Letter to the Editor

Questions remain regarding the presence of fungal species biofilm in women with vulvovaginal candidiasis

Recurrent vulvovaginal candidiasis (RVVC) is a recalcitrant medical condition that affects many women of reproductive age. The importance of biofilm formation by Candida in RVVC has been recently questioned. This study aimed to elucidate the fundamental growth modes of Candida in the vagina of patients with RVVC or sporadic vulvovaginal candidiasis (VVC) and to assess their roles in the persistence of RVVC.

Vaginal tissues were sampled from twelve patients clinically and microbiologically diagnosed as RVVC or VVC at a post-antifungal-treatment and asymptomatic period. High-resolution scanning electron microscopy, fluorescence in situ hybridization in combination with Candida-specific 18S rRNA probes and viable fungal burden were used to qualitatively and quantitatively evaluate Candida growth in the human vagina. The presence of Candida biofilm extracellular polymeric substances was examined using confocal laser scanning microscopy and biopsy sections pre-stained with Concanavalin A. Histopathological analysis was carried out on infected vaginal tissues stained with hematoxylin and eosin. Lastly, the susceptibility of epithelium-associated Candida biofilms to fluconazole at the peak serum concentration was evaluated.

Candida species grew on the vaginal epithelium of RVVC patients as morphologically disparate biofilms including monolayers, microcolonies, and macro-colonies, in addition to sporadic adherent cells. Candida biofilm growth on the vaginal epithelium was associated with mild lymphocytic infiltration of the vaginal mucosa. These epithelium-based Candida biofilms presented an important characteristic contributing to the persistence of RVVC that is the high tolerance to fluconazole.

In summary, our study provides direct evidence to support the presence of Candida biofilms in RVVC and an important role of biofilm formation in disease persistence.

Recurrent vulvovaginitis is a growing problem that affects millions of women worldwide. In many cases it is treated as vulvovaginal candidiasis, but there is not always microbiological confirmation.

To determine the etiology of vulvovaginitis in a group of patients.

This is a cross-sectional study in which the data from the medical records of 316 adult patients who consulted for vulvovaginitis were analyzed. Eighty nine percent of the cases had already suffered previous episodes.

The median age was 34 (265 patients were between 16 and 45 years old). Yeasts were isolated in culture from 211 (66.8%) patients, although pseudo-hyphae and yeasts were observed in only 166 samples (52.5%) in the direct microscopic examination. Multiple predisposing factors were found, among which the use of contraceptives or previous antibiotics stand out. Most of the patients (almost 90%) had been treated with antifungals, with or without microbiological confirmation. Candida albicans was isolated in 187 (88.6%) patients, followed by Candida glabrata in 6 (2.8%) patients. Association with bacterial vaginosis was found in 35.1% and with intermediate bacterial microbiota in 33.2% of the cases. A remarkably high proportion of C. albicans isolates resistant to fluconazole (80.1%) and itraconazole (58.8%) was found.

A microbiological analysis is essential to confirm the diagnosis of vulvovaginal candidiasis, whether simple, complicated, or recurrent. Identifying the isolated yeast species and determining its susceptibility to antifungal agents are particularly important.

Las vulvovaginitis recurrentes son un problema creciente que afecta a millones de mujeres en todo el mundo. En muchos casos, se tratan como candidiasis, aunque no siempre se tiene la confirmación microbiológica.

Determinar la etiología de la vulvovaginitis en una muestra de pacientes.

Este es un estudio transversal donde se analizan los datos clínicos y microbiológicos de 316 pacientes adultas que consultaron por vulvovaginitis y que en un 89% de los casos ya habían cursado episodios previos.

La mediana de edad fue de 34 años (265 pacientes tenían hasta 45 años), en los cultivos de 211 (66,8%) pacientes crecieron levaduras, aunque solamente se visualizaron en el examen microscópico directo en 166 (52,5%) de los casos. Se encontraron múltiples factores predisponentes, entre los que se destaca el uso de anticonceptivos y la toma previa de antibióticos. La gran mayoría de ellas habían sido tratadas con antifúngicos (91% de las pacientes en las que se había aislado Candida y el 83% de los casos en que no se aisló), con o sin confirmación microbiológica. Candida albicans se aisló en 187 casos (88,6%) y Candida glabrata en seis (2,8%). Se encontró asociación con vaginosis bacteriana en el 35,1% de las pacientes y con microbiota bacteriana intermedia en el 33,2% de los casos. Hubo una considerable proporción de aislamientos de C. albicans resistentes a fluconazol (80,1%) y a itraconazol (58,8%).

Es imprescindible la realización de un análisis microbiológico para confirmar el diagnóstico de la candidiasis vulvovaginal, que puede ser simple, complicada o recidivante. Es muy importante la identificación de las especies de levaduras aisladas y la determinación de la sensibilidad a los antifúngicos.