Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

Abstract

Introduction: Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs) and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. Methods: One hundred fi fty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. Results: Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. Conclusions: Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions.

Prevalence, virulence factors and antifungal susceptibility of Candida spp. isolated from bloodstream infections in a tertiary care hospital in Brazil

“…Proteinase production aids host immune system evasion through the degradation of albumin, α‐macroglobulin and other human proteins . Membrane phospholipid hydrolysis by phospholipase leads to cell lysis and causes tissue damage . In this study, virulence attributes production was more intense in C. albicans than in the other studied species.…”

“…Virulence factor production is also important for the establishment of candidemia. The production of extracellular hydrolytic enzymes, such as phospholipase and proteinase, can facilitate adherence and escape from the host immune system and can cause tissue damage . Haemolysin is another virulence factor that facilitates disseminated infection .…”

“…The production of extracellular hydrolytic enzymes, such as phospholipase and proteinase, can facilitate adherence and escape from the host immune system and can cause tissue damage. 14,15 Haemolysin is another virulence factor that facilitates disseminated infection. 15 Both C. albicans and NCA species can produce these virulence factors.…”

Potential Targets for Antifungal Drug Discovery Based on Growth and Virulence in Candida albicans

“…Evidence from one study strongly suggested that the invasive C. albicans strains exhibited significantly stronger extracellular phospholipase activity than the noninvasive strains (69). Mattei et al (2013) reported that high levels of phospholipase and germ tube production in C. albicans can facilitate permeability of the epithelial barrier because phospholipase activity is concentrated in hyphal tips (70).In addition, the secreted aspartyl proteinases (Saps) of C. albicans are important virulence factors which make this pathogen more adapted than others to overcoming residual host barriers to infection (71,72).…”

Identificação De Microrganismos Veiculados Por Vetores Mecânicos No Ambiente Hospitalar Em Uma Cidade Da Região Noroeste Do Estado Rio Grande Do Sul

“…Os isolados com características de bacilos gram-negativos foram submetidos às técnicas de identificação para enterobactérias (citocromo-oxidase, produção de indol, motilidade, produção de sulfeto de hidrogênio, utilização de citrato, produção de urease, desaminação de fenilalanina, descarboxilação de aminoácidos (lisina, ornitina e arginina), oxidação-fermentação de açúcares (glicose, lactose e sacarose) e o kit comercial para não fermentadores NFII (Probac do Brasil -São Paulo) conforme as instruções do fabricante as leveduras foram submetidas aos testes de urease e da formação do tubo germinativo. [16][17][18][19] As análises microbiológicas foram realizadas no laboratório de microbiologia da Universidade Regional Integrada do Alto Uruguai e das Missões -Santo Ângelo/RS.…”