|Year : 2016 | Volume
| Issue : 3 | Page : 406-407
In vitro demonstration of potential virulence determinants among clinical isolates of various Candida species and its clinical implication in a Teaching Hospital in Eastern India
RR Ghosh, M Ghosh, M Chatterjee, M Banerjee
Department of Microbiology, R.G. Kar Medical College and Hospital, Kolkata, West Bengal, India
|Date of Submission||16-Feb-2014|
|Date of Acceptance||30-Dec-2015|
|Date of Web Publication||12-Aug-2016|
R R Ghosh
Department of Microbiology, R.G. Kar Medical College and Hospital, Kolkata, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Ghosh R R, Ghosh M, Chatterjee M, Banerjee M. In vitro demonstration of potential virulence determinants among clinical isolates of various Candida species and its clinical implication in a Teaching Hospital in Eastern India. Indian J Med Microbiol 2016;34:406-7
|How to cite this URL:|
Ghosh R R, Ghosh M, Chatterjee M, Banerjee M. In vitro demonstration of potential virulence determinants among clinical isolates of various Candida species and its clinical implication in a Teaching Hospital in Eastern India. Indian J Med Microbiol [serial online] 2016 [cited 2020 Oct 1];34:406-7. Available from: http://www.ijmm.org/text.asp?2016/34/3/406/188385
Over the last three decades, Candida species has emerged as an important cause of healthcare-associated and opportunistic infection. 
The present study was intended to identify different species of Candida isolated from clinical specimens and to examine their potential virulence determinants in vitro which might help in clinical correlation to administer rational and justified therapy.
One hundred and twenty Candida spp. were isolated from various clinical specimens following standard protocol. Among all the isolates, 43 were obtained from nail samples, 22 from blood, 14 from deep tracheal aspirate and bronchoalveolar lavage samples, 23 from oral swabs or buccal washings of immunocompromised patients, ten from buccal ulcer samples, six from urine and two from gastric lavage samples.
Yeast suspension was prepared to evaluate different virulence factors. The turbidity was matched to 0.5 McFarland standards. 
For determination of phospholipase activity, egg yolk agar media,  Sabouraud Dextrose Agar containing 7% blood and 3% glucose for haemolytic activity  and tween 80 opacity test media for detection of esterase activity were used.  The adherence assay as described by Kimura and Pearsall  and biofilm production by visual method  were followed. ATCC Candida parapsilosis 90661 and ATCC Candida albicans 40028 were taken as controls.
40 were C. albicans, 30 C. tropicalis, 22 C. parapsilosis, 12 C. lusitaniae, 8 C. glabrata, 6 C. krusei and 2 C. stellatoidea. Fifty-nine (49.1%) isolates showed haemolysin production, 53 (44.1%) expressed phospholipase, 38 (31.6%) expressed esterase, 47 (39.1%) strains gave positive result in adherence assay and 58 (48.3%) Candida isolates were biofilm producers. Expression of virulence markers was found in 28/40 (70%) strains of C. albicans, whereas only 36/80 (45%) of non-albicans Candida strains showed the same.
There is a significant increase in the incidence of Candidiasis over the past two decades.
C. albicans (33.3%) was the most commonly isolated species in the present study. Non-albicans Candida spp. (66.7%) exceeded the total isolated C. albicans (33.3%).
Significant statistical valuation was arrived at when C. albicans and non-albicans Candida strains were compared for expression of virulence traits (P = 0.0118, odds ratio 2.852, 95% confidence interval 1.272-6.393) which is in accordance with the previous studies of Inci et al., 2012  and Gokce et al., 2007.  They also found significantly higher expression of virulence factors among albicans than non-albicans Candida. In our study, haemolysin was the major virulence factor expressed by Candida isolates 59 (49.1%) irrespective of its species. However, the results of interspecies expression of haemolysin reveal highest haemolytic activity in C. tropicalis followed by C. krusei, C. glabrata and C. albicans which corroborate with the result of Yigit et al., 2011.  In the present study, 23/40 (57.5%) strains of C. albicans were biofilm producers while 35/80 (43.75%) non-albicans Candida strains were biofilm positive, an observation which corroborates with Yigit et al. 
Virulence of Candida may vary as it depends on the type of species and the clinical sample from which it has been isolated [Figure 1]. Hence, the significance of virulence determination in rational antifungal therapy cannot be ignored and should be adopted as a routine procedure in the laboratory.
|Figure 1: One hundred per cent stack column showing the distribution of Candida spp. expressing virulence markers in different clinical samples|
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Conflicts of interest
There are no conflicts of interest.
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