Kumar Vikash, Parida Satya Narayan, Dhar Souvik, Bisai Kampan, Sarkar Dhruba Jyoti, Panda Soumya Prasad, Das Basanta Kumar
Biotechnology Laboratory, ICAR-Central Inland Fisheries Research Institute, Barrackpore, India.
College of Fisheries, Rani Lakshmi Bai Central Agricultural University, Jhansi, India.
Front Microbiol. 2024 Aug 30;15:1416411. doi: 10.3389/fmicb.2024.1416411. eCollection 2024.
The aquatic environment, independent of their host, is more favorable to pathogenic bacteria than the terrestrial environment. Consequently, pathogenic bacteria can reach very high densities around aquatic animals and can cause high mortality. The conventional approach, such as antibiotics, has minimal effectiveness. Additionally, due to the emergence of (multiple) resistance, their use is under intense scientific and public scrutiny. Hence, there is a need for the development of alternative control techniques, with an emphasis on prevention, which is likely to be more cost-effective. In this study, a potential bacterial strain was isolated from polluted river sediment and characterized using a comprehensive range of techniques including biochemical, 16S rRNA sequencing and antibiogram assay. The pathogenicity of the bacteria was tested on fingerlings found as non-pathogenic. Further, the bacteria were found to synthesize silver nanoparticles (AgNPs) using AgNO as a substrate. The obtained AgNPs were characterized by various methods, including UV-vis spectroscopy, FTIR (Fourier-transform infrared spectroscopy), and Transmission Emission Microscopy (TEM). The study found that the AgNPs were 20 nm in size on average. The antimicrobial activity of synthesized AgNPs was examined against the model freshwater pathogenic bacteria, and both the MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) were 0.156 μM, while biofilm inhibition activity was also observed at 0.156 μM. The AgNPs showed no haemolytic activity at 0.313 μM. Our findings suggest that mediated bacteriogenic AgNPs modulate the activity of common pathogenic bacteria . The thoroughness of our research process gives us confidence in the potential of applying AgNPs in aquaculture as a considerable strategy to control the infection.
与陆地环境相比，水生环境在独立于宿主的情况下，对病原菌更为有利。因此，病原菌在水生动物周围可达到很高的密度，并可导致高死亡率。传统方法，如抗生素，效果甚微。此外，由于（多重）耐药性的出现，其使用受到了科学界和公众的严格审查。因此，需要开发替代控制技术，重点是预防，这可能更具成本效益。在本研究中，从污染的河流沉积物中分离出一种潜在的细菌菌株，并使用包括生化、16S rRNA测序和抗菌谱分析在内的一系列综合技术对其进行了表征。在被发现无致病性的鱼种上测试了该细菌的致病性。此外，发现该细菌以AgNO为底物合成银纳米颗粒（AgNPs）。通过各种方法对获得的AgNPs进行了表征，包括紫外可见光谱、傅里叶变换红外光谱（FTIR）和透射发射显微镜（TEM）。研究发现，AgNPs的平均尺寸为20纳米。检测了合成的AgNPs对典型淡水病原菌的抗菌活性，其最低抑菌浓度（MIC）和最低杀菌浓度（MBC）均为0.156 μM，同时在0.156 μM时也观察到了生物膜抑制活性。AgNPs在0.313 μM时未表现出溶血活性。我们的研究结果表明，介导的细菌源性AgNPs可调节常见病原菌的活性。我们研究过程的全面性使我们有信心将AgNPs应用于水产养殖，作为控制感染的一项重要策略。
