School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu 225009, China.
School of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China.
Sci Total Environ. 2023 Nov 15;899:165695. doi: 10.1016/j.scitotenv.2023.165695. Epub 2023 Jul 22.
Exposure to sub-inhibitory concentrations (sub-MICs) of antibiotics could induce the biofilm formation of microorganisms, but its underlying mechanisms still remain elusive. In the present work, biofilm formation by Salmonella Typhimurium M3 was increased when in the presence of tetracycline at sub-MIC, and the highest induction was observed with tetracycline at 1/8 MIC. The integration of RNA-sequencing and untargeted metabolomics was applied in order to further decipher the potential mechanisms for this observation. In total, 439 genes and 144 metabolites of S. Typhimurium M3 were significantly expressed after its exposure to 1/8 MIC of tetracycline. In addition, the co-expression analysis revealed that 6 genes and 8 metabolites play a key role in response to 1/8 MIC of tetracycline. The differential genes and metabolites were represented in 12 KEGG pathways, including five pathways of amino acid metabolism (beta-alanine metabolism, tryptophan metabolism, arginine and proline metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, and glutathione metabolism), three lipid metabolism pathways (biosynthesis of unsaturated fatty acids, fatty acid degradation, and fatty acid biosynthesis), two nucleotide metabolism pathways (purine metabolism, and pyrimidine metabolism), pantothenate and CoA biosynthesis, and ABC transporters. Metabolites (anthranilate, indole, and putrescine) from amino acid metabolism may act as signaling molecules to promote the biofilm formation of S. Typhimurium M3. The results of this work highlight the importance of low antimicrobial concentrations on foodborne pathogens of environmental origin.
亚抑菌浓度（sub-MIC）的抗生素暴露会诱导微生物形成生物膜，但其中的潜在机制仍不清楚。在本研究中，当沙门氏菌 Typhimurium M3 处于四环素的亚抑菌浓度时，生物膜的形成增加，而在四环素 1/8 MIC 时观察到最高的诱导。为了进一步揭示这一观察结果的潜在机制，应用了 RNA 测序和非靶向代谢组学的整合。总共，在沙门氏菌 Typhimurium M3 暴露于四环素 1/8 MIC 后，有 439 个基因和 144 个代谢物显著表达。此外，共表达分析表明，有 6 个基因和 8 个代谢物在对四环素 1/8 MIC 的反应中发挥关键作用。差异表达的基因和代谢物代表了 12 个 KEGG 途径，包括 5 个氨基酸代谢途径（β-丙氨酸代谢、色氨酸代谢、精氨酸和脯氨酸代谢、苯丙氨酸、酪氨酸和色氨酸生物合成以及谷胱甘肽代谢）、3 个脂质代谢途径（不饱和脂肪酸的生物合成、脂肪酸降解和脂肪酸生物合成）、2 个核苷酸代谢途径（嘌呤代谢和嘧啶代谢）、泛酸和辅酶 A 生物合成以及 ABC 转运蛋白。来自氨基酸代谢的代谢物（邻氨基苯甲酸、吲哚和腐胺）可能作为信号分子，促进沙门氏菌 Typhimurium M3 的生物膜形成。这项工作的结果强调了低抗菌浓度对食源性病原体的环境来源的重要性。
