Antifungal suscepitibility profile of candida spp. oral isolates obtained from denture wearers

Candida Species Diversity in Oral Cavity of Type 2 Diabetic Patients and their In vitro Antifungal Susceptibility

Objective:

To identify and compare the species variation and Colony Forming Units of the species and antifungal susceptibility from oral rinse samples of individuals in poorly-controlled, moderately-controlled and well controlled diabetes patients with control group.

Subjects and Methods:

Study group comprised of well-controlled, moderately-controlled and poorly controlled Type II diabetic patients grouped according to the level of glycated hemoglobin concentration with 50 patients in each group and 50 healthy individuals. Oral rinse samples were collected in a sterile container with phosphate-buffered saline and then transported immediately for various mycological investigations and antifungal susceptibility tests. Statistical analysis was performed.

Results:

There was a significant difference in frequency of Candida in poorly controlled diabetes when compared to moderately controlled diabetes, well controlled diabetes and normal patients (P = 0.045). A higher number of colony count was seen among poorly controlled diabetes than well controlled, moderately controlled and non diabetic subjects. A comparatively low number of non-albicans were seen in healthy individuals. C. albicans showed an increased resistance to fluconazole in DM patients in comparison to control group (P = 0.001). Other species showed a variable sensitivity pattern.

Conclusion:

The decreased immunity and change in oral habitat in diabetic patients creates a diversification in various species of Candida. These non albicans vary in their susceptibility and pathogenesis. A definite identification of these diverse species in the oral cavity of such patients and their susceptibility mandates proper management to avoid recurrence and drug resistance.

In Vitro Antifungal Susceptibility of Candida Species Isolated from Iranian Patients with Denture Stomatitis

Background

Candida-associated denture stomatitis (CADS) is a common fungal infection in people who wear dentures. The main objective of this study was to make molecular identification of causative agents of CADS and in vitro antifungal susceptibility testing (AFST) in the Iranian patients with denture stomatitis.

Methods

A total of 134 Candida spp. were obtained from patients with denture stomatitis. The Candida spp. were identified using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) involving the universal internal transcribed spacer (ITS1 and ITS4) primers, which were subjected to digestion with MspI and BlnI restriction enzymes. The in vitro antifungal susceptibility of Candida spp. to fluconazole (FLC), terbinafine (TRB), itraconazole (ITC), voriconazole (VRC), posaconazole (POS), ketoconazole (KET), amphotericin B (AMB), and caspofungin (CAS) was evaluated using the Clinical and Laboratory Standards Institute M27-A3 and M27-S4 guidelines.

Results

Overall, C. albicans was the most commonly isolated species (n = 84; 62.6%), followed by C. glabrata (n = 23; 17.2%), C. tropicalis (n = 16; 12%), and C. parapsilosis (n = 11; 8.2%). Posaconazole had the lowest geometric mean minimum inhibitory concentration (MIC) (0.03 μg/ml), followed by AMB (0.05 μg/ml), ITC (0.08 μg/ml), VRC (0.11 μg/ml), CAS (0.12 μg/ml), KET (0.15 μg/ml), and FLC (0.26 μg/ml).

Discussion

Our study showed that C. albicans was most prevalent in Iranian patients with CADS and was susceptible to both azoles and amphotericin B. In addition, POS could be an appropriate alternative to the current antifungal agents used for the treatment of CADS, as well as in the treatment of recurrent candidiasis.

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

The aim of this study was to isolate and identify Candida species from the oral cavity of denture wearers with denture-related stomatitis who were attended at the University Federal of Pará (Belém City, Pará State, Brazil). A total of 36 denture wearers with denture-related stomatitis were included, and type I (50%), type II (33%) and type III (17%) stomatitis were observed. Candida spp. were isolated from 89% of the cases and included five different Candida species. C. albicans was the most frequently recovered species (78% of the cases), followed by C. famata and C. tropicalis. We observed a significant association between Candida species isolation and unsatisfactory denture condition (p = 0.0017). Our results demonstrated the highly frequency of Candida species isolation in denture wearers with denture-related stomatitis and showed the relationship between these species and poor denture maintenance.

Frequent detection of 'azole' resistant Candida species among late presenting AIDS patients in northwest Ethiopia

BACKGROUND

The chronic use of antifungal agents in the treatment of fungal infection in general and oropharyngeal candidiasis mainly in AIDS patient's leads to the selection of strain resistant to these therapies and a shift in the spectrum of Candida species. This study determines the species diversity and in vitro susceptibility of Candida isolates from late presenting AIDS patients in northwest Ethiopia.

METHODS

Two hundred and twenty one HIV/AIDS patients were assessed with a standardized evaluation form at enrolment. Oral rinses were cultured on CHROMagar plates at 37°C for 48 hours and Candida species identification were made following standard microbiological techniques. In vitro drug susceptibility tests were made using broth microdilution method.

RESULTS

The colonization rate of Candida species was found to be 82.3% (177/215). C. albicans was the predominant species isolated from 139 (81%) patients but there was a diversity of other species. C. glabrata was the most frequent non-albicans species isolated in 22.5% (40/177) of the patients followed by C. tropicalis 14.1% (27/177), C. krusei 5.6% (10) and other unidentifiable Candida species 4% (7/177). Recurrent episodes of oropharyngeal candidiasis and previous exposure to antifungal drugs were found to be predisposing factors for colonization by non-albicans species. Irrespective of the Candida species identified 12.2% (11/90), 7.7% (7/90) and 4.7% (4) of the isolates were resistant to fluconazole, ketoconazole and itraconazole, respectively. In contrast, resistance to micafungin, amphotericin B and 5-Fluorocytosine was infrequent.

CONCLUSION

HIV/AIDS patients are orally colonized by single or multiple albicans and non- albicans Candida species that are frequently resistant to azoles and occasionally to amphotericin B, 5-Fluorocytosine and micafungin. These highlight the need for national surveillance for examining Candida epidemiology and resistance to antifungal drugs.

Photodynamic inactivation of four Candida species induced by photogem(®)

This study evaluated the in vitro susceptibility of C. albicans, C. dubliniensis, C. tropicalis and C. krusei to photodynamic therapy (PDT) induced by Photogem^®and light emitted diode (LED). Suspensions of each Candida strain were treated with three photosensitizer (PS) concentrations (10, 25 and 50 mg/L) and exposed to 18, 25.5 and 37.5 J/cm² LED light fluences (λ ~ 455 nm). Control suspensions were treated only with PS concentrations, only exposed to the LED light fluences or not exposed to LED light or PS. Sixteen experimental conditions were obtained and each condition was repeated three times. From each sample, serial dilutions were obtained and aliquots were plated on Sabouraud Dextrose Agar. After incubation of plates (37 °C for 48 hours), colonies were counted (cfu/mL) and the data were statistically analyzed by ANOVA and the Tukey test (α=0.05). Complete killing of C. albicans was observed after 18 J/cm² in association with 50 mg/L of PS. C. dubliniensis were inactivated after 18 J/cm² using 25 mg/L of PS. The inactivation of C. tropicalis was observed after photosensitization with 25 mg/L and subsequent illumination at 25.5 J/cm². For C. krusei, none of the associations between PS and light resulted in complete killing of this species. PDT proved to be effective for the inactivation of C. albicans, C. dubliniensis and C. tropicalis. In addition, reduction in the viability of C. krusei was achieved with some of the PS and light associations.