A bacterial infectivity challenge model of Edwardsiella ictaluri in striped catfish was developed. All experiments were conducted using a bacterial isolate of E. ictaluri that had been recovered during a natural outbreak of bacillary necrosis of Pangasianodon (BNP) in farmed striped catfish Pangasianodon hypophthalmus in Vietnam. Time of immersion in 107 CFU.ml-1 had a significant effect on mortality. The immersion bacterial dose of 107 CFU/ml for 30 s resulted in a cumulative percentage mortality of 63%. Three to four days post-bacterial challenge, fish showed gross clinical signs of natural BNP and E. ictaluri was recovered and identified from these fish. Moreover, a cohabitation challenge was evaluated as an alternative challenge method, although the mortalities among the infected fish were lower at around 15%-40%. This study confirmed the horizontal transmission of E. ictaluri in striped catfish and elucidated that cohabitation challenge could be used in reproducing the disease under controlled conditions.

中文翻译：

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建立爱德华氏菌在条纹Cat鱼Pangasianodon hypophthalmus（Sauvage）中的细菌感染性模型。

建立了条纹striped鱼中爱德华氏菌的细菌感染力攻击模型。所有实验均使用捕食的大肠杆菌分离株进行，该分离株是在越南养殖条纹cat鱼Pangasianodon hypophthalmus的自然繁殖的Pangasianodon（BNP）细菌坏死过程中回收的。浸泡在107 CFU.ml-1中的时间对死亡率有显着影响。107 CFU / ml的浸入细菌剂量持续30 s导致的累积百分死亡率为63％。细菌攻击后三到四天，鱼显示出天然BNP的总体临床体征，并且从这些鱼中发现并鉴定出鱼。此外，虽然被感染鱼类的死亡率较低，大约为15％-40％，但仍将同居挑战作为替代挑战方法进行了评估。