Quantum dots: a next generation approach for pathogenic microbial biofilm inhibition; mechanistic insights, existing challenges, and future potential

Quantum Dots (QDs) have emerged as versatile nanomaterials with origins spanning organic, inorganic, and natural sources, revolutionizing various biomedical applications, particularly in combating pathogenic biofilm formation. Biofilms, complex structures formed by microbial communities enveloped in exopolysaccharide matrices, pose formidable challenges to traditional antibiotics due to their high tolerance and resistance, exacerbating inefficacy issues in antibiotic treatments. QDs offer a promising solution, employing physical mechanisms like photothermal or photodynamic therapy to disrupt biofilms. Their efficacy is noteworthy, with lower susceptibility to resistance development and broad-spectrum action as compared to conventional antibiotic methods. The stability and durability of QDs ensure sustained biofilm activity, even in challenging environmental conditions. This comprehensive review delves into the synthesis, properties, and applications of Carbon Quantum Dots (CQDs), most widely used QDs, showcasing groundbreaking developments that position these nanomaterials at the forefront of cutting-edge research and innovation. These nanomaterials exhibit multifaceted mechanisms, disrupting cell walls and membranes, generating reactive oxygen species (ROS), and binding to nucleic materials, effectively inhibiting microbial proliferation. This opens transformative possibilities for healthcare interventions by providing insights into biofilm dynamics. However, challenges in size control necessitate ongoing research to refine fabrication techniques, ensure defect-free surfaces, and optimize biological activity. QDs emerge as microscopic yet potent tools, promising to contribute to a brighter future where quantum wonders shape innovative solutions to persistently challenging issues posed by pathogenic biofilms. Henceforth, this review aims to explore QDs as potential agents for inhibiting pathogenic microbial biofilms, elucidating the underlying mechanisms, addressing the current challenges, and highlighting their promising future potential.

Isolation, survival & transfer of R-plasmid of Salmonella typhimurium in Dal Lake of Kashmir (India)

Six strains of S. typhimurium were isolated from water samples of Dal Lake, Srinagar (India). These strains could survive and multiply in the Lake water and its filtrate. Viable count of this bacterium increased abruptly on 6th day of incubation with a peak level on 7th and 9th day, followed by sharp decline on 12th-14th day. Viable count was higher at 37 degrees C than at room temperature. At 4 degrees C this bacterium survived for longer time than at 22 degrees C or 37 degrees C. Viable count was higher and survival longer in the filtrate than in Lake water. Drug resistance could be transferred to Escherichia coli recipient strains from S. typhimurium, both in filtrate and Dal Lake water at 4 degrees C, 22 degrees C and 37 degrees C. The prolonged survival of pathogenic bacteria and transfer of R-plasmid in Dal Lake water could be a health hazard.