Candida albicans biotypes in persistent root canal infections in a Finnish population.

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Phenotypes and randomly amplified polymorphic DNA profiles of Candida albicans isolates from root canal infections in a Finnish population

A total of thirty-seven Candida albicans isolates from root canal infections in a Finnish population were subtyped using phenotypic and genotypic methods. A previously described biotyping method based on the presence of five different enzymes, assimilation of eleven different carbohydrates and boric acid sensitivity of the yeasts was used to determine the phenotype. Commercially available API ZYM and API 20 C test kits were used to determine the presence of enzymes and assimilation of carbohydrates. The sensitivity of the isolates to boric acid was tested by their ability to grow on yeast-nitrogen-agar with incorporated boric acid (1.8 mg · ml-1). Combination of the tests revealed a total of 14 different phenotypes. The majority of the isolates, 26 strains, were classifiable into three major phenotypes: 16 isolates (43.2%) belonged to phenotype A1R, six (16.2%) to A1S and four (10.8%) to B1S. The remaining 11 phenotypes represented only a single isolate each. The randomly amplified polymorphic DNA profiles were used to determine the genotypes. For this purpose two different primers, RSD6 and RSD12 were used to develop a combination randomly amplified polymorphic DNA profile for each isolate. Altogether 31 genotypes were noted among the 37 isolates, of which only three pairs of isolates presented with congruent phenotypic and genotypic profiles. The heterogeneity of both the phenotypic and randomly amplified polymorphic DNA profiles of C. albicans isolates from root canal infections is akin to previous reports from other oral and non-oral sources in different geographic locales.link_to_subscribed_fulltex

Yeasts in apical periodontitis

WOS: 000226594700005PubMed ID: 12764075Microbiological reports of apical periodontitis have revealed that yeasts can be isolated from approximately 5-20% of infected root canals. They occur either in pure cultures or together with bacteria. Almost all isolated yeasts belong to the genus Candida, and the predominant species is C. albicans. Pheno- and genotypic profiles of C. albicans isolates show heterogeneity comparable with those of isolates from other oral sites. C. albicans expresses several virulence factors that are capable of infecting the dentin-pulp complex, including dentinal tubules. This causes, consequentially, an inflammatory response around the root apex, which suggests a pathogenic role for this organism in apical periodontitis. Yeasts are particularly associated with persistent root canal infections that do not respond favorably to conservative root canal therapy. This may be due to the resistance of all oral Candida species against a commonly used topical medicament, calcium hydroxide. However, other antimicrobial agents may offer alternative therapeutic approaches and improve the treatment of these persistent cases of apical periodontitis

In vitro evaluation of the antimicrobial activity of endodontic sealers Avaliação in vitro da atividade antimicrobiana de cimentos endodônticos

The purpose of this study is to evaluate the antimicrobial activity of the endodontic sealers: N-Rickert, Sealapex, AH Plus, Mineral Trioxide Aggregate (MTA) and portland cement. The Agar diffusion method was used in plates previously inoculated with the following microorganisms: C. albicans, S. aureus, E. faecalis, E. coli. The diameters of microbial inhibition zones were measured after 24 hours of incubation in kiln at 37&deg;C. According to the methodology used, it was possible to conclude that only the sealers AH Plus and N-Rickert presented antimicrobial activity against C. albicans, S. aureus, and E. coli; no antimicrobial activity in MTA, Sealapex and portland cement was observed. N-Rickert presented the largest inhibition zones varying from 8 to 18 mm, and the microorganism E. faecalis was resistant against all sealers tested.<br>O objetivo deste estudo é avaliar a capacidade antimicrobiana dos cimentos obturadores de canal: N-Rickert, Sealapex, AH Plus e também do Agregado Trióxido Mineral (MTA) e Cimento de Portland. O método utilizado foi a difusão em Ágar, em placas previamente inoculadas com os seguintes microorganismos: C. albicans, S. aureus, E. faecalis, E. coli. A leitura do diâmetro do halo de inibição do crescimento microbiano foi realizada, após 24 horas de incubação, em estufa a 37&deg;C. De acordo com a metodologia empregada, foi possível concluir que: somente os cimentos obturadores AH Plus e N-Rickert apresentaram atividade antimicrobiana contra C. albicans, S. aureus e E. coli; não foi observada atividade antimicrobiana no cimento de Portland, MTA e Sealapex. O cimento N-Rickert apresentou halos de inibição maiores variando de 8 a 18 mm. O microorganismo E. faecalis foi resistente contra todos os cimentos testados