title: Hemolytic capability and expression of a putative haem oxygenase-encoding gene by blood isolates of Candida tropicalis are influenced by iron deprivation and the presence of hemoglobin and erythrocytes.
abstract: Although hemolytic activity is known to be a putative virulence factor contributing to candidal pathogenesis, its production by Candida tropicalis, a species closely related to Candida albicans, is poor understood. The present study was undertaken to evaluate the hemolytic activity and the expression level of a putative haem oxygenase encoding gene by blood isolates of C. tropicalis following growth in iron deprivation, and in the presence of hemoglobin and erythrocytes. The lowest values of hemolytic activity were observed in cell-free culture supernatants of isolates growing in iron-restricted medium (RPMI medium and RPMI medium supplemented with iron chelator bathophenanthrolindisulphonic acid). Hemolysis was increased in the presence of either hemoglobin or erythrocytes. Reverse transcriptase PCR analysis showed that the putative haem oxygenase encoding gene (CtHMX1), potentially related with iron uptake, was up-regulated (p < 0.001) following growth in iron deprivation and in the presence of hemoglobin; CtHMX1 was repressed in the presence of human erythrocytes (p < 0.001). Our data suggest that hemoglobin had positive effect in the production of hemolytic factor and gene expression related to iron uptake in C. tropicalis.
authors.affiliation: Department of Microbiology, State University of Londrina, Paraná, Brazil; State University of North of Paraná, Brazil.
authors.forename: Emanuele Julio Galvão
authors.initials: EJ
authors.lastname: França
authors.affiliation: Technological Federal University of Paraná, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Furlaneto-Maia
authors.affiliation: Department of Microbiology, State University of Londrina, Paraná, Brazil. Electronic address: furlaneto@uel.br.
authors.forename: Márcia Cristina
authors.initials: MC
authors.lastname: Furlaneto
mesh_terms: D001769:Blood / Q000382:microbiology*; D041022:Candida tropicalis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D002177:Candidiasis / Q000097:blood / Q000382:microbiology; D003470:Culture Media; D004271:DNA, Fungal / Q000302:isolation & purification; D004912:Erythrocytes / Q000378:metabolism*; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics; D005658:Fungi / Q000254:growth & development; D006419:Heme Oxygenase (Decyclizing) / Q000235:genetics* / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006460:Hemolysin Proteins; D006461:Hemolysis; D006801:Humans; D007501:Iron / Q000378:metabolism*; D012331:RNA, Fungal / Q000302:isolation & purification; D015854:Up-Regulation; D037521:Virulence Factors / Q000378:metabolism
chemical_list: D003470:Culture Media; D004271:DNA, Fungal; D005656:Fungal Proteins; D006454:Hemoglobins; D006460:Hemolysin Proteins; D012331:RNA, Fungal; D037521:Virulence Factors; D007501:Iron; D006419:Heme Oxygenase (Decyclizing)
keywords: Hemoglobin; Hemolytic activity; Iron deprivation; Putative CtHMX1 gene