Chromogenic Medium for Direct Susceptibility Testing of Candida spp. Isolated from Urine

Abstract

Currently, there has been an increased frequency of fungal infections. Candida albicans and other Candida spp. have been proven to be major causes for urinary tract infection. Increased resistance to antifungals indicates the need to develop strategies in order to prevent the spread of resistance. Chromogenic medium have been proven to be useful in the detection of yeasts in clinical specimens containing mixed cultures of Candida. The aim of this study was to compare the results of antifungal susceptibility testing with fluconazole and amphotericin B on strains of Candida spp. isolated from urine, conducted on a Mueller-Hinton Agar with Glucose and Methylene Blue (MHAGMB) medium and on a Hicrome Candida® Agar with 2% Glucose (HCAG) medium. We used 40 samples of Candida spp. isolated from urine samples from inpatients and outpatients. The results showed that both media presented high rates of agreement, above 94%. The use of the HCAG medium decreases the release time of the results by 24-48 h, which may be decisive for initiating the correct drug treatment.

CHROMagar Orientation Medium Reduces Urine Culture Workload

“…To do this for all urine specimens was beyond the capabilities of the LIS. A reduction in TAT was expected, as it has been reported by de Vasconcelos et al that using chromogenic media for rapid identification of Candida species in urine reduced TAT by between 24 and 48 h (17).…”

“…Chromogenic media may also promote more rapid identification of the etiological agent(s) of infection and may provide clinicians with relevant information regarding their choice of empirical antimicrobial therapy for their patients. Consequently, this may decrease inappropriate use of antibacterial and antifungal agents (1,4,16,17). Published data support performing antimicrobial susceptibility testing on colonies taken directly from CHROMagar Orientation (CO) medium (Becton, Dickinson, Cockeysville, MD) (1,14).…”

Susceptibility testing of Candida albicans by disk diffusion method: A comparison of the culture media used

“…(10,22) A alternativa é a técnica de DD, pois é simples, barata e reprodutível, portanto pode ser utilizada em laboratórios clínicos. (5,11) O protocolo M44-A para teste de susceptibilidade define que deverá ser utilizado o meio Mueller-Hinton suplementado com glicose 2% e 0,5 μg/mL de azul de metileno. (6) Este método de difusão em disco é semelhante ao méto-do de Kirby-Bauer, utilizado globalmente na rotina para os testes de susceptibilidade bacteriana.…”

“…As placas foram lidas visualmente após um período de incubação de 24 horas a 35ºC e foram medi-dos os halos formados em torno dos discos de antifúngicos e expressos em milímetros. (11,12) Após a leitura e mensuração dos halos, em milíme-tros, os resultados foram comparados com a tabela fornecida pelo fabricante (Cecon). Para anfotericina B, halo > 10 mm (Sensível) e <10 mm (Resistente); nistatina, halo >10 mm (Sensível) e ≤10 mm (Resistente); cetoconazol, halo > 20 mm (Sensível), halo [10][11][12][13][14][15][16][17][18][19][20] Valor dos halos medidos em milímetro (mm).…”

“…(9,10) A alternativa é o DD, pois é uma técnica simples, barata e reprodutível, que pode ser utilizada em laboratórios clínicos. (5,11) A metodologia de disco-difusão em agar para a avaliação da sensibilidade de cepas de Candida spp. fornece um resultado quantitativo (halo de inibição) e um resultado qualitativo (sensível ou resistente).…”