Lakshman P. Samaranayake

Candida species are the most common fungal pathogens isolated from the oral cavity. Their oral existence both as a commensal and an opportunist pathogen has intrigued clinicians and scientists for many decades, and recent investigations have revealed many attributes of this fungus contributing to its pathogenicity. In addition, the advent of the human immunodeficiency virus infection and AIDS has resulted in a resurgence of oral Candida infections. Clinicians are witnessing not only classic forms of the diseases but also newer clinical variants such as erythematous candidosis, rarely described hithertofore. Therefore, this review is an attempt at detailing the current knowledge on Candida and oral candidoses together with the newer therapeutic regimes employed in treating these mycoses.

This review has provided an overview of variants of oral mucosal candidiasis and current therapeutic techniques followed by an outline of the rare oral mycoses and their management. The advent of the HIV infection and the increasing prevalence of compromised individuals in the community as a consequence of surgical and medical advances have resulted in a resurgence of opportunistic infections, including oral candidiasis and other rare mycoses that were once considered exotic. It is now recognized that oral candidiasis may present in many clinical guises, including the classic white lesion of thrush as well in as nondescript, red mucosal lesions that may confound the unwary clinician. Other mycotic diseases, such as aspergillosis, cryptococcosis, histoplasmosis and mucormycosis, may manifest intra-orally, both as primary lesions and as secondary manifestations of systemic disease. Periodontal manifestations of mycotic diseases are rare. If at all, such lesions may present as erythematous areas as in linear gingival erythema and rarely as ulcerations in exotic mycoses. Most of the oral mycoses respond well to either topical or systemic therapy with the polyenes or azoles. In general, the management of oral fungal infections has been revolutionized by the triazole group of drugs, fluconazole and itraconazole, although recent reports indicate an alarming increase of resistant organisms, in particular to fluconazole. © 2009 Blackwell Munksgaard.

A total of 80 Candida isolates representing 14 species were examined for their respective responses to an in vitro hemolytic test. A modification of a previously described plate assay system where the yeasts are incubated on glucose (3%)-enriched sheep blood agar in a carbon dioxide (5%)-rich environment for 48 h was used to evaluate the hemolytic activity. A group of eight Candida species which included Candida albicans (15 isolates), C. dubliniensis (2), C. kefyr (2), C. krusei (4), C. zeylanoides (1), C. glabrata (34), C. tropicalis (5), and C. lusitaniae (2) demonstrated both alpha and beta hemolysis at 48 h postinoculation. Only alpha hemolysis was detectable in four Candida species, viz., C. famata (3), C. guilliermondii (4), C. rugosa (1), and C. utilis (1), while C. parapsilosis (5) and C. pelliculosa (1) failed to demonstrate any hemolytic activity after incubation for 48 h or longer. This is the first study to demonstrate the variable expression profiles of hemolysins by different Candida species.