Antifungal activity of sustainable histone deacetylase inhibitors against planktonic cells and biofilms of Candida spp. and Cryptococcusneoformans.

The limited therapeutic options for fungal infections and the increased incidence of fungal strains resistant to antifungal drugs, especially Candida spp., require the development of new antifungal drugs and strategies. Histone deacetylase inhibitors (HDACi), like vorinostat, have been studied in cancer treatment and have antifungal effects, acting alone or synergistically with classical antifungals. Here we investigated the antifungal activity of two novel sustainable HDACi (LDT compounds) based on vorinostat structure. Molecular docking simulation studies reveal that LDT compounds can bind to Class-I HDACs of Candida albicans, C. tropicalis, and Cryptococcus neoformans, which showed similar binding mode to vorinostat. LDT compounds showed moderate activity when tested alone against fungi but act synergistically with antifungal azoles against Candida spp. They reduced biofilm formation by more than 50% in C. albicans (4 µg/mL), with the main action in fungal filamentation. Cytotoxicity of the LDT compounds against RAW264.7 cells was evaluated and LDT536 demonstrated cytotoxicity only at the concentration of 200 µmol/L, while LDT537 showed IC50 values of 29.12 µmol/L. Our data indicated that these sustainable and inexpensive HDACi have potential antifungal and antibiofilm activities, with better results than vorinostat, although further studies are necessary to better understand the mechanism against fungal cells.

Fungal infections are neglected diseases that affect more than a billion people worldwide. Some histone deacetylase inhibitors can act against fungal cells. Our data reveal that HDACi LDT536 and LDT537 have potential antibiofilm and antifungal activities.

Inhibitory effects of Lactobacillus casei Shirota against both Candida auris and Candida spp. isolates that cause vulvovaginal candidiasis and are resistant to antifungals.

BACKGROUND: Vulvovaginal candidiasis (VVC), the second leading cause of genital infection in women of reproductive age, is caused by yeasts of the genus Candida. Treatment is usually empirical and performed with azoles, which have shown increasing ineffectiveness due to resistance from these species. This therapeutic challenge has led to the search for new treatment strategies. Lactobacillus spp. produce several components with microbicidal effects, such as lactic acid. These species are the main components of a healthy vaginal microbiota and have been used as probiotics. The aim of this work was to investigate the in vitro inhibitory effects of Lactobacillus casei Shirota on both the Candida spp. that cause VVC and on C. auris. METHODS: The microbicidal effects of L. casei Shirota on the main VVC-causing species, C. albicans, C. tropicalis, C. norvegensis and C. parapsilosis, in addition to C. auris were investigated by counting the Colony-forming Units (CFUs) after cocultivation. The antifungal activity of lactic acid against these Candida strains was assessed using the microtiter broth dilution method to determine the minimum inhibitory concentrations (MICs). The effects of L. casei Shirota on hyphal and early biofilm formation was measured by optical microscopy. RESULTS: L. casei Shirota showed inhibitory action against all tested Candida spp., ranging from 66.9 to 95.6% inhibition depending on the species. This inhibition is possibly related to the production of lactic acid, since lactic acid has shown microbicidal action against these same Candida spp. at a concentration of 5 mg/mL, which corresponds to half of the normal physiological concentration. In addition, L. casei Shirota was able to reduce the formation of C. albicans hyphae and early biofilms, showing strong anti-Candida effects. CONCLUSIONS: These results suggest that L. casei Shirota has antifungal activity against the Candida species that cause VVC. L. casei also has microbicidal action against C. auris.

Estudo comparativo da ação sanitizantes de uso caseiros em hortaliças contaminadas com Ancilostomídeos / Comparative sanitizers study of domestic aplication in vegetables contaminated with hookworms / Estudio comparativo de la acción higiénica de los cuidadores en vegetales contaminados con anquilostomas

Objetivo: O presente trabalho tem como objetivo verificar a efetividade de sanitizantes de uso caseiros quanto a capacidade de paralisar e desinfetar larvas de Ancilostomídeos. Método Para obtenção das larvas de Ancilostomídeos foi utilizado o método de Hoffman, Pons e Janer (HPJ). Em seguida, foram preparadas lâminas com o sedimento e adicionou-se concentrações diferentes de saneantes empregados na rotina doméstica. Simultaneamente, foi avaliado, através de microscopia óptica, o tempo cronometrado que cada saneante em diferentes concentrações, necessitaria para paralisação completa do helminto. Resultados: O ácido acético e o hipoclorito não apresentaram efetividade em nenhuma das concentrações testadas. Já o vinagre de álcool puro na diluição de 40% paralisou 90% das larvas em um período de 14 minutos e 31 segundos. O vinagre composto de álcool, na concentração de 40% foi capaz de paralisar mais de 90% das larvas em um tempo médio de 9 minutos e 50 segundos. Conclusão: A utilização de 40% de sanitizantes de vinagre se mostraram eficazes na desinfecção de larvas de Ancilostomídeos. No entanto, este estudo alerta que a eliminação de larvas não é segura quando se leva em conta a concentração usada na rotina doméstica atual.

Objective: The present work aims to verify the effectiveness of homemade sanitizers for the ability to paralyze and disinfect hookworm larvae. Method: To obtain hookworm larvae, the method of Hoffman, Pons, and Janer (HPJ) was applied. The next slides were prepared with the sediment, and different sanitizing concentrations, routinely used in the domestic, were added. Simultaneously, we evaluated, by optical microscopy, the chronometer time that each sanitizer in different concentrations, would require for complete helminth paralysis. Results: Acetic acid and hypochlorite were not effective in any of the tested concentrations. Pure alcohol vinegar in the 40% dilution paralyzed 90% of the larvae in 14 minutes and 31 seconds. The vinegar composed of alcohol, in the 40% concentration, was able to paralyze more than 90% of the larvae in an 9,50 minutes average. Conclusion: The use of 40% of vinegar sanitizers proved to be useful in disinfecting hookworms larvae. However, this study cautions that larvae elimination is not safe when taking into account the concentration handled in the current domestic routine.

Objetivo: el presente trabajo tiene como objetivo verificar la efectividad de los desinfectantes caseros para la capacidad de paralizar y desinfectar larvas de anquilostomas. Método: para obtener larvas de anquilostomas, se utilizó el método de Hoffman, Pons y Janer (HPJ). Luego se prepararon los portaobjetos con el sedimento y se agregaron diferentes concentraciones de agentes desinfectantes utilizados en la rutina doméstica. Simultáneamente, se evaluó, usando microscopía óptica, el tiempo cronometrado que cada desinfectante en diferentes concentraciones necesitaría para completar la parálisis del helminto. Resultados: el ácido acético y el hipoclorito no fueron efectivos en ninguna de las concentraciones probadas. El vinagre puro de alcohol en la dilución al 40% paralizó el 90% de las larvas en un período de 14 minutos y 31 segundos. El vinagre compuesto de alcohol, en la concentración del 40%, fue capaz de paralizar más del 90% de las larvas en un tiempo promedio de 9 minutos y 50 segundos. Conclusión: el uso del 40% de desinfectantes de vinagre demostró ser eficaz para desinfectar larvas de anquilostomas. Sin embargo, este estudio advierte que la eliminación de las larvas no es segura cuando se tiene en cuenta la concentración utilizada en la rutina doméstica actual.

A Wor1-Like Transcription Factor Is Essential for Virulence of Cryptococcus neoformans.

Gti1/Pac2 transcription factors occur exclusively in fungi and their roles vary according to species, including regulating morphological transition and virulence, mating and secondary metabolism. Many of these functions are important for fungal pathogenesis. We therefore hypothesized that one of the two proteins of this family in Cryptococcus neoformans, a major pathogen of humans, would also control virulence-associated cellular processes. Elimination of this protein in C. neoformans results in reduced polysaccharide capsule expression and defective cytokinesis and growth at 37°C. The mutant loses virulence in a mouse model of cryptococcal infection and retains only partial virulence in the Galleria mellonella alternative model at 30°C. We performed RNA-Seq experiments on the mutant and found abolished transcription of genes that, in combination, are known to account for all the observed phenotypes. The protein has been named Required for cytokinesis and virulence 1 (Rcv1).