First Isolation of Candida dubliniensis from Oral Cavities of Dermatological Patients in Nanjing, China

Abstract

Candida dubliniensis is an emerging pathogen capable of causing both superficial and systemic infections. Although C. dubliniensis and C. albicans are phenotypically similar, the two species differ in terms of epidemiology and the ability to rapidly develop resistance to fluconazole. C. dubliniensis is primarily associated with oral candidiasis of human immunodeficiency virus (HIV)-infected individuals. In this study, we describe the first recovery of C. dubliniensis from oral cavities of non-HIV-infected patients with dermatological diseases in Nanjing, China. The isolates were phenotypically characterized as C. dubliniensis by their production of brown rough colonies and chlamydospores on tobacco agar and their inability to grow on hypertonic Sabouraud dextrose agar or to assimilate xylose or α-methyl-D-glycoside. The species identification was subsequently confirmed by amplification and sequencing of the internal transcribed spacer region (ITS). Three C. dubliniensis isolates out of 128 (2.3%) presumptive C. albicans/C. dubliniensis ones were finally identified. Further sequence analysis separated the three isolates into two of the four reported ITS genotypes. Antifungal susceptibility testing showed that they were susceptible to fluconazole, itraconazole, voriconazole, micafungin, and amphotericin B. This study adds to the accumulating evidence that C. dubliniensis is widely distributed in non-HIV-infected populations worldwide.

Isolation of Candida spp. from denture-related stomatitis in Pará, Brazil

“…Among the colonized denture wearers in our study, C. albicans was the major isolated species, followed by C. famata and C. tropicalis , which were the most frequent non- C. albicans species. These results corroborated the findings of other studies, 11 , 14 , 21 , 25 , 26 , 27 including other Brazilian studies. 16 , 28 , 29 , 30 Additionally, Sant’Ana et al 31 reported that the presence of two or more species in the same patient can predispose the patient to recurrent stomatitis, and double isolations were also observed in denture wearers with DRS in the present study.…”

Species Distribution, Virulence Factors, and Antifungal Susceptibility Among Candida parapsilosis Complex Isolates Recovered from Clinical Specimens

“…For instance, Trevino-Rangel et al [19] reported that 17 % (5/30), 7 % (2/30), and 60 % (3/5) of C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis isolates, respectively, were significant producers of protease. On the other hand, a number of studies identified a high proportion of proteaseproducing C. parapsilosis sensu stricto isolates, ranging from 66.1 to 100 % [32,[38][39][40]. Similarly, recent reports found also a high proportion of isolates of both C. metapsilosis and C. orthopsilosis exhibiting protease activity [19,32,38].…”

“…On the other hand, a number of studies identified a high proportion of proteaseproducing C. parapsilosis sensu stricto isolates, ranging from 66.1 to 100 % [32,[38][39][40]. Similarly, recent reports found also a high proportion of isolates of both C. metapsilosis and C. orthopsilosis exhibiting protease activity [19,32,38]. According to Ge et al [32], the reasons for this variability among studies are unknown, but it may be due to the media used for enzymatic tests, as sensitivity of different media varies; another potential reason might be related to the different incubation temperatures used in the assays (30 or 37°C).…”

“…Treviño-Rangel et al [19] showed that 97 % (29/30) of C. orthopsilosis, 80 % (4/5) of C. metapsilosis, and 63 % (19/30) of C. parapsilosis sensu stricto possessed secreted phospholipase activity. A study by Ge et al [32] also reported a remarkably high proportion of both C. parapsilosis sensu stricto and C. metapsilosis isolates producing phospholipase in vitro [90.5 % (19/21) and 91.7 % (11/12), respectively]. Some reasons have been proposed to explain the wide variation in phospholipase activity of C. parapsilosis, including the use of different media for enzymatic test, small sample size, and/or inherent biological variation among isolates [32].…”

The effect of Rosmarinus officinalis essential oil on germ tube formation in Candida dubliniensis recovered from denture users

“…This finding is corroborated by studies of C. dubliniensis isolated from the oral cavity 15 and from denture users presenting with stomatitis 5,6 . Although the pathogenesis of oral infection due to C. dubliniensis is poorly understood, germ tube formation is the primary virulence factor that triggers yeast proliferation during the infection process 7,18 . Depending on the isolate, different percentages of cells forming germ tubes were observed (Figure 1, p = 0.06), variation that might be related to variability in the adaptation of each isolate to the incubation conditions in the test.…”