Tianjin Key Lab of Aqua-Ecology and Aquaculture, College of Fisheries, Tianjin Agricultural University, Tianjin, 300384, China.
J Aquat Anim Health. 2021 Dec;33(4):243-251. doi: 10.1002/aah.10141. Epub 2021 Oct 4.
Pseudomonas alcaligenes infection is rare in aquaculture. In this study, we provide the first report on the characterization of P. alcaligenes from koi (a variant of Common Carp Cyprinus carpio) in China. A gram-negative bacterium was isolated from the diseased koi and was named KCP-516. Morphological and biochemical tests as well as phylogenetic tree analyses derived from 16S ribosomal RNA, gyrase subunit A, and gyrase subunit B gene sequencing all strongly indicated that the isolate KCP-516 was P. alcaligenes. In liquid medium, the optimal growth conditions were 25°C, 2.5% NaCl, and pH 8. The pathogenicity of the isolate was demonstrated in koi, with 7.0 × 10 CFU/g fish weight identified as the dose lethal to 50% of test fish. The results will provide a scientific reference for the diagnosis and treatment of P. alcaligenes infection.
产碱假单胞菌感染在水产养殖中较为罕见。本研究首次报道了中国锦鲤（鲤鱼的一种变种）中产碱假单胞菌的特征。从患病锦鲤中分离到一株革兰氏阴性菌，命名为 KCP-516。基于 16S 核糖体 RNA、拓扑异构酶亚基 A 和拓扑异构酶亚基 B 基因测序的形态学和生化试验以及系统发育树分析均强烈表明，该分离株 KCP-516 为产碱假单胞菌。在液体培养基中，最适生长条件为 25°C、2.5%NaCl 和 pH8。该分离株对锦鲤具有致病性，以 7.0×10 CFU/g 鱼重作为对 50%试验鱼致死的剂量。研究结果将为产碱假单胞菌感染的诊断和治疗提供科学参考。
