A retrospective analysis of antifungal susceptibilities of Candida bloodstream isolates from Singapore hospitals.
BACKGROUND
Worldwide, Candida albicans is the most common Candida species implicated in bloodstream infections. However, the proportion of non-albicans bloodstream infections is increasing. Fluconazole resistance is known to be more common in non-albicans species, but is also reported in C. albicans. This retrospective study was performed to determine the species epidemiology of Candida bloodstream infections in Singapore hospitals, and to perform susceptibility testing to a range of antifungal drugs.


METHODS
Candida spp. isolated from bloodstream infections from October 2004 to December 2006 were collected from 3 participating hospitals: a tertiary referral hospital (Singapore General Hospital), a secondary referral hospital (Changi General Hospital) and an obstetrics/paediatric hospital [KK Women's and Children's Hospital (KKWCH)]. Isolate collection was also retrospectively extended to January 2000 for KKWCH because of the limited number of cases from this hospital. Isolates were identified by a common protocol, and antifungal susceptibility testing was performed by microbroth dilution (Sensititre One, Trek Diagnostics, United Kingdom).


RESULTS
The most common isolates were C. albicans (37%), C. tropicalis (27%) and C. glabrata (16%). There were differences in species distribution between institutions, with C. parapsilosis and C. albicans predominant in KKWCH, and C. albicans and C. tropicalis predominant in the other 2 institutions. Fluconazole resistance was detected in 3.2% of all Candida spp., and 85.3% were classified as susceptible. All C. albicans and C. parapsilosis were susceptible to fluconazole and voriconazole, while susceptibility to fluconazole was much more variable for C. glabrata and C. krusei.


CONCLUSIONS
This study shows that C. albicans remains the predominant Candida species isolated from bloodstream infections in the 3 participating hospitals. However, non-albicans species accounted for nearly two-thirds of all cases of candidaemia. Resistance to fluconazole was uncommon, and was generally confined to C. krusei and C. glabrata.
Tan
Thean Yen
TY
Division of Laboratory Medicine, Changi General Hospital, Singapore. thean_yen_tan@cgh.com.sg
Tan
Ai Ling
AL
Tee
Nancy W S
NW
Ng
Lily S Y
LS
D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification*; D002177:Candidiasis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D025141:Drug Resistance, Fungal / Q000187:drug effects*; D005260:Female; D016469:Fungemia / Q000453:epidemiology / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology
D000935:Antifungal Agents