Non-Candida albicans Candida Species: Virulence Factors and Species Identification in India

Document Type : Original Articles


1 Department of Microbiology, Uttar Pradesh University of Medical Sciences, Saifai, India

2 Department of Community Medicine, Gajra Raja Medical College, Gwalior, India



Background and Purpose: The predominant cause of candidiasis was Candida albicans which has recently changed to non-Candida albicans Candida s(NCAC) (i.e., Candida spp. other than the C. albicans). The NCAC spp., earlier considered non-pathogenicor minimally virulent, are now considered a primarycause of morbidity and mortality inimmunocompromised individuals. Given the NCAC spp. has become more common in clinical cases, this study aimed to determine the prevalence of NCAC spp. in different clinical specimens and assess a few of their virulence factors.
Material and Methods: Routine samples for bacterial culture and sensitivity that showed colony characteristics, like Candida on Blood Agar and microscopic features resembling Candida spp., were processed further. Candida isolatesunderwent tests for chlamydosporeformation and biochemical tests, including sugar fermentation and sugar assimilation tests. They were grown at 42 oC, and their colony color was identified using HiCrome™ Candida Differential Agar, HiCandidaIdentification Kit, and VITEK-2 Compact[A1] . Virulence factors, such as adherence to buccal epithelialcells (ABEC), biofilm formation, hemolytic activity, andproduction of coagulase enzyme were also tested.
Results: Mean age of the patients was 38.46 with a male-female ratio of 1.36:1. In total, 137 Candidaisolates were recovered; 45.3%, 19.7%, and 13.9% of the isolates were isolated from urine, vaginal swabs, and oropharyngeal swabs, respectively. Moreover, 55 (40.1%) isolates of C. albicans and 82 (59.9%) isolates of the NCAC spp. were C. tropicalis (23.4%) in NCAC spp. Furthermore, C. albicans (3; 50%) was the most common spp. in cases of candidemia. Haemolysin production (85.5%) and ABEC (78.2%) were the major virulence factors in C. albicans. C. tropicalis (59.4%) and C. dubliniensis (50%) showed maximum ABEC. Biofilm forming capacity was higher in C. tropicalis (78.1%) than C. albicans (67%).
Conclusion: Results of this study suggest varied prevalence and virulence based on geographical locations, even within a subcontinent. It clearly indicates the emergence of the NCAC spp. and their predominance in different body fluids. Identification of Candida to the spp. level should become a routine in all laboratories.