Genetic relatedness among Candida tropicalis isolates from sporadic cases of fungemia in two university hospitals in Korea

OBJECTIVE: To compare the epidemiology and genetic relatedness of Candida tropicalis isolates causing bloodstream infection (BSI) in two hospitals. SETTING: Two tertiary-care hospitals in Korea. METHODS: A retrospective molecular epidemiologic analysis using pulsed-field gel electrophoresis (PFGE) was performed with 49 C. tropicalis isolates from sporadic cases of BSI. The isolates were collected from 27 patients at Chonnam National University Hospital (CUH) during a 6-year period and 22 patients at Asan Medical Center (AMC) during a 2-year period. RESULTS: Based on the PFGE patterns, the average similarity value (S_AB) for the 27 isolates from CUH was 0.84 ± 0.08, which was significantly higher than that for the 22 isolates from AMC (0.78 ± 0.06; P < .001). Of the 49 strains from patients at the 2 hospitals, 9 isolates were placed into 3 subtypes with S_AB values of 1.0, which indicated that they were identical. All 9 of these strains were isolated from CUH patients, and each type strain was isolated sporadically during a period ranging from 4 months to 3 years. On comparison of the clinical characteristics of the patients of the 2 hospitals, the CUH strains were isolated more frequently from non-neutropenic patients and patients with central venous catheter-related fungemia; cases from CUH had a better outcome than those from AMC (P < .05). CONCLUSIONS: These data show that the clinical and epidemiologic characteristics of C. tropicalis fungemia may differ markedly among hospitals and that some cases of C. tropicalis fungemia may be caused by endemic strains within a hospital.