Effect of low‐dose Piscirickettsia salmonis infection on haematological‐biochemical blood parameters in Atlantic salmon (Salmo salar). Issue 4 (29th July 2022)

• Record Type: Journal Article
• Authors: Isla, Adolfo; Sánchez, Patricio; Ruiz, Pamela; Albornoz, Romina; Pontigo, Juan P.; Rauch, María Cecilia; Hawes, Christopher; Vargas‐Chacoff, Luis; Yáñez, Alejandro J.
• Is Part Of: Journal of fish biology. Volume 101:Issue 4(2022)
• Page Start: 1021
• Page End: 1032
• Publication Date: 2022-07-29
• Subjects: haematocrit -- iron -- LDH -- Piscirickettsia salmonis -- white blood cell; Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.15167
• Languages: English
• ISSNs: 0022-1112

Abstract

Abstract: Piscirickettsia salmonis is the etiological agent of Piscirickettsiosis, a severe disease that affects Atlantic salmon ( Salmo salar ) farmed in Chile and many other areas (Norway, Scotland, Ireland, Canada and the USA). This study investigated the effects of low‐dose P. salmonis infection (1 × 10 2 CFU/ml) on Atlantic salmon. In this study, we challenged fish with an isolated representative of the EM‐90 genogroup via intraperitoneal injection for 42 days. Infected fish displayed decreased haematocrit and haemoglobin levels at day 13 post‐infection, indicating erythropenia, haemolysis and haemodilution. Conversely, their white blood cell counts increased on days 13 and 21 post‐infection. Additionally, their iron levels decreased from day 2 post‐infection, indicating iron deficiency and an inability to retrieve stored iron before infection. Their magnesium levels also decreased at day 28 post‐infection, possibly due to osmoregulatory problems. Also, we observed an increase in lactate dehydrogenase activity on days 5, 21, and 28 post‐infection, suggesting early symptoms of hepatotoxicity. Later analyses determined a decrease in plasma glucose levels from day 2 post‐infection. This may be attributed to the hypoxic conditions caused by P. salmonis, leading to an excess utilization of stored carbohydrates. Our results suggest that the blood parameters we studied are useful for monitoring the physiological status of Atlantic salmon infected with P. salmonis .