Genotyping of Candidaalbicans isolates from oropharyngeal candidiasis in head and neck cancer patients in Iran: Molecular epidemiology and SAP2 gene expression.

OBJECTIVE: Multilocus sequence typing is a powerful method for genotyping of clinical isolates of Candidaalbicans. Cross-contamination between the patients is an important reason for nosocomial infections. Oropharyngeal candidiasis (OPC) caused by C. albicans is an important problem in patients with head and neck cancer, in Cancer Institute of Tehran. Here we studied the endemic genotypes of C. albicans isolates and the relationship between geographic distributions, potential cross-contaminations and the expression of SAP2 gene, an important gene in oral candidiasis, with MLST groups. MATERIAL AND METHODS: A total of 32 clinical strains of C. albicans isolated from head and neck cancer patients with oropharyngeal candidiasis were subjected to MLST analysis and SAP2 gene expression was analyzed by Real-time PCR. RESULTS: We identified 75 polymorphic sites in 7 loci of C. albicans isolates and 30 diploid sequence types which 27 of them were found as new. After eBURST analysis, our results determined that CC 124 was the most prevalent group among all CCs. SAP2 gene showed high expression in almost all OPC patients' isolates, compared to the control. CONCLUSION: We found few genetically-related as well as identical isolates among the 32 Candida strains which indicated low cross-contaminations among the patients. There was no relationship between C. albicans MLST profiles and their geographic distribution, cancer type and SAP2 gene expression. This lack of correlation was possibly due to the small understudy population; hence, finding more relevance requires studies with a higher number of samples.

Oropharyngeal candidiasis in head and neck cancer patients in Iran: Species identification, antifungal susceptibility and pathogenic characterization.

OBJECTIVE: Oropharyngeal candidiasis (OPC) is the most frequent opportunistic fungal infection in head and neck cancer patients. This study was done to identify the Candida species, which cause OPC, and to evaluate their antifungal susceptibility pattern and pathogenic characteristics in Iranian head and neck cancer patients treated by radiotherapy. MATERIAL AND METHODS: The oral clinical samples were determined by culturing on CHROMagar, carbohydrate assimilation and ITS sequencing methods. Biofilm formation, phospholipase and proteinase activity and antifungal susceptibility were examined too. RESULTS: Among 54 patients with confirmed OPC, 39 (72.22%) patients were male and 15 (27.77%) were female. The most frequently Candida species from a total of 60 isolates was C. albicans (53.3%), followed by C. tropicalis (21.66%), C. glabrata (15%), C. kefyr (5%) and C. dubliniensis (1.66%). All the isolates were high-producers of biofilm. All of Candida isolates were proteinase positive and 47 isolates (81.04%) represented phospholipase activity. The maximum and minimum rates of antifungal resistance belonged to ketoconazole (93.75% of C. albicans and 89.28% of Candida non-albicans) and fluconazole (62.50% and 42.85% of C. albicans and Candida non-albicans), respectively. The most effective antifungal against all candida isolates was fluconazole. CONCLUSION: Our data can estimate abundance of OPC in male and female head and neck cancer patients and is helpful to use effective strategies for antifungal treatment, prophylaxis, and preventive therapies in these patients.

Socioeconomic determinants as risk factors for squamous cell carcinoma of the head and neck: a case-control study in Iran.

Our aim was to assess the association between different components of sociodemographic status and the risk of developing squamous cell carcinoma (SCC) of the head and neck after we had adjusted for the influence of the known behavioural risk factors of smoking and drinking alcohol. We selected 146 patients with histopathologically-confirmed SCC of the head and neck, and matched them for age and sex with 266 healthy controls for this case-control study. Personal details, occupation, socioeconomic status, smoking, and alcohol consumption were recorded. The association of sociodemographic variables with oral cancer was evaluated both separately and with a composite socioeconomic index. Chi squared tests, adjusted odds ratios (OR), and 95% CI were computed using logistic regression to estimate the effect. There was a significant difference between the two groups in the composite socioeconomic index (p<0.001). The group with "low" socioeconomic status had the highest risk of oral cancer (OR=3.89, 95% CI 1.28 to 11.82). Better-educated people with higher incomes had a lower risk of SCC of the head and neck after we had controlled for behavioural risk factors. However, marital and employment status and place of residence were not significantly associated with risk. Our findings confirm that some socioeconomic determinants were associated with the development of oral cancer in this study group.