Mutants with heteroresistance to amphotericin B and fluconazole in Candida

Brazilian Journal of Microbiology

A.l.r. Claudino²  R.f. Peixoto Junior²  M.s.c. Melhem¹  M.w. Szeszs¹  J.p. Lyon¹  J.k. Chavasco²  M.c. Franco² 

[1] ,Universidade Federal de Alfenas Departamento de Ciências Biológicas Alfenas MG ,Brasil

关键词: Amphotericin B;    antifungal agents;    Candida spp.;    fluconazole;    heteroresistance;    resistant mutants;   

DOI  :  10.1590/S1517-83822009000400028

来源: SciELO

【 摘 要 】

Several studies have reported the occurrence of infections caused by Candida yeasts as well as the increasing prevalence of non albicans species. The aim of the present work is focused on the obtaining of heteroresistance to amphotericin B and fluconazole in Candida species using two distinct methodologies: selection and induction. Resistant samples were obtained by selective pressure using a medium with fluconazole for growth, followed by growth in a medium with amphotericin B. The selective pressure was also created beginning with growth in amphotericin B medium followed by growth in fluconazole medium. Concomitantly, samples were submitted to the induction of resistance through cultivation in increasing concentrations of fluconazole, followed by cultivation in increasing concentrations of amphotericin B. Subsequently, the induction began with amphotericin B followed by fluconazole. Three samples resistant to fluconazole and amphotericin B were obtained, two by induction (C. glabrata and C. tropicalis) and one by selection (C. tropicalis). Both C. tropicalis originated from the same wild sample. After successive transfers for drug free medium, only the sample obtained by selection was able to maintain the resistance phenotype. These results suggest that the phenotype of heteroresitance to fluconazole and amphotericin B can be produced by two methodologies: selection and induction.

【 授权许可】

CC BY-NC   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License