Subspecies differentiation of Salmonella by PCR-RFLP of the ribosomal operon using universal primers.

A polymerase chain reaction (PCR)-based method was developed to aid identification of bacteria to subspecies level. The method used primers that annealed to highly conserved regions of the bacterial rRNA operon, which are proposed to be universal for all bacteria. The resulting PCR products gave unique electrophoretic patterns due to restriction fragment length polymorphisms (RFLP) within the rRNA operon, allowing differentiation to the subspecies level. Six serotypes of Salmonella choleraesuis are presented to demonstrate the specificity of PCR-RFLP patterns for building an identification database. As the database continues to accumulate, the method proves to be specific and rapid for identifying bacteria based on stable genetic characteristics.