Identification of Rickettsia prowazekii using the polymerase chain reaction

Polymerase chain reaction (PCR) was used to identify Rickettsia prowazekii, the etiologic agent of epidemic typhus. For the PCR, Thermus thermophilus thermostable DNA polymerase was applied with buffer containing a relatively low Mg²⁺ concentration (1.5-2 mM with dNTP's at 250 μM each). A primer pair used to amplify a 448-base-pair (bp) fragment of R. prowazekii genome was Anethesized on the basis of the DNA sequence of gene rpa14/16, coding for a precursor of the mature polypeptides of molecular weight (Mr) 14,000 and/or 16,000 (16kD) from R. prowazekii strain E. For determining the specificity of the primer pair, purified genomic DNAs of 16 rickettsial and 10 other bacterial strains were used.