Probiotics for Prevention and Treatment of Candidiasis and Other Infectious Diseases: Lactobacillus spp. and Other Potential Bacterial Species

The resident microbiota in the human body, such as the oral cavity, gastrointestinal tract and genitourinary tract, is able to provide resistance to disease. However, imbalances in the microbial components can promote the growth of opportunistic microorganisms, such as yeasts of genus Candida. Fungal infections present as a major cause of infectious diseases and the microorganisms of genus Candida are the most frequently isolated pathogenic fungi in human fungal infections. Bacillus spp. and Lactobacillus spp. are bacteria that have probiotic effects used in commercially available products and in studies that aim for the development of probiotics able to inhibit the microbial pathogenicity and restore the balance of resident microbiota. Thus, with increasing fungus resistance to the use of antifungal agents, which are capable of causing serious side effects to the host organism unable to destroy the target microorganism, it becomes important to develop therapeutic and/or prophylactic alternatives that have a different and an effective mechanism of action with capacity to combat fungal infections without harming the patient. Probiotic bacteria provide an alternative strategy for the prevention and treatment of candidiasis and other infectious diseases

Terapia fotodinâmica em esporos de bacillus atrophaeus e bacillus subtilis: estudos com LASER, LED, azul de metileno, rosa bengala e verde malaquita

Os esporos de Bacillus spp. são encontrados amplamente distribuídos na natureza, podendo ocasionar contaminação do meio ambiente e, eventualmente, doenças ao homem e animais. Em resposta a crescente resistência microbiana, a terapia fotodinâmica (PDT) surge para atuar como um tratamento alternativo e eficaz. O presente estudo teve como objetivo comparar e avaliar a ação exercida pelo LASER de baixa intensidade (vermelho visível) e pelo diodo emissor de luz verde (LED) em esporos de Bacillus atrophaeus e Bacillus subtilis na PDT, com o uso dos fotossensibilizadores azul de metileno (37,5 M), rosa bengala (12,5 M) e verde malaquita (300 M). Utilizou-se cepa padrão de Bacillus atrophaeus (ATCC 9372) e Bacillus subtilis (ATCC 19659). As cepas foram cultivadas, durante 7 dias, em Ágar Nutriente acrescidas de 0,003% de sulfato de manganês e analisadas quanto a formação de esporos (coloração de Wirtz-Conklin). Os esporos foram suspensos em água destilada esterilizada e centrifugados por 10 min a 653 Xg. As suspensões receberam choque térmico de 70 °C por 30 min. As suspensões foram padronizadas com 106 células/mL. Em placas de 96 poços adicionou-se 0,1 mL de suspensão dos esporos de Bacillus atrophaeus ou de Bacillus subtilis e 0,1 mL do fotossensibilizador ou de solução de NaCl a 0,9%, sendo agitadas durante 5, 10 e 30 minutos e irradiadas. Realizaram-se diluições seriadas. Alíquotas de 0,1 mL das diluições foram semeadas em placas com Ágar Infusão Cérebro-Coração e incubadas a 37 °C por 48 horas. Os resultados foram analisados estatisticamente (ANOVA, teste de Tukey, p<0,05). As maiores reduções observadas em UFC/mL (Log10) para os esporos de Bacillus atrophaeus foram 0,71 Log10 para azul de metileno (10 min); 2,49 Log10 para rosa bengala (30 min) e 0,42 Log10 para verde...The spores of Bacillus spp. are found widely distributed in nature, which may cause contamination of the environment and eventually diseases to humans and animals. In response to increasing microbial resistance, photodynamic therapy (PDT) appears to act as an alternative treatment and effective. The present study aimed to compare and evaluate the action exerted by low intensity laser and green light emitting diode (LED) in spores of Bacillus atrophaeus and Bacillus subtilis in PDT, with the use of photosensitizers blue methylene (37.5 M), rose bengal (12.5 M) and malachite green (300 M). It was used a standard strain of Bacillus atrophaeus (ATCC 9372) and Bacillus subtilis (ATCC 19659). The strains were cultivated for 7 days in Nutrient Agar added to 0.003% of manganese sulphate and analyzed for the formation of spores (Wirtz-Conklin staining). The spores were suspended in sterile distilled water and centrifuged for 10 min at 653 Xg. The suspensions were heat shock at 70 °C for 30 min. The suspensions were standardized to 106 cells / mL. In 96-well plates were added 0.1 ml of Bacillus subtilis or Bacillus atrophaeus and 0.1 ml of the photosensitizer or NaCl 0.9%, stirred for 5, 10 and 30 minutes and irradiated. Serial dilutions were performed. Aliquots of 0.1 mL of the dilutions were plated on Brain Heart Infusion Agar and incubated at 37 °C for 48 hours. The results were analyzed statistically (ANOVA, Tukey test, p<0.05). The highest observed reductions in CFU/ml (Log10) for Bacillus atrophaeus were 0.71 Log10 for methylene blue (10 minutes), 2.49 Log10 for rose bengal (30 min) and 0.42 Log10 for malachite green (10 min). In relation to Bacillus subtilis the largest reductions were 0.82 Log10 for methylene blue (10 minutes), 3.86 Log10 for rose bengal (30 min) and 0.63 Log10 for malachite green (10 min). The conclusion... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Photodynamic inactivation of virulence factors of Candida strains isolated from patients with denture stomatitis

Candida species are major microorganisms isolated in denture stomatitis (DS), an inflammatory process of the mucosa underlying removable dental prostheses, and express a variety of virulence factors that can increase their pathogenicity. The potential of Photodynamic inactivation (PDI) in planktonic culture, biofilms and virulence factors of Candida strains was evaluated. A total of 48 clinical Candida isolates from individuals wearing removable maxillary prostheses with DS were included in the study. The effects of erythrosine (ER, 200μM) and a green LED (λ 532±10nm, 237mW/cm(2) and 42.63J/cm(2)) in a planktonic culture were evaluated. The effect of the addition of ER at a concentration of 400μM together with a green LED was evaluated in biofilms. The virulence factors of all of the Candida strains were evaluated before and after the PDI process in cells derived from biofilm and planktonic assays. All of the Candida species were susceptible to ER and green LED. However, the biofilm structures were more resistant to PDI than the planktonic cultures. PDI also promoted slight reductions in most of the virulence factors of C. albicans and some of the Candida tropicalis strains. These results suggest that the addition of PDI is effective for reducing yeasts and may also reduce the virulence of certain Candida species and decrease their pathogenicity.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Influence of artificial saliva in biofilm formation of Candida albicans in vitro

Due to the increase in life expectancy, new treatments have emerged which, although palliative, provide individuals with a better quality of life. Artificial saliva is a solution that contains substances that moisten a dry mouth, thus mimicking the role of saliva in lubricating the oral cavity and controlling the existing normal oral microbiota. This study aimed to assess the influence of commercially available artificial saliva on biofilm formation by Candida albicans. Artificial saliva I consists of carboxymethylcellulose, while artificial saliva II is composed of glucose oxidase, lactoferrin, lysozyme and lactoperoxidase. A control group used sterile distilled water. Microorganisms from the oral cavity were transferred to Sabouraud Dextrose Agar and incubated at 37°C for 24 hours. Colonies of Candida albicans were suspended in a sterile solution of NaCl 0.9%, and standardisation of the suspension to 106 cells/mL was achieved. The acrylic discs, immersed in artificial saliva and sterile distilled water, were placed in a 24-well plate containing 2 mL of Sabouraud Dextrose Broth plus 5% sucrose and 0.1 mL aliquot of the Candida albicans suspension. The plates were incubated at 37°C for 5 days, the discs were washed in 2 mL of 0.9% NaCl and placed into a tube containing 10 mL of 0.9% NaCl. After decimal dilutions, aliquots of 0.1 mL were seeded on Sabouraud Dextrose Agar and incubated at 37°C for 48 hours. Counts were reported as CFU/mL (Log10). A statistically significant reduction of 29.89% (1.45 CFU/mL) of Candida albicans was observed in saliva I when compared to saliva II (p = 0.002, considering p&#8804;0.05)