Isolation frequency and epidemiological characterization of yeast-like fungi and co-infected bacteria isolated from clinical patient

Pathogenic yeast-like fungi and bacteria are found all over the world, and are a frequent cause of invasive disease in immunocompromised hosts. However, there is a paucity of data on pathogenic yeast-like fungi in Korea. In this study, the characterization of pathogenic yeast-like fungi and co-infected bacteria isolated from 715 patients (ranging in age from 29 days to 99 years, with a mean age of 49 years) that were collected from general hospitals (from April 2011 to March 2013) in Busan were investigated. A total of 744 pathogenic yeast-like fungi and 170 six bacterial strains were isolated from clinical samples. The majority of isolates from sputum and urine samples were obtained from patients. The isolation frequency by sex was similar in females (48.6%) and males (51.4%). It was higher in individuals over 60 years of age (67.5%) than in younger individuals. The Candida species most frequently isolated from clinical samples was Candida albicans (64.0%), followed by Candida tropicalis (18.1%), Candida glabrata (8.6%), Candida parapsilosis (5.0%), Candida krusei (0.7%), and other Candida species (1.9%). The non-Candida species isolated most frequently from clinical samples was the Trichosporon species (1.2%). Although C. albicans was the most common species in almost clinical samples, C. tropicalis (47.6%) was most common species in urine samples. Staphylococcus aureus (15.3%) and Klebsiella pneumoniae (10.2%) were commonly isolated from patients infected with C. albicans. Although the epidemiology of pathogenic yeast-like fungal infection has been reported, these results are the first on the distribution of yeast-like fungi and co-infected bacteria from patients in Korea. Key words: Pathogenic yeast-like fungus, co-infected bacteria, infectious disease, epidemiology, Korea.