Pal Rahul, Ansari Moiz A, Saibabu Venkata, Das Shrayanee, Fatima Zeeshan, Hameed Saif
Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram 122413, India.
J Pathog. 2018 Jan 31;2018:3759704. doi: 10.1155/2018/3759704. eCollection 2018.
Significance of methylene blue (MB) in photodynamic therapy against microbes is well established. Previously, we have reported the antifungal potential of MB against . The present study attempts to identify additional antimicrobial effect of MB against another prevalent human pathogen, (MTB). We explored that MB is efficiently inhibiting the growth of at 15.62 g/ml albeit in bacteriostatic manner similar to its fungistatic nature. We uncovered additional cell surface phenotypes (colony morphology and cell sedimentation rate) which were impaired only in . Mechanistic insights revealed that MB causes energy dependent membrane perturbation in both and . We also confirmed that MB leads to enhanced reactive oxygen species generation in both organisms that could be reversed upon antioxidant supplementation; however, DNA damage could only be observed in . We provided evidence that although biofilm formation was disrupted in both organisms, cell adherence to human epithelial cells was inhibited only in . Lastly, RT-PCR results showed good correlation with the biochemical assay. Together, apart from the well-established role of MB in photodynamic therapy, this study provides insights into the distinct antimicrobial mode of actions in two significant human pathogens, and which can be extrapolated to improve our understanding of finding novel therapeutic options.
亚甲蓝（MB）在光动力疗法中对微生物的重要性已得到充分证实。此前，我们已报道过MB对……的抗真菌潜力。本研究试图确定MB对另一种常见人类病原体——结核分枝杆菌（MTB）的额外抗菌作用。我们发现，MB在浓度为15.62 μg/ml时能有效抑制结核分枝杆菌的生长，尽管其抑菌方式与其抑真菌性质类似。我们还发现了仅在结核分枝杆菌中受损的其他细胞表面表型（菌落形态和细胞沉降率）。机制研究表明，MB在结核分枝杆菌和……中都会引起能量依赖性的膜扰动。我们还证实，MB会导致两种生物体中活性氧的生成增加，补充抗氧化剂后这种增加可被逆转；然而，仅在结核分枝杆菌中观察到DNA损伤。我们提供的证据表明，虽然两种生物体中的生物膜形成均被破坏，但仅在结核分枝杆菌中细胞对人上皮细胞的黏附受到抑制。最后，逆转录-聚合酶链反应（RT-PCR）结果与生化分析结果具有良好的相关性。总之，除了MB在光动力疗法中已确立的作用外，本研究还深入探讨了MB在两种重要人类病原体——结核分枝杆菌和……中的不同抗菌作用模式，这有助于增进我们对寻找新型治疗方案的理解。
