EVALUATION OF VITEK 2 SYSTEM FOR CLINICAL IDENTIFICATION OF CANDIDA SPECIES AND THEIR ANTIFUNGAL SUSCEPTIBILITY TEST

Background: Accurate and rapid identification of Candida species is necessary for proper diagnosis and treatment of candidiasis due to emergences of drug-resistant strains especially among immunocompromised patients. Objectives: Identification of Candida clinical isolates to the species level using different phenotypic and molecular methods. Biofilm-forming ability and antifungal resistance were also studied. Methodology: Sixty-nine Candida strains were isolated from 220 immunocompromised patients. Identification was performed using chromogenic Candida agar, VITEK 2 system and multiplex polymerase chain reaction (PCR). Biofilm formation was detected by the tube method and antifungal susceptibility was tested using the VITEK2 system. Results: The most common source of Candida isolates was from urine (33.3%) and ICUs (56.6%). VITEK 2 system detected 9 spp.: C. albicans (34.8%), C. tropicalis (21.7%), C. famata (8.7%), C. lusitaniae (7.2%), C. cruzi (7.2%), C. ciferri (5.8%), C. dubliniensis (5.8%), C. parapsilosis (5.8 %) and C. glabrata. Candida isolates showed high resistance to flucytocine (49.3%), and high sensitivity to fluconazole, micafungin, voriconazole and caspofungin (88.4%, 81.2% and 81.2 % respectively). Only 30.4% of all Candida isolates were biofilm producers. There was a positive relationship between antifungal resistance and biofilm formation among Candida isolates. Conclusion: C. albicans was the predominant species. Chromogenic Candida agar and VITEK 2 system were valuable tests compared to PCR in speciation of Candida isolates. Antifungal susceptibility was significantly related to biofilm production and its evaluation is important for proper treatment..

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Evaluation of semisolid agar method for antifungal susceptibility test of T. rubrum

Bangabandhu Sheikh Mujib Medical University Journal ◽

10.3329/bsmmuj.v7i1.29140 ◽

2016 ◽

Vol 7 (1) ◽

pp. 11

Author(s):

Sultana Razia ◽

Shahida Anwar ◽

Md. Ruhul Amin Miah ◽

Najmun Nahar ◽

Ripon Barua

Keyword(s):

Antifungal Agents ◽

Antifungal Susceptibility ◽

Antifungal Drugs ◽

Test Method ◽

Susceptibility Test ◽

Broth Microdilution ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Antifungal Susceptibility Test ◽

Mic Value

Background: With increasing fungal disease many newer antifungal drugs are available with different spectrum of activity. Antifungal susceptibility test will help clinicians for selection of effective drug and thereby treatment of patient. Objective: The study was undertaken to perform a simple screening drug susceptibility test of T. rnbrum by Semi Solid Agar Antifungal Susceptibility (SAAS) Method: Perfonnance of susceptibility method was assessed by comparing the MICs of three commonly prescribed antifungal agents namely- tluconazole (FCZ), itraconazole (ITZ) and terbinafine (TER) to the CLSI (Clinical and Laboratory Standard Institute) recommended M-38, a broth microdilution method. Results: In SAAS method, among twenty nine T. rubrum, twenty five (86.2%) were susceptible (MIC range 0.5-64 µg/ml) to Fluconazole (FCZ) and four (13.7%) were resistant (MIC value >64 µg/ml). In broth microdilution method, among twenty nine T. rubrum, twenty six (89.6%) were susceptible (MIC range 0.3-64 µg/ml) to FCZ and three (10.3%) were resistant (MIC value >64 µg/ml). In case of both ITZ and TER, all were susceptible (MIC range 0.3-64 µg/ml) to both methods. The SAAS method demonstrated the susceptibility pattern of T. rubrum against FCZ, ITZ and TER usually within 72 to 96 hours after organism isolation and results were concordance with the results of CLSI broth microdilution method. Conclusion: Though it is a newer method with proper standardization of the test method, SAAS method is simple and easily applicable screening method for susceptibility testing of antifungal agents against dermatophytes in any microbiology laboratories.

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