Anucleated live E. coli vaccine

摘要

An E. coli strain producing metabolically active but non-reproductive, anucleated live cells, which contain the K99 surface antigen, is obtained by transferring the K99 plasmid from a K99+ entero pathogenic E. coli strain into an E. coli strain which generates progeny of cells that lack the ability to multiply. From the resulting E. coli strain a "live" vaccine is prepared. Separation and purification of the anucleated live cells from growing cells is the basis for the "live" and chemically and/or physically unmodified vaccine. The vaccine induces the production of antibodies against growing and infective enteropathogenic K99+ E. coli in cattle and is, thus effective against coliform enteritis.