Identification of candida albicans and nonalbicans candida resistant species in tobacco users and oral squamous cell carcinoma patients: Comparison of HiCrome agar and automated VITEK 2 system

INTRODUCTION: Candida is most common fungal pathogen in the immunocompromised and medically ill patients. Higher prevalence of Candida albicans has been reported in tobacco users and oral squamous cell carcinoma (OSCC) patients which may be due to immunosuppression. Recently, emergence of nonalbicans candida (NAC) species resistant to conventional antifungal treatment has been observed that requires accurate identification of organisms at species level for reduction of progression of suspicious oral lesions toward malignancy. AIMS AND OBJECTIVES: To detect and compare the prevalence of C. albicans and NAC species smokeless tobacco chewers, histopathologically confirmed oral squamous cell carcinoma patients and the normal individuals. Effectiveness of automated Vitek 2 system in comparison to HiCrome agar color media in the identification of the candida species was also evaluated. METHODOLOGY: One hundred and fifty patients (90 males, 60 females) aged between 20 and 76 years were divided into three groups: Group I individuals with habit of chewing Gutka, and betel quid/pan masala with or without tobacco, Group II individuals with clinically and histopathologically confirmed oral squamous cell carcinoma and Group III comprised of controls. Salivary samples were cultured on HiCrome agar color media and results were compared with those of Vitek 2 system in the accurate identification of candida species. Data were statistically analyzed and Chi-square test was used to estimate the effectiveness of color and Vitek method in the identification of candida species in all the three groups. P < 0.05 was considered to be statistically significant. RESULTS: HiCrome agar color method identified six candida isolates C. albicans, Candida tropicalis, Candida krusei and Candida glabrata isolates in all the three groups, with 0.00 unidentified organisms (P = 0.00001) whereas VITEK 2 system identified five isolates of candida; C. albicans, Candida famat, Candida ciferri, Candida gulleri, C. tropicalis, unidentified organisms were observed in 26% of subjects. Further confirmation by supplemental tests indicated the presence of two or three organisms of different species/or subspecies with low reactivity biopattern. Higher incidence of opportunistic infections was seen in Group II OSCC patients (P = 0.00001). CONCLUSION: The results suggested that there is shift toward NAC species, with higher species diversity in OSCC patients followed by gutka, betel quid/pan masala with or without tobacco users. Conventional agar media culture methods of species identification should be used in conjunction with automated Vitek 2 method for better control of candida-associated oral cancer.