STUDY OF BIOFILM FORMATION AS A VIRULENCE MARKER IN CANDIDA SPECIES ISOLATED FROM VARIOUS CLINICAL SPECIMENS.

CORRESPONDING ADDRESS:
Dr. Vivek Hittinahalli,
NABH Assessor
Associate Professor,
Dr B.R Ambedkar Medical College
E-Mail: vivekhitt@yahoo.com,
Phone: 0091 7760984581.

ABSTRACT: BACKGROUND: Candida species can be either commensals or opportunistic pathogens with the ability to cause a variety of infections, ranging from superficial to life threatening. Nosocomial infections due to candida are also becoming increasingly important. Early and prompt diagnosis, proper treatment and prevention of candidemia due to biofilms pose a major challenge for microbiologists and clinicians worldwide. Added to this is the emerging trend of antifungal drug resistance among the biofilm producing strains of Candida. AIMS: The aim of this study was to detect biofilm production in Candida species isolated from various clinical samples obtained from patients hospitalized in Dr. B.R Ambedkar Medical College and Hospital.  MATERIALS AND METHODS: A total of 108 Candida species (Candida albicans49 and non-albicans Candida59 species) isolated from various specimens (urine, blood, respiratory tract, genital samples, plastic devices and pus samples) were included in the study.The various candida isolates were identified by using conventional methods and their ability to produce biofilm was detected by the tube method. RESULTS: Out of 108 candida species, non-albicans Candida 59(54.63%) was the predominant species isolated. Biofilm positivity was seen with 71(65.74%) isolates and the biofilm production was observed more with non-albicans Candida species 44(61.97%) compared to C.albicans species 27(38.03%). Among the non-albicans Candida species, strong biofilm producers were C.krusei(80.77%) and C.tropicalis(72.73%). Biofilm positivity was found to be higher in the bloodstream Candida isolates (81.82%) compared to isolates from other sites. CONCLUSION: The present study suggests an increasing prevalence of non-albicans Candida species in the various clinical samples isolated and also shows them as strong biofilm producers compared to C.albicans species. These data suggest that, biofilm formation as a potential virulence factor might have a higher significance for non-albicans Candida species than for C.albicans and also that the biofilm structure varies with the different species and strains of candida, the nature of the colonized surface and its localization. Thus more remains to be determined about biofilms formed by the non-albicans Candida species as they are now frequently encountered species in catheter associated candidaemias.
KEY WORDS: Candida, biofilm, non-albicans Candida, candidaemia