title: 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.
  
  
  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.
authors: Kuwait University, Faculty of Dentistry, Health Sciences Center, Kuwait. Electronic address: arjuna@hsc.edu.kw.
authors: Arjuna N B
authors: AN
authors: Ellepola
authors: University of Queensland, School of Dentistry, Brisbane, Australia.
authors: L P
authors: LP
authors: Samaranayake
authors: Kuwait University, Faculty of Medicine, Health Sciences Center, Kuwait.
authors: Z U
authors: ZU
authors: Khan
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001393:Azoles / Q000494:pharmacology / Q000627:therapeutic use; D002176:Candida albicans / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism* / Q000472:pathogenicity; D002180:Candidiasis, Oral / Q000188:drug therapy / Q000382:microbiology*; D003778:Dentures; D003920:Diabetes Mellitus; D054714:Echinocandins / Q000494:pharmacology; D004789:Enzyme Activation; D005110:Extracellular Space; D006801:Humans; D008826:Microbial Sensitivity Tests; D010740:Phospholipases / Q000096:biosynthesis*; D011090:Polyenes / Q000494:pharmacology / Q000627:therapeutic use; D012907:Smoking; D037521:Virulence Factors
chemical_list: D000935:Antifungal Agents; D001393:Azoles; D054714:Echinocandins; D011090:Polyenes; D037521:Virulence Factors; D010740:Phospholipases
keywords: Antimycotics; Candida albicans; Phospholipase