Diets containing corn naturally contaminated with deoxynivalenol reduces the susceptibility of rainbow trout (Oncorhynchus mykiss)to experimentalFlavobacterium psychrophiluminfection

Abstract

The objective of this study was to determine if deoxynivalenol (DON) exposure alters the susceptibility of rainbow trout to bacterial coldwater disease caused by Flavobacterium psychrophilum. Rainbow trout were fed a nutritionally complete diet containing corn that was naturally contaminated with DON at a desired concentration of <0.5 (control and pair‐fed treatments), 4 or 6 ppm over 7 weeks to apparent satiation. After 4 weeks, fish were infected by intraperitoneal injection with F. psychrophilum (3.03x106 CFU mL−1) via intraperitoneal injection and monitored for morbidity and mortality. A significant linear reduction in feed intake was associated with increasing dietary levels of DON contamination over the initial 4 weeks. There was a significant reduction (P < 0.05) in cumulative per cent mortality in DON‐fed groups (4.1 ppm, 11%; 5.9 ppm, 7%) in comparison to control (46%) and pair‐fed (25%) groups at 21 days post infection. Mortality of trout pair‐fed the control diet was also significantly lower (P < 0.05) than the control group fed to apparent satiation. A replicate trial using genetically similar fish and the same experimental design produced similar results. These results suggest that DON exposure and restricted feed intake provided a protective effect for rainbow trout infected with F. psychrophilum.

Autophagy modulation in rainbow trout Oncorhynchus mykiss L. and resistance to experimental infection with Flavobacterium psychrophilum

“…Fish treated with CQ and reduced nutrition also had increased (but not statistically significant) LC3II in the liver as well. Yet, all three treatments examined, including reduced nutrition and DON, as demonstrated previously (Ryerse et al., 2015, 2016), and additionally CQ, decreased susceptibility to F. psychrophilum in the present experiments.…”

“…Although there was no significant difference in survival between treatments for the first infection trial after pretreatment with the different diets for 6 days, the trend of the mortality between different treatments was quite similar to that in the second infection trial here and that seen previously for DON and pair‐fed treatments when fish were pretreated for 4 weeks (Ryerse et al., 2016). It seems to be necessary to pretreat the fish for a sufficient duration to elicit the protective effect, at least for rainbow trout infected with F. psychrophilum .…”

Autophagy modulation in rainbow trout Oncorhynchus mykiss L. and resistance to experimental infection with Flavobacterium psychrophilum

“…Fish treated with CQ and reduced nutrition also had increased (but not statistically significant) LC3II in the liver as well. Yet, all three treatments examined, including reduced nutrition and DON, as demonstrated previously (Ryerse et al., 2015, 2016), and additionally CQ, decreased susceptibility to F. psychrophilum in the present experiments.…”

“…Although there was no significant difference in survival between treatments for the first infection trial after pretreatment with the different diets for 6 days, the trend of the mortality between different treatments was quite similar to that in the second infection trial here and that seen previously for DON and pair‐fed treatments when fish were pretreated for 4 weeks (Ryerse et al., 2016). It seems to be necessary to pretreat the fish for a sufficient duration to elicit the protective effect, at least for rainbow trout infected with F. psychrophilum .…”

Purified deoxynivalenol or feed restriction reduces mortality in rainbow trout, Oncorhynchus mykiss (Walbaum), with experimental bacterial coldwater disease but biologically relevant concentrations of deoxynivalenol do not impair the growth of Flavobacterium psychrophilum

“…Pair‐fed rainbow trout also had significantly reduced mortality as previously described (Ryerse et al . ); however, in the present study, there was no significant difference in mortality between fish fed diets containing DON and those that were pair‐fed. Feed containing soya bean meal naturally contaminated with DON was also associated with a reduction in mortalities in juvenile channel catfish experimentally infected with Edwardsiella ictaluri (Manning et al .…”

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

“…Interestingly, Manning, et al [ 21 ] demonstrated that feeding diets containing 5 and 10 mg DON kg −1 significantly decreased mortality of channel catfish during a trial of 21-day post-challenge with the pathogenic bacterium ( Edwardsiella ictaluri ). This finding was supported by Ryerse, et al [ 52 ], who observed a significant reductions in the cumulative mortality of rainbow trout fed diets containing 4.1 or 5.9 mg·kg −1 DON from naturally contaminated corn compared to control and pair-fed groups following infection with Flavobacterium psychrophilum . Likewise, feeding a diet containing 6.4 mg·kg −1 purified DON significantly reduced mortality of rainbow trout after experimental F. psychrophilum infection compared to the control group (<0.1 mg·kg −1 DON) [ 51 ].…”

Autophagy modulation in rainbow trout Oncorhynchus mykiss L. and resistance to experimental infection with Flavobacterium psychrophilum

“…Fish treated with CQ and reduced nutrition also had increased (but not statistically significant) LC3II in the liver as well. Yet, all three treatments examined, including reduced nutrition and DON, as demonstrated previously (Ryerse et al., 2015, 2016), and additionally CQ, decreased susceptibility to F. psychrophilum in the present experiments.…”

“…Although there was no significant difference in survival between treatments for the first infection trial after pretreatment with the different diets for 6 days, the trend of the mortality between different treatments was quite similar to that in the second infection trial here and that seen previously for DON and pair‐fed treatments when fish were pretreated for 4 weeks (Ryerse et al., 2016). It seems to be necessary to pretreat the fish for a sufficient duration to elicit the protective effect, at least for rainbow trout infected with F. psychrophilum .…”

Purified deoxynivalenol or feed restriction reduces mortality in rainbow trout, Oncorhynchus mykiss (Walbaum), with experimental bacterial coldwater disease but biologically relevant concentrations of deoxynivalenol do not impair the growth of Flavobacterium psychrophilum

“…Pair‐fed rainbow trout also had significantly reduced mortality as previously described (Ryerse et al . ); however, in the present study, there was no significant difference in mortality between fish fed diets containing DON and those that were pair‐fed. Feed containing soya bean meal naturally contaminated with DON was also associated with a reduction in mortalities in juvenile channel catfish experimentally infected with Edwardsiella ictaluri (Manning et al .…”

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

“…Interestingly, Manning, et al [ 21 ] demonstrated that feeding diets containing 5 and 10 mg DON kg −1 significantly decreased mortality of channel catfish during a trial of 21-day post-challenge with the pathogenic bacterium ( Edwardsiella ictaluri ). This finding was supported by Ryerse, et al [ 52 ], who observed a significant reductions in the cumulative mortality of rainbow trout fed diets containing 4.1 or 5.9 mg·kg −1 DON from naturally contaminated corn compared to control and pair-fed groups following infection with Flavobacterium psychrophilum . Likewise, feeding a diet containing 6.4 mg·kg −1 purified DON significantly reduced mortality of rainbow trout after experimental F. psychrophilum infection compared to the control group (<0.1 mg·kg −1 DON) [ 51 ].…”

Autophagy modulation in rainbow trout Oncorhynchus mykiss L. and resistance to experimental infection with Flavobacterium psychrophilum

“…Fish treated with CQ and reduced nutrition also had increased (but not statistically significant) LC3II in the liver as well. Yet, all three treatments examined, including reduced nutrition and DON, as demonstrated previously (Ryerse et al., 2015, 2016), and additionally CQ, decreased susceptibility to F. psychrophilum in the present experiments.…”

“…Although there was no significant difference in survival between treatments for the first infection trial after pretreatment with the different diets for 6 days, the trend of the mortality between different treatments was quite similar to that in the second infection trial here and that seen previously for DON and pair‐fed treatments when fish were pretreated for 4 weeks (Ryerse et al., 2016). It seems to be necessary to pretreat the fish for a sufficient duration to elicit the protective effect, at least for rainbow trout infected with F. psychrophilum .…”

Purified deoxynivalenol or feed restriction reduces mortality in rainbow trout, Oncorhynchus mykiss (Walbaum), with experimental bacterial coldwater disease but biologically relevant concentrations of deoxynivalenol do not impair the growth of Flavobacterium psychrophilum

“…Pair‐fed rainbow trout also had significantly reduced mortality as previously described (Ryerse et al . ); however, in the present study, there was no significant difference in mortality between fish fed diets containing DON and those that were pair‐fed. Feed containing soya bean meal naturally contaminated with DON was also associated with a reduction in mortalities in juvenile channel catfish experimentally infected with Edwardsiella ictaluri (Manning et al .…”

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

“…Interestingly, Manning, et al [ 21 ] demonstrated that feeding diets containing 5 and 10 mg DON kg −1 significantly decreased mortality of channel catfish during a trial of 21-day post-challenge with the pathogenic bacterium ( Edwardsiella ictaluri ). This finding was supported by Ryerse, et al [ 52 ], who observed a significant reductions in the cumulative mortality of rainbow trout fed diets containing 4.1 or 5.9 mg·kg −1 DON from naturally contaminated corn compared to control and pair-fed groups following infection with Flavobacterium psychrophilum . Likewise, feeding a diet containing 6.4 mg·kg −1 purified DON significantly reduced mortality of rainbow trout after experimental F. psychrophilum infection compared to the control group (<0.1 mg·kg −1 DON) [ 51 ].…”