Expression of SAP5 and SAP9 in Candida albicans biofilms: comparison of bloodstream isolates with isolates from other sources. (November 2013)

• Record Type: Journal Article
• Authors: Joo, Min Young; Shin, Jong Hee; Jang, Hee-Chang; Song, Eun Song; Kee, Seung Jung; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook
• Is Part Of: Medical mycology. Volume 51:Number 8(2013)
• Page Start: 892
• Page End: 896
• Publication Date: 2013-11
• Subjects: Medical mycology -- Periodicals; Veterinary mycology -- Periodicals; Mycology -- Periodicals; Mycoses -- Periodicals; Pathogenic fungi -- Periodicals; 616.969005
• DOI: 10.3109/13693786.2013.824623
• Languages: English
• ISSNs: 1369-3786

Abstract

<abstract> <title>Abstract</title> <p>Secreted aspartic proteases (Sap), encoded by a family of 10 <italic>SAP</italic> genes, are key virulence determinants in <italic>Candida albicans</italic>. Although biofilm-associated bloodstream infections (BSIs) are frequently caused by <italic>C. albicans, SAP</italic> gene expression in <italic>C. albicans</italic> biofilms formed by BSI isolates has not been evaluated. We compared the expression of two <italic>SAP</italic> genes, <italic>SAP5</italic> and <italic>SAP9</italic>, in <italic>C. albicans</italic> biofilms formed by BSI isolates with those formed by isolates from other body sites. Sixty-three <italic>C. albicans</italic> isolates were analyzed, comprising 35 BSI isolates and 28 from other sites. A denture-strip biofilm model was used, and expression of the two <italic>SAP</italic> genes was quantified by real-time RT-PCR during planktonic or biofilm growth. Mean <italic>SAP5</italic> expression levels of the BSI isolates were 3.59-fold and 3.86-fold higher in 24-h and 48-h biofilms, respectively, than in planktonic cells. These results did not differ from those for isolates from other sites (2.71-fold and 2.8-fold for 24-h and 48-h biofilms, respectively). By contrast, mean <italic>SAP9</italic> expression during biofilm formation was higher in BSI isolates (2.89-fold and 3.29-fold at 24 and 48 h, respectively) than in isolates from other sites (1.27-fold and 1.32-fold at 24 and 48 h, respectively; both, <italic>P</italic> < 0.001). These results show, for the first time, that both <italic>SAP5</italic> and <italic>SAP9</italic> are upregulated in <italic>C. albicans</italic> biofilms formed by BSI isolates, and that BSI isolates may have a greater capacity to express <italic>SAP9</italic> under biofilm conditions than isolates from other sites.</p> </abstract>