Effects of zinc supplementation on Shiga toxin 2e-producingEscherichia coli in vitro

The Journal of Veterinary Medical Science

Masuo SUEYOSHI¹  Ryoko UEMURA²  Tomoko KATSUGE²  Shinya GOTO²  Yosuke SASAKI³ 

[1] Center for Animal Disease Control, University ofMiyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889–2192, Japan;Department of Veterinary Sciences, Faculty ofAgriculture, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889–2192,Japan;Organization for Promotion of Tenure Track, Universityof Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889–2192, Japan

关键词: edema disease;    hemolysis;    shiga toxin 2e;    shiga toxin-producing Escherichia coli;    zinc;   

DOI  :  10.1292/jvms.16-0471

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

Swine edema disease is caused by Shiga toxin (Stx) 2e–producing Escherichiacoli (STEC). Addition of highly concentrated zinc formulations to feed has beenused to treat and prevent the disease, but the mechanism of the beneficial effect isunknown. The purpose of the present study was to investigate the effects of highlyconcentrated zinc formulations on bacterial growth, hemolysin production, and an Stx2erelease by STEC in vitro. STEC strain MVH269 isolated from a piglet withedema disease was cultured with zinc oxide (ZnO) or with zinc carbonate(ZnCO3), each at up to 3,000 ppm. There was no effect of zinc addition onbacterial growth. Nonetheless, the cytotoxic activity of Stx2e released into thesupernatant was significantly attenuated in the zinc-supplemented media compared to thatin the control, with the 50% cytotoxic dose values of 163.2 ± 12.7, 211.6 ± 33.1 and 659.9± 84.2 after 24 hr of growth in the presence of ZnO, ZnCO3, or no supplementalzinc, respectively. The hemolytic zones around colonies grown on sheep blood agarsupplemented with zinc were significantly smaller than those of colonies grown on controlagar. Similarly, hemoglobin absorbance after exposure to the supernatants of STEC culturesincubated in sheep blood broth supplemented with zinc was significantly lower than thatresulting from exposure to the control supernatant. These in vitrofindings indicated that zinc formulations directly impair the factors associated with thevirulence of STEC, suggesting a mechanism by which zinc supplementation prevents swineedema disease.

【 授权许可】

Unknown