Susceptibility variation of Malassezia pachydermatis to antifungal agents according to isolate source

Malassezia pachydermatis is associated with dermatomycoses and otomycosis in dogs and cats. This study compared the susceptibility of M. pachydermatis isolates from sick (G1) and healthy (G2) animals to azole and polyene antifungals using the M27-A3 protocol. Isolates from G1 animals were less sensitive to amphotericin B, nystatin, fluconazole, clotrimazole and miconazole.

Synthesis and QSAR studies of novel triazole compounds containing thioamide as potential antifungal agents

Eighteen novel triazole compounds containing thioamide were designed and synthesized. Their structures were confirmed by elemental analysis, H-1 NMR, IR, and MS. The title compounds exhibited certain antifungal activity. And the geometry structures of the title compounds were optimized by means of the density functional theory (DFT) method at B3LYP/6-31G* level. The quantitative structure-activity relationship (QSAR) of the title compounds was systematically investigated. A correlative equation between FA and DELH, V was well established by using the multiple linear regression (MLR). (c) 2006 Elsevier Ltd. All rights reserved.

Correlation of the in vitro antifungal drug susceptibility with the in vivo activity of fluconazole in a murine model of cerebral infection caused by Cryptococcus gattii

Forty Cryptococcus gattii strains were submitted to antifungal susceptibility testing with fluconazole, itraconazole, amphotericin B and terbinafine. The minimum inhibitory concentration (MIC) ranges were 0.5-64.0 for fluconazole, < 0.015-0.25 for itraconazole, 0.015-0.5 for amphotericin B and 0.062-2.0 for terbinafine. A bioassay for the quantitation of fluconazole in murine brain tissue was developed. Swiss mice received daily injections of the antifungal, and their brains were withdrawn at different times over the 14-day study period. The drug concentrations varied from 12.98 to 44.60 mu g/mL. This assay was used to evaluate the therapy with fluconazole in a model of infection caused by C. gattii. Swiss mice were infected intracranially and treated with fluconazole for 7, 10 or 14 days. The treatment reduced the fungal burden, but an increase in fungal growth was observed on day 14. The MIC for fluconazole against sequential isolates was 16 mu g/mL, except for the isolates obtained from animals treated for 14 days (MIC = 64 mu g/mL). The quantitation of cytokines revealed a predominance of IFN-gamma and IL-12 in the non-treated group and elevation of IL-4 and IL-10 in the treated group. Our data revealed the possibility of acquired resistance during the antifungal drug therapy.

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.

Oral candidosis and the therapeutic use of antifungal agents in dentistry

This paper reviews the current concepts of mycology and candidal infections as they relate to the oral cavity. Proposed classification for the presentation of oral candidosis is outlined as are examples of these topical infections, such as erythematous, pseudomembranous and hyperplastic candidosis, as well as angular chelitis and median rhomboid glossitis. The diagnosis and principles of management of oral candidosis are discussed, the therapeutic agents available for the management of these infections are presented and a treatment protocol for the management of patients with oral candidosis is given.

Prevalência e susceptibilidade de leveduras vaginais

Entre as vulvovaginites, a candidíase é apontada como a causa mais freqüente em mulheres na idade fértil. Atualmente, várias pesquisas mostram aumento na freqüência das espécies não-albicans e grande preocupação com episódios de repetição, assim como sua relação com a resistência ao tratamento. OBJETIVO: O presente estudo teve como objetivo verificar a distribuição de gêneros e espécies de leveduras causadoras de vaginite e analisar o perfil de sensibilidade das leveduras frente às drogas antifúngicas. MATERIAL E MÉTODO: Foram colhidas amostras de fluido vaginal de 250 pacientes para cultura, realizados identificação e antifungigrama dos isolados. RESULTADOS: Leveduras do gênero Candida estavam presentes em 27,6% das amostras. Candida albicans foi a levedura mais isolada em 74% dos casos, seguida de Candida glabrata, em 14,5%; Candida tropicalis, em 7,3%; e Candida parapsilosis, em 4,3%. Todos os isolados Candida albicans foram sensíveis à anfotericina B, e apenas um isolado da espécie não-albicans apresentou concentração inibitória mínima (CIM) mais elevada (2µg/ml). em Candida albicans, 5,9% das amostras mostraram-se sensíveis, dependendo da dose de fluconazol, e 9,8%, resistentes. Apenas um isolado mostrou-se resistente, com CIM de 8µg/ml, para itraconazol. Nas espécies não-albicans, 11,7% dos isolados foram considerados resistentes ao fluconazol e 23,5, ao itraconazol. CONCLUSÃO: Candida albicans foi a espécie mais freqüentemente encontrada na microbiota vaginal; no entanto, outras espécies foram também comuns nessa população. Porcentual importante de isolados de Candida albicans e não-albicans foi resistente a fluconazol e itraconazol, mostrando a importância de realização de testes de identificação e antifungigrama para os episódios de candidíase vaginal.

Correlation Between Etest (R), Disk Diffusion, and Microdilution Methods for Antifungal Susceptibility Testing of Candida Species From Infection and Colonization

The correlation between the microdilution (MD), Etest (R) (ET), and disk diffusion (DD) methods was determined for amphotericin B, itraconazole and fluconazole. The minimal inhibitory concentration (MIC) of those antifungal agents was established for a total of 70 Candida spp. isolates from colonization and infection. The species distribution was: Candida albicans (n = 27), C. tropicalis (n = 17), C. glabrata (n = 16), C. parapsilosis (n = 8), and C. lusitaniae (n = 2). Non-Candida albicans Candida species showed higher MICs for the three antifungal agents when compared with C. albicans isolates. The overall concordance (based on the MIC value obtained within two dilutions) between the ET and the MD method was 83% for amphotericin B, 63% for itraconazole, and 64% for fluconazole. Considering the breakpoint, the agreement between the DD and MD methods was 71% for itraconazole and 67% for fluconazole. The DD zone diameters are highly reproducible and correlate well with the MD method, making agar-based methods a viable alternative to MD for susceptibility testing. However, data on agar-based tests for itraconazole and amphotericin B are yet scarce. Thus, further research must still be carded out to ensure the standardization to other antifungal agents. J. Clin. Lab. Anal. 23:324-330, 2009. (C) 2009 Wiley-Liss, Inc.

Prevalence and antifungal susceptibility of Candida parapsilosis complex isolates collected from oral cavities of HIV-infected individuals

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 mu g 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.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal inhibitory concentration (MIC). A total of 71 Candida isolates from HIV-positive patients were examined with the following species represented: C. albicans (59), C. tropicalis (9), C. glabrata (1), C. guilliermondii (1) and C. krusei (1). A total of 15 Candida isolates were evaluated from control individuals comprised of 11 C. albicans and 4 C. tropicalis samples. Our results demonstrated that the tested antifungal agents showed good activity for most isolates from both groups; however, variability in MIC values among isolates was observed.

In vitro antifungal susceptibility of Candida spp. isolates from patients with chronic periodontitis and from control patients

Superinfection by Candida can be refractory to conventional periodontal treatments in specific situations, such as in immunocompromised patients. In these cases, the systemic therapy with antifungal drugs could be indicated. The aim of this study was to analyse antifungal susceptibility of Candida spp. strains isolated from chronic periodontitis patients and from control individuals. A total of 39 C. albicans isolates, 9 C. tropicalis, 2 C. glabrata and 5 Candida spp. from control individuals and 30 C. albicans, 3 C. tropicalis and 2 C. glabrata from periodontitis patients were tested. In the control group, 1 isolate of C. glabrata was resistant to ketoconazole and 1 Candida spp. was resistant to amphotericin B, ketoconazole and miconazole. Among the isolates of periodontitis group, 1 (3.33%) C. albicans isolate was resistant to flucytosine and ketoconazole. According to the obtained results, it could be concluded that fluconazole was the most effective drug against the several Candida species studied. There were not expressive differences in the susceptibility of isolates from periodontitis patients or from control individuals.

Candiduria in adults and children: prevalence and antifungal susceptibility in outpatient of Jataí-GO

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)