Differences in proteolytic activity and gene profiles of fungal strains isolated from the total parenteral nutrition patients

Abstract

Fungal infections constitute a serious clinical problem in the group of patients receiving total parenteral nutrition. The majority of species isolated from infections of the total parenteral nutrition patients belong to Candida genus. The most important factors of Candida spp. virulence are the phenomenon of “phenotypic switching,” adhesins, dimorphism of fungal cells and the secretion of hydrolytic enzymes such as proteinases and lipases, including aspartyl proteinases. We determined the proteolytic activity of yeast-like fungal strains cultured from the clinical materials of patients receiving total parenteral nutrition and detected genes encoding aspartyl proteinases in predominant species Candida glabrata—YPS2, YPS4, and YPS6, and Candida albicans—SAP1–3, SAP4, SAP5, and SAP6. C. albicans released proteinases on the various activity levels. All C. glabrata strains obtained from the clinical materials of examined and control groups exhibited secretion of the proteinases. All 13 isolates of C. albicans possessed genes SAP1–3. Gene SAP4 was detected in genome of 11 C. albicans strains, SAP5 in 6, and SAP6 in 11. Twenty-six among 31 of C. glabrata isolates contained YPS2 gene, 21 the YPS4 gene, and 28 the YPS6 gene. We observed that clinical isolates of C. albicans and C. glabrata differed in SAPs and YPSs gene profiles, respectively, and displayed differentiated proteolytic activity. We suppose that different sets of aspartyl proteinases genes as well as various proteinase-activity levels would have the influence on strains virulence.

Synergistic Effect of Quinic Acid Derived From Syzygium cumini and Undecanoic Acid Against Candida spp. Biofilm and Virulence

“…In C. albicans , SAPs known as sap protein family (Sap 1–10) are involved in the maintenance of cell wall integrity and regulation of attachment of C. albicans with human epithelial cells and neutrophils ( Buu and Chen, 2013 ). Other than C. albicans , some NAC species including C. dubliniensis, C. tropicalis, C. parapsilosis , and C. glabrata are also capable of producing SAPs ( Naglik et al, 2003 ; Sikora et al, 2011 ). In this study, qualitative measurement of SAPs production in all the tested strains revealed the intense reduction upon treatment with QA-UDA combinations.…”

“…SAPs have been recognized as one of the virulence factors of Candida spp. particularly, in C. albicans , ten aspartyl proteinases (Sap1–Sap10) facilitate the active penetration into the host cells ( Smolenski et al, 1997 ; Sikora et al, 2011 ). Among the 10 Saps, Sap1–Sap8 secretes and diffuses into surrounding medium, while Sap9 and Sap10 attaches to the cell surface ( Mayer et al, 2013 ).…”

Candida nivariensis in comparison to different phenotypes of Candida glabrata

“…Most C. glabrata strains (71%) tested positive for all three analysed genes – genotype YPS2 + YPS4 + YPS6 . The results of this study confirm the previously undertaken ones on the prevalence of those genes in C. glabrata strains isolated from patients under long‐term total parenteral nutrition . Most of the analysed C. nivariensis strains did not present any of the tested genes.…”

“…The results of this study confirm the previously undertaken ones on the prevalence of those genes in C. glabrata strains isolated from patients under long-term total parenteral nutrition. 28 Most of the analysed C. nivariensis strains did not present any of the tested genes. This could indicate a lower virulence potential than in C. glabrata.…”

Candida glabrata: a review of its features and resistance

“…In C. albicans, ten genes encoding for lipases have been identified and it has been shown that mutants were significantly less virulent in a murine intravenous infection model. Sequences similar to C. albicans (LIP1-10) were also detected in C. tropicalis, but not in C. glabrata [78][79][80][81][82].…”