Geovani Moreira da Cruz

Samples of stingless honey from six species of stingless bees collected at nine stations in different Brazilian states were analyzed by chemometric methods for moisture, impurities and solid residues, ash, pH, electrical conductivity, proteins, proline, identification of adulteration, presence of substances such as phytochemical analysis, color and levels of HMF. The color (C) varied between water white and dark amber. Proteins (mL) varied from 0.00 (S5) to 2.00 (S4). Lund test from 0.00% (S5) to 3.10% (S6), total phenols (TP%) from 0.04 to 13.45 mg/100 g GAE, total flavonoids from (TF%) 0.03 to 0.11 mg/100 g QE, and HMF from 0.00 to 14.28 mg/kg. There was an increased amount of PRO in S7 and S8. S1, S4, S7 and S8 had the best antioxidant activity (EC₅₀). A heat map showed that S2 was the sample with the highest %Brix, %insoluble solids, %humidity and pH, but the lowest TP%. S7 had the highest C, proline (PRO), TF%, EC₅₀ and EC. S4 had high %A and intermediate results between groups 9, 5, 6 and groups 1, 3, 8. The sample honey S6 showed a high content of TP (13.45 ± 0.98 mg/100 g of GAE). In contrast, stingless honey samples exhibited better DPPH scavenging activity (EC₅₀: 21.45 ± 0.54 to 53.71 ± 0.24 mg/mL). The chemometric classification of stingless bee honey revealed that the physicochemical properties contributed significantly to the classification of stingless bee honey from different bee species. With all the information presented here, the results obtained and correlations from multivariate statistical analysis, we propose the creation of a standard for the technical regulation of Brazilian native bee honey, based on the literature and quality parameters described here.

Historically, the study of oral fungal species was limited by the inability to cultivate most of them. However, advances in metagenomic techniques have enabled the direct identification of microbial genomes from human samples, markedly broadening our understanding of the oral mycobiome. This narrative review aims to analyze the available scientific evidence on the composition and dynamics of the oral mycobiome, as well as its influence on the development of local pathological conditions. The oral mycobiome is highly diverse, with emphasis on genus Candida, followed by Cladosporium, Aureobasidium and Saccharomyces. Candida albicans remains the most frequently identified species in both health and diseases state. However, individuals with oral candidiasis present a higher detection of Candida dubliniensis, Candida parapsilosis, Pichia kudriavzevii, Antrodiella micra and Cladosporium sphaerospermum. In dental caries, C. albicans and C. dubliniensis are associated with advanced lesions, whereas Debaryomyces and Rhodotorula may exert protective effects against Streptococcus mutans, a cariogenic bacterium. In periodontitis, an increase in yeast-bacteria interactions is observed. Additionally, C. albicans has been implicated in oral carcinogenesis through multiple mechanisms. These findings highlight the need for a deeper understanding of the oral mycobiome to enable early detection of oral diseases and the development of therapeutic approaches.

Candida spp. can cause systemic infections with high mortality in immunocompromised patients. Phytotherapy may be an alternative for adjunctive treatment of fungal infections. This study evaluated the phytochemical profile, cytotoxicity, genotoxicity, and antibiofilm activity of the hydroalcoholic extract of Origanum vulgare L. against Candida albicans, Candida tropicalis, and Candida dubliniensis. The extraction and quantification (flavonoids and phenols) were performed, and its antioxidant activity (DPPH) and the presence of bio-active compounds were investigated using high-performance liquid chromatography with Diode Array Detection (HPLC-DAD). Cytotoxicity and genotoxicity tests were conducted using HaCat cell lines. Antifungal activity on planktonic cultures was evaluated using the standard (CLSI M27-S4). The analysis of the extract on biofilms was verified with different exposure times. The extract demonstrated the presence of bioactive molecules, and antioxidant activity. The cytotoxicity test showed viability >70%. Genotoxicity revealed the presence of a few micronuclei in some dilutions. The Minimum Fungicidal Concentration was obtained for C. albicans and C. tropicalis. In the biofilm analysis, there was a reduction of more than 60% in all Candida spp. species at the 24 h exposure time. The findings suggest that the O. vulgare extract exhibits activity against Candida spp. and shows biocompatibility in human keratinocytes.

Historically, the study of oral fungal species was limited by the inability to cultivate most of them. However, advances in metagenomic techniques have enabled the direct identification of microbial genomes from human samples, markedly broadening our understanding of the oral mycobiome. This literature review aims to analyze the available scientific evidence on the composition and dynamics of the oral mycobiome, as well as its influence on the development of local pathological conditions. The oral mycobiome is highly diverse, with emphasis on genus Candida, followed by Malassezia, Aspergillus, Saccharomyces, Cladosporium, Trichosporon and Geotrichum. Candida albicans remains the most frequently identified species in both health and diseases state. However, individuals with oral candidiasis present a higher detection of Candida dubliniensis, Candida parapsilosis, Pichia kudriavzevii, Antrodiella micra and Cladosporium sphaerospermum. In dental caries, C. albicans and C. dubliniensis are associated with advanced lesions, whereas Malassezia and Rhodotorula may exert protective effects against cariogenic bacteria. In periodontitis, an increase in yeast-bacteria interactions is observed. Additionally, C. albicans has been implicated in oral carcinogenesis through multiple mechanisms. These findings highlight the need for a deeper understanding of the oral mycobiome to enable early detection of oral diseases and the development of therapeutic approaches.

Natural compound-based strategies have gained attention as alternatives to conventional antifungal therapies, particularly in the management of Candida infections affecting the oral cavity, such as denture stomatitis. Our aim was to investigate the antifungal activity of the polyphenol pterostilbene (PTE) on clinical Candida isolates and microcosm biofilms from denture stomatitis, as well as to evaluate its toxicity and therapeutic efficacy in Galleria mellonella. PTE exhibited fungicidal effects against Candida albicans and Candida dubliniensis at 32 µg/mL. Time-kill assays demonstrated complete inhibition of viability for both strains within 8 h of exposure. In addition, PTE exhibited broad-spectrum antimicrobial activity, significantly reducing the counts of streptococci, mutans streptococci, staphylococci, and yeasts within microcosm biofilms. In vivo, PTE showed no signs of toxicity in G. mellonella at concentrations up to 20× MIC. Prophylactic treatment with PTE enhanced larval survival in experimental candidiasis caused by both C. albicans and C. dubliniensis. Moreover, prophylactic treatment decreased the fungal burden of C. albicans in the G. mellonella hemolymph, while the recruitment of hemocytes involved in host defense mechanisms remained unaltered. In summary, PTE demonstrated antimicrobial activity against Candida planktonic cells and complex biofilms associated with denture stomatitis, exhibiting favorable biocompatibility and in vivo antifungal efficacy in G. mellonella model.

Os microrganismos podem ser utilizados como mecanismo biológico para combater neoplasias em tecidos profundos muitas das vezes inoperáveis em estado intermediário terminal. Visto isso, o objetivo do presente estudo foi demonstrar o conjunto de informações a respeito da possibilidade de uma terapia eficaz para tumores malignos e benignos, através de microrganismos geneticamente modificados que possam auxiliar no tratamento dessa patologia. A metodologia foi realizada através de uma revisão de literatura, fazendo uso de site governamentais, artigos científicos para correlacionar informações e enfatizar os benefícios da administração de microrganismos em tratamento oncológico. Logo, os resultados foram observados na revisão de literatura cientifica e que alguns gêneros específicos de bactérias geneticamente modificadas possuem o potencial para se proliferarem dentro de um tecido neoplásico, e que espécies de microrganismos possuem mais afinidades que outras em determinada região anatômica do corpo. Conclui-se que uma administração correta utilizando esporos ou enterobactérias geneticamente modificadas é relevante para lise de células neoplásicas, e que mais pesquisas a respeito do tema devem ser investigadas.

Staphylococcus aureus and Acinetobacter baumannii are opportunistic pathogens, and both are involved in different oral infections. This work aimed to analyze the phytochemical composition of Myrciaria cauliflora hydroethanolic extract and to evaluate its antimicrobial and antibiofilm action against Staphylococcus aureus (ATCC 6538) and Acinetobacter baumannii (ATCC 19606; multi-resistant clinical strains 58004, 50098, 566006, and H557). Myrciaria cauliflora hydroethanolic extract was prepared, and the content of soluble solids, flavonoids, and phenols was quantified. High-performance liquid chromatography (HPLC) was performed later. The minimum inhibitory concentration was determined using the broth microdilution method according to the Clinical and Laboratory Standards Institute, standard M7-A6, and subsequently, its minimum bactericidal concentration was determined. Then, the most effective concentrations were analyzed against biofilms. Statistical analysis was performed using the ANOVA method with Tukey’s test. The soluble solids content in the prepared hydroethanolic extract of M. cauliflora was 2.22%. Additionally, the total flavonoid content, measured using the quercetin standard curve, was 0.040 mg/mL. Furthermore, the total phenol content, determined using the gallic acid standard curve, was 0.729 mg/mL. HPLC analysis presented peaks of gallic acid (11.80 m), p-coumaric acid (12.09 m), cinnamic acid derivative (19.02 m), and ellagic acid (29.83 m). The extract demonstrated antimicrobial and antibiofilm action against all tested strains. However, the most effective antibacterial concentration against all the tested bacteria was 5.55 mg/mL. Therefore, these chemical components justify that M. cauliflora hydroethanolic extract is effective in reducing biofilm formation in S. aureus (standard strain) and A. baumannii (standard and clinical strains).

ASTRACT Stingless bees (meliponinae) play an important role in the ecosystems of the global tropics and subtropics as pollinators of an exceptionally large and diverse number of plants. They are known in Brazil as native or indigenous bees and also as stingless bees. Several species of native bees are threatened by impacts on the environment, such as habitat conversion and climate change. They are gaining more and more attention as pollinators, for their beneficial results on some crops of fruits and coffee. Honey produced by meliponinae is considered a complete and nutritious food, but there are few scientific studies about the characterization of its main chemical compounds associated with biological properties. Various substances such as sugars, amino acids, organic acids, mineral elements, vitamins and flavonoids, phenolic compounds, enzymes, aromatic substances, and pigments have been identified in native bee honey. It has properties that bring benefits to human health. Physicochemical parameters are methods that define and compare the constitution and chemical substances of honeys with the purpose of defining a standard quality for the product. There is still no quality standard for honey from native bees established by the Ministry of Agriculture, which raises doubts about the quality of honeys sold. The present work shows the occurrence of several native bees in Brazil and mentions several state laws regarding the breeding and management of native bees and the production of honey. However, there is no legislation on the quality control of such a product at a national level, only a proposal to create quality control parameters for honey from native bees, described in the literature, which is mentioned in the present work RESUMO As abelhas sem ferrão (meliponídeos) desempenham um papel importante nos ecossistemas dos trópicos e subtrópicos globais como polinizadores de um número excepcionalmente grande e diversificado de plantas. São conhecidas no Brasil como abelhas nativas ou indígenas e também como abelhas sem ferrão. Várias espécies de abelhas nativas estão ameaçadas por impactos no ambiente, como a conversão de habitats e as alterações climáticas. Estão ganhando cada vez mais atenção como polinizadores, por seus resultados benéficos em algumas culturas de frutas e café. O mel produzido por meliponíneos é considerado um alimento completo e nutritivo, mas existem escassos estudos científicos apontando para a caracterização de seus principais compostos químicos associados às propriedades biológicas. Várias substâncias tais como açúcares, aminoácidos, ácidos orgânicos, elementos minerais, vitaminas e flavonoides, compostos fenólicos, enzimas, substâncias aromáticas e pigmentos foram identificadas no mel de abelhas nativas. Possui propriedades que trazem benefícios à saúde humana. Os parâmetros físico-químicos são métodos que definem e comparam a constituição e as substâncias químicas dos méis com o propósito de definir uma qualidade padrão ao produto. Ainda não há um padrão de qualidade de méis de abelhas nativas estabelecida pelo Ministério da Agricultura, o que gera uma dúvida sobre a qualidade dos méis comercializados. O presente trabalho mostra a ocorrência de várias abelhas nativas no Brasil e menciona várias leis estaduais a respeito da criação e manejo de abelhas nativas e a produção de mel. Entretanto, não existe, em nível nacional, uma legislação sobre o controle de qualidade de tal produto, somente uma proposta de criação de parâmetros de controle de qualidade de méis de abelhas nativas, descrita na literatura, a qual é mencionada no presente trabalho.