RESUMO
Candidemia is the most frequent invasive mycosis in hospitalized patients worldwide. Fungal infection in central nervous system is a life-threatening complication which aggravates patients' prognosis. This article summarizes relevant aspects on the clinical characteristics of this pathology, mechanisms of fungus invasion, local immune response to Candida albicans and the impact of genetic defects on innate immune receptors that increase susceptibility to the acquisition of this form of mycosis.
Assuntos
Candidíase Invasiva , Infecções do Sistema Nervoso Central , Candida albicans , Candidíase Invasiva/diagnóstico , HumanosRESUMO
Vulvovaginal candidiasis (VVC) is the most common infection caused by Candida albicans and greatly reduces the quality of life of women affected by it. Due to the ineffectiveness of conventional treatments, there is growing interest in research involving compounds of natural origin. One such compound is curcumin (CUR), which has been proven to be effective against this microorganism. However, some of CUR's physicochemical properties, especially its low aqueous solubility, make the therapeutic application of this compound difficult. Thus, the incorporation of CUR in mucoadhesive liquid crystalline systems (MLCSs) for vaginal administration may be an efficient strategy for the treatment of VVC. MLCSs are capable of potentiating the compound's action, releasing it in a controlled manner, and can enable longer exposure at the site of infection. In this study, MLCSs consisting of oleic acid and ergosterol 5:1 (w/w) as the oily phase, PPG-5-CETETH-20 as the surfactant, and a polymer dispersion of 1% chitosan as the aqueous phase, were developed for the application of CUR (MLCS-CUR) in VVC treatment. The formulations were characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), oscillatory rheometry, continuous shear rheometry, texture profile analysis, and in vitro mucoadhesion. In addition, the antimicrobial activity was evaluated in vitro, and the effects on local fungal burden and cytokine profiles were investigated in a murine model of VVC. PLM and SAXS showed that the developed formulations presented a characteristic of a microemulsion. However, after the addition of artificial vaginal mucus (AVM), PLM showed that the formulations had structures similar to the "Maltese cross" characteristic of lamellar MLCS. Mucoadhesive test results showed an increase in the mucoadhesive strength of these formulations. Rheology analyses suggested long-lasting action of the formulation at the infected site. The in vitro antimicrobial activity assays suggested that CUR possesses antifungal activity against Candida albicans, determined after its incorporation into the MLCS. Further, MLCS-CUR was also more effective in vivo in the control of vaginal infection than treatment with fluconazole. Immunological assays showed that the ratio of pro-inflammatory (IL-1ß) to anti-inflammatory (TGF-ß) cytokines has decreased and that there is a reduction in the number of polymorphonuclear neutrophils recruited to the vaginal lumen, showing that treatment with MLCS-CUR was effective in modulating the inflammatory reaction associated with the infection. The results suggest that MLCSs could potentially be used in the treatment of VVC with CUR.
Assuntos
Candidíase Vulvovaginal/tratamento farmacológico , Curcumina/farmacologia , Curcumina/uso terapêutico , Cristais Líquidos/química , Antifúngicos/química , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Linhagem Celular , Curcumina/química , Liberação Controlada de Fármacos , Feminino , Humanos , Vagina/microbiologiaRESUMO
Invasive candidiasis encompassing Candida bloodstream infections and deep-seated candidiasis can become a persistent health problem. These infections are caused by Candida species and have high morbidity and mortality rates. Species distribution, access to diagnosis, treatment and mortality are different around the world. The mortality rate is high in South America (30-70%), and Candida albicans is the most prevalent species in this region. However, a global epidemiological shift to non-albicans species has been observed. In this group, C. parapsilosis is the species most frequently detected, followed by C. tropicalis, and at a slower rate, C. glabrata, which has also increased, in addition to the emerging C. auris, resistance to several drugs. This article summarizes relevant aspects of candidemia pathogenesis, such as the mechanisms of fungal invasion, immune response, and the impact of genetic defects that increase host susceptibility to developing the infection. We also discuss relevant aspects of treatment and future challenges in South America.
RESUMO
Vulvovaginal candidiasis (VVC) and recurrent vulvovaginal candidiasis (RVVC) are two forms of a disease caused by Candida spp. ß-defensin (BD) is one of the most important families of antimicrobial peptides in the female genital tract and includes molecules that exert essential local functions as antimicrobial and PMN chemoattractant peptides. However, the information on their role during murine and human VVC and RVVC is limited. Thus, we analyzed the behavior and contribution of BD1 to the local response in a VVC mice model and the local cytokine profile and human BD1 and BD3 expression in cervicovaginal lavage from patients with VVC and RVVC. We demonstrated that, in patients with RVVC BD1, mRNA and protein expression were severely diminished and that the aspartate proteinase and lipase secreted by C. albicans are involved in that decrease. This study provides novel information about the pathogenesis of VVC and describes a highly efficient C. albicans escape strategy for perpetuating the infection; these results may contribute to the development of new or combined treatment approaches.
RESUMO
Candida albicans is the prevalent etiological agent in acute vulvovaginal infection and the most severe chronic condition known as recurrent vulvovaginal candidiasis (VVC). A critical role of local innate immunity in defense and pathogenesis of vaginal infection by Candida is proposed. The fungal recognition by the innate immune receptor is an essential step for the induction of local responses including cytokines and antimicrobial peptides (AMPs) production for host protection. Using TLR2-deficient mice, we characterized the early innate immune response during VVC. Intravaginal challenge of TLR2-/- mice with C. albicans demonstrated that in response to the initial massive penetration, a strong local inflammatory reaction with recruitment of polymorphonuclear neutrophils was developed. Both interleukin 1ß (IL1ß)-regarded as the hallmark of VVC immunopathogenesis-and IL6 were increased in vaginal lavage. Murine beta defensin 1 (mBD1), a constitutive AMP with fungicidal and chemotactic activity, was significantly upregulated in wild type (WT) animals in response to infection. Interestingly, in the absence of TLR2 recognition, levels of mBD1 RNA more than twice higher than those in WT infected animals were observed. Interestingly, our results demonstrate that TLR2 signaling is important to control the fungal burden in the vaginal tract. These finding provide new evidence about the role of this innate receptor during VVC.
Assuntos
Candidíase Vulvovaginal/genética , Receptor 2 Toll-Like/metabolismo , Animais , Candida albicans , Candidíase Vulvovaginal/microbiologia , Citocinas/genética , Citocinas/metabolismo , Feminino , Predisposição Genética para Doença , Inflamação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 2 Toll-Like/genéticaRESUMO
Vulvovaginal candidiasis is an old disease that, even in a modern world, continues to have a high incidence. Despite the therapeutic advances, treatments are not always effective, and our understanding of the pathogenesis of this fungal infection is still incomplete. A discussion is presented in this article on the most significant developments related to the fungal virulence factors, the role of the immunological mechanisms involved in the vaginal protection, and the genetic alterations that confer susceptibility to the recurrent form of this mycosis. Current treatments, the use of new agents with antifungal activity, as well as the development of strategies, such as vaccination, are approached in the context of the complex scenario that governs the interactions between Candida and its host.
Assuntos
Candidíase Vulvovaginal , Antifúngicos/uso terapêutico , Biofilmes , Candida/imunologia , Candida/isolamento & purificação , Candida/patogenicidade , Candidíase Vulvovaginal/tratamento farmacológico , Candidíase Vulvovaginal/genética , Candidíase Vulvovaginal/imunologia , Candidíase Vulvovaginal/microbiologia , Adesão Celular , Suscetibilidade a Doenças , Drogas em Investigação/uso terapêutico , Estrogênios/fisiologia , Feminino , Vacinas Fúngicas , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Infecções Oportunistas/imunologia , Infecções Oportunistas/microbiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Especificidade da Espécie , Vagina/imunologia , Vagina/microbiologia , VirulênciaRESUMO
In recent years, the rise of human fungal infections has been associated to lack of early diagnosis, uneffective antifungal therapies and vaccines. Disturbance in immune homeostasis, which can be caused by medical interventions and immunosuppression nduced by disease, are well known as risk factors for these pathologies. Cells of the innate immune system are equipped with surface and cytoplasmic receptors for recognition of microorganisms called pattern recognition receptors (PRRs). PRRs recognize specific pathogen-associated molecular patterns (PAMPs) that are crucial for the activation and killing of pathogenic fungi by immune system. This review will outline the PRRs and cells required for effective antifungal immunity, with a special focus on the major antifungal cytokine IL-17. Finally, naturally occurring human mutations involved in the increased susceptibility to fungal infections are also discussed.