Avaliação de fatores de virulência de isolados clínicos e ambientais do complexo Candida parapsilosis

• Main Author: Chacon, Dayane Araújo
• Publication Date: 2019
• Format: Bachelor thesis
• Language: eng
• Source: Repositório Institucional da UFRN
• Download full: https://repositorio.ufrn.br/handle/123456789/35819
• topic: Candida parapsilosis complex; Virulence factors; Clinical and environmental isolates

Background: In recent years, an attack of infections related to Candida-non-Candida albicans (CNCA) species and species of the Candida parapsilosis Complex frequently associated with infection has been observed. Over the past two decades, the prevalence of infections caused by C. parapsilosis Complex has increased dramatically. And because they are yeast commonly found as commensals of the human skin, C. parapsilosis Complex species are important agents of nosocomial infections, presenting as opportunistic fungal pathogen, being also associated with candidemia, and together with four other species Candida (C. albicans, C. glabrata, C. tropicalis and C. krusei) represent 90% of isolates from patients with candidemia. Objectives: The present work aimed to compare the pathogenic potential of environmental isolates (pigeon droppings), with clinical isolates (blood culture) of C. parapsilosis complex, through phenotypic analysis of in vitro virulence factors. Methods: In order to analyze the virulence factors, adherence tests were performed on human buccal epithelial cells (HBEC), enzyme secretion (phospholipases) and protease activity of all C. parapsilosis isolates. The results were also compared with reference strains of C. albicans ATCC 90098 and C. parapsilosis ATCC 22019. Results: Clinical isolates of C. parapsilosis showed a greater ability to adhere to the HBEC, with an average of 144.4 ± 67.5 cells adhered, as opposed to the environmental isolates, which had an average of 77.3 ± 63.4 cells adhered. Regarding protease activity, 78.3% (18/23) of the clinical isolates showed protease activity, while 78.3% (18/23) of the environmental isolates showed protease activity. Environmental isolates had a similar average phospholipase production than clinical isolates (Pz = 0.70 ± 0.08 and 0.77 ± 0.19, respectively). Conclusions: Our results suggest a similar pathogenic potential between clinical and environmental isolates, which may lead to infection of those who frequent pigeon environments, such as public squares, emphasizing that studies that evaluate the pathogenicity of environmental isolates of C. parapsilosis are still lacking in the literature.