Wang S, Zeng X F, Wang Q W, Zhu J L, Peng Q, Hou C L, Thacker P, Qiao S Y
J Anim Sci. 2015 Oct;93(10):4750-60. doi: 10.2527/jas.2015-9284.
Sublancin is an antimicrobial peptide produced by 168 containing 37 amino acids. The objective of this study was to investigate its inhibitory efficacy against both in vitro and in vivo. In the in vitro study, we determined that sublancin had a minimum inhibitory concentration of 8 μM against , which was much higher than the antibiotic lincomycin (0.281 μM). Scanning electron microscopy showed that sublancin damaged the morphology of . The in vivo study was conducted on broilers for a 28-d period using a completely randomized design. A total of 252 chickens at 1 d of age were randomly assigned to 1 of 6 treatments including an uninfected control; an infected control; 3 infected groups supplemented with sublancin at 2.88, 5.76, or 11.52 mg activity/L of water; and an infected group supplemented with lincomycin at 75 mg activity/L of water (positive control). Necrotic enteritis was induced in the broilers by oral inoculation of on d 15 through 21. Thereafter, the sublancin or lincomycin were administered fresh daily for a period of 7 days. The challenge resulted in a significant decrease in ADG ( < 0.05) and a remarkable deterioration in G:F ( < 0.05) during d 15 to 21 of the experiment. There was a sharp increase of numbers in the cecum ( < 0.05). The addition of sublancin or lincomycin reduced caecal counts ( < 0.05). The counts had a tendency to decrease in the lincomycin treatment ( = 0.051) but were the highest in the sublancin treatment (5.76 mg activity/L of water). A higher villus height to crypt depth ratio in the duodenum and jejunum as well as a higher villus height in the duodenum were observed in broilers treated with sublancin or lincomycin ( < 0.05) compared with infected control broilers. It was observed that sublancin and lincomycin decreased IL-1β, IL-6, and tumor necrosis factor-α levels ( < 0.05) in the ileum compared with the infected control. In conclusion, although sublancin's minimum inhibitory concentration is much higher than lincomycin in vitro, less sublancin is needed to control necrotic enteritis induced by in vivo than lincomycin. These novel findings indicate that sublancin could be used as a potential antimicrobial agent to control necrotic enteritis.
杆菌溶素是由168株产生的一种含37个氨基酸的抗菌肽。本研究的目的是调查其在体外和体内的抑制效果。在体外研究中，我们确定杆菌溶素对……的最低抑菌浓度为8μM，这远高于抗生素林可霉素（0.281μM）。扫描电子显微镜显示杆菌溶素破坏了……的形态。体内研究采用完全随机设计，对肉鸡进行了为期28天的实验。总共252只1日龄的鸡被随机分配到6种处理中的1种，包括未感染对照组；感染对照组；3个感染组，分别在水中添加2.88、5.76或11.52mg活性的杆菌溶素；以及1个在水中添加75mg活性林可霉素的感染组（阳性对照）。在第15至21天通过口服接种……诱导肉鸡发生坏死性肠炎。此后，每天新鲜给予杆菌溶素或林可霉素，持续7天。在实验的第15至21天，攻毒导致平均日增重显著下降（P<0.05），料重比显著恶化（P<0.05）。盲肠中……数量急剧增加（P<0.05）。添加杆菌溶素或林可霉素可减少盲肠……数量（P<0.05）。林可霉素处理组的……数量有下降趋势（P=0.051），但杆菌溶素处理组（5.76mg活性/L水）的数量最高。与感染对照肉鸡相比，用杆菌溶素或林可霉素处理的肉鸡十二指肠和空肠的绒毛高度与隐窝深度比值更高，十二指肠的绒毛高度也更高（P<0.05）。观察到与感染对照相比，杆菌溶素和林可霉素降低了回肠中白细胞介素-1β、白细胞介素-
