dubliniensis isolates were exposed to sublethal concentrations of nystatin for 1 h. Following this exposure, the drug was removed and PAFE, adhesion to BEC, GT formation and relative CSH were determined by a previously described turbidometric method, adhesion RAD001 chemical structure assay, germ tube induction assay and biphasic aqueous-hydrocarbon assay respectively. MIC (μg/ml) of C. dubliniensis isolates to nystatin ranged from 0.09 to 0.78. The nystatin-induced mean PAFE (hours) on C. dubliniensis isolates was 2.17.
Compared with the controls, exposure to nystatin suppressed the ability of C. dubliniensis isolates to adhere BEC, GT formation and relative CSH by a mean percentage reduction of 74.45% (P < 0.0001), 95.92% (P < 0.0001) and 34.81 (P < 0.05) respectively. Hence, brief exposure of C. dubliniensis isolates to nystatin would continue to wield an antifungal effect by suppressing growth as well as its adhesion attributes. Candida dubliniensis is now well recognised as an opportunistic pathogen associated with recurrent oral candidosis in AIDS patients. It has also been
isolated from the oral cavity of diabetic patients and from the sputum of cystic fibrosis patients. The fact that C. dubliniensis has been isolated from the upper respiratory tract specimens and from blood suggests that it can disseminate to other sites as well.[1-4] In addition, resistance to fluconazole has been observed in C. dubliniensis isolates obtained from AIDS patients and stable fluconazole resistance Carfilzomib concentration can be readily induced in C. dubliniensis following exposure to the drug in vitro. Furthermore, a breakthrough in C. dubliniensis fungemia occurred in a patient during prolonged exposure to voriconazole. More recently, it was revealed that longitudinal genotyping of C. dubliniensis isolates from HIV-infected patients may acquire itraconazole resistance, even in the absence of prior azole therapy. Adherence of Candida to host mucosal surfaces is a major determinant of successful microbial colonisation and
subsequent Protein tyrosine phosphatase infection, and its critical role in the pathogenesis of oral candidiasis is well recognised. Such attachment enables the organisms to avoid dislodgement due to the cleansing action of mucosal secretions and facilitates infection. Various in vitro and animal studies have provided evidence for a relationship between the proclivity of Candida species to adhere to mucosal surfaces and their presence in infections.[8, 9] Therefore, candidal adherence to human buccal epithelial cells (BEC) is considered as the critical initial step in the pathogenesis of oral candidosis. In addition, germ tubes (GT), which mark the onset of hyphal growth have been implicated in the pathogenesis of candidiasis, as these cylindrical extrusions, unlike the blastospore form, are known to facilitate yeast adherence to epithelial cells and impart resistance to phagocytic killing.