Extracellular phospholipase production of oral Candida albicans isolates from smokers, diabetics, asthmatics, denture wearers and healthy individuals following brief exposure to polyene, echinocandin and azole antimycotics

Abstract Objective Candida albicans is the primary causative agent of oral candidosis, and one of its key virulent attributes is considered to be its ability to produce extracellular phospholipases that facilitate cellular invasion. Oral candidosis can be treated with polyenes, and azoles, and the more recently introduced echinocandins. However, once administered, the intraoral concentration of these drugs tend to be sub-therapeutic and rather transient due to factors such as the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, the pathogenic yeasts may undergo a brief exposure to antifungal drugs. We, therefore, evaluated the phospholipase production of oral C. albicans isolates following brief exposure to sub-therapeutic concentrations of the foregoing antifungals. Materials and methods Fifty C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sub-therapeutic concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for one hour. Thereafter the drugs were removed and the phospholipase production was determined by a plate assay using an egg yolk-agar medium. Results The phospholipase production of these isolates was significantly suppressed with a percentage reduction of 10.65, 12.14, 11.45 and 6.40% following exposure to nystatin, amphotericin B, caspofungin and ketoconazole, respectively. This suppression was not significant following exposure to fluconazole. Conclusions Despite the sub-therapeutic, intra oral, bioavailability of polyenes, echinocandins and ketoconazole, they are likely to produce a persistent antifungal effect by suppressing phospholipase production, which is a key virulent attribute of this common pathogenic yeast.

Clindamicina para el tratamiento de infecciones dentales / Clindamycin for the treatment of dental infections

La clindamicina es un antibiótico de amplio espectro con actividad contra los aerobios grampositivos y una extensa gama de bacterias anaerobias, entre ellas los patógenos productores de betalactamasa. Los estudios in vitro e in vivo han demostrado que este fármaco alcanza una concentración elevada en el punto de infección, reduce la virulencia de las bacterias y refuerza las actividades fagocíticas de los linfocitos inmunitarios del huésped. La clindamicina por vía oral se absorbe con rapidez y eficacia, y su concentración permanece por encima de la concentración inhibidora mínima de la mayoría de los organismos por lo menos durante 6 horas. En este análisis, presentaremos pruebas de la eficacia e inocuidad de la clindamicina en el tratamiento de las infecciones odontogénicas con datos de estudios preclínicos y clínicos, los cuales avalan la aplicación general de este antibiótico como antiinfeccioso en el campo de la odontología.

Clindamycin is an antibiotic of wide range of action with a great activity against aerobic gram-positive germs and a broad spectrum of anaerobic bacteria, among which we can find the pathogenic agents that produce Beta-lactamase. The in vitro and in vivo have shown that this medicine reaches a high concentration at the infection point, reduces the bacteria virulence, and strengthens the phagocytic activity of the immunizing lymphocyte of the host. Clindamycin through oral ingestion is absorbed very quickly and effectively, and its concentration remains the same above the minimum inhibitory concentration of most of the organisms at least for six hours. In this analysis, we will introduce some proofs about the effectiveness and innocuousness of clindamycin in the treatment of odontogenic infections. This data is based upon clinical and pre-clinical studies that support the general use of this mentioned antibiotic as an anti-infectious agent in the field of odontology.

DNA fingerprinting elicited evolutionary trend of oral Candida tropicalis isolates from diverse geographic locales.

PURPOSE: To study molecular profiles of oral Candida tropicalis isolates from five different geographic locales to determine the molecular diversity, clonality and evolutionary trends of this opportunistic pathogen. METHODS: A total of 36 strains from five countries (China, Canada, Scotland, Japan and Tanzania) were genotyped by PCR fingerprinting with 11 separate primers. Of these, primers RSG9, RSG8, T3B and RSD12 generated complex fingerprinting patterns. RESULTS: Three significantly dissimilar profiles were derived from the primer T3B and particularly focused on tDNA suggested the prevalence of genetic subtypes within the species. Comparison of tDNA and rDNA (RSD12) fingerprints of C. tropicalis suggested that rDNA is much more heterogeneous than the relatively distinct tDNA. Further analysis of similarity coefficient (SAB) of gel profiles derived from computer-generated dendrograms indicated some degree of similarity in isolates from five-disparate geographic locales as well as the presence of unique isotypes in each region. CONCLUSIONS: This study demonstrates the evolutionary divergence of distinct genetic subgroups within Candida tropicalis .

Oral Candida infections--a review.

Candida species are the commonest agents of oral mycoses. They cause a variety of diseases including the new variant, erythematous candidosis, which is frequently described in HIV infection. Due to these and other reasons the classification of oral candidosis has been recently revised, and further more new therapeutic regimes have been described. Hence in this article an overview of oral Candida infections is presented with special emphasis on current concepts related to classification and treatment.