In this study, natural radioactivity concentrations of fish feed and feed raw materials were assessed. Several feeds and raw materials were provided from the suppliers who dominate the aquaculture sector. 226 Ra, 232 Th and 40 K concentrations were determined by using a high-purity germanium detector. The measured activity con-

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In this study, a disease case caused with 15% mortality on gilthead sea bream (Sparus aurata) which was cultured in the Antalya Bay in the Mediterranean coast of Turkey was investigated in July 2015. Lethargy, loss of equilibrium, petechae on the operculums and the dorsal part of the body, pillar of the gills were recorded in the diseased fish. Internally, ascites, splenomegaly and hemorrhages on the intestinal tissue and muscle were observed. Occurrence of parasite was not detected. According to the results of phenotypical test and 16S rDNA sequencing analysis, the isolated bacterial species was identified as Staphylococcus hominis. Histopathologically, hyperplasia of primary lamellae, lamellar telangiectasia, edema and hemorrhages on the gill arch, numerous melanomacrophage centers (MMCs) in the spleen tissue, vacuoler degeneration, necrose and hemorrhages in the liver, multifocal necrosis, and numerous MMC in the kidney were determined and hemorrhages in the tunica propria region of the intestine were observed. It was determined that he isolates showed different susceptibility against antimicrobial agents.

The aim of this study is to inform isolations of Shewanella putrefaciens, Aeromonas sobria and Aeromonas veronii from the silver European eel fish (Anguilla anguilla) caught from the Gulf of Antalya, Turkey. Three silver eel fish samples as freshly dead (mean weight 75 g) were obtained by a local fisherman. For presumptive identification of the bacterial strains, the strains were identified using a variety of phenotypic characteristics. The further identification of the strains was performed with PCR. Clinically, the silver eel samples showed pale gills, losses of scale, necrotic lesions on dorsal, hemorrhagies on the jaws, lateral and ventral sides of the body and around the anus and hemoragic anal fin. At necropsy, the fish had enlarged and pale spleen and the gastrointestinal tract was empty. After 72 hours, 10 bacterial strains were isolated. 6 strains as Shewanella putrefaciens, 2 strains as Aeromonas sobria and 2 strains as Aeromonas veronii were identified according to the phenotypical characteristics and PCR study results. The eel fish stocks in natural conditions are decreasing and this problem may be multifactorial such as disease, migration and overhunting. As a result of this study, Aeromonas veronii was first isolated from Anguilla anguilla.

This study was aimed to determine the current antibiotic resistance of Lactococcus garvieae, which causes significant economic losses in rainbow trout (Oncorhynchus mykiss) farms. For the study, three farms located around a stream were visited in two consecutive disease outbreaks. Bacteria were isolated from the diseased fish and all bacterial isolates were identified using conventional and molecular methods. Then, they were examined for 5 different antibiotic resistance genes and their antibiotic susceptibility profiles were determined using the disc diffusion technique. The results of the study revealed that all 16 isolates had a different antibiotic resistance profile and each should be considered as a separate strain. Additionally, they showed that there may be different L. garvieae strains within and between farms, using the same water source. Comparison of the results with previous studies from the region and different regions of the country revealed that antibiotic resistance is increasing in L. garvieae, and screenings on a limited number of isolates may not give an accurate picture of the final status of antibiotic resistance. These outcomes of the study are discussed in terms of treatment strategies that trout farms in the region should follow when treating lactococcosis.