With the development of aquaculture, there is an urgent demand for an alternative antibacterial agent to reduce the drug resistance and environmental pollution caused by the abuse of antibiotics. Recently, silver nano...With the development of aquaculture, there is an urgent demand for an alternative antibacterial agent to reduce the drug resistance and environmental pollution caused by the abuse of antibiotics. Recently, silver nanoparticles（Ag NPs） have been viewed as a novel type of antimicrobial agents due to their unique advantages. In this study,Ag NPs were biosynthesized with the ginger rhizomes extract. The biosynthesized Ag NPs were characterised by UV–visible spectroscopy, transmission electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy. Furthermore, the antimicrobial activities of the Ag NPs were fully analyzed against six typical aquatic pathogens. The results indicated that the components in ginger extract could function as the chemical reductant to synthesize Ag NPs. Moreover, compared with the Ag NPs synthesized by chemical methods, the biosynthesized Ag NPs were smaller, and had higher stability and antibacterial activity. Therefore, the biosynthesized Ag NPs using ginger extract may have prospective applications in aquaculture.展开更多
The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify mic...The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify microbial risks.To assess the levels of bacterial pathogens and health risks in urban recreational water,we analyzed pathogen diversity and quantified four pathogens in 46 water samples collected from waterbodies in Beijing Olympic Forest Park in one year.The pathogen diversity revealed by 16 S r RNA gene targeted next-generation sequencing（NGS） showed that 16 of 40 genera and 13 of 76 reference species were present.The most abundant species were Acinetobacter johnsonii,Mycobacterium avium and Aeromonas spp.Quantitative polymerase chain reaction（q PCR） of Escherichia coli（uid A）,Aeromonas（aer A）,M.avium（16S r RNA）,Pseudomonas aeruginosa（oaa） and Salmonella（inv A） showed that the aer A genes were the most abundant,occurring in all samples with concentrations of 10^（4–6） genome copies/100 m L,followed by oaa,inv A and M.avium.In total,34.8% of the samples harbored all genes,indicating the prevalence of these pathogens in this recreational waterbody.Based on the q PCR results,a quantitative microbial risk assessment（QMRA） showed that the annual infection risks of Salmonella,M.avium and P.aeruginosa in five activities were mostly greater than the U.S.EPA risk limit for recreational contacts,and children playing with water may be exposed to the greatest infection risk.Our findings provide a comprehensive understanding of bacterial pathogen diversity and pathogen abundance in urban recreational water by applying both NGS and q PCR.展开更多
Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides...Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications.展开更多
基金The Scientific Research Projects of Shandong University under contract No.J15LE03the Key Research and Development Program of Shandong Province under contract No.2016GNC111016the Key Research and Developement Program of Yantai under contract No.2016ZH059
文摘With the development of aquaculture, there is an urgent demand for an alternative antibacterial agent to reduce the drug resistance and environmental pollution caused by the abuse of antibiotics. Recently, silver nanoparticles（Ag NPs） have been viewed as a novel type of antimicrobial agents due to their unique advantages. In this study,Ag NPs were biosynthesized with the ginger rhizomes extract. The biosynthesized Ag NPs were characterised by UV–visible spectroscopy, transmission electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy. Furthermore, the antimicrobial activities of the Ag NPs were fully analyzed against six typical aquatic pathogens. The results indicated that the components in ginger extract could function as the chemical reductant to synthesize Ag NPs. Moreover, compared with the Ag NPs synthesized by chemical methods, the biosynthesized Ag NPs were smaller, and had higher stability and antibacterial activity. Therefore, the biosynthesized Ag NPs using ginger extract may have prospective applications in aquaculture.
基金supported by the Key Program of the National Natural Science Foundation of China(No.51138006)the National Key Research on Water Environment Pollution Control in China(No.2012ZX07301-001)
文摘The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify microbial risks.To assess the levels of bacterial pathogens and health risks in urban recreational water,we analyzed pathogen diversity and quantified four pathogens in 46 water samples collected from waterbodies in Beijing Olympic Forest Park in one year.The pathogen diversity revealed by 16 S r RNA gene targeted next-generation sequencing（NGS） showed that 16 of 40 genera and 13 of 76 reference species were present.The most abundant species were Acinetobacter johnsonii,Mycobacterium avium and Aeromonas spp.Quantitative polymerase chain reaction（q PCR） of Escherichia coli（uid A）,Aeromonas（aer A）,M.avium（16S r RNA）,Pseudomonas aeruginosa（oaa） and Salmonella（inv A） showed that the aer A genes were the most abundant,occurring in all samples with concentrations of 10^（4–6） genome copies/100 m L,followed by oaa,inv A and M.avium.In total,34.8% of the samples harbored all genes,indicating the prevalence of these pathogens in this recreational waterbody.Based on the q PCR results,a quantitative microbial risk assessment（QMRA） showed that the annual infection risks of Salmonella,M.avium and P.aeruginosa in five activities were mostly greater than the U.S.EPA risk limit for recreational contacts,and children playing with water may be exposed to the greatest infection risk.Our findings provide a comprehensive understanding of bacterial pathogen diversity and pathogen abundance in urban recreational water by applying both NGS and q PCR.
文摘Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications.
