In vitro differential activity of phospholipases and acid proteinases of clinical isolates of Candida

Abstract

Introduction: Candida yeasts are commensals; however, if the balance of normal flora is disrupted or the immune defenses are compromised, Candida species can cause disease manifestations. Several attributes contribute to the virulence and pathogenicity of Candida, including the production of extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate the in vitro activity of phospholipases and acid proteinases in clinical isolates of Candida spp. Methods: Eighty-two isolates from hospitalized patients collected from various sites of origin were analyzed. Phospholipase production was performed in egg yolk medium and the production of proteinase was verified in a medium containing bovine serum albumin. The study was performed in triplicate. Results: Fifty-six (68.3%) of isolates tested were phospholipase positive and 16 (44.4%) were positive for proteinase activity. C. tropicalis was the species with the highest number of positive isolates for phospholipase (91.7%). Statistically significant differences were observed in relation to production of phospholipases among species (p<0,0001) and among the strains from different sites of origin (p=0.014). Regarding the production of acid protease, the isolates of C. parapsilosis tested presented a larger number of producers (69.2%). Among the species analyzed, the percentage of protease producing isolates did not differ statistically (χ2=1.9 p=0.5901 (χ2=1.9 p=0.5901). Conclusions: The majority of C. non-albicans and all C. albicans isolates were great producers of hydrolytic enzymes and, consequently, might be able to cause infection under favorable conditions.

Enzymatic activity profile of a Brazilian culture collection of Candida albicans isolated from diabetics and non‐diabetics with oral candidiasis

“…D'Eça Júnior et al . also found a similar percentage of PL positive activity (76.6%) among clinical isolates of C. albicans , but a lower proportion of SAP‐positive isolates (48.9%) was observed by them. Others found percentages greater than 90% for both PL and SAP activity among clinical isolates of C. albicans .…”

“…The literature contains substantial data showing that the expression of these different extracellular hydrolytic enzymes has a large variation intra and inter species of Candida . Moreover, several studies focused on the production of PLs and SAPs by clinical isolates of Candida species obtained from different patients, such as those healthy with normal oral mucosa or oral candidiasis, or those with systemic diseases, such as diabetes mellitus .…”

Comparison of Virulence Factors of Different Candida Species Isolated from the Oral Cavity of Cancer Patients and Normal Individuals

“…An aliquot (10 µL) of the yeasts suspension was inoculated on the test medium and incubated at 37°C for seven days. The proteinase activity was measured as the diameter of clear zones around the colonies (19,20). Proteinase activity was determined using the amido black staining solution.…”

Candida parapsilosisand the neonate: epidemiology, virulence and host defense in a unique patient setting

“…Phospholipase activity of C. parapsilosis appears to be strain dependent as a large range of phospholipase activity has been reported [60,61,64,69–71]. The role of phospholipase in virulence remains unclear, although increased phospholipase activity is associated with increased adherence to epithelial cells (Figure 2b) [64].…”