RESUMEN
Bacterial resistance to conventional antibiotics has created an urgent need to develop enhanced alternatives. Nanocomposites combined with promising antibacterial nanomaterials can show improved antimicrobial activity compared to that of their components. In this work, green synthesized CuO nanoparticles (NPs) supported on an anionic clay with a hydrotalcite-like structure such as Zn-Al layered double hydroxide (LDH) nanocomposite were investigated as antimicrobial agents. This nanocomposite was synthesized using Micromonospora sp. ISP-2 27 cell-free supernatant to form CuO NPs on the surface of previously synthesized LDH. The prepared samples were characterized using UV-Vis spectrophotometry, XRD, FTIR, Field emission scanning electron microscopy with EDX, zeta potential, and hydrodynamic particle size. UV-vis spectral analysis of the biosynthesized CuO NPs revealed a maximum peak at 300 nm, indicating their successful synthesis. The synthesized CuO NPs had a flower-like morphology with a size range of 43-78 nm, while the LDH support had a typical hexagonal layered structure. The zeta potentials of the CuO NPs, Zn-Al LDH, and CuO NPs/LDH nanocomposite were -21.4, 22.3, and 30.8 mV, respectively, while the average hydrodynamic sizes were 687, 735, and 528 nm, respectively. The antimicrobial activity of the produced samples was tested against several microbes. The results demonstrated that the nanocomposite displayed superior antimicrobial properties compared to those of its components. Among the microbes tested, Listeria monocytogenes ATCC 7644 was more sensitive (30 ± 0.34) to the biosynthesized nanocomposite than to CuO NPs (25 ± 0.05) and Zn-Al LDH (22 ± 0.011). In summary, the use of nanocomposites with superior antimicrobial properties has the potential to offer innovative solutions to the global challenge of antibiotic resistance by providing alternative treatments, reducing the reliance on traditional antibiotics, and contributing to the development of more effective and targeted therapeutic approaches.
RESUMEN
BACKGROUND AND AIMS: Hepatitis C virus (HCV) has emerged as the major pathogen of liver disease worldwide. The aim of this study was to quantitate and evaluate the performance of HCV-NS4 antigen as an alternative approach for confirmation of viremia. METHODS: Detection of HCV-NS4 was assessed in 883 patients with chronic hepatitis C. Areas under the ROC curves (AUC) were used to assess and compare diagnostic accuracy of ELISA for HCV-NS4 with quantitative HCV-RNA as a gold standard. RESULTS: HCV-NS4 was identified at 27 kDa using Western blot. AUC for HCV-NS4 detection was 0.95 for all patients with different liver pathologies: 0.93 for liver fibrosis (LF), 0.95 for liver cirrhosis (LC) and 0.98 for hepatocellular carcinoma (HCC). The mean ± SD (µg/mL) of HCV-NS4 in LF was 94.2 ± 55.6; in LC was 99.3 ± 64.8 and in HCC was 124.9 ± 70.3. CONCLUSIONS: HCV-NS4 antigen detection using ELISA is a reliable test in the confirmation of HCV infection.
