A Study of Virulence Factors: Proteinase, Phospholipase, and Biofilm in HIV/AIDS Patients

Objectives: Candida species, considered as one of the most pathogenic yeasts, is frequently isolated from the immunocompromised patients. The aim of the study was to determine proteinase, phospholipase and adherence activities by Candida species isolated from HIV/AIDS patients that contribute both to the pathogenesis of superficial and systemic candidiasis. Material and methods: The present investigation deals with a detailed study of three hundred and fourteen samples recovered from diverse clinical sources viz; sputum, blood, urine, oral swab and CSF samples from HIV/AIDS patients studied. The identification of Candida species was done by germ tube test, cornmeal agar test, sugar assimilation and fermentation tests and Vitek-2 yeast identification system. Proteinase and phospholipase estimation and adherence assay was determined for all the isolates. Results: One hundred and forty three isolates of Candida species were recovered from three hundred and fourteen diverse clinical sources. C.albicans (82.51%) was the predominant species followed by C.tropicalis (6.29%), C.krusei (4.89%), C.parapsilosis (3.49%) and C.glabrata (2.79%). 100% C.parapsilosis >89% C.tropicalis >83.9% C.albicans >75% C.glabrata >42.8% C.krusei exhibited phospholipase activity whereas 80% C.parapsilosis >77% C.tropicalis >75% C.glabrata >61.1% C.albicans >42.8% C.krusei exhibited proteinase activity and 83.8% C.albicans >80% C.parapsilosis >77.7% C.tropicalis >75% C.glabrata >71.4% C.krusei exhibited adherence activity. Conclusion: The present study showed an isolation of C.albicans followed by C.tropicalis, C.krusei, C. parapsilosis and C.glabrata in different clinical samples from HIV/AIDS patients. The overall numbers of C.albicans producing proteinase, phospholipase and inducing biofilm formation were more than the number of Candida Non. albicans producing these virulence factors. This result suggests that the biofilm production is important for Candida species in addition to other mechanisms to establish infections.