First Report of Candida sp. from Rainbow Trout (Oncorhynchus mykiss, Walbaum) Fry in Turkey

In this study, we isolated Candida sp. for the first time from fry of rainbow trout ( Oncorhynchus mykiss ) in Turkey. Candida species caused disease in fry (average 0.2 g) which was observed at 10°C water temperature in February 2016. Due to yeast accumulation on gills, whitish areas was seen and fusion of secondary lamella in gills were observed under microscope. The microbiological samples of kidney, spleen and gills were streaked onto trypticase soy agar (TSA) and tryptone yeast extract salts ( TYES ) agar plates and incubated at 22°C in TSA and 18°C in TYES agar for 48 h. Thirteen isolates were obtained and Gram staining was performed. The all of the isolates were determined as yeast cell based on cellular morphology by using light microscopy . The identification was performed by ITS (Internal transcribed spacer) region sequence analysis and sequence data demonstrated that representative isolate D11 belonged to genus Candida . The yeast infection might have seen in early development stages (larvae and fry) due to the intensive antibiotic use against rainbow trout fry syndrome (RTFS) disease.