Candida dubliniensis: A rare cause of nail infection.
Abstract Candida dubliniensis is a newly described fungal opportunistic pathogen that is closely related phylogenetically to C. albicans. It is mostly isolated from patients with immunodeficiency and few cases develop quick resistance to routine treatment and delay in result outcome. Here we report a case of 21-year-old healthy female who presented clinically with onychomycosis of the toe nail resistant to terbinafine and fluconazole.
Key words Candida dublinienisis, nail infection.
Candida dubliniensis is a newly described fungal opportunistic pathogen that is closely related phylogenetically to C. albicans and is commonly associated with oral candidiasis in human immunodeficiency virus patients and occasionally isolated from immunocompetent individuals.1,2 It was first described in 1995.3
Until then it had been misidentified as candida albicans if only germ tube test was used for identification as both the species have many similarities in their microscopic morphology and ability to form germ tubes in serum.4,5
Here we report a case of 21-year-old female with toe nail infection due to Candida dubliniensis.
A 21-year-old female came to our skin out patient department for consultation for her toe nail infection. Her problem was persisting for the last one year. She took various medications like fluconazole, terbinafine in varying regimes from different practitioners with no relief. There was history of wearing socks and shoes continuously during her duty for long hours. There was no complaint of pain or swelling in the toes. On examination right foot toe nail was discolored at the distal end. Clinically she was diagnosed as having fungal toe nail infection. Nail clippings were sent for fungal culture in the department of microbiology.
On direct examination fungal hyphae were observed.
On culture, growth of Candida dubliniensis was found positive on CHROMagar(r). While going through literature it was found that this infection is more common in immunocompromised individuals so a battery of investigation was done to find out any immunosuppression.
Hemoglobin was 12.6 gm% and fasting blood sugar 86 mg%. Peripheral blood film did not show immature cells. ELISA for HIV was nonreactive. Patient was not on steroids for any disease.
Candida dubliniensis is a cosmopolitan fungus and various retrospective studies have shown that previously it had been identified as C. albicans, with which C. dubliniensis is closely related and shares a number of characteristics. One test for distinguishing C. dubliniensis from C. albicans, is laboratory culture of the organism at 42degC when only most of C. albicans strains grow.3,6 There are also significant differences in the conditions that lead to the formation of chlamydospores in C. albicans and C. dubliniensis, although they are otherwise phenotypically very similar.3
Mostly the isolates of C. dubliniensis are sensitive to fluconazole. In one study it was observed that 16 out of 20 isolates were sensitive to fluconazole, while four were resistant but all 20 were susceptible to itraconazole, ketoconazole and amphotericin B. So it was hypothesized that C. dubliniensis has the ability to rapidly develop resistance to fluconazole, especially in patients who are on long-term therapy.7 Like in C. albicans first line treatment for C. dubliniensis is also fluconazole but few cases develop quick resistance to treatment as happened in our case who was earlier put on fluconazole and terbinafine by various practitioners in different regimens with no relief. Amphotericin B and itraconazole are two other anti fungal medications effective in treating C. dubliniensis. So we started her with itraconazole 100mg twice daily for one month and then in monthly pulses for three months with which she showed significant improvement.
One publication suggested that C. dubliniensis is less virulent than C. albicans and is more susceptible to the fungicidal effect of human neutrophils which explains the overall low incidence of C. dubliniensis even among the susceptible hosts.8 Although it is mostly seen in immunocompromised patients but our case was healthy young female of 21 years with no obvious cause of immunosuppression except for the fact that she used to wear socks and shoes regularly and continuously which is otherwise also a risk factor for developing fungal infections. This can be the reason why her disease was limited to toe nail only for the last one year. This fact is also supported by more recent studies which suggest that C. dubliniensis becomes resistant to fluconazole during the course of therapy, thereby, causing difficulty in clinical result outcome.9
This case is being presented for its rarity and to emphasize the need for early diagnosis and cure of the infection since antifungal agents have to be given for long time. Correct diagnosis will shorten the treatment and limit the side effects.
So it is recommended that whenever a fungal culture is sent to the laboratory for fungal examination, if candida is isolated, further subcultures for species identification should be performed. With this characterization, specific treatment can be given to eliminate the infection and hence prevent resistance.
1. Gilfillan GD, Sullivan DJ, Haynes K et al. Candida dubliniensis: Phylogeny and putative virulence factors. Microbiology 1998;144:829-38.
2. Pincus DH, Coleman DC, Pruitt WR et al. Rapid identification of Candida dubliniensis with commercial yeast identification systems. J Clin Microbiol 1999;37;3533-39.
3. Sullivan D, Westerneng TJ, Haynes KA et al. Candida dubliniensis sp. phenotypic and molecular characterization of a novel species associated with oral candidosis in HIV infected individuals. Microbiology 1995;141:1507-21.
4. Warren NG, Hazen KC. Candida, Cryptococcus and other yeast of medical importance. In: Murray PR, Baron EJ, Pfaller MA et al, editors. Manual of Clinical Microbiology, 7 ed. Washington DC: ASM Press; 1999; 1184-99.
5. Odds FC, Nuffel LV, Dams G. Prevalence of Candida dubliniensis isolates in a yeast stock collection. J Clin Microbiol. 1998;36:1467. Letter.
6. Kamiyama A, Niimi M, Tokunaga M,. Nakayama H. Adansonian study of Candida albicans: intraspecific homogeneity excepting C. stellatoidea strains. J Med Vet Mycol 1989;27:229-41.
7. Moran GP, Sullivan DJ, Henman MC et al. Antifungal drug susceptibilities of oral Candida dubliniensis isolates from human immunodeficiency virus (HIV)-infected and non-HIV-infected subjects and generation of stable fluconazole-resistant derivatives in vitro. Antimicrob. Agents Chemother 1997;41:617.
8. Vilela MMS, Kamei K, Sano A et al. Pathogenicity and virulence of Candida dubliniensis comparison with C. albicans. Med Mycol 2002:40:249-57.
9. Jabra-Rikz MA, Falkler WA, Merz WG et al. Retrospective identification and characterization of C. dubliniensis isolates among C. albicans, clinical laboratory isolates from human immunodeficiency virus infected and non HIV infected. J Clin Microbiol. 2000. 38:2423-26.
J Kalsy, J Kaur, *Department of Dermatology Venereology, Leprosy Government Medical College Amritsar, Punjab., **Department of Dermatology Venereology, Leprosy Sri Guru Ram Das Institute of Medical, Sciences and Research Amritsar, Punjab.
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|Publication:||Journal of Pakistan Association of Dermatologists|
|Date:||Dec 31, 2012|
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