Virulence factors associated with Candida albicans infection in patients with recurrent vulvovaginal candidiasis.

ANGIOLINI SC, RODRIGUEZ E, CASTILLO GDV, MIRÓ MS, ICELY PA, CAEIRO JP AND CE SOTOMAYOR

Córdoba

Congreso; XIX Forum on Fungal Infection in the Clinical Practice, INFOCUS 2021; 2021

INFOCUS

Recurrent mucosal fungal infections in humans emerge associated with host predisposing factors, intrinsic characteristics of the pathogen, and ineffective antifungal therapies. Vulvovaginal Candidiasis (VVC), is an acute inflammatory disease, and a frequent reason for gynecological consultation that affects up to 75% of women of childbearing age once in their life, but 9% of women undergo a recurrent form of mycosis with at least four episodes per year, defined as RVVC. C. albicans is the most prevalent agent, as part of the vaginal microbiome can begin the yeast-hyphae transition to establish the infection. This morphotype change is regulated by a complex network of sensor elements of the microenvironment and is coupled to regulatory transcription factors that code for the formation of the hypha, the production of adhesins, the generation of hydrolytic enzymes, and factors associated with the biofilm formation. These attributes of virulence are relevant for the outcome of infection. Objective: Our aim was to characterize the virulence pattern of different C. albicans clinical isolates from RVVC patients. Methods: We work with 12 isolates of C. albicans recovered from symptomatic patients with RVVC. The fungus was identified by MALDITOF. Two strains collection C. albicans-SC5314 (virulent strain) and C. albicans ATCC-36801 (attenuated strain) were included with comparative purpose. We evaluated: morphogenesis (elongation tests); adhesion to epithelial cells from the female genital tract (FGT), biofilm formation capacity (BFC) (XTT assay), and the activity of hydrolytic enzymes such as lipases (LIP) (Rhodamine-B plate assay) and Aspartyl proteinases (SAP) (agar method supplemented with Bovine Serum Albumin) Results: All strains developed hyphal morphotype after 2h and 70% of isolates exhibited strong hyphal growth compared to C. albicans-SC5314 (p<0.0001). 82% of the evaluated strains showed more than 3 C. albicans adhered per HeLa cells after 1h of incubation. Regarding the BFC, 77% of the isolates have poor BFC (like the attenuated strain), 15% moderate BFC, and 8% high BFC, comparable to the virulent model strain. The analysis of the correlation between the adherence cell capacity and biofilm formation has an R2=0.48 with a statistical significance (p<0.01). About hydrolytic enzymes, 78% of the isolates exhibited SAP activity, with high production levels compared to control attenuated strain (p<0.01), and similar values to the enzymatic activity of C.albicans-SC5314. LIP activity was detected in all RVVC clinical isolates (100%), with comparable levels observed in C. albicans-ATCC36801 attenuated strain (p=NS) and significantly different when compared with C. albicans-SC5314 (p<0,0001). Conclusion: High morphogenic capacity, increased adherence to the epithelium and enhanced SAP activity was the dominant profile of RVVC isolates. Identification and knowledge of C.albicans virulence attributes exhibited during the recurrence of mycosis are relevant for a better understanding of the pathogenesis of this infection.