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

ObjectiveCandida 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 methodsFifty 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.ResultsThe 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.ConclusionsDespite 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.

Oral Candida carriage among cigarette‐ and waterpipe‐smokers, and electronic cigarette users

“…Moreover, tobacco smoking has been reported to induce changes in the oral microbiome including alterations in the composition and carriage of Candida species (Eggert, McLeod & Flowerdew, ; Soysa & Ellepola, ). For instance, compared with never‐smokers, oral Candida carriage is higher among cigarette‐smokers, which may predispose them to oral fungal infections such as candidiasis (Baboni, Barp, Izidoro, Samaranayake & Rosa, ; Ellepola, Samaranayake & Khan, ; Keten et al., ; Muzurovic, Hukic, Babajic & Smajic, ).…”

Impact of Brief Exposure to Drugs with Antifungal Properties on the Susceptibility of Oral <b><i>Candida dubliniensis</i></b> Isolates to Lysozyme and Lactoferrin

“…MIC values for nystatin and chlorhexidine were obtained by the broth dilution technique by performing twofold serial dilutions of the drugs in microtiter plates using an inoculum of 1-5 × 10 5 colony-forming units (CFU)/mL [18,22]. The MIC values were obtained visually and spectrophotometrically at 595 nm following 24 h of incubation at 37 ° C. The MIC was defined as the lowest concentration of the drug that inhibited growth of Candida, as indicated by the absence of turbidity (optically clear).…”

“…Interpretive susceptibility breakpoints for fluconazole were those recommended by Clinical and Laboratory Standards Institute document M27-A2. Due to the lack of defined susceptibility breakpoints for amphotericin B and ketoconazole, an isolate was considered susceptible with an MIC breakpoint of ≤1.0 µg/mL for amphotericin B and 0.125 µg/mL for ketoconazole as determined in previous studies [18][19][20][21][22]25]. Isolates with MIC of ≤2.0 µg/mL for caspofungin were considered as susceptible [23,25].…”

Comparative Evaluation of in Vitro Virulence of Mould Isolates from Clinical Cases and from Air Samples and Their Mortality Rates in Galleria mellonella Larvae

“…Plaklar 37°C'de 72 saat bekletildikten sonra değerlendirilmiştir. Fosfolipaz aktivitesi koloni etrafında görülebilir bir zon oluşması olarak kabul edilmiştir (9) . Esteraz aktivitesi Tween 80 opasite test besiyeri kullanılarak incelenmiştir [10 g bakteriyolojik pepton (Sigma), 5 g sodyum klorid (Sigma), 0.1 g kalsiyum klorid (Sigma), 15 g agar (Difco), 1000 mL distile su].…”