Pathological findings in southern bluefin tuna, Thunnus maccoyii (Castelnau), infected with Cardicola forsteri (Cribb, Daintith & Munday, 2000) (Digenea: Sanguinicolidae), a blood fluke

2001 ◽  
Vol 24 (4) ◽  
pp. 225-229 ◽  
Author(s):  
S E Colquitt ◽  
B L Munday ◽  
M Daintith





PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e45742 ◽  
Author(s):  
Nicole T. Kirchhoff ◽  
Melanie J. Leef ◽  
Victoria Valdenegro ◽  
Craig J. Hayward ◽  
Barbara F. Nowak


2008 ◽  
Vol 25 (1-2) ◽  
pp. 66-75 ◽  
Author(s):  
Hamish M. Aiken ◽  
Craig J. Hayward ◽  
Philip Crosbie ◽  
Marianne Watts ◽  
Barbara F. Nowak


Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1248
Author(s):  
Cecilia Power ◽  
Shannon Evenden ◽  
Kirsten Rough ◽  
Claire Webber ◽  
Maree Widdicombe ◽  
...  

The parasitic blood flukes Cardicola forsteri and C. orientalis are an ongoing health concern for Southern Bluefin Tuna Thunnus maccoyii (SBT) ranched in Australia. In this study we compared the effect of treatment, company, and ranching year on blood fluke infections in ranched SBT. SBT were sampled during the 2018 and 2019 ranching seasons from praziquantel (PZQ) treated pontoons and untreated pontoons managed by two companies. Severity of infection was diagnosed by several criteria including adult fluke counts from hearts, egg counts from gill filaments and the use of specific quantitative polymerase chain reaction (qPCR) for detection of C. forsteri and C. orientalis ITS-2 DNA in SBT hearts and gills. PZQ treatment remains highly effective against C. forsteri infection. Prevalence and intensity of Cardicola spp. infection was lower in 2019 than 2018 for Company A in treated pontoons at week 12 and week 17 of ranching, and lower for Company A than Company B in untreated pontoons at month 5 of ranching. Results indicate re-infection may be less likely in the environment near Company A pontoons, and consistent years of treatment may have lowered the parasite load in the environment. qPCR demonstrated higher sensitivity when comparing diagnostic methods for C. forsteri in heart, and higher specificity when comparing diagnostic methods for Cardicola spp. in gills. Continuing to monitor blood fluke infections in ranched SBT can help to detect changes in drug efficacy over time and help industry to develop a best practice for treatment.





Aquaculture ◽  
2006 ◽  
Vol 254 (1-4) ◽  
pp. 40-45 ◽  
Author(s):  
H.M. Aiken ◽  
C.J. Hayward ◽  
B.F. Nowak


Aquaculture ◽  
2009 ◽  
Vol 293 (3-4) ◽  
pp. 204-210 ◽  
Author(s):  
Hamish Aiken ◽  
Craig Hayward ◽  
Angus Cameron ◽  
Barbara Nowak


Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 79
Author(s):  
Barbara F. Nowak ◽  
Mai Dang ◽  
Claire Webber ◽  
Lukas Neumann ◽  
Andrew Bridle ◽  
...  

Melanomacrophage centres (MMCs) are aggregates of macrophages accumulating various pigments. They have been proposed as an indicator of fish immune response. Blood flukes are common parasites in farmed fish. Two cohorts of wild Southern Bluefin Tuna (Thunnus maccoyi) were examined at transfer, before treatment against blood flukes (pre-treatment) and at harvest. MMCs were assessed in histological sections using image analysis, while Cardicola forsteri and Cardicola orientalis infection severity was determined using qPCR, count of adult flukes in heart flushes and count of eggs in gill filaments. Fish from both cohorts showed the same pattern in the changes in the surface area of MMCs. The surface area of splenic MMCs increased over the ranching duration and was positively correlated to the PCR determined copy numbers of Cardicola forsteri ITS2 rDNA in the gills of those fish. However, the infection with blood fluke was more variable, both between cohorts and individuals within the same cohort. Eggs of blood fluke were detected in renal MMCs using histology. Cardicola forsteri had a higher prevalence than Cardicola orientalis. This study contributes to our understanding of blood fluke infections in Southern Bluefin Tuna and their interactions with MMCs.



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