Urinary Tract Infections (UTIs) are among one of the most common infections in women, with uropathogenic E. coli (UPEC) being involved in 80% of cases. In addition, E. coli exhibits an increasing resistance to broad s...Urinary Tract Infections (UTIs) are among one of the most common infections in women, with uropathogenic E. coli (UPEC) being involved in 80% of cases. In addition, E. coli exhibits an increasing resistance to broad spectrum antimicrobial agents as well as the subsequent generations of these drugs. The genetic diversity and antibiotic resistance patterns of both clinical and environmental E. coli isolates were studied to predict the potential of transmission of organisms and genes for antibiotic resistance from three different major eco-habitats including the gut of iguanas’ fresh and marine waters and the human urinary tract. (GTG)<sub>5 </sub>and BOX-PCR extragenic DNA fingerprinting allowed for the tracking of the relatedness of four different ecotype groups. Both DNA fingerprinting methods targeted non-protein coding or exogenous palindromic DNA and demonstrated shared origin and intraspecies level of genomic diversity within the population of the studied bacteria. DNA fingerprinting based on BOX-PCR was less discriminating than the (GTG)<sub>5</sub>-PCR, and produced five major clades. BOX-PCR analysis indicated that 44% of the UTI E. coli isolates was comprised within a single clade, therefore it correlated better with ecotype distribution. The (GTG)<sub>5</sub> PCR based co-clustering analysis showed that the clinical isolates appeared to have a closer relationship to iguana E. coli isolates than to the fresh and marine water isolates. However, in accordance with the BOX PCR co-clustering analysis, the clinical isolates were most similar to the marine water isolates, followed by the freshwater and iguana E. coli isolates. Seventy two percent of antibiotic resistance patterns were shared by the UTI strains with E. coli isolated from freshwater, followed by iguana.展开更多
Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy resul...Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy result reveals that the band gap energy of ZnO/Nb2O5 nanoparticles to be 3.8 eV. The XRD results show that the crystallite size is to be 31.9 nm. The ICPMS data indicate the presence of 3,3461,328 counts of 93 Nb and 577,906,390 counts of 66 Zn. An improvement in the photocatalytic degradation of Indigocarmine dye (IC) in comparison to commercially available pure ZnO was observed. The photodegradation efficiency for ZnO/Nb2O5 and ZnO were found to be 97.4% and 52.1% respectively. The enhancement in photocatalytic activity of ZnO/ Nb2O5 was ascribed to the extended light absorption range and suppression of electron hole pair recombination upon Nb loading. The antibacterial activity of ZnO/Nb2O5 nanoparticles was investigated. These particles were shown to have an effective bactericide.展开更多
Objective proteins synthesized from genetically recombined Escherichia coli strain (E. coli) have been successfully produced by microbe fermentation, but complicated separation and purification steps always make again...Objective proteins synthesized from genetically recombined Escherichia coli strain (E. coli) have been successfully produced by microbe fermentation, but complicated separation and purification steps always make against the maintenance of activities as well as increase the cost. Aiming at simplifying the process, an idea of administrating directly the microencapsulated genetically recombined E. coli is proposed. In this paper, study on culture of E. coli DH5α immobilized in alginate/chitosan (ACA) microcapsule is presented. It was found that E. coli DH5α grew well in the microcapsule with stable growth period longer than that of suspension culture, and cell aggregation phenomenon was observed. In vivo experiments showed that ACA microcapsules with E. coli DH5α stayed over 48 h in mouse intestine, and the morphology of microcapsules was kept intact. These preliminary results have demonstrated that administration of microencapsulated E. coli DH5α is safe, which layed the foundation for microencapsulated genetically recombined E. coli as carriers of gene engineering drugs.展开更多
文摘Urinary Tract Infections (UTIs) are among one of the most common infections in women, with uropathogenic E. coli (UPEC) being involved in 80% of cases. In addition, E. coli exhibits an increasing resistance to broad spectrum antimicrobial agents as well as the subsequent generations of these drugs. The genetic diversity and antibiotic resistance patterns of both clinical and environmental E. coli isolates were studied to predict the potential of transmission of organisms and genes for antibiotic resistance from three different major eco-habitats including the gut of iguanas’ fresh and marine waters and the human urinary tract. (GTG)<sub>5 </sub>and BOX-PCR extragenic DNA fingerprinting allowed for the tracking of the relatedness of four different ecotype groups. Both DNA fingerprinting methods targeted non-protein coding or exogenous palindromic DNA and demonstrated shared origin and intraspecies level of genomic diversity within the population of the studied bacteria. DNA fingerprinting based on BOX-PCR was less discriminating than the (GTG)<sub>5</sub>-PCR, and produced five major clades. BOX-PCR analysis indicated that 44% of the UTI E. coli isolates was comprised within a single clade, therefore it correlated better with ecotype distribution. The (GTG)<sub>5</sub> PCR based co-clustering analysis showed that the clinical isolates appeared to have a closer relationship to iguana E. coli isolates than to the fresh and marine water isolates. However, in accordance with the BOX PCR co-clustering analysis, the clinical isolates were most similar to the marine water isolates, followed by the freshwater and iguana E. coli isolates. Seventy two percent of antibiotic resistance patterns were shared by the UTI strains with E. coli isolated from freshwater, followed by iguana.
文摘Niobium doped Zincoxide nanoparticles has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, IR Spectroscopy, SEM, XRD, ICPMS and EDAX data. The UV-Visible spectroscopy result reveals that the band gap energy of ZnO/Nb2O5 nanoparticles to be 3.8 eV. The XRD results show that the crystallite size is to be 31.9 nm. The ICPMS data indicate the presence of 3,3461,328 counts of 93 Nb and 577,906,390 counts of 66 Zn. An improvement in the photocatalytic degradation of Indigocarmine dye (IC) in comparison to commercially available pure ZnO was observed. The photodegradation efficiency for ZnO/Nb2O5 and ZnO were found to be 97.4% and 52.1% respectively. The enhancement in photocatalytic activity of ZnO/ Nb2O5 was ascribed to the extended light absorption range and suppression of electron hole pair recombination upon Nb loading. The antibacterial activity of ZnO/Nb2O5 nanoparticles was investigated. These particles were shown to have an effective bactericide.
文摘Objective proteins synthesized from genetically recombined Escherichia coli strain (E. coli) have been successfully produced by microbe fermentation, but complicated separation and purification steps always make against the maintenance of activities as well as increase the cost. Aiming at simplifying the process, an idea of administrating directly the microencapsulated genetically recombined E. coli is proposed. In this paper, study on culture of E. coli DH5α immobilized in alginate/chitosan (ACA) microcapsule is presented. It was found that E. coli DH5α grew well in the microcapsule with stable growth period longer than that of suspension culture, and cell aggregation phenomenon was observed. In vivo experiments showed that ACA microcapsules with E. coli DH5α stayed over 48 h in mouse intestine, and the morphology of microcapsules was kept intact. These preliminary results have demonstrated that administration of microencapsulated E. coli DH5α is safe, which layed the foundation for microencapsulated genetically recombined E. coli as carriers of gene engineering drugs.
