Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

AbstractPost-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candidamay undergo a brief exposure to antifungal drugs.Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated.Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively.Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively.Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans.

Papillary thyroid carcinoma: How much should the surgeon read from Fine needle aspiration cytology reports.

Objective: During routine fine needle aspiration cytodiagnosis of papillary thyroid carcinoma (PTC), a number of cases are diagnosed as suspicious; or it is suggested that PTC or a neoplasm be ruled out by histopathology. Since these diagnostic labels are likely to put the clinicians in a difficult situation while planning the management, this study aims to find out how much the surgeon should read from these reports. Materials and Methods: The patients were divided into two groups. Group A included 38 cases diagnosed as PTC or suspicious of PTC. Group B included 40 cases in which it was suggested that PTC/a neoplasm to be ruled out and non-neoplastic lesions with one or more cytologic features of PTC. The two groups were compared with clinical, imaging and cytomorphologic features. Results: A significant difference was observed with respect to age between Group A and Group B (P<0.001). The frequency of the following five cytologic features was significantly higher in Group A: papillary formation (P<0.001), psammoma bodies (P=0.054), fine nuclear chromatin (P=0.010), frequent nuclear grooves (P<0.001) and intra-nuclear cytoplasmic inclusion (P<0.001). Three or more of the five cytologic features were also reported in significantly higher number of Group A cases (P<0.001). Majority (81.8%) of the cases with subsequent histology in Group A were confirmed as PTC as opposed to 7.7% in Group B (P<0.001). Conclusions: Thus, cases with definitive cytodiagnosis of PTC and suggestive of PTC (Group A) should be taken much more seriously by the surgeons as compared to Group B cases.