Naslov
Observation of Bonamia exitiosa (Haplosporidia) in European flat oyster (Ostrea edulis) at the Croatian coast

Autori
Oraić, Dražen ; Beck, Relja ; Pavlinec, Željko ; Zupičić, Ivana Giovanna ; Zrnčić, Snježana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
19th International Conference on Fish and Shellfish Diseases / Mladineo, Ivona - Porto : European Association of Fish Pathologists (EAFP), 2019, 505-505

Skup
19th Conference on Fish and Shellfish Diseases (EAFP 2019)

Mjesto i datum
Porto, Portugal, 09.09.2019. - 12.09.2019

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Ostrea edulis, Bonamia exitiosa, Croatian Adriatic Sea

Sažetak
Introduction: The production of the European flat oyster (Ostrea edulis) has a long tradition in Croatia and the total annual production is about 60 tons. There are several cultivation areas but the majority of production is located in the southern part of the Adriatic Sea, Mali Ston Bay. The molluscs diseases surveillance program is in force and several sampling points are defined as well as timing and number of samples. Flat oysters are submitted for listed diseases analysis, bonamiosis and marteiliosis, twice per year, in springtime and autumn. The positive Bonamia exitiosa samples were observed during the period from 2016 until now. Methodology: Totally 60 samples (n=30) of oysters were analysed for the presence of Bonamia spp. The diagnostic tests employed for the detection of Bonamia spp. were a cytological examination of stained heart tissue impression smears, polymerase chain reaction (PCR) and histology. PCR positive samples were sequenced for small subunit ribosomal DNA gene. All sequences were subjected to a homology search through BLAST (http://www.ncbi.nlm.nih. gov/BLAST/). Samples of Pacific oyster (Crassostrea gigas) as putative vector species were analysed using the same protocol. Results: B. exitiosa was detected at two locations namely the Bay of Medulin where 2/30 oysters were infected and on 5 locations in the Bay of Mali Ston where 17/150 oysters were infected. The finding of B. exitiosa was repeated in the Bay of Medulin in November 2016 where 1/30 examined oysters, and in July 2017 where 3/30 oysters, and finally, in November 2017 where 1/30 oysters were positive. In 2018, B. exitiosa was detected in June at another two locations ; 3/30 in Savudrija and 2/30 Limski Bay while location tested positive in previous years was negative. The parasites were not visualized in smears or histology, but the PCR confirmed its’ presence. Phylogenetic analysis revealed 100% homology with various isolates of B. exitiosa. Conclusion: The prevalence of B. exitiosa was very low and findings were not accompanied by mortality events. The further work should be focused on epidemiology research which should clarify the onset of the parasite.

Izvorni jezik
Engleski

Znanstvena područja
Veterinarska medicina

POVEZANOST RADA