Abstract: ObjectiveMolecular typing 12 strains of the Salmonella enteritidis isolated from different origins.MethodsThe genomic DNA of different Salmonella enteritis strains were extracted and random amplified polymorphic DNA (RAPD)system was developed and optimized.22 random primers were tested to the analysis on 12 strains of Salmonella enteritis isolated from different sources,and the clear and constant finger prints were selected for statistical analysis.Results4 effective primers named OPG-03,OPG-06,OPG-07 and OPG-13 were selected,with which each strain could be amplified 4 to 10 DNA fragments of 100bp~2 000bp.42 RAPD bands were amplified,83.3% of them being polymorphic.The comparative research of the cluster analysis based on the RAPD bands spectra showed that the similarity coefficient between two different strains varied from 42.6% to 100%,and 12 Salmonella enteritis strains in this experiment could be classified to 5 groups according to their genetic relationship.ConclusionUsing RAPD to subtype and character Salmonella enteritis at molecular level is more rapid and sensitive than other typing methods,which indicate broad future of application.