Turkey was the largest rainbow trout producer of the European countries in 2016,1 and the reason for this production is mainly attributed to its egg and fry production. Flavobacterium psychrophilum cause the highest rates of mortality when the fry reach the feeding stage.2 Serologic 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 methods is costly, labor-intensive and requires technical expertise, therefore, molecular serotyping using mPCR is a relevant alternative.3 The objective of this study was to determine the serotyping of F. psychrophilum by multiplex PCR isolated from Turkey. In the present study twenty‐five, F. psychrophilum isolates from rainbow trout, Çoruh trout, and brook trout were identified by Duplex 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 and could not be assigned to any molecular serotyping profile.
The determination of serotyping and regional differences of F. psychrophilum were aimed. This study reports the no connection between the serotyping profile of F. psychrophilum, sampling sites or geographical origin. 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.
This research was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) [No: 116O626].
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