The distribution of species and susceptibility of amphotericin B and fluconazole of yeast pathogens isolated from sterile sites in Taiwan

Abstract

To study the demographic changes of yeasts causing invasive infections in Taiwan, especially with respect to species distribution and antifungal susceptibility, we analyzed isolates obtained from four sterile sites of patients in 19 hospitals in 2002 (155 strains) and again from the same hospitals in 2006 (208 strains). Blood was the most common source of the yeasts, accounting for 73.8% of the total isolates, followed by ascites (21.5%), cerebrospinal fluid (3%), and synovia (1.7%). Candida albicans was the most frequently recovered species (50.1% of the total), followed by Candida tropicalis (20.7%), Candida glabrata (11.6%), Candida parapsilosis (8.5%), Cryptococcus neoformans (3.9%), Candida krusei (0.8%), and nine other species (4.3%). There were one (0.3%) and seven (1.9%) isolates with minimum inhibitory concentrations (MICs) of amphotericin B ≥2 mg/l after 24 h and 48 h incubation, respectively. In addition, there were 15 (4.3%) and 31 (8.6%) isolates with MICs of fluconazole ≥64 mg/l under the same conditions. The MIC₉₀ value of amphotericin B was 1 mg/l. The MIC₉₀ values of fluconazole were 4 mg/l after 24 h incubation and 32 mg/l after 48 h incubation. Interestingly, MICs for fluconazole ≥64 mg/l after 24 h were significantly higher for isolates obtained in 2006 than those in 2002 after 24 h (7.1% vs. 0.7%, p =0.009) and 48 h (13.5% vs. 2%, p =0.0003) incubations. The demographic difference between these two surveys is mainly due to one species, C. tropicalis.

Keywords:

• yeast
• Candida species
• TSARY
• invasive infections
• drug susceptibility

Acknowledgements

We would like to thank Bristol Myers Squibb and Pfizer for supplying the amphotericin B and fluconazole, respectively. We also thank the 19 participating hospitals for providing clinical isolates and information regarding those isolates. They are Asia East Memorial Hospital, Buddhist Tzu-Chi General Hospital, Chang Gung Memorial Hospital at Kaohsiung, Chiayi Christian Hospital, Chang-Hwa Christian Hospital, Cheng Ching Hospital, Chung Shan Medical Dental College Hospital, Kaohsiung Military Hospital, Kaohsiung Medical College Chung-Ho Memorial Hospital, Kuan-Tien General Hospital, Lo-Hsu Foundation Inc. Lo-Tung Poh Ai Hospital, Miin Sheng General Hospital, National Cheng Kung University Hospital, Show Chwan Memorial Hospital, St. Mary Hospital, Taipei Municipal Hoping Hospital, Veterans General Hospital–Taichung, Veterans General Hospital-Kaohsiung, Zen Ai General Hospital, and Tungs' Taichung Metroharbor Hospital, Sha Lu branch. This study was supported by the grant NHRI CL-096-PP07.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This paper was first published online on Early Online on 01 February 2010.