Experimental systemic virulence of oral Candida dubliniensis isolates in comparison with Candida albicans, Candida tropicalis and Candida krusei.

There are no previous studies on the comparative virulence of Candida dubliniensis with other non-albicans species. The aim of this study was to compare the virulence and infection kinetics of C. dubliniensis and other species. Candida albicans, C. dubliniensis, Candida tropicalis and Candida krusei (reference strains) were inoculated intravenously in mice. For infection kinetics evaluation, a group of five animals were sacrificed after 6 h, 3, 7, 14 and 21 days. Microbiological evaluations (liver, spleen, kidneys, lungs and brain) and histopathological examination of the kidney were performed. The results of virulence evaluation were analysed using Kaplan-Meier survival analysis (5%). Candida dubliniensis-inoculated mice survived for longer periods compared with those with C. albicans (P = 0.005). No differences were detected in relation to C. tropicalis (P = 0.326) and C. krusei (P = 0.317). Most of the organs were persistently colonised by C. albicans and C. dubliniensis even by day 21. Tendency of C. krusei clearance was observed in all organs. Fungal masses and renal lesions were observed after inoculation of C. albicans, C. dubliniensis and C. tropicalis. Within the limits of the study, data on survival rate and dissemination capacity suggest that C. dubliniensis is less virulent than C. albicans.

Experimental pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes.

A possible correlation between the presence of discontinuous fringes and high virulence has been previously suggested. The aim of this study was to compare the pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes on mice. For C. albicans, two discontinuous fringe morphotype isolates (PN 69, PN 74), two continuous fringe morphotype isolates (N 60, N 33) and one reference strain were used. For C. dubliniensis, three discontinuous fringe morphotype isolates (97487, 97464, 97519), two continuous fringe morphotype isolates (97040, 98026) and one reference strain were used. Swiss male mice were inoculated with a standardised suspension of the microorganisms and observed for 35 days. The pathogenicity of the isolates was analysed according to parameters proposed previously. Three isolates were considered pathogenic: PN 74, N 60 and 98026. Strain N 60 killed the highest amount of mice (80%). Animals inoculated with C. albicans did not show differences on survival estimate. Candida dubliniensis 98026 was more pathogenic than samples 97464 and 97519. On the other hand, the sample 97487 showed a higher pathogenicity when compared with 97040 (Kaplan-Meier test, P = 0.008). Strains with continuous fringe morphotypes were also associated with Candida sp. virulence in vivo.

Efetividade de um novo produto a base de gel de triclosan e Pimpinella anisum na anti-sepsia de mãos em Odontologia / Effectiveness of a new product with triclosan and Pimpinella anisum for hand antisepsis in Odontology

O objetivo deste estudo foi avaliar a efetividade antimicrobiana de um novo anti-séptico para mãos a base de triclosan e Pimpinella anisum. Foi realizado estudo in vitro incluindo cepas de Staphylococcus aureus (ATCC 6.538), Escherichia coli (ATCC 25.922), Proteus mirabilis, Citrobacter freundii (CCUT 22.001), Enterobacter aerogenes (IAL 2.482) e Candida albicans (20 isolados clínicos). A metodologia utilizada foi de diluição em ágar (Müeller Hinton ou RPMI/MOPS) e os resultados foram expressos em valores de concentração inibitória mínima (CIM). A CIM para Escherichia coli, Citrobacter freundii e Entterobacter aerogenes foi de 0,03%; para Staphylococcus aureus 6,25%; Proteus mirabilis 12,5% e Candida albicans 12,5%. Para avaliação in vivo foram incluídos 60 voluntários dividos em três grupos: Produto A (triclosan, álcool etílico e Pimpinella anisum - Erva doce); Produto B (irgasan e álcool etílico a 70%) e controle (clorexidina 2% gel). Para a realização da coleta, as mãos foram divididas em oito partes iguais sendo que a coleta inicial e a final foram realizadas em quatro partes alternadas diferentes das mãos. As amostras foram coletadas com auxílio de swab esterilizado, umedecido em solução salina esterilizada e semeadas em duplicata em ágar sangue. Após a incubação, por 48 horas/37ºC, foram obtidos valores de unidades formadoras de colônias. O estudo in vivo demonstrou redução significativa das contagens em todos os grupos estudados (p < 0,001), sendo de 92,5% para o produto A, 91,1% para o produto B e 98,4% para o controle. Não houve diferença estatisticamente significativa entre as reduções de contagens dos grupos testados (p = 0,30). Concluiu-se que o novo produto apresentou alta efetividade antimicrobiana similar a dos demais grupos testados.