Oral Candida isolates in patients undergoing radiotherapy for head and neck cancer: prevalence, azole susceptibility profiles and response to antifungal treatment

Abstract

Oral pseudomembranous candidiasis and mucositis were assessed in 39 patients receiving a total dose of 39-70 Gy radiotherapy for head and neck cancer. Mucositis was scored using the Radiation Therapy Oncology Group criteria, and oral candidiasis was diagnosed on the basis of clinical evaluation and quantitative laboratory findings. Radiation-induced mucositis was observed in 9/39 patients. Only 3/39 patients discontinued radiotherapy due to acute severe mucosal effects. Candidiasis (colony-forming units 35 to > or = 60/lesion) associated with mucositis was diagnosed in 30/39 patients: the most frequent aetiology of the infection was Candida albicans (n = 23), followed by Candida glabrata (n = 3), Candida krusei (n = 2), Candida tropicalis (n = 1) and Candida kefyr (n = 1). Patients with confirmed oral pseudomembranous candidiasis were treated with either fluconazole 200 mg/day or itraconazole 200 mg/day for 2 weeks. Clinical improvement and concomitant negative Candida cultures (mycologic cure) were the criteria determining a response to antifungal treatment. Etest revealed very low voriconazole MICs (0.004-0.125 microg/ml) for all isolates, and fluconazole resistance for eight C. albicans strains (MIC > 64 microg/ml) and for the C. krusei isolates (MIC > 32 microg/ml). The same strains showed itraconazole susceptibility dose dependence (MIC 0.5 microg/ml). Despite the itraconazole susceptible dose dependent MIC readings, all patients with oral pseudomembranous candidiasis caused by these strains responded to antifungal treatment with 200 mg/day itraconazole. Oral mycologic surveillance of patients undergoing radiotherapy for head and neck malignancies and susceptibility testing of isolates may be indicated in cases with mucositis-associated confirmed oral pseudomembranous candidiasis to ensure prompt administration of targeted antifungal treatment. On the basis of the low MIC values found, clinical evaluation of voriconazole is indicated for management of oral pseudomembranous candidiasis refractory to other azoles.

Sensitivity and lower protease activity of Candida albicans species isolated from Egyptian cancer patients after exposure to cytotoxic and/or radiotherapy treatment

“…This complies with a previous report, where C. albicans constituted 56.3% of patients receiving radiotherapy for head and neck neoplasms, while each of C. glabrata and C. tropicalis was present in 12.5% of the total patients (Tudela et al, 2002). Furthermore, most of the OPC samples from cancer patients in different regions were also identified as C. albicans with a range of 33 to 76% of the total isolates (Laverdiere et al, 2002;AlAbeid et al, 2004;Belazi et al, 2004). This study also showed higher prevalence of C. albicans in both solid and haematological cancer types, followed by C. krusei, then C. glabrata and finally, C. tropicalis in solid cancer types.…”

Antifungal suscepitibility profile of candida spp. oral isolates obtained from denture wearers

“…samples obtained from healthy individuals, with no signs of oral candidiasis. Several studies have reported the prevalence and antifungal susceptibility testing in individuals with oral candidiasis manifestations (2,4,10,14), but only a few studies have focused on samples obtained from Candida carriers without signs of infection (21).…”

Prevalence of drug-resistant opportunistic microorganisms in oral cavity after treatment for oral cancer

“…Among those that originate in the oral cavity, representative microorganisms include Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans (1,2). Most of these organisms have become drug-resistant, which has resulted in difficulties in curing the related infectious diseases.…”

“…Immunocompromised situations are frequently seen in older individuals, infants, people infected with HIV, and individuals with cancer; oral cancer can reduce immunity in the maxillofacial region (1,2). The principal treatments for oral cancer are surgical excision, radiotherapy, and chemotherapy, given alone or in combination (9).…”