title: An assessment of candidal colonization and species differentiation in head and neck cancer patients receiving radiation.
abstract: BACKGROUND
  Oral colonization with Candida species has been observed in upto 93% of patients receiving radiation for head and neck cancer. With immunosuppression there is a trend of emergence of rare species. The present study aimed to assess species and colonization of candida at different stages of radiation therapy for head and neck cancer.
  
  
  METHODS
  Oral rinses of thirty cancer patients receiving a six weeks course of radiation therapy for head and neck cancer were taken at two intervals; first at the start of radiation (0 Grays), and second at completion of radiation (60 Grays). The oral rinse was streaked onto a differential media (CHROMagar®) plates and incubated at 37ºC for 48 hours. Colony forming units (CFU) were counted and species were differentiated. Fifteen healthy controls were compared.
  
  
  RESULTS
  The candida albicans colony count (CFU/ml) at baseline, 0 Grays radiation ranged from 50 to 1820 CFU/ml in cases and from 0 to 300 CFU/ml in controls. C. albicans was seen in all cases (100%) and most of the controls (86.66%). Other species such as C. Krusei, C. parapsilosis, C .tropicalis, and C. glabrata were observed with a frequency of 10%, 6.66%, 3.33%, and 3.33% respectively in the cases. However, no species other than C. albicans was observed in controls.
  
  
  CONCLUSIONS
  Immunosupression of radiation therapy patients led to the development of species other than Candida albicans, which is the most prevalent species. Thus it can be inferred that there is emergence of the opportunistic fungal pathogens in patients with immunosupression.
authors.affiliation: Department of Oral and Maxillofacial Pathology, College of Dental Sciences, Chitwan Medical College,Bharatpur, Chitwan, Nepal.
authors.forename: M
authors.initials: M
authors.lastname: Shrestha
authors.affiliation: Department of Oral Pathology and Microbiology, Manipal college of Dental Sciences, Mangalore, India.
authors.forename: K
authors.initials: K
authors.lastname: Boaz
authors.affiliation: Department of Oral Pathology and Microbiology, Manipal college of Dental Sciences, Mangalore, India.
authors.forename: N
authors.initials: N
authors.lastname: Srikant
authors.affiliation: Department of Community Density, College of Dental Science, Chitwan Medical College, Bharatpur, Chitwan, Nepal.
authors.forename: A
authors.initials: A
authors.lastname: Shakya
mesh_terms: D000328:Adult; D000368:Aged; D002175:Candida; D002176:Candida albicans; D041221:Candida glabrata; D041022:Candida tropicalis; D002180:Candidiasis, Oral / Q000209:etiology* / Q000382:microbiology; D016022:Case-Control Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications / Q000532:radiotherapy*; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged
keywords: candidal colonization; CHROMagar®; differential media; immunosupression.