Antifungal susceptibility of invasive Candida bloodstream isolates from the Asia-Pacific region.

Abstract

Bloodstream infections caused by Candida species are of increasing importance and associated with significant mortality. We performed a multi-centre prospective observational study to identify the species and antifungal susceptibilities of invasive bloodstream isolates of Candida species in the Asia-Pacific region. The study was carried out over a two year period, involving 13 centers from Brunei, Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam. Identification of Candida species was performed at each study center, and reconfirmed at a central laboratory. Susceptibility testing was performed using a commercial broth dilution panel (Sensititre YeastOne YST-010, Thermofisher, United Kingdom) with susceptibility categorisation (S=susceptible, S-DD= susceptible dose-dependent) applied using breakpoints from the Clinical Laboratory Standards Institute. Eight hundred and sixty-one Candida isolates were included in the study. The most common species were C.albicans (35.9%), C.tropicalis (30.7%), C.parapsilosis (15.7%), and C.glabrata (13.6%). Non-albicans species exceeded C. albicans species in centers from all countries except Taiwan. Fluconazole susceptibility was almost universal for C.albicans (S=99.7%) but lower for C.tropicalis (S=75.8%, S-DD=6.1%), C.glabrata (S-DD=94.9%), and C.parapsilosis (S=94.8%). Echinocandins demonstrated high rates of in vitro susceptibility (S>99%) against C.albicans, C.tropicalis, and C.parapsilosis This study demonstrates that non-albicans species are the most common isolates from bloodstream infections in most countries in the Asia-Pacific region, with C.tropicalis as the predominant species. Because of the prevalence of reduced susceptibility to fluconazole in non-albicans species, the study indicates that echinocandins should be the antifungal of choice in clinically unstable or high-risk patients with documented candidemia.