Radiation used for head and neck cancer increases virulence in Candida tropicalis isolated from a cancer patient

BMC Infectious Diseases

Research Article

Luzmarina Hernandes¹  Elaine Sciuniti Benites Mansano¹  Ellen Sayuri Miazima²  Francielle Abigail Vilugron Rodrigues²  Terezinha Inez Estivalet Svidzinski²  Eliane Martins da Silva² 

[1] Department of Histopathology, State University of Maringá, Av. Colombo, 5760, C.P. 87020900, Maringá, Paraná, Brazil;Department of Medical Mycology, State University of Maringá, Av. Colombo, 5760, C.P, 87020-900, Maringá, PR, Brazil;

关键词: Gamma radiation;    Candida tropicalis;    Infection;    Biofilm;    Virulence;   

DOI  :  10.1186/s12879-017-2879-6

 received in 2017-08-07, accepted in 2017-12-04,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundStudies have shown that radiation from radiotherapy increases the yeast colonization of patients. However it is not clear, if such radiation alters the yeast itself. The aim of the present study was therefore to report the direct impact of gamma radiation on Candida tropicalis.MethodsC. tropicalis was obtained from a patient with a carcinoma, a suspension of this yeast containing 2.0 × 103 colony forming units per milliliter was prepared. It was submitted to gamma radiation dosage similar to that used in the treatment of head and neck cancer. After a cumulative dose of 7200 cGy some virulence attributes of C. tropicalis, including macro and micromorphological characteristics, adhesion and biofilm abilities, murine experimental infection and phagocytosis resistance were evaluated on irradiated and non-irradiated yeasts.ResultsAfter irradiation the colony morphology of the yeast was altered from a ring format to a smooth appearance in most colonies. Scanning electron microscopy revealed notable differences in the structures of both these colonies and the yeast cells, with the loss of pseudohyphae following irradiation and an increase in extracellular matrix production. The adherence and biofilm production of the yeast was greater following irradiation, both in terms of the number of yeasts and total biomass production on several abiotic surfaces and TR146 cells. The phagocytic index of the irradiated yeasts was not statistically different; however, the presence of cellular debris was detected in the kidneys of infected animals. Mice infected with irradiated yeasts developed an infection at the site of the yeast inoculation, although systemic infection was unchanged.ConclusionsOur findings show for the first time that C. tropicalis, one of the most important yeasts from colonization, which cause fatal candidemia in cancer patients, is affected by gamma irradiation, with changes to its virulence profile.

【 授权许可】

CC BY   
© The Author(s). 2017