Endocarditis Caused by Candida dubliniensis

Chandy

2015

Mycoses

The phenomenon of postantifungal effect (PAFE), which is the suppression of candidal growth following brief exposure to antifungal agents, is linked with candidal pathogenicity. Adhesion to buccal epithelial cells (BEC), germ tube (GT) formation and relative cell surface hydrophobicity (CSH) are all adhesion traits of candidal pathogenicity. Ability to produce haemolysin by Candida species is also a determinant of its pathogenicity. There is no information on either the PAFE or its impact on adhesion traits and haemolysin production of oral Candida dubliniensis isolates following exposure to 5-fluorocytosine (5-FC). Hence, the focus of this investigation was to research the in vitro PAFE, adhesion to BEC, GT formation, relative CSH and haemolysin production on 20 C. dubliniensis isolates following exposure to 5-FC. Following obtaining the minimum inhibitory concentration (MIC) of 5-FC, isolates of C. dubliniensis were exposed to sub-lethal concentrations (×3 MIC) of 5-FC for 1 h. After this brief exposure, the antimycotic was removed and PAFE, adhesion to BEC, GT formation, relative CSH and haemolysin production was determined by formerly described in vitro methods. MIC (μg/ml) of C. dubliniensis isolates to 5-FC ranged from 0.002 to 0.125. The mean PAFE (hours) elicited by 5-FC on C. dubliniensis isolates was approximately 1 h. Exposure to 5-FC suppressed the ability of C. dubliniensis isolates to adhere BEC, GT formation, relative CSH and haemolysin activity by a mean percentage reduction in 50.98%, 29.51%, 36.79% and 12.75% (P < 0.001 for all) respectively. Therefore, brief exposure of C. dubliniensis isolates to 5-FC appears to exert an antifungal effect by subduing its growth, adhesion traits as well as haemolysin production.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In vitro postantifungal effect, adhesion traits and haemolysin production of Candida dubliniensis isolates following exposure to 5‐fluorocytosine

Chandy

2015

Mycoses

“…For instance, this microbe has been isolated from blood and upper respiratory tract specimens, suggesting dissemination to other ecological environments besides the mouth . Moreover, C. dubliniensis has been implicated as a cause of spondylodiscitis, endocarditis, multifocal osteomyelitis and leptomeningeal disease . Interestingly, C. dubliniensis resistance to fluconazole, voriconazole and itraconazole has also been reported , implying that this Candida species is clinically important in relation to both oral and systemic candidosis and in antimycotic resistance.…”

mentioning

confidence: 99%

Caspofungin‐induced in‐vitro post‐antifungal effect and its impact on adhesion related traits of oral Candida dubliniensis and Candida albicans isolates

Chandy

Microbiology and Immunology

et al. 2016

Adhesion to buccal epithelial cells (BEC) and denture acrylic surfaces (DAS), germ tube (GT) formation and cell surface hydrophobicity (CSH) are all virulence traits involved in the pathogenicity of Candida. Post-antifungal effect (PAFE) also have a bearing on pathogenicity and virulence of Candida. Candida dubliniensis is associated with oral and systemic candidosis, which can be managed with caspofungin. There is no published information on caspofungin-induced PAFE and its impact on adhesion traits of C. dubliniensis isolates. Thus, the purpose of this investigation was to determine the in vitro duration of PAFE on 20 C. dubliniensis isolates following transient exposure to caspofungin. Furthermore the impacts of caspofungin-induced PAFE on adhesion to BEC and DAS, GT formation and CSH of these isolates were also determined. After establishing the minimum inhibitory concentration (MIC) of caspofungin, C. dubliniensis isolates were exposed to sub-lethal concentrations (Â3 MIC) of caspofungin for 1 hr. Thereafter the duration of PAFE, adhesion to BEC and DAS, GT formation and CSH were determined by previously described in-vitro assays. MIC (mg/mL) of C. dubliniensis isolates to caspofungin ranged from 0.004 to 0.19. Caspofungin-induced mean PAFE on C. dubliniensis isolates was 2.17 hr. Exposure to caspofungin suppressed the ability of C. dubliniensis isolates to adhere to BEC and DAS, form GT and CSH by 69.97%, 71.95%, 90.06% and 32.29% (P < 0.001 for all), respectively. Thus, transient exposure of C. dubliniensis isolates to caspofungin produces an antifungal effect not only by suppressing its growth but also by altering its adhesion traits.

“…Candida dubliniensis is an opportunistic fungi associated with recurrent oral candidosis in HIV‐infected as well as diabetic patients. This pathogen has also been recovered from sputum of cystic fibrosis patients, upper respiratory tract specimens, and blood, as well as from a case of endocarditis involving a prosthetic aortic valve, suggesting dissemination of the yeast to other sites as well . In addition, it has been suggested that C. dubliniensis may also play an important role in the establishment and persistence of C. dubliniensis ‐induced denture stomatitis …”

Section: Introductionmentioning

confidence: 99%

Impact of short‐term exposure of antifungal agents on hemolysin activity of oral Candida dubliniensis isolates from Kuwait and Sri Lanka

Jayathilake

J of Invest & Clin Dent

2015