Affiliation:
1. Tianjin Fisheries Research Institute, 442 Jiefangnan Road, Tianjin 300221, PR China
2. College of Chongqing University of Arts and Sciences, College of Landscape Architecture and Life Science, Chongqing 402160, PR China
3. Prevention and Cure Center for Animal Disease in Tianjin, North of Yixingfu, Tianjin 300221, PR China
Abstract
Bacillus cereus is commonly considered a bacterium pathogenic to mammals, but several studies have suggested that it also induces diseases in fish. In 2017 and 2018, 2 strains of B. cereus, NQ-2017-17 and NQ-2018-8, were isolated from diseased large-scale loach Paramisgurnus dabryanus in Tianjin, China, and were considered to be the pathogens responsible for the disease. These stains were identified as B. cereus based on the results of 16S rDNA gene sequence analysis, Vitek biochemical tests, physiological and biochemical tests, and B. cereus group species-specific PCR. Strains NQ-2017-7 and NQ-2018-8 were found to contain virulence genes (e.g. hblA, hblC, hblD, entFM, and bceT) causing pathological damage to the spleen, kidneys, liver, and gills of loach. The median lethal dose (LD50) of NQ-2017-7 and NQ-2018-8 for loach were 1.0 ×106.64 and 1.0 ×106.49 CFU ml-1, respectively. To our knowledge, this is the first report of loach disease caused by a member of the genus Bacillus.
Publisher
Inter-Research Science Center
Subject
Aquatic Science,Ecology, Evolution, Behavior and Systematics