Comparison of oral candidiasis characteristics in head-and-neck cancer patients before and during radiotherapy.

Background: Patients undergoing head-and-neck radiotherapy are susceptible to Candida colonization and infection. This study aimed to identify oral Candida species type (ST), colony count (CC), and oropharyngeal candidiasis (OPC) in head-and-neck cancer patients, undergoing radiotherapy, before and 2 weeks after radiation. Materials and Methods: In this quasi-experimental study, head-and-neck cancer patients undergoing radiotherapy (up to 6000 cGy) were recruited. Samples were taken before and 2 weeks after radiation therapy (RT). CC was assigned using Sabouraud dextrose agar culture medium and morphological studies were performed to confirm OPC. For identification, polymerase chain reaction-restriction fragment length polymorphism was performed. Data were analyzed using Chi-square-test and kappa coefficient. P < 0.05 was considered statistically significant. Results: Twenty-one of 33 patients were Candida positive. The detected fungal species included Candida albicans (60%), Candida tropicalis (22%), Candida glabrata (9%), and other species (9%). Following RT, OPC and CC changed significantly (P = 0.003 and P = 0.001, respectively), whereas ST did not significantly change (P = 0.081). Two new species (Candida krusei and Candida parapsilosis) were detected after the intervention. The OPC, CC, and ST changes after RT were not significantly related to malignancy site or radiation dose (P > 0.05). Conclusion: The present study showed that OPC, CC, and ST were not related to the malignancy site. Following RT, OPC and CC changed significantly, while ST showed no significant change. The radiation dose and malignancy site had no effects on the OPC, CC, or ST alterations following RT.

Effect of nystatin and licorice on yeasts isolated from the oral lesions of patients with cancer under chemotherapy (in vitro study).

Background: Oral candidiasis is one of the most common manifestations of patients with cancer under chemotherapy. Due to many side effects of chemical antifungal products and various advantages of herbal extracts like licorice, this study was performed to compare the antifungal effects of nystatin and licorice on yeasts isolated from oral mucosa of patients with cancer receiving chemotherapy. Materials and Methods: In this in vitro study, a total number of 30 patients with oral candidiasis who received chemotherapy were examined. The samples were prepared by using swabs taken from the lesions, and after 48 h, they were transferred and cultured on Sabouraud dextrose agar. The antifungal effect of licorice was compared with nystatin using agar disk diffusion method. These data were entered in SPSS statistical software and were analyzed with Kruskal-Wallis and Mann-Whitney tests. (α = 5%). Results: Four types of candida were identified among all 30 oral lesions (Candida albicans, Candida glabrata, Candida stellatoidea, and Candida SP). The mean inhibition zone diameter around nystatin showed a significant difference (P < 0.001) between C. albicans (9.486), C. glabrata (8.627), C. stellatoidea (7.00), and C. sp (7.06) but the inhibition zone diameter around licorice was almost zero in all groups. Conclusion: Licorice extracts did not show any antifungal effects whereas nystatin showed the most antifungal effect against C. albicans.

Comparison of proteinase activity, hemolysin production, and adherence ability of Candida albicans isolates obtained from gastroesophageal lesions and urinary tract infections.

Background: Adhesion of Candida to host cell receptors, hemolysin production, and proteinase activity are assumed as principal virulence factors and infection establishment. These virulence factors are essential for colonization, biofilm formation, and attack on the host cells. Materials and Methods: A total of 97 Candida albicans isolates obtained from gastroesophageal lesions and urinary tract infections were included in the study. Adhesion assay, proteinase activity, and hemolysin production were measured. Statistical analysis was performed using the independent t-test and Chi-square test to compare quantitative and qualitative data between the two groups. Results: The adherence ability to the buccal epithelial cells was the same in the two groups. Proteinase activity was seen in all clinical isolates. Hemolytic activities were not statistically significant in the two groups. Conclusion: Our results recommend that the pathogenicity of C. albicans in the mucous membranes cannot be connected to the infected site.

The evaluation of the overexpression of the ERG-11, MDR-1, CDR-1, and CDR-2 genes in fluconazole-resistant Candida albicans isolated from Ahvazian cancer patients with oral candidiasis.

INTRODUCTION: Resistance to azole drugs has been observed in candidiasis due to their long-term use and poor response to treatment. Resistance to azole drugs in Candida albicans isolates is controlled by several genes including ERG11, CDR1, CDR2, and MDR1. In this study, the expression of the mentioned genes was evaluated in C. albicans isolates susceptible and resistant to fluconazole. METHODS: After identifying the Candida isolates using morphological and molecular methods, the minimum inhibitory concentration (MIC) and drug susceptibility were determined using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) method. RNA was then extracted and cDNA was synthesized from 24 C. albicans isolates from patients with cancer. Then, the mean expressions of these genes were compared in two groups using real-time polymerase chain reaction (RT-PCR). RESULTS: A total of 74 Candida isolates were obtained from the oral cavity of 61 cancer patients with oral candidiasis. After 24 h, 21.6% of the isolates were fluconazole-resistant, 10.8% were identified as dose-dependent, and the rest of the isolates (67.6%) were fluconazole-sensitive. The mean expressions of the CDR1 and MDR1 genes were significantly higher in the resistant isolates than in the sensitive ones. However, the ERG11 and CDR2 genes were not significantly increased in the resistant isolates. CONCLUSION: The increased mean expressions of the CDR1 and MDR1 genes had a greater effect on fluconazole resistance among the drug-resistant strains of C. albicans in chemotherapy patients. It seemed that the accumulation of chemotherapeutic drugs in this organism stimulated some regulatory factors and increased the expression of these two genes and ultimately helped to further increase their expression and resistance to fluconazole.

Identification of Candida Species and Antifungal Susceptibility in Cancer Patients with Oral Lesions in Ahvaz, Southern West of Iran.

BACKGROUND: Oral candidiasis is a common disease in cancer patients subject to chemotherapy. The aim of this study was to evaluate the risk factors of rising oral candidiasis incidence and to identify the Candida species isolated from oral lesions of cancer patients and their antifungal sensitivity. MATERIALS AND METHODS: A total of 645 patients with cancer were examined. Several Candida species were isolated from specimens and identified by morphological and molecular methods. The susceptibility of isolates to amphotericin B, fluconazole, and nystatin was also investigated. RESULTS: A total of 74 isolates of Candida were recovered from oral cavity of 61 cancer patients with oral candidiasis. The isolates included Candida albicans (n = 56; 75.5%), Candida glabrata (n = 4; 5.4%), Candida krusei (n = 5; 7%), Candida tropical (n = 7; 9.4%), and Candida kefyr (n = 2; 2.7%). A total (n = 72; 98.65%) of isolates were susceptible to nystatin, (n = 58; 78.4%) of them were susceptible to fluconazole, and (n = 8; 10.8%) of susceptible dose-dependent isolates were specified, (n = 46; 62.16%) of isolates were susceptible to amphotericin B. CONCLUSION: Finally, in addition to emphasis on topical nystatin application in the first stage of oral candidiasis in these patients, using alternative systemic drugs such as fluconazole and amphotericin B can be considered for the resistant candida isolates to nystatin.

Identification of Candida species in patients with oral lesion undergoing chemotherapy along with minimum inhibitory concentration to fluconazole.

BACKGROUND: Various species of Candida, especially Candida albicans was known as the most important etiological agent of fungal infections. Oral candidiasis is the most common fungal infection in patients undergoing chemotherapy. The purpose of this study was to identify Candida species from oral lesions of these patients and antifungal susceptibility of the clinical isolates. MATERIALS AND METHODS: Among 385 patients with cancer, 55 (14.3%) showed oral lesions. Oral swabs were performed to identify the yeasts using direct smear and CHROMagar medium. Micro dilution method was prepared in different concentrations of fluconazole and minimum inhibitory concentration and minimum fungicidal concentration of each species were compared. RESULTS: Oral candidiasis confirmed in 36 cases by direct examination and culture. C. albicans and non-albicans represented in 26 (72.2%) and 10 (27.8%) of the isolates, respectively. 76.5% of C. albicans and 23.5% non-albicans isolates were resistant to fluconazole. Data were shown that 62% and 30.7% of resistant strains of C. albicans were found in patient with gastrointestinal cancer and lymphoma respectively. CONCLUSION: Data were shown that C. albicans is the most commonly identified species in oral candidiasis and majority of fluconazole resistant C. albicans were found in patients with gastrointestinal cancer and lymphoma. Therefore, we recommend an alternative drug instead of fluconazole as a first line of treatment for these type of cancers and administration of fluconazole in patients undergoing chemotherapy should be prescribed in accordance with the type of cancer.