Arai Nobuo, Shibahara Tomoyuki, Nishiura Reina, Tamamura-Andoh Yukino, Nishiura Hayate, Muneta Yoshihiro, Sawada Hiroshi, Watanabe-Yanai Ayako, Iwata Taketoshi, Akiba Masato, Kusumoto Masahiro
Division of Zoonosis Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
Division of Hygiene Management Research, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
Sci Rep. 2024 Dec 28;14(1):31407. doi: 10.1038/s41598-024-83039-6.
Salmonella enterica serovar 4,[5],12:i:- sequence type 34 (ST34) has recently become a global concern for public and animal health. The acquisition of mobile genetic element ICEmST, which contains two copper tolerance gene clusters, cus and pco, influences the epidemic success of this clone. Copper is used as a feed additive in swine at levels that potentially lead to selection pressure for Enterobacteriaceae; however, it remains unclear whether the copper tolerance system of ICEmST functions in vivo. We performed competition assays with Salmonella 4,[5],12:i:- ST34 wildtype (WT) and deletion mutants of ICEmST (ΔICEmST, Δcus, and Δpco) in groups of mice fed 0, 150, and 500 ppm CuSO. In the competition of WT against ΔICEmST and Δcus, the competitive index of the 500 ppm-fed group was significantly lower than that of the 0 ppm-fed group. In the swine experiment, all individuals were fed 150 ppm CuSO. The number of ICEmST-positive strain in the feces was significantly greater than that of ICEmST-negative strain. The serum inflammatory markers were significantly increased in swine infected with the ICEmST-positive strain. These data suggest that ICEmST, especially cus, provides Salmonella with the ability to colonize in the intestine, even at high copper concentrations, leading to swine salmonellosis.
肠炎沙门氏菌血清型4,[5],12:i:-序列型34（ST34）最近已成为全球公共卫生和动物健康关注的问题。获得含有两个耐铜基因簇cus和pco的移动遗传元件ICEmST，影响了该克隆在流行中的成功。铜在猪饲料中的添加水平可能会对肠杆菌科产生选择压力；然而，ICEmST的耐铜系统在体内是否起作用仍不清楚。我们在喂食0、150和500 ppm硫酸铜的小鼠组中，用肠炎沙门氏菌4,[5],12:i:- ST34野生型（WT）和ICEmST缺失突变体（ΔICEmST、Δcus和Δpco）进行了竞争试验。在WT与ΔICEmST和Δcus的竞争中，喂食500 ppm组的竞争指数显著低于喂食0 ppm组。在猪实验中，所有个体都喂食150 ppm硫酸铜。粪便中ICEmST阳性菌株的数量显著多于ICEmST阴性菌株。感染ICEmST阳性菌株的猪血清炎症标志物显著增加。这些数据表明，ICEmST，尤其是cus，使沙门氏菌即使在高铜浓度下也能在肠道中定殖，导致猪沙门氏菌病。
