1.Identification of local clinical Candida isolates using CHROMagar CandidaTM as a primary identification method for various Candida species
Madhavan, P.* ; Jamal, F. ; Chong, P.P. ; Ng, K.P.
Tropical Biomedicine 2011;28(2):269-274
The objective of our study was to study the effectiveness of CHROMagar CandidaTM
as the primary identification method for various clinical Candida isolates, other than the
three suggested species by the manufacturer. We studied 34 clinical isolates which were
isolated from patients in a local teaching hospital and 7 ATCC strains. These strains were first
cultured in Sabouraud dextrose broth (SDB) for 36 hours at 35ºC, then on CHROMagar plates
at 30ºC, 35ºC and 37ºC. The sensitivity of this agar to identify Candida albicans, Candida
dubliniensis, Candida tropicalis, Candida glabrata, Candida rugosa, Candida krusei and
Candida parapsilosis ranged between 25 and 100% at 30ºC, 14% and 100% at 35ºC, 56% and
100% at 37ºC. The specificity of this agar was 100% at 30ºC, between 97% and 100% at 35ºC,
92% and 100% at 37ºC. The efficiency of this agar ranged between 88 and 100% at 30ºC, 83%
and 100% at 35ºC, 88% and 100% at 37ºC. Each species also gave rise to a variety of colony
colours ranging from pink to green to blue of different colony characteristics. Therefore, the
chromogenic agar was found to be useful in our study for identifying clinical Candida isolates
2.Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Candida glabrata, Candida parapsilosis and Candida rugosa from two major hospitals in Kuala Lumpur, Malaysia
Madhavan, P. ; Chong, P.P ; Farida, J. ; Fauziah, O. ; Cheah, Y.K. ; Arunkumar Karunanidhi, A. ; Ng, K.P.
Tropical Biomedicine 2019;36(1):183-193
The purpose of this study is to characterize 3 non-albicans Candida spp. that were
collected from two major hospitals in a densely populated area of Kuala Lumpur for their
susceptibilities to azole and genetic background. Fifteen non-albicans Candida clinical isolates
in two major hospitals in Kuala Lumpur area of Malaysia were collected by convenience
sampling during 2007 and 2010. The genetic diversity of 15 non-albicans Candida species
comprising C. glabrata (n = 5), C. parapsilosis (n = 5) and C. rugosa (n = 5) were assessed by
RAPD-PCR typing. Strains were initially identified using biochemical tests and CHROMagar
Candida medium. Fluconazole and voriconazole susceptibilities were determined by E-test
method. Commercial kits were used for DNA extraction and amplification with RAPD primers
(OPA02, OPA03 and OPA08). PCR conditions were optimized and simultaneous identification
was possible by agarose gel electrophoresis of PCR products and the bands obtained were
analyzed using BioNumerics Applied Maths v.6.6 software. The RAPD primers used in this
study generated 100% polymorphic profile. Cluster analysis using the RAPD-PCR profile showed
12.5-25% similarity among the strains. The genetic diversity was based on the strain
susceptibility towards both the azoles, site of isolation and place according to their unique
banding patterns. In contrast, strains susceptible to azoles were found to be genetically
similar with clonal dissimilarity. The use of OPA02, OPA03 and OPA08 primers in differentiating
non-albicans Candida spp. underscores the higher resolution of RAPD-PCR as a reliable tool
for strain/species level differentiation.