Clinical listonellosis in meagre (Argyrosomus regius) from recirculated aquaculture system in Turkey

Abstract

Vibriosis caused by Listonella anguillarum was reported in several fish species from both fresh and saltwater conditions. This pathogen causes disease in rainbow trout, sea bass, and sea bream in Turkey, however, it has not been reported from meagre (Argyrosomus regius) before. Great loss of meagre was observed in the Recirculated Aquaculture System at the Faculty of Fisheries of Izmir Katip Celebi University, which had been transferred from a commercial hatchery for a nutrition experiment. Clinical signs of vibriosis were observed in infected fish, i.e. haemorrhage in the anal area and pectoral fins, mostly as tail ulcers. Petechial haemorrhages in the muscle, liver, peritoneal membranes and pyloric caeca were determined by necropsy. A Gram-negative, rod-shaped, motile bacterium was isolated, showing a positive reaction to oxidase, catalase and gelatin tests, and being sensitive to O/129. Biochemical identification tests and PCR amplifications identified the bacterium as Listonella anguillarum. In slide agglutination test with anti L. anguillarum O1 (ATCC43305) serum, all isolates were positive. The isolated bacteria was resistant to oxytetracycline, sensitive to enrofloxacin, flumequine, phosphomycin, furozulidone, kanamycin and oxolinic acid. In this study, the isolated bacteria from meagre were determined as Listonella anguillarum O1 with biochemical, moleculer identification and agglutination tests.

Πολύπλευρη διερεύνηση της αιτιολογίας της χρόνιας συστηματικής κοκκιωμάτωσης και της χρόνιας εκλωτικής δερματοπάθειας του κρανιού, Argyrosomus regius

“…Το ίδιο παθογόνο βακτήριο απομονώθηκε από κρανιούς (βάρους: 20 g) που εκτρέφονταν σε κλειστό κύκλωμα ανακύκλωσης του νερού για τις ανάγκες πειράματος διατροφής στην Τουρκία (Dinçtürk & Tanrıkul 2018). Τα κλινικά σημάδια που παρατήρησαν περιλάμβαναν ακανόνιστη συμπεριφορά κολύμβησης, σκούρο χρωματισμό του δέρματος, αιμορραγίες στην περιοχή της έδρας και στα θωρακικά πτερύγια καθώς και εξελκώσεις στην περιοχή της ουράς.…”