METHODS: The extracts were prepared and initially assessed for their phytochemical composition and antibacterial activity. Then, AgNPs were synthesized from these extracts at room temperature, and various analytical techniques, including UV-visible spectroscopy, X-ray diffraction (XRD), ATIR-FTIR, zeta sizer, scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDXA), were used to characterize the NPs. After confirmation of prepared NPs, they were subjected to their antibacterial activity.
RESULTS: HPLC analysis demonstrated the presence of eight phytoconstituents in organic ginger extracts. The absorption spectra of the silver suspension exhibited surface plasmon resonance peaks with maxima between 420 and 448 nm. Functional groups like C-H, N-H, OH, C-O-C, C=O, and C-O were identified in both the organic and aqueous extracts of Z. officinale, playing a key role in the formation of AgNPs, as characterized by ATR-FTIR analysis. Both ginger organic and aqueous extract synthesized AgNPs crystalline structure was shown in XRD analysis and the particle size distribution showed average diameter of 200.5 nm of AgNPs from aqueous extracts. Scanning Electron Microscopy displayed spherical structure and EDA results showed the percentage of elements in synthesized AgNPs using plant extracts. Most promising antibacterial activity was obtained against Escherichia coli ie 20.83±0.53 for 100 µg/mL.
CONCLUSION: The results of the current study showed that AgNPs synthesized from different ginger extracts have promising antibacterial properties and can be potential candidates for alternative treatment options for bacterial infections.
METHODS: The hospital wastewater samples were collected from the sewage water effluent of a tertiary hospital at Universiti Sains Malaysia, located on the east coast of Malaysia. These samples underwent serial filtration and centrifugation processes for phage recovery. The phage solutions were undergoing a screening test by spot assay using clinical isolates of Klebsiella pneumoniae AmpC strain as amplification hosts. The isolated AmpC-phages were further studied and characterised to determine the phage's host range, temperature, pH, and chloroform stabilities. High-Resolution Transmission Electron Microscopy (HRTEM) was performed to determine the phage type.
RESULTS: Thirty HWW samples were analyzed using four K. pneumoniae AmpC strains resulting in a total of 120 screening plates. The AmpC-Klebsiella pneumoniae (AmpC-KP) phages were detected in 31.70% (38/120) of the plates. The AmpC-KP phages had lytic diameters ranging from 1-3 mm, and a phage titer ranged from4×103-3.2×107 PFU/ml. The phages had a narrow-host range stable at a temperature range from -20-50˚C. The phages were also stable at pH ranging from 4 to 9 and at different concentrations of chloroform (5%,10%). Based on HRTEM, Siphoviridea was identified.
CONCLUSIONS: The AmpC-phages were abundant in hospital wastewater, and HWW was a good source for AmpC-KP phages. The isolated AmpC phages had a high effectivity and specificity for AmpC-KP with a narrow host range and could survive under harsh conditions such as (temperature, pH, and chloroform).