ABSTRACT
Objective: The aim of this in vitro study was to evaluate the efficacy of photodynamic inactivation (PDI) with erythrosine (E), using a light-emitting diode (LED) on planktonic cultures of Streptococcus mutans. Material and Methods: A Streptococcus mutans strain (UA 159) was used to prepare the suspensions containing 107 cells/mL, which was tested under different experimental conditions: a) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); b) LED irradiation only (P-L+); c) treatment with erythrosine only (E+L-); and d) no LED irradiation or photosensitizer (P) treatment, which served as a control group (P-L-). After treatment, strains were seeded onto MSBS agar for determination of the number of colony-forming units (CFU/mL). Results: The results were submitted to analysis of variance and the Tukey test (p < 0.05). No reduction in the number of CFU/mL was observed in the treatment group with erythrosine (E+L+) when compared to the control (P-L-). Conclusion: PDI using erythrosine did not reduce the number of CFUs per millimeter within the parameters in this study. (AU)
Objetivo: o objetivo deste estudo in vitro foi avaliar a eficácia da inativação fotodinâmica (PDI) com a eritrosina (E), usando diodo de emissão de luz azul (LED) em culturas planctônicas de Streptococcus mutans. Material e métodos: a cepa de Streptococcus mutans (UA 159) foi usada para o preparo das suspensões padrões contendo 107 células/mL, as quais foram testadas em diferentes condições experimentais a) irradiação com LED em presença da eritrosina como fotossensibilizador (E+L+); b) irradiação com LED apenas (F-L+); c) tratamento com eritrosina apenas (E+L-); e d) tratamento sem irradiação com LED ou fotossensibilizador (F), que serviu como grupo controle (F-L-). Após o tratamento, as cepas foram semeadas em ágar MSBS para determinação do número de unidades formadoras de colônias (UFC/mL). Resultados: os resultados foram submetidos à análise de variância e teste de Tukey (p < 0.05). Não foi observada redução no número de UFC/mL no grupo de tratamento com eritrosina (E+L+) quando comparado ao grupo controle (F-L-). Conclusão: a PDI usando etritrosina e LED não reduziu o número de UFCs por milímetro com os parâmetros utilizados neste estudo.(AU)
Subject(s)
Streptococcus mutans , Photosensitizing Agents , Dental Caries , ErythrosineABSTRACT
Dried, fresh and glycolic extracts of Zingiber officinale were obtained to evaluate the action against G. mellonella survival assay against Enterococcus faecalis infection. Eighty larvae were divided into: 1) E. faecalis suspension (control); 2) E. faecalis + fresh extract of Z. officinale (FEO); 3) E. faecalis + dried extract of Z. officinale (DEO); 4) E. faecalis + glycolic extract of Z. officinale (GEO); 5) Phosphate buffered saline (PBS). For control group, a 5 μL inoculum of standardized suspension (107 cells/mL) of E. faecalis (ATCC 29212) was injected into the last left proleg of each larva. For the treatment groups, after E. faecalis inoculation, the extracts were also injected, but into the last right proleg. The larvae were stored at 37 °C and the number of dead larvae was recorded daily for 168 h (7 days) to analyze the survival curve. The larvae were considered dead when they did not show any movement after touching. E. faecalis infection led to the death of 85% of the larvae after 168 h. Notwithstanding, in treatment groups with association of extracts, there was an increase in the survival rates of 50% (GEO), 61% (FEO) and 66% (DEO) of the larvae. In all treatment groups, the larvae exhibited a survival increase with statistically significant difference in relation to control group (p=0.0029). There were no statistically significant differences among treatment groups with different extracts (p=0.3859). It may be concluded that the tested extracts showed antimicrobial activity against E. faecalis infection by increasing the survival of Galleria mellonella larvae.
Extratos seco, fresco e glicólico de Zingiber officinale foram obtidos para avaliar suas ações por meio de ensaio de sobrevivência em G. mellonella contra infecção por Enterococcus faecalis. Oitenta larvas foram divididas em: 1) Suspensão de E. faecalis (controle); 2) E. faecalis + extrato fresco de Z. officinale (FEO); 3) E. faecalis + extrato seco de Z. officinale (DEO); 4) E. faecalis + extrato glicólico de Z. officinale (GEO); 5) Solução tampão fosfato salina (PBS). Para o grupo de controle, 5 µL de inóculo de suspensão padronizada (107 células/mL) de E. faecalis (ATCC 29212) foi injetado na última proleg esquerda de cada lagarta. Para os grupos com tratamento, após a injeção de E. faecalis, os extratos foram injetados na última proleg direita. Após as injeções, as lagartas foram armazenadas a 37 °C e o número de animais mortos foi registrado diariamente em 168 h (7 dias) para analisar a curva de sobrevivência. As lagartas foram consideradas mortas quando elas não mostraram qualquer movimento após o toque. A infecção por E. faecalis levou à morte de 85% das lagartas após 168 h. Não obstante, nos grupos de tratamento com associação dos extratos, houve um aumento nas taxas de sobrevivência de 50% (GEO), 61% (FEO) e 66% (DEO) das lagartas. Em todos os grupos com tratamento, as lagartas apresentaram um aumento na sobrevivência, com diferença estatisticamente significativa em relação ao grupo controle (p=0,0029). Não houve diferença estatisticamente significativa entre os tratamentos com os diferentes extratos (p=0,3859). Pode concluir-se que os extratos testados mostraram atividade antimicrobiana contra a infecção por E. faecalis, aumentando a sobrevivência das lagartas de G. mellonella.
Subject(s)
Humans , Receptors, GABA-A/chemistry , Binding Sites , Benzamidines/chemistry , Benzamidines/metabolism , Benzamidines/pharmacology , Conserved Sequence , Crystallography, X-Ray , Cell Membrane/chemistry , Cell Membrane/metabolism , Drug Design , GABA-A Receptor Agonists/chemistry , GABA-A Receptor Agonists/metabolism , GABA-A Receptor Agonists/pharmacology , Genetic Predisposition to Disease , Glycosylation , Models, Molecular , Mutation/genetics , Protein Structure, Quaternary , Protein Structure, Tertiary , Protein Subunits , Polysaccharides/chemistry , Polysaccharides/metabolism , Receptors, GABA-A/genetics , Synaptic TransmissionABSTRACT
The ability to produce enzymes, such as hemolysins, is an important virulence factor for the genus Candida.The objective of this study was to compare the hemolytic activity between C. albicansand non-albicans Candida species. Fifty strains of Candida species, isolated from the oral cavity of patients infected with HIV were studied. The isolates included the following species: C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis, C. dubliniensis, C. norvegensis, C. lusitaniae, and C. guilliermondii. Hemolysin production was evaluated on Sabouraud dextrose agar containing chloramphenicol, blood, and glucose. A loop-full of pure Candidaculture was spot-inoculated onto plates and incubated at 37ºC for 24 h in a 5% CO2 atmosphere. Hemolytic activity was defined as the formation of a translucent halo around the colonies. All C. albicansstrains that were studied produced hemolysins. Among the non-albicans Candidaspecies, 86% exhibited hemolytic activity. Only C. guilliermondiiand some C. parapsilosis isolates were negative for this enzyme. In conclusion, most non-albicans Candidaspecies had a similar ability to produce hemolysins when compared to C. albicans.
Subject(s)
Humans , Candida/metabolism , HIV Infections/microbiology , Hemolysin Proteins/biosynthesis , Culture Media , Candida albicans/isolation & purification , Candida albicans/metabolism , Candida/isolation & purification , Reference Values , Species Specificity , Statistics, Nonparametric , Virulence FactorsABSTRACT
An essential factor to the virulence of the genus Candida is the ability to produce enzymes and this may be crucial in the establishment of fungal infections. AIM:This study investigated in vitro enzymatic activities of Candida species and their virulence in an in vivo Galleria mellonella experimental model. METHODS: Twenty-four clinical strains of Candida spp. isolated from the human oral cavity were evaluated, including the following species: C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis, C. norvegensis, C. lusitaniae and C. guilliermondii. All Candida strains were tested in vitro for production of proteinase and phospholipase. The Candida strains were also injected into Galleria mellonella larvae to induce experimental candidiasis, and after 24 hours, the survival rate was assessed. RESULTS: Phospholipase and proteinase activity were observed in 100% of the C. albicans strains. In the non-albicans species, proteinase and phospholipase activity were observed in 25 and 43% of the studied strains, respectively. The most pathogenic Candida species in G. mellonella were C. albicans, C. dubliniensis and C. lusitaniae, whereas C. glabrata was the least virulent species. Furthermore, a positive significant correlation was found between both enzymatic activities with virulence in G. mellonella. CONCLUSIONS: The virulence of Candida strains in G. mellonella is related to the quantity of proteinases and phospholipases production of each strain.