50th Annual IAAAM Meeting and Conference , Durban, South Africa, 18 - 22 May 2019, pp.12
Turkey was the largest rainbow trout producer of the European countries in 20161, and the reason for this production is mainly attributed to its egg and fry production. Flavobacterium psychrophilum cause the highest rates of mortality in the starting to feeding stages of the fish2. Diversity among F. psychrophilum isolates was reported at different levels, and a variety of typing schemes (e.g., biotypes, serotypes, and genotypes) was proposed accordingly3. Serological differences among F. psychrophilum isolates were reported since the pioneering studies in the nineties, and different serotyping schemes were proposed 4,5,6. Serotyping by conventional serological methods is costly, labor-intensive and requires significant technical expertise. Therefore, molecular serotyping using mPCR is a relevant alternative to traditional serotyping3. The objective of this study was to determine the serotyping differences of F. psychrophilum isolated from Turkey. In the present study twenty‐five, F. psychrophilum isolates recovered from rainbow trout, coruh trout and brook trout were identified by Duplex PCR using F. psychrophilum specific primers of gyrA and gyrB genes. Also molecular serotyping was done by multiplex PCR. The Multiplex PCR‐based serotyping study showed that three Turkish F. psychrophilum isolates were type‐0, eight isolates were type‐1, ten isolates were type‐2 and three isolates were type‐3. Isolate FP‐123 from East Anatolia showed a different band pattern could not be assigned to any molecular serotyping profile.
In conclusion, this study reports the no connection between the serotyping profile of F. psychrophilum, sampling sites or geographical origin could be identified. F. psychrophilum isolates from Turkey were serotyped by using molecular serotyping for the first time. Additionally, one F. psychrophilum isolate showed a unique serotype profile different from the recognized four serotypes. The unique serotype should be studied by using ELISA and slide agglutination tests and full genome sequencing.