目的:本研究评价茶多酚(TP)的抗菌特性和作用机制,Nisin,和ε-聚赖氨酸(PL)对抗犬链球菌(S.canis),次要链球菌(S.minor),变形链球菌(S.mutans),和放线菌(A.oris),伴侣动物中常见的人畜共患病原体。
结果:从猫科动物口腔中分离出致病菌株,并使用最小抑制浓度(MIC)测试进行评估,抑制区测定,生长动力学,和生物膜抑制研究。在单一代理商中,PL对所有四种病原体表现出最低的MIC值。TP对S.minor表现出明显的抗性,和Nisin对抗S.mutans。TP的联合治疗(Comb),Nisin,和PL以13:5:1的比例表现出广谱抗菌活性,保持低MIC值,形成大的抑制区,延长细菌滞后期,降低增长率,并抑制生物膜的形成。RNA测序和代谢组学分析表明,TP,Nisin,和PL通过犬的磷酸烯醇丙酮酸依赖性磷酸转移酶系统抑制各种膜结合的碳水化合物特异性转移酶,破坏碳水化合物的摄取。它们还下调糖酵解和柠檬酸循环,抑制细胞能量代谢。此外,它们调节肽聚糖糖基转移酶和D-丙氨酰-D-丙氨酸羧肽酶的活性,干扰肽聚糖交联和细菌细胞壁稳定性。
结论:梳子疗法通过靶向多种细菌途径显著增强抗菌疗效,在食品和药物抗菌剂中提供潜在的应用。
OBJECTIVE: This study evaluates the antibacterial characteristics and mechanisms of combined tea polyphenols (TPs), Nisin, and ε-polylysine (PL) against Streptococcus canis, Streptococcus minor, Streptococcus mutans, and Actinomyces oris, common zoonotic pathogens in companion animals.
RESULTS: Pathogenic strains were isolated from feline oral cavities and assessed using minimum inhibitory concentration (MIC) tests, inhibition zone assays, growth kinetics, and biofilm inhibition studies. Among single agents, PL exhibited the lowest MIC values against all four pathogens. TP showed significant resistance against S. minor, and Nisin against S. mutans. The combination treatment (Comb) of TP, Nisin, and PL in a ratio of 13:5:1 demonstrated broad-spectrum antibacterial activity, maintaining low MIC values, forming large inhibition zones, prolonging the bacterial lag phase, reducing growth rates, and inhibiting biofilm formation. RNA sequencing and metabolomic analysis indicated that TP, Nisin, and PL inhibited various membrane-bound carbohydrate-specific transferases through the phosphoenolpyruvate-dependent phosphotransferase system in S. canis, disrupting carbohydrate uptake. They also downregulated glycolysis and the citric acid cycle, inhibiting cellular energy metabolism. Additionally, they modulated the activities of peptidoglycan glycosyltransferases and d-alanyl-d-alanine carboxypeptidase, interfering with peptidoglycan cross-linking and bacterial cell wall stability.
CONCLUSIONS: The Comb therapy significantly enhances antibacterial efficacy by targeting multiple bacterial pathways, offering potential applications in food and pharmaceutical antimicrobials.