Isolation, Identification, and Pathogenicity of Aeromonas veronii, the Causal Agent of Hemorrhagic Septicemia in Channel Catfish (Ictalurus punctatus) in China

Herein, we isolated the pathogenic strain ZZ051 from hemorrhagic channel catfish (Ictalurus punctatus). Physiological and biochemical identification, 16S rRNA gene sequence analysis, and MALDI-TOF-MS showed that the ZZ051 strain was Aeromonas veronii. After artificial infection, the diseased fish showed symptoms similar to the natural disease, and the characteristics of the bacteria reisolated from the tissues were the same as those of the original infection, indicating that the isolated strain ZZ051 was the pathogen responsible for the channel catfish disease. The ZZ051 isolate was highly sensitive to enrofloxacin but resistant to florfenicol. This study provided a theoretical basis for preventing and controlling hemorrhagic disease in channel catfish.