ISOLATION, MOLECULAR IDENTIFICATION AND ANTIBIOTIC SENSITIVITY TESTING OF DISEASE-CAUSING BACTERIA IN ONCORHYNCHUS MYKISS FISH CULTIVATED IN ISPARTA - ÇUKURKÖY DISTRICT

Abstract

Aquaculture is a very important production sector in our country, due to its annual income of approximately 1.2 billion dollars and providing a large employment for fish harvest. However, bacterial infections are a major threat to the fish farming industry. Temperature changes also contribute to the increase of infectious diseases. Oncorhynchus mykiss or rainbow trout is the most farmed freshwater fish in Turkey and is important for the development of strategies to combat common infections in its aquaculture. Therefore, the aim of this study is to determine the bacterial infections that cause losses in rainbow trout farming. In addition, the species identification and antibiotic susceptibility information of the bacteria causing the disease will help to better understand the etiology of the disease and to develop more effective treatment methods in the field of fish farming.

Within the scope of our study, diseased fish were collected from a trout farm in Isparta - Çukurköy district and microbiological samples were made from their kidneys and spleens. After obtaining pure colonies, the types of pathogens were tried to be determined by the 16S rRNA gene sequence analysis method. As a result, many different bacterial genera have been identified, including Yersinia, Lactococcus, Kocuria, Aeromonas, Corynebacterium, and Staphylococcus. A widespread and predominant Lactococcus infection was detected as a result of the first trout pathogen investigation from this region.