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Made available in DSpace on 2022-04-29T08:30:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Previous studies showed that the crude extract obtained from Streptococcus mutans inhibited the growth of Candida albicans reference strains. In this study, we evaluated whether the antifungal effects of S. mutans extract can be extended to clinical Candida isolates, including C. albicans and non-abicans strains with different susceptibilities to fluconazole. We verified that S. mutans extract increased the survival of Galleria mellonella larvae infected with C. albicans and C. glabrata and inhibited the fungal cells in hemolymph. These antifungal effects occurred for both fluconazole-susceptible and fluconazole-resistant strains. However, larvae infected by C. krusei were not affected by S. mutans extract. Lay Summary: Streptococcus mutans crude extract shows antifungal effects on clinical Candida strains susceptible and resistant to fluconazole in Galleria mellonella model. Department of Biosciences and Oral Diagnosis Institute of Science and Technology Sao Paulo State University (UNESP) Sao Jose Dos Campos Department of Organic Chemistry Institute of Chemistry Sao Paulo State University (UNESP) Department of Biosciences and Oral Diagnosis Institute of Science and Technology Sao Paulo State University (UNESP) Sao Jose Dos Campos Department of Organic Chemistry Institute of Chemistry Sao Paulo State University (UNESP)

Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.

Made available in DSpace on 2021-06-25T10:19:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01. Added 1 bitstream(s) on 2021-07-15T14:34:31Z : No. of bitstreams: 1 S0001-37652020000700935.pdf: 1312301 bytes, checksum: 34676b8593495a4ad85a05f1288ce6ff (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Candida is a human fungal pathogen that causes a wide range of diseases. Candida albicans is the main etiologic agent in these diseases; however, infections can be caused by non-albicans Candida species. Virulence factors such as biofilm production, which protect the fungus from host immunity and anti-fungal drugs, are important for the infection. Therefore, available antifungal drugs for candidiasis treatment are limited and the investigation of new and effective drugs is needed. Verapamil is a calcium channel blocker with an inhibitory effect on hyphae development, adhesion, and colonization of C. albicans. In this study, we investigated the effect of verapamil on cell viability and its antifungal and anti-biofilm activity in non-albicans Candida species. Verapamil was not toxic to keratinocyte cells; moreover, C. krusei, C. parapsilosis, and C. glabrata were susceptible to verapamil with a minimal inhibitory concentration (MIC) of 1250 μM; in addition, this drug displayed fungistatic effect at the evaluated concentrations. After treatment with verapamil, reduced viability, biomass, and mitochondrial activity were observed in biofilms of the non-albicans Candida species C. krusei, C. glabrata, and C. parapsilosis. These findings highlight the importance of the study of verapamil as an alternative treatment for infections caused by non-albicans Candida species. São Paulo State University (UNESP) Department of Biosciences and Oral Diagnosis Institute of Science and Technology, Avenida Engenheiro Francisco José Longo 777 São Paulo State University (UNESP) Department of Biosciences and Oral Diagnosis Institute of Science and Technology, Avenida Engenheiro Francisco José Longo 777

Made available in DSpace on 2018-12-11T17:35:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The objective of this study was to evaluate the influence of microbe-microbe interactions to identify a strain of Lactobacillus that could reduce the filamentation of Candida albicans ATCC 18804 using in vitro and in vivo models. Thus presenting a probiotic effect against the fungal pathogen. First, we analyzed the ability of 25 clinical isolates of Lactobacillus to reduce filamentation in C. albicans in vitro. We found that L. paracasei isolate 28.4 exhibited the greatest reduction of C. albicans hyphae (p = 0.0109). This reduction was confirmed by scanning electron microscopy analysis. The influence of C. albicans filamentation was found to be contributed through reduced gene expression of filament associated genes (TEC1 and UME6). In an in vivo study, prophylactic provisions with L. paracasei increased the survival of Caenorhabditis elegans worms infected with C. albicans (p = 0.0001) by 29%. Prolonged survival was accompanied by the prevention of cuticle rupture of 27% of the worms by filamentation of C. albicans, a phenotype that is characteristic of C. albicans killing of nematodes, compared to the control group. Lactobacillus paracasei isolate 28.4 reduced the filamentation of C. albicans in vitro by negatively regulating the TEC1 and UME6 genes that are essential for the production of hyphae. Prophylactic provision of Lactobacillus paracasei 28.4 protected C. elegans against candidiasis in vivo. L. paracasei 28.4 has the potential to be employed as an alternative method to control candidiasis. Department of Biosciences and Oral Diagnosis Institute of Science and Technology UNESP – Univ Estadual Paulista, Francisco Jose Longo 777, Sao Dimas Division of Infectious Diseases Rhode Island Hospital Alpert Medical School of Brown University Department of Biosciences and Oral Diagnosis Institute of Science and Technology UNESP – Univ Estadual Paulista, Francisco Jose Longo 777, Sao Dimas FAPESP: 2013/25181-8 FAPESP: 2014/12458-4 FAPESP: 2015/09770-9

The use of invertebrates for in vivo studies in microbiology is well established in the scientific community. Larvae of Galleria mellonella are a widely used model for studying pathogenesis, the efficacy of new antimicrobial compounds, and immune responses. The immune system of G. mellonella larvae is structurally and functionally similar to the innate immune response of mammals, which makes this model suitable for such studies. In this review, cellular responses (hemocytes activity: phagocytosis, nodulation, and encapsulation) and humoral responses (reactions or soluble molecules released in the hemolymph as antimicrobial peptides, melanization, clotting, free radical production, and primary immunization) are discussed, highlighting the use of G. mellonella as a model of immune response to different human pathogenic microorganisms.

Made available in DSpace on 2018-12-11T17:06:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-01-01 Due to the increase of bacterial resistance, medicinal alternatives are being explored. Punica granatum L. is an effective herbal extract with broad spectrum of action and bactericidal, antifungal, anthelmintic potential and being able to modulate the immune response. The aim was to evaluate the antimicrobial activity of pomegranate glycolic extract (PGE) against the periodontal pathogen Porphyromonas gingivalis by using Galleria mellonella as in vivo model. Fifteen larvae were used per group. Injection of high concentration (200, 100, and 25 mg/mL) of PGE showed a toxic effect, leading them to death. A suspension of P. gingivalis (106 cells/mL) was inoculated in the left last proleg and PGE (12.5, 6.25, 3.1, and 2.5 mg/mL) were injected into the right proleg. The larvae were then kept at 37°C under the dark. Injection of PGE at any dose statistically improved larvae survival rates. The data were analysed (log-rank test, Mantel-Cox, P < 0.05) and showed that all concentrations of PGE (12.5, 6.25, 3.1, and 2.5 mg/mL) presented higher larval survival rates, with significant statistical difference in relation to control group (P. gingivalis). In conclusion, the PGE had antimicrobial action against P. gingivalis in vivo model using G. mellonella. Department of Biosciences and Oral Diagnosis Laboratory of Microbiology and Immunology Institute of Science and Technology Universidade Estadual Paulista (UNESP), Av. Engenheiro Francisco José Longo 777 Department of Biosciences and Oral Diagnosis Laboratory of Microbiology and Immunology Institute of Science and Technology Universidade Estadual Paulista (UNESP), Av. Engenheiro Francisco José Longo 777