TITLE:
Ultrastructural Analysis of in Vitro Adherence and Production of Acid Proteases by Clinical Isolates of Candida parapsilosis Sensu Stricto Following Growth in the Presence of Keratinous Substrates from Human Source
AUTHORS:
Ana Flávia L. Specian, Luciana Furlaneto-Maia, Célia G. T. J. Andrade, Marcia Cristina Furlaneto
KEYWORDS:
Adherence; Keratinic Substrates; SEM; Acid Proteinase
JOURNAL NAME:
Advances in Microbiology,
Vol.3 No.8A,
December
13,
2013
ABSTRACT: Candida parapsilosis is an increasingly
important human pathogen. However, little is known about its potential to cause disease. The aims of the present study were
to analyse the
production of acid proteinases by clinical isolates of C. parapsilosis in the presence of different
keratinous substrates from human sources (stratum corneum, nail and hair) and to verify the capability of yeast cells to adhere
and grow as biofilm on these substrates. By scanning electron microscopy, it was observed that all C.
parapsilosis sensu stricto isolates adhered to the keratinous substrates. For the isolate recovered from onychomycosis, the cell population attached to
stratum corneum and hair keratin consisted mainly of blastoconidia.
Differently, on nail keratin, pseudohyphae production was observed. Overall, there was a loose association
between yeast cells and keratinous substrates. However, on stratum corneum, flocculent extracellular material
was seen evolving cells from the onychomycosis isolate by forming a
biofilm-like structure. The
isolates recovered from onychomycosis and cutaneous lesion produced higher amount of acid proteinases in medium supplemented with nail keratin and stratum
corneum keratin, respectively, than that in salt
medium (absence of keratin). Furthermore, no
differences were observed in the amount of acid proteinases produced by the
isolate recovered from tracheal secretion in the media tested (absence and
presence of keratin substrates). The information
derived from this study will further our understanding of acid proteinase
production by C. parapsilosis isolates and provide an insight into pathogenic mechanisms in C. parapsilosis particularly from isolates recovered from superficial mycoses.