9: Oral fungal infections

Chapter 9 Oral fungal infections

Candida species are fungi that are frequently encountered in the mouth of healthy individuals and as such can be considered to be normal residents of the oral microflora. The actual incidence of oral candidal carriage is estimated to be between 35 and 55% of healthy individuals, depending on the population group studied. Other fungi, such as Saccharomyces spp., Geotrichum spp. and Cryptococcus spp. are also encountered (Table 9.1), but their occurrences are rare and these are not generally implicated with oral infection. While Candida species are normally harmless commensals, when conditions in the mouth alter to one that favours proliferation of Candida, a shift to a pathogenic state can occur. As such, Candida infection is invariably an opportunistic one dependent upon some form of underlying host predisposition. Infection with Candida is described in the literature as a candidosis (candidoses, pl) or candidiasis (candidiases, pl). Both terms are widely used, although candidosis is often preferred due to its consistent use of the ‘osis’ stem with the terminology for other fungal infections. The term Candida originates from the Latin word candid, meaning white.

Table 9.1 Fungal species recovered from the human mouth.

Candida species Other fungal species (rare)
Candida albicans Paracoccidioides brasiliensis
Candida glabrata Aspergillus spp.
Candida tropicalis Cryptococcus neoformans
Candida krusei Histoplasma capsulatum
Candida lusitaniae Mucor spp.
Candida dubliniensis Saccharomyces spp.
Candida kefyr Geotrichum spp.
Candida guilliermondii Rhizopus spp.
Candida parapsilosis  

Evasion of host defences Promotes retention in the mouth
Invasion and destruction of host tissue Enhances pathogenicity

Hydrolytic enzymes

Destruction of host tissues by Candida may be facilitated by the release of hydrolytic enzymes into the local environment and secreted aspartyl proteinases (SAPs) and phospholipases are the enzymes most frequently implicated with C. albicans.

Jan 5, 2015 | Posted by in General Dentistry | Comments Off on 9: Oral fungal infections
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