ABSTRACT
INTRODUCTION: Antifungal susceptibility testing assists in finding the appropriate treatment for fungal infections, which are increasingly common. However, such testing is not very widespread. There are several existing methods, and the correlation between such methods was evaluated in this study. METHODS: The susceptibility to fluconazole of 35 strains of Candida sp. isolated from blood cultures was evaluated by the following methods: microdilution, Etest, and disk diffusion. RESULTS: The correlation between the methods was around 90%. CONCLUSIONS: The disk diffusion test exhibited a good correlation and can be used in laboratory routines to detect strains of Candida sp. that are resistant to fluconazole.
Subject(s)
Humans , Antifungal Agents/pharmacology , Candida/drug effects , Fluconazole/pharmacology , Microbial Sensitivity Tests/methods , Candida/classification , Candida/isolation & purificationABSTRACT
INTRODUÇÃO: Candida parapsilosis é a segunda ou terceira levedura mais isolada de hemoculturas em várias partes do mundo. É um patógeno comumente isolado no Brasil e no Ceará. Apresenta capacidade de formar biofilmes em cateteres e outros dispositivos médicos e esses fatores contribuem para a disseminação dessa levedura. OBJETIVOS: Identificar e avaliar a suscetibilidade aos antifúngicos de C. parapsilosis isoladas de amostras de sangue e urina de pacientes atendidos em hospitais no Ceará. MÉTODOS: Foram isoladas e identificadas 57 cepas de C. parapsilosis. As cepas foram identificadas por testes fenotípicos e moleculares. A suscetibilidade foi avaliada pelo método de microdiluição em caldo (protocolo do Clinical and Laboratory Standards Institute [CLSI] M27-A3). Foram avaliados cinco antifúngicos (anfotericina B, caspofungina, fluconazol, itraconazol e voriconazol). RESULTADOS E CONCLUSÃO: As cepas foram identificadas como C. parapsilosis por testes fenotípicos e confirmadas pelos testes moleculares. Quanto ao perfil de sensibilidade, elas se mostraram sensíveis aos antifúngicos testados, sendo a resistência ainda um fenômeno raro entre cepas de C. parapsilosis isoladas no Ceará.
INTRODUCTION: C. parapsilosis is the second or third most isolated yeast from blood cultures in various parts of the world. It is a commonly isolated pathogen in Brazil and Ceará. C. parapsilosis is liable to form biofilms on catheters and other medical devices, which contributes to the spread of this yeast. OBJECTIVE: The objective of this study was to identify and assess the antifungal susceptibility of C. parapsilosis isolates from blood and urine samples collected from patients in hospitals in Ceará. METHODS: We isolated and identified 57 strains of C. parapsilosis. The strains were identified by phenotypic and molecular tests. The susceptibility to antifungals was assessed by broth microdilution (Clinical and Laboratory Standards Institute [CLSI] protocol M27A3). We tested five antifungals (amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole). RESULTS AND CONCLUSION: The strains were identified as C. parapsilosis by phenotypic tests and confirmed by molecular tests. As to the sensitivity profile, the strains were sensitive to the antifungal agents, hence resistance is still a rare phenomenon among C. parapsilosis isolates in Ceará.
ABSTRACT
Systemic fungal infections are responsible for high mortality rates. Several species of fungi may be involved, but Candida spp. is the most prevalent. Simvastatin is used to lower cholesterol and also exhibits antifungal action. The aim of this study was to evaluate the synergistic action of simvastatin with fluconazole against strains of Candida spp. Susceptibility testing was performed according to protocol M27-A3, by broth microdilution method and the synergistic effect of simvastatin and fluconazole was calculated based on FICI (Fractional Inhibitory Concentration Index). Eleven strains were evaluated, and simvastatin showed a synergistic effect with fluconazole against 10 (91%) of the Candida spp. strains tested. Simvastatin may be a valuable drug in the treatment of systemic infections caused by Candida spp.
Infecções fúngicas sistêmicas são responsáveis por altas taxas de mortalidade. Várias espécies de fungos podem estar envolvidas, mas Candida spp é a mais prevalente. A sinvastatina é usada para diminuir o colesterol e também exibe ação antifúngica. O objetivo deste estudo foi avaliar a ação sinérgica de sinvastatina e fluconazol contra cepas de Candida spp. O teste de susceptibilidade foi realizado de acordo com o protocolo M27-A3, pelo método de micro diluição em caldo e o efeito sinérgico de sinvastatina e fluconazol foi calculado com base no ICIF (Índice de Concentração Inibitória Fraccionada). Onze cepas foram avaliadas, e a sinvastatina mostrou um efeito sinérgico com o fluconazol em dez (91%) das cepas de Candida spp. Sinvastatina pode ser uma droga valiosa no tratamento de infecções sistêmicas causadas por Candida spp.
Subject(s)
Humans , Antifungal Agents/pharmacology , Candida/drug effects , Fluconazole/pharmacology , Simvastatin/pharmacology , Candida/classification , Drug Synergism , Microbial Sensitivity TestsABSTRACT
A evolução da resistência fúngica pode ser avaliada pelo teste de susceptibilidade aos antifúngicos. Os protocolos mais utilizados para testes de susceptibilidade são a micro diluição em caldo (MDC), disco difusão (DD) e E-test. O objetivo principal deste estudo foi comparar os testes de sensibilidade realizados pelos métodos de MDC e DD para a anfotericina B e o fluconazol contra cepas de Candida spp. isoladas em Fortaleza/CE. Foram utilizadas 40 C. albicans, 50 C. tropicalis e 47 C. parapsilosis, isoladas de amostras de sangue e urina de pacientes atendidos no Hospital Geral de Fortaleza. Os testes foram realizados pelos métodos MDC e DD, de acordo com os protocolos M27-A3 e M44-A2 do CLSI. As metodologias foram comparadas e calculadas os percentuais de concordância. Para a anfotericina B e fluconazol, ocorreu um predomínio de cepas com susceptibilidade. O percentual de concordância para as metodologias foi acima de 97% e não foram detectados erros graves. A utilização de DD para realização de testes de susceptibilidade antifúngica pode ser aplicada na rotina laboratorial, pois é uma técnica fácil, barata, e de confiança quando comparada ao teste de MDC, sem comprometer os resultados para as cepas de C. albicans, C. tropicalis e C. parapsilosis.
The evolution of fungal resistance can be evaluated by testing susceptibility to antifungal agents. The protocols for susceptibility testing most common are Broth Microdilution (BMD), Disk Diffusion (DD) and E-test. The objective of this study was to compare the susceptibility tests conducted by the BMD and DD methods for amphotericin B and fluconazole against Candida spp. isolated in Fortaleza/CE. Were used 40 C. albicans, 50 C. tropicalis and 47 C. parapsilosis isolated from blood and urine samples of patients treated at Fortaleza General Hospital. The tests were conducted by the BMD and DD methods according to protocols M27-A3 and M44-A2 of the CLSI. These methods were compared and the percentages of agreement were calculated. For amphotericin B and fluconazole was a predominance of strains with reduced susceptibility. The percentage of agreement for the methods tested was above 97%. No serious errors were detected. The use of DD for performing antifungal susceptibility testing can be applied in routine laboratory tests, since one technique is easy, inexpensive, and reliable when compared to the BMD without compromising the results for the strains of C. albicans, C. tropicalis and C. parapsilosis.
Subject(s)
Antifungal Agents/pharmacology , Candida albicans , Candida tropicalis , Candidiasis , Microbial Sensitivity TestsABSTRACT
Trichosporon spp. are yeasts capable of causing invasive disease, which mainly affect immunocompromised patients. A clinical strain of T. asahii was isolated from the blood cultures of patients admitted to the General Hospital of Fortaleza. Susceptibility tests were conducted by disk diffusion and broth microdilution. The isolated strain of T. asahii was resistant to fluconazole. The patient used amphotericin B and caspofungin in order to facilitate the microbiological cure. It was the first isolation and identification of T. asahii in blood culture in Ceará, Brazil.
Trichosporon spp. são leveduras capazes de causar doença invasiva, que afetam principalmente pacientes imunocomprometidos. Uma cepa clínica de T. asahii foi isolada em hemocultura de paciente internado no Hospital Geral de Fortaleza. Os testes de suscetibilidade foram realizados por difusão em disco e microdiluição em caldo. A cepa isolada do T. asahii foi resistente ao fluconazol, o paciente fez uso de anfotericina B e caspofungina então a cura microbiológica ocorreu. Foi o primeiro isolamento e identificação de T. asahii em hemocultura no Ceará, Brasil.