Lymphoid complications, Wilms Tumor complications
- Abstract
Fusarium species have emerged as responsible for a broad spectrum of infections, including superficial, locally invasive and disseminated ones, especially in the hospital environment. Since there are few reports of invasive and disseminated fusariosis in children, the aim of this study was to report four cases of nosocomial infection caused by this microorganism in children with cancer hospitalized in a public children's hospital located in Brazil. Two of these patients were female and two were male. All patients presented febrile neutropenia, while three patients had acute lymphocytic leukemia and one patient had Wilms' tumor as underlying disease. In two cases, fungi were isolated from blood and identified as Fusarium oxysporum species complex after phenotypic and genotypic studies, while in two other cases fungi were isolated from skin biopsies and identified as Fusarium solani species complex. One patient died 12 days after the onset of cutaneous lesions. All isolates, after susceptibility testing, presented high levels of minimum inhibitory concentration for itraconazole, voriconazole and amphotericin B. Considering the emergence of filamentous fungi as etiologic agents of nosocomial infections, health professionals should be aware of the problems these infections, especially fungal ones, may cause to debilitated patients.
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- 2018
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29. Proanthocyanidin polymeric tannins from Stryphnodendron adstringens are effective against Candida spp. isolates and for vaginal candidiasis treatment.
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de Freitas ALD, Kaplum V, Rossi DCP, da Silva LBR, Melhem MSC, Taborda CP, de Mello JCP, Nakamura CV, and Ishida K
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- Administration, Intravaginal, Animals, Antifungal Agents administration & dosage, Antifungal Agents isolation & purification, Biofilms growth & development, Candida albicans growth & development, Candida glabrata growth & development, Candidiasis, Vulvovaginal microbiology, Disease Models, Animal, Dose-Response Relationship, Drug, Female, Gels, Mice, Inbred BALB C, Phytotherapy, Plant Bark, Plant Extracts administration & dosage, Plant Extracts isolation & purification, Plant Stems, Plants, Medicinal, Proanthocyanidins administration & dosage, Proanthocyanidins isolation & purification, Antifungal Agents pharmacology, Biofilms drug effects, Candida albicans drug effects, Candida glabrata drug effects, Candidiasis, Vulvovaginal drug therapy, Fabaceae chemistry, Plant Extracts pharmacology, Proanthocyanidins pharmacology
- Abstract
Ethnopharmacological Relevance: The stem bark of Stryphnodendron adstringens (Mart.) Coville is popularly used as anti-inflammatory, astringent and in the treatment of wounds and vaginal infections. Several pharmacological activities have been scientifically proven by in vitro and in vivo experimental assays for antibacterial, antiviral, antiprotozoan, anti-inflammatory and antioxidant., Aim of the Study: We investigated whether proanthocyanidin polymeric tannins from the Stryphnodendron adstringens stem bark with antifungal activity against Candida albicans in vitro are also active against planktonic and biofilm cells of Candida non-albicans (CNA, including fluconazole-resistant isolates) and are capable of controlling Candida vaginitis in vivo., Materials and Methods: A total of 46 clinical isolates and 5 reference Candida spp. strains were used in this study. The antifungal effects in vitro of tannins (F2 and sub-fraction F2.4) from S. adstringens stem bark were evaluated using a broth microdilution assay (for planktonic yeasts and biofilm dispersion cells) or by XTT assay (for biofilm sessile cells). For in vivo antifungal activity analysis, mice with vaginal infection by C. albicans or C. glabrata were treated with a topical gel containing F2 (alone or combined with oral fluconazole), and the vaginal histopathology and fungal burden (by CFU counts from vaginal homogenates) were analyzed., Results: F2 and F2.4 inhibited the proliferation of planktonic cells of Candida spp., especially that of fluconazole- and/or amphotericin B-resistant isolates. F2 and F2.4 also inhibited the proliferation of Candida biofilm dispersion cells. Moreover, a gel containing F2 efficiently controlled vaginal infection by C. albicans and C. glabrata in mice, with no noticeable toxicity to vaginal tissue., Conclusions: Our data show that proanthocyanidin polymeric tannins obtained from S. adstringens have antifungal activity in vitro against C. albicans and CNA (including fluconazole-resistant isolates) and presented efficacy in the control of candidiasis in murine model. Therefore, these tannins have potential use in the treatment of vaginal candidiasis, representing interesting alternatives to current antifungals., (Copyright © 2018. Published by Elsevier B.V.)
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- 2018
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30. Yeast isolation and identification in water used in a Brazilian hemodialysis unit by classic microbiological techniques and Raman spectroscopy.
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Montanari LB, Sartori FG, Ribeiro DBM, Leandro LF, Pires RH, Melhem MSC, de Mello CA, and Martins CHG
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- Brazil, Fluconazole, Humans, Microbial Sensitivity Tests, Renal Dialysis, Environmental Monitoring, Spectrum Analysis, Raman, Water Microbiology, Yeasts growth & development
- Abstract
The use of poorly treated water in hemodialysis centers may lead to fungal contamination, which poses a serious threat to immunologically debilitated hemodialysis patients. This study aimed to isolate and identify yeast species in the water of a Brazilian hemodialysis center by using classic microbiological techniques and Raman spectroscopy. For 12 months, a total of 288 water samples were collected from different points of the hemodialysis treatment distribution center. One hundred and forty-six yeast species were isolated and identified in the samples that tested positive for the presence of yeasts such as Candida parapsilosis (100 isolates, or 68.50%), C. guilliermondii (17 isolates, or 11.65%), Rhodotorula mucilaginosa (23 isolates, or 15.75%), R. glutinis (three isolates, or 2.05%), and Trichosporon inkin (three isolates, or 2.05%). Yeast susceptibility to the antifungal fluconazole was also assayed. Only two C. guilliermondii isolates were resistant to fluconazole: the minimal inhibitory concentrations were higher than 64 μg/mL. The different yeast species present in the water of a Brazilian hemodialysis center call for more effective water disinfection procedures in this unit. Raman spectroscopy is an excellent tool to identify yeast species and is potentially applicable in routine water monitoring in hemodialysis units.
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- 2018
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31. Endocarditis due to Rhodotorula mucilaginosa in a kidney transplanted patient: case report and review of medical literature.
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Cabral AM, da Siveira Rioja S, Brito-Santos F, Peres da Silva JR, MacDowell ML, Melhem MSC, Mattos-Guaraldi AL, Hirata Junior R, and Damasco PV
- Abstract
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.
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- 2017
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32. Multicenter, International Study of MIC/MEC Distributions for Definition of Epidemiological Cutoff Values for Sporothrix Species Identified by Molecular Methods.
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Espinel-Ingroff A, Abreu DPB, Almeida-Paes R, Brilhante RSN, Chakrabarti A, Chowdhary A, Hagen F, Córdoba S, Gonzalez GM, Govender NP, Guarro J, Johnson EM, Kidd SE, Pereira SA, Rodrigues AM, Rozental S, Szeszs MW, Ballesté Alaniz R, Bonifaz A, Bonfietti LX, Borba-Santos LP, Capilla J, Colombo AL, Dolande M, Isla MG, Melhem MSC, Mesa-Arango AC, Oliveira MME, Panizo MM, Pires de Camargo Z, Zancope-Oliveira RM, Meis JF, and Turnidge J
- Subjects
- Caspofungin, Humans, Microbial Sensitivity Tests, Sporothrix classification, Sporothrix isolation & purification, Terbinafine, Amphotericin B pharmacology, Antifungal Agents pharmacology, Echinocandins pharmacology, Flucytosine pharmacology, Lipopeptides pharmacology, Naphthalenes pharmacology, Sporothrix drug effects, Sporotrichosis drug therapy, Triazoles pharmacology
- Abstract
Clinical and Laboratory Standards Institute (CLSI) conditions for testing the susceptibilities of pathogenic Sporothrix species to antifungal agents are based on a collaborative study that evaluated five clinically relevant isolates of Sporothrix schenckii sensu lato and some antifungal agents. With the advent of molecular identification, there are two basic needs: to confirm the suitability of these testing conditions for all agents and Sporothrix species and to establish species-specific epidemiologic cutoff values (ECVs) or breakpoints (BPs) for the species. We collected available CLSI MICs/minimal effective concentrations (MECs) of amphotericin B, five triazoles, terbinafine, flucytosine, and caspofungin for 301 Sporothrix schenckii sensu stricto , 486 S. brasiliensis , 75 S. globosa , and 13 S. mexicana molecularly identified isolates. Data were obtained in 17 independent laboratories (Australia, Europe, India, South Africa, and South and North America) using conidial inoculum suspensions and 48 to 72 h of incubation at 35°C. Sufficient and suitable data (modal MICs within 2-fold concentrations) allowed the proposal of the following ECVs for S. schenckii and S. brasiliensis , respectively: amphotericin B, 4 and 4 μg/ml; itraconazole, 2 and 2 μg/ml; posaconazole, 2 and 2 μg/ml; and voriconazole, 64 and 32 μg/ml. Ketoconazole and terbinafine ECVs for S. brasiliensis were 2 and 0.12 μg/ml, respectively. Insufficient or unsuitable data precluded the calculation of ketoconazole and terbinafine (or any other antifungal agent) ECVs for S. schenckii , as well as ECVs for S. globosa and S. mexicana These ECVs could aid the clinician in identifying potentially resistant isolates (non-wild type) less likely to respond to therapy., (Copyright © 2017 American Society for Microbiology.)
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- 2017
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33. Antifungal Activity of the Biphosphinic Cyclopalladate C7a against Candida albicans Yeast Forms In Vitro and In Vivo .
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Muñoz JE, Rossi DCP, Ishida K, Spadari CC, Melhem MSC, Garcia DM, Caires ACF, Taborda CP, and Rodrigues EG
- Abstract
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 .
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- 2017
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34. Candidaemia due to Candida parapsilosis species complex at a hospital in Brazil: Clinical characteristics and antifungal susceptibility profile.
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Alencar DSO, Tsujisaki RAS, Spositto FLE, Nunes MO, Almeida AA, Martins MDA, Melhem MSC, and Chang MR
- Subjects
- Adult, Aged, Amphotericin B pharmacology, Antifungal Agents therapeutic use, Brazil epidemiology, Candida parapsilosis drug effects, Candidemia drug therapy, Candidemia microbiology, Child, Preschool, Cross Infection microbiology, Drug Resistance, Fungal, Hospital Units, Humans, Infant, Microbial Sensitivity Tests, Middle Aged, Mycological Typing Techniques, Renal Dialysis, Tertiary Care Centers, Triazoles pharmacology, Antifungal Agents pharmacology, Candida parapsilosis isolation & purification, Candidemia epidemiology, Cross Infection epidemiology
- Abstract
Background: Recent decades have seen a global emergence of candidaemia caused by non-Candida albicans Candida species, particularly the Candida parapsilosis complex., Aims: To evaluate the clinical features and antifungal susceptibility profiles of isolates belonging to the C. parapsilosis species complex in patients with candidaemia in a midwestern Brazilian tertiary-care teaching hospital., Methods: Yeast identification was performed using an automated Vitek 2 Compact system. PCR-RFLP was employed for species differentiation., Results: Five cases of infection by C. parapsilosis sensu stricto and two by Candida orthopsilosis were found. Of the seven cases, five were adult patients undergoing haemodialysis. The only isolate of C. parapsilosis sensu stricto resistant to fluconazole (MIC=8μg/ml) was obtained from a patient on a long-term regimen with this drug. This was the only patient who evolved to death., Conclusions: Resistance to antifungal agents poses a therapeutic challenge, especially for non-C. albicans Candida species, and requires continuous monitoring using susceptibility tests because resistance in vitro can be predictive of treatment failure. In the present study, in vitro antifungal susceptibility proved consistent with clinical outcome., (Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.)
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- 2017
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35. Gas Chromatography-Triple Quadrupole Mass Spectrometry Analysis and Vasorelaxant Effect of Essential Oil from Protium heptaphyllum (Aubl.) March.
- Author
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Mobin M, de Lima SG, Almeida LTG, Silva Filho JC, Rocha MS, Oliveira AP, Mendes MB, Carvalho FAA, Melhem MSC, and Costa JGM
- Subjects
- Analgesics chemistry, Analgesics pharmacology, Animals, Anti-Inflammatory Agents chemistry, Anti-Inflammatory Agents pharmacology, Cyclohexenes chemistry, Cyclohexenes pharmacology, Endothelial Cells drug effects, Gas Chromatography-Mass Spectrometry methods, Limonene, Male, Oils, Volatile pharmacology, Phenylephrine chemistry, Phenylephrine pharmacology, Rats, Rats, Wistar, Resins, Plant chemistry, Terpenes chemistry, Terpenes pharmacology, Vasodilator Agents chemistry, Vasodilator Agents pharmacology, Burseraceae chemistry, Oils, Volatile chemistry
- Abstract
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 μ M), EOPh (3-750 μ g/mL) induced relaxation, and the essential oil had a concentration-dependent vasorelaxant effect, without involvement of endothelial mediators.
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- 2017
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36. Species distribution and antifungal susceptibility profile of Candida isolates from bloodstream infections in Lima, Peru.
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Bustamante B, Martins MA, Bonfietti LX, Szeszs MW, Jacobs J, Garcia C, and Melhem MSC
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- Candidemia epidemiology, Humans, Peru epidemiology, Species Specificity, Antifungal Agents pharmacology, Candida classification, Candida drug effects, Candidemia microbiology, Drug Resistance, Fungal physiology
- Abstract
Yeast identification and in vitro susceptibility testing provide helpful information for appropriate administration of antifungal treatments; however, few reports from the Latin American region have been published. The aim of this study was to identify the species present in isolates from bloodstream infections diagnosed in nine hospitals in Lima, Peru and to determine their in vitro susceptibility to four antifungal drugs. We tested and identified 153 isolates collected between October 2009 and August 2011 using standard methods. PCR and PCR-RFLP assays were performed to distinguish Candida albicans from Candida dubliniensis and to identify species of the Candida parapsilosis and Candida glabrata complexes. Antifungal susceptibility testing for fluconazole, anidulafungin and voriconazole was performed using the CSLI M27-A3 method, and amphotericin B susceptibility was determined using the Etest method. The most frequently isolated species were: C. albicans (61; 39.9 %), C. parapsilosis (43; 28.1 %), C. tropicalis (36; 23.5%) and C. glabrata (8; 5.2 %). The overall susceptibility rates were 98.0 %, 98.7 %, 98.0 % and 97.4 % for amphotericin B, fluconazole, voriconazole and anidulafungin, respectively. No isolate was resistant to more than one drug. These results showed that the rate of resistance to four antifungal drugs was low among Candida bloodstream isolates in Lima, Peru., (© 2014 The Authors.)
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- 2014
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37. Prevalence and antifungal susceptibility of Candida parapsilosis complex isolates collected from oral cavities of HIV-infected individuals.
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Moris DV, Melhem MSC, Martins MA, Souza LR, Kacew S, Szeszs MW, Carvalho LR, Pimenta-Rodrigues MV, Berghs HAM, and Mendes RP
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- Amphotericin B pharmacology, Candida classification, Candidiasis, Oral complications, Candidiasis, Oral drug therapy, Caspofungin, Echinocandins pharmacology, Female, Fluconazole pharmacology, HIV Infections microbiology, Humans, Lipopeptides, Male, Microbial Sensitivity Tests, Mycological Typing Techniques, Polymorphism, Restriction Fragment Length, Pyrimidines pharmacology, Triazoles pharmacology, Voriconazole, Antifungal Agents pharmacology, Candida drug effects, Candida isolation & purification, Candidiasis, Oral microbiology, HIV Infections complications, Mouth microbiology
- Abstract
At present, few data are available on the prevalence and antifungal susceptibility of Candida parapsilosis complex isolates from HIV-infected individuals. The C. parapsilosis complex comprises three species, C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. Fifteen of 318 Candida isolates were identified as members of the C. parapsilosis complex by PCR and restriction fragment length polymorphism (RFLP). The prevalence of C. parapsilosis complex isolates was 4.7 %, 2.2 % being identified as C. parapsilosis sensu stricto and 2.5 % as C. metapsilosis, while no C. orthopsilosis was isolated. This is believed to be the first study that has identified isolates of C. metapsilosis obtained from the oral cavity of HIV-infected individuals. Antifungal susceptibility tests indicated that all the isolates were susceptible to amphotericin B (AMB), fluconazole (FLC), ketoconazole (KTC), itraconazole (ITC), voriconazole (VRC) and caspofungin (CASPO). Although isolates of C. parapsilosis sensu stricto and C. metapsilosis were susceptible to FLC, isolates of C. metapsilosis showed a tendency for higher MICs (≥1.0 µg ml(-1)). Based upon the frequency of candidiasis and the fact that certain isolates of the C. parapsilosis complex respond differently to FLC therapy, our data may be of therapeutic relevance with respect to susceptibility and potential resistance to specific antifungal agents. Our data suggest that C. metapsilosis can be a human commensal; its importance as a pathogen has yet to be confirmed.
- Published
- 2012
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38. Prevalence, distribution and antifungal susceptibility profiles of Candida parapsilosis, Candida orthopsilosis and Candida metapsilosis bloodstream isolates.
- Author
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Bonfietti LX, Martins MDA, Szeszs MW, Pukiskas SBS, Purisco SU, Pimentel FC, Pereira GH, Silva DC, Oliveira L, and Melhem MSC
- Subjects
- Brazil, Candida genetics, Candida isolation & purification, Genotype, Humans, Microbial Sensitivity Tests, Molecular Typing methods, Mycological Typing Techniques methods, Mycology methods, Polymorphism, Restriction Fragment Length, Prevalence, Antifungal Agents pharmacology, Candida classification, Candida drug effects, Candidemia epidemiology, Candidemia microbiology
- Abstract
The Candida parapsilosis group encompasses three species: C. parapsilosis, Candida orthopsilosis and Candida metapsilosis. These species are phenotypically indistinguishable, and molecular methods are needed for their detection. We analysed 152 unique blood culture isolates of the C. parapsilosis group obtained during 1997-2011. The isolates were screened by PCR amplification of the gene encoding secondary alcohol dehydrogenase, followed by digestion with the restriction enzyme BanI. Isolates with RFLP patterns distinct from those of the C. parapsilosis group were characterized as C. parapsilosis sensu stricto (90.8 %), C. orthopsilosis (8.6 %) and C. metapsilosis (0.6 %). Antifungal susceptibility tests indicated that all isolates were susceptible to itraconazole, amphotericin B and caspofungin. Although C. orthopsilosis and C. metapsilosis isolates were susceptible to fluconazole, higher MICs (≥2 mg l(-1)) were observed for C. orthopsilosis. Three isolates (2.0 %) of C. parapsilosis sensu stricto were resistant to voriconazole. Five C. parapsilosis isolates (3.3 %) were intermediate, and a single isolate (0.7 %) was resistant (MIC 16 mg l(-1)) to fluconazole. These data were confirmed using reference strains. It was observed that C. parapsilosis isolates were less susceptible to all triazoles, and this finding deserves further attention to assess the appearance of cross-resistance phenomena. In conclusion, C. metapsilosis and C. orthopsilosis are involved in a small but significant number of invasive infections in Brazil.
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- 2012
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39. Comparative analysis of Etest and broth microdilution method (AFST-EUCAST) for trends in antifungal drug susceptibility testing of Brazilian Cryptococcus neoformans isolates.
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Dias ALT, Matsumoto FE, Melhem MSC, da Silva EG, Auler ME, de Siqueira AM, and Paula CR
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- Antifungal Agents pharmacology, Brazil, Humans, Reagent Kits, Diagnostic, Sensitivity and Specificity, Cryptococcosis microbiology, Cryptococcus neoformans drug effects, Microbial Sensitivity Tests methods
- Abstract
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.
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- 2006
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