Proteomics of drug resistance in Candida glabrata biofilms

Abstract

Candida glabrata is a fungal pathogen that causes a variety of mucosal and systemic infections among compromised patient populations with higher mortality rates. Previous studies have shown that biofilm mode of the growth of the fungus is highly resistant to antifungal agents compared with the free-floating or planktonic mode of growth. Therefore, in the present study, we used 2-D DIGE to evaluate the differential proteomic profiles of C. glabrata under planktonic and biofilm modes of growth. Candida glabrata biofilms were developed on polystyrene surfaces and age-matched planktonic cultures were obtained in parallel. Initially, biofilm architecture, viability, and antifungal susceptibility were evaluated. Differentially expressed proteins more than 1.5-fold in DIGE analysis were subjected to MS/MS. The transcriptomic regulation of these biomarkers was evaluated by quantitative real-time PCR. Candida glabrata biofilms were highly resistant to the antifungals and biocides compared with the planktonic mode of growth. Candida glabrata biofilm proteome when compared with its planktonic proteome showed upregulation of stress response proteins, while glycolysis enzymes were downregulated. Similar trend could be observed at transcriptomic level. In conclusion, C. glabrata biofilms possess higher amount of stress response proteins, which may potentially contribute to the higher antifungal resistance seen in C. glabrata biofilms.

Fluconazole resistance in Candida glabrata is associated with increased bud formation and metallothionein production

“…More recently, the overexpression of 17 gene products and the downregulation of seven proteins in C. glabrata biofilms formed in the wells of polystyrene culture plates was shown by our group as a result of antifungal exposure of the biofilm phase of C. glabrata (Seneviratne et al, 2010). However, in the present study, where changes in the proteome following FL exposure of the planktonic phase of C. glabrata were evaluated, not one of these (up-or downregulated) proteins was observed, which demonstrates the versatility of this fungus in adapting to different environmental conditions.…”

Histidine Decarboxylase Is Identified as a Potential Biomarker of Intestinal Mucosal Injury in Patients with Acute Intestinal Obstruction

“…Therefore, 2-D DIGE is a more accurate quantitative and qualitative method than 2-DE (37) and thus has been applied in proteomic studies of human diseases including cancer (38)(39)(40), autoimmune uveitis (41), chronic inflammatory demyelinating polyneuropathy (42) and psychiatric disease (43). In addition, 2-D DIGE has also been applied for purification of human monoclonal antibodies (44) and determination of drug resistance (45).…”

Silver Nanoparticles to Fight Candida Coinfection in the Oral Cavity

“…In general, C. glabrata biofilms have reduced thickness, are less profuse, and are devoid of hyphae compared with C. albicans biofilms (Samaranayake et al, 2005;Seneviratne et al, 2010). Consequently, all these features can help to explain the better effect of SN against C. glabrata biofilms, which is still of major clinical importance because this species is known to be resistant to conventional antifungal drugs, making it difficult to eliminate.…”

“…Many different mechanisms have been proposed to clarify Candida biofilm resistance, such as the robust biofilm architecture, decreased metabolic activity, altered gene expression, the extracellular matrix, the presence of "persister cells," and higher antioxidative capacities (Mah and O'Toole, 2001;Ramage et al, 2005;Seneviratne et al, 2010). Thus, this process is multifactorial and the accurate mechanism by which Candida species in the biofilm mode can acquire resistance remains to be understood.…”