Adherence to buccal epithelial cells, enzymatic and hemolytic activities ofCandida isolatesfrom HIV-infected individuals

Abstract

Candida spp., along with other microorganisms are usually found in the normal flora of the human oral mucosa. However in HIV-infected individuals these yeasts can become opportunistic pathogens and lead to mucosal infections. The transformation from a harmless commensal to a virulent pathogen under conditions of dysfunctional host defense system is attributable to an extensive repertoire of selectively expressed virulence determinants. The present study was undertaken to analyze the production of four important virulence factors viz. adherence to buccal epithelial cells (BEC), proteinase activity, phospholipase activity and hemolysis, and to evaluate the correlation between these virulence factors in 65 Candida isolates from HIV-infected individuals with oral candidiasis. A total of 95.3%, 67.7%, 41.5% and 100% of the Candida isolates showed adherence to BEC, and proteinase, phospholipase and hemolytic activities, respectively. Production of proteinase and phospholipase enzymes was seen in 89.7% and 59.0% of C. albicans isolates and 34.6% and 15.4% of non-Candida albicans Candida (NAC) isolates, respectively. C. albicans showed significantly greater level of virulence factor expression with regards to adherence to BEC (P < 0.001), phospholipase production (P < 0.044) and hemolysis (P = 0.037) as compared to NAC. A correlative relationship between proteinase activity and adherence to BEC, as well as phospholipase production was noted.

Phospholipase, esterase and hemolytic activities of Candida spp. isolated from onychomycosis and oral lichen planus lesions

“…Hemolytic activity of Candida species did reports in many studies, previously [20,21,23,33]. In the study by Mane et al [20], 100% of the C. albicans isolates had beta hemolytic activity.…”

“…The complex is visible as insoluble crystals around the colony. The hemolytic factor of Candida species was described by many investigators [19,20,21,33,36]. Since C. albicans can utilize iron that is contained in hemoglobin and can rosset complement, opsonized surface red blood cell (SRBC), a hemolysis assay was developed to determine hemolytic factor to lyse erythrocytes [21].…”

Comparison of the hemolytic activity between C. albicans and non-albicans Candida species

“…In the present study, we evaluated a number of C. glabrata (n = 13) similar to the number of C. albicans (n = 20) strains, while the number of samples of C. glabrata was much lower compared to C. albicans in previously cited studies. 17,22 These data show the need for more studies with C. glabrata, which recently was shown to have the ability to produce α or β hemolysis. This species has emerged as a potential pathogen in the oral cavity of immunocompromised patients and little is known about its role in infection.…”

“…However, Mane et al 22 analyzed the hemolytic production of 65 Candida isolates from HIV-infected individuals and verified that C. albicans (n = 39) produced more hemolysin compared to all other species, including C. glabrata (n = 8). Ramesh et al 17 also evaluated the hemolytic capacity of 50 Candida strains from HIV patients, and verified that C. albicans (n = 45) produced a significantly higher amount of hemolysin than C. glabrata (n = 5).…”

Oral colonization by yeasts in HIV-positive patients in Brazil

“…Phospholipase and proteinase production was found in 100% of C. albicans isolates during this study. However, MANE et al 21 verified production of phospholipase and proteinase in only 59% and 89.7%, Among the isolates of non-albicans species identified in this study, 39% showed phospholipase activity and 21% exhibited proteinase activity. Previous studies also reported that proteinases and phospholipases are produced at high rates in C. albicans, whilst non-albicans Candida species usually present low rates of these enzymes 5,8 .…”