Ellepola A N, Samaranayake L P
Faculty of Dentistry, University of Hong Kong, Hong Kong.
J Oral Pathol Med. 1998 Aug;27(7):325-32. doi: 10.1111/j.1600-0714.1998.tb01964.x.
The major aetiologic agent of oral candidosis is C. albicans, and adhesion to oral mucosal surfaces is considered a vital prerequisite for successful colonisation and subsequent infection by this agent. Although many antimycotics are available for the treatment of oral candidosis, the diluent effect of saliva and the cleansing action of the oral musculature often tend to reduce the availability of the agents below that of the effective therapeutic concentration. Therefore, the yeasts undergo only a limited exposure to the antifungals during therapy. Hence, the main aim of the present study was to determine the in vitro adhesion of ten isolates of oral C. albicans to buccal epithelial cells (BEC) following a short exposure to sublethal concentrations of four antifungal agents. The yeasts were exposed to sublethal concentrations of nystatin (x6 MIC), 5-fluorocytosine (x8 MIC), ketoconazole (x4 MIC) and fluconazole (x4 MIC) for a period of 1 h. Following subsequent removal of the drug, the adhesion of these isolates to BEC was assessed by a previously described adhesion assay. The mean percentage reductions of candidal adhesion to BEC following exposure to sublethal concentrations of nystatin, 5-fluorocytosine, ketoconazole and fluconazole were 72.88%, 16.52%, 40.16% and 24.36%, respectively. Ultrastructural studies revealed that short exposure to nystatin and the azoles (but not 5-fluorocytosine) resulted in aberrant cellular features. These findings indicate that subtherapeutic levels of antifungals may modulate candidal colonisation of the oral mucosa and thereby suppress the invasive potential of the pathogen.
口腔念珠菌病的主要病原体是白色念珠菌，其对口腔黏膜表面的黏附被认为是该病原体成功定植并随后引发感染的关键先决条件。尽管有许多抗真菌药物可用于治疗口腔念珠菌病，但唾液的稀释作用和口腔肌肉组织的清洁作用往往会使药物的可利用度降低至有效治疗浓度以下。因此，在治疗过程中酵母仅受到有限的抗真菌药物作用。因此，本研究的主要目的是确定在短暂暴露于四种抗真菌药物的亚致死浓度后，十株口腔白色念珠菌分离株对颊上皮细胞（BEC）的体外黏附情况。将酵母暴露于制霉菌素（x6 MIC）、5-氟胞嘧啶（x8 MIC）、酮康唑（x4 MIC）和氟康唑（x4 MIC）的亚致死浓度下1小时。在随后去除药物后，通过先前描述的黏附试验评估这些分离株对BEC的黏附情况。暴露于制霉菌素、5-氟胞嘧啶、酮康唑和氟康唑亚致死浓度后，念珠菌对BEC黏附的平均百分比降低分别为72.88%、16.52%、40.16%和24.36%。超微结构研究表明，短暂暴露于制霉菌素和唑类药物（但不是5-氟胞嘧啶）会导致细胞特征异常。这些发现表明，亚治疗水平的抗真菌药物可能会调节口腔黏膜念珠菌的定植，从而抑制病原体的侵袭潜力。
