Enzymatic and hemolytic activities of Candida dubliniensis strains

Abstract

SUMMARYCandida dubliniensis is an opportunistic yeast that has been recovered from several body sites in many populations; it is most often recovered from the oral cavities of human immunodeficiency virus-infected patients. Although extensive studies on epidemiology and phylogeny of C. dubliniensis have been performed, little is known about virulence factors such as exoenzymatic and hemolytic activities. In this study we compared proteinase, hyaluronidase, chondroitin sulphatase and hemolytic activities in 18 C. dubliniensis and 30 C. albicans strains isolated from AIDS patients. C. albicans isolates produced higher amounts of proteinase than C. dubliniensis (p < 0.05). All the tested C. dubliniensis strains expressed hyaluronidase and chondroitin sulphatase activities, but none of them were significantly different from those observed with C. albicans (p > 0.05). Hemolytic activity was affected by CaCl 2 ; when this component was absent, we did not notice any significant difference between C. albicans and C. dubliniensis hemolytic activities. On the contrary, when we added 2.5 g% CaCl 2 , the hemolytic activity was reduced on C. dubliniensis and stimulated on C. albicans tested strains (p < 0.05).

Incidence and Virulence Traits of Candida Dubliniensis Isolated From Clinically Suspected Patients

“…C. dubliniensis possesses homologues of seven C. albicans secretory aspartyl proteinase genes (SAP) [29]. A prior study reported that proteinase activity of C. dubliniensis resulted in Pz range from 0.61 to 0.84 (mean = 0.75) [6], which is insignificantly low level of enzyme production when compared to the present result. In our study, proteinase production was observed at 66.66% and Pz ranged from 0.5-0.9 (mean=0.47) ( Table 1).…”

“…C. dubliniensis have been isolated from a wide range of geographical locations including Europe, North and South America, and Australia [22]. It recovered from several body sites in many populations, but it is most frequently recovered from the oral cavities of HIV-infected patients [6], and 15-30% has been reported from oral cavities of HIV-infected and AIDS patients [23]. Due to the use of inefficient sampling and identification methods or the sampling on the wrong anatomic sites, the prevalence of C. dubliniensis in normal healthy individuals has been underestimated probably [2].…”

“…Biofilm production was also associated with high-level antifungal drug resistance of the associated organisms [10]. Although extensive studies on epidemiology and phylogeny of C. dubliniensis have been performed, little is known about virulence factors such as extracellular enzymes and hemolytic activities [6]. Therefore, the present study was aimed to determine virulence factor (production of proteinase, phospholipase, lipase, esterase, biofilm formation, and hemolytic activity) of C. dubliniensis isolated from urine sample.…”

“…dubliniensis has recently been added up to the rising list of potential opportunistic pathogenic yeasts, and it has been recovered from several body sites in many populations; it is most frequently recovered from the oral cavities of HIV-infected patients [6]. Extracellular hydrolytic enzymes seem to play an important role in Candidal overgrowth [7].…”

Fluconazole and amphotericin-B resistance are associated with increased catalase and superoxide dismutase activity in Candida albicans and Candida dubliniensis

“…Enzymes involved in virulence, such as aspartyl proteinases, phospholipases, chondroitin sulfatase, and hyaluronidase, have been thoroughly studied. De Bernardis et al 24 and Linares et al 25 demonstrated that the level of aspartyl proteinase was signifi cantly higher in C. albicans than in C. dubliniensis, while no differences in phospholipase, chondroitin sulfatase, and hyaluronidase activities were observed [24][25][26] . In this study, we investigated the effect of fl uconazole and amphotericin B resistance on the SOD and catalase activities of C. albicans and C. dubliniensis.…”