Frequency of Candida species in the oral cavity of narcotics and stimulants smokers in Isfahan, using polymerase chain reaction-restriction fragment length polymorphism method

Candida species are a group of coexistent microorganisms in the oral cavity that opportunistically cause disease in vulnerable people, including addicts. This study is aimed at identifying and determining the frequency of Candida species in the oral cavity of the addicts to inform the epidemiological panel and to warn to prevent the resistance of the species.

In this study, sampling was done from the oral cavity of 83 addicts who referred to Addiction Treatment Centers in Isfahan, Iran, using moist sterile swab. The presence of yeast on the direct microscope slides of 58 samples was confirmed. To carry out culture and the primary identification, Sabouraud dextrose agar medium with chloramphenicol as well as HiCrome Candida agar medium was used. Isolates were identified by polymerase chain reaction (PCR) restriction fragment length polymorphism (using specific primers ITS1-ITS4 and MSP I enzyme) and Duplex PCR test (using specific primers CDU1-CDU2/CAL1-CAL2).

Out of 93 Candida isolates which had been isolated from 58 culture-positive samples of the oral cavity, Candida albicans (41.93%) were the most prevalent species, followed by Candida dubliniensis (24.73%), Candida glabrata (21.50%), Candida kefyr (8.60%), Candida tropicalis (2.15%), and Candida parapsilosis (1.07%), respectively. In 33 cases (56.90%), the presence of more than one Candida species was observed.

Compared to the studies conducted on the oral cavity of healthy controls, smoking certain drugs can have a significant effect on the presence and frequency of Candida species, particularly C. dubliniensis and C. glabrata.