Exoenzymes Activity and Biofilm Production in Candida Species Isolated from Various Clinical Specimens in Benha University Hospital, Egypt

Abstract

Background: The frequency of severe systemic fungal diseases has increased in the last few decades. Aims: This study was done to speciate the candida isolates, to determine their antifungal susceptibility pattern and to detect biofilm formation and exoenzymes (phospholipase and proteinase) production. Place and Duration of Study: This is a Six-months Cross sectional study conducted in ICU and Microbiology & Immunology departments, Benha University, Egypt Methodology: The study was conducted on 75 Candida spp. isolated from various clinical samples of patients admitted in ICU. The Candida isolates were identified upto species level. Antifungal susceptibility testing was done by disc diffusion method. The biofilm formation was assessed by inoculating the isolates in conical polystyrene test tube containing Sabouraud’s dextrose broth supplemented with glucose. Proteinase activity was detected by using plates containing bovine serum albumin (BSA) agar. Phospholipase activity was detected by using egg yolk agar. Results: Seventy five Candida spp. were isolated from different clinical samples. C. albicans was isolated from 39(52%) samples. Non-albicans Candida (NAC) spp. were isolated from 36 (48%) clinical specimens. Forty one (54.7%) out of 75 Candida species isolates obtained from the clinical isolates produced biofilm. Out of 39 C. albicans isolates 20 (51.3%) produced biofilm, while out of 36 NAC species isolates 21 (58.3%) produced biofilm. The number of total proteinase positive isolates were 50 (66.7%). C. albicans was higher than that of the NAC isolates (29 [66.7%] versus 21 [58.3%]). Phospholipase positive isolates of C. albicans was higher than that of the NAC isolates (32[82.1%] versus 37[49.3%]). All isolates were susceptible to amphotericin B and ketoconazole. Resistance to fluconazole was found in 8 isolates (22.2%) of NAC spp. and 2 isolates (5.1%) of C. albicans isolates. Conclusion: The isolation of C. albicans were 39 (52%) in different clinical samples and isolation of NAC spp. were 36(48%). So NAC spp.  is no longer overlooked as these organisms are emerging pathogens. The number of NAC producing proteinase, phospholipase and biofilm are more than the number of C. albicans producing these virulence factors. The C. albicans and NAC showed 100% susceptiblity to amphotericin B  and ketokonazole while fluconazole showed resistance in 22.2% of NAC spp. and 5.1% of C. albicans isolates. All resistant Candida species to fluconazole were biofilm producers.