Biotyping and Virulence Properties of Skin Isolates of Candida parapsilosis

Abstract

The biotype and virulence of skin isolates of Candida parapsilosis were compared with blood isolates of the same fungus. Morphotype, resistotype, and electrophoretic karyotype determinations did not reveal any special cluster with a unique or dominant pathogenic feature among all of the isolates, regardless of their source. However, all cutaneous isolates had uniformly elevated secretory aspartyl-protease (Sap) activity, more than four times higher than the enzyme activity of the blood isolates. They were also highly vaginopathic in a rat vaginitis model, being significantly more virulent than blood isolates in this infection model. In contrast, skin isolates were nonpathogenic in systemic infection of cyclophosphamide-immunodepressed mice, while some blood isolates were, in this model, highly pathogenic (median survival time, 2 days, with internal organ invasion at autopsy). Finally, skin isolates did not differ, as a whole, from blood isolates in their adherence to plastic. This property was associated with a morphotype, as defined by a colony with continuous fringe, which was present among both skin and blood isolates. While confirming the genetic heterogenicity of C. parapsilosis, our data strongly suggest that the potential of this fungus to cause mucosal disease is associated with Sap production and is substantially distinct from that of systemic invasion.

Haemolytic and proteinase activities in clinical isolates of Candida parapsilosis and Candida tropicalis with reference to the isolation anatomic site

“…The occurrence of Saps has been previously demonstrated in C. parapsilosis and C. tropicalis isolates obtained from distinct clinical samples. [19][20][21][22] However, this is the first report that correlates protease production by isolates of different species obtained from the same anatomic site. Considering isolates recovered from tracheal secretion, the C. parapsilosis isolates had higher activity than C. tropicalis isolates.…”

“…18 Most of the clinical isolates of C. parapsilosis and C. tropicalis are proteinase producers. [19][20][21][22] As well for C. albicans, the relationship between the production of Saps and invasiveness has been established for C. tropicalis. Proteinases were observed on the surface of fungal elements penetrating tissues during disseminated infection and evading macrophages after phagocytosis of yeast cells.…”

Phenotypic Switching and β‐N‐Acetylhexosaminidase Activity of the Pathogenic Yeast Trichosporon asahii

“…Determination of extracellular enzymatic activity: 1) Secreted aspartic proteinase activity. The activity was measured spectrophotometrically (2). Cells were incubated in YYG medium (1.17% yeast carbon base, 0.01% yeast extract, 0.27% glucose) at 37 C for 48 hr.…”

Phospholipase and protease activities in clinical Candida isolates with reference to the sources of strains

“…Phospholipase and protease activities are considered to play important roles in the pathogenesis of opportunistic fungi. There are a number of publications available examining phospholipase and protease production in C. albicans isolates from various sources [1][2][3][4][5][6][7][8][9][10]17] and on their role in the pathogenesis of invasive candidosis [10]. The roles of these two hydrolytic enzymes in C. albicans, the most pathogenic species of the genus, seems to be related to its virulence, while only a few reports in the literature investigate their existence and relationship to virulence in other yeast species.…”

“…Strains with higher proteolytic activity were shown to be more virulent [6]. De Bernardis et al [7] reported high acid-proteinase-secretory activity in vitro in all C. parapsilosis strains isolated from outpatients with vaginitis. Yamamoto et al [30] found 13 of 18 strains of C. tropicalis and 11 of 18 strains of C. parapsilosis had proteolitic activity while none of the 52 C. glabrata strains tested had this activity.…”