CHARACTERIZATION OF SALMONELLA-ENTERITIDIS STRAINS

A study was conducted to characterize 318 Salmonella enteritidis strai ns that were mainly isolated from poultry and their environment in Can ada. Biotype, phagetype (PT), plasmid profile (PP), hybridization with a plasmid-derived virulence sequence probe, antibiotic resistance, ou ter membrane proteins (OMPs), and lipopolysaccharide (LPS) profiles we re determined. Relationships of these properties to one another, and t heir diagnostic and pathogenic significance were assessed. Biotyping i ndicated that failure to ferment rhamnose was sometimes useful as a ma rker for epidemiologically related strains. Phagetyping was the most e ffective method for subdividing S. enteritidis; it distinguished 12 PT s. Phagetype 13 was occasionally associated with septicemia and mortal ity in chickens. The strains belonged to 15 PPs. A 36 megadalton (MDa) plasmid was found in 97% of the strains. Only the 36 MDa plasmid hybr idized with the probe. Seventeen percent of the strains were drug resi stant; all strains were sensitive to cipronoxacin. Thirty-five of 36 s trains possessed the same OMP profile, and 36 of 41 strains contained smooth LPS.