Azizi Arash, Rezaei Masood
Associate professor, Department of Oral Medicine, Faculty of Dentistry, Ahwaz Jundi Shapoor University of Medical Sciences, Ahvaz, Iran.
J Dent Res Dent Clin Dent Prospects. 2009 Summer;3(3):78-81. doi: 10.5681/joddd.2009.020. Epub 2009 Sep 16.
Candidiasis is a common opportunistic infection in immunocompromised patients. Radiation to the head and neck affects the oral mucous membrane and produces xerostomia. Xerostomia alters the oral mucosa and predisposes them to colonization by Candida species. The aim of this study was evaluation of Candida species before and after radiotherapy.
Twenty patients undergoing radiation therapy were selected. None of the patients had taken any antibiotics and antifungals during the 3-month period prior to the study and did not take any during the study; in addition, they did not have any systemic conditions predisposing them to Candida infections. Swabs were collected from all the patients for Candida species culturing procedures 3±1 days before treatment and 2 and 4 weeks after radiotherapy. Swabs were inoculated on 2% Sabouraud's dextrose agar. Different types of Candida species are specified by colony color. Analysis of variance was used to assess the difference between the periods before and after treatment.
Mean age of the patients were 59.4 years. Ten patients were Candida-positive before the initiation of radiotherapy. Eighteen and 20 patients were Candida-positive after two and four weeks of radiotherapy, respectively. The most frequent type of Candida in this study was Candida albicans both before and after radiotherapy.
The present study suggests that patients undergoing head and neck radiotherapy should take antifungal agents, especially sugar-free agents, topical fluoride and salivary substitutes. The most commonly found Candida in this study was Candida albicans, which might be attributed to its high pathogenecity.
念珠菌病是免疫功能低下患者常见的机会性感染。头颈部放疗会影响口腔黏膜并导致口干。口干会改变口腔黏膜，使其易被念珠菌属定植。本研究的目的是评估放疗前后念珠菌属的情况。
选取20例接受放射治疗的患者。在研究前3个月内，所有患者均未服用任何抗生素和抗真菌药物，且在研究期间也未服用；此外，他们没有任何易患念珠菌感染的全身性疾病。在治疗前3±1天以及放疗后2周和4周，从所有患者处采集拭子用于念珠菌属培养程序。将拭子接种在2%的沙氏葡萄糖琼脂上。不同类型的念珠菌属通过菌落颜色来确定。采用方差分析来评估治疗前后各时期的差异。
患者的平均年龄为59.4岁。10例患者在放疗开始前念珠菌检测呈阳性。放疗2周和4周后，念珠菌检测呈阳性的患者分别为18例和20例。本研究中最常见的念珠菌类型在放疗前后均为白色念珠菌。
本研究表明，接受头颈部放疗的患者应服用抗真菌药物，尤其是无糖型药物、局部用氟化物和唾液替代品。本研究中最常见的念珠菌是白色念珠菌，这可能归因于其高致病性。
