To find out whether smoking affects the prevalenee and intraotal distiibution of Candida albieans, swabs and saliva samiiles from 100 healthy persons, smokers and non-smokers, were eultured lor the presenee of this fungus. The prevalenee was the same (35%) in both smokers and non-smokers. Among carriers, the mean eoneentration of C. albicans eolony-forming units in saliva of smokers was twice that of the non-smokers, and the i.solation frequeney of C. albicans at eaeh of 5 mueosal sites was also higher in smokers than in non-smoker.s. However, a wide variation was found, and these differenees were not signilieant at the 0.05 level. Men were carriers more often than women (p < ().t)25), and the nnicosal site from which C. albicans was reeovered most often was the posterior dorsum of the tongue. Although il has previously been elaimed that cigarette smoking influences the carrier state of C albicans. the ptesent study suggests that the effect is only slight.

Rapid identification of yeast species isolates from clinical samples is particularly important given their innately variable antifungal susceptibility profiles. Here, we have evaluated the utility of pyrosequencing analysis of a portion of the internal transcribed spacer 2 region (ITS2) for identification of pathogenic yeasts. A total of 477 clinical isolates encompassing 43 different fungal species were subjected to pyrosequencing analysis in a strictly blinded study. The molecular identifications produced by pyrosequencing were compared with those obtained using conventional biochemical tests (AUXACOLOR2) and following PCR amplification and sequencing of the D1-D2 portion of the nuclear 28S large rRNA gene. More than 98% (469/477) of isolates encompassing 40 of the 43 fungal species tested were correctly identified by pyrosequencing of only 35 bp of ITS2. Moreover, BLAST searches of the public synchronized databases with the ITS2 pyrosequencing signature sequences revealed that there was only minimal sequence redundancy in the ITS2 under analysis. In all cases, the pyrosequencing signature sequences were unique to the yeast species (or species complex) under investigation. Finally, when pyrosequencing was combined with the Whatman FTA paper technology for the rapid extraction of fungal genomic DNA, molecular identification could be accomplished within 6 h from the time of starting from pure cultures.

Two new cryptic sister species, Candida orthopsilosis and Candida metapsilosis, were recently identified by consistent DNA sequence differences among several genes within the genetically heterogeneous Candida parapsilosis complex. Here, we present data demonstrating that Pyrosequencing analysis of 20 nucleotides of internal transcribed spacer region 2 rapidly and robustly distinguishes between these three closely related Candida species.