复方中草药对河豚假交替单胞菌诱发虾夷扇贝脓疱病的防治效果OACHSSCD

[Objective]This study aims to investigate the preventive and therapeutic effects of compound Chinese herbal medicines(CCHM)on pustule disease in Yesso scallop(Patinopecten yessoensis)caused by Pseudoalteromonas tetraodonis,and to provide potential compound herbal schemes for the green prevention and control of this disease.[Methods]A CCHM composed of Astragalus membranaceus,Rheum officinale,Scutellaria baicalensis and Coptis chinensis at a mass ratio of 4∶3∶2∶1 was supplemented to the diet at a mass fraction of 0.5%,and P.yessoensis were fed continuously with this diet for 12 d.According to the 72 h LD50 determined in pre-experiments,an artificial infection challenge test was performed via adductor muscle injection with 0.1 mL bacterial suspension of P.tetraodonis at a concentration of 2.09×108 CFU/mL.During the experiment,a dominant bacterial strain was isolated from the lesions,identified to the species level through morphological observation,physiological and biochemical tests,and 16S rRNA gene sequence analysis.The effects of CCHM on survival rate,hepatic tissue structure,hepatic antioxidant enzyme activities,and non-specific immune indices were also evaluated.[Results]The strain A1 was identified as P.tetraodonis.Feeding with CCHM significantly increased the survival rate of infected scallops(from 32%to 88%,P<0.05)and effectively alleviated histopathological damage in the hepatic tissues.Furthermore,CCHM significantly enhanced the activities of hepatic catalase(CAT)and glutathione peroxidase(GSH-Px)(by approximately 167%and 376%,respectively,P<0.05),maintained stable leukocyte counts during infection,and differentially regulated the expression of hepatic pro-inflammatory factors,significantly up-regulated hepatic tumor necrosis factor-α(TNF-α)level and down-regulated interleukin-17(IL-17)level in infected scallops(P<0.05).[Conclusion]The addition of CCHM at a mass fraction of 0.5%to the feed can effectively prevent and control pustule disease in Yesso scallop(P.yessoensis)induced by P.tetraodonis.