Characterization of Philasterides dicentrarchi isolates that are pathogenic to turbot: Serology and cross-protective immunity

► The antigenicity of seven Philasterides dicentrarchi isolates was evaluated. ► The cross-protective immunity induced by the isolates in turbot was analyzed. ► WB allowed us to separate the seven isolates in two groups. ► In terms of protection, the isolates can also be classified into two groups. ► A vaccine containing ciliates from both groups may protect against all isolates.