Fluconazole levels in serum and cerebrospinal fluid according to daily dosage in patients with cryptococcosis and other fungal infections

ABSTRACT Fluconazole is extensively used for the treatment of candidiasis and cryptococcosis. Among other factors, successful treatment is related to appropriate fluconazole levels in blood and cerebrospinal fluid. In the present study, fluconazole levels were determined in 15 patients, 14 of whom had AIDS and 13 had neurocryptococcosis. The only selection criterion was treatment with fluconazole, which was performed with a generic or similar form of the drug. Fluconazole level was determined by high performance liquid chromatography and the susceptibility profile of Cryptococcus spp. isolated from the patients was assessed by broth microdilution. Blood and cerebrospinal fluid fluconazole levels were found to be related to the fluconazole daily dose, and exceeded the minimum inhibitory concentration of this antifungal for the Cryptococcus spp. isolates. A good correlation was observed between serum and cerebrospinal fluid drug concentration. In conclusion, treatment with non-original fluconazole under usual medical practice conditions results in appropriate blood and cerebrospinal fluid levels of the drug for inhibiting Cryptococcus spp. susceptible to this antifungal drug. The relatively common failures of neurocryptococcosis treatment appear not to be due to insufficient fluconazole levels in the cerebrospinal fluid, especially with the use of daily doses of 400-800 mg.

Essential oils and major compounds of Hedychium coronarium Koenig (Zingiberaceae) against pathogenic yeast of Candida and Cryptococcus genus / Óleos essenciais e compostos majoritários de Hedychium coronarium Koenig (Zingiberaceae) contra leveduras patogênicas dos gêneros Candida e Cryptococcus

Among the major causative agents of invasive fungal infections stands out the opportunistic yeasts of Candida and Cryptococcus. Regarding the problem of the high incidence of infections by these agents and the difculty of treating the low stockpile of antifungal drugs and the high toxicity of most therapies, the search for new antifungal compounds has been highlighted in recent decades. Hedychium coronarium, popularly known as "lírio-do-brejo" or "gengibre-branco" features several previously reported biological activities, including antimicrobial activity. Compound 1.8-cineole is the major compound in essential oil extracted from roots of H. coronarium, while caryophyllene oxide presents itself as the major in essential oil extracted from leaves of this plant. Our data show strong antifungal activity of compounds, against species of Candida albicans, Candida parapsilosis, Candida krusei, Cryptococcus neoformans and Cryptococcus gattii, with minimal inhibitory concentration and minimal fungicidal concentration equal to 0.2 % (v/v) for essential oil extracted from roots, while the essential oil extracted from leaves showed no activity against yeasts. The caryophyllene oxide showed higher antifungal activity for Cryptococcus spp. Thus, our results showed that the essential oil of rhizome is a promising antifungal agent against pathogenic yeasts.(AU)

Candida spp e Cryptococcus spp estão classifcadas entre os maiores causadores de infecções fúngicas invasivas em pacientes imunocomprometidos. Diante a alta incidência destas infecções por estes agentes e a difculdade do sucesso no tratamento, decorrente do baixo arsenal de fármacos antifúngicos e da alta toxicidade presente na maioria dos esquemas terapêuticos, a busca por novos compostos antifúngicos tem sido alvo de diversos estudos nas últimas décadas. Hedychium coronarium, popularmente conhecido como "lírio-do-brejo" ou "gengibre-branco", apresenta diversas atividades biológicas já descritas, entre elas a atividade antimicrobiana. O composto 1.8-Cineol é o composto majoritário presente no óleo essencial extraído de raízes de H. coronarium e o composto óxido de cariofleno é o composto majoritário extraído das folhas desta planta. Nossos resultados mostram que os compostos extraídos de H. coronarium apresentam forte atividade contra Candida albicans, Candida parapsilosis, Candida krusei, Cryptococcus neoformans e Cryptococcus gattii, com valores de concentração inibitória minima e concentração fungicida minima igual a 0,2 % (v/v) para o óleo essencial extraído das raízes, enquanto que o óleo essencial extraído das folhas, não mostrou atividade contras as leveduras. O composto óxido de cariofleno mostrou maior atividade antifúngica para Crytopcoccus spp. Assim, nossos dados mostraram que o óleo essencial extraído das raízes de H. coronarium, é um agente antifúngico promissor contra leveduras patogênicas.(AU)

Simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcusspecies

ABSTRACTThe antifungal activity of some statins against different fungal species has been reported. Thus, at the first moment, the in vitro antifungal activity of simvastatin, atorvastatin and pravastatin was tested againstCandida spp. and Cryptococcus spp. Then, in a second approach, considering that the best results were obtained for simvastatin, this drug was evaluated in combination with antifungal drugs against planktonic growth and tested against biofilms ofCandida spp. and Cryptococcus spp. Drug susceptibility testing was performed using the microdilution broth method, as described by the Clinical and Laboratory Standards Institute. The interaction between simvastatin and antifungals against planktonic cells was analyzed by calculating the fractional inhibitory concentration index. Regarding biofilm susceptibility, simvastatin was tested against growing biofilm and mature biofilm of one strain of each tested yeast species. Simvastatin showed inhibitory effect against Candida spp. andCryptococcus spp. with minimum inhibitory concentration values ranging from 15.6 to 1000 mg L-1 and from 62.5 to 1000 mg L-1, respectively. The combination of simvastatin with itraconazole and fluconazole showed synergism against Candidaspp. and Cryptococcus spp., while the combination of simvastatin with amphotericin B was synergistic only againstCryptococcus spp. Concerning the biofilm assays, simvastatin was able to inhibit both growing biofilm and mature biofilm ofCandida spp. and Cryptococcus spp. The present study showed that simvastatin inhibits planktonic cells and biofilms ofCandida and Cryptococcus species.

Silver nanoparticle production by the fungus Fusarium oxysporum: nanoparticle characterisation and analysis of antifungal activity against pathogenic yeasts

The microbial synthesis of nanoparticles is a green chemistry approach that combines nanotechnology and microbial biotechnology. The aim of this study was to obtain silver nanoparticles (SNPs) using aqueous extract from the filamentous fungus Fusarium oxysporum as an alternative to chemical procedures and to evaluate its antifungal activity. SNPs production increased in a concentration-dependent way up to 1 mM silver nitrate until 30 days of reaction. Monodispersed and spherical SNPs were predominantly produced. After 60 days, it was possible to observe degenerated SNPs with in additional needle morphology. The SNPs showed a high antifungal activity against Candida and Cryptococcus , with minimum inhibitory concentration values ≤ 1.68 µg/mL for both genera. Morphological alterations of Cryptococcus neoformans treated with SNPs were observed such as disruption of the cell wall and cytoplasmic membrane and lost of the cytoplasm content. This work revealed that SNPs can be easily produced by F. oxysporum aqueous extracts and may be a feasible, low-cost, environmentally friendly method for generating stable and uniformly sized SNPs. Finally, we have demonstrated that these SNPs are active against pathogenic fungi, such as Candida and Cryptococcus .

Environmental isolation, biochemical identification, and antifungal drug susceptibility of Cryptococcus species

Introduction The incidence of opportunistic fungal infections has increased in recent years and is considered an important public health problem. Among systemic and opportunistic mycoses, cryptococcosis is distinguished by its clinical importance due to the increased risk of infection in individuals infected by human immunodeficiency virus. Methods To determine the occurrence of pathogenic Cryptococcus in pigeon excrement in the City of Araraquara, samples were collected from nine environments, including state and municipal schools, abandoned buildings, parks, and a hospital. The isolates were identified using classical tests, and susceptibility testing for the antifungal drugs (fluconazole, itraconazole, voriconazole, and amphotericin B) independently was also performed. After collection, the excrement samples were plated on Niger agar and incubated at room temperature. Results A total of 87 bird dropping samples were collected, and 66.6% were positive for the genus Cryptococcus. The following species were identified: Cryptococcus neoformans (17.2%), Cryptococcus gattii (5.2%), Cryptococcus ater (3.5%), Cryptococcus laurentti (1.7%), and Cryptococcus luteolus (1.7%). A total of 70.7% of the isolates were not identified to the species level and are referred to as Cryptococcus spp. throughout the manuscript. Conclusions Although none of the isolates demonstrated resistance to antifungal drugs, the identification of infested areas, the proper control of birds, and the disinfection of these environments are essential for the epidemiological control of cryptococcosis. .

In vitro susceptibility to antifungal agents of environmental Cryptococcus spp. isolated in the city of Ribeirão Preto, São Paulo, Brazil

Infections by Cryptococcus strains other than C. neoformans have been detected in immunocompromised patients. Of these strains, three are considered human pathogens: C. albidus, C. laurenttii, and C. uniguttulatus. This study deals with the in vitro susceptibility of Cryptococcus to drugs such as amphotericin B, itraconazole, fluconazole, and 5-fluorocytosine. Environmental Cryptococcus isolates (50) distributed as follows: C. neoformans var. neoformans (16), C. albidus (17), C. laurentii (14), and C. uniguttulatus (3) were evaluated by the micro and macrodilution techniques, according to EUCAST and NCCLS recommendations, respectively. Considering both methodologies the respective minimal inhibitory concentrations (MIC) were 0.125 and 2 æg/ml for amphotericin B, 0.06 and 8 æg/ml for itraconazole, and 0.5 and more than 64 æg/ml for fluconazole and 5-fluorocytosine. Agreement percentages for the two methodologies were 100 percent for amphotericin B and fluconazole for all the strains tested. For itraconazole, the agreement percentage was 81.3 percent in the C. neoformans strain and 100 percent for all the others. All species had a agreement percentage of 94.1 to 100 percent when susceptibility to 5-fluorocytosine was tested. It is concluded that environmental isolates of C. neoformans var. neoformans, C. albidus, C. laurentii, and C. uniguttulatus may show high MICs against certain drugs, suggesting in vitro primary resistance to the antifungals tested.

Systemic humicolus cryptococcosis.

We report a 71/2-year-boy with disseminated systemic cryptococcosis. Although other species have been incriminated, this appears to be the first report of Cryptococcus humicolus. The child was HIV negative. He was treated with amphotericin B and fluconazole with intensive supportive care. The child responded after 6 weeks and is now on maintenance fluconazole therapy.

Identificación de levaduras de interés médico / Identification of yeasts of medical interest

De distintas muestras clínicas, se aislaron 238 cepas de levaduras. Para identificarlas, se emplearon pruebas convencionales como la emisión de tubos germinativos y producción de clamidosporos para identificar a Candida albicans. Las levaduras que no presentaron los caracteres antes mencionados, se identificaron mediante equipo comercial que mide la actividad enzimática de las levaduras en presencia de cicloheximida y de diferentes azúcares (Candifast de International Mycoplasma S.A.). De las levaduras aisladas, 194 resultaron ser Candida albicans y 44 cepas correspondieron a otras especies de Candida y a otros géneros de levaduras

Susceptibilidad "in vitro" de cepas de Cryptococcus a 5 drogas antifúngicas / In vitro susceptibility of Cryptococcus strains to 5 antifungal drugs

Se estudió la susceptibilidad "in vitro" de 24 cepas de 3 espécies del género Cryptococcus a 5 drogas antifúngicas (antrotericina B, 5 fluorocitosina, ketoconazol, itraconazol y miconazol). Las mismas se agruparon según su especie, variedad y origen de aislamiento. Para determinar la concentración inhibitoria mínima (C.I.M.) de cada droga se empleó el método de dilución en agar con el medio básico nitrogenado para levaduras, adicionado de glucosa. Se obtuvo además la media geométrica de estos valores para cada grupo y se comparó cada uno de ellos. Los resultados obtenido fueron homogéneos con la sola excepción de las cepas de Cryptococcus sp (no neoformans), en las cuales se detectaron elevados valores de C.I.M. para la 5 fluorocitosina