ABSTRACT
A composite of Zinc oxide loaded with 5-weight % silver decorated on carbon nanotubes (Ag-loaded ZnO: CNT) was synthesized using a simple refluxed chemical method. The influence of deviation in the weight % of carbon nanotube loading on photocatalytic dye degradation (methylene blue and rose bengal) and antibiotic (antimicrobial and antifungal) performance was investigated in this study. The light capture ability of Ag-loaded ZnO:CNT in the visible region was higher in photocatalytic activity than that of Ag-loaded ZnO and ZnO:CNT. The bandgap of the Ag-loaded ZnO: CNT was tuned owing to the surface plasmon resonance effect. The photocatalytic degradation investigations were optimized by varying the wt% in CNTs, pH of dye solution, concentration of the dye solution, and amount of catalytic dose. Around 100% photocatalytic efficiency in 2 min against MB dye was observed for Ag doped ZnO with 10 wt% CNT composite at pH 9, at a rate constant 1.48 min-1. Bipolaris sorokiniana fungus was first time tested against a composite material, which demonstrated optimum fungal inhibition efficiency of 48%. They were also tested against the bacterial strains Staphylococcus aureus, Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium, which showed promising antibacterial activity compared to commercially available drugs. The composite of Ag doped ZnO with 5 wt% CNT has shown competitive zone inhibition efficacy of 21.66 ± 0.57, 15.66 ± 0.57, 13.66 ± 0.57 against bacterial strains Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium which were tested for the first time against Ag-loaded ZnO:CNT.
Subject(s)
Anti-Bacterial Agents , Antifungal Agents , Nanotubes, Carbon , Silver , Zinc Oxide , Zinc Oxide/chemistry , Zinc Oxide/pharmacology , Silver/chemistry , Silver/pharmacology , Nanotubes, Carbon/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Catalysis , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Staphylococcus aureus/drug effects , Methylene Blue/chemistry , Methylene Blue/pharmacology , Coloring Agents/chemistry , Coloring Agents/pharmacology , Rose Bengal/chemistry , Rose Bengal/pharmacology , Microbial Sensitivity Tests , Salmonella typhimurium/drug effects , Hydrogen-Ion Concentration , Photolysis , Photochemical ProcessesABSTRACT
In this work, silver (Ag) doped zinc oxide (ZnO) nanoparticles were synthesized using zinc chloride, zinc nitrate, and zinc acetate precursors with (0 to 10) wt % Ag doping by a simple reflux chemical method. The nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet visible spectroscopy, and photoluminescence spectroscopy. The nanoparticles are studied as a photocatalyst for visible light driven annihilation of methylene blue and rose bengal dyes. The 5 wt % Ag doped ZnO displayed optimum photocatalytic activity toward methylene blue and rose bengal dye degradation at the rate of 13 × 10-2 min-1 and 10 × 10-2 min-1, respectively. Here we report antifungal activity for the first time using Ag doped ZnO nanoparticles against Bipolaris sorokiniana, displaying 45% efficiency for 7 wt % Ag doped ZnO.
ABSTRACT
INTRODUCTION: India is one of the countries in the world which contribute to the global burden of multidrug-resistant tuberculosis (MDR-TB). GeneXpert is a method recommended by the World Health Organization (WHO) that uses five overlapping probes (Probe A to E) to detect mutation in the beta subunit of ribonucleic acid (RNA) polymerase gene (Rpoß) responsible for rifampicin resistance in Mycobacterium tuberculosis (MTB). METHOD: All the pulmonary and extrapulmonary samples received in tuberculosis (TB) laboratory for testing of MTB from January 2018 to December 2020 were analyzed for bacillary load and rifampicin resistance was identified by analyzing the number of missing probes. RESULTS: During the study period, a total of 10,021 samples were tested for MDR-TB. Out of those samples, 2674 samples were positive for MTB of which 2321 were pulmonary samples and 353 were extra-pulmonary samples. Rifampicin resistance was detected in 385 pulmonary samples and 63 extrapulmonary samples. These samples were further differentiated according to the bacillary load. The highest number of mutations was observed in Probe E followed by Probe B, Probe A, and Probe D, and the lowest was observed in Probe C. Also, mutations were associated when all probes were present or a few combinations of probes were missing. CONCLUSION: GeneXpert assay is a rapid molecular method that detected MTB and rifampicin resistance with a two-hour turnaround. It uses molecular beacons to detect mutation in the Rpoß gene. This study can be useful in analyzing the prevalence and epidemiology of MTB in a particular demographic area and also the addition of a few more probes can enhance the identification of the mutation in other codons and therefore better therapeutic interventions can be developed accordingly.