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
• Anti-Bacterial Agents chemistry   immunology   pharmacology   MeSH
• SELEX Aptamer Technique MeSH
• Aptamers, Nucleotide chemistry   genetics   immunology   pharmacology   MeSH
• Escherichia coli drug effects   immunology   MeSH
• Escherichia coli Infections drug therapy   immunology   MeSH
• Complement C1 chemistry   immunology   MeSH
• Humans MeSH
• Lipopolysaccharides chemistry   immunology   MeSH
• Molecular Sequence Data MeSH
• Base Sequence MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Aptamers, Nucleotide MeSH
• Complement C1 MeSH
• Lipopolysaccharides MeSH