RESUMEN
The increasing incidence of vulvovaginal candidiasis (VVC) and the emergence of fluconazole resistance are an indisputable fact. However, little information is available regarding the correlation between fluconazole resistance in vaginal Candida albicans and the expression of drug efflux pump genes. In this study, we investigated the species distribution, fluconazole susceptibility profiles and the mechanisms of fluconazole resistance in Candida strains. In total, 785 clinical Candida isolates were collected from patients with VVC. C. albicans was the most frequently isolated species(n = 529) followed by C. glabrata (n = 164) and C. krusei (n = 57). Of all Candida isolates, 4.7% were resistant to fluconazole. We randomly selected 18 fluconazole resistant isolates of C. albicans to evaluate the expression of CDR1, CDR2, MDR1 and FLU1 genes. Compared with fluconazole-susceptible C. albicans isolates, CDR1 gene expression displayed 3.16-fold relative increase, which was statistically significant. CDR2, MDR1 and FLU1 overexpression was observed in several fluconazole-resistant C. albicans isolates, but statistical significance was not achieved. These results demonstrate a high frequency of non-albicans species (32.6%); however, C. albicans is the most common Candida species implicated in vaginitis, and this strain displays considerable fluconazole resistance. Meanwhile, our study further indicates that fluconazole resistance in C. albicans may correlate with CDR1 gene overexpression.
Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Antifúngicos/farmacología , Candida/aislamiento & purificación , Candidiasis Vulvovaginal/microbiología , Farmacorresistencia Fúngica , Fluconazol/farmacología , Proteínas Fúngicas/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Candida/clasificación , Candida/efectos de los fármacos , Candida/genética , Candidiasis Vulvovaginal/tratamiento farmacológico , Femenino , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica , HumanosRESUMEN
E(rns) is an envelope glycoprotein of classical swine fever virus (CSFV) and has an unusual feature of RNase activity. In the present study, we demonstrate that E(rns) counteracts Newcastle disease virus (NDV)-mediated induction of IFN-beta. For this purpose, E(rns) fused to the enhanced green fluorescent protein (EGFP) was transiently expressed in porcine kidney 15 (PK15) cells. In luciferase activity assay, E(rns)-EGFP was found to prevent IFN-beta promoter-driven luciferase expression and block the induction of IFN-beta promoter mediated by NDV in a dosedependent manner. Through IFN-specific semi-quantitative RT-PCR detection, obvious decrease of IFN-beta mRNA in NDV-infected PK15 cells was observed in the presence of E(rns)-EGFP. In contrast, EGFP alone showed none of this block capacity. In addition, E(rns)-EGFP mutations with RNase inactivation were also found to block NDV-mediated induction of IFN-beta. These evidences establish a novel function for CSFV E(rns) glycoprotein in counteraction of the IFN-beta induction pathway.
Asunto(s)
Virus de la Fiebre Porcina Clásica/metabolismo , Interferón beta/genética , Virus de la Enfermedad de Newcastle/fisiología , Proteínas del Envoltorio Viral/metabolismo , Animales , Línea Celular , Virus de la Fiebre Porcina Clásica/genética , Regulación de la Expresión Génica , Glicoproteínas/genética , Glicoproteínas/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Cinética , Luciferasas/genética , Luciferasas/metabolismo , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribonucleasas/metabolismo , Transducción de Señal/genética , Transducción de Señal/fisiología , Porcinos , Transfección , Proteínas del Envoltorio Viral/genéticaRESUMEN
E(rns) is an envelope glycoprotein of classical swine fever virus (CSFV) with unusual RNase activity. Recently, E(rns) was found to have a new function of counteracting the beta-interferon (IFN-beta) induction pathway. In this study, wildtype ErnsSM and two mutated E(rns) proteins ErnsH297k and ErnsH346k were expressed in insect cells and purified for RNase activity and function analysis. RNase activity assay in vitro demonstrated that only wildtype E(rns) protein had RNase activity. However, both wildtype ErnsSM and the two mutated E(rns)ErnsH297k and ErnsH346k as exogenous proteins had a block effect on Newcastle disease virus (NDV)-mediated IFN-beta promoter induction.