Shewanella putrefaciens as an emerging pathogen of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis

Abstract

Shewanella putrefaciens has been recognized as an emerging important pathogen in aquaculture. However, scarce information is available on the characterization and microbial control of S. putrefaciens as a causal agent of hepatopancreas necrosis disease in Chinese mitten crab Eriocheir sinensis. In this study, a multi-resistant S. putrefaciens isolate (DZ-A) was identified as a causal pathogen of hepatopancreas necrosis disease in Chinese mitten crabs. It showed a lethal dose (LD50) of 2.20 × 105 CFU ml-1 in Chinese mitten crabs, and multiple resistance to aminoglycoside, chloramphenicol, macrolide, penicillin, peptide, and tetracycline antimicrobials. In addition, Bdellovibrio powder exhibited a significant antibacterial effect against the pathogenic S. putrefaciens, and conferred significant protection to challenged Chinese mitten crabs with relative percentage survivals of 80.00% to 93.33% via significant improvement in their immune response and antioxidant capability. The findings of this study provide valuable insights into the phenotypic characterization and biological control of pathogenic S. putrefaciens in Chinese mitten crabs.