Copper-modified palygorskite is effective in preventing and treating diarrhea caused by Salmonella typhimurium

Abstract

The aim of this research was to develop effective alternative therapies to reduce antibiotic use in animal agriculture. In this study, the efficacy of copper-modified palygorskite (CM-Pal) in preventing diarrhea caused by Salmonella was specifically examined both in vitro and in vivo. The CM-Pal was prepared with palygorskite (Pal) and copper nitrate. The antibacterial activity of the CM-Pal was detected by comparing the differences in cell numbers on plate count agar before and after adding the CM-Pal to Salmonella typhimurium cultures. Seventy ICR mice were then allocated into seven groups. Five groups (the treatment groups) were infected with S. typhimurium by intraperitoneal (i.p.) injection and were given Pal, CM-Pal, montmorillonite powder, gentamicin, and physiological saline, respectively. One group (the prevention group) was given CM-Pal before infection with S. typhimurium. Another group (the uninfected group) was not infected with S. typhimurium. The effects of Pal, CM-Pal, montmorillonite powder, and gentamicin on the treatment or prevention of diarrhea in the mice were examined by stool studies, fecal scoring, and assessment of growth performance and villus height. The CM-Pal had satisfactory anti-bacterial properties in vitro: the antibacterial rate was 100% after 2 h incubation with S. typhimurium NJS1 cultures (1×10⁶ colony-forming units (CFU)/ml). In the in vivo experiment, the CM-Pal exerted superior effects in the treatment and prevention of diarrhea in mice compared with Pal, montmorillonite powder, and gentamicin. In the CM-Pal group, no mice showed signs of diarrhea at 24 h post infection (p.i.), and all mice fully recovered from infection. However, the Pal group, montmorillonite group, and gentamicin group only recovered after 48, 48, and 96 h, respectively. The villus height level in the CM-Pal treatment group recovered at 3 d p.i. However, the recovery time of the other groups was longer (at least 5 d). The CM-Pal prevention group had a better effect on weight gain than the other groups. This study suggested that CM-Pal may be an effective alternative to conventional antibiotics for the treatment and prevention of animal diarrhea caused by Salmonella.

摘要

目的

研究开发一种抗生素替代品,应用于动物细菌性 腹泻病的治疗。

创新点

将凹凸棒石的吸附作用、肠道粘膜保护作用和铜 离子的杀菌作用巧妙的结合在一起,能够替代抗生 素,在动物细菌性腹泻的预防和治疗中发挥作用。

方法

用硝酸铜和凹凸棒石粘土(Pal)制备铜离子改性 的凹凸棒石粘土(CM-Pal )。通过比较添加 CM-Pal 前后沙门氏菌数量的变化检测抗菌活性。 体内试验,将70 只小鼠分为7 组,其中5 组感染 沙门氏菌后分别给予Pal、CM-Pal、蒙脱石散、 庆大霉素和生理盐水;1 组在感染沙门氏菌之前 给予CM-Pal,作为预防组;1 组不感染沙门氏菌, 作为未感染组。通过粪便形态、粪便计分、生长 性能和肠绒毛高度等指标判断对沙门氏菌引起 的小鼠腹泻的预防和治疗效果。

结论

体外抑菌试验显示,CM-Pal 与沙门氏菌作用2 h 后抗菌率达100%。体内试验也显示,CM-Pal 组 小鼠24 h 后腹泻症状消失,所有小鼠恢复正常。 但是其他组小鼠(Pal 组、蒙脱石散组和庆大霉 素组)分别在48、48 和96 h 后才恢复正常。CM-Pal 治疗组小鼠肠绒毛的高度在感染3 d后恢复正常, 但是其他组小鼠肠绒毛高度恢复正常至少需要 5 d。CM-Pal 预防组小鼠增重高于其他组小鼠。 本研究表明,CM-Pal 在预防和治疗由沙门氏菌引 起的腹泻方面能够替代抗生素具有较好的效果。