Rv1904促进结核分枝杆菌生物被膜形成的多维度表征

Multidimensional characterization of biofilm formation promoted by Mycobacterium tuberculosis Rv1904

摘要:

结核分枝杆菌(Mycobacterium tuberculosis, M. tb)是结核病的致病菌，其形成的生物被膜是导致耐药性增强的关键因素之一。本研究旨在探究Rv1904在M. tb生物被膜形成中的作用，构建了耻垢分枝杆菌(Mycobacterium smegmatis)与结核分枝杆菌重组菌株，并对其进行系统的生物学表征，包括菌落形态、生物被膜形成能力、滑动与聚集表型、特定基因转录水平、环境胁迫耐受性、胞内存活能力以及多种化合物敏感性等。结果显示，Rv1904显著促进生物被膜的形成，上调脂肪酸合成基因fabg4的转录水平，增强菌株对温度波动、氧化损伤及营养缺乏等非生物胁迫的耐受能力，从而提高其在宿主细胞内的存活能力。在使用的7种化合物中，氨硫脲(thioacetazone, TB1)抑制生物被膜的能力最强。综上所述，Rv1904通过促进生物被膜的形成增强环境适应力，从而提高M. tb的生存优势，而TB1能显著抑制结核分枝杆菌Rv1904介导形成的生物被膜。本研究揭示了Rv1904在生物被膜调控中的关键作用，为靶向生物被膜的抗结核药物研发提供了潜在新靶点。

Abstract:

Mycobacterium tuberculosis (M. tb), the causative agent of tuberculosis, forms biofilms that contribute significantly to enhanced drug resistance. This study aimed to investigate the role of Rv1904 in the biofilm formation of M. tb. Recombinant strains were constructed for both Mycobacterium smegmatis and M. tb, followed by systematic biological characterization in terms of colony morphology, biofilm-forming ability, sliding motility and aggregation phenotypes, transcription levels of specific genes, tolerance to environmental stresses, intracellular survival capacity, and susceptibility to multiple compounds. The results demonstrated that Rv1904 markedly promoted biofilm formation, upregulated the transcription of the fatty acid synthesis gene fabg4, and enhanced bacterial tolerance to abiotic stresses such as temperature fluctuations, oxidative damage, and nutrient deprivation. These effects collectively improved intracellular survival within host cells. Among the seven tested compounds, thioacetazone (TB1) exhibited the strongest inhibitory effect on biofilm formation. In conclusion, Rv1904 enhances the environmental adaptation and survival advantage of M. tb by promoting biofilm formation, whereas TB1 effectively suppresses Rv1904-mediated biofilm formation. This study reveals the critical role of Rv1904 in biofilm regulation and provides a potential new target for the development of anti-tuberculosis drugs targeting biofilms.