DNA aptamers were developed against lipopolysaccharide (LPS) from E. coli O111:B4 and shown to bind both LPS and E. coli by a colorimetric enzyme-based microplate assay. The polyclonal aptamers were coupled to human C1qrs protein either directly using a bifunctional linker or indirectly using biotinylated aptamers and a streptavidin-C1qrs complex. Both systems significantly reduced colony counts when applied to E. coli O111:B4 and K12 strains across a series of 10x dilutions of the bacteria in the presence of human serum; it was diluted 1: 10(3) in order to avoid significant bacterial lysis by the competing alternate pathway of complement activation. A number of candidate DNA aptamer sequences were cloned and sequenced from the anti-LPS aptamer library for future screening of antibacterial or "antibiotic" potential and to aid in eventual development of an alternative therapy for antibiotic-resistant bacterial infections.

• MeSH
• antibakteriální látky chemie   imunologie   farmakologie   MeSH
• aptamerová technika SELEX MeSH
• aptamery nukleotidové chemie   genetika   imunologie   farmakologie   MeSH
• Escherichia coli účinky léků   imunologie   MeSH
• infekce vyvolané Escherichia coli farmakoterapie   imunologie   MeSH
• komplement C1 chemie   imunologie   MeSH
• lidé MeSH
• lipopolysacharidy chemie   imunologie   MeSH
• molekulární sekvence - údaje MeSH
• sekvence nukleotidů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• antibakteriální látky MeSH
• aptamery nukleotidové MeSH
• komplement C1 MeSH
• lipopolysacharidy MeSH

The effect of a 20-min exposure to antibody-quantum dot (Ab-QD) conjugates on colony counts of Escherichia coli was assessed by the spread-plate method and compared with exposure to unconjugated QDs having only amine or carboxyl groups on their surfaces. Under these conditions, Ab-QD conjugates generally exhibited >90% reduction in colony-forming units as compared to untreated E. coli and E. coli treated with unconjugated QDs after incubation for as long as 41 h. The antibacterial effect of Ab-QD conjugates vs. unconjugated QDs on Salmonella enterica subsp. enterica serovar Typhimurium was also assessed by means of a disk-diffusion technique which demonstrated greater growth inhibition (approximately 3 mm greater) by Ab-QD conjugate-impregnated disks than by unconjugated-QD-only-impregnated disks at a 10-microg disk load. At a 25-microg disk load, both treatment groups exhibited nearly equal growth inhibition.

• MeSH
• antibakteriální látky farmakologie   MeSH
• biotechnologie metody   MeSH
• Escherichia coli účinky léků   růst a vývoj   MeSH
• imunokonjugáty MeSH
• kvantové tečky * MeSH
• mikrobiální testy citlivosti metody   MeSH
• monoklonální protilátky * chemie   imunologie   farmakologie   MeSH
• počet mikrobiálních kolonií MeSH
• protilátky bakteriální * chemie   imunologie   farmakologie   MeSH
• Salmonella typhimurium účinky léků   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• antibakteriální látky MeSH
• imunokonjugáty MeSH
• monoklonální protilátky * MeSH
• protilátky bakteriální * MeSH