Molecular typing methods for S. enteritidis.

The predominance of certain phage types of Salmonella enteritidis in various countries makes further epidemiological subgrouping necessary. Today this is achieved by using molecular typing methods. For various bacterial species, plasmid profiling, the pattern of outer membrane proteins and lipopolysaccharides, the fingerprinting of total genomic DNA including ribotyping, and multilocus enzyme electrophoretic typing, have proven very useful. When such methods have been applied to S. enteritidis, they revealed a homogeneous, clonal structure in contemporary PT4 isolates. Furthermore they indicate that the clone observed today emerged from a heterogeneous population before the onset of the epidemic.