Gabriela Lacet Silva Ferreira

Antifungal activity, mode of action and anti-biofilm effects of Laurus nobilis Linnaeus essential oil against Candida spp.

OBJECTIVE The present study demonstrated the antifungal potential of the chemically characterized essential oil (EO) of Laurus nobilis L. (bay laurel) against Candida spp. biofilm adhesion and formation, and further established its mode of action on C. albicans. METHODS L. nobilis EO was obtained and tested for its minimum inhibitory and fungicidal concentrations (MIC/MFC) against Candida spp., as well as for interaction with cell wall biosynthesis and membrane ionic permeability. Then we evaluated its effects on the adhesion, formation, and reduction of 48hC. albicans biofilms. The EO phytochemical profile was determined by gas chromatography coupled to mass spectrometry (GC/MS). RESULTS The MIC and MFC values of the EO ranged from (250 to 500) μg/mL. The MIC values increased in the presence of sorbitol (osmotic protector) and ergosterol, which indicates that the EO may affect cell wall biosynthesis and membrane ionic permeability, respectively. At 2 MIC the EO disrupted initial adhesion of C. albicans biofilms (p<0.05) and affected biofilm formation with no difference compared to nystatin (p>0.05). When applied for 1min, every 8h, for 24h and 48h, the EO reduced the amount of C. albicans mature biofilm with no difference in relation to nystatin (p>0.05). The phytochemical analysis identified isoeugenol as the major compound (53.49%) in the sample. CONCLUSIONS L. nobilis EO has antifungal activity probably due to monoterpenes and sesquiterpenes in its composition. This EO may affect cell wall biosynthesis and membrane permeability, and showed deleterious effects against C. albicans biofilms.

Does Scientific Evidence for the Use of Natural Products in the Treatment of Oral Candidiasis Exist? A Systematic Review

In view of the limitations of antifungal agents used in the treatment of oral candidiasis and the wide variety of natural products that have been studied as treatment of this disease, this systematic literature review proposed to evaluate whether scientific evidence attesting to the efficacy of natural products in the treatment of this disease exists. A systematic search in PubMed, MEDLINE, SciELO, Lilacs, and Cochrane Library databases was accomplished using the associations among the keywords Candida albicans, phytotherapy, biological products, denture stomatitis, and oral candidiasis in both English and Portuguese. Four independent observers evaluated the methodological quality of the resulting articles. Three studies were included for detailed analysis and evaluated according to the analysis protocol based on the CONSORT (Consolidated Standards of Reporting Trials) 2010 statement. The tested products were different in all studies. Two studies mentioned random samples, but no study described the sample allocation. No study mentioned sample calculations, a prior pilot study, or examiner calibration, and only one trial reported sample losses. Differences between the tested products and the methodological designs among these studies did not allow the existence of scientific evidence related to the effectiveness of these products for the proposed subjects to be confirmed.

ATIVIDADE ANTIBACTERIANA IN VITRO DE FITOCONSTITUINTES SOBRE MICORGANISMOS DO BIOFILME DENTÁRIO

Objective: To evaluate the in vitro antibacterial activity of citronellol, linalool, thymol, and D-limonene against Streptococcus mutans, S. salivarius and S. oralis. Material and Methods: It was performed a screening by the diffusion technique on solid medium. Absorbent paper discs were soaked with 30 µl of the tested substance and then placed on petri dishes containing Mueller Hinton agar previously sown with the bacterial inoculum. After incubation for 24 h at 37 °C, it was measured the halo of growth inhibition with the aid of a manual caliper. Chlorhexidine (2%) was used as positive control. Tests were performed in triplicate. Results: For citronellol, the means of the diameters of the halos, in millimeters (mm), were 10.7, 10.0, and 9.8 against S. mutans, S. salivarius and S. oralis respectively. The values found for thymol were 7.3, 7.3 and 8.3 mm, respectively. The phytochemical D-limonene exhibited means of 8.0, 6.7 and 6.0 mm, respectively. For linalool, the means of the halos were 8.0 mm, 9.0 mm and 8.2 mm. Chlorhexidine was found to show means of 17, 16.8 and 19.7 mm on S. mutans, S. oralis and S. salivarius respectively. Conclusion: The products under test showed antibacterial activity, being therefore potential substances to be applied for dental caries prevention. DESCRIPTORS: Biological Agents. Streptococcus mutans. Streptococcus oralis.

A Randomized Clinical Trial of Schinus terebinthifolius Mouthwash to Treat Biofilm-Induced Gingivitis.

Objectives. This study aimed to investigate the efficacy of a Schinus terebinthifolius (ST) mouthwash in reducing gingival inflammation levels (GI) and biofilm accumulation (BA) in children with gingivitis. Methods. This was a randomized, controlled, triple blind, and phase II clinical trial, with children aged 9–13 years (n = 27) presenting with biofilm-induced gingivitis. The sample was randomized into experimental (0.3125% ST, n = 14) and control (0.12% chlorhexidine/CHX, n = 13) groups. Products were masked as regards color, flavor and aroma. Intervention protocol consisted in supervised rinsing of 10 mL/day for 01 minute for 10 days. Gingival bleeding and simplified oral hygiene indexes were used to assess the efficacy variables, measured at baseline and after intervention by calibrated examiners. Data were statistically treated with paired t-test, unpaired t-test, and Wilcoxon and Mann-Whitney tests (α = .05). Results. It was found that both ST and CHX were able to significantly reduce GI levels after 10 days (P < 0.001) and there was no significant difference between them (P > 0.05). CHX was the only product able to significantly reduce BA after 10 days when compared to baseline (P < 0.05). Conclusion. ST mouthwash showed significant anti-inflammatory activity (equivalent to CHX), but it was not able to reduce biofilm accumulation.

Antibiofilm Activity and Mechanism of Action of the Disinfectant Chloramine T on Candida spp., and Its Toxicity against Human Cells

We evaluated the antifungal and anti-biofilm activity, mechanism of action and cytotoxicity of chloramine T trihydrate (CAT) against Candida spp. The Minimum Inhibitory and Fungicidal Concentrations (MIC/MFC) of CAT were determined. Changes in CAT-treated C. albicans growth kinetics and micromorphology were evaluated, as well as the mechanism of action, and its effects on biofilm. Cytotoxicity was assessed by the hemolysis method. The data were analyzed by inferential statistics (p ≤ 0.05). CAT showed antifungal activity against all strains, with MIC values ranging between 1.38 and 5.54 mmol/L (MIC75%: 2.77 mmol/L). CAT demonstrated an immediate and sustained action on C. albicans growth kinetics, particularly at 2 × MIC. This compound likely acts on the cell wall and membrane permeability simultaneously and was found to cause changes in C. albicans micromorphology. Tha antibiofilm activity of CAT was similar to that of sodium hypochlorite (p > 0.05) against mature biofilms. CAT was more effective than NaOCl in reducing mature biofilm upon 1-min exposure at 2 × MIC (24 h) and 4 × MIC (48 h) (p < 0.05). Toxicological analysis revealed that CAT had hemolytic activity between 61 and 67.7% as compared to 100% by NaOCl. CAT has antifungal and anti-biofilm properties, probably acting on both cell wall and membrane permeability, and showed low toxicity in vitro.

FATORES DE RISCO À SEGURANÇA DO ENFERMEIRO NA UNIDADE DE TERAPIA INTENSIVA DE UM HOSPITAL GERAL

Introducao: As unidades de terapia intensiva constituem locais onde a enfermagem presta assistencia qualificada a pacientes graves. Objetivo: Identificar os fatores de riscos aos quais o enfermeiro intensivista esta exposto e que podem ocasionar acidentes de trabalho. Material e Metodos: Foi utilizada uma abordagem indutiva com procedimento comparativo e estatistico atraves da observacao direta extensiva, utilizando questionarios. A amostra foi composta por 15 enfermeiros atuantes ha dois anos ou mais em um hospital de referencia de Joao Pessoa – PB. Dentre os itens avaliados nos questionarios, buscou-se caracterizar e avaliar as exigencias do contexto de trabalho e os riscos aos quais os enfermeiros estao expostos. Resultados: Verificou-se que 60% dos sujeitos responderam que as vezes o ritmo de trabalho e excessivo; 73,3% disseram que as vezes as condicoes de trabalho sao precarias; 46,6% responderam que frequentemente existe muito barulho no ambiente de trabalho; 53,4% assinalaram que e bastante exigido ter controle das emocoes. Alem disso, 86,7% dos participantes referiram ter sentido tres ou mais vezes dores no corpo e 46,6% referiram tres ou mais episodios de estresse desencadeado pelo convivio com a dor, o sofrimento e a morte. Conclusao: Foram identificados riscos biologicos, como acidentes com perfurocortantes e fluidos gerais de pacientes, riscos fisicos, a exemplo de exposicao a radiacao e ruidos, riscos quimicos devido a exposicao a substâncias como antissepticos, ergonomicos, associados a esforcos repetidos entre outros, assim como risco ocupacional, remetendo principalmente ao ritmo de trabalho excessivo. DESCRITORES Riscos Ocupacionais. Unidade de Terapia Intensiva. Equipe de Enfermagem. Saude do Trabalhador. Enfermagem do Trabalho.