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Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill
Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill
Lisa K. Nolan
The plasmid DNA of 30 Escherichia coli isolates from chickens was extracted and examined using techniques designed to isolate large plasmids. This plasmid DNA was examined for the presence of certain known virulence-related genes including cvaC, tra7 and some aerobactin-related sequences. Seventeen of the 30 isolates contained from one to four plasmids greater than 50 kb in size. Eleven of these 17 strains possessed plasmids greater than 100 kb in size. Therefore, E. coli isolates of chickens frequently contain large plasmids, and many of these plasmids are likely to contain virulence related sequences.
Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan
Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan
Lisa K. Nolan
Three of four plasmids from a virulent wild-type avian Escherichia coli were cloned or transformed into an avirulent laboratory recipient E. coli DH5a and tested for the ability to confer a virulence phenotype. The three plasmids transformed into E. coli DH5a were 5, 6, and 56 kb. A fourth plasmid of 64 kb was not successfully transformed. Parameters used to measure virulence included presence of type 1 pili and a smooth lipopolysaccharide (LPS) layer, motility, production of Colicin V, resistance to host complement, and embryo lethality. The 5-kb plasmid encoded for ampicillin resistance, whereas the 6-kb plasmid encoded for tetracycline …