Xu Yanzhao, Wang Qing, Dong Mengmeng, Song Huishuai, Hang Bolin, Sun Yawei, Zhang Huihui, Hu Jianhe
College of Animal Science and Veterinary Medicine, Henan Institute of Science and Technology, Xinxiang, China.
Front Microbiol. 2023 Jan 24;14:1102789. doi: 10.3389/fmicb.2023.1102789. eCollection 2023.
As a promising substitute for antibiotics, increasing attention has been given to the clinical application of antimicrobial peptides (AMPs). In this study, the mode of action of the HJH-3 against Pullorum was investigated. The structure and properties of HJH-3 were examined , and minimum inhibitory concentrations (MICs) were determined to evaluate its antimicrobial spectrum. The time-kill kinetics of HJH-3 was determined. The hemolytic activity of HJH-3 was determined by measuring the hemoglobin ultraviolet absorption value, and the cytotoxicity was determined using a CCK-8 kit. The protective effect of HJH-3 on chickens infected with . Pullorum was evaluated . The results demonstrated that HJH-3 exhibited strong antibacterial activity against Gram-negative pathogens at MIC values of 1.5625-25 μg/mL and against Gram-positive pathogens at MIC values of 25-50 μg/mL. HJH-3 also showed activity against the (100 μg/mL) and (6.25-12.5 μg/mL). HJH-3 at 100 μg/mL completely killed Pullorum after co-incubation for 6 h. Likewise, the hemolysis rate of CRBCs treated with 100 μg/mL HJH-3 (7.31%) was lower than that of CRBCs treated with 100 μg/mL pexiganan (40.43%). Although the hemolysis rate of CRBCs treated with 400 μg/mL HJH-3 was increased to 13.37%, it was much lower than that of 400 μg/mL pexiganan (57.27%). In regards to cytotoxicity, HJH-3 had almost no-effect on the CEF proliferation, pexiganan decreased CEFs proliferation from 56.93 to 31.00% when increasing the concentration from 50 to 200 μg/mL. In a chicken infection model, the results showed that the antibiotic prevention and HJH-3 prevention groups exhibited the best treatment effect, with the chickens being protected from the lethal dose of Pullorum, a decreased number of bacteria in the blood and spleen, and less pathological changes in intestinal segments. The prevention of infection by HJH-3 was similar to that by Ampicillin; the effect of treatment after infection was lower than that of treatment before infection, and the survival rate of infected chicks treated with HJH-3 was 70%, which was still higher than that of the infected chickens. These results suggest that HJH-3 has good clinical application potential and can be used as a substitute for antibiotics for the prevention and treatment of . Pullorum infection.
作为抗生素的一种有前景的替代品，抗菌肽（AMPs）的临床应用受到了越来越多的关注。在本研究中，研究了HJH-3对鸡白痢沙门氏菌的作用方式。检测了HJH-3的结构和性质，并测定了最低抑菌浓度（MICs）以评估其抗菌谱。测定了HJH-3的时间杀菌动力学。通过测量血红蛋白紫外吸收值测定HJH-3的溶血活性，并使用CCK-8试剂盒测定细胞毒性。评估了HJH-3对感染鸡白痢沙门氏菌的鸡的保护作用。结果表明，HJH-3对革兰氏阴性病原体在MIC值为1.5625 - 25μg/mL时表现出较强的抗菌活性，对革兰氏阳性病原体在MIC值为25 - 50μg/mL时表现出较强的抗菌活性。HJH-3对白色念珠菌（100μg/mL）和烟曲霉（6.25 - 12.5μg/mL）也有活性。100μg/mL的HJH-3与鸡白痢沙门氏菌共孵育6小时后可完全杀死该菌。同样，用100μg/mL HJH-3处理的鸡红细胞（CRBCs）的溶血率（7.31%）低于用100μg/mL匹克米星处理的CRBCs的溶血率（40.43%）。虽然用400μg/mL HJH-3处理的CRBCs的溶血率增加到了13.37%，但仍远低于400μg/mL匹克米星的溶血率（57.27%）。关于细胞毒性，HJH-3对鸡胚成纤维细胞（CEF）增殖几乎没有影响，当匹克米星浓度从50μg/mL增加到200μg/mL时，其对CEF增殖的抑制率从56.93%降至31.00%。在鸡感染模型中，结果表明抗生素预防组和HJH-3预防组表现出最佳治疗效果，鸡受到保护免受致死剂量鸡白痢沙门氏菌的感染，血液和脾脏中的细菌数量减少，肠道段的病理变化减轻。HJH-3预防感染的效果与氨苄西林相似；感染后治疗的效果低于感染前治疗，用HJH-3治疗的感染雏鸡的存活率为70%，仍高于感染鸡。这些结果表明，HJH-3具有良好的临床应用潜力，可作为抗生素的替代品用于预防和治疗鸡白痢沙门氏菌感染。
